JPH1026914A - Rotary type brush for electrophotographic device and production of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformly apply the action of the brush bristles of a rotary type brush to a noncontact surface by specifying an angle at which pile fabric is wrapped around a rotary shaft in the direction of its diameter, thereby restricting the action of the brush bristles on the noncontact surface in the direction of the long shaft of the brush. SOLUTION: An angle θ at which the pile-fabric strip 4 is wrapped around the rotary shaft 2 in the direction of its diameter is set to 5-30 deg.. Thus, the direction of the spiral of the strip 4 is approached the direction of the diameter of the rotary shaft 2, that is, the direction of the rotation of the rotary shaft 2, and the action of the rotating brush-bristles on the noncontact surface is made uniform. Therefore, in the case it is used as a cleaner for removing toner from a transfer drum, the toner is uniformly removed from the surface of the drum. With the angle θ at which it is wrapped being 5 deg. or less, it takes long time to wrap the bandlike body 4, decreasing production efficiency. With the angle exceeding 30 deg., the torsion of the pile fabric 4 increases and an irregularity in wraparound makes electrification, toner supply, toner removal, discharge, and so on ununiform.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary brush for an electrophotographic apparatus used in an image forming apparatus such as a copying machine, a facsimile, a printer, etc., which uses an electrophotographic method.

[0002]

2. Description of the Related Art In an electrophotographic image forming apparatus, an electrostatic latent image carrier such as a photosensitive drum is charged by a charging device, and a charged image is exposed to a document image to form an electrostatic latent image. Then, the latent image is developed into a visible toner image by a developing device, and the toner image is transferred to a transfer material by a transfer device and fixed. The developer remaining on the electrostatic latent image carrier after the transfer device is cleaned by a cleaner, and the residual charge is erased by an eraser.

In such an image forming apparatus, as a charging device, a developing device, a transfer device, a cleaner, and an eraser,
In recent years, brush-type brushes have been widely used. There are two types of brush type: a stationary type that is fixed to a brush on a flat plate and a rotary type that rotates while rotating a brush roller.
A rotary type is more desired.

[0004] Such a rotary brush 40 is shown in FIG.
As shown in (1), a belt is used in which a conductive pile fabric is spirally wound around a rotating shaft, and the pile fibers are used as brush bristles.

However, the spirally wound brush bristles are not parallel to the diametrical direction of the rotating shaft but are obliquely implanted. Accordingly, the rotation of the rotary brush 40 produces an effect of transporting the particles on the contact surface of the brush bristles to one side of the long axis of the brush 40. That is, originally, it is necessary to uniformly generate various actions over the entire longitudinal direction of the rotary brush 40 by the brush bristles. However, since the pile of the pile fabric is spirally wound and formed, In the long axis direction of the mold brush 40, that is, in the rotation axis direction,
The effect will be uneven. Therefore, the rotary brush 40 as a toner supply device
When the toner is used, the toner particles are supplied to one side of the long axis of the brush bristles, that is, one side on the photosensitive drum. Alternatively, if the rotary brush 40 is used as a cleaner, the toner may not be sufficiently removed from the photosensitive drum.

Therefore, in the present invention, in a rotary brush for an electrophotographic apparatus, the generation of the action of the brush bristle on the surface to be contacted along the long axis direction of the brush is suppressed, so that the brush bristle of the rotary brush is reduced. It is an object of the present invention to make it possible to uniformly impart an effect to a surface to be contacted.

[0007]

Means for Solving the Problems Accordingly, the present inventors have:
In order to solve the above problems, the following inventions have been created. That is, according to the present invention, in a rotary brush for an electrophotographic apparatus in which a band of a pile fabric is spirally wound around a rotation axis, the winding angle of the pile fabric with respect to the diameter direction of the rotation shaft is 5 to 30. °, a rotary brush for an electrophotographic apparatus was created. When the winding angle is 5 to 30 °, the ability of the rotary brush to convey the rotary shaft in the axial direction decreases.

Further, according to the present invention, in a method for manufacturing a rotary brush for an electrophotographic apparatus in which a band of pile fabric is spirally wound around a rotary shaft, the outer diameter of the rotary shaft is R, The width of the band is W, the winding angle θ of the band with respect to the diameter direction of the rotating shaft is θ = 90 ° −COS ⁻¹ (W / πR), and the winding angle is 5 to 30 °. Thus, a method of manufacturing a rotary brush for an electrophotographic apparatus characterized by setting the outer diameter R of the rotating shaft and / or the width R of the belt-shaped body was created.

When the winding angle θ of the band is 90 ° -CO
When defined as S ^-1 (W / πR), the strip can cover the entire outer peripheral surface of the rotating shaft without any gap. If the winding angle θ at this time is in the range of 5 to 30 °, the outer diameter R of the rotating shaft and / or the width R of the belt-like body are set by the above equation, and the axial direction of the rotating shaft by the rotating brush is set. The transfer ability to the container becomes small.

[0010]

Next, an embodiment of the present invention will be described in detail. The rotary brush for an electrophotographic apparatus of the present invention can be used without particular limitation as long as it is a rotary brush used for an electrophotographic apparatus. Specifically, the present invention can be applied to various brushes such as a charging brush, a developing brush, a transfer brush, a cleaning brush, a paper peeling brush, and a discharging brush. In particular, since the transfer ability in the long axis direction of the brush is reduced, the brush involved in adding particles to the contact surface of the brush bristles or removing particles from the contact surface of the brush bristles. It is preferably applied. Examples of such a rotary brush include a transfer brush and a cleaning brush. However, even when used for brushes other than these brushes, according to the rotary brush of the present invention, since the winding angle is small, the twist of the band of the pile fabric is reduced, and the unevenness of the winding is reduced. The action of the hair on the contact surface is made uniform,
Good charging action, developing action, peeling action and static elimination action can be obtained.

The pile fabric used in the present invention is composed of a base fabric and pile fibers. The pile fibers, which are brush bristles, are woven in a W-shaped or V-shaped shape with respect to the base cloth and are pile-woven, so that the pile fibers are in an upright state with respect to the base cloth, and further, the pile fibers are prevented from falling out of the base cloth. Is formed by applying an adhesive or the like to the back side of the base cloth. If this pile fabric is a predetermined band, it is used as it is, otherwise, it is cut and used.

The pile fabric is provided with necessary characteristics according to the purpose of use as a rotary brush in an electrophotographic apparatus. When used as a charging brush, a transfer brush, a static elimination brush or the like, a conductive pile fabric is used. When a conductive pile fabric is formed, conductive fibers are used as at least pile fibers, and a conductive adhesive is used for fixing the pile fibers to the base fabric. Preferably, the base fabric is also a conductive fiber. Examples of such conductive fibers include metal wires such as tungsten, stainless steel, gold, platinum, iron, copper, and aluminum. In addition, conductive resin fibers such as rayon, nylon, acetate, cuprammonium, vinylidene, vinylon, ethylene fluoride, polyurethane, polyester, polyethylene, polyvinyl chloride, polyclar, polynosic, polypropylene, etc. In addition, a material in which a resistance adjuster such as metal powder, metal whisker, metal oxide, and semiconductor material is dispersed can be used. In this case, a desired resistance value can be appropriately obtained depending on the amount of dispersion. Instead of dispersion, the fiber surface may be coated with a resistance adjusting material. When a conductive pile fabric is used, it is preferable to perform a flame-retardant treatment or a non-flammable treatment in order to prevent ignition and fire spread when a high voltage is applied.

[0013] In order to spirally wind the band of the pile fabric around the rotating shaft, the band is arranged at a predetermined winding angle on the rotating shaft having a conductive adhesive applied to the surface thereof.
While rotating the rotating shaft, the belt is applied to the surface of the rotating shaft and adhered. At this time, for one rotation axis, only one band-shaped body, it is possible to cover the entire peripheral surface of the rotation shaft with one spiral winding and wind it without gaps, or using a plurality of band-shaped bodies, A plurality of spiral windings may be formed for one rotation shaft to cover the peripheral surface of the rotation shaft. In addition,
In this case, the band used may have the same width,
Different widths may be used.

At this time, assuming that the winding angle of the band of the pile fabric is 5 to 30 ° with respect to the diameter direction of the rotating shaft, the spiral direction of the band is close to the diameter direction of the rotating shaft, that is, the rotating direction of the rotating shaft. Therefore, the action of the rotating brush bristles on the contacted surface is made uniform. Therefore, for example, when the rotary brush of the present invention is used as a supply device for supplying the toner particles to the photosensitive drum surface, the toner is uniformly supplied to the drum surface, and the toner is removed from the transfer drum. When used as a cleaner, toner is uniformly removed from the drum surface.

If the winding angle is smaller than 5 °, it takes a long process time to wind the belt around the rotating shaft, and the production efficiency is reduced. If it exceeds 30 °, the pile fabric is twisted. Due to the winding unevenness caused by the increase, charging, toner supply, toner removal, charge elimination, and the like become non-uniform.

When a band having a width W is used with respect to a rotation axis having an outer diameter R, and a winding angle θ is given by θ = 90 ° −COS ⁻¹ (W / πR), a band having a width W is obtained. The body is wound so as to completely cover the outer peripheral surface of the rotating shaft. That is, as shown in FIG. 1, when the belt having a width W is wound so as to cover the entire outer peripheral surface of the rotation shaft having the outer diameter R, the point A of the belt and B ′ of the belt are obtained.
The points will be coincident. In this case, AB ′
The distance should be equal to the circumference (πR) of the axis of rotation. From this, the relationship shown in the above equation holds between the winding angle θ, the width W of the belt-shaped body, and the outer diameter R. By selecting the outer diameter R of the rotating shaft and the width W of the belt-like body so that the winding angle θ is 5 to 30 °, the brush bristles easily and uniformly act on the contact surface. Rolled brushes can be manufactured.

[0017]

According to the present invention, the pile of the pile fabric is wound around the rotating shaft at a winding angle of 5 to 30 °. When the winding angle of the brush bristles with respect to the long axis direction of the brush is within this range, the transfer ability in the long axis direction by the brush bristles can be reduced, and the uniformity of the action of the brush bristles on the contact surface can be ensured. Is done. Therefore, when this rotary brush is used as a toner supply device or a toner cleaning device by applying a voltage to a conductive pile fabric band via a rotary shaft, toner particles are transferred to the length of the rotary brush. The toner particles can be uniformly supplied to the contacted surface along the axial direction, and the toner particles can be removed from the contacted surface.

According to the method of the present invention, when a band having a width of W or a rotating shaft having an outer diameter of R is used, the entire outer peripheral surface of the rotating shaft is covered with one kind of band without any gap, and ~
The value of the diameter of the rotating shaft, the width of the strip, or both values can be obtained so that a winding angle of 30 ° can be obtained. Therefore, it is possible to easily obtain a rotary brush in which the bristle acts uniformly by the band-shaped body of the pile fabric.

[0019]

The present invention will be specifically described below with reference to examples. FIG. 2 shows a rotary brush 10 of the present embodiment. The rotary brush 10 is formed by attaching the belt-shaped body 4 to the entire peripheral surface of a thick shaft portion from the center of the rotary shaft 2. The pile fabric constituting the belt-shaped body 4 of this embodiment is prepared by using a spuntetron (manufactured by Toray Industries, Inc.) which is a spun polyester yarn, and as the pile fiber, the single yarn denier is 6.25 denier. Conductive fiber SA-
7 (manufactured by Toray Industries, Inc.), and
A pile fabric woven at a density of 0 / inch ² was used. The pile fibers upright from the base fabric act as brush bristles of the rotary brush, and are formed to have substantially the same length.

The pile fabric was cut into a strip 4 having a width of 6 mm. As the rotating shaft 2 around which the band 4 is wound, a conductive metal rod having a length sufficient for the entire width of the photosensitive drum and an outer diameter of 6 mm at the thick shaft portion was used. According to the band 4 and the rotating shaft 2, the brush winding angle θ is θ = 90 ° −COS ⁻¹ (6/6 × π) = 90 ° −COS ⁻¹ (1 / π) = 18.6. °. Then, at this winding angle θ, when the belt-shaped body 4 is wound around the circumferential surface over the entire length of the brush rotating shaft coated with the conductive adhesive in the major axis direction, as shown in FIG. However, a rotary brush 10 covered with the strip 4 without gaps was formed.

As a comparative example, the pile fabric constituting the band 4 of this embodiment is cut into a 13 mm wide band.
When the winding angle θ ′ is calculated in the same manner using the same metal rod (outer diameter 6 mm) as the rotation axis as in the present embodiment, 43.
6 °, and the belt was wound around the rotating shaft at the winding angle θ ′ to form the rotary brush of the comparative example. Similarly, in the comparative example as well, the entire peripheral surface of the rotating shaft was covered by the belt-shaped body without any gap.

The rotary brushes of the embodiment and the comparative example are attached to the photosensitive drum at a position where the brush bristles are sufficiently in contact with each other, and a power supply for applying a charging voltage is applied to the brush rotating shaft. Connected.

The brush bristles of the rotary brush 10 of the embodiment include:
After the toner is charged and attached, the rotary brush 10 is moved to the position shown in FIG.
Is rotated in the direction of the arrow shown by the solid line, and the charged toner adheres to the photosensitive drum 20. The toner is moved to the surface of the photosensitive drum 20, which is the contact surface of the brush hair, as shown in FIG. Without biasing in the direction of the arrow shown by the dotted line,
The toner was uniformly applied over the entire width of the photosensitive drum 20. On the other hand, when the charged toner was similarly applied to the surface of the photosensitive drum with respect to the rotary brush of the comparative example, the toner was uneven in the width direction of the surface of the photosensitive drum, that is, It was applied to one side (the direction of the arrow indicated by the dotted line in FIG. 3).

[0024]

According to the present invention, in a rotary brush for an electrophotographic apparatus in which a pile fabric is spirally wound on a rotating shaft, the brush bristles can act uniformly along the axial direction of the rotating shaft. it can.

[Brief description of the drawings]

FIG. 1 shows a relationship between a winding angle θ, a width R, and an outer diameter R in a state where a belt-shaped body having a width W is wound around a rotation axis having an outer diameter R so as to cover the entire outer peripheral surface thereof. FIG.

FIG. 2 is a view showing a rotary brush according to the embodiment.

FIG. 3 is a diagram illustrating a state in which a rotary brush is rotationally driven to apply toner to a photosensitive drum.

FIG. 4 is a view showing a conventional rotary brush.

Claims (2)

[Claims] 1. A rotary brush for an electrophotographic apparatus in which a pile of pile fabric is spirally wound around a rotating shaft, wherein the winding angle of the pile fabric with respect to the diameter direction of the rotating shaft is 5 to 30 °. A rotary brush for an electrophotographic apparatus. 2. A method of manufacturing a rotary brush for an electrophotographic apparatus in which a band of pile fabric is spirally wound around a rotation axis, wherein R is an outer diameter of the rotation axis, and The width is W, and the winding angle θ of the belt-like body with respect to the diameter direction of the rotating shaft is θ = 90 ° −COS ⁻¹ (W / πR). The winding angle θ is 5 to 30 °. A method of manufacturing a rotary brush for an electrophotographic apparatus, comprising setting an outer diameter R of a rotating shaft and / or a width R of a belt-shaped body.