JP2014088259A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase a degree of freedom in design when a paper dust storage unit is provided.SOLUTION: A paper dust storage unit 33 is provided at an area further shifted toward a separation roller 23B than a paper dust conveyance unit 31. Therefore, a space closer to the separation roller 23B than the paper dust conveyance unit 31 can be effectively utilized. Thus, a degree of freedom in design when a paper dust storage unit 33 is provided can be increased.

Description

  The present invention relates to an image forming apparatus that forms an image on a sheet.

  For example, in the image forming apparatus described in Patent Document 1, paper dust is distributed and conveyed to one side and the other side in the width direction by an auger having a spiral blade provided in the center in the width direction. The width direction is a direction parallel to the axial direction of the transport roller.

  Then, the paper powder conveyed by the auger is stored in the paper powder storage unit. The paper dust storage part is provided at a position shifted downward from the drive shaft that drives the auger.

JP 2010-222107 A

  In recent years, there has been a strong demand for downsizing image forming apparatuses. In many cases, it is difficult to provide a paper dust storage unit having a large volume in a portion below the drive shaft. If the volume of the paper dust storage unit is small, a large amount of paper dust cannot be stored, and the paper powder may overflow from the paper powder storage unit at an early stage.

  In view of the above points, an object of the present invention is to increase the degree of design freedom when providing a paper dust storage unit.

  In order to achieve the above object, the present invention provides a roller (23B) that rotates in contact with a sheet and conveys the sheet, and is provided downstream of the roller (23B) in the sheet conveying direction and is conveyed by the roller (23B). The image forming unit (5) that forms an image on the sheet and the sheet conveyance path (L1) from the roller (23B) to the image forming unit (5) are provided to remove paper dust adhering to the sheet. A paper dust removing unit (29), a paper dust conveying unit (31) for conveying the paper dust removed by the paper dust removing unit (29) in a width direction parallel to the axial direction of the roller (23B), and a paper dust A paper dust storage unit (33) that is provided at a position shifted to the roller (23B) side from the transport unit (31) and stores the paper powder transported by the paper powder transport unit (31) is provided. To do.

  In other words, the present invention has a configuration in which the paper dust storage part (33) is provided at a position shifted to the roller (23B) side from the paper powder transport part (31). For this reason, it becomes possible to effectively utilize the space on the roller (23B) side from the paper dust conveying section (31). Therefore, the degree of freedom in design when providing the paper dust storage unit (33) can be increased.

  Incidentally, the reference numerals in parentheses for each of the above means are examples showing the correspondence with the specific means described in the embodiments described later, and the present invention is indicated by the reference numerals in the parentheses of the above respective means. It is not limited to specific means.

1 is a central sectional view of an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a diagram illustrating a main frame 21 and a paper feed unit 35A of the image forming apparatus according to the embodiment of the present invention. It is a figure which shows the state which opened MP tray 25. FIG. FIG. 4 is a diagram illustrating characteristics of an image forming apparatus according to an embodiment of the present invention, and is a cross-sectional view of a paper feed unit 35A. 3 is a perspective view of a paper feed frame 35 and the like according to the embodiment of the present invention. FIG. It is a perspective view of paper feed unit 35A concerning an embodiment of the present invention. It is a figure which shows the state which opened MP tray 25. FIG.

  The “embodiment of the invention” described below shows an example of the embodiment. In other words, the invention specific items described in the claims are not limited to the specific means and structures shown in the following embodiments.

  In this embodiment, the present invention is applied to an electrophotographic image forming apparatus. Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the arrow etc. which show the direction attached | subjected to each figure were described in order to make it easy to understand the relationship between each figure, and this invention is not limited to the direction attached | subjected to each figure. Absent.

(First embodiment)
1. Outline of Image Forming Apparatus As shown in FIG. 1, an electrophotographic image forming unit 5 that forms an image on a sheet such as a recording sheet is accommodated in a housing 3 of the image forming apparatus 1. The image forming unit 5 includes a process cartridge 7, an exposure device 9, a fixing device 11, and the like.

  Incidentally, the image forming unit 5 according to the present embodiment is a color electrophotographic system. Therefore, the image forming unit 5 has a plurality of process cartridges 7. A plurality of process cartridges 7 are arranged along a direction orthogonal to the axial direction of the photosensitive drum 7A. Each process cartridge 7 corresponds to four colors of yellow, magenta, cyan, and black.

  Each process cartridge 7 is detachably attached to the apparatus main body. The process cartridges 7 are substantially the same in structure and the like except for the color of the developer stored therein. Specifically, each process cartridge 7 includes a photosensitive drum 7A, a charger 7B, a developer 7C, and the like.

  Note that the apparatus main body refers to a portion that is not attached or detached or replaced by a user such as the housing 3 or the main frame 21 shown in FIG. The main frame 21 is a pair of plate-like members separated from each other in the width direction.

  The devices constituting the image forming unit 5 such as the process cartridge 7 are assembled to each main frame 21 while being disposed between the pair of main frames 21. Incidentally, the width direction is a direction parallel to the axial direction of the photosensitive drum 7A.

  The photosensitive drum 7A carries a developer image transferred to the sheet. The charger 7B charges the photosensitive drum 7A. The exposure device 9 exposes the charged photosensitive drum 7A corresponding to the image data to form an electrostatic latent image on the photosensitive drum 7A. The developing device 7C supplies a developer to the photosensitive drum 7A and forms a developer image corresponding to the electrostatic latent image. As shown in FIG. 1, the photosensitive drums 7 </ b> A are arranged in a plurality in the axial direction perpendicular to the sheet conveying direction and along the sheet conveying direction.

  The belt 13 conveys the sheet. A transfer portion 15 is disposed at a position facing each photosensitive drum 7A with the belt 13 interposed therebetween. The transfer unit 15 transfers the developer image carried on the photosensitive drum 7 </ b> A to a sheet conveyed on the belt 13. The developer images carried on the respective photosensitive drums 7A are superimposed and transferred onto the sheet and then heated by the fixing device 11 to be fixed on the sheet.

  A first feeder mechanism 19 and a second feeder mechanism 23 are provided upstream of the belt 13 in the sheet conveying direction. The first feeder mechanism 19 sends out the sheets placed on the paper feed tray 17 one by one toward the image forming unit 5 side.

  A sheet to be conveyed to the image forming unit 5 is placed on the sheet feeding tray 17. The paper feed tray 17 is detachably attached to the apparatus main body. The first feeder mechanism 19 includes a pickup roller 19A, a separation roller 19B, a separation pad 19C, and the like.

  The pickup roller 19 </ b> A imparts a conveying force to the sheet by rotating in contact with the sheet placed on the sheet feeding tray 17. The separation roller 19B separates a plurality of overlapped sheets in cooperation with the separation pad 19C.

  The second feeder mechanism 23 sends out the sheets placed on the multipurpose sheet feeding tray 25 (hereinafter referred to as MP tray 25) shown in FIG. 3 one by one toward the image forming unit 5 side. The MP tray 25 is provided on a cover 25 </ b> A provided on the front side of the image forming unit 5 in the housing 3.

  The second feeder mechanism 23 has the same configuration as the first feeder mechanism 19. That is, as shown in FIG. 1, a pickup roller 23A, a separation roller 23B, a separation pad 23C, and the like are provided. The pickup roller 23A rotates in contact with the sheet placed on the MP tray 25.

  A plurality of overlapped sheets sent out by the pickup roller 23A are separated by a separation roller 23B and a separation pad 23C. The separated sheet is conveyed to the image forming unit 5 side by the separation roller 23B.

  The pair of registration rollers 27 </ b> A and 27 </ b> B stops the conveyance of the sheet sent from the first feeder mechanism 19 or the second feeder mechanism 23. Thus, after the posture is corrected, the sheet enters the image forming unit 5 at a preset timing.

  Incidentally, in this embodiment, the registration roller 27A is a metal roller in which a fluororesin film is formed on the circumferential surface in contact with the sheet. The registration roller 27B is a roller having a circumferential surface that comes into contact with a sheet and made of a material having a large friction coefficient such as rubber. The registration rollers 27A and 27B are supplied with driving force by a motor or the like (not shown), and convey the sheet while sandwiching the sheet.

2. Paper Powder Removal Unit As shown in FIG. 4, a paper dust removal unit 29 is provided in the sheet conveyance path L <b> 1 from the separation roller 23 </ b> B to the image forming unit 5. The paper dust removing unit 29 removes the paper dust adhering to the sheet. The paper dust removing unit 29 includes a registration roller 27A and a sliding contact member 29A. The sliding contact member 29A is in contact with the circumferential surface of the rotating registration roller 27A.

  The registration roller 27A is frictionally charged by rotating in contact with the sliding contact member 29A. The paper dust adhering to the sheet is attracted to the registration roller 27A by the electrostatic attraction generated in the charged registration roller 27A. Thereafter, the paper dust adsorbed on the registration roller 27A is scraped off by the sliding contact member 29A when the registration roller 27A rotates.

  Further, the paper dust removing unit 29 is provided over the entire width direction of the transport path L1. Specifically, the slidable contact member 29A is in contact with the registration roller 27A over substantially the entire longitudinal direction of the registration roller 27A. For this reason, it becomes possible to remove paper dust from the entire surface of the sheet on which the developer image is transferred, and a good image is formed on the sheet.

  The paper dust removed from the registration roller 27A is conveyed in the width direction by the paper dust conveying unit 31. The width direction is also a direction parallel to the axial direction of the separation roller 23B. The paper dust conveyed by the paper dust conveyance unit 31 is stored in the paper powder storage unit 33.

  The paper dust storage unit 33 is provided at a position shifted to the separation roller 23B side from the paper powder conveyance unit 31 in the sheet conveyance direction. In other words, the paper dust storage unit 33 is provided at a position shifted to the upstream side in the transport direction from the paper powder transport unit 31.

  Note that “the paper dust storage unit 33 is provided at a position shifted to the separation roller 23B side from the paper powder conveyance unit 31 in the sheet conveyance direction”, for example, as shown in FIG. When the paper dust storage unit 33, the separation roller 23B, and the sheet conveyance direction are projected on a virtual plane orthogonal to the projected plane, the projected paper powder storage unit 33 is projected in the projected sheet conveyance direction. The case where it has shifted | deviated to the separation roller 23B side is said. Further, the paper dust storage unit 33 and the separation roller 23B are disposed at positions that overlap when projected onto the virtual plane.

  Moreover, as shown in FIG. 5, the paper dust storage part 33 is provided in the site | part shifted in the width direction with respect to the separation roller 23B. Correspondingly, the paper dust transport unit 31 includes a first paper powder transport unit 31A and a second paper powder transport unit 31B. That is, the first paper dust conveying unit 31A conveys the paper dust in one direction in the width direction. The second paper powder conveyance unit 31B conveys paper powder in the other direction in the width direction.

  Here, “one direction” is a direction from the first paper dust conveying unit 31A toward the second paper dust conveying unit 31B. The “other direction” is a direction from the second paper dust conveyance unit 31B toward the first paper dust conveyance unit 31A. For this reason, each of the first paper dust conveying unit 31A and the second paper dust conveying unit 31B conveys the paper dust toward the boundary portion 31C between the first paper dust conveying unit 31A and the second paper dust conveying unit 31B.

  Further, the separation roller 23B is disposed at a substantially center in the width direction. The drive shaft 23D that transmits the driving force to the separation roller 23B extends in the width direction from one end in the width direction and reaches the separation roller 23B.

  For this reason, the drive shaft 23D is located on the side opposite to the boundary portion 31C with the separation roller 23B interposed therebetween in the width direction. That is, in the present embodiment, the drive shaft 23D is not provided in the space on the paper powder storage unit 33 side with respect to the separation roller 23B.

  The paper dust storage unit 33 is provided at a position shifted in the width direction toward the second paper dust transport unit 31B with respect to the separation roller 23B. And the paper dust storage part 33 is provided in the range corresponding to the conveyance path | route L1. That is, the paper dust storage unit 33 is provided in an area from the center in the width direction of the transport path L1 to the other end in the width direction (the right end side in FIG. 5) where the drive shaft 23D does not exist.

  In addition, a boundary portion 31 </ b> C between the first paper dust conveyance unit 31 </ b> A and the second paper dust conveyance unit 31 </ b> B is set at a site corresponding to the position of the paper dust storage unit 33. Therefore, the paper dust removed in the region on the separation roller 23B side with respect to the boundary portion 31C is directed from the one end side in the width direction (left end side in FIG. 5) toward the boundary portion 31C in the first paper dust conveying portion 31A. Be transported.

  On the other hand, the paper dust removed in the region on the paper dust storage unit 33 side with respect to the boundary portion 31C is separated from the other end side in the width direction (the right end side in FIG. 5) by the second paper dust transport unit 31B. It is conveyed toward. In addition, the paper dust conveyance part 31 which concerns on this embodiment, ie, the 1st paper dust conveyance part 31A and the 2nd paper dust conveyance part 31B, is an auger which has a spiral blade | wing.

  That is, the first paper dust transport unit 31A is a screw-shaped first auger having a spiral first blade 33D and extending in the width direction. The second paper dust transport unit 31B is a screw-like second auger that has a spiral second blade 33E formed in the opposite direction to the first blade 33D and extends in the width direction.

  The first auger and the second auger, that is, the first paper dust transport unit 31A and the second paper dust transport unit 31B rotate in the same direction. For this reason, 31 A of 1st paper dust conveyance parts convey paper dust to one direction. The second paper powder conveyance unit 31B conveys the paper powder in the other direction.

  In the present embodiment, the first paper dust transport unit 31A and the second paper powder transport unit 31B are integrated with each other as shown in FIG. For this reason, in this embodiment, it is not necessary to drive the 1st paper dust conveyance part 31A and the 2nd paper dust conveyance part 31B separately.

  That is, if only one of the first paper dust transport unit 31A and the second paper powder transport unit 31B (in this embodiment, the second paper powder transport unit 31B) is driven, the entire paper powder transport unit 31 is driven. it can. Specifically, the rotational driving force transmitted to the registration roller 27A is decelerated by the transmission unit 31D, and the second paper powder conveyance unit 31B is driven.

3. In the present embodiment, as shown in FIG. 4, the separation roller 23 </ b> B and the pickup roller 23 </ b> A, the paper dust removing unit 29, the paper dust conveying unit 31, and the paper dust storing unit 33 are assembled to the paper feeding frame 35. Yes. That is, parts related to paper feeding such as the separation roller 23B are integrated with the paper feeding frame 35 to constitute a paper feeding unit 35A.

  For this reason, in the present embodiment, as shown in FIG. 2, components related to paper feeding such as the separation roller 23B are integrated with the paper feeding frame 35 and assembled to the pair of main frames 21 as a paper feeding unit 35A. ing.

  Further, as shown in FIG. 4, the paper feed unit 35 </ b> A also includes a lid portion 33 </ b> B that closes the opening portion 33 </ b> A of the paper dust storage portion 33. The lid portion 33 </ b> B closes an opening portion 33 </ b> A provided on the upper side of the paper dust storage portion 33 so as to be openable and closable.

  As shown in FIG. 3, the paper feed unit 35 </ b> A is disposed at a position that is exposed to the outside when the front cover 25 </ b> B provided in the apparatus main body is opened. For this reason, when a member located above the sheet feeding unit 35A such as the image forming unit 5 is removed from the apparatus main body, the lid 33B is exposed to the outside as shown in FIG.

4). Features of the Image Forming Apparatus According to the Present Embodiment In the present embodiment, the paper powder storage unit 33 is provided at a position shifted from the paper powder transport unit 31 toward the separation roller 23B. For this reason, it is possible to effectively utilize the part where the parts such as the drive shaft 23 </ b> D are not arranged, that is, the space on the separation roller 23 </ b> B side from the paper dust conveying unit 31 as the paper dust storing unit 33. Therefore, the degree of freedom in design when providing the paper dust storage unit 33 can be increased.

  Specifically, the volume of the paper dust storage unit 33 can be increased without increasing the size of the image forming apparatus 1. As a result, product life and maintenance cycle can be extended by making it possible to store a large amount of paper dust.

  And in this embodiment, the separation roller 23B is located in the approximate center of the width direction, and the paper dust storage part 33 is provided in the site | part which shifted | deviated to the other side with respect to the separation roller 23B. Further, the drive shaft 23D is provided on the side opposite to the boundary portion 31C with respect to the separation roller 23B.

  Accordingly, in the present embodiment, the drive shaft 23D does not exist at a portion shifted to the other end side (the right end side in FIG. 5) with respect to the separation roller 23B. Therefore, if the paper dust storage part 33 is provided on the boundary 31C side with respect to the separation roller 23B, the space on the separation roller 23B side from the paper powder conveyance part 31 can be effectively utilized.

  In addition, the present embodiment is characterized by including a lid portion 33 </ b> B that closes an opening portion 33 </ b> A provided in the paper dust storage portion 33 so as to be opened and closed. Thereby, in this embodiment, the user can easily perform maintenance such as removing paper dust stored in the paper dust storage unit 33.

  In addition, the present embodiment is characterized by including a paper feed frame 35 that can be assembled to the pair of main frames 21 by integrating the separation roller 23B and the like. Accordingly, in the present embodiment, the separation roller 23B and the like can be easily assembled to the pair of main frames 21 as the paper feed unit 35A. Therefore, it is possible to reduce the number of assembly steps of the image forming apparatus 1.

  In addition, the present embodiment is characterized in that the paper dust storage unit 33 is provided in a range corresponding to the conveyance path L1. As a result, the volume of the paper dust storage unit 33 can be increased without increasing the widthwise dimension of the image forming apparatus 1.

(Other embodiments)
In the above-described embodiment, the paper feed frame 35 is configured by one frame. However, the present invention is not limited to this, and the paper feed frame 35 may be configured by a plurality of frames.

  In the above-described embodiment, the first paper dust transport unit 31A and the second paper powder transport unit 31B, that is, the paper powder transport unit 31 is an auger having spiral blades, but the present invention is not limited thereto. For example, a powder transfer device such as a belt conveyance device or an eccentric pump may be used.

  In the above-described embodiment, as shown in FIG. 5, the first paper dust conveyance unit is obtained by integrating the rotation shaft provided with the first blade 33 </ b> D and the rotation shaft provided with the second blade 33 </ b> E. 31A and the 2nd paper dust conveyance part 31B were integrated. However, the present invention is not limited to this. For example, the rotating shaft may be eliminated and only the first blade 33D and the second blade 33E may be used, and the blades 33D and 33E may be integrated.

  Moreover, in the above-mentioned embodiment, 31 A of 1st paper dust conveyance parts and the 2nd paper dust conveyance part 31B were integrated, However, this invention is not limited to this, For example, 1st paper dust The transport unit 31A and the second paper dust transport unit 31B may be separated.

  Moreover, in the above-mentioned embodiment, although the paper dust storage part 33 was provided in the site | part which shifted | deviated to the width direction with respect to the separation roller 23B, this invention is not limited to this, For example, paper dust storage The part 33 may be provided on the upper side of the separation roller 23B.

  In the above-described embodiment, the separation roller 23B is provided at the center in the width direction. However, the present invention is not limited to this, and may be, for example, one end in the width direction or the other end in the width direction. .

  In the above-described embodiment, the drive shaft 23D is provided on the side opposite to the boundary 31C across the separation roller 23B in the width direction. However, the present invention is not limited to this, for example, Either (a) the drive shaft 23D has a configuration extending in the entire width direction, or (b) the drive shaft 23D has a configuration extending on the same side as the boundary portion 31C with respect to the separation roller 23B. Also good.

  Moreover, in the above-mentioned embodiment, although the paper dust storage part 33 was provided in the range corresponding to the conveyance path | route L1, this invention is not limited to this, and is outside the range corresponding to the conveyance path | route L1. May be provided.

In the above-described embodiment, the present invention is applied to the second feeder mechanism 23, but the present invention is not limited to this, and can be applied to the first feeder mechanism 19.
In the above-described embodiment, the present invention is applied to a direct tandem image forming apparatus. However, the present invention is not limited to this. For example, an intermediate transfer image forming apparatus or an inkjet image forming apparatus is used. It can also be applied to devices.

  Further, the paper dust removing unit 29 according to the above-described embodiment is configured to include the charged registration roller 27A and the sliding contact member 29A. However, the present invention is not limited to this, and for example, paper A dedicated roller (paper dust removing roller) for electrostatically adsorbing powder may be provided, and the paper dust removing roller may be brought into contact with the sliding contact member 29A.

  In the above-described embodiment, the driving force is input to both the registration roller 27A and the registration roller 27B. However, the circumferential surface in contact with the sheet is made of a material having a large friction coefficient such as rubber. The driving force may be input only to the roller 27B, and the registration tor 27A may be driven to rotate.

  Further, the present invention is not limited to the above-described embodiment as long as it matches the gist of the invention described in the claims.

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus 3 ... Case 5 ... Image forming part 7 ... Process cartridge 7A ... Photosensitive drum 7B ... Charger 9 ... Exposure device 11 ... Fixing device 13 ... Belt 15 ... Transfer part 17 ... Paper feed tray 19 ... 1st Feeder mechanism 19A ... Pickup roller 19B ... Separation roller 19C ... Separation pad 21 ... Main frame 23 ... Second feeder mechanism 23A ... Pickup roller 23B ... Separation roller 23C ... Separation pad 23D ... Drive shaft 25 ... Multipurpose paper feed tray (MP tray) 25A ... Cover 27A ... Registration Roller 27B ... Registration Roller 29 ... Paper Powder Removal Unit 29A ... Sliding Contact Member 31 ... Paper Powder Transport Unit 31A ... First Paper Powder Transport Unit 31B ... Second Paper Powder Transport Unit 31C ... Border 33 ... Paper dust storage part 33D ... 1st blade | wing 33E ... 2nd blade | wing 33A ... Opening part 33 B ... Lid 35 ... Paper feed frame 35A ... Paper feed unit

Claims (10)

A roller that rotates in contact with the sheet and conveys the sheet;
An image forming unit that is provided downstream of the roller in the sheet conveying direction and forms an image on the sheet conveyed by the roller;
A paper dust removing unit that is provided in a sheet conveyance path from the roller to the image forming unit and removes paper dust adhering to the sheet;
A paper dust conveying unit that conveys the paper dust removed by the paper dust removing unit in a width direction parallel to the axial direction of the roller;
An image forming apparatus comprising: a paper powder storage unit that is provided at a position shifted to the roller side from the paper powder transport unit and stores the paper powder transported by the paper powder transport unit.   The image forming apparatus according to claim 1, wherein the paper dust storage unit is provided at a portion shifted in the width direction with respect to the roller. The paper dust removing unit is provided over the entire width direction of the transport path,
The paper dust conveying unit includes a first paper dust conveying unit that conveys paper powder in one direction in the width direction, and a second paper dust conveying unit that conveys paper powder in the other direction in the width direction. ,
Further, the first paper dust conveying unit and the second paper dust conveying unit convey paper dust toward a boundary portion between the first paper dust conveying unit and the second paper dust conveying unit. The image forming apparatus according to claim 2. The roller is located at the approximate center in the width direction, and the paper dust storage part is provided at a position shifted to the second paper powder conveying part side with respect to the roller;
The image forming apparatus according to claim 3, wherein a boundary portion between the first paper dust conveyance unit and the second paper dust conveyance unit is a portion corresponding to a position of the paper dust storage unit. . The first paper dust conveying unit is a screw-shaped first auger having a spiral first blade and extending in the width direction,
The second paper dust conveyance unit is a screw-shaped second auger having a spiral second blade formed in the opposite direction to the first blade, and extending in the width direction,
The image forming apparatus according to claim 4, wherein the first auger and the second auger rotate in the same direction.   The image forming apparatus according to claim 5, wherein the first auger and the second auger are integrated. A driving shaft that transmits a driving force to the roller and that extends in the width direction;
The image forming apparatus according to claim 4, wherein the drive shaft is provided on the opposite side of the boundary portion with the roller interposed therebetween in the width direction.   The image forming apparatus according to claim 1, wherein the paper dust storage unit is provided in a range corresponding to the conveyance path.   The image forming apparatus according to claim 1, further comprising: a lid that closes an opening provided in the paper dust storage unit so as to be openable and closable. A pair of main frames provided on both sides of the image forming unit;
The frame comprising: the roller, the paper dust removing unit, the paper dust transporting unit, and the paper dust storing unit being integrated and assembled to the pair of main frames. The image forming apparatus according to claim 1.