JPH01102583A - Electrostatic recorder - Google Patents

Abstract

PURPOSE:To execute full color recording by one operating by providing plural developed image forming means having an exposure light source for forming a latent image by executing an exposure from a substrate side on a photosensitive body formed on a light transmission substrate, a developing means and a destaticizing light source. CONSTITUTION:A photosensitive drum 1 is formed by laminating a photosensitive body 11 in order of a transparent conductive oxide and an amorphous silicon layer on the outside periphery of a glass cylinder 10 being a translucent substrate. Also, in a position which faces the outside periphery of the photosensitive drum 1, four groups of developed image forming units U1-U4 are arranged in order from the upstream side in the rotational direction, the photosensitive body 11 is exposed from the substrate 10 side successively by said units, respectively and a latent image is formed, it is developed by toners whose colors are different, respectively, and thereafter, a processing for destaticization from the substrate side is repeated, and a toner developed image of three primary colors or black and three primary colors is formed. In such a way, the development by toners of three primary colors or black and three primary colors can be executed by one operation.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention i relates to an electrostatic recording device, and more specifically, to so-called electrophotographic color recording that performs multicolor recording using a plurality of types of toner of different colors. Regarding equipment.

[Conventional technology]

Various electrostatic recording devices capable of multicolor recording, so-called electrophotographic color copying devices, have been developed and put into practical use.

Conventional recording apparatuses of this type generally have a configuration in which a conventional general method of recording with black toner on a white recording paper is repeated using a plurality of toners of different colors. Therefore, to perform full-color recording, a total of four colors, black and the subtractive primary colors (yellow, magenta, cyan), are usually required.
It is necessary to sequentially record four times on the same recording paper using colored toners (Electrophotography Society Symposium Proceedings [How far has hard copy colorization technology come? J 1987)
Therefore, conventionally, it takes a relatively long time to obtain a single image, and there are problems such as color shift occurring relatively frequently.

In view of the problem of the conventional technology, that is, the number of recording operations required is the same as the number of toner colors, the applicant of the present application previously filed an invention in Japanese Patent Application No. 139231/1983. Briefly, this invention forms an electrostatic latent image charged to both positive and negative potentials on a photoreceptor that can be charged to both positive and negative polarities, and develops this with toner charged to both positive and negative polarities. However, this invention can only perform recording using two types (two colors) of toner.

[Problems to be Solved by the Invention] As described above, no electrostatic recording device has been developed that can record with four toner colors required for full-color recording in one operation. Full-color recording using an electronic recording device has problems such as requiring a long time and low accuracy.

The present invention was made in view of these circumstances, and
An object of the present invention is to provide an electrostatic recording device which enables development using toners of three primary colors or three primary colors and black toner in one operation and enables high-precision full-color recording in a relatively short processing time.

[Means for solving problems]

The electrostatic recording device of the present invention includes a light-transmitting substrate, a photoreceptor formed on the substrate, and an exposure light source that exposes the photoreceptor from the substrate side to form a latent image.

The image forming apparatus includes a plurality of image forming means having a developing means and a static eliminating light source that exposes the photoreceptor after development from the substrate side to eliminate static electricity.

[Effect]

In the electrostatic recording device of the present invention, the photoreceptor is sequentially exposed from the substrate side by each of the plurality of N image forming means to form a latent image, which is developed with toner of a different color, and then from the substrate side. By repeating the process of eliminating static electricity using the static eliminating light source, toner images of three primary colors or black and three primary colors are formed.

[Embodiments of the invention]

Hereinafter, the present invention will be explained with reference to the drawings showing embodiments thereof.

FIG. 1 is a schematic side view showing an embodiment of the configuration of the electrostatic recording device according to the present invention.

In the figure, 1 is a photosensitive drum. This photosensitive drum 1 has a photosensitive member 11 laminated on the outer periphery of a glass cylinder 1o as a transparent substrate.

The photoreceptor 11 has photosensitive layers stacked on a glass cylinder 10 in the order of TCO (transparent conductive oxide) and a-5t (amorphous silicon) layers.

Note that ITO (yttrium tin oxide), SnO2, etc. can be used as the TCO layer, and P-type or N-type a-Si, a-5iC, a-SiN, etc. can be used as the a-Si layer. , a type 1 a-53:H layer on top of that, and a-S i N + a-S r on top of that.
C+ a-S s O or a-C may be laminated, or a-5iN laminated on the top layer mentioned above.
, a-SiC, or a-C on the upper layer of a-SiO:
H or a-C:H:F may be laminated, or a
- It is also possible to use P-type or N-type μc-Si (microcrystalline silicon) as the Si layer.

A photosensitive drum 1 is placed at a position 1 facing the outer periphery of the photosensitive drum 1.
From the upstream side in the rotational direction, there are four sets of visual image forming units, specifically, 1.2.3.4 lJl! Image forming unit) IJI, U2. U3. I4 is arranged.

The image forming unit 01 (02, 03, 04) is arranged on the photoreceptor 11 side (outer periphery) of the photoreceptor drum 1.
A charging corotron 21 (22, 23, . . . ) uniformly charges the toner to, for example, +400V, and a developing device 31 (32, 33, . ...) are arranged facing the outer periphery of the photosensitive drum 1, and a don't date of the image frame is given from a memory (not shown), etc., and the photosensitive drum 1 is moved according to this.
An exposure light source 21 (22, 23
...) and a static eliminating light source 81 (82, 83, 82, 83,
) are arranged facing the inner periphery of the photosensitive drum l.

In the embodiment shown in FIG. 1, the static eliminating light source 83 of the third visible image forming unit U3 is replaced by the fourth visible image forming unit U4.
The charging corotron 24 of the fourth visible image forming unit U4 shares the static eliminating light source 84 of the fourth visible image forming unit U4.
The charging corotron of No. 3 is shared by 25, and the developing unit 31.3 of No. 1.2.3 is used.
2 and 33 perform reversal development using toners of the three primary colors, and the developing device 34 of the fourth gJlts forming unit U4 performs regular development using black toner.

These image forming units [1, U2 . U3. At the position downstream of I4, there are respective developing units 31, 32, 33 .
A transfer roller 5. transfers the toner n image developed in step 34 onto the recording paper 4; A cleaner 6 and the like for removing toner remaining on the surface of the photoreceptor 11 of the photoreceptor drum 1 is arranged.

Each exposure light source 7H72, 73, 74) forms an image on the photoconductor 11 of the photoconductor drum 1 as a dot (stored in a memory, etc. not shown) that represents the image to be recorded by separating it into black and the three primary colors. used for Specifically, each exposure light source 71 (72, 73, 74) has an emission wavelength of 600 to 750 ns and an array density of light emitting elements of 1.
A red LED array of 8 to 16 dots per screen is suitable.

Note that each exposure light source 71 (72, 73, 74) is
In addition to the ED array, it is also possible to use a combination of various continuous light sources and liquid crystal shutters.

1.2.3 Visual image forming unit) l11. lI2. U3
The developing units 31, 32, and 33 each perform reversal development using toner of the three primary colors. Further, the developing device 34 of the fourth image forming unit 114 performs regular development using black toner.

Each static elimination light source 81 (82, 84) is connected to the photoreceptor 11
is exposed from inside the glass cylinder 10 of the photosensitive drum 1 to remove static electricity.

The operation of the electrostatic recording apparatus of the present invention having such a configuration is as follows.

First, a toner image of one of the three primary colors, for example yellow, is formed by the first image forming unit (1). That is, the charging corotron 21 of the first image forming unit UI charges the photoreceptor 11 at <+400V as shown in FIG. 2(a).
charge evenly.

Next, an electrostatic latent image to be reproduced in one of the three primary colors, for example yellow, is formed by the exposure light source 71 of the first visible image forming unit 1-Ul, and this is transferred to the first visible image forming unit Ut. This state in which reversal development is performed using yellow toner by the developing device 31 is shown in FIG.

Then, as described above, the photoreceptor 11 on which a visible image has been formed with yellow toner is neutralized from the circular curve of the photosensitive drum 1, that is, from the glass cylinder lO side, by the static eliminating light source 81 of the first visible image forming unit nod U1. . As a result, as shown in Figure 2 (C1),
The entire surface of the photoreceptor 11, including the portion where the toner image has already been formed, is neutralized.

This completes the formation of a visible image using one color toner (yellow toner in this example) by the first visible image forming unit Ill, so next the formation of a pond-colored visible image by the second visible image forming unit u2 is completed. Let's do it.

That is, similarly to the formation of a yellow visible image by the first visible image forming unit U1 described above, the charging corotron 22 of the second visible image forming unit U2 charges the surface of the photoreceptor 11 as shown in FIG. 2(d). is uniformly charged to +400V, and then the exposure light source 72 forms a latent image to be reproduced, for example, as a magenta W4 image. The developer 32 of the image forming unit t12 performs reversal development using magenta toner. This state is shown in FIG. 2 (Q), in which magenta toner is shown at rOJ.

Then, as described above, the photoreceptor 11 on which a developed image has been formed with magenta toner is neutralized from the inner periphery of the photosensitive drum 1, that is, from the glass cylinder lO side, by the electric discharge light source 82 of the second head image forming unit U2. As a result, as shown in FIG.
The entire surface of 1 is neutralized.

In the example shown in FIG. 2 ( ), the yellow toner developed by the first developing unit u1 is first developed by the first developing unit u1, and then the yellow toner is developed by the second developing unit u1.
The magenta toner developed by the developing image forming unit U2 overlaps the same area on the photoreceptor 11, and is reproduced as red through subtractive color mixing.

Next, the above-mentioned first image forming unit υ3
Similarly to the case of the image forming unit U1 and the second image forming unit u2, a developed image is formed using toner of the remaining three primary colors, that is, cyan.

Note that after the cyan toner image is formed by the third image forming unit u3, the surface of the photoreceptor 11 is not neutralized by the electric discharge light source, and the surface of the photoreceptor 11 is not newly charged by the charging corotron. Therefore, the charged state of the surface of the photoreceptor 11 at this point is the third W4@! This is the same state as when a latent image to be reproduced in cyan is formed by the exposure light source 73 after being charged to +400V by the charging corotron 23 of the forming unit U3.

Then, a latent image to be reproduced in black is formed by the exposure light source 74 of the fourth image forming unit u4.

In this case, as a result of the charging to +400V by the charging corotron 23 of the third visual image forming unit U3 and the formation of a cyan latent image by the exposure light source 73, the parts other than the cyan latent image (of course, the parts other than the cyan latent image are reproduced as black). (including the part that should be) is maintained at a high potential of +400V.

Therefore, the exposure light source 74 of the fourth image forming unit υ4 forms a black latent image for regular development, that is, a latent image in which the portion to be reproduced in black remains at a high potential.

After this black latent image is formed, regular development is performed using black toner in the developing device 34 of the fourth visible image forming unit u4, thereby forming a black toner visible image.

As described above, a full-color toner image reproduced by subtractive color mixing using EJIr color and black toners is formed on the surface of the photoreceptor 11, so that the fourth image forming unit) [14
After electricity is removed from the surface of the photoreceptor 11 using the electricity removal light source 84, the toner image is transferred onto the recording paper 4 by the transfer roller 5. Finally, the residual toner on the surface of the photoreceptor 11 is removed by the cleaner 6, and the series of processes is completed.

As described above, in the apparatus of the present invention, since the exposure for forming a latent image is performed from the inner circumference of the photosensitive drum 1, the latent image can be formed overlapping the area where a developed toner image has already been formed. Full-color recording is possible.

Also, facing the outer periphery of the photosensitive drum 1, each developing image forming unit 01, 02. Charged corotron 21.22 of U3,114
....

Developing units 31, 32..., are arranged, and the photosensitive drum l
Each visible image forming unit Ul, IJ2 . U3
．． U4 exposure light source 71.72..., static elimination light source 81.8
2..., it is possible to narrow the arrangement interval of each member and downsize the entire device.

Furthermore, since the photoreceptor 11 is exposed to light from the side of the glass cylinder 10 that is the substrate, it is possible to use electrons as movable carriers with positive charging, which increases the sensitivity of the photoreceptor 11. It becomes possible to improve.

Furthermore, since the black toner is developed by the fourth visible image forming unit U4 by regular development, the static eliminating light source of the third visible image forming unit 03 is shared with the static eliminating light source 84 of the fourth visible image forming unit U4. and a fourth image forming unit u
It becomes possible to share the charging corotron of No. 4 with the charging corotron 23 of the third visual image forming unit U3, and the number of constituent members is reduced.

FIG. 3 is a schematic side view showing the configuration of the factors of the electrostatic recording device of the present invention showing another embodiment of the present invention.

In the embodiment of the present invention, three sets of image forming units 1.2.3, U1, U2. By U3, only the three primary color toners are developed, and no developed image is formed using the black toner.

Specifically, each image forming unit Ul, t12. t13
Each has a charging corotron 21 (22, 23), an exposure light source 71 (72°73), a developing device 31 (32, 33), and a static eliminating light source 81 (82, 83), each of which is similar to the previous embodiment. Then, toner images of each of the bicyclic colors are sequentially formed. In this case, the black toner image is formed by mixing the three primary colors.

〔Effect of the invention〕

As detailed above, according to the electrostatic recording device of the present invention, l
Since full-color recording is possible in operation, the processing time is shortened to approximately A compared to the method of developing one color at a time, and the frequency of occurrence of color misregistration is also reduced, achieving high image quality.

Further, as in the above embodiment, when each member is arranged on both the outer circumferential surface and the inner circumferential surface of the photosensitive drum, the apparatus can be made smaller.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view showing the configuration of the main parts of the electrostatic recording device of the present invention, and FIG. FIG. 3 is a schematic side view showing the configuration of essential parts of another embodiment of the present invention. 1...Photosensitive drum 4...Recording paper 5...Transfer roller 6...Cleaner 10...Glass cylinder 11...Photoreceptor 21-24...Charging corotron 31-34...Developing device 71-74
...Exposure light source 81-84...Static elimination light source patent Applicant: Sanyo Electric Co., Ltd. Agent Patent attorney: Noboru Kono

Claims (1)

[Scope of Claims] 1. A latent image carrier having a photoreceptor in which a photoreceptor layer is laminated in the order of transparent conductive oxide and amorphous silicon on a light-transmitting substrate, and a charging means for charging the photoreceptor. , an exposure light source that exposes the photoreceptor charged by the charging means from the substrate side of the latent image carrier to form an electrostatic latent image on the photoreceptor; and a toner image by developing the electrostatic latent image. and a static eliminating light source that exposes the photoreceptor after being developed by the developing means from the substrate side of the latent image carrier to eliminate the static charge, A plurality of sets of visible image forming means are arranged from the upstream side in the moving direction, a transfer means for transferring the toner image on the photoreceptor onto a sheet of paper, and a cleaning means for removing residual toner on the photoreceptor. An electrostatic recording device characterized by: 2. Three sets of the visible image forming means are provided, first, second, and third from the upstream side in the direction of relative movement with the latent image carrier, and the developing means of each visible image forming means performs reversal development with toner of the three primary colors. An electrostatic recording device according to claim 1, which is configured to perform the following. 3. Four sets of the visible image forming means are provided, ie, first, second, third, and fourth from the upstream side in the direction of relative movement with the latent image carrier;
, after performing reversal development with the toners of the three primary colors by the developing means of the third visible image forming means, the charge is removed by the static eliminating light source of the third visible image forming means, and the charging is performed by the charging means of the fourth visible image forming means. 2. The electrostatic recording apparatus according to claim 1, wherein regular development is carried out using black toner by the developing means of the fourth image forming means without performing regular development. 4. Claim 1, wherein the transparent substrate is glass.
The electrostatic recording device described in Section 1. 5. The electrostatic recording device according to claim 1, wherein the latent image carrier is formed into a drum shape. 6. The electrostatic recording device according to claim 1, wherein the photoreceptor is formed by laminating indium tin oxide or SnO_2 as a transparent conductive oxide on the glass. 7. The photoreceptor is made of P as the amorphous silicon layer.
type or N type a-Si, a-SiC or a-SiN
layer, an i-type a-Si:H layer on top of it, and a-SiN, a-SiC, a-SiO or a-C
An electrostatic recording device according to claim 1, which is formed by laminating a plurality of layers. 8. A-C:H or a-C:H:F on the a-SiN, a-SiC, or a-SiO layer laminated on the i-type a-Si:H layer of the photoreceptor. An electrostatic recording device according to claim 7, which is formed by laminating a plurality of layers. 9. The electrostatic recording device according to claim 7, wherein the amorphous silicon layer is a stack of P-type or N-type microcrystalline silicon. 10. The exposure light source has an emission wavelength of 600 to 750 nm.
m, red L with array density of 8 to 16 dots per mm
The electrostatic recording device according to claim 1, which is an ED array. 11. The electrostatic recording apparatus according to claim 1, wherein the exposure means is a combination of a light source and a liquid crystal shutter. 12. The electrostatic recording device according to claim 1, wherein the static eliminating light source is a white lamp, an LED array with an emission wavelength of 500 to 750 nm, or a fluorescent glow lamp with an emission wavelength of 400 to 750 nm. 13. The electrostatic recording device according to claim 1, wherein the emission wavelength of the exposure light source is shorter than the emission wavelength of the static elimination light source. 14. The electrostatic recording apparatus according to claim 1, wherein the development of the electrostatic latent image by the developing means is performed by a non-contact development method. 15. The electrostatic recording apparatus according to claim 1, wherein the electrostatic latent image is developed by the developing means using conductive toner. 16. The electrostatic recording according to claim 1, wherein the static eliminating light source of the visible image forming means disposed on the most downstream side in the direction of relative movement with the latent image carrier is located downstream of the cleaning means. Device.