JPH0443373A - color image forming device - Google Patents

Abstract

PURPOSE:To prevent contamination in a machine caused by the scattering of toner by consisting of abutting member which separates from an intermediate transfer body when a cartridge is mounted to a main body device and abuts on the intermediate transfer body when it is detached from the main body device. CONSTITUTION:When the cartridge 15 is mounted on the main body device 24, one end of a separating and contacting lever 25 abuts on the abutting part 22 of the main body, and the abutting member 21 provided in the lever 25 is separated from the intermediate transfer body 2. On the contrary, when the cartridge 15 is detached from the main body device 24, the lever 25 is released from the abutting part 22 of the main body, so that the member 21 abuts on the intermediate transfer body 2. Since the member 21 abuts on the transfer body 2, the toner after cleaning the transfer body 2 does not drop from the cartridge 15 when the cartridge 15 is detached from the main body device 24. Thus, maintenance is easily performed and the contamination in the machine caused by the scattering of the toner at the time of exchanging the intermediate transfer body is prevented.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is a method for sequentially transferring toner images formed by toner particles of different colors on a latent image carrier such as a photoreceptor or an insulator onto an intermediate transfer member. The present invention relates to a color image forming apparatus that forms a composite image (color image) and finally transfers this composite image to a transfer material.

(Prior Art) In recent years, transfer type color image forming apparatuses form toner images of specific colors sequentially on a latent image carrier such as a photoconductor or an insulator, and multiplex each toner image onto a transfer material. Transfer methods have come to be used.

For example, Japanese Patent Application Laid-open No. 55-90972 discloses that as a transfer method, a toner image of three or four colors such as yellow, cyan, magenta, and black formed on an image carrier is transferred to an intermediate layer as compared to the following. A color image forming apparatus employs a method in which a composite image is formed by overlapping images on an intermediate transfer member on a drum or belt, which is an image carrier, and the composite image is transferred all at once from the intermediate transfer member to a transfer material. Proposed.

A conventional color image forming apparatus will be described below with reference to the drawings.

FIG. 4 is a side view of a conventional color image forming apparatus. In FIG. 4, reference numeral 1 denotes a photoreceptor having a photoconductive layer on its surface, which rotates in the direction of arrow a. Around the photoreceptor 1, there is a charger 7 for uniformly charging the photoreceptor, a laser scanner for writing to form an electrostatic latent image on the photoreceptor, and L.
Optical system 4 as an exposure means such as an ED head, developing machines 3a to 3d photoreceptor 1 as developing means for visualizing an electrostatic latent image
A cleaning device 6 is disposed on the downstream side in the rotational direction of the photoreceptor from the position where the intermediate transfer member 2 and the intermediate transfer member 2 are in contact with each other. The developing units 3a to 3d contain toner of each color of yellow, magenta, cyan, and black, and are provided so as to be able to approach and separate from the photoreceptor 1 in the force directions of arrows A and b'.

The photoreceptor 1 is in contact with an intermediate transfer member 2 serving as an intermediate transfer means that rotates in the direction of arrow C on the downstream side of the developing device 3a with respect to the rotation direction. The intermediate transfer member 2 is made by dispersing a substance such as carbon in resin, and has a resistance value of 10'Ωcm to 1012Ωc.
It is made of material controlled to m.

A cleaning device 9 is disposed so as to be able to approach and separate from the intermediate transfer body 2 in the directions of arrows d and d', and is used to clean residual toner on the intermediate transfer body. It consists of magnetic brushes, conductive brushes, etc.

Reference numeral 11 denotes an intermediate transfer device for transferring toner from the photoconductor 1 to the intermediate transfer body 2, which includes a corona discharger to which a high voltage is applied, a metal roller, and a conductive device to which carbon, etc. is dispersed in a resin and a high voltage is applied. It is composed of a roller and is arranged inside the intermediate transfer body at a position where the intermediate transfer body 2 and the photoreceptor l are in contact with each other.

5 is a transfer material 13 moving in the direction of arrow e from the intermediate transfer body 2;
A transfer device for transferring the toner, 8 a registration roller that aligns the timing of the transfer material 13 with the composite image on the intermediate transfer body 2 and conveys the transfer material 13, 10 fixes the toner on the transfer material to the transfer material A fixing device 12 is a transfer material cassette that stores transfer materials.

Regarding the color image forming apparatus configured as above,
The operation will be explained below. First, in a dark area, the surface of a photoreceptor having high resistance is uniformly charged by a charger 7 that generates corona ions by corona discharge, and an optical system 4 consisting of a laser scanner or an LED head is used.
By exposing the photoreceptor 1 to light according to image data, an electrostatic latent image is formed on the photoreceptor, which is a photoconductor.

Next, the electrostatic latent image on the photoreceptor 1 is developed with yellow toner from the developing device 3a, thereby obtaining a yellow toner image on the photoreceptor. Next, the yellow toner image is transferred by the intermediate transfer device 11 onto the intermediate transfer body 2 which is in contact with the photoreceptor.

Residual toner that has not been transferred from the photoreceptor 1 to the intermediate transfer member 2 is cleaned by a cleaning device 6, and the surface of the photoreceptor 1 is refreshed. Thereafter, the same steps as described above are repeated for each color component, and toner images of specific colors are successively superimposed on the intermediate transfer member 2 to obtain a composite image.

The transfer body 13 sent out from the transfer material cassette 12 is aligned with the composite image obtained on the intermediate transfer body 2 by the registration rollers 8, and guided to a transfer section between the intermediate transfer body 2 and the transfer device 5. The composite image on the intermediate transfer body 2 is transferred all at once onto a transfer material 13 in a transfer section by a transfer device 5 which is a corona discharger to which a high voltage is applied. The composite image transferred onto the transfer material 13 at once is guided to the fixing device 10, fixed on the transfer material 13 by heat and pressure, and then discharged.

The toner of the composite image that has not been completely transferred to the transfer material 13 by the transfer device 5 remains on the intermediate transfer member 2 as residual toner. This residual toner is removed by cleaning device 9 and refreshed. The cleaning device 9 is configured to be able to move toward and away from the intermediate transfer body 2, and is kept at a position apart from the intermediate transfer body 2 until one composite image is obtained, and the resulting composite image is transferred. After the toner is transferred onto the transfer material 13 by the device 5, the toner comes into contact with the toner to clean the remaining toner. When replacing the intermediate transfer body 2, only the intermediate transfer body is individually taken out from the main unit, and the cleaning device 9 is exposed after the intermediate transfer body is taken out.

(Problems to be Solved by the Invention) However, the conventional configuration has the following problems.

l) The intermediate transfer member and the cleaning device for cleaning the intermediate transfer member are separately incorporated into the apparatus, and service maintenance by a service person is frequently required.

2) Since the cleaning device is exposed when replacing the intermediate transfer member, the interior of the device is contaminated by toner scattering.

3) The cleaning device for the intermediate transfer body requires a separation mechanism for the intermediate transfer body, and the alignment accuracy between the intermediate transfer body and the cleaning device is very important, but in the conventional configuration, the intermediate transfer body and cleaning The devices are assembled separately, making alignment difficult and causing poor cleaning.

4) Since the intermediate transfer body cleaning device moves toward and away from the intermediate transfer body, toner scatters in the vicinity of the cleaning device.

Therefore, an object of the present invention is to provide a color image forming apparatus that can solve the above problems.

(Means for Solving the Problems) For this purpose, the present invention provides an electrostatic potential for each color component by individually exposing a light image separated for each color component onto a uniformly charged latent image carrier. an exposure means for forming an image, a developing means for developing the electrostatic latent image of each component with a developer of a different color to make it into an individual image, and a sequential intermediate image on the latent image carrier. A cartridge that houses in an integrated unit an intermediate transfer body that is superimposed and transferred onto the transfer body to form a composite image and a cleaning device that can be brought into and out of contact with the intermediate transfer body; A contact member provided on the upstream side and downstream side of the apparatus, which is separated from the intermediate transfer body when the cartridge is installed in the main unit, and comes into contact with the intermediate transfer body when removed from the main unit. It is.

(Function) In the above configuration, when the intermediate transfer device, which is formed into a cartridge as an integrated unit, and the cleaning device that can come into contact with and separate from the intermediate transfer body are attached to the main unit, the contact member separates from the intermediate transfer body, making it easy to Can perform maintenance. Furthermore, when removed from the main unit, the contact member contacts the intermediate transfer member on the upstream and downstream sides of the cleaning device with respect to the rotational direction of the intermediate transfer member, thereby eliminating contamination inside the machine due to toner scattering when replacing the intermediate transfer member. , it is possible to reliably prevent toner from falling from the intermediate transfer cleaning device.

(Example) Next, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a side view showing a schematic configuration of a color image forming apparatus of the present invention, in which 1 is a photoreceptor as a latent image carrier, 2 is an intermediate transfer body, and 3a to 3d are developing means for each color component. 4 is an optical system as an exposure means, 5 is a transfer device,
6 is a cleaning device, 7 is a charger, 8 is a register roller, 9 is a cleaning device, 10 is a fixing device, 11 is an intermediate transfer device, 12 is a transfer material cassette, 13 is a transfer material,
Since these are the same as the conventional device shown in FIG. 4, detailed explanation will be omitted. Reference numeral 15 denotes a cartridge in which the intermediate transfer body 2, the intermediate transfer device 11, and the cleaning device 9 are integrated into one unit. FIG. 2 is a detailed view of the cartridge 15. Reference numeral 16 denotes a cleaning blade made of urethane rubber or the like which is used for cleaning with a magnetic brush or a conductive brush. Reference numeral 18 denotes a lever that is rotatably supported on the main unit 24 by a rotation shaft 28. One end of this lever 18 is forked at one end and engaged with one end of the separation lever 23, and the other end is engaged with the plunger 29 of the solenoid 20. connected. A spring 19 biases the lever 18 in a direction in which the cleaning blade 16 moves away from the intermediate transfer member 2 .

Reference numeral 25 denotes a separation lever supported by a rotary shaft 27 on the cartridge 15 on the upstream and downstream sides of the cleaning device 9 with respect to the movement of the intermediate transfer body 2 in the direction of arrow C; At the end opposite to 2,
A contact member 21 made of an elastic material such as a sheet-like film, rubber, or sponge is provided. 26 is a spring that urges the separating lever 25 in the direction in which the contact member 21 contacts the intermediate transfer body 2; 22 is a spring that the end of the separating lever 25 comes into contact with when the cartridge 15 is not installed in the main unit 24; This is a main body abutting portion provided on the main body device 24 so as to separate the abutting member 21 from the intermediate transfer member 2 against the spring 26 .

This device has the above-mentioned configuration, and its operation will be explained next.

After uniformly charging the photoreceptor 1, the optical system 4 charges the photoreceptor 1.
is exposed according to the image data to form an electrostatic latent image, this electrostatic latent image is developed to form a toner image, and the operation of transferring this toner image to the intermediate transfer body 2 is repeated for each color component, The color image forming operation in which toner images of different colors are superimposed and transferred onto the transfer member 2 to form a composite image and then the composite image is transferred all at once to the transfer material 13 is the same as that of the conventional apparatus shown in FIG. be.

As shown in FIG. 2, the cartridge 15 is
When attached to the main body contact portion 2, one end of the separation lever 25
2 and rotates counterclockwise against the spring 26 according to the device operation.
1 is separated from the intermediate transfer body 2.

As described above, when the cartridge 15 is attached to the main unit 24, the solenoid 20 is energized and the lever 18 is moved by the spring 1 by the plunger 29 which is absorbed in the direction of the arrow f.
When rotated clockwise against 9, the separation lever 23
rotates counterclockwise to remove the cleaning blade 16.
is brought into contact with the intermediate transfer body 2.

In addition, when the residual toner is not being cleaned, that is, when a composite image is being created on the intermediate transfer body 2, the solenoid is de-energized so that the lever 18 is rotated counterclockwise by the spring 19. The rotation of this lever 18 causes the separation lever 23 to be rotated in the clockwise direction h', so that the cleaning blade 16 is in a position separated from the intermediate transfer body 2 and cleans the composite image on the intermediate transfer body 2. It will not be disturbed.

Further, as shown in FIG. 3, when the cartridge 15 is removed from the main unit 24, the separation lever 25 is released from the main body abutting portion 22, so the spring 26 causes the separation lever 25 to move clockwise. The contact member 21 is rotated around the rotation shaft 27 and comes into contact with the intermediate transfer member 2 . Therefore, the toner after cleaning the intermediate transfer body 2 does not fall from the cartridge 15 when the cartridge 15 is removed from the main device 24 because the intermediate transfer body 2 and the contact member 21 are in contact with each other.

In the above embodiments, a photoreceptor having a photoconductive layer on the surface was used as the latent image carrier, but an insulator may also be used to achieve the same effects as in the above embodiments.

(Effects of the Invention) As explained above, the present invention provides an electrostatic latent image for each color component by individually exposing a light image separated into each color component onto a latent image carrier charged in a negative manner. an exposure means for forming an electrostatic latent image for each component, a developing means for developing the electrostatic latent image of each component individually with a developer of a different color, and an intermediate transfer means for sequentially transferring the developed image on the latent image carrier. a cartridge that accommodates in an integrated unit an intermediate transfer body that is superimposed and transferred onto a body to form a composite image, and a cleaning device that can be brought into and out of contact with the intermediate transfer body; and a contact member provided on the upstream and downstream sides of the cartridge, which is spaced from the intermediate transfer body when the cartridge is installed in the main unit, and abuts against the intermediate transfer body when the cartridge is removed from the main unit. Easy maintenance because of the
Further, it is possible to eliminate internal contamination due to toner scattering when replacing the intermediate transfer member.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which Fig. 1 is a side view showing a schematic configuration of a color image forming apparatus, and Fig. 2 is a side view of a state in which an intermediate transfer body in the form of a cartridge is installed in the main unit. 3 is a side view of the intermediate transfer body removed from the main unit, and FIG. 4 is a side view of an image forming apparatus using a conventional intermediate transfer body. 1... Photoreceptor, 2... Intermediate transfer body, 38-3d...
- Developing means, 4... Exposure means, 9... Cleaning device, 15... Cartridge, 16... Cleaning blade, 21... Contact member, 24... Main unit.

Claims (1)

[Scope of Claims] Exposure means for forming an electrostatic latent image for each color component by individually exposing an optical image separated for each color component onto a uniformly charged latent image carrier; A developing means for individually developing electrostatic latent images of each component with developers of different colors, and a composite image by sequentially superimposing and transferring the developed images on the latent image carrier onto an intermediate transfer member. a cartridge that houses an intermediate transfer body that forms an intermediate transfer body and a cleaning device that can be moved into and out of contact with the intermediate transfer body in an integrated unit; and a contact member that is separated from the intermediate transfer member when the cartridge is installed in the main unit and comes into contact with the intermediate transfer member when the cartridge is removed from the main unit.