JPS593448A - Image forming method - Google Patents

Abstract

PURPOSE:To allow colored developers corresponding to wavelengths to remain on a photoreceptor and to obtain a color image by irradiating imagewise the photoreceptor through the colored developers with plural light beams having different wavelengths. CONSTITUTION:Three kinds of developers 22; blue (B), green (G) and red (R) which are electrostatically charged negative and are semitransparent are uniformly coated on a transparent conductive plate 21. A photoreceptor 23 is provided on the plate 21 so as to face to the same. The photoreceptor 23 is constituted on an n type or bipolar photosensitive layer 23b on a conductive substrate 23a. The G light, B light and R light having different wavelengths are irradiated from the substrate 21 side. In the case of, for example, the G light, the is transmitted through the developer of G and a light carrier 25 is generated in the layer 23b. The G toner which is electrostatically charged negative sticks on the positive charge remaining there. The same effect can be obtained at the cases of the B light and the R light. The images of the respective colors are obtd. and if these images are transferred, a color image is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image forming method, and more particularly to an image forming method for forming a color image using a colored developer.

Office automation has been steadily progressing in recent years, and there has been a demand for communicating or filing higher density information. This information is most often communicated or stored as electrical or magnetic signals. Various means have been proposed or used to visualize electrical signals (or magnetic signals, etc.). An example of this is an electrophotographic laser beam printer.

FIG. 1 is a schematic diagram of a laser beam printer, and in the figure, 1 is a signal light source such as a laser.

A light beam generated from a laser light source 1 hits a scanner 2, passes through a lens 3, and scans a photoreceptor 4. The photoreceptor 4, which has been previously charged by the charger 5, is discharged only in the portion irradiated with the light beam, and an electrostatic latent image is formed. The obtained latent image is visualized by the developing device 6 and becomes a toner image. This toner image is sent to a transfer section and transferred to a transfer material 8 by a transfer charger 7, and then a fixing device (not shown)
is fixed and becomes a hard copy. - The force photoreceptor 4 is irradiated by a discharge lamp 9 and is further cleaned of residual toner by a cleaner 10 in preparation for the next copy cycle.

FIG. 2 shows a display device using a laser beam, and the same members as in FIG. 1 are given the same reference numerals. A toner image is formed on the photoreceptor 4 through the same steps as in FIG. The toner image is transferred to the transparent protective glass 11 and the illumination lamp 1 by rotating Boo'JP+/P2 in the direction of the arrow.
2 and is sent to a display section having 2 and displayed there.

Although it is possible to obtain or display monochrome images in this manner, it is now desired to go further and form or display two-color or multi-color images.

Figure 3 shows the schematic structure of a conventional color copying machine. In the figure, 13, 14, and 15 are color developing devices for yellow and magenta, respectively.

Contains cyan developer. When copying the original 16, for example, if the filter 17 is green, it will be magenta, if the filter 17 is blue, it will be yellow, and if it is red, it will be cyan. The latent images on the photoreceptor 4 are developed and transferred onto a transfer paper 8 in an overlapping manner.

This rotates the transfer paper three times along the transfer path igVC,
This is done by superimposing each of the three colors yellow, magenta, and cyan on a photosensitive drum on a transfer paper so that there is no color shift.

The transfer paper onto which the developed image has been transferred is sent to a fixing device 19, where the image is melted and fixed.

FIG. 4 shows a color information display device.

Components that are the same as those shown in FIGS. 1-3 are provided with the same reference numerals. As shown in the figure, a latent image is formed by irradiating a photosensitive drum 4 with a modulated light beam from a laser light source 1, and is developed by a yellow developer 13 to form a transfer roll 2.
Transfer to 0.

Similarly, latent images corresponding to magenta and cyan are formed on the photosensitive drum 4, and the magenta developing device 14. After being visualized by the cyan developer 15, it is transferred to the transfer roll 20 so as to be superimposed on the previous color. Transfer roll 2
0 is rotated and sent to the display section, where it is illuminated by an illumination lamp 12 and a color image is displayed through the glass 11.

However, in the display device shown in FIG. 4, the photosensitive drum and the transfer roll each have to be rotated three times in order to obtain an image, and it takes time to display the image. There is still color shift when overlapping color images on the transfer roll. Color toners that have been used once cannot be reused because they are mixed, and must be discarded, resulting in a waste of resources.

SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming method capable of solving the above-mentioned conventional drawbacks and obtaining a Victorian color image with -1 exposure.

The gist of the present invention is to provide a mixed developer in which a plurality of light beams having different wavelengths, a triboelectric colored developer that selectively transmits these light beams, and a transparent conductive developer. Using a substrate and a photoreceptor, the transparent conductive substrate is coated with a mixed developer in almost a single layer, and the surface of the photoreceptor is uniformly charged with a polarity opposite to that of the developer. Applying a DC bias between the transparent conductive substrate and the transparent conductive substrate coated with the mixed developer and irradiating the photoreceptor with the light beam at a position closest to the photoreceptor through the transparent conductive substrate; The objective is to hold a developer corresponding to the light beam reaching the photoreceptor on the transparent conductive substrate. According to the present invention, a color image can be easily obtained, and since the developer can be recovered when applied to a display device, the developer is not wasted unnecessarily.

The present invention will be described in detail below based on the drawings. FIG. 5 shows the principle and configuration of the present invention. Blue (hereinafter also referred to as B) and green (hereinafter referred to as G) are placed on the transparent conductive substrate 21 shown in the figure.
Three types of negatively charged translucent developers 22, ie, red (hereinafter also referred to as R), are uniformly coated in a substantially single layer.

This conductive substrate uses Nesa glass or conductive Mylar (trade name) coated with indium oxide. 23 is a photoreceptor having an N-type or bipolar photosensitive layer 23b provided on a conductive substrate 23a. For example, green light is irradiated from the transparent conductive substrate 21 side at a position where the photoreceptor 23 is closest to the conductive substrate. The developer acts as a light filter before the green light reaches the photoreceptor. The green light passes through only the green developer and reaches the photoreceptor.

A DC voltage is applied between the photoreceptor 23 and the transparent conductive substrate 21 by a power source 24, with the photoreceptor side being positive.

When the green light reaches the photoreceptor in this state, photocarriers 25 are generated within the photoreceptor layer, a positive photocharge remains near the surface of the photoreceptor, and the negatively charged green developer is transferred onto the photoreceptor. Attract. Blue and red developers do not deposit on the photoreceptor because they do not transmit green light. Even when blue light or red light is irradiated, blue developer or red developer selectively adheres to the photoreceptor, respectively, in the same manner as described above. In this way, a green, blue or red color image is formed on the photoreceptor.

However, since the direction of the applied direct current (earth direction) is positive with the photoconductor side, the negatively charged developer is subject to electrostatic force toward the photoconductor even in areas that are not irradiated with light, which may cause background fogging. In order to prevent background fog and obtain even better images, it is recommended that the surface of the photoreceptor be negatively charged in advance as shown in FIG.

When the surface of the photoreceptor is negatively charged by the charger 26, the negatively charged developer 22 is electrically repelled by the surface of the photoreceptor. However, for example, at the position where the green light passes through the green developer and reaches the photoreceptor, the negative charge on the surface of the photoreceptor is discharged, so the negatively charged green developer is Adheres to the photoreceptor surface. Similarly, blue or red developer adheres when blue or red light is irradiated.

(J FIG. 7 is a schematic sectional view of a more specific example device.

In the figure, 3 is a lens, 2 is a scanner, 27 is a half mirror, 528 is a developer coater, 26 is a charger, 2
9 and 30 are power supplies, 9 is a weight remover, a lamp, and 31 is a plurality of light beam sources having different wavelengths. Developer 2
8 can be anything that is normally used and used, but B,
A developing device using a so-called two-component developer, which is a mixture of G and H mixed developers and iron powder, is optimal.

Blue, green, and red developers are highly resistive colored particles that are triboelectrically charged. If this developer is positively triboelectrically charged, contrary to the above embodiment, the power source 2
The polarities 9 and 30 are opposite to those shown in the figure, the photosensitive layer used is a P-type or bipolar photosensitive layer, and the charger 25 is selected to positively charge the surface of the photoreceptor.

A DC bias is applied between the developing device 28 and the transparent conductive substrate 21 with the transparent conductive substrate side being positive. By adjusting the applied bias, the B, G, and R mixed developer negatively charged by friction in the developing device L can be uniformly coated on the transparent conductive substrate in a substantially uniform layer. The mixed developer is sent toward the photoreceptor, and at a position where the photoreceptor and the transparent conductive substrate are closest to each other, a signal-modulated light beam is exposed from the transparent conductive substrate side to form an image as described above. The light sources 31 are each J3
．． Although the laser generates G and R lights, it may be an LED or the like, or it may be another light source, or a white light source with a color filter applied thereto to supply B, G, and R lights. Each light source independently participates in image writing. For example, when blue light and green light are generated simultaneously, both the blue developer and the green developer adhere to the photoreceptor, resulting in a mixed color. The image formed is the first
As shown in FIGS. 2 and 3, the image may be transferred to paper or the like and used as a notebook, or it may be displayed as is as shown in FIGS. 2 and 4.

A display device using the present invention is shown in Fig. NK8 and Fig. 9. In FIG. 8, 11 is a transparent protective part such as glass;
2 is a display lighting rung, 32 is a toner scattering prevention cover,
33 and 34 are cleaners. The same reference numerals are attached to the same members as in the detailed drawings 1 to 7. The photoreceptor is
An image is formed in the image forming section 35 located close to the photoreceptor 23 and the transparent conductive substrate 21, and after being neutralized by the static eliminating lamp 9 so as not to leave any optical history, the image is sent to the display section by the rotation of pulleys P1 and P2. It will be done. After displaying, the photoreceptor is cleaned with a cleaner 33.

The developer cleaned here is returned to the developer coating device 28 again. Moreover, even after image formation, the transparent conductive substrate 2
The developer remaining on the developer 1 is also cleaned by the cleaner 34, and the developer cleaned here is also returned to the developer coating device 28.

FIG. 9 is a cross-sectional view of an embodiment for displaying an image formed on a transparent conductive substrate 21. FIG. In this case, the image to be displayed may be produced by turning on the light source 31 with a pulse opposite to that used in the case of FIG. 8 in which the image on the photoreceptor is displayed. That is, for example, when displaying a red image, the green and blue light sources are turned on, and the red light source is not turned on. In this way, the green and blue developers adhere to the photoreceptor 23, and the red developer adheres to the transparent conductive substrate 23.
1, and is sent to the display section by rotation of pulley P in the direction of the arrow. Also in this case, the used developer is recovered to the developer carrier 28 by the cleaners 33, 34 and the developer scattering cover 32, and can be reused.

All of the developer used in the above embodiments is returned to the developer coater. Therefore, the mixing ratio of the plurality of color developers does not change, and the developer is not consumed significantly.

In the above-described embodiments of the present invention, full-color display cannot be performed as in the color copy described above in FIG. 4, but Victorian color display consisting of a combination of at least three colors can be performed in one exposure. Obtainable. It is quite useful for obtaining information equivalent to normally used office documents.

FIG. 10 shows a schematic diagram of an apparatus for transferring a color image formed on a photoreceptor to a transfer material based on the principle shown in FIGS. 5 to 7. An image is formed on the photoreceptor 23 by the method described above. The image on the photoreceptor is transferred to a transfer charger 7.
The image is transferred onto the transfer paper 8 by the following steps. Thereafter, the transfer paper is sent to a fixing device 19, where the image is fixed. Although FIG. 10 shows an example in which an image on a photoreceptor is transferred, a configuration in which an image formed on a transparent conductive substrate 21 is transferred in a similar manner may also be used.

FIG. 11 shows an explanatory diagram of the principle and configuration of another embodiment of the present invention. In FIG. 11, 21 is a transparent conductive substrate, and 23 is a photoreceptor having a P-type or bipolar photosensitive layer 23b provided on a conductive substrate 23a.

For example, blue (hereinafter also referred to as B), green (hereinafter also referred to as G), red (hereinafter referred to as R) are coated on the transparent conductive substrate 21.
Three types of negatively charged translucent developers are coated uniformly in almost a single layer. For example, blue and red light is simultaneously irradiated from the side opposite to the developer carrying surface of the transparent conductive substrate 21 at a position where the photoreceptor and the transparent conductive substrate are closest to each other. Since the developer is placed in the middle of the optical path, the developer acts as a light filter before the light reaches the photoreceptor. The blue and red light passes through the blue and red developers, respectively, and reaches the photoreceptor.

On the other hand, the surface of the photoreceptor is previously charged with a charger 35 to have a polarity opposite to that of the developer, that is, to be positively charged. Further, between the conductive substrate 23a of the photoconductor and the transparent conductive substrate 21, a DC bias is applied to the power supply 36 so that the photoconductor side is negative.
Apply voltage accordingly. The amount of charge of the charger 35 on the surface of the photoreceptor is set so that the potential is higher than that of the transparent conductive substrate 21 (0 potential). At locations where the blue light and red light reach the photoreceptor, the positive charges on the surface of the photoreceptor are discharged, and the potential becomes lower than that of the transparent conductive substrate 21. This situation is shown in FIG.

In FIG. 12, Vo indicates the potential of the transparent conductive substrate 21 (0 potential), and V indicates the surface potential of the photoreceptor 23. In FIG. VL indicates the surface potential of the bright area of the photoreceptor after exposure, and VD indicates the surface potential of the dark area. Further, VB indicates the potential of the conductive substrate 23a of the photoreceptor.

As a result of the above, at the position where the photoreceptor is irradiated with blue light and red light, the potential Vr is more negative than the potential Vo of the conductive substrate, so the negatively charged developer is transferred to the transparent conductive substrate 2.
It remains attracted to the 1st side. In addition, since the green developer does not transmit either blue light or red light, the potential of the photoreceptor surface is still V at the position of the green developer.
The green developer with a high n value adheres to the surface of the photoreceptor 23. In this way, a green image is obtained on the photoreceptor, and a mixed color image of blue and red is obtained on the conductive substrate. Furthermore, if the light source for providing exposure is, for example, green light, green developer remains on the transparent conductive substrate 21, and other developers adhere to the photoreceptor. In the present invention, by selecting the light source for irradiation, it is possible to freely select the color of the developer deposited on the photoreceptor or the transparent conductive substrate.

FIG. 13 shows a sectional view of a more specific device of this embodiment. 3 is a lens, 2 is a scanner, 27 is a half mirror 12
8 is a developer coating device which is a developer carrier, 35 is a charger, 30 and 36 are power sources, 9 is a static elimination lamp, 31
is a laser light source. The developing device 28 may be of any type commonly used, but a so-called two-component developing device in which a mixed developer of B, G, and R is mixed with iron powder is most suitable. blue,
Green and red developers are highly resistive colored particles that are triboelectrically charged.

If the developer is triboelectrically charged in a positive manner, contrary to the embodiment shown in FIG. A charger 35 uses a bipolar photoconductive layer to negatively charge the surface of the photoreceptor.

FIG. 14 is a modification of the embodiment shown in FIG. 13, in which a transparent conductive substrate 37 is fixed instead of the transparent conductive substrate 21, and a thin transparent insulating film 38 is moved. The apparatus shown in FIG. 14 can also be applied as an embodiment of the present invention, the principle of which is shown in FIG.

Now, in FIGS. 13 and 14, a DC bias is applied between the developing device 28 and the transparent conductive substrate 21 or 37 with the transparent conductive substrate side being positive. +3 negatively charged by friction on the developing device
．． By adjusting the applied bias, the G and R mixed developer can be coated almost uniformly on the transparent conductive substrate.The mixed developer is sent toward the photoreceptor, and the photoreceptor and the transparent conductive substrate are A signal-modulated light beam is exposed from the transparent conductive substrate side at the closest position, and an image is formed as described above. The light sources 31 are lasers that generate B, G, and R lights, respectively, but they may also be LEDs, other light sources, or B lasers that are equipped with a white light source and a color filter.
, G, and R light may be used. Each light source independently participates in image writing. For example, if blue light and green light are generated at the same time, both the blue developer and the green developer will be applied to the transparent conductive substrate 21 or the insulating film 38.
Attach to the second. Doyo 10 is added to the image formed in this way.
It may be transferred to paper or the like using the device shown in the figure to make a hard copy, or it may be displayed as is using the device shown in FIG. 8 or 9.

FIG. 15 illustrates the principle and configuration of yet another embodiment of the present invention. 15, 39 is a conductive substrate, 23 is a photoreceptor having a P-type or bipolar photosensitive layer 23b on the conductive substrate 23a, 40 is a charger, and 28 is a developing device as a developer carrier. . A DC bias is applied between the photoreceptor 23 and the conductive substrate 39 by a power source 41 so that the side of the conductive substrate is positive.

First, the surface of the photosensitive plate is uniformly charged by the charger 40. The upper button of the developer carrier 28 selects three types of mixed developer, for example, blue (hereinafter also referred to as B), green (hereinafter also referred to as G), and red (hereinafter also referred to as R), depending on the wavelength of light. Holds a mixture of transparent developer.

This mixed developer is negatively charged by friction.

By bringing the mixed developer into contact with a photoreceptor whose surface is uniformly positively charged, the mixed developer is adhered to the surface of the photoreceptor in almost a single layer.

shoot The developer acts as a filter before the light reaches the photoreceptor. The blue light passes through only the blue developer and reaches the photoreceptor. The portion of the photoreceptor where the light reaches is discharged with positive charges, weakening the electrostatic attraction between the blue developer and the photoreceptor.

After the blue light is irradiated, the conductive substrate 39 to which a DC bias is applied between the conductive substrate 39 and the photoreceptor is brought close to the photoreceptor. Positive charges are induced in the conductive substrate 39, and electrostatic attraction acts between it and the mixed developer.

As a result, only the developer B, which has a weak electrostatic attraction with the photoreceptor, is transferred onto the conductive substrate 51.

The above principle will be explained using FIG. 16. In FIG. 16, VA indicates the potential on the surface of the photoreceptor, Vr indicates the potential in the bright area, and VD indicates the potential in the dark area.

Vo indicates the potential of the conductive substrate 39. The amount of charge on the surface of the photoreceptor by the charger 40 is set to be higher than the potential of the conductive substrate 39 due to the DC bias. On the other hand, since the amount of charge due to friction of the developer is only a few inches of the amount of charge on the surface of the photoreceptor, the portion of the photoreceptor that the light reaches discharges a charge of 90 or more to the conductive substrate 23b side of the photoreceptor. I'll do what I do. Therefore, the potential VL of the exposed surface of the photoreceptor becomes lower than the potential of the conductive substrate 39. Note that the surface of the photoreceptor where the light does not reach remains at the high potential VD.

As a result of the above, at the portion where the blue light reaches the photoreceptor surface, that is, at the position of the blue developer, the potential V r of the photoreceptor surface is low, and when the conductive substrate 39 approaches (including comes into contact with) the photoreceptor, The blue developer is deposited on the higher potential conductive substrate 39. In addition, since the green and red developers do not transmit blue light, the potential of the photoreceptor surface is still V at the positions of the green and red developers.
With high n, green and red developers are retained on the photoreceptor.

In the above description, if the light source providing exposure is, for example, green light, the green developer will be deposited on the conductive substrate 39, and the other developers will be held on the photoreceptor. Alternatively, if blue and green light are applied simultaneously, the blue and green developer will be deposited on the conductive substrate 39 and the red developer will be retained on the photoreceptor. In this way, in the present invention, the color of the developer deposited on the photoreceptor or conductive substrate 2 can be freely selected by selecting various light sources for providing exposure.

In order to coat the surface of the photosensitive member with the mixed developer almost in one layer, a bias can be applied to the developer carrier 28 as shown in FIG. 17 or 18. 17th
The figure shows an example in which the amount of mixed developer attached to the surface of the photoreceptor is adjusted by controlling the power source 42, and FIG. .

FIG. 19 shows a more specific configuration diagram of this embodiment. The developer carrier 28 is a developing device that is commonly used, and includes B, B,
A so-called two-component developer in which a mixed developer of G and H and iron powder are mixed is most suitable. The developers of B, G, and R are high-resistance particles that are triboelectrically charged. If the developer is triboelectrically charged, the polarity of the power source 41 is opposite to that shown in the figure, the photosensitive layer used is an N-type or bipolar photoconductive layer, and the charger 40 is placed on the surface of the photoreceptor. is negatively charged. The trench conductive substrate 39 may have a thin insulating film on its surface.

The light sources 31 are signal-modulated, respectively.

Although it is a laser that generates an R light beam, it may also be an LED or other light source, or a white light source equipped with a color filter.

It may also be one that supplies R light. Each light source independently participates in image writing. For example, when blue light and green light are generated simultaneously through signal modulation, both blue and green developers adhere to the conductive substrate 39 .

The image thus formed is transferred to the transfer paper 8 by the transfer charger 7.
The image may be transferred to a computer and then fixed in a fixing device 19 to make a hard copy, or it may be displayed as is as shown in FIG. Although FIG. 19 shows an example of transferring an image on a conductive substrate, an image formed on a photoreceptor may also be transferred.

Further, in the present invention, a transparent conductive substrate 39 is used as a conductive substrate.
Exposure may be performed using a signal-modulated light beam from the transparent conductive substrate side at a position where the photoreceptor and the transparent conductive substrate are close to each other (including in contact with each other). This situation is shown in FIG. The principle is similar to the embodiment shown in FIG. 19 described above, but in this case, a droplet bias is applied between the photoreceptor 23 and the transparent conductive substrate 39a by the power supply 41 with the transparent conductive substrate side being positive. Therefore, the efficiency of generating photocarriers by exposure to light is further improved, making it even more effective.

FIG. 21 illustrates a display device to which this embodiment is applied. In FIG. 21, 11 is a transparent protective portion such as glass, 12 is a display illumination lamp, 32 is a toner scattering prevention cover, and 33
．． 34 is a cleaner. Here, the conductive substrate 39a
is transparent. Transparent conductive substrate 3 on which an image is formed in the image forming section
9a is sent to a display section consisting of a glass 11° lamp 12 by rotation of pulley P1. After displaying, the image is cleaned by a cleaner 34. The developer cleaned here is returned to the developing device 28 again. Further, after image formation, the photoreceptor 23 is neutralized by a static eliminating lamp 9 so as not to leave any light history, and then cleaned by a cleaner 33, and the developer cleaned here is also returned to the developing device 28.

Although FIG. 21 shows an example in which an image on the transparent conductive substrate 39a is displayed, it is obvious that an image on a photoreceptor can also be displayed. In this case, compared to the case where an image on the transparent conductive substrate 23 is displayed as shown in FIG.
The light source may be turned on using reverse pulses. That is, for example, when displaying a green image, the red and blue light sources are turned on, and the green light source is not turned on. In this way, the green developer is retained on the photoreceptor,
Red and blue developers move onto the conductive substrate. In this case as well, the used developer can be returned to the developer carrier. As a result of the above, all the developer to be used is returned to the developing device 28, so that the mixing ratio of the plurality of color developers does not change and the developer is not consumed.

In the 211g+ embodiment, it is desired to perform a full-color display like the color copy described earlier in FIG. 4, but it is possible to obtain a Victorian color display consisting of a combination of at least three colors with one exposure. . It is quite useful for obtaining information equivalent to normally used office documents.

In addition, in FIGS. 19 to 21, the same reference numerals are given to the same members as the previous ones.

The colored developer used in the present invention is obtained, for example, by mixing a resin with a dye. It is better for the developer used to have as high a color saturation as possible. When the color density of the developer is high, the filter effect of the developer becomes even stronger by increasing the exposure of the corresponding light source. Using three light beams of the three primary colors of light, blue-violet, green, and red, blue-violet,
It is best to use a mixed developer in which green and red developers are mixed. However, it is not necessarily necessary to mix three colors of developers; for example, in order to obtain a two-color display, two-color developers and corresponding two-color light sources may be used.

Furthermore, if it is desired to display four or more colors, a necessary number of light sources and a developer having a transmission spectrum characteristic that selectively transmits each light source are mixed with the necessary number of colors.

As described in detail above, according to the present invention, a multicolor Victorian color image can be obtained by one-shot exposure, and the capacity for information display can be increased. However, if it is used only for display without providing a hard copy, an economical device can be obtained without consuming developer.

[Brief explanation of the drawing]

1 to 4 are schematic diagrams of a conventional image forming apparatus, FIGS. 5 and 6 are configuration explanatory diagrams of one embodiment of the present invention, and FIG.
10 is a schematic diagram of a more specific device of the above embodiment, FIG. 11 is an explanatory diagram of the configuration of another embodiment of the present invention, and FIG.
2 is a graph showing the potentials of the photoreceptor and the conductive substrate, FIGS. 13 and 1413fi are schematic diagrams of a more specific device of the embodiment of FIG. 11, and FIG. 15 is a graph of still another embodiment of the present invention. 16 is a graph showing the potentials of the photoreceptor and the conductive substrate, and FIGS. 17 to 21 are schematic diagrams of a more specific apparatus W of the embodiment of FIG. 15. In the figure, 31... Laser light source, 2... Scanner, 3... Lens, 21... Transparent conductive substrate, 22...
- Mixed developer, 23 - Photoreceptor, 36... Bias power source, 35... Charger, 28... Developer. Applicant Gyanon Co., Ltd. Shiba Zego; 40

Claims (3)

[Claims] (1) Multiple light beams with different wavelengths,
Using a mixed developer containing a triboelectrically charged colored developer that selectively transmits each of these light beams, a transparent conductive substrate, and a photoreceptor, the mixed developer is approximately spread on the transparent conductive substrate. coating the surface of the photoreceptor in a single layer, uniformly charging the surface of the photoreceptor with a polarity opposite to that of the developer, applying a DC bias between the photoreceptor and the transparent conductive substrate, and applying the coating of the mixed developer. At a position closest to the transparent conductive substrate and the photoreceptor, the photoreceptor is irradiated with the light beam through the transparent conductive substrate, and a developer corresponding to the light beam that reaches the photoreceptor is held on the transparent conductive substrate. An image forming method characterized by: (2) The mixed developer is carried on a developer carrier, and a DC bias is applied between the developer carrier and the transparent conductive substrate. Image formation method. (3) Claim 2, further comprising a means for returning the developer used for development to the developer carrier.
Image forming method described in Section 2.