EP2641452B1 - Panel heater with temperature monitoring - Google Patents

Panel heater with temperature monitoring Download PDF

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Publication number
EP2641452B1
EP2641452B1 EP11805429.5A EP11805429A EP2641452B1 EP 2641452 B1 EP2641452 B1 EP 2641452B1 EP 11805429 A EP11805429 A EP 11805429A EP 2641452 B1 EP2641452 B1 EP 2641452B1
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EP
European Patent Office
Prior art keywords
measuring
current path
measurement current
heating
current paths
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
EP11805429.5A
Other languages
German (de)
French (fr)
Other versions
EP2641452A1 (en
Inventor
Christoph Degen
Dang Cuong Phan
Mitja Rateiczak
Andreas Schlarb
Stefan Droste
Robert Drese
Gunther Vortmeier
Patrick Weber
Olaf Eckelt
Walter Schreiber
Giordano Soma
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Saint Gobain Glass France SAS
Compagnie de Saint Gobain SA
Original Assignee
Saint Gobain Glass France SAS
Compagnie de Saint Gobain SA
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Priority to EP11805429.5A priority Critical patent/EP2641452B1/en
Publication of EP2641452A1 publication Critical patent/EP2641452A1/en
Application granted granted Critical
Publication of EP2641452B1 publication Critical patent/EP2641452B1/en
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Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B1/00—Details of electric heating devices
    • H05B1/02—Automatic switching arrangements specially adapted to apparatus ; Control of heating devices
    • H05B1/0227—Applications
    • H05B1/023—Industrial applications
    • H05B1/0236—Industrial applications for vehicles
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B3/00—Ohmic-resistance heating
    • H05B3/84—Heating arrangements specially adapted for transparent or reflecting areas, e.g. for demisting or de-icing windows, mirrors or vehicle windshields
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B3/00—Ohmic-resistance heating
    • H05B3/20—Heating elements having extended surface area substantially in a two-dimensional plane, e.g. plate-heater
    • H05B3/22—Heating elements having extended surface area substantially in a two-dimensional plane, e.g. plate-heater non-flexible
    • H05B3/26—Heating elements having extended surface area substantially in a two-dimensional plane, e.g. plate-heater non-flexible heating conductor mounted on insulating base
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B3/00—Ohmic-resistance heating
    • H05B3/20—Heating elements having extended surface area substantially in a two-dimensional plane, e.g. plate-heater
    • H05B3/22—Heating elements having extended surface area substantially in a two-dimensional plane, e.g. plate-heater non-flexible
    • H05B3/26—Heating elements having extended surface area substantially in a two-dimensional plane, e.g. plate-heater non-flexible heating conductor mounted on insulating base
    • H05B3/265—Heating elements having extended surface area substantially in a two-dimensional plane, e.g. plate-heater non-flexible heating conductor mounted on insulating base the insulating base being an inorganic material, e.g. ceramic
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B2203/00—Aspects relating to Ohmic resistive heating covered by group H05B3/00
    • H05B2203/035—Electrical circuits used in resistive heating apparatus

Definitions

  • the invention is in the technical field of surface heaters and relates to a surface heater with temperature monitoring.
  • Surface heating elements with an electrical heating layer are used in manifold ways. They are well known as such and have been described many times in the patent literature. For example only in this context, the documents DE 102008018147 A1 . DE 102008029986 A1 . DE 10259110 B3 and DE 102004018109 B3 directed.
  • transparent panel radiators are used in motor vehicles as windshields, since the field of vision of windshields may not have any visual restrictions due to legal requirements. Due to the heat generated by the heating layer condensed moisture, ice and snow can be removed within a short time. In living rooms they can be used instead of conventional radiators for living room heating, for which purpose they are mounted, for example, on walls or free standing.
  • Surface heating elements can be used equally as heatable mirrors or transparent decorative parts.
  • the problem may arise that due to objects located on the heating layer, the heat produced is no longer sufficiently dissipated to the environment. As a result, a local overheating ("hot spot") may occur. This can happen, for example, in surface heating elements used for space heating by accidentally covered over garments. Due to the local overheating, the heating layer can be impaired and possibly even damaged.
  • hot spot a local overheating
  • the object of the present invention is to develop conventional surface heating elements in such a way that in particular transparent Surface heating a temperature monitoring in a simple and reliable way is possible.
  • a surface heating element with at least one planar substrate and an electrically conductive, heatable, preferably transparent coating is shown.
  • the heatable coating is designed so that its electrical resistance changes with a variation of the temperature.
  • the heatable coating extends over at least part of a substrate surface of the planar substrate.
  • the surface heating element is further provided with at least two connection electrodes provided for electrical connection to the two poles of a voltage source, which are electrically connected to the conductive coating in such a way that a heating current flows in a heating field formed by the conductive coating by applying a supply voltage.
  • the heating field has one or more heating current paths for conducting the heating current introduced via the two connection electrodes, which is introduced into the conductive coating by means of a conductive coating which is free, i. coating-free (electrically isolated) separation areas, for example, line-shaped separation areas (dividing lines) are formed.
  • the heating current paths are thus formed by the conductive coating. With a transparent coating, the heating current paths are accordingly transparent.
  • the surface heating element according to the invention can be designed in many ways and serve, for example as a flat radiator for living room heating, as a heated mirror, heated decorative part or heated disc, especially windshield or rear window of a motor vehicle, this list is merely exemplary and is not intended to limit the invention in any way.
  • the surface heating element comprises one or more measuring current paths formed as conductor tracks in the conductive coating, which measuring paths are at least partially different from the heating current paths.
  • the measuring current paths are free in the conductive coating by means of the conductive coating, that is coating-free (electrically isolated) separation areas, for example, line-shaped separation areas (dividing lines), molded.
  • the measuring current paths are thus formed by the conductive coating.
  • the measuring current paths are transparent.
  • each measuring current path is thermally coupled at least to a partial area of the heating field and has at least two connecting sections for connecting a measuring device for determining its electrical resistance.
  • the measuring current paths are provided for conducting a measuring current introduced via the connection sections for measuring the electrical resistance.
  • the measuring current paths can have a greater electrical resistance per length than the heating current paths, which results, for example, from a smaller width of the measuring current paths transversely to the direction of extent.
  • the surface heating element according to the invention thus advantageously makes it possible to determine the temperature of the measuring current paths thermally coupled in each case to at least one subarea of the heating field by determining the electrical resistance of the measuring current paths. In this way, in particular local overheating in the area of the heating field can be detected reliably and safely.
  • the measuring current paths can be produced in a simple manner by structuring the conductive coating, the measuring current paths being transparent in the case of a transparent conductive coating, so that the temperature of the heating field can be monitored in a particularly advantageous manner even in transparent surface heating elements.
  • the measuring current paths are formed at least in sections, in particular completely, in an edge strip which is electrically separate from the heating field and surrounds the heating field. This measure allows a particularly simple contacting of the connection sections of the measuring current paths in the edge strip.
  • the measuring current paths for the detection of near-edge hot spots may have a course extending along the substrate edge.
  • the measuring current paths can in particular at least partially in be formed from each other different portions of the edge strip, whereby a spatially resolved detection of hot spots in the heating field is possible.
  • each measuring current path is formed so that they repeatedly change their path direction in a spatially limited zone of the edge strip, hereinafter referred to as "measuring zone".
  • the measuring current paths may have, for example, a meandering curved course in the measuring zones, it being equally possible for any other course to be provided with a mutual or opposing change in the path direction.
  • each measuring current path comprises a plurality of oppositely curved current path sections. In each case, a relatively large proportion of the conductor track of a measuring current path is contained in the measuring zones, which is accompanied by a correspondingly large voltage drop of a measuring voltage applied to the terminal sections.
  • the measuring zones thus enable detection of hot spots with high sensitivity and particularly good spatial resolution. It may also be advantageous if the measuring zones are spatially distributed over at least a portion of the edge strip, in particular spatially evenly distributed, whereby a particularly good spatial resolution in the detection of hot spots of the heating field is possible.
  • the measuring current paths are electrically separated from the heating field. This can be achieved, for example, in that the measuring current paths are completely contained within the edge strip that is electrically insulated from the heating field. By this measure heating and measuring current are electrically isolated, so that the determination of the electrical resistance of the measuring current paths is particularly simple.
  • one or more measuring current paths each have a measuring current path section which is part of a heating current path or is formed by a complete heating current path.
  • a connection electrode connected to the heating current path can serve in particular as a connection section of a measuring current path.
  • the electrical resistance of the path portion of a measuring current path not formed by the heating current path may in particular be greater than that in the rest of the measuring current path, which can be realized in a simple manner by a correspondingly smaller width of the conductor track.
  • measuring current paths of the space requirement in the edge strip is reduced, so that more measuring current paths can be formed with a given dimensioning of the edge strip in the conductive coating.
  • the formation of measuring zones in the edge strip is facilitated.
  • connection electrodes are electrically connected to two interconnected measuring current paths, in each of which two measuring current paths are connected in series, each measuring current path series being arranged via a connection section arranged between the two serially connected measuring current paths for connecting the measuring device for determining the electrical resistance.
  • the measuring current paths can be connected to a Wheatstone bridge known per se to those skilled in the art, which enables a particularly accurate detection of changes in the resistance of the measuring current paths.
  • At least one measuring current path serves as a reference current path for detecting a reference resistance for other measuring current paths.
  • the invention furthermore extends to an arrangement having a surface heating element as described above, which has at least one measuring device connected to the connection sections of the measuring current paths for determining electrical resistances and a control and monitoring device connected to the measuring device in terms of data technology.
  • the control and monitoring device is set up by the program in such a way that the supply voltage applied to the connection electrodes is switched off or at least reduced if the electrical resistance of a measuring current path exceeds a predeterminable (selectable) threshold value.
  • the control and monitoring device is for this purpose electrically connected to a device coupled to the voltage source for providing the supply voltage, by means of which the supply voltage can be reduced or switched off.
  • control and monitoring device with a visual and / or acoustic output device for outputting optical and / or acoustic signals is connected by data technology, wherein the control and monitoring device is arranged so that an optical and / or acoustic Signal is output, if the electrical resistance of a measuring current exceeds the said or another predeterminable threshold.
  • the invention further extends to a method for operating a surface heating element having at least one planar substrate and an electrically conductive coating which extends over at least part of the substrate surface and electrically connected to at least two connection electrodes provided for electrical connection to the two poles of a voltage source is that by applying a supply voltage, a heating current flows in a heating field.
  • the surface heating element may in particular be a surface heating element as described above.
  • the electrical resistance of one or more measuring current paths thermally coupled to the heating field is determined, wherein the measuring current paths are each formed by coating-free separating regions, for example dividing lines, in the conductive coating and are formed by the conductive coating.
  • the supply voltage is reduced or switched off, if the electrical resistance of a measuring current exceeds a predeterminable threshold value.
  • an optical and / or acoustic signal is output if the electrical resistance of a measuring current path exceeds said or another predeterminable threshold value.
  • the invention further extends to the use of a surface heating element as described above as functional and / or decorative single piece and as built-in furniture, appliances and buildings, especially as a radiator in living rooms, such as wall-mounted or free-standing radiator, as well as in locomotion for locomotion on land, in the air or on water, especially in motor vehicles, for example, as a windshield, rear window, side window and / or glass roof.
  • a surface heating element as described above as functional and / or decorative single piece and as built-in furniture, appliances and buildings, especially as a radiator in living rooms, such as wall-mounted or free-standing radiator, as well as in locomotion for locomotion on land, in the air or on water, especially in motor vehicles, for example, as a windshield, rear window, side window and / or glass roof.
  • FIG. 1 considered, as the first embodiment of the invention, a designated generally by the reference numeral 1 surface heating element or a surface heating element 1 containing arrangement 39 is illustrated.
  • the surface heater 1 is used for surface heat generation and can be used for example instead of a conventional radiator for heating a living room. He can to this Purpose, for example, attached to a wall or integrated into it, but also a free-standing mounting is possible. It is also conceivable to form the surface heating element 1 as a mirror or decorative part.
  • Another exemplary application of the surface heating element 1 is the use as a vehicle window, in particular windshield, of a motor vehicle.
  • the surface heating element 1 comprises at least one planar substrate 2 made of an electrically insulating material, the surface heating element 1 having a single substrate 2 as a single-pane glass and two bonded substrates 2 firmly bonded together by a thermoplastic adhesive layer as a composite pane.
  • the substrate 2 can be made of a glassy material, for example float glass, cast glass or ceramic glass or a non-glass material, for example plastic, in particular polystyrene (PS), polyamide (PA), polyester (PE), polyvinyl chloride (PVC), polycarbonate (PC), polymethyl methacrylate (PMA) or polyethylene terephthalate (PET).
  • PS polystyrene
  • PA polyamide
  • PE polyester
  • PVC polyvinyl chloride
  • PC polycarbonate
  • PMA polymethyl methacrylate
  • PET polyethylene terephthalate
  • any material having sufficient chemical resistance, suitable dimensional and dimensional stability, and, if desired, sufficient optical transparency may be used.
  • plastic in particular based on polyvinyl butyral (PVB), ethylene-vinyl acetate (EVA) and polyurethane (PU), can be used as the adhesive layer for bonding the two substrates 2 in a composite pane.
  • PVB polyvinyl butyral
  • EVA ethylene-vinyl acetate
  • PU polyurethane
  • the surface heating element comprises a rectangular substrate 2 with a circumferential substrate edge 4, which is composed of two short edges 5 and two long edges 6. It is understood that the invention is not limited to this, but that the substrate 2 can also have any other form suitable for practical use, for example a square, round or oval shape. Depending on the application of the surface heating element 1, the substrate 2 may be rigid or flexible. The same applies to its thickness, which can vary widely and for a glass substrate 2, for example, in the range of 1 to 24 mm.
  • a planar heat generation of the surface heating element 1 comprises an electrically conductive, heatable coating 3, which is applied here for example on a (main) surface or substrate surface 42 of the substrate 2.
  • the coating decreases 3 more than 50%, preferably more than 70%, more preferably more than 80% and even more preferably more than 90% of the substrate surface 42 of the substrate 2 a.
  • the coating 3 can be applied over the full area to the substrate surface 42.
  • the area covered by the coating 3 can, depending on the application, for example, range from 100 cm 2 to 25 m 2 .
  • such a carrier can be a plastic film which consists, for example, of polyamide (PA), polyurethane (PU), polyvinyl chloride (PVC), polycarbonate (PC), polyester (PE) or polyvinyl butyral (PVB).
  • a support can also be bonded to adhesive films (eg PVB films) and bonded as a three-layered layer structure to the two substrates 2 of a composite pane.
  • the coating 3 contains or consists of an electrically conductive material.
  • TCO transparent conductive oxides
  • TCO is preferably indium tin oxide, fluorine-doped tin dioxide, aluminum-doped tin dioxide, gallium-doped tin dioxide, boron-doped tin dioxide, tin zinc oxide or antimony-doped tin oxide.
  • the coating 3 may consist of a conductive single layer or a layer structure which contains at least one conductive partial layer.
  • such a layer construction comprises at least one conductive partial layer, preferably silver (Ag), and further partial layers such as anti-reflection and blocking layers.
  • the thickness of the coating 3 may vary widely depending on the application, wherein the thickness at any point may be, for example, in the range of 30 nm to 100 microns. In the case of TCO, the thickness is, for example, in the range of 100 nm to 1.5 ⁇ m, preferably in the range of 150 nm to 1 ⁇ m and more preferably in the range of 200 nm to 500 nm.
  • the coating 3 can be subjected to high thermal loads, see above that it withstands the temperatures required for bending (tempering) a pane of glass used as substrate 2, typically more than 600 ° C without impairment of function. Equally, however, a thermally low-loadable coating 3 can be provided, which is applied after the tempering of the glass sheet. Likewise, the coating 3 can be applied to a substrate 2 which will not be biased.
  • the sheet resistance of the coating 3 is preferably less than 20 ohms per unit area and is for example in the range of 0.25 to 20 ohms per unit area. In the exemplary embodiment shown, the sheet resistance of the conductive coating 3 is a few ohms per unit area and is, for example, 1 to 2 ohms per unit area.
  • CVD chemical vapor deposition
  • PVD physical vapor deposition
  • the coating 3 is applied to the substrate 2 by sputtering (magnetron sputtering).
  • Fig. 1 it can be advantageous for its practical application, for example, as a freestanding radiator or windshield of a motor vehicle when it is transparent to visible light in the wavelength range of 350 nm to 800 nm, wherein the term "transparency" is a light transmittance of more than 50%, preferably more than 70% and especially preferably more than 80%.
  • This can be achieved, for example, by a transparent substrate 2 made of glass and a transparent coating 3 based on silver (Ag).
  • the conductive coating 3 is provided along the substrate edge 4 with a peripheral, electrically insulated, first parting line 7, which here, for example, a distance of a few cm, in particular 1 to 2 cm, from the substrate edge 4 has.
  • An outer edge strip 8 of the conductive coating 3 is electrically divided by an inner remainder of the conductive coating 3, which serves as a heating field 9, through the first parting line 7.
  • the edge strip 8 causes an electrical insulation of the heating field 9 to the outside and protects it against penetrating from the substrate edge 4 corrosion.
  • the coating 3 can be circumferentially removed to improve the edge insulation in a, for example, a few millimeters wide part of the edge strip 8, which Fig. 1 not shown in detail.
  • connection electrodes 10, 11 are provided with the heating field 9, which are arranged here, for example, at the lower long edge 6 near the right short edge 5.
  • the connection electrodes 10, 11 are used to apply a supply voltage supplied from the outside to the heating field 9, wherein areally heat is emitted from the heating field 9 by the introduced heating current.
  • the two connection electrodes 10, 11 can be connected for this purpose to the two poles of a voltage source (not shown).
  • the connecting electrodes 10, 11, which are in each case in the form of quarter-slices, are for example made of a metallic printing paste in the printing process, in particular screen printing processes.
  • connection electrodes 10, 11 for example, from a metal foil, and then to electrically connect them to the heating field 9, in particular by soldering. It is irrelevant whether first the coating 3 is deposited on the substrate 2 and then the connection electrodes 10, 11 are produced or whether first the connection electrodes 10, 11 are manufactured and then the coating 3 is deposited.
  • the specific electrical resistance for connection electrodes 10, 11 produced in particular in the printing method is, for example, in the range from 2 to 4 ⁇ Ohm.cm.
  • the heater 9 is divided by a family of electrically insulated, second parting lines 30 in a plurality of electrically parallel connected Walkerstrompfade 12.
  • the heating current paths 12 each begin at the one, first connection electrode 10 and terminate at the other, second connection electrode 11, the part of the heating field 9 immediately adjacent to the two connection electrodes 10, 11 being free of second separation lines 30.
  • a defined profile of the heating current introduced by the two connection electrodes 10, 11 in the heating field 9 can be achieved along the heating current paths 12 defined by the second separating lines 30.
  • the electrical resistance for a desired heating power can be set specifically.
  • the subdivision of the heating field 9 by separating lines for generating parallel heating current paths 12 is known per se, for example, from the patents mentioned above, so that it need not be discussed further here.
  • the dividing lines 7, 30, in which the conductive coating 3 is in each case completely removed, can be produced, for example, by laser writing be incorporated into the conductive coating 3 by means of laser cutting robot. It should be noted that the in Fig. 1 shown layout of the second parting lines 30 is only an example and that equally differently extending Edelstrompfade 12 may be provided in the surface heating element 1.
  • a measuring current path 13 which is electrically insulated from the heating field 9, is formed in the conductive coating 3 in the form of a conductor track.
  • the measuring current path 13 is formed by the conductive material of the coating 3, for which purpose a boundary line circumscribing the measuring current path 13 is introduced into the edge strip 8, for example by means of lasering Fig. 1 the clarity is not shown in detail.
  • the measuring current path 13 is electrically divided from the remaining edge strip 8.
  • the measuring current path 13 extends a little along the lower long edge 6, the right short edge 5 adjoining thereto and the upper long edge 6 adjoining it approximately up to the height of a left heating field top 20 and on the opposite way back to a second terminal portion 15 at the level of the two terminal electrodes 10, 11, whereby a conductor loop is formed.
  • the two connection sections 14, 15 of the measuring current path 13 are electrically connected to connection lines 34 of an electrical measuring device 16. They may be provided for this purpose with electrically-galvanically coupled electrodes, which in Fig. 1 not shown in detail.
  • the measuring current path 13 with the intermediate measuring device 16 is short-circuited to a measuring circuit for measuring an electrical voltage or an electric current for determining the electrical resistance of the measuring current path 13.
  • the arrangement of the two connection sections 14, 15 on the substrate edge 4 allows a particularly simple contacting. It is understood that the exact course of the measuring current path 13 within the edge strip 8 can be made optional, so that the invention does not rely on the in Fig. 1 shown course is limited.
  • the measuring current path 13 here has, for example, a homogeneous cross-sectional area, which consists of a constant thickness (corresponding to one with a constant thickness on the Substrate 2 applied coating 3) and width of the conductor path transverse to its extension results. Accordingly, the measuring current path 13 has a substantially identical electrical resistance, so that a measuring voltage applied to the two connection sections 14, 15 drops at least approximately uniformly over the measuring current path 13.
  • the thickness of the conductor track which is perpendicular to the substrate 2 or substrate surface 42 and transverse to the direction of extent of the measuring current path 13 is, for example, in the range from 50 to 100 nanometers (nm).
  • the width of the conductor track which is dimensioned parallel to the substrate 2 or substrate surface 42 and transversely to the extent of the measuring current path 13 is, for example, in a range of more than 100 micrometers ( ⁇ m) and less than 5 millimeters (mm). Due to the relatively small width of the measuring current path 13, its electrical resistance is substantially greater than the electrical resistance of each Edelstrompfads 12 in the heating field 9.
  • the width of the Edelstrompfade 12 is for example more than 10 mm and is in particular 30 mm.
  • Fig. 8 Considering, for a surface heating element 1 with a glass substrate 2 and a transparent coating 3 based on the conductive material silver (Ag), the change in resistance of the coating 3 that accompanies a temperature change is illustrated by way of example.
  • the electrical resistance R (ohms) of the coating 3 is plotted over its temperature T (° C). It can be seen that there is an at least approximately linear relationship between the electrical resistance around the temperature T, so that an increase in the temperature of the coating 3 is always accompanied by an increase in the electrical resistance.
  • a temperature increase of 50 ° C increases the electrical resistance here, for example, by about 10 ohms, so that local or global temperature increases can be detected reliably and safely.
  • a localized overheating occurs in the heating field 9 near the upper long edge 6. This can happen, for example, that a towel or garment is hung over the upper long edge 6, whereby the dissipation of the heat generated in the heating field 9 is hindered to the environment.
  • the local temperature increase in the heating field 9 leads to an increase in temperature in a section of the hot spot adjacent to the hot spot.
  • the reason for this is the thermal coupling between the heating field 9 and the measuring current path 13, which is based predominantly on heat conduction of the substrate 2, and in a small proportion of radiant heat. As a result, the measuring current path 13 is heated, so that its electrical resistance increases.
  • This change in resistance can be detected by the measuring device 16, wherein even relatively small changes in resistance in the measuring current path 13 can be reliably and reliably measured with a good signal-to-noise ratio.
  • the measuring current path 13 is electrically insulated from the heating field 9, a measurement of the electrical resistance of the measuring current path 13 can take place independently of the heating current.
  • a glassy substrate 2 for example, is a rather poor heat conductor, the thermal coupling between the heating field 9 and the measuring current path 13 is relatively small, but in practice a significant increase in the resistance of the measuring current path 13 can also be achieved in this case be observed at least by him adjacent hot spots. It would be conceivable to provide an additional thermal coupling between the heating field 9 and the measuring current path 13 in the edge strip 8.
  • the heating field 9 and the edge strip 8 could be connected by a layer of electrically insulating material with good thermal conductivity, which is applied to the substrate 2 and is not removed when forming the first dividing line 7.
  • the measuring current path 13 can be assigned a zone 19, referred to below as a "detection zone", of the heating field 9, which is thermally coupled to the measuring current path 13 in such a way that a change in temperature causes a (significant) change in resistance Measuring current path 13 causes.
  • the respective size of the detection zone 19 depends on the thermal coupling between the heating field 9 and the measuring current path 13, wherein a better thermal coupling causes a larger detection zone 19 and vice versa.
  • the detection zone 19 extends over a portion of the heating field 9 adjacent to the measuring current path 13, wherein the detection zone 19 can also extend over the complete heating field 19 with correspondingly good thermal coupling.
  • these can be, for example, those areas of the heating field 9 in which, in all likelihood, hot spots occur due to incorrect operation.
  • the measuring device 16 may be coupled to a control and monitoring device 40 of the surface heating element 1 such that the supply voltage applied to the connection electrodes 10, 11 is switched off or at least reduced so much that further overheating is avoided.
  • the control and monitoring device 40 can be set up so that the supply voltage is switched off or at least reduced by a predetermined or predeterminable amount as soon as the increase in resistance in the measuring current path 13 exceeds an optionally predetermined or predeterminable threshold value.
  • a stepwise reduction of the supply voltage can be provided based on detected resistance values.
  • control and monitoring device 40 may be coupled to an optical and / or acoustic output device 41 so that a local overheating of the heating field 9 is displayed optically and / or acoustically. The user can then take appropriate measures such as a manual shutdown or reduction of the supply voltage of the surface heating element 1.
  • FIG. 2 taken, wherein a further embodiment of the surface heating element 1 according to the invention is illustrated. To avoid unnecessary repetition, only the differences from the embodiment of Fig. 1 explained and otherwise reference is made to the statements made there.
  • the surface heating element 1 comprises three measuring current paths 13, 13 ', 13 "incorporated in the conductive coating 3 in the form of strip conductors within the edge strip 8, which are each electrically insulated from the heating field 9.
  • the three conductor loops differ only in their respective course extends a first measuring current path 13, starting from a first terminal portion 14 at the level of the two terminal electrodes 10, 11 approximately to the height of the left Schufeldecks 20 and on the reverse Way back back to a second terminal portion 15 at the level of the two terminal electrodes 10, 11.
  • a second Meßstrompfad 13 'extends starting from a first terminal portion 14' at the level of the two terminal electrodes 10, 11, only a small piece along the upper long Rands 6 and back again in the opposite way.
  • the second measuring current path 13 uses part of the conductor track of the first measuring current paths 13, so that the first and second measuring current paths 13, 13' in particular share a common second connection section 15.
  • a third measuring current path 13 "extends, starting from a first connection section 14" at the level of the two connection electrodes 10, 11, along the lower long edge 6 and on a reversed path back to a second connection section 15 ".
  • the measuring current paths 13, 13 ', 13 are respectively short-circuited by the connection lines 34 of a separate measuring device 16 to a measuring circuit, which are designated here in this order as measuring circuits A, B and C. While the two measuring circuits A, B are for detecting a temperature-dependent Resistance change for detecting hot spots in the heating field 9, the measuring circuit C is used only as a reference circle. If the detection zones 19 of the measuring current paths 13, 13 ', 13 "cover only a portion of the Schufelds 9, can by the two measuring circuits A and B a spatially resolved detection of hot spots, wherein the spatial proximity of a hot spot to the measuring circuit A or B is detectable.
  • the measuring circuit C is associated with a detection zone 19, in which at least in certain applications in practice (eg space heating) no hot spots should occur.
  • a reference signal dependent on the instantaneous temperature of the heating field 9 can be generated by the measuring circuit C, which enables a reliable and reliable determination of hot spots on the basis of a change in the resistance of the measuring circuits A and B.
  • the surface heater 1 of Fig. 2 thus allows a particularly reliable, spatially resolved detection of hot spots. It is understood that in Fig. 2 illustrated measuring devices 16 may equally be realized by a single measuring device 16.
  • FIG. 3 taken, wherein a further embodiment of the surface heating element 1 according to the invention is illustrated. To avoid unnecessary repetition, only the differences to those in Fig. 2 shown embodiment explained and otherwise reference is made to the statements made there.
  • the surface heating element 1 comprises three measuring current paths 13, 13 ', 13 "formed as conductor tracks in the conductive coating 3 within the marginal strip 8, which are each electrically insulated from the heating field 9.
  • the three measuring current paths 13, 13', 13" have a different course as in Fig. 2 and are used without reference circle exclusively for detecting hot spots 17, one of which is shown by way of example.
  • the first measuring current path 13, which belongs to measuring circuit A, extends analogously to Fig. 2 , starting from a first connection section 14 at the height of the two connection electrodes 10, 11, approximately up to the height of the left Bankfeldecks 20 and on the opposite way back to a second connection section 15 at the level of the two connection electrodes 10, 11.
  • the second measuring current path thirteenth ' which belongs to measuring circle B, extends, starting from a first connection section 14' at the level of the two connection electrodes 10, 11, approximately to the middle of the upper long edge 6 and in the opposite way back again.
  • the second measuring current path 13 ' uses part of the conductor track of the first measuring current path 13, so that the first and second measuring current paths 13, 13' in particular share a common second connection section 15.
  • the third measuring current path 13 "extends, starting from a first connection section 14" at the level of the two connection electrodes 10, 11, along the right short edge 5 and on the opposite way back again.
  • the third measuring current path 13 "utilizes part of the common conductor track of the first and second measuring current paths 13, 13 ', so that the first, second and third measuring current paths 13, 13', 13" in particular use a common second connection section 15
  • Measuring circuits 13, 13 ', 13 "associated detection zones 19 each cover only a portion of the heating field 9, the measurement circuits A, B, C allow a spatially resolved detection of hot spots 17, wherein the spatial proximity of a hot spot 17 to the measuring circuit A, B or C is detectable Fig. 3 hot spot 17 illustrated by way of example in the region of the upper long edge 6 has the greatest spatial proximity to the first measuring current path 13 or measuring circuit A and therefore causes there a strongest temperature rise and thus a greatest change in the electrical resistance. Since the hot spot 17 in the measuring circuits B and C no correspondingly large change in resistance caused, the spatial position of the hot spot 17 can be clearly assigned to the detection zone 19 of the measuring circuit A.
  • FIG. 4 taken, wherein a further embodiment of the surface heating element 1 according to the invention is illustrated. Again, to avoid unnecessary repetition, only the differences to those in Fig. 3 illustrated embodiment and otherwise reference is made to the statements made there.
  • the surface heating element 1 comprises a plurality of unspecified measuring current paths within the edge strip 8, which are each electrically insulated from the heating field 9 and the measuring circuits A, B, C, etc. result.
  • Each measuring current path comprises a spatially limited zone 18, hereinafter referred to as "measuring zone” in which the conductor changes its course direction several times (ie has a plurality of oppositely curved conductor track sections), wherein the conductor track sections within the measuring zone 18 with close spacing are close together.
  • the measuring current paths have, for example, a meandering curved course in the schematically illustrated measuring zones 18. As in Fig.
  • each measuring current path is connected to an adjacent Meßstrompfad (measuring circuit).
  • the measuring zones 18 of the various measuring circuits A, B, C, etc. are spatially separated from each other and distributed with approximately equal intervals along the upper long edge 6 and right short edge 5. Since the measuring voltage drops predominantly in the region of the measuring zones 18, the detection zones 19 of the measuring circuits A, B, C, etc. can each be assigned to the measuring zones 18, so that a spatially resolved detection of hot spots is possible, wherein the spatial proximity of a hot spot to the Measuring zone 18 of a measuring circuit A, B, C, etc. is detectable.
  • a hot spot 17 is shown, which is located in the vicinity of the two measuring zones 18 of the measuring circuits A and B.
  • the hot spot 17 will cause a strongest temperature increase or increase in resistance in the measuring zone 18 of the measuring circuit A and subordinate in the measuring zone 18 of the measuring circuit B.
  • the surface heater 1 of Fig. 4 thus enables a highly sensitive and particularly accurate spatially resolved detection of hot spots 17 by the distributed measuring zones 18 of the various measuring circuits.
  • FIG. 5 taken, wherein a further embodiment of the surface heating element 1 according to the invention is illustrated. To avoid unnecessary repetition, again only the differences to those in the FIGS. 1 to 4 illustrated embodiments and otherwise reference is made to the statements made there.
  • the surface heater 1 of Fig. 5 differs from the previous embodiments by the partial course of Meßstrompfaden 13 within the Schufelds 9, as well as their contacting. These are analogous to Fig. 2 two measuring circuits A and B, and a reference circle C provided.
  • a first measuring current path 13 uses a path section of a heating current path 12, which is, for example, a heating current path 12 adjoining the first dividing line 7.
  • the first measuring current path 13 extends within the heating field 9 from the first connection electrode 10 (in FIG Fig. 5 left terminal electrode), which serves here as a first terminal portion 14, along the lower short edge 5 and the adjoining left long edge 6.
  • the Bankstrompfad 12 changes in its course along the left long edge 6 several times in opposite directions its direction.
  • the first measuring current path 13 extends as a conductor track incorporated in the coating 3 along the upper long edge 6 and the adjoining short edge 5, and a short distance along the lower long edge 6, where it reaches the second connection electrode 11 (FIG. in Fig. 5 right connection electrode) ends in a second connection section 15.
  • the two connecting lines 34 with the intermediate measuring device 16 contact the first connecting electrode 10 and the second connecting section 15 of the first measuring current path 13 for forming the measuring circuit A.
  • the first measuring current path 13 thus comprises a heating field section 22 located in the heating field 9 and an edge strip section 23 located in the edge strip 8 ,
  • a second measuring current path 13 ' likewise runs partially in the heating field 9 and uses a different section of the same heating current path 12 as the first measuring current path 13.
  • the second measuring current path 13' extends from the second connection electrode 11 (in FIG Fig. 5 right connection electrode) in the heating current path 12 for a short distance along the lower long edge 6 and the right short edge 5 adjacent thereto.
  • the second measuring current path 13 ' leaves the heating field 9, merges into the edge strip 8 and continues from there completely within the edge strip 8.
  • the second parting line 7, by which the edge strip 8 is electrically separated from the heating field 9, is not formed for this purpose there.
  • the second measuring current path 13 ' extends as in the coating 3 molded conductor along the right short edge 5, and a short distance along the lower long edge 6, where it ends at the level of the second connection electrode 11 in a second connection portion 15' .
  • the two connection lines 34 with the intermediate measuring device 16 contact the second connection electrode 11 and the second connection section 15 'of the second measuring current path 13' for forming the measuring circuit B.
  • the second measuring current path 13 'thus likewise includes a heating field section 22 located in the heating field 9 and one in the edge strip 8 located edge strip section 23rd
  • the electrical resistance within the heater 9 is substantially smaller than in the edge strip 8.
  • the width or cross-sectional area each of the first and second measuring current paths 13, 13 'within the heating field for example, 2 to 100 times, in particular 85 times, the width or cross-sectional area in the edge strip 8. It is understood that the width within the heating field 9 from Layout of Edelstrompfade 12 depends and can vary widely.
  • the measurement voltage for measuring a change in resistance drops substantially over the edge strip portions 23.
  • the detection zones 19 of the two measuring current paths 13, 13 'can thus be assigned to the edge strip sections 23.
  • a spatially resolved detection of hot spots in the heating field 9 by the edge strip portions 23 of the two measuring current paths 13, 13 ' is possible.
  • a particular advantage of this embodiment is that the conductor tracks of the measuring circuits A and B respectively require only relatively little space in the edge strip 8, so that the measuring circuits A, B can also be formed with narrow edge strips 8.
  • a measurement of the electrical resistance in the measuring circuits A, B can be carried out simultaneously for feeding heating current through a potential difference between measuring and supply voltage.
  • Analogous to Fig. 2 serves a third Meßstrompfad 13 "for forming a measuring circuit C.
  • the third Meßstrompfad 13" extending from a first terminal portion 14 "at the level of the two terminal electrodes 10, 11 in the form of a built-in coating 3 conductor along the lower long edge 6 and of the upper long edge 6 adjoining thereto and runs back in the opposite direction, for which purpose the interconnect incorporated into the coating 3 in the area of the left heater top 20 merges into the edge strip section 23 of the first measuring current path 13.
  • a connecting line 34 of the measuring device 16 contacts the first connection section 14 "of the third measurement current path 13", the other connection line 34 connected to the first connection electrode 10 connecting line 34 of the measuring circuit A.
  • the measuring circuit C is used only as a reference circle and allows determination of hot spots on the basis of one of the current temperature of the heating f elds 9 dependent reference signal, so that a particularly reliable and secure detection of hot spots is possible.
  • FIG. 6 taken, wherein a further embodiment of the surface heating element 1 according to the invention is illustrated. Again, to avoid unnecessary repetition, only the differences to that are shown Fig. 5 illustrated embodiment and otherwise reference is made to the statements made there.
  • the surface heater 1 of Fig. 6 differs from the surface radiator of Fig. 5 only in that the edge strip portion 23 of the first measuring current path 13 in the region of the upper long edge 6 several times its course in opposite directions (oppositely curved Meßstrompfadabitese) changes and here, for example, has a meandering curved course.
  • the measuring voltage is substantially adjacent to that at the upper long edge 6 Edge strip portion 23 drops, so that the sensitivity and spatial resolution for detecting hot spots is increased in this area.
  • the surface heater 1 differs from the in the FIGS. 1 to 6 Illustrated surface radiators 1 by the virtually complete course of Meßstrompfaden within the heating field 9, as well as by contacting the measuring current paths.
  • four measuring circuits A, B, C and D are formed, as will be explained in more detail below.
  • Fig. 7A Be first Fig. 7A considered, wherein the layout of the surface heater 1 is shown. Accordingly, the surface heater 1 here, for example, a mirror-symmetrical structure with respect to an axis of symmetry 27, which extends centrally of the two short edges 5.
  • the two connection electrodes 10, 11 are each divided into three electrically insulated first to third electrode sections 24-26, the three electrode sections 24-26 of a same connection electrode 10, 11 are electrically connected to each other in a plane other than the coating 3 (which not shown in detail).
  • the two connection electrodes 10, 11 are in Fig. 7A also shown in an enlarged view.
  • measuring current paths 13, 13 ', 13 ", 13"' formed, each consisting of a path portion of a Schustrompfads 12, 12 'and a much narrower, incorporated into the conductive coating 3 of the heating field 9 conductor, hereinafter referred to as "measuring current "labeled, put together.
  • the surface heating element 1 comprises for this purpose on each side of the symmetry axis 27 each two measuring current paths, namely a first measuring flow path 28 and a second measuring flow path 29, and a third measuring flow path 35 and a fourth measuring flow path 36, each by third dividing lines 37 in the conductive Coating 3 are formed for example by means of laser.
  • the measuring current paths 28, 29, 35, 36 have a (eg significantly) smaller width or cross-sectional area compared to the heating current paths 12, which is accompanied by a correspondingly greater electrical resistance, so that the measuring current paths 13, 13 ', 13 ", 13 “', the measuring voltage substantially above the measuring current paths 28, 29, 35, 36 drops.
  • the first measuring flow path 28 extend and the third measuring flow path 35 each in the heating field 9 between a first heating current path 12, which adjoins the first dividing line 7, and an adjacent, inner second heating current path 12 'up to a (common) first Meßstrombahnende 38 approximately at the central height of the left short substrate edge 5.
  • the first measuring current path 28 extends in the region of the second connection electrode 11 in a second electrode gap 32 between the first electrode portion 24 and the second electrode portion 25 of the second connection electrode 11 and then merges into a first electrode gap 31 between the two connection electrodes 10, 11 until it runs out in a separate first pad 44.
  • the first measuring current path 28 is electrically connected to the part of the first heating current path 12 situated below the axis of symmetry 27.
  • the third measuring current path 35 extends in the region of the first connection electrode 10 in a second electrode gap 32 between the first electrode section 24 and the second electrode section 25 of the first connection electrode 10 and then passes into the first electrode gap 31 between the two connection electrodes 10, 11, where they expires in a third pad 46.
  • the third measuring current path 35 is electrically connected to the part of the first heating current path 12 located above the axis of symmetry 27.
  • the first measuring flow path 28 and the third measuring flow path 35 are electrically separated from the first and second heating current paths 12, 12 '.
  • the second measuring flow path 29 and the fourth measuring flow path 36 which lie further in each case, extend in the heating field 9 between the second heating current path 12 'and an adjacent third heating current path 12 "up to a respective second measuring flow path end 43.
  • the second measuring flow path 29 extends in the region of the second terminal electrode 11 in a third electrode gap 33 between the second electrode portion 25 and the third electrode portion 26 of the second terminal electrode 11 and then passes into the first electrode gap 31 between the two terminal electrodes 10, 11 where it terminates in a second pad 45
  • the second measuring current path 29 is electrically connected to the second heating current path 12 'in the second measuring current path end 43.
  • the fourth measuring current path 36 extends in the region of the first connecting electrode 10 in a third electrode gap 33 between the second electrode section 25 and the third th Electrode portion 26 of the first terminal electrode 10 and then passes into the first electrode gap 31 between the two terminal electrodes 10, 11, where it terminates in a fourth pad 47.
  • the fourth measuring flow path 36 is electrically connected to the second heating current path 12 '.
  • the second measuring flow path 29 and the fourth measuring flow path 36 are electrically separated from the first and second heating current paths 12, 12 '.
  • the first measuring current path 13 corresponding to the measuring circuit A, is connected in series with a second measuring current path 13 ', corresponding to the measuring circuit B.
  • the first measuring current path 13 extends, starting from the first electrode section 24 of the second connecting electrode 11 in the first heating current path 12, to the first measuring current end 38, where it merges into the third measuring current path 35.
  • the third measuring current path 35 is short-circuited to the second measuring current path 29, which is part of the second measuring current path 13 '.
  • the third pad 46 and the second pad 45 are electrically connected to each other (which is not shown in detail). These two connection pads 45, 46 together form a first connection section 14.
  • the second measurement current path 13 merges at the associated second measuring flow path end 43 into the second heating current path 12', which is electrically connected to the second electrode section 25 of the first connection electrode 10.
  • the third measuring current path 13 " corresponding to the measuring circuit C, is connected in series with a fourth measuring current path 13"', corresponding to the measuring circuit D.
  • the third measuring current path 13 extendends, starting from the second electrode section 25 of the second connection electrode 11 in the second heating current path 12 'to the associated second measuring flow path end 43, where it merges into the fourth measuring flow path 36.
  • the fourth measuring flow path 36 is short-circuited with the first measuring flow path 28, which is part of the fourth measuring current path 13 "'.
  • the fourth pad 47 and the first pad 44 are electrically connected. These two connection pads 44, 47 together form a second connection section 15.
  • the fourth measurement current path 13 "'changes into the first heating current path 12, which is electrically connected to the first electrode section 24 of the first connection electrode 10.
  • resistor R1 corresponds to measuring circuit A
  • resistor R2 to measuring circuit B
  • resistor R3 to measuring circuit C
  • resistor R4 to measuring circuit D
  • First electrode 10 is connected, for example, to the negative pole of a voltage source and second electrode 11 to the positive pole of the voltage source.
  • a measuring device 16 for determining electrical voltage changes is electrically connected to a node between the two resistors R1 and R2 and another node between the two resistors R3 and R4, so that there is a Wheatstone bridge circuit. These two nodes correspond to the two connection sections 14, 15, which result from an electrical connection of the second and third connection pads 45, 46 and of the first and fourth connection pads 44, 47, respectively.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Ceramic Engineering (AREA)
  • Surface Heating Bodies (AREA)
  • Resistance Heating (AREA)
  • Control Of Resistance Heating (AREA)

Description

Die Erfindung liegt auf dem technischen Gebiet der Flächenheizkörper und betrifft einen Flächenheizkörper mit Temperaturüberwachung.The invention is in the technical field of surface heaters and relates to a surface heater with temperature monitoring.

Stand der TechnikState of the art

Flächenheizkörper mit einer elektrischen Heizschicht werden in mannigfacher Weise eingesetzt. Sie sind als solche wohlbekannt und bereits vielfach in der Patentliteratur beschrieben worden. Lediglich beispielhaft sei in diesem Zusammenhang auf die Druckschriften DE 102008018147 A1 , DE 102008029986 A1 , DE 10259110 B3 und DE 102004018109 B3 verwiesen. So werden beispielsweise transparente Flächenheizkörper in Kraftfahrzeugen als Windschutzscheiben eingesetzt, da das Sichtfeld von Windschutzscheiben aufgrund gesetzlicher Vorgaben keine Sichteinschränkungen aufweisen darf. Durch die von der Heizschicht erzeugte Wärme können binnen kurzer Zeit kondensierte Feuchtigkeit, Eis und Schnee entfernt werden. In Wohnräumen können sie anstelle herkömmlicher Heizkörper zur Wohnraumheizung dienen, zu welchem Zweck sie beispielsweise an Wänden oder frei stehend montiert werden. Flächenheizkörper können gleichermaßen als heizbare Spiegel oder transparente Dekorteile eingesetzt werden.Surface heating elements with an electrical heating layer are used in manifold ways. They are well known as such and have been described many times in the patent literature. For example only in this context, the documents DE 102008018147 A1 . DE 102008029986 A1 . DE 10259110 B3 and DE 102004018109 B3 directed. For example, transparent panel radiators are used in motor vehicles as windshields, since the field of vision of windshields may not have any visual restrictions due to legal requirements. Due to the heat generated by the heating layer condensed moisture, ice and snow can be removed within a short time. In living rooms they can be used instead of conventional radiators for living room heating, for which purpose they are mounted, for example, on walls or free standing. Surface heating elements can be used equally as heatable mirrors or transparent decorative parts.

Nun kann bei Flächenheizkörpern in der Praxis das Problem auftreten, dass durch auf der Heizschicht befindliche Gegenstände die produzierte Wärme nicht mehr in ausreichender Weise an die Umgebung abgeleitet wird. In der Folge kann eine lokale Überhitzung ("Hot Spot") auftreten. Dies kann beispielsweise bei zur Raumheizung eingesetzten Flächenheizkörpern durch versehentlich übergelegte Kleidungsstücke passieren. Durch die lokale Überhitzung kann die Heizschicht beeinträchtigt und gegebenenfalls sogar geschädigt werden.Now, in the case of surface heaters in practice, the problem may arise that due to objects located on the heating layer, the heat produced is no longer sufficiently dissipated to the environment. As a result, a local overheating ("hot spot") may occur. This can happen, for example, in surface heating elements used for space heating by accidentally covered over garments. Due to the local overheating, the heating layer can be impaired and possibly even damaged.

Die US-Patentanmeldung Nr. 2010/0163675 A1 zeigt eine Scheibe und ein Verfahren gemäß der Oberbegriffe von Patentanspruch 1 und 12.The U.S. Patent Application No. 2010/0163675 A1 shows a disc and a method according to the preambles of claims 1 and 12th

Aufgabenstellungtask

Demgegenüber besteht die Aufgabe der vorliegenden Erfindung darin, herkömmliche Flächenheizkörper in einer Weise weiterzubilden, dass für insbesondere transparente Flächenheizkörper eine Temperaturüberwachung in einfacher und zuverlässiger Weise ermöglicht ist. Diese und weitere Aufgaben werden nach dem Vorschlag der Erfindung durch einen Flächenheizkörper und eine Anordnung mit einem solchen Flächenheizkörper mit den Merkmalen der nebengeordneten Patentansprüche gelöst. Vorteilhafte Ausgestaltungen der Erfindung sind durch die Merkmale der Unteransprüche angegeben.In contrast, the object of the present invention is to develop conventional surface heating elements in such a way that in particular transparent Surface heating a temperature monitoring in a simple and reliable way is possible. These and other objects are achieved according to the proposal of the invention by a surface heater and an arrangement with such a surface heater with the features of the independent claims. Advantageous embodiments of the invention are indicated by the features of the subclaims.

Erfindungsgemäß ist ein Flächenheizkörper mit mindestens einem flächigen Substrat und einer elektrisch leitfähigen, heizbaren, vorzugsweise transparenten Beschichtung gezeigt. Die heizbare Beschichtung ist so ausgebildet, dass sich deren elektrischer Widerstand mit einer Variation der Temperatur ändert. Die heizbare Beschichtung erstreckt sich zumindest über einen Teil einer Substratfläche des flächigen Substrats. Der Flächenheizkörper ist weiterhin mit mindestens zwei zum elektrischen Verbinden mit den beiden Polen einer Spannungsquelle vorgesehenen Anschlusselektroden versehen, die mit der leitfähigen Beschichtung elektrisch so verbunden sind, dass durch Anlegen einer Speisespannung ein Heizstrom in einem von der leitfähigen Beschichtung gebildeten Heizfeld fließt. Das Heizfeld weist zu diesem Zweck einen oder mehrere Heizstrompfade zur Leitung des über die beiden Anschlusselektroden eingeleiteten Heizstroms auf, welche in die leitfähige Beschichtung mittels von der leitfähigen Beschichtung freier, d.h. beschichtungsfreier (elektrisch isolierter) Trennbereiche, beispielsweise linienförmige Trennbereiche (Trennlinien) eingeformt sind. Die Heizstrompfade werden somit von der leitfähigen Beschichtung gebildet. Bei einer transparenten Beschichtung sind die Heizstrompfade dementsprechend transparent.According to the invention, a surface heating element with at least one planar substrate and an electrically conductive, heatable, preferably transparent coating is shown. The heatable coating is designed so that its electrical resistance changes with a variation of the temperature. The heatable coating extends over at least part of a substrate surface of the planar substrate. The surface heating element is further provided with at least two connection electrodes provided for electrical connection to the two poles of a voltage source, which are electrically connected to the conductive coating in such a way that a heating current flows in a heating field formed by the conductive coating by applying a supply voltage. For this purpose, the heating field has one or more heating current paths for conducting the heating current introduced via the two connection electrodes, which is introduced into the conductive coating by means of a conductive coating which is free, i. coating-free (electrically isolated) separation areas, for example, line-shaped separation areas (dividing lines) are formed. The heating current paths are thus formed by the conductive coating. With a transparent coating, the heating current paths are accordingly transparent.

Der erfindungsgemäße Flächenheizkörper kann in vielfacher Weise ausgebildet sein und beispielsweise als flächiger Heizkörper zur Wohnraumheizung, als heizbarer Spiegel, heizbares Dekorteil oder heizbare Scheibe, insbesondere Windschutz- oder Heckscheibe eines Kraftfahrzeugs dienen, wobei diese Aufzählung lediglich beispielhaft ist und die Erfindung keinesfalls einschränken soll.The surface heating element according to the invention can be designed in many ways and serve, for example as a flat radiator for living room heating, as a heated mirror, heated decorative part or heated disc, especially windshield or rear window of a motor vehicle, this list is merely exemplary and is not intended to limit the invention in any way.

Nach dem Vorschlag der Erfindung umfasst der Flächenheizkörper einen oder mehrere in die leitfähige Beschichtung als Leiterbahnen eingeformte Messstrompfade, die zumindest abschnittsweise von den Heizstrompfaden verschieden sind. Die Messstrompfade sind in die leitfähige Beschichtung mittels von der leitfähigen Beschichtung freier, das heißt beschichtungsfreier (elektrisch isolierter) Trennbereiche, beispielsweise linienförmige Trennbereiche (Trennlinien), eingeformt. Die Messstrompfade werden somit von der leitfähigen Beschichtung gebildet. Bei einer transparenten Beschichtung sind die Messstrompfade transparent. Dabei ist jeder Messstrompfad zumindest mit einem Teilbereich des Heizfelds thermisch gekoppelt und verfügt über wenigstens zwei Anschlussabschnitte zum Anschluss einer Messeinrichtung zum Bestimmen seines elektrischen Widerstands. Im Unterschied zu den Heizstrompfaden, welche zum Leiten des über die Anschlusselektroden eingeleiteten Heizstroms dienen, sind die Messstrompfade zum Leiten eines über die Anschlussabschnitte eingeleiteten Messstroms zum Messen des elektrischen Widerstands vorgesehen. Dabei können die Messstrompfade einen größeren elektrischen Widerstand pro Länge als die Heizstrompfade haben, der sich beispielsweise durch eine geringere Breite der Messstrompfade quer zur Erstreckungsrichtung ergibt.According to the proposal of the invention, the surface heating element comprises one or more measuring current paths formed as conductor tracks in the conductive coating, which measuring paths are at least partially different from the heating current paths. The measuring current paths are free in the conductive coating by means of the conductive coating, that is coating-free (electrically isolated) separation areas, for example, line-shaped separation areas (dividing lines), molded. The measuring current paths are thus formed by the conductive coating. With a transparent coating, the measuring current paths are transparent. In this case, each measuring current path is thermally coupled at least to a partial area of the heating field and has at least two connecting sections for connecting a measuring device for determining its electrical resistance. In contrast to the heating current paths, which serve for conducting the heating current introduced via the connection electrodes, the measuring current paths are provided for conducting a measuring current introduced via the connection sections for measuring the electrical resistance. In this case, the measuring current paths can have a greater electrical resistance per length than the heating current paths, which results, for example, from a smaller width of the measuring current paths transversely to the direction of extent.

Der erfindungsgemäße Flächenheizkörper ermöglicht somit in vorteilhafter Weise eine Bestimmung der Temperatur der jeweils mit zumindest einem Teilbereich des Heizfelds thermisch gekoppelten Messstrompfade, indem der elektrische Widerstand der Messstrompfade bestimmt wird. Auf diese Weise können insbesondere lokale Überhitzungen im Bereich des Heizfelds zuverlässig und sicher erfasst werden.The surface heating element according to the invention thus advantageously makes it possible to determine the temperature of the measuring current paths thermally coupled in each case to at least one subarea of the heating field by determining the electrical resistance of the measuring current paths. In this way, in particular local overheating in the area of the heating field can be detected reliably and safely.

In dem erfindungsgemäßen Flächenheizkörper können die Messstrompfade in einfacher Weise durch Strukturieren der leitfähigen Beschichtung hergestellt werden, wobei die Messstrompfade bei einer transparenten leitfähigen Beschichtung transparent sind, so dass in besonders vorteilhafter Weise auch in transparenten Flächenheizkörpern die Temperatur des Heizfelds überwacht werden kann.In the surface heating element according to the invention, the measuring current paths can be produced in a simple manner by structuring the conductive coating, the measuring current paths being transparent in the case of a transparent conductive coating, so that the temperature of the heating field can be monitored in a particularly advantageous manner even in transparent surface heating elements.

Bei einer vorteilhaften Ausgestaltung des erfindungsgemäßen Flächenheizkörpers sind die Messstrompfade zumindest abschnittsweise, insbesondere vollständig, in einem vom Heizfeld elektrisch getrennten, das Heizfeld umgebenden Randstreifen ausgebildet. Diese Maßnahme ermöglicht eine besonders einfache Kontaktierung der Anschlussabschnitte der Messstrompfade im Randstreifen. Zudem können die Messstrompfade für die Erfassung randnaher Hot Spots einen entlang des Substratrands sich erstreckenden Verlauf haben. Dabei können die Messstrompfade insbesondere zumindest abschnittsweise in voneinander verschiedenen Teilbereichen des Randstreifens ausgebildet sein, wodurch eine ortsaufgelöste Erfassung von Hot Spots im Heizfeld möglich ist.In an advantageous embodiment of the surface heating element according to the invention, the measuring current paths are formed at least in sections, in particular completely, in an edge strip which is electrically separate from the heating field and surrounds the heating field. This measure allows a particularly simple contacting of the connection sections of the measuring current paths in the edge strip. In addition, the measuring current paths for the detection of near-edge hot spots may have a course extending along the substrate edge. In this case, the measuring current paths can in particular at least partially in be formed from each other different portions of the edge strip, whereby a spatially resolved detection of hot spots in the heating field is possible.

Bei einer weiteren vorteilhaften Ausgestaltung des erfindungsgemäßen Flächenheizkörpers sind ein oder mehrere Messstrompfade jeweils so ausgebildet, dass sie in einer räumlich begrenzten Zone des Randstreifens, im Weiteren als "Messzone" bezeichnet, mehrfach ihre Pfadrichtung ändern. Die Messstrompfade können in den Messzonen beispielsweise einen mäandrisch geschwungenen Verlauf haben, wobei gleichermaßen jeder andere Verlauf mit einer wechselseitigen bzw. gegensinnigen Änderung der Pfadrichtung vorgesehen sein kann. Anders ausgedrückt, umfasst jeder Messstrompfad eine Mehrzahl gegensinnig gekrümmter Strompfadabschnitte. In den Messzonen ist jeweils ein relativ großer Anteil der Leiterbahn eines Messstrompfads enthalten, was mit einem entsprechend großen Spannungsabfall einer an die Anschlussabschnitte angelegten Messspannung einhergeht. Die Messzonen ermöglichen somit eine Erfassung von Hot Spots mit hoher Sensitivität und besonders guter Ortsauflösung. Dabei kann es weiterhin von Vorteil sein, wenn die Messzonen zumindest über einen Teilbereich des Randstreifens räumlich verteilt, insbesondere räumlich gleichmäßig verteilt, angeordnet sind, wodurch eine besonders gute Ortsauflösung bei der Erfassung von Hot Spots des Heizfelds ermöglicht ist.In a further advantageous embodiment of the surface heating element according to the invention one or more measuring current paths are each formed so that they repeatedly change their path direction in a spatially limited zone of the edge strip, hereinafter referred to as "measuring zone". The measuring current paths may have, for example, a meandering curved course in the measuring zones, it being equally possible for any other course to be provided with a mutual or opposing change in the path direction. In other words, each measuring current path comprises a plurality of oppositely curved current path sections. In each case, a relatively large proportion of the conductor track of a measuring current path is contained in the measuring zones, which is accompanied by a correspondingly large voltage drop of a measuring voltage applied to the terminal sections. The measuring zones thus enable detection of hot spots with high sensitivity and particularly good spatial resolution. It may also be advantageous if the measuring zones are spatially distributed over at least a portion of the edge strip, in particular spatially evenly distributed, whereby a particularly good spatial resolution in the detection of hot spots of the heating field is possible.

Bei einer weiteren vorteilhaften Ausgestaltung des erfindungsgemäßen Flächenheizkörpers sind die Messstrompfade vom Heizfeld elektrisch getrennt. Dies kann beispielsweise dadurch erreicht werden, dass die Messstrompfade vollständig innerhalb des vom Heizfeld elektrisch isolierten Randstreifens enthalten sind. Durch diese Maßnahme sind Heiz- und Messstrom elektrisch getrennt, so dass sich die Bestimmung des elektrischen Widerstands der Messstrompfade besonders einfach gestaltet.In a further advantageous embodiment of the surface heating element according to the invention, the measuring current paths are electrically separated from the heating field. This can be achieved, for example, in that the measuring current paths are completely contained within the edge strip that is electrically insulated from the heating field. By this measure heating and measuring current are electrically isolated, so that the determination of the electrical resistance of the measuring current paths is particularly simple.

Bei einer weiteren vorteilhaften Ausgestaltung des erfindungsgemäßen Flächenheizkörpers verfügen ein oder mehrere Messstrompfade jeweils über einen Messstrompfadabschnitt, der Teil eines Heizstrompfads ist oder von einem vollständigen Heizstrompfad gebildet wird. In diesem Fall kann eine mit dem Heizstrompfad verbundene Anschlusselektrode insbesondere als Anschlussabschnitt eines Messstrompfads dienen. Der elektrische Widerstand des nicht vom Heizstrompfad gebildeten Pfadabschnitts eines Messstrompfads kann insbesondere größer sein als jener im übrigen Messstrompfad, was durch eine entsprechend kleinere Breite der Leiterbahn in einfacher Weise realisierbar ist. Durch diese Maßnahme kann in vorteilhafter Weise eine vereinfachte Herstellung der Messstrompfade erreicht werden. Zudem ist beispielsweise bei teilweise im Randstreifen verlaufenden Messstrompfaden der Platzbedarf im Randstreifen verringert, so dass mehr Messstrompfade bei gegebener Dimensionierung des Randstreifens in die leitfähige Beschichtung eingeformt werden können. Andererseits ist die Ausbildung von Messzonen im Randstreifen erleichtert.In a further advantageous embodiment of the surface heating element according to the invention, one or more measuring current paths each have a measuring current path section which is part of a heating current path or is formed by a complete heating current path. In this case, a connection electrode connected to the heating current path can serve in particular as a connection section of a measuring current path. The electrical resistance of the path portion of a measuring current path not formed by the heating current path may in particular be greater than that in the rest of the measuring current path, which can be realized in a simple manner by a correspondingly smaller width of the conductor track. By this measure, a simplified production of the measuring current paths can be achieved in an advantageous manner. In addition, for example, when running partially in the edge strip measuring current paths of the space requirement in the edge strip is reduced, so that more measuring current paths can be formed with a given dimensioning of the edge strip in the conductive coating. On the other hand, the formation of measuring zones in the edge strip is facilitated.

Bei einer weiteren vorteilhaften Ausgestaltung des erfindungsgemäßen Flächenheizkörpers sind die Anschlusselektroden mit zwei zueinander parallelen verschalteten Messstrompfadreihen, in denen jeweils zwei Messstrompfade seriell verschaltet sind, elektrisch verbunden, wobei jede Messstrompfadreihe über einen zwischen den beiden seriell verschalteten Messstrompfaden angeordneten Anschlussabschnitt zum Anschluss der Messeinrichtung zur Bestimmung des elektrischen Widerstands verfügen. Durch diese Maßnahme können die Messstrompfade zu einer dem Fachmann an sich bekannten Wheatstone-Brücke verschaltet werden, welche eine besonders genaue Erfassung von Widerstandsänderungen der Messstrompfade ermöglicht.In a further advantageous embodiment of the surface heating element according to the invention, the connection electrodes are electrically connected to two interconnected measuring current paths, in each of which two measuring current paths are connected in series, each measuring current path series being arranged via a connection section arranged between the two serially connected measuring current paths for connecting the measuring device for determining the electrical resistance. As a result of this measure, the measuring current paths can be connected to a Wheatstone bridge known per se to those skilled in the art, which enables a particularly accurate detection of changes in the resistance of the measuring current paths.

Bei einer weiteren vorteilhaften Ausgestaltung des erfindungsgemäßen Flächenheizkörpers dient zumindest ein Messstrompfad als Referenzstrompfad zur Erfassung eines Referenzwiderstands für andere Messstrompfade. Dies ermöglicht eine besonders zuverlässige Erfassung von Hot Spots im Heizfeld, da temperaturbedingte Widerstandsänderungen von Messstrompfaden aufgrund von Änderungen der Umgebungstemperatur oder bestimmungsgemäßer Wärmeabgabe des Heizfelds erfassbar sind.In a further advantageous embodiment of the surface heating element according to the invention, at least one measuring current path serves as a reference current path for detecting a reference resistance for other measuring current paths. This enables a particularly reliable detection of hot spots in the heating field, since temperature-induced changes in resistance of measuring current paths can be detected due to changes in the ambient temperature or the intended heat output of the heating field.

Die Erfindung erstreckt sich weiterhin auf eine Anordnung mit einem wie oben beschriebenen Flächenheizkörper, welche zumindest eine an die Anschlussabschnitte der Messstrompfade angeschlossene Messeinrichtung zum Bestimmen elektrischer Widerstände sowie eine mit der Messeinrichtung datentechnisch verbundene Steuer- und Kontrolleinrichtung aufweist. Dabei ist die Steuer- und Kontrolleinrichtung programmtechnisch so eingerichtet, dass die an die Anschlusselektroden angelegte Speisespannung abgeschaltet oder zumindest reduziert wird, falls der elektrische Widerstand eines Messstrompfads einen vorbestimmbaren (wählbaren) Schwellwert übersteigt. Durch diese Maßnahme kann eine lokale Überhitzung des Heizfelds in vorteilhafter Weise automatisch behoben werden. Die Steuer- und Kontrolleinrichtung ist zu diesem Zweck mit einer mit der Spannungsquelle zum Bereitstellen der Speisespannung gekoppelten Einrichtung, durch welche die Speisespannung reduziert oder abgeschaltet werden kann, elektrisch verbunden.The invention furthermore extends to an arrangement having a surface heating element as described above, which has at least one measuring device connected to the connection sections of the measuring current paths for determining electrical resistances and a control and monitoring device connected to the measuring device in terms of data technology. In this case, the control and monitoring device is set up by the program in such a way that the supply voltage applied to the connection electrodes is switched off or at least reduced if the electrical resistance of a measuring current path exceeds a predeterminable (selectable) threshold value. By this measure, a local overheating of the heating field can be automatically remedied automatically in an advantageous manner. The control and monitoring device is for this purpose electrically connected to a device coupled to the voltage source for providing the supply voltage, by means of which the supply voltage can be reduced or switched off.

Bei einer vorteilhaften Ausgestaltung der erfindungsgemäßen Anordnung ist die Steuer- und Kontrolleinrichtung mit einer optischen und/oder akustischen Ausgabeeinrichtung zur Ausgabe von optischen und/oder akustischen Signalen datentechnisch verbunden, wobei die Steuer- und Kontrolleinrichtung so eingerichtet ist, dass ein optisches und/oder akustisches Signal ausgegeben wird, falls der elektrische Widerstand eines Messstrompfads den genannten oder einen anderen vorbestimmbaren Schwellwert übersteigt. Durch diese Maßnahme kann in vorteilhafter Weise ein Nutzer alarmiert werden, wenn eine Überhitzung vorliegt, so dass entsprechende Maßnahmen ergriffen werden können. Insbesondere kann ein Nutzer bereits vor einer Abschaltung der Speisespannung alarmiert werden.In an advantageous embodiment of the arrangement according to the invention, the control and monitoring device with a visual and / or acoustic output device for outputting optical and / or acoustic signals is connected by data technology, wherein the control and monitoring device is arranged so that an optical and / or acoustic Signal is output, if the electrical resistance of a measuring current exceeds the said or another predeterminable threshold. By this measure, a user can be alerted in an advantageous manner, if overheating is present, so that appropriate measures can be taken. In particular, a user can be alerted already before switching off the supply voltage.

Die Erfindung erstreckt sich weiterhin auf ein Verfahren zum Betreiben eines Flächenheizkörpers mit mindestens einem flächigen Substrat und einer elektrisch leitfähigen Beschichtung, die sich zumindest über einen Teil der Substratfläche erstreckt und mit mindestens zwei zum elektrischen Verbinden mit den beiden Polen einer Spannungsquelle vorgesehenen Anschlusselektroden elektrisch so verbunden ist, dass durch Anlegen einer Speisespannung ein Heizstrom in einem Heizfeld fließt. Bei dem Flächenheizkörper kann es sich insbesondere um einen wie oben beschriebenen Flächenheizkörper handeln. In dem erfindungsgemäßen Verfahren wird der elektrische Widerstand eines oder mehrerer mit dem Heizfeld thermisch gekoppelter Messstrompfade bestimmt, wobei die Messstrompfade jeweils durch beschichtungsfreie Trennbereiche, beispielsweise Trennlinien, in die leitfähige Beschichtung eingeformt und von der leitfähigen Beschichtung gebildet sind.The invention further extends to a method for operating a surface heating element having at least one planar substrate and an electrically conductive coating which extends over at least part of the substrate surface and electrically connected to at least two connection electrodes provided for electrical connection to the two poles of a voltage source is that by applying a supply voltage, a heating current flows in a heating field. The surface heating element may in particular be a surface heating element as described above. In the method according to the invention, the electrical resistance of one or more measuring current paths thermally coupled to the heating field is determined, wherein the measuring current paths are each formed by coating-free separating regions, for example dividing lines, in the conductive coating and are formed by the conductive coating.

Bei einer vorteilhaften Ausgestaltung des erfindungsgemäßen Verfahrens wird die Speisespannung reduziert oder abgeschaltet, falls der elektrische Widerstand eines Messstrompfads einen vorbestimmbaren Schwellwert übersteigt.In an advantageous embodiment of the method according to the invention, the supply voltage is reduced or switched off, if the electrical resistance of a measuring current exceeds a predeterminable threshold value.

Bei einer weiteren vorteilhaften Ausgestaltung des erfindungsgemäßen Verfahrens wird ein optisches und/oder akustisches Signal ausgegeben, falls der elektrische Widerstand eines Messstrompfads den genannten oder einen anderen vorbestimmbaren Schwellwert übersteigt.In a further advantageous embodiment of the method according to the invention, an optical and / or acoustic signal is output if the electrical resistance of a measuring current path exceeds said or another predeterminable threshold value.

Die Erfindung erstreckt sich weiterhin auf die Verwendung eines wie oben beschriebenen Flächenheizkörpers als funktionales und/oder dekoratives Einzelstück und als Einbauteil in Möbeln, Geräten und Gebäuden, insbesondere als Heizkörper in Wohnräumen, beispielsweise als wandmontierbarer oder frei stehender Heizkörper, sowie in Fortbewegungsmitteln zur Fortbewegung auf dem Lande, in der Luft oder zu Wasser, insbesondere in Kraftfahrzeugen beispielsweise als Windschutzscheibe, Heckscheibe, Seitenscheibe und/oder Glasdach.The invention further extends to the use of a surface heating element as described above as functional and / or decorative single piece and as built-in furniture, appliances and buildings, especially as a radiator in living rooms, such as wall-mounted or free-standing radiator, as well as in locomotion for locomotion on land, in the air or on water, especially in motor vehicles, for example, as a windshield, rear window, side window and / or glass roof.

Es versteht sich, dass die vorstehend genannten und nachstehend zu erläuternden Merkmale nicht nur in den angegebenen Kombinationen, sondern auch in anderen Kombinationen oder in Alleinstellung einsetzbar sind, ohne den Rahmen der vorliegenden Erfindung zu verlassen.It is understood that the features mentioned above and to be explained below can be used not only in the specified combinations but also in other combinations or alone, without departing from the scope of the present invention.

Kurze Beschreibung der ZeichnungenBrief description of the drawings

Die Erfindung wird nun anhand von Ausführungsbeispielen näher erläutert, wobei Bezug auf die beigefügten Figuren genommen wird. Es zeigen in vereinfachter, nicht maßstäblicher Darstellung:

Fig. 1
eine schematische Draufsicht eines ersten Ausführungsbeispiels des erfindungsgemäßen Flächenheizkörpers mit einem im Randstreifen verlaufenden Messstrompfad;
Fig. 2-4
jeweils schematische Draufsichten verschiedener Varianten des Flächenheizkörpers von Fig. 1 mit mehreren im Randstreifen verlaufenden Messstrompfaden;
Fig. 5
eine schematische Draufsicht eines weiteren Ausführungsbeispiels des erfindungsgemäßen Flächenheizkörpers, bei dem die Messstrompfade teilweise im Heizfeld und teilweise im Randstreifen verlaufenden;
Fig. 6
eine schematische Draufsicht einer Variante des Flächenheizkörpers von Fig. 5;
Fig. 7A-7C
eine schematische Draufsicht (Fig. 7A) eines weiteren Ausführungsbeispiels des erfindungsgemäßen Flächenheizkörpers, mit Messstrompfaden (Fig. 7B) im Heizfeld, die als Wheatstone-Brücke (Fig. 7C) verschaltet sind;
Fig. 8
ein Diagramm zur Veranschaulichung der temperaturabhängigen Änderung des elektrischen Widerstands der Heizbeschichtung eines Flächenheizkörpers.
The invention will now be explained in more detail by means of embodiments, reference being made to the accompanying figures. In a simplified, not to scale representation:
Fig. 1
a schematic plan view of a first embodiment of the surface heating element according to the invention with a running in the edge strip measuring current path;
Fig. 2-4
each schematic plan views of different variants of the surface heater of Fig. 1 with a plurality of measuring paths running in the marginal strip;
Fig. 5
a schematic plan view of another embodiment of the surface heating element according to the invention, in which the measuring current paths partially in the heating field and partially extending in the edge strip;
Fig. 6
a schematic plan view of a variant of the surface heater of Fig. 5 ;
Figs. 7A-7C
a schematic plan view ( Fig. 7A ) of a further embodiment of the surface heating element according to the invention, with measuring current paths ( Fig. 7B ) in the heating field, which is called Wheatstone bridge ( Fig. 7C ) are interconnected;
Fig. 8
a diagram illustrating the temperature-dependent change in the electrical resistance of the heating coating of a surface heater.

Ausführliche Beschreibung der ZeichnungenDetailed description of the drawings

Im Weiteren gemachte Lage- und Richtungsangaben wie "oben", "unten", links" und "rechts" beziehen sich auf die in den Figuren dargestellten Flächenheizkörper und dienen ausschließlich zum Zwecke einer einfacheren Beschreibung der Erfindung. Es versteht sich, dass die Flächenheizkörper jeweils auch anders orientiert sein können, so dass diese Angaben nicht als einschränkend aufzufassen sind.Positional and directional details, such as "top", "bottom", "left" and "right", refer to the surface heating elements shown in the figures and serve exclusively for the purpose of simplifying the description of the invention may also be oriented differently, so that these statements are not to be construed as limiting.

Sei zunächst Figur 1 betrachtet, worin als erstes Ausführungsbeispiel der Erfindung ein insgesamt mit der Bezugszahl 1 bezeichneter Flächenheizkörper bzw. eine den Flächenheizkörper 1 enthaltende Anordnung 39 veranschaulicht ist. Der Flächenheizkörper 1 dient zur flächigen Wärmeerzeugung und kann beispielsweise anstelle eines herkömmlichen Heizkörpers zur Heizung eines Wohnraums eingesetzt werden. Er kann zu diesem Zweck beispielsweise an einer Wand befestigt oder in diese integriert werden, wobei aber auch eine frei stehende Montage möglich ist. Denkbar ist auch, den Flächenheizkörper 1 als Spiegel oder Dekorteil auszubilden. Eine andere beispielhafte Anwendung des Flächenheizkörpers 1 ist die Nutzung als Fahrzeugscheibe, insbesondere Windschutzscheibe, eines Kraftfahrzeugs.Be first FIG. 1 considered, as the first embodiment of the invention, a designated generally by the reference numeral 1 surface heating element or a surface heating element 1 containing arrangement 39 is illustrated. The surface heater 1 is used for surface heat generation and can be used for example instead of a conventional radiator for heating a living room. He can to this Purpose, for example, attached to a wall or integrated into it, but also a free-standing mounting is possible. It is also conceivable to form the surface heating element 1 as a mirror or decorative part. Another exemplary application of the surface heating element 1 is the use as a vehicle window, in particular windshield, of a motor vehicle.

Der Flächenheizkörper 1 umfasst zumindest ein flächiges Substrat 2 aus einem elektrisch isolierenden Material, wobei der Flächenheizkörper 1 als Einscheibenglas über ein einzelnes Substrat 2 und als Verbundscheibe über zwei durch eine thermoplastische Klebeschicht fest miteinander verbundene Substrate 2 verfügt. Das Substrat 2 kann aus einem gläsernen Material, beispielsweise Floatglas, Gussglas oder Keramikglas oder einem nichtgläsernen Material, beispielsweise Kunststoff, insbesondere Polystyrol (PS), Polyamid (PA), Polyester (PE), Polyvinylchlorid (PVC), Polycarbonat (PC), Polymethylmethacrylat (PMA) oder Polyethylenterephtalat (PET) bestehen. Allgemein kann jedes Material mit ausreichender chemischer Beständigkeit, geeigneter Form- und Größenstabilität, sowie, falls erwünscht, hinreichender optischer Transparenz verwendet werden. Als Klebeschicht zur Verbindung der beiden Substrate 2 in einer Verbundscheibe kann beispielsweise Kunststoff, insbesondere auf Basis von Polyvinylbutyral (PVB), Ethylen-Vinyl-Acetat (EVA) und Polyurethan (PU), eingesetzt werden.The surface heating element 1 comprises at least one planar substrate 2 made of an electrically insulating material, the surface heating element 1 having a single substrate 2 as a single-pane glass and two bonded substrates 2 firmly bonded together by a thermoplastic adhesive layer as a composite pane. The substrate 2 can be made of a glassy material, for example float glass, cast glass or ceramic glass or a non-glass material, for example plastic, in particular polystyrene (PS), polyamide (PA), polyester (PE), polyvinyl chloride (PVC), polycarbonate (PC), polymethyl methacrylate (PMA) or polyethylene terephthalate (PET). In general, any material having sufficient chemical resistance, suitable dimensional and dimensional stability, and, if desired, sufficient optical transparency may be used. For example, plastic, in particular based on polyvinyl butyral (PVB), ethylene-vinyl acetate (EVA) and polyurethane (PU), can be used as the adhesive layer for bonding the two substrates 2 in a composite pane.

In dem in Fig. 1 gezeigten Ausführungsbeispiel umfasst der Flächenheizkörper ein rechteckiges Substrat 2 mit einem umlaufenden Substratrand 4, der sich aus zwei kurzen Rändern 5 und zwei langen Rändern 6 zusammensetzt. Es versteht sich, dass die Erfindung hierauf nicht eingeschränkt ist, sondern dass das Substrat 2 auch jede andere für die praktische Anwendung geeignete Form haben kann, beispielsweise eine quadratische, runde oder ovale Form. Abhängig von der Anwendung des Flächenheizkörpers 1 kann das Substrat 2 starr oder flexibel sein. Entsprechendes gilt für dessen Dicke, die breit variieren kann und für ein gläsernes Substrat 2 beispielsweise im Bereich von 1 bis 24 mm liegt.In the in Fig. 1 In the embodiment shown, the surface heating element comprises a rectangular substrate 2 with a circumferential substrate edge 4, which is composed of two short edges 5 and two long edges 6. It is understood that the invention is not limited to this, but that the substrate 2 can also have any other form suitable for practical use, for example a square, round or oval shape. Depending on the application of the surface heating element 1, the substrate 2 may be rigid or flexible. The same applies to its thickness, which can vary widely and for a glass substrate 2, for example, in the range of 1 to 24 mm.

Für eine flächige Wärmeerzeugung umfasst der Flächenheizkörper 1 eine elektrisch leitfähige, heizbare Beschichtung 3, die hier beispielsweise auf einer (Haupt-)Oberfläche bzw. Substratfläche 42 des Substrats 2 aufgebracht ist. Beispielsweise nimmt die Beschichtung 3 mehr als 50%, bevorzugt mehr als 70%, insbesondere bevorzugt mehr als 80% und noch stärker bevorzugt mehr als 90% der Substratfläche 42 des Substrats 2 ein. Die Beschichtung 3 kann insbesondere vollflächig auf die Substratfläche 42 aufgebracht sein. Die von der Beschichtung 3 bedeckte Fläche kann, je nach Anwendung, beispielsweise von 100 cm2 bis 25 m2 reichen. Ebenso wäre es möglich, die Beschichtung 3 nicht auf das Substrat 2, sondern anstelle dessen auf einen flächenhaften Träger aufzubringen, der anschließend mit dem Substrat 2 verklebt wird. Bei einem solchen Träger kann es sich insbesondere um eine Kunststofffolie handeln, die beispielsweise aus Polyamid (PA), Polyurethan (PU), Polyvinylchlorid (PVC), Polycarbonat (PC), Polyester (PE) oder Polyvinylbutyral (PVB) besteht. Alternativ kann ein solcher Träger auch mit Klebefolien (z.B. PVB-Folien) verbunden und als dreilagiger Schichtenaufbau mit den beiden Substraten 2 einer Verbundscheibe verklebt werden.For a planar heat generation of the surface heating element 1 comprises an electrically conductive, heatable coating 3, which is applied here for example on a (main) surface or substrate surface 42 of the substrate 2. For example, the coating decreases 3 more than 50%, preferably more than 70%, more preferably more than 80% and even more preferably more than 90% of the substrate surface 42 of the substrate 2 a. In particular, the coating 3 can be applied over the full area to the substrate surface 42. The area covered by the coating 3 can, depending on the application, for example, range from 100 cm 2 to 25 m 2 . Likewise, it would be possible not to apply the coating 3 to the substrate 2, but instead to a planar carrier, which is then adhesively bonded to the substrate 2. In particular, such a carrier can be a plastic film which consists, for example, of polyamide (PA), polyurethane (PU), polyvinyl chloride (PVC), polycarbonate (PC), polyester (PE) or polyvinyl butyral (PVB). Alternatively, such a support can also be bonded to adhesive films (eg PVB films) and bonded as a three-layered layer structure to the two substrates 2 of a composite pane.

Die Beschichtung 3 enthält oder besteht aus einem elektrisch leitfähigen Material. Beispiele hierfür sind Metalle mit einer hohen elektrischen Leitfähigkeit wie Silber, Kupfer, Gold, Aluminium oder Molybdän, Metall-Legierungen wie mit Palladium legiertes Silber, sowie transparente, leitfähige Oxide (TCO = Transparent Conductive Oxides). Bei TCO handelt es sich vorzugsweise um Indiumzinnoxid, fluordotiertes Zinndioxid, aluminiumdotierts Zinndioxid, galliumdotiertes Zinndioxid, bordotiertes Zinndioxid, Zinnzinkoxid oder antimondotiertes Zinnoxid. Dabei kann die Beschichtung 3 aus einer leitfähigen Einzelschicht oder einem Schichtenaufbau, der zumindest eine leitfähige Teilschicht enthält, bestehen. Beispielsweise umfasst ein solcher Schichtenaufbau mindestens eine leitfähige Teilschicht, vorzugsweise Silber (Ag), und weitere Teilschichten wie Entspiegelungs- und Blockerschichten. Die Dicke der Beschichtung 3 kann je nach Anwendung breit variieren, wobei die Dicke an jeder Stelle beispielsweise im Bereich von 30 nm bis 100 µm liegen kann. Im Falle von TCO liegt die Dicke beispielsweise im Bereich von 100 nm bis 1,5 µm, bevorzugt im Bereich von 150 nm bis 1 µm und stärker bevorzugt im Bereich von 200 nm bis 500 nm. Vorteilhaft ist die Beschichtung 3 thermisch hoch belastbar, so dass sie die zum Biegen (Vorspannen) einer als Substrat 2 verwendeten Glasscheibe erforderliche Temperaturen von typischer Weise mehr als 600°C ohne Funktionsbeeinträchtigung übersteht. Gleichermaßen kann aber auch eine thermisch gering belastbare Beschichtung 3 vorgesehen sein kann, die nach dem Vorspannen der Glasscheibe aufgebracht wird. Ebenso kann die Beschichtung 3 auf ein Substrat 2 aufgebracht werden, welches nicht vorgespannt wird. Der Flächenwiderstand der Beschichtung 3 ist vorzugsweise geringer als 20 Ohm pro Flächeneinheit und liegt beispielsweise im Bereich von 0,25 bis 20 Ohm pro Flächeneinheit. Im gezeigten Ausführungsbeispiel beträgt der Flächenwiderstand der leitfähigen Beschichtung 3 einige Ohm pro Flächeneinheit und beträgt beispielsweise 1 bis 2 Ohm pro Flächeneinheit.The coating 3 contains or consists of an electrically conductive material. Examples are metals having a high electrical conductivity such as silver, copper, gold, aluminum, or molybdenum, metal alloys such as palladium alloyed with silver, as well as transparent conductive oxides (TCO = T ransparent C onductive O xides). TCO is preferably indium tin oxide, fluorine-doped tin dioxide, aluminum-doped tin dioxide, gallium-doped tin dioxide, boron-doped tin dioxide, tin zinc oxide or antimony-doped tin oxide. In this case, the coating 3 may consist of a conductive single layer or a layer structure which contains at least one conductive partial layer. By way of example, such a layer construction comprises at least one conductive partial layer, preferably silver (Ag), and further partial layers such as anti-reflection and blocking layers. The thickness of the coating 3 may vary widely depending on the application, wherein the thickness at any point may be, for example, in the range of 30 nm to 100 microns. In the case of TCO, the thickness is, for example, in the range of 100 nm to 1.5 μm, preferably in the range of 150 nm to 1 μm and more preferably in the range of 200 nm to 500 nm. Advantageously, the coating 3 can be subjected to high thermal loads, see above that it withstands the temperatures required for bending (tempering) a pane of glass used as substrate 2, typically more than 600 ° C without impairment of function. Equally, however, a thermally low-loadable coating 3 can be provided, which is applied after the tempering of the glass sheet. Likewise, the coating 3 can be applied to a substrate 2 which will not be biased. The sheet resistance of the coating 3 is preferably less than 20 ohms per unit area and is for example in the range of 0.25 to 20 ohms per unit area. In the exemplary embodiment shown, the sheet resistance of the conductive coating 3 is a few ohms per unit area and is, for example, 1 to 2 ohms per unit area.

Die Beschichtung 3 wird beispielsweise aus der Gasphase abgeschieden, zu welchem Zweck an sich bekannte Verfahren wie chemische Gasphasenabscheidung (CVD = Chemical Vapor Deposition) oder physikalische Gasphasenabscheidung (PVD = Physical Vapor Deposition) eingesetzt werden können. Vorzugsweise wird die Beschichtung 3 durch Sputtern (Magnetron-Kathodenzerstäubung) auf das Substrat 2 aufgebracht.The coating 3 is deposited, for example, from the gas phase, for which purpose known per se methods such as chemical vapor deposition (CVD = C hemical V apor D eposition) or physical vapor deposition (PVD = P hysical V apor D eposition) can be used. Preferably, the coating 3 is applied to the substrate 2 by sputtering (magnetron sputtering).

Bei dem in Fig. 1 veranschaulichten Flächenheizkörper 1 kann es für seine praktische Anwendung beispielsweise als frei stehender Heizkörper oder Windschutzscheibe eines Kraftfahrzeugs von Vorteil sein, wenn er für sichtbares Licht im Wellenlängenbereich von 350 nm bis 800 nm transparent ist, wobei unter dem Begriff "Transparenz" eine Lichtdurchlässigkeit von mehr als 50%, vorzugsweise mehr als 70% und insbesondere bevorzugt mehr als 80% zu verstehen ist. Dies kann beispielsweise durch ein transparentes Substrat 2 aus Glas und eine transparente Beschichtung 3 auf Basis von Silber (Ag) erreicht werden.At the in Fig. 1 it can be advantageous for its practical application, for example, as a freestanding radiator or windshield of a motor vehicle when it is transparent to visible light in the wavelength range of 350 nm to 800 nm, wherein the term "transparency" is a light transmittance of more than 50%, preferably more than 70% and especially preferably more than 80%. This can be achieved, for example, by a transparent substrate 2 made of glass and a transparent coating 3 based on silver (Ag).

Im Flächenheizkörper 1 ist die leitfähige Beschichtung 3 entlang des Substratrands 4 mit einer umlaufenden, elektrisch isolierten, ersten Trennlinie 7 versehen, welche hier beispielsweise einen Abstand von einigen cm, insbesondere 1 bis 2 cm, vom Substratrand 4 hat. Durch die erste Trennlinie 7 wird ein äußerer Randstreifen 8 der leitfähigen Beschichtung 3 von einem innen liegenden Rest der leitfähigen Beschichtung 3, der als Heizfeld 9 dient, elektrisch abgeteilt. Der Randstreifen 8 bewirkt eine elektrische Isolierung des Heizfelds 9 nach außen und schützt es gegen vom Substratrand 4 vordringende Korrosion. Zusätzlich kann die Beschichtung 3 zur Verbesserung der Randisolierung in einem beispielsweise einige Millimeter breiten Teil des Randstreifens 8 umlaufend entfernt sein, was in Fig. 1 nicht näher dargestellt ist.In the surface heating element 1, the conductive coating 3 is provided along the substrate edge 4 with a peripheral, electrically insulated, first parting line 7, which here, for example, a distance of a few cm, in particular 1 to 2 cm, from the substrate edge 4 has. An outer edge strip 8 of the conductive coating 3 is electrically divided by an inner remainder of the conductive coating 3, which serves as a heating field 9, through the first parting line 7. The edge strip 8 causes an electrical insulation of the heating field 9 to the outside and protects it against penetrating from the substrate edge 4 corrosion. In addition, the coating 3 can be circumferentially removed to improve the edge insulation in a, for example, a few millimeters wide part of the edge strip 8, which Fig. 1 not shown in detail.

In dem Flächenheizkörper 1 dient nur das Heizfeld 9 zur flächigen Wärmeerzeugung. Zu diesem Zweck sind zwei mit dem Heizfeld 9 elektrisch-galvanisch verbundene Anschlusselektroden 10, 11 vorgesehen, welche hier beispielsweise am unteren langen Rand 6 nahe des rechten kurzen Rands 5 angeordnet sind. Die Anschlusselektroden 10, 11 dienen zum Anlegen einer von außen zugeführten Speisespannung an das Heizfeld 9, wobei durch den eingeleiteten Heizstrom flächenhaft Wärme vom Heizfeld 9 abgegeben wird. Die beiden Anschlusselektroden 10, 11 können zu diesem Zweck mit den beiden Polen einer Spannungsquelle (nicht gezeigt) verbunden werden. Die hier beispielsweise jeweils in Form von Viertelscheiben ausgeführten Anschlusselektroden 10, 11 sind beispielsweise aus einer metallischen Druckpaste im Druckverfahren, insbesondere Siebdruckverfahren, hergestellt. Alternativ wäre es auch möglich, die beiden Anschlusselektroden 10, 11 beispielsweise aus einer Metallfolie vorzufertigen und anschließend mit dem Heizfeld 9 insbesondere durch Löten elektrisch zu verbinden. Dabei ist es unerheblich, ob zunächst die Beschichtung 3 auf dem Substrat 2 abgeschieden und anschließend die Anschlusselektroden 10, 11 hergestellt werden oder ob zunächst die Anschlusselektroden 10, 11 gefertigt und anschließend die Beschichtung 3 abgeschieden wird. Der spezifische elektrische Widerstand für insbesondere im Druckverfahren hergestellte Anschlusselektroden 10, 11 liegt beispielsweise im Bereich von 2 bis 4 µOhm·cm.In the surface heating element 1, only the heating field 9 serves for areal heat generation. For this purpose, two electrically-galvanically connected connection electrodes 10, 11 are provided with the heating field 9, which are arranged here, for example, at the lower long edge 6 near the right short edge 5. The connection electrodes 10, 11 are used to apply a supply voltage supplied from the outside to the heating field 9, wherein areally heat is emitted from the heating field 9 by the introduced heating current. The two connection electrodes 10, 11 can be connected for this purpose to the two poles of a voltage source (not shown). The connecting electrodes 10, 11, which are in each case in the form of quarter-slices, are for example made of a metallic printing paste in the printing process, in particular screen printing processes. Alternatively, it would also be possible to prefabricate the two connection electrodes 10, 11, for example, from a metal foil, and then to electrically connect them to the heating field 9, in particular by soldering. It is irrelevant whether first the coating 3 is deposited on the substrate 2 and then the connection electrodes 10, 11 are produced or whether first the connection electrodes 10, 11 are manufactured and then the coating 3 is deposited. The specific electrical resistance for connection electrodes 10, 11 produced in particular in the printing method is, for example, in the range from 2 to 4 μOhm.cm.

Wie in Fig. 1 dargestellt, ist das Heizfeld 9 durch eine Schar elektrisch isolierter, zweiter Trennlinien 30 in eine Mehrzahl elektrisch parallel geschalteter Heizstrompfade 12 unterteilt. Die Heizstrompfade 12 fangen jeweils an der einen, ersten Anschlusselektrode 10 an und enden an der anderen, zweiten Anschlusselektrode 11, wobei der an die beiden Anschlusselektroden 10, 11 unmittelbar angrenzende Teil des Heizfelds 9 frei von zweiten Trennlinien 30 ist. Somit kann ein definierter Verlauf des durch die beiden Anschlusselektroden 10, 11 eingeleiteten Heizstroms im Heizfeld 9 entlang der durch die zweiten Trennlinien 30 definierten Heizstrompfade 12 erreicht werden. Durch die Breite bzw. Querschnittsfläche und Länge der Heizstrompfade 12 kann der elektrische Widerstand für eine gewünschte Heizleistung gezielt eingestellt werden. Die Unterteilung des Heizfelds 9 durch Trennlinien zum Erzeugen paralleler Heizstrompfade 12 ist an sich bekannt, beispielsweise aus den eingangs genannten Patentschriften, so dass hier nicht näher darauf eingegangen werden muss. Die Trennlinien 7, 30, in denen die leitfähige Beschichtung 3 jeweils komplett entfernt ist, können beispielsweise durch Laserschreiben mittels Laser-Schneidroboter in die leitfähige Beschichtung 3 eingearbeitet werden. Es sei daraufhingewiesen, dass es sich bei dem in Fig. 1 gezeigten Layout der zweiten Trennlinien 30 lediglich um ein Beispiel handelt und dass gleichermaßen anders verlaufende Heizstrompfade 12 im Flächenheizkörper 1 vorgesehen sein können.As in Fig. 1 illustrated, the heater 9 is divided by a family of electrically insulated, second parting lines 30 in a plurality of electrically parallel connected Heizstrompfade 12. The heating current paths 12 each begin at the one, first connection electrode 10 and terminate at the other, second connection electrode 11, the part of the heating field 9 immediately adjacent to the two connection electrodes 10, 11 being free of second separation lines 30. Thus, a defined profile of the heating current introduced by the two connection electrodes 10, 11 in the heating field 9 can be achieved along the heating current paths 12 defined by the second separating lines 30. By the width or cross-sectional area and length of the heating current paths 12, the electrical resistance for a desired heating power can be set specifically. The subdivision of the heating field 9 by separating lines for generating parallel heating current paths 12 is known per se, for example, from the patents mentioned above, so that it need not be discussed further here. The dividing lines 7, 30, in which the conductive coating 3 is in each case completely removed, can be produced, for example, by laser writing be incorporated into the conductive coating 3 by means of laser cutting robot. It should be noted that the in Fig. 1 shown layout of the second parting lines 30 is only an example and that equally differently extending Heizstrompfade 12 may be provided in the surface heating element 1.

Wie in Fig. 1 weiterhin dargestellt, ist innerhalb des Randstreifens 8 ein vom Heizfeld 9 elektrisch isolierter Messstrompfad 13 in Form einer Leiterbahn in die leitfähige Beschichtung 3 eingeformt. Der Messstrompfad 13 wird durch das leitfähige Material der Beschichtung 3 gebildet, wobei zu diesem Zweck in den Randstreifen 8 beispielsweise mittels Laserung eine den Messstrompfad 13 umschreibende Trennlinie eingebracht wird, welche in Fig. 1 der Übersichtlichkeit halber nicht näher dargestellt ist. Durch diese Trennlinie, in der die leitfähige Beschichtung 3 vollständig entfernt ist, wird der Messstrompfad 13 vom restlichen Randstreifen 8 elektrisch abgeteilt. Ausgehend von einem ersten Anschlussabschnitt 14 auf Höhe der beiden Anschlusselektroden 10, 11 verläuft der Messstrompfad 13 ein Stück entlang des unteren langen Rands 6, des daran angrenzenden rechten kurzen Rands 5 und des daran angrenzenden oberen langen Rands 6 in etwa bis zur Höhe eines linken Heizfeldecks 20 und auf dem umgekehrten Weg wieder zurück bis zu einem zweiten Anschlussabschnitt 15 auf Höhe der beiden Anschlusselektroden 10, 11, wodurch eine Leiterschleife gebildet wird. Die beiden Anschlussabschnitte 14, 15 des Messstrompfads 13 sind mit Anschlussleitungen 34 einer elektrischen Messeinrichtung 16 elektrisch verbunden. Sie können zu diesem Zweck mit elektrisch-galvanisch gekoppelten Elektroden versehen sein, was in Fig. 1 nicht näher dargestellt ist. Durch die beiden Anschlussleitungen 14, 15 wird der Messstrompfad 13 mit der zwischengeschalteten Messeinrichtung 16 zu einem Messkreis zum Messen einer elektrischen Spannung oder eines elektrischen Stroms zum Bestimmen des elektrischen Widerstands des Messstrompfads 13 kurzgeschlossen. Die Anordnung der beiden Anschlussabschnitte 14, 15 am Substratrand 4 ermöglicht eine besonders einfache Kontaktierung. Es versteht sich, dass der genaue Verlauf des Messstrompfads 13 innerhalb des Randstreifens 8 wahlfrei gestaltet werden kann, so dass die Erfindung nicht auf den in Fig. 1 gezeigten Verlauf eingeschränkt ist.As in Fig. 1 Furthermore, within the edge strip 8, a measuring current path 13, which is electrically insulated from the heating field 9, is formed in the conductive coating 3 in the form of a conductor track. The measuring current path 13 is formed by the conductive material of the coating 3, for which purpose a boundary line circumscribing the measuring current path 13 is introduced into the edge strip 8, for example by means of lasering Fig. 1 the clarity is not shown in detail. Through this dividing line, in which the conductive coating 3 is completely removed, the measuring current path 13 is electrically divided from the remaining edge strip 8. Starting from a first connection section 14 at the level of the two connection electrodes 10, 11, the measuring current path 13 extends a little along the lower long edge 6, the right short edge 5 adjoining thereto and the upper long edge 6 adjoining it approximately up to the height of a left heating field top 20 and on the opposite way back to a second terminal portion 15 at the level of the two terminal electrodes 10, 11, whereby a conductor loop is formed. The two connection sections 14, 15 of the measuring current path 13 are electrically connected to connection lines 34 of an electrical measuring device 16. They may be provided for this purpose with electrically-galvanically coupled electrodes, which in Fig. 1 not shown in detail. Through the two connecting lines 14, 15, the measuring current path 13 with the intermediate measuring device 16 is short-circuited to a measuring circuit for measuring an electrical voltage or an electric current for determining the electrical resistance of the measuring current path 13. The arrangement of the two connection sections 14, 15 on the substrate edge 4 allows a particularly simple contacting. It is understood that the exact course of the measuring current path 13 within the edge strip 8 can be made optional, so that the invention does not rely on the in Fig. 1 shown course is limited.

Der Messstrompfad 13 hat hier beispielsweise eine homogene Querschnittsfläche, die sich aus einer gleich bleibenden Dicke (entsprechend einer mit konstanter Dicke auf das Substrat 2 aufgebrachten Beschichtung 3) und Breite der Leiterbahn quer zu ihrer Erstreckung ergibt. Demnach hat der Messstrompfad 13 einen im Wesentlichen gleichen elektrischen Widerstand, so dass eine an die beiden Anschlussabschnitte 14, 15 angelegte Messspannung zumindest annähernd gleichmäßig über dem Messstrompfad 13 abfällt. Im vorliegenden Ausführungsbeispiel liegt die senkrecht zum Substrat 2 bzw. Substratfläche 42 und quer zur Erstreckungsrichtung des Messstrompfads 13 sich bemessende Dicke der Leiterbahn beispielsweise im Bereich von 50 bis 100 Nanometer (nm). Die parallel zum Substrat 2 bzw. Substratfläche 42 und quer zur Erstreckung des Messstrompfads 13 sich bemessende Breite der Leiterbahn liegt beispielsweise in einem Bereich von oberhalb von 100 Mikrometer (µm) und kleiner als 5 Millimeter (mm). Aufgrund der relativ geringen Breite des Messstrompfads 13 ist sein elektrischer Widerstand wesentlich größer als der elektrische Widerstand eines jeden Heizstrompfads 12 im Heizfeld 9. Die Breite der Heizstrompfade 12 beträgt beispielsweise mehr als 10 mm und beträgt insbesondere 30 mm.The measuring current path 13 here has, for example, a homogeneous cross-sectional area, which consists of a constant thickness (corresponding to one with a constant thickness on the Substrate 2 applied coating 3) and width of the conductor path transverse to its extension results. Accordingly, the measuring current path 13 has a substantially identical electrical resistance, so that a measuring voltage applied to the two connection sections 14, 15 drops at least approximately uniformly over the measuring current path 13. In the present exemplary embodiment, the thickness of the conductor track which is perpendicular to the substrate 2 or substrate surface 42 and transverse to the direction of extent of the measuring current path 13 is, for example, in the range from 50 to 100 nanometers (nm). The width of the conductor track which is dimensioned parallel to the substrate 2 or substrate surface 42 and transversely to the extent of the measuring current path 13 is, for example, in a range of more than 100 micrometers (μm) and less than 5 millimeters (mm). Due to the relatively small width of the measuring current path 13, its electrical resistance is substantially greater than the electrical resistance of each Heizstrompfads 12 in the heating field 9. The width of the Heizstrompfade 12 is for example more than 10 mm and is in particular 30 mm.

Es sei nun ergänzend Fig. 8 betrachtet, worin für einen Flächenheizkörper 1 mit einem gläsernen Substrat 2 und einer transparenten Beschichtung 3 auf Basis des leitfähigen Materials Silber (Ag) die mit einer Temperaturänderung einher gehende Widerstandsänderung der Beschichtung 3 beispielhaft veranschaulicht ist. In dem dargestellten Diagramm ist der elektrische Widerstand R (Ohm) der Beschichtung 3 über deren Temperatur T (°C) aufgetragen. Erkennbar besteht zwischen dem elektrischen Widerstand Rund der Temperatur T ein zumindest annähernd linearer Zusammenhang, so dass eine Temperaturerhöhung der Beschichtung 3 stets mit einer Zunahme des elektrischen Widerstands einhergeht. Eine Temperaturzunahme um 50°C erhöht den elektrischen Widerstand hier beispielsweise um ca. 10 Ohm, so dass lokale oder globale Temperaturerhöhungen zuverlässig und sicher erfasst werden können.It is now supplementary Fig. 8 Considering, for a surface heating element 1 with a glass substrate 2 and a transparent coating 3 based on the conductive material silver (Ag), the change in resistance of the coating 3 that accompanies a temperature change is illustrated by way of example. In the illustrated diagram, the electrical resistance R (ohms) of the coating 3 is plotted over its temperature T (° C). It can be seen that there is an at least approximately linear relationship between the electrical resistance around the temperature T, so that an increase in the temperature of the coating 3 is always accompanied by an increase in the electrical resistance. A temperature increase of 50 ° C increases the electrical resistance here, for example, by about 10 ohms, so that local or global temperature increases can be detected reliably and safely.

Mit fortgesetzter Bezugnahme auf Fig. 1 sei nun angenommen, dass eine lokale Überhitzung ("Hot Spot") im Heizfeld 9 nahe des oberen langen Rands 6 auftritt. Dies kann beispielsweise dadurch passieren, dass ein Handtuch oder Kleidungsstück über den oberen langen Rand 6 gehängt wird, wodurch das Ableiten der im Heizfeld 9 erzeugten Wärme an die Umgebung behindert wird. Die lokale Temperaturerhöhung im Heizfeld 9 führt zu einer Temperaturerhöhung in einem dem Hot Spot benachbarten Abschnitt des Messstrompfads 13. Grund hierfür ist die thermische Kopplung zwischen dem Heizfeld 9 und dem Messstrompfad 13, die überwiegend auf Wärmeleitung des Substrats 2, sowie in einem geringen Anteil auch Strahlungswärme beruht. Hierdurch wird der Messstrompfad 13 erwärmt, so dass sein elektrischer Widerstand zunimmt. Diese Widerstandsänderung kann durch die Messeinrichtung 16 erfasst werden, wobei selbst relativ kleine Widerstandsänderungen im Messstrompfad 13 mit einem guten Signal-Rausch-Verhältnis zuverlässig und sicher gemessen werden können. Da der Messstrompfad 13 vom Heizfeld 9 elektrisch isoliert ist, kann eine Messung des elektrischen Widerstands des Messstrompfads 13 unabhängig vom Heizstrom erfolgen. Zwar handelt es sich bei einem beispielsweise gläsernen Substrat 2 um einen eher schlechten Wärmeleiter, so dass die thermische Kopplung zwischen dem Heizfeld 9 und dem Messstrompfad 13 relativ gering ist, jedoch kann in der Praxis auch in diesem Fall eine signifikante Erhöhung des Widerstands des Messstrompfads 13 zumindest durch ihm benachbarte Hot Spots beobachtet werden. Denkbar wäre es, eine zusätzliche thermische Kopplung zwischen dem Heizfeld 9 und dem Messstrompfad 13 im Randstreifen 8 vorzusehen. Beispielsweise könnten das Heizfeld 9 und der Randstreifen 8 durch eine Lage aus elektrisch isolierendem Material mit guter Wärmeleitfähigkeit verbunden werden, welche auf das Substrat 2 aufgebracht und beim Ausbilden der ersten Trennlinie 7 nicht entfernt wird.With continued reference to Fig. 1 Let it be assumed that a localized overheating ("hot spot") occurs in the heating field 9 near the upper long edge 6. This can happen, for example, that a towel or garment is hung over the upper long edge 6, whereby the dissipation of the heat generated in the heating field 9 is hindered to the environment. The local temperature increase in the heating field 9 leads to an increase in temperature in a section of the hot spot adjacent to the hot spot The reason for this is the thermal coupling between the heating field 9 and the measuring current path 13, which is based predominantly on heat conduction of the substrate 2, and in a small proportion of radiant heat. As a result, the measuring current path 13 is heated, so that its electrical resistance increases. This change in resistance can be detected by the measuring device 16, wherein even relatively small changes in resistance in the measuring current path 13 can be reliably and reliably measured with a good signal-to-noise ratio. Since the measuring current path 13 is electrically insulated from the heating field 9, a measurement of the electrical resistance of the measuring current path 13 can take place independently of the heating current. Although a glassy substrate 2, for example, is a rather poor heat conductor, the thermal coupling between the heating field 9 and the measuring current path 13 is relatively small, but in practice a significant increase in the resistance of the measuring current path 13 can also be achieved in this case be observed at least by him adjacent hot spots. It would be conceivable to provide an additional thermal coupling between the heating field 9 and the measuring current path 13 in the edge strip 8. For example, the heating field 9 and the edge strip 8 could be connected by a layer of electrically insulating material with good thermal conductivity, which is applied to the substrate 2 and is not removed when forming the first dividing line 7.

Allgemein kann dem Messstrompfad 13 eine von der speziellen Gestaltung des Flächenheizkörpers 1 abhängige Zone 19, im Weiteren als "Detektionszone" bezeichnet, des Heizfelds 9 zugeordnet werden, die mit dem Messstrompfad 13 thermisch so gekoppelt ist, dass eine Temperaturänderung eine (signifikante) Widerstandsänderung im Messstrompfad 13 bewirkt. Die jeweilige Größe der Detektionszone 19 hängt von der thermischen Kopplung zwischen dem Heizfeld 9 und dem Messstrompfad 13 ab, wobei eine bessere thermische Kopplung eine größere Detektionszone 19 bewirkt und umgekehrt. Typischer Weise, jedoch nicht zwingend, erstreckt sich die Detektionszone 19 über einen an den Messstrompfad 13 angrenzenden Teilbereich des Heizfelds 9, wobei sich die Detektionszone 19 bei entsprechend guter thermischer Kopplung auch über das komplette Heizfeld 19 erstrecken kann.In general, the measuring current path 13 can be assigned a zone 19, referred to below as a "detection zone", of the heating field 9, which is thermally coupled to the measuring current path 13 in such a way that a change in temperature causes a (significant) change in resistance Measuring current path 13 causes. The respective size of the detection zone 19 depends on the thermal coupling between the heating field 9 and the measuring current path 13, wherein a better thermal coupling causes a larger detection zone 19 and vice versa. Typically, but not necessarily, the detection zone 19 extends over a portion of the heating field 9 adjacent to the measuring current path 13, wherein the detection zone 19 can also extend over the complete heating field 19 with correspondingly good thermal coupling.

Beispielsweise ist der in Fig. 1 gezeigte Flächenheizkörper 1 durch den speziellen Verlauf des Messstrompfads 13 und eine Detektionszone 19, die nur einen Teilbereich des Heizfelds 9 abdeckt, dafür ausgelegt, eine lokale Temperaturzunahme im Heizfeld 9 vorwiegend in der näheren Umgebung des oberen langen Rands 6 und des rechten kurzen Rands 5 des Heizfelds 9 zu erfassen. In der praktischen Anwendung können dies beispielsweise jene Bereiche des Heizfelds 9 sein, in denen aller Voraussicht nach durch Fehlbedienung Hot Spots auftreten.For example, the in Fig. 1 surface heating element 1 shown by the special course of the measuring current path 13 and a detection zone 19, which only a portion of the heating field 9, designed to detect a local increase in temperature in the heating field 9 predominantly in the vicinity of the upper long edge 6 and the right short edge 5 of the heating field 9. In practical application, these can be, for example, those areas of the heating field 9 in which, in all likelihood, hot spots occur due to incorrect operation.

In der Anordnung 39 kann die Messeinrichtung 16 mit einer Steuer- und Kontrolleinrichtung 40 des Flächenheizkörpers 1 so gekoppelt sein, dass die an die Anschlusselektroden 10, 11 angelegte Speisespannung abgeschaltet oder zumindest so weit reduziert wird, dass eine weitere Überhitzung vermieden wird. Die Steuer- und Kontrolleinrichtung 40 kann zu diesem Zweck programmtechnisch so eingerichtet sein, dass die Speisespannung abgeschaltet oder zumindest um einen vorbestimmten bzw. vorbestimmbaren Betrag reduziert wird, sobald die Widerstandszunahme im Messstrompfad 13 einen wahlfrei vorbestimmten bzw. vorbestimmbaren Schwellwert übersteigt. Ebenso kann eine stufenweise Reduzierung der Speisespannung auf Basis erfasster Widerstandswerte vorgesehen sein. Alternativ oder zusätzlich kann die Steuer- und Kontrolleinrichtung 40 mit einer optischen und/oder akustischen Ausgabeeinrichtung 41 so gekoppelt sein, dass eine lokale Überhitzung des Heizfelds 9 optisch und/oder akustisch angezeigt wird. Der Nutzer kann dann entsprechende Maßnahmen wie eine manuelle Abschaltung oder Reduzierung der Speisespannung des Flächenheizkörpers 1 ergreifen.In the arrangement 39, the measuring device 16 may be coupled to a control and monitoring device 40 of the surface heating element 1 such that the supply voltage applied to the connection electrodes 10, 11 is switched off or at least reduced so much that further overheating is avoided. For this purpose, the control and monitoring device 40 can be set up so that the supply voltage is switched off or at least reduced by a predetermined or predeterminable amount as soon as the increase in resistance in the measuring current path 13 exceeds an optionally predetermined or predeterminable threshold value. Likewise, a stepwise reduction of the supply voltage can be provided based on detected resistance values. Alternatively or additionally, the control and monitoring device 40 may be coupled to an optical and / or acoustic output device 41 so that a local overheating of the heating field 9 is displayed optically and / or acoustically. The user can then take appropriate measures such as a manual shutdown or reduction of the supply voltage of the surface heating element 1.

Es wird nun Bezug auf Fig. 2 genommen, worin ein weiteres Ausführungsbeispiel des erfindungsgemäßen Flächenheizkörpers 1 veranschaulicht ist. Um unnötige Wiederholungen zu vermeiden, werden lediglich die Unterschiede zum Ausführungsbeispiel von Fig. 1 erläutert und ansonsten wird auf die dort gemachten Ausführungen Bezug genommen.It will now be referred to Fig. 2 taken, wherein a further embodiment of the surface heating element 1 according to the invention is illustrated. To avoid unnecessary repetition, only the differences from the embodiment of Fig. 1 explained and otherwise reference is made to the statements made there.

Demnach umfasst der Flächenheizkörper 1 drei in Form von Leiterbahnen innerhalb des Randstreifens 8 in die leitfähige Beschichtung 3 eingearbeitete Messstrompfade 13, 13', 13", die jeweils vom Heizfeld 9 elektrisch isoliert sind. Die drei Leiterschleifen unterscheiden sich nur durch deren jeweiligen Verlauf. So erstreckt sich ein erster Messstrompfad 13, ausgehend von einem ersten Anschlussabschnitt 14 auf Höhe der beiden Anschlusselektroden 10, 11 in etwa bis zur Höhe des linken Heizfeldecks 20 und auf umgekehrtem Weg wieder zurück bis zu einem zweiten Anschlussabschnitt 15 auf Höhe der beiden Anschlusselektroden 10, 11. Ein zweiter Messstrompfad 13' erstreckt sich, ausgehend von einem ersten Anschlussabschnitt 14' auf Höhe der beiden Anschlusselektroden 10, 11, nur ein kleines Stück entlang des oberen langen Rands 6 und auf umgekehrtem Weg wieder zurück. Dabei nutzt der zweite Messstrompfad 13' einen Teil der Leiterbahn der ersten Messstrompfads 13, so dass sich der erste und zweite Messstrompfad 13, 13' insbesondere einen gemeinsamen zweiten Anschlussabschnitt 15 teilen. Ein dritter Messstrompfad 13" erstreckt sich, ausgehend von einem ersten Anschlussabschnitt 14" auf Höhe der beiden Anschlusselektroden 10, 11, entlang des unteren langen Rands 6 und auf umgehrtem Weg wieder zurück zu einem zweiten Anschlussabschnitt 15".Accordingly, the surface heating element 1 comprises three measuring current paths 13, 13 ', 13 "incorporated in the conductive coating 3 in the form of strip conductors within the edge strip 8, which are each electrically insulated from the heating field 9. The three conductor loops differ only in their respective course extends a first measuring current path 13, starting from a first terminal portion 14 at the level of the two terminal electrodes 10, 11 approximately to the height of the left Heizfeldecks 20 and on the reverse Way back back to a second terminal portion 15 at the level of the two terminal electrodes 10, 11. A second Meßstrompfad 13 'extends, starting from a first terminal portion 14' at the level of the two terminal electrodes 10, 11, only a small piece along the upper long Rands 6 and back again in the opposite way. In this case, the second measuring current path 13 'uses part of the conductor track of the first measuring current paths 13, so that the first and second measuring current paths 13, 13' in particular share a common second connection section 15. A third measuring current path 13 "extends, starting from a first connection section 14" at the level of the two connection electrodes 10, 11, along the lower long edge 6 and on a reversed path back to a second connection section 15 ".

Die Messstrompfade 13, 13', 13" sind jeweils durch die Anschlussleitungen 34 einer separaten Messeinrichtung 16 zu einem Messkreis kurzgeschlossen, die hier in dieser Reihenfolge als Messkreise A, B und C bezeichnet sind. Während die beiden Messkreise A, B zum Erfassen einer temperaturabhängigen Widerstandsänderung zum Detektieren von Hot Spots im Heizfeld 9 dienen, wird der Messkreis C lediglich als Referenzkreis eingesetzt. Falls die Detektionszonen 19 der Messstrompfade 13, 13',13" jeweils nur einen Teilbereich des Heizfelds 9 abdecken, kann durch die beiden Messkreise A und B eine ortsaufgelöste Erfassung von Hot Spots erfolgen, wobei die räumliche Nähe eines Hot Spots zum Messkreis A oder B detektierbar ist. Andererseits ist dem Messkreis C eine Detektionszone 19 zugeordnet, in der zumindest bei bestimmten Anwendungen in der Praxis (z.B. Raumheizung) keine Hot Spots auftreten sollten. Somit kann durch den Messkreis C ein von der momentanen Temperatur des Heizfelds 9 abhängiges Referenzsignal erzeugt werden, das eine zuverlässige und sichere Bestimmung von Hot Spots auf Basis einer Widerstandsänderung der Messkreise A und B ermöglicht. Der Flächenheizkörper 1 von Fig. 2 erlaubt somit eine besonders zuverlässige, ortsaufgelöste Erfassung von Hot Spots. Es versteht sich, dass die in Fig. 2 dargestellten Messeinrichtungen 16 gleichermaßen durch eine einzige Messeinrichtung 16 realisiert sein können.The measuring current paths 13, 13 ', 13 "are respectively short-circuited by the connection lines 34 of a separate measuring device 16 to a measuring circuit, which are designated here in this order as measuring circuits A, B and C. While the two measuring circuits A, B are for detecting a temperature-dependent Resistance change for detecting hot spots in the heating field 9, the measuring circuit C is used only as a reference circle.If the detection zones 19 of the measuring current paths 13, 13 ', 13 "cover only a portion of the Heizfelds 9, can by the two measuring circuits A and B a spatially resolved detection of hot spots, wherein the spatial proximity of a hot spot to the measuring circuit A or B is detectable. On the other hand, the measuring circuit C is associated with a detection zone 19, in which at least in certain applications in practice (eg space heating) no hot spots should occur. Thus, a reference signal dependent on the instantaneous temperature of the heating field 9 can be generated by the measuring circuit C, which enables a reliable and reliable determination of hot spots on the basis of a change in the resistance of the measuring circuits A and B. The surface heater 1 of Fig. 2 thus allows a particularly reliable, spatially resolved detection of hot spots. It is understood that in Fig. 2 illustrated measuring devices 16 may equally be realized by a single measuring device 16.

Es wird nun Bezug auf Fig. 3 genommen, worin ein weiteres Ausführungsbeispiel des erfindungsgemäßen Flächenheizkörpers 1 veranschaulicht ist. Um unnötige Wiederholungen zu vermeiden, werden lediglich die Unterschiede zu dem in Fig. 2 gezeigten Ausführungsbeispiel erläutert und ansonsten wird auf die dort gemachten Ausführungen Bezug genommen.It will now be referred to Fig. 3 taken, wherein a further embodiment of the surface heating element 1 according to the invention is illustrated. To avoid unnecessary repetition, only the differences to those in Fig. 2 shown embodiment explained and otherwise reference is made to the statements made there.

Demnach umfasst der Flächenheizkörper 1 drei als Leiterbahnen in die leitfähige Beschichtung 3 eingeformte Messstrompfade 13, 13', 13" innerhalb des Randstreifens 8, die jeweils vom Heizfeld 9 elektrisch isoliert sind. Die drei Messstrompfade 13, 13', 13" haben einen anderen Verlauf als in Fig. 2 und werden ohne Referenzkreis ausschließlich zum Detektieren von Hot Spots 17 eingesetzt, von denen einer beispielhaft eingezeichnet ist. Der erste Messstrompfad 13, welcher zu Messkreis A gehört, erstreckt sich analog zu Fig. 2, ausgehend von einem ersten Anschlussabschnitt 14 auf Höhe der beiden Anschlusselektroden 10, 11, in etwa bis zur Höhe des linken Heizfeldecks 20 und auf umgekehrtem Weg wieder zurück bis zu einem zweiten Anschlussabschnitt 15 auf Höhe der beiden Anschlusselektroden 10, 11. Der zweite Messstrompfad 13', welcher zu Messkreis B gehört, erstreckt sich, ausgehend von einem ersten Anschlussabschnitt 14' auf Höhe der beiden Anschlusselektroden 10, 11, in etwa bis zur Mitte des oberen langen Rands 6 und auf umgekehrtem Weg wieder zurück. Dabei nutzt der zweite Messstrompfad 13' einen Teil der Leiterbahn des ersten Messstrompfads 13, so dass sich der erste und zweite Messstrompfad 13, 13' insbesondere einen gemeinsamen zweiten Anschlussabschnitt 15 teilen. Der dritte Messstrompfad 13" erstreckt sich, ausgehend von einem ersten Anschlussabschnitt 14" auf Höhe der beiden Anschlusselektroden 10, 11, entlang des rechten kurzen Rands 5 und auf umgekehrtem Weg wieder zurück. Dabei nutzt der dritte Messstrompfad 13" einen Teil der gemeinsamen Leiterbahn der ersten und zweiten Messstrompfade 13, 13', so dass sich der erste, zweite und dritte Messstrompfad 13, 13', 13" insbesondere einen gemeinsamen zweiten Anschlussabschnitt 15. Falls die den drei Messstrompfaden 13, 13', 13" zugeordneten Detektionszonen 19 jeweils nur einen Teilbereich des Heizfelds 9 abdecken, ermöglichen die Messkreise A, B, C eine ortsaufgelöste Erfassung von Hot Spots 17, wobei die räumliche Nähe eines Hot Spots 17 zum Messkreis A, B oder C detektierbar ist. Der in Fig. 3 beispielhaft im Bereich des oberen langen Rands 6 dargestellte Hot Spot 17 hat die größte räumliche Nähe zum ersten Messstrompfad 13 bzw. Messkreis A und verursacht deshalb dort einen stärksten Temperaturanstieg und damit eine größte Änderung des elektrischen Widerstands. Da der Hot Spot 17 in den Messkreisen B und C keine entsprechend große Widerstandsänderung verursacht, kann die räumliche Lage des Hot Spots 17 eindeutig der Detektionszone 19 des Messkreises A zugeordnet werden.Accordingly, the surface heating element 1 comprises three measuring current paths 13, 13 ', 13 "formed as conductor tracks in the conductive coating 3 within the marginal strip 8, which are each electrically insulated from the heating field 9. The three measuring current paths 13, 13', 13" have a different course as in Fig. 2 and are used without reference circle exclusively for detecting hot spots 17, one of which is shown by way of example. The first measuring current path 13, which belongs to measuring circuit A, extends analogously to Fig. 2 , starting from a first connection section 14 at the height of the two connection electrodes 10, 11, approximately up to the height of the left Heizfeldecks 20 and on the opposite way back to a second connection section 15 at the level of the two connection electrodes 10, 11. The second measuring current path thirteenth ', Which belongs to measuring circle B, extends, starting from a first connection section 14' at the level of the two connection electrodes 10, 11, approximately to the middle of the upper long edge 6 and in the opposite way back again. In this case, the second measuring current path 13 'uses part of the conductor track of the first measuring current path 13, so that the first and second measuring current paths 13, 13' in particular share a common second connection section 15. The third measuring current path 13 "extends, starting from a first connection section 14" at the level of the two connection electrodes 10, 11, along the right short edge 5 and on the opposite way back again. In this case, the third measuring current path 13 "utilizes part of the common conductor track of the first and second measuring current paths 13, 13 ', so that the first, second and third measuring current paths 13, 13', 13" in particular use a common second connection section 15 Measuring circuits 13, 13 ', 13 "associated detection zones 19 each cover only a portion of the heating field 9, the measurement circuits A, B, C allow a spatially resolved detection of hot spots 17, wherein the spatial proximity of a hot spot 17 to the measuring circuit A, B or C is detectable Fig. 3 hot spot 17 illustrated by way of example in the region of the upper long edge 6 has the greatest spatial proximity to the first measuring current path 13 or measuring circuit A and therefore causes there a strongest temperature rise and thus a greatest change in the electrical resistance. Since the hot spot 17 in the measuring circuits B and C no correspondingly large change in resistance caused, the spatial position of the hot spot 17 can be clearly assigned to the detection zone 19 of the measuring circuit A.

Es wird nun Bezug auf Fig. 4 genommen, worin ein weiteres Ausführungsbeispiel des erfindungsgemäßen Flächenheizkörpers 1 veranschaulicht ist. Um unnötige Wiederholungen zu vermeiden, werden wiederum lediglich die Unterschiede zu dem in Fig. 3 gezeigten Ausführungsbeispiel erläutert und ansonsten wird auf die dort gemachten Ausführungen Bezug genommen.It will now be referred to Fig. 4 taken, wherein a further embodiment of the surface heating element 1 according to the invention is illustrated. Again, to avoid unnecessary repetition, only the differences to those in Fig. 3 illustrated embodiment and otherwise reference is made to the statements made there.

Demnach umfasst der Flächenheizkörper 1 eine Mehrzahl nicht näher bezeichneter Messstrompfade innerhalb des Randstreifens 8, die jeweils vom Heizfeld 9 elektrisch isoliert sind und die Messkreise A, B, C usw. ergeben. Im Unterschied zu Fig. 3 umfasst jeder Messstrompfad eine räumlich begrenzte Zone 18, im Weiteren als "Messzone" bezeichnet, in der die Leiterbahn mehrmals ihre Verlaufsrichtung ändert (d.h. eine Mehrzahl gegensinnig gekrümmter Leiterbahnabschnitte aufweist), wobei die Leiterbahnabschnitte innerhalb der Messzone 18 mit geringem Zwischenabstand dicht nebeneinander liegen. Die Messstrompfade haben in den schematisch dargestellten Messzonen 18 beispielsweise einen mäandrisch geschwungenen Verlauf. Wie in Fig. 4 dargestellt, verfügen einander benachbarte Messstrompfade über gemeinsame Wegstücke, wobei jeder Messstrompfad mit einem benachbarten Messstrompfad (Messkreis) verbunden ist. Die Messzonen 18 der verschiedenen Messkreise A, B, C usw. sind räumlich voneinander getrennt und mit in etwa gleichen Zwischenabständen entlang des oberen langen Rands 6 und rechten kurzen Rands 5 verteilt angeordnet. Da die Messspannung überwiegend im Bereich der Messzonen 18 abfällt, können die Detektionszonen 19 der Messkreise A, B, C usw. jeweils den Messzonen 18 zugeordnet werden, so dass eine ortsaufgelöste Erfassung von Hot Spots möglich ist, wobei die räumliche Nähe eines Hot Spots zur Messzone 18 eines Messkreis A, B, C usw. detektierbar ist. In Fig. 4 ist beispielhaft ein Hot Spot 17 eingezeichnet, der sich in der Nähe der beiden Messzonen 18 der Messkreise A und B befindet. Somit wird der Hot Spot 17 einen stärksten Temperaturanstieg bzw. Widerstandszunahme in der Messzone 18 des Messkreises A und nachrangig in der Messzone 18 des Messkreises B bewirken. Der Flächenheizkörper 1 von Fig. 4 ermöglicht somit eine hochsensitive und besonders genaue ortsaufgelöste Erfassung von Hot Spots 17 durch die verteilt angeordneten Messzonen 18 der verschiedenen Messkreise.Accordingly, the surface heating element 1 comprises a plurality of unspecified measuring current paths within the edge strip 8, which are each electrically insulated from the heating field 9 and the measuring circuits A, B, C, etc. result. In contrast to Fig. 3 Each measuring current path comprises a spatially limited zone 18, hereinafter referred to as "measuring zone" in which the conductor changes its course direction several times (ie has a plurality of oppositely curved conductor track sections), wherein the conductor track sections within the measuring zone 18 with close spacing are close together. The measuring current paths have, for example, a meandering curved course in the schematically illustrated measuring zones 18. As in Fig. 4 shown, have adjacent measuring current paths on common path pieces, each measuring current path is connected to an adjacent Meßstrompfad (measuring circuit). The measuring zones 18 of the various measuring circuits A, B, C, etc., are spatially separated from each other and distributed with approximately equal intervals along the upper long edge 6 and right short edge 5. Since the measuring voltage drops predominantly in the region of the measuring zones 18, the detection zones 19 of the measuring circuits A, B, C, etc. can each be assigned to the measuring zones 18, so that a spatially resolved detection of hot spots is possible, wherein the spatial proximity of a hot spot to the Measuring zone 18 of a measuring circuit A, B, C, etc. is detectable. In Fig. 4 For example, a hot spot 17 is shown, which is located in the vicinity of the two measuring zones 18 of the measuring circuits A and B. Thus, the hot spot 17 will cause a strongest temperature increase or increase in resistance in the measuring zone 18 of the measuring circuit A and subordinate in the measuring zone 18 of the measuring circuit B. The surface heater 1 of Fig. 4 thus enables a highly sensitive and particularly accurate spatially resolved detection of hot spots 17 by the distributed measuring zones 18 of the various measuring circuits.

Es wird nun Bezug auf Fig. 5 genommen, worin ein weiteres Ausführungsbeispiel des erfindungsgemäßen Flächenheizkörpers 1 veranschaulicht ist. Um unnötige Wiederholungen zu vermeiden, werden wiederum lediglich die Unterschiede zu den in den Figuren 1 bis 4 veranschaulichten Ausführungsbeispielen erläutert und ansonsten wird auf die dort gemachten Ausführungen Bezug genommen.It will now be referred to Fig. 5 taken, wherein a further embodiment of the surface heating element 1 according to the invention is illustrated. To avoid unnecessary repetition, again only the differences to those in the FIGS. 1 to 4 illustrated embodiments and otherwise reference is made to the statements made there.

Der Flächenheizkörper 1 von Fig. 5 unterscheidet sich von den vorherigen Ausführungsbeispielen durch den teilweisen Verlauf von Messstrompfaden 13 innerhalb des Heizfelds 9, sowie durch deren Kontaktierung. Dabei sind analog zu Fig. 2 zwei Messkreise A und B, sowie ein Referenzkreis C vorgesehen. So nutzt ein erster Messstrompfad 13 einen Pfadabschnitt eines Heizstrompfads 12, bei dem es sich hier beispielsweise um einen an die erste Trennlinie 7 angrenzenden Heizstrompfad 12 handelt. Dabei erstreckt sich der erste Messstrompfad 13 innerhalb des Heizfelds 9 von der ersten Anschlusselektrode 10 (in Fig. 5 linke Anschlusselektrode), die hier als erster Anschlussabschnitt 14 dient, entlang des unteren kurzen Rands 5 und des daran angrenzenden linken langen Rands 6. Anschließend wechselt der Heizstrompfad 12 bei seinem Verlauf entlang des linken langen Rands 6 mehrmals gegensinnig seine Verlaufsrichtung. Im Bereich des oberen linken Heizfeldecks 20 verlässt der erste Messstrompfad 13 das Heizfeld 9, geht in den Randstreifen 8 über und verläuft fortan vollständig innerhalb des Randstreifens 8. Die erste Trennlinie 7, durch welche der Randstreifen 8 vom Heizfeld 9 elektrisch abgeteilt wird, ist zu diesem Zweck dort nicht ausgebildet. Im Randstreifen 8 erstreckt sich der erste Messstrompfad 13 als in die Beschichtung 3 eingearbeitete Leiterbahn entlang des oberen langen Rands 6 und des daran angrenzenden kurzen Rands 5, sowie ein kurzes Stück entlang des unteren langen Rands 6, wo er auf Höhe der zweiten Anschlusselektrode 11 (in Fig. 5 rechte Anschlusselektrode) in einem zweiten Anschlussabschnitt 15 endet. Die beiden Anschlussleitungen 34 mit der zwischengeschalteten Messeinrichtung 16 kontaktieren die erste Anschlusselektrode 10 und den zweiten Anschlussabschnitt 15 des ersten Messstrompfads 13 zur Formung des Messkreises A. Der erste Messstrompfad 13 umfasst somit einen im Heizfeld 9 befindlichen Heizfeldabschnitt 22 und einem im Randstreifen 8 befindlichen Randstreifenabschnitt 23.The surface heater 1 of Fig. 5 differs from the previous embodiments by the partial course of Meßstrompfaden 13 within the Heizfelds 9, as well as their contacting. These are analogous to Fig. 2 two measuring circuits A and B, and a reference circle C provided. Thus, a first measuring current path 13 uses a path section of a heating current path 12, which is, for example, a heating current path 12 adjoining the first dividing line 7. In this case, the first measuring current path 13 extends within the heating field 9 from the first connection electrode 10 (in FIG Fig. 5 left terminal electrode), which serves here as a first terminal portion 14, along the lower short edge 5 and the adjoining left long edge 6. Then the Heizstrompfad 12 changes in its course along the left long edge 6 several times in opposite directions its direction. In the area of the upper left Heizfeldecks 20 of the first Meßstrompfad 13 leaves the heater 9, goes into the edge strip 8 and henceforth runs completely within the edge strip 8. The first dividing line 7, by which the edge strip 8 is electrically divided from the heating field 9, is closed this purpose is not trained there. In the edge strip 8, the first measuring current path 13 extends as a conductor track incorporated in the coating 3 along the upper long edge 6 and the adjoining short edge 5, and a short distance along the lower long edge 6, where it reaches the second connection electrode 11 (FIG. in Fig. 5 right connection electrode) ends in a second connection section 15. The two connecting lines 34 with the intermediate measuring device 16 contact the first connecting electrode 10 and the second connecting section 15 of the first measuring current path 13 for forming the measuring circuit A. The first measuring current path 13 thus comprises a heating field section 22 located in the heating field 9 and an edge strip section 23 located in the edge strip 8 ,

Ein zweiter Messstrompfad 13' verläuft gleichermaßen teilweise im Heizfeld 9 und nutzt dabei einen anderen Abschnitt desselben Heizstrompfads 12 wie der erste Messstrompfad 13. Dabei erstreckt sich der zweite Messstrompfad 13' von der zweiten Anschlusselektrode 11 (in Fig. 5 rechte Anschlusselektrode) im Heizstrompfad 12 ein kurzes Stück entlang des unteren langen Rands 6 und des daran angrenzenden rechten kurzen Rands 5. Im Bereich des oberen rechten Heizfeldecks 21 verlässt der zweite Messstrompfad 13' das Heizfeld 9, geht in den Randstreifen 8 über und verläuft fortan vollständig innerhalb des Randstreifens 8. Die zweite Trennlinie 7, durch welche der Randstreifen 8 vom Heizfeld 9 elektrisch abgeteilt wird, ist zu diesem Zweck dort nicht ausgebildet. Im Randstreifen 8 erstreckt sich der zweite Messstrompfad 13' als in die Beschichtung 3 eingeformte Leiterbahn entlang des rechten kurzen Rands 5, sowie ein kurzes Stück entlang des unteren langen Rands 6, wo er auf Höhe der zweiten Anschlusselektrode 11 in einem zweiten Anschlussabschnitt 15' endet. Die beiden Anschlussleitungen 34 mit der zwischengeschalteten Messeinrichtung 16 kontaktieren die zweite Anschlusselektrode 11 und den zweiten Anschlussabschnitt 15' des zweiten Messstrompfad 13' zur Formung des Messkreises B. Der zweite Messstrompfad 13' umfasst somit gleichermaßen einen im Heizfeld 9 befindlichen Heizfeldabschnitt 22 und einem im Randstreifen 8 befindlichen Randstreifenabschnitt 23.A second measuring current path 13 'likewise runs partially in the heating field 9 and uses a different section of the same heating current path 12 as the first measuring current path 13. In this case, the second measuring current path 13' extends from the second connection electrode 11 (in FIG Fig. 5 right connection electrode) in the heating current path 12 for a short distance along the lower long edge 6 and the right short edge 5 adjacent thereto. In the region of the upper right heating field 21, the second measuring current path 13 'leaves the heating field 9, merges into the edge strip 8 and continues from there completely within the edge strip 8. The second parting line 7, by which the edge strip 8 is electrically separated from the heating field 9, is not formed for this purpose there. In the edge strip 8, the second measuring current path 13 'extends as in the coating 3 molded conductor along the right short edge 5, and a short distance along the lower long edge 6, where it ends at the level of the second connection electrode 11 in a second connection portion 15' , The two connection lines 34 with the intermediate measuring device 16 contact the second connection electrode 11 and the second connection section 15 'of the second measuring current path 13' for forming the measuring circuit B. The second measuring current path 13 'thus likewise includes a heating field section 22 located in the heating field 9 and one in the edge strip 8 located edge strip section 23rd

Da die Breite bzw. Querschnittsfläche des Heizfeldabschnitts 22 der beiden Messstrompfade 13, 13' jeweils wesentlich größer ist als jene im Randstreifenabschnitt 23, ist der elektrische Widerstand innerhalb des Heizfelds 9 wesentlich kleiner als im Randstreifen 8. Im gezeigten Ausführungsbeispiel beträgt die Breite bzw. Querschnittsfläche des ersten bzw. zweiten Messstrompfads 13, 13' innerhalb des Heizfelds 9 jeweils beispielsweise das 2- bis 100-fache, insbesondere 85-fache, der Breite bzw. Querschnittsfläche im Randstreifen 8. Es versteht sich, dass die Breite innerhalb des Heizfelds 9 vom Layout der Heizstrompfade 12 abhängt und breit variieren kann. Somit fällt die Messspannung zur Messung einer Widerstandsänderung im Wesentlichen über den Randstreifenabschnitten 23 ab. Die Detektionszonen 19 der beiden Messstrompfade 13, 13' können somit den Randstreifenabschnitten 23 zugeordnet werden. Für den Fall, dass die Detektionszonen 19 jeweils nur einen Teil des Heizfelds 9 überdecken, ist eine ortsaufgelöste Erfassung von Hot Spots im Heizfeld 9 durch die Randstreifenabschnitte 23 der beiden Messstrompfade 13, 13' möglich. Ein besonderer Vorteil dieser Ausführungsform liegt darin, dass die Leiterbahnen der Messkreise A und B jeweils nur relativ wenig Platz im Randstreifen 8 benötigen, so dass die Messkreise A, B auch bei schmalen Randstreifen 8 ausgebildet werden können. Eine Messung des elektrischen Widerstands in den Messkreisen A, B kann simultan zum Einspeisen von Heizstrom durch einen Potenzialunterschied zwischen Mess- und Speisespannung erfolgen.Since the width or cross-sectional area of Heizfeldabschnitts 22 of the two measuring current paths 13, 13 'each is substantially larger than those in the edge strip portion 23, the electrical resistance within the heater 9 is substantially smaller than in the edge strip 8. In the illustrated embodiment, the width or cross-sectional area each of the first and second measuring current paths 13, 13 'within the heating field 9, for example, 2 to 100 times, in particular 85 times, the width or cross-sectional area in the edge strip 8. It is understood that the width within the heating field 9 from Layout of Heizstrompfade 12 depends and can vary widely. Thus, the measurement voltage for measuring a change in resistance drops substantially over the edge strip portions 23. The detection zones 19 of the two measuring current paths 13, 13 'can thus be assigned to the edge strip sections 23. In the event that the detection zones 19 each cover only a part of the heating field 9, a spatially resolved detection of hot spots in the heating field 9 by the edge strip portions 23 of the two measuring current paths 13, 13 'is possible. A particular advantage of this embodiment is that the conductor tracks of the measuring circuits A and B respectively require only relatively little space in the edge strip 8, so that the measuring circuits A, B can also be formed with narrow edge strips 8. A measurement of the electrical resistance in the measuring circuits A, B can be carried out simultaneously for feeding heating current through a potential difference between measuring and supply voltage.

Analog zu Fig. 2 dient ein dritter Messstrompfad 13" zur Formung eines Messkreises C. So erstreckt sich der dritte Messstrompfad 13", ausgehend von einem ersten Anschlussabschnitt 14" auf Höhe der beiden Anschlusselektroden 10, 11 in Form einer in die Beschichtung 3 eingearbeiteten Leiterbahn entlang des unteren langen Rands 6 und des daran angrenzenden oberen langen Rands 6 und verläuft auf umgekehrtem Weg wieder zurück, zu welchem Zweck die in die Beschichtung 3 eingearbeitete Leiterbahn im Bereich des linken Heizfeldecks 20 in den Randstreifenabschnitt 23 des ersten Messstrompfads 13 übergeht. Eine Anschlussleitung 34 der Messeinrichtung 16 kontaktiert den ersten Anschlussabschnitt 14" des dritten Messstrompfads 13", die andere Anschlussleitung 34 die mit der ersten Anschlusselektrode 10 verbundene Anschlussleitung 34 des Messkreises A. Der Messkreis C wird lediglich als Referenzkreis eingesetzt und ermöglicht eine Bestimmung von Hot Spots auf Basis eines von der momentanen Temperatur des Heizfelds 9 abhängigen Referenzsignals, so dass eine besonders zuverlässige und sichere Erfassung von Hot Spots möglich ist.Analogous to Fig. 2 serves a third Meßstrompfad 13 "for forming a measuring circuit C. Thus, the third Meßstrompfad 13" extending from a first terminal portion 14 "at the level of the two terminal electrodes 10, 11 in the form of a built-in coating 3 conductor along the lower long edge 6 and of the upper long edge 6 adjoining thereto and runs back in the opposite direction, for which purpose the interconnect incorporated into the coating 3 in the area of the left heater top 20 merges into the edge strip section 23 of the first measuring current path 13. A connecting line 34 of the measuring device 16 contacts the first connection section 14 "of the third measurement current path 13", the other connection line 34 connected to the first connection electrode 10 connecting line 34 of the measuring circuit A. The measuring circuit C is used only as a reference circle and allows determination of hot spots on the basis of one of the current temperature of the heating f elds 9 dependent reference signal, so that a particularly reliable and secure detection of hot spots is possible.

Es wird nun Bezug auf Fig. 6 genommen, worin ein weiteres Ausführungsbeispiel des erfindungsgemäßen Flächenheizkörpers 1 veranschaulicht ist. Um unnötige Wiederholungen zu vermeiden, werden wiederum lediglich die Unterschiede zu dem anhand Fig. 5 veranschaulichten Ausführungsbeispiel erläutert und ansonsten wird auf die dort gemachten Ausführungen Bezug genommen.It will now be referred to Fig. 6 taken, wherein a further embodiment of the surface heating element 1 according to the invention is illustrated. Again, to avoid unnecessary repetition, only the differences to that are shown Fig. 5 illustrated embodiment and otherwise reference is made to the statements made there.

Der Flächenheizkörper 1 von Fig. 6 unterscheidet sich von dem Flächenheizkörper von Fig. 5 lediglich darin, dass der Randstreifenabschnitt 23 des ersten Messstrompfads 13 im Bereich des oberen langen Rands 6 mehrmals seine Verlaufsrichtung gegensinnig (gegensinnig gekrümmte Messstrompfadabschnitte) ändert und hier beispielsweise einen mäandrisch geschwungenen Verlauf hat. Durch diese Maßnahme kann erreicht werden, dass die Messspannung im Wesentlichen in dem an den oberen langen Rand 6 angrenzenden Randstreifenabschnitt 23 abfällt, so dass die Empfindlichkeit und Ortsauflösung zur Erfassung von Hot Spots in diesem Bereich erhöht ist.The surface heater 1 of Fig. 6 differs from the surface radiator of Fig. 5 only in that the edge strip portion 23 of the first measuring current path 13 in the region of the upper long edge 6 several times its course in opposite directions (oppositely curved Meßstrompfadabschnitte) changes and here, for example, has a meandering curved course. As a result of this measure, it is possible to achieve that the measuring voltage is substantially adjacent to that at the upper long edge 6 Edge strip portion 23 drops, so that the sensitivity and spatial resolution for detecting hot spots is increased in this area.

Es wird nun unter Bezugnahme auf Fig. 7A-7C ein weiteres Ausführungsbeispiel des erfindungsgemäßen Flächenheizkörpers 1 erläutert. Der Flächenheizkörper 1 unterscheidet sich von den in den Figuren 1 bis 6 veranschaulichten Flächenheizkörpern 1 durch den praktisch vollständigen Verlauf von Messstrompfaden innerhalb des Heizfelds 9, sowie durch die Kontaktierung der Messstrompfade. Dabei werden vier Messkreise A, B, C und D gebildet, wie im Weiteren näher erläutert wird.It will now be referring to Figs. 7A-7C a further embodiment of the surface heating element 1 according to the invention explained. The surface heater 1 differs from the in the FIGS. 1 to 6 Illustrated surface radiators 1 by the virtually complete course of Meßstrompfaden within the heating field 9, as well as by contacting the measuring current paths. In this case, four measuring circuits A, B, C and D are formed, as will be explained in more detail below.

Sei zunächst Fig. 7A betrachtet, worin das Layout des Flächenheizkörpers 1 dargestellt ist. Demnach hat der Flächenheizkörper 1 hier beispielsweise einen spiegelsymmetrischen Aufbau bezüglich einer Symmetrieachse 27, welche sich mittig der beiden kurzen Ränder 5 erstreckt. Zudem sind die beiden Anschlusselektroden 10, 11 jeweils in drei voneinander elektrisch isolierte erste bis dritte Elektrodenabschnitte 24-26 geteilt, wobei die drei Elektrodenabschnitte 24-26 einer selben Anschlusselektrode 10, 11 in einer von der Beschichtung 3 verschiedenen Ebene elektrisch miteinander verbunden sind (was nicht näher dargestellt ist). Die beiden Anschlusselektroden 10, 11 sind in Fig. 7A auch in einer vergrößerten Darstellung gezeigt.Be first Fig. 7A considered, wherein the layout of the surface heater 1 is shown. Accordingly, the surface heater 1 here, for example, a mirror-symmetrical structure with respect to an axis of symmetry 27, which extends centrally of the two short edges 5. In addition, the two connection electrodes 10, 11 are each divided into three electrically insulated first to third electrode sections 24-26, the three electrode sections 24-26 of a same connection electrode 10, 11 are electrically connected to each other in a plane other than the coating 3 (which not shown in detail). The two connection electrodes 10, 11 are in Fig. 7A also shown in an enlarged view.

Es sind vier Messstrompfade 13, 13', 13", 13"' ausgebildet, die sich jeweils aus einem Pfadabschnitt eines Heizstrompfads 12, 12' und einer wesentlich schmäleren, in die leitfähige Beschichtung 3 des Heizfelds 9 eingearbeiteten Leiterbahn, im Weiteren als "Messstrombahn" bezeichnet, zusammensetzen. Wie in Fig. 7A dargestellt, umfasst der Flächenheizkörper 1 zu diesem Zweck auf jeder Seite der Symmetrieachse 27 jeweils zwei Messstrombahnen, nämlich eine erste Messstrombahn 28 und eine zweite Messstrombahn 29, sowie eine dritte Messstrombahn 35 und eine vierte Messstrombahn 36, die jeweils durch dritte Trennlinien 37 in die leitfähige Beschichtung 3 beispielsweise mittels Laserung eingeformt sind. Die Messstrombahnen 28, 29, 35, 36 haben gegenüber den Heizstrompfaden 12 eine (z. B. wesentlich) geringere Breite bzw. Querschnittsfläche, was mit einem entsprechend größeren elektrischen Widerstand einhergeht, so dass in den Messstrompfaden 13, 13', 13", 13"' die Messspannung im Wesentlichen über den Messstrombahnen 28, 29, 35, 36 abfällt. Dabei erstrecken sich die erste Messstrombahn 28 und die dritte Messstrombahn 35 jeweils im Heizfeld 9 zwischen einem ersten Heizstrompfad 12, welcher an die erste Trennlinie 7 angrenzt, und einem daran angrenzenden, innen liegenden zweiten Heizstrompfad 12' bis zu einem (gemeinsamen) ersten Messstrombahnende 38 in etwa auf mittiger Höhe des linken kurzen Substratrands 5. Die erste Messstrombahn 28 verläuft im Bereich der zweiten Anschlusselektrode 11 in einem zweiten Elektrodenzwischenraum 32 zwischen dem ersten Elektrodenabschnitt 24 und dem zweiten Elektrodenabschnitt 25 der zweiten Anschlusselektrode 11 und geht dann in einen ersten Elektrodenzwischenraum 31 zwischen den beiden Anschlusselektroden 10, 11 über, bis sie in einem separaten ersten Anschlussfleck 44 ausläuft. Am ersten Messstrombahnende 38 ist die erste Messstrombahn 28 in den unterhalb der Symmetrieachse 27 befindlichen Teil des ersten Heizstrompfads 12 elektrisch angeschlossen. Die dritte Messstrombahn 35 erstreckt sich im Bereich der ersten Anschlusselektrode 10 in einem zweiten Elektrodenzwischenraum 32 zwischen dem ersten Elektrodenabschnitt 24 und dem zweiten Elektrodenabschnitt 25 der ersten Anschlusselektrode 10 und geht dann in den ersten Elektrodenzwischenraum 31 zwischen den beiden Anschlusselektroden 10, 11 über, wo sie in einem dritten Anschlussfleck 46 ausläuft. Am ersten Messstrombahnende 38 ist die dritte Messstrombahn 35 an den oberhalb der Symmetrieachse 27 befindlichen Teil des ersten Heizstrompfads 12 elektrisch angeschlossen. Im Übrigen sind die erste Messstrombahn 28 und die dritte Messstrombahn 35 vom ersten und zweiten Heizstrompfad 12, 12' elektrisch abgeteilt.There are four measuring current paths 13, 13 ', 13 ", 13"' formed, each consisting of a path portion of a Heizstrompfads 12, 12 'and a much narrower, incorporated into the conductive coating 3 of the heating field 9 conductor, hereinafter referred to as "measuring current "labeled, put together. As in Fig. 7A illustrated, the surface heating element 1 comprises for this purpose on each side of the symmetry axis 27 each two measuring current paths, namely a first measuring flow path 28 and a second measuring flow path 29, and a third measuring flow path 35 and a fourth measuring flow path 36, each by third dividing lines 37 in the conductive Coating 3 are formed for example by means of laser. The measuring current paths 28, 29, 35, 36 have a (eg significantly) smaller width or cross-sectional area compared to the heating current paths 12, which is accompanied by a correspondingly greater electrical resistance, so that the measuring current paths 13, 13 ', 13 ", 13 "', the measuring voltage substantially above the measuring current paths 28, 29, 35, 36 drops. In this case, the first measuring flow path 28 extend and the third measuring flow path 35 each in the heating field 9 between a first heating current path 12, which adjoins the first dividing line 7, and an adjacent, inner second heating current path 12 'up to a (common) first Meßstrombahnende 38 approximately at the central height of the left short substrate edge 5. The first measuring current path 28 extends in the region of the second connection electrode 11 in a second electrode gap 32 between the first electrode portion 24 and the second electrode portion 25 of the second connection electrode 11 and then merges into a first electrode gap 31 between the two connection electrodes 10, 11 until it runs out in a separate first pad 44. At the first measuring current end 38, the first measuring current path 28 is electrically connected to the part of the first heating current path 12 situated below the axis of symmetry 27. The third measuring current path 35 extends in the region of the first connection electrode 10 in a second electrode gap 32 between the first electrode section 24 and the second electrode section 25 of the first connection electrode 10 and then passes into the first electrode gap 31 between the two connection electrodes 10, 11, where they expires in a third pad 46. At the first measuring current end 38, the third measuring current path 35 is electrically connected to the part of the first heating current path 12 located above the axis of symmetry 27. Incidentally, the first measuring flow path 28 and the third measuring flow path 35 are electrically separated from the first and second heating current paths 12, 12 '.

Die zweite Messstrombahn 29 und die vierte Messstrombahn 36, welche jeweils weiter innen liegen, erstrecken sich im Heizfeld 9 zwischen dem zweiten Heizstrompfad 12' und einem angrenzenden dritten Heizstrompfad 12" bis zu einem jeweiligen zweiten Messstrombahnende 43. Die zweite Messstrombahn 29 erstreckt sich im Bereich der zweiten Anschlusselektrode 11 in einem dritten Elektrodenzwischenraum 33 zwischen dem zweiten Elektrodenabschnitt 25 und dem dritten Elektrodenabschnitt 26 der zweiten Anschlusselektrode 11 und geht dann in den ersten Elektrodenzwischenraum 31 zwischen den beiden Anschlusselektroden 10, 11 über, wo sie in einem zweiten Anschlussfleck 45 ausläuft. Am zugehörigen zweiten Messstrombahnende 43 ist die zweite Messstrombahn 29 an den zweiten Heizstrompfad 12' elektrisch angeschlossen. Die vierte Messstrombahn 36 erstreckt sich im Bereich der ersten Anschlusselektrode 10 in einem dritten Elektrodenzwischenraum 33 zwischen dem zweiten Elektrodenabschnitt 25 und dem dritten Elektrodenabschnitt 26 der ersten Anschlusselektrode 10 und geht dann in den ersten Elektrodenzwischenraum 31 zwischen den beiden Anschlusselektroden 10, 11 über, wo sie in einem vierten Anschlussfleck 47 ausläuft. Am zugehörigen zweiten Messstrombahnende 43 ist die vierte Messstrombahn 36 an den zweiten Heizstrompfad 12' elektrisch angeschlossen. Im Übrigen sind die zweite Messstrombahn 29 und die vierte Messstrombahn 36 vom ersten und zweiten Heizstrompfad 12, 12' elektrisch abgeteilt.The second measuring flow path 29 and the fourth measuring flow path 36, which lie further in each case, extend in the heating field 9 between the second heating current path 12 'and an adjacent third heating current path 12 "up to a respective second measuring flow path end 43. The second measuring flow path 29 extends in the region of the second terminal electrode 11 in a third electrode gap 33 between the second electrode portion 25 and the third electrode portion 26 of the second terminal electrode 11 and then passes into the first electrode gap 31 between the two terminal electrodes 10, 11 where it terminates in a second pad 45 The second measuring current path 29 is electrically connected to the second heating current path 12 'in the second measuring current path end 43. The fourth measuring current path 36 extends in the region of the first connecting electrode 10 in a third electrode gap 33 between the second electrode section 25 and the third th Electrode portion 26 of the first terminal electrode 10 and then passes into the first electrode gap 31 between the two terminal electrodes 10, 11, where it terminates in a fourth pad 47. At the associated second measuring flow path end 43, the fourth measuring flow path 36 is electrically connected to the second heating current path 12 '. Incidentally, the second measuring flow path 29 and the fourth measuring flow path 36 are electrically separated from the first and second heating current paths 12, 12 '.

Sei nun Fig. 7B betrachtet, worin die verschiedenen Messkreise schematisch dargestellt sind. Dabei ist der erste Messstrompfad 13, entsprechend dem Messkreis A, mit einem zweiten Messstrompfad 13', entsprechend dem Messkreis B, in Serie verschaltet. Der erste Messstrompfad 13 erstreckt sich, ausgehend vom ersten Elektrodenabschnitt 24 der zweiten Anschlusselektrode 11 im ersten Heizstrompfad 12, bis zum ersten Messstrombahnende 38, wo er in die dritte Messstrombahn 35 übergeht. Die dritte Messstrombahn 35 ist mit der zweiten Messstrombahn 29 kurzgeschlossen, welche Teil des zweiten Messstrompfads 13' ist. Zu diesem Zweck sind der dritte Anschlussfleck 46 und der zweite Anschlussfleck 45 elektrisch miteinander verbunden (was nicht näher dargestellt ist). Diese beiden Anschlussflecke 45, 46 bilden gemeinsam einen ersten Anschlussabschnitt 14. Der zweite Messstrompfad 13' geht am zugehörigen zweiten Messstrombahnende 43 in den zweiten Heizstrompfad 12' über, der mit dem zweiten Elektrodenabschnitt 25 der ersten Anschlusselektrode 10 elektrisch verbunden ist. Andererseits ist der dritte Messstrompfad 13", entsprechend dem Messkreis C, mit einem vierten Messstrompfad 13"', entsprechend dem Messkreis D, in Serie verschaltet. Der dritte Messstrompfad 13" erstreckt sich, ausgehend vom zweiten Elektrodenabschnitt 25 der zweiten Anschlusselektrode 11 im zweiten Heizstrompfad 12' bis zum zugehörigen zweiten Messstrombahnende 43, wo er in die vierte Messstrombahn 36 übergeht. Die vierte Messstrombahn 36 ist mit der ersten Messstrombahn 28 kurzgeschlossen, welche Teil des vierten Messstrompfads 13"' ist. Zu diesem Zweck sind der vierte Anschlussfleck 47 und der erste Anschlussfleck 44 elektrisch verbunden. Diese beiden Anschlussflecke 44, 47 bilden gemeinsam einen zweiten Anschlussabschnitt 15. Der vierte Messstrompfad 13"' geht in den ersten Heizstrompfad 12 über, der mit dem ersten Elektrodenabschnitt 24 der ersten Anschlusselektrode 10 elektrisch verbunden ist. Somit sind einerseits die Messkreise A und B und andererseits die Messkreise C und D seriell verschaltet.Be now Fig. 7B considered, wherein the various measuring circuits are shown schematically. In this case, the first measuring current path 13, corresponding to the measuring circuit A, is connected in series with a second measuring current path 13 ', corresponding to the measuring circuit B. The first measuring current path 13 extends, starting from the first electrode section 24 of the second connecting electrode 11 in the first heating current path 12, to the first measuring current end 38, where it merges into the third measuring current path 35. The third measuring current path 35 is short-circuited to the second measuring current path 29, which is part of the second measuring current path 13 '. For this purpose, the third pad 46 and the second pad 45 are electrically connected to each other (which is not shown in detail). These two connection pads 45, 46 together form a first connection section 14. The second measurement current path 13 'merges at the associated second measuring flow path end 43 into the second heating current path 12', which is electrically connected to the second electrode section 25 of the first connection electrode 10. On the other hand, the third measuring current path 13 ", corresponding to the measuring circuit C, is connected in series with a fourth measuring current path 13"', corresponding to the measuring circuit D. The third measuring current path 13 "extends, starting from the second electrode section 25 of the second connection electrode 11 in the second heating current path 12 'to the associated second measuring flow path end 43, where it merges into the fourth measuring flow path 36. The fourth measuring flow path 36 is short-circuited with the first measuring flow path 28, which is part of the fourth measuring current path 13 "'. For this purpose, the fourth pad 47 and the first pad 44 are electrically connected. These two connection pads 44, 47 together form a second connection section 15. The fourth measurement current path 13 "'changes into the first heating current path 12, which is electrically connected to the first electrode section 24 of the first connection electrode 10. Thus, on the one hand, the measurement circuits A and B and on the other hand, the measuring circuits C and D connected in series.

In Fig. 7C ist das Ersatzschaltbild des Flächenheizkörpers 1 gezeigt. Dabei entspricht Widerstand R1 dem Messkreis A, Widerstand R2 dem Messkreis B, Widerstand R3 dem Messkreis C und Widerstand R4 dem Messkreis D. Die erste Elektrode 10 wird beispielsweise mit dem Minuspol einer Spannungsquelle und die zweite Elektrode 11 mit dem Pluspol der Spannungsquelle verbunden. Eine Messeinrichtung 16 zur Bestimmung elektrischer Spannungsänderungen ist mit einem Knoten zwischen den beiden Widerständen R1 und R2 und einem weiteren Knoten zwischen den beiden Widerständen R3 und R4 elektrisch verbunden, so dass sich eine Wheatstone'sche Brückenschaltung ergibt. Diese beiden Knoten entsprechen den beiden Anschlussabschnitten 14, 15, die sich aus einer elektrischen Verbindung des zweiten und dritten Anschlussflecks 45, 46 bzw. des ersten und vierten Anschlussflecks 44, 47 ergeben.In Fig. 7C the equivalent circuit of the surface heater 1 is shown. In this case, resistor R1 corresponds to measuring circuit A, resistor R2 to measuring circuit B, resistor R3 to measuring circuit C and resistor R4 to measuring circuit D. First electrode 10 is connected, for example, to the negative pole of a voltage source and second electrode 11 to the positive pole of the voltage source. A measuring device 16 for determining electrical voltage changes is electrically connected to a node between the two resistors R1 and R2 and another node between the two resistors R3 and R4, so that there is a Wheatstone bridge circuit. These two nodes correspond to the two connection sections 14, 15, which result from an electrical connection of the second and third connection pads 45, 46 and of the first and fourth connection pads 44, 47, respectively.

Die dabei erzielte Wheatstone'sche Brückenschaltung ermöglicht eine besonders einfache und hoch-sensitive Erfassung einer Änderung der Widerstände R1-R4. Dies kann durch die folgende Formel erfolgen: U / U 0 = 1 / 4 ΔR 2 / R − ΔR 1 / R − ΔR 4 / R + ΔR 3 / R

Figure imgb0001
worin U0 die an die beiden Anschlusselektroden 10, 11 angelegte Versorgungsspannung der Messbrücke und U die Brückenspannung darstellen. Mit ΔR1 bis ΔR4 sind die jeweiligen Widerstandsänderungen an den Widerständen R1 bis R4 bezeichnet.The achieved Wheatstone bridge circuit allows a particularly simple and highly sensitive detection of a change in the resistors R1-R4. This can be done by the following formula: U / U 0 = 1 / 4 .DELTA.R 2 / R - .DELTA.R 1 / R - .DELTA.R 4 / R + .DELTA.R 3 / R
Figure imgb0001
 wherein U 0 represent the applied to the two terminal electrodes 10, 11 supply voltage of the measuring bridge and U represent the bridge voltage. With ΔR1 to ΔR4, the respective resistance changes to the resistors R1 to R4 are designated.

BezugszeichenlisteLIST OF REFERENCE NUMBERS

11
FlächenheizkörperPanel heater
22
Substratsubstratum
33
Beschichtungcoating
44
Sub stratrandSub stratrand
55
kurzer Randshort edge
66
langer Randlong edge
77
erste Trennliniefirst dividing line
88th
Randstreifenedge strips
99
Heizfeldheating field
1010
erste Anschlusselektrodefirst connection electrode
1111
zweite Anschlusselektrodesecond connection electrode
12, 12', 12"12, 12 ', 12 "
HeizstrompfadHeizstrompfad
13, 13', 13", 13"'13, 13 ', 13 ", 13"'
MessstrompfadMeasuring current path
1414
erster Anschlussabschnittfirst connection section
1515
zweiter Anschlussabschnittsecond connection section
1616
Messeinrichtungmeasuring device
1717
Hot SpotHot Spot
1818
Messzonemeasurement zone
1919
Detektionszonedetection zone
2020
linkes Heizfeldeckleft heating field deck
2121
rechtes Heizfeldeckright Heizfeldeck
2222
HeizfeldabschnittHeizfeldabschnitt
2323
RandstreifenabschnittEdge strip section
2424
erster Elektrodenabschnittfirst electrode section
2525
zweiter Elektrodenabschnittsecond electrode section
2626
dritter Elektrodenabschnittthird electrode section
2727
Symmetrieachseaxis of symmetry
2828
erste Messstrombahnfirst measuring current path
2929
zweite Messstrombahnsecond measuring current path
3030
zweite Trennliniesecond dividing line
3131
erster Elektrodenzwischenraumfirst electrode gap
3232
zweiter Elektrodenzwischenraumsecond electrode gap
3333
dritter Elektrodenzwischenraumthird electrode gap
3434
Anschlussleitungconnecting cable
3535
dritte Messstrombahnthird measuring current path
3636
vierte Messstrombahnfourth measuring current path
3737
dritte Trennliniethird dividing line
3838
erstes Messstrombahnendefirst measuring current end
3939
Anordnungarrangement
4040
Steuer- und KontrolleinrichtungControl and monitoring device
4141
Ausgabeeinrichtungoutput device
4242
Substratflächesubstrate surface
4343
zweites Messstrombahnendesecond measuring current end
4444
erster Anschlussfleckfirst pad
4545
zweiter Anschlussflecksecond pad
4646
dritter Anschlussfleckthird pad
4747
vierter Anschlussfleckfourth pad

Claims (15)

  1. Panel heater (1) with at least one flat substrate (2) and an electrically conductive coating (3), which extends at least over part of a substrate area (42) and is electrically connected to at least two connecting electrodes (10, 11) provided for electrical connection to the two terminals of a voltage source, such that by applying a feed voltage, a heating current flows in a heating field (9), wherein the panel heater (1) is provided with one or a plurality of heating current paths (12) and one or a plurality of measurement current paths (13), wherein the measurement current paths (13) differ at least in sections from the heating current paths (12), and wherein the measurement current paths (13) are respectively thermally coupled at least to a portion of the heating field (9) and have at least two connecting sections (14, 15) for connecting a measuring device (16) for ascertaining the electrical resistance of the measurement current path, characterized in that the measurement current paths (13) are respectively formed into the conductive coating (3) by coating-free separating regions (30) and are formed by the conductive coating (3).
  2. Panel heater (1) according to claim 1, wherein the measurement current paths (13) are formed into the conductive coating (3) at least in sections, in particular completely, in an edge strip (8) surrounding the heating field (9) and electrically isolated from the heating field (9).
  3. Panel heater (1) according to claim 2, wherein the measurement current paths (13) are implemented at least in sections in portions of the edge strip (8) different from each other.
  4. Panel heater (1) according to claim 2 or 3, wherein one or a plurality of measurement current paths (13) are in each case implemented such that they change their path direction repeatedly in a spatially limited measuring zone (18) of the edge strip (8).
  5. Panel heater (1) according to claim 4, wherein the measuring zones (18) are disposed spatially distributed at least over a portion of the edge strip (8).
  6. Panel heater (1) according to one of claims 1 through 5, wherein the measurement current paths (13) are electrically isolated from the heating field (9).
  7. Panel heater (1) according to one of claims 1 through 5, wherein one or a plurality of measurement current paths (13) have in each case a measurement current path section, which is part of a heating current path (12) or is formed by a heating current path (12).
  8. Panel heater (1) according to one of claims 1 through 7, wherein the connecting electrodes (10, 11) are electrically connected to two measurement current path arrays (A-B, C-D) connected in parallel, in which, in each case, two measurement current paths (13, 13'; 13", 13"') are connected to each other in series, wherein each measurement current path array (A-B, C-D) has a connecting section (14, 15) disposed between the two serially connected measurement current paths for connecting the measuring device (16).
  9. Panel heater (1) according to one of claims 1 through 8, wherein at least one measurement current path (13) serves as a reference current path for ascertaining a reference resistance for other measurement current paths (13).
  10. Arrangement (39) with a panel heater (1) according to one of claims 1 through 9, which has at least one measuring device (16) connected to the connecting sections (14, 15) of the measurement current paths (13) for ascertaining electrical resistances as well as a control and monitoring device (40) with a data link to the measuring device (16), wherein the control and monitoring device (40) is designed such that the feed voltage is reduced or turned off when the electrical resistance of a measurement current path (13) exceeds a predefinable threshold value.
  11. Arrangement (39) according to claim 10, wherein the control and monitoring device (40) has a data link to an optical and/or acoustic output device (41) for outputting optical and/or acoustic signals, wherein the control and monitoring device is designed such that an optical and/or acoustic signal is outputted when the electrical resistance of a measurement current path exceeds the predefinable threshold value.
  12. Method for operating a panel heater (1) with at least one flat substrate and an electrically conductive coating (3), which extends at least over part of the substrate area and is electrically connected to at least two connecting electrodes (10, 11) provided for electrical connection to the two terminals of a voltage source such that by applying a feed voltage, a heating current flows in a heating field (9), wherein the electrical resistance of one or a plurality of measurement current paths (13) thermally coupled to the heating field (9) is ascertained, characterized in that the measurement current paths are formed into the conductive coating in each case by coating-free separating regions (30) and are formed by the conductive coating.
  13. Method according to claim 12, wherein the feed voltage is reduced or turned off when the electrical resistance of a measurement current path (13) exceeds a predefinable threshold value.
  14. Method according to claim 12 or 13, wherein an optical and/or acoustic signal is outputted if the electrical resistance of a measurement current path (13) exceeds a predefinable threshold value.
  15. Use of a panel heater (1) according to one of claims 1 through 9 as a functional and/or decorative individual piece and as a built-in part in furniture, devices, and buildings, in particular as a heater in living spaces, for example, as a wall mountable or freestanding heater, as well as in means of transportation for travel on land, in the air, or on water, in particular in motor vehicles, for example, as a windshield, rear window, side window, and/or glass roof.
EP11805429.5A 2010-11-18 2011-11-18 Panel heater with temperature monitoring Active EP2641452B1 (en)

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PCT/EP2011/070426 WO2012066112A1 (en) 2010-11-18 2011-11-18 Panel heater with temperature monitoring
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Families Citing this family (34)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2616259B1 (en) 2010-09-15 2019-04-10 Magna Mirrors Of America, Inc. Slider window assembly
ES2676660T3 (en) * 2011-06-10 2018-07-23 Saint-Gobain Glass France Heated composite panel that has a safety function
US20140265756A1 (en) * 2013-03-12 2014-09-18 Hussmann Corporation Door for a refrigerated merchandiser
JP6011430B2 (en) * 2013-04-12 2016-10-19 株式会社デンソー Radiant heater air conditioning system
US9475364B2 (en) 2013-10-14 2016-10-25 Magna Mirrors Of America, Inc. Sealing system for movable window of rear window assembly
WO2015148362A1 (en) * 2014-03-24 2015-10-01 Rtr Technologies, Inc. Radiant heating system for a surface structure, and surface structure assembly with radiant heater
DE202014003827U1 (en) * 2014-05-08 2015-08-12 I.G. Bauerhin Gmbh Heating device with a temperature detection associated therewith for heating surfaces in the interior of a vehicle
DE102014007163B3 (en) * 2014-05-15 2015-09-24 Florian Gerber Monitoring system for motor vehicles
CN105304463A (en) * 2014-07-10 2016-02-03 英属开曼群岛商精曜有限公司 Vertical flat plate type heater
US9579955B2 (en) 2014-08-26 2017-02-28 Magna Mirros Of America, Inc. Rear slider window assembly with heated movable window
DE102014116283B4 (en) 2014-11-07 2016-05-19 Webasto SE Method for processing a first component and a second component and device
CN104647838A (en) * 2015-02-02 2015-05-27 翔实节能玻璃（昆山）有限公司 Electric heating decorative glass plate and manufacturing method thereof
DE102015119252B4 (en) * 2015-11-09 2024-02-01 Webasto SE Device for a heater for a vehicle
US10023026B2 (en) 2015-11-20 2018-07-17 Magna Mirrors Of America, Inc. Vehicle rear slider window assembly with enhanced rail attachment
US10239397B2 (en) 2015-11-24 2019-03-26 Magna Mirrors Of America, Inc. Sealing system for movable window of rear window assembly
WO2017151348A1 (en) * 2016-02-29 2017-09-08 Illinois Tool Works, Inc. Hybrid heater for vehicle sensor system
US10188015B2 (en) * 2016-09-20 2019-01-22 Qualcomm Incorporated Hybrid design of heat spreader and temperature sensor for direct handheld device skin temperature measurement
DE102016118829A1 (en) * 2016-10-05 2018-04-05 Webasto SE Electric heater for mobile applications
US10524313B2 (en) 2017-02-09 2019-12-31 Magna Mirrors Of America, Inc. Rear slider window assembly with laminated heating element
DE102017206656A1 (en) * 2017-04-20 2018-10-25 Bayerische Motoren Werke Aktiengesellschaft Self-regulating window heating device for a motor vehicle and motor vehicle
CN107484280B (en) * 2017-09-15 2019-11-08 福耀玻璃工业集团股份有限公司 A kind of heatable side window glass
JP6869882B2 (en) 2017-12-21 2021-05-12 株式会社ニフコ Plane heating element and windshield device for vehicles
CN108566690A (en) * 2018-03-09 2018-09-21 嘉兴志嘉智能电器有限公司 Resistance heater wire structures
TWI679917B (en) * 2018-04-10 2019-12-11 許詔智 Electric heating device
TWI801559B (en) * 2018-04-17 2023-05-11 美商瓦特洛威電子製造公司 All aluminum heater
US11938793B2 (en) 2019-03-14 2024-03-26 Magna Mirrors Of America, Inc. Sealing system for movable window of vehicular rear window assembly
US20230073820A1 (en) * 2020-02-12 2023-03-09 Saint-Gobain Glass France Vehicle pane with integrated temperature sensor
GB202003994D0 (en) 2020-03-19 2020-05-06 Pilkington Group Ltd Laminated glass, electrical isolation measurement system having the same, method of manufacturing the same and use of the same
KR102310383B1 (en) * 2020-04-20 2021-10-12 현대자동차주식회사 Glass plate having heat generating function and manufacturing method of the same
US11912110B2 (en) 2020-06-05 2024-02-27 Magna Mirrors Of America, Inc. Sealing system for movable window of vehicular rear slider window assembly
KR20220104393A (en) * 2021-01-18 2022-07-26 주식회사 불카누스 Plate heating element
EP4306367A1 (en) * 2022-07-12 2024-01-17 Zanini Auto Grup, S.A. Sensor cover for vehicles and method for heating said sensor cover for vehicles
DE102022134064A1 (en) 2022-12-20 2024-06-20 Marquardt Gmbh Translucent surface heating element
DE202022002800U1 (en) 2022-12-20 2023-06-29 Marquardt GmbH Translucent surface heating element

Family Cites Families (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5324965B1 (en) 1971-07-31 1978-07-24
GB1431754A (en) * 1972-05-18 1976-04-14 Tarka Controls Ltd Vehicle window heaters
US3868492A (en) * 1972-05-18 1975-02-25 Tarka Controls Ltd Heated windows in road vehicles
US4808799A (en) * 1987-11-07 1989-02-28 Libbey-Owens-Ford Co. Crack detecting window panel and method of producing same
US4894513A (en) 1988-07-05 1990-01-16 Ppg Industries, Inc. Heatable windshield temperature control
US4902875A (en) * 1988-11-04 1990-02-20 Ppg Industries, Inc. Power discontinuity sensor for a dual feed heatable windshield
JPH06227367A (en) * 1993-02-05 1994-08-16 Asahi Glass Co Ltd Windowpane heater
DE10259110B3 (en) 2002-12-18 2004-07-22 Saint-Gobain Glass Deutschland Gmbh Plate element with heated surface coating e.g. heated window, room heating panel or surface heating element for domestic appliance, with coating divided into sectors for uniform heat distribution
DE102004018109B3 (en) 2004-04-14 2005-06-16 Saint-Gobain Glass Deutschland Gmbh Plate element with conductor structure, e.g. for resistance heating in radiation heating bodies, has multipole plug connector element with non-conducting body permanently connected to plate element, inserted in peripheral/end opening
DE102004050158B3 (en) * 2004-10-15 2006-04-06 Saint-Gobain Sekurit Deutschland Gmbh & Co. Kg Transparent disc with a heatable coating
DE102008018147A1 (en) 2008-04-10 2009-10-15 Saint-Gobain Sekurit Deutschland Gmbh & Co. Kg Transparent disc with a heatable coating and low-resistance conductive structures
DE102008029986B4 (en) 2008-06-24 2017-03-23 Saint-Gobain Sekurit Deutschland Gmbh & Co. Kg Transparent disc with a heatable coating
US8383994B2 (en) * 2008-12-30 2013-02-26 Ppg Industries Ohio, Inc. Transparency having sensors

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