JP4120834B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus that includes a pickup roller that sandwiches a recording sheet on a manual feed tray and supplies the recording sheet to an internal recording apparatus paper conveyance path and a pad member.

  In image forming apparatuses such as conventional copiers, facsimile machines, and printers, a photosensitive drum that transfers a toner image onto recording paper, a fixing roller that fixes a toner image transferred from the photosensitive drum onto recording paper, A paper discharge roller that discharges the recording paper on which the toner image is fixed to the paper discharge tray, a recording paper conveyance path for conveying the recording paper, a manual feed tray, and a recording paper conveyance path that sandwiches the recording paper on the manual feed tray A pickup roller and a pad member. According to this image forming apparatus, the recording paper on the manual feed tray is nipped by the pickup roller and the pad member and supplied to the internal recording paper conveyance path. Then, the recording paper is conveyed through the recording paper conveyance path, and the toner image is transferred by the photosensitive drum. The recording paper to which the toner image has been transferred is further conveyed through the recording paper conveyance path, and the toner image transferred to the recording paper is fixed by a fixing roller. The recording paper on which the toner image has been fixed is transported through a recording paper transport path disposed downstream of the fixing roller in the recording paper transport direction, and is discharged to a paper discharge tray by a paper discharge roller.

Here, in the conventional image forming apparatus, in order to prevent a plurality of recording sheets from being simultaneously supplied to the inside by the pickup roller (prevention of no feed), a part of the opposing surface of the pad member facing the pickup roller The film was affixed so that the film was in close contact.
JP 2001-261177 A JP 2004-137021 A

  However, since the recording paper on the manual feed tray is supplied obliquely from above the opposing surface facing the pickup roller of the pad member, the recording paper hits the opposing surface of the pad member, and the recording paper further advances. Be blocked. As a result, there is a problem that the recording paper is not sandwiched between the two at the pressure contact portion between the pickup roller and the pad member and is not supplied to the internal recording paper conveyance path (no feed occurs).

  In view of the above circumstances, an object of the present invention is to provide an image forming apparatus that can reliably supply a recording sheet on a manual feed tray to a recording sheet conveyance path.

The invention according to claim 1 is an image forming apparatus including a manual feed tray, a pickup roller that sandwiches the recording paper on the manual feed tray and supplies the recording paper to a recording paper conveyance path, and the pad member The pad member protrudes from the one end surface that hangs down from the surface facing the pickup roller of the pad member to the pickup roller side, and is pressed by the pickup roller to bend toward the recording paper conveyance path side, and the recording paper A guide film having a protrusion that guides the pressure roller to the pressure contact portion between the pickup roller and the pad member, and the guide film is curved so that the protrusion is pressed by the pickup roller and curved toward the recording paper conveyance path side. characterized in that a positioning member for positioning with respect to the pad member, is provided

According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the positioning member is a protrusion provided in the pad member, and the protrusion is formed in a through hole formed in the guide film. By inserting the guide film, the guide film is positioned with respect to the pad member .

  According to a third aspect of the present invention, in the image forming apparatus according to the first or second aspect, the guide film is affixed to the one end face located on the manual feed tray side of the pad member. To do.

According to a fourth aspect of the present invention, in the image forming apparatus according to any one of the first to third aspects, the contact portion between the guide film and the pickup roller is formed by the contact between the pickup roller and the pad member. It is located above the press contact portion and located below the lower end portion of the manual feed tray.

According to the first aspect of the invention, the recording paper on the manual feed tray is nipped by the pickup roller and the pad member and supplied to the internal recording paper conveyance path. Here, the pad member is provided with a guide film that protrudes from one end surface of the pad member that faces the pickup roller facing the pickup roller toward the pickup roller and guides the recording paper to the pressure contact portion between the pickup roller and the pad member. Therefore, the recording paper on the manual feed tray is guided to the press contact portion between the pickup roller and the pad member. As a result, the recording paper is sandwiched between the pickup roller and the pad member and supplied to the recording paper conveyance path. Thus, according to the present invention, the recording sheets on the manual feed tray can be reliably supplied to the recording sheet conveyance path one by one.
Further, the guide film is pressed by the pickup roller so that the protruding portion of the guide film that protrudes from the one end surface that hangs down from the opposing surface of the pad member toward the pickup roller is curved toward the recording paper conveyance path side. The upper recording paper is guided to the pressure contact portion between the pickup roller and the pad member from the pressing portion between the pickup roller and the protruding portion of the guide film. Accordingly, the recording paper on the manual feed tray can be easily and surely guided to the press contact portion between the pickup roller and the pad member.

  According to the third aspect of the present invention, since the guide film is affixed to the one end surface of the pad member that is located on the manual feed tray side, the pickup roller and the pickup roller are placed before the recording paper on the manual feed tray contacts the pad member. The pressure contact portion with the pad member can be guided. Further, the film and one end surface of the pad member are bonded with an adhesive previously applied to the film, and can be easily replaced with a new film when the film is broken or deteriorated.

  According to the fourth aspect of the present invention, the contact portion between the guide film and the pickup roller is located above the pressure contact portion between the pickup roller and the pad member, and is located below the lower end portion of the manual feed tray. Therefore, the recording paper on the manual feed tray can be easily guided from the lower end portion of the manual feed tray to the pressure contact portion between the pickup roller and the pad member through the contact portion between the guide film and the pickup roller.

  Next, an image forming apparatus according to an embodiment of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the image forming apparatus 10 includes an image forming apparatus main body 12 serving as a casing. A paper feed cassette 14 is disposed below the image forming apparatus main body 12. A flapper 16 is provided inside the paper feed cassette 14. A predetermined size of recording paper is laminated on the upper portion of the flapper 16. A pickup roller 18 is disposed in the vicinity of the paper feed cassette 14. The flapper 16 is urged upward by a spring member 20 so that the uppermost surface of the recording paper stacked on the paper feed cassette 14 is in contact with the pickup roller 18. In this state, when the pickup roller 18 is rotationally driven, the recording paper is fed to the first recording paper conveyance path 22 one by one by the frictional force.

  A feed roller 24 and a press roller 26 are disposed downstream of the pickup roller 18 in the recording paper feeding direction. By the feed roller 24 and the press roller 26, the recording paper is conveyed downstream in the recording paper conveyance direction through the first recording paper conveyance path 22. A photosensitive drum 28 and a transfer roller 30 are disposed on the downstream side of the feed roller 24 and the press roller 26 in the recording paper conveyance direction. A paper dust removing roller 32 and a corona charger 34 are disposed along the periphery of the photosensitive drum 28. A developing unit 36 is disposed in the vicinity of the photosensitive drum 28. Further, an exposure head 38 is disposed in the vicinity of the developing device 36.

  The paper dust removing roller 32 is composed of a conductive sponge or the like, and removes toner and paper dust adhering to the surface of the photosensitive drum 28 after transfer. The corona charger 34 uniformly charges the surface of the photosensitive drum 28 by discharge from the corotron. An electrostatic latent image is formed by exposing the photosensitive drum 28 uniformly charged by the paper dust removing roller 32 and the corona charger 34 according to the image recording signal by the exposure head 38. Then, the toner in the developing device 36 is transferred to the electrostatic latent image formed on the photosensitive drum 28, and the electrostatic latent image is visualized. Further, the transfer roller 30 described above is disposed at a position facing the photosensitive drum 28 with the recording paper interposed therebetween, and the toner formed on the surface of the photosensitive drum 28 when a predetermined voltage is applied to the transfer roller 30. The image is transferred onto the recording paper by the transfer roller 30.

  A fixing roller 40 and a press roller 42 are disposed on the downstream side of the photosensitive drum 28 and the transfer roller 30 in the recording paper conveyance direction. The toner image transferred to the recording paper is fixed by the recording paper being sandwiched between the fixing roller 40 and the press roller 42 and heated and pressed.

  A pair of paper discharge rollers 58 is disposed downstream of the fixing roller 40 and the press roller 42 in the recording paper conveyance direction. Further, a discharge tray 44 is formed in the image forming apparatus main body 12, and the recording sheet conveyed through the first recording sheet conveyance path 22 is discharged to the discharge tray 44 by a pair of discharge rollers 58.

  A manual feed tray 50 is attached to the side surface of the image forming apparatus main body 12. A pickup roller 52 for the manual feed tray 50 is disposed near the lower end of the manual feed tray 50. A pad member 54 is disposed at a position facing the pickup roller 52. The recording paper on the manual feed tray 50 is nipped by the pressure contact portion between the pickup roller 52 and the pad member 54 and supplied to the inside of the image forming apparatus main body 12.

  Here, as shown in FIG. 2, a film (guide film) 48 is affixed to the end surface 54 </ b> A located on the manual feed tray 50 side of the pad member 54. The film 48 is made of polyethylene terephthalate (PET: POLYETHYLENE TEREPHTHALATE) having a thickness of 0.1 mm. That is, a plurality of through holes (not shown) are formed in the lower region portion 48A of the film 48, and a plurality of protrusions 54C formed below the end surface 54A of the pad member 54 are inserted into the through holes, respectively. As a result, the film 48 is positioned with respect to the pad member 54. Further, the upper region portion (protruding portion) 48B of the film 48 protrudes above the facing surface 54B of the pad member 54 facing the pickup roller 52. The upper region 48B of the film 48 is pressed from the pickup roller 52, and the upper region 48B of the film 48 is curved toward the second recording paper conveyance path 56 described later. In this way, the pickup roller 52 and the upper region 48B of the film 48 are in contact with each other at the pressing portion P.

  A second recording paper transport path (recording paper transport path) 56 is provided on the downstream side of the pickup roller 52 and the pad member 54 in the recording paper transport direction. The second recording paper conveyance path (recording paper conveyance path) 56 is connected to the first recording paper conveyance path 22 located between the pickup roller 18, the feed roller 24 and the press roller 26.

  Next, the operation of the image forming apparatus 10 of this embodiment will be described.

  As shown in FIG. 1, the recording paper placed on the inclined manual feed tray 50 is supplied to the inside of the image forming apparatus main body 12 by the pickup roller 52 and the pad member 54. Here, as shown in FIG. 2, the film 48 attached to the end surface 54 </ b> A of the pad member 54 has an upper region portion 48 </ b> B of the film 48 protruding from the facing surface 54 </ b> B of the pad member 54. Since it is pressed by the pickup roller 52 so as to curve toward the side, the pressing portion P is formed by the pickup roller 52 and the upper region portion 48 </ b> B of the film 48. For this reason, the recording paper on the manual feed tray 50 is guided to the pressing portion P, and the recording paper guided to the pressing portion P is guided to the pressure contact portion between the pickup roller 52 and the pad member 54 via the pressing portion P. As a result, the recording paper on the manual feed tray 50 can be easily and reliably guided to the press contact portion one by one, and no feed can be prevented.

  In particular, since the film 48 is affixed to the end surface 54A located on the side of the manual feed tray of the pad member 54, before the recording paper on the manual tray 50 contacts the opposing surface 54B of the pad member 54, the pickup roller 52 and the film It can be led to a pressing portion P formed by the upper region portion 48B of the 48. Further, the film 48 and the end face 54A of the pad member 54 are bonded with an adhesive previously applied to the film 48, and can be easily replaced with a new film when the film 48 is damaged or deteriorated.

  In the above embodiment, the configuration in which the upper region 48B of the film 48 is pressed by the pickup roller 52 has been described as an example. However, the present invention is not limited to this configuration, and the film 48 is, for example, the end surface 54A of the pad member 54. And the upper region 48B of the film 48 may be bent toward the second recording paper conveyance path 56 side. In this configuration, the recording paper on the manual feed tray 50 can be guided to the pressure contact portion between the pickup roller 52 and the opposing surface 54B of the pad member 54 without pressing the upper region portion 48B of the film 48 against the pickup roller 52.

1 is a schematic configuration diagram of an image forming apparatus according to an embodiment of the present invention. 1 is an enlarged view of a main part of an image forming apparatus according to an embodiment of the present invention.

Explanation of symbols

10 Image forming device 48 Film (guide film)
48B Upper area part (protrusion part)
52 Pickup roller 54 Pad member 54A End face (one end face)
56 Second recording paper transport path (recording paper transport path)
P Pressing part (contact part)

Claims (4)

An image forming apparatus having a manual feed tray, and a pickup roller and a pad member that sandwich the recording paper on the manual feed tray and supply the paper to the recording paper conveyance path,
In the pad member,
The one end surface of the pad member that hangs down from the facing surface facing the pickup roller protrudes toward the pickup roller side, and is pressed by the pickup roller to bend toward the recording paper conveyance path side. A guide film having a protruding portion that leads to a pressure contact portion between the roller and the pad member ;
A positioning member that positions the guide film with respect to the pad member such that the protruding portion is pressed by the pickup roller and curved toward the recording paper conveyance path;
An image forming apparatus comprising: The positioning member is a protrusion provided on the pad member,
The image forming apparatus according to claim 1, wherein the guide film is positioned with respect to the pad member by inserting the protrusion into a through hole formed in the guide film .   The image forming apparatus according to claim 1, wherein the guide film is attached to the one end surface of the pad member that is located on a manual feed tray side. The contact portion between the guide film and the pickup roller is located above the pressure contact portion between the pickup roller and the pad member, and is located below the lower end portion of the manual feed tray. Item 4. The image forming apparatus according to any one of Items 1 to 3 .

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