JPS5950462A - Color electronic copying device - Google Patents

Abstract

PURPOSE:To reduce the color deviation based on misregistration of a copy picture, by intercepting high frequency components in a scanning light by a color filter to extend the width of sticking of a yellow toner when the development is performed with the yellow toner. CONSTITUTION:A blue filter 52 of a color filter 5f consists of a low pass filter which has many granular projections different in refractive index on the surface. Under the control of a microcomputer 19, a photosensitive drum 6 is exposed to the light transmitted through a green filter 51 at the first original scanning time, and the development is performed with a magenta toner. The photosensitive drum 6 is exposed to the light transmitted through the blue filter 52 at the second original scanning time, and the development is performed with the yellow toner, and the width of sticking of the yellow toner is increased because high frequency components are cut. The photosensitive drum 6 is exposed to the light transmitted through a red filter at the third original scanning time, and the development is performed with a cyan toner, and transfer and fixing are performed. Thus, the color deviation due to misregistration of the copy picture is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a color electronic copying apparatus that prevents misregistration of yellow toner and other color toners by increasing the adhesion width of yellow toner, which is visually less noticeable.

Color electronic copying equipment scans color originals with light.

For example, a photoreceptor is exposed to light using blue, red, and green filters, and developed with yellow, cyan, and magenta developing toners that correspond to the spectral R light of each color, and then the developed image of each color toner is copied. Copies of color images are made by transferring and superimposing images.

However, in this color electronic copying device, the developed images of three photosensitive drums corresponding to yellow, cyan, and magenta color toners are transferred to copy paper sequentially, or the yellow, cyan, and magenta toners are transferred to one photosensitive drum. As the color toners are developed sequentially and pressure is applied to transfer them to the copy paper after each development, the toners shown in Figure 1 (a), (b),
As shown in (c), there is a possibility that the original l will become copied images 2 and 3 with color misregistration due to misregistration.

The present invention has been made in view of the above, and provides a color electronic copying device in which the adhesion width of yellow toner is reduced so that it is less visually noticeable in order to reduce color shift caused by misregistration of copied images. It is something.

The color electronic copying apparatus according to the present invention will be explained in detail below.

FIG. 2 shows an embodiment of the present invention, in which a platen 2 on which a document l is placed, a console 3 having a start key (not shown), a number-of-copies display (not shown), etc. are connected to a copying machine 4. is located at the top of the. ? ! A scanning system 5 (light source lamp 5a-mirror 5b,
5c.

5d, a lens mirror 5e, a color filter 5f), a photosensitive drum 6 that is exposed to 'ti'g light by the scanning system 5, a transfer drum 7 that contacts the photosensitive drum 6 at a transfer section 6a, and qf.
Paper feed tray i that supplies copy paper to the ll-+ section 6a
8a and 8b are provided. Photosensitive drum 6
Around the , there is a charge, corotron 9 and 1g slits) l(
], an interimage lamp 11 for erasing the non-image area band 1 of the photosensitive drum 6, and a latent image 'r of the photosensitive drum 6.
Developing unit 13 that develops based on the 6th position (the color filter 5f described above is the green filter 5J, the blue filter 52
, a red filter 53, and the developing section 13 has magenta, yellow, and cyan developing sections 13a, corresponding to the three colors.
13b.

13c), a transfer corotron 14 provided in the transfer section 6a, a cleaner 15 for removing the toner after transfer from the photosensitive drum 6 (the toner removed by the brush 15a is sucked by the fan 151), and the photosensitive drum. An erase lamp 16 for erasing the residual potential of 6 is provided. A transport unit 17 and a fixing unit 18 are provided downstream of the transfer unit 6a, and a microcomputer 19 for controlling the operation of the copying machine 4 is also provided. The microcomputer 19 has an input interface 19a that inputs sensor signals and operation command signals from various sensors in the copying machine 4 or the console 3, and a ROM 19b that stores programs necessary for arithmetic processing of input signals. 0PU 19c that performs predetermined calculations; RAMx 9d that temporarily stores calculation results and data; and an output that outputs control signals to various control objects of the copying machine 4 or the display section of the console 3 based on the calculation results. Interface 19e
has.

Blue filter 52 in the color filter 5f described above
has a characteristic of blocking 20 or more high frequencies among spatial frequencies, and is composed of, for example, a low-pass filter having a large number of granular protrusions with different refractive indexes on its surface.

Regarding the above configuration, to explain its operation, after placing the original l on the platen 2, turn on the start switch (not shown) of the console 3, and control the microcomputer 19 (
(omitted from the description below), the scanning system 5 scans the document. During the first document scanning, the green filter 51 is placed in the optical path, and the photosensitive drum 6 is exposed to the green component in the scanning light. A developing section 13a develops the latent image resulting from the exposure using magenta toner, and this developed image is transferred to the copy paper held by the transfer tongue 7 at the transfer section 6a. Thereafter, when the second document scan is performed, the blue filter 52 is placed in the optical path, and the photosensitive drum 6 is exposed to the blue component in the scanning light. Developing section 13t)
When the latent image resulting from the exposure is developed with yellow toner, the high frequency of the blue component light is cut, so the latent f-square width becomes a dog, and the yellow toner adhesion width becomes a dog. (See pages 86 to 89 of the January 1976 issue of "Photography Industry" [Camera Performance and Evaluation: From Resolution to MTF]). This yellow toner development is transferred to the copy sheet held by the transfer drum 7 in the same manner as the first transfer. lastly,
When the third document scan is performed, the red filter 53 is moved into the optical path, and the photosensitive drum 6 is exposed to the red component in the scanning light. Dive 1♀ based on this exposure! The developing section 13c develops the image using cyan toner, and the copy paper, which is still gripped by the transfer drum 7, undergoes the final transfer of the developed image. The copy paper that has been transferred three times is released from the transfer drum 7 and transported to the transport bell) 17.
The image is then discharged through the fixing section 18.

Figures 3 (a), (b), and (c) show that the yellow toner has a dog-shaped adhesion width, (a) shows that green is reproduced by overlapping cyan toner, and (b) shows magenta. Red is reproduced by overlapping toners, and (c) shows that black is reproduced by overlapping blue toners.

In the above embodiment, the blue filter is configured with a low-pass filter to cut high frequencies, thereby reducing the adhesion width of the yellow toner. 1
The Sakae bias voltage may be set low.

As explained above, according to the color copying apparatus according to the present invention, the adhesion width of the yellow toner, which is visually less noticeable, is made smaller than the adhesion width of other color toners, thereby preventing color shift due to misregistration of copied images. can be reduced.

[Brief explanation of drawings]

Figures 1 (a), (b), and (c) show color shift due to misregistration9. Opening. FIG. 2 is an explanatory diagram showing a practical example of the present invention. FIGS. 3(a), 3(b), and 3(c) are explanatory diagrams showing copy images according to the present invention. Explanation of symbols 1... Original 2... Platen 3... Console 4... Main body 5... Scanning system
6... Photosensitive drum 7... Transfer drum 8a, 8b
,...Paper feed tray 9...Charging section 10...
Exposure section 11...Interimage lamp 13...fJL Image section 14...Transfer corotron 15
... Cleaning section 16 ... Erase lamp 17.
...transhode belt 18...fixing M 19...microcomputer 51.
...Green Filter: 2...Blue Filter 53...Red Filter Agent Patent Attorney Kiyoshi Muraki 11th Edition::
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Claims (1)

[Scope of Claims] Filter means for exposing a photoreceptor to spectral light based on the scanning of a color original, developing means for developing a latent image with color toner corresponding to 1-minute light exposure, and fixing after transferring the developed image to copy paper. and a transfer/fixing means for reproducing a copy image, and the filter means is characterized in that when development is performed with yellow toner, the filter means blocks high frequency components in the scanning light and expands the adhesion width of the yellow toner. Color electronic copying device.