DE2060380A1 - Process for the production of color electrophotographic material - Google Patents

Description

DR. B. WIEGAND DIPL-ING. W. NIEMANN 2060380

DR. M. KÖHLER DIPL-ING. G GERNHARDT

MUNICH HAMBURG TELEPHONE: 55 54 7 «8000 MÖNCHEN 15,

TELEGRAMS: KARPATENT NUSSBAUMSTRASSE 10

December 8, 197o

W. 4o 239/70 7 / RS

Ilford Limited Ilford, Essex (England)

Method of making color electrophotographic material

The invention relates to color electrophotography Material and its manufacture.

Electrophotographic material usually comprises a layer of photoconductive material which acts as a coating is applied to a carrier substrate which has been made electrically conductive, or a layer of photoconductive material which is applied as a coating to a layer of electrically conductive material, which in turn forms a coating on a carrier base. To make an image on such an electrophotographic material to generate, the material is electrically charged. The charged material is then exposed to imagewise light and

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the charge is dissipated in the areas on which the light falls. The image is usually developed by that one applies to the material a toner comprising particles which are attached to the photoconductive layer stick in areas that are still charged. It is possible to make color electrophotographic material, and one type of material proposed includes it The surface of the photoconductor layer is a mosaic of areas or areas, each of which is selectively spectrally for light in one of the three ranges of the red spectrum,

Green and blue have been sensitized. The expression "Addiction"

how it is used refers to the visible Spectrum, unless otherwise stated.

In another type of electrophotographic process, the material is not initially charged, but when such a material is exposed imagewise to light the photoconductive material is electrically conductive in the areas on which the light falls. These areas can then toned by an electrolytic process to form an image. If this procedure is modified color electrophotographic copies can be obtained. Electrophotographic material is used for this, which comprises a photoconductive layer having on its surface discrete areas, each of which is selective has been spectrally sensitized for one of the three areas of the spectrum red, blue and green, being in each A chemical substance is present in these areas that is capable of forming a dye image that resides in its Color complementary to the color of what is absorbed by the area Light3 is. After imagewise exposure, the material is electrolytically developed to form the image to 3babili3ieren and to prevent a chemical reaction at a later stage in those areas

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takes place - which have been influenced by light. the Layer is then chemically through a coupling-type Developer designed to give a three color dye image.

The term ^M f arbenelektrophotograph.isch.es material of the mosaic type ", as used hereinafter, denotes electrophotographic material which comprises a photoconductive layer which has been spectrally sensitized in more than one region of the spectrum and in such a way that; every single area of the surface is sensitive to light from only one area of the spectrum.

It is known that when a sensitizing dye is on top of the surface of a non-sensitized photoconductive layer is applied ', the layer itself sensitive to by the sensitizing dye absorbed light becomes, although the lower areas of the layer of photoconductive substance do not have a dye contain. It is thus possible to create a mosaic of areas, each for a different area of the spectrum is sensitive, in which one successively sensitizing dye on a photoconductive layer by applying a grid pattern using conventional copying or printing processes. It is also possible to produce such a mosaic pattern by electrophotographic material; for example, with a such a method a spectrally non-sensitized photoconductive Layer charged and exposed to a raster pattern of light, the charge remaining on the surface toned in a sensitizing liquid, which in this way sensitizes these areas of the photoconductor.

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Y / other raster exposures showing different areas of the Exposing the material, followed by the application of various sensitizers, enables the build-up the mosaic pattern of paraffin sensitization of individual areas of the photoconductive layer.

However, both of the above-described methods of making color electrophotographic material suffer the type of mosaic has the serious disadvantage that an exact alignment of the raster images for the three successive Awareness raising is necessary in order for this to be applied in an appropriate manner to the different areas of the population photoconductive surface are applied so that the areas do not overlap. One purpose of the invention is to provide a method for the manufacture of mosaic type color photographic material in which a exact alignment of the raster image is not necessary.

According to a first feature of the invention, it is provided that in the manufacture of mosaic type color electrophotographic material as defined above is from spectrally unsensitized electrophotographers Material that charges electrophotographic material, exposing it to a light pattern of a wavelength, to which the non-sensitized photoconductor is sensitive to the surface of the electrophotographic Discharge material in the areas that are struck by the light, the areas that remain charged sensitized on the surface of the photoconductor by means of a sensitizing agent which they oppose Sensitizes light of a region of the spectrum, charges the material again and exposes it to light in total the area of the spectrum for which some areas

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have just been sensitized, whereby the charge on the material is selectively destroyed in these areas, so that these areas are not sensitized in a subsequent sensitization process.

If necessary, electrophotographic material manufacture which has a mosaic pattern which is selectively sensitive to only two areas of the spectrum, then after completing the above steps it is only necessary to apply a sensitizing agent, which sensitizes the remainder of the surface of the electrophotographic material that is still charged. It however, as noted above, it is common to use color electrophotography To manufacture mosaic-type material comprising a plurality of areas each for Light is one of the three main areas of the spectrum that is sensitive. To such color electrophotographic material of the To make a type of mosaic by applying the invention, it is necessary to complete a further series of stages of the above Kind of run. After completing the first series of steps, electrophotographic material remains, the one has a photoconductive surface with areas that have been selectively sensitized to a region of the spectrum, these areas carry no charge and the remainder of the surface of the photoconductor carry some charge. The electrophotographioche Material is then exposed to a different pattern of light of a wavelength to which the

not-

is sensitive sensitized photoconductor to thereby discharge the charge on d r surface of the photoconductive material in the areas that are hit by the light, and which still carry a charge. The areas of the photoconductive material that still have a charge that remains on it are

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lizing agent toned it for someone else's light Area of the spectrum is sensitized j the material is charged again and then uniformly exposed to light, which includes the two areas of the spectrum for which areas of the electrophotographic material has already been sensitized in order to thereby selectively reduce the charge on the surface of the photoconductor in these areas to destroy, and finally the material is tinted using a sensitizer, which removes the rest the areas of the photoconductor that are still charged, sensitized to a third area of the spectrum. According to another feature of the invention is therefore in the Manufacture of mosaic type color electrophotographic material as defined above at the Areas the surface of the photoconductive layer, respectively are sensitive to only one of the three main areas of the spectrum, from spectrally unsensitized electrophotographic Material provided, whereby the electrophotographic material is charged, it is light of a wavelength, to which the non-sensitized photoconductor is sensitive is exposed by a grid ^ of a series of lines which are opaque to light of such wavelength are, on a transparent substrate, the areas that are charged on the surface of the photoconductor remain, by means of a sensitizer, which sensitizes them to light in a region of the spectrum, recharges the material and light as a whole exposes in that area of the spectrum to which some areas of it have just been sensitized, and before or simultaneously with or after this total exposure, the material is light of a wavelength for which the non-sensitized Photoconductor is sensitive, exposed by a grid, which is a series of lines that are opaque

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for light of such a wavelength are included on a transparent background, the lines at the second exposure at an angle to the lines of the grid in the first exposure, the material by means of a sensitizer which tones those remaining charged on the surface of the photoconductor Areas sensitized to light of another area of the spectrum, the material recharges and it exposes a total of light that includes the two areas of the spectrum for which areas of the electrophotographic Materials have already been sensitized and the material is toned using a sensitizer that sensitizes the rest of the areas of the photoconductor that are still charged to a third region of the spectrum.

Preferably, the two patterns of light encountered by the electrophotographic material at a first and a in a second exposure is exposed in such a way that the areas which are only for one of the three areas of the spectrum are sensitive, are the same.

Eventually, if required, for example, more of the photoconductive layer become red sensitive should be, then set the light pattern so that the red-sensitive areas are larger in area than the others Areas are.

A method of making color electrophotographic Material of the mosaic type in which areas are only sensitive to one of the three areas of the spectrum results from the use of two grids, one of which consists of a grid, the other a row

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encompassed by opaque lines on a transparent background, the area covered by the opaque Lines is occupied, preferably occupying a third of the area of the grid and each impermeable Line preferably has the same width.

The first exposure to light of a wavelength to which the non-sensitized photoconductor is sensitive is executed using this grid. The second such exposure is made using a Running grid that has opaque lines of equal width, the area of which is opaque Lines on this grid occupies half the area of the grid. This exposure is carried out in such a way that the lines on this grid are at an angle to the lines on the grid during the first exposure. In this way, equal areas or areas of the surface of the photoconductor for the three main areas of the spectrum should be sensitized. If necessary, the grid can have partially opaque lines.

According to another embodiment of the method according to the invention is therefore in the manufacture of color electrophotographic material as above is defined in which individual areas are sensitive to only one of four areas of the spectrum, of spectrally non-sensitized electrophotographic material, the electrophotographic Material charges through it light of a wavelength to which the non-sensitized photoconductor is sensitive exposes a grid consisting of a series of lines opaque to light of such wavelength

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comprises a transparent background, the areas that remain charged on the surface of the photoconductor by means of a sensitizer which sensitizes the material for light of a region of the spectrum, recharges the material and exposes it to light in the region of the spectrum for which some areas thereof have just been sensitized, and before or simultaneously with or after this overall exposure exposes the material to light of a wavelength to which the unsensitized photoconductor is sensitive through a grid comprising a series of lines which are opaque to light of such wavelength , on a transparent background, the lines in said second exposure running substantially at an angle of 6o ° to the lines of the grid in the first exposure, the material by means of a sensitizer which tones the areas on the surface of the Photoconductor loaded ver remain, sensitized to light of a second region of the spectrum, recharges the material and exposes it as a whole to light that includes the two regions of the spectrum to which regions of the electrophotographic material are already sensitized, and before or simultaneously with or after this Gesa. mexposure the material light of a wavelength _}

to which the unexposed photoconductor is sensitive, exposing it through a grid consisting of a series of lines, which are opaque to light of such a wavelength, on a transparent background, the lines in said third exposure at an angle of approximately 60 ° to both the lines in the first exposure and to the lines in the second exposure, the material tones with a sensitizer, which tones the areas that are on the surface dea I'ho-

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The material remains charged and is sensitized to light in a third region of the spectrum charges and exposes it as a whole to light spanning the three areas of the spectrum for which areas of the electrophotographic The material has already been sensitized and the material has been sensitized that tones the rest of the areas of the photoconductor that are still charged for a fourth area of the spectrum sensitized.

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In one embodiment of this form the invention includes The grid used in the first grid exposure is a series of lines that are opaque to all light are, on a transparent background, whereby the areas that are occupied by the opaque lines, occupy a third of the area of the grid. It is also preferable that each opaque line has the same width.

In this embodiment of the invention, the second raster exposure is preferably under.Application of a Raster executed with lines, the lines that are opaque to all light, on a transparent one Has a background, the areas of the opaque lines taking up half the area of the grid. Furthermore, each preferably has an impermeable line the same width · In a modified version In this form of the invention, however, the second line grid has lines on a transparent background are impermeable to light of a wavelength to which the non-sensitized photoconductor is sensitive, which, however, transmit light of a wavelength for which areas of the photoconductor in the first sensitization process have been made sensitive. For example, when exposed to white light through a grid of this type the entire photoconductor layer is exposed to light in the region of the spectrum for which some regions thereof have just been sensitized. Usually that is non-sensitized photoconductors only for light of the ultraviolet Area of the spectrum sensitive. If so the grid comprised yellow lines on a clear background and the first sensitization process, areas of the material sensitive to red light, then

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exposure of the material to white light (which contains ultraviolet light) through this grid both the red-sensitive and the non-sensitized Areas of the material discharged in the area of the material that is cleared from the clear surfaces of the Grid is covered. However, only the red sensitive areas in the area of the material that covered by the yellow lines of the grid.

Therefore, in another embodiment of the Process according to the invention in the manufacture of color electrophotographic material of the Type of mosaic, as defined above, with areas for only one of the three areas of the spectrum are sensitive from what is not spectrally sensitized electrophotographic material provided that one charges the electrophotographic material, it Light of a wavelength for which the non-sensitized Photoconductor is sensitive, exposed by a grid, which is a series of lines that are opaque to light of such a wavelength, encompassed on a transparent background, the areas, that remain charged on the surface of the photoconductor, by means of a sensitizer that they for Sensitizes light of a region of the spectrum, charges the material again, and exposes it through a grid, which comprises a series of lines on a transparent background that are opaque to light from that person Area of the spectrum to which the non-sensitized Photoconductor is sensitive, but it is light in

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let through the area of the spectrum for which the areas just toned have been sensitized, wherein the lines in the second exposure are at an angle to the lines of the grid in the first exposure run the material using a sensitizer tones that the areas that remain charged on the surface of the photoconductor are exposed to light from another Sensitized area of the spectrum, the material again loads, and exposes it to light that covers two areas of the spectrum includes the areas of the electrophotographic material for which have already been sensitized, and the material using a sensitizer that sensitizes the rest of the areas of the photoconductor that are still charged to a third area of the spectrum.

In all of the aforementioned embodiments of this form of the invention, the lines preferably run on the Grid on the second exposure at right angles to the lines on the first exposure, but it can be seen that the same result can be obtained by changing the arrangement for the second raster exposure so. that there is an angle other than a right angle to the lines in the first raster exposure is. A change in the line width may also be used to reduce overall uneven areas in the To create a mosaic. In fact, the width of the lines on the grids can be chosen in this way for the second raster exposure will achieve any desired result in terms of the mosaic areas or areas produced will.

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The distance between the lines in the grids is determined by the required resolution. Generally are about 40 to 120 lines per cm (100 to 300 lines per inch) are required.

In another embodiment of the invention it is possible to produce electrophotographic material whose photoconductive surface is a mosaic of surfaces each of which has been spectrally sensitized to one of four regions of the spectrum. thats why according to this embodiment of the invention during manufacture of color electrophotographic material of the mosaic type as defined above, wherein individual areas are only sensitive to one of four areas of the spectrum, from those which are not spectrally sensitized electrophotographic material provided that electrophotographic material is charged, it is light exposes a wavelength to which the non-sensitized photoconductor is sensitive through a grid, of a series of lines that are opaque to light of such wavelength on a transparent one Background includes the areas that remain charged on the surface of the photoconductor by means of a sensitizing agent tones, which sensitizes them to light in a region of the spectrum, recharges the material, and it exposes all to light in that area of the spectrum to which some areas of it are just sensitizing and before or simultaneously with or after this overall exposure the material is light exposes a wavelength to which the non-sensitized photoconductor is sensitive through a grid,

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which comprises a series of lines which are opaque to light of such a wavelength on a transparent background, the lines in the second exposure running essentially at an angle τοη 60 ° to the lines of the haster in the first exposure, the material by means of a sensitizer that sensitizes the areas remaining charged on the surface of the photoconductor to light of a second region of the spectrum, recharges the material, and exposes it as a whole to light comprising the two regions of the M spectrum for which regions of the electrophotographic material have already been sensitized, and before, simultaneously with or after this overall exposure, the material exposes light of a wavelength to which the non-sensitized photoconductor is sensitive, through a grid consisting of a series of lines that are impermeable to light of such a wavelength comprises a transparent background, the Lines in the third exposure are at an angle of approximately 60 ° to both the lines in the first exposure and to the lines in the second exposure, the material tones by means of a sensitizer which tones the areas that are on the "

Surface of the photoconductor remain charged, sensitized to light of a third region of the spectrum, recharges the material. and exposes it as a whole to light encompassing the three regions of the spectrum for which Areas of the electrophotographic material have already been sensitized, and the material by means of a Sensitizer tones the rest of the areas of the photoconductor that are still charged for a fourth Sensitized area of the spectrum. It can be seen

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that the line screens that are used in the exposures, which in the embodiment just described of the invention are required, can consist of a transparent background having a grid, which have lines which are opaque to all light, or which, as previously described, have lines which are only opaque to light to which the unsensitized photoconductor is sensitive.

Preferably, the width of the lines on the grids is chosen so that equal areas or areas in the final Mosaic patterns can be generated. For example, the first grid is I / 4, the second i / j5 and impermeable to the third 1/2 of its area.

It can be seen that if for any reason it is necessary, the areas of the mosaic are not are the same, the width of the lines on the grids can be chosen to give any desired result is produced.

Preferably, the photoconductor consists of a layer of zinc oxide in a binder instead of Zinc oxide can, however, also be used with other organic or inorganic photoconductive substances.

The preferred type of sensitizer for Use in the method according to the invention comprises charged particles which are themselves in a particular area of the spectrum are sensitized. Such particles can be in the form of a powder, an aerosol spray, or in Form of a liquid can be applied.

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A particularly useful liquid that can be used to . Sensitizing the areas of the photoconductor to a region of the spectrum is described in the British patent application Mr. 59825/69 (German patent application .......). According to this application is a liquid sensitizer to the surface of a charged Farbsensibilisieren photo- leather layer by electrophotographic material is provided which comprises a loaded suspension of färbstoffsensi- d-stabilized Zinkoxydteilchen in an insulating liquid carrier. Optionally, a resin fixative, e.g. An alkyd resin, and also a means for regulating the charge, e.g. B. a metallic soap such as ferric stearate is present.

Preferably all of the particles are the same Dye sensitized.

When the mosaic type color electrophotographic material is to be used in a process, at which a latent image is formed by an electrolytic process ^ as described above, is'

Each sensitizer is assigned a color former which forms a dye that is complementary in its color to the color of the light absorbed by the sensitizer.

The invention is explained in more detail with reference to the drawing.

Figs. 1 to 3 illustrate the preparation of color electrophotographic material of the mosaic type,

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which includes three sets of domains, one of which is sensitive to an area of the spectrum. Fig. 4 to illustrate the manufacture of mosaic type color electrophotographic material comprising four sets of Includes areas each of which is sensitive to an area of the spectrum.

Fig. 1 shows electrophotographic material after the first stage in the preparation of the mosaic material.

Figure 2 shows the same electrophotographic material after the second stage in the manufacture of the mosaic material.

Fig. 3 shows mosaic type color electrophotographic material produced by the tiering method according to of the invention.

used

The "spectrally non-sensitized electrophotographic Material was prepared by adding a suspension of 12 parts by weight of photoconductive zinc oxide (from Imperial Smelting Go. Ltd., Avonmouth, England) in a toluene solution of 1 part resin (E87-09 from Cray Valley Products ltd, St. Mary Gray, Kent, England) applied to a conductive substrate as a coating, the resin being present as a binder. The paper was charged negatively compared to an 8kV corona device after drying.

The charged electrophotographic material was lake by a raster (A) 30 at a distance of about 30 cm (12 inches) from a 48 W-WoIfr »· cleat, dis worked at 2850 ⁰ K, exposed. (The grid (A) used was a glass grid, of which a third of the area passed through

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opaque black lines were covered, which were evenly spaced across the grid, being about There were 120 lines per cm (300 lines ^ e inch).) After exposure, the material was then made by immersion in a sensitizing toner for 3 minutes sensitized. The composition of the toner was 1.0 g of dye (Blue T patent) sensitized Zinc oxide, 0.025 g iron (III) stearate, 2.0 g alkyd resin (Mitehalac 716 resin from W.A. Mitchell and Smith, Mitcham, Surrey, England) and 250 ml odorless paraffin (Isopar G Esbo Chemicals Ltd, London, England) as the carrier. After drying, the material (in high magnification) Lines as shown schematically in FIG in which areas 1 are the non-sensitized Areas and areas 2 the red-sensitive areas are. The material may appear white when viewed occasionally, but when examined very carefully it it is found to show light blue-green lines (area 2).

After drying, the electrophotographic material was negatively charged against an 8kY corona charger and exposed approximately 30 cm (12 inches) from a 100 watt tungsten lamp covered with an Ilford 204 red filter (filter # 204 in Ilford Color Filters Handbook published by Ilford Limited, England) This exposure discharges the material in the areas sensitized with the zinc oxide colored (Patent Blue Y) , ie the red sensitive areas.

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The material was then lake by a raster (B) 30 at a distance of about 30 cm (12 inches) of a 48 V-WoIframlampe who worked at 2850 ⁰ K, exposed, said lines to in the frame (B) perpendicular the lines of the grid (A) ran during the previous exposure. The grid (B) is made of clear glass on which there are parallel, opaque lines covering half the area of the grid, there being about 120 lines per cm (300 lines per inch).

The material was then placed in a sensitizing fluid sensitized, which was similar to the liquid used above, except that the zinc oxide was through the use of another dye (Rose Bengal dye) had been sensitized.

Fig. 2 schematically shows an enlarged part of the photographic material after the completion thereof Step.

In FIG. 2, areas 1 are the non-sensitized areas, and areas 2 are the red-sensitized areas Areas and areas 3 the green-sensitized Areas.

After drying, the material was again negatively charged to an 8 kV corona charger and in one A distance of approximately 30 cm (12 inches) from a 100 W woIfram lamp, which was covered with an Ilford 110 yellow filter (Filter No. 110 in Ilford Color Filters Handbook) ^ exposed. The material was then saisibilisct in a liquid,

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which was similar to the liquid described above except that the zinc oxide had been sensitized with a different dye (Auramine 0). This completes the mosaic pattern, and Fig. 3 schematically illustrates an enlarged part of the color electrophotographic material. In this figure, areas 2 are the red-sensitized areas, areas 3 are the green-sensitized areas, and areas 4 are the blue-sensitized areas. The sets of areas g 2, 3 and 4 are essentially the same.

Mosaic type color electrophotographic material is thus by an electrophotographic process without the need to provide careful alignment of the grids used.

The sensitizing fluids used in this example are more detailed in the simultaneous British patent Ur. 59825/69 (German patent application ·. ·· ... written.

Figs. 4 through 7 illustrate a method of making color electrophotographic material, which comprises 4 sets of regions, each of which is sensitive to only one area of the spectrum. In Figure 4 shows an enlarged portion of electrophotographic material after a raster exposure.

In Fig. 4, the areas 11 do not mean that - sensitized material, and areas 12 are the Areas that have been sensitized through the use of sensitizer A. The grid, the exposure to produce this material

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used includes a number of lioht-impermeable Lines on a transparent background, the areas occupied by the opaque lines quarter the area of the grid, with each line being the same width.

In Pig. 5, the same electrophotographic material is shown after a second raster exposure and awareness level has taken place. Like in Pig. 4, the areas 11 denote the non-sensitized Material and the areas 12 the material which has been sensitized by the sensitizer A is, while the areas 13 denote the material, which has been sensitized by a sensitizer B.

The screen used in the second exposure comprises a series of opaque lines on one transparent background with the same number of lines per cm (per inch) as the first grid. In which In the second grid, the impermeable lines make up a third the area of the grid, and each line has the same width again. On the second exposure, the second grid at an angle of approximately 60 ° to the first grid with respect to the lines in each grid applied.

The material after the second exposure and sensitization stage comprises a series of parallelograms as shown in FIG. A process to ensure that the final material has 4 sets of areas, each set of which is an equal area as the other has is the angle at which

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■ η INI 1MB fill

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the third grid is to be applied, and also the line spacing from the third grid to determine the dimensions of these parallelograms. When the long diagonal of the parallelogram is taken as a unit of length, then the line spacing in the third grid should be two lines per unit of length. The third grid will applied in a direction parallel to the short diagonal wire of the parallelograms.

Pig. 6 shows a material after such a third exposure and after sensitization with a third Sensitizer O. In der Pig. 6 is not that— sensitized material with 11 caused by the sensitizer A sensitized areas are with 12 sensitized by the sensitizer B. Areas are at 13 and those by the sensitizer C sensitized areas are denoted by 14.

Provided that the third screen has the correct spacing and is used at the correct angle, there are no adjustment problems, since regardless of the position on the screen relative to the lines already laid on the material, after exposure and sensitization by the sensitizer C, the areas so sensitized take up half the area of each parallelogram present on the Matedal, and thus a quarter of the total area of the surface.

Pig. 7 shows the material of the pig. 6 after a final charge and sensitization stage has taken place Has. Thus, in the end material, the surfaces 12 with the sensitizing agent A, the surfaces 13 with the,

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Sensitizer B, the areas 14 with the sensitizer C and the areas 15 with the sensitizer D sensitized.

It can be seen that in the manufacture of the materials shown in Figs. 4-7 the same type of sensitizing solutions as used in the preparation of the material shown in Figures 1-3 and either before or simultaneously with or after each raster exposure, after the first raster exposure the material is subjected to an overall exposure to light in the region of the spectrum for which the areas that have already been sensitized are sensitive.

In this way a color electrophotographic material has been produced which is a mosaic of like Has sets of areas, each set of which is sensitive to one of the four areas of the spectrum. This material has no registration or alignment problems encountered with the use of any of the Halftones occur during the required exposure as a result of the application of any of the halftones during the required exposure.

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Claims (5)

Claims / l) A method for producing mosaic-type color electrophotographic material from spectrally unsensitized electrophotographic material, characterized in that the electrophotographic material is charged, exposed to a light pattern of a wavelength to which the unsensitized photoconductor is sensitive, around the surface to discharge the electrophotographic material in the areas that are hit by the light, the charged remaining Berei- M before sensitized on the surface of the photoconductor by means of a sensitizer, which sensitizes the spectrum to light an area, load the material again and-total to light in the region of the spectrum to which some regions thereof have just been sensitized, whereby the charge on the material is selectively destroyed in those regions so that these regions are not sensitized in a subsequent sensitization process be ized. 2. A process for the production of electrophotographic material with a mosaic pattern which is selective against % over only two areas of the spectrum, characterized in that the work steps according to claim 1 are carried out and then a sensitizer is applied to the material which covers the rest of the surface of the electrophotographic material that is still charged is sensitized to light in a different region of the spectrum. 3 · Process for the production of Moaaikart color photographic material, in which areas respectively 1 0 Γ: Π? 7/11 0 0 BAD ORfGiNAL are sensitive to only one of the three main areas of the spectrum of spectrally non-sensitized, electro photographic material, characterized in that the electrophotographic material is charged, it is light of a wavelength to which the non-sensitized photoconductor is sensitive, by a grid which comprises a series of lines, which are opaque to light of such a wavelength, on a transparent background, which tones areas which remain charged on the surface of the photoconductor by means of a sensitizer which they for light of an area of the spectrum is sensitized, the material is recharged and all of it is exposed to light in this area of the spectrum for which some areas thereof have just been sensitized, and before or simultaneously with or after this overall exposure the material is light of a wavelength for which the non-sensitized photoconductor is is sensitive by one A screen comprising a series of lines opaque to light of such a wavelength on a transparent substrate, the lines in the second exposure at an angle to the lines in the screen in the first exposure exposing the material to a sensitizing agent tone, which sensitizes the areas remaining charged on the surface of the photoconductor to light of another area of the spectrum, recharges the material and exposes it as a whole to light that comprises the two areas of the spectrum for which areas of the electrophotographic material have already been sensitized , and the material with a sensitizer tones the remainder of the areas of the photoconductor that are still charged to a third area of the spectrum. 1098 ° 7/1380
BAD ORfGINAL. 4 »Method according to claim 3, characterized in that the lines on the second raster exposure cross the lines of the grid used at the first grid exposure at a right angle. 5. A process for the production of farbenelektrophotographischem material of Mosaikärt, in which individual portions are each sensitive to only one of four regions of the spectrum, characterized overall ~ x denotes that one loads the electrophotographic material of spectrally-sensitized, electrophotographic material, it exposes light of a wavelength to which the unsensitized photoconductor is sensitive through a grid comprising a series of lines opaque to light of such wavelength on a transparent substrate, the areas that remain charged on the surface of the photoconductor , by means of a sensitizing agent which sensitizes the material to light of an area of the spectrum, recharges the material and exposes it altogether to light in the area of the spectrum to which some areas of it "have just been sensitized, and before or simultaneously with or after this Total i- % do g exposes the material to light of a wavelength to which the non-sensitized photoconductor is sensitive through a grid comprising a series of lines opaque to light of such wavelength on a transparent substrate, the lines in the case of the said second Exposure essentially run at an angle of 60 ° to the lines of the grid in the first exposure, the material tones by means of a sensitizing agent, which makes the areas that remain charged on the surface of the photoconductor for light of a second region of the spectrum. 109827/13 8 0 sized, the material is recharged and it exposes a total of light, which the two areas of the spectrum on which Areas of the electrophotographic material are already sensitized, included, and before or at the same time with or after this overall exposure the material is light of a wavelength for which the non-sensitized Photoconductor is sensitive, due to a grid that is exposed to a series of lines such as light Wavelength opaque, includes on a transparent background, the lines in said third exposure at an angle of approximately 60 ° to both the lines on the first exposure and to the lines run in the second exposure, the material tones by means of a sensitizer, which the areas that remain charged on the surface of the photoconductor for light of a third area of the Sensitized spectrum, the material is recharged and it exposes a total of light that the three areas of the spectrum includes for which areas of the electrophactographic material have already been sensitized, and that Material using a sensitizer tones the rest of the areas of the photoconductor that are still charged are sensitized to a fourth area of the spectrum. 109827/1380