JPH06161329A - Image forming device - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide an image forming apparatus capable of easily removing deposits adhering to the edge portion of a cleaning blade that abuts in the counter direction without damaging the photoreceptor. Is. [Structure] When the photoconductor 1 rotates in the direction of the solid arrow,
The cleaning blade 2 is arranged so that it comes into contact with the counter direction, and the cleaning blade cleaning member 5 is allowed to enter the contact portion between the cleaning blade 2 and the photoconductor 1. Then, at the time of this approach, the photoconductor 1 is reversed in the direction of the dashed arrow.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus equipped with a cleaning device.

[0002]

2. Description of the Related Art In an image forming apparatus such as a copying machine, a facsimile or a printer, an electrostatic latent image is formed on a photoconductor and the electrostatic latent image is visualized as a toner image. After the transfer to the recording medium, toner, paper dust, and other foreign matter that did not contribute to the transfer are left on the surface of the photoconductor, so remove them to remove them from the photoconductor. I have to.

A cleaning device which achieves such a function is provided facing the photoconductor, and a cleaning blade is used alone or a cleaning blade and a cleaning brush are used in combination, so that the cleaning device can be used. The deposits are scraped off. In this type of cleaning device, a cleaning blade made of an elastic material such as rubber is brought into contact with the surface of the photoconductor, and the contact direction is set to the counter direction to scrape and remove the adhered matter. ing.

While the adhering matter is scraped off and removed by such a cleaning blade, the adhering matter remains adhered to the edge portion thereof, and if the adhering matter is left as it is, there is a possibility that cleaning failure may occur. Therefore,
In a certain type of such a cleaning device, the extraneous matter adhering to the edge portion is scraped off by a special cleaning member. For example, from a position on the downstream side in the rotation direction of the photoconductor, a cleaning blade cleaning member is inserted into the contact portion between the edge portion and the photoconductor, and when the cleaning blade cleaning member enters or exits, the edge portion The adhered matter that has adhered is scraped off (Japanese Patent Laid-Open No. 52-11522).
(See No. 3).

However, when such a cleaning member enters or leaves, the surface of the photoconductor may be scratched by the cleaning member. If such a scratch is attached to the surface of the photoconductor, the image quality is adversely affected. give.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to make it possible to easily remove deposits adhering to the edge portion of a cleaning blade abutting in the counter direction without damaging the photoreceptor. To provide a forming apparatus.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a photosensitive member which is rotationally driven and a surface of the photosensitive member when the photosensitive member is rotated in the forward direction to perform an image forming process. On the other hand, a cleaning blade that abuts in the counter direction and scrapes off and removes the adhering substances adhering to the surface of the photoconductor after the transfer process, and a cleaning blade abutting part in the normal rotation direction of the photoconductor in the rotating direction. Enters between the cleaning blade and the photoconductor from a position on the downstream side, and then exits to the original position after this entry. At the time of this entry or exit, the scraped deposits are removed from the cleaning blade for cleaning. The cleaning blade cleaning member and the photosensitive member are driven to rotate in the normal direction, and when the cleaning member enters, the surface of the photosensitive member moves in the same direction as the entering direction of the cleaning member. It proposes a structure in which a photosensitive member drive means to reverse drive the body.

The cleaning blade is effective when the contact pressure is reduced when the cleaning member enters.

Further, it is effective to make the approach angle of the cleaning member to the photoconductor smaller than the contact angle of the cleaning blade to the photoconductor.

Further, it is effective that the cleaning member is mainly composed of a leaf spring, and the leading end of the leaf spring on the entrance side is made of urethane rubber coated with a low friction coefficient material.

Further, the cleaning member is mainly composed of a leaf spring, and a soft elastic body having a low friction coefficient and having a bent portion protruding toward the outside of the photoconductor is attached to the leading end portion of the leaf spring. It is effective when attached.

Further, it is effective that the urethane rubber has a wedge shape that gradually becomes thinner toward the tip.

[0013]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a configuration diagram of a cleaning device portion provided in an image forming apparatus according to an embodiment of the present invention.

Reference numeral 1 designates a drum-shaped photosensitive member, and a known toner image is formed on the surface thereof by subjecting the photosensitive member 1 to charging, exposure, development, etc., as is well known. . This toner image is transferred to a recording medium such as transfer paper, but on the surface of the photoconductor 1, after the transfer, toner that did not contribute to the transfer, paper dust, other foreign matter, etc. (Hereinafter, these are collectively referred to as "adhered matter") remaining and adhered.

When various processes such as charging, exposure, development, transfer, etc. are performed, the photosensitive member 1 is rotationally driven in the direction of the solid arrow. The rotation of the photoconductor 1 in this direction is hereinafter referred to as "the photoconductor rotates normally". The cleaning blade 2 of the cleaning device comes into contact with the surface of the photoconductor 1 in the counter direction when the photoconductor 1 normally rotates in order to execute the image forming process as described above. That is, the cleaning blade 2 is in contact with the photoconductor 1 in a posture facing the direction of rotation of the photoconductor 1 that rotates normally.

The cleaning blade 2 is made of an elastic material such as rubber. As shown in FIG. 2, the edge portion 2a of the cleaning blade 2 is brought into contact with the surface of the photosensitive member 1 at a predetermined pressure to scrape off the adhering substances. To be done. The adhering material that has been removed and dropped is discharged to the outside of the casing portion 4 of the cleaning device by the transport screw member 3.

As described above, while the adhering matter is scraped off and removed by the cleaning blade 2, the adhering matter remains adhered to the edge portion 2a. May occur. In FIG. 1, reference numeral 5 indicates a cleaning blade cleaning member for scraping off and cleaning the adhered matter adhering to the edge portion.

The cleaning member 5 is constructed as follows, for example. That is, the member 5 is mainly composed of the leaf spring 6, and the rubber portion 7 is covered on the tip thereof. The cleaning member 5 has its base end fixed to the swing rod 10, and the swing rod 10 is displaced and driven by a driving means such as a solenoid (not shown) between a broken line position and a solid line position in FIG. It is like this.

The cleaning member 5 is normally attached to the contact portion 16 (FIG. 2) of the cleaning blade 2 with respect to the photoreceptor 1.
The photosensitive member is placed at a position downstream of the photosensitive member in the rotation direction (normal rotation direction) and apart from the contact portion. Less than,
This position is called the "standby position". In FIG. 1, the position is indicated by a broken line.

The cleaning blade 2 is fixedly attached to a pressure lever 9 pivotally supported by a shaft 8. A tension spring 13 is hung between the pressure lever 9 and the plunger rod 12 of the solenoid 11. FIG. 2 shows a state in which the solenoid 11 is excited, and in this state, the plunger rod 12 attracts the spring 13 and the pressing lever 9 is rotated to the left about the shaft 8 by a slight amount. In such a state, the edge portion 2a of the cleaning blade 2 is in contact with the surface of the photoconductor 1 with a relatively high pressure so that the adhering matter on the photoconductor 1 can be scraped off. In such a contact state, the cleaning blade 2 is bent relatively largely as shown in the figure.

During the copying operation, the solenoid 11 is held in the excited state, and the cleaning member 5 is placed in the standby position shown in FIG. 2 (the position shown by the broken line in FIG. 1). When the copying operation is completed, in FIG. 1, the photoconductor 1 starts reversing in the direction of the broken line arrow, and the swing rod 10 starts turning around the pivot 14 from the broken line position to the solid line position.
At the same time, the excited state of the solenoid 11 shown in FIG. 2 is released.

Then, the pressure lever 9 whose rotation in the clockwise direction is regulated by the spring 13 until now is slightly rotated in the clockwise direction, and accordingly, the edge portion 2a with respect to the photosensitive member 1 is rotated. The contact pressure is reduced. For example, assuming that the contact pressure during cleaning is 100%, 20-30%
It is reduced to a certain degree. In this case, the edge part 2
The contact state of a is maintained without being separated from the photoconductor 1.

When the swing rod 10 turns counterclockwise from the standby position, the rubber portion 7 on the tip side of the cleaning member 5 enters between the edge portion 2a and the photosensitive member 1. In FIG. 1, the cleaning member 5 shown by the solid line is in the state where the entry is completed,
After that, the swing rod 10 is pivotally displaced to the original standby position shown by the broken line, and the rubber portion 7 slips out of the previous contact portion 16 and retreats.

When the rubber portion 7 enters the contact portion,
Or, when leaving, the adhered matter adhered to the edge portion 2a is
It is scraped off by the rubber part 7. Cleaning member 5
Thus, the function of removing and cleaning the deposits attached to the edge portion is performed. Such cleaning is performed every time the copy operation is completed.

Incidentally, as the cleaning member 5 retreats, the solenoid 11 is re-energized, and the contact pressure at the edge is set high again.

FIG. 3 shows a cleaning blade cleaning process step by step. Further, FIG. 4 is a timing diagram of forward and reverse rotations of the photoconductor.

Although the rotation of the photosensitive member 1 is stopped after the copying is completed, in FIG. 3A, the cleaning member 5 tries to start the approach movement after some time has elapsed after the stop. This is a state just before. When the photoconductor 1 starts reverse rotation (rotation in the direction of the dashed arrow) from the state shown in FIG. 3A, at the same time, the downward movement of the cleaning member 5 is started and the blade contact force is weakened. To be

FIG. 3B shows a state before the rubber portion 7 of the cleaning member 5 has entered the contact portion 16, and FIG. 3C shows the state before the rubber member 7 has entered the contact portion. Shows the state. When the cleaning member 5 has finished entering, the reverse rotation of the photoconductor 1 stops (FIG. 4). After that, at the same time when the next copying operation is started, the photoconductor 1 starts to rotate in the normal direction, the cleaning member 5 starts this retreat movement, and the rubber portion 7 comes out of the contact portion 6. At the same time, the blade contact pressure is returned to the previous high pressure.

FIG. 3 (d) shows a state in which the urethane rubber portion 7 is in the middle of withdrawal. At the time of this withdrawal, the rubber portion 7 becomes wrinkled, and the adhering material 18 adhering to the vicinity of the edge portion 2a is removed. Scrape from. In this example, when the cleaning member exits, the adhered matter is removed and cleaned.

The rubber portion 7 of the cleaning member 5 is, for example,
It is made of urethane rubber in which a substance such as fatty acid is dispersed, and due to its elasticity, it moves while being squeezed by the edge portion 2a when the cleaning member exits, so that it is possible to easily scrape off the deposits on the edge portion. . If the urethane rubber portion is further covered with a material having a low friction coefficient, the entry and exit can be made smoother, and the edge portion and the photoconductor can be less likely to deteriorate.

The feature of the present invention lies in the cleaning member 5
Is the point of reversing the photoconductor 1 when entering. That is, as shown in FIG.
When approaching toward, the approach direction and the moving direction of the surface of the photoconductor 1 are made the same.

If the moving direction of the surface of the photosensitive member 1 is opposite to the moving direction of the cleaning member 5, that is, the counter direction, the surface of the photosensitive member is damaged by the cleaning member. It will be easier. In the case of this example, since the photoconductor rotates in reverse in accordance with the approach of the cleaning member, it is possible to prevent the surface of the photoconductor from being scratched easily, and since the approach resistance of the cleaning member also becomes small, the driving force of this is made small. can do.

As the photoconductor driving means for driving the photoconductor 1 in the normal direction and driving the photoconductor in the reverse direction when the cleaning member enters, a main motor (not shown) of the present image forming apparatus or a photoconductor dedicated As an example, a drive motor (not shown) that normally rotates or reversely rotates at the timing shown in FIG. 4 can be adopted.

As described above, in the present embodiment, the contact pressure of the cleaning blade when the cleaning member 5 enters is reduced as compared with that at the time of cleaning. With such a configuration, the cleaning member can smoothly enter the abutting portion, and the effect of cleaning and removing the deposit on the edge portion can be further enhanced. Further, the force for driving the cleaning member can be reduced, and further, the leaf spring 6 may have a weak stiffness.

Here, in FIG. 5, the angle α is the contact angle of the cleaning blade 2 with respect to the photoconductor 1,
Further, the angle β is the approach angle of the cleaning member 5 with respect to the photoconductor. As shown in this figure, the approach angle β is equal to the contact angle α
Is smaller than. With such a configuration, the cleaning member can easily enter the abutting portion, and the rubber portion 7 can surely contact the edge portion 2a, so that the cleaning and removing effect of the adhering substances can be further enhanced. You can

FIG. 6 shows a state in which the cleaning member enters at such an entrance angle and then exits. However, when the angle condition as described above is satisfied, the rubber portion 7 is removed.
Will positively wrap around the lower end portion 2a ₁ of the edge portion 2a, and the effect of removing the deposit 18 can be enhanced.
The rubber part 7 made of urethane rubber is
If the cleaning member is formed of a wedge-shaped member that becomes thinner toward the tip, the cleaning member can be made to more easily enter the contact portion.

In FIG. 7, the cleaning member 5 of FIG.
As seen from the direction, if the tip edge of the rubber portion (substantially cleaner portion) 7 is slanted, it is possible to make the entry into the contact portion easier.

FIG. 8 (a) shows another example of the cleaning blade cleaning unit, which removes adhered substances when the cleaning member enters.

The cleaning member 25 is mainly composed of a leaf spring 26, and a bent portion of the tip end portion of the leaf spring 26, which is abdominal surface facing the photoconductor 1, protrudes outward from the photoconductor 1. A soft elastic body 27 having a low coefficient of friction, which has a portion 27a ((b) in the figure), is attached.

FIG. 8A shows a state in which the soft elastic body 27 of the cleaning member 25 is entering the abutting portion 16, and when the cleaning member 25 further continues to enter from this state, FIG. As shown in FIG. 7, the bent portion 27a bounces in the direction of arrow B due to this self-elasticity, and at this time, the adhered matter 18 attached to the edge portion 2a is scraped off. That is, when the cleaning member 25 enters, the adhered matter is cleaned and removed by utilizing the waist of the bent portion 27a.

FIG. 8 (b) shows a state in which the cleaning member 25 has completed the entering operation, after which the cleaning member 25 moves upward and backward. At this time, the bent portion 27a is the edge portion 2a.
While being spread in a flat shape by the
It passes through between and and after that, it returns to the previous bent state.
(C) of the figure shows the next in-progress state, after which the bent portion 27a becomes the state shown in (a) of the figure.

According to this example, since the bent portion 27a reliably wipes off the adhered matter on the edge portion, the effect of removing the adhered matter can be further enhanced. Then, the elastic body 27 is
Since the material has a low friction coefficient, it is possible to further facilitate the entry of the cleaning member into the contact portion. The soft elastic body may be covered with a low friction coefficient material.

FIG. 9 is a view of the cleaning member 25 of FIG. 8A as seen from the direction of arrow C. When the tip end edge of the soft elastic body 27 is slanted, the soft elastic body 27 is further prevented from entering the contact portion 16. , Can be easy.

FIG. 10 shows an example of a cleaning device which uses a weight to generate a blade contact force.

In this cleaning device section, the fur brush 19 is used in combination with the cleaning blade 2. A weight 20 is attached to the pressure lever 9. On the other hand, the cleaning blade cleaning member 5 is attached to the attachment member 22 pivotally supported by the shaft 21. The mounting member 22 is connected to the plunger rod 12 of the solenoid 11 via a link rod 23.

When the solenoid 11 is excited,
The mounting member 22 is held at the broken line position, and the cleaning member 5 is at the standby position shown by the broken line. On the other hand, when the excitation of the solenoid 11 is released, the mounting member 22 is swung clockwise from the position of the broken line by the force of the spring (not shown), and the cleaning member 5 is released.
The rubber portion 7 enters into the contact portion 16. Then, when the solenoid 11 is excited from the released state, the mounting member 22 pivots from the solid line position to the broken line position, and at this time, the rubber portion 7 retreats from the contact portion 16. At this time, the rubber portion 7 cleans and removes the deposit on the edge portion. When the rubber portion 7 enters, the photoconductor 1 reverses in the direction of the dashed arrow.

A compression spring 24 is interposed between the plunger rod 12 and the weight 20, and when the solenoid 11 is de-excited and the cleaning member 5 enters the abutting portion 16, the spring 24 is pressed by the spring 20. Is lifted to reduce the contact pressure of the cleaning blade 2 against the photoconductor 1. On the other hand, the solenoid 11 is excited, and the cleaning member 5 is contacted by the contact portion 1.
After exiting from 6, the spring 24 moves the plunger rod 1
Go down with 2 and away from the weight 20, this time the weight 20
The contact pressure of the cleaning blade 2 is set only by its own weight. This contact pressure is a high pressure required for cleaning.

[0049]

According to the structure of the first aspect of the present invention, the adhering matter adhered to the edge portion of the cleaning blade abutting in the counter direction does not damage the photoconductor,
It can be easily removed. Further, since the intrusion resistance of the cleaning member is also small, this driving force can be made small, and it is not necessary to select a cleaning member having a strong rigidity.

According to the second aspect of the invention, the cleaning member can easily enter the abutting portion, and the effect of cleaning and removing the adhering substances can be further enhanced. Further, since the ingress resistance of the cleaning member is also small, this driving force can be made small, and it is not necessary to select a cleaning member having a strong rigidity.

According to the third aspect of the invention, the cleaning member can easily enter the abutting portion, and the effect of cleaning and removing the deposit can be further enhanced.

According to the fourth aspect of the invention, the cleaning member can be smoothly moved into and out of the contact portion, and the edge portion and the photoconductor can be prevented from being deteriorated.

According to the fifth aspect of the invention, the effect of removing the adhering substances can be further enhanced, and the edge portion and the photoconductor can be made less likely to deteriorate.

According to the sixth aspect of the invention, the cleaning member can be made to enter the contact portion more smoothly.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a cleaning device unit included in an image forming apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a state in which a cleaning blade is performing a cleaning operation in the same cleaning device section.

FIG. 3 is a diagram for sequentially explaining a step of cleaning a deposit on an edge portion of a cleaning blade.

FIG. 4 is a diagram showing rotation and stop timings of a photoconductor.

FIG. 5 is a diagram for explaining a contact angle of a cleaning blade and an approach angle of a cleaning member.

FIG. 6 is a view showing a pattern in which the attached rubber on the edge portion is cleaned and removed by the rubber tip portion of the cleaning member.

FIG. 7 is a side view of the main parts of the above cleaning member.

FIG. 8 is a diagram showing a step of cleaning and removing adhered matters with a cleaning member of another configuration example.

FIG. 9 is a side view of a main part of a cleaning member of another configuration example.

FIG. 10 is a configuration diagram showing another example of a cleaning device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Cleaning blade 5 Cleaning blade cleaning member 6 Leaf spring 25 Cleaning blade cleaning member 26 Leaf spring 27 Soft elastic body 27a Bent portion

Claims (6)

[Claims] 1. A photosensitive member which is rotationally driven, and when the photosensitive member is rotated in the forward direction to perform an image forming process, the photosensitive member is brought into contact with the surface of the photosensitive member in a counter direction so as to have a surface of the photosensitive member after a transfer step. The cleaning blade that scrapes off and removes the adhered matter on the photoconductor, and in the normal rotation state of the photoconductor, the position of the cleaning blade and the photoconductor from the position on the downstream side of the cleaning blade abutting portion on this rotation direction. The cleaning blade cleaning member that moves in between and retreats to its original position after this entry, and at the time of this entry or exit, removes the scraped deposits from the cleaning blade and cleans it, and drives the photoconductor forward. At the same time, when the cleaning member enters, the photosensitive member drive means for driving the photosensitive member in reverse is provided so that the surface of the photosensitive member moves in the same direction as the cleaning member enters. Image forming apparatus to be used. 2. The cleaning blade has a contact pressure of
The image forming apparatus according to claim 1, wherein the image forming apparatus is reduced when the cleaning member enters. 3. The approach angle of the cleaning member with respect to the photosensitive member,
The image forming apparatus according to claim 1, wherein the cleaning blade has a smaller contact angle with the photoconductor. 4. The image forming apparatus according to claim 1, wherein the cleaning member is mainly composed of a leaf spring, and the leading end portion of the leaf spring on the entry side is made of urethane rubber coated with a low friction coefficient material. . 5. The cleaning member is mainly composed of a leaf spring, and a soft elastic body having a low friction coefficient and having a bent portion protruding toward the outside of the photoconductor is attached to the leading end portion of the leaf spring on the entrance side. The image forming apparatus according to claim 1, which is attached. 6. The image forming apparatus according to claim 4, wherein the urethane rubber has a wedge shape that gradually becomes thinner toward the tip.