JPH01166066A - Color electrophotographic image forming device - Google Patents

Abstract

PURPOSE:To miniaturize the title device and to easily obtain a color image and a monochrome image by integrally exchanging developing devices incorporating toner housing devices. CONSTITUTION:The toner housing device 10, a stirring blade wheel 11, a stirring blade wheel 12, a developing sleeve 13, a magnet roll 14, and a toner replenishing roll 15 are provided in the developing device 5Y. And the developing device 5Y can be exchanged for a developing device 5BK housing black toner in order to obtain the distinct monochrome image. In case of developing and copying the monochrome image, the developing device 5Y is exchanged for the developing device 5BK and the image is developed when the black toner. Thus, the exchange of the toner between the developing device 5Y and the developing device 5BK is performed between the developing device 5Y and the developing device 5BK which are covered with a cover part 19 and where the toner housing device 10 is housed inside. Thus, the miniaturization of the device can be attained and the operation for replenishing and exchanging the toner can be easily executed.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Field of Industrial Application The present invention relates to a color electrophotographic image forming apparatus capable of forming full-color images and monochrome images by replacing developing devices.

(2) Conventional technology An electrophotographic image forming apparatus that forms full-color or monochrome images includes a charger that charges a photoreceptor drum, an image exposure unit that exposes an image to the photoreceptor drum, and an electrostatic image on the photoreceptor drum. A developing device that develops the toner image with toner, a transfer device that transfers the toner image on the photosensitive drum onto recording paper, and the like are arranged around the photosensitive drum.

Among these, the developing device in an electrophotographic image forming apparatus for full-color images is composed of three developing devices each containing yellow (Y), magenta (M), and cyan (C) toner, and has three photosensitive drums. While rotating, yellow (Y), magenta (M), and cyan (C) toner images are formed on the photosensitive drum, and these toner images are transferred to recording paper to obtain a full-color image. I have to.

In such a full-color electrophotographic image forming apparatus, the mixing ratio of yellow (Y), magenta (M), and cyan (C) toners is not always perfect. For this reason, especially when attempting to form a monochrome image, the monochrome image may become reddish or bluish, making it difficult to obtain a clear monochrome image.

Therefore, in order to obtain a clear monochrome image, we decided to use yellow (
In addition to Y), magenta (M), and cyan (C), a developing device containing black (BK) toner is installed, and black images are produced by
Instead of mixing the three colors of yellow (Y), magenta (M), and cyan (C), development is performed using black (B K ) toner.

(3) Problems to be solved by the invention However, since it is necessary to provide a developing device containing black (BK) toner in addition to yellow (Y), magenta (M), and cyan (C), the device There is a problem in that it becomes larger. Further, there is also the problem that the replenishment and replacement operations of each toner are complicated.

(4) Means for Solving the Problems The present invention has been made in view of the above-mentioned problems, and it is possible to miniaturize the device by replacing the developing device, and to facilitate toner replenishment and replacement operations. In order to achieve this objective, in a color electrophotographic image forming apparatus in which multiple developing devices are arranged around the photoreceptor and the developing devices can be replaced, toner is stored in the developing device. The developing unit has a built-in storage device and a toner storage device and is configured to be replaced as one unit.

(5) Examples Hereinafter, the present invention will be explained based on the drawings.

FIG. 1 is a diagram showing an embodiment of an electrophotographic image forming apparatus according to the present invention.

In FIG. 1, an original (not shown) placed on a platen glass 1 is read by an image reading device 2, and the image data of the original read by the image reading device 2 is subjected to image processing. It is then supplied to the laser exposure device 4.

The laser exposure device 4 irradiates the image light modulated with image data light of the original onto the photosensitive drum 3, and an electrostatic latent image is formed on the surface of the photosensitive drum 3 by this image light. The electrostatic latent image is formed into a toner image on the surface of the photoreceptor drum 3 by the developing device 5C1, the developing device 5M, and the developing device 5Y.

The developing device 5C1, the developing device 5M, and the developing device 5Y store cyan (C), magenta (M), and yellow (Y) toner, respectively. ), magenta (M), and cyan (C) toner images are sequentially formed on the photoreceptor drum 3 by image light irradiated onto the photoreceptor drum 3 from the laser exposure device 4 .

The toner image thus formed is transferred by a transfer device 7 onto recording paper (not shown) supplied from a paper feeder 6. The transferred toner image is heated and fixed by a fixing device i, and after being fixed, it is discharged outside the machine.

The main bodies of the developing device 5C1, the developing device 5M, the developing device 5Y, and a developing device 58, which will be described later, are constructed as shown in FIG.

However, in FIG. 2, the developing device 5y and the developing device 58 are representative.
Disclosed only to

In FIG. 2, the inside of the developing device 5Y includes a toner storage device 10, an agitation impeller 11, an agitation impeller 12, a developing sleeve 13, a magnet roll 14, and a toner supply roller 1.
5 is provided. A lid part 19 is provided at the top of the developing device 5Y, and covers the internal toner storage device 10, stirring impeller IL, stirring impeller 12, developing sleeve 13, magnet roll 14, and toner replenishment roller 15 to prevent toner from being removed. Prevents scattering. Note that the gap between the developing sleeve 13 and the photosensitive drum 3 is maintained by a roller (not shown) that is provided coaxially with the developing sleeve 13 and comes into contact with the photosensitive drum 3.

Toner 16 is stored at the bottom of the toner storage device 10,
The toner 16 is scooped up toward the upper left in FIG. 2 by rotating the wiper plate 10a clockwise. Wire board 10
The toner 16 scooped up by a is moved to the left in FIG. 2 by the rotation of the toner supply roller 150 and is supplied to the stirring impeller 11. The stirring impeller 11, together with the stirring impeller 12, stirs the magnetic carrier and the toner 16, and as the stirring impeller 120 rotates counterclockwise, the developer made of the magnetic carrier and the toner 16 is attached to the developing sleeve 13. . A magnet roll 14 is rotating inside the developing sleeve 13.
and the magnet roll 14 constitute a magnetic brush using the developer described above.

A thin layer of developer is formed on the surface of the developing sleeve 13 by the above-mentioned magnetic brush. formatted by. From the surface of the thin layer of developer, toner 16 flies toward the electrostatic latent image on the photoreceptor drum 3 due to the AC bias, and the toner 16 flies toward the electrostatic latent image on the photoreceptor drum 30.
The electrostatic latent image formed on the surface is reversely developed and becomes a toner image.

During this development, a bias voltage consisting of a DC component and an AC component is applied to the developing sleeve 13, and by controlling the bias voltage, each of yellow (Y), macenter (M), and cyan (C) toners is This is to adjust for variations in the developing conditions due to differences in the development conditions, as well as fluctuations in the developing conditions that occur when replacing the developing device 5Y or developing device 58, which will be described next.

The developing device 5Y shown in FIG. 1 stores black (BK) toner in order to obtain a clear monochrome image.
When developing and copying a monochrome image, the developing device 5Y is replaced with a developing device 58K and development is performed using black (B K ) toner. The developing device 58 has the same configuration as the developing device 5Y shown in FIG.

When replacing the developing device 5Y with the developing device 58, first change the developing device 5Y to the developing device 58.
It is started by rotating the eccentric cam 18 provided on the right side of Y (see FIG. 2) clockwise. Eccentric cam 1
By the rotation of 8, the fixed state of the developing device 5Y is released, and the developing device 5Y is pulled out toward you (in the direction perpendicular to the plane of the paper in FIG. 1).

Next, the developing device 58K is inserted into the space vacated by the pulled out developing device 5Y from the front to the back in the direction perpendicular to the plane of the paper in FIG. When the developer 58K reaches a predetermined position and the insertion is completed, the developer 58K is fixed to the developer 58 by rotating the eccentric cam 18 counterclockwise. This completes the replacement of the developing device 5Y with the developing device 5BK.

To obtain a full-color image, the developer 58K is replaced with the developer 5Y in the same way as the developer 5Y is replaced with the developer 5BK described above.

In this way, toner exchange between the developing device 5Y and the developing device 5BK is performed between the developing device 5Y and the developing device 58 in which the toner storage device 10 is housed inside and covered with the lid portion 19. Therefore, users can easily replace toner without getting their hands dirty with toner.

A command is issued to the image reading device 2 in the following manner. That is, when the developing device 5Y is set (that is, when obtaining a color image), the developing device 5C1 is
A command is issued to the image reading device 2 to select one of the filter 9R, the filter 9G, and the filter 9B depending on which of the developing device M and the developing device 5Y is to be used for development. Also, when the developing device 5BK is set (that is, when obtaining a monochrome image), the filter 9ND
A command is issued to the image reading device 2 to select.

Another method for replacing the developing device is to integrate the image forming body and the developing device portion into a unit and place it on a pedestal rail, and then once pull it out and then replace the developing device.

In this case, the developing device can be replaced by a structure that allows it to be directly removed from the above-mentioned unit. Further, the position of the developing device to be replaced is not limited to the lowest position, but can also be placed at the highest position or in the middle.

(6) Effects of the Invention As explained above, the present invention provides a color electrophotographic image forming apparatus in which a plurality of developing devices are arranged around a photoreceptor and the developing devices can be replaced. Since the developing device having a built-in storage device and a toner storage device is configured to be replaced together, it is possible to downsize the device by replacing the developing device. Furthermore, by replacing the developing device, color images and monochrome images can be easily obtained, and toner replenishment and replacement operations can be easily performed.

[Brief explanation of the drawing]

FIG. 1 is a schematic front view showing an embodiment of an electrophotographic image forming apparatus according to the present invention; FIG. 2 is a schematic front view showing an enlarged developing device of the electrophotographic image forming apparatus according to the present invention; The figure is a front view showing a filter used for color separation in an electrophotographic image forming apparatus according to the present invention. 2... Image reading device 3... Photosensitive drum 4... Laser exposure device δ... Developing device 6... Paper feeding device 7... Transfer device 8... - Fixing device 9... Filter 10... Toner storage device 11... Stirring impeller 12... Stirring impeller 13... Developing sleeve 14... Magnet roll 15 - ... Toner supply roller 16 ... Toner 17 ... Eclipse plate 18 ... Eccentric cam 19, φ, ◆Lid part

Claims (1)

[Claims] In a color electrophotographic image forming apparatus in which a plurality of developing devices are arranged around a photoreceptor and the developing devices can be replaced,
A color electrophotographic image forming apparatus characterized in that the developing device has a built-in toner storage device, and the developing device with the built-in toner storage device can be replaced as a unit.