JPS5926950B2 - Color copying method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a color electrophotographic copying method.

Conventionally, in the color electrophotographic copying method, a photoreceptor is exposed to light using a color-separated image of an original using a color filter, and the resulting electrostatic latent image is used to print a color toner that is complementary to the color of the color filter used for color separation. Generally, a method is well known in which the process of developing and transferring the obtained color toner image onto a recording sheet is repeated as many times as necessary by changing the color of the color filter.

However, this method has the disadvantage that it is very difficult to align the toner images of different colors so that they are superimposed on each other without misalignment on the recording sheet, and that it takes a relatively long time to obtain a copy of one sheet. . Various proposals have been made for the purpose of eliminating such drawbacks.

It is also an object of the present invention to provide a color copying method capable of eliminating the above-mentioned drawbacks.

The present invention will be described below with reference to the drawings.

FIG. 1 schematically shows only the main parts of a color copying apparatus for carrying out the present invention. That is, in FIG. 1, the belt-shaped photoreceptor 2 is hung around pulleys 21 and 22, and its upper surface is exposed to light. parallel to glass 1,
They are also stretched across to face each other. Therefore, when the original 0 is placed at a fixed position on the original placing glass 1, the original surface and the surface of the photoreceptor 1 to be exposed are parallel to each other and face each other. Fiber bundles 30, 40, and 50 are optical. A large number of fibers, such as clad glass fibers and a focusing optical transmitter known by the product name Self-Otsu, are bundled together.
Individual optical. The aggregate surfaces of the fiber's finest end surfaces form slit-like elongated end surfaces that correspond to each other at both ends. Here, in order to make the explanation more concrete, we will use optical. It is assumed that the fiber 1 is a convergent optical transmission medium. Then, the individual convergent light transmitters are trimmed to a length that can form an erect, life-size real image, and a large number of convergent light transmitters are arranged close to each other in a direction perpendicular to the length direction and parallel to each other. They are arranged in a plurality of rows, and as shown in FIG. 2, they are integrated by a support 30a. In FIGS. 1 and 2, the direction perpendicular to the drawings is optical. This is the direction in which the fibers are aligned. As shown in FIG. 2, near the upper end face of the fiber bundle 30, there is a light source lamp 31 of a tube light.
But optical. It is provided parallel to the alignment direction of the fibers.

A charger 32 and a developing device 33 are disposed in parallel with each other near the lower end of the fiber bundle 30 with the fiber bundle 30 interposed therebetween. The fiber bundle 30, the light source lamp 31, the charger 32, and the developing device 33 are integrated with each other to form a unit. A similar unit includes a fiber bundle 40, a light source lamp 41, a charger 42, a developing device 43, and a fiber bundle 5.
0, light source lamps 51, 61. A combination of a charger 52 and a developing device 53 constitutes each. As shown in Figure 1, these three units are integrated with each other,
Configure set 3. In FIG. 1, the reference numeral 5 indicates a lamp cooling cylinder which also serves as a reflecting mirror, and the reference numeral 6 indicates a reflecting shade. Although the individual units have similar configurations, each unit has its own unique structure, such as changing the width of a bundle of fibers for each color in accordance with the exposure characteristics of the color separation. It's okay to do so. What is required is that when constructed as a set, each individual fiber bundle is assigned a light source lamp, a charger, and a developing device. Although the light source lamp 61 is not absolutely necessary, its provision allows two light source lamps to be assigned to each individual fiber bundle. When the individual units are integrated into a set, a charger belonging to one of any two adjacent units is brought into contact with a developing device belonging to the other unit. Then, in any unit, the arrangement is determined in the order of charger, fiber bundle, and developing device when viewed from the reference side. This standard is based on
In FIG. 1, it is on the left side. By the way, the fiber bundles 30, 40, and 50 of set 3 are composed of optical fibers. The fibers are colored, and the fiber bundle itself is equivalent to a colored filter. That is, the fiber bundle 30 has a color separation function equivalent to that of a blue filter, which is a precolor for yellow, and the fiber bundles 40 and 50 have green and cyan precolors, respectively, which are precolors for magenta. It has the same function as the red filter, which is a color. Of course, a normal color filter 1 may be used, but if the color filter 1 is used as in this example, the color filter 1 becomes unnecessary and the apparatus is further simplified. Now, as shown in FIG.
It is arranged so that it can move parallel to the document surface between the two. At this time, in this example, optical. Since a converging light transmitter is used as the fiber, the optical distance from the upper end of the fiber bundle to the document surface (distance taking into account the refractive index of the document mounting glass 1) is the same as that of the photoreceptor 2 from the lower end. be equal to the distance to the surface to be exposed. The developing devices 33, 43, and 53 are powder flow type developing devices. this is,
As shown in FIG. 2, a partition plate 33a is set upright in a space whose cross-sectional shape resembles that of a rectangle with one lower side removed, and from the outside, an air pump and a charger are used to connect the partition plate 33a to either positive or negative depending on the photoreceptor. injects an air stream containing charged toner powder into the
A toner powder stream can be formed as shown by arrow 34 in FIG. The developing device 33 uses yellow toner, and the developing devices 43 and 53 use magenta and cyan toner, respectively. Now, the color copying process using this apparatus will be explained below.

First, original 0 is placed at a fixed position on original placing glass 1 . Next, when the device is operated, the light source lamp 31 is first turned on.
, 41, 51, and 61 light up, the charger 32 starts discharging, and the set 3 starts moving at a constant speed in the direction of the arrow, with the charger 32 in front. charger 42
, 52, developing devices 33, 43, 53, etc., start operating from the position where they reach the upper part of the pulley 22 as the set 3 moves. Then, as the set 3 moves, the original 0 is illuminated by the light source lamps 31, 41, 51, 61, etc., and the reflected light from the original 0 first passes through the fiber bundle 30 and is colored blue in the illumination section. An electrostatic latent image corresponding to the separated partial image is formed on the surface of the photoreceptor 2 charged by the charger 32 by slit exposure.
The electrostatic latent image thus formed is visualized by a toner powder flow of yellow toner by the developing device 33.
The surface of the developed photoreceptor 2 is immediately charged by the charger 42, and a green color separation and a corresponding electrostatic latent image are formed by the fiber bundle 40, and this electrostatic latent image is transferred to the developing device 43. The image is visualized by the flow of magenta toner powder. A similar process is repeated by the unit to which the fiber bundle 50 belongs, and a cyan toner image is further superimposed on the already superimposed yellow visible image and magenta visible image, so that set 3 is obtained. When the photoreceptor 2 moves to the position indicated by the broken line in FIG. 1, a color image corresponding to the original 0 is obtained on the surface of the photoreceptor 2. This color image is a mirror image of document 0. The series of chargers and developing devices stop their operation when they each reach above the pulley 21 as the set 3 moves in the direction of the arrow. Next, the photoreceptor 2 is rotated counterclockwise by the pulley 21, and the recording sheet S is forced into the transfer roller 7 and the photoreceptor 2 in synchronization with the movement of the color image. Then, when passing through this position, the color image is transferred onto the recording sheet S as a normal image. During this time, set 3 returns to the starting position. The transferred color image is fixed onto the recording sheet S when passing through a fixing section 8 consisting of a belt and rollers. Thereafter, the recording sheet S on which the color image has been fixed is ejected from the apparatus, and in this way, a color copy image corresponding to the original is obtained. Now, when looking at the color copying method according to the present invention from the above-mentioned problems of the time required for alignment and copying, firstly, in the present color copying method, the original and the photoreceptor are stationary relative to each other during the copying process. Since a color image is formed all at once by the movement of the set 3, no color shift occurs at all.

Next, the time required for copying depends on the speed of movement of set 3. This moving speed is determined according to the color separation of the blue color, which takes the longest time to be exposed. now,
Suppose that the moving speed of set 3 is set sufficiently small to 3/sec.
07!1m, the speed of the photoreceptor 2 during transfer is 120mm per second, the document length is 360mTfL (B4 size), and the length of set 3 in the moving direction is 120mT1.
L, it takes 60 seconds to obtain a copy of a single page using the conventional method of repeating color separation, development, and visible image transfer for such an original size, whereas the present invention takes 60 seconds. Case 2
A color copy of one leaf can be obtained in 0 seconds. Therefore,
The present invention can improve both copying speed and image quality compared to conventional methods. As described above, according to the present invention, it is possible to provide a color copying method that can obtain a color copy image without any color shift in a short time.

Moreover, in the present invention, optical. Since a bundle of fibers is used as the imaging system, it is easier to miniaturize the apparatus compared to the case where an ordinary lens is used to perform full-surface exposure or slit exposure. Incidentally, for the purpose of developing with black toner, a unit using a bundle of uncolored fibers and a developing device for black toner may be set in parallel with the above unit group.

Furthermore, it goes without saying that any static eliminating means such as an AC corona charger may be interposed between the charger belonging to one of the two units adjacent to each other and the developing device belonging to the other.

[Brief explanation of the drawing]

FIG. 1 shows a color copying apparatus for carrying out the present invention.
FIG. 2 is a schematic front view showing one example of the unit. 0...Original, 2...Photoconductor, 3...
...Set, 30...Wire bar bundle, 31...
...Light source lamp, 32...Charger one,
33...Developing device, S...Recording sheet.

Claims (1)

[Claims] 1. An original is placed in a fixed position, and the surface of a belt-shaped photoreceptor, which is hung around two pulleys, to be exposed is stretched parallel to and opposite to the original. A large number of fibers with individual optical fibers at each end. A light source lamp for illumination is placed near one end face of a fiber bundle, which is formed by bundling the fibers so that the collective faces of the fibers form slit-shaped end faces that correspond to each other. A charger and a powder flow type developing device are provided in parallel to the alignment direction of the fibers, and a charger and a powder flow developing device are provided near the other end face, respectively, parallel to the alignment direction and sandwiching the fiber bundle, and these fiber bundles, light source lamps, chargers, The developing device is integrated into a unit, and at least three similar units are arranged so that the slit-shaped end surfaces of the respective fiber bundles are parallel to each other, and in two units adjacent to each other, one charger is connected to the other. At least three of these units are integrated into a set, and each fiber bundle is provided with a filter of a different color to provide a color separation function to the set, and the individual developing units are arranged so as to be in contact with the developing device. The device uses toner of a complementary color to the color of the filter provided on the fiber bundle belonging to the same unit as the developing device, and this set is placed between the document and the surface of the photoconductor to be exposed. The charger and the developing device are movably arranged parallel to the document surface so that the light source lamp is close to the document surface, and the charger and the developing device are close to the surface to be exposed. , activating the developing device and moving the set at a uniform speed in one direction with a charger in front of the stationary original and the photoreceptor to obtain a color visible image corresponding to the original on the photoreceptor; A color copying method characterized in that the photoreceptor is then rotated to transfer the color visible image onto a recording sheet. 2. A color copying method according to claim 1, characterized in that the individual fiber bundles are colored in different colors so that color separation can be performed without a filter.