JPS62135851A - Color image forming device - Google Patents

Abstract

PURPOSE:To reproduce a sharp color image which has no color shift and superior in reflectivity by sticking transparent toner on the top surface or reverse surface sides or on both top and reverse surface sides by a developing means. CONSTITUTION:A color image forming device includes an image exposing device 6, uniform exposing devices 7B, 7G, and 7R, developing devices 8Y, 8M, 8C, and 8T which perform noncontacting development, electrostatic dischargers 9Y and 9M which smooth the surface potential of a photosensitive body 4 after development, a before-transfer processor 10, a transfer 11, a separator 12, a before-cleaning electrostatic discharging device 13, a cleaning device 14, etc. The uniform exposing device 7B at the most upstream side consists of a white light lamp and a green light transmission filter and a monochromatic image with image density similar to that of a monochromatic copying machine can be formed by exposing a primary latent image formation surface to white light uniformly without the filter and developing the image. Consequently, an image which has a transparent layer on the top surface or reverse surface side or no both surface sides of a color image is formed without any color shift.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in a color image forming apparatus using a photoreceptor having a color separation function member.

[Background of the invention]

The present inventors first performed charging and image exposure on a photoreceptor having a color separation function member, and then repeated uniform exposure with specific light and development with color toner to form a color toner image on the photoreceptor. Completed various inventions regarding color image forming devices for compositing (
(Japanese Patent Application No. 185440, No. 187044, etc.).

This color image forming apparatus forms a color image on the photoreceptor with one image exposure, so there is no color shift.
Furthermore, since the toners of each color constituting a color image are separated and adhered to each other, there is less chance of color smudging or changes in hue depending on the transfer rate from the photoreceptor to the transfer material.

On the other hand, color image forming group M using a conventional photoreceptor includes a photoreceptor without a color separation function member (a photoreceptor as a device and a photoreceptor as a recording material). ) by repeating charging, image exposure for color separation, and development.
A method that combines color toner images on a photoreceptor or a transfer material (sometimes a transfer material is used as a device, and another is used as a recording material) for each development. Therefore, color shift and color staining are likely to occur.

In addition, in a device that transfers a composite color image, there is a problem in that the hue tends to change depending on the transfer rate. In order to solve this problem of easy hue change and further improve the reflectivity of the color image surface, in conventional color image forming apparatuses, transparent toner is first attached to the photoreceptor, and then transparent toner is applied on the photoreceptor. The method for forming color images was published in 1986-2.
5215 and 25216. In this method, after charging the photoreceptor or performing image exposure without passing through a color separation filter, a developing means using transparent toner is applied to the surface of the photoreceptor to adhere transparent toner, and then color separation is performed. This is a method of repeating image exposure, charging, and development with a color donor.

The present inventors have discovered that transparent toner can be attached before and after color image formation even in a color image forming apparatus using a photoreceptor having a color separation function member that performs image exposure only once. The present invention was completed based on this knowledge.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a color image forming apparatus using a photoreceptor having a color separation function member, which can reproduce clear color images with excellent reflectivity and no color shift.

[Structure of the invention]

In the present invention, a charging means, an image exposure means, a uniform exposure means for specific light, and a plurality of developing means are disposed on a photoreceptor having a color separation function member, and the charging means and the image exposure means are connected to each other. After forming a primary latent image on the photoreceptor, color toner is formed on the photoreceptor by repeating the formation of a color-separated electrostatic image from the primary latent image using a uniform exposure means using specific light and development using a developing means. In an apparatus for forming a color image by combining images, a developing means using transparent toner is provided in addition to the plurality of developing means used for forming the color image, and the developing means is used to form a color image on the upper side or the lower side of the color image. Alternatively, there is a color image forming apparatus characterized in that transparent toner is attached to both upper and lower surfaces, and this configuration achieves the above object.

〔Example〕

The present invention will be explained below using illustrated examples.

FIGS. 1 to 4 are schematic partial cross-sectional views showing examples of the layer structure of a photoreceptor used in the color image forming apparatus of the present invention, and FIGS. 5 to 7 show color separation functional members of the photoreceptor, respectively. FIGS. 8 and 9 are partial plan views showing an example of the distribution shape of a certain color separation filter, and FIGS. 10 and 11, FIGS. Figure 13 shows the composite toner image formed on the photoreceptor and the image transferred to the recording material using the apparatus shown in Figure 8, respectively.
Cross-sectional view showing an example of a composite toner image in a fixed state, first
4, FIG. 15, FIG. 16, and FIG. 17 respectively show examples of the composite toner image formed on the photoreceptor by the apparatus of FIG. 9, and the composite toner image transferred and fixed to the recording material. FIG.

In FIGS. 1 to 4, 1 is a conductive member formed into an appropriate shape structure as required, such as a cylindrical shape or an endless belt shape, and 2 is an inorganic photoconductor, an organic photoconductor (G), and a blue CB1. This is an insulating layer including a layer 3a consisting of a distribution of minute color separation filters. The insulating layer 3 of the photoreceptor 4 in FIG.
The insulating layer 3 of the photoreceptor 4 shown in FIG. 3
The insulating layer 3 of the photoconductor 4 shown in the figure is one having a transparent insulating layer on the insulating layer 3 of FIG. 2, and the photoconductor 4 of FIG.
The insulating layer 3 of FIG. 1 has a transparent insulating layer on top of the insulating layer 3 of FIG.

R2G, B in the filter layer 3a of these insulating IW3
The distribution shape of the filter etc. is not particularly limited, but the striped distribution shown in Figure 5 is used for easy pattern formation, and the mosaic distribution shown in Figures 6 and 7 is used to reproduce delicate multicolor images. It is used in a suitable manner. And R,G,
The individual size of the B filter etc. is the length 10 shown by t in the figure.
A range of 200 μm to 200 μm is suitable from the viewpoint of image resolution, color reproducibility, ease of forming a distribution pattern, etc.

In the color image forming apparatus shown in FIGS. 8 and 9, a charger 5, a charger 5,
Image exposure device M6, uniform exposure device 7B, 7G, 7R A 1-component or two-component developer is formed in a layer thickness that does not contact the surface of the photoreceptor 4, and an alternating current bias is used as a development bias to remove toner from the developer layer. Developing devices 8Y, 8M, 80.8T for performing non-contact development by making the particles fly, or dischargers 9Y, 9M for smoothing the surface potential of the photoreceptor 4 after development, white light or toner layer. A pre-transfer treatment device 10, a transfer device 11, a separator 12, which uses an infrared exposure lamp and a corona discharger, which have good permeability even for light, or a pre-cleaning static eliminator 13, which uses an exposure lamp and a corona discharger. , a cleaning device 14 is disposed, and color images as shown in FIGS. 1O to 17 are formed by the steps described below.

The photoreceptor 4 rotates in the direction of the arrow shown in FIGS. 8 and 9,
A charger 5 performs corona discharge to uniformly charge the surface of the photoreceptor 4. When the photoreceptor 4 uses an n-type semiconductor such as cadmium sulfide for the photoconductor tN2, the corona discharge of the charger 5 is a positive discharge, and when the photoconductive layer 2 uses a p-type semiconductor such as selenium. If it is a negative discharge. As a result, the image exposure device 6 causes an image exposure beam to be incident on the charged surface of the photoreceptor 4 . At this time, the image exposure device 60 and the discharger 61 perform corona discharge of alternating current or direct current having the opposite sign to that of the charger 5. As a result, a primary latent image consisting of charge density is formed on the photoreceptor 4. In this next layer image forming step, the surface potential of the photoreceptor 4 is set to a potential at which toner adheres by changing conditions such as the discharge of the discharge device 61 and the relative positional relationship between the discharge and the image exposure device 9. It is possible to set the potential to such a level that no particles adhere to the surface. Note that, regardless of whether the optical system or the document table is of a reciprocating type or a document passing type, the image exposure device M6 uses transmitted light rather than reflected light from the document. It's okay.

When forming a color image as shown in FIG. 10.11, the surface potential of the photoreceptor 4 is set to a potential to which toner adheres in the primary latent image forming step described above, and a developing device containing transparent toner T is used. Transparent toner T is attached to the surface of the photoreceptor 4 by 8T, and when the surface reaches the position of uniform exposure device 7B, blue light is uniformly incident on the surface by uniform exposure device 7B, thereby A potential pattern is generated on the surface of the B filter portion of the photoreceptor 4 from the previously formed primary latent image,
The potential pattern is developed by a developing device 8Y containing yellow toner Y to form a yellow toner image consisting of yellow toner T attached to the B filter portion, and the potential of the surface on which the yellow toner image is formed is determined as shown in FIG. In the apparatus, a discharger 61 is used to smooth the surface, and in the apparatus shown in FIG. 9, green light is uniformly incident on the smoothed surface by a uniform exposure device 7G. A potential pattern is generated on the surface of the filter portion, and this potential pattern is developed by the developing device 8M containing magenta toner M to form a magenta toner image consisting of the magenta toner M attached to the G filter portion. The potential of the formed surface is again smoothed by the discharger 61 in the apparatus shown in FIG. 8, and by the discharger 9M in the apparatus shown in FIG.
makes the red light uniformly incident on the photoreceptor 4.
A potential pattern is generated on the surface of the R filter portion, and this potential pattern is developed by a developing device 80 containing cyan toner C to form an ant toner image consisting of the cyan toner C adhering to the R filter portion. Thereby, the 10th
As shown in the figure, a color image is formed on the photoreceptor 4 by combining a layer of transparent toner T and yellow, magenta, and cyan toner images thereon. Next, the toners are easily transferred by the transfer pretreatment device 10 and transferred to the recording material P fed by the paper feeder 15 by the transfer device 1.
Transfer by 1. As a result, as shown in FIG. 11, a color image and a layer of transparent toner T are formed on the recording material P so as to cover the surface thereof. The recording material P to which this toner has been transferred is separated from the photoreceptor 4 by the separator 12, and is transported to the fixing device 17 by the conveying means 16.
The toner is fixed by the fixing device 17 and discharged outside the machine.

On the other hand, the surface of the photoreceptor 4 to which the toner has been transferred is neutralized by a pre-cleaning static eliminator 13 provided as necessary, and then a cleaning blade or a cleaning roller of the cleaning device [14] comes into contact with the surface of the photoreceptor 4. Residual toner is removed and the image is subjected to the next color image forming process. The color image formation shown in FIG. 10 is performed by four rotations of the photoreceptor 4 in the apparatus shown in FIG. 8, and by two rotations in the apparatus shown in FIG.

When forming a color image as shown in FIG. 12.13, the surface potential of the photoreceptor 4 is set to a potential at which toner does not adhere in the -next layer image forming step, and the uniform exposure device 7B is applied to the surface of the photoreceptor 4.
makes blue light uniformly incident on the photoreceptor 4.
The potential pattern generated in the B filter part of is transferred to the developing device 8T.
After developing to form a transparent toner image, without smoothing the potential, further development is performed in a developing device 8Y to form a yellow toner image superimposed on the transparent toner image. In the device shown in the figure, the paper is smoothed by a discharger 61, and in the device shown in FIG. The potential pattern generated on the G filter portion of the photoconductor 4 is transferred to the developing device 8T and 8M as before.
A transparent toner image and a magenta toner image are formed on the transparent toner image and a magenta toner image is formed thereon.The electric potential of the surface on which this toner image is formed is again transferred to the discharger 61 in the apparatus shown in FIG.
In the apparatus shown in the figure, red light is smoothed by a discharger 9M, and red light is uniformly incident on this smoothed surface by a uniform exposure device 7R. The pattern is developed by developing devices 8T and 80 to form a transparent toner image and a cyan toner image thereon. As a result, as shown in FIG. 12, a transparent toner image and a color image are formed on the photoreceptor 4 overlapping the transparent toner image. After that, the image is transferred to the recording material P in the same manner as in FIG. 10.11, thereby forming a color image on the recording material P as shown in FIG. 13. Of course, fixing of the color image on the transfer material P, cleaning of the photoreceptor 4, etc. are performed in the same manner. The color image formation shown in FIG. 12 is performed using the photoreceptor 4 in the apparatus shown in FIG. This is done by three rotations, and in the apparatus shown in FIG. 9, it is made by four rotations.

As described above, when a transparent toner layer or a transparent toner image is first formed on the photoreceptor 4 and a color image is formed thereon, the transfer efficiency of the color image is improved.
A recorded image with high image density is obtained, and the surface of the recorded image is coated with a transparent layer, giving it deep color and gloss. Furthermore, if the transparent toner T contains or is coated with an ultraviolet absorber or cleaning aid, the color will fade even if the colored toner contains a coloring agent with low light fastness such as a dye. In addition, the cleaning effect of the photoreceptor 4 can be improved.

When forming a color image as shown in Fig. 14.15, a primary latent image is formed in the same manner as in Fig. 12.13, and the 12th latent image is
．． As in the case of FIG. 13, uniform exposure devices 7B, 7G, 7
Repeating uniform exposure with H and development of the potential pattern formed thereby with the developing devices 8Y, 8M, and 80,
As a result, the charger 5 charges the surface of the photoreceptor 4 on which a color image has been formed, and the developing device 8T attaches transparent toner to the charged surface, and as shown in FIG. A color image and a layer of transparent toner are formed to cover it, and the rest is transferred to the recording material P in the same manner as in FIGS. 10111 and 12.13, as shown in FIG. 15. A single layer of transparent toner is formed on a recording material P, and a color image is formed thereon. Fixing of color images on recording material P, etc. is also described in Section 10.1.
This is done in the same way as in Figure 1 and Figures 12 and 13. Asahi 14
The color image formation shown in the figure is performed by rotating the photoreceptor 4 four times in the device shown in FIG. 8, and by approximately two revolutions in the device shown in FIG. Attachment @8
If a corona discharger similar to the charger is provided between 0 and 8T, the color image formation shown in FIG. 14 can be performed in one rotation of the photoreceptor 4.

When forming a color image as shown in Figure 16.17, a primary latent image is formed in the same manner as in Figure 12.13, and development after uniform exposure is performed first using a developer containing color toner. Uniform exposure device 7B is used in the same manner as in the case of FIG. 12.13, except that the exposure device 8Y, 8Mt, or 8c is used first, and then the developing device 8T is used.

Uniform exposure and development devices 8Y and 8M using 7G and 7H.

By repeating the overlapping development using 8c and 8T, a color image and a transparent toner image are formed on the photoreceptor 4 as shown in FIG. 16, and this is transferred to the recording material P. As shown in FIG. 17, a transparent toner image and a color image are formed on the recording material P. and,
The color image formation shown in FIG. 16 is performed by solo rotation of the photoreceptor 4 in the apparatus shown in FIG. 8, and by three rotations in the apparatus shown in FIG. If the developing device 8T in the device shown in FIG. 8 is positioned at the most downstream side as in the device shown in FIG. 9, the color image shown in FIG. become.

As described above, when a color image is first formed on the photoreceptor 4 and then a single layer of transparent toner or a transparent toner image is formed thereon, transfer holes are mainly caused by unevenness on the surface of the recording material. Mistakes only occur during the transfer of transparent toner.
Therefore, the color image is transferred in an orderly manner, and image holes in the transfer are reduced. In addition, the transparent toner as the base prevents the effects of unevenness on the surface of the recording material from appearing on the surface of the color image, resulting in improved printing and appearance with a good surface condition of the color image. Further, the color toner easily penetrates into the transparent toner during fixing, thereby increasing the depth of color and producing a glossy image.

The color image forming apparatus shown in FIGS. 8 and 9 can also form a color image in which a single layer of transparent toner or a transparent toner image is provided on both the upper and lower sides of the color image.

Furthermore, if the original image is a monochrome image, a color image that appears to be a monochrome image is formed. This monochromatic image is produced by the photoreceptor 4.
It is formed by toner of a specific color adhering to one kind of filter part or toner of each specific color adhering to multiple types of filter parts, and the image density appears to be lower than the monochrome image obtained with a monochrome copying machine. It's easy to become someone who gets rejected.

On the other hand, in the apparatus shown in FIG. 8, uniform exposure device 7B
. By developing with one or more of
In the apparatus shown in the figure, it is preferable that the uniform exposure device 7 is located at the most upstream side.
B consists of a white light lamp and a green light transmitting filter, the filter is retracted, the primary latent image forming surface is uniformly exposed to white light, and then development is performed in the same manner as described above. It is possible to form a monochromatic image with similar image density. In this case, of course, a single layer of transparent toner or a transparent toner image can be formed on the upper side or the lower side, or on the upper or lower side. Since monochromatic images are often black, a developing device containing black toner may be provided for this purpose.

The present invention is not limited to the illustrated example, but also relates to a color image forming apparatus described in Japanese Patent Application No. 59-199547 that uses a photoreceptor in which a filter layer is provided on the base side, and a photoreceptor in which a photoconductive layer has a color separation function. The present invention can also be applied to the color image forming apparatus described in Japanese Patent Application No. 59-201085 which uses . In addition, in the apparatus shown in FIGS. 8 and 9, in place of the discharger 61 of the image exposure device 6, or together with the discharger 61, the function similar to that of the discharger 61 or the function of the discharger 61 can be supplemented immediately downstream. It is also possible to provide a discharger for operation.

〔Effect of the invention〕

According to the color image forming apparatus of the present invention, it is possible to form an image having a transparent layer on the top side, bottom side, or both sides of the color image without color shift, and the obtained color image has excellent color and gloss. become something. Furthermore, not only so-called color images but also monochrome images can be formed with the same image density using a monocolor copying machine.

[Brief explanation of drawings]

FIGS. 1 to 4 are schematic partial cross-sectional views showing examples of the layer structure of a photoreceptor used in the color image forming apparatus of the present invention, and FIGS. 5 to 7 show color separation functional members of the photoreceptor, respectively. FIGS. 8 and 9 are partial plan views showing an example of the distribution shape of a certain color separation filter, and FIGS. 10 and 11, FIGS. Figure 13 shows the composite toner image formed on the photoreceptor and the image transferred to the recording material using the apparatus shown in Figure 8, respectively.
Cross-sectional view showing an example of a composite toner image in a fixed state, first
4, FIG. 15, FIG. 16, and FIG. 17 respectively show examples of the composite toner image formed on the photoreceptor by the apparatus of FIG. 9, and the composite toner image transferred and fixed to the recording material. FIG. DESCRIPTION OF SYMBOLS 1... Conductive member, 2... Photoconductive layer, 3...
...Insulating layer, 3a...Filter layer, R,
G, B...filter part, 4...photoreceptor, 5...
- Charger, 6... Image exposure device, 61,
9Yl 9M...Discharger, 7B, 7G, 7R...Uniform exposure device, 8Y, 8M, 8
T...Developing device, 11...Transfer device, 12...Separator, 14
. . . Cleaning device, 17 . . . Fixing device. Patent Applicant Konishi Roku Photo Industry Co., Ltd. Agent Patent Attorney Haru Yasu - Figure 1 Figure Z Figure 3 Figure 5 Figure 6 Figure 7 Figure 6 Figure 9

Claims (2)

[Claims] (1) A photoreceptor having a color separation function member is provided with a charging means, an image exposure means, a uniform exposure means for specific light, and a plurality of developing means, and is exposed to light by the charging means and image exposure means. After forming a primary latent image on the photoreceptor, a color toner image is synthesized on the photoreceptor by repeating the formation of a color-separated electrostatic image from the primary latent image using a uniform exposure means for specific light and development using a developing means. In addition to the plurality of developing means used for forming the color image, a developing means using transparent toner is provided, and the developing means is used to form a color image on the upper side or the lower side or on both upper and lower sides of the color image. A color image forming apparatus characterized in that transparent toner is attached to the side. (2) The developing means forms a developer layer on the sleeve to a thickness that does not contact the surface of the photoreceptor, and causes the toner to fly from the developer layer on the sleeve and adhere to the photoreceptor using the alternating current component of the developing bias. A color image forming apparatus according to claim 1.