JPH07248713A - Cleaning device of electrophotographic device - Google Patents

Abstract

PURPOSE:To surely remove residual developer stuck to the top end of a cleaning blade, paper powder, etc., in a cleaning device of electrophotographic device removing developer remaining on a photoreceptor after image is transferred by using the cleaning blade. CONSTITUTION:A blade holder 30 is provided freely turnably around a supporting shaft 35 and energized by an energizing member 36 to press the top end of the cleaning blade 31 on the photoreceptor 11. Moreover, the cam 41 of a driving means 40 turning the blade holder 30 against the energizing member 36 to separate the cleaning blade 31 from the photoreceptor 11 is provided in the proximity to the top end part 30a of the blade holder 30. After the recording of several times, the rotation of the photoreceptor 11 is stopped, the cam 41 is actuated to repeatedly separate the cleaning blade 31 from the photoreceptor 11 and it is beaten with the separated cleaning blade by the energizing force of the energizing member 36 several times in each separation, to remove the residual developer, the paper powder, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention can be applied to an electrophotographic apparatus such as a laser printer, a laser copying machine or a laser facsimile which records on a sheet by an electrophotographic method. More specifically, the present invention relates to a cleaning device for removing residual developer remaining on the photoconductor after image transfer using a cleaning blade in such an electrophotographic device.

[0002]

2. Description of the Related Art Conventionally, in this type of cleaning device,
Residual developer or paper dust adheres to the tip of the cleaning blade that is pressed against the photoreceptor over time, and the residual developer or paper dust enters between the cleaning blade tip and the photoreceptor surface Therefore, there is a problem in that the tip of the cleaning blade is separated and a gap is partially formed, and the residual developer slips through the gap to cause cleaning failure.

Therefore, in the conventional cleaning device, the photosensitive member is slightly rotated in the reverse direction to reduce the adhesive force of the residual developer and paper dust adhered to the tip of the cleaning blade to remove the developer (Patent Document 1). 63-278087 gazette). The cleaning blade is oscillated in the longitudinal direction to reduce the adhesive force of the residual developer, paper dust and the like adhering to the tip of the cleaning blade and remove it (see JP-A-63-98687). When the cleaning blade is separated from the photoconductor, the cleaning agent removes the residual developer, paper dust and the like adhering to the cleaning blade (see Japanese Utility Model Laid-Open No. 59-60668). By doing so, there is one that is designed to solve the above-mentioned problems.

[0004]

However, in such a conventional cleaning device, there is a problem that residual developer, paper dust, etc. adhering to the tip of the cleaning blade cannot be surely removed.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a cleaning device for an electrophotographic apparatus, which uses a cleaning blade to remove the residual developer on the photoreceptor after image transfer, and to remove the residual developer attached to the tip of the cleaning blade. This is to ensure that paper dust and the like can be removed.

[0006]

Therefore, the present invention provides
As shown in the illustrated embodiments below, a blade holder 30 that rotatably supports a fulcrum such as a support shaft 35.
A cleaning blade 31 supported by the blade holder 30, a biasing member 36 for biasing the blade holder 30 to press the tip of the cleaning blade 31 against the photoconductor 11, and a biasing member 36 against the biasing member 36. To rotate the blade holder 30 to rotate the cleaning blade 3
Drive unit 40 for separating 1 from the photoconductor 11 and the drive unit 40 for stopping the rotation of the photoconductor 11 after recording a plurality of sheets.
Is operated to repeatedly separate the cleaning blade 31 from the photoconductor 11, and each time the separated cleaning blade 31 is separated, a control unit that hits the photoconductor 11 by the urging force of the urging member 36 is provided. It is characterized by

According to a second aspect of the present invention, as shown in the following illustrated embodiments, in the cleaning device 15 of the electrophotographic apparatus according to the first aspect, when the rotation of the photoconductor 11 is stopped, the control means is used. It is characterized in that the photoconductor 11 is slightly reversed.

[0008]

When the residual developer, paper dust or the like T attached to the tip of the cleaning blade 31 is dropped, the rotation of the photoconductor 11 is stopped and the driving means 40 is operated to operate the blade holder 3
By rotating 0, the tip of the cleaning blade 31 is separated from the photoconductor 11, and the separated cleaning blade 31 is struck against the photoconductor 11 by the urging force of the urging member 36, and this is repeated several times.

According to the second aspect of the invention, after recording a plurality of sheets, the photosensitive member 11 is slightly reversed, and then the rotation of the photosensitive member 11 is stopped.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 9 shows a schematic configuration of the entire internal mechanism of a laser printer including a cleaning device according to an embodiment of the present invention.

Reference numeral 10 in the figure denotes a printer main body. Inside the printer body 10, a drum-shaped photosensitive member 11 is provided at the substantially center. Around the photoconductor 11, a charging device 12, a developing device 13, a transfer device 14, and a cleaning device 15 according to the present invention are arranged in a driving direction indicated by an arrow in the figure. An optical writing device 16 is arranged above the charging device 12. Then, on the right side of the printer body 10 in the drawing, a paper feed cassette 17 accommodating the paper S is detachably provided.

When recording on the paper S, the paper feed roller 18 is rotationally driven to feed the paper S from the paper feed cassette 17 in the direction of the arrow A in the figure, and the paper S is timed to register rollers. The pair 19 conveys it to the lower side of the photoconductor 11.

The photoconductor 11 is rotationally driven in the clockwise direction shown by the arrow, and at that time, the surface of the photoconductor 11 is uniformly charged by the charging device 12, and then the laser beam from the optical writing device 16 is irradiated to the photoconductor 11. Form an electrostatic latent image on top. This latent image is visualized by the developer when passing through the position of the developing device 13. Then, this visible image is transferred by the transfer device 14 onto the upper surface of the sheet S conveyed to the lower side of the photoconductor 11.

After the image transfer, the sheet S is fixed to the fixing device 2
The image is conveyed to 0, and the transferred image is fixed by the fixing device 20.
After the fixing, the sheet S discharged from the fixing device 20 is conveyed, discharged by the pair of discharge rollers 21, and stacked on the discharge tray 22.

On the other hand, the residual developer on the surface of the photoconductor 11 after the image transfer is removed by the cleaning device 15.

By the way, the cleaning device 1 of the present invention
More specifically, 5 is configured as shown in FIG. Reference numeral 25 in the drawing is a cleaning case. The cleaning case 25 is in the shape of a horizontally long box, and has a recess 25a formed in the upper upper surface on the right side in the drawing, a horizontally long window hole 25b is formed in the bottom of the recess, and a horizontally long developer recovery port 26 is provided in the right side surface. The cleaning case 25 is arranged in parallel with the developer recovery port 26 toward the photoconductor 11 side.

A blade holder 30 is provided in the cleaning case 25. The blade holder 30 is formed in a horizontally long flat plate shape, and as shown in FIG. 2, the upper end portion 30a is slightly bent forward, and locking portions 30b and arms 30c are provided at both lengthwise end portions, respectively. The locking portion 30b is provided by tilting backward from both ends of the upper end portion of the blade holder 30. The arm 30c protrudes like an ear from the center of both ends in the length direction of the blade holder 30,
Bend it forward.

The base end of the cleaning blade 31 is fixed to the front surface of the lower end of the blade holder 30. The cleaning blade 31 is formed in a horizontally long plate shape using an elastic material such as polyurethane.

Therefore, as shown in FIG. 1, the arms 30c are attached to the support shafts 35 extending between the side plates of the cleaning case 25, and the blade holder 30 is rotatable about the support shafts 35. The upper end portion 30a of the blade holder 30 projects toward the recess 25a through the window hole 25b, and one end of the biasing member 36 is hooked on the tip of the locking portion 30b.
The urging member 36 hooks the other end to a hooking portion 25c that is appropriately provided in the cleaning case 25. Then, the blade holder 30 is rotated counterclockwise about the support shaft 35 by the urging force of the urging member 36, and the cleaning blade 31 protruding from the developer recovery port 26.
Is pressed against the surface of the photoreceptor 11.

On the other hand, the driving means 4 is provided in the recess 25a.
0 is set. The drive means 40 includes a pair of cams 41. The cam 41 is formed into a substantially oval shape and has pushing portions 41a formed on both sides in the radial direction. Then, the rotary shaft 42 is attached to both ends, and the upper end portion 30 of the blade holder 30 is attached.
It is provided close to the rear surface of a. The rotating shaft 42 is rotatably provided by supporting both ends by side plates (not shown), and is operably provided by a motor (not shown) of the driving means 40.

During cleaning, however, as shown in FIG. 4, the residual developer t remaining on the photoconductor 11 after image transfer is blocked by the tip of the cleaning blade 31 and removed, and the inside of the cleaning case 25 is removed. Drop it and collect it.

By the way, with the passage of time, as shown in the drawing, residual developer, paper dust T, etc. adhere to the tip of the cleaning blade 31. When the residual developer, paper dust T, etc. enter between the tip of the cleaning blade 31 and the surface of the photoconductor 11, a gap is formed, and the residual developer t slips through the gap to cause cleaning failure. Therefore, in the cleaning device 15, after the recording of a plurality of sheets, it is necessary to drop the residual developer, paper dust, etc. T attached to the tip of the cleaning blade 31.

Therefore, when the residual developer, paper dust or the like T is dropped from the tip of the cleaning blade 31, first, the rotation of the photosensitive member 11 is stopped by the control means, and the drive means 40 is operated to rotate the rotary shaft 42 thereof. To rotate the cam 41.

At this time, when the cam 41 is rotated 1/4, as shown in FIG. 5, the pushing portion 41a moves the upper end portion 30a of the blade holder 30 against the urging member 36 to the right in the figure. Push. Therefore, the blade holder 30 is rotated counterclockwise about the support shaft 35 to separate the tip of the cleaning blade 31 from the photoconductor 11. Then, the adhesive force of the developer, paper powder, or the like T adhering to the tip of the cleaning blade 31 is weakened, and a part thereof is separated from the surface of the photoconductor 11.

When the cam 41 is further rotated by 1/2 turn, the pushing portion 41a on the cam surface separates from the upper end portion 30a of the blade holder 30. At that time, the blade holder 30 is rotated by the urging force of the urging member 36, and as shown in FIG. 6, the tip of the cleaning blade 31 is struck against the surface of the photoconductor 11 and the impact thereof causes the cleaning blade 31 to move. The developer, paper dust, etc. T attached to the tip is dropped as shown by the arrow.

When the cam 41 is further rotated by 3/4 rotation, the cleaning blade 31 is again separated from the photoconductor 11 and the cam 41 is rotated as in FIG.
After one rotation, the cleaning blade 31 is again struck on the photoconductor 11 as in FIG.

In this way, the cleaning blade 31 is repeatedly separated from the photoconductor 11, and each time the separated cleaning blade 31 is separated, the cleaning blade 31 is struck by the urging force of the urging member 36 several times, and Due to the impact, residual developer, paper dust, etc. T attached to the tip of the cleaning blade 31 is dropped. Then, at the time of the next cleaning, the residual developer and paper dust T adhering to the photoconductor 11 are blocked and removed by the tip of the cleaned cleaning blade 31.

In the illustrated embodiment described above, when the residual developer, paper dust or the like T is dropped, the photoconductor 1 is controlled by the control means.
Stopped 1 immediately. However, the control means may slightly reverse the photoconductor 11 and then stop the photoconductor 11.

As a result, when the separated cleaning blade 31 is struck against the photoconductor 11 by the urging force of the urging member 36, as shown in FIG.
There is no need to worry about crushing the residual developer, paper dust or the like T adhered to 1 or the photoconductor 11.

Although not shown in the drawings, the driving means 4 is constituted by a single motor that drives the photoconductor 11 and is rotatable in forward and reverse directions.
It is also possible to adopt a configuration in which 0 is drive-controlled. in this case,
Only when the photoconductor 11 rotates in the reverse direction, the drive means 40 is operated by engaging with a one-way clutch or the like.

Further, in the above-described illustrated embodiment, the example in which the cam 41 is used as the driving means 40 for separating the cleaning blade 31 from the photoconductor 11 is shown. However, although not shown, the cleaning blade 31 may be configured to use, for example, a solenoid as the driving unit 40 for separating the cleaning blade 31 from the photoconductor 11.

[0032]

Therefore, according to the present invention, when the residual developer, paper dust or the like adhering to the tip of the cleaning blade is dropped, the cleaning blade is repeatedly beaten against the photosensitive member so that the residual developer adhering to the cleaning blade can be removed. It is possible to reliably remove paper dust and the like. Then, the cleaned cleaning blade can be pressed against the photoconductor to sufficiently remove the residual developer, paper dust and the like on the photoconductor.

According to the second aspect of the present invention, when the cleaning blade is struck, the developer, paper dust, etc. adhered to the cleaning blade and the photoconductor are not crushed,
They can be reliably removed.

[Brief description of drawings]

FIG. 1 is an enlarged schematic side view of a cleaning device and a photoconductor in a laser printer equipped with a cleaning device according to an embodiment of the present invention, with a part thereof shown in section.

FIG. 2 is an enlarged perspective view of a part of a cleaning blade and a blade holder included in the cleaning device.

FIG. 3 is an enlarged perspective view of a part of driving means provided in the cleaning device.

FIG. 4 is a state explanatory view showing a state in which residual developer, paper dust, and the like are attached to the tip of the cleaning blade.

FIG. 5 is a state explanatory view showing a state in which the cleaning blade is separated from the photoconductor by operating the driving means.

FIG. 6 is a state explanatory view showing a state in which residual cleaning blade, paper dust and the like are dropped by hitting the separated cleaning blade on the photoconductor.

FIG. 7 is a state explanatory view showing a state in which the photosensitive member is slightly rotated in the reverse direction and then stopped in another example of removing the residual developer, paper dust and the like.

FIG. 8 is a state explanatory view showing a state where the separated cleaning blade is struck on the photosensitive member.

FIG. 9 is a schematic configuration diagram of an entire internal mechanism of the laser printer.

[Explanation of symbols]

 11 Photoreceptor 15 Cleaning Device 30 Blade Holder 31 Cleaning Blade 35 Spindle (fulcrum) 36 Biasing Member 40 Drive Means T Residual Developer and Paper Powder

Claims (2)

[Claims] 1. A blade holder rotatably supported about a fulcrum, a cleaning blade supported by the blade holder, and an urging member for urging the blade holder to press the tip of the cleaning blade against a photosensitive member. A member and a driving means for rotating the blade holder against the biasing member to separate the cleaning blade from the photoconductor, and after the recording of a plurality of sheets, the rotation of the photoconductor is stopped to operate the drive means. The cleaning blade is repeatedly separated from the photoconductor, and a control unit that taps the photoconductor with the urging force of the urging member several times each time the separated cleaning blade is separated is provided. Cleaning device. 2. The photosensitive member is slightly reversed by the control means when stopping the rotation of the photosensitive member.
A cleaning device for an electrophotographic apparatus according to 1.