JPS6199162A - Multi-color image forming method - Google Patents

Abstract

PURPOSE:To adjust easily color balance in the stage of using a photosensitive body having a distribution layer of plural kinds of filters to form a multi-color image by changing the developing magnetic field to be generated between the photosensitive body and a developer carrying body of a developing device. CONSTITUTION:The photosensitive body 4 constituted of an insulating layer 2 consisting of the distribution of plural kinds of the filters, a photoconductive layer 1 and a conductive layer 3 is subjected to electrostatic charging and image exposure. The filter part of the specific kind among the filters on the surface of the layer 2 is then subjected to the full-surface exposure by a lamp to generate a potential pattern and the image of a yellow toner TY is formed by, for example, a developing device 8Y. The quantity of the toner to be transferred from the developer layer to the body 4 is controlled by changing the bias voltage to be impressed to the developer carrying body 81 by a bias power source 80 in the stage of said development, by which the density of the tone image of each color in the formation of the multi-color image is adjusted.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a multicolor image forming method using a photoreceptor suitable for forming multicolor images by electrophotography.

[Prior art]

Many methods and devices used therefor have been proposed for the purpose of obtaining multicolor images by electrophotography, but they can be generally classified into the following types. Part 1
One method is to use a single photoconductor and repeat the formation of a latent image by image exposure and development with color toner depending on the number of separated colors 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 in which colors are layered on the transfer material. The second method uses a device having a plurality of photoconductors corresponding to the number of separated colors, simultaneously exposes each photoconductor with a light image of each color, and transfers the latent image formed on each photoconductor to color toner. In this method, the image is developed with a 100% polyurethane resin, and then transferred onto a transfer material in order to obtain a multicolor image by overlapping the colors.

The first method has a major drawback in that it is necessary to repeat a plurality of latent image formation and development processes, which takes time to record an image, and that it is extremely difficult to speed up the process. In addition, the second method uses multiple photoreceptors in parallel, which is advantageous in terms of high speed, but requires multiple photoreceptors, an optical system, a developing means, etc., making the device complex, large, and expensive. Due to the price, it is not practical. In addition, both methods have the major drawback that it is difficult to align images during multiple image formations and transfers, and it is not possible to completely prevent image color misregistration. It also has the disadvantage that it is difficult to adjust.

In order to fundamentally solve these problems, it is sufficient to record a multicolor image on a single photoreceptor with one image exposure, but the reality is that such a system has not yet been developed.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned circumstances, and it is possible to form a multicolor image on a single photoreceptor at high speed with one image exposure, and the apparatus can be configured compactly. Furthermore, it is an object of the present invention to provide a multicolor image forming method in which color balance can be easily adjusted.

[Structure of the Invention] The present invention has an insulating layer on one side of a photoconductive layer and a conductive layer on the other side, and at least one of the insulating layer and the conductive layer is translucent and is a multi-A type photoconductive layer. A photoreceptor for forming a multicolor image having a layer consisting of a distribution of filters is used, and after the photoreceptor is charged and imagewise exposed, a specific type of filter among the filters is applied to the surface of the insulating layer of the photoreceptor. In a method of forming a multicolor image by repeating full-surface exposure that generates a potential pattern in a portion and development of the potential pattern, changing the developing electric field generated between the photoreceptor and a developer transport carrier of a developing device. The above object is achieved by a method for forming a multicolor image, which is characterized by adjusting the color reproduction of a multicolor image.

〔Example〕

The present invention will be explained below with reference to illustrated examples.

In the following explanation, a full-color reproduction photoreceptor is used as a color separation filter using red, green (G), and blue (B) filters that transmit substantially only red light, green light, and blue light, respectively. and a multicolor image forming method using the same will be described, however, the colors of the color separation filter and the color of the toner used in combination with the color separation filter in the present invention are not limited thereto.

1 to 13 are cross-sectional views schematically showing examples of the laminated structure of the photoreceptor used in the method of the present invention, and FIGS. 14 to 16 are filter layers showing examples of the distribution of color separation filters, respectively. A plan view, FIG. 1-7 is a process diagram for explaining the multicolor image forming method of the present invention, and FIG. 18 is a schematic sectional view of a developing device for explaining the developing method used in the present invention.
Figure 19 is a developer density graph showing an example of changing the developing electric field to adjust color reproduction, Figures 20, 21 and 23.
Each figure is a schematic front view showing an example of a recording apparatus that implements the method of the present invention, and FIG. 22 is a schematic side view showing an exposed portion of the recording apparatus shown in FIG. 21.

In FIGS. 1 to 13, 1 represents sulfur, selenium, amorphous silicon, or sulfur, selenium, or tellurium.

Photoconductors such as alloys containing arsenic, antimony, etc., or oxides of metals such as zinc, aluminum, antimony, bismuth, cadmium, molybdenum, etc.

Inorganic photoconductors such as iodides, sulfides, selenides, or vinylcarbazole, anthracenephthalocyanine, trinitrofluorenone, polyhinylcarpazole,
Organic photoconductive substances such as polyvinylanthracene and polyvinylpyrene are mixed into insulating binder resins such as polyethylene, polyester, polypropylene, polystyrene, polyvinyl chloride, polyvinyl acetate, polycarbonate, acrylic resin, silicone resin, fluorine resin, and epoxy resin. a photoconductive layer consisting of a dispersed organic photoconductor; 2 an insulating layer; 3
is a conductive layer. 1 to 4 and 9.
The insulating layer 2 shown in the figures to FIG. 13 is transparent and red (R
), green (G), and blue (Bl).
The insulating layer 2 in FIGS. 9 and 13 is entirely a filter layer 2a.
Insulating materials such as transparent resins are colored by adding coloring agents such as red, green, and blue dyes, respectively, and are adhered in a predetermined pattern onto the photoconductive Ml by means such as printing. It can be formed by On the other hand, some of the insulating layers 2 in FIGS. 2 to 4 and 10 to 12 are filter layers 2a, and the second
The insulating layer 2 shown in FIGS. 1 and 10 is formed by providing a transparent insulating layer 2b made of transparent resin or the like on the photoconductive layer 1, and then using the same method as the above-described method for forming the filter layer or by printing or vapor depositing a coloring agent. 3 and 11, in which the filter layer 2a is provided in a predetermined pattern by a method such as
The insulating layer 2 in the figure further has a transparent insulating layer 2b on the filter layer 2a, and the insulating layer M2 in FIGS. A transparent insulating layer 2b is provided thereon. The transparent insulating layer 2b between the photoconductive layer 1 and the filter layer 2a in the insulating layer 2 of FIGS. 2, 3, 10, and 11
The entire layer or a partial layer on the photoconductive layer 1 side may be a transparent adhesive layer. That is, these insulating layers 2 may be formed into a film and bonded to the photoconductive layer 1 with a transparent adhesive. Unlike the above, the insulating layer 2 shown in FIGS. 5 to 8 does not have a filter layer, and is not limited to being translucent, but may be non-transparent. The conductive layer 3 in FIGS. 1-4 is made entirely of aluminum and iron, as in conventional photoreceptors.

It is a non-transparent conductive layer made of metals such as nickel and copper, or alloys thereof. On the other hand, the conductive layer 3 in FIGS. 5 to 13 is a light-transmitting conductive layer that is in contact with the photoconductive layer 1 and contains aluminum, silver, lead, zinc, nickel, gold, and chromium. , vapor deposited or sputtered layers of metals such as molybdenum, titanium/platinum, or indium oxide, tin oxide.

Consisting of a vapor deposited layer of metal oxide such as indium oxide-tin,
It consists of a laminated layer of a conductive thin layer 3C that can transmit light and a filter layer 31L similar to that of the insulating layer 2 described above or a transparent layer 3b. The conductive layer 3 having such a filter layer 3a has a conductive thin layer 3c when a conductive substance such as a conductive pre-oil is used for the filter layer 3a or the transparent layer-3b.
It is not necessary to provide

In the present invention, the photoreceptor 4 having the laminated structure as described above is used in the form of a cylinder, a belt, or a plate.6.
, &o, 9th° to 1st□9° photosensitive) Filter layer 2a of the insulating layer 2 and filter layer 3a of the conductive layer 3 in the body 4
The six array patterns of R, G, and B filters have exactly the same order, and the same color filters correspond to each other, but the first
In the photoreceptor 4 shown in FIG. 3, the arrangement order is different and different color combinations are used.

The shape and arrangement of the R, G, and B filters in the filter layers 2a and 3a are not particularly limited, but a striped arrangement as shown in FIG. 14 is preferred because pattern formation is easy. A mosaic arrangement as shown in FIGS. 15 and 16 is preferable in that delicate multicolor images can be reproduced.

The direction in which the R, G, and B 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. For example, in the case of a rotating drum-shaped photoreceptor, whether the length direction of the stripe is parallel or perpendicular to the axis of the photoreceptor,
Alternatively, it may be in a helical direction. However, R, G, B
If the individual size of the filter is too large, the resolution and color mixing properties of the image will decrease, resulting in deterioration of the image quality.If the individual size of the filter is too large, the image quality will deteriorate; , it becomes easier to be influenced by other adjacent color parts, and it becomes difficult to form a filter distribution pattern. Therefore, in the case of a distribution of three types of filters as shown in the example shown, one of the repeating arrays Cycle length l is 30-50
It is preferable that the width or size is 0 μm. Note that the combination of color separation filters is not limited to the three types of R, G, and B, and the colors and number of types can be changed, so if the number of types changes, the above-mentioned preferred range of length l should be applied. will also change.

Next, the multicolor image forming method of the present invention using the above-mentioned photoreceptor 4 will be explained with reference to FIGS. 17 to 19. Note that FIG. 17 shows an example in which an n-type semiconductor photoconductor such as cadmium sulfide is used for the photoconductive layer 1 of the photoreceptor 4, and FIG. 17 is the same as FIGS. 1 to 8. Reference numerals indicate members with the same function.

FIG. 17 [1] shows a state in which the photoreceptor 4 is uniformly charged from the insulating layer 2 side by the positive corona discharge of the charger 5. In this state, frontal charges are generated on the surface of the insulating layer 20,
Correspondingly, negative charges are induced at the interface between the photoconductive layer 1 and the insulating layer 2, and as a result, the surface potential E of the photoreceptor 4 becomes uniform as shown in the graph.

FIG. 17 [2] shows a change in the charging state of the photoreceptor 4 due to the red component LR of the image exposure light that the image exposure device 6 makes incident on the above-mentioned charged portion. This image exposure device 6 includes a discharger 61
The photoreceptor 4 is given image exposure to the photoreceptor 4 while discharging an alternating current or an electric charge of the opposite sign to that of the charger 5. In this case, the photoreceptor 4 has the structure shown in FIGS. It has a layer structure as shown in FIG. 4 or FIGS. 9 to 13. When the photoreceptor 4 has a layer structure as shown in FIGS. 5 to 8 in which the insulating layer 2 does not include a filter layer, image exposure is applied from the side of the conductive layer 3 having the filter layer 3a. become.

- In the photoreceptor 4 shown in FIGS. 9 to 13, image exposure may be applied from the conductive layer 3 side. In the illustrated example, the red component of the imagewise exposure passes through the R filter portion of the insulating layer 2 and makes the portion of the photoconductive layer 1 below it conductive. Negative charges at the interface with the insulating layer 2 disappear.

Further, since the G and B filter portions do not transmit the red component LR, the negative charges of the photoconductive layer 1 remain in those portions. As a result, the surface potential Eij of the photoreceptor 4:
The R filter part where the negative charge has disappeared also has the remaining G,
The B filter portion is also uniform due to the discharge of the discharger 61. This is because the positive charges on the surface of the insulating layer N2 are distributed in accordance with the negative charges at the boundary between the photoconductive layer 1 and the insulating layer 2, and a balance is maintained. The green and blue components of image exposure give similar results. Therefore, the image exposure device 6
The state of the surface of the photoreceptor 40 subjected to imagewise exposure does not function as an electrostatic image. The above also applies to the case where image exposure is applied from the side of the conductive layer 3 having the filter layer 3a.

FIG. 17 [3] shows the charged state of the photoconductor 4 when the blue light LB obtained by passing the light from the photoconductor 7 through the filter FB is uniformly incident on the surface subjected to the above-mentioned image exposure. It shows the change in In the case of the photoreceptor 4 shown in FIGS. 9 to 13, this entire surface exposure may be performed from the side opposite to the image exposure. The blue light LB does not pass through the R and G filter parts and does not change them, but it passes through the B filter part and makes the photoconductive layer 1 in that part conductive. This neutralizes the charges at the upper and lower interfaces of the photoconductive layer 1 in the B filter portion. As a result, in the B filter portion, a potential pattern appears on the surface of the insulating layer 20 that provides a complementary color image of blue formed by the previous imagewise exposure. This is shown in Figure 17 [3]
The graph below shows this.

FIG. 17 [4] shows a state in which an electrostatic image formed by full-surface exposure to blue light LB is developed by a developing device 8Y containing negatively charged yellow toner TY, which is a complementary color to blue. . The yellow toner TY is shown in Fig. 17 [3
9 R, G where the potential did not change and the stains adhered only to the surface of the insulating layer 2 in the B filter part where the stain position changed after full exposure.
It does not adhere to the filter part. As a result, a color-separated one-color yellow toner image is formed on the surface of the photoreceptor 4. The potential pattern formed by full-surface exposure is partially canceled out by development, but it is usually not uniform.

The lower graph in FIG. 17 [4] shows this situation.

FIG. 17 [5] shows a state in which the surface potential of the photoreceptor 4 after development is made uniform by discharge from the charger 9 similar to the discharger 61 of the image exposure device 6.

This step prevents toner of different colors from adhering to the previously developed toner image during subsequent development, resulting in color smearing.

The photoreceptor 4 with a uniform surface potential as shown in Fig. 17 [5]
For that, do the same as [3], but this time the lamp 7
The entire surface is exposed to green light obtained by passing the light through a green filter. As a result, a potential pattern that gives a complementary color image of green appears in the G filter portion this time. This electrostatic image is processed by a developing device containing magenta toner as shown in Fig. 17 [4].
] When the image is developed in the same manner as above, magenta toner adheres only to the G filter portion, forming a magenta toner image.

As a result, an image consisting of yellow toner and magenta toner is formed on the photoreceptor 4.Furthermore, as in FIG. 17 [5], the potential of the developing surface is made uniform by the charger 9, and as in [3] Next, the entire surface is exposed to red light obtained by the combination of the lamp 7 and the red filter, and the potential pattern forming the red complementary color image formed in the R filter portion is converted into a cyan toner image by a developing device containing cyan toner. develop. According to the explanation regarding FIG. 17 [2] above, all charges have disappeared in the R filter part, and even if the entire surface is exposed to red light, a potential pattern will not be formed in the R filter part. It is easy to be misunderstood that there is no such thing, but the above explanation is about the strong red component part of image exposure, and the potential appears in other parts, such as the blue image part and the dark red light part. , which forms a potential pattern that is developed with cyan toner.

In this way, a full-color image without color shift or color turbidity is formed, and the formed color image is transferred to a recording paper or the like by conventionally known means and fixed.

Although the above explanation is based on an example in which an n-type optical semiconductor is used for the photoconductive layer 1 of the photoreceptor 4, it is of course possible to use a p-type optical semiconductor such as selenium. In that case, the basic process remains unchanged except that the positive and negative signs of the charges in the above explanation are all reversed.

In any case, if it is difficult to inject charges into the photoreceptor 4 using the charger 5, uniform irradiation with light may be used in combination.

In this embodiment, the development in the above image forming process is carried out by a developing device as shown in FIG.
The surface gap between the developer transport carrier 81 and the developer transport carrier 81 is
The non-contact development condition is set to be larger than the layer thickness of the upper developer (the layer thickness under conditions where there is no potential difference between the photoreceptor 4 and the developer transport carrier 81).

In the developing device shown in FIG. 18, a magnet body 82 provided inside a developer transport carrier 81 made of a non-magnetic material such as aluminum or stainless steel rotates in the direction of the arrow, and the developer transport carrier 81 rotates in the opposite direction. do,.

The developer adsorbed from the developer reservoir 83 to the surface of the developer transport carrier 81 is moved in the direction of rotation of the developer transport carrier 81 by the magnetic force of the N and S magnetic poles on the surface of the magnet body 820. On the way, the layer thickness is regulated by the layer thickness regulating blade 84 to form a developer layer, and the developer layer is in the development area A.
In this step, the electrostatic image on the photoreceptor 4 is developed. The development is performed by setting the surface gap between the developer transport carrier 81 and the photoreceptor 4 to be larger than the layer thickness of the developer layer regulated by the layer thickness regulating blade 84, and using the bias power source 8 for development.
0, a bias voltage is applied to the developer transport carrier 81 to generate a development electric field in the development area A, thereby causing the toner to fly from the developer layer, for example. By changing the bias voltage applied to the developer transport carrier 81 by the bias power supply 80, the amount of toner transferred from the developer layer to the photoreceptor 4 is controlled, and each color toner in the multicolor image formation described above is controlled. Adjust the image density.

85 transfers the developer layer that has passed through the development area A to a developer transport carrier 8.
A cleaning blade 86 removes the developer from the developer reservoir 83 and returns it to the developer reservoir 83, a stirring blade 86 agitates the developer in the developer reservoir 83 to make the developer uniform and gives frictional charge to the toner, and 87 a toner blade. From hopper 88 to developer reservoir fi
831c) Toner replenishment a-ra for increasing toner supply 89 is a protective resistor provided in a circuit that applies a bias voltage from the bias power supply 80 to the developer transport carrier 81. The developer has
It can be used with either a so-called one-component developer using a non-magnetic toner or a magnetic toner, or a so-called two-component developer containing a mixture of toner and a magnetic carrier such as iron powder.

Note that during development, a method may be used in which the surface of the photoreceptor is directly rubbed with the developer layer, but after the second development, in order to avoid damage to the previously formed toner image, the developer layer is not exposed to light. The above-mentioned developing method that does not contact the body surface, for example, U.S. Pat.
Publication No. 656, Japanese Patent Application No. 58-57446, Japanese Patent Application No. 1983
It is preferable to use the developing method described in the specifications of Japanese Patent Application No. 238295-238295 and Japanese Patent Application No. 58-238296. These methods use non-magnetic toner that can freely select the coloring, use a component developer or a two-component developer, and create an alternating electric field in the development area so that the electrostatic image support and the developer layer do not come into contact with each other. Developing is performed after that. A developing device that performs such non-contact development is not limited to the example shown in FIG. 18, but has an electrode such as a wire electrode or a grid electrode in the developing area A that does not hinder the transfer of toner from the developer layer to the photoreceptor 4. It is also possible to change the developing electric field by changing the voltage applied to the electrode.The point is to make the toner fly from the developer layer and transfer to the photoreceptor 4 under the developing electric field. Any material that can change the developing electric field may be used. and,
The above-mentioned developing method involves transferring only toner from a composite developer onto a developer transporting carrier, and developing with the toner on the developer transporting carrier in an alternating electric field.
565 and Japanese Patent Application No. 58-231434, JP-A-56-1999 discloses a dipping method, a linear or mesh control electrode is provided, and development is carried out using a one-component developer in an alternating electric field.
It goes without saying that the method described in Japanese Patent Application No. 125753 and the method described in Japanese Patent Application No. 1982-97973 in which a similar control electrode is provided and development is carried out with a two-component developer in an alternating electric field are also included. .

In FIG. 19, cadmium sulfide is used in the photoconductive layer 1 of the photoreceptor 4, and a negative charge is injected into the photoreceptor 4 by a charger 5, and by exposing the entire surface to light, the white area becomes -100V and the black area becomes -100V. For an example in which an electrostatic image consisting of a 400 V potential pattern is formed, a bias voltage in which a DC voltage of 150 V and an AC voltage of 1 kHz are superimposed is applied to the developer transport carrier 81 by the bias power supply 80 to perform development. The graph shows the relationship between the electrostatic image potential and the developed density when the electrostatic image potential is applied, and shows that the developed density, that is, the amount of adhered toner of each color, can be adjusted by changing the effective value vac of the alternating current component of the bias voltage. In FIG. 19, the drum-shaped photoreceptor 4 rotates in the direction of the arrow in FIG.
The rotation speed in the direction of the arrow of the developer transport carrier 81 having an outer diameter of 30 ffilI is 65 rpm, and the developer transport carrier 81 has 8 N and S magnetic poles spaced at equal intervals in the circumferential direction to produce a maximum magnetic flux density of 900 Gauss on the surface of the developer transport carrier 81. The rotational speed of the magnet body 82 in the direction of the arrow is 70 rpm, the layer thickness regulating gap between the layer thickness regulating blade 84 and the developer transport carrier 81 is 250 μm, and the developer has a weight average particle diameter of about 20 μm and magnetic powder is dispersed in the resin. A two-component developer consisting of an insulating magnetic carrier and rear containing a specific resistance of lXl014 Ωcm and a negatively triboelectrically charged insulating non-magnetic toner having a weight average particle size of about 13 μm is used, and a layer is formed on the developer transport carrier 81. Thickness approximately 600μm
These are the results obtained by developing under conditions to form a developer layer.

Adjustment of the color reproduction of a multicolor image is not limited to the example of changing the amplitude of the AC component in Figure 19, but can also be done by changing the level of the DC bias voltage, changing the frequency or waveform of the AC component, or a combination of two or more of these. This may also be done by changing the . Note that when changing the frequency of the alternating current component, the developing density decreases as the frequency increases, but the amount of adhered toner images of each color may be adjusted by changing the frequency within that range. The preferred range of frequencies used is 0.3~
It is 5 kHz.

By the method of the present invention described above, a clear multicolor image with excellent color balance and no color shift or color distortion can be easily obtained.

Table 1 shows the process by which colors in an original image are reproduced by the method of the present invention described above.

In Table 1 below, the symbols rC- and J indicate the existence of charges between the insulating layer and the photoconductive layer of the image-exposed photoreceptor, and the symbol "
The symbol "○" indicates that a potential pattern appears on the surface of the photoreceptor due to full-surface exposure, and the symbol "0" indicates that toner adheres. Also, the symbol "↓" indicates that the above 1 state is maintained as it is, and the blank space indicates an area where light passes through the insulating layer during image exposure and toner does not adhere.
Y, M, and C in the attached toner column are yellow toners.

Indicates that magenta toner and cyan toner are attached.

In order to make the multicolor image obtained by the method of the present invention as described above even more excellent in resolution and clear, it is preferable to use a toner having a weight average particle diameter of 50 μm or less, particularly about 1 to 30 μm, for development. This is preferable in terms of toner scattering and transportation. Such color toners include the known binder resins commonly used in toners, various colors such as organic and inorganic pigments and dyes, achromatic colorants, and various magnetic substances and additives used as necessary. made by known technology. In addition, in the case of a two-component developer, various known carriers such as iron powder, ferrite powder, which are usually used for electrostatic images, magnetic carriers such as those coated with resin, or those with magnetic material dispersed in resin are used. However, in order to reproduce fine dots and lines or to improve gradation, particles consisting of magnetic particles and resin, for example, a resin dispersion system of magnetic powder and resin, can be used. It is desirable to use resin-coated magnetic particles, preferably spherical, with an xi average particle diameter of 50 μm or less, particularly 30 μm or less and 5 μm or more.

Note that the weight average particle diameter of toner and carrier is
Based on the value measured with a counter (manufactured by Coulter). Furthermore, in order to prevent problems such as the problem that charges are easily injected into the carrier particles due to the Asumi pressure and the carrier tends to adhere to the photoreceptor surface, which hinders good image formation, and the problem that the bias voltage is not applied sufficiently, , the carrier has a resistivity of 108 ΩCm or more, preferably 10
An insulating material having an insulation value of 15 Ωcm or more, particularly preferably 10 Ωam or more is preferable. For example, magnetization is 50em with resin dispersion type.
u, □ A carrier with a specific resistance of 1014 Ω (m or more) is suitably used in the present invention. The above specific resistance of the carrier is determined by placing the particles in a container having a cross-sectional area of 0.50Cjl+2 and tapping it, then filling it. I on the particle
Apply a load of Ky/cm', and place 1 between the load and the bottom electrode.
This value is obtained by applying a voltage that generates an electric field of 02 to 5 v/Crn, reading the current value flowing at that time, and performing a predetermined calculation.The thickness of the carrier particles at this time is IIl! It is assumed to be about ff1.

Next, the recording apparatus shown in FIGS. 20 to 23 that implements the method of the present invention described above will be described.

The recording device shown in FIG.
The photoreceptor 4 having the layer structure shown in FIGS.
．． The recording device shown in FIG. 22 uses the photoreceptor 4 having the layer structure shown in FIGS. 5 to 13, and the recording device shown in FIG. 23 uses the photoreceptor 4 having the layer structure shown in FIGS. 9 to 13. . 20 to 23, the same reference numerals as in FIG. 17 indicate the same functional members, and others F. 10 is a color recording filter, FR is a red filter, 8M is a developing device containing magenta toner, 8C is a developing device containing cyan toner, and 10 is a toner image formed on the photoreceptor 4 as described with reference to FIG. A transfer device 11 transfers the toner image onto the recording paper P; a separator 1 separates the recording paper P onto which the toner image has been transferred from the photoreceptor 4;
2 is a fixing device that fixes the toner image on the recording paper P; 13 and 14 are photoreceptors 4f after transfer; a static eliminator and a light holder for removing static electricity; 15 is a cleaning device that removes residual toner from the surface of the photoreceptor 4; It is. All of these recording devices can superimpose toner images of up to three colors during one rotation of the photoreceptor 4 (as with conventional multicolor image recording devices, they can superimpose toner images of a single color or two colors). It is a recording device that can of course also record images. The toner image forming process in these recording apparatuses is already clear from the explanation with reference to FIGS. Since it is the same as in a recording device, a duplicate explanation will be omitted, but in the recording device shown in FIGS. The image exposure device 6 uses a mirror 62 to perform image exposure from the side of the light-transmitting conductive layer having the filter layer inside the photoreceptor 4 to the portion to which the discharge device 61 applies discharge. Developing devices 8Y to 8G are No. 18.19
It goes without saying that the developing density can be adjusted by changing the developing electric field as described in the figure. To give an example of this adjustment, the AC component frequency and DC component of the developing bias are set to the same 2kHz and 50V for each developing device 8Y to 8C,
The effective value of the AC component can be adjusted in the range of 300 to 4000 V by turning the adjustment knob corresponding to each color, and the effective value of the AC component of the developing bias of each developing device 8Y to 8C is set to 1500 V. When a full-color image was reproduced using this method, a reproduced image with the same tone as the original image was obtained. However, while the other image forming conditions described in Fig. 18 were kept constant, only the AC component effective value of the developing bias was changed. 1700 V for developing devices 8Y and 8M.

A reproduced image was obtained in which red was emphasized overall.

The recording apparatus that implements the method of the present invention is not limited to the above example, but may be one in which a toner image of one color is formed and superimposed each time the photoreceptor 4 makes one rotation or one reciprocation. It's okay. In such a recording apparatus, the charger 9 can be omitted and the discharger 61 can be used for discharging at the same time as image exposure, and the lamp 7 and filter FB can also be used.
A full-surface exposure device consisting of a combination of a switching filter in which lamp 7 and filters FB, FC) and FR are used by switching is provided at the position of the full-surface exposure device consisting of a combination of developing devices 8Y to 8C, thereby omitting the full-surface exposure device between developing devices 8Y to 8C. so that
You can also do it. Further, in the present invention, the developing electric field during development may be changed manually by the operator of the recording device operating a variable transformer of the bias power supply, etc.
This is an automatic method in which a color reproduction detection means is provided and the computer in the recording device automatically controls the output of the bias power supply based on the information. I described an example of a color copying machine used,
The embodiments of the present invention are not limited thereto, and can be widely used in various multicolor image recording devices, color photographic printers, and the like.

It goes without saying that the combination of the color of the separation filter and the color of the toner corresponding thereto can be arbitrarily selected depending on the purpose.

〔Effect of the invention〕

According to the present invention, the entire surface charging and image exposure, which conventionally required multiple times, can be performed in one time, thereby eliminating the occurrence of color shift, making it easy to adjust color balance and density, and producing high-quality images. It is also possible to obtain excellent effects such as miniaturization, speeding up, and reliability of multicolor electrophotographic devices.

[Brief explanation of the drawing]

1 to 13 are cross-sectional views schematically showing examples of the laminated structure of the photoreceptor used in the method of the present invention, and FIGS. 14 to 16 are filter layers showing examples of the distribution of color separation filters, respectively. FIG. 17 is a process diagram for explaining the multicolor image forming method of the present invention, FIG. 18 is a schematic sectional view of a developing device for explaining the developing method used in the present invention, and FIG. 19 is a plan view. FIGS. 20, 21 and 23 are a developed density graph showing an example of changing the developing electric field to adjust color reproduction; FIGS. This figure is a schematic side view showing the exposure portion of the recording apparatus of FIG. 21. 1... Photoconductive layer, 2... Insulating layer, 2a...
- Filter layer, R, G, B... Color separation filter, 2b... Transparent insulating layer, 3... Conductive layer, 3a.
... Filter layer, 3b... Transparent layer, 3C... Conductive thin layer, 4... Photoreceptor, 5... Charger,
6... Image exposure device, 61... Discharge device,
62... Mirror, 7... Lamp, FB, Fo, FR... Filter, 8Y, 8M, F2O... Developing device, 80...
Bias power supply, 81...Developer transport carrier, 82...
Magnet body, 83...Developer reservoir, 84...
Layer thickness regulating blade, 9... Charger, P... Recording paper, 10...
- Transfer device, 11... Separator, 12... Fixing device, 13... Static eliminator, 14... Exposure device for static elimination, 15... Cleaning device. Patent Applicant Konishi Roku Photo Industry Co., Ltd. Agent Patent Attorney Haru Yasushi ← 1 Fig. 1 112 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 6 Fig. 9 Fig. 10 Fig. 1 etc. Figure 13 Figure '16 6θ Figure 19 Figure 20 ? (Figure 2) Figure 23 Procedure HD original

Claims (1)

[Claims] A photoconductive layer having an insulating layer on one side and a conductive layer on the other side, at least one of the insulating layer or the conductive layer being transparent and having a layer consisting of a distribution of multiple types of filters. A photoreceptor for color image formation is used, and after the photoreceptor is charged and imagewise exposed, an entire surface exposure is performed to generate a potential pattern in a specific type of filter portion of the filters on the surface of the insulating layer of the photoreceptor. In a method of forming a multicolor image by repeating development of the potential pattern, color reproduction of the multicolor image is adjusted by changing a developing electric field generated between the photoreceptor and a developer transport carrier of a developing device. A multicolor image forming method characterized by: