JP2009269709A - Paper feeding device and image forming device with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paper feeding device of simple structure capable of eliminating paper chips adhered to a separating roller, and to provide an image forming device with the same. <P>SOLUTION: This paper feeding device 20 of an image forming device 100 includes: a pick-up roller 29; a pair of paper feeding rollers 30 structured of a feed roller 30a and a retard roller 30b; and a paper feeding conveyance passage 37. A nearly rectangular sheet-like cleaning member 41 having a free end 41a capable of cleaning the roller surface by abutting on the surface of the retard roller 30b is provided in the paper feeding conveyance passage 37 on an upstream side in the conveying direction. An undersurface of the free end part 41a is provided with a brush portion 42 capable of cleaning the roller surface by abutting on the surface of the retard roller 30b in a tip thereof. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a digital copying machine or a laser printer, and more particularly to a paper feeding apparatus.

  2. Description of the Related Art Conventionally, in an image forming apparatus, for example, as a paper feeding method for paper contained in a paper feeding cassette, a pickup roller that feeds paper from the paper feeding cassette and a paper feeding that separates and feeds the paper delivered by the pickup roller one by one. A paper feeding device having a paper roller pair is used.

  In such a sheet feeding device, a plurality of upper sheets are normally sent out by a pickup roller. The pair of paper feed rollers includes a paper feed roller that rotates and conveys the paper, and a separation roller that separates the paper one by one. Then, by utilizing the friction between the pair of paper feed rollers and the paper, one of the papers fed out by the pickup roller and contacting the paper feed roller is separated and conveyed.

  However, in such a paper feeding method that separates and conveys paper using friction, paper dust or the like is easily generated. When such paper dust or the like adheres to the surface of the separation roller, the frictional resistance between the separation roller and the paper decreases, and there is a possibility that the paper cannot be separated and conveyed one by one. Further, when paper dust or the like adheres to the surface of the photosensitive drum, there is a possibility that an image defect may occur.

  Therefore, a method for removing paper dust and the like adhering to the surface of the pair of paper feed rollers has been proposed. For example, in Patent Document 1, due to friction on a roller, a cleaning roller member that removes deposits such as paper dust on the roller is brought into contact with at least one of a conveyance (feed) roller and a separation roller. A method for removing paper dust or the like and preventing paper dust or the like from entering the image forming unit is disclosed.

As another method for separating and conveying sheets one by one, for example, in Patent Document 2, a blade is rotatably supported and a spring is urged toward a sheet feeding roller, and the leading end of the sheet is fed to the sheet feeding roller. And the sheet fed by the pickup roller between the sheet feeding roller and the blade is passed between the sheet feeding roller and the blade, so that the force for stopping the sheet conveyance is larger than the sheet pressing force, and the sheets are separated one by one. A method for preventing the sheet from being rubbed strongly to cause sheet contamination is disclosed.
Japanese Patent Laid-Open No. 3-128732 JP-A-5-254684

  However, in the method of Patent Document 1, it is necessary to secure a space for disposing the cleaning roller member in the apparatus main body, which may increase the size and complexity of the apparatus. In the method of Patent Document 2, the blade pressed against the paper feed roller is for directly contacting the paper and separating the paper one by one. Using this blade, the paper dust attached to the roller surface is removed. Removal is not disclosed or suggested. In addition, since the blade is provided as a separate member so as to be rotatable, there is a possibility that the apparatus becomes large or complicated.

  In view of the above problems, an object of the present invention is to provide a paper feeding device that can remove paper dust and the like attached to a separation roller with a simple configuration, and an image forming apparatus including the paper feeding device.

  In order to achieve the above-mentioned object, the present invention separates and transports a front feed roller that feeds paper from a paper storage section provided in the apparatus main body and a paper fed from the front feed roller one by one. A pair of paper feed rollers for transporting the paper and a separation roller for separating the paper one by one, and the paper feed roller pair sandwiched in the paper transport direction, A feeding path that guides the sheet fed from the forward feeding roller to the downstream side of the pair of feeding rollers, the position facing the separation roller of the feeding path from the upstream side in the feeding direction Further, a cleaning member having a free end portion that abuts on the surface of the separation roller and can clean the roller surface is provided.

  Further, the present invention is characterized in that a brush portion protruding from the free end portion and having a tip abutting against the separation roller and capable of cleaning the roller surface is provided.

  In the invention, it is preferable that the brush portion is formed of a brush-like member.

  According to the present invention, the cleaning member is made of an elastic material.

  The present invention also provides an image forming apparatus including the paper feeding device.

  According to the first configuration of the present invention, the free end portion that can contact the surface of the separation roller and clean the roller surface at a position facing the pair of paper feed rollers in the transport path of the paper feed device from the upstream side in the transport direction. By protruding the cleaning member, the roller surface of the separation roller can be cleaned with a simple configuration, so that the sheets can be reliably separated and conveyed one by one while preventing the apparatus configuration from becoming complicated and large. it can.

  According to the second configuration of the present invention, in the first sheet feeding device, the free end portion is further provided with a brush portion whose tip is in contact with the surface of the separation roller and capable of cleaning the roller surface. The roller surface of the separation roller can be reliably cleaned.

  According to the third configuration of the present invention, in the second paper feeding device, the brush portion is made of a brush-like member, whereby damage to the roller surface of the separation roller can be prevented.

  According to the 4th structure of this invention, in the said 1st-3rd paper supply apparatus, damage to the roller surface of a separation roller can be prevented by comprising a cleaning member from an elastic material. .

  According to the fifth configuration of the present invention, the image forming apparatus including any one of the first to fourth sheet feeding devices can perform image formation in which sheet feeding and image defects are prevented. it can.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side sectional view showing a configuration of an image forming apparatus provided with a sheet feeding device according to a first embodiment of the present invention.

  In an image forming apparatus (for example, a printer) 100, when performing an image forming operation, a photosensitive drum 5 that rotates clockwise in the drawing is uniformly charged by a charging unit 4, and an exposure unit (laser scanning unit) based on document image data. Etc.) An electrostatic latent image is formed on the photosensitive drum 5 by the laser beam from 7, and a developer (hereinafter referred to as toner) is attached to the electrostatic latent image by the developing unit 8 to form a toner image.

  The toner is supplied to the developing unit 8 from the toner container 9. The image data is transmitted from a personal computer (not shown) or the like. Further, a static elimination device (not shown) for removing residual charges on the surface of the photosensitive drum 5 is provided on the downstream side of the cleaning device 6.

  As described above, the paper 26 (see FIG. 2) moves from the paper feed cassette (paper storage unit) 10 or the manual feed tray 11 through the paper transport path 12 and the registration roller pair 13 toward the photosensitive drum 5 on which the toner image is formed. The toner image formed on the surface of the photosensitive drum 5 is transferred onto a sheet by the transfer roller 14 (image transfer unit). The sheet on which the toner image has been transferred is separated from the photosensitive drum 5 and conveyed to a fixing unit 15 having a fixing roller pair 15a to fix the toner image. The sheet that has passed through the fixing unit 15 is conveyed to the upper part of the apparatus by the sheet conveying path 16 and is discharged from the discharge roller pair 17 to the discharge tray 18.

  FIG. 2 is a side cross-sectional view showing the periphery of the sheet feeding device of the present embodiment. Portions common to those in FIG. 1 are denoted by common reference numerals and description thereof is omitted. In the cassette frame 25, a paper stacking plate 28 supported so as to be rotatable around a fulcrum 28a is disposed, and the paper 26 is placed on the paper stacking plate 28. Reference numeral 31 denotes a rear end cursor for aligning the rear ends of the paper 26 and is provided so as to be movable in the transport direction (left-right direction) of the paper 26.

  A push-up plate 33 that rotates together with the sector gear 32 is disposed below the sheet stacking plate 28, and a gear (hereinafter referred to as a cassette side gear) 34 is connected to the sector gear 32. When the sheet feeding cassette 10 is inserted into the apparatus main body and the cassette side gear 34 is engaged with a gear (not shown; hereinafter referred to as apparatus main body side gear) 36 connected to a motor (not shown). The driving force is transmitted to the paper stacking plate 28 through the sector gear 32 and the push-up plate 33, and the paper stacking plate 28 is lifted.

  A paper feeding device 20 is provided on the apparatus main body side. The paper feed device 20 is provided with a pickup roller (forward feed roller) 29, a paper feed roller pair 30, and a paper feed conveyance path (conveyance path) 37. The paper feed roller pair 30 includes a feed roller (paper feed roller) 30a and a retard roller (separation roller) 30b. The feed roller 30a is rotated by a driving unit (not shown) to convey the paper 26.

  The retard roller 30b is controlled by a torque limiter (not shown) or the like to pass through the nip of the pair of paper feed rollers 30 as compared with the feed roller 30a, and rotates according to the feed roller 30a. The paper feed conveyance path 37 is provided in the conveyance direction of the paper 26 with the paper feed roller pair 30 interposed therebetween, and guides the paper P sent out by the pickup roller 29 downstream in the conveyance direction of the paper feed roller pair. A downstream end of the paper feed conveyance path 37 in the conveyance direction communicates with the paper conveyance path 12 (see FIG. 1).

  The apparatus main body is provided with a sensor (not shown) for detecting the upper end of the paper 26, and by rotating the motor by a predetermined amount according to the detection result of the sensor and gradually raising the tip of the push-up plate 33, The paper 26 set on the paper stacking plate 28 is pressed against a pickup roller 29 provided on the apparatus main body side with a predetermined pressure. Here, when the copy start button of the apparatus main body is turned on, the pickup roller 29 and the feed roller 30a of the paper feed roller pair 30 are rotationally driven in the direction of the arrow in the figure.

  A plurality of sheets 26 are usually sent to the pair of paper feed rollers 30 by the pickup roller 29. The plurality of sheets fed to the pair of sheet feed rollers 30 are separated only by the uppermost sheet due to the friction generated by the rotation of the retard roller 30b whose nip passage speed is lower than that of the feed roller 30a. It is conveyed toward. Reference numeral 35 denotes a cassette cover whose front side is exposed to the outside and constitutes a part of the exterior surface of the apparatus main body.

  3 is a partial perspective view showing the sheet feeding device of the present embodiment from above, FIG. 4 is a partially enlarged perspective view showing from below, and FIG. 5 is a partial plan view showing from below. FIG. 6 is a perspective view of the cleaning member used in the paper feeding device of the present embodiment as viewed from below, and FIG. 7 is an enlarged view showing the periphery of the cleaning member and the retard roller of the paper feeding device of the present embodiment. It is a partial side view. Portions common to FIGS. 1 and 2 are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIGS. 3 to 5, a substantially rectangular sheet-like cleaning member 41 is connected to the sheet feed conveyance path 37 at a position facing the retard roller 30 b of the sheet feed conveyance path 37 from the upstream side in the conveyance direction (arrow direction). It protrudes substantially parallel. As shown in FIGS. 6 and 7, the foremost lower portion of the free end portion 41a of the cleaning member 41 is in contact with the surface of the retard roller 30b.

  When the retard roller 30b rotates in the direction of the arrow in FIG. 3, the free end portion 41a of the cleaning member 41 rubs the roller surface to remove foreign matters such as paper dust attached to the roller surface and clean it. It has become. The cleaning member 41 can be fixed to the paper feeding / conveying path 37 using an adhesive means such as an adhesive or a double-sided tape. In addition, the cleaning member 41 forms a part of the paper feed conveyance path 37.

  Further, as shown in FIGS. 6 and 7, a brush portion 42 formed from a brush-like member protrudes from the lower surface of the free end portion 41 a of the cleaning member 41. The tip of the brush portion 42 is in contact with the retard roller 30b upstream of the free end portion 41a of the cleaning member 41 in the rotational direction (the arrow direction in FIG. 7). When the retard roller 30b rotates, the brush portion 42 rubs the roller surface to remove foreign matters such as paper dust attached to the roller surface and cleans it.

  The material of the cleaning member 41 and the brush portion 42 is not particularly limited as long as the surface of the retard roller 30b can be cleaned. However, by forming the material from the elastic material, the roller surface of the retard roller 30b can be prevented from being damaged. it can. As an elastic material forming the cleaning member 41, for example, a synthetic resin sheet such as a polyethylene terephthalate (PET) sheet (Lumirror sheet) can be used.

  Moreover, the cleaning effect of the roller surface can also be enhanced by using a relatively hard synthetic resin such as urethane as the elastic material. Further, as the elastic material forming the brush portion 42, a synthetic resin brush such as PET can be used as described above, and the roller surface cleaning effect can be obtained by using a relatively hard synthetic resin such as urethane. Can also be increased.

  Next, the operation of the paper feeding device 20 will be described. FIG. 8 is a partial side view showing the paper feeding device of this embodiment. In FIG. 8, a broken line arrow indicates the conveyance direction of the paper 26 (see FIG. 1). When the copy start button on the apparatus main body is turned on and the pickup roller 29 and the paper feed roller pair 30 are rotationally driven in the direction of the arrow, the paper 26 is sent to the paper feed roller pair 30 by the pickup roller 29. .

  From the plurality of sheets sent to the pair of paper feed rollers 30, only the uppermost sheet is separated by the retard roller 30b that rotates following the feed roller 30a (in the direction of the arrow) as described above toward the paper conveyance path 12. Be transported. At this time, due to the rotation of the retard roller 30b, the roller surface is rubbed and cleaned by the brush portion 42 and then by the free end portion 41a of the cleaning member 41.

  Thus, since the brush part 42 which contacts the surface of the retard roller 30b protrudes from the free end part 41a of the cleaning member 41 and the roller surface is cleaned by the free end part 41a and the brush part 42, the retard roller One rotation of 30b makes it possible to clean twice by the brush portion 42 and the cleaning member 41, and the roller surface can be cleaned by two different methods. In addition, after the paper powder or the like on the roller surface is lifted and scraped off by the brush portion 42, the brush portion 42 can be further cleaned by the brush portion 42. Therefore, according to this embodiment, the surface of the retard roller 30b can be more reliably cleaned.

  However, the configuration of the cleaning member 41 is not particularly limited to the present embodiment. In addition, for example, the roller surface can be cleaned only by the brush portion 42 provided at the free end 41 a of the cleaning member 41. Moreover, the brush part 42 is not an essential component of the present invention, and the brush part 42 may be configured not to be used.

  FIG. 9 is an enlarged partial side view showing the periphery of the cleaning member and the retard roller of the sheet feeding device according to the second embodiment of the present invention. Portions common to those in FIG. 7 are denoted by common reference numerals and description thereof is omitted. In this embodiment, since only the brush portion 42 is brought into contact with the retard roller 30b, paper dust or the like on the surface of the retard roller 30b can be lifted and scraped off by the brush portion 42, and the roller surface is more reliably cleaned. be able to. Since other configurations are the same as those of the first embodiment, description thereof is omitted.

  FIG. 10 is an enlarged partial side view showing the periphery of the cleaning member and the retard roller of the paper feeding device according to the third embodiment of the present invention. Portions common to those in FIG. 7 are denoted by common reference numerals and description thereof is omitted. In the present embodiment, only the cleaning member 41 is used to clean the surface of the retard roller 30b. Thereby, when the retard roller 30b rotates, the paper dust and the like on the surface of the retard roller 30b can be removed by the free end 41a of the cleaning member 41. Since other configurations are the same as those of the first embodiment, description thereof is omitted.

  As described above, a sheet-like shape having a free end portion 41a that is in contact with the surface of the retard roller 30b and can clean the roller surface at a position facing the paper feed roller pair 30 in the paper feed conveyance path 37 on the upstream side in the conveyance direction. By providing the cleaning member 41, even if paper dust or the like is generated due to friction between the paper 26 and the paper feed roller pair 30, the paper dust can be removed.

  Further, since the cleaning member 41 can form a part of the paper feed conveyance path 37, the conveyance of the paper 26 can be stabilized. Accordingly, since the surface of the retard roller 30b can be cleaned with a simple configuration, the sheets 26 can be reliably separated and conveyed one by one while preventing the apparatus configuration from becoming complicated and large. Moreover, the surface of the retard roller 30b can be more reliably cleaned by providing the brush portion 42 in contact with the surface of the retard roller 30b at the free end 41a of the cleaning member 41.

  Moreover, in the said embodiment, since the cleaning member 41 and the brush part 42 were formed from the elastic material, damage to the roller surface of the retard roller 30b can be prevented. Note that the shape, size, and the like of the cleaning member 41 and the brush portion 42 used in the above embodiment are not particularly limited as long as they can contact the surface of the retard roller 30b and clean the roller surface. For example, the shape of the cleaning member 41 can be a shape suitable for the conveyance of the paper 26, such as being curved according to the shape of the paper feed conveyance path 37 to form a part of the conveyance path. In addition, the cleaning member 41 may be in the form of a blade, for example.

  In the above embodiment, the retard roller 30b that rotates following the feed roller 30a is used. However, the retard roller 30b that rotates in the same direction as the feed roller 30a (the opposite direction to the above embodiments) can also be used. . In such a case, for example, the free end 41a of the cleaning member 41 abuts against the retard roller 30b directly in the first embodiment and the third embodiment so as to be a counter via the brush portion 42 in the second embodiment. The cleaning member 41 can be set as appropriate, for example, formed from an elastic material having a hardness that can sufficiently withstand sliding with the roller surface.

  In addition, this invention is not limited to the said embodiment, A various change is possible in the range which does not deviate from the meaning of this invention. For example, although the present embodiment is applied to sheet feeding from a sheet feeding cassette, it can also be applied to sheet feeding from a manual feed tray. Although the printer has been described as an example of the image forming apparatus here, the present invention can of course be applied to other image forming apparatuses such as a copying machine and a facsimile.

  The present invention separates and transports a front feed roller that feeds paper from a paper storage section provided in the apparatus main body and a paper fed from the front feed roller one by one. A pair of sheet feed rollers each including a sheet feed roller and a separation roller for separating the sheets one by one, and the sheet feed roller pair sandwiched in the sheet conveyance direction, are fed from the forward feed roller A feeding path that guides a sheet to the downstream side of the pair of feeding rollers, and a surface of the separation roller at a position facing the separation roller of the feeding path from the upstream side in the feeding direction. And a cleaning member having a free end that can contact the roller and clean the roller surface.

  As a result, the roller surface of the separation roller can be cleaned with a simple configuration, and the sheets can be reliably separated and conveyed one by one while preventing the apparatus configuration from becoming complicated and large. In addition, by providing a brush portion at the free end that protrudes from the surface of the separation roller so that the roller surface can be cleaned, the roller surface of the separation roller can be more reliably cleaned.

  Further, by constituting the brush portion from a brush-like member, damage to the roller surface of the separation roller can be prevented. Further, by constituting the cleaning member from an elastic material, it is possible to prevent damage to the roller surface of the separation roller. Further, by using the image forming apparatus including the paper feeding device, it is possible to perform image formation in which paper feeding and image defects are prevented.

FIG. 2 is a side cross-sectional view illustrating a configuration of an image forming apparatus including a sheet feeding device according to the first embodiment of the present invention. These are side surface sectional views showing the periphery of the sheet feeding device of the present embodiment. These are the fragmentary perspective views which looked at the paper feeder of this embodiment from the upper part. These are the fragmentary perspective views which looked at the paper feeder of this embodiment from the lower side. These are the fragmentary top views which looked at the paper feeder of this embodiment from the lower side. These are the perspective views which looked at the cleaning member used for the paper feeder of this embodiment from the lower side. These are the expansion partial side views which show the cleaning member and retard roller periphery of the paper feeder of this embodiment. These are the partial side views which show the paper feeder of this embodiment. These are the expansion partial side views which show the cleaning member and retard roller periphery of the paper feeder which concerns on 2nd Embodiment of this invention. These are the expanded partial side views which show the cleaning member and retard roller periphery of the paper feeder which concerns on 3rd Embodiment of this invention.

Explanation of symbols

10 Paper cassette (paper compartment)
20 Paper feeder 29 Pickup roller (forward feed roller)
30 Paper feed roller pair 30a Feed roller (paper feed roller)
30b retard roller (separation roller)
37 Paper feed path (transport path)
DESCRIPTION OF SYMBOLS 41 Cleaning member 41a Free end part 42 Brush part 100 Image forming apparatus

Claims (5)

A forward feed roller that feeds paper from a paper container provided in the apparatus body;
The paper fed from the forward feed roller is separated and conveyed one by one, and is composed of a paper feed roller for conveying the paper and a separation roller for separating the paper one by one With Laura pair,
A paper feed device provided with a paper feed roller pair sandwiched in a paper feed direction and guiding a paper fed from the forward feed roller to a downstream side of the paper feed roller pair,
A cleaning member having a free end that abuts against the surface of the separation roller and can clean the roller surface protrudes at a position facing the separation roller in the conveyance path from the upstream side in the conveyance direction. Paper feeder.   The paper feeding device according to claim 1, wherein a brush portion that protrudes from the free end portion so as to be in contact with the separation roller and clean the surface of the roller.   The sheet feeding device according to claim 2, wherein the brush portion is formed of a brush-like member.   The sheet feeding device according to claim 1, wherein the cleaning member is made of an elastic material.   An image forming apparatus comprising the paper feeding device according to claim 1.

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