JPS6326661A - Photosensitive body and image forming method - Google Patents

Abstract

PURPOSE:To easily obtain a high-quality image at high speed without causing color slurring by forming a color separation functioning member having an insulating surface, and a photoconductive layer having bipolar electric charge transfer ability. CONSTITUTION:The layer 2a to be formed as the photoconductive layer 2 on the conductive substrate 1 contains a charge generating material 2g and the bipolar charge transfer material 2t. The insulating layer 3 is formed by attaching an insulating material of resins each colored with a different colorant for forming one of color separating filters (B, R, and G), respectively, to the layer 2a by means of printing, vapor deposition, or the like in a prescribed pattern, thus permitting the charged potential of a photosensitive body to be stabilized in the charged potential and to stably form high-quality images without causing color slurring.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a photoreceptor and an image forming method, and more particularly to a photoreceptor and an image forming method suitable for forming multicolor images using electrophotography.

Conventional Technology Many methods and devices used therefor have been proposed for the purpose of obtaining multicolor images using electrophotography, but they can generally be divided into the following types: . One method is to repeatedly form a latent image and develop with color toner according to the number of separated colors using a photoconductor, or to overlap the colors on the photoconductor, or to transfer the colors to a transfer material each time the development is performed. This is a method of layering. Another method uses a device having multiple photoconductors corresponding to the number of separated colors, exposes each photoconductor with a light image of each color at the same time, and uses color toner to cover the latent image formed on each photoconductor. In this method, the images are developed and sequentially transferred onto a transfer material to overlap the colors to obtain a multicolor image.

In the former method, the latent image formation and development process must be repeated multiple times, and the major drawback is that it takes time to record the image, and that it is extremely difficult to speed up the process. In addition, in the case of overlapping toner images on a photoreceptor, the potential drop in the previously developed toner adhesion area is not sufficient.
Another drawback is that toner that is developed later tends to adhere to previously developed toner areas that should not originally adhere, resulting in color turbidity.

The latter method uses multiple photoreceptors in parallel, which is advantageous in terms of speed, but requires multiple photoreceptors, an optical system, a developing means, etc., making the device complex, large, and expensive. Therefore, there is a drawback that it is not practical.

Furthermore, both types have a major drawback in that it is difficult to align images when image formation and transfer are repeated multiple times, and color shift of images cannot be completely prevented.

Process leading to the invention In order to fundamentally solve these problems, the present inventors first invented an apparatus that can form a multicolor image by performing image exposure once on a photoreceptor. did.

The apparatus forms a multicolor image as follows using a photoreceptor provided with an electrically conductive member, a photoconductive layer, and an insulating layer including a filter layer consisting of a plurality of different types of filters. That is, by applying electrical charge and image exposure to the surface of the photoreceptor, an image is formed due to the charge density at the interface between the insulating layer and the photoconductive layer,
A potential pattern is formed on the filter part of the photoreceptor by exposing the entire surface of the image forming surface to light that passes through only one type of filter part of the plurality of types of filters, and the potential pattern is applied to a specific color. A monochromatic toner image is formed by a developing device containing toner. After charging to smooth the potential, the entire surface is exposed to light that passes through a different filter part than the previous one, and development is performed using a developing device that stores toner of a different color than the previous one. A second color toner image is formed on the body. Thereafter, charging, full-surface exposure, and development are repeated as many times as necessary. As a result, toner of different colors adheres to each filter portion of the photoreceptor, forming a multicolor image (Japanese Patent Laid-Open No. 60-225855 and Japanese Patent Application No. 59-187).
No. 044, No. 59-185440, No. 6072295
(See specification No. 24). According to this multicolor image forming method,
Since only one image exposure is required, there is no risk of color misregistration.

In this multicolor image forming method, color reproduction is performed by so-called additive color mixing in which colors are not superimposed at the same position in principle. In other words, for example, to reproduce black using toners of three colors, yellow, magenta, and cyan, these toners are arranged on a recording medium so that they do not overlap each other, and black is produced as a composite of the reflected light of each color component. expressed. Of course, in reality, subtractive color mixing, which is the mixing of three color toners, also occurs during the development, transfer, separation, and fixing steps. Therefore, in addition to solving the above-mentioned color shift problem, the fidelity of color reproduction is high.

As a result of repeated studies, the inventor of the present invention has found that the above-mentioned multicolor image forming method has solved the problems of the conventional methods described above, but the following problems still remain. It has been found.

(1) When a single layer is used as the photoconductive layer of a photoreceptor, charge is usually injected from a conductive substrate or a charge injection layer is provided on the substrate side.

For example, aluminum substrates are not preferred for selenium photoconductive layers, and nickel or stainless steel substrates are preferred.

When such a photoreceptor is used, prior to the above-mentioned image exposure process, charges are transferred from the charge injection layer into the photoconductive layer by charging the surface of the insulating layer, and the interface between the insulating layer and the photoconductive layer is transferred. However, during the image exposure process under charging with a polarity opposite to that of the previous charging, all the charges may not be able to move to the interface due to charge mobility or internal traps. .

Therefore, the potential contrast obtained becomes small. Furthermore, it takes time to complete the transfer of charges, which is disadvantageous from the viewpoint of speeding up processing.

(2) In addition to the above-mentioned photoconductive layers, the photoconductive layer includes a charge generation layer containing a charge generation substance (hereinafter sometimes referred to as CGL) and a charge transfer layer containing a charge transfer substance (hereinafter referred to as CGL).
There is a structure in which two layers are laminated: CTL (sometimes referred to as CTL). A photoreceptor configured in this way has the advantage of being able to easily obtain a panchromatic spectral sensitivity distribution that matches the light source and filter, and has a wide range of material selection, and also has good charge retention ability. It is.

However, in the image forming method described above, when using a photoreceptor in which conductive substrates CTL, CGL, and an insulating layer having a mosaic filter are laminated in this order, charging and uniform exposure (
For example, by uniform exposure with white light), positive and negative charges are generated in the CGL, one charge moves through the CTL layer, and the other charge is accumulated at the interface between the insulating layer and the photoconductive layer. However, by the next image exposure under reverse polarity charging, CG
The charge generated in L and to be transferred to the conductive substrate side is
Since the polarity is opposite to that of the charge transferred in the previous process, CTL
(CTL usually has an electron transfer type and a hole transfer type, and only one of electrons and holes moves.), and therefore has no photosensitivity.

As a result of intensive research, the inventors of the present invention succeeded in solving the above problem by imparting charge transfer ability of both positive and negative polarities to the photoconductive layer.

23. Object of the Invention The present invention retains the advantages of the image forming methods described in Japanese Patent Application Laid-open No. 60-225855, Japanese Patent Application No. 59-187044, and Japanese Patent Application No. 59-185440, and furthermore It is an object of the present invention to provide an image forming method capable of solving the above-mentioned remaining problems and stably forming a high-quality image by stabilizing the charging potential of a photoreceptor without causing color shift.

E1 Structure of the Invention The first aspect of the present invention relates to a photoreceptor having a color separation function section, a photoconductive layer having a bipolar charge transfer ability, and having an insulating surface side.

A second aspect of the present invention is to apply a photoreceptor from the side of the color separation function to a photoreceptor having a photoconductive layer having a bipolar charge transfer ability and having an insulating surface side. The present invention relates to an image forming method that repeats the steps of performing image exposure, then performing full-surface exposure with specific light to form a potential pattern in a portion corresponding to the color separation functional portion, and developing.

To, Example Hereinafter, the present invention will be described in detail with reference to illustrated examples.

Note that the illustrated example uses red light and
An example is shown in which three types of filters, red, green, and blue, which transmit green light and blue light, and three types of corresponding color toners are used. It is not limited.

1 to 11 and FIGS. 15 and 16 are cross-sectional views schematically showing the structure of the photoreceptor used in the present invention, and FIGS. 12 to 14 are cross-sectional views of the insulating layer of the photoreceptor, respectively. FIGS. 17 and 23 are plan views showing examples of filter arrangement in the filter distribution layer; FIGS. 17 and 23 are schematic configuration diagrams showing examples of apparatus for implementing the method of the present invention;
22 and 22 are process diagrams of the method of the present invention, and FIG. 20 is a graph showing time-series changes in the surface potential of the photoreceptor according to the process. FIG. 24 is a sectional view of the developing device.

In Figures 1 to 8, 1 is made of metals such as aluminum, iron, nickel, copper, etc. or their alloys, conductive films, etc., and is shaped into a cylinder, an endless helt, a sheet, etc. as required. Conductive substrate formed into an appropriate shape and structure, 10
1 is a transparent conductive layer formed by depositing or sputtering these metal alloys, tin oxide, indium oxide, etc.; 2 is a photoconductive layer (details will be described later); 3 is various polymers;
An insulating layer (details will be described later) including a distribution layer 3a of a color separation filter of red (R), green (G), blue (Japanese), etc. formed of a resin or the like and a coloring agent such as a pigment or dye. be.

Figures 1 to 6 show a charge generating material (C) as photoconductive N2.
This is an example using a layer (hereinafter sometimes referred to as (CGM+CTM)) 2a containing 2g of GM) and 2t of a bipolar charge transfer material (CTM).

The insulating layer 3 in the photoreceptor shown in FIG. 1 is formed by printing an insulating material such as a resin colored with a coloring agent to form a color separation filter on the photoconductive layer 2, using photoresist, or the like.
The insulating layer 3 in the photoreceptor of FIG. 2, which is formed by depositing it in a predetermined pattern by means such as vapor deposition, is a transparent N layer previously formed on the photoconductive layer 2 by a conventionally known means.
A filter layer 3a with a predetermined pattern is formed on the surface of fAalN 3b, and the insulation N in the photoreceptor shown in FIG.
3 is a filter layer 3a sandwiched between transparent insulating layers 3b, and the insulating layer 3 in the photoreceptor shown in FIG.
A filter layer 3a is formed on the photoconductive layer 2 side, and a transparent insulating layer 3b is formed on the outside thereof. These filter layers 3a are formed by printing, vapor deposition, photoresist, dyeing, or other means.

The insulating layer 3 may be formed by first forming an insulating film or sheet containing the filter layer 3a, and attaching or adhering it onto the photoconductive layer 2 by appropriate means.

Additionally, the present applicant had previously proposed a photoreceptor (patent application filed in 1983).
-199547). For example, as shown in FIG. 5, an insulating layer 3c is provided on one surface of the photoconductive layer 2, and a transparent conductive layer 3c is provided on the other surface. and an insulating layer 3a consisting of a color separation filter are sequentially deposited to form a laminated structure. The transparent conductive layer +01 is formed by, for example, vapor depositing a metal.

In the photoreceptor having this structure, charging, which will be described later, is performed from the side of the insulating layer 3c, and image exposure and overall exposure are performed from the side of the insulating layer 3a, which is a color separation filter.

Further, as shown in FIG. 6, for example, in the case of a drum-shaped photoreceptor, a transparent insulating layer 3b is provided on the photoconductive layer 2, and a minute gap md is provided on the transparent insulating layer 3b so that R, G, and day filters are separated from each other. A layer 103 (similar to the layer 3a) can also be provided coaxially. That is, a cylindrical body +03 consisting of R, G, and 3 filters is coaxially fitted onto a drum-shaped photoreceptor having no filter, leaving a minute gap md, and integrated. By adopting such a structure, FIGS. 12, 13 and 1
Any filter layer having the structure shown in FIG. 4 (details will be described later) can be selected, replaced, and used. however,
The gap md causes the image of the filter cell to become extremely blurred and the insulating layer
The size should not be too large so as not to be projected onto the photoconductive layer.

Further, the transparent insulating layer 3b and the filter layer 3-2 may not be completely separated from each other, but may be in contact with each other.

The photoreceptor shown in FIGS. 7 and 8 has a charge generation layer 2c and a bipolar charge transfer layer 2b laminated as photoconductive N2.

The photoreceptor shown in FIG. 7 has a CTL 2b on a conductive substrate 1,
The photoreceptor shown in FIG. 8, which has a structure in which CQL2C and an insulating layer 3 are sequentially deposited and laminated, has a structure similar to that shown in FIG. Transparent insulating layer 3C on CTL2b side, CGLZ
It has a structure in which a transparent conductive layer +01 and an insulating layer 3a consisting of a color separation filter are sequentially deposited and laminated on the c side.

The distribution layer 3a of the color separation filter, which is formed by adhesion of colorants, colored resins, etc. on the insulating layer 3, has R, G,
Although the shape and arrangement of fine filters such as El are not particularly limited, those shown in FIGS. S, 10, and 11 are used. In addition, a striped distribution as shown in Fig. 12 is preferable because the pattern formation is knotty, and a pattern with a striped distribution as shown in Fig. 12 is preferable because it reproduces a delicate multicolor image.
A mosaic distribution as shown in the figure and FIG. 14 is preferable. The direction in which the R, G, B, etc. filters are arranged may be in any direction in the spreading direction of the photoreceptor, not only in a mosaic distribution but also in a stripe distribution.

That is, for example, in the case of a rotating drum-shaped photoreceptor, the arrangement direction may be parallel to, perpendicular to, or oblique to the axis of the photoreceptor.

The types of filters are not limited to the three types of R, G, and B, but also three types of other colors, such as Y (yellow), M (magenta),
It may be C (cyan), or when used for two colors instead of full color, it may be a color separation filter in which a white light transmitting portion and a specific color light (for example, red) transmitting portion are distributed. If the individual sizes of filters such as R (red), G (green), and B (blue) become too large, image resolution and color mixing will decrease, resulting in deterioration of image quality, and if they become too small, toner Even if the particle size is the same as or smaller than the particle size, it will be easier to receive shadows from other adjacent color areas, and it will be difficult to form the distribution pattern of the filter. For the distribution of three types of filters, the length! ! It is preferable that the width or size is such that 1.12 is 30 to 500 μm. Of course, if the number of types of filters changes, the preferable range of the above-mentioned length 11.2□ will also change.

Note that each filter preferably has a high abrasive resistance. If the resistance is low, they can be electrically insulated from each other by providing a gap or interposing an insulator. Note that the filter having the structure of the photoreceptor shown in FIGS. 5 and 8 may have a low resistance.

The layer 3a made of the color separation filter as described above is not provided,
A photoreceptor whose photoconductive layer is provided with a color separation function can also be used. FIGS. 15 and 16 show an example of a photoreceptor previously proposed by the present applicant (Japanese Patent Application No. 59-201085).

The photoreceptor shown in FIG. 15 has photoconductive parts 2R12G and 2B having a required spectral sensitivity distribution on the conductive substrate 1, for example, red (R
), green (Q), and blue (B), and includes a photoconductive layer +02 including a large number of photoconductive parts capable of transferring bipolar charges,
A transparent insulating layer 3b is provided thereon.

In the photoreceptor shown in FIG. 16, a bipolar charge transfer layer 112b is provided on a conductive substrate 1, a charge generation layer 112a made of 2R12G is provided on a portion having a different spectral sensitivity distribution, and a charge generation layer 112a made of 2R12G is provided on top of the bipolar charge transfer layer 112b. It has a structure in which a transparent insulating layer 3b is provided. In the photoreceptor shown in FIG. 16, a photoconductive layer +12 is constituted by a charge generation layer 112a and a charge transfer layer 112b.

Photoconductive layer 102 in FIG. 15 and charge generation layer 1 in FIG. 16
The planar structure of 12a may be the same planar structure as shown in FIG. 12, FIG. 13, or FIG. 14, similar to the insulating layer made of the color separation filter described above.

A desirable embodiment of the present invention is to generate charges on the side of the photoconductive layer irradiated with the imagewise exposure light and -like exposure light, that is, on the side of the color separation filter, both during imagewise exposure and during charge injection prior to imagewise exposure. do.

The reason is as follows. If a charge is generated on the side opposite to the side irradiated with imagewise exposure light during imagewise exposure, the imagewise exposure light will be absorbed by the photoconductive layer in front of it, resulting in a significant decrease in photosensitivity and changes in spectral sensitivity. This makes it difficult to obtain high-quality images. By generating charges in the layer on the imagewise exposure light irradiation side as described above, absorption of the imagewise exposure light midway is almost negligible, and charge generation is sufficiently performed.

Furthermore, even when charge is injected prior to imagewise exposure, if charges are generated on the side opposite to the -like exposure light irradiation side, the uniform exposure light will be absorbed by the photoconductive layer in front of it, and the charge generation will be delayed. Efficiency decreases. In other words, it is preferable to uniformly expose the photoconductive layer and to generate charges on the imagewise exposed side and to move the charges.

The thickness of the photoconductive layer 2 having bipolar charge transfer ability used in the photoreceptor of the present invention is suitably in the range of 10 to 100 μm, preferably 20 to 60 μm. The appropriate thickness is 10 to 100 μm, preferably 15 to 50 μm.

If the charge generation layer 2C12d is too thick, satisfactory photosensitivity cannot be obtained, so the appropriate thickness is in the range of about 0.1 to 10 μm, and it can be formed by a vapor deposition method, a plating method, etc. .

The photoconductive layer 2a and the charge transfer layer 2b are mainly made of a substance that has the function of transferring both positive and negative charges, that is, a bipolar charge transfer substance. The charge transfer layer 2b includes at least a substance that transfers positive and negative charges, or includes both a substance that transfers only positive charges and a substance that transfers only negative charges. Charge generation layer 2
a contains at least a charge-generating substance and a bipolar charge-transfer substance.

At this time, when the charge generation substance does not have charge transfer ability, a bipolar charge transfer substance is added as in the charge transfer layer 2b, and when the charge generation substance has only one charge transfer ability, , add at least a charge transfer substance of opposite polarity. Even when the charge generating substance has a bipolar charge transfer ability, a charge transfer substance is added as necessary. In addition, a charge transfer substance can be added to both 2a and 2b if necessary.

The photoconductive layer 2a and the charge transfer layer 2b can contain a binder resin, a Lewis acid and/or a Bronsted acid, etc., if necessary. For example, by mixing these together in a solvent and applying this mixed solution to the substrate 1.101 or the charge generation layer 2d.
The photoconductive layer 2a or the charge transfer layer 2b can be formed by coating and drying the photoconductive layer 2a or the charge transfer layer 2b.

The blending ratio of each component in the photoconductive layer 2a and the charge transfer layer 2b is preferably within the range of 0 to 400 parts by weight of the binder resin to 100 parts by weight of the charge transfer substance, particularly 100 to 400 parts by weight of the binder resin. 200 parts by weight is desirable. Further, it is desirable that the amount of the charge generating substance in the photoconductive layer 2a is 10 to 400 parts by weight.

Next, examples of bipolar charge transfer substances are shown. Photosensitive layers using these can be charged to both polarities using the Carlson method,
It has photosensitivity. Note that the P type and N type described below mean that they have the ability to move holes or electrons, respectively.

Charge transfer complex (TC complex) with (U.S. Pat. No. 34823)
7 specification).

(2) A eutectic complex in which a eutectic complex of 5% N-type trifluoride and polycarbonate resin is dispersed in an equimolar matrix of polycarbonate and P-type substituted triphene (US Pat. No. 3,615,414).

Since this alone does not have sensitivity in the wavelength range of 400 to 500n+n, a photoconductive substance is further added. These additives include, for example, Hg S , P b 30 a , Cd S
It is preferable to add a necessary amount of inorganic photoconductive substance fine powder such as . This results in panchromatic sensitization.

(3) Phthalocyanine dyes such as metal phthalocyanine and metal-free phthalocyanine (4) In addition, P-type and N-type charge transfer substances can be contained together to impart bipolar charge transfer ability.

Specific examples of such substances are as follows.

(i) Okori-rualkane type substance (P type) skin A=CH:l or OCH.

(ii) Biladurin-based substances (P-type) R = R's For example, (iii) Oxadiazole-based substances (P-type), e.g. (iv) Hydrazone-based substances (P-type), e.g. (v) Styryl-based substances (P-type) ) RrlCH= CH'r-A r (state office)? −
0, S + R = alkyl Ar = 1 negative, unsubstituted phenyl For example (vi)) Riphenylamine compound'If (P type) For example (vilO Biphenylamine type substance (p type) For example (ix) Carbazole type substance (P type) For example, the photoconductive layer 2a and the charge generation layer 2d, which are made of a fluorenone derivative such as (x) trinitrofluorenone (TNF) (N soybean inorganic substance or organic dye), may be formed by vapor deposition or a charge generation substance as necessary. It is provided by applying a solution containing a binder resin and, if necessary, a charge transfer substance.

Note that the charge generation layer 2C12d is composed of the above-mentioned (CGM+CTM) layer 2 so that the generated charges can be sufficiently transferred.
It consists of 2g of charge generation material, 2t of charge transfer material and binder resin, and the amount of 2g of charge generation material is about 30
It is more preferable to increase the amount to 95% by weight.

The charge-generating substance contained in the charge-generating layers 2c, 2d and the photoconductive layer 2a may be any material as long as it absorbs light in the entire visible range and generates free charges in consideration of color reproduction, and also has a charge transfer ability. Even better if it is.

The material of the charge generation substance 2g in the charge generation layers 2c, 2d and (CGM+CTM) layer 2a is Se, Se-T.
e, metals such as Se-Te-As, CdS.

In addition to inorganic compounds such as ZnS, CdS, e2, ZnO, etc., the following organic dyes can be used.

(1) Phthalocyanine dyes such as metal phthalocyanine and metal-free phthalocyanine (ii) Azo dye such as monoazo dye and disazo dye A-N-N-Ar-N=N-A and (iii) perulonic acid anhydride and perylene dyes such as perylenic acid imide (iv) indigo and thioindigo indigoid dyes (V) polycyclic quinone dyes such as anthrone, dibenzpyrenequinone, pyrantrone, violanthrone, and isobiocinthrone (vl) anthraquinone dyes vii) quinacridone dye (vi) cyanine dye (ix) benzimidazole dye (x) dioxane dye Examples of the binder resin used in each layer of 2a to 2d above include polyethylene, polypropylene, acrylic resin, methacrylic resin, Vinyl chloride resin, vinyl acetate resin, epoxy resin, polyurethane resin, phenolic resin,
Addition polymer resins such as polyester resins, alkyd resins, and polycarbonate resins, polyaddition polymer resins, polymer bond polymer resins, and 2 of the repeating units of these resins
Examples of copolymer resins containing at least one of the following include vinyl chloride-vinyl acetate copolymer resins, vinyl chloride-maleic anhydride copolymer resins, and the like. However, the binder resin is
The resin is not limited to these, and resins commonly used for such purposes can be used.

(5) In addition to the substances (1) to (3) above, amorphous silicon is an inorganic photoconductive substance that alone has bipolar charge transfer ability.

As an example of a photoconductor having a photoconductive layer mainly composed of amorphous silicon (a-3i), a charge generation layer made of amorphous hydrogenated and/or fluorinated silicon is coated with an amorphous hydrogenated and/or fluorinated carbide layer. The photoreceptor has a structure in which a surface modification layer made of silicon is provided, and a charge transport layer made of amorphous hydrogenated and/or fluorinated silicon carbide is provided below the charge generation layer.

When the above surface modified layer is expressed as a S il -x Cx, it satisfies 0.3≦X≦0.8, so it is resistant to mechanical damage, and the first problem in image quality due to white streaks, etc.
FIG. 7 shows an a-3i electrophotographic photoreceptor for positive charging. This photoreceptor includes a drum-shaped conductive support substrate 1 such as A1, and a charge transport layer 42 made of a-3iC2H lightly doped with an element of Group IA (for example, boron) of the periodic table; :H and a carbon atom content of 0.30≦X≦0.80 (for example, 0.5
0) amorphous hydrogenated silicon carbide (a-3i+-
It has a structure in which a surface modified layer 45 consisting of xcx:H) is laminated. The photoconductive layer 43 has a dark resistivity ρ.

The ratio of resistivity ρ when irradiated with light is sufficiently large as an electrophotographic photoreceptor, and the photosensitivity (particularly to light in the visible and infrared regions) is good.

The above a-3iC2H layer 45 is indispensable for modifying the surface of the photosensitive layer and making the a-3i photoreceptor practically excellent. That is, it enables the basic operations of an electrophotographic photoreceptor, such as charge retention on the surface and attenuation of the surface potential due to light irradiation. Therefore, the repetitive characteristics of charging and optical attenuation become very stable, and good potential characteristics can be reproduced even if left for a long period of time (for example, one year or more). On the other hand, in the case of a photosensitive layer having a-3i:H as its surface, it is easily affected by humidity, air, ozone atmosphere, etc., and the potential characteristics change significantly over time.

In addition, the film thickness of the a-3iC:H layer 45 is set to 400 ≤ 55
It is also important to select within the range of 000 people (particularly 400≦t<2000 people. In other words, if the film thickness exceeds 5000 people, the residual potential becomes too high and the photosensitivity decreases. Also, if the film thickness is less than 400, the dark decay will increase.

Further, the charge generation layer 43 has a thickness of 1 to 10 μm, preferably 2 to 10 μm.
The thickness is preferably 5 μm. If the thickness of the charge generation layer 43 is less than 1 μm, the photosensitivity will not be sufficient, and if it exceeds 10 μm, the residual potential will increase, which is insufficient for practical use. Charge transport layer 42
is preferably 10 to 50 μm.

Note that each of the above layers needs to contain hydrogen.

In particular, the hydrogen content in the photoconductive layer 43 is essential to compensate for dangling bonds and improve photoconductivity and charge retention, and is preferably 10 to 30%. This content range includes surface modification layer 45, charge transport layer 4
The same applies to 2.

The image forming apparatus shown in FIG. 18 forms a multicolor image by the method of the present invention using a drum-shaped image carrier 4 made of the photoreceptor as described above.

That is, the image carrier 4 rotates in the direction of the arrow, and the charger 5 charges it to a uniform potential while uniformly exposing its surface, and the image exposure device S scans the document with white light on the charged surface. Image exposure is performed by making reflected light or transmitted light incident through a slit in the charger while charging it with an alternating current or a charger that generates corona discharge of the opposite sign to the charger 5, and then coloring the charged surface. The exposure device 7B uniformly enters the blue light L8 that has passed through the blue filter F8, thereby forming an electrostatic latent image that provides a complementary color image of blue on the image exposure surface, and transfers the electrostatic latent image to the developer. A developing device 8Y using yellow toner performs development, and a charger 9Y performs corona discharge on the image carrier 4 after development, similar to the charger of the image exposure device 6.
is discharged to smooth the potential of the image carrier 4, and the color exposure device 7G emits green light through a green filter F onto the potential smooth surface, and the electrostatic charge is incident on the - direction to give a complementary color image of green. A latent image is formed, the electrostatic latent image is developed by a developing device 8M using magenta toner as a developer, and a charger 9M similar to the charger 9Y performs corona discharge on the image carrier 4 after development. The potential of the image carrier 4 is smoothed, and a color exposure device 7R is applied to the smoothed surface.
A developing device that uses cyan toner as a developer to form an electrostatic latent image that emits red light through a red filter F and uniformly enters I to form a complementary color image of red. 8C is developed, thereby forming a multicolor image consisting of a superposition of yellow, magenta, and cyan three-color toner images on the image carrier surface. This multicolor image is transferred by a transfer device 10 to a recording paper P fed by a paper feeding device (not shown), and the transferred recording paper is transferred to an image carrier 4 by a separator 11.
It is separated from the surface, a multicolor image is fixed by a fixing device (not shown), and the image is discharged outside the machine. The surface of the image carrier 4, onto which the multicolor image has been transferred, is neutralized by a static eliminator 12 that performs exposure and discharge, and residual toner is removed by a cleaning device 13, returning to a state in which the next multicolor image can be formed.

Each step of the multicolor image forming method of the present invention performed by the apparatus shown in FIG. 18 as described above will be further explained with reference to FIGS. 1S and 20. 19 and 20, a photoreceptor having the structure shown in FIG. 1 is used as the image carrier 4, and a material having electron and hole mobility is used as the material constituting the photoconductive layer 2. An example will be shown, and in FIGS. 19 and 20, the same reference numerals as in FIGS. 1 and 12 to 14 indicate the same functional members. In addition, Fig. 2 to Fig. 11, Fig. 1
There is no difference in principle even when photoreceptors having the structures shown in FIGS. 5 to 17 are used.

FIG. 19 is a diagram illustrating the generation and movement of charges in the process from the formation of a charge layer at the interface between the insulating layer 3 and the photoconductive layer 2 to the overall exposure ratio of specific light.

As shown in FIG. 19 [1], when uniform exposure with white light or infrared light from the light source 5b is performed at the same time as negative discharge by the charger 5a of the -order charging device 5, the surface of the insulating layer 3 At the same time, positive and negative charges consisting of electrons and holes are generated on the upper layer side of the photoconductive layer 2 by the −-like exposure light, and among these, the negative charges pass through the photoconductive layer 2. Move to the conductive substrate 1.

Next, as shown in Fig. 1S [2], when image exposure is performed while positive or alternating current corona discharge is being performed by the secondary charger 6, red light is emitted. To explain, the negative charge on the surface of the insulator N3 is partially dissipated by positive or alternating current corona discharge in parts other than the R filter part. In the R filter section, the red light LR passes through the R filter section and irradiates the photoconductive layer 2, so positive and negative charges are generated near the surface, and the negative charges neutralize the trapped positive charges. Since the generated positive charges escape to the ground circuit through the photoconductive layer 2 and the conductive substrate 1, the positive charges at the interface between the insulating layer and the photoconductive layer disappear, and the negative charges on the surface of the insulating layer 3 also disappear. Virtually disappear.

Next, as shown in Figure 19 [3], there is a blue light.

When the entire surface is exposed to light, blue light does not pass through the parts other than the B filter part, so there is no change, but the blue light passes through the B filter part, and some of the positive charges underneath are transferred to the photoconductive layer 2. through the conductive substrate 1.

FIG. 20 [1] shows a state in which the image carrier 4 rotates and is uniformly charged by uniform exposure and negative corona discharge from the charger 5, and the surface of the insulating layer 3 is negatively charged. Correspondingly, a positively charged layer is formed at the interface between the photoconductive layer 2 and the insulating layer 3, and as a result, the surface of the image carrier 4 exhibits a uniform potential as seen in the potential E graph.

FIG. 20 [2] shows the change in the charged surface due to the red component, I, of the original image exposure that the image exposure device 6 makes incident on the above-mentioned charged surface, and the red component Lll shows the R filter portion of the insulating layer 3. By passing through the photoconductive layer 2 and generating charges near the surface of the photoconductive layer 2, the positive charges trapped by the negative charges disappear, and by moving the generated holes to the conductive substrate, light is released in that area. The positive charge on the interface between the conductive layer 2 and the insulating layer 3 disappears, and the negative charge on the surface of the insulating layer 3 is also erased by the discharge from the charger of the image exposure device 6, so that no charge exists (the principle is For the sake of explanation, I will focus on the red component, the part with strong l.) On the other hand, since the red component does not pass through the G and B filter portions, the negative charge of the photoconductive layer 2 remains in those portions, and even if discharge is performed by the discharger, the image exposure device 6
After passing through the position, a photoconductive layer 2 is formed on the surface of the insulating layer 3.
The positive charge leaves a negative charge. However, not only the R filter part where the charge has disappeared, but also the G and B parts where the charge remains.
Also in the filter portion, the surface potential of the image carrier 4 due to positive and negative charges is balanced and becomes almost O as seen in the graph of the potential E. Although not shown in FIG. 20, the green and blue components of image exposure give similar results, and the integrated state of these is the state of image exposure performed by the image exposure device 6. In this state, a primary latent image is formed which does not function as an electrostatic image.

FIG. 20 [3] shows that the blue filter F is exposed by the color exposure device 7B.
The figure shows a state in which the blue light transmitted through the light is uniformly incident on the above-mentioned image exposure surface. Blue glow.

does not pass through the R and G filter parts, so there is no change in those parts, but it passes through the B filter part and makes the photoconductive layer 2 below it conductive, thereby making the photoconductive layer in that part conductive. 2 is erased, and as a result, a potential appears on the surface of the insulating layer 3 on the surface of the insulating layer 3, as shown in the graph of potential E, which gives a complementary color image of the day formed by the previous image exposure. .

The steps up to this point are the same as those already explained with reference to FIG. 1S.

FIG. 20 [4] shows a state in which an electrostatic latent image formed by full-surface exposure to blue light L3 is developed by a developing device 8Y using yellow toner TY, which is the complementary color of the day it was negatively charged, as a developer. There is. The yellow toner TY adheres only to the B filter portion that shows a potential, and does not adhere to the R and G filter portions that do not show a potential. As a result, a color-separated one-color yellow toner image is formed on the surface of the image carrier 4. The potential of the B filter part is yellow toner TY.
However, as shown in the graph of potential E, it still remains, and in the next development, another toner may adhere to this area, causing color smudging.

FIG. 20C5) shows a state in which corona discharge is performed by the charger 9Y on the surface of the image carrier 4 developed by the developing device 8Y in order to prevent other toner from adhering to the B filter portion. ing. This discharge by the charger 9Y, unlike the strong discharge by the charger 5, has little effect on the R and G filter portions, and mainly lowers the potential of the filter portion to which the yellow toner TY is attached. Therefore, the surface potential of the image carrier 4 uniformly shows almost 0 as seen in the graph of the potential E. This prevents other toner from adhering to the B filter portion to which the yellow toner TY has adhered in the next developing process, and color clouding is prevented from occurring.

Therefore, this yellow toner image is formed as shown in FIG.
When the entire surface of the image carrier 4 (5) is exposed by the green light LG by the color exposure device 7G, an image potential appears in the G filter portion, as described in FIG. 20 (3). When this electrostatic latent image is developed by a developing device 8M using magenta toner as a developer, the magenta toner adheres only to the G filter portion and a magenta toner image is formed as in FIG. 20 [4]. This means that the two color toner images are superimposed. Corona discharge is also performed on this image forming surface by the charger 9M to lower the potential of the G filter portion to which the magenta toner has adhered, thereby preventing other toner from adhering to that portion. These processes are shown in FIGS. 20 [6], [7] and [8].

Furthermore, even if the surface of the image carrier 4 on which the two-color toner image is formed is exposed entirely to the red light LR by the color exposure device 7R, no image potential appears in the R filter portion, so the static The electrolytic latent image is not developed by the developing device 8C using cyan toner as a developer, and no cyan toner image is formed. As a result, a clear red image consisting of yellow and magenta without color shift or color turbidity is formed on the image carrier 4.

FIG. 20 above shows an example in which the photoconductive layer 2 of the image carrier 4 has a higher mobility of holes than electrons for image exposure. Of course, it is possible to use a photosensitive layer with a high value, and in that case, the basic process is the same except that the positive and negative signs of the charges are all reversed.

That is, by imparting bipolar charge transfer ability, the charging polarity can be determined so that a better image can be formed in accordance with the characteristics of the photoconductive layer, and the sensitivity of the photoreceptor can be increased. Furthermore, although the surface potential of the image bearing member 4 after charging in FIG. 20 [2] is set to almost O, it may be slightly biased toward the negative or positive side.

Table 1 shows the relationship between the colors of the original image and image formation using the three primary color toners using the above-mentioned three-color separation method.

In the table, 2 indicates a primary latent image, ○ indicates an electrostatic latent image, ■ indicates a toner image, ↓ indicates a state in which the state in the upper column is maintained, and a blank indicates a state in which no image exists. There is. Also, - in the attached toner column indicates that no toner is attached, Y...
M and C indicate that yellow toner, magenta toner, and cyan toner are attached, respectively.

(Margins below) Furthermore, FIG. 21 shows the situation in which the surface potentials at each filter portion B, G, and R of the photoreceptor change according to the above-mentioned image forming process, and 5.6.7B on the horizontal axis, 8Y, 9Y
, 7G, 8M, 9M, and 7R18C indicate steps in which members with the same reference numerals as those in FIG. 14 or FIG. 20 act on the image carrier 4, respectively, and E3. G and R indicate the highest or average potential of each filter portion.

Figures 22 [1] to [3] and Figures 1S showing the generation and movement of charges when the photoreceptor shown in Figure 7 is used [1] to [
3].

Fig. 22 differs from Fig. 1S only in that the photoconductive layer 2 is of a functionally separated type consisting of a charge transfer Fi 2b and a charge generation layer 2c, and the generation and movement of charges are exactly the same as in Fig. 19. It is.

In the multicolor image forming apparatus shown in FIG. 23, a toner image of one color is formed in one rotation of the image carrier 4, and the entire surface is covered by lamps equipped with blue, green, and red colors that are used either selectively or simultaneously. The multicolor image forming apparatus differs from the multicolor image forming apparatus shown in FIG. 18 in that exposure is performed and the surface potential of the image carrier 4 after development is made uniform using the charger 6 of the image exposure device. Similar to the multicolor image forming apparatus shown in FIG. 18, this multicolor image forming apparatus also performs the same image forming operation as described with reference to FIGS. It is possible to form monochromatic images with excellent resolution. That is, when forming a three-color image, for example, the image carrier 4 is uniformly exposed and charged by the charger 5a, image exposure is performed through the charger 6, and then the surface of the image carrier 4 is exposed to blue light from the lamp 7. The entire surface is exposed to light, and the potential pattern formed thereby is developed by the developing device 8Y to form a yellow toner image. This toner image is produced by developing devices 8M, 8C18K,
It passes through without being affected by the pre-transfer charger 14, the transfer device 10, the separator 11, the cleaning device 13, and the charger 5.

When the image carrier 4 on which the toner image has been formed reaches the position of the charger 6, it undergoes corona discharge to make the surface potential uniform, and the entire surface is exposed to green light obtained from the lamp 7, forming a potential pattern. be done. Next, this is the developing device 8M
A magenta toner image is formed. In the same way, the surface potential is made uniform, a potential pattern is formed using red light, and development is performed by the developing device 8C. If it is desired to obtain an even darker image, after the potential is smoothed, the whole surface exposure means 7 is used to apply white light or toner. The filter is irradiated with a highly transparent infrared light lamp to form a potential pattern and developed using an 8K developing device.
Development is performed by adding black toner to obtain a color toner image.

This multicolor image forming apparatus has a simple configuration that is almost the same as a monochrome copying machine except for the increased number of developing devices, and has the advantage of being smaller and lower in cost. In FIG. 23, the same reference numerals as in FIG. 18 indicate the same functional members.

A magnetic brush developing device as shown in FIG. 24 is preferably used as the developing devices 8Y to 8K in the multicolor image forming apparatus shown in FIGS. 18 and 23.

The developing device shown in FIG. 24 includes a developing sleeve 81 and a magnet body 82 having N and S magnetic poles on the inner peripheral surface of the developing sleeve 81.
Of these, one rotates and conveys the developer adsorbed to the surface of the developing sleeve 81 from the developer reservoir 83 by the magnetic force of the magnet body 82 in the direction of the arrow. A developer layer is formed by regulating the amount of conveyance by the thickness regulating blade 84, and the developer layer is applied to the image carrier 4 in the developing area facing the developing sleeve 81.
Develop according to the potential pattern. During development, a developing bias voltage is applied to the developing sleeve 81 by a bias power supply 80 . Furthermore, even when development is not performed as necessary (when development is turned off), it is possible to prevent toner from transferring from the developing sleeve 81 to the image bearing member 4 or from the image bearing member 4 to the developing sleeve 81. To prevent this, a bias voltage may be applied to the developing sleeve 81.

In addition, when the development is OFF, the intersection of the development (when ON)! Either the bias component is canted to leave only the DC bias component, the system is placed in a floating state, it is grounded, a DC bias of the same polarity as the toner is applied, or the developing device is separated from the image carrier.

Moreover, these treatments can also be used in combination. 85 is a cleaning blade that removes the developer layer that has passed through the developing area from the developing sleeve 81 and returns it to the developer reservoir 83; 86 is a stirring blade that agitates the developer in the developer reservoir 83 to make it uniform and triboelectrically charges the toner. A means 88 is a toner replenishing roller that replenishes toner from the toner hopper 87 to the developer reservoir 83.

The developer used in such a developing device may be a so-called one-component developer consisting only of toner, or a two-component developer consisting of toner and a magnetic carrier. For development, a method may be used in which the developer layer, that is, the surface of the image carrier is directly rubbed with a magnetic brush, but especially after the second development, the developer layer should be kept at IqI to avoid damage to the formed toner image. ? A developing method that does not contact the surface of the storage medium, for example, U.S. Patent No. 3,893,
Specification No. 418, Japanese Unexamined Patent Publication No. 18656/1983, especially Japanese Patent Application No. 57446/1982, and Japanese Patent Application No. 238295/1983
It is preferable to use the methods described in the specifications of Japanese Patent Application No. 58-238296. Among these methods, a one-component or two-component developer containing a non-magnetic toner whose coloring can be freely selected is used, an alternating electric field is formed in the development area, and development is performed without contact between the electrostatic image carrier and the developer layer. It is preferable to do this. In this non-contact development, the gap between the developing sleeve and the surface of the photoreceptor is set to be larger than the layer thickness of the developer layer on the developing sleeve (provided there is no potential difference between the two), and this gap and layer thickness are Development is carried out under various conditions as described above.

The color toner used for development consists of known binding resins, organic and inorganic pigments, dyes and other chromatic and achromatic colorants, and various magnetic additives, which are commonly used in toners.
Toner for electrostatic development made by known technology can be used, and as a carrier, iron powder, ferrite powder, which are usually used for electrostatic images, resin-coated materials thereof, or magnetic material dispersed in internal resin can be used. Various known carriers, such as magnetic carriers such as

In addition, the applicant filed the patent application No. 58-24966 earlier.
The developing method described in No. 9, No. 240066 may be used.

In the present invention, as a charger for charging the surface of the image bearing member that has been developed before every second and subsequent full-surface exposure, a charger that performs biased or unbiased AC corona discharge is used. , or a DC charger is used. In particular, in the case of a DC charger, a scorotron charger with a grid that can control the charging potential is preferable to a corotron charger with only a charging wire, and the charging potential is approximately the same as that at the end of the secondary charging simultaneous image exposure process. It is preferable that there be. For example, if the potential of the toner adhesion area is biased toward positive when the secondary charging and simultaneous exposure process ends at OV, set the grid of the scorotron charger to approximately OV (for example, ground it) and apply a negative voltage to the charging wire. Just apply it.

The effects of the above-mentioned charging treatment include, as already mentioned, the effect of sufficiently lowering the residual potential of the area to which toner has adhered during the previous development and preventing other toner from adhering to the same area. This also provides the effect of preventing an increase in the potential on the surface of the photoreceptor due to dark decay of the potential of the photoconductive layer, and the effect of imparting a sufficient amount of charge to the toner so that a toner image can be transferred satisfactorily later. Regarding this, see Figure 18 and 2.
In order to compare with the embodiment of the present invention described in connection with Figure 0, a three-color image was formed under the same conditions except that the chargers 9Y and 9M immediately after the developing devices 8Y and 8M were removed. The recorded image had poor color tone and was very inferior compared to the original image. On the other hand, in the case of the above-mentioned embodiment, not only was a recorded image with clear colors almost the same as the original image obtained, but the toner transfer rate was also increased, and the toner was collected in the cleaning device 13. The effect of reducing the amount of toner used was also obtained.

As is clear from the above, the charging process for the purpose of averaging before development is extremely important for obtaining a good multicolor image.

Specifically, in the image forming apparatus shown in FIG. 18, the image carrier 4 is made of a photoreceptor with the layer structure shown in FIG. A 20 μm thick polyethylene film with a 2 μm thick filter printed on it was used, and a silicon face (Shin-Etsu Silicone KR-10) was used on the printed surface.
The adhesive layer using 1) was constructed as shown in Fig. 4. 1st
RlG in Figure 3 includes a filter layer 3a in which β5.12 of the distribution of the filter part is both 100 μm, and the diameter is 20 μm.
The image carrier 4 having a diameter of 0 mm was rotated in the direction of the arrow at a linear velocity of 50 mm/sec.

While irradiating the image carrier 4 with white light from the light source 5a, -
After charging the charger 5b with a corotron charger, the surface potential of the image carrier 4 becomes -2.5 kV, and the image exposure device 6
It is assumed that the surface potential of the image carrier 4 becomes +100 V after discharging with a scorotron charger, and each developing device 8
Y~8C is made of non-magnetic stainless steel with an outer diameter of 25 mm.
The developing sleeve rotates counterclockwise at a rotation speed of 153 rpm,
The internal magnet body has 8 magnetic poles in the circumferential direction that provide a maximum magnetic flux density of 800G to the surface of the developing sleeve, and the rotation speed is 800 rpm.
The magnetic brush developing device rotates clockwise at a rotational speed of m to convey the developer layer, and each of the developing devices 8Y to 8C has an average particle diameter of 5 μm for yellow, magenta, and cyan, respectively.
Using a developer in which a toner with a triboelectric charge amount of +10 to +20 μc/g and a carrier made of a resin containing dispersed magnetic material with an average particle size of 25 μm and a specific resistance of 1013 Ωcm or more are mixed at a weight ratio of 1:4, The layer thickness of the developer layer formed on the developing sleeve of each developing device 8Y to 8C is 0.5 mm, the gap between the image carrier and the developing sleeve is 0.7 mm, and each developing device 8Y to 8C performs development, respectively. Sometimes, a developing bias in which a DC voltage of +50V and an AC voltage with an effective value of 1 kV and a frequency of 2 kHz are superimposed is applied to the developing sleeve, and the smoothing by the chargers 9Y and 9M is performed by the first
As an example, the second condition is to apply a DC voltage of +100■ to the back plate and an AC voltage of 6 kV to the charging electrode.
As an example, the back plate is grounded and the charged electrode is connected to +5.5
Apply a DC voltage of kV to increase the grid voltage by +100
When three-color images were copied under conditions of V, very clear images with good color reproduction were obtained in both the first and second examples with no color shift.

The potential contrast obtained was 200 to 400 square meters for the entire surface exposed to each specific light.

All of the above explanations have been made regarding an example of a color copying machine using so-called three-color separation filters and three primary color toners, but the present invention is not limited to the illustrated example, and the number and colors of separation filters and their It goes without saying that the combination of corresponding toner colors can also be arbitrarily selected depending on the purpose. For example, processes for obtaining two-color copies are also conceivable.

In addition, "charging" in the above description includes cases where the surface potential of the photoreceptor becomes O when charging is performed, and cases where the surface charge disappears.

Furthermore, in the above explanation, the spectral characteristics of light for full-surface exposure can be obtained using green (G), blue (Japanese), and red (R) filters, but they can also be obtained by means other than filters. Deyo(, also its spectral characteristics are G, B
, R, but the point is that it has spectral characteristics such that a latent image is formed only on a specific filter section (not limited to one type) corresponding to the specific light on the photoreceptor by full exposure to the specific light. Bye.

In addition, the image forming method of this embodiment is to form an electrostatic latent image by simultaneous exposure, secondary charging, image exposure, and tertiary charging, and then to form an electrostatic latent image on a specific filter using specific light. This includes an image forming method in which potential pattern formation and development are repeated (Japanese Patent Application No. 60-229524).

Moreover, the uniform exposure simultaneously with the -order charging can be carried out separately in the photosensitive layer. That is, the same effect can be produced even if uniform exposure is performed after -order charging.

Details of the invention As explained above, the present invention has the following effects.

(Photoconductor 11 is equipped with a color separation function section and has an insulating surface, so latent images for each color can be formed with one image exposure.
High-quality images can be easily obtained at high speed without causing color shift or color turbidity.

(2) Since the photoquaternary layer has an ambivalent charge transfer ability,
In the process of image formation, the charges of one polarity can be moved, and the charges of the other polarity can be moved, so that a charged layer can be reliably formed by -order charging. As a result, sufficient potential contrast can be stably obtained, color balance can be easily achieved, and a high-quality image can be formed.

[Brief explanation of drawings]

The drawings all show embodiments of the present invention, and FIGS. 1, 2, 3, 4, 5, 6, 7, and 8 show the photoreceptor. Cross-sectional view of FIG. 9, FIG. 10,
11, 12, 13 and 14 are plan views of color separation filters, 15, 16 and 17 are sectional views of other photoreceptors, and 18 is an image forming device. Schematic diagram of Figure 19 [1], [2], [3] and Figure 20 [1]
, [2], [3], [4], [5],
[6], [7], and [8] are process flow diagrams showing the image forming process. Figure 21 is a graph showing how the surface potential of the photoreceptor changes over time in accordance with the process. Figure 22 [1] , [2], [3] 11. lZi〆special／#
/, fl, y/z, f are process flow diagrams showing other image forming steps, FIG. 23 is a schematic diagram of another image forming apparatus, and FIG. 24 is a sectional view of a developing device. In addition, in the symbols shown in the drawings, 1...-m----------1 conductive substrate 2, l 1
2-・-・---m-photoconductive layer 2a, 102...---
---------Bipolar charge transfer photoconductive layer 2b, 1
12b, 42 -------...-1---- Bipolar charge transfer layer 2c,
2d, I 12a, 43 --- Charge generation layer 2g ---- Charge generation material 2t ---
------One charge transfer substance 3----・----m---・Insulating layer 3 a --------- Calendar day consisting of one color separation filter --- ---1.-Blue color separation filter G
−−−−−・・−・−Green color separation filter R−−−−−
−−−−−−・−Red color separation filter 4-1−−−・−
・-Photoreceptor 5.9Y, 9M・−・−・−・−−−−・Charger 6−
---------- Image exposure device 7.7B, 7G,
7R-------・-1----・-Full surface exposure device Fs,
Fc, Fc -------・--～---・Filter 8Y, 8M, 8C18K・-------～--・
This is a developing device. Agent Patent Attorney Hiroshi Aisaka Figure 5a Figure 6 Figure 7 Figure 8 Figure 21

Claims (1)

[Scope of Claims] 1. A photoreceptor having a color separation functional section, a photoconductive layer having a bipolar charge transfer ability, and having an insulating surface. 2. Imagewise exposure is performed from the side of the color separation function on a photoconductor, which is provided with a color separation function, a photoconductive layer having a bipolar charge transfer ability, and whose surface side is insulating, and then . An image forming method that repeats the steps of exposing the entire surface to specific light to form a potential pattern in a portion corresponding to the color separation function portion, and developing.