JPH10123788A - Color display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a color picture with less color slurring by one electrophotographic process by superposing a needless pixel picture by black toner on a display sheet having an RGB color filter incorporated. SOLUTION: A laser exposure device 3 irradiates a photoreceptor 1 electrified to a specified potential with a laser light beam in accordance with the needless pixel picture (non-light emitting pixel picture), so that the latent image of the needless pixel picture is formed on the photoreceptor 1. A black developing device 4 abuts on the photoreceptor 1, the black toner 11 is electrostatically attracted to the photoreceptor 1 by the device 4 in accordance with the latent image of the needless pixel picture, and the needless pixel picture by the toner 11 is formed. Thus, the needless pixel picture by the toner 11 formed on the photoreceptor 1 is transferred on a transparent sheet 12. A transparent sheet driving means 13 stops driving on a position where the leading end part of the needless pixel picture by the toner 11 is superposed on the lower end part of the sheet 14. At this time, a white light surface 15 irradiates the sheet 14 and the needless pixel picture by the toner 11 with a white light beam from behind.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color display device capable of forming a color image by one electrophotographic process.

[0002]

2. Description of the Related Art There are color laser printers and the like as devices for realizing color display using an electrophotographic process. Hereinafter, a conventional color laser printer will be described.

FIG. 3 is a diagram showing a color image display method using a conventional color laser printer. In FIG. 3, 1 is a photoreceptor, 2 is a charger, 3 is a laser exposure device,
4 is a black developing device, 5 is a yellow developing device, 6 is a magenta developing device, 7 is a cyan developing device, 8 is an intermediate transfer member, 9 is a transfer roller, and 10 is a recording medium.

The operation of the color laser printer configured as described above will be described below.
The photoconductor 1 is charged to a certain potential by the charger 2. The laser exposure device 3 irradiates a laser beam corresponding to black data to the photoconductor 1 charged to a constant potential to form a latent image for black toner on the photoconductor 1. Here, first, the black developing device 4 comes into contact with the photoconductor 1. Then, the black toner is electrostatically attracted onto the photoreceptor 1 in accordance with the black toner latent image to form a black toner image. The black toner image formed in this way moves with the rotation of the photoconductor 1 and the intermediate transfer member 8
Is transferred onto the intermediate transfer member 8 at the contact point. By repeating the above procedure, a cyan toner image, a magenta toner image, and a yellow toner image are sequentially formed on the photoreceptor 1 and transferred onto the intermediate transfer member 8 each time.

[0005] After the above four processes, the black, cyan, magenta,
A four-layer yellow toner image is formed. The four layers of toner images are transferred from the intermediate transfer member 8 to the recording medium 10 by electrostatic attraction by a transfer roller 9 kept at a certain potential, and the toner images transferred onto the recording medium 10 are fixed (not shown). The image is fixed by the device to realize color image display.

[0006]

However, the conventional color laser printer requires four electrophotographic processes to form a color image, which hinders a reduction in the time required to display a color image. I was
Further, since a color image is formed by superimposing four color toners (= fine particles) in four layers, color misregistration and the like are likely to occur.

Accordingly, an object of the present invention is to provide a color display device capable of obtaining a color image with less color misregistration by one electrophotographic process without performing four electrophotographic processes. I do.

[0008]

According to the first aspect of the present invention,
A display sheet incorporating RGB color filters, a series of electrophotographic process means for forming an unnecessary pixel (non-light emitting pixel) image for each of the RGB pixels on the display sheet by a single process using black toner, A transparent sheet for holding an unnecessary pixel image formed by the black toner formed by the photographic process means, a transparent sheet driving means for driving the transparent sheet and superimposing it on the display sheet, and Light source means for irradiating light from behind the unnecessary pixel image with black toner,
And a toner reusing means for feeding back to the electrophotographic processing means for collecting and reusing the unnecessary black toner after the display is completed.

According to a second aspect of the present invention, there is provided the color display device according to the first aspect, wherein the display sheet has RGB color filters arranged in stripes.

[0010]

According to the first aspect of the present invention, color display can be realized by one electrophotographic process.

According to the second aspect of the invention, it is possible to reduce the color shift in the vertical direction. Hereinafter, embodiments of the present invention will be described. FIG. 1 is a schematic configuration diagram of a color display device using an electrophotographic process according to an embodiment of the present invention, and FIG. 2 is a diagram showing an arrangement of color filters built in the display sheet.

In FIG. 1, reference numeral 11 denotes a black toner, and unnecessary pixels for color display are formed by a series of electrophotographic process means including a photosensitive member 1, a charger 2, a laser exposure device 3, and a black developing device 4. An image (non-light emitting pixel image) is formed. The transparent sheet 12 holds an unnecessary pixel image (non-light-emitting pixel image) by the black toner 11 formed by a series of electrophotographic processes. Reference numeral 13 denotes a transparent sheet driving unit that independently drives the transparent sheet 12 to perform alignment between the display sheet 14 and the transparent sheet 12. Display sheet 14
Incorporates RGB color filters. Reference numeral 15 denotes a white light source, which emits white light from behind the superposed display sheet 14 and transparent sheet 12. Reference numeral 16 denotes a toner reusing unit that collects the black toner 11 that is no longer required at the time of switching the screen and uses the black developing device 4 of the electrophotographic process.
, The toner is reused.

The color image forming operation of the color display device according to the present embodiment configured as described above will be described in more detail. First, the photoconductor 1 is charged to a certain potential by the charger 2. The laser exposure device 3 irradiates a laser beam corresponding to an unnecessary pixel image (non-emission pixel image) to the photoconductor 1 charged to a certain potential, and forms a latent image of the unnecessary pixel image on the photoconductor 1. Here, the black developing device 4 comes into contact with the photoconductor 1. Then, the black toner 11 is electrostatically attracted onto the photoconductor 1 by the black developing device 4 in accordance with the latent image of the unnecessary pixel image, and an unnecessary pixel image is formed by the black toner 11. The unnecessary pixel image formed by the black toner 11 thus formed moves with the rotation of the photoconductor 1 in the direction of the arrow. Then, at a contact point between the photoconductor 1 and the transparent sheet 12, an unnecessary pixel image formed by the black toner 11 formed on the photoconductor 1 is transferred onto the transparent sheet 12.

The transparent sheet 12 is a transparent sheet driving means 1
3 rotates in the direction of the arrow in the figure.
The unnecessary pixel image due to the black toner 11 transferred onto 2 moves to the display sheet 14 side with the rotation. The transparent sheet driving means 13 stops driving at a position where the leading end of the unnecessary pixel image formed by the black toner 11 and the lower end of the display sheet 14 overlap. At this time, white light is emitted from the display sheet 14 and the white light source 15 as light source means from behind the unnecessary pixel image formed by the black toner. Here, the RGB color filters built in the display sheet 14 transmit only the color corresponding to each filter characteristic, that is, the R filter transmits R light, the G filter transmits G light, and the B filter transmits B light. Further, the color filter portion blocked by the unnecessary pixel image by the black toner 11 looks black because the black toner 11 blocks the white light from the white light source 15. Therefore, as shown in FIG. 1, the unnecessary pixel image portion made of black toner is black, and the light transmitted through the color filter portion built in the display sheet 14 transmits a color corresponding to each filter characteristic.
The additive color mixing makes the colors look like a combination of RGB. A color image is formed as described above.

When rewriting or erasing a screen,
Unnecessary pixel images due to the black toner 11 held on the transparent sheet 12 are removed and collected. At this time, the removed and collected black toner 11 is fed back to the black developing device 4 by the toner reusing means 16 for reuse. can do. Further, the arrangement of the RGB color filters built in the display sheet 14 is changed to the transparent sheet 12 as shown in FIG.
By forming a stripe in the same direction as the rotation direction of
It is possible to reduce the positional deviation of the unnecessary pixel image in the rotation direction due to the black toner 11 on the transparent sheet 12 and the color deviation due to the variation of the stop position accuracy of the transparent sheet driving means 13.

As described above, according to the embodiment of the present invention,
By superimposing unnecessary pixel images with black toner on a display sheet with a built-in RGB color filter, a color image with less color shift can be obtained in one electrophotographic process without performing four electrophotographic processes. Can be obtained.

[0017]

According to the present invention, an unnecessary pixel image made of black toner is superimposed on a display sheet having a built-in RGB color filter, so that one electrophotographic process can be performed without performing four electrophotographic processes. Therefore, a color image can be obtained, and the configuration of the apparatus can be simplified.
In addition, the display speed can be greatly improved because of a single electrophotographic process. In addition, by arranging the color filters built in the display sheet in a stripe shape, color shift in the sheet rotation direction can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a color display device using an electrophotographic process according to an embodiment of the present invention.

FIG. 2 is a diagram showing an arrangement of color filters incorporated in a display sheet according to an embodiment of the present invention.

FIG. 3 is a diagram showing a color image display method using a conventional color laser printer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photoreceptor 2 Charger 3 Laser exposure device 4 Black developing device 5 Yellow developing device 6 Magenta developing device 7 Cyan developing device 8 Intermediate transfer member 9 Transfer roller 10 Recording medium 11 Black toner 12 Transparent sheet 13 Transparent sheet driving means 14 Display sheet 15 White light source 16 Toner recycling means

Claims (2)

[Claims] 1. A display sheet incorporating RGB color filters, and a series of electrophotographic processing means for forming an unnecessary pixel image for each of the RGB pixels on the display sheet by a single process using black toner. A transparent sheet holding an unnecessary pixel image formed by the black toner formed by the electrophotographic process means, a transparent sheet driving means for driving the transparent sheet and superimposing on the display sheet, and a superimposed display sheet; Light source means for irradiating light from behind the unnecessary pixel image by the black toner on the transparent sheet, and feedback to the electrophotographic process means for removing and collecting and reusing the unnecessary black toner after the display is completed. And a toner reusing means for performing the operation. 2. The color display device according to claim 1, wherein the display sheet has RGB color filters arranged in stripes.