JPH1124523A - Process cartridge unit and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To soften the contact pressure of a cleaning blade with a photoreceptor belt in a process cartridge unit without using special parts. SOLUTION: The holder 11 of the cleaning blade 10 can be turned around a supporting point 23. The holder 11 is provided with a leaf spring 24 pushing up and energizing the holder 11 so that the blade 10 may be brought into contact with the photoreceptor belt 9 with specified pressure. In the case of keeping the unit, a waste toner cartridge 22 is pulled out so as not to push up the spring 24, and the blade 10 is separated from the belt 9 by the rotation of the holder 11 by gravity, so that the contact pressure of the blade 10 with the belt 9 is softened. In the case of using the unit, by inserting the cartridge 22 and pushing up the spring 24 by the upper surface of the cartridge 22, the holder 11 is restored to a specified position, and the blade 10 is turned to the belt 9 side and comes in contact with the surface of the belt 9 with the specified pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image forming apparatus such as a laser printer, a facsimile, a copier or a laser color printer, and a process cartridge unit to be attached to and detached from the image forming apparatus.

[0002]

2. Description of the Related Art In an image forming apparatus as described above in recent years, a process cartridge unit (hereinafter, simply referred to as a PCU if necessary) in which a photosensitive member, a charging portion, a cleaning portion and the like are integrated. ) Has become mainstream, and the size and weight of the device have been reduced.

[0003] Among the PCUs using a belt-shaped photoreceptor, there is a type in which a cleaning device for the photoreceptor belt is of a fixed type. At present, the photoreceptor belt and the cleaning blade are kept in contact with each other at a predetermined pressure during storage after assembling such constituent elements and before use after shipping. In such a state, there is a possibility that the photoreceptor belt may be damaged by the contact of the two or the cleaning blade may be set, so that improvement has been desired.

Accordingly, the present invention provides an image wherein the contact pressure between the photosensitive belt and the cleaning blade for the photosensitive belt can be reduced without using special parts during storage and before use after shipping. An object is to provide a forming apparatus and a process cartridge unit.

[0005]

According to a first aspect of the present invention, there is provided a process cartridge unit including a developing unit and an image carrier, which is detachable from an image forming apparatus main body. Cleaning means for cleaning the surface of the image carrier which can be moved toward and away from the body, and biasing means which can be moved toward and away from the cleaning means and presses the cleaning means against the image carrier at the time of contact; And a mounting portion for a waste toner cartridge. When the waste toner cartridge is mounted on the mounting portion, the urging means is pressed by the surface of the waste toner cartridge, and the cleaning means is moved against the image carrier. And press it.

According to another aspect of the image forming apparatus of the present invention,
In order to achieve the above object, there is provided an image forming apparatus in which a process cartridge unit including a developing unit and an image carrier can be detachably attached to an apparatus main body.
A cleaning unit for cleaning the surface of the image carrier, the process cartridge unit being capable of coming into contact with and separating from the image carrier; Urging means for urging the cleaning means in the vicinity of a receiving portion of the process cartridge unit in the apparatus main body when the process cartridge unit is mounted on the receiving portion. And pressing means for bringing the cleaning means into contact with the image bearing member.

According to a second aspect of the present invention, in order to achieve the above object, the apparatus main body includes an immovable portion housing, and a front portion housing which can be opened about the lower side with respect to the immovable portion housing. Have a body,
The non-moving part housing is provided with a holding and rotating member that enables the process cartridge unit to rotate in the same direction as the opening direction of the front housing.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a conceptual sectional view showing a schematic configuration of an image forming apparatus to which the present invention is applied. 1 in the figure
Is a main body of the image forming apparatus, and 2 is a PCU. The main body 1 of the image forming apparatus is constituted by a main body frame 3 serving as a stationary housing and a front frame 4 serving as a front housing capable of opening a transfer paper transport path. The front frame 4 is rotatable around a rotation support shaft 5 provided on the main body frame 3 serving as a rotation fulcrum, and closes as shown in FIG.
When opening or removing the jam or clearing the jam, open clockwise in the figure,
The open state is maintained by a tension spring (not shown) or the like. Further, the main body frame 3 includes a PCU guide 6 for rotatably holding the PCU 2 immediately inside the front frame 4.

The PCU 2 is attached to the image forming apparatus main body 1 as described above.
As shown in FIG. 2, the front frame 4 is opened by rotating the front frame 4 to the right in the figure around the rotation support shaft 5 in advance, and the PCU 2 is lowered from above and placed on the PCU guide 6 as shown in FIG. After setting, the front frame 4 is rotated to the left in the figure, and the PCU 2 is rotated together with the PCU guide 6 in the same direction to the state shown in FIG.

[0010] The PCU 2 is mainly configured as shown in FIGS.
A pair of rollers, that is, a photoreceptor belt 9 wrapped between a driving roller 7 and a driven roller 8, a cleaning blade 10 for slidingly contacting the surface of the photoreceptor belt 9 with a predetermined pressure for cleaning, and a holder 11 thereof, An intermediate transfer belt 14 is wound around rollers, that is, a driving roller 12 and a driven roller 13.

FIG. 3 shows the details of the configuration of the PCU 2 which is an embodiment of the process cartridge unit according to the present invention. The PCU 2 includes, in addition to the photosensitive belt 9 and the intermediate transfer belt 14 described above, a case 15, a transfer roller 16,
Transfer brush (bias means) 17, intermediate transfer belt 14
Cleaning blade 18 and transport screw 1
9, a conveying screw 20 for the photoreceptor belt 9, and a waste toner conveying path 21. At the bottom of the PCU 2, a waste toner cartridge 22 is detachable from the case 15.

The operation of the PCU 2 will be briefly described by taking a multicolor image formation as an example. First, the toner image on the photosensitive belt 9 is transferred by the transfer brush 17 to the intermediate transfer belt 1.
4, the photoreceptor belt 9 is cleaned by a cleaning blade 10 for each color, and a toner image of a predetermined color is sequentially formed on the photoreceptor belt 9. Is transferred to the same position on the intermediate transfer belt 14 to form a color toner image in which several colors are superimposed on the intermediate transfer belt 14. This intermediate transfer belt 14
The upper color toner image is transferred to a recording medium such as paper or plastic by the transfer roller 16. Intermediate transfer belt 1
The cleaning blade 18 provided at the position of the drive roller 12 is freely movable toward and away from the intermediate transfer belt 14, and is separated from the intermediate transfer belt 14 in the process of receiving the toner image from the photoreceptor belt 9; After the image is transferred from the recording medium 14 to the recording medium, the toner is brought into contact with the recording medium to scrape off residual toner (waste toner) on the intermediate transfer belt 14 after the image transfer. The waste toner scraped by the cleaning blade 18 is transported by the transport screw 19 for the intermediate transfer belt 14 and transported to the waste toner cartridge 22 via the waste toner transport path 21. Waste toner is scraped off from the photoreceptor belt 9 by a cleaning blade 10, and is also transported to a waste toner cartridge 22 by a transport screw 20 for the photoreceptor belt 9.
It is possible to recover waste toner without replacing the toner cartridge, thereby extending the life of the process cartridge.

The holder 1 of the cleaning blade 10
Reference numeral 1 denotes a plate which is rotatable in the vertical direction in the figure around a fulcrum 23, and which pushes up and urges the holder 11 to bring the cleaning blade 10 into contact with the photosensitive belt 9 with a predetermined pressure. Base end of spring 24 (left end in the figure)
Is fixed. Tip of leaf spring 24 (right end in the figure)
Is attached to the holder 11 slightly away from the holder 11 when no external force is applied from below in the figure, so that the urging force does not act on the holder 11. Of course, leaf spring 24
Instead, as shown in FIG. 4, a spring 25 (A),
It is also possible to use a combination of the leaf spring 24 and the spring 25 (B), a rubber 26 (C) having elasticity, a foamed polyurethane 27 (D), or the like.

The external force for pushing up the leaf spring 24 is applied using the upper surface of the waste toner cartridge 22. That is, the illustrated PCU 2 removes the waste toner cartridge 22 from the case 15 during storage after assembling the components and before use after shipment. Then, since a force for pushing up the leaf spring 24 is not applied, the own weight of the holder 11 of the cleaning blade 10 (specifically, a moment generated around the fulcrum 23 due to the fact that the right portion of the fulcrum 23 in the figure is heavier than the left portion thereof) ), FIG.
As shown in (A), the holder 11 rotates so that the cleaning blade 10 is separated from the photosensitive belt 9. Then, the cleaning blade 1 with respect to the photosensitive belt 9
The pain of the photoreceptor belt 9 and the setting of the cleaning blade 10 due to the contact pressure of 0 being loosened and being kept in contact with the predetermined pressure are prevented. FIG. 6 is an enlarged view showing a state where the contact pressure of the cleaning blade 10 with respect to the photosensitive belt 9 is loose.

Then, the case 15 is moved from the above state.
5B, the upper surface of the waste toner cartridge 22 pushes up the leaf spring 24, the holder 11 returns to a predetermined position, and the cleaning blade 10 9 and slightly contacts the surface of the photoreceptor belt 9 at a predetermined pressure.

FIG. 7 is a sectional view conceptually showing one embodiment of the image forming apparatus according to the present invention. The present embodiment is not configured to push up the leaf spring 24 using the waste toner cartridge 22 as in the PCU 2 described above, but to a pushing member 30 for pushing up the leaf spring 24 on the main body frame 3 of the image forming apparatus main body 1. Is provided. That is, with the front frame 4 opened, the PCU 2 is set on the PCU guide 6 as shown in FIG.
When the U guide 6 is rotated in the same direction, the PCU guide 6
A pressing member 30 provided immediately inside the cleaning blade 10 contacts the holder 11 of the cleaning blade 10 from below, and the holder 1
1, the cleaning blade 10 is brought into contact with the photoreceptor belt 9 at a predetermined pressure. The other configuration and operation are the same as those of the PCU 2 described above, and thus the description is omitted.
As the pressing member 30, a protrusion-shaped member may be provided in the main body frame 3, but may be replaced by any member, device, or the like originally in the main body frame 3.

[0017]

As described above, the process cartridge unit according to the present invention, as described above, includes a cleaning means which can be brought into contact with and separated from the image bearing member, and a cleaning means which can be brought into contact with and separated from the cleaning means so that the cleaning means can be used at the time of contact. Biasing means for pressing against the carrier, and when the waste toner cartridge is mounted on the mounting portion, the biasing means is pressed by the surface of the waste toner cartridge, and the cleaning means is pressed against the image carrier. The contact pressure between the photoreceptor belt and the cleaning belt for the photoreceptor belt is loosened without using special parts during storage after assembly of the components and before use after shipment. The photoreceptor belt may be damaged by contact between the photoreceptor belt and the photoreceptor belt cleaning blade, or the photoreceptor belt cleaning may be damaged. There is an effect that blade that is eliminated or Tsu poor.

As described above, in the image forming apparatus according to the present invention, the process cartridge unit detachably mountable to the apparatus main body is provided with cleaning means capable of coming in contact with and separating from the image carrier, and Biasing means for pressing and urging the cleaning means against the image carrier at the time of contact, the urging means when the process cartridge unit is mounted near the receiving portion of the process cartridge unit in the apparatus main body. Since the pressing means for contacting the cleaning means and pressing the cleaning means against the image carrier is provided, even when the process cartridge unit according to claim 1 is not used or cannot be used, the above-mentioned claim is provided. There is an effect that the same effect as in item 1 can be obtained.

[Brief description of the drawings]

FIG. 1 is a conceptual sectional view illustrating a schematic configuration of an image forming apparatus according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a state where a process cartridge unit is set in an image forming apparatus main body in the apparatus of FIG.

FIG. 3 is a sectional view showing one embodiment of a process cartridge unit according to the present invention.

FIG. 4 is a cross-sectional view showing an alternative example of a unit for urging a holder of a cleaning blade for a photoreceptor belt in the process cartridge unit of FIG. 3;

FIG. 5 is a sectional view showing the operation of the process cartridge unit of FIG.

FIG. 6 is an enlarged sectional view showing the operation of the process cartridge unit of FIG.

FIG. 7 is a sectional view conceptually showing an embodiment of the image forming apparatus according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image forming apparatus main body 2 PCU (process cartridge unit) 3 Main body frame 4 Front frame 5 Rotation support shaft 6 PCU guide 9 Photoconductor belt 10 Cleaning blade 11 Holder 14 Intermediate transfer belt 16 Transfer roller 17 Transfer brush (bias means) 18 Cleaning Blade 22 waste toner cartridge 24 leaf spring 30 pressing member

Claims (3)

[Claims] 1. A process cartridge unit including a developing unit and an image carrier, which is detachable from an image forming apparatus main body, wherein said means for cleaning said image carrier surface is detachable from said image carrier. An urging means which can be brought into contact with and separated from the cleaning means and presses the cleaning means against the image carrier at the time of contact; and a mounting portion for a waste toner cartridge, A process cartridge unit, wherein when the toner cartridge is mounted, the urging means is pressed by a surface portion of the waste toner cartridge, and the cleaning means is pressed against the image carrier. 2. An image forming apparatus in which a process cartridge unit including a developing unit and an image carrier is detachable from an apparatus main body, wherein the process cartridge unit is capable of moving toward and away from the image carrier. Cleaning means for the surface of the carrier, and biasing means for pressing and biasing the cleaning means against the image carrier at the time of contact with the cleaning means;
When the process cartridge unit is mounted on the receiving portion near the receiving portion of the process cartridge unit in the apparatus main body, the urging means is brought into contact with the cleaning means, and the cleaning means is brought into contact with the image carrier. An image forming apparatus, comprising: a pressing unit for pressing and urging the image forming apparatus. 3. The apparatus main body includes an immovable portion housing and a front housing that can be opened about a lower side of the immovable portion housing, wherein the immovable portion housing includes the process cartridge. 3. The image forming apparatus according to claim 2, further comprising a holding and rotating member that allows the unit to rotate in the same direction as the opening direction of the front case.