JP5325599B2 - Brush body, brush roller using the same, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a simple-structure brush body which is greatly improved in durability while satisfactorily maintaining the cleaning capability for reliably removing, for a long time, matter adhering to the surface of a body to be cleaned. <P>SOLUTION: Each straight brush thread 37b is implanted so as to extend upward from between both leg portions 37b and 37d of each looped brush thread 37c implanted so as to extend upward in a substantially semicircular shape from a base fabric 37a. The height of the straight brush thread 37b is set greater than the height of the top of the loop shape portion 37e of the looped brush thread 37c. The back of the straight brush thread 37b mainly provides cleaning action is supported by the looped brush thread 37c, thereby maintaining upright state of the straight brush thread 37b for a long term. Accordingly, so-called bristle inclination is prevented to maintain satisfactory cleaning state. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a brush body having a plurality of brush hairs planted in a raised shape on a surface of a base fabric, a brush roller using the brush body, and an image forming apparatus.

  In general, a brush body having a large number of brush hairs is widely used in devices and instruments in various fields. For example, in image forming apparatuses such as copying machines, printers, and fax machines, and other apparatuses that employ an electrophotographic system, foreign matters such as toner (developer), paper dust, or dust tend to adhere to each part. A brush body may be used to remove such attached contaminants. For example, as shown in FIGS. 9 and 10, when the charging roller 2 is arranged so as to rotate in contact with the photosensitive drum 1 as the image carrier, the cleaning member for the charging roller 2 is arranged. The brush body 3 may be used.

  That is, the above-described roller contact charging method is attracting attention because it has a relatively low voltage to be handled and has the advantage of generating less ozone than the corotron method. However, the photosensitive drum (image carrier) is notable. The toner external additive having a small diameter remaining on the surface of 1 may adhere to the surface of the charging roller 2 and become contaminated to adversely affect the charging operation. Therefore, for example, as in Patent Document 1 below, it has been conventionally performed to remove the dirt on the surface by bringing the brush body 3 into contact with the surface of the charging roller as a cleaning member.

Japanese Patent Laid-Open No. 3-130787 Japanese Patent Laid-Open No. 5-188738 JP 2005-195950 A JP-A-6-289759

  However, it is difficult for the conventional cleaning member to contact uniformly along the entire length of the charging roller in the axial direction, and a part of the cleaning member comes into contact with the surface of the charging roller to cause uneven contact pressure. It may not be possible to clean the dirt uniformly over the entire circumference. In addition, since the conventional cleaning member is configured to clean the charging roller after the charging roller is dissociated from the photosensitive drum, a dissociation mechanism such as an electromagnetic clutch and its sequence control are required, and the device is It tends to be complicated and expensive.

  On the other hand, a countermeasure for removing dirt on the surface of the charging roller by moving a cleaning member made of a small piece of adhesive tape or the like in contact with a part of the charging roller has been proposed (for example, the following patents) Reference 2). However, this system has technical problems such as difficulty in managing the mounting of the cleaning member, which is an adhesive member, on the actual machine, and inadequate cleaning operation corresponding to the dirt unevenness of the charging roller. Further, there has been a proposal that the brush roller is brought into contact with the surface of the charging roller without being dissociated from the surface to prevent the brush body from falling and the durability is improved (for example, as described below). Patent Documents 3 and 4), and it is difficult to improve durability while maintaining good cleaning ability.

  Accordingly, the present invention has a simple configuration and has a cleaning ability for reliably removing contaminants attached to the surface of the object to be cleaned, for example, toner external additives and paper dust on the surface of the charging means and the image carrier over a long period of time. An object of the present invention is to provide a brush body, a brush roller using the brush body, and an image forming apparatus that can easily and significantly improve durability while maintaining good conditions.

In order to achieve the above object, in the brush body according to the present invention, the brush bristle planted to form a raised shape on the surface of the substrate contacts the rotating cleaning roller and cleans the cleaning roller. in the body, the brush bristles has one end implanted in the base body, a first bristle free ends of the other end is in contact with the object to be cleaned rollers, looped both ends is embedded in the base body and a second brush hairs, said second bristles, suppress the inclination of the first bristle said first bristle inclined Ri by the contact between the object to be cleaned roller is brought into contact Configuration is adopted.

According to the present invention having such a configuration, when the brush body is moved in a state where the brush body is in contact with the surface of the object to be cleaned, the tip portion of the first brush hair is the surface of the object to be cleaned. The deposits on the surface of the object to be cleaned are removed by the rubbing action of the first brush bristles . At that time, in particular, when the brush body is moved in a direction in which the first brush hairs and the loop-like second brush hairs are alternately arranged, the first brush hairs mainly performing the cleaning action as described above. However, it will be supported by the loop-like second brush hair from behind, and the rising state of the first brush hair will be maintained for a long period of time. As a result, when the brush body is used over a long period of time, so-called hair fall is prevented and a good cleaning action is maintained.

The first bristle and second bristles looped in the present invention is to do a first bristle having the same shape in the direction connecting the legs to each other of the second bristles of the loop is appropriately along with being arranged so as to contact adjacent in pitch phase, wherein in the first second direction perpendicular to the direction of the irregular shape of the second bristle of said shaped first brush bristles and loop The bristles are arranged so that the bristles are adjacent to each other at an appropriate pitch phase, and the arrangement phase of the bristles of the same shape in the first direction is alternately shifted by approximately a half pitch before and after the second direction. It is desirable to have a configuration.

According to the present invention having such a configuration, the contaminant deposits on the surface of the object to be cleaned pass through a portion between a pair of adjacent loop-shaped second brush hairs at a specific arrangement position. also, in its slipped adherent contaminants are trapped in the first bristles arranged next stage which is arranged behind the loop between portions of the second bristles adjacent. This compensates for the deterioration of the cleaning performance at the portion between the adjacent loop-shaped second brush bristles, and the cleaning function of the brush body is greatly improved.

In the present invention, it is desirable that one of the first brush bristles and the loop-shaped second brush bristles is formed of a conductive material, for example, the loop-shaped second brush bristles. It is possible that the bristles are formed of a conductive material and the first brush bristles are formed of an insulating material.

According to the present invention having such a configuration, it is possible to perform a cleaning action utilizing the conductivity of the first brush hair or the loop-shaped second brush hair .

  Moreover, in the brush roller concerning this invention, it is possible to set it as the structure fixed to the state by which the brush body mentioned above was wound around the metal core which makes a substantially cylindrical shape.

  According to the present invention having such a configuration, the cleaning action of the brush body is efficiently performed by rotation, and the entire brush body is favorably supported in a highly rigid state by the metal cored bar.

  In the present invention, in the brush roller fixed in a state where the brush body is wound, the brush body has the first direction as the axial direction of the brush roller, and the second direction as the brush roller. The brush body can be configured to be fixed to the brush roller so as to be in the rotation direction.

According to the present invention having such a configuration, when the brush roller rotates, the first brush hairs and the loop-like second brush hairs appear alternately, so that the first cleaning operation is mainly performed. One brush hair is supported from behind by the second brush hair in a loop shape.

On the other hand, the present invention having the above-described configuration can be applied to, for example, an image forming apparatus, and the brush roller is attached to a charging unit of an image carrier used in an electrophotographic image forming process. It can be configured to be used in a cleaning device that removes kimono. Further, the brush roller at that time can be configured to also remove the deposits on the image carrier used in the electrophotographic image forming process. Furthermore, the sequence and if the brush bristles of a different shape are adjacent at appropriate pitch phase, said first adjacent bristles, the second brush bristles said loop downstream in the rotation direction of the brush roller With the arrangement, the brush roller can be used in a cleaning device that removes deposits on the charging means of the image carrier used in the electrophotographic image forming process.

  Further, when the present invention is applied to the image forming apparatus in this way, it is possible to configure so that an appropriate alternating electric field is applied to the brush roller.

  If an alternating electric field is applied to the brush roller as in this configuration and an electric current is passed, the electric adhesion force can be reduced by removing the remaining toner external additive and adhering contaminants such as paper dust. Therefore, the attached contaminants are easily separated from the surface of the image carrier and the charging roller. As a result, adhering contaminants are particularly well blown off by the rubbing action of the straight brush yarn, and the cleaning efficiency of the charging means and the surface of the image carrier is improved, so that image deterioration such as charging failure is reduced. Fog due to surface contamination of the image carrier is prevented and the life of the charging means is improved. In addition, since the toner having a small particle diameter remaining on the image carrier is disturbed to fly from the image carrier, the cleaning performance for the charging means and the surface of the image carrier is further improved. It will be. Further, according to such a cleaning action, the attached contaminants transferred to the straight brush yarn or the loop brush yarn side are collected outside without performing special sequence control.

As described above, in the present invention, the first brush hair is implanted so as to rise from behind between the leg portions of the loop-shaped second brush hair so as to stand up from the base, and the cleaning action is mainly used. behind the first bristles and supported by the second bristle looped maintained over time the rising state of the first bristle carried out, to prevent falling-called hair to maintain good cleaning status Since it is configured as described above, it has a simple configuration, for example, it is durable while maintaining good cleaning ability to reliably remove the surface contamination of the charging means and the image carrier by, for example, toner external additives and paper powder over a long period of time. The reliability of the brush body, the brush roller using the brush body, and the image forming apparatus can be greatly improved at low cost.

1 is a longitudinal sectional view illustrating a structural example of a copying machine as an example of an image forming apparatus to which the present invention is applied. FIG. 2 is a longitudinal sectional explanatory view schematically showing a photosensitive drum unit according to the first embodiment of the present invention used in the copying machine shown in FIG. 1. FIG. 3 is an external perspective explanatory view schematically showing a state in which a brush body of a charging cleaning roller used in the image forming apparatus shown in FIGS. 1 and 2 is developed. FIG. 4 is a front explanatory view schematically showing an enlarged structure of a brush body of the charging cleaning roller shown in FIG. 3. FIG. 5 is an explanatory side view schematically showing an enlarged structure of the brush body of the charging cleaning roller shown in FIGS. 3 and 4. FIG. 6 is an external perspective explanatory view schematically showing an enlarged part of the brush body of the charging cleaning roller shown in FIGS. 3 to 5. FIG. 7 is an external perspective explanatory view schematically showing an enlarged charge cleaning roller in which the brush body shown in FIGS. 3 to 6 is wound around a metal core. FIG. 5 is a longitudinal sectional explanatory view schematically showing a photosensitive drum unit according to a second embodiment of the present invention. It is an external perspective view illustrating the structure of a conventional photosensitive drum unit. FIG. 10 is a longitudinal sectional view of the conventional photosensitive drum unit shown in FIG. 9.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Prior to that, a schematic structure of a digital copying machine as an image forming apparatus to which the present invention is applied will be described according to an image forming operation. . Here, the digital copying machine is an apparatus provided with a scanner for image reading, a communication function for performing communication via a FAX or a LAN, and the like. In the following embodiment, it is assumed that the recording method is an electrophotographic method.

  First, a case where a copy operation is performed will be described with reference to FIG. When a document is set on the document table 10 and a copy start button on an operation unit (not shown) is pressed, a main motor (not shown) starts to rotate, and cut sheets stored in the sheet feeding cassette 11 or the like. Only one sheet-like recording medium P is fed by the pickup roller 12. At this time, roller pairs 12a and 12b are provided to prevent the sheet-like recording medium P from being double-fed, and the upper feed roller 12a of the roller pair conveys the sheet-like recording medium P in the feeding direction, The separation roller 12b conveys the sheet-like recording medium P in the direction opposite to the conveyance direction. The separation roller 12b feeds the sheet-like recording medium P one by one and transports it to the transport unit. Further, the transported sheet-like recording medium P is transported to the stopped registration roller 15 by the first transport roller 13 and the second transport roller 14. A medium detection sensor 16 that detects the sheet-like recording medium P is disposed immediately before the registration roller 15. After a predetermined time has elapsed since the sheet-like recording medium P was detected by the medium detection sensor 16, The rotation of the first transport roller 13 and the second transport roller 14 is stopped. As a result, the sheet-like recording medium P is conveyed by the first conveying roller 13 and the second conveying roller 14 for a predetermined time while the leading edge of the sheet-like recording medium P remains in contact with the stopped registration roller 15. Therefore, a loop of the sheet-like recording medium P of about 5 mm is formed between the registration roller 15 and the second conveyance roller 14. By forming this loop, the leading edge of the sheet-like recording medium P is aligned with the nip portion of the registration roller 15, so that the skew of the sheet-like recording medium P is corrected. Thereafter, the sheet-like recording medium P is conveyed to the transfer area in accordance with the timing at which the toner image reaches the transfer area by the rotation of the registration roller 15.

  On the other hand, in the image reading unit 17, the document illumination lamp 18 is turned on, and a document (not shown) placed on the document table 10 starts to be illuminated. This is the start of the image forming operation. The document illumination lamp 18 is mounted in a reading scanner unit 19, and the reading scanner unit 19 is disposed below the document table 10. The reading scanner unit 19 includes a document illumination lamp 18 and a plurality of reflecting mirrors, moves at a constant speed, and reads a document. The reading scanner unit 19 optically scans the document placed on the document table 10, guides the reflected light to a CCD unit 20 having a lens (not shown), and converts the document image into a one-dimensional solid-state imaging device (see FIG. (Not shown). A charge coupled device CCD is used as the solid-state imaging device. Thereafter, an analog signal of the image read by the CCD is converted into a digital signal by an analog / digital (A / D) converter, and gradation processing, scaling processing, editing, etc. are performed by an image processing unit (not shown). Output after various image processing.

  Based on the image data created by the image reading unit 17, the laser scanner unit 21 emits a laser beam, a polygon mirror 22, an imaging lens (not shown), a first mirror (not shown), a second mirror. A photosensitive drum 23 serving as an image carrier is irradiated through a mirror (not shown), and an original image is formed on the photosensitive drum 23. A charging roller 25 as a charging means for uniformly charging the photosensitive drum 23 is disposed upstream of the irradiation position where the laser beam 24 from the laser scanner unit 21 is irradiated in the rotation direction of the photosensitive drum 23. The charging roller 25 uniformly charges the photosensitive drum 23 to form a charged surface, and the charged surface is irradiated with the laser beam 24 from the laser scanner unit 21 to form an electrostatic latent image. A developing device 26 for developing the electrostatic latent image is disposed downstream of the irradiation position in the rotation direction of the photosensitive drum 23. A region where the photosensitive drum 23 and the developing device 26 face each other is a developing region where the electrostatic latent image is developed. When the electrostatic latent image reaches the developing area by the rotation of the photosensitive drum 23, toner is supplied from the developing roller 26c to the electrostatic latent image to form a toner image. A transfer charging roller 28 for transferring the toner image to the sheet-like recording medium P is disposed on the downstream side in the rotation direction of the photosensitive drum 23 from the developing portion. The transfer charging roller 28 is pressed against the photosensitive drum 23 with a predetermined pressure by a pressure spring (not shown). The area where the photosensitive drum 23 and the transfer charging roller 28 face each other is a transfer area where the toner image is transferred to the recording paper.

  The registration roller 15 starts to rotate at a predetermined timing before the toner image reaches the transfer area by the rotation of the photosensitive drum 23, and the sheet-like recording medium P is conveyed to the transfer area. Therefore, the toner image is transferred to the sheet-like recording medium P conveyed to the transfer area. The sheet-like recording medium P to which the toner image has been transferred is separated from the photosensitive drum 23 by a static elimination needle (not shown), conveyed to a conveyance unit, and conveyed to a fixing device 29. Thereafter, the sheet-like recording medium P is fixed with an image by the heat and pressure of the fixing roller 31a and the pressure roller 31b, and is discharged to the outside by the paper discharge roller 32. On the other hand, in the image forming unit, the toner remaining on the photosensitive drum 23 is removed by the cleaning blade 30 to prepare for the next image formation.

  Next, the charging cleaning device attached to the charging roller 25 as the above-described charging means will be described. Prior to that, an image carrier unit having the above-described photosensitive drum (image carrier) 23 inside, that is, a photosensitive member. The configuration of the drum unit (image carrier unit) 33 will be described based on the image forming operation.

  The photosensitive drum unit 33 is particularly configured as shown in FIG. 2, but for the convenience of space, the arrangement relationship of each part with respect to the photosensitive drum (image carrier) 23 is shown with a slight shift in the rotational direction from FIG. Yes. As shown in the figure, around the photosensitive drum 23, there are a charging roller 25 as a charging means by a contact charging method, a developing device 26 as a developing means, a cleaning blade 30 as a carrier cleaning means, and the like. , And are integrally arranged to form one unit. The photosensitive drum 23 includes an electrophotographic photosensitive member having a photoconductive layer such as OPC or a-Si on the outer peripheral surface of a conductive base layer such as aluminum. It is configured to be rotationally driven at a predetermined peripheral speed in the direction of the illustrated arrow A (counterclockwise direction) around the center.

  A charging roller 25 as a charging unit is disposed so as to come into contact with the outer peripheral surface of the photosensitive drum (image carrier) 23, and a power source is connected to a metal core 25 a that is a rotating shaft of the charging roller 25. A predetermined DC bias, or a DC and AC bias is applied from 25b, whereby the outer peripheral surface of the photosensitive drum 23 is uniformly charged with a predetermined polarity and potential. At this time, the charging roller 25 has a configuration in which a conductive layer 25c is formed on the outer periphery of the metal cored bar 25a, and a resistance layer 25d is formed on the outer peripheral side of the conductive layer 25c. Is pressed at a predetermined pressure in a direction toward the rotation shaft 23a of the photosensitive drum 23. The charging roller 25 having such a configuration is rotated and rolled at the same peripheral speed as the photosensitive drum 23 in the direction of arrow B (clockwise direction) around the rotation shaft 25a during the image forming operation. It has become.

  When the outer peripheral surface of the above-described photosensitive drum (image carrier) 23 is uniformly charged by the discharge action of the charging roller 25 as the charging means, the laser beam 24 from the laser scanner unit 21 is slit-exposed. As a result, an electrostatic latent image corresponding to the image data is formed. In order to develop the electrostatic latent image, toner (not shown) in a toner container 26a provided in the developing device 26 is conveyed to the developing roller 26c by the stirring blade 26b. The toner conveyed to the developing roller 26c is scraped off by the developing blade 26d, and a uniform toner coat layer is formed on the developing roller 26c. As the toner moves from the toner coat layer to the charged photosensitive drum 23 with an electric attractive force, the electrostatic latent image on the surface of the photosensitive drum 23 is visualized to form a toner image. The toner image formed here is transferred to the sheet-like recording medium P. Since the transfer efficiency at that time is not 100%, residual toner remains on the photosensitive drum 23. Residual toner, paper dust, and the like after transfer on the surface of the photosensitive drum 23 are scraped off from the surface of the photosensitive drum 23 by the sliding contact action of the cleaning blade 30.

  On the other hand, the above-described cleaning blade 30 is used to remove a small amount of residual toner adhering to the surface of the photosensitive drum (image carrier) 23, a toner external additive having a small particle diameter, or contaminants such as paper dust. In some cases, these deposits may adhere to the outer peripheral surface of the charging roller 25 as a charging means and cause charging failure. For this reason, the charging roller 25 is disposed so as to come into contact with the charging cleaning roller 37 used in the charging cleaning device. The deposits are removed. Deposits such as toner external additives removed from the charging roller 25 are collected in a box-like collection container 38.

  Here, the above-described charging cleaning roller 37 constitutes a brush roller comprising a brush body having a plurality of brush bristles, and the charging cleaning roller 37 as the brush roller is electrophotographic as described above. It is used in a cleaning device that removes deposits on the charging roller 25 as a charging means of a photosensitive drum that is an image carrier used in an image forming process of the type. The charging cleaning roller 37 includes a plurality of brush threads 37b and 37c planted so as to form a raised shape on the surface of a base cloth 37a having a flat developed shape as shown in FIG. . The planar brush body having such a configuration is wound around and fixed to a substantially cylindrical metal core bar 37i, and is configured as a charging cleaning roller 37 as a brush roller. The detailed configuration of both types of brush yarns 37b and 37c described above will be described next. Actually, the brush yarns 37b and 37c are woven into the base fabric 37a in an extremely dense state. It is schematically represented by the state.

  That is, as shown in FIGS. 4 to 6, the brush body constituting the charging cleaning roller 37 is substantially linear from the surface of the base cloth 37 a made of a long belt-like member. It has straight-hair brush yarn 37b planted so as to stand up, and loop-like brush yarn 37c planted so as to stand up in a substantially semicircular arc shape from the base cloth 37a. Among them, the loop-shaped brush thread 37c has a pair of leg portions 37d and 37d planted on the base cloth 37a, and a loop-shaped portion 37e for connecting the leg portions 37d and 37d. It has been made into a configuration. The loop-shaped portion 37e extends so as to form a substantially semicircular shape in a front view in the direction from the upstream side toward the downstream side in the rotation direction of the charging roller 25 described above, and the radius of the semicircular shape. The straight bristle brush yarn 37b is arranged in a portion corresponding to the above.

  Here, when the axial direction of the charging cleaning roller 37 described above is a first direction and the tangential direction to the rotation direction of the charging cleaning roller 37 orthogonal to the first direction is a second direction, the straight brush thread 37b and the loop shape The brush threads 37c are arranged in a staggered arrangement as described below with respect to the first and second directions. That is, in the present embodiment, the brush body 37b has the first direction as the axial direction of the charging cleaning roller 37 as a brush roller and the second direction as the rotation direction of the charging cleaning roller 37 as the brush roller. , 37 c are fixed to the charging cleaning roller 37. The straight bristle brush yarn 37b and the loop-like brush yarn 37c are arranged so that the brush yarns of the same shape are adjacent to each other at an appropriate pitch phase in the first direction (axial direction). Further, the irregularly shaped brush yarns are alternately arranged at an appropriate pitch phase in the second direction (rotation tangential direction), and the arrangement phase in the first direction (axial direction) is: They are alternately shifted by approximately a half pitch before and after the second direction (rotational tangential direction).

  In the present embodiment, the direction in which the leg portions 37d and 37d of the loop-shaped brush thread 37c described above are connected to each other is set to substantially coincide with the first direction (axial direction). In the direction (axial direction), the same-shaped brush thread, that is, either the straight bristle thread 37b or the loop-shaped brush thread 37c, has an approximately equal interval in the first direction (axial direction). Are arranged side by side so as to be adjacent to each other. Further, in the second direction (rotational direction) orthogonal to the first direction (axial direction), as described above, the irregularly shaped brush yarn, that is, the straight brush yarn 37b and the loop brush yarn 37c are alternately arranged. Are arranged side by side.

  Thus, the straight brush yarn 37b and the loop-like brush yarn 37c in the present embodiment are appropriately arranged in the first direction connecting both the leg portions 37d, 37d of the loop-like brush yarn 37c. In the second direction orthogonal to the first direction, the brush yarns having different shapes out of the straight brush yarn 37b and the loop brush yarn 37c are arranged so as to be alternately adjacent to each other in the pitch phase. They are arranged so that they are adjacent to each other at an appropriate pitch phase, and the arrangement phases of the brush threads having the same shape in the first direction are alternately shifted by approximately half a pitch before and after the second direction. ing.

  That is, in the present embodiment, the arrangement in which the above-described irregularly shaped brush yarns 37 b and 37 c are adjacent to each other at an appropriate pitch phase is adjacent to the straight brush yarn 37 b on the downstream side in the rotation direction of the charging cleaning roller 37. The loop brush yarn 37c is arranged in a so-called staggered arrangement. According to such a staggered arrangement, the loop brush yarn 37c is arranged behind the straight bristle brush yarn 37b in the second direction which is the rotation direction of the charging cleaning roller 37. . Accordingly, when the straight hair brush thread 37b tries to tilt in the rotation direction as the charging cleaning roller 37 rotates, the straight hair brush thread 37b is supported by the loop-shaped brush thread 37c arranged behind it. It will be.

  More specifically, the straight brush thread 37b described above is loop-shaped brush thread 37c in a front view when viewed in the first direction from the upstream side to the downstream side in the rotation direction of the charging cleaning roller 37. It arrange | positions so that it may stand up on the central perpendicular of the line | wire which connected both the leg parts 37d and 37d. When the distance between the legs 37d and 37d is “W”, the straight brush thread 37b is located at a substantially central position between the legs 37d and 37d, that is, in the first direction ( The straight brush thread 37b is erected at a position separated from one leg portion 37d by “W / 2” in the axial direction).

  The straight bristle brush yarn 37b is raised so as to be substantially perpendicular to the surface of the base cloth 37a, that is, the surface of the charging cleaning roller 37, and similarly when viewed in the second direction. When viewed from the front, it is provided so as to protrude upward through the top of the loop-shaped portion 37e of the loop-shaped brush yarn 37c. That is, when the total height of the straight hair brush thread 37b from the surface of the base cloth 37a is "L", the total height "L" of the straight hair brush thread 37b is the loop-shaped portion 37e of the loop brush thread 37c. It is set to be higher than the total height “H” at the top (L> H).

  In particular, in the present embodiment, the distance “W” between the leg portions 37d and 37d of the loop brush thread 37c3 described above is set to 3 mm, for example, and the surface of the base cloth 37a, that is, the charging cleaning roller 37. The total height “H” from the surface of the loop-shaped brush yarn 37c to the topmost portion of the loop-shaped portion 37e is set to be less than 1.5 mm, whereby the relationship of W> 2H is established. Has been made. Further, the bristle length “L” of the straight bristle brush yarn 37b is set to 2 mm, for example, so that the above-described relationship of L> H is established.

  As the straight hair brush yarn 37b at this time, for example, insulating fibers such as rayon or nylon having a thickness of 2 denier, a density of 100 Kf, and a hair length of 2.0 L are used. The loop-shaped brush thread 37c is formed of a conductive material. As the conductive material at that time, for example, a fiber having a thickness of 3 denier and a density of 100 Kf is used. The conductive fabric has a bristle length such that the total height “H” from the surface of the base fabric 37a to the topmost portion of the loop-shaped brush yarn 37c is 1.5 mm. There are two methods for imparting electrical conductivity to the fiber: a method of kneading a conductive material in the raw yarn stage and a method of coating the fiber surface with a processing fluid containing the conductive material after spinning. In order to achieve this, a method of kneading a conductive substance in the raw yarn stage is advantageous. Examples of the conductive material described above include metals such as silver, copper and nickel, metal compounds such as zinc oxide and tin oxide, and fine particles such as carbon. In this embodiment, the conductive material has stable conductivity and low conductivity. Carbon is used from the viewpoint of cost. In addition, the material which has electroconductivity is employ | adopted also for the base fabric 37a mentioned above.

  In particular, as shown in FIG. 7, the end edge portion of the base cloth 37 a described above is a belt-like member extending along the staggered arrangement direction of the straight brush yarn 37 b and the loop brush yarn 37 c. The charge cleaning roller 37 is wound around a metal core bar 37i coated with a conductive adhesive layer 37f. The edge portion of the base fabric 37a extends in a direction inclined in the staggered arrangement direction with respect to the second direction which is the rotation direction of the charging cleaning roller 37. A staggered arrangement of the bristle brush yarn 37b and the looped brush yarn 37c is formed favorably.

  As described above, according to the present embodiment, when the charging cleaning roller 37 made of the brush body is in contact with the outer peripheral surface of the charging roller 25 that is the object to be cleaned, the straight hair having a large overall height is first obtained. The tip portion of the brush thread 37b is rubbed against the outer peripheral surface of the charging roller (object to be cleaned) 25, and deposits on the surface of the charging roller 25 are removed mainly by the rubbing action of the straight brush thread 37b. The At this time, the rotational movement direction of the charging cleaning roller (brush roller) 37 is the second direction in which the straight bristle brush yarn 37b and the loop-like brush yarn 37c are alternately arranged. The back of the straight bristle brush yarn 37b is supported by a looped brush yarn 37c that is arranged adjacent to the downstream side in the rotation direction of the charging cleaning roller 37. As a result, the rising state of the straight bristle brush yarn 37b is maintained for a long period of time, and when the charging cleaning roller 37 is used for a long period of time, so-called hair fall is prevented and a good cleaning state is maintained. It is like that.

  At this time, the adhering matter on the surface of the charging roller 25 that is the object to be cleaned may slip through a portion between a pair of adjacent loop-shaped brush yarns 37c, 37c. For this reason, in this embodiment, the loop-shaped brush The yarn 37c and the straight brush yarn 37b are arranged in a so-called staggered arrangement. That is, as described above, the adhering matter that has passed through the portion between the loop-shaped brush yarns 37c, 37c is captured by the straight hair brush yarn 37b at the next-stage arrangement position arranged rearward in the rotation direction, This compensates for the deterioration of the cleaning performance between the adjacent loop-shaped brush threads 37c, 37c, and greatly improves the cleaning function of the charging cleaning roller (brush body) 37. As a result, the occurrence of image defects caused by deposits is suppressed as much as possible.

  At this time, if one of the straight-hair brush yarn 37b and the loop-like brush yarn 37c is formed of a conductive material, the deposit on the charging roller 25 that is blown off by the brush yarn is removed from the conductive material. Since it is held by the brush thread made of, it is possible to prevent the removed deposits from floating and falling. Further, when the loop-like brush yarn 37c having a height lower than that of the straight bristle brush yarn 37b is formed of a conductive material, the holding effect of the deposits scraped off by the straight bristle brush yarn 37b is high, and the surface of the charging roller 25 is cleaned. Will be improved.

  On the other hand, the charging cleaning roller 37 in the second embodiment shown in FIG. 8 in which the same reference numerals are assigned to the same components as those in the first embodiment described above, together with the outer surface of the charging roller 25, is a photosensitive drum (image The support member 23 is disposed so as to contact the outer surface of the support member 23, and the cleaning operation of the charging roller 25 and the cleaning operation of the outer surface of the photosensitive drum 23 are simultaneously performed. In other words, in the present embodiment, the charging cleaning roller 37 as a brush roller is configured to also remove deposits on the photosensitive drum 23 as an image carrier used in an electrophotographic image forming process.

  That is, the charging cleaning roller 37 in the present embodiment is disposed so as to be in contact with the outer peripheral surface of the photosensitive drum 23 over almost the entire length in the longitudinal direction (axial direction). It is rubbed with a contact width (nip) of 12 mm.

  Further, in the second embodiment, an alternating electric field is applied to the looped brush yarn 37c made of conductive fibers constituting the charging cleaning roller 37. More specifically, first, as described above, a power source 25b for applying a DC bias or a DC and AC bias to the charging roller 25 as a charging unit is connected to the charging roller 25 via an on / off switch 25e. It is connected to the. The power supply 25b is connected to the charging cleaning roller 37 through a capacitor 37g for forming an alternating electric field and an on / off switch 37h in series. The alternating electric field applied to the charging cleaning roller 37 at this time is configured to output at 300 V to 3500 V, preferably 500 V to 3000 V, and at a frequency of 50 KHz to 100 KHz. The photosensitive drum (image carrier) 23 side is grounded.

  In such a configuration, the residual toner that has adhered to the outer surface of the photosensitive drum (image carrier) 23 due to a strong electrostatic action, a toner external additive having a small particle diameter, or a deposit made of paper powder, Even if it passes through the cleaning blade 30 of the cleaning device, an alternating electric field is applied from the power source 25b to the charging cleaning roller 37 and a current is caused to flow through the loop-like brush thread 37c. The charging roller 25 is reached in a state where the adhesion force of the deposit is reduced. Then, the adhering matter on the outer surface of the photosensitive drum 23 and the charging roller 25 is efficiently removed so as to be blown off by the charged cleaning roller 37 that is rotationally driven, particularly by the straight-hair brush yarn 37b.

  In addition, the application of the alternating electric field described above can simultaneously obtain the effect that the toner having a small particle diameter remaining on the surface of the photosensitive drum (image carrier) 23 is disturbed and easily fly from the photosensitive drum 23. Further, the cleaning performance with respect to the surfaces of the charging roller 25 and the photosensitive drum 23 is further improved.

  Furthermore, in the present embodiment, the loop-like brush thread 37c constituting the charging cleaning roller 37 contacts the charging roller 25 and the photosensitive drum 23, which are objects to be cleaned, and removes charges from the adhered material. Since the bristle brush thread 37b is configured to contact the charging roller 25 and the photosensitive drum 23, which are the objects to be cleaned, to actively scrape off the deposits, the deposits stay on the charging cleaning roller 37. And will not accumulate quickly. When the contact charging device having the charging cleaning roller 37 according to the present embodiment is compared with a conventional contact charging device, the lifetimes of the charging roller 25 and the charging cleaning roller 37 are about 2.5 times longer, respectively. And it was confirmed that the film was stretched about 5 times.

  When one of the above-described changeover switches 25e is turned on and the photosensitive drum (image carrier) 23 is charged by the charging roller 25, the other changeover switch 37h is turned off. At this time, the charging cleaning roller 37 removes and collects deposits by only rubbing the surfaces of the photosensitive drum 23 and the charging roller 25. Further, when one of the changeover switches 25e is turned off and no alternating electric field is applied to the charging roller 25, for example, at the time of front multi-rotation or rear multi-rotation, the change-over switch 37h is turned on and applied to the charging cleaning roller 37. Only an alternating electric field is applied. In this way, the same power source as the power source 25b of the charging roller 25 is used for the charging cleaning roller 37, so that the same alternating electric field as the charging frequency can be applied, and the occurrence of moire due to frequency interference can be prevented. Easy to do.

  In this embodiment, only the alternating electric field is applied to the charging cleaning roller 37, but a DC voltage may be applied in a superimposed manner. In the present embodiment, an alternating electric field is applied to the loop brush yarn 37c using a conductive material. For example, the loop brush yarn 37c is formed of a conductive material and has straight hair. As in the configuration in which the brush thread 37b is formed of an insulating material, depending on conditions and applications, either or both of the loop-shaped brush thread 37c and the straight brush thread 37b are made of a conductive material to generate an alternating electric field. It can also be configured to apply.

  Furthermore, in the present embodiment, a cartridge in which charging, developing, and cleaning are integrated is used, but the same configuration may be used even when separate units are used.

    As mentioned above, although the embodiment of the invention made by the present inventor has been specifically described, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. Not too long.

  For example, regarding the shape and material of the charging cleaning roller constituting the charging cleaning means, the life of the main body of the image forming apparatus, the relationship with the photosensitive drum, the particle size and amount of toner used, the rotational speed of the photosensitive drum, etc. However, the present invention is not limited to the above-described embodiment as long as the purpose of cleaning the charging roller is achieved.

  Furthermore, although the above-described embodiment is an application of the present invention to a digital copying machine, the present invention can be similarly applied to other image forming apparatuses such as printers and facsimiles.

  The image forming apparatus according to the present invention described above can be widely applied to a wide variety of image forming apparatuses such as copying machines, printers, and facsimiles.

DESCRIPTION OF SYMBOLS 10 Document stand 11 Paper feed cassette P Sheet-like recording medium 12 Pickup roller 13 1st conveyance roller 14 2nd conveyance roller 15 Registration roller 16 Medium detection sensor 17 Image reading part 18 Document illumination lamp 19 Scanner unit 20 CCD unit 21 Laser scanner unit 22 Polygon mirror 23 Photosensitive drum (image carrier)
23a Rotating shaft 24 Laser light 25 Charging roller (charging means)
25a Metal core 25b Power supply 25c Conductive layer 25d Resistive layer 25e Changeover switch 26 Developer 26a Toner container 26b Agitating blade 26c Developing roller 26d Developing blade 28 Transfer charging roller 29 Fixing device 31a Fixing roller 30 Cleaning blade 33 Photosensitive drum unit Body unit)
37 Charging cleaning roller (charging cleaning means)
38 Recovery container 37a Base fabric 37b Straight brush yarn 37c Loop brush yarn 37d Leg portion 37e Loop shape portion 37i Metal core 37f Adhesive layer 37g Capacitor 37h Changeover switch

Claims (10)

In the brush body in which the bristle planted so as to form a raised shape on the surface of the substrate contacts the rotating cleaning roller and cleans the cleaning roller,
The brush bristle has one end planted on the base and the other free end of the brush bristle contacting the cleaning roller, and a loop-like second brush with both ends planted on the base. Hair, and
The first brush bristle and the loop-shaped second brush bristle are adjacent to each other at an appropriate pitch phase in the first direction connecting both legs of the loop-shaped second brush bristle. In the second direction orthogonal to the first direction, the irregularly shaped brush hairs of the first brush hairs and the loop-like second brush hairs are appropriately disposed in the second direction. Are arranged adjacent to each other with a pitch phase of
The brush body, wherein the second brush bristle is configured so that the first brush bristle tilted by contact with the roller to be cleaned is in contact with the first brush bristle and prevents the first brush bristle from falling down. .   The brush body according to claim 1, wherein the arrangement phase of the bristles having the same shape in the first direction is alternately shifted by approximately a half pitch before and after the second direction. 2. The brush body according to claim 1 , wherein any one of the first brush bristles and the loop-shaped second bristles is formed of a conductive material. In the brush body in which the bristle planted so as to form a raised shape on the surface of the substrate contacts the rotating cleaning roller and cleans the cleaning roller,
The brush bristle has one end planted on the base and the other free end of the brush bristle contacting the cleaning roller, and a loop-like second brush with both ends planted on the base. Hair, and
The second brush bristles are configured such that the first brush bristles that are tilted by contact with the roller to be cleaned come into contact with each other to suppress the fall of the first brush bristles,
The brush body, wherein the loop-shaped second brush hair is made of a conductive material, and the first brush hair is made of an insulating material.   5. A brush roller, wherein the brush body according to any one of claims 1 to 4 is fixed in a state of being wound around a substantially cylindrical cored bar. 2. The brush roller fixed to a state in which the brush body according to claim 1 is wound, wherein the brush body has the first direction as an axial direction of the brush roller and the second direction as the brush roller. A brush roller characterized by being fixed so as to be in a rotational direction.   The image forming apparatus, wherein the brush roller according to claim 5 or 6 is used in a cleaning device for removing deposits on a charging means of an image carrier used in an electrophotographic image forming process. apparatus.   8. The image forming apparatus according to claim 7, wherein the brush roller also removes deposits on an image carrier used in an electrophotographic image forming process.   The brush roller according to claim 6, wherein the irregularly shaped brush bristles are adjacent to each other at an appropriate pitch phase, and are arranged adjacent to the first brush bristles and downstream of the brush roller in the rotation direction. The second brush bristles are arranged, and the brush roller is used in a cleaning device that removes deposits on charging means of an image carrier used in an electrophotographic image forming process. An image forming apparatus. The image forming apparatus according to claim 7, wherein an appropriate alternating electric field is applied to the brush roller.

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