EP1747501B1 - Procede et dispositif pour encrer un element applicateur d'imprimante ou de photocopieuse electrophotographique - Google Patents
Procede et dispositif pour encrer un element applicateur d'imprimante ou de photocopieuse electrophotographique Download PDFInfo
- Publication number
- EP1747501B1 EP1747501B1 EP05747766A EP05747766A EP1747501B1 EP 1747501 B1 EP1747501 B1 EP 1747501B1 EP 05747766 A EP05747766 A EP 05747766A EP 05747766 A EP05747766 A EP 05747766A EP 1747501 B1 EP1747501 B1 EP 1747501B1
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- EP
- European Patent Office
- Prior art keywords
- roller
- applicator element
- layer thickness
- inked
- component mixture
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- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- G03G15/00—Apparatus for electrographic processes using a charge pattern
- G03G15/06—Apparatus for electrographic processes using a charge pattern for developing
- G03G15/08—Apparatus for electrographic processes using a charge pattern for developing using a solid developer, e.g. powder developer
- G03G15/09—Apparatus for electrographic processes using a charge pattern for developing using a solid developer, e.g. powder developer using magnetic brush
- G03G15/0907—Apparatus for electrographic processes using a charge pattern for developing using a solid developer, e.g. powder developer using magnetic brush with bias voltage
Definitions
- the invention relates to a method and an arrangement for coloring an applicator element of an electrophotographic printer or copier, in which a two-component mixture of electrically charged toner particles and ferromagnetic carrier particles adhering to the outer surface of a roller is guided past a surface of an applicator element to be inked.
- a printer or copier for producing multicolored images on a carrier material.
- image development processes in which the charge image is toned with toner over an air gap.
- Applicator elements in particular applicator rollers or endless belts, are often used in such developer stations in order to guide toner material past the charge image to be developed.
- the charge image is located on a photoconductor, eg on a photoconductor belt or a photoconductor drum.
- the toner material is electrically charged and adheres electrostatically to the surface of the applicator element.
- Such arrangements for coloring a charge image by means of an applicator element are, for example, from the documents US 5,734,955 ; WO 03/036393 ; US 6,285,837 and US 2004/0002015 known.
- the layer thickness of the layer of toner material transferred to the photoconductor is not constant, especially due to fluctuations in the layer thickness of the toner material layer on the applicator element.
- the variations are caused by a change in the parameters of the two-component mixture, in particular by changes in the toner concentration, the tboelectric charge and the two-component mixture resistance.
- variations in print quality are dependent on a change in parameters of the electrophotography process, in particular on the charging and discharging of the photoconductor. Such short- and long-term fluctuations influence the print quality of the printed images produced by a different coloring of print images to be produced. Additional variations in print quality are possible by mechanical and electrical device settings of individual printing units or individual printing systems, which also variations in the quality of the printed products produced, which are superimposed on the above-described fluctuations and can amplify them.
- the charge images are not developed via an air gap as described above but in direct contact with the photoconductor.
- the surface of the applicator element touches the inked surface of the photoconductor.
- a two-component mixture of electrically charged toner particles and ferromagnetic carrier particles is used to create a layer of toner particles on the surface of the applicator element that electrostatically adheres to that surface.
- the two-component mixture is transported by means of a so-called magnetic roller, in whose Inner magnetic elements are arranged stationary.
- the poles of these magnetic elements are radially aligned so that one pole of each magnetic element faces the roller surface. In the region of these poles, accumulations of the two-component mixture are generated by the magnetic field, since the ferromagnetic carrier particles are held in the region of the magnetic elements.
- Part of the surface of the magnetic roller can be guided through a so-called mixture sump of the developer station, whereby still abraded on the roll surface adhering two-component mixture and new two-component mixture is deposited.
- the amount of the two-component mixture deposited on the roll surface can be limited by means of a doctor blade.
- so-called magnetic brushes are formed, wherein in particular a magnetic element is arranged stationary relative to a point with the smallest distance between the magnetic roller and the applicator element in order to produce a magnetic brush which touches at least the surface of the applicator element to be inked.
- the dissolution of the toner particles from the ferromagnetic carrier particles and the deposition of the toner particles on the applicator roller can be promoted by the application of a so-called transfer auxiliary voltage between the applicator element and the magnetic roller system.
- the layer thickness of the inked areas on the photoconductor is achieved by changing the electrophotography parameters, in particular the potential difference of the charge image between charged and discharged areas is increased and the bias voltage is changed.
- the charge image is then developed with a bicomponent magnetic brush, thereby producing a relatively thick toner layer on the photoconductor at the higher potential difference.
- this influence on the layer thickness inevitably has an influence on other print quality parameters, such as e.g. Dot diameter, line widths, full-surface homogeneity and balance of negative and positive characters result.
- two-component printing systems which, depending on the layer of toner material produced on the photoconductor, control the amount of toner which is supplied to the two-component mixture.
- Applicant's Pagestream printer family printers supply toner material to the two-component mixture of the developer station depending on the toner layer formed on the photoconductor.
- fresh toner from a reservoir, in particular from a buffer, supplied to the developer station.
- the toner concentration in the two-component mixture in the developer station increases, whereby the ratio of toner particles and carrier particles in the two-component mixture increases, and more toner particles are contained in the magnetic brush used for coloring the photoconductor.
- this regulation serves above all to reintroduce the amount of toner material removed by coloring the charge images from the two-component mixture to this mixture and to achieve a constant coloring of the printed images produced.
- a flexible adjustment of the amount of toner used to develop the charging device is not possible because changes in the printed image by supplying or not supplying toner material only after a large number of generated print images are effective and thus only a relatively sluggish control option is given.
- the object of the invention is to provide a method and arrangement for coloring an applicator element of an electrophotographic Specify a printer or copier, by which a desired preset layer thickness of toner particles to be inked areas of the photoconductor is generated in a simple manner and a high quality of the printed image is guaranteed.
- the layer thickness of the toner particle layer is precisely adjusted or regulated to a preset value.
- the optical density of a print image to be generated can be adjusted in a simple manner, in particular with the aid of further electrophotography parameters in other areas. It can further be ensured by the method according to the invention that even with changes in the properties of the two-component mixture, in particular when the carrier particles are aged, a toner particle layer on the surface of the applicator element has a constant, i. with a preset, layer thickness is generated.
- a second aspect of the invention relates to an apparatus for forming a toner particle layer having a preset layer thickness on the surface of an applicator element.
- This device has a roller on the outer surface of which adheres a two-component mixture of electrically charged toner particles and ferromagnetic carrier particles. Furthermore, the device comprises an applicator element, in the surface of which it is to be inked, the two-component mixture adhering to the surface of the roller can be guided past.
- the device comprises means for generating an electric field which exerts at least a force on a part of the electrically charged toner particles of the two-component mixture which is located between the surface of the roller and the surface to be inked of the applicator element.
- the apparatus comprises means for varying the strength of the electric field to adjust the layer thickness of the toner particle layer formed by the toner particles transferred to the inking surface of the applicator element.
- a measuring arrangement is provided for determining an actual value as a measure of the layer thickness.
- the device comprises means for comparing the determined actual value with a setpoint determined by the preset layer thickness. The means for varying the strength of the electric field change and / or adjust the strength of the electric field as a function of the deviation of the determined actual value from the desired value.
- Such an arrangement ensures that the layer thickness produced on the surface of the applicator element reaches exactly a preset value.
- This preset layer thickness is achieved with the aid of the device according to the invention even if the mixing properties of the two-component mixture change due to the aging of the carrier particles or changed material properties of the toner particles.
- the inventive arrangement thus high print quality can be achieved over a long period.
- the layer thickness produced on the surface of the applicator element is precisely adjusted to the preset value, whereby the layer thickness can also be changed in a simple manner by changing the setpoint value.
- a third aspect of the invention relates to a method for adjusting the inking degree of one on one side of a Carrier material to be formed toner image in which a adhering to the outer surface of a roller two-component mixture of electrically charged toner particles and ferromagnetic carrier particles is guided past a surface to be inked an applicator.
- a adhering to the outer surface of a roller two-component mixture of electrically charged toner particles and ferromagnetic carrier particles is guided past a surface to be inked an applicator.
- the toner particle layer formed on the surface to be inked of the applicator element by the transferred toner particles Preset layer thickness is generated.
- the degree of inking of the toner image to be formed on the side of the support material is adjusted by means of further electrophotography parameters.
- the layer thickness of the toner particle layer produced on the surface of the applicator element always has a constant, preset layer thickness, the degree of inking of the printed image being changeable and presettable by a change in the brightness setting of the print image to be generated with the aid of an operating unit , is not adjusted via the layer thickness of the toner particle layer produced on the surface of the applicator element, but via the further electrophotography parameters, for example via the spot size, the auxiliary voltage for transferring toner material from the surface of the applicator element to the areas of a photoconductor to be inked and / or from the transfer auxiliary voltage between the photoconductor and a substrate.
- the transfer auxiliary voltage is between the Photoconductor and this intermediate carrier and between the intermediate carrier and the carrier material and electrophotography parameters, by the degree of inking of the printed image, ie the brightness of the printed image, set and / or can be changed.
- the inventive method allows a simple and more accurate control of the brightness of the printed image to be generated, ie the degree of inking of the printed image to be generated on the substrate is easily adjustable. Due to the constant layer thickness, it is further achieved that a constant preset layer thickness can always be assumed for changing the inking degree of the toner image to be formed on the carrier material, whereby the adjustment of the brightness can take place independently of the layer thickness control and thus simpler. A so-called drifting away the brightness of the generated print images is thereby avoided.
- a fourth aspect of the invention relates to an apparatus for adjusting the inking degree of a toner image to be formed on one side of a substrate having a roller on the outer surface of which adheres a two-component mixture of electrically charged toner particles and ferromagnetic carrier particles.
- the device comprises an applicator element, in the surface of which it is to be inked, the two-component mixture adhering to the surface of the roller can be guided past.
- Means are provided for generating an electric field having an adjustable field strength, wherein the electric field exerts at least a force on a portion of the electrically charged toner particles of the two-component mixture between the surface of the roller and the surface of the applicator element to be inked.
- the toner particle layer formed on the surface to be inked of the applicator element by the toner particles transferred onto the surface to be inked has a preset value Layer thickness.
- the device comprises means for setting further electrophotography parameters for adjusting the inking level of the toner image to be produced on the side of the carrier material.
- the degree of inking of the toner image to be generated or of the printed image to be generated is changed and adjusted independently of the layer thickness produced on the surface of the applicator element.
- the layer thickness of the toner particle layer produced on the surface of the applicator element can be adjusted independently of the further electrophotography parameters, whereby only the further electrophotography parameters have to be changed in a suitable manner for setting the inking level or the brightness.
- the other electrophotography parameters can thus be assumed that a constant preset layer thickness.
- the brightness or the inking degree can be adjusted with high precision. Effects of aging phenomena, in particular of the carrier particles of the two-component mixture on the degree of inking or on the brightness of the toner image / printed image formed on the carrier material, do not occur in the device according to the invention.
- a fifth aspect of the invention relates to a method for coloring an applicator element of a printer or copier, wherein a two-component mixture of electrically charged toner particles and ferromagnetic carrier particles adhering to the outer surface of a roller is guided past a surface to be inked of an applicator element.
- a two-component mixture of electrically charged toner particles and ferromagnetic carrier particles adhering to the outer surface of a roller is guided past a surface to be inked of an applicator element.
- When passing the two-component mixture at least a part of the toner particles contained in the two-component mixture is transferred to the surface of the applicator element to be inked. It becomes an electric field is generated, which exerts a force on at least a portion of the electrically charged toner particles of the two-component mixture, which is located between the surface of the roller and the surface to be inked of the applicator element.
- the optical density of the printed image produced is easily adjustable over a wide range, without other properties of print quality, in particular without the dot diameter of individual dots, the line thickness, the edge smoothness, the homogeneous Vollvideinfärbung and raster image to influence.
- the provision of an applicator element ensures that a layer of toner particles already produced on the surface of the photoconductor is not damaged again by carrier particles.
- the method according to the invention makes it possible, in particular, to steplessly adjust the layer thickness of the toner particle layer produced on the applicator element and to preclude print image impairment by so-called depletion effects.
- the change in the layer thickness independently of other pressure parameters is achieved in particular by the fact that it depends essentially only on the set electric field strength.
- a constant print quality is achieved with an independent change in the coloration of the inked image, whereby a significantly lower toner consumption and thus low printing costs with higher quality of the print material is achieved.
- no so-called over-toning of the latent charge image must take place by the process according to the invention in order to ensure reliable coloration even of large areas.
- the method according to the invention achieves other parameters of the electrophotography process, in particular the potential difference between charged and discharged areas of the photoconductor and the potential difference between the applicator element and the photoconductor, independently of the layer thickness of the toner material transferred to the photoconductor, which is generated on the photoconductor with the aid of the applicator element.
- the layer thickness can be changed very quickly by changing the potential difference between roller and applicator element.
- the electrophotography process is stabilized and a high quality of the printed image produced is achieved.
- the service life of the two-component mixture is increased, since an increase in the degree of inking does not necessarily result in an increase in the toner particle content in the two-component mixture.
- long-term changing mixture parameters such as mixture resistance, can be easily compensated for by increasing the electric field strength, thereby increasing the useful life of the carrier particles and reducing the cost of consumables.
- the layer thickness by detecting the coloring of a colored area of the printed image on the photoconductor or a subsequent carrier material with the aid of a sensor arrangement and adjusting the intensity of the electric field as a function of the detected degree of coloration.
- the degree of coloration detected by the sensor arrangement can be used to automatically adjust the basic coloration in the printer or copier.
- a sixth aspect of the invention relates to an arrangement for coloring an applicator element of an electrophotographic printer or copier.
- the assembly includes a roller having on its outer surface a two-component mixture of electrically charged toner particles and ferromagnetic carrier particles. Furthermore, the arrangement contains an applicator element, on whose surface to be colored, the two-component mixture adhering to the surface of the roller can be guided past.
- the assembly further includes means for generating an electric field acting on at least the portion of the two-component mixture located between the surface of the roller and the surface of the applicator element to be inked, wherein the electric field passes at least a portion of that present in the two-component mixture as the two-component mixture advances Toner particles on the inked surface of the applicator element transmits.
- a control unit controls the strength of the electric field such that the transferred toner particles produce a preset layer thickness on the surface to be inked.
- Such an arrangement according to the invention ensures that the layer thickness of a layer of toner material to be applied to a photoconductor can be set in a simple manner independently of further electrophotography parameters.
- the layer thickness of the toner layer produced on areas to be inked of a charge image is essentially independent of the potential difference between regions of the photoconductor to be inked and not to be inked.
- carrier particles can also be used in the two-component mixture over a relatively long period of time, since a desired layer thickness of the toner layer generated on the applicator element can be achieved by changing the strength of the electric field. Also, by this arrangement, a very rapid and flexible change in the layer thickness of the toner layer formed on the applicator element is possible.
- a seventh aspect of the invention relates to a printer or copier for producing multicolor print images on a substrate having at least two developer stations.
- the first developer station contains electrically charged toner particles of a first color and the second developer station electrically charged toner particles of a second color different from the first color.
- an applicator element is provided, on the surface of which it is to be inked, in each case a toner particle layer of the toner particles contained in the respective developer station having a preset layer thickness is produced by a method according to the invention.
- Such a printer or copier can easily produce high-quality print images because, especially in multicolor printing for producing mixed colors, the toner amounts of the respective color separation are of crucial importance for the color tone of the mixed color.
- the surface of the applicator element arranged in the respective developer station on the surface to be inked has a defined layer thickness independently of the aging of the carrier particles contained in the respective developer station.
- An eighth aspect of the invention relates to a printer or copier for producing multicolor print images on a substrate having at least two developer stations.
- the first developer station contains electrically charged toner particles of a first color and the second developer station electrically charged toner particles of a second color different from the first color. Every developer station comprises an inventive arrangement according to one of the preceding aspects.
- Constant preset layer thicknesses are produced on the surface of the respective applicator element by means of such a printer or copier, as a result of which high-quality print images are also achieved in multicolor printing when printing on a plurality of toner images.
- FIG. 1 a developer unit 10 for developing a charge image contained on a photoconductor belt 12 is shown.
- the photoconductor belt 12 is in the direction of arrow P1 driven at a substantially constant speed.
- the developer unit 10 includes an applicator roller 14, a magnetic roller 16 and a mixing wheel 18.
- the lower part of the mixing wheel 18 is located in the so-called mixed sump of the developer unit 10 in which a two-component mixture of toner particles and carrier particles is contained.
- the toner particles are electrically charged and adhere to the ferromagnetic carrier particles.
- the carrier particles serve essentially to transport the toner particles by means of the magnetic roller 16.
- the magnetic elements are permanent magnets, in particular natural magnets, which extend in the interior of the roller 16 over its entire length.
- the longitudinal axes through the poles of the magnetic elements 22, 24, 26 are radially aligned, with the south poles of the magnetic elements 22 and 26 aligned towards the roller surface and the north pole of the magnetic element 24 towards the roller surface.
- the opposite poles of the magnetic elements 22, 24, 26 are not shown.
- so-called magnetic brushes are formed on the surface of the magnetic roller 16, are formed by the raised accumulations of toner particles and carrier particles in these areas.
- the ferromagnetic carrier particles are held together with toner particles adhering to them in the region of the magnetic elements by the magnetic field of these magnetic elements 22, 24, 26 and aligned along the field lines of the magnetic field, whereby the protruding brush shape is generated.
- the mixing wheel 18 is driven in the direction of the arrow P2, whereby the toner particles and carrier particles located in the mixture sump 20 are mixed, wherein the toner particles are tischoelektrisch charged by the friction generated during mixing.
- the two-component mixture of toner particles and carrier particles are whirled up to the magnetic roller 16, whereby a part of the two-component mixture impinges on the surface of the magnetic roller 16 and is held on the surface of the magnetic roller 16, particularly by the magnetic fields of the magnetic elements 22 and 24.
- the layer thickness of the layer of the two-component mixture located on the surface of the magnetic roller 16 is limited by a doctor blade 28.
- Magnetic roller 16 includes a metal sleeve 30 which is coated with a ceramic layer of suitable roughness and has good adhesive properties for transporting the bicomponent mixture.
- the metal sleeve 30 is connected to a first potential of a DC voltage source DC1.
- the DC voltage source DC1 is infinitely adjustable, wherein the voltage of the DC voltage source DC1 is adjusted by means of a control unit.
- the applicator roller 14 includes a metal sleeve 32 which is connected to a second potential of the DC voltage source DC1.
- an electric field is generated between the metal sleeve 32 of the applicator roller 14 and the metal sleeve 30 of the magnetic roller 16, the electric field being greatest at the point 46 with the smallest distance between the applicator roller 14 and the magnetic roller 16.
- the electric field between the applicator roller 14 and the magnet roller 16 causes the toner particles adhered to the carrier particles to detach from the carrier particles and be deposited on the surface of the applicator roller 14.
- the amount of the toner particles dissolved out of the two-component mixture and deposited on the applicator roller 14 is of the potential difference between the first potential and the second potential, ie From the voltage generated by the DC voltage source DC1.
- the layer thickness of the toner particle layer formed on the applicator roller 14 can be easily adjusted.
- area 34 there is a charge image on photoconductor belt 12, i. a latent print image.
- the photoconductor belt 12 is moved in the direction of the arrow P1, at the same time the applicator roller 14 is driven in the direction of the arrow P4.
- the rotational speed of the photoconductor belt 12 and the rotational speed of the applicator roller 14 are substantially the same, so that no speed difference occurs in the region of a transfer printing point 36 between the photoconductor belt 12 and the applicator roller 14.
- the inked areas of the charge image 34 are colored in the transfer area 36 with toner material, wherein substantially all of the toner material layer located on the surface of the applicator roller 14, which is opposite the inked area, is transferred to the photoconductor belt.
- a toner image on the photoconductor belt which corresponds substantially to the printed image to be generated.
- a toner image remains in the region 40, which corresponds to the negative of the printed image in the region 38.
- toner material located on the surface of the applicator roller 14 is scraped from its surface. The scraped toner material falls back into the mixture sump and is thereby fed back to the electrophotography process.
- the toner material which may still be present on the surface of the applicator roller 14 in the regions from which the layer of toner material has been transferred to the photoconductor belt 12 is removed from the surface of the applicator roller 14.
- further cleaning devices may be provided additionally or alternatively to the doctor blade 42, as described in particular in the international patent application WO 03/036393 A2 are known.
- the structure of the magnetic roller 16 is described in detail.
- an air gap is provided between the surface of the applicator roller 14 and the photoconductor belt 16, so that the development of the charge image contained in the region 34 with toner material takes place via an air gap.
- the photoconductor belt 12 includes an electrically conductive layer 44 which is connected to a second potential of a second DC voltage source DC2.
- the first potential of the DC voltage source DC1 is connected in the second potential in the DC voltage source DC1 and thus to the metal sleeve 32 of the applicator roller 14.
- the DC voltage source DC2 With the aid of the DC voltage source DC2 thus an electric field between the electrically conductive layer 44 and the metal sleeve 32 is generated, whereby the transfer of toner particles from the applicator roller 14 on the inked areas 34 of the photoconductor belt 12 is at least promoted.
- the DC voltage source DC2 is infinitely adjustable, so that the strength of the electric field between the metal sleeve 32 and the electrically conductive layer 44 can be controlled in a wide range.
- FIG. 2 the developer unit 10 according to a second embodiment of the invention is shown. Like elements have the same reference numerals.
- a stationary counterelectrode 48 with two electrode plates 50, 52 is arranged in the interior of the applicator roller 14. In the region 46 with the smallest distance between the applicator roller 14 and the magnet roller 16, the electrode plate 5 is arranged opposite to the roller 16.
- the counter electrode 48 with the electrode plates 50, 52 is in the same manner as the metal sleeve 32 according to the first embodiment after FIG. 1 is connected to the second potential of the DC voltage source DC1 and the first potential of the DC voltage source DC2.
- a plastic roller can be used as applicator 14, which contains no metal sleeve 32.
- An alternating voltage is superimposed on the DC voltage generated by the DC voltage source DC1, which is generated by means of an AC voltage source AC1.
- the amount of AC voltage generated by the AC voltage source AC1 is preferably infinitely adjustable by means of a control unit.
- the AC voltage generated by the AC voltage source AC1 serves, in particular, to dissolve the toner particles adhering to the carrier particles, in particular in the region 46, whereby the dissolved toner particles are drawn toward the surface of the applicator roller 14 with the aid of the DC voltage generated by the DC voltage source DC1 and adhere electrostatically to the surface of the applicator roller 14.
- the DC voltage generated by the DC voltage source DC2 is one of an AC voltage source AC2 generated alternating voltage superimposed.
- the toner particles are released from the surface of the applicator roller 14.
- the applicator roller may be a metal sleeve similar to the metal sleeve 32 FIG. 1 which serves as an electrode.
- the second electrode plate 52 is arranged in the interior of the applicator roller 14 stationary relative to the transfer printing region 36.
- only one AC voltage source AC1 or AC2 may be provided.
- the carrier particles have in the described Au exitsformen a diameter of about 50 microns and are in the FIGS. 1 and 2 shown as circles.
- the toner particles have a diameter of about 7 microns and are in the FIGS. 1 and 2 represented as points. Both in the embodiment according to FIG. 1 as well as in the embodiment according to FIG. 2 For example, by changing the DC voltage DC1, the film thickness generated on the applicator roller 14 can be controlled.
- the layer thickness of the toner particle layer produced on the applicator roller 14, on the photoconductor belt 12 or a subsequent carrier material, such as an endless transfer belt or a carrier material to be printed is subsequently determined, then this determined layer thickness can be compared with a desired value and, depending on the result of the comparison, the amount of be controlled by the DC voltage source DC1 DC voltage generated, whereby the layer thickness is controlled.
- the degree of coloration of the toner particle layer produced on the applicator roller 14, the photoconductor belt 12 or a subsequent carrier material can be determined and compared with a desired value.
- the voltage source DC1 is controlled to match that on the applicator roller 14 to be produced layer thickness of the toner particle layer to the desired value.
- an optical sensor, a capacitive sensor and / or a laser triangulation sensor can be used as the sensor.
- the developer unit 10 When installed in an electrophotographic printer or copier, the developer unit 10 is preferably enclosed by a suitable housing.
- the force vector of the electric field generated by the DC voltage DC1 acting on the toner particles is directed toward the applicator roller 14.
- the entire toner particle layer is transferred from the applicator roller 14 to the photoconductor belt 12 in the areas of the photoconductor belt to be developed, ie in the areas to be inked.
- the layer thickness of the toner particle layer on the photoconductor belt 12 in the regions 38 to be inked is thus independent of the transfer auxiliary voltage DC1.
- the strength of the electric field of the DC voltage sources DC1 and DC2 is preferably infinitely adjustable, whereby a very variable layer thickness adjustment is possible in a wide range.
- the produced Druckguteinfärbung is preferably determined on the photoconductor belt as an actual color using a suitable sensor arrangement.
- the DC voltage generated by the DC1 voltage source is changed with the aid of a control loop until the actual coloration determined then corresponds to the sole coloration.
- the voltage of the DC voltage source DC1 is increased, whereby the amount of toner deposited on the surface of the applicator roller 14 and thus the amount of toner developed on the photoconductor belt 12 increases and approaches the target coloring.
- the voltage of the DC voltage source DC1 is correspondingly reduced.
- the mixture parameters of the two-component mixture changed as a result of the aging of the carrier particles influence the toner attachment to the carrier particles, they are regulated by the described control of the layer thickness or the coloring, so that a constant coloring of the charge images to be developed takes place in a consistent quality.
- the carrier particles can be used longer in the electrophotographic process in the developer unit 10 of the printer, whereby costs can be reduced.
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- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Developing Agents For Electrophotography (AREA)
- Dry Development In Electrophotography (AREA)
- Printers Or Recording Devices Using Electromagnetic And Radiation Means (AREA)
- Color Electrophotography (AREA)
- Magnetic Brush Developing In Electrophotography (AREA)
- Developing For Electrophotography (AREA)
Abstract
Claims (23)
- Procédé de génération d'une couche de particules de toner ayant une épaisseur de couche préréglée à la surface d'un élément applicateur, dans lequel
un mélange de deux composants, adhérant à la surface extérieure d'un rouleau (16) et constitué de particules de toner électriquement chargées et de particules de support ferromagnétiques, est amené devant une surface à colorer d'un élément applicateur (14),
lors du passage du mélange de deux composants, au moins une partie des particules de toner contenue dans le mélange de deux composants est transférée sur la surface à colorer de l'élément applicateur (14),
un champ électrique est généré qui exerce au moins une force sur une partie des particules de toner électriquement chargées du mélange de deux composants, laquelle se trouve entre la surface du rouleau (16) et la surface à colorer de l'élément applicateur (14),
l'intensité du champ électrique est modifiée afin de régler l'épaisseur de couche de la couche de particules de toner formée par les particules de toner transférées sur la surface à colorer de l'élément applicateur (14),
une valeur réelle est détectée comme mesure de l'épaisseur de couche à l'aide d'un système de mesure, l'épaisseur de couche d'au moins une région d'une image formée par du toner qui a été colorée à l'aide de l'élément applicateur (14) sur la surface d'un photoémetteur étant détectée comme valeur réelle à l'aide du système de mesure,
la valeur réelle détectée est comparée à une valeur de consigne déterminée par une épaisseur de couche préréglée,
et l'intensité du champ électrique est réglée et/ou modifiée en fonction de l'écart entre la valeur réelle déterminée et la valeur de consigne. - Procédé selon la revendication 1, caractérisé en ce que la valeur réelle est déterminée à l'aide d'un capteur d'épaisseur de couche capacitif, d'un capteur d'épaisseur de couche optique ou d'un capteur destiné à déterminer la densité optique de l'image formée par du toner qui a été colorée.
- Procédé selon l'une des revendications précédentes, caractérisé en ce que l'intensité du champ électrique est modifiée progressivement afin de modifier progressivement l'épaisseur de couche.
- Procédé selon l'une des revendications précédentes, caractérisé en ce que la surface à colorer de l'élément applicateur (14) est amenée devant la surface du rouleau (16), en ce que le sens de rotation du rouleau (16) est avantageusement le même que le sens de transport de l'élément applicateur (14), et en ce que la vitesse de rotation du rouleau (16) et celle de l'élément applicateur (14) sont sensiblement égales.
- Procédé selon l'une des revendications précédentes, caractérisé en ce que l'élément applicateur (14) est un rouleau applicateur ou un applicateur à bande.
- Procédé selon l'une des revendications précédentes, caractérisé en ce que à l'intérieur du rouleau (16) est disposé de façon fixe au moins un élément magnétique (22, 24, 26) dont le champ magnétique agit sur les particules de support, en ce que sur la surface du rouleau (16) est formé un amas saillant du mélange de deux composants, notamment une brosse magnétique.
- Procédé selon l'une des revendications précédentes, caractérisé en ce qu'une image latente se trouvant sur un photoconducteur (16) est colorée et développée à l'aide de la couche de particules de toner générée sur l'élément applicateur (14).
- Procédé selon la revendication 6 ou 7, caractérisé en ce que l'élément magnétique (22, 24, 26) est disposé à l'emplacement (46) où la distance entre l'élément applicateur (14) et le rouleau (16) est la plus faible, et en ce que l'axe des pôles (N, S) de l'élément magnétique (22, 24, 26) est orienté radialement par rapport au rouleau (16).
- Procédé selon l'une des revendications précédentes, caractérisé en ce que le mélange de deux composants est préparé à l'aide d'un dispositif de préparation de mélange de telle sorte qu'il contient un pourcentage préréglé de particules de toner.
- Procédé selon l'une des revendications 7 à 9, caractérisé en ce que l'élément magnétique (22, 24, 26) contient un aimant permanent et/ou un élément électromagnétique.
- Procédé selon l'une des revendications précédentes, caractérisé en ce que l'épaisseur de couche sur le photoconducteur (12) est détectée à l'aide d'un système de capteurs, le niveau de coloration et/ou l'épaisseur de couche de la couche formée par les particules de toner sont détectés par le système de capteurs.
- Procédé selon la revendication 11, caractérisé en ce que l'on utilise comme système de capteurs un capteur optique destiné à détecter le niveau de coloration, un capteur de triangulation à laser et/ou un capteur capacitif.
- Procédé selon l'une des revendications 10 ou 11, caractérisé en ce que l'épaisseur de couche détectée est comparée à une valeur de consigne, et en ce que l'intensité du champ électrique est réglée en fonction du résultat de la comparaison.
- Procédé selon l'une des revendications précédentes, caractérisé en ce que l'on règle l'épaisseur de couche générée par les particules de toner transférées sur l'élément applicateur (14).
- Procédé selon la revendication 14, caractérisé en ce que l'intensité du champ électrique est utilisée comme grandeur de réglage, le champ électrique étant réglé avantageusement en modifiant la différence de potentiel ou la tension appliquée entre la surface du rouleau (16) et la surface de l'élément applicateur (14).
- Procédé selon l'une des revendications précédentes, caractérisé en ce qu'un écart de réglage est détecté en comparant la valeur de mesure détectée par le système de capteurs et la valeur de consigne.
- Procédé selon l'une des revendications précédentes, caractérisé en ce que le rouleau (16) contient un manchon métallique (32) qui s'étend sensiblement sur toute la longueur du rouleau (16), la couche (32) servant d'électrodes, avantageusement le corps de base du rouleau (16) étant un manchon métallique (32).
- Procédé selon l'une des revendications précédentes, caractérisé en ce que l'élément applicateur (14) contient une couche électriquement conductrice (30) qui s'étend dans un plan parallèle à la surface de l'élément applicateur (14) et qui sert d'électrode.
- Procédé selon l'une des revendications précédentes, caractérisé en ce que dans l'élément applicateur (14) et/ou dans le rouleau (16) sont disposées des électrodes immobiles qui sont placées l'une en face de l'autre.
- Procédé selon l'une des revendications précédentes, caractérisé en ce qu'il est prévu un rouleau de mélange (18) qui permet de mélanger uniformément les particules de support et les particules de toner contenues dans le mélange de deux composants et à l'aide duquel on prépare le mélange de deux composants.
- Procédé selon la revendication 20, caractérisé en ce que le mélange de deux composants préparé est amené au rouleau (16), la hauteur de la couche du mélange de deux composants, générée à la surface du rouleau, est limitée à l'aide d'une raclette de dosage (28).
- Dispositif de génération d'une couche de particules de toner ayant une épaisseur de couche préréglée sur la surface d'un élément applicateur, ledit dispositif comportant
un rouleau (16) à la surface extérieure duquel adhère un mélange de deux composants constitué de particules de toner chargées électriquement et de particules de support ferromagnétiques,
un élément applicateur (14), le mélange de deux composants adhérant à la surface du rouleau (16) pouvant être amené devant la surface à colorer dudit élément applicateur,
des moyens pour générer un champ électrique qui exerce au moins une force sur une partie des particules de toner, chargées électriquement, du mélange de deux composants qui se trouve entre la surface du rouleau (16) et la surface à colorer de l'élément applicateur (14),
des moyens pour modifier l'intensité du champ électrique afin de régler l'épaisseur de couche de la couche de particules de toner formée par les particules de toner transférées sur la surface à colorer de l'élément applicateur (14),
un système de mesure pour déterminer une valeur réelle comme mesure de l'épaisseur de couche, le système de mesure détectant comme valeur réelle l'épaisseur de couche d'au moins une région d'une image formée par du toner qui a été colorée à l'aide de l'élément applicateur (14) sur la surface d'un photoconducteur,
des moyens pour comparer la valeur réelle déterminée à une valeur de consigne déterminée par une épaisseur de couche préréglée,
les moyens destinés à modifier l'intensité du champ électrique réglant et/ou modifiant l'intensité du champ électrique en fonction de l'écart entre la valeur réelle déterminée et la valeur de consigne. - Appareil d'impression ou de copie destiné à générer des images d'impression polychromes sur un matériau de support, lequel appareil possède au moins deux stations de développement,
la première station de développement contenant des particules de toner, chargées électriquement, d'une première couleur et la seconde station de développement contenant des particules de toner, chargées électriquement, d'une seconde couleur différente de la première couleur,
et chaque station de développement possédant un dispositif de génération d'une couche de particules de toner ayant une épaisseur de couche préréglée sur la surface d'un élément applicateur selon la revendication 22.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE102004024047A DE102004024047A1 (de) | 2004-05-14 | 2004-05-14 | Verfahren und Vorrichtung zum Einfärben eines Applikatorelements eines elektrofotografischen Druckers oder Kopierers |
PCT/EP2005/005005 WO2005111735A2 (fr) | 2004-05-14 | 2005-05-09 | Procede et dispositif pour encrer un element applicateur d'imprimante ou de photocopieuse electrophotographique |
Publications (2)
Publication Number | Publication Date |
---|---|
EP1747501A2 EP1747501A2 (fr) | 2007-01-31 |
EP1747501B1 true EP1747501B1 (fr) | 2011-04-20 |
Family
ID=34969126
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP05747766A Expired - Fee Related EP1747501B1 (fr) | 2004-05-14 | 2005-05-09 | Procede et dispositif pour encrer un element applicateur d'imprimante ou de photocopieuse electrophotographique |
Country Status (7)
Country | Link |
---|---|
US (1) | US8401409B2 (fr) |
EP (1) | EP1747501B1 (fr) |
JP (1) | JP2007537473A (fr) |
CN (1) | CN100524078C (fr) |
CA (1) | CA2566360A1 (fr) |
DE (2) | DE102004024047A1 (fr) |
WO (1) | WO2005111735A2 (fr) |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102007010275A1 (de) | 2007-03-02 | 2008-09-04 | OCé PRINTING SYSTEMS GMBH | Verfahren zum Drucken und Kopieren von Tonerbildern auf ein Trägermaterial mit Reduktion der Belichtung bei ausgewählten Bildelementen |
DE102007019311A1 (de) * | 2007-04-24 | 2008-11-06 | OCé PRINTING SYSTEMS GMBH | Vorrichtung und Verfahren zum Reinigen einer mit Tonerteilchen versehenen Trägeroberfläche |
US8472159B2 (en) * | 2008-09-02 | 2013-06-25 | Xerox Corporation | Method to charge toner for electrophotography using carbon nanotubes or other nanostructures |
DE102016107772B3 (de) * | 2016-04-27 | 2017-05-11 | Océ Holding B.V. | Verfahren zum Übertragen eines Tonerbildes von einem Transferelement auf einen Aufzeichnungsträger |
US10795281B2 (en) | 2017-08-24 | 2020-10-06 | Hp Indigo B.V. | Compensating voltages for electrophotography printing devices |
Family Cites Families (18)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5640862A (en) | 1979-09-11 | 1981-04-17 | Canon Inc | Developing device |
JPS58203468A (ja) * | 1982-05-21 | 1983-11-26 | Hitachi Metals Ltd | 乾式リ−ダ−プリンタ− |
JPS61105573A (ja) * | 1984-10-29 | 1986-05-23 | Toshiba Corp | 現像装置 |
JPH07107618B2 (ja) | 1986-05-15 | 1995-11-15 | ミノルタ株式会社 | 現像装置 |
US5030977A (en) | 1990-02-15 | 1991-07-09 | Acuprint, Inc. | Printed image magnetic signal level control apparatus and method |
JPH0493965A (ja) * | 1990-08-07 | 1992-03-26 | Ricoh Co Ltd | 現像装置 |
JPH09211970A (ja) * | 1996-02-07 | 1997-08-15 | Hitachi Ltd | 現像装置及びそれを用いたカラー電子写真装置 |
US5734955A (en) * | 1996-01-11 | 1998-03-31 | Xerox Corporation | Development system |
JP2000029255A (ja) * | 1998-07-10 | 2000-01-28 | Fuji Xerox Co Ltd | 画像形成装置 |
JP2000250276A (ja) * | 1999-03-04 | 2000-09-14 | Canon Inc | 現像装置及びこの現像装置を備える画像形成装置 |
US6285837B1 (en) * | 2000-09-25 | 2001-09-04 | Xerox Corporation | System for determining development gap width in a xerographic development system using an AC field |
DE10225182A1 (de) * | 2001-06-13 | 2003-01-23 | Kyocera Corp | Bildgebungsvorrichtung |
DE10137861A1 (de) * | 2001-08-02 | 2003-02-27 | Oce Printing Systems Gmbh | Verfahren zum Steuern eines Druckers oder Kopierers unter Verwendung eines Tonermarkenbandes sowie eines nach dem Triangulationsprinzip arbeitenden Reflexsensors |
DE10152892A1 (de) | 2001-10-26 | 2003-05-08 | Oce Printing Systems Gmbh | Verfahren und Vorrichtung zur Reinigung von Trägerelementen in Druckern oder Kopierern unter Anwendung von Magnetfeldern |
DE10204873C1 (de) * | 2002-02-06 | 2003-10-09 | Infineon Technologies Ag | Herstellungsverfahren für Speicherzelle |
US6868240B2 (en) * | 2002-03-15 | 2005-03-15 | Kyocera Corporation | Method for developing in hybrid developing apparatus |
JP2004021127A (ja) * | 2002-06-19 | 2004-01-22 | Canon Inc | 磁性トナー、該トナーを用いた画像形成方法及びプロセスカートリッジ |
JP2004054036A (ja) * | 2002-07-22 | 2004-02-19 | Ricoh Co Ltd | 現像装置及び画像形成装置 |
-
2004
- 2004-05-14 DE DE102004024047A patent/DE102004024047A1/de not_active Ceased
-
2005
- 2005-05-09 CN CNB2005800152145A patent/CN100524078C/zh not_active Expired - Fee Related
- 2005-05-09 DE DE502005011282T patent/DE502005011282D1/de active Active
- 2005-05-09 EP EP05747766A patent/EP1747501B1/fr not_active Expired - Fee Related
- 2005-05-09 CA CA002566360A patent/CA2566360A1/fr not_active Abandoned
- 2005-05-09 US US11/579,243 patent/US8401409B2/en not_active Expired - Fee Related
- 2005-05-09 WO PCT/EP2005/005005 patent/WO2005111735A2/fr active Application Filing
- 2005-05-09 JP JP2007512057A patent/JP2007537473A/ja not_active Withdrawn
Also Published As
Publication number | Publication date |
---|---|
US20120039620A1 (en) | 2012-02-16 |
CA2566360A1 (fr) | 2005-11-24 |
EP1747501A2 (fr) | 2007-01-31 |
WO2005111735A2 (fr) | 2005-11-24 |
JP2007537473A (ja) | 2007-12-20 |
CN100524078C (zh) | 2009-08-05 |
WO2005111735A3 (fr) | 2006-01-05 |
US8401409B2 (en) | 2013-03-19 |
DE502005011282D1 (de) | 2011-06-01 |
DE102004024047A1 (de) | 2005-12-08 |
CN1977222A (zh) | 2007-06-06 |
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