JP2009083957A - Image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming device capable of reducing noise caused when conveying a paper due to interference of the paper with an inner face of a paper conveyance passage. <P>SOLUTION: This image forming device is constituted by providing a plurality of ribs 35 protruding along the direction of conveyance on a paper conveyance face 30a of a conveyance unit 30 and arranging sound absorbing members 31 in a plurality of sections (six sections in this case) over the whole conveyance width region of the conveyance unit 30 among clearances formed by each rib 35. A sheet material 33 is arranged to cover the whole paper conveyance face 30a from above the sound absorbing members 31 and the ribs 35. <P>COPYRIGHT: (C)2009,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 method for reducing paper conveyance noise generated during paper conveyance.

  In recent years, as the image forming function has become more sophisticated and the apparatus has become more compact, it has become necessary to rapidly change the transport direction of the paper transported within the image forming apparatus main body. Is provided with a curved conveying section, and it is becoming necessary to further reduce the radius of curvature in the curved conveying section. For this reason, particularly in a high-speed machine, the sheet conveyance sound generated in the curved conveyance unit has become a problem as noise.

  As a method for reducing the sheet conveying sound, conventionally, a method of reducing frictional resistance by reducing a contact area between the sheet and the inner surface of the curved conveying unit by providing a rib on the inner surface of the curved conveying unit is used. . However, even if ribs are provided, interference between the leading edge of the paper and the ribs is unavoidable, and the paper arrival time to the image forming unit is not constant due to paper feeding delay due to friction or charging of the paper due to static electricity. Sometimes it became unstable. In addition, the generation of paper powder accompanying friction may have an adverse effect on the scanning optical system and the photoreceptor in the apparatus.

In view of this, a method for smoothly transporting a sheet by reducing interference between the sheet and the inner surface of the transport path has been proposed. For example, Patent Document 1 discloses a resin sheet that directly connects an end portion of a sheet transport guide or via an elastic member. An image forming apparatus is disclosed that prevents the generation of a rubbing sound of a sheet by covering with a sheet. Further, Patent Document 2 discloses a paper transport device in which a paper guide member is formed of a flexible sheet, and an end portion is serrated to reduce a contact area with the paper and reduce sliding noise. . Further, in Patent Document 3, a tape such as a polyfluorinated ethylene resin or a polyester resin that smoothes the paper running surface (conveying surface) corresponding to the location where the recording medium forms a convex curved surface is attached as a scratching noise preventing means. An image forming apparatus is disclosed.
Japanese Patent No. 3827026 Japanese Patent Laid-Open No. 10-129985 JP 2006-82899 A

  However, when the surface of the paper transport guide is covered with an elastic member and a resin sheet as in Patent Document 1, the shape and thickness of the paper transport guide may change, and the paper may not be smoothly guided. Further, in the methods of Patent Documents 2 and 3, although the scratching noise between the paper conveyance surface and the paper can be reduced, it is possible to completely suppress the collision noise between the front or rear edge of the paper and the inner wall of the paper conveyance path in the curved surface conveyance unit. It was not possible to effectively reduce the sheet conveying sound.

  SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide an image forming apparatus that effectively reduces the occurrence of sheet conveyance noise due to interference between a sheet and a sheet conveyance path inner wall.

  In order to achieve the above object, the present invention provides a sheet feeding device, a sheet conveying path for conveying the sheet fed from the sheet feeding apparatus to each part of the apparatus main body, and a sheet on the sheet conveyed through the sheet conveying path. In the image forming apparatus including an image forming unit for forming an image on the sheet, a plurality of ribs project along the conveyance direction on the sheet conveyance surface forming the sheet conveyance path, and a gap between the ribs is formed. A sound absorbing member that fills at least part of the sound absorbing member and a sheet material that covers the sound absorbing member and the rib are provided.

  According to the present invention, in the image forming apparatus configured as described above, the sound absorbing member and the sheet material are arranged in a curved conveyance unit of the sheet conveyance path.

  According to the present invention, in the image forming apparatus configured as described above, the sound absorbing member is bonded to the sheet conveying surface and the back surface of the sheet material via an adhesive member.

  In the image forming apparatus having the above-described configuration, the sum of the thicknesses of the sound absorbing member and the adhesive member is substantially equal to the height of the rib.

  According to the first configuration of the present invention, the sound absorbing member that fills the gap between the ribs protruding from the sheet conveying surface absorbs the sheet conveying sound generated by the interference between the sheet and the sheet conveying surface, and the rib and the sound absorbing member. By reducing the friction between the sheet and the sheet conveying surface by the sheet material covering the sheet, the sheet conveying sound can be effectively suppressed. Further, by disposing the sound absorbing member so as to fill the gap between the ribs, it is possible to suppress the sheet conveying sound without changing the shape of the conveying surface.

  According to the second configuration of the present invention, in the image forming apparatus having the first configuration, the sound absorbing member and the sheet material are arranged in the curved conveyance section of the sheet conveyance path, so that the leading edge and the trailing edge of the sheet in particular. It is possible to effectively reduce the sheet conveyance sound at the curved conveyance unit where the two collide with each other.

  Further, according to the third configuration of the present invention, in the image forming apparatus having the first or second configuration, the sound absorbing member is bonded to the sheet conveying surface and the back surface of the sheet material via the adhesive member. Adhesive area of the agent is widened and sufficient adhesive strength can be obtained. Further, since the sound absorbing member and the sheet material are in close contact with each other, the sheet conveying sound can be efficiently absorbed by the sound absorbing member.

  According to the fourth configuration of the present invention, in the image forming apparatus having the third configuration, the sheet material is corrugated by making the sum of the thickness of the sound absorbing member and the adhesive member substantially equal to the height of the rib. The sheet material can be arranged flat.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing the internal configuration of the image forming apparatus of the present invention. In FIG. 1, reference numeral 100 denotes an image forming apparatus, and here, a digital multifunction peripheral is shown as an example. In the image forming apparatus 100, when performing a copy operation, in the image forming unit 3 in the multifunction machine main body 2, the photosensitive drum 5 having a small diameter that rotates in the direction A in the figure is uniformly charged by the charging unit 4. An electrostatic latent image is formed on the photosensitive drum 5 by a laser beam from an exposure unit (laser scanning unit or the like) 7 based on the document image data read by the reading unit 6, and developed into an electrostatic latent image by the developing unit 8. An agent (hereinafter referred to as toner) is attached to form a toner image. The toner is supplied to the developing unit 8 from the toner container 9.

  The sheet is conveyed from the sheet feeding mechanism 10 to the image forming unit 3 via the sheet conveying path 11 and the registration roller pair 12 toward the photosensitive drum 5 on which the toner image is formed as described above. 3, the toner image on the surface of the photosensitive drum 5 is transferred to the sheet by the transfer roller 13 (image transfer unit). The sheet onto which the toner image has been transferred is separated from the photosensitive drum 5 and conveyed to a fixing unit 14 having a fixing roller pair 14a to fix the toner image. The sheet that has passed through the fixing unit 14 is sent to a sheet conveyance path 15 branched in a plurality of directions, and is conveyed in a conveyance direction by path switching mechanisms 21 and 22 having a plurality of path switching guides provided at branch points of the sheet conveyance path 15. Are distributed as they are (or after being sent to the paper conveyance path 16 and double-sided copying), and discharged to the paper discharge section including the first discharge tray 17a and the second discharge tray 17b.

  Although not shown, a static elimination device that removes residual charges on the surface of the photosensitive drum 5 is provided on the downstream side of the cleaning device 18. Further, the paper feed mechanism 10 is detachably attached to the multifunction machine main body 2 and includes a plurality of paper feed cassettes 10a and 10b for storing paper and a stack bypass (manual feed tray) 10c provided above the paper feed cassettes 10a and 10b. These are connected to the image forming unit 3 including the photosensitive drum 5 and the developing unit 8 by the paper transport path 11.

  Specifically, the sheet conveyance path 15 first branches into a left and right fork on the downstream side of the fixing roller pair 14a, and one path (a path branching rightward in FIG. 1) communicates with the first discharge tray 17a. It is configured as follows. The other path (the path that branches in the left direction in FIG. 1) branches into the upper and lower forks via the conveying roller pair 19, and the other path (the path that branches in the upper direction in FIG. 1) is the second discharge tray. It is comprised so that it may communicate with 17b. On the other hand, the other path (the path that branches downward in FIG. 1) is configured to communicate with the sheet conveyance path 16.

  FIG. 2 is a schematic cross-sectional view showing the sheet conveyance path of the image forming apparatus of the present invention. Portions common to FIG. 1 are denoted by the same reference numerals and description thereof is omitted. 2 shows a state in which the image forming apparatus is viewed from the back side of the sheet of FIG. 1, and the arrangement of the photosensitive drum 5 and each roller is opposite to that in FIG. Further, here, the paper conveyance path 11 (indicated by an arrow in the drawing) until the paper fed from the paper feed cassette 10a is conveyed to the image forming unit 3 is described.

  As shown in FIG. 2, the paper feed cassette 10a includes a pickup roller 25 and a paper feed roller pair 27 including a paper feed roller 27a and a separation roller 27b as a paper feed device, and the pickup roller 25 is provided with the paper feed cassette 10a. Are arranged so as to come into contact with the upper surface end on the downstream side in the transport direction of the paper stacked on the paper. The pickup roller 25 and the paper feed roller 27a rotate in conjunction with a drive transmission mechanism (not shown).

  The paper fed from the paper feed cassette 10 a passes through the paper transport path 11 and is transported to the registration roller pair 12. The registration roller pair 12 composed of the registration rollers 12a and 12b is disposed in the vicinity of the upstream side of the photosensitive drum 5, and temporarily stops the conveyed paper and synchronizes with the image formation timing on the surface of the photosensitive drum 5. Then, it is conveyed again to the nip portion between the photosensitive drum 5 and the transfer roller 13. In addition, the registration roller pair 12 abuts against the leading edge of the paper to form a slack, and also serves to correct the skew of the paper. Between the paper feed cassette 10a and the registration roller pair 12, arm-type sensors 29a and 29b that detect the passage of the paper by directly abutting the leading edge of the paper are disposed.

  Reference numeral 30 denotes a conveyance unit that constitutes a part (one conveyance surface) of the sheet conveyance path 11, and a registration roller 12a, a transfer roller 13, and the like are arranged. The sheet conveyed from the paper feed roller pair 27 is conveyed in the direction of the registration roller pair 12 along the curved conveyance unit 11 a of the sheet conveyance path 11. A sound absorbing member 31 and a sheet material 33 are disposed in the vicinity of the curved conveyance unit 11 a of the conveyance unit 30.

  3 and 4 are perspective views of the transport unit 30 in FIG. 2, in which FIG. 3 shows a state in which the sound absorbing member 31 is disposed on the paper transport surface 30a, and FIG. 4 shows that the paper transport surface 30a is further moved from the state of FIG. The state covered with the material 33 is shown. 3 and 4 show a state in which the transport unit 30 is viewed from the paper transport path 11 side (left side in FIG. 2), and the leading end of the paper collides with the paper transport surface 30a of the transport unit 30 from a diagonally downward direction. Then, the sheet is conveyed in the direction of the registration roller 12a along the sheet conveyance surface 30a.

  As shown in FIG. 3, a plurality of ribs 35 project from the sheet conveyance surface 30 a along the conveyance direction, and the sound absorbing member 31 covers the entire conveyance width in the gap formed by each rib 35. It is arranged at a plurality of locations (here, 6 locations). Then, as shown in FIG. 4, the sheet material 33 is disposed so as to cover the entire area of the sheet conveyance surface 30 a from above the sound absorbing member 31.

  FIG. 5 is an enlarged cross-sectional view of the paper conveyance surface 30a (cross-section BB ′ in FIG. 4). As shown in FIG. 5, the sound absorbing member 31 is disposed so as to fill the gap between the ribs 35, and is fixed to the front surface of the paper transport surface 30 a and the back surface of the sheet material 33 via a double-sided adhesive sheet 37. When the sheet material 33 is bonded only to the tip of the rib 35, the bonding area is small and the bonding strength is weak. However, the bonding area is reduced by bonding the sheet material 33 to the surface of the sound absorbing member 31 as shown in FIG. It becomes wide and sufficient adhesive strength can be obtained, and peeling of the sheet material 33 can be prevented. In the configuration of FIG. 5, only one sheet material 33 is coated on the rib 35, and the height of the sheet conveyance surface 30 a (the height of the rib 35) varies only by the thickness of the sheet material 33. For this reason, the conveyance sound can be reduced without changing the conveyance state of the sheet.

  Further, since the sound absorbing member 31 and the sheet material 33 are in close contact with each other, the sound absorbing member 31 can efficiently absorb the impact sound caused by the collision of the front end of the paper and the sound of the rear end colliding due to the stiffness of the paper. Furthermore, since the combined thickness of the sound absorbing member 31 and the double-sided pressure-sensitive adhesive sheet 37 is substantially equal to the height of the rib 35, the sheet material 33 does not wave and the surface of the sheet material 33 can be maintained flat.

  The sound absorbing member 31 is not particularly limited as long as it is a material having elasticity capable of absorbing the collision sound of the paper, and sponge, foamed urethane, soft rubber, nonwoven fabric, or the like can be used. Further, as the sheet material 33, a resin sheet having excellent surface slidability can be used. As the resin sheet, a polymer polyethylene sheet, a sheet made of polyethylene terephthalate (PET), or a sheet coated with a fluorine resin on the surface is used. In particular, the polymer polyethylene sheet is excellent in smoothness and slidability. It is preferably used because static electricity hardly occurs due to friction. Further, instead of the double-sided pressure-sensitive adhesive sheet 37, the sheet conveyance surface 30a and the sound absorbing member 31 or the sound absorbing member 31 and the sheet agent 33 may be bonded using an adhesive.

  Even if the sound absorbing member 31 is not disposed in all the gaps of the ribs 35, a sufficient sound absorbing effect can be obtained if it is disposed in a plurality of locations in the gap. Here, in order to obtain a stable sound absorbing effect, it is preferable to arrange the sound absorbing members 31 substantially uniformly over the entire conveyance width as shown in FIG.

  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, in the above-described embodiment, only the example in which the present invention is applied to the curved conveyance unit provided in the sheet conveyance path from the paper feeding mechanism to the image forming unit has been described. However, the places where the present invention is applied are limited thereto. For example, any distance between the fixing unit and the paper discharge unit (the paper conveyance path 15 in FIG. 1) or a double-side conveyance path (the paper conveyance path 16 in FIG. 1) used during duplex printing can be used. Of course, the present invention can also be applied to the paper conveyance path provided at the location.

  In each of the above-described embodiments, only the image forming apparatus using cut paper cut to a predetermined size has been described, but the present invention can be used in an image forming apparatus using roll paper in exactly the same manner. The present invention can be applied to other types of copying machines, such as tandem color copying machines and analog type monochrome copying machines, as well as image forming apparatuses such as facsimiles and laser printers, in addition to digital multifunction machines. is there.

  The present invention relates to a sheet feeding device, a sheet conveying path that conveys a sheet fed from the sheet feeding apparatus to each part of the apparatus main body, and an image formation that forms an image on the sheet conveyed through the sheet conveying path. A plurality of ribs projecting along a conveyance direction on a sheet conveyance surface that forms a sheet conveyance path, and a sound absorbing member that fills at least a part of a gap between the ribs; A sheet material for covering the sound absorbing member and the rib is provided.

  As a result, the sheet conveying sound generated when the sheet passes through the sheet conveying path can be effectively suppressed without substantially changing the shape of the conveying surface. Therefore, image formation that meets the increasing demand for noise reduction in recent years. The apparatus can be realized with a simple and low-cost configuration.

  In addition, since the sound absorbing member and the sheet material are arranged in the curved conveyance unit where the conveyance sound is likely to be generated due to the collision of the leading edge and the trailing edge of the sheet, the image forming apparatus can more effectively reduce the sheet conveying sound. Furthermore, since the sound absorbing member, the sheet conveying surface and the sheet material are bonded using an adhesive member, and the sum of the thickness of the sound absorbing member and the bonding member is substantially equal to the height of the rib, the sound absorbing member, the sheet conveying surface, and It is an image forming apparatus with excellent usability that can firmly absorb the sheet conveyance sound by firmly adhering the sheet material, and can maintain the smooth conveyance of the sheet by flattening the sheet material surface. .

1 is a schematic cross-sectional view showing an internal configuration of an image forming apparatus according to the present invention. FIG. 4 is a schematic cross-sectional view showing a paper conveyance path until a fed paper is conveyed to the image forming unit. FIG. 5 is a perspective view showing a state in which a sound absorbing member is arranged on a paper transport surface of a transport unit. FIG. 4 is a perspective view illustrating a state in which a sheet conveyance surface is covered with a sheet material. FIG. 3 is an enlarged cross-sectional view of a sheet conveyance surface.

Explanation of symbols

DESCRIPTION OF SYMBOLS 3 Image formation part 5 Photosensitive drum 10 Paper feed mechanism 10a, 10b Paper feed cassette 11, 15, 16 Paper conveyance path 11a Curve conveyance part 12 Registration roller pair 13 Transfer roller 30 Conveyance unit 30a Paper conveyance surface 31 Sound absorbing member 33 Sheet material 35 Rib 37 Double-sided adhesive sheet (adhesive member)
100 Image forming apparatus

Claims (4)

A sheet feeding device, a sheet conveying path that conveys the sheet fed from the sheet feeding apparatus to each part of the apparatus main body, and an image forming unit that forms an image on the sheet conveyed through the sheet conveying path. In the provided image forming apparatus,
A plurality of ribs project from the sheet conveying surface forming the sheet conveying path along the conveying direction, and a sound absorbing member that fills at least a part of the gap between the ribs, and covers the sound absorbing member and the ribs. An image forming apparatus comprising: a sheet material to be processed.   The image forming apparatus according to claim 1, wherein the sound absorbing member and the sheet material are arranged in a curved conveyance unit of the sheet conveyance path.   The image forming apparatus according to claim 1, wherein the sound absorbing member is bonded to the sheet conveying surface and the back surface of the sheet material via an adhesive member.   The image forming apparatus according to claim 3, wherein a sum of thicknesses of the sound absorbing member and the adhesive member is substantially equal to a height of the rib.

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