JP2006184429A - Cleaning device, process cartridge, and electronic photographic image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve sealability at the ends of a cleaning member without raising the abutting pressure of the cleaning member on a photoreceptor drum. <P>SOLUTION: The cleaning device comprises the photoreceptor drum 1, the cleaning member 6 consisting of a cleaning blade 61 and a sheet metal 62 supporting the same, and removing toner on the photoreceptor drum 1 by bringing the edge of the cleaning blade 61 into pressurized contact with the photoreceptor drum 1, a cleaning container 51 for containing the toner removed from the cleaning member 6, a sealing member 63 for obstructing the toner leakage at the ends of the cleaning member 6, and an auxiliary sealing member 64 for obstructing the toner leakage in the clearances of the cleaning member 6 and the cleaning container 51. The shape of the auxiliary sealing member 64 is formed wider in the width abutting on the sheet metal 62 than the width abutting on the cleaning blade 61. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a cleaning device, a process cartridge, and an electrophotographic image forming apparatus to which the process cartridge can be attached and detached. Here, the electrophotographic image forming apparatus forms an image on a recording medium using an electrophotographic image forming process. For example, an electrophotographic copying machine, an electrophotographic printer (for example, an LED printer, a laser beam printer, etc.) An electrophotographic facsimile, an electrophotographic word processor, and the like are included. Further, as the process cartridge, the cleaning means and the electrophotographic photosensitive member are integrally formed into a cartridge, and the cartridge can be attached to and detached from the main body of the electrophotographic image forming apparatus.

  An image forming apparatus such as a printer using an electrophotographic process uniformly charges a drum-shaped electrophotographic photosensitive member as an image carrier, and electrostatically charges the photosensitive drum by selective exposure to the photosensitive drum. A latent image is formed. The latent image is visualized with a developer (hereinafter referred to as toner), and the toner image is transferred to a recording medium. Further, heat or pressure is applied to the transferred toner image to fix the toner image on the recording medium. As a result, an image is recorded on the recording medium. Such an apparatus involves toner replenishment and maintenance of various process means. Therefore, in order to facilitate this toner replenishment operation and maintenance, a cartridge in which the photosensitive drum and the charging means, the developing means, the cleaning means, etc. as the process means are combined into a cartridge has been put into practical use. ing.

  Such a process cartridge includes a cleaning unit in which a photosensitive drum, a charging unit, and a cleaning unit are integrally attached to a first frame, a developing unit, and a toner container are assembled to a second frame. And a developing unit rotatably attached to the frame. As the cleaning means, in a cleaning member composed of a cleaning blade made of an elastic material such as urethane rubber and a sheet metal supporting the cleaning blade, the edge of the cleaning blade is brought into pressure contact with the surface of the photosensitive drum, and the photosensitive drum A configuration that scrapes off and removes the residual toner on the top is in practical use. In such a cleaning means using a cleaning blade, not all the toner scraped off is stored in the toner storage part of the cleaning unit. It is necessary to prevent leakage outside the casing.

The seal structure at both ends of the cleaning member is disposed in the gap between the cleaning member and the cleaning container, and is disposed so as to contact the end of the cleaning member, an auxiliary seal member that assists the seal at the end of the cleaning member, and the photosensitive member and the cleaning blade. It is comprised with the letter-shaped sealing member (refer patent document 1). The seal member and the auxiliary seal member are made of an elastic member such as polyurethane foam. The auxiliary seal member is pressed and compressed when the cleaning member is attached to the cleaning container, thereby sealing a gap between the cleaning member and the cleaning container and preventing toner leakage due to lateral running of the toner.
Japanese Patent Laid-Open No. 08-202242 (page 10, FIG. 5)

  In recent years, in an electrophotographic image forming apparatus using a process cartridge, further improvement in image quality has been demanded, and higher resolution has been advanced. Along with this, a spherical toner called a polymerized toner is used as the toner, and the toner particle size is becoming finer. When the toner has a spherical shape and becomes fine particles, it is necessary to further improve the sealing performance at both ends of the cleaning member.

  As means for improving the sealing performance at the end of the cleaning member, it is conceivable to increase the thickness of the sealing member or the auxiliary seal, increase the contact pressure against the photosensitive drum or the cleaning member, and improve the sealing performance. However, when the contact pressure of the seal member to the photosensitive drum increases, the drum driving torque increases. When the contact pressure of the auxiliary seal member to the cleaning member increases, it is conceivable that the surface layer of the photosensitive drum is easily scraped at the end of the cleaning member.

  Accordingly, the present invention provides a cleaning device that suppresses leakage of toner from the gap between the cleaning member and the cleaning container without increasing the contact pressure to the cleaning member, a process cartridge having the cleaning device, and an electrophotographic image An object is to provide a forming apparatus.

  In order to solve the above-described problems, an invention according to the present invention includes an elastic member and an elastic member support member for supporting the elastic member in a cleaning device that removes the developer attached to the image carrier. A cleaning member for removing the developer on the surface of the image carrier by pressing the edge of the elastic member against the image carrier; and the developer removed from the image carrier by the cleaning member And a cleaning container to be removed and disposed at both ends of the end surface having the edge of the cleaning member so that the removed developer does not leak from the end of the cleaning member so as to slide on the surface of the image carrier. An auxiliary seal member disposed in a gap between the cleaning member and both ends of the cleaning member, and the auxiliary seal member. In the region in contact with the cleaning member and the cleaning container, the width in contact with the sheet metal is wider than the width in which the cleaning member is in contact with the elastic member. It is a cleaning device.

  As described above, according to the present invention, the shape of the auxiliary seal disposed in the gap between the both ends of the cleaning member and the cleaning container is brought into contact with the elastic member support member rather than the seal width in contact with the cleaning blade. By widening the seal width, the sealing performance of the gap between the cleaning member and the cleaning container can be improved without increasing the repulsive force of the auxiliary seal member applied to the tip of the elastic member.

Example 1
Embodiments of a process cartridge and a color electrophotographic image forming apparatus according to the present invention will be described with reference to the drawings.

(Overall configuration of image forming apparatus)
First, the overall configuration of the image forming apparatus will be described with reference to FIG. The image forming apparatus 100 shown in FIG. 1 has four process cartridge mounting portions (not shown) arranged in parallel in the vertical direction. Each of the cartridges 7 mounted on the mounting portion includes one electrophotographic photosensitive drum (1a to 1d). The photosensitive drum 1 is rotatably supported by a cleaning frame 51 as a first frame, and is rotated counterclockwise in the drawing by a driving means (not shown). Around the photosensitive drum 1, the following components are arranged in order according to the rotation direction. Charging means (2a to 2d) for uniformly charging the surface of the photosensitive drum 1; a scanner unit (3a to 3d) for forming an electrostatic latent image on the photosensitive drum 1 by irradiating a laser beam based on image information; A developing unit (4a to 4d) as a second frame for developing the electrostatic latent image using toner as a developer, and electrostatic transfer means 5 for transferring the toner image on the photosensitive drum 1 to the recording medium S. Cleaning members (6a to 6d) for removing the toner remaining on the surface of the photosensitive drum 1 after the transfer are disposed. Here, the photosensitive drum 1, the charging unit 2, the developing unit 4, and the cleaning unit 50 are integrated into a cartridge to form a process cartridge 7.

  The photosensitive drum 1 is obtained by coating an organic photoconductive layer (OPC photosensitive member) on the outer peripheral surface of an aluminum cylinder having a diameter of 30 mm, for example. Both ends of the photosensitive drum 1 are rotatably supported by support members. A driving force from a driving motor (not shown) is transmitted to one end. As a result, the photosensitive drum 1 is driven to rotate counterclockwise. As the charging means 2, a contact charging type as shown in FIG. 2 is used. The charging member is a conductive roller formed in a roller shape, and this roller is brought into contact with the surface of the photosensitive drum 1. Then, a charging bias voltage is applied to this roller. As a result, the surface of the photosensitive drum 1 is uniformly charged.

  The scanner unit 3 is arranged in a substantially horizontal direction of the photosensitive drum 1. Then, image light corresponding to the image signal is irradiated to polygon mirrors 9a to 9d rotated by a scanner motor (not shown) by a laser diode (not shown). The image light reflected by the mirror 9 selectively exposes the surface of the charged photosensitive drum 1 through the imaging lenses 10a to 10d. Thereby, an electrostatic latent image corresponding to the image signal is formed.

  As shown in FIG. 2, the developing unit 4 includes a toner container 41a containing yellow toner, a toner container 41b containing magenta toner, a toner container 41c containing cyan toner, and a black toner container. It has a toner container 41d containing toner and a developing frame 45. The toner is fed into the toner supply roller 43 by the toner transport mechanism 42 in the toner container 41. Then, toner is applied to the outer periphery of the developing roller 40 and charges are applied to the toner by the roller 43 and the developing blade 44 pressed against the outer periphery of the developing roller 40 as a developing member. Then, a latent image formed on the photosensitive drum 1 is developed by applying a developing bias to the developing roller 40. The developing roller 40 is disposed to face the photosensitive drum 1.

  On the other hand, as shown in FIG. 1, the image forming apparatus is provided with an electrostatic transfer belt 11 that circulates and moves so as to face and contact all the photosensitive drums 1a to 1d. The transfer belt 11 is a film-like member having a volume resistivity of 10 ^ 11 to 10 ^ 14 Ω · cm and a thickness of about 150 μm. Then, the recording medium S is conveyed to the transfer position by the transfer belt 11 and the toner image on the photosensitive drum 1 is transferred.

  Transfer rollers 12a to 12d are juxtaposed at positions facing the inside of the transfer belt 11 and facing the four photosensitive drums 1a to 1d. Positive charges are applied from the transfer roller 12 to the recording medium S via the transfer belt 11. As a result, the toner image on the photosensitive drum 1 is transferred to the recording medium S. The transfer belt 11 is stretched by four rollers, that is, a driving roller 13, driven rollers 14a and 14b, and a tension roller 15, and rotates (in the direction of the arrow in the figure). As a result, the transfer belt 11 circulates and the toner image is transferred while the recording medium S is conveyed from the driven roller 14a side to the drive roller 13 side.

  The feeding unit 16 feeds and conveys the recording medium S to the image forming unit. A plurality of recording media S are stored in the feeding cassette 17. At the time of image formation, the feeding roller 18 and the registration roller pair 19 are driven and rotated according to the image forming operation. As a result, the recording media S in the cassette 17 are separated and fed one by one. The leading edge of the recording medium S hits the roller pair 19 and stops temporarily. The recording medium S is fed to the transfer belt 11 by the registration roller pair 19 in synchronization with the rotation of the transfer belt 11 and the toner image.

  The fixing unit 20 fixes the toner images of a plurality of colors transferred to the recording medium S. It comprises a rotating heating roller 21a and a pressure roller 21b that is in pressure contact with it and applies heat and pressure to the recording medium S. That is, the recording medium S on which the toner image on the photosensitive drum 1 is transferred is conveyed by the fixing roller pair 21 when passing through the fixing unit 20. Then, heat and pressure are applied by the fixing roller pair 21. As a result, the toner images of a plurality of colors are fixed on the surface of the recording medium S.

  The image forming operation is as follows. First, the cartridges 7a to 7d are sequentially driven in accordance with the image formation timing. Then, the photosensitive drums 1a to 1d are rotationally driven according to the drive. Then, the scanner units 3 corresponding to the respective cartridges 7 are sequentially driven. By this driving, the charging unit 2 applies a uniform charge to the peripheral surface of the photosensitive drum 1. The unit 3 exposes the circumferential surface of the photosensitive drum 1 according to the image signal to form an electrostatic latent image on the photosensitive drum 1. The developing roller 40 develops the electrostatic latent image.

  As described above, on the recording medium S, the toner images on the photosensitive drums 1 are sequentially transferred by the electric field formed between the photosensitive drums 1 and the transfer rollers 12. The recording medium S to which the four color toner images are transferred is separated from the transfer belt 11 by the curvature of the driving roller 13. Then, it is carried into the fixing unit 20. After the toner image is thermally fixed by the fixing unit 20, the recording medium S is discharged from the discharge unit 24 to the outside of the main body by the discharge roller pair 23.

(Process cartridge)
Next, the process cartridge in which the position embodiment of the present invention is implemented will be described. FIG. 2 is a main cross section of the cartridge 7 containing toner. The cartridge 7a containing yellow toner, the cartridge 7b containing magenta toner, the cartridge 7c containing cyan toner, and the cartridge 7d containing black toner have the same configuration.

  The cartridge 7 (7a to 7d) includes a photosensitive drum 1 (1a to 1d), a charging unit 2 (2a to 2d), a cleaning member 61 (6a) including a cleaning blade 61 and a sheet metal 62 for supporting the cleaning blade. To 6d) as a first frame, and a developing unit 4 (4a to 4d) as a second frame having a developing means.

  In the cleaning unit 50, the photosensitive drum 1 is rotatably attached to the cleaning frame 51. As described above, the charging unit 2 and the cleaning member 6 are disposed on the circumference of the photosensitive drum 1. Further, the residual toner removed from the surface of the photosensitive drum 1 by the cleaning member 6 is sent to the waste toner container 53 by the toner feeding mechanism 52. The waste toner container is integrated with the cleaning unit.

  Then, as shown in FIG. 3, the driving force of a driving motor (not shown) is transmitted to the cleaning unit 50 via the coupling member 70, so that the photosensitive drum 1 is rotationally driven according to the image forming operation. The cleaning frame 51 is provided with a cartridge rotation stop 51a as a main body positioning boss for preventing the process cartridge from rotating due to its own weight or a moment due to a driving force in the main body of the image forming apparatus. The cleaning frame 51 is provided with a shutter member 72 that protects the photosensitive drum, and a shutter receiving member 73 that opens and closes the shutter member by a link operation.

  Next, as shown in FIG. 4, the development unit 4 transmits the drive from the drive motor to the development drive gear 71 and transmits the drive to the development roller 40 through a drive train (not shown). The developing roller 40 is rotatably supported by the developing frame 45 via a bearing member. Further, as described above, the toner supply roller 43 and the developing blade 44 are arranged on the circumference of the developing roller 40, respectively. Further, in the toner container 41, a toner transport mechanism 42 for stirring the stored toner and transporting it to the roller 43 is provided.

  Further, the developing unit 4 has a hanging structure that is rotatably supported with respect to the cleaning unit 50. That is, the developing unit 4 is provided with holes 47a and 48a, which are provided in bearing members 47 and 48 attached to both ends of the unit 4, respectively, and serving as rotation centers, and shafts that fit into the cleaning frame 51 in the holes. 62 and 63 are inserted, and the developing unit 4 is rotatably attached to the cleaning unit 50.

(Main configuration of the embodiment of the present invention)
In the cleaning device for the process cartridge 7, a cleaning member 6 including a cleaning blade 61 as an elastic member and a sheet metal 62 as an elastic member support member that supports the cleaning blade 61 is fastened to a cleaning container 51. The edge of the cleaning blade 61 is in contact with the photosensitive drum 1 supported by the cleaning container 51. 5 and 6 show the configuration of the cleaning container 51, the cleaning member 6, the seal member 63, and the auxiliary seal member 64. FIG. The seal member 63 is provided at both ends of the end surface including the edge of the cleaning blade 61 so as to rub against the photosensitive drum. The auxiliary seal member 64 is disposed in the gap between the both ends of the cleaning member 6 and the cleaning container 51. When the cleaning member 6 is fastened to the cleaning container 51, the auxiliary seal member 64 is pressed and compressed to end the cleaning member 6 and the end of the cleaning container 51. Seal the gap at. As shown in FIG. 7, the auxiliary seal 64 is attached to the cleaning container 51 so that the end face of the auxiliary seal member 64 is in contact with the end face of the cleaning container 51, and the double-sided tape 65 integrated with the auxiliary seal member 64 is used. Is brought into close contact with the cleaning container 51.

  FIG. 8 shows the state of the seal member 63 and the auxiliary seal member 64 with the photosensitive drum attached. When the photosensitive drum is attached to the cleaning container, the tip of the cleaning blade 61 bends in the A direction, the auxiliary seal member 64 is further compressed, and the repulsive force from the auxiliary seal member 64 at the tip of the cleaning blade 61 increases. When the thickness of the auxiliary seal member 64 is increased in order to improve the sealing performance between the cleaning member 6 and the cleaning container 51, the repulsive force from the auxiliary seal member 64 further increases. Then, it is conceivable that the pressure contact force between the cleaning blade 61 and the photosensitive drum 1 increases and the surface layer of the photosensitive drum 1 is scraped at the end of the cleaning blade 61. Further, as another means for improving the sealing performance, even if the width of the auxiliary seal member 64 is widened and the contact width with the cleaning member 64 is widened, the repulsive force of the auxiliary seal member 64 against the cleaning blade 61 is not applied. Increases by the amount of contact width widened.

  Therefore, in this embodiment, as a means for improving the sealing performance in the gap between the cleaning member 6 and the cleaning container 51 without increasing the repulsive force against the cleaning blade 61, as shown in FIG. 9, the shape of the auxiliary seal member 64 The seal width b in contact with the sheet metal 62 is made wider than the seal width a in contact with the cleaning blade 61. With such a shape, the sealing performance in the gap between the sheet metal 62 and the cleaning container 51 can be improved without increasing the repulsive force of the auxiliary seal member 64 against the cleaning blade 61.

  As described above, according to this embodiment, the developer removed from the photosensitive drum is located at both ends of the end surface having the edge of the cleaning member 6 so that the developer does not leak from the end of the cleaning member 6. A seal member 63 disposed so as to rub against the surface of the body drum 1; and an auxiliary seal member 64 disposed in a gap between both ends of the cleaning member 6 and the cleaning container 51, and the auxiliary seal member In the region where 64 is in contact with the cleaning member 6 and the cleaning container 51, the width of the cleaning member 6 in contact with the sheet metal 62 is larger than the width of contact with the cleaning blade 61 as an elastic member. It is wide.

(Example 2)
FIG. 10 shows the shape of the auxiliary seal member 64 that can improve the sealing performance in the gap between the cleaning member 6 and the cleaning container 51 without increasing the repulsive force of the auxiliary seal member 64 against the cleaning blade (elastic member) 61. A second embodiment will be described.

  The auxiliary seal member 64 in this embodiment gradually increases in seal width from the seal width a at the tip of the cleaning blade 61 to the seal width b in the cleaning blade support sheet metal (elastic member support member) 62. By adopting such a shape, the repulsive force of the auxiliary seal member 64 at the tip of the cleaning blade 61 can be suppressed, and the sealing performance in the gap between the cleaning member 6 and the cleaning container 51 can be further improved.

(Example 3)
FIG. 11 shows an auxiliary seal member 64 that can improve the sealing performance in the gap between the cleaning member 6 and the cleaning container 51 without increasing the repulsive force of the auxiliary seal member 64 against the cleaning blade (elastic member) 61. The 3rd Example about a shape is shown.

  The auxiliary seal member 64 in this embodiment has a sheet metal (elastic member support member) 62 that is larger than the seal width a that is in contact with the cleaning blade 61 while ensuring a clearance S between the end surfaces of the cleaning container 51 and the auxiliary seal member 64. It is characterized by a shape in which the seal width b in contact with is wider. By providing the gap M, when the auxiliary seal member 64 is attached, both ends R close to the end surface T abutting against the cleaning container 51 in the auxiliary seal member 64 can be grasped. Thereby, it is possible to improve the pasting accuracy on the end face T and to suppress the repulsive force of the auxiliary seal member 64 against the cleaning blade. And the sealing performance in the gap between the sheet metal 62 and the cleaning container 51 can be improved.

  In each of the embodiments described above, the developer removed from the photosensitive drum is located at both ends of the end surface having the edge of the cleaning member 6 so that the developer does not leak from the end of the cleaning member 6. A sealing member 63 disposed so as to rub against the surface of the cleaning member 6, and an auxiliary sealing member 64 disposed in a gap between both ends of the cleaning member 6 and the cleaning container 51. In a region where the cleaning member 6 is in contact with the cleaning container 51, the width where the cleaning member 6 is in contact with the sheet metal 62 is larger than the width where the cleaning member 6 is in contact with the cleaning blade 61 as an elastic member. Wide. As a result, the sealing performance of the gap between the cleaning member and the cleaning container can be improved without increasing the repulsive force of the auxiliary seal member applied to the tip of the cleaning blade.

1 is an overall configuration diagram showing an embodiment of a color electrophotographic image forming apparatus according to the present invention. FIG. 4 is a cross-sectional explanatory view of a process cartridge according to the present invention. It is a perspective view of a process cartridge according to the present invention. FIG. 3 is a perspective view of a developing unit according to the present invention. The block diagram of the cleaning member which concerns on this invention, a sealing member, and an auxiliary | assistant sealing member. The block diagram of the cleaning member, seal | sticker, and auxiliary seal which concern on this invention. The attachment figure of an auxiliary seal. 1 is a configuration diagram of a photosensitive drum, a cleaning member, a seal member, and an auxiliary seal according to the present invention. The auxiliary seal shape which shows the 1st example concerning the present invention. The auxiliary seal shape which shows the 2nd Example which concerns on this invention. The auxiliary seal shape which shows the 3rd example concerning the present invention.

Explanation of symbols

C contact position S recording medium t developer
1 (1a-1d) Electrophotographic photosensitive drum
2 (2a ~ 2d) Charging means
3 (3a-3d) Scanner unit
4 (4a-4d) Development unit (second frame)
5 Electrostatic transfer means
6 Cleaning material
7 (7a-7d) Process cartridge
8 (8a ~ 8d) Force imparting member (separation means)
9 (9a-9d) Polygon mirror
10 (10a to 10d) Imaging lens
11 Electrostatic transfer belt
12 (12a-12d) Transfer roller
13 Drive roller
14 Followed roller
15 Tension roller
16 Paper source
17 Feed cassette
18 Feed roller
19 Registration roller
20 Fixing part
21 Fixing roller
21b Pressure roller
23 Discharge roller
24 Discharge section
40 Developing roller (developing member)
41 (41a to 41d) Toner container
42 Toner transport mechanism
43 Toner supply roller
44 Developing blade
45 Development frame
47 Bearing member (main body drive side)
47a hole
47b Force receiver
48 Bearing member (Non-drive side)
49 Side cover
50 Cleaning unit (first frame)
51 Cleaning frame
52 Toner feed mechanism
53 Waste toner chamber
61 Cleaning blade
62 Cleaning blade support sheet metal
63 Seal member
64 Auxiliary seal member
70 Coupling material
71 Development drive gear
72 Shutter material
73 Shutter receiving member
100 Image forming equipment L Laser light

Claims (4)

In the cleaning device for removing the developer adhering to the image carrier,
A cleaning member having an elastic member and an elastic member support member for supporting the elastic member, wherein the cleaning member removes the developer on the surface of the image carrier by pressing the edge of the elastic member against the image carrier. When,
A cleaning container for storing the developer removed from the image carrier by the cleaning member;
A seal member disposed at both ends of the end surface having the edge of the cleaning member so as to rub against the surface of the image carrier so that the removed developer does not leak from the end of the cleaning member; An auxiliary seal member disposed in a gap between both ends of the cleaning member and the cleaning container;
Have
In the region where the auxiliary seal member is in contact with the cleaning member and the cleaning container, the width where the cleaning member is in contact with the elastic member is wider than the width where the cleaning member is in contact with the elastic member. A cleaning device characterized by that.   2. The cleaning device according to claim 1, wherein the auxiliary seal member is made of an elastic member such as urethane foam or felt.   A process cartridge comprising an electrophotographic photosensitive member as the image carrier and the cleaning device according to claim 1, and detachable from an electrophotographic image forming apparatus main body.   An electrophotographic image forming apparatus, wherein the process cartridge according to claim 3 is detachably attached to an electrophotographic image forming apparatus main body.

Images