JPH113016A - Cleaning device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve nonconformity such as the resticking of toner to a fur brush, the deterioration of blade cleaning capacity caused by the resticking and the infeasibility of removing an electric charge on a photoreceptor or the like by removing the toner stuck and accumulated on a member arranged in the vicinity of the fur brush. SOLUTION: This device is a cleaning device cleaning residual toner after transfer arranged opposed to the surface of the photoreceptor 10 constituting an electrophotographic image forming part, and is provided with the cur brush 21 rotating in contact with the surface of the photoreceptor, a cleaning blade 26 removing the residual toner after transfer in contact with the photoreceptor 10 on the downstream side of the fur brush 21, a blade bracket 24 supporting the cleaning blade 26 and a cleaning case 27 surrounding a part of the fur brush 21. In this case, the cleaning device 16 is provided with at least one or more toner scraping members 29 so as to be brought into contact with a member other than the photoreceptor arranged in the vicinity of the fur brush 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a cleaning device in an electrophotographic image forming apparatus, and more particularly, to a cleaning device having a configuration capable of effectively preventing toner from adhering and accumulating inside the cleaning device.

[0002]

2. Description of the Related Art In an electrophotographic image forming apparatus such as a copying machine, a printer, and a facsimile apparatus, an electrostatic latent image formed on a photoreceptor is developed with toner supplied from a developing device. An image is formed by transferring and fixing the developed image on a transfer sheet. After the transfer is completed, the toner remaining on the photoconductor is removed by a cleaning device to prepare for the next image forming step. I have. As a conventional cleaning device, a blade cleaning system for removing residual toner by bringing a blade into contact with the surface of a photoreceptor (Japanese Patent Laid-Open No. 55-4145)
Japanese Patent Application Laid-Open No. 58-144875, and a technique in which a fur brush is disposed in front of the blade in the photoconductor rotation direction for blade cleaning and used as an auxiliary means.

[0003]

FIG. 4 is a cross-sectional view of a conventional cleaning device.
Via a casing 2, a fur brush 3 disposed in the casing 2, a collecting coil 4, a blade bracket 6 rotatable about a bracket rotation support shaft 5, and a blade holder 7 fixed to the blade bracket 6. It has a cleaning blade 8 attached, a seal member 9 for sealing a gap between the bracket 6 and the casing 2, and the like. As described above, a cleaning method for cleaning transfer residual toner on a photoreceptor using a fur brush and a blade has been widely and generally used. Although this cleaning type cleaning device can reliably clean the transfer residual toner on the photoconductor at the initial stage, it has the following technical problems. First, the fur brush 3 is used as an auxiliary means for cleaning the blade, and it is necessary to remove toner on the photoconductor in advance upstream of a contact portion between the tip of the blade 8 and the photoconductor 10. Accordingly, a function of limiting the amount of toner reaching the tip of the blade is exhibited.
After cleaning the toner on the photoreceptor, the fur brush 3 contacts the brush portion with the flicking member 2.
The configuration is such that toner attached to the inside and outside of the fur brush is swept out of the brush by a. The swept-out toner is collected by the collection coil 4 into a collection bag. However, since a part of the flickered toner moves in the cleaning case, it is transferred to various parts (for example, T1 and T2) in the cleaning case. They adhere and accumulate over time.
In particular, when the fluidity of the toner is reduced in a high-temperature and high-humidity environment, or when the flickering speed of the fur brush is high in a high-speed machine, the speed at which the toner moves is increased. The amount of toner (toner blocking amount) attached to the toner increases.

As described above, when the amount of toner adhering and accumulating (soft blocking) in the cleaning case due to the flicking increases, the toner at a position (for example, T2) close to the fur brush among the accumulated toner over time is removed. , Reattach to the fur brush after flicking,
When the toner on the contaminated fur brush adheres to the photoreceptor again, it is not possible to limit the amount of toner entering the blade tip. For this reason, the amount of toner that cannot be completely removed by the blade increases, which adversely affects the next image forming process. Further, by forming the fur brush as a blade cleaning assisting means with a medium conductor and electrically conducting (grounding) the fur brush to the outside, the photosensitive member in an excessively charged state due to the charge generated during transfer. Some have the effect of dropping charge from the body. However, in such a fur brush, a problem due to toner blocking is more severe than in the case of a fur brush made of an insulator. In other words, when the amount of toner attached during fur implantation of the fur brush increases, the outer peripheral surface of the brush is completely covered with the toner. Generally, the toner is often made of an electrically high-resistance substance. Therefore, when the outer peripheral surface of the brush is covered with the toner, the apparent resistance value of the brush increases. Then, even if a fur brush that is grounded is used, it is difficult to remove the charge on the photoconductor that is excessively charged by the transfer. As described above, if the flickering effect of the brush is reduced and the amount of toner adhering to the brush is increased due to the toner accumulated or floating in the casing of the cleaning device, the cleaning assist function of the brush is reduced. The burden on the cleaning operation by the blade increases, and the toner cannot be completely cleaned by the cleaning operation by the blade, resulting in a cleaning failure over time, which causes image disturbance.

[0005] The first aspect of the present invention is to remove toner adhering and accumulating on members arranged near the fur brush, so that toner re-adheres to the fur brush, and the blade cleaning ability decreases due to the re-adhesion. An object of the present invention is to eliminate problems such as inability to remove charges on a photoconductor. In order to solve the above problem, it is possible to provide a vibrating member for vibrating the constituent elements of the cleaning device to drop and collect the toner to be attached. The vibrating member has disadvantages that it causes an increase in size and cost of the device and lower reliability of components. Generally, a support is provided on the back side of the blade to hold the blade in pressure contact with the photoconductor. However, when the cleaning unit is reduced in size by reducing the size of the apparatus, the blade is heated. Close to the brush, so that the support is close to the fur brush. For this reason, there is a problem that the toner scattered from the fur brush is more likely to adhere to the support than in the normal case, and the toner is more likely to be fixed. A second aspect of the present invention is to provide a toner cleaning device capable of preventing toner sticking by vibrating a member in which toner sticking is particularly likely to occur without increasing the size of the vibration member. The purpose is.

[0006]

In order to achieve the above object, a first aspect of the present invention is a cleaning apparatus which is disposed opposite to a surface of a photoreceptor constituting an electrophotographic image forming section and cleans transfer residual toner. A fur brush rotating in contact with the surface of the photoreceptor, a cleaning blade in contact with the photoreceptor downstream of the fur brush to remove transfer residual toner, a blade bracket for supporting the cleaning blade, A cleaning case surrounding a part of the brush, wherein the cleaning device includes at least one or more toner scrapers so as to contact a member other than the photoreceptor arranged near the fur brush. A member is provided. The cleaning device according to claim 2, wherein the cleaning device includes a blade excitation mechanism that vibrates the blade bracket and the cleaning blade, and the toner that contacts a member other than the photoconductor when the blade bracket is vibrated by the blade excitation mechanism. It is characterized in that the scraping member removes toner which is to be accumulated on the member.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to embodiments shown in the drawings. FIG. 1 is a schematic configuration diagram of an image forming unit of an image forming apparatus to which the present invention is applied.
FIG. 3 is a sectional view of an example of a cleaning device. Since the electrophotographic image forming process is well known, its description is omitted. In FIG. 1, a charging device 12, an exposure unit 13, a developing device 14, a transfer device 15, and a cleaning device 16 are sequentially arranged on the outer peripheral surface of a photosensitive drum 10 that rotates at a constant speed in the direction of the arrow. Charge, exposure, development,
Transfer and cleaning steps are performed. FIG. 2 is a cross-sectional view of the cleaning device 16 according to the present invention during operation. The cleaning device 16 includes a cleaning case 20, a fur brush 21 and a collection coil 22 disposed in the cleaning case 20, a bracket rotating support, and the like. Blade bracket 24 rotatable about shaft 23
And a cleaning blade 26 attached via a blade holder 25 fixed to the blade bracket 24.
And a seal member 2 that is inserted between the upper portion of the cleaning case 20 and the bracket 24 to close the gap therebetween.
7, a flicking member 28 for removing toner attached to the fur brush, a toner scraping member 29,
An excitation mechanism 40 described later is provided. Toner scraping member 2
Reference numeral 9 denotes a mylar-shaped member having elasticity in which a distal end is cut into a plurality of irregularities, and a base end of which is formed by a case 20.
Is adhered and fixed to the portion 20a facing the photoconductor. The toner scraping member 29 is a means for sliding the bracket 24 at a tip end thereof when the excitation mechanism 40 described later oscillates the bracket 24 to scrape the toner accumulated on the lower bent piece 24c described later. It is.

[0008] The blade excitation mechanism 40 is used to prevent the toner from accumulating on the blade edge.
6 is a means for applying vibration and impact to 6, but in this embodiment, a part of the blade bracket 24, which is close to the fur brush, is also excited at the same time.
The toner scraping member disposed in contact with this portion removes toner that is to adhere to this portion. The excitation mechanism 40 is not provided, and the toner scraping member 2
It is sufficiently possible to remove the toner that is going to adhere to the lower bent piece or the like only by providing 9. That is, by making the material, configuration, shape, and arrangement of the toner scraping member 29 easy to vibrate by the vibration generated by the operation of the image forming apparatus, the scraping operation can be performed during the copying operation which is performed daily. Can be enforced.

FIGS. 3 (a) and 3 (b) are perspective views showing a blade supporting structure including a blade excitation mechanism 40. A blade bracket 24 fixes an upper part of a blade holder 25 holding a blade 26 with a screw 30. A base 24a;
It has two bent pieces 24b with both side edges of the base 24a bent upward and a lower bent piece 24c with the front end edge of the base 24a bent downward. Since the blade 26 is hot-melt bonded to the blade holder 25 and the blade holder 25 is fixed to the blade bracket 24 with screws or the like, the blade 26, the blade holder 25, and the blade bracket 24 are integrated into a blade bracket. It rotates in the vertical direction about the rotation support shaft 23. Further, this integrated product is supported so as to be able to advance and retreat in the longitudinal direction of the blade 26. By applying an appropriate pressing force to this integrated product, the blade 2
6 is pressed against the surface of the photoreceptor 10 so that the photoreceptor 10
The transfer device 15 arranged along the outer periphery of the printer 1 cleans and removes the untransferred toner that cannot be completely transferred. The rotation support shaft 23 is fixed to a fixing portion of the apparatus main body (not shown), and the rotation support shaft 23 is rotatably supported by a hole 24b 'formed in the bent piece 24b of the bracket. Lower bending piece 2
The tip of 4c protrudes to a position near the fur brush 21 because of the necessity of disposing the seal member 27. As a result, the toner most easily accumulates on this tip, and the fur brush comes into contact with the accumulated toner, so Adhesion is likely to occur.

In the present invention, as described above, the lower bent piece 24
c, the tip of the toner scraping member 29 fixed to the case portion 20a opposed to the tip of the lower bent piece 24c is arranged close to the tip of the lower bent piece 24c, and the tip is scraped by vibration (shock) from an excitation mechanism 40 described later. The taking member 29 is attached to the lower bent piece 24c.
To scrape off the toner by sliding
In order to effectively perform this scraping, as shown in FIG. 3 (b), while the tip edge of the scraping member 29 is made uneven, the corresponding tip edge of the lower bent piece 24c is also substantially the same. The projections and depressions are arranged so that one projection fits into the other depression. In this example, the uneven portion on the side of the scraping member 29 slightly floats only the protrusion to make it easy to enter the concave portion on the other side. In FIG. 3B, the scraping member 29 is used.
Although the irregularities at the tip of are not shown in the irregularities of the lower bent side 24c, they are actually entered. In addition, what was shown as the shape of each uneven | corrugated | grooved part is only an example, and may be zigzag shape, a waveform, and other shapes.

Further, it is needless to say that the toner adhering to the tip of the scraping member 29 is also removed by sliding contact with the lower bent piece 24c when vibration or impact is applied from the excitation mechanism. Absent. Further, a scraping member 29,
Each lower end of the lower bent piece 24c may have a linear edge, or only one may have an uneven shape, a zigzag shape, or the like. Further, at least the lower edge of the scraping member 29 may be formed in a brush shape. Although the fur brush 21 is illustrated to rotate in the counter direction with respect to the photoconductor 10,
It may be rotated in the trading direction. The fur brush 21 is in contact with the photoreceptor 10 in a state in which the tip of the brush portion is bitten. Then, a certain amount of untransferred toner on the photoreceptor 10 and toner clogged by the blade 26 are adhered to the brush and rotated. Thereafter, the toner in the fur brush 21 is swept out of the brush by a fur brush flicker 28 integrally formed with the cleaning case 20. The swept toner is conveyed to the collection coil 22 along the inner surface of the cleaning case 20. Thereafter, it is collected into a collection bottle (not shown) by the rotation of the collection coil 22 along the spiral shape of the collection coil 22.

The blade excitation mechanism 40 is rotatably supported by the shaft member 41 protruding from the outer surface of the opposite bending piece 24b and the tip of the shaft member 41 in a coaxial positional relationship with the support shaft 23. Roller 42, an elastic member (coil spring) 43 wound around the outer periphery of the support shaft 23 to urge the bracket 24 in a pressing direction indicated by an arrow, and is disposed to face the roller 42 and rotated by a driving unit (not shown). And a cam 44. The shaft member 41 may be configured to be rotatably supported on the bent piece 24b, or may be non-rotatable, but the roller 42 has a cam follower surface 45 described later.
In order to facilitate rolling over the entire circumference, it is preferable that the direction of the roller 42 can be changed by 360 degrees.
Alternatively, instead of the roller 42, it is preferable that the tip of the shaft member 41 is made of a material having a small frictional resistance and is formed in a curved shape so as to be movable along the cam follower surface 45.

The cam 44 is made of, for example, a circular ring-shaped member. The cam 44 rotates in one direction indicated by an arrow with the center thereof as a rotation axis, and the cam follower surface 45 on the front side with which the roller 42 contacts is not a flat surface, (Height in the axial direction of the cam) gradually increases along the rotation direction,
A step 45a is formed at the end of the surface. Therefore, when the cam 44 rotates in the direction of the arrow while the roller 42 is in contact with the lower portion 45a 'of the step 45a, the roller 42 moves while being relatively separated from the step 45a, and gradually moves during the movement. Bracket 24 while resisting elastic member 23
Moves leftward in FIG. 3 (a). And roller 42
Reaches the high place 45a "of the step 45a,
When the bracket 24 returns rightward due to the force of the elastic member 23 when it falls over the bottom portion 45a 'after riding over a ". The impact at this time causes the bracket 24 including the blade 26 to vibrate (swing left and right). Since the lower bent piece 24c of the bracket swings due to this vibration, the tip of the scraping member 29 made of an elastic material can scrape off the toner attached to the lower bent piece 24c.

This excitation mechanism has a small number of parts and can be installed in a small space, so that it is possible to avoid an increase in the size of the apparatus. In the above description, the cam follower surface 45 is a surface whose height gradually increases.
Prior to 5a, the surface may be flat (no difference in height) and may be inclined from the front of the step 45a.

Further, even if no special excitation mechanism is provided, the distal end of the toner scraping member 29 is kept in contact with the distal end of the lower bent piece 24c, and the vibrations caused by the operation of the machine are used for both. It is possible to effectively prevent accumulation of toner by scraping off the toner to be attached to each other, but it is clear that the provision of the excitation mechanism further improves the toner scraping effect. In the above embodiment, only the case where the toner adhering to the lower bent piece 24c of the bracket is scraped has been described. However, this is only an example, and therefore, it is a component of the cleaning device arranged near the fur brush. A configuration in which a scraping member is disposed in proximity to a portion where toner easily accumulates, and the attached toner is removed by relatively operating the scraping member by vibration or impact from the bracket side. Are all included in the scope of the present invention. Therefore, the toner scraping member may be provided at a plurality of locations.

[0016]

As described above, in the cleaning device according to the first aspect, a member other than the photosensitive member disposed near the fur brush, for example, a portion extending from the blade bracket,
One end of the toner scraping member is disposed close to a part of the cleaning case (including the case where the concave and convex portions are alternately engaged with each other) so that the toner attached to both of them is removed from each other. Since the toner accumulated on the member near the brush does not adhere to and contaminate the fur brush, an excessive load is not applied to the blade, and cleaning failure can be prevented over time. In this embodiment, the attached toner can be effectively dropped by the vibration of the machine itself and the like, and the accumulation can be prevented without providing any special excitation means. Also, by removing the toner that adheres and accumulates on the member arranged near the fur brush, the toner re-adheres to the fur brush, the blade cleaning ability decreases due to the re-adhesion, and the charge on the photoconductor is removed. Inconveniences such as inability can be resolved. In the cleaning device according to the second aspect, by swinging the bracket side in conjunction with the blade excitation mechanism, the scraping effect of the toner scraping member is increased, and the size and cost of the device are maintained. 1 can be achieved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an image forming unit of an image forming apparatus to which the present invention is applied.

FIG. 2 is a cross-sectional view of an example of the cleaning device of the present invention.

FIGS. 3A and 3B are perspective views showing a blade support structure including a blade excitation mechanism of the present invention.

FIG. 4 is a sectional view of a conventional cleaning device.

[Explanation of symbols]

Reference Signs List 10 photoreceptor drum, 12 charger, 13 exposure unit, 1
4 developing device, 15 transfer device, 16 cleaning device,
Reference Signs List 20 cleaning case, 21 fur brush, 22
Collection coil, 23 Bracket rotation support shaft, 24 Blade bracket, 24a Base, 24b Bending piece, 24
b 'hole, 24c lower bent piece, 25 blade holder, 26 cleaning blade, 27 cleaning case, 28 flicking member, 29 toner scraping member, 40 excitation mechanism.

Claims (2)

[Claims] 1. A cleaning device which is disposed opposite to a surface of a photoreceptor constituting an electrophotographic image forming unit and cleans transfer residual toner, comprising: a fur brush which rotates in contact with the surface of the photoreceptor; A cleaning blade that contacts a photosensitive member on a downstream side of the brush to remove transfer residual toner, a blade bracket that supports the cleaning blade, and a cleaning case that surrounds a part of the fur brush. A cleaning device provided with at least one or more toner scraping members so as to be in contact with members other than the photoconductor disposed near the fur brush; 2. The cleaning device according to claim 1, further comprising a blade excitation mechanism for vibrating the blade bracket and the cleaning blade, wherein when the blade excitation mechanism vibrates the blade bracket, the toner scraping unit comes into contact with a member other than the photoconductor. A cleaning device, wherein toner which is to be accumulated on the member is removed by a member.