JPH09274384A - Developing cartridge and color image forming apparatus - Google Patents

Abstract

(57) Abstract: It is possible to prevent the performance of the optical detection unit of the remaining toner amount from being deteriorated due to the scattered toner. SOLUTION: A cleaning member 9 is attached to an outer peripheral surface of a toner container 1, and an attachment position of the cleaning member 9 is a position to fill a gap between a developing unit and a shutter 7 at a developing position. This prevents scattered toner from adhering to the inside of the shutter 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic color image forming apparatus such as a copying machine or a printer, and a developing cartridge detachably attached to the color image forming apparatus. The present invention relates to a developer amount detecting mechanism for detecting the amount of developer in the inside.

[0002]

2. Description of the Related Art Conventionally, as a method of detecting the amount of toner in a toner container of a developing device or a developing cartridge, a transparent window member is provided in the toner container, and light is transmitted through the window member to optically determine the toner amount. The method of detection was taken. In order to reliably detect the amount of toner by this method, it is necessary to clean the window member appropriately, and it has been common to use a stirring blade in the toner container as this cleaning means. further,
The developing cartridge is generally provided with a shutter that protects the developing roller, which is a developer carrying member, from being touched by a user before the developing cartridge is mounted in the main body of the image forming apparatus, and opens after the mounting.

[0003]

By the way, in order to accurately detect the toner amount, the optical path of the optical detecting means must be arranged so as to pass through the lower surface of the toner container. This is because the optical detection means determines the toner-free advance notice from the light transmission time until the stirring blade in the toner container cleans the window member and the toner falls on the window member again.
At that time, the shutter that protects the developing unit including the toner container and the developing container is required to have an opening shape so as not to block the optical path when it reaches the developing position.

However, the scattered toner generated in the developing process adheres to the inner surface of the shutter, and a considerably large amount of toner adheres near the end of the life of the developing cartridge.
The adhered toner drops due to vibration during the developing operation or the impact of the detaching operation from the image forming apparatus, and enters the optical path. As a result, the received light detection amount of the optical detection means becomes unstable, and there is a possibility that erroneous detection or the function may stop.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a developing cartridge capable of preventing the performance deterioration of the toner amount optical detecting means due to the scattered toner, and a color image forming apparatus provided with the developing cartridge.

[0006]

The above object can be achieved by a developing cartridge and a color image forming apparatus according to the present invention. In summary, the present invention is a developing cartridge that can be detachably attached to an image forming apparatus main body, and contains a developing container that rotatably supports at least a developer carrying member, and a developer.
A developing unit having a developer container provided with a light-transmittable window member, and at least the developer carrier is covered before being mounted on the main body of the image forming apparatus, and is opened / closed in association with the mounting operation or the image forming operation. In the developing cartridge, the main body of the image forming apparatus is provided with an optical means for detecting the remaining amount of the developer in the developer container, and the developing unit is rubbed with the protecting member. The developing cartridge is provided with a cleaning member for cleaning.

It is preferable that the cleaning member is arranged at a developing position so as to fill a gap between the developing unit and the protective member. For the cleaning member, it is preferable to use a urethane foam-based material having 30 to 40 cells / cm per unit length.

It is preferable that the developing cartridge is rotationally moved around an axis parallel to an image carrier axis which is a rotation center of an image carrier provided in the main body of the image forming apparatus, with the parallel axis as a center. . After mounting the developing cartridge on the image forming apparatus main body, it is preferable that only the protective member is held on the image forming apparatus main body, and the developing unit performs a rotation operation in order to keep its posture constant.

According to another aspect of the present invention, there is provided a color image forming apparatus having a plurality of developing cartridges which can be attached to and detached from a main body of the image forming apparatus, and an optical means for detecting a remaining amount of the developer. Is a developing unit having at least a developing container that rotatably supports a developer carrier and a developer container that contains a developer and that has a light-transmittable window member, and is attached to the image forming apparatus main body. In the color image forming apparatus, which has at least the protection member that covers the developer carrier and that opens and closes in association with the mounting operation or the image forming operation, the developing unit includes a cleaning member that slides on the protection member. There is provided a color image forming apparatus characterized in that.

At least two developing cartridges are provided in the main body of the image forming apparatus, and the developing cartridges are parallel to the axis of the image carrier, which is the center of rotation of the image carrier provided in the main body of the image forming apparatus. It is preferable to form a multicolor image by rotationally moving around the axes about the parallel axes.

[0011]

DETAILED DESCRIPTION OF THE INVENTION The developing cartridge and the color image forming apparatus according to the present invention will be described in more detail with reference to the drawings.

FIG. 4 shows an embodiment of the color image forming apparatus. In the figure, a photosensitive drum 1 which is an image carrier for forming a latent image which is a source of an image by being exposed to a laser beam emitted from a scanner unit 28 is provided at an approximately center of the apparatus. It is arranged with the axis 21a as the center of rotation, and four colors (yellow, magenta, cyan,
Black developing cartridge 100 (100Y, 100)
M, 100C, 100B) is fixed to the developing rotation unit 24, and the leading end of the fed transfer paper is fixed to the circumference by a gripper or the like, and the transfer drum 22 for transferring the developed image onto the photosensitive drum 21. , And a cleaner 26 for removing the toner remaining on the photosensitive drum 1 during transfer.
Are arranged.

As shown in FIG. 3, the developing rotary unit 24 rotates about a rotary shaft 14 parallel to the image carrier shaft 21a, and a plurality of developing cartridges 100 rotate around the rotary shaft 14 while the photosensitive drums rotate. The latent image of each color component formed on 1 is developed.

In the vicinity of the transfer drum 22, a fixing device 23 that completes transfer a plurality of times while being wound around the transfer drum 22 and fixes the toner on the separated and guided transfer paper 23.
Is provided. The cleaner 26 is formed as a drum cartridge 27 integrally with the photosensitive drum 21 and the like, and is attachable to and detachable from the apparatus main body in the drum axial direction.

In the schematic structure as described above, the transfer sheets separated and fed one by one from the sheet feeding cassette 29 by the sheet feeding roller 32 are sent to the transfer drum 22 at a timing by the registration roller 33 and transferred. The leading edge of the paper is gripped by a gripper (not shown). further,
The remaining portion of the transfer paper is electrostatically attracted to the surface of the transfer drum 22 by the attraction roller 30.

The transfer paper held on the transfer drum 22 passes through a transfer portion between the photosensitive drum 21 and the transfer drum 22, and a yellow toner image is first transferred. Next, when the leading edge of the transfer paper comes to the transfer portion again, the magenta toner image is transferred, and similarly, the toner images of each color of cyan and black are transferred. When the transfer of the toner image of the final color is completed, the transfer paper is separated from the transfer drum 22 by the separation claw 31 and is conveyed to the fixing device 23, where the fixing device 23 fixes the toner image of each color to thereby obtain a multicolor image. Is obtained.

Next, the developing cartridge, which is a characteristic part of the present invention, will be described with reference to FIGS.

The developing cartridge 100 includes a developing container 1,
And a toner container 2 which is a developer container for accommodating toner, and a shutter 7 which is a protection member provided on the outer periphery of the toner container 2. The developing container 1 is rotatably supported as a developing unit. The toner container 2 is provided with a developing roller 3 which is a developer bearing member, a blade 4 which is in contact with the developing roller 3 to apply a thin layer of toner and imparts a charge, and a supply roller 5 which supplies toner to the developing roller 3. A rotatably supported stirring member 6 supplies toner to the developing container 1.

Further, on the upper wall surface and the bottom wall surface of the toner container 2 which face each other and pass through the center of the stirring member 6, a window member for transmitting the light of the optical detecting means for detecting the remaining amount of the toner in the toner container 2 is provided. 10a and 10b are provided, respectively.

Further, as described above, the shutter member 7 composed of the first and second shutters 7a and 7b is disposed on the outer periphery of the developing container 1 and the toner container, and each of the shutters 7a and 7b is an optical member. Openings 8a and 8b are provided to secure the optical paths of the detection means.

A cleaning member 9 extending in the longitudinal direction is attached to a part of the outer surface of the developing container 1 so as to rub the shutter 7. The cleaning member 9 is intended to clean the scattered toner attached to the inner surface of the shutter member 7.

For the cleaning member 9, a material such as urethane foam having good slidability, softness, and less permanent deformation is suitable. Further, as the urethane foam, the number of cells per unit length is about 30 to 40 / cm, and it is possible to prevent generation of rubbing noise during rubbing by using coarse mesh.

Further, the cleaning member 9 is disposed so as to fill the gap between the developing unit and the shutter 7 at the developing position, so that the scattered toner during the development can be prevented from entering between the developing unit and the shutter 7. It can be prevented.

In the color image forming apparatus having the above-described structure, the developing unit including the developing container 1 and the toner container 2 performs a rotation operation to keep its posture constant.
When the development is switched, the outer shutter 7 is rotated. At that time, the cleaning member 9 attached to the developing container 1
However, the inner surface of the shutter 7 is rubbed at least once before the next development. By this rubbing operation, the toner adhering to the inner surface of the shutter 7 is scraped off by the cleaning member 9, and it is possible to prevent the performance deterioration of the optical detecting means of the remaining toner amount due to the scattered toner, and to detect the optical detecting means. It is possible to maintain good accuracy.

[0025]

As is apparent from the above description, according to the present invention, it is possible to prevent the performance deterioration of the toner amount optical detecting means due to the scattered toner, and to prevent the optical detecting means from erroneously detecting or stopping its function. It is possible to provide a developing cartridge capable of preventing the above, capable of highly reliable and highly accurate toner amount detection, and a color image forming apparatus including the developing cartridge.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a developing cartridge according to the present invention.

FIG. 2 is a partial perspective view of the developing cartridge of FIG.

FIG. 3 is a cross-sectional view showing a developing rotation unit equipped with four developing cartridges.

FIG. 4 is a configuration diagram showing an embodiment of a color image forming apparatus according to the present invention.

[Explanation of symbols]

 1 Development Container 2 Toner Container (Developer Container) 3 Development Roller (Developer Carrier) 7 Shutters (Protective Member) 8a, 8b Opening 9 Cleaning Member 11 Optical Detection Means 11a Light Emitting Member 11b Light Receiving Member 100 Development Cartridge

Claims (10)

[Claims] 1. A developing cartridge detachably mountable to a main body of an image forming apparatus, comprising: a developing container for rotatably supporting at least a developer carrying member; and a developing member-containing window member for transmitting light. A developing unit having a developer container; and a protective member which covers at least the developer carrier before being mounted on the main body of the image forming apparatus and which opens and closes in association with a mounting operation or an image forming operation. In a developing cartridge, the apparatus main body is provided with an optical detecting means for detecting the remaining amount of the developer in the developer container, wherein the developing unit is provided with a cleaning member for rubbing the protection member. Developing cartridge. 2. The developing cartridge according to claim 1, wherein the cleaning member is provided at a developing position so as to fill a gap between the developing unit and the protection member. 3. The developing cartridge according to claim 2, wherein the cleaning member is made of a urethane foam material having a cell number per unit length of 30 to 40 cells / cm. 4. A periphery of an axis parallel to an image carrier axis which is a rotation center of an image carrier provided in the image forming apparatus main body,
3. The developing cartridge according to claim 1, wherein the developing cartridge rotates about the parallel axes. 5. After mounting on the main body of the image forming apparatus, only the protective member is held on the main body of the image forming apparatus, and the developing unit performs a rotation operation to keep its posture constant. Development cartridge. 6. A color image forming apparatus comprising: a plurality of developing cartridges that can be attached to and detached from a main body of the image forming apparatus; and an optical unit that detects a remaining amount of the developer, wherein the developing cartridge includes at least a developer carrier. A developing unit having a developing container rotatably supported and a developer container containing a developer and having a light-transmittable window member, and at least the developer carrying unit before being attached to the image forming apparatus main body. In a color image forming apparatus having a protective member that covers a body and opens and closes in association with a mounting operation or an image forming operation of the developing cartridge, the developing unit is provided with a cleaning member that rubs the protective member. A color image forming apparatus characterized by the above. 7. The color image forming apparatus according to claim 6, wherein the cleaning member is provided at a developing position so as to fill a gap between the developing unit and the protective member. 8. The color image forming apparatus according to claim 6, wherein the cleaning member is made of a urethane foam material having 30 to 40 cells / cm per unit length. 9. The image forming apparatus main body is provided with at least two or more developing cartridges, and the developing cartridges include an image carrier shaft that is a rotation center of an image carrier provided in the image forming apparatus main body. 7. The color image forming apparatus according to claim 6, wherein a multicolor image is formed by rotationally moving around the parallel axes about the parallel axes. 10. The color according to claim 6, wherein after the developing cartridge is mounted, only the protective member is held by the main body of the image forming apparatus, and the developing unit performs a rotation operation to keep its posture constant. Image forming apparatus.