EP1407186A1 - Optical device, particularly a liquid-crystal imaging device, and mirror therefor - Google Patents
Optical device, particularly a liquid-crystal imaging device, and mirror thereforInfo
- Publication number
- EP1407186A1 EP1407186A1 EP02745483A EP02745483A EP1407186A1 EP 1407186 A1 EP1407186 A1 EP 1407186A1 EP 02745483 A EP02745483 A EP 02745483A EP 02745483 A EP02745483 A EP 02745483A EP 1407186 A1 EP1407186 A1 EP 1407186A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- sheet
- light
- lamp
- liquid crystal
- optical device
- 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.)
- Withdrawn
Links
- 239000004973 liquid crystal related substance Substances 0.000 title claims abstract description 75
- 230000003287 optical effect Effects 0.000 title claims abstract description 54
- 238000003384 imaging method Methods 0.000 title abstract description 4
- 229910052751 metal Inorganic materials 0.000 claims description 10
- 239000002184 metal Substances 0.000 claims description 10
- 239000000463 material Substances 0.000 claims description 7
- DMFGNRRURHSENX-UHFFFAOYSA-N beryllium copper Chemical compound [Be].[Cu] DMFGNRRURHSENX-UHFFFAOYSA-N 0.000 claims description 4
- 230000001681 protective effect Effects 0.000 claims description 3
- 239000002966 varnish Substances 0.000 claims description 3
- 230000000903 blocking effect Effects 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 229920003023 plastic Polymers 0.000 description 3
- 239000000853 adhesive Substances 0.000 description 2
- 230000001070 adhesive effect Effects 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- VVQNEPGJFQJSBK-UHFFFAOYSA-N Methyl methacrylate Chemical compound COC(=O)C(C)=C VVQNEPGJFQJSBK-UHFFFAOYSA-N 0.000 description 1
- 229920005372 Plexiglas® Polymers 0.000 description 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 238000004026 adhesive bonding Methods 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000003292 glue Substances 0.000 description 1
- 125000001475 halogen functional group Chemical group 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 230000004297 night vision Effects 0.000 description 1
- 238000002310 reflectometry Methods 0.000 description 1
- 238000004513 sizing Methods 0.000 description 1
- 238000005496 tempering Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
- G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
- G02B6/0013—Means for improving the coupling-in of light from the light source into the light guide
- G02B6/0015—Means for improving the coupling-in of light from the light source into the light guide provided on the surface of the light guide or in the bulk of it
- G02B6/0018—Redirecting means on the surface of the light guide
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
- G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
- G02B6/0013—Means for improving the coupling-in of light from the light source into the light guide
- G02B6/0023—Means for improving the coupling-in of light from the light source into the light guide provided by one optical element, or plurality thereof, placed between the light guide and the light source, or around the light source
- G02B6/0026—Wavelength selective element, sheet or layer, e.g. filter or grating
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
- G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
- G02B6/0013—Means for improving the coupling-in of light from the light source into the light guide
- G02B6/0023—Means for improving the coupling-in of light from the light source into the light guide provided by one optical element, or plurality thereof, placed between the light guide and the light source, or around the light source
- G02B6/0028—Light guide, e.g. taper
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
- G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
- G02B6/0033—Means for improving the coupling-out of light from the light guide
Definitions
- the invention relates to the field of optical devices, in particular liquid crystal imagers, as well as the mirrors associated with these optical devices.
- the preferred field of application of the invention is the field of liquid crystal imagers also called LCD imagers (LCD being the abbreviation for the English terminology "liquid crystal display”).
- LCD liquid crystal display
- Liquid crystal imagers are usually lit from behind the imager, the front of the imager being occupied by the liquid crystal display.
- This lighting is generally produced by often tubular lamps, which lamps are advantageously on the one hand positioned parallel to the liquid crystal screen and on the other hand housed in an optically suitable support which support is called light box.
- the number and size of the lamps varies depending on the size of the liquid crystal display and the uniformity of lighting required for the particular application being considered.
- the invention is particularly applicable to liquid crystal imagers used in aircraft, planes or helicopters, military.
- the liquid crystal imagers of military aircraft have a day lighting stage producing intense and relatively uniform lighting using numerous lamps also called day lamps as well as a night lighting stage producing more light. weak, more uniformly distributed, and needing to be filtered by infrared, in particular to avoid annoying or blinding pilots wearing certain equipment such as night vision goggles, night lighting being carried out using one or more two lamps also called night lamps.
- Day lamps and night lamps generally operate alternately. The day lamps are placed as close as possible to the liquid crystal screen so as to illuminate this screen as directly as possible with maximum intensity. The general direction of the light emitted by the night lamps will therefore be less direct.
- the invention therefore relates to a liquid crystal imager and the mirror associated therewith, this mirror being placed on the path of the light which comes from the night lamps and which will illuminate the liquid crystal screen.
- an optical device is provided. . and more precisely a liquid crystal imager in which on the one hand the day lamps are located just behind the liquid crystal screen and on the other hand the night lamp (s) are located at the bottom of the light box, behind the lamps day, an infrared filter being placed between the day lamps and the night lamps.
- Figure 1 schematically shows a sectional view of a liquid crystal imager according to the first prior art.
- a light box 1 is closed by a liquid crystal screen 5.
- the light box 1 is separated into two compartments by an infrared filter 4.
- Arrows in lines mixed represent light rays from day 2 lamps. Dashed arrows represent light rays from night 3 lamps.
- the first prior art has several drawbacks.
- a drawback of the first prior art relates to the large depth P of the light box 1.
- Another disadvantage of the first prior art lies in the large dimensions of the infrared filter 4 which are of the same order of magnitude as those of the liquid crystal screen 5, which dimensions can for example typically reach a side of about ten centimeters.
- the infrared filter 4 consists of treated glass of small thickness, which makes it relatively fragile, expensive and difficult to cut.
- Another drawback of the first prior art is due to the fact that the efficiency of the day stage is altered by the presence of the infrared filter 4 which is located just behind the day 2 lamps and which does not reflect towards the liquid crystal screen 5 the light received from the day 2 lamps.
- an optical device and more specifically a liquid crystal imager in which on the one hand the day lamps are arranged at the bottom of the light box and on the other hand a night lamp is mounted at the bottom of a separate and filtered conduit so as to illuminate the end of an optical prism which is cut so as to be able to diffuse the light coming from the night lamp uniformly over the entire surface of the liquid crystal screen.
- Figure 2 schematically shows a sectional view of a liquid crystal imager according to the second prior art.
- a light box 1 is closed by a liquid crystal screen 5.
- the light box 1 is closed by a liquid crystal screen 5.
- the rear part of the light box 1 that is to say near the bottom 10 of the light box 1, there are several day 2 lamps.
- the bottom 10 of the light box 1 is reflective so as to be able to reflect towards the liquid crystal screen 5 the light emitted by the day 2 lamps towards the rear of the light box 1.
- a night lamp 3 located at the bottom of a duct 9.
- Arrows in dashed lines represent light rays coming from the day 2 lamps.
- Arrows in dashed lines represent light rays coming from the night lamp 3.
- An optical prism 6 is placed between the liquid crystal screen 5 and the day lamps 2, part of the optical prism 6 being located at the outlet of the conduit 9.
- the shape of the optical prism 6 is such that at least part of the light coming from the night lamp 3 and having passed through the conduit 9 first crosses the face 61 of the optical prism 6, then is reflected by the face 62 of the prism optical 9, then arrives on the face 63 of the prism to be finally diffused towards the liquid crystal screen 5 by a diffuser 8 situated against the face 63.
- the optical prism 6 is cut so as to diffuse the light arriving on its face 63 plain formally over the entire surface of the liquid crystal screen 5 via the diffuser 8.
- a layer 7 of adhesive situated against the face 64 of the optical prism 6 contributes to making this optical prism 6 integral with the light box 1 .
- An infrared filter 4 situated against the face 61 of the optical prism 6 makes it possible to filter the light coming from the night lamp 3 before it arrives on the liquid crystal screen 5.
- the second prior art has several drawbacks.
- One drawback of the second prior art concerns the use of an optical prism 6 which is made of heavy and fragile glass.
- Another drawback of the second prior art lies in the production of the optical prism 6, this production being in fact difficult and costly.
- Another drawback of the second prior art caused by the use of the optical prism 6 for the night stage is the limitation of the performance of the day stage of the optical imager, the optical prism remaining permanently between the crystal screen 5 liquids and daytime lamps 2.
- a large imager is for example an imager having a liquid crystal screen in the form of a square having more than ten centimeters on one side, for example twenty centimeters on one side.
- an optical device and more specifically a liquid crystal imager in which on the one hand the day lamps are arranged at the bottom of the light box and on the other hand one or two night lamps are mounted each on the side of the light box so as to illuminate the edge of a night light guide.
- This night light guide is substantially planar and is structured so as to be able to return perpendicular to one of its faces the light which arrives perpendicular to one and / or the other of its sections.
- This light guide can also be used in an imager according to the invention.
- An example of such a night light guide is shown in FIG. 3.
- FIG. 3 schematically represents a perspective view of an element belonging to a liquid crystal imager according to a third prior art represented in FIG.
- the element being a light guide.
- This light guide can also be used in the context of the invention.
- the light guide is in the form of a substantially planar element which is structured so as to return substantially perpendicularly to one of its faces, for example face 111 ",.. the received light perpendicularly to one and / or the other of its edges 110.
- the path of light is shown here by arrows Stick In order to be able to return the light received perpendicular to one of its edges 110 perpendicularly to its face 111, by diffusion or diffraction, the structure of the light guide is particular.
- the face 111 is striated , it has a set of ridges 112 parallel to each other, instead of having ridges on one of its faces, the light guide may include microprisms obtained by hot compression, for example.
- PM A that is to say of plexiglass (registered trademark)
- the type of light guide used in the imager according to the third prior art or according to inve ntion is for example a "flat collimator” from "Briteview Technologies” (registered trademark) which is described in particular in a document entitled “A1.3: flat collimator: a backlighting assembly utilizing microprisms for high energy efficiency” written by "CY. TAI & H. ZOU ”published in“ SID 94 Applications Digest ”.
- FIG. 4 schematically shows a sectional view of a liquid crystal imager according to a third prior art.
- a light box 1 is closed by a liquid crystal screen 5.
- the bottom 10 of the light box 1 is reflective so as to be able to reflect towards the liquid crystal screen 5 the light emitted by the day 2 lamps towards the rear of the light box 1.
- the light guide 11 described for example in FIG. 3.
- the face 111 of the light guide 11 is arranged parallel to the surface of the liquid crystal screen 5.
- an infrared filter 4 Between each of the lamps 3 and each of the slices 110 of the light guide 11, there is an infrared filter 4. Arrows in mixed lines represent light rays coming from the daytime running lights 2. Arrows in dotted lines represent light rays coming from the night lamp 3. Part of the light emitted by the day 2 lamps crosses the light guide 1 1 for arrive on the LCD screen 5. Part of the light emitted by the night lamps 3 passes through the infrared filter 4, enters the light guide 11 through the edge 1 10 of this guide 11 to exit through the face 111 of this same guide 11, in order to reach the LCD screen 5.
- a disadvantage of the third prior art is that it has a width L of the imager which is too large, due to the successive presence, along the width L, of a night lamp 3, of an infrared filter 4, of a light guide 11, and possibly also an infrared filter 4 and a night lamp 3.
- the problem of the first and second prior art is to have many drawbacks, while the problem of the third prior art is present a major drawback in particular for certain applications such as liquid crystal imagers.
- the object of the invention is to provide an optical device and in particular a liquid crystal imager in which all or part of the drawbacks of the various prior arts are reduced or eliminated.
- the optical device according to the invention is preferably a liquid crystal imager.
- the invention because of its numerous advantages detailed below, can nevertheless be applied to other optical devices than liquid crystal imagers.
- the optical device according to the invention has, over all or part of the various prior arts, the following advantages: firstly it can be housed in a relatively small space in particular at the level of the lateral dimensions (in width), secondly it is relatively light , simple to make and inexpensive, thirdly it is compatible with the presence of two night lamps.
- the invention relates to both an optical device, its preferred field of application which is a liquid crystal imager, as well as a mirror which is the particularly innovative element of said optical device.
- a bent optical device comprising at least one lamp and a conduit guiding at least part of the light coming from the lamp, characterized in that the optical device comprises, at a bent part of the optical device, a mirror constituted by a sheet which is folded so, on the one hand that it can be partially introduced into the conduit, and on the other hand, once introduced and blocked " in the duct, to reflect, in a determined direction, a part of there light coming from the lamp.
- a liquid crystal imager comprising a liquid crystal screen located at the front part of the imager, at least one night lamp, a conduit guiding at least part of the light coming from the night lamp, and a substantially planar night light guide structured so as to return substantially perpendicular to one of its surfaces the light entered by one of its sections, characterized in that the night lamp is located at the rear part of the imager and in that the imager also includes a mirror constituted by a sheet which is folded so, on the one hand that it can be partially introduced into the duct, and on the other hand, once introduced and blocked in the duct, to reflect, in the direction of the edge of the night light guide, part of the light coming from the night lamp.
- a mirror for an optical device characterized in that the mirror is constituted by a sheet which is folded so as to present, a main part, substantially planar, having at least two sides substantially parallel to each other. and comprising at least one reflecting face, a substantially planar end portion, an intermediate portion, substantially planar and having at least two sides substantially parallel to each other, two substantially planar flaps, the two flaps being respectively attached to each of the two parallel sides of the intermediate part and being substantially perpendicular to the intermediate part, the main part being attached by one of its sides substantially parallel to one of the sides of the intermediate part not attached to a flap and by the other of its substantially parallel sides at the extremal part, and in that the angle between the p main part and the intermediate part as well as the angle between the main part and the extremal part are obtuse angles.
- FIG. 1 schematically shows a sectional view of a liquid crystal imager according to a first prior art
- FIG. 2 schematically shows a sectional view of a liquid crystal imager according to a second prior art
- FIG. 3 schematically shows a perspective view of an element belonging to a liquid crystal imager according to a third prior art shown in Figure 4 or according to the invention, said element being a light guide;
- FIG. 4 schematically shows a sectional view of a liquid crystal imager according to a third prior art
- FIG. 5 schematically shows a sectional view of a liquid crystal imager according to the invention
- FIG. 6 schematically shows a perspective view of an element belonging to a liquid crystal imager according to the invention shown in Figure 5, said element being a mirror.
- FIG. 5 schematically represents a sectional view of a liquid crystal imager according to the invention.
- a light box 1 is closed by a liquid crystal screen 5.
- the bottom 10 of the light box 1 is reflective so as to be able to reflect towards the liquid crystal screen 5 the light emitted by the day 2 lamps towards the rear of the light box 1.
- the night light guide 11 described for example in FIG. 3 and indifferently called light guide 11.
- the duct 9 is intended to guide the light or at least one part of the light from the night lamp 3.
- the night lamp 3 could be located in the duct 9 or behind the duct 9, provided that the relative arrangement of the duct 9 and the night lamp 3 allows the duct 9 to guide a portion of the light from the night lamp 3 which is sufficient to illuminate the liquid crystal screen 5 in the envisaged application.
- a second night lamp 3 could also be located on the other side of the light box 1.
- the average direction of propagation of the light emitted by the night lamp 3 is not the same in the duct 9 as in the guide 11, the optical architecture of the night stage is therefore bent between the outlet of the conduit 9 and the edge 110 of the light guide 11 through which the light enters the guide 11.
- the face 111 of the light guide 11 is arranged parallel to the surface of the liquid crystal screen 5.
- a mirror 12 for bending said optical architecture is constituted by a folded sheet comprising several parts including two lateral parts connected by a central part.
- One of the lateral parts is the extreme part 13 which is located in the duct 9 and which advantageously allows the self-centering and the blocking of the sheet in the duct 9, leaving the sheet only with a degree of freedom which is the possibility of sliding in the conduit 9.
- the other lateral part 15 acts as a stop when the extremal part 13 slides in the conduit 9.
- the extremal part 13 slides in the conduit 9 until the extremal part 15 arrives in abutment against the face 111 of the light guide 11.
- the central part 14 of the sheet is reflective at least for part of the light emitted by the night lamp 3 so that the light coming from the night lamp 3 and leaving the duct 9 is at least partially reflected by the central part 14 of the sheet, that is to say of the mirror 12, in the direction of the edge 110 of the light guide 11.
- an infrared filter 4 intended to filter the light coming from the night lamp 3 before this light reaches the light guide 11.
- Arrows in phantom lines represent light rays from day 2 lamps.
- Arrows in dotted lines represent light rays from night lamp 3. Part of the light emitted by day 2 lamps crosses the light guide 11 to arrive on the LCD screen 5.
- the night lamp 3 is advantageously the same as the day 2 lamps.
- the interior of the duct is painted white to reflect the light coming from the night lamp 3.
- the sheet which constitutes the mirror is folded into at least three parts, a central part reflecting the light coming from the lamp and two lateral parts connected together by the central part, the lateral part closest to the lamp being able to slide in the conduit, the side part furthest from the lamp being able to act as a stop when sliding the side part closest to the lamp.
- the mirror is constituted by a sheet which is folded so as to present, a main part, an extremal part, an intermediate part and two flaps.
- the main part is substantially planar, has at least two sides which are substantially parallel to each other and comprises at least one reflecting face.
- the extremal part is substantially flat.
- the intermediate part is substantially planar and has at least two sides that are substantially parallel to each other.
- the two flaps are substantially planar, are respectively attached to each of the two parallel sides of the intermediate part and are substantially perpendicular to the intermediate part.
- the main part is attached by one of its sides substantially parallel to one of the sides of the intermediate part not attached to a flap and by the other of its sides substantially parallel to the extremal part.
- the angle between the main part and the intermediate part as well as the angle between the main part and the extremal part are obtuse angles.
- the main part, the intermediate part, the extremal part, as well as the flaps are substantially rectangular.
- Figure 6 schematically shows a perspective view of such a mirror.
- the mirror is constituted by a folded sheet which comprises several parts, among which the extremal part 15, the main part 14 with its reflecting face 140, the intermediate part 13, and the two flaps 131 and 132. Between the extremal part 15 and the main part 14 is a fold 162. Between the main part 14 and the intermediate part 13 is a fold 161. The two substantially parallel sides of the main part 14 are the two folds 162 and 161.
- the flaps 131 and 132 on the one hand and the intermediate part 13 are respectively folds 164 and 165.
- the two substantially parallel sides of the intermediate part 13 are the two folds 164 and 165.
- the free side of the intermediate part 13 is constituted by one edge 163.
- dashed lines is shown an example of a 9 " -of obfongue duct, the oblong shape being due to the elongated tube shape of the night lamp 3.
- the assembly constituted by the intermediate part 13 and the flaps 131 and 132 can slide inside the duct 9. This sliding movement inside the duct 9 is limited by a stop constituted by the extremal part 15 which will abut against the light guide not shown in FIG. 6 for reasons of clarity.
- the mirror is mainly composed advantageously of three parts, a central reflecting part, two lateral parts which are situated on either side of the central part and which are a sliding part and a part which stops at sliding.
- the reflecting part is constituted by the main part 14 with its reflecting face 140
- the sliding part is constituted by the intermediate part 13 and the two flaps 131 and 132
- the part which stops at sliding consists of the end portion 15.
- both the sheet constituting the mirror is a sheet which is sufficiently thin to be sufficiently elastic and the dimensions of the sheet are sufficiently large with respect to the dimensions of the duct, so that the sheet can both self-center and block itself. in the conduit.
- the thin nature of the sheet allows it to be elastic and gives it a spring effect.
- the thin nature of the sheet has the advantage of taking up little space in the duct and leaving most of the interior volume of the duct free for the propagation of light from the night lamp (s).
- the thinness of the sheet is however limited since the sheet must have minimum rigidity in order to maintain its general shape and minimum solidity. It is the combination of these two properties of elasticity and sizing of the sheet which allow said sheet to be able to self-center and block in the conduit.
- the dimensions of the sheet and more precisely of the sliding part of the sheet relative to the dimensions of the duct are sufficiently small and on the other hand the sheet and more precisely the sliding part of the sheet is sufficiently elastic, so that the sliding part of the sheet can be introduced into the duct and slide in the duct.
- the dimensions of the sheet and more precisely of the sliding part of the sheet with respect to the dimensions of the conduit are sufficiently large and on the other hand the sheet and more precisely the sliding part of the sheet is sufficiently elastic, so that the sliding part of the sheet once introduced into the duct and having slid in the duct until the stop part of the sheet has come into abutment against the light guide can self-center and lock in the position reached.
- the spring effect also allows the absorption of slight variations in the dimensions of the mirror and / or of the conduit, from one mirror and / or from one conduit to the other.
- the assembly and disassembly of the mirror constituted by a sheet is carried out in an extremely simple and rapid manner, they can even be carried out by hand without using a tool; indeed, the only delicate part of the mirror is the reflecting face of the main part, but this face being internal, it is little exposed.
- the assembly and disassembly does not require any adjustment operation, which makes them particularly attractive.
- the sheet which is thin enough to center itself and block in the duct has a thickness of a few tenths of a millimeter.
- the thickness of the sheet is for example three tenths of a millimeter.
- the sheet is preferably a metal sheet.
- the sheet could also be made of stainless steel or metallized plastic, but these two materials have drawbacks.
- Stainless steel offers less good possibilities than metal in terms of quality of reflection because it is less easy to put on layers of reflective coating.
- Metallized plastic has the drawback of being either a little too flexible in thin layers or a little too brittle in thicker layers; metallized plastic also lacks stiffness.
- the material of the sheet is advantageously cuprous.
- the material of the sheet is preferably beryllium copper of formula CuBe 2 which allows the sheet to have a more pronounced spring effect.
- the sheet of beryllium copper sheet is advantageously heat treated by producing an tempering at approximately 320 ° C. for approximately 3 hours and 45 minutes.
- the sheet is a metal sheet which is at least partially tinned so as to better reflect the light of the night lamp.
- Tinning means covering with tin.
- At least the surface 140 is then tinned.
- the sheet is preferably tinned in its entirety.
- Other methods for obtaining the desired quality of reflectivity of the mirror can be envisaged, but it is particularly simple and effective.
- At least the tinned part of the metal sheet is preferably covered with a transparent protective varnish in the light of the lamp, in order to reduce the risks of deterioration of this tinned part.
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- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Planar Illumination Modules (AREA)
- Liquid Crystal (AREA)
Abstract
The invention relates to the field of optical devices, particularly liquid-crystal imaging devices, and the mirrors associated with said optical devices. The inventive optical device is bent and comprises at least one lamp (3) and a conduit (9) which guides at least part of the light from the lamp (3). Moreover, the bent part of the optical device is provided with a mirror (12) comprising a sheet which is folded such that said sheet can: (i) be partially inserted into the conduit (9) and (ii), once inserted and blocked in position in the conduit (9), reflect part of the light from the lamp (3) in a pre-determined direction. In particular, the invention can be used in liquid-crystal imaging devices for military aircraft.
Description
DISPOSITIF OPTIQUE, NOTAMMENT IMAGEUR A CRISTAUX LIQUIDES, OPTICAL DEVICE, ESPECIALLY IMAGING WITH LIQUID CRYSTALS,
ET MIROIR ASSOCIEAND ASSOCIATED MIRROR
L'invention concerne le domaine des dispositifs optiques, notamment les imageurs à cristaux liquides, ainsi que les miroirs associés à ces dispositifs optiques.The invention relates to the field of optical devices, in particular liquid crystal imagers, as well as the mirrors associated with these optical devices.
Le domaine préférentiel d'application de l'invention est le domaine des imageurs à cristaux liquides encore appelés imageurs LCD (LCD étant l'abréviation de la terminologie anglo-saxonne « liquid cristal display »). Les imageurs à cristaux liquides sont généralement éclairés par l'arrière de l'imageur, l'avant de l'imageur étant occupé par l'écran à cristaux liquides. Cet éclairage est généralement réalisé par des lampes souvent tubulaires, lesquelles lampes sont avantageusement d'une part positionnées parallèlement à l'écran à cristaux liquides et d'autre part logées dans un support optiquement adapté lequel support est appelé boîte à lumière. Le nombre et la taille des lampes varient en fonction de la taille de l'écran à cristaux liquides et de l'uniformité d'éclairage requise par l'application particulière envisagée.The preferred field of application of the invention is the field of liquid crystal imagers also called LCD imagers (LCD being the abbreviation for the English terminology "liquid crystal display"). Liquid crystal imagers are usually lit from behind the imager, the front of the imager being occupied by the liquid crystal display. This lighting is generally produced by often tubular lamps, which lamps are advantageously on the one hand positioned parallel to the liquid crystal screen and on the other hand housed in an optically suitable support which support is called light box. The number and size of the lamps varies depending on the size of the liquid crystal display and the uniformity of lighting required for the particular application being considered.
L'invention s'applique particulièrement aux imageurs à cristaux liquides utilisés dans les aéronefs, avions ou hélicoptères, militaires. En effet, les imageurs à cristaux liquides des aéronefs militaires- possèdent un étage d'éclairage jour produisant un éclairage intense et relativement uniforme à l'aide de nombreuses lampes aussi appelées lampes jour ainsi qu'un étage d'éclairage nuit produisant un éclairage plus faible, diffusé plus uniformément, et nécessitant d'être filtré en infrarouge notamment pour éviter de gêner ou d'aveugler les pilotes portant certains équipements comme des lunettes de vision nocturne, l'éclairage nuit étant réalisé à l'aide d'une ou de deux lampes aussi appelées lampes nuit. Les lampes jour et les lampes nuit fonctionnent généralement alternativement. Les lampes jour sont placées le plus près possible de l'écran à cristaux liquides de manière à éclairer cet écran le plus directement possible avec une intensité maximale. La direction générale de la lumière émise par les lampes nuit sera par conséquent moins directe. L'invention concerne alors un imageur à cristaux liquides ainsi que le miroir qui lui est associé, ce miroir étant placé sur le chemin de la lumière qui est issue des lampes nuit et qui va éclairer l'écran à cristaux liquides.
Selon un premier art antérieur, il est prévu un dispositif optique..et plus précisément un imageur à cristaux liquides dans lequel d'une part les lampes jour sont situées juste derrière l'écran à cristaux liquides et d'autre part la ou les lampes nuit sont situées au fond de la boîte à lumière, derrière les lampes jour, un filtre infrarouge étant disposé entre les lampes jour et les lampes nuit.The invention is particularly applicable to liquid crystal imagers used in aircraft, planes or helicopters, military. Indeed, the liquid crystal imagers of military aircraft have a day lighting stage producing intense and relatively uniform lighting using numerous lamps also called day lamps as well as a night lighting stage producing more light. weak, more uniformly distributed, and needing to be filtered by infrared, in particular to avoid annoying or blinding pilots wearing certain equipment such as night vision goggles, night lighting being carried out using one or more two lamps also called night lamps. Day lamps and night lamps generally operate alternately. The day lamps are placed as close as possible to the liquid crystal screen so as to illuminate this screen as directly as possible with maximum intensity. The general direction of the light emitted by the night lamps will therefore be less direct. The invention therefore relates to a liquid crystal imager and the mirror associated therewith, this mirror being placed on the path of the light which comes from the night lamps and which will illuminate the liquid crystal screen. According to a first prior art, an optical device is provided. . and more precisely a liquid crystal imager in which on the one hand the day lamps are located just behind the liquid crystal screen and on the other hand the night lamp (s) are located at the bottom of the light box, behind the lamps day, an infrared filter being placed between the day lamps and the night lamps.
La figure 1 représente schématiquement une vue en coupe d'un imageur à cristaux liquides selon le premier art antérieur. Une boîte 1 à lumière est fermée par un écran 5 à cristaux liquides. La boîte 1 à lumière est séparée en deux compartiments par un filtre infrarouge 4. Dans la partie avant de la boîte 1 à lumière, c'est-à-dire entre l'écran 5 à cristaux liquides et le filtre infrarouge 4 se trouvent plusieurs lampes jour 2. Dans la partie arrière de la boîte 1 à lumière, c'est-à-dire entre le filtre infrarouge 4 et le fond de la boîte 1 à lumière, se trouvent une ou plusieurs lampes nuit 3. Des flèches en traits mixtes représentent des rayons lumineux issus des lampes jour 2. Des flèches en traits pointillés représentent des rayons lumineux issus des lampes nuit 3.Figure 1 schematically shows a sectional view of a liquid crystal imager according to the first prior art. A light box 1 is closed by a liquid crystal screen 5. The light box 1 is separated into two compartments by an infrared filter 4. In the front part of the light box 1, that is to say between the liquid crystal screen 5 and the infrared filter 4 are several daytime lights 2. In the rear part of the light box 1, that is to say between the infrared filter 4 and the bottom of the light box 1, there are one or more night lights 3. Arrows in lines mixed represent light rays from day 2 lamps. Dashed arrows represent light rays from night 3 lamps.
Le premier art antérieur présente plusieurs inconvénients. Un inconvénient du premier art antérieur concerne la profondeur P importante de la boîte 1 à lumière. Un autre inconvénient du premier art antérieur réside dans les dimensions élevées du filtre infrarouge 4 qui sont du même ordre de grandeur que celles de l'écran 5 à cristaux liquides, lesquelles dimensions peuvent par exemple atteindre typiquement une dizaine de centimètres de côté. Or, le filtre infrarouge 4 est constitué en verre traité de faible épaisseur, ce qui le rend relativement fragile, coûteux et délicat à découper. Un autre inconvénient du premier art antérieur est dû au fait que le rendement de l'étage jour est altéré par la présence du filtre infrarouge 4 qui est situé juste derrière les lampes jour 2 et qui ne réfléchit pas vers l'écran 5 à cristaux liquides la lumière reçue en provenance des lampes jour 2. Lorsque l'écran 5 à cristaux liquides est de forme rectangulaire et non pas carrée, un autre inconvénient du premier art antérieur provient de la différence de longueur entre les lampes jour 2 et les lampes nuit 3 se traduisant par deux références composant distinctes, une par type de lampe, ce qui a tendance à augmenter le nombre de références composant pour
l'imageur à cristaux liquides. Un autre inconvénient du premier art antérieur est de créer des halos de lumière autour de la ou des lampes nuit 3.The first prior art has several drawbacks. A drawback of the first prior art relates to the large depth P of the light box 1. Another disadvantage of the first prior art lies in the large dimensions of the infrared filter 4 which are of the same order of magnitude as those of the liquid crystal screen 5, which dimensions can for example typically reach a side of about ten centimeters. However, the infrared filter 4 consists of treated glass of small thickness, which makes it relatively fragile, expensive and difficult to cut. Another drawback of the first prior art is due to the fact that the efficiency of the day stage is altered by the presence of the infrared filter 4 which is located just behind the day 2 lamps and which does not reflect towards the liquid crystal screen 5 the light received from the day 2 lamps. When the liquid crystal screen 5 is rectangular and not square, another disadvantage of the first prior art comes from the difference in length between the day 2 lamps and the night 3 lamps. resulting in two separate component references, one for each type of lamp, which tends to increase the number of component references for the liquid crystal imager. Another drawback of the first prior art is to create halos of light around the night lamp (s) 3.
Selon un deuxième art antérieur, il est prévu un dispositif optique et plus précisément un imageur à cristaux liquides dans lequel d'une part les lampes jour sont disposées au fond de la boîte à lumière et d'autre part une lampe nuit est montée au fond d'un conduit séparé et filtré de manière à éclairer l'extrémité d'un prisme optique qui est taillé de façon à pouvoir diffuser la lumière issue de la lampe nuit uniformément sur toute la surface de l'écran à cristaux liquides. La figure 2 représente schématiquement une vue en coupe d'un imageur à cristaux liquides selon le deuxième art antérieur. Une boîte 1 à lumière est fermée par un écran 5 à cristaux liquides. Dans la partie arrière de la boîte 1 à lumière, c'est-à-dire près du fond 10 de la boîte 1 à lumière, se trouvent plusieurs lampes jour 2. Le fond 10 de la boîte 1 à lumière est réfléchissant de manière à pouvoir réfléchir vers l'écran 5 à cristaux liquides la lumière émise par les lampes jour 2 vers l'arrière de la boîte 1 à lumière. D'un côté de la boîte 1 à lumière, derrière le fond 10 réfléchissant, se trouve une lampe nuit 3 située au fond d'un conduit 9. Des flèches en traits mixtes représentent des rayons lumineux issus des lampes jour 2. Des flèches en traits pointillés représentent des rayons lumineux issus de la lampe nuit 3. Un prisme optique 6 se trouve placé entre l'écran 5 à cristaux liquides et les lampes jour 2, une partie du prisme optique 6 étant située à la sortie du conduit 9. La forme du prisme optique 6 est telle qu'au moins une partie de la lumière étant issue de la lampe nuit 3 et ayant traversée le conduit 9 d'abord traverse la face 61 du prisme optique 6, puis soit réfléchie par la face 62 du prisme optique 9, ensuite arrive sur la face 63 du prisme pour être finalement diffusée en direction de l'écran 5 à cristaux liquides par un diffuseur 8 situé contre la face 63. Le prisme optique 6 est taillé de manière à diffuser la lumière arrivant sur sa face 63 uniformément sur toute la surface de l'écran 5 à cristaux liquides par l'intermédiaire du diffuseur 8. Une couche 7 d'adhésif située contre la face 64 du prisme optique 6 contribue à rendre solidaire ce prisme optique 6 de la boîte 1 à lumière. Un filtre infrarouge 4 situé contre la face 61 du prisme optique 6 permet de filtrer la lumière issue de la lampe nuit 3 avant son arrivée sur l'écran 5 à cristaux liquides.
Le deuxième art antérieur présente plusieurs inconvénients.- Un inconvénient du deuxième art antérieur concerne l'utilisation d'un prisme optique 6 lequel est en verre lourd et fragile. Un autre inconvénient du deuxième art antérieur réside dans la réalisation du prisme optique 6, cette réalisation étant en effet difficile et coûteuse. Un autre inconvénient du deuxième art antérieur entraîné par l'utilisation du prisme optique 6 pour l'étage nuit est la limitation des performances de l'étage jour de l'imageur optique, le prisme optique restant en permanence entre l'écran 5 à cristaux liquides et les lampes jour 2. Un autre inconvénient du deuxième art antérieur résulte de la forme même du prisme optique 6 laquelle empêche la mise en place d'une deuxième lampe nuit 3 de l'autre côté de la boîte 1 à lumière, empêchant ainsi la réalisation d'un imageur de grandes dimensions comportant un écran 5 à cristaux liquides de grandes dimensions également ; en effet, pour être éclairé par diffusion de manière suffisamment uniforme avec une intensité suffisante, ce type d'écran 5 à cristaux liquides de grandes dimensions nécessite souvent l'utilisation de deux lampes nuit 3. Un imageur de grandes dimensions est par exemple un imageur présentant un écran à cristaux liquides sous la forme d'un carré ayant plus d'une dizaine de centimètres de côté, par exemple une vingtaine de centimètres de côté. Selon un troisième art antérieur, il est prévu un dispositif optique et plus précisément un imageur à cristaux liquides dans lequel d'une part les lampes jour sont disposées au fond de la boîte à lumière et d'autre part une ou deux lampes nuit sont montées chacune sur le côté de la boîte à lumière de manière à éclairer la tranche d'un guide de lumière nuit. Ce guide de lumière nuit est sensiblement plan et est structuré de manière à pouvoir renvoyer perpendiculairement à l'une de ses faces la lumière qui arrive perpendiculairement à l'une et/ou l'autre de ses tranches. Ce guide de lumière peut également être utilisé dans un imageur selon l'invention. Un exemple d'un tel guide de lumière nuit est représenté à la figure 3. La figure 3 représente schématiquement une vue en perspective d'un élément appartenant à un imageur à cristaux liquides selon un troisième art antérieur représenté au niveau de la figure 4, ledit élément étant un guide de lumière. Ce guide de lumière peut aussi être utilisé dans le cadre de l'invention. Le guide de lumière se présente sous la forme d'un élément sensiblement plan qui est structuré de manière à renvoyer sensiblement
perpendiculairement à l'une de ses faces, par exemple la face 111", .. la lumière reçue perpendiculairement à l'une et/ou l'autre de ses tranches 110. Le cheminement de la lumière est ici représenté par des flèches en traits pointillés. Afin de pouvoir renvoyer perpendiculairement à sa face 111 , par diffusion ou par diffraction, la lumière reçue perpendiculairement à l'une de ses tranches 110, la structure du guide de lumière est particulière. Ici, par exemple, la face 111 est striée, elle comporte un ensemble de stries 112 parallèles entre elles. Au lieu de comporter des stries sur l'une de ses faces, le guide de lumière peut comporter des microprismes obtenus par compression à chaud par exemple. Le matériau du guide de lumière est par exemple du PM A, c'est-à-dire du plexiglas (marque déposée), car celui-ci présente une très bonne transparence optique. Le type de guide de lumière utilisé dans l'imageur selon le troisième art antérieur ou selon l'invention est par exemple un « flat collimator » de « Briteview Technologies » (marque déposée) lequel est notamment décrit dans un document intitulé « A1.3 : flat collimator : a backlighting assembly utilizing microprisms for high energy efficiency » écrit par « C-Y. TAI & H. ZOU » paru dans « SID 94 Applications Digest ».According to a second prior art, there is provided an optical device and more specifically a liquid crystal imager in which on the one hand the day lamps are arranged at the bottom of the light box and on the other hand a night lamp is mounted at the bottom of a separate and filtered conduit so as to illuminate the end of an optical prism which is cut so as to be able to diffuse the light coming from the night lamp uniformly over the entire surface of the liquid crystal screen. Figure 2 schematically shows a sectional view of a liquid crystal imager according to the second prior art. A light box 1 is closed by a liquid crystal screen 5. In the rear part of the light box 1, that is to say near the bottom 10 of the light box 1, there are several day 2 lamps. The bottom 10 of the light box 1 is reflective so as to be able to reflect towards the liquid crystal screen 5 the light emitted by the day 2 lamps towards the rear of the light box 1. On one side of the light box 1, behind the reflective bottom 10, is a night lamp 3 located at the bottom of a duct 9. Arrows in dashed lines represent light rays coming from the day 2 lamps. Arrows in dashed lines represent light rays coming from the night lamp 3. An optical prism 6 is placed between the liquid crystal screen 5 and the day lamps 2, part of the optical prism 6 being located at the outlet of the conduit 9. The shape of the optical prism 6 is such that at least part of the light coming from the night lamp 3 and having passed through the conduit 9 first crosses the face 61 of the optical prism 6, then is reflected by the face 62 of the prism optical 9, then arrives on the face 63 of the prism to be finally diffused towards the liquid crystal screen 5 by a diffuser 8 situated against the face 63. The optical prism 6 is cut so as to diffuse the light arriving on its face 63 plain formally over the entire surface of the liquid crystal screen 5 via the diffuser 8. A layer 7 of adhesive situated against the face 64 of the optical prism 6 contributes to making this optical prism 6 integral with the light box 1 . An infrared filter 4 situated against the face 61 of the optical prism 6 makes it possible to filter the light coming from the night lamp 3 before it arrives on the liquid crystal screen 5. The second prior art has several drawbacks. One drawback of the second prior art concerns the use of an optical prism 6 which is made of heavy and fragile glass. Another drawback of the second prior art lies in the production of the optical prism 6, this production being in fact difficult and costly. Another drawback of the second prior art caused by the use of the optical prism 6 for the night stage is the limitation of the performance of the day stage of the optical imager, the optical prism remaining permanently between the crystal screen 5 liquids and daytime lamps 2. Another disadvantage of the second prior art results from the very shape of the optical prism 6 which prevents the installation of a second night lamp 3 on the other side of the light box 1, thus preventing producing a large-sized imager comprising a large-size liquid crystal screen 5 also; in fact, to be lit by diffusion in a sufficiently uniform manner with sufficient intensity, this type of large liquid crystal screen 5 often requires the use of two night lamps 3. A large imager is for example an imager having a liquid crystal screen in the form of a square having more than ten centimeters on one side, for example twenty centimeters on one side. According to a third prior art, there is provided an optical device and more specifically a liquid crystal imager in which on the one hand the day lamps are arranged at the bottom of the light box and on the other hand one or two night lamps are mounted each on the side of the light box so as to illuminate the edge of a night light guide. This night light guide is substantially planar and is structured so as to be able to return perpendicular to one of its faces the light which arrives perpendicular to one and / or the other of its sections. This light guide can also be used in an imager according to the invention. An example of such a night light guide is shown in FIG. 3. FIG. 3 schematically represents a perspective view of an element belonging to a liquid crystal imager according to a third prior art represented in FIG. 4, said element being a light guide. This light guide can also be used in the context of the invention. The light guide is in the form of a substantially planar element which is structured so as to return substantially perpendicularly to one of its faces, for example face 111 ",.. the received light perpendicularly to one and / or the other of its edges 110. The path of light is shown here by arrows Stick In order to be able to return the light received perpendicular to one of its edges 110 perpendicularly to its face 111, by diffusion or diffraction, the structure of the light guide is particular. Here, for example, the face 111 is striated , it has a set of ridges 112 parallel to each other, instead of having ridges on one of its faces, the light guide may include microprisms obtained by hot compression, for example. example of PM A, that is to say of plexiglass (registered trademark), because it has very good optical transparency The type of light guide used in the imager according to the third prior art or according to inve ntion is for example a "flat collimator" from "Briteview Technologies" (registered trademark) which is described in particular in a document entitled "A1.3: flat collimator: a backlighting assembly utilizing microprisms for high energy efficiency" written by "CY. TAI & H. ZOU ”published in“ SID 94 Applications Digest ”.
La figure 4 représente schématiquement une vue en coupe d'un imageur à cristaux liquides selon un troisième art antérieur. Une boîte 1 à lumière est fermée par un écran 5 à cristaux liquides. Dans la partie arrière de la boîte 1 à lumière, c'est-à-dire près du fond 10 de la boîte 1 à lumière, se trouvent plusieurs lampes jour 2. Le fond 10 de la boîte 1 à lumière est réfléchissant de manière à pouvoir réfléchir vers l'écran 5 à cristaux liquides la lumière émise par les lampes jour 2 vers l'arrière de la boîte 1 à lumière. Entre l'écran 5 à cristaux liquides et les lampes jour 2 se trouve le guide 11 de lumière décrit par exemple à la figure 3. De chaque côté de la boîte 1 à lumière, se trouve une lampe nuit 3 disposée face à l'une des tranches 110 du guide 11 de lumière. La face 111 du guide 11 de lumière est disposée parallèlement à la surface de l'écran 5 à cristaux liquides. Entre chacune des lampes 3 et chacune des tranches 110 du guide 1 1 de lumière, se trouve un filtre infrarouge 4. Des flèches en traits mixtes représentent des rayons lumineux issus des lampes jour 2. Des flèches en traits pointillés représentent des rayons lumineux issus de la lampe nuit 3. Une partie de la lumière émise par les lampes jour 2 traverse le guide 1 1 de lumière pour
arriver sur l'écran 5 à cristaux liquides. Une partie de la lumière émise par les lampes nuit 3 traverse le filtre infrarouge 4, rentre dans le guide 11 de lumière par la tranche 1 10 de ce guide 11 pour ressortir par la face 111 de ce même guide 11 , afin d'arriver sur l'écran 5 à cristaux liquides. Un inconvénient du troisième art antérieur est de présenter une largeur L de l'imageur qui est trop importante, due à la présence successive, le long de la largeur L, d'une lampe nuit 3, d'un filtre infrarouge 4, d'un guide 11 de lumière, et éventuellement encore d'un filtre infrarouge 4 et d'une lampe nuit 3. Le problème des premier et deuxième arts antérieurs est de présenter de nombreux d'inconvénients, tandis que le problème du troisième art antérieur est de présenter un inconvénient majeur notamment pour certaines applications comme les imageurs à cristaux liquides.Figure 4 schematically shows a sectional view of a liquid crystal imager according to a third prior art. A light box 1 is closed by a liquid crystal screen 5. In the rear part of the light box 1, that is to say near the bottom 10 of the light box 1, there are several day 2 lamps. The bottom 10 of the light box 1 is reflective so as to be able to reflect towards the liquid crystal screen 5 the light emitted by the day 2 lamps towards the rear of the light box 1. Between the liquid crystal screen 5 and the day lamps 2 is the light guide 11 described for example in FIG. 3. On each side of the light box 1, there is a night lamp 3 arranged facing one slices 110 of the light guide 11. The face 111 of the light guide 11 is arranged parallel to the surface of the liquid crystal screen 5. Between each of the lamps 3 and each of the slices 110 of the light guide 11, there is an infrared filter 4. Arrows in mixed lines represent light rays coming from the daytime running lights 2. Arrows in dotted lines represent light rays coming from the night lamp 3. Part of the light emitted by the day 2 lamps crosses the light guide 1 1 for arrive on the LCD screen 5. Part of the light emitted by the night lamps 3 passes through the infrared filter 4, enters the light guide 11 through the edge 1 10 of this guide 11 to exit through the face 111 of this same guide 11, in order to reach the LCD screen 5. A disadvantage of the third prior art is that it has a width L of the imager which is too large, due to the successive presence, along the width L, of a night lamp 3, of an infrared filter 4, of a light guide 11, and possibly also an infrared filter 4 and a night lamp 3. The problem of the first and second prior art is to have many drawbacks, while the problem of the third prior art is present a major drawback in particular for certain applications such as liquid crystal imagers.
Le but de l'invention est de proposer un dispositif optique et notamment un imageur à cristaux liquides dans lequel tout ou partie des inconvénients des différents arts antérieurs sont diminués ou supprimés. Le dispositif optique selon l'invention est de préférence un imageur à cristaux liquides. L'invention, en raison de ses nombreux avantages détaillés ci- après, peut néanmoins s'appliquer à d'autres dispositifs optiques que les imageurs à cristaux liquides. Le dispositif optique selon l'invention possède, sur tout ou partie des différents arts antérieurs, les avantages suivants : premièrement il peut se loger dans un espace relativement restreint notamment au niveau de l'encombrement latéral (en largeur), deuxièmement il est relativement léger, simple à réaliser et peu coûteux, troisièmement il est compatible avec la présence de deux lampes nuit. L'invention concerne à la fois un dispositif optique, son domaine d'application préférentiel qui est un imageur à cristaux liquides, ainsi qu'un miroir qui est l'élément particulièrement innovant dudit dispositif optique.The object of the invention is to provide an optical device and in particular a liquid crystal imager in which all or part of the drawbacks of the various prior arts are reduced or eliminated. The optical device according to the invention is preferably a liquid crystal imager. The invention, because of its numerous advantages detailed below, can nevertheless be applied to other optical devices than liquid crystal imagers. The optical device according to the invention has, over all or part of the various prior arts, the following advantages: firstly it can be housed in a relatively small space in particular at the level of the lateral dimensions (in width), secondly it is relatively light , simple to make and inexpensive, thirdly it is compatible with the presence of two night lamps. The invention relates to both an optical device, its preferred field of application which is a liquid crystal imager, as well as a mirror which is the particularly innovative element of said optical device.
Selon l'invention, il est prévu un dispositif optique coudé comportant au moins une lampe et un conduit guidant au moins une partie de la lumière issue de la lampe, caractérisé en ce que le dispositif optique comporte, au niveau d'une partie coudée du dispositif optique, un miroir constitué par une feuille qui est pliée de manière, d'une part à pouvoir être partiellement introduite dans le conduit, et d'autre part, une fois introduite et
bloquée "dans le conduit, à réfléchir, dans une direction déterminée, une partie de là lumière issue de la lampe.According to the invention, there is provided a bent optical device comprising at least one lamp and a conduit guiding at least part of the light coming from the lamp, characterized in that the optical device comprises, at a bent part of the optical device, a mirror constituted by a sheet which is folded so, on the one hand that it can be partially introduced into the conduit, and on the other hand, once introduced and blocked " in the duct, to reflect, in a determined direction, a part of there light coming from the lamp.
Selon l'invention, il est aussi prévu un imageur à cristaux liquides comportant un écran à cristaux liquides situé au niveau de la partie avant de l'imageur, au moins une lampe nuit, un conduit guidant au moins une partie de la lumière issue de la lampe nuit, et un guide de lumière nuit sensiblement plan et structuré de manière à renvoyer sensiblement perpendiculairement à l'une de ses surfaces la lumière entrée par l'une de ses tranches, caractérisé en ce que la lampe nuit est située au niveau de la partie arrière de l'imageur et en ce que l'imageur comporte aussi un miroir constitué par une feuille qui est pliée de manière, d'une part à pouvoir être partiellement introduite dans le conduit, et d'autre part, une fois introduite et bloquée dans le conduit, à réfléchir, en direction de la tranche du guide de lumière nuit, une partie de la lumière issue de la lampe nuit. Selon l'invention, il est également prévu un miroir pour dispositif optique, caractérisé en ce que le miroir est constitué par une feuille qui est pliée de manière à présenter, une partie principale, sensiblement plane, présentant au moins deux côtés sensiblement parallèles entre eux et comprenant au moins une face réfléchissante, une partie extrémale sensiblement plane, une partie intermédiaire, sensiblement plane et présentant au moins deux côtés sensiblement parallèles entre eux, deux rabats sensiblement plans, les deux rabats étant respectivement rattachés à chacun des deux côtés parallèles de la partie intermédiaire et étant sensiblement perpendiculaires à la partie intermédiaire, la partie principale étant rattachée par l'un de ses côtés sensiblement parallèles à l'un des côtés de la partie intermédiaire non rattachés à un rabat et par l'autre de ses côtés sensiblement parallèles à la partie extrémale, et en ce que l'angle entre la partie principale et la partie intermédiaire ainsi que l'angle entre la partie principale et la partie extrémale sont des angles obtus.According to the invention, there is also provided a liquid crystal imager comprising a liquid crystal screen located at the front part of the imager, at least one night lamp, a conduit guiding at least part of the light coming from the night lamp, and a substantially planar night light guide structured so as to return substantially perpendicular to one of its surfaces the light entered by one of its sections, characterized in that the night lamp is located at the rear part of the imager and in that the imager also includes a mirror constituted by a sheet which is folded so, on the one hand that it can be partially introduced into the duct, and on the other hand, once introduced and blocked in the duct, to reflect, in the direction of the edge of the night light guide, part of the light coming from the night lamp. According to the invention, there is also provided a mirror for an optical device, characterized in that the mirror is constituted by a sheet which is folded so as to present, a main part, substantially planar, having at least two sides substantially parallel to each other. and comprising at least one reflecting face, a substantially planar end portion, an intermediate portion, substantially planar and having at least two sides substantially parallel to each other, two substantially planar flaps, the two flaps being respectively attached to each of the two parallel sides of the intermediate part and being substantially perpendicular to the intermediate part, the main part being attached by one of its sides substantially parallel to one of the sides of the intermediate part not attached to a flap and by the other of its substantially parallel sides at the extremal part, and in that the angle between the p main part and the intermediate part as well as the angle between the main part and the extremal part are obtuse angles.
L'invention sera mieux comprise et d'autres particularités et avantages apparaîtront à l'aide de la description ci-après et des dessins joints, donnés à titre d'exemples, où :The invention will be better understood and other features and advantages will become apparent from the following description and the attached drawings, given by way of examples, in which:
- la figure 1 représente schématiquement une vue en coupe d'un imageur à cristaux liquides selon un premier art antérieur ;
- la figure 2 représente schématiquement une vue en coupe d'un imageur à cristaux liquides selon un deuxième art antérieur ;- Figure 1 schematically shows a sectional view of a liquid crystal imager according to a first prior art; - Figure 2 schematically shows a sectional view of a liquid crystal imager according to a second prior art;
- la figure 3 représente schématiquement une vue en perspective d'un élément appartenant à un imageur à cristaux liquides selon un troisième art antérieur représenté au niveau de la figure 4 ou bien selon l'invention, ledit élément étant un guide de lumière ;- Figure 3 schematically shows a perspective view of an element belonging to a liquid crystal imager according to a third prior art shown in Figure 4 or according to the invention, said element being a light guide;
- la figure 4 représente schématiquement une vue en coupe d'un imageur à cristaux liquides selon un troisième art antérieur ;- Figure 4 schematically shows a sectional view of a liquid crystal imager according to a third prior art;
- la figure 5 représente schématiquement une vue en coupe d'un imageur à cristaux liquides selon l'invention ;- Figure 5 schematically shows a sectional view of a liquid crystal imager according to the invention;
- la figure 6 représente schématiquement une vue en perspective d'un élément appartenant à un imageur à cristaux liquides selon l'invention représenté au niveau de la figure 5, ledit élément étant un miroir.- Figure 6 schematically shows a perspective view of an element belonging to a liquid crystal imager according to the invention shown in Figure 5, said element being a mirror.
La figure 5 représente schématiquement une vue en coupe d'un imageur à cristaux liquides selon l'invention. Une boîte 1 à lumière est fermée par un écran 5 à cristaux liquides. Dans la partie arrière de la boîte 1 à lumière, c'est-à-dire près du fond 10 de la boîte 1 à lumière, se trouvent plusieurs lampes jour 2 lesquelles sont toutes parallèles entre elles. Le fond 10 de la boîte 1 à lumière est réfléchissant de manière à pouvoir réfléchir vers l'écran 5 à cristaux liquides la lumière émise par les lampes jour 2 vers l'arrière de la boîte 1 à lumière. Entre l'écran 5 à cristaux liquides et les lampes jour 2 se trouve le guide 11 de lumière nuit décrit par exemple à la figure 3 et indifféremment appelé guide 11 de lumière. D'un côté de la boîte 1 à lumière, dans la partie arrière de la boîte 1 à lumière, se trouve une lampe nuit 3 située au fond d'un conduit 9. Le conduit 9 est destiné à guider la lumière ou au moins une partie de la lumière issue de la lampe nuit 3. La lampe nuit 3, pourrait être située dans le conduit 9 ou derrière le conduit 9, à condition que la disposition relative du conduit 9 et de la lampe nuit 3 permette au conduit 9 de guider une partie de la lumière issue de la lampe nuit 3 qui soit suffisante pour éclairer l'écran 5 à cristaux liquides dans l'application envisagée. Une deuxième lampe nuit 3 pourrait aussi se trouver de l'autre côté de la boîte 1 à lumière. La direction moyenne de propagation de la lumière émise par la lampe nuit 3 n'est pas la même dans le conduit 9 que dans le guide 11 , l'architecture optique de l'étage nuit est donc coudé
entre la sortie du conduit 9 et la tranche 110 du guide 11 de lumière par laquelle tranche la lumière rentre dans le guide 11. La face 111 du guide 11 de lumière est disposée parallèlement à la surface de l'écran 5 à cristaux liquides. Au niveau du passage coudé de l'architecture optique de l'étage nuit, se trouve un miroir 12 permettant de couder ladite architecture optique. Le miroir 12 est constitué par une feuille pliée comportant plusieurs parties parmi lesquelles deux parties latérales reliées par une partie centrale. L'une des parties latérales est la partie extrémale 13 qui est située dans le conduit 9 et qui permet avantageusement l'autocentrage et le blocage de la feuille dans le conduit 9, ne laissant à la feuille qu'un degré de liberté qui est la possibilité de coulisser dans le conduit 9. L'autre partie latérale 15 fait office de butée lors du coulissement de la partie extrémale 13 dans le conduit 9. La partie extrémale 13 coulisse dans le conduit 9 jusqu'à ce que la partie extrémale 15 arrive en butée contre la face 111 du guide 11 de lumière. La partie centrale 14 de la feuille est réfléchissante au moins pour une partie de la lumière émise par la lampe nuit 3 de manière à ce que la lumière issue de la lampe nuit 3 et sortie du conduit 9 soit au moins partiellement réfléchie par la partie centrale 14 de la feuille, c'est-à-dire du miroir 12, en direction de la tranche 110 du guide 11 de lumière. Dans le conduit 9 ou à l'extrémité du conduit 9 se trouve un filtre infrarouge 4 destiné à filtrer la lumière issue de la lampe nuit 3 avant que cette lumière n'atteigne le guide 11 de lumière. Des flèches en traits mixtes représentent des rayons lumineux issus des lampes jour 2. Des flèches en traits pointillés représentent des rayons lumineux issus de la lampe nuit 3. Une partie de la lumière émise par les lampes jour 2 traverse le guide 11 de lumière pour arriver sur l'écran 5 à cristaux liquides. Une partie de la lumière émise par les lampes nuit 3 traverse le filtre infrarouge 4, parcourt le conduit 9 en étant éventuellement réfléchie sur les parois de ce conduit 9, est réfléchie par la partie centrale 14 du miroir 12, rentre dans le guide 11 de lumière par la tranche 1 10 de ce guide 1 1 pour ressortir par la face 111 de ce même guide 11 , afin d'arriver sur l'écran 5 à cristaux liquides. Derrière les lampes jour 2, comme derrière la lampe nuit 3, il y a au moins un capteur 20 chargé de contrôler l'intensité des lampes. La lampe nuit 3 est avantageusement la même que les lampes jour 2. De préférence, l'intérieur du conduit est peint en blanc pour réfléchir la lumière issue de la lampe nuit 3.
De préférence la feuille qui constitue le miroir est pliée en au moins trois parties, une partie centrale réfléchissant la lumière issue de la lampe et deux parties latérales reliées entre elles par la partie centrale, la partie latérale la plus proche de la lampe pouvant coulisser dans le conduit, la partie latérale la plus loin de la lampe pouvant faire office de butée lors du coulissement de la partie latérale la plus proche de la lampe.FIG. 5 schematically represents a sectional view of a liquid crystal imager according to the invention. A light box 1 is closed by a liquid crystal screen 5. In the rear part of the light box 1, that is to say near the bottom 10 of the light box 1, there are several day 2 lamps which are all parallel to each other. The bottom 10 of the light box 1 is reflective so as to be able to reflect towards the liquid crystal screen 5 the light emitted by the day 2 lamps towards the rear of the light box 1. Between the liquid crystal screen 5 and the day lamps 2 is the night light guide 11 described for example in FIG. 3 and indifferently called light guide 11. On one side of the light box 1, in the rear part of the light box 1, is a night lamp 3 located at the bottom of a duct 9. The duct 9 is intended to guide the light or at least one part of the light from the night lamp 3. The night lamp 3 could be located in the duct 9 or behind the duct 9, provided that the relative arrangement of the duct 9 and the night lamp 3 allows the duct 9 to guide a portion of the light from the night lamp 3 which is sufficient to illuminate the liquid crystal screen 5 in the envisaged application. A second night lamp 3 could also be located on the other side of the light box 1. The average direction of propagation of the light emitted by the night lamp 3 is not the same in the duct 9 as in the guide 11, the optical architecture of the night stage is therefore bent between the outlet of the conduit 9 and the edge 110 of the light guide 11 through which the light enters the guide 11. The face 111 of the light guide 11 is arranged parallel to the surface of the liquid crystal screen 5. At the bent passage of the optical architecture of the night floor, there is a mirror 12 for bending said optical architecture. The mirror 12 is constituted by a folded sheet comprising several parts including two lateral parts connected by a central part. One of the lateral parts is the extreme part 13 which is located in the duct 9 and which advantageously allows the self-centering and the blocking of the sheet in the duct 9, leaving the sheet only with a degree of freedom which is the possibility of sliding in the conduit 9. The other lateral part 15 acts as a stop when the extremal part 13 slides in the conduit 9. The extremal part 13 slides in the conduit 9 until the extremal part 15 arrives in abutment against the face 111 of the light guide 11. The central part 14 of the sheet is reflective at least for part of the light emitted by the night lamp 3 so that the light coming from the night lamp 3 and leaving the duct 9 is at least partially reflected by the central part 14 of the sheet, that is to say of the mirror 12, in the direction of the edge 110 of the light guide 11. In the duct 9 or at the end of the duct 9 there is an infrared filter 4 intended to filter the light coming from the night lamp 3 before this light reaches the light guide 11. Arrows in phantom lines represent light rays from day 2 lamps. Arrows in dotted lines represent light rays from night lamp 3. Part of the light emitted by day 2 lamps crosses the light guide 11 to arrive on the LCD screen 5. Part of the light emitted by the night lamps 3 passes through the infrared filter 4, travels through the conduit 9, possibly being reflected on the walls of this conduit 9, is reflected by the central part 14 of the mirror 12, enters the guide 11 of light through the edge 1 10 of this guide 1 1 to emerge through the face 111 of this same guide 11, in order to arrive on the screen 5 with liquid crystals. Behind the day 2 lamps, as behind the night 3 lamp, there is at least one sensor 20 responsible for monitoring the intensity of the lamps. The night lamp 3 is advantageously the same as the day 2 lamps. Preferably, the interior of the duct is painted white to reflect the light coming from the night lamp 3. Preferably the sheet which constitutes the mirror is folded into at least three parts, a central part reflecting the light coming from the lamp and two lateral parts connected together by the central part, the lateral part closest to the lamp being able to slide in the conduit, the side part furthest from the lamp being able to act as a stop when sliding the side part closest to the lamp.
D'une manière préférentielle, le miroir est constitué par une feuille qui est pliée de manière à présenter, une partie principale, une partie extrémale, une partie intermédiaire et deux rabats. La partie principale est sensiblement plane, présente au moins deux côtés sensiblement parallèles entre eux et comprend au moins une face réfléchissante. La partie extrémale est sensiblement plane. La partie intermédiaire est sensiblement plane et présente au moins deux côtés sensiblement parallèles entre eux. Les deux rabats sont sensiblement plans, sont respectivement rattachés à chacun des deux côtés parallèles de la partie intermédiaire et sont sensiblement perpendiculaires à la partie intermédiaire. De plus, la partie principale est rattachée par l'un de ses côtés sensiblement parallèles à l'un des côtés de la partie intermédiaire non rattachés à un rabat et par l'autre de ses côtés sensiblement parallèles à la partie extrémale. Par ailleurs, l'angle entre la partie principale et la partie intermédiaire ainsi que l'angle entre la partie principale et la partie extrémale sont des angles obtus. De préférence, la partie principale, la partie intermédiaire, la partie extrémale, ainsi que les rabats, sont sensiblement rectangulaires. La figure 6 représente schématiquement une vue en perspective d'un tel miroir. Sur la figure 6, le miroir est constitué par une feuille pliée qui comporte plusieurs parties, parmi lesquelles la partie extrémale 15, la partie principale 14 avec sa face réfléchissante 140, la partie intermédiaire 13, et les deux rabats 131 et 132. Entre la partie extrémale 15 et la partie principale 14 se trouve une pliure 162. Entre la partie principale 14 et la partie intermédiaire 13 se trouve une pliure 161. Les deux côtés sensiblement parallèles de la partie principale 14 sont les deux pliures 162 et 161. Entre les rabats 131 et 132 d'une part et la partie intermédiaire 13 se trouvent respectivement des pliures 164 et 165. Les deux côtés sensiblement parallèles de la partie intermédiaire 13 sont les deux pliures 164 et 165. Le côté libre de la partie intermédiaire 13 est constituée par une
arête 163. En traits pointillés est représenté un exemple de conduit 9" -de forme obfongue, la forme oblongue étant due à la forme en tube allongé de la lampe nuit 3. L'ensemble constitué par la partie intermédiaire 13 et les rabats 131 et 132 peut coulisser à l'intérieur du conduit 9. Ce mouvement de coulissement à l'intérieur du conduit 9 est limitée par une butée constituée par la partie extrémale 15 qui va venir en butée contre le guide de lumière non représenté sur la figure 6 pour des raisons de clarté.Preferably, the mirror is constituted by a sheet which is folded so as to present, a main part, an extremal part, an intermediate part and two flaps. The main part is substantially planar, has at least two sides which are substantially parallel to each other and comprises at least one reflecting face. The extremal part is substantially flat. The intermediate part is substantially planar and has at least two sides that are substantially parallel to each other. The two flaps are substantially planar, are respectively attached to each of the two parallel sides of the intermediate part and are substantially perpendicular to the intermediate part. In addition, the main part is attached by one of its sides substantially parallel to one of the sides of the intermediate part not attached to a flap and by the other of its sides substantially parallel to the extremal part. Furthermore, the angle between the main part and the intermediate part as well as the angle between the main part and the extremal part are obtuse angles. Preferably, the main part, the intermediate part, the extremal part, as well as the flaps, are substantially rectangular. Figure 6 schematically shows a perspective view of such a mirror. In FIG. 6, the mirror is constituted by a folded sheet which comprises several parts, among which the extremal part 15, the main part 14 with its reflecting face 140, the intermediate part 13, and the two flaps 131 and 132. Between the extremal part 15 and the main part 14 is a fold 162. Between the main part 14 and the intermediate part 13 is a fold 161. The two substantially parallel sides of the main part 14 are the two folds 162 and 161. Between the flaps 131 and 132 on the one hand and the intermediate part 13 are respectively folds 164 and 165. The two substantially parallel sides of the intermediate part 13 are the two folds 164 and 165. The free side of the intermediate part 13 is constituted by one edge 163. In dashed lines is shown an example of a 9 " -of obfongue duct, the oblong shape being due to the elongated tube shape of the night lamp 3. The assembly constituted by the intermediate part 13 and the flaps 131 and 132 can slide inside the duct 9. This sliding movement inside the duct 9 is limited by a stop constituted by the extremal part 15 which will abut against the light guide not shown in FIG. 6 for reasons of clarity.
Le miroir est principalement composé avantageusement de trois parties, une partie réfléchissante centrale, deux parties latérales qui sont situées de part et d'autre de la partie centrale et qui sont une partie coulissante et une partie butée au coulissement.The mirror is mainly composed advantageously of three parts, a central reflecting part, two lateral parts which are situated on either side of the central part and which are a sliding part and a part which stops at sliding.
Sur la figure 6, représentant un exemple préférentiel de miroir, la partie réfléchissante est constituée par la partie principale 14 avec sa face réfléchissante 140, la partie coulissante est constituée par la partie intermédiaire 13 et les deux rabats 131 et 132, la partie butée au coulissement est constituée par la partie extrémale 15.In FIG. 6, representing a preferred example of a mirror, the reflecting part is constituted by the main part 14 with its reflecting face 140, the sliding part is constituted by the intermediate part 13 and the two flaps 131 and 132, the part which stops at sliding consists of the end portion 15.
De préférence, à la fois la feuille constituant le miroir est une tôle suffisamment mince pour être suffisamment élastique et les dimensions de la feuille sont suffisamment grandes par rapport aux dimensions du conduit, pour que la feuille puisse à la fois s'autocentrer et se bloquer dans le conduit. Le caractère mince de la tôle permet à celle-ci d'être élastique et lui confère un effet ressort. Le caractère mince de la tôle a en plus l'avantage de prendre peu de place dans le conduit et de laisser l'essentiel du volume intérieur du conduit libre pour la propagation de la lumière issue de la ou des lampes nuit. Le caractère mince de la tôle est toutefois limité car la feuille doit posséder une rigidité minimum afin de conserver sa forme générale et une solidité minimale. C'est la conjugaison de ces deux propriétés d'élasticité et de dimensionnement de la feuille qui permettent à ladite feuille de pouvoir s'autocentrer et se bloquer dans le conduit. En effet, d'abord, d'une part les dimensions de la feuille et plus précisément de la partie coulissante de la feuille par rapport aux dimensions du conduit sont suffisamment petites et d'autre part la feuille et plus précisément la partie coulissante de la feuille est suffisamment élastique, pour que la partie coulissante de la feuille puisse être introduite dans le conduit et coulisser dans le conduit. Ensuite, d'une part les dimensions de la feuille et plus
précisément de la partie coulissante de la feuille par rapport aux dimensFoxis du conduit sont suffisamment grandes et d'autre part la feuille et plus précisément la partie coulissante de la feuille est suffisamment élastique, pour que la partie coulissante de la feuille une fois introduite dans le conduit et ayant coulissée dans le conduit jusqu'à ce que la partie butée de la feuille soit arrivée en butée contre le guide de lumière puisse s'autocentrer et se bloquer dans la position atteinte. L'effet ressort permet également l'absorption de légères variations de dimensions du miroir et/ou du conduit, d'un miroir et/ou d'un conduit à l'autre. Le montage et le démontage du miroir constitué par une feuille s'effectuent de manière extrêmement simple et rapide, ils peuvent même s'effectuer à la main sans l'aide d'outil ; en effet, la seule partie délicalte du miroir est la face réfléchissante de la partie principale, mais cette face étant interne, elle est peu exposée. Le montage et le démontage ne nécessitent pas d'opération de réglage, ce qui les rend particulièrement attrayants.Preferably, both the sheet constituting the mirror is a sheet which is sufficiently thin to be sufficiently elastic and the dimensions of the sheet are sufficiently large with respect to the dimensions of the duct, so that the sheet can both self-center and block itself. in the conduit. The thin nature of the sheet allows it to be elastic and gives it a spring effect. The thin nature of the sheet has the advantage of taking up little space in the duct and leaving most of the interior volume of the duct free for the propagation of light from the night lamp (s). The thinness of the sheet is however limited since the sheet must have minimum rigidity in order to maintain its general shape and minimum solidity. It is the combination of these two properties of elasticity and sizing of the sheet which allow said sheet to be able to self-center and block in the conduit. Indeed, firstly, on the one hand the dimensions of the sheet and more precisely of the sliding part of the sheet relative to the dimensions of the duct are sufficiently small and on the other hand the sheet and more precisely the sliding part of the sheet is sufficiently elastic, so that the sliding part of the sheet can be introduced into the duct and slide in the duct. Then, on the one hand the dimensions of the sheet and more precisely of the sliding part of the sheet with respect to the dimensions of the conduit are sufficiently large and on the other hand the sheet and more precisely the sliding part of the sheet is sufficiently elastic, so that the sliding part of the sheet once introduced into the duct and having slid in the duct until the stop part of the sheet has come into abutment against the light guide can self-center and lock in the position reached. The spring effect also allows the absorption of slight variations in the dimensions of the mirror and / or of the conduit, from one mirror and / or from one conduit to the other. The assembly and disassembly of the mirror constituted by a sheet is carried out in an extremely simple and rapid manner, they can even be carried out by hand without using a tool; indeed, the only delicate part of the mirror is the reflecting face of the main part, but this face being internal, it is little exposed. The assembly and disassembly does not require any adjustment operation, which makes them particularly attractive.
Sur la figure 6, tout ce qui précède est rendu possible par un choix judicieux des dimensions ainsi que de l'élasticité de la partie intermédiaire 13 et des rabats 131 et 132. Lesdites dimensions sont avantageusement sensiblement identiques à celles de l'intérieur du conduit, l'introduction de la partie coulissante de la feuille dans le conduit, puis son autocentrage et son blocage étant réalisés grâce à ladite élasticité. C'est en particulier l'élasticité des rabats qui en s'écartant l'un de l'autre peuvent centrer et bloquer dans le conduit la partie coulissante de la feuille, c'est-à-dire l'ensemble constitué par la partie intermédiaire et les rabats, c'est pour cela que l'on parle d'autocentrage ; pour permettre cet autocentrage et ce blocage dans le conduit, la dimension des rabats est légèrement supérieure à la dimension correspondante du conduit. La largeur des rabats est donc légèrement supérieure à la largeur du conduit.In FIG. 6, all of the above is made possible by a judicious choice of the dimensions as well as the elasticity of the intermediate part 13 and of the flaps 131 and 132. Said dimensions are advantageously substantially identical to those of the interior of the duct. , the introduction of the sliding part of the sheet into the duct, then its self-centering and its blocking being achieved thanks to said elasticity. It is in particular the elasticity of the flaps which, deviating from one another, can center and block in the duct the sliding part of the sheet, that is to say the assembly formed by the part intermediate and flaps, this is why we speak of self-centering; to allow this self-centering and this blocking in the conduit, the dimension of the flaps is slightly greater than the corresponding dimension of the conduit. The width of the flaps is therefore slightly greater than the width of the duct.
Une autre possibilité, moins bonne, consisterait à prendre une feuille non élastique de dimensions légèrement inférieures à celles du conduit, et une fois cette feuille introduite dans le conduit, de la bloquer par collage en introduisant de la colle entre les rabats de la feuille et les extrémités oblongues du conduit. Mais le centrage de la partie coulissante de la feuille dans le conduit est alors moins précis, car la feuille de dimensions relativement petites par rapport à celles du conduit peut
facilement bouger à l'intérieur du conduit selon d'autres degrés de liberté que la direction de coulissement. En outre, le montage du miroir à l'aide d'une colle et à fortiori le démontage du même miroir est beaucoup moins pratique que dans le cas préférentiel de l'invention où l'autocentrage et le blocage s'effectuent grâce à l'élasticité et au dimensionnement de la feuille constituant le miroir.Another, less good, possibility would be to take a non-elastic sheet of dimensions slightly smaller than those of the duct, and once this sheet introduced into the duct, to block it by gluing by introducing glue between the flaps of the sheet and the oblong ends of the conduit. But the centering of the sliding part of the sheet in the duct is then less precise, because the sheet of relatively small dimensions compared to those of the duct can easily move inside the duct according to degrees of freedom other than the sliding direction. In addition, the mounting of the mirror using an adhesive and a fortiori the disassembly of the same mirror is much less practical than in the preferred case of the invention where the self-centering and blocking are effected by the elasticity and dimensioning of the sheet constituting the mirror.
De préférence, la feuille qui est suffisamment mince pour s'autocentrer et se bloquer dans le conduit, présente une épaisseur valant quelques dixièmes de millimètre. L'épaisseur de la feuille vaut par exemple trois dixièmes de millimètre.Preferably, the sheet which is thin enough to center itself and block in the duct, has a thickness of a few tenths of a millimeter. The thickness of the sheet is for example three tenths of a millimeter.
La feuille est de préférence une tôle métallique. La feuille pourrait aussi être en inox ou en plastique métallisé, mais ces deux matériaux présentent des inconvénients. L'inox offre des possibilités moins bonnes que le métal en termes de qualité de réflexion car il est moins facile de mettre dessus des couches de revêtement réfléchissant. Le plastique métallisé présente l'inconvénient d'être ou un peu trop souple en faible épaisseur ou un peu trop cassant en épaisseur plus importante ; le plastique métallisé manque également de raideur.The sheet is preferably a metal sheet. The sheet could also be made of stainless steel or metallized plastic, but these two materials have drawbacks. Stainless steel offers less good possibilities than metal in terms of quality of reflection because it is less easy to put on layers of reflective coating. Metallized plastic has the drawback of being either a little too flexible in thin layers or a little too brittle in thicker layers; metallized plastic also lacks stiffness.
Le matériau de la feuille est avantageusement cuivreux. Le matériau de la feuille est préférentiellement du cuivre béryllium de formule CuBe2 lequel permet à la feuille de présenter un effet ressort plus prononcé. Pour améliorer encore la qualité de l'effet ressort de la feuille constituant le miroir, la feuille en tôle de cuivre béryllium est avantageusement traitée thermiquement par réalisation d'un revenu à environ 320°C pendant environ 3 heures et 45 minutes.The material of the sheet is advantageously cuprous. The material of the sheet is preferably beryllium copper of formula CuBe 2 which allows the sheet to have a more pronounced spring effect. To further improve the quality of the spring effect of the sheet constituting the mirror, the sheet of beryllium copper sheet is advantageously heat treated by producing an tempering at approximately 320 ° C. for approximately 3 hours and 45 minutes.
De préférence, la feuille est une tôle métallique qui est au moins partiellement étamée de manière à mieux réfléchir la lumière de la lampe nuit. Etamer signifie recouvrir d'étain. Au moins la surface 140 est alors étamée. Par souci de simplification du procédé d'étamage et de diminution de son coût, la feuille est préférentiellement étamée dans sa totalité. D'autres procédés pour obtenir la qualité voulue de réflectivité du miroir sont envisageables mais celui-ci est particulièrement simple et efficace. Au moins la partie étamée de la tôle métallique est de préférence recouverte d'un vernis de protection transparent à la lumière de la lampe, afin de diminuer les risques de détérioration de cette partie étamée.
Preferably, the sheet is a metal sheet which is at least partially tinned so as to better reflect the light of the night lamp. Tinning means covering with tin. At least the surface 140 is then tinned. For the sake of simplification of the tinning process and reduction of its cost, the sheet is preferably tinned in its entirety. Other methods for obtaining the desired quality of reflectivity of the mirror can be envisaged, but it is particularly simple and effective. At least the tinned part of the metal sheet is preferably covered with a transparent protective varnish in the light of the lamp, in order to reduce the risks of deterioration of this tinned part.
Claims
1. Dispositif optique coudé comportant au moins une lampe (3) et un conduit (9) guidant au moins une partie de la lumière issue de la lampe (3), caractérisé en ce que le dispositif optique comporte, au niveau d'une partie coudée du dispositif optique, un miroir (12) constitué par une feuille qui est pliée de manière, d'une part à pouvoir être partiellement introduite dans le conduit1. Angled optical device comprising at least one lamp (3) and a conduit (9) guiding at least part of the light coming from the lamp (3), characterized in that the optical device comprises, at the level of a part angled of the optical device, a mirror (12) consisting of a sheet which is folded so that, on the one hand, it can be partially introduced into the duct
(9), et d'autre part, une fois introduite et bloquée dans le conduit (9), à réfléchir, dans une direction déterminée, une partie de la lumière issue de la lampe (3).(9), and secondly, once introduced and blocked in the conduit (9), to reflect, in a determined direction, part of the light from the lamp (3).
2. Imageur à cristaux liquides comportant un écran (5) à cristaux liquides situé au niveau de la partie avant de l'imageur, au moins une lampe nuit (3), un conduit (9) guidant au moins une partie de la lumière issue de la lampe nuit (3), et un guide (11) de lumière nuit sensiblement plan et structuré de manière à renvoyer sensiblement perpendiculairement à l'une (111) de ses surfaces la lumière entrée par l'une (110) de ses tranches, caractérisé en ce que la lampe nuit (3) est située au niveau de la partie arrière de l'imageur et en ce que l'imageur comporte aussi un miroir (12) constitué par une feuille qui est pliée de manière, d'une part à pouvoir être partiellement introduite dans le conduit (9), et d'autre part, une fois introduite et bloquée dans le conduit (9), à réfléchir, en direction de la tranche (110) du guide (11 ) de lumière nuit, une partie de la lumière issue de la lampe nuit (3). 2. Liquid crystal imager comprising a liquid crystal screen (5) located at the front part of the imager, at least one night lamp (3), a conduit (9) guiding at least part of the light emitted of the night lamp (3), and a substantially flat night light guide (11) structured so as to return substantially perpendicular to one (111) of its surfaces the light entered by one (110) of its sections , characterized in that the night lamp (3) is located at the rear part of the imager and in that the imager also includes a mirror (12) consisting of a sheet which is folded in a manner part to be able to be partially introduced into the conduit (9), and secondly, once introduced and blocked in the conduit (9), to reflect, towards the edge (110) of the guide (11) of night light , part of the light from the night lamp (3).
3. Dispositif optique, notamment imageur à cristaux liquides, selon l'une quelconque des revendications précédentes, caractérisé en ce que, à la fois la feuille (12) est une tôle suffisamment mince pour être suffisamment élastique et les dimensions de la feuille (12) sont suffisamment grandes par rapport aux dimensions du conduit (9), pour que la feuille (12) puisse à la fois s'autocentrer et se bloquer dans le conduit (9).3. Optical device, in particular a liquid crystal imager, according to any one of the preceding claims, characterized in that both the sheet (12) is a sufficiently thin sheet to be sufficiently elastic and the dimensions of the sheet (12 ) are large enough with respect to the dimensions of the conduit (9), so that the sheet (12) can both self-center and lock in the conduit (9).
4. Dispositif optique, notamment imageur à cristaux liquides, selon l'une quelconque des revendications précédentes, caractérisé en ce que la feuille (12) est pliée en au moins trois parties, une partie centrale (14) réfléchissant la lumière issue de la lampe (3) et deux parties latérales (15 ; 13, 131 , 132) reliées entre elles par la partie centrale (14), la partie latérale la plus proche (13, 131 , 132) de la lampe (3) pouvant coulisser dans le conduit (9), la partie latérale la plus loin (15) de la lampe (3) pouvant faire office de butée lors du coulissement de la partie latérale la plus proche (13, 131 , 132) de la lampe (3).4. Optical device, in particular liquid crystal imager, according to any one of the preceding claims, characterized in that the sheet (12) is folded into at least three parts, a central part (14) reflecting the light coming from the lamp (3) and two lateral parts (15; 13, 131, 132) interconnected by the central part (14), the nearest lateral part (13, 131, 132) of the lamp (3) being able to slide in the conduit (9), the farthest side part (15) of the lamp (3) being able to act as a stop when the nearest side part (13, 131, 132) of the lamp (3) slides.
5. Dispositif optique, notamment imageur à cristaux liquides, selon l'une quelconque des revendications précédentes, caractérisé en ce que l'intérieur du conduit (9) est peint en blanc pour réfléchir la lumière.5. Optical device, in particular a liquid crystal imager, according to any one of the preceding claims, characterized in that the interior of the duct (9) is painted white to reflect light.
6. Dispositif optique, notamment imageur à cristaux liquides, selon l'une quelconque des revendications précédentes, caractérisé en ce que la feuille (12) est une tôle métallique.6. Optical device, in particular liquid crystal imager, according to any one of the preceding claims, characterized in that the sheet (12) is a metal sheet.
7. Dispositif optique, notamment imageur à cristaux liquides, selon la revendication 6, caractérisé en ce que le matériau de la feuille (12) est cuivreux.7. An optical device, in particular a liquid crystal imager, according to claim 6, characterized in that the material of the sheet (12) is cuprous.
8. Dispositif optique, notamment imageur à cristaux liquides, selon la revendication 7, caractérisé en ce que le matériau de la feuille (12) est du cuivre béryllium de formule CuBe2.8. An optical device, in particular a liquid crystal imager, according to claim 7, characterized in that the material of the sheet (12) is beryllium copper of formula CuBe 2 .
9. Dispositif optique, notamment imageur à cristaux liquides, selon l'une quelconque des revendications 6 à 8, caractérisé en ce que la feuille (12) est une tôle métallique qui est au moins partiellement étamée- de manière à mieux réfléchir la lumière de la lampe (3).9. Optical device, in particular liquid crystal imager, according to any one of claims 6 to 8, characterized in that the sheet (12) is a metal sheet which is at least partially tinned so as to better reflect the light from the lamp (3).
10. Dispositif optique, notamment imageur à cristaux liquides, selon la revendication 9, caractérisé en ce qu'au moins la partie étamée10. Optical device, in particular liquid crystal imager, according to claim 9, characterized in that at least the tinned part
(140) de la tôle métallique (12) est recouverte d'un vernis de protection transparent à la lumière de la lampe (3).(140) of the metal sheet (12) is covered with a protective varnish transparent to the light of the lamp (3).
11. Dispositif optique, notamment imageur à cristaux liquides, selon l'une quelconque des revendications précédentes, caractérisé en ce que l'épaisseur de la feuille (12) vaut quelques dixièmes de millimètre.11. Optical device, in particular liquid crystal imager, according to any one of the preceding claims, characterized in that the thickness of the sheet (12) is worth a few tenths of a millimeter.
12. Miroir pour dispositif optique, caractérisé en ce que le miroir (12) est constitué par une feuille qui est pliée de manière à présenter, une partie principale (14), sensiblement plane, présentant au moins deux côtés (161 , 162) sensiblement parallèles entre eux et comprenant au moins une face réfléchissante (140), une partie extrémale (15) sensiblement plane, une partie intermédiaire (13), sensiblement plane et présentant au moins deux côtés (164, 165) sensiblement parallèles entre eux, deux rabats (131 , 132) sensiblement plans, les deux rabats (131 , 132) étant respectivement rattachés à chacun des deux côtés (164, 165) parallèles de la partie intermédiaire (13) et étant sensiblement perpendiculaires à la partie intermédiaire (13), la partie principale (14) étant rattachée par l'un (161) de ses côtés sensiblement parallèles à l'un (161) des côtés de la partie intermédiaire (13) non rattachés à un rabat (131 , 132) et par l'autre (162) de ses côtés sensiblement parallèles à la partie extrémale (15), et en ce que l'angle entre la partie principale (14) et la partie intermédiaire (13) ainsi que l'angle entre la partie principale (14) et la partie extrémale (15) sont des angles obtus. 12. Mirror for optical device, characterized in that the mirror (12) is constituted by a sheet which is folded so as to present, a main part (14), substantially planar, having at least two sides (161, 162) substantially parallel to each other and comprising at least one reflecting face (140), an end portion (15) substantially planar, an intermediate portion (13), substantially planar and having at least two sides (164, 165) substantially parallel to each other, two flaps (131, 132) substantially planar, the two flaps (131, 132) being respectively attached to each of the two sides (164, 165) parallel to the intermediate part (13) and being substantially perpendicular to the intermediate part (13), the main part (14) being attached by one (161) of its sides substantially parallel to one (161) of the sides of the intermediate part (13) not attached to a flap (131, 132) and by the other (162) of s sides substantially parallel to the end part (15), and in that the angle between the main part (14) and the intermediate part (13) as well as the angle between the main part (14) and the end part ( 15) are obtuse angles.
13. Miroir selon la revendication 12, caractérisé en ce quë a partie principale (14), la partie intermédiaire (13), la partie extrémale (15), ainsi que les rabats (131 , 132), sont sensiblement rectangulaires.13. Mirror according to claim 12, characterized in that a main part (14), the intermediate part (13), the extreme part (15), as well as the flaps (131, 132), are substantially rectangular.
14. Miroir selon l'une quelconque des revendications 12 à 13, caractérisé en ce que la feuille (12) est une tôle métallique.14. Mirror according to any one of claims 12 to 13, characterized in that the sheet (12) is a metal sheet.
15. Miroir selon la revendication 14, caractérisé en ce que le matériau de la feuille (12) est cuivreux.15. Mirror according to claim 14, characterized in that the material of the sheet (12) is cuprous.
16. Miroir selon la revendication 15, caractérisé en ce que le matériau de la feuille (12) est du cuivre béryllium de formule CuBe2.16. Mirror according to claim 15, characterized in that the material of the sheet (12) is beryllium copper of formula CuBe 2 .
17. Miroir selon l'une quelconque des revendications 14 à 16, caractérisé en ce que la feuille (12) est une tôle métallique qui est au moins partiellement étamée de manière à mieux réfléchir la lumière de la lampe (3).17. Mirror according to any one of claims 14 to 16, characterized in that the sheet (12) is a metal sheet which is at least partially tinned so as to better reflect the light of the lamp (3).
18. Miroir selon la revendication 17, caractérisé en ce qu'au moins la partie étamée (140) de la tôle métallique (12) est recouverte d'un vernis de protection transparent à la lumière de la lampe (3).18. Mirror according to claim 17, characterized in that at least the tinned part (140) of the metal sheet (12) is covered with a protective varnish transparent to the light of the lamp (3).
19. Miroir selon l'une quelconque des revendications 12 à 18, caractérisé en ce que l'épaisseur de la feuille (12) vaut quelques dixièmes de millimètres. 19. Mirror according to any one of claims 12 to 18, characterized in that the thickness of the sheet (12) is worth a few tenths of a millimeter.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR0108281A FR2826465B1 (en) | 2001-06-22 | 2001-06-22 | OPTICAL DEVICE, IN PARTICULAR LIQUID CRYSTAL IMAGER, AND MIRROR THEREFOR |
FR0108281 | 2001-06-22 | ||
PCT/FR2002/001894 WO2003001110A1 (en) | 2001-06-22 | 2002-06-04 | Optical device, particularly a liquid-crystal imaging device, and mirror therefor |
Publications (1)
Publication Number | Publication Date |
---|---|
EP1407186A1 true EP1407186A1 (en) | 2004-04-14 |
Family
ID=8864674
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP02745483A Withdrawn EP1407186A1 (en) | 2001-06-22 | 2002-06-04 | Optical device, particularly a liquid-crystal imaging device, and mirror therefor |
Country Status (4)
Country | Link |
---|---|
US (1) | US6958789B2 (en) |
EP (1) | EP1407186A1 (en) |
FR (1) | FR2826465B1 (en) |
WO (1) | WO2003001110A1 (en) |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR100873068B1 (en) * | 2002-06-28 | 2008-12-11 | 삼성전자주식회사 | Back light assembly and liquid crystal display device using the same |
KR101115800B1 (en) * | 2004-12-27 | 2012-03-08 | 엘지디스플레이 주식회사 | Light-emitting device package, method for fabricating the same and backlight unit |
US7771103B2 (en) * | 2005-09-20 | 2010-08-10 | Guardian Industries Corp. | Optical diffuser with IR and/or UV blocking coating |
US10020587B2 (en) | 2015-07-31 | 2018-07-10 | At&T Intellectual Property I, L.P. | Radial antenna and methods for use therewith |
EP3888346A4 (en) | 2019-02-19 | 2022-08-24 | Edgy Bees Ltd. | Estimating real-time delay of a video data stream |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2548126A (en) * | 1946-06-14 | 1951-04-10 | Beacon Products Corp | Luminous display device |
DE3806421A1 (en) * | 1987-03-04 | 1988-11-24 | Citizen Watch Co Ltd | LIGHTING DEVICE FOR A LIQUID CRYSTAL DISPLAY DEVICE |
US5293262A (en) * | 1988-03-15 | 1994-03-08 | Mitsubishi Denki Kabushiki Kaisha | Liquid crystal display device having heat-insulating members and driving circuit boards attached to rear edges of light box |
US5982090A (en) * | 1997-07-11 | 1999-11-09 | Kaiser Aerospace And Electronics Coporation | Integrated dual mode flat backlight |
DE19957611A1 (en) * | 1999-11-30 | 2001-06-07 | Osram Opto Semiconductors Gmbh | Lighting arrangement |
-
2001
- 2001-06-22 FR FR0108281A patent/FR2826465B1/en not_active Expired - Fee Related
-
2002
- 2002-06-04 US US10/480,158 patent/US6958789B2/en not_active Expired - Lifetime
- 2002-06-04 EP EP02745483A patent/EP1407186A1/en not_active Withdrawn
- 2002-06-04 WO PCT/FR2002/001894 patent/WO2003001110A1/en active Application Filing
Non-Patent Citations (1)
Title |
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See references of WO03001110A1 * |
Also Published As
Publication number | Publication date |
---|---|
WO2003001110A1 (en) | 2003-01-03 |
US20040155993A1 (en) | 2004-08-12 |
FR2826465A1 (en) | 2002-12-27 |
FR2826465B1 (en) | 2003-09-05 |
US6958789B2 (en) | 2005-10-25 |
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