JPH09160458A - Cleaning device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the refreshing effect of a rotary brush and to enhance the cleaning performance by constituting the rotary brush so that the brush bristles thereof are made to flick not only in the rotating direction of the brush but also in the various directions. SOLUTION: A mesh plate 11 gets into the flick action because the brush bristles 6 are successively brought into contact with it when a brush body 16 is rotated. The aperture part of the plate 11 is provided with an aperture end surface obliquely arranged in the advancing direction of the bristles 6. Toner T attached to a member to be cleaned 1 is recovered to a brush roller 16 at a nip part formed by a cleaning counter roller 2 and the bristles 6. The toner recovered to the roller 16 is flicked by the plate 11. At this time, since the tip parts of the bristles 6 are moved along a shape formed by the end surface of the aperture part of the plate 11, the bristles 6 are also flicked in the lateral direction with respect to the rotating direction in addition to a conventional flick effect.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning device in an image forming apparatus such as an electrophotographic facsimile, a copying machine, and a printer. More specifically, the present invention relates to a cleaning device that wipes with a fur brush the toner remaining on the surface of a moving body formed in a roller shape, a drum shape, or a belt shape.

[0002]

2. Description of the Related Art Heretofore, there has been known a brush cleaner type cleaning device for cleaning toner remaining on and adhering to the surface of a photoconductor of an electrophotographic apparatus or a moving body such as an intermediate transfer belt by using a rotating brush. In such a brush cleaner type cleaning device, it is necessary to collect the toner wiped with the brush from the brush and refresh the brush.

As a refreshing mechanism of a brush cleaner, a collecting roller system is widely known (for example,
Japanese Patent Publication No. 1-60148). FIG. 8 shows the configuration.

In the figure, reference numeral 50 is a rotary drum having a photosensitive member 50a on its surface, 80 is a charge eliminating electrode, and 90 is a cleaning device. The cleaning device 90 has a brush core 91a.
A conductive brush fiber 91b made of synthetic fibers mixed with carbon is planted around the fur brush 91 which is rotated by the motor M1 and a conductive brush which is applied with a voltage from the power source E and is rotated by the motor M2. And a toner scraping blade 94 provided in contact with the collecting roller 93.

In the apparatus having this structure, the powder developer remaining on the photoconductor 50a is cleaned by using the fur brush 91, and the powder developer attached to the fur brush 91 is electrically biased by the collecting roller 93. Collect by electrostatic force. The toner on the collecting roller 93 is scraped off by the toner scraping blade 94.

However, in this system, the rotating collecting roller must be arranged on the back surface of the fur brush, and the apparatus needs such a power source for applying a voltage to the collecting roller and a rotation driving mechanism. There is a problem that it tends to be large and complicated.

On the other hand, the flicker bar system is widely known as a simplified refresh mechanism. A linear plate or a bar is installed so as to bite into the bristles, and the toner bitten into the bristles is mechanically repelled (flicked) to be refreshed.

As an example, the configuration of this system disclosed in Japanese Patent Laid-Open No. 55-130568 is shown in FIG.

The photosensitive drum P having the residual toner 65 adhered to the surface thereof is rotationally driven in the direction of arrow c, and the residual toner 65 is removed from the surface thereof. The cleaner brush 60 is rotatably driven in the direction of the arrow d in the figure to rub the surface of the drum P, and the residual toner 65 is rubbed from the surface.
Wipe off. The cleaner brush 60 has brush bristles 68 planted on its peripheral surface.

A flicker bar 63 is provided in parallel with the axis of the cleaner brush 60 at a position where it contacts the brush bristles 68 of the cleaner brush 60.

First, the residual toner 65 on the surface of the drum P is
As the cleaner brush 60 is driven to rotate, it is wiped and removed by the brush bristles 68. The toner attached to the brush hair is
It is knocked off from the brush bristles 68 at a position where it abuts against the tapping bar 63. The toner that has been knocked off is indicated by the arrow e.
The toner is conveyed by an airflow flowing in a direction to reach a toner collecting device (not shown).

[0012]

However, in this conventional method, a flick member having a shape extending in a direction perpendicular to the brush rotating direction (axial direction of the brush body) has been used. Therefore, the flick direction of the fur brush is constant along the brush rotation direction. The movement of the brush tip is shown in FIG. The tip of the rotationally driven brush is
The tapping bar 63 provided perpendicularly to the traveling direction is hit and hit, and then repelled. The movement of the tip portion drew a linear trajectory as shown by the arrow in the figure, and the movement of the tip portion of the entire brush was limited to a certain direction. Therefore, the flick performance does not reach a completely refreshed state of the brush bristles, and as a result, cleaning failure may occur on the member to be cleaned 1.

[0013] Therefore, it is an object of the present invention to provide a cleaning device that has a simple structure that does not increase in size and complexity and that has a significantly improved refresh function and further improved cleaning performance.

[0014]

In order to solve the above problems, the present invention provides a fur brush that is rotatable while contacting the surface of a moving body provided in an image forming apparatus, and at least a brush bristle of the fur brush. A flick member installed so as to be able to contact with the tip of the fur brush, and cleaning the toner remaining on the surface of the moving body, the flick member is at least in a region in contact with the fur brush. It is characterized in that it has a guide surface arranged obliquely with respect to the moving direction of the bristles.

[0015]

1 is an explanatory view of a cleaning device 3 of the present invention.

In the figure, reference numeral 1 denotes a movable body such as a photosensitive belt, that is, a member to be cleaned, which is conveyed in the direction of the arrow together with the toner T before cleaning. The member to be cleaned 1 is cleaned by the cleaning device 3 at the winding portion of the cleaning facing roller 2.

The cleaning device 3 mainly comprises the member 1 to be cleaned.
It comprises a frame 7 having an opening facing toward, a brush body 16 rotatably provided in the frame 7, and a mesh member 11 for removing toner from the brush body 16.

The brush body 16 is composed of a metal roller 5 integrally formed with the shaft 4 and brush bristles 6 further planted on the peripheral surface thereof. The brush body 16 is rotationally driven in the clockwise direction in the figure while being in contact with the member to be cleaned 1, and the traveling directions of the two are opposite to each other at the contact portion.

The material of the brush bristles 6 is made semi-conductive by dispersing a conductive material such as carbon black in a synthetic fiber such as rayon, nylon or acrylic polymer, and has a specific resistance of 10 ³ to 10 ¹⁰ Ω.・ It is about cm.

The bristle density of the brush bristles 6 is 30,000 to 10
0000 pieces / square inch, the fiber thickness of the brush bristles 6 is 6 to
10D (D: denier), the length of the brush bristles is 5 mm, and the amount of bite between the brush bristles 6 and the member to be cleaned 1 is 0.
When the distance is set to 5 to 1 mm, the member to be cleaned 1 can be satisfactorily cleaned.

The shaft 4 of the brush body 16 has a power source 1 for attracting the toner adhering to the member to be cleaned.
7, a voltage having a polarity opposite to that of the toner and having a magnitude of 100 to 500 V is applied.

Reference numeral 9 in the drawing denotes a toner carrying coil, which carries the waste toner separated from the brush bristles 6 to a waste toner box (not shown) provided outside the cleaning device 3. A scattering prevention mylar 10 is provided at the opening of the frame 7 in order to prevent the toner from scattering.

Although not shown in the drawing, a charger (charging device) for aligning the charging polarities of the toner T before cleaning may be arranged.

The mesh plate 11 is such that the brush bristles 6 are brought into contact with each other as the brush body 16 rotates to cause a flicking action. The opening of the mesh plate 11 has an opening end face arranged obliquely with respect to the moving direction of the brush bristles 6, and has the function of flicking the brush bristles in an oblique direction different from the moving direction.

The mesh plate 11 is arranged in parallel with the axis 4 of the brush body 16, both sides of which are fixed to the frame 7 by stays 8 and the amount of bite into the brush bristles 6 is kept constant. As a result, a predetermined nip width L is formed between the brush bristles 6 and the mesh plate 11 as shown in FIG.

If the amount of bite is too small, only the tip of the brush enters the mesh plate, and the movement of the brush is small, so the flicking action is small and the toner that has entered deep inside the brush bristles cannot be swept out. . If the bite amount is too large, the torque for rotating the brush becomes excessive and the mechanical load increases. Not only that, but because the brush is strongly pressed against the mesh plate, the brush bristles coming from behind are pushed by the bristles that are already in contact with the flick member before they are almost in contact with the flick member. Cannot be efficiently impacted by. Further, the effect of removing the toner is lost due to the fact that there is no gap for removing the toner between the brush bristles, which in turn impairs the cleaning performance of the cleaning device. From the above circumstances, the amount of bite between the mesh plate 11 and the brush bristles 6 is preferably 1 to 3 mm.

FIG. 2 shows a view of the mesh plate 11 as seen from the direction of arrow q. The holes 18 are fixing holes for fixing the mesh plate 11 to the stay 8 with screws or the like. In order for the brush to be evenly flicked, the mesh width L1 shown by L1 in the figure
Is preferably wider than the brush bristle width L2 indicated by L2 in the figure.
The mesh plate is a thin stainless plate having a thickness of 0.5 to 1 mm, and was manufactured by the photoresisting method.

The mesh shape is a rhombus shape as shown in FIG. 3, and the mesh opening portion in the drawing is the movement direction of the brush bristles indicated by the white arrow in the x direction, the direction orthogonal to the movement direction and the direction parallel to the axis 4 in the y direction. Then, the pitch width in the y direction a = 3 to 8 m
Pitch width in the m and x directions b = 5 to 10 mm, angle α = 15 to 70 ° with respect to the brush advancing direction (more preferably 1
5 to 50 °) and a mesh having a line width d = 0.5 to 1 mm are preferably used.

When the angle α formed by the end face of the mesh opening with respect to the direction of movement of the brush is 15 to 70 °, good refreshing performance can be obtained. In addition, the angle α is further 50 °
In the following, since the movement resistance generated when the brush 6 bites into the mesh 11 and comes into contact with the mesh 11 is reduced, the driving load for driving the device is reduced, and defects such as brush bristles and cutting are eliminated. , And more preferable.

According to the cleaning device configured as described above,
The toner T attached to the member to be cleaned 1 is conveyed in the direction of arrow s in the figure. Then, in the nip portion formed by the cleaning facing roller 2 and the brush bristles 6, the brush roller 16 is electrically and mechanically recovered. The toner collected by the brush roller 16 is flicked by the mesh plate.

At this time, since the tip of the brush bristles 6 moves along the shape of the end face of the opening of the mesh, in addition to the flick effect as shown in the prior art, the flick is performed laterally with respect to the rotational direction. Will be done.

Further, the brush body 16 and the mesh plate 11 are
The tip of the brush bristles 6 can be flicked multiple times because it has a sufficient nip width (L in FIG. 4). For example,
When the brush outer diameter is φ30 mm and the bite depth is 2 mm, the nip width is about 15 mm. At this time, if the mesh pitch y in the y direction is 7 mm or less, the maximum distance in the y direction at the mesh opening is the maximum. However, since it does not exceed the half of the nip width, the brush bristles 6 contact the frame line of the mesh two or more times while passing through the nip portion and are flicked.

The movement of the tip of the brush bristles 6 is conceptually shown in FIG. FIG. 5 is an enlarged view of the mesh plate 11 seen from the axial direction of the brush. The brush bristles 6 of the brush body 16 bite into the mesh plate with a nip width L as shown in FIG.
When the brush is rotationally driven, the tip portion of a certain brush bristle 6 draws a locus as indicated by an arrow Q in the figure when projected onto a plane formed by the mesh plate 11. That is, when approaching the mesh plate 11 from the right-hand direction in the figure and reaching the inside of the nip L, first, the mesh plate 1 is drawn at the point A in the figure of the frame of the mesh 11.
It touches 1 and is beaten. Then, it is guided along the end face of the frame of the mesh 11 and moves to the point B. When the brush body 16 further rotates, it is released from the guide action of the frame at point B, is repelled, is hit again at point C of the frame, and moves to point D by rotation. Thereafter, similarly, the ball is hit diagonally, moves zigzag, and linearly moves outside the range of the nip L.

As described above, since the opening end face of the frame of the mesh which acts as a flicker is arranged obliquely with respect to the traveling direction of the brush, the brush bristles 6 are slanted and moved zigzag. . Further, the brush bristles adjacent to each other in the longitudinal direction of the brush body 16 are compressed or released due to the timings of contact of the brush bristles with the end face of the mesh frame opening being slightly different and the width of the mesh opening being changed. Or

As described above, unlike the conventional technique in which the brush bristles 6 move only in a straight line, the tip portion of the brush bristles 6 makes various movements, so that the detachment of the toner adhering to the brush is significantly promoted. Therefore, the refreshing performance of the tip portion of the brush bristles 6 is significantly improved, and as a result, the cleaning performance of the cleaning device for cleaning the member to be cleaned is also significantly improved.

When the above cleaning device is applied to an image forming apparatus having a system speed (moving speed of a member to be cleaned) of 100 to 1000 mm / sec, the rotation speed of the brush is 1
Good cleaning performance was obtained in the range of 00 to 500 rpm, and no unwiped image was observed.

Further, while the image forming apparatus is stopped, the brush bristles 6 of the rotary brush are not cleaned,
Since it is in contact with the flick member and is still pressed and bent, when it is left for a long period of time, creep occurs, which causes a creep phenomenon in which the bristle has a curl. At the portion where the bristles of the brush are creeped, the force with which the brush comes into contact with the member to be cleaned becomes weak, which causes defective cleaning. When the flick member of the present invention is applied, the bristles of the brush are repelled in various directions as described above, so that the recovery of creep is performed quickly, and therefore, cleaning failure does not occur even after being left for a long period of time.

The member to be cleaned by the cleaning device of the present invention is, for example, a photosensitive drum or photosensitive belt of an image forming apparatus, a drum-shaped or belt-shaped intermediate transfer member, or a roller member. The cleaning device of the invention is applicable to various things.

[Other Embodiments] The embodiments of the present invention have been described above, but the present invention can be implemented in various forms. For example, although the mesh shape is a rhombic mesh in the above description, various shapes can be used as shown in FIGS. 6 (1) to 6 (4). 6 (1) to (4), the moving direction of the brush bristles indicated by the white arrow in the drawing is the x direction, and the direction orthogonal to the moving direction and parallel to the axis 4 of the brush body 16 is the y direction.

FIG. 6A shows a parallel diagonal linear mesh as an example of the mesh shape. The pitch width c in the y direction in the figure is preferably c = 1.5 to 4.0 mm. Such a mesh may be formed by meshing a thin metal plate by a photoresist method similarly to the above-mentioned rhombic mesh, or may be a flicker member by stretching a wire having a circular cross section.

FIG. 6B is an example of a triangular mesh. With this shape, the number of flicks of the brush 6 in the nip increases as much as the number of mesh frames parallel to the brush rotation axis increases as compared with the above-mentioned diamond mesh. Further, since the beam portion of the mesh is increased, it is possible to obtain a component having excellent strength.

FIG. 6C is an example of a hexagonal mesh. In FIGS. 6 (1) to 6 (3), the angle α is preferably 15 to 70 °, more preferably 15 to 50 °, as in the case of the rhombic mesh described above. a, b, d
The same applies to dimensional values such as.

FIG. 6 (4) is an example of a round hole mesh. The opening hole diameter f is 4 to 10 mm, and the distance w between the adjacent openings is 0.5 to 1 mm. Even in such a shape, since the end faces of the mesh openings contact the brush bristles at various angles, the same effect as that of the above-described mesh shape is achieved.

The mesh member as the flick member is not limited to the above metal material, and various other materials such as a resin material or a rubber-like elastic material can be used. As the resin material, crystalline nylon, polyacetal, polypropylene or the like having excellent slipperiness and abrasion resistance are suitable. Further, as the rubber-like elastic body, silicone rubber or fluororubber, which is excellent in slipperiness, abrasion resistance and toner releasability, is preferable.

These are formed on the mesh member by, for example, injection molding or extrusion molding. The mesh holes may be formed by punching a sheet-shaped material.

Furthermore, a mesh may be formed by braiding a PET, nylon, rayon resin fiber thread or the like having excellent abrasion resistance into a net shape.

Although various mesh forms have been exemplified above,
The present invention can be modified in various ways.

The mesh plate is not limited to a flat plate. For example, as shown in FIG. 7, the brush may be curved along the peripheral surface of a virtual cylinder centered on the brush rotation axis so as to contact the bristles at a predetermined distance from the rotation axis. With this configuration, it is easier to make the nip width in contact with the brush larger than that of the flat plate mesh. Increasing the nip width increases the number of times the brush bristles 6 are flicked by the frame line of the mesh,
It is possible to further enhance the refreshing effect of the brush.

A voltage may be applied to the mesh in order to prevent the toner from adhering to and depositing on the mesh plate 11. The characteristics of the applied voltage have a polarity opposite to the charging polarity of the toner, and its absolute value is preferably 50 to 100V.

[0050]

According to the present invention, the brush bristles of the rotating brush of the cleaning device are not only flicked in the rotating direction of the brush but are flicked in various directions. Therefore, the effect of refreshing the brush by the flick member is obtained. Is significantly improved. Further, the number of flicks per one rotation is not limited to one but a plurality of times. This also improves the refresh effect. These effects significantly improve the cleaning performance of the cleaning device.

Further, since the bristle is flicked in various directions, the bristle creep does not easily occur, and the creep of the bristle that has creeped is recovered quickly after being left for a long time, and as a result, the durability of the cleaning device is improved. To do.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a cleaning device according to the present invention.

FIG. 2 is an explanatory diagram of a brush roller and a mesh member of the cleaning device according to the present invention.

FIG. 3 is an enlarged explanatory view of a mesh member according to the present invention.

FIG. 4 is a sectional view of a main part of a cleaning device according to the present invention.

FIG. 5 is an explanatory diagram of movement of brush bristles.

6 (1) to (4) are other examples of the mesh member of the present invention.

FIG. 7 is an explanatory view of another embodiment of the present invention (curved plate mesh).

FIG. 8 Example of prior art (collection roller system)

FIG. 9: Example of conventional technology (flicker bar system)

FIG. 10 is an explanatory diagram of movement of brush bristles in the conventional technique of FIG.

[Explanation of symbols]

 1 member to be cleaned of image forming apparatus 3 cleaning device 6 brush bristles 11 mesh member 16 brush body (brush roller)

Claims (5)

[Claims] 1. A fur brush capable of rotating while contacting a surface of a moving body provided in an image forming apparatus, and a flick member installed so as to be capable of contacting at least tips of brush bristles of the fur brush. In the cleaning device for cleaning the toner remaining on the surface of the moving body, the flick member has at least a surface arranged obliquely to a moving direction of the brush bristles of the fur brush in a region in contact with the fur brush. Characteristic cleaning device. 2. A cleaning device for cleaning toner remaining on the surface of a moving body, which is provided in an image forming apparatus, comprising: a fur brush rotatable while contacting the surface of the moving body; A cleaning member, which is provided so as to be capable of contacting the tip and has a surface having a surface forming a predetermined angle α with respect to the moving direction of the brush bristles of the fur brush in a region in contact with the fur brush. apparatus. 3. The cleaning device according to claim 2, wherein the predetermined angle α is 15 ° to 70 °. 4. The cleaning device according to claim 2, wherein the predetermined angle α is 15 ° to 50 °. 5. The closest distance N between the mesh member and the center of the rotation axis of the fur brush is R-3 ≦ N ≦ R-1 [unit: mm] with respect to the brush outer radius R. The cleaning device according to claim 2 or 4.