JP2011248276A - Roll brush - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a roll brush capable of suppressing deterioration of brushing performance by preventing deflection of its shaft.SOLUTION: A cleaning brush 22 composes a shaft 22a and brush bristles 22b planted on the surface of the shaft 22a and is used in an electrophotographic apparatus. Cross-sectional shape of the shaft 22a varies in the axial direction of the shaft 22a. The brush bristles 22b have lengths that make their tips located at a constant radial distance R from the center axis of the shaft 22a along the axial direction of the shaft 22a.

Description

  The present invention relates to a roll brush having a shaft and brush bristles raised on the surface of the shaft and used in an electrophotographic apparatus.

  2. Description of the Related Art Conventionally, in an electrophotographic apparatus, various roll brushes having brushed hairs are provided on the surface of a shaft.

  For example, as shown in FIG. 6A, the electrophotographic apparatus cleaning device 100 disclosed in Patent Document 1 has a photosensitive member circumferential surface on the upstream side in the photosensitive member rotation direction of a charging roller 102 that charges the photosensitive member 101. A cleaning brush roller 110 for cleaning is provided.

  Here, in this type of cleaning roll brush 200, as shown in FIG. 7 (a), the shaft diameter D of the shaft 202, so that the cleaning ability of the brush bristles 201 in the longitudinal direction is uniform. And the brush length L of the bristle 201 is comprised so that it may become uniform in a longitudinal direction, and, thereby, the whole surface of a to-be-cleaned body can be cleaned uniformly.

  However, on the circumferential surface of the photosensitive member, the state of contamination of the surface in the longitudinal direction of the photosensitive member is not uniform, and some of the contamination may be more noticeable than the contamination of other portions. The above Patent Document 1 solves this problem.

  Specifically, in Patent Document 1, as shown in FIG. 6A, the toner is transferred from one side of the developer carrier 104 in the longitudinal direction of the developer carrier 104 via a screw type agitator 103. It is gradually transferred to the peripheral surface and supplied from the developer carrying member 104 to the photosensitive member 101. At that time, some of the additives contained in the toner are more easily transferred to the developer carrier 104 than the toner. Therefore, a part of the additive adheres to one end portion of the peripheral surface of the developer carrying member 104 and also moves to one end portion on the surface of the photosensitive member 101.

  As a result, a large amount of additive adheres to one end side of the photoconductor 101. In this case, if the cleaning ability in the longitudinal direction of the cleaning brush roller is constant, the surface of the object to be cleaned that is heavily soiled There is a risk that the part cannot be sufficiently cleaned.

  Therefore, in the cleaning brush roller 110 in the cleaning device 100 disclosed in Patent Document 1, as shown in FIG. 6B, the bending rigidity of the brush fibers on the one end side E1 in the longitudinal direction is set to the brush on the other end side E2 in the longitudinal direction. While being higher than the bending rigidity of a fiber, the outer diameter of the longitudinal direction one end side E1 with a high cleaning capability is set smaller than the outer diameter of the longitudinal other end side E2 with a low cleaning capability.

  Thereby, the cleaning capability of the cleaning brush roller 110 is enhanced over the entire longitudinal direction so that the entire surface of the object to be cleaned can be efficiently cleaned.

  On the other hand, in the cleaning member, the cleaning member is not in contact at the end compared to the central portion in the longitudinal direction of the photosensitive member, and the repulsive force acting between the photosensitive member and the cleaning member is easily escaped, and the central portion in the longitudinal direction. The contact pressure is lower at the end portion than at the end portion, which may cause a problem that the end portion cannot be sufficiently cleaned as compared with the central portion in the longitudinal direction of the photosensitive member.

  In order to solve this problem, as shown in FIG. 8, in the cleaning member 300 disclosed in Patent Document 2, the shaft 301 is formed so as to gradually become thicker from the center in the longitudinal direction toward both ends. In addition, the length of the hair 302 made of resin fiber or the like is formed so as to gradually increase from the central portion in the longitudinal direction toward both end portions.

  Thus, the setting of the contact pressure of the cleaning member 300 with respect to the photosensitive member for scraping off the developer that has contacted the photosensitive member and scraped off the surface thereof is gradually increased from the central portion in the longitudinal direction toward both ends. With this configuration, it is possible to prevent the developer from being easily fused at both ends in the longitudinal direction of the photoreceptor, and to obtain a stable image over a long period of time.

JP 2003-241603 A (released on August 29, 2003) JP-A-6-186890 (published July 8, 1994)

  Incidentally, in the electrophotographic apparatus, as described above, various roll brushes are provided. In other words, in addition to the cleaning roll brush in the above-described cleaning device, the roll brush includes a brush on the surface of a shaft such as a charging roll brush in a charging device, a toner stirring roll brush in a developing device, and a toner supply roll brush. There are various roll brushes with raised hair.

  However, in various types of roll brushes 200 in which brush bristles are raised on the surface of such a shaft, as shown in FIG. When the brush bristles 201 are brought into contact with each other, the axial central portion of the shaft 202 is bent. For this reason, the contact pressure of the brush bristle 201 against the opposite object at the axial center of the shaft 202 is weakened, which causes a problem in brushing performance such as poor cleaning, poor charging, or poor toner supply. ing.

  The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to provide a roll brush that can prevent a shaft from bending and suppress a reduction in brushing performance.

  In order to solve the above problems, the roll brush of the present invention has a shaft and brush bristles raised on the surface of the shaft. In the roll brush used in an electrophotographic apparatus, the cross-sectional shape of the shaft is: The brush bristles are non-uniform in the axial direction of the shaft, and the brush bristles have a length of a constant radius centered on the axis of the shaft in the axial direction of the shaft.

  According to the above invention, the cross-sectional shape of the shaft is not uniform in the axial direction of the shaft. Therefore, it is possible to thicken the axially central portion of the shaft that is easily bent, for example, thereby increasing the shaft rigidity of the axially central portion of the shaft and preventing the shaft from being bent.

  By the way, as described above, when the cross-sectional shape of the shaft is non-uniform in the axial direction of the shaft, and further, the length of the brush bristles raised on the surface of the shaft is the same length in the axial direction of the shaft In the bristle with a thick shaft diameter, the radius around the shaft axis becomes large. As a result, there is a portion where the tip of the bristle is in contact with the abutted surface in the axial direction of the shaft and a portion not in contact with it, and the brushing performance is deteriorated such as a cleaning failure, a charging failure or a toner supply failure. Cause.

  Therefore, in the present invention, the bristle has a length with a constant radius centered on the axis of the shaft in the axial direction of the shaft.

  As a result, the line connecting the tips of the bristles is parallel to the abutted surface, and the brush bristles are uniformly contacted in the longitudinal direction of the abutted surface.

  Therefore, the roll brush which can prevent the bending of a shaft and can suppress the reduction of brushing performance can be provided.

  In the roll brush of the present invention, it is preferable that the cross-sectional shape of the shaft is circular, and that the outer diameter dimension of the shaft is larger in the axial center portion of the shaft than both axial end portions.

  As a result, in the shaft, in general, since the central portion in the axial direction is easily bent, by forming the outer diameter of the shaft in the central portion in the axial direction that is easy to be bent larger than both axial end portions, the central portion in the axial direction. The shaft rigidity can be increased to prevent the shaft from bending. In addition, the length of the bristle at the axial center of the shaft is shorter than the length of the bristle at both axial ends, which increases the rigidity of the bristle itself and makes the contact pressure on the contacted surface uniform. It becomes.

  In the roll brush according to the present invention, the shaft has a circular cross-sectional shape, and a plurality of radial shaft protrusions that protrude radially in the radial direction of the circular cross-section are on the surface of the shaft. Can be made equal and parallel to the axis of the shaft. The radial shaft protrusions having the same included angles are, for example, a two-way protrusion with an included angle of 180 degrees, a three-way protrusion with an included angle of 120 degrees, a four-way protrusion with an included angle of 90 degrees, and an included angle in the cross-sectional shape of the shaft. 72-degree 5-way projections, etc. are possible.

  As a result, the material cost of the shaft can be suppressed, the eccentricity can be prevented efficiently, and the rigidity of the shaft can be increased.

  In the roll brush of the present invention, the radial shaft protrusion may be formed with a defect portion along the axial direction of the shaft.

  Thereby, the material cost of the shaft can be further suppressed, and the rigidity of the shaft can be increased efficiently. Further, since the developer can be passed through the defective portion, the stirring efficiency of the developer can be increased.

  In the roll brush of the present invention, the cross-sectional shape of the shaft is circular, and a helical shaft protrusion that protrudes spirally along the axial direction of the shaft is formed on the surface of the shaft. It is possible that

  As a result, the material cost of the shaft can be suppressed, the eccentricity can be prevented efficiently, and the rigidity of the shaft can be increased. Further, the developer can be conveyed to one end side of the shaft by the rotation of the shaft.

  Moreover, in the roll brush of this invention, it is preferable that the said shaft consists of resin.

  Thereby, even if it is the cross-sectional shape of a complicated shaft, it becomes possible to shape | mold easily compared with a metal.

  As described above, in the roll brush of the present invention, the cross-sectional shape of the shaft is not uniform in the axial direction of the shaft, and the brush hair is centered on the axis of the shaft in the axial direction of the shaft. It has a certain radius length.

  Therefore, there is an effect of providing a roll brush that can prevent the shaft from being bent and suppress the deterioration of the brushing performance.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates an embodiment of a roll brush according to the present invention, and is a cross-sectional view illustrating a configuration of a cleaning brush as a roll brush. It is a whole block diagram which shows the image formation part of the electrophotographic apparatus provided with the said cleaning brush. (A) is sectional drawing which shows the structure of the modification in a roll brush, (b) is a perspective view which shows the structure of the shaft in this roll brush. (A) is sectional drawing which shows the structure of the other modification in a roll brush, (b) is a perspective view which shows the structure of the shaft in this roll brush. It is sectional drawing which shows the structure of the further another modification in a roll brush. (A) is sectional drawing which shows the structure of the conventional electrophotographic apparatus, (b) is a perspective view which shows the structure of the brush roller for cleaning as a roll brush used for this electrophotographic apparatus. (A) is sectional drawing which shows the structure of the other conventional roll brush, (b) is sectional drawing for demonstrating the bending of this roll brush. It is a perspective view which shows the structure of the further another conventional roll brush.

  One embodiment of the present invention will be described below with reference to FIGS.

  FIG. 2 is an overall configuration diagram showing an image forming unit in an electrophotographic apparatus provided with the roll brush of the present embodiment. The electrophotographic apparatus outputs data read by a scanner provided in the electrophotographic apparatus or data from an external device (for example, an image processing apparatus such as a personal computer) connected to the electrophotographic apparatus as an image. Is.

  As shown in FIG. 2, the image forming unit 30 includes a photosensitive drum 1, a charging device 2, an exposure device 3, a developing device 10, a transfer roll 4, a conveyance belt 5, a charging control device 7, A cleaning device 20 is provided. Around the photosensitive drum 1, along the rotation direction, the charging device 2, the exposure device 3, the developing device 10, the transfer roll 4, the transport belt 5, the charging control device 7, and the cleaning. The apparatus 20 is arranged in this order.

  The photosensitive drum 1 is an electrostatic latent image carrier in an electrophotographic apparatus and has a cylindrical shape.

  The charging device 2 is in physical contact with the photosensitive drum 1 to uniformly charge the surface of the photosensitive drum 1 to a predetermined potential. The charging device 2 is made of, for example, a charging brush, and is installed adjacent to and opposed to the photosensitive drum 1 with the rotation axes thereof being parallel to each other.

  The exposure device 3 exposes the surface of the photosensitive drum 1 charged by the charging device 2 with a laser beam or the like based on data from an image processing apparatus such as a personal computer, for example, so that the surface of the photosensitive drum 1 is statically exposed. This is for forming an electrostatic latent image. As the exposure apparatus 3, for example, a semiconductor laser or a light emitting diode can be used.

  The developing device 10 supplies a developer to the surface of the photosensitive drum 1, and develops, that is, develops the electrostatic latent image formed on the surface of the photosensitive drum 1 as a developer image. In the developing device 10, after the developer is stirred by the developer stirring roll 13, the developer is supplied to the developing roll 11 with a constant thickness by the developer supply roll 12, and the developing roll 11 contacts the photosensitive drum 1. By contacting, the developer is supplied to the surface of the photosensitive drum 1. In the developing device 10 of the present embodiment, for example, a developer composed of a non-magnetic one-component developer is used, and a so-called non-magnetic one-component developing system is employed. In the present invention, not only the non-magnetic one-component developer but all developers can be targeted.

  The conveyance belt 5 is for conveying a recording medium 6 such as PPC (Plain Paper Copy) paper to the photosensitive drum 1 after a developer image is formed on the surface of the photosensitive drum 1.

  The transfer roll 4 is for transferring the developer image on the surface of the photosensitive drum 1 to a recording medium 6 as a transfer material. The surface direction of the sheet metal and the surface direction of the recording medium 6 are parallel to each other. It is installed so as to be adjacent to the photosensitive drum 1 with the conveyance belt 5 interposed therebetween. The recording medium 6 is, for example, paper, OHP, or the like. The transfer roll 4 is made of, for example, a urethane rubber roll.

  The charge control device 7 controls the charge of the remaining positive and negative developer remaining on the photosensitive drum 1 after transfer so that, for example, all the negative developer remains negative. Note that the charging control device 7 may not exist.

  The cleaning device 20 includes a cleaning brush 22 as a roll brush, and removes developer, paper dust, and the like remaining on the surface of the photosensitive drum 1. The cleaning device 20 will be described in detail later.

  The operation of forming an image in the electrophotographic apparatus having the above configuration will be described below with reference to FIG.

  The surface of the photosensitive drum 1 is uniformly charged by the charging device 2. The photosensitive drum 1 whose surface is charged is exposed based on data by the exposure device 3, and an electrostatic latent image is formed on the surface of the photosensitive drum 1. Then, a developer is supplied to the surface of the photosensitive drum 1 by the developing roller 11 of the developing device 10, and the electrostatic latent image on the surface of the photosensitive drum 1 is developed and visualized. Subsequently, the recording medium 6 is conveyed to the photosensitive drum 1 by the conveyance belt 5, and the developer image on the surface of the photosensitive drum 1 is transferred to the recording medium 6 by the transfer roll 4. After the transfer, the remaining developer, paper dust, and the like are subjected to charge control to be negative or positive by the charge control device 7 and then removed by the cleaning brush 22. Image formation is performed in such a cycle.

  Next, details of the cleaning device 20 of the present embodiment will be described below with reference to FIGS. FIG. 1 is a cross-sectional view showing a configuration of the cleaning brush 22 of the present embodiment, and FIGS. 3 to 5 are diagrams showing a configuration of a modified example of a roll brush such as the cleaning brush 22.

  As described above, the cleaning device 20 according to the present embodiment removes an object to be cleaned such as developer and paper dust remaining on the surface of the photosensitive drum 1 as shown in FIG. A cleaning brush 22, a conductive roller 23 that contacts the cleaning brush 22, and a cleaning member 24 that slides on the conductive roller 23 are provided. The cleaning device 20 is an example, and for example, the conductive roller 23 and the cleaning member 24 may not exist.

  The cleaning brush 22 is in physical contact with the photosensitive drum 1 and removes a cleaning object such as developer and paper powder remaining on the surface of the photosensitive drum 1. The conductive roller 23 in contact with the cleaning brush 22 adsorbs the negative developer remaining adsorbed at the tip of the brush bristles 22b having the positive polarity of the cleaning brush 22 by being charged to, for example, positive polarity. The remaining developer adsorbed on the conductive roller 23 is removed by a cleaning member 24 that slides on the conductive roller 23.

  In the present embodiment, the cleaning brush 22 has a characteristic configuration. Hereinafter, the configuration of the cleaning brush 22 having this characteristic will be described in detail.

  As shown in FIG. 1, the cleaning brush 22 of the present embodiment is composed of a roll brush having a shaft 22a and brush bristles 22b raised on the surface of the shaft 22a. The brush bristles 22b are made of nylon fibers having a thickness of, for example, 6 dtex, and are, for example, those obtained by directly electrostatically flocking a shaft 22a coated with an adhesive. Thereby, the cleaning brush 22 can be manufactured easily.

  In addition, the manufacturing method of the cleaning brush 22 is not necessarily limited to this, and may be, for example, the brush bristles 22b made of pile yarn woven into the ground yarn made of warp and weft. In this case, the bristles 22b made of pile yarn woven into the ground yarn are wound around the shaft 22a. Then, for example, the tip of the pile yarn is cut so that the tip line is aligned. As another manufacturing method, the hairs of the brush bristles 22b may be planted on a flexible substrate such as a film.

  Here, in the present embodiment, the cross-sectional shape of the shaft 22a, that is, the cross-sectional shape in the direction orthogonal to the axial direction of the shaft 22a is not uniform in the axial direction of the shaft 22a. Specifically, the cross-sectional shape of the shaft 22a is circular, and the outer diameter dimension D1 of the axial center portion of the shaft 22a is larger than the outer diameter dimension D2 of both axial ends of the shaft 22a. . The brush bristles 22b have a length of a constant radius R centered on the axis of the shaft 22a in the axial direction of the shaft 22a. The outer diameter dimension D1 is, for example, 7 mm, the outer diameter dimension D2 is, for example, 6 mm, and the constant radius R is, for example, 5 mm. Therefore, the length of the brush bristles 22b is 1.5 to 2 mm. However, these dimensions are not necessarily limited to this.

  That is, when the shaft diameter D of the shaft 202 and the brush length L of the brush bristles 201 are configured to be uniform in the longitudinal direction as in the conventional roll brush 200 shown in FIG. As shown in FIG. 7B, generally, when both ends of the shaft 202 are held and the brush bristles 201 are brought into contact with an opposite object (not shown), the central portion in the axial direction of the shaft 202 is bent. . For this reason, the contact pressure of the brush bristle 201 against the opposite object at the axial center of the shaft 202 is weakened, which causes a problem in brushing performance such as poor cleaning, poor charging, or poor toner supply. ing.

  Therefore, the cleaning brush 22 of the present embodiment has the above-described configuration. That is, in the cleaning brush 22 of the present embodiment, the cross-sectional shape of the shaft 22a is not uniform in the axial direction of the shaft 22a. Therefore, it is possible to thicken the axially central portion of the shaft 22a that is easily bent, thereby increasing the shaft rigidity of the axially central portion of the shaft 22a and preventing the shaft 22a from being bent.

  As described above, the cross-sectional shape of the shaft 22a is not uniform in the axial direction of the shaft 22a, and the length of the brush bristles 22b raised on the surface of the shaft 22a is the same in the axial direction of the shaft 22a. In this case, the radius around the axis of the shaft 22a in the brush bristles 22b having a thick shaft diameter is increased. As a result, there is a portion where the tip of the brush bristles 22b is in contact with the photosensitive drum 1 which is a contact surface in the axial direction of the shaft 22a, and a portion which does not come into contact with the surface. This causes a reduction in brushing performance such as supply failure.

  Therefore, in the present embodiment, the brush bristles 22b have a length of a constant radius R centered on the axis of the shaft 22a in the axial direction of the shaft 22a.

  As a result, the line connecting the tips of the brush bristles 22b becomes parallel to the photosensitive drum 1, and the brush bristles 22b come into uniform contact in the longitudinal direction of the photosensitive drum 1.

  Therefore, it is possible to provide the cleaning brush 22 that can prevent the shaft 22a from being bent and suppress the deterioration of the brushing performance.

  And in the cleaning brush 22 of this Embodiment, while the cross-sectional shape of the shaft 22a is circular especially, the outer-diameter dimension of the shaft 22a is larger in the axial center part of a shaft than an axial direction both ends. Accordingly, in the shaft 22a, the central portion in the axial direction is generally easily bent, so that the outer diameter dimension of the shaft 22a at the central portion in the axial direction that is easily bent is larger than both axial end portions. The shaft rigidity at the center can be increased to prevent the shaft 22a from bending. Further, since the length of the brush bristles 22b at the central portion in the axial direction of the shaft 22a is shorter than the length of the bristles 22b at both end portions in the axial direction, the rigidity of the brush bristles 22b themselves is increased and the contact with the photosensitive drum 1 is increased. The contact pressure is made uniform and the cleaning property is improved.

  Here, in the cleaning brush 22 of the present embodiment, the shaft 22a is made of resin such as ABS resin. Thereby, even if it is the cross-sectional shape of the complicated shaft 22a, it becomes possible to shape | mold easily compared with a metal.

  By the way, although the cleaning brush 22 as a roll brush was demonstrated in the above, the roll brush of this Embodiment is applicable not only to the cleaning brush 22 but another roll brush.

  For example, the present invention can also be applied to the above-described charging brush of the charging device 2, the developing brush 11 in the developing device 10, the developer supply roll 12, and the developer stirring roll 13. Thereby, it is possible to suppress a reduction in brushing performance such as a cleaning failure, a charging failure or a toner supply failure.

  In the present embodiment, as an example in which the cross-sectional shape of the shaft 22a is not uniform in the axial direction of the shaft 22a, as shown in FIG. 1, the outer diameter D1 of the central portion in the axial direction of the shaft 22a. However, what has become larger than the outer diameter dimension D2 of the axial direction both ends in the shaft 22a was demonstrated. The roll brush having such a shape is preferable as the cleaning brush 22, the charging brush of the charging device 2, or the developing roll 11 and the developer supply roll 12 in the developing device 10.

  However, the present invention is not necessarily limited to this shape.

  For example, as shown in FIG. 3B, the shaft 41 is formed in a circular shape as a cross-sectional shape, and a plurality of radial shaft protrusions 41a projecting radially in the radial direction of the circular cross-section are formed on the surface of the shaft 41 It is possible to make the included angle equal and continuously form the shaft 41 in parallel along the axis. The radial shaft protrusions having the same included angles are, for example, a two-way protrusion with an included angle of 180 degrees, a three-way protrusion with an included angle of 120 degrees, a four-way protrusion with an included angle of 90 degrees, and an included angle in the cross-sectional shape of the shaft. 72-degree 5-way projections, etc. are possible.

  Then, as shown in FIG. 3A, the brush brush 42 is raised on the surface of the shaft 41, whereby the roll brush 40 is completed. As a result, the material cost of the shaft 41 can be suppressed, and the rigidity of the shaft 41 can be increased efficiently and with no eccentricity. In the roll brush 40 of this form, the vertical conveyance of the developer becomes easy and the torque can be reduced. Therefore, application to the developer supply roll 12 and the developer stirring roll 13 is preferable.

  In the above-described roll brush 40, as shown in FIGS. 4A and 4B, it is also possible to form a defect 41b along the axial direction of the shaft 41 in the radial shaft protrusion 41a. Thereby, the material cost of the shaft 41 can be further suppressed, and the rigidity of the shaft 41 can be increased efficiently. Further, since the developer can be passed through the defect portion 41b, the stirring efficiency of the developer can be increased. In this form of roll brush 40, the developer can be transported in the vertical direction, and the torque can be further reduced. Therefore, application to the developer supply roll 12 and the developer stirring roll 13 is preferable.

  In the roll brush of the present embodiment, for example, as shown in FIG. 5, the cross-sectional shape of the shaft 51 is circular, and the surface of the shaft 51 is spiral along the axial direction of the shaft 51. It is possible to provide a roll brush 50 in which a spiral shaft protrusion 51a that protrudes in a straight line is formed. Brush hairs 52 are planted on the shaft 51 and the helical shaft protrusion 51a.

  As a result, the material cost of the shaft 51 can be suppressed, and the rigidity of the shaft 51 can be increased efficiently and with no eccentricity. Further, the rotation of the shaft 51 allows the developer to be conveyed to one end side of the shaft 51. In the roll brush 50 of this form, the lateral conveyance of the developer becomes easy. Therefore, application to the cleaning brush 22, the developing roll 11 in the developing device 10, the developer supply roll 12, and the developer stirring roll 13 is preferable.

  The present invention relates to a roll brush used in an electrophotographic apparatus, which has a shaft and brush bristles raised on the surface of the shaft, and includes, for example, a cleaning brush, a charging brush of a charging device, and a developing device. The present invention can be applied to roll brushes such as a developing roll, a developer supply roll, and a developer stirring roll.

1 Photosensitive drum (contacted surface)
2 Charging device 10 Developing device 11 Developing roll 12 Developer supply roll 13 Developer stirring roll 20 Cleaning device 22 Cleaning brush 22a Shaft 22b Brush hair 30 Image forming unit 40 Roll brush 41 Shaft 41a Radial shaft protrusion 41b Defect portion 42 Brush hair 50 Roll brush 51 Shaft 51a Spiral shaft protrusion 52 Brush hair D1 Outer diameter D2 Outer diameter R Constant radius

Claims (6)

In a roll brush used in an electrophotographic apparatus, having a shaft and brush bristles raised on the surface of the shaft,
The cross-sectional shape of the shaft is not uniform in the axial direction of the shaft,
The roll brush according to claim 1, wherein the brush bristles have a length with a constant radius centered on the axis of the shaft in the axial direction of the shaft. The shaft has a circular cross-sectional shape,
2. The roll brush according to claim 1, wherein an outer diameter of the shaft is larger at a central portion in the axial direction of the shaft than at both end portions in the axial direction. The shaft has a circular cross-sectional shape,
On the surface of the shaft, a plurality of radial shaft protrusions projecting radially in a radial direction in a circular cross section are formed with the same included angle and parallel to the shaft axis. The roll brush according to claim 1.   The roll brush according to claim 3, wherein the radial shaft protrusion is formed with a defective portion along the axial direction of the shaft. The shaft has a circular cross-sectional shape,
The roll brush according to claim 1, wherein a spiral shaft protrusion that protrudes spirally along the axial direction of the shaft is formed on a surface of the shaft. .
The roll brush according to claim 1, wherein the shaft is made of resin.

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