JPH0279868A - Multicolor printer - Google Patents

Abstract

PURPOSE:To eliminate the mixture of colors and to easily increase or decrease the number of colors by printing the image of a 1st color in an electrophotogra- phic process and printing the images of a 2nd and subsequent colors in screen printing. CONSTITUTION:A photosensitive body 1 is electrostatically charged by an electrostatic charger 2 uniformly and the image corresponding to the 1st color is exposed on the photosensitive body 1 by an exposing device 3. The image is developed by a developing device 4, so that a toner image is formed on the photosensitive body 1. The toner image is transferred on a recording paper 5 by a transfer device 6 and fixed by a fixation device 7 to record the image of the 1st color. Then, the recording paper 5 where the image of the 1st color is recorded is conveyed to a screen printing part, where a cam 12 for driving a negative for printing acts in synchronism with the recording paper 5 and the inked negative for printing 10 is closely brought into contact with the recording paper 5, so that the image of the 2nd color is printed in the screen printing. Thus, the mixture of colors does not occur and the image having the degree of freedom of color can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a multicolor printing device that combines an electrophotographic method and other printing methods.

[Prior Art] Fig. 3 is a block diagram showing a conventional two-color printing device disclosed in, for example, Japanese Patent Application Laid-Open No. 116553/1983. In the figure, (1) is a photoreceptor, (2) is a charged vessel, (3a) is the first
(3b) is the second exposure device that corresponds to the image of the second color; (4a) is the first developing device that develops the first color; (4b) is the first developing device that develops the first color; a second developing device for developing the second color; (5) recording paper on which the image is recorded; (6)
(7) is a transfer device for transferring the image formed on the photoreceptor (1) onto the recording paper (5), (7) is a fixing device for fixing the image on the recording paper (5), and (8) is a A cleaning device (9) is used to remove the toner remaining after transfer on the photoreceptor (1), and a discharge lamp (9) is used to erase the charge on the photoreceptor. Also, Figure 4 shows 2
FIG. 3 is a diagram showing the potential levels of each process for color recording, in which (18) is black toner and (19) is red toner.

Next, the operation will be explained. The photoreceptor (1) is connected to the charger (2
), the entire surface is charged uniformly. The potential at this time is defined as an initial charging level vS as shown in FIG. 4(a). Next, the photoreceptor (1) is exposed to an image corresponding to a first color (hereinafter referred to as black) by the first n-th optical device (3a).

At this time, the potential of the exposed photoreceptor (1) attenuates to approximately OV (volts) as shown in FIG. 4(b). after that,
Development is performed by the first developing device (4a) using black, positively charged toner.

By performing development, black toner (18) adheres to the portions from which the charges have been removed, as shown in FIG. 4(C).

Next, an image corresponding to a second color (hereinafter referred to as red) is exposed by the second exposure device (3b).

At this time, the potential of the exposed photoconductor (1) also decreases to approximately Ov, as in the first exposure. This situation can be seen in the fourth
Shown in Figure (d). Next, using red, positively charged, charged toner,
Development is performed by the second developing device (4b), and red toner (19) adheres to the portion from which the electric charge has been removed, as shown in FIG. 4(e). Next, the toner on the photoreceptor (1) is transferred onto a recording paper (5) by a transfer device (6) and fixed by a fixing device (7). On the other hand, the photoreceptor (1) is cleaned of residual toner by a cleaning device (8), exposed entirely to light by a discharge lamp (9), and then used repeatedly.

[Problem to be solved by the invention] Since the conventional multicolor printing device was configured as described above,
It requires the same number of exposure devices and developing devices as the number of colors, which has disadvantages such as an increase in the price of the printing device and the occurrence of color mixture. Furthermore, since the amount of toners other than black used is small, there is a problem that colors are limited to colors such as red, blue, and yellow.

This invention was made to solve the above problems, and it is low cost, does not mix colors, allows you to freely select colors,
To obtain a multicolor printing device that can easily increase or decrease the number of colors.

[Means for Solving the Problems] A multicolor printing device according to the present invention is a combination of an electrophotographic device that prints a first color image and a stencil printing device that prints subsequent color images. .

[Operation] Since the stencil printing device of the present invention that prints images of the second and subsequent colors has a non-variable stencil plate, it is not possible to change the content on a page-by-page basis, for example, unlike an electrophotographic device. However, in the case of computer output printers, most of the parts that are printed in colors other than black are format parts such as forms, so the ability to freely select colors, no color mixing, and low cost are more important than variability. That is often more important. This invention was made based on such a demand for a multicolor printing device, and the stencil printing device of this invention that prints images of the second and subsequent colors is a fixed image, is inexpensive, and does not mix colors. , images with color freedom can be obtained.

[Example] An embodiment of the present invention will be described below with reference to the drawings.

In Figure 1, (1) is a photoconductor, (2) is a photoconductor (1
), (3) is an exposure device that supports variable images, (4) is a developer, (5) is a recording paper that records images, (6) is a photoreceptor on (1) A transfer device transfers the toner image onto the recording paper (5), a fixing device (7) fixes the toner image on the recording paper (5), and a fixing device (8) removes the remaining toner remaining after transfer on the photoreceptor (1). (9) is a static eliminating lamp that uniformly exposes the entire surface of the photoreceptor (1); (lO) is a stencil plate; (11) is an original holding mechanism; (12) is a cam that moves the original up and down for printing. , (13) is a back plate made of foamable material, (14) is an ink supply section, (
15) is a paper ejection roller. Next, the operation will be explained.

The photoreceptor (1) is uniformly charged by a charger (2), and the photoreceptor (1) is exposed to an image corresponding to a first color by an exposure device (3). A toner image is formed on the photoreceptor (1) by developing with a developing device (4). The toner image is transferred onto a recording paper (5) by a transfer device (6) and fixed by a fixing device (7) to record an image of the first color. The photoreceptor (1) is cleaned by a cleaning device (8), exposed entirely to light by a static elimination lamp (9), and used again and again.

The recording paper (5) on which the first color image has been recorded is sent to the stencil printing section. In the stencil printing section, the stencil plate (10) is attached to the original holding mechanism (11), and the ink supply section (
14) Printing ink is supplied from. Recording paper (5)
The cam (12) for driving the original is operated in synchronization with the cam (12) for driving the original, and by bringing the ink-covered original (lO) into close contact with the recording paper (5), the second color is stencil printed.

In the above embodiment, the stencil printing section that prints the second color image is arranged immediately after the electrophotographic printing section that forms the first color image, but the electrophotographic printing section and the stencil printing section A part of a paper buffer may be provided between the copies to temporarily hold the recording paper, and the same effect as in the above embodiment can be obtained.

A case where a part of the paper buffer is provided will be explained with reference to FIG. In the figure, (17) is a part of the paper buffer where the recording paper is temporarily held after printing the first color, and (16)
is a paper detector that detects the presence or absence of paper in a part of the paper buffer.

Incidentally, since the symbols (1) to (15) are the same as those in the above embodiment, the explanation will be omitted.

Next, the operation will be explained.

The operation of the electrophotographic printing section is the same as in FIG. The recording paper (5) that has come out of the fixing device (7) is stored in a part of the paper buffer (1
7), the paper detector (16) detects the presence or absence of recording paper in the paper buffer part (17), and when there is recording paper, the subsequent stencil printing section is operated. By setting the printing speed of the stencil printing section faster than the printing speed of the electrophotographic printing section, both printing sections can be operated asynchronously with each other without the recording paper becoming stagnant in the paper buffer part (17). Further, in the above embodiment, the case where there is one stencil printing unit is explained, but it is also possible to further increase the number of stencil printing units in series.

[Effects of the Invention] As described above, according to the present invention, the first color image is printed by an electrophotographic process, and the second and subsequent color images are printed by stencil printing. Although the images of the second and subsequent colors are fixed, it is possible to obtain a multicolor printing device that is inexpensive, does not cause color mixing, can freely select colors, and can easily increase or decrease the number of colors.

[Brief explanation of the drawing]

FIG. 1 is a basic configuration diagram of a multi-color printing device according to an embodiment of the present invention, FIG. 2 is a similar configuration diagram of another embodiment of the invention, and FIG. 3 is a configuration diagram showing a conventional two-color printing device. 4(a) to 4(e) are diagrams showing the potential levels in FIG. 3. In the figure, (1) is a photoreceptor, (2) is a charger, (3)
is the exposure device, (4) is the developer, (5) is the recording paper, (・6
) is the transfer device, (7) is the fixing device, (8) is the cleaning device, (9)
is a static elimination lamp, (10) is a stencil plate, (11) is an original holding mechanism, (12) is a cam, (13) is a back plate,
(14) is an ink supply unit, (15) is a paper ejection roller,
(16) is a paper detector, and (17) is a part of a paper buffer. In addition, in the figures, the same reference numerals indicate the same or equivalent parts. Agent Masuo Oiwa

Claims (1)

[Claims] A first color image is printed by an electrophotographic process, and a second color image is printed by an electrophotographic process.
A multicolor printing device characterized by printing subsequent color images by stencil printing.