JPS62172380A - Electrophotographic color printer device - Google Patents

Abstract

PURPOSE:To inexpensively and simply prevent color mixing on printing by forming a full exposure means having the light of wavelength with a low toner transmission ratio to an already formed image between a developing process and the succeeding electrostatic charging process. CONSTITUTION:A photosensitive body 1 is rotated in a direction A and charged 2, red information is exposed 3 and the 1st electrostatic latent image is formed. The latent image is inversely developed 4 and red toner adheres to an optically attenuated part. When the whole surface of the photosensitive body 1 is exposed by a red destaticizing lamp 5, only a non-image part is exposed because the red toner acts as a mask. The photosensitive part 1 is charged 6 again and the red toner part is lowered. Then, black image information is exposed 7, the 2nd electrostatic latent image is formed and the latent image is inversely developed 8 to form a black toner developed image. Thus, two red and black toner developed images are transferred 9 to paper S. The residual transfer toner on the photosensitive body 1 is scraped by a cleaning brush 11 and the whole surface of the photosensitive body 1 is exposed by a destaticizing lamp 12. Thus, color mixing on printing can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a technique for performing multicolor printing in a printing device using the ``Bacophotography'' method.

[Conventional technology]

FIG. 3 is a block diagram of a conventional multicolor recording device disclosed in, for example, Japanese Unexamined Patent Publication No. 8762.
(2) is the first charger that charges the photoreceptor fi+, (3) is the l-th exposure section that forms an electrostatic latent image of vJl on the photoreceptor H1, and (4) is the first charger that charges the photoreceptor fi+. 1 exposed area +31 V
(5) is a first developing machine that converts the first electrostatic latent image formed on the photoconductor ill into a head image using a magnetic brush method using red toner; ) is a second static eliminator that attenuates the potential on the photoreceptor film on which a red toner image is formed, (6) is a second charger that recharges the photoreceptor +11, and (7) is a static eliminator that attenuates the potential on the photoreceptor film on which a red toner image is formed. A second exposure section (8) forms a second electrostatic latent image on the photoconductor on which the red toner image has been formed; (9) is a transfer device that transfers the two-color toner image formed on the photoconductor (11) onto the paper S; troll is a transfer device that transfers the residual charge on the photoconductor (1) A first remover (11) is a cleaner brush that removes residual toner on the photoreceptor III;
+2) is a removal lamp for removing all the residual charge on the photoreceptor +11 after removing the residual toner.

The printing process of the two-color recording apparatus configured as above will be explained. Further, the positions on the photoreceptor ill in each process are shown in FIG.

The photoreceptor [1] rotates in the direction shown in Fig. 3A, but in the process, it is first uniformly charged to a potential of vBl by the first charger (21 [Fig. 4 (a1)]. 1 exposure section (31
As a result, the red image information is exposed, and the potential of that portion is attenuated to approximately OV [FIG. 4(b)]. This potential drop portion is reversely developed in the first developing device (41), and the red toner R is attached.
FIG. 4 (O)] where the potential rises to the toner potential VT1.

Next, the grid voltage of the second static eliminator (5) is set to 7TI, AC corona static elimination is performed, and the potentials of the image area and the non-image area are all equal to vl. [Figure 4 1dl]. Next, the second charger (6) raises the potential for the photoreceptor to vsg, and when the black image information is exposed in the second exposure section (7), the potential of that part becomes Attenuates to almost OV. Figure 4 (f+). %B developer (8) is used to develop the black toner Bt- on the potential drop area of the grain (Photo 4 + GL).

In the above process, a two-color toner image of red and ring is formed on the photoreceptor film, and this image is corona-transferred onto the paper S by the transfer device (9). The toner transferred to the paper is fixed by a fixing device (not shown). On the other hand, after the transfer, the photoreceptor il+ is charged once with a first static eliminator (lot), and then the residual toner is scraped off with a cleaner brush (river), and then the residual toner is removed with a static elimination lamp (1"4). is removed, and the first charging process is started again.

In the process described above, after the first development, fIJJ
The photoconductor il is
The purpose is to make the potential on l uniform throughout the area so that black toner adheres to the red toner adhered area in the second development.

[Problem that the invention seeks to solve]

Since the conventional multicolor recording device is configured as described above, an AC static eliminator with a grid is required, and the toner charge VT due to the attached toner charge varies depending on changes in the amount of attached toner, etc. Due to this fluctuation, it is difficult to align the potentials of the image area and the non-image area on the photoreceptor, resulting in a problem that color mixing is likely to occur.

The present invention was made to solve the above-mentioned problems, and it is an object of the present invention to inexpensively and easily obtain an electrophotographic color printer device that does not cause color mixing even if the toner potential changes.

[Means for solving problems]

The electrophotographic color printer device according to the present invention is provided with an entire surface exposure means having a wavelength of light having a low transmittance of the toner of the developed image instead of the grid-equipped AC corona static eliminator.

[Effect]

In the present invention, the entire surface exposure means for exposing the developed image toner with light having a low transmittance utilizes the photosensitive phenomenon of the photoreceptor and converts the developed toner into an asking toner. When charging, the potential of the toner-attached area in the developed area is made higher than the potential of the non-image area to prevent color mixing.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, (11~+41.161~(9), (II
).

θ2) is the same as that explained in the conventional example. (6)
is a red static elimination lamp consisting of a red filter and a fluorescent lamp.

FIG. 2 shows changes in the potential of the photoreceptor ill during each process in a color printer having such a configuration.

The photoreceptor (1) rotates in the direction indicated by A in FIG. D exposure section (red image information is exposed from 31 to form a first electrostatic latent image)
FIG. 2 (b1). Red toner adheres to the light-attenuated portion of the image which is reversely developed in the first developing device 141.
Figure 2 (C)]. Thereafter, when the entire surface of the photoreceptor (11) is exposed using the red static eliminating 2 pump (5), the red toner acts as a mask and only the non-image area is exposed [FIG. 2(d)].

The photoconductor +13 is charged again by the second charger (6), but the part where the red toner is not attached becomes low due to the optical fatigue phenomenon caused by the red static elimination light [second charger]. Figure (e)]. Next, black image information is exposed from the second exposure section () to form a second electrostatic latent image [second
(fl), the second developing device (8) performs reversal development to form a black toner image [Fig. 2+g+, l.

The toner images of two colors, red and black, formed on the photoreceptor (1) in this way are corona-transferred onto the sheet S by the transfer device (9), and then fused by a fixing device (not shown). It will be established.

Transfer residual toner on the photoreceptor +11 with a cleaner brush (
Photoconductor III n that was scraped off and cleaned in the river,
The entire surface is exposed to light using a static elimination lamp ryr. Here, the entire surface exposure using the charge eliminating lamp 0'4 is an important process not only for simply removing the residual charge on the photoreceptor +11, but also for eliminating the distribution of the charged potential due to the optical fatigue phenomenon of the photoreceptor.

The photoreceptor il+ after this static elimination is again transferred to the first band 'α
Enter the process.

In the above embodiment, an example of two-color printing, red and black, was shown, but other colors may be used. However, as long as a selenium-based photoreceptor is used, the optical fatigue phenomenon is likely to be greater at long wavelengths, so the effect will be somewhat smaller for other colors.

Furthermore, although the above embodiment is an example of printing in two colors, red and black, it is also possible to further add a third color such as blue. In this case, after black development, red static eliminating light is irradiated again, and then the process for the third color is started.

〔Effect of the invention〕

As described above, according to the present invention, by providing the entire surface exposure means for controlling the light of the wavelength with low transmittance of the toner of the image already formed between the developing process and the next charging process, it is possible to What is the effect of being able to prevent color mixing more cheaply and simply than before?

[Brief explanation of drawings]

FIG. 1 is a diagram showing the configuration of an embodiment of an electrophotographic color printer device of the present invention, FIG. 2 is a diagram showing changes in magnetic potential for explaining an embodiment of the invention, and FIG. FIG. 4 is a diagram showing the configuration of a conventional multicolor recording apparatus, and is an explanatory diagram showing potential changes in the conventional example. In the figure, +11 is the photoreceptor, (21 and (6) are the first.
The second charger, (3) and (7) are the first charger. @2 exposure section,
+41 and (8) are the first. The second developer, (5) is a red static elimination lamp, (9) is a transfer device, (the river is a cleaner brush, 0
'4 is a static elimination lamp. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] A rotating photoreceptor, an image forming means including a plurality of charging devices, an exposure unit, and a developing device arranged in order in the rotational direction of the photoreceptor, and means for transferring the toner image formed on the photoreceptor onto plain paper;
In an electrophotographic printer that uses a means to clean and neutralize the photoreceptor after transfer, between the developing process and the next charging process,
An electrophotographic color printer device characterized in that it is provided with an entire surface exposure means having a wavelength of light that has a low rate of transmission through toner of an already formed image.