JPS60214376A - Color copying machine - Google Patents

Abstract

PURPOSE:To take a copy of desired color without replacing a developing machine by installing 2-3 developing machines which supply toner of optional color and scatter toner sticking on a surface over the surface of a photosensitive drum during development at development positions. CONSTITUTION:Developing machines 21-23 each consists of a housing 25 with a toner supply port 24, a couple of developing rolls 26 which are installed rotatably in the housing 25 and have 10<2>-10<8>OMEGA-cm specific surface resistance, and a metallic blade 27 which foms one-two toner film layers on the surfaces of the developing rolls 26. For example, red toner, green toner, and blue toner are loaded in the developing machines 21-23 and when a bias voltage VB is impressed to each roll 26 on every turn of the drum 6, toner of each color is scattered toward the photosensitive drum 6 and sticks on a latent image. In this case, the number of rotation of the developing rolls 26 are controlled to make a density adjustment, so three developing machines are used in combination to take a copy of any color.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a color copying apparatus capable of making color copies of only a single arbitrary color without requiring replacement of a developing machine.

[Prior art]

An example of a conventional color copying apparatus is the one shown in FIG. 1, which includes a mechanical section 1, a console 20 for setting various conditions necessary for copying, and a mechanical section that operates based on output signals from the console 20 and various sensors. 1, and a drive section 40 that controls the motors, corotrons, power supplies, etc. of each mechanism in accordance with the output commands from the control section 30.

The mechanical unit 1 includes a platen 2 on which an original document 50 is placed, a drive mechanism 3 that reciprocates the platen 2 during scanning with the document 50 placed thereon, and a motor 4 that serves as a drive source for the drive mechanism 3. , irradiates the original 50 with light during scanning, and also irradiates the original 50 with light.
A scanning unit 5 that images the reflected light from 0 on a predetermined position via a filter, and the light from the scanning unit 5 is imaged on the surface and a latent image for each color of cyan, magenta, and yellow is formed during three rotations. A charger 7 uniformly charges the surface of the photoreceptor drum 6 prior to exposure, and a toner of each color can be attached to the latent image formed on the photoreceptor drum 6. Developing machine 8 m * 8b for developing each of cyan, magenta and yellow forming a visual image during three rotations of the drum
*8C, a motor 9 that drives the photoreceptor drum 6, a paper feed cassette (10) that stores a large number of sheets of copy paper 60 of the required size, and a feeder that is timed to match the arrival of the visible image at the transfer position. A paper feed belt 11 that feeds only one sheet of paper from a paper cassette 10, and a motor 12 that drives the paper feed bell (11).

A conveyor roller 13 conveys the fed paper to the transfer position, a transfer device 14 transfers a visible image from the photoreceptor surface to the paper 6-0 conveyed to the transfer position, and fixes the transferred image on the copy paper. and a fixing device 15.

A cleaner 16 that removes residual toner adhering to the surface of the photoreceptor drum 6 that has been transferred, and copy paper 6 that has been fixed.
1 and a discharge tray 17 that accommodates the 1.

The control unit 30 stores an input interface 30b that sends signals obtained by digitizing information from various units and the console 20 to the path line 30m at predetermined timing, and a program for carrying out color copying processing. ROM 30 a, 0PU 30 d, which executes various processes according to the programs in ROM 30 e, and 0P.
Temporarily stores processing results and data by U30d
and an output interface 19f that sends control commands output as the processing results of the 0PU 30d to the drive unit 40 at a predetermined timing and format.

In the above configuration, a color document to be copied is placed on the platen 2, and the number of copies, reduction ratio, mode, copy size, etc. of the console 20 are set using predetermined buttons.

Next, by pressing the start button on the console 20, the motors 4 and 9, as well as the charger 7, the transfer device 14, and the fixing device 15 are driven.

As the motor 4 rotates, the platen 2 starts traveling and the lamp of the scanning unit 5 lights up, and the first latent image is transferred to the surface of the photoreceptor drum 6 charged by the charger 7 through the red filter. It is formed. Next, the developing device 8a is selected, cyan toner is applied to the latent image surface to develop cyan, and the copy paper fed by the paper feed bell 11 is transferred while being wound around the transfer drum of the transfer device 14. After the transfer, residual toner on the drum surface is removed and the drum is charged again. Here, a green filter is inserted into the optical path of the scanning section 5 to form a second latent image on the surface of the photoreceptor drum 6.

The developing device 8b is selected and magenta toner is applied to the latent image surface to develop magenta. Furthermore, the magenta image is transferred onto the copy paper wrapped around the transfer drum in an aligned state.

Transfer two colors. Next, it is scanned and exposed through a blue filter, yellow toner is attached to the developer 8o' (i-selected, and the final color image is printed by further transfer, and the copy paper is peeled off from the transfer drum and fixed. Vessel 1
5, and after fixing, is discharged onto a discharge tray 17. Elicolor copying is now complete.

However, when a conventional color developing device is equipped with a black developing device, when copying a single-color original containing only text (for example, black) in colors such as red or blue, it is necessary to Replace the machine with another developing machine of the desired color.

If the system is comprised of only color developing machines, it will be necessary to replace the developing machine of the desired color in the developing machine set position for single-color copying, which not only makes the operation cumbersome; It has been impossible to reproduce hues other than the three primary colors unless the developer 4a of the desired color is prepared in advance. In addition, if you try to set up developing machines for desired colors, there is a problem in that the size of the apparatus becomes large.

[Object and structure of the invention]

The present invention has been made in view of the above.

In order to be able to copy the desired color without replacing the developing machine, two or three non-magnetic component developing machines were installed, and the developing roll was rotated at a predetermined circumferential speed ratio to deposit the color. To provide a color copying device in which toner of a desired color is caused to fly onto the surface of a photoreceptor during development.

〔Example〕

Below, a color copying apparatus according to the present invention will be explained in detail.

FIG. 2 shows an embodiment of the present invention, and the same parts as in FIG. Developing units 21, 22, and 23 are installed at the developing position for causing the toner to fly toward the surface of the photoreceptor drum 6 during development.

The developing machines 21 to 23 have the same structure, and the toner supply port 24
a pair of developing rolls 26 which are rotatably installed in the housing 25 and have a surface having a specific resistance of 102 to 108 Ω-, and a toner film is further coated on the surface of the developing rolls 26. The metal blade 27 is formed of two layers. The developing roll 26 is disposed at a distance of 0.1 wm to 0.5 tm from the surface of the monolithic drum 6, and the limit amount of toner adhering to the surface is determined by the circumferential speed of the roll. Each of the developing rolls 26 is driven by motors 2Ba to 28c, and their rotation is controlled by a driving section 40. Furthermore, a bias voltage of several hundred volts is applied by the drive unit 40 to each of the developing rolls 26 in contact with the photosensitive drum 6 during development.

In the above configuration, the color copying process is common to the present invention, so redundant explanation will be omitted. In Fig. 2, for example, red toner is injected into the developing machine 21, green toner is injected into the developing machine 22, and W toner is injected into the developing machine 23. By applying the voltage VB' (i-, the toner of each color adhering to the surface of the roll 26 flies toward the photoreceptor drum 6 and adheres to the latent image. In this case, the rotation speed of the developing roll 26 is controlled. By doing this, the amount of toner can be changed and the density can be adjusted, making it possible to make copies of any color by combining three developing machines.

In addition, if you use a combination of toner colors that are complementary, such as red toner in the developing machine 21 and cyan toner in the developing machine 22, red toner and cyan toner can be used in only two developing machines by controlling the rotation speed of the rolls.
Any single color between cyan and black can be expressed. Therefore, the single color copy can be changed to toner color,
- This can be easily done by selecting off.

Furthermore, since it is possible to control the amount of toner adhesion by controlling the rotational speed of the developing roll 26, it is possible to perform development with one developing machine and then control the amount of incorrectly developed with a second developing machine. Measures can also be taken.

〔Effect of the invention〕

As explained above, according to the color copying apparatus of the present invention,
Two or three non-magnetic component developing machines are installed at the developing position,
Since the developing roller is rotated at a predetermined circumferential speed ratio and attached toner of any color is caused to fly onto the surface of the photoreceptor during development, it is possible to obtain all kinds of monochrome and multicolor color copies.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a conventional color copying apparatus, and FIG. 2 is a block diagram showing an embodiment of the present invention. Explanation of symbols 2...Platen, 5...Scanning section, 6...Photoconductor. Ram, 7... Charger, 10... Paper feed cassette. 11...Paper feed belt, 14...Transfer device, 15...
, fuser, 20...console, 21, 22゜23
Developing machine, 24... Toner supply port, 25... Housing, 26... Developing roll, 27... Metal foil, 28m, 28b, 28c" motor, 30...
- Control unit, 40... Drive unit. Figure 1 L 1,,,a Yu9 Figure 2

Claims (1)

[Scope of Claims] A color copying apparatus that scans an original to form a latent image on a photoreceptor, develops this latent image with color toner, and transfers it to copy paper. At least two non-magnetic-component iA imagers equipped with 1) L image rolls in which toner of a predetermined color adheres to an outer peripheral surface having a predetermined resistivity; A control means is provided for controlling the rotational speed of the developing roll according to the required amount of toner, and applying a predetermined bias voltage to the developing roll of a developing device to be developed, thereby causing the toner on the surface of the roll to fly to the surface of the photoreceptor. A color copying device characterized by its sharpness.