JP3000936B2 - Cleaning equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning apparatus used for an electrophotographic recording apparatus such as an electrophotographic copying machine or a printer, and more particularly to a cleaning apparatus which can perform cleaning while avoiding a seam portion of a photosensitive belt. About.

[0002]

2. Description of the Related Art Many types of electrophotographic recording apparatuses used in electrophotographic copying machines and printers have been proposed. One of them is an electrophotographic recording apparatus which forms an image on a photosensitive belt. Photo recording devices are known.

For example, JP-A-3-163472 discloses a plurality of support rollers, a photosensitive belt which is wound around the support rollers and is moved in a predetermined direction by the rotation of the rollers, and the photosensitive belt is exposed to light by exposure. A laser unit for writing a latent image, a developing device for developing the latent image written by the laser unit, a transfer device for transferring the image developed by the developing device onto a conveyed sheet, and the transfer device There is disclosed an image forming apparatus having a cleaning device for removing excess toner not transferred.

In this conventional apparatus, the photosensitive belt is moved to a predetermined position (for example, a position close to a tension roller, a position close to a fixing unit, etc.) so that a joint portion of the photosensitive belt is not included in a region where a latent image is formed. The timing of image formation is controlled by temporarily stopping in ()).

In the cleaning device, a cleaning blade for removing excess toner adhering to the photosensitive belt is held at a position away from the surface of the photosensitive belt during image formation. Only the surface of the photosensitive belt is pressed against the surface. This is because the seam of the photosensitive belt has a step because the ends are stuck up and down, and when the seam is cleaned during image formation, the step causes uneven rotation of the photosensitive belt, This is because the image is disturbed.

[0006]

As described above, in the conventional cleaning apparatus, both the exposure and the transfer are performed while cleaning the joint portion of the photosensitive belt which causes the rotation unevenness of the photosensitive belt. The configuration is not performed.

However, in this configuration, the distance from the transfer unit to the cleaning blade and the distance from the cleaning blade to the exposure position need to be at least one image. Therefore, it is necessary to make the circumference of the photosensitive belt longer than necessary, and the electrophotographic recording apparatus becomes large,
There is a problem that the printing speed is reduced during continuous printing.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and it is possible to avoid a change in load when cleaning a joint portion of a photosensitive belt and to reduce the size of an electrophotographic recording apparatus. An object of the present invention is to provide a cleaning device that enables high-speed printing.

[0009]

According to the present invention, there is provided a cleaning blade which is pressed against a photosensitive belt and removes toner adhered to the photosensitive belt, and is provided near the cleaning blade to detect a position of a joint of the photosensitive belt. A seam detection sensor and, when a position of a seam portion of the photosensitive belt approaches the cleaning blade, receiving a detection signal output from the seam detection sensor and moving the cleaning blade away from the photosensitive belt; And means.

[0010] The blade moving means moves the cleaning blade in the vertical direction or in the rotating direction.

According to the cleaning device of the present invention, when the seam portion of the photosensitive belt approaches the vicinity of the cleaning blade, the blade moving means receiving the detection signal output from the seam detection sensor detaches the cleaning blade from the photosensitive belt. As a result, the seam of the photosensitive belt is avoided. Therefore, there is no load fluctuation caused by cleaning the joint of the photosensitive belt.

In addition, since cleaning can be performed even during image formation, printing can be performed using the entire surface of the photosensitive belt only by restricting the writing position of the latent image.

The cleaning blade comprises a first cleaning blade and a second cleaning blade arranged at a predetermined interval, and the blade moving means detects a seam of the photosensitive belt when the seam approaches the first cleaning blade. Receiving the detection signal output from the first cleaning blade and detaching the first cleaning blade from the photosensitive belt and pressing the second cleaning blade against the photosensitive belt, and when the joint of the photosensitive belt approaches the second cleaning blade, When the first cleaning blade is pressed against the photosensitive belt and the second cleaning blade is separated from the photosensitive belt, one of the cleaning blades is always pressed against the photosensitive belt. Belt pressure is stable and rotation unevenness is reduced. It can be.

Furthermore, if the sum of the pressing force of the first cleaning blade against the photosensitive belt and the pressing force of the second cleaning blade against the photosensitive belt is controlled to be constant,
The rotation unevenness of the photosensitive belt can be almost eliminated.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a side view showing the configuration of an electrophotographic recording apparatus provided with the cleaning device of the present invention.

As shown in FIG. 1, an electrophotographic recording apparatus A
Has a plurality of support rollers 1, a photosensitive belt 2 wound around the support rollers 1, a laser unit 3, a developing roller 4, a transfer roller 5, and a cleaning device 6.

The support roller 1 is rotated by a drive motor (not shown) or the like, whereby the photosensitive belt 2 moves in the direction of the arrow.

The photosensitive belt 2 is a sheet-like photosensitive member formed by laminating a photosensitive layer on the surface of a film of, for example, polyethylene terephthalate. Has a step.

The laser unit 3 includes, for example, a laser device and a polygon mirror which scans a laser beam L emitted from the laser device and irradiates the photosensitive belt 2 with the laser beam, and writes a latent image on the photosensitive belt 2.

The developing roller 4 is provided in a developing device (not shown) provided with a developer, and develops a latent image written on the photosensitive belt 2 by the laser unit 3.

The transfer roller 5 transfers the image developed by the developing roller 4 to a sheet P conveyed by the pick roller 7.
Transfer to the top. The image transferred to the sheet P is fixed by the fixing unit 8.

The cleaning device 6 includes a first cleaning blade 10 and a second cleaning blade 11 which are pressed against the photosensitive belt 2 to remove excess untransferred toner attached to the photosensitive belt 2, and a first cleaning blade 10.
And a seam detection sensor 12 for detecting the position of the seam portion 2a of the photosensitive belt 2 and the seam detection sensor 1
Blade moving means 13 which receives the detection signal output from the second cleaning blade 2 and moves the first cleaning blade 10 and the second cleaning blade 11 based on the detection signal.
And

The first cleaning blade 10 and the second cleaning blade 11 are installed at a predetermined interval.
For example, the seam detection sensor 12 irradiates the photosensitive belt 2 with light from a light source (not shown), converts the reflected light into an electric signal by a photoelectric conversion element, and changes the mesh portion 2a from a change in the electric signal. It is configured to detect.

As shown in FIG. 1, the blade moving means 13 has a driving motor 13a and a first gear portion 13b which is rotated by the driving motor 13a and has an inclined tooth row.
And a second gear portion 13c meshed with the first gear portion 13b and having the first cleaning blade 10 supported thereon.
And the idle gear portion 13 meshed with the first gear portion 13b
d, the third gear portion 1 meshed with the idle gear portion 13d and having the second cleaning blade 11 supported thereon.
3e.

Next, the operation of the electrophotographic recording apparatus A will be described.

A laser beam L is emitted from a laser device of the laser unit 3 based on a signal output from an image reading device (not shown) or the like, and the laser beam L is irradiated on the photosensitive belt 2 to be exposed. 2 is written with a latent image. The written latent image is developed by the developing roller 4, and the developed image is transferred by the transfer roller 5 onto the sheet P conveyed by the pick roller 7. After the image transferred to the paper P is fixed by the fixing unit 8,
It is discharged to a tray (not shown).

Even after the image is transferred to the sheet P by the transfer roller 5, since the untransferred toner remains on the photosensitive belt 2, the photosensitive drum is cleaned by the cleaning device 6.
After the cleaning, the process proceeds to the next printing process.

FIGS. 2 and 3 are explanatory views showing the operation of the cleaning device 6 of the present invention.

When the seam detecting sensor 12 detects that the seam portion 2a of the photosensitive belt 2 has approached the first cleaning blade 10, as shown in FIG. 2, the drive motor 13a having received the detection signal is driven to rotate forward. The rotational force is transmitted to the second gear 13c and the third gear 13e, so that the first cleaning blade 10 moves downward and the second cleaning blade 11 moves upward.

As shown in FIG. 3, when the joint 2a of the photosensitive belt 2 passes through the first cleaning blade 10, the drive motor 13a rotates in the reverse direction, and the first cleaning blade 10 moves upward and the second cleaning blade 10 moves upward. Blade 11
Moves down. The above operation is performed every time the seam portion 2a of the photosensitive belt 2 approaches the first cleaning blade 10.

FIG. 4 shows each cleaning blade 10, 1
6 is a graph illustrating how the pressing force (load) changes with time over time. As shown in FIG. 4, the start, stop, reverse rotation start, and stop timings of the drive motor 13a are set in advance.
The drive motor 13a is controlled such that the sum of the pressing force of the first cleaning blade 10 on the photosensitive belt 2 and the pressing force of the second cleaning blade 11 on the photosensitive belt 2 is always constant. Therefore, while the joint 2 a of the photosensitive belt 2 passes through the cleaning device 6, the photosensitive belt 2
The load does not fluctuate.

The cleaning of the joint 2a of the photosensitive belt 2 is performed by the first cleaning blade 10 by preliminarily rotating the photosensitive belt 2 before or after printing.

According to the cleaning device 6 of the present invention, the joint 2a of the photosensitive belt 2 is
When approaching the vicinity of 0, the blade moving means 13 having received the detection signal output from the seam detection sensor 12 separates the first cleaning blade 10 from the photosensitive belt 2 to avoid the seam 2a of the photosensitive belt 2. Will do. Accordingly, since there is no load variation due to cleaning of the joint 2a of the photosensitive belt 2, image defects such as transfer deviation and writing deviation do not appear, high quality images can be obtained, and a high resolution engine and a color engine can be obtained. Also applicable to

Further, since cleaning can be performed even during image formation, printing can be performed using the entire surface of the photosensitive belt 2 only by regulating the writing position of the latent image, and high-speed printing is possible. In addition, the size of the electrophotographic recording apparatus can be reduced.

The cleaning blade comprises a first cleaning blade 10 and a second cleaning blade 11 which are arranged at a predetermined interval.
When the seam portion 2a of the photosensitive belt 2 approaches the first cleaning blade 10, the first cleaning blade 1
0 is separated from the photosensitive belt 2 and the second cleaning blade 11 is pressed against the photosensitive belt 2 to make the photosensitive belt 2
When the seam portion 2a approaches the second cleaning blade 11, the first cleaning blade 10 is pressed against the photosensitive belt 2 and the second cleaning blade 11 is separated from the photosensitive belt 2. One of the cleaning blades always has the photosensitive belt 2
, The pressing force on the photosensitive belt 2 is stabilized, and the rotation unevenness can be further reduced.

Further, the driving motor 13a is controlled so that the sum of the pressing force of the first cleaning blade 10 against the photosensitive belt 2 and the pressing force of the second cleaning blade 11 against the photosensitive belt 2 is constant. , Photosensitive belt 2
Can be almost eliminated, and a higher quality image can be obtained.

FIG. 5 is an explanatory view showing a modification of the cleaning device of the present invention. As shown in FIG. 5, the cleaning device 20 includes a support gear 21 that supports the first cleaning blade 10, and a first gear meshed with the support gear 21.
A gear 22, a support gear 23 for supporting the second cleaning blade 11, and a second gear 2 meshed with the support gear 23
4, and the first gear 22 and the second gear 24 mesh with each other. According to the cleaning device 20, the first
The gear 2 is connected to the motor 2 connected to the joint position sensor 12.
By rotating the first and second cleaning blades 10 and 11 in the rotation direction, the installation space can be reduced and the apparatus can be downsized.

The present invention is not limited to the above embodiment, and various changes can be made within the scope of the technical matters described in the claims. For example, the number and shape of the cleaning blades, the number and arrangement of the seam detection sensors, and the structure and arrangement of the blade moving means are not limited to those shown in the drawings, and can be appropriately changed.

[0039]

According to the cleaning device of the present invention, when the joint of the photosensitive belt approaches the vicinity of the cleaning blade, the blade moving means which has received the detection signal output from the joint detection sensor moves the cleaning blade to the photosensitive belt. And avoids the seam of the photosensitive belt. Therefore, load fluctuations caused by cleaning the joint of the photosensitive belt do not occur, so that image defects such as transfer deviation and writing deviation do not appear, high-quality images can be obtained, and high-resolution engines and color engines can be obtained. Applicable.

Further, since cleaning can be performed even during image formation, printing can be performed using the entire surface of the photosensitive belt only by regulating the writing position of the latent image, and high-speed printing is possible. In addition, the size of the electrophotographic recording device can be reduced.

The cleaning blade comprises a first cleaning blade and a second cleaning blade arranged at a predetermined interval, and the blade moving means detects a seam detection sensor when the seam of the photosensitive belt approaches the first cleaning blade. Receiving the detection signal output from the first cleaning blade and detaching the first cleaning blade from the photosensitive belt and pressing the second cleaning blade against the photosensitive belt, and when the joint of the photosensitive belt approaches the second cleaning blade, In the case where the first cleaning blade is pressed against the photosensitive belt and the second cleaning blade is separated from the photosensitive belt, one of the cleaning blades is always pressed against the photosensitive belt. , The pressing force to the photosensitive belt is stable, and the rotation unevenness is improved. You can do it without.

Further, by controlling the sum of the pressing force of the first cleaning blade against the photosensitive belt and the pressing force of the second cleaning blade against the photosensitive belt,
The rotation unevenness of the photosensitive belt can be almost eliminated, and a higher quality image can be obtained.

[Brief description of the drawings]

FIG. 1 is a side view showing a configuration of an electrophotographic recording apparatus provided with a cleaning device of the present invention.

FIG. 2 is an explanatory view showing the operation of the cleaning device of the present invention in a state where the first cleaning blade is in pressure contact with the photosensitive belt and the second cleaning blade is separated from the photosensitive belt.

FIG. 3 is an explanatory view showing the operation of the cleaning device of the present invention in a state where the second cleaning blade is pressed against the photosensitive belt and the first cleaning blade is separated from the photosensitive belt.

FIG. 4 is a pressing force (load) of each cleaning blade.
Is a graph for explaining how changes over time.

FIG. 5 is an explanatory view showing a modification of the cleaning device of the present invention.

[Explanation of symbols]

 A: Electrophotographic recording apparatus 1: Support roller 2: Photosensitive belt 2a: Joint portion 3: Laser unit 4: Developing roller 5: Transfer roller 6: Cleaning device 7: Pick roller 8: Fixing unit 10: First cleaning blade 11: Second cleaning blade 12: Seam detection sensor 13: Blade moving means 20: Cleaning device

Claims (3)

(57) [Claims] A cleaning blade that is pressed against the photosensitive belt and removes toner attached to the photosensitive belt; a seam detection sensor that is installed near the cleaning blade and detects a position of a seam portion of the photosensitive belt; When the position of the seam portion approaches the vicinity of the cleaning blade, a blade moving unit that receives a detection signal output from the seam detection sensor and detaches the cleaning blade from the photosensitive belt,
Wherein the cleaning blade comprises a first cleaning blade and a second cleaning blade arranged at a predetermined interval, and the blade moving means moves a seam portion of the photosensitive belt close to the first cleaning blade. Receiving a detection signal output from the seam detection sensor, detaching the first cleaning blade from the photosensitive belt, and pressing the second cleaning blade against the photosensitive belt; When the first cleaning blade approaches the second cleaning blade, the first cleaning blade is pressed against the photosensitive belt, and the second cleaning blade is pressed.
The cleaning blade is detached from the photosensitive belt, and control is performed such that the sum of the pressing force of the first cleaning blade against the photosensitive belt and the pressing force of the second cleaning blade against the photosensitive belt is constant. And a cleaning device. 2. The cleaning apparatus according to claim 1, wherein said blade moving means moves said cleaning blade in a vertical direction. 3. The cleaning apparatus according to claim 1, wherein said blade moving means moves said cleaning blade in a rotating direction.