JP6697945B2 - Paper peeling device and image forming device - Google Patents

Description

  The present invention relates to a sheet peeling device and an image forming apparatus, and in particular, for example, is provided adjacent to a downstream side of a transfer position where a toner image is transferred from an image carrier to a sheet in a sheet conveying direction, and a sheet from the image carrier is removed. The present invention relates to a sheet peeling device and an image forming apparatus that promote peeling.

  An example of a conventional paper peeling device is disclosed in Patent Document 1. The paper stripping device of Patent Document 1 is an insulating or semi-conductive guide member with which a paper discharged from a transfer position comes into contact, and a plate-like member that is provided in contact with the back surface of the guide member and is electrically grounded. And a member (ground member). The guide member is provided with a plurality of ribs that are provided so as to be arranged at a predetermined interval in a direction orthogonal to the paper transport direction and extend along the paper transport direction.

  Further, it is known to provide an applied member to which a predetermined voltage is applied, instead of the ground member, on the back surface side of the guide member. By applying a voltage having a polarity opposite to the charge polarity of the sheet to the applied member, the sheet is properly attracted by the guide member side.

JP, 11-174858, A

  In the technique of Patent Document 1, the guide member is composed of only a plurality of ribs extending in the paper transport direction. For this reason, when the conveyed sheet is displaced from the reference position in the width direction, the side portions of the sheet may droop by being largely protruded from the ribs, and the sheet may come into contact with the applied member or the ground member. . Toner and paper dust may be attached to the applied member or the grounding member, so that when the paper comes into contact with the applied member or the grounding member, the paper is contaminated.

  Therefore, a main object of the present invention is to provide a novel sheet peeling device and image forming apparatus.

  Another object of the present invention is to provide a sheet peeling device and an image forming apparatus capable of appropriately preventing contact of a sheet with an applied member or a ground member.

A first aspect of the present invention is a sheet peeling device provided on the downstream side of a transfer position where a toner image is transferred from an image carrier to a sheet, the guide member having a plurality of guide ribs for guiding the sheet, and The plate-shaped member to be applied is provided on the back side of the plurality of guide ribs, and a predetermined voltage is applied. The plurality of guide ribs are provided so as to be arranged at predetermined intervals in a direction orthogonal to the paper conveyance direction. a first rib extending along the direction, respectively provided at positions corresponding to both side portions of the sheet, and a second rib extending in a direction oblique to the sheet conveyance direction seen including, a plurality of guide ribs and the application member The sheet peeling device further includes a strip-shaped conductive member that is provided on an upstream side portion in the sheet conveyance direction between the guide ribs and has a rough surface on the guide rib side .

In the first aspect of the invention, the paper peeling device is a device that is provided on the downstream side of the transfer position where the toner image formed on the image carrier is transferred to the paper, in the paper transport direction, and promotes peeling of the paper from the image carrier. The guide member has a plurality of guide ribs, and a plate-shaped applied member provided on the back surface side of the guide rib. The plurality of guide ribs provided on the guide member include a first rib and a second rib. The first ribs are ribs extending along the paper transport direction, and are provided so as to be arranged at predetermined intervals in the paper width direction that is a direction orthogonal to the paper transport direction. On the other hand, the second ribs are ribs that extend obliquely with respect to the paper transport direction, that is, are inclined in the paper width direction with respect to the paper transport direction, and are provided at positions corresponding to both sides of the paper. Further, a belt-shaped conductive member provided between the plurality of guide ribs and the applied member is further provided. The conductive member is formed of, for example, a conductive non-woven fabric, and the surface of the conductive member on the guide rib side, that is, the surface on the paper side is roughened.

According to the first aspect of the present invention, the second ribs extending obliquely with respect to the sheet conveying direction are provided at the positions corresponding to both side portions of the sheet, so that the applied member does not weaken the force of attracting the sheet and the applied member does not weaken. The contact of the sheet with the member can be appropriately prevented. Further, since the direction of discharge from the applied member is dispersed or diffused by the conductive member, it is possible to make the toner image less likely to be scattered.

  A second invention is according to the first invention, and in the second rib, the side edge of the sheet is an upstream side end and a downstream side in the sheet transport direction of the second rib, assuming that the sheet is transported at a reference position. It is arranged so as to pass between the ends.

  According to the second aspect of the present invention, it is possible to appropriately cope with whether the sheet deviates from the reference position to the left or right.

  A third invention is according to the first or second invention, and the second rib is formed so as to widen in the sheet transport direction with reference to the center of the sheet in the width direction.

  According to the third aspect of the present invention, the leading edge of the conveyed sheet is less likely to be caught by the second rib, so that the occurrence of sheet jam or the leading edge of the sheet is prevented.

  A fourth invention is according to any one of the first to third inventions, and the second ribs are provided at positions corresponding to both side portions of a plurality of sheets having different sizes.

  According to the fourth aspect, since the second ribs are provided at a plurality of positions according to the paper size, it is possible to appropriately handle a plurality of papers of different sizes.

  A fifth invention is according to any one of the first to fourth inventions, and the arrangement density of the plurality of guide ribs arranged at both ends of the guide member in the width direction of the sheet is determined by the guide member width direction in the sheet width direction. It is set to be larger than the arrangement density of the plurality of guide ribs arranged in the central portion of. That is, in the fifth aspect, the gap between the guide ribs is larger in the central portion than in both side portions of the guide member, and the surface of the applied member is exposed to the paper side in a larger area.

  According to the fifth aspect, it is possible to appropriately prevent the contact of the sheet with the applied member and to secure the force with which the applied member attracts the sheet.

A sixth invention is according to any one of the first to fifth inventions, and the paper transporting surface of the first rib and the paper transporting surface of the second rib are formed flush with each other.

A seventh invention is according to any of the first to sixth, in the rear side of the plurality of guide ribs, a plurality of small projections of the same projection height is formed by dispersing, a plurality of small projections It is brought into contact with the surface of the applied member.

According to the seventh aspect of the invention, the distances between the sheet conveying surface of the plurality of guide ribs and the surface of the applied member can be made uniform with good accuracy over the entire distance.

An eighth invention is according to any one of the first to seventh inventions, wherein the guide member further has a rectangular frame-shaped frame integrally connecting and holding the plurality of guide ribs, and the plurality of guide ribs convey the sheet. The downstream end in the direction of the frame extends outward from the downstream end of the frame in the paper transport direction.

A ninth aspect of the present invention is a sheet peeling device provided on the downstream side of a transfer position where a toner image is transferred from an image carrier onto a sheet, in the sheet conveying direction, and a guide member having a plurality of guide ribs for guiding the sheet, and A plurality of guide ribs are provided on the back side of the guide ribs and are provided with a grounded plate-shaped grounding member. The plurality of guide ribs are provided so as to be arranged at a predetermined interval in a direction orthogonal to the paper conveyance direction and extend along the paper conveyance direction. a first rib provided at positions corresponding to both sides of the paper, seen including a second rib extending in a direction oblique to the sheet transport direction, in the sheet conveying direction between the plurality of guide ribs and a ground member The paper peeling device further includes a belt-shaped conductive member that is provided in the upstream portion and has a rough surface on the guide rib side .

In the ninth invention, the paper peeling device is a device which is provided on the downstream side of the transfer position where the toner image formed on the image carrier is transferred to the paper, in the paper transport direction, and promotes the peeling of the paper from the image carrier. The guide member has a plurality of guide ribs, and a plate-shaped grounding member provided on the back side of the guide ribs. The plurality of guide ribs provided on the guide member include a first rib and a second rib. The first ribs are ribs extending along the paper transport direction, and are provided so as to be arranged at predetermined intervals in the paper width direction that is a direction orthogonal to the paper transport direction. On the other hand, the second ribs are ribs extending obliquely with respect to the paper transport direction, that is, inclined with respect to the paper transport direction in the paper width direction, and are provided at positions corresponding to both sides of the paper. Further, a belt-shaped conductive member provided between the plurality of guide ribs and the ground member is further provided. The conductive member is formed of, for example, a conductive non-woven fabric, and the surface of the conductive member on the guide rib side, that is, the surface on the paper side is roughened.

According to the ninth aspect of the invention, the second ribs extending obliquely with respect to the sheet conveying direction are provided at the positions corresponding to both side portions of the sheet. The contact of the paper can be properly prevented.

A tenth invention is according to the ninth invention, and in the second rib, the side edge of the sheet is the upstream end and the downstream side in the sheet transport direction of the second rib, assuming that the sheet is transported at the reference position. It is arranged so as to pass between the ends.

According to the tenth aspect , it is possible to appropriately deal with whether the sheet deviates from the reference position to the left or right.

An eleventh invention is according to the ninth or tenth invention, and the second rib is formed so as to widen in the sheet transport direction with reference to the center of the sheet in the width direction.

According to the eleventh aspect , since the leading edge of the conveyed sheet is less likely to be caught by the second rib, it is possible to prevent the occurrence of sheet jam and the leading edge of the sheet.

A twelfth invention is according to any one of the ninth to eleventh inventions, and the second ribs are provided at positions corresponding to both side portions of a plurality of sheets of different sizes.

According to the twelfth aspect , since the second ribs are provided at a plurality of locations according to the paper size, it is possible to appropriately handle a plurality of papers of different sizes.

A thirteenth invention is according to any one of the ninth to twelfth inventions, and the arrangement density of the plurality of guide ribs arranged at both ends of the guide member in the width direction of the paper is determined by the density of the guide member in the paper width direction. It is set to be larger than the arrangement density of the plurality of guide ribs arranged in the central portion of. That is, in the fourteenth aspect, the gap between the guide ribs is larger in the central portion than in both side portions of the guide member, and the surface of the grounding member exposed on the sheet side is large.

According to the thirteenth aspect , it is possible to appropriately prevent the contact of the sheet with the ground member and to secure the force of the ground member to attract the sheet.

A fourteenth invention is according to any one of the ninth to thirteenth inventions, and the paper transporting surface of the first rib and the paper transporting surface of the second rib are formed flush with each other.

A fifteenth invention is according to any one of the ninth to fourteenth inventions, in which a plurality of small protrusions having the same protruding height are dispersedly formed on the back side of the plurality of guide ribs, and the plurality of guide protrusions are formed. It is brought into contact with the surface of the ground member.

According to the fifteenth aspect, the distances between the sheet conveying surfaces of the plurality of guide ribs and the surface of the grounding member can be made uniform over the whole with high accuracy.

A sixteenth invention is according to any one of the ninth to fifteenth inventions, wherein the guide member further has a rectangular frame-shaped frame that integrally holds and holds the plurality of guide ribs, and the plurality of guide ribs convey the sheet. The downstream end in the direction of the frame extends outward from the downstream end of the frame in the paper transport direction.

A seventeenth aspect of the present invention is to provide a transfer device for transferring a toner image onto a sheet, a fixing device for fixing the toner image on the sheet, and a downstream side of the transfer device in the sheet conveying direction and an upstream side of the fixing device. An image forming apparatus including the sheet peeling device according to any one of the first to sixteenth inventions.

According to the seventeenth invention, the same effect as that of the first through sixteenth inventions can be obtained, and the contact of the sheet with the applied member or the grounding member can be appropriately prevented.

  According to the present invention, since the second ribs extending obliquely with respect to the sheet conveying direction are provided at the positions corresponding to both sides of the sheet, it is possible to appropriately prevent the sheet from contacting the applied member or the ground member.

  The above-mentioned objects, other objects, features and advantages of the present invention will become more apparent from the detailed description of the embodiments below with reference to the drawings.

It is an illustration figure which shows schematic structure of the image forming apparatus provided with the paper peeling apparatus which is 1st Example of this invention. FIG. 2 is an illustrative view showing a peripheral portion of a paper peeling device in the image forming apparatus of FIG. 1. 1 is a perspective view showing a paper peeling device that is a first embodiment of the present invention. It is a top view which shows the paper peeling apparatus of FIG. It is an illustration figure for demonstrating arrangement|positioning of the guide rib in the paper peeling apparatus of FIG. It is an illustration figure which shows the paper peeling apparatus which is 2nd Example of this invention. It is an illustration figure which shows the paper peeling apparatus which is 3rd Example of this invention.

[First embodiment]
With reference to FIGS. 1 and 2, a sheet peeling device 10 according to a first embodiment of the present invention is used in an image forming apparatus 100 that forms an image on a sheet by an electrophotographic method. As will be described later in detail, the sheet peeling device 10 is provided on the downstream side of the transfer position in the sheet conveying direction of the transfer position where the toner image formed on the intermediate transfer belt (image carrier) 54 is transferred to the sheet, and the intermediate transfer belt 54 is provided. The guide member 70 has a plurality of guide ribs 80 and 82, and an applied member 72 provided on the back side of the guide ribs 80 and 82.

  First, the basic configuration of the image forming apparatus 100 will be schematically described. In this embodiment, the image forming apparatus 100 is a multifunction peripheral (MFP) having a copying function, a printer function, a scanner function, a facsimile function, and the like.

  As shown in FIG. 1, the image forming apparatus 100 includes an apparatus main body 12 including an image forming unit 30 and the like, and an image reading apparatus 14 arranged above the apparatus main body 12.

  The image reading device 14 includes a document mounting table 16 formed of a transparent material. A document pressing cover 18 is openably and closably attached above the document placing table 16 via a hinge or the like. The document pressing cover 18 is provided with an ADF (automatic document feeder) 24 for automatically feeding the documents placed on the document tray 20 one by one to the image reading position 22. Although illustration is omitted, on the front surface side of the document placing table 16, an operation unit such as a touch panel and operation buttons for receiving an input operation such as a print instruction by a user is provided.

  Further, the image reading device 14 includes an image reading unit 26 including a light source, a plurality of mirrors, an imaging lens, a line sensor, and the like. The image reading unit 26 exposes the surface of the document with a light source, and guides the reflected light reflected from the surface of the document to an imaging lens by a plurality of mirrors. Then, the reflected light is imaged on the light receiving element of the line sensor by the imaging lens. The line sensor detects the brightness and chromaticity of the reflected light formed on the light receiving element, and generates image data based on the image on the document surface. A CCD (Charge Coupled Device), a CIS (Contact Image Sensor), or the like is used as the line sensor.

  A control unit 28 including a CPU and a memory, an image forming unit 30, and the like are built in the apparatus body 12. The control unit 28 transmits a control signal to each part of the image forming apparatus 100 including the sheet peeling device 10 according to an input operation to an operation unit such as a touch panel, and causes the image forming apparatus 100 to perform various operations. .. The control unit 28 is also a control unit of the paper peeling device 10 in order to control the entire image forming apparatus 100.

  The image forming unit 30 includes an exposure unit 32, a developing device 34, a photoconductor drum 36, a cleaner unit 38, a charging device 40, an intermediate transfer belt unit 42, a transfer roller 44, a sheet peeling device 10, a fixing unit 46, and the like, and a feeding unit. An image is formed on the paper conveyed from the paper tray 48 or the manual paper feed tray 50, and the paper on which the image is formed is discharged to the paper discharge tray 52. Image data read by the image reading unit 26, image data transmitted from an external computer, or the like is used as image data for forming an image on a sheet.

  The image data handled by the image forming apparatus 100 corresponds to four color images of black (K), cyan (C), magenta (M), and yellow (Y). Therefore, each of the developing device 34, the photoconductor drum 36, the cleaner unit 38, and the charging device 40 is provided four by four so as to form four kinds of latent images corresponding to each color, and these four image stations are formed. Composed.

  The photoconductor drum 36 is an image carrier in which a photosensitive layer is formed on the surface of a cylindrical base body having conductivity, and the charger 40 is a member that charges the surface of the photoconductor drum 36 to a predetermined potential. is there. The exposure unit 32 is configured as a laser scanning unit (LSU) including a laser emitting unit and a reflection mirror, and exposes the surface of the charged photosensitive drum 36 to expose an electrostatic latent image corresponding to image data. An image is formed on the surface of the photosensitive drum 36. The developing device 34 visualizes the electrostatic latent image formed on the surface of the photoconductor drum 36 with toner of four colors (YMCK). The cleaner unit 38 also removes the toner remaining on the surface of the photoconductor drum 36 after development and image transfer.

  The intermediate transfer belt unit 42 includes an intermediate transfer belt 54, a driving roller 56, a driven roller 58, four intermediate transfer rollers 60, and the like, and is arranged above the photoconductor drum 36. The intermediate transfer belt 54 is provided so as to be in contact with each photoconductor drum 36, and the toner images of the respective colors formed on the photoconductor drums 36 are sequentially superposed on the intermediate transfer belt 54 by using the intermediate transfer roller 60. By performing the transfer by the transfer, a multicolor toner image is formed on the intermediate transfer belt 54. Further, the transfer roller 44 is provided so as to press the intermediate transfer belt 54 between itself and the drive roller 56, and when the paper passes through the transfer nip portion between the intermediate transfer belt 54 and the transfer roller 44, The toner image formed on the intermediate transfer belt 54 is transferred to the paper.

  The sheet peeling device 10 includes a guide member 70, an applied member 72, and the like, and is a transfer position where the toner image formed on the intermediate transfer belt 54 is transferred to a sheet, that is, a transfer between the intermediate transfer belt 54 and the transfer roller 44. It is provided on the downstream side of the nip portion in the sheet conveying direction and adjacent to the transfer roller 44 side (the side facing the intermediate transfer belt 54). The paper peeling device 10 is a device for attracting the paper to which the toner image is transferred and not guiding the paper to the intermediate transfer belt 54 side, and guiding the paper toward the fixing unit 46 side. The specific configuration of the sheet peeling device 10 will be described later.

  The fixing unit 46 includes a heat roller 62 and a pressure roller 64, and is arranged above the transfer roller 44. The heat roller 62 is set to have a predetermined fixing temperature, and when the paper passes through the nip area between the heat roller 62 and the pressure roller 64, the toner image transferred onto the paper is melted, After being mixed and pressed, the toner image is thermally fixed on the paper.

  In the apparatus main body 12 as described above, the first paper for sending the paper from the paper feed tray 48 or the manual paper feed tray 50 to the paper discharge tray 52 via the registration roller 68, the transfer roller 44 and the fixing unit 46. The transport path L1 is formed. Further, when performing double-sided printing on a sheet, the sheet after the single-sided printing is completed and passed through the fixing unit 46 is returned to the first sheet conveyance path L1 at the upstream side of the transfer roller 44 in the sheet conveyance direction. The second sheet transport path L2 is formed. A plurality of transport rollers 66 for supplementarily applying a propulsive force to the sheet are appropriately provided in the first sheet transport path L1 and the second sheet transport path L2.

  When performing single-sided printing (image formation) in the apparatus main body 12, the sheets are guided one by one from the paper feed tray 48 or the manual paper feed tray 50 to the first paper transport path L1, and the transport rollers 66 cause the registration rollers 68 to move. Be transported to. Then, the registration roller 68 conveys the paper to the transfer roller 44 (transfer nip portion) at the timing when the front end of the paper and the front end of the image information on the intermediate transfer belt 54 are aligned, and the toner image is transferred onto the paper. .. Then, by passing through the fixing unit 46 (fixing nip portion), the unfixed toner on the sheet is melted by heat and fixed, and the sheet is discharged onto the sheet discharge tray 52.

  On the other hand, when performing double-sided printing, when single-sided printing is completed and the trailing edge of the sheet that has passed through the fixing unit 46 reaches the conveyance roller 66 near the discharge tray 52, the conveyance roller 66 is rotated in the reverse direction. As a result, the paper runs backward and is guided to the second paper transport path L2. The sheet guided to the second sheet transporting path L2 is transported by the transporting roller 66 through the second sheet transporting path L2, and is guided to the first sheet transporting path L1 at the upstream side of the registration roller 68 in the sheet transporting direction. At this point, the front and back of the paper are reversed, and thereafter, the paper passes through the transfer roller 44 and the fixing unit 46, so that printing is performed on the back surface of the paper.

  Next, the configuration of the paper peeling device 10 will be described with reference to FIGS. As described above, the paper peeling device 10 is provided adjacent to the downstream side of the transfer position where the toner image formed on the intermediate transfer belt 54 is transferred to the paper in the paper transport direction.

  As shown in FIGS. 2 to 5, the sheet peeling device 10 holds a guide member 70 having a plurality of guide ribs 80, 82, an applied member 72 provided on the back side of the guide ribs 80, 82, and the guide member 70. A holder 74 and the like are provided.

  The guide member 70 is formed of a synthetic resin such as ABS, polycarbonate and polypropylene, and has a plurality of guide ribs 80, 82 for guiding the sheet toward the fixing unit 46 and both end portions of the guide ribs 80, 82 on the back side. And a frame 84 having a rectangular frame shape for integrally connecting and holding the.

  The applied member 72 is a flat plate-shaped electrode (electrode plate) formed of metal such as stainless steel and aluminum, and is provided on the back surface side of the guide ribs 80, 82, that is, the surface opposite to the paper transport surface. . The length of the applied member 72 in the paper transport direction is 17 mm, for example. A power source (not shown) is connected to the applied member 72, and a predetermined voltage is applied from the power source to the applied member 72.

  The paper peeling device 10 also includes a paper detection actuator 76. The sheet detection actuator 76 is a member for detecting a sheet that has passed through the sheet peeling device 10 (that is, a sheet that has passed through the transfer roller 44), and is rotatably provided. When the sheet detection actuator 76 is rotated forward (in the sheet conveyance direction) as the sheet passes over the guide ribs 80 and 82 of the sheet peeling device 10, a photo sensor or the like (not shown) detects this.

  In such a paper peeling device 10, a predetermined voltage having a polarity opposite to the charging polarity of the paper is applied to the applied member 72 at the timing when the paper passes through the transfer roller 44 and the paper peeling device 10. As a result, the sheet that has passed through the transfer roller 44 is attracted to the applied member 72 side (that is, the guide member 70 side) by an electrical action, and the sticking of the sheet to the intermediate transfer belt 54 is prevented. In this embodiment, the sheet after passing through the transfer roller 44 is positively charged, so that a negative voltage having a polarity opposite to the charging polarity of the sheet is applied to the applied member 72. The sheet attracted toward the guide member 70 by the applied member 72 is guided by the plurality of guide ribs 80 and 82 of the guide member 70, and is conveyed toward the fixing unit 46 side so as to slide on the guide ribs 80 and 82.

  Here, as the number of printed sheets increases, toner, paper dust, and the like adhere to the applied member 72, so it is necessary to prevent contact of the paper with the applied member 72 in order to prevent the paper from being soiled. is there.

  However, if the guide member only has a plurality of ribs extending in the paper conveying direction as in the conventional paper peeling device, when the conveyed paper is laterally displaced or skewed from the reference position, the paper is not There is a case in which the side portion largely hangs out of the rib and hangs down, so that the sheet comes into contact with the applied member. In order to prevent the contact of the paper with the applied member, it is conceivable to increase the distance between the surface of the rib (paper transport surface) and the surface of the applied member, or to increase the number of ribs. In this case, the force with which the applied member attracts the paper becomes weak, and the paper may not be properly attracted to the guide member side.

  Therefore, in the first embodiment, in addition to the first ribs 80 extending along the sheet conveyance direction, the guide member 70 is provided with second ribs 82 extending obliquely with respect to the sheet conveyance direction on both sides of the sheet. By providing them at the positions corresponding to, the sheet to be contacted with the applied member 72 is prevented without weakening the force with which the applied member 72 attracts the sheet. The details will be described below.

  The plurality of guide ribs 80, 82 included in the guide member 70 form a part of the first sheet transporting path L1 and include the first rib 80 and the second rib 82. When it is not necessary to distinguish the first rib 80 and the second rib 82 in the description, they are simply described as guide ribs 80 and 82.

  The first ribs 80 are ribs extending along the paper transport direction, and are provided so as to be arranged at predetermined intervals in the paper width direction that is a direction orthogonal to the paper transport direction. An imaginary line extending from the first rib 80 to the downstream side in the sheet transport direction is directed toward the sheet transport surface of a pre-fixing guide (not shown) provided on the upstream side in the sheet transport direction of the fixing unit 46.

  The second ribs 82 extend in an oblique direction with respect to the paper transport direction, that is, are ribs inclined in the paper width direction with respect to the paper transport direction, and correspond to both side portions of the paper (that is, both end portions in the paper width direction). It is provided at each position. The second ribs 82 are arranged symmetrically with respect to the center line of the guide member 70 in the paper width direction. The inclination angle of the second ribs 82 with respect to the sheet conveying direction is not particularly limited, but is preferably 15 to 45 degrees, for example. Further, as can be seen from FIG. 5, the second ribs 82 are provided at positions corresponding to both sides of a plurality of sheets of different sizes such as A4, B4, and A3. That is, the second ribs 82 are provided at a plurality of positions according to the paper size so as to accommodate a plurality of papers having different sizes. By inclining the second ribs 82 with respect to the sheet conveying direction in this manner, the second ribs 78 become wider in the sheet width direction, and thus, even when the conveyed sheet is laterally displaced from the reference position. This makes it difficult for the side portions of the paper to protrude from the guide ribs 80 and 82.

  Further, when the second ribs 82 are provided at positions corresponding to both sides of the sheet, the side edges of the sheet to be conveyed are the upstream side ends of the second ribs 82, assuming that the sheet is conveyed at the reference position. It is preferably arranged so as to pass between the section and the downstream end. As a result, it is possible to properly cope with the sheet laterally displaced from the reference position to the left or right. Further, the second rib 82 is formed so as to widen in the sheet transport direction with reference to the widthwise center of the sheet. As a result, the leading edge of the conveyed sheet is less likely to be caught by the second rib 82, and the occurrence of sheet jams and the leading edge of the sheet are prevented.

  Further, in the first embodiment, the arrangement density of the guide ribs 80, 82 arranged at both ends in the paper width direction is set to be higher than the arrangement density of the guide ribs 80, 82 arranged in the central part in the paper width direction. It That is, the central portion of the guide member 70 has a larger gap between the guide ribs 80 and 82 than the both side portions thereof, and the surface of the applied member 72 exposed on the sheet side is larger. This is because the density of the guide ribs 80, 82 is increased at both sides where the paper easily contacts the applied member 72, and the contact of the paper with the applied member 72 is appropriately prevented, while the paper is applied to the applied member 72. This is because the density of arrangement of the guide ribs 80 and 82 is reduced in the central portion where it is difficult to contact the 72 to secure the force with which the applied member 72 attracts the sheet.

  Further, in the first embodiment, the sheet conveying surface of the first rib 80 and the sheet conveying surface of the second rib 82 are formed flush with each other (that is, at the same height). Although not shown, a plurality of small protrusions having the same protruding height are formed dispersedly on the back side of the guide ribs 80, 82. When the member 72 to be applied is attached to the back side of the guide ribs 80, 82, the small protrusions of the guide ribs 80, 82 are brought into contact with the surface of the member 72, so that the sheet conveying surface of the guide ribs 80, 82 and the member 72 to be applied. The distance from the surface of the can be made uniform with high accuracy. Further, the end portions of the guide ribs 80, 82 on the downstream side in the sheet conveying direction are extended outward than the end portions of the frame 84 on the downstream side in the sheet conveying direction.

  As described above, according to this embodiment, the second ribs 82 extending obliquely with respect to the sheet conveying direction are provided at the positions corresponding to both side portions of the sheet, so that the force applied by the applied member 72 can attract the sheet. It is possible to appropriately prevent the sheet from coming into contact with the applied member 72 without weakening.

[Second Embodiment]
Next, with reference to FIG. 6, a paper peeling device 10 according to a second embodiment of the present invention will be described. The second embodiment differs from the above-described first embodiment in that a conductive member 90 is further provided. Since the configuration of the other parts is the same, the parts common to the above-mentioned first embodiment are designated by the same reference numerals, and the overlapping description will be omitted or simplified.

  As shown in FIG. 6, in the sheet peeling device 10 of the second embodiment, a belt-shaped conductive member 90 is provided at an upstream side portion in the sheet transport direction between the plurality of guide ribs 80 and 82 and the applied member 72. Is further provided. The surface of the conductive member 90, which is a surface on the guide rib 80, 82 side, has a rough surface shape. For example, the conductive member 90 is formed of a conductive non-woven fabric, and is attached to the surface of the applied member 72 using a conductive adhesive or the like.

  The toner image on the paper immediately after transfer is easily affected by electricity and easily scattered, but the surface portion of the applied member 72 on the upstream side in the paper transport direction should be covered by the conductive member 90 having a rough surface. Since the direction of discharge from the applied member 72 is dispersed or diffused by the conductive member 90, it is possible to make the toner image less likely to scatter.

  The range in which the conductive member 90 is provided, that is, the range in which the conductive member 90 covers the surface of the applied member 72 is not particularly limited, and can be appropriately changed according to the distance between the transfer position and the applied member 72. However, the cost increases if the range in which the conductive member 90 is provided is increased. Further, the toner image on the sheet is easily affected by electricity on the upstream side in the sheet conveying direction. Therefore, it is preferable that the conductive member 90 is provided so as to cover a predetermined range on the upstream side of the applied member 72 in the sheet conveying direction. Specifically, in order to appropriately exert the effect of suppressing the scattering of the toner image and reduce the cost, the conductive member 90 covers the range of 25 to 50% on the upstream side of the applied member 72 in the paper transport direction. Is preferably provided. In the second embodiment, the conductive member 90 is provided so as to cover the range of about 40%.

  According to the second embodiment, as in the first embodiment, it is possible to properly prevent the sheet from coming into contact with the applied member 72. Further, since the conductive member 90 having a rough surface is provided, it is possible to suppress the scattering of the toner image on the paper.

  In the second embodiment described above, the applied member 72 and the conductive member 90 are formed by separate members, but the applied member 72 and the conductive member 90 may be formed by a single member. For example, the surface of the applied member 72 may be roughened to provide a band-shaped conductive member 90 having a rough surface between the plurality of guide ribs 80 and 82 and the applied member 72. Good.

[Third Embodiment]
Next, with reference to FIG. 7, a paper peeling device 10 according to a third embodiment of the present invention will be described. The third embodiment differs from the above-described first embodiment in that a peeling electrode 92 is further provided. Since the configuration of the other parts is the same, the parts common to those in the above-described first embodiment are designated by the same reference numerals, and overlapping description will be omitted or simplified.

  As shown in FIG. 7, the paper peeling device 10 of the third embodiment further includes a peeling electrode 92 provided on the downstream side of the guide member 70 and the applied member 72 in the paper conveyance direction. The peeling electrode 92 is a flat plate-shaped electrode formed of metal such as stainless steel and aluminum, and is attached to the end portion of the holder 74 on the upstream side in the sheet conveying direction so as to extend in the sheet width direction. In the third embodiment, a sawtooth electrode is used as the peeling electrode 92, and a plurality of triangular tooth-shaped discharge protrusions arranged at predetermined intervals in the paper width direction are provided on the end surface of the peeling electrode 92 on the side of the first paper transport path L1. It is formed. A power source (not shown) is connected to the peeling electrode 92, and a predetermined voltage is applied from the power source to the peeling electrode 92.

  In such a paper peeling device 10, a predetermined voltage having a polarity opposite to the charging polarity of the paper is applied to the applied member 72 at the timing when the paper passes through the transfer roller 44 and the paper peeling device 10. A predetermined voltage having a polarity opposite to the charging polarity of the paper is applied to the peeling electrode 92. For example, a voltage of the same magnitude as that of the applied member 72 is applied to the peeling electrode 92. As a result, the sheet that has passed through the transfer roller 44 is pulled toward the guide member 70 by the electrical action of the peeling electrode 92 and the applied member 72, and the sheet is prevented from sticking to the intermediate transfer belt 54.

  According to the third embodiment, like the first embodiment, it is possible to appropriately prevent the sheet from contacting the applied member 72. Further, since the peeling electrode 92 is provided, the paper can be pulled closer to the guide member 70 side.

[Fourth Embodiment]
Subsequently, a paper peeling device 10 according to a fourth embodiment of the present invention will be described. Although not shown, the fourth embodiment is different from the above-described first embodiment in that a grounding member is provided instead of the applied member 72. Since the configuration of the other parts is the same, the parts common to those in the above-described first embodiment are designated by the same reference numerals, and overlapping description will be omitted or simplified.

  Briefly described, in the paper peeling device 10 of the fourth embodiment, a flat plate-shaped grounding member is provided on the back side of the plurality of guide ribs 80 and 82. The ground member is made of metal such as stainless steel and aluminum, and is grounded, for example, via a diode.

  In such a paper peeling device 10, when the paper approaches the paper peeling device 10, since the paper after passing through the transfer roller 44 is positively charged, a negative electric charge is dielectricized to the grounding member. By concentrating this electric charge on the surface side of the ground member, an attractive force due to an electrostatic force acts between the paper and the ground member, and the paper is attracted to the guide member 70 side. The sheet pulled toward the guide member 70 by the grounding member is guided by the plurality of guide ribs 80 and 82, and is conveyed toward the fixing unit 46 so as to slide on the guide ribs 80 and 82.

  According to the fourth embodiment, as in the first embodiment, the second ribs 82 extending obliquely with respect to the sheet conveying direction are provided at the positions corresponding to the both side portions of the sheet, so that the grounding member fixes the sheet. It is possible to appropriately prevent the sheet from coming into contact with the ground member without weakening the attractive force.

  In each of the above-described embodiments, the applied member 72 or the ground member is formed in a flat plate shape, but the present invention is not limited to this, and the applied member 72 or the ground member may be formed in a curved plate shape. In accordance with this, the guide ribs 80 and 82 can also be curved along the applied member 72 or the ground contact member.

  Further, in each of the above-described embodiments, the second rib 82 is formed so as to extend linearly in an oblique direction with respect to the paper transport direction, but the second rib 82 has a curved or bent shape in the oblique direction. May extend. That is, the inclination angle of the second ribs 82 with respect to the paper transport direction may change on the way.

  Further, in each of the above-described embodiments, the sheet conveyance surface of the first rib 80 and the sheet conveyance surface of the second rib 82 are flush with each other (that is, at the same height). The surface and the paper transport surface of the second rib 82 do not necessarily have to be flush with each other. For example, the paper transporting surface of the second rib 82 can be lower than the paper transporting surface of the first rib 80. Further, for example, the paper transport surface of the second rib 82 is lower than the paper transport surface of the first rib 80 in the upstream portion of the paper transport direction, and the paper transport surface of the first rib 80 in the downstream portion of the paper transport direction. The height may be gradually increased toward the downstream side in the sheet conveying direction so as to be flush with the conveying surface. As a result, the leading edge of the conveyed sheet is less likely to be caught by the second rib 82, and the occurrence of sheet jam or sheet leading edge bending is prevented.

  Furthermore, in each of the above-described embodiments, the image forming apparatus 100 is a multi-function peripheral including a copying machine, a facsimile, a printer, and the like. However, the image forming apparatus 100 may be a copying machine, a facsimile, a printer, or the like. Alternatively, it may be a multi-function machine that combines at least two of these.

  Although the configuration changes from the first embodiment shown in the above second to fourth embodiments have been individually described, each of the technical features described in each embodiment or each modification is , Can be combined with each other.

  Further, all of the specific numerical values, materials, shapes, and the like mentioned above are merely examples, and can be appropriately changed according to the needs of the product specifications and the like.

10... Paper peeling device 30... Image forming unit 54... Intermediate transfer belt (image carrier)
44... Transfer roller 46... Fixing unit 70... Guide member 72... Applied member 80... First rib 82... Second rib 84... Frame 90... Conductive member 92... Peeling electrode 100... Image forming apparatus

Claims (17)

A paper peeling device provided downstream of a transfer position for transferring a toner image from an image carrier to a paper,
A guide member having a plurality of guide ribs for guiding the sheet; and a plate-shaped member to be applied which is provided on the back side of the plurality of guide ribs and to which a predetermined voltage is applied,
The plurality of guide ribs,
First ribs provided so as to be lined up at a predetermined interval in a direction orthogonal to the paper transport direction and extending along the paper transport direction;
Respectively provided at positions corresponding to both side portions of the paper, seen including a second rib extending in a direction oblique to the sheet transport direction,
The sheet peeling device further comprising: a belt-shaped conductive member that is provided in an upstream side portion in the sheet transport direction between the plurality of guide ribs and the applied member and has a rough surface on the guide rib side .   The sheet peeling device according to claim 1, wherein the second rib is arranged so that a side edge of the sheet passes between an upstream end and a downstream end of the second rib in the sheet transport direction. ..   The sheet peeling device according to claim 1, wherein the second rib is formed so as to widen in the sheet transport direction with reference to the widthwise center of the sheet.   The sheet peeling device according to claim 1, wherein the second ribs are provided at positions corresponding to both side portions of the plurality of sheets having different sizes.   The arrangement density of the plurality of guide ribs arranged at both end portions of the guide member in the width direction of the paper is higher than the arrangement density of the plurality of guide ribs arranged at the center portion of the guide member in the width direction of the paper. The sheet peeling device according to any one of claims 1 to 4, which is set to be large. Wherein the first rib sheet conveying surface of the second rib sheet conveyance surface of the formed flush, paper separation device according to any one of claims 1 to 5. On the back side of the plurality of guide ribs, a plurality of small protrusions having the same protruding height are formed in a dispersed manner.
The plurality of small protrusions are in contact with the surface of the object application member, the sheet peeling apparatus according to any one of claims 1 to 6. The guide member further includes a rectangular frame-shaped frame that integrally connects and holds the plurality of guide ribs,
End of the downstream side in the sheet conveying direction of the plurality of guide ribs are extended outward from the end portion on the downstream side in the sheet conveying direction of the frame, according to any one of claims 1 to 7 Paper peeling device. A paper peeling device provided downstream of a transfer position for transferring a toner image from an image carrier to a paper,
A guide member having a plurality of guide ribs for guiding the sheet; and a plate-shaped grounding member provided on the back side of the plurality of guide ribs and grounded,
The plurality of guide ribs,
First ribs provided so as to be lined up at a predetermined interval in a direction orthogonal to the paper transport direction and extending along the paper transport direction;
Respectively provided at positions corresponding to both side portions of the paper, seen including a second rib extending in a direction oblique to the sheet transport direction,
The sheet peeling device further comprising a belt-shaped conductive member provided on an upstream side portion in the sheet transport direction between the plurality of guide ribs and the ground member and having a rough surface on the guide rib side . The sheet peeling device according to claim 9 , wherein the second rib is arranged such that a side edge of the sheet passes between an upstream end and a downstream end of the second rib in the sheet transport direction. . Said second rib, based on the widthwise center of the sheet, the formed so as to extend toward the sheet conveying direction, the sheet peeling apparatus according to claim 9 or 10, wherein. It said second rib is provided at a position corresponding to each of both side portions of the plurality of different paper sizes, paper separation apparatus according to any one of claims 9 to 11. The arrangement density of the plurality of guide ribs arranged at both ends of the guide member in the width direction of the paper is higher than the arrangement density of the plurality of guide ribs arranged in the center part of the guide member in the width direction of the paper. The sheet peeling device according to any one of claims 9 to 12 , which is set to be large. Wherein the first rib sheet conveying surface of the second rib sheet conveyance surface of the formed flush, paper separation apparatus according to any one of claims 9 to 13. On the back side of the plurality of guide ribs, a plurality of small protrusions having the same protruding height are dispersedly formed,
The plurality of small protrusions are in contact with the surface of the ground member, the sheet peeling apparatus according to any one of claims 9 to 14. The guide member further includes a rectangular frame-shaped frame that integrally connects and holds the plurality of guide ribs,
End of the downstream side in the sheet conveying direction of the plurality of guide ribs are extended outward from the end portion on the downstream side in the sheet conveying direction of the frame, according to any one of claims 9 to 15 Paper peeling device. A transfer device that transfers a toner image onto paper,
The fixing device for fixing the toner image on the sheet, and a downstream side of the transfer device in the sheet conveying direction and is provided on the upstream side of the fixing device, the paper separation according to any one of claims 1 to 16 An image forming apparatus including a device.

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