JP2007099491A - Paper feeding device and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve problems wherein paper dust adhered and deposited to/on a top plate part covering a part above a paper feeding tray drops on a sheet of paper due to shock caused when inserting a tray and image defect occurs. <P>SOLUTION: A configuration of this paper feeding device is provided with the paper feeding tray 17 for storing a sheet of paper 21, an air spraying part 19 for spraying air to a side end part of the paper 21 stored on the paper feeding tray 17, the top plate part 26 covering the part above the paper feeding tray 17, and a paper dust recovery part 20 for recovering the paper dust 27 adhered to the top plate part 26. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile machine, and a multifunction machine, and more particularly to a paper feeding device used in the image forming apparatus.

  In recent years, along with the diversification of recording media, in addition to paper other than plain paper, such as thick paper, OHP paper, tracing paper, etc., whiteness and gloss have been added to the paper surface to meet the market demand for colorization. Opportunities are increasing to form images on paper such as coated paper and glossy paper that have been subjected to a coating process. Of these, OHP paper, tracing paper, coated paper, and glossy paper have a higher surface smoothness than plain paper, so when multiple sheets are stacked on top of each other, close contact acts between the sheets. Power is greater than plain paper.

  In general, in an image forming apparatus such as a copying machine or a printer, sheets stored in a sheet feeding tray are separated and conveyed one by one, but the adhesion between the sheets when stacked on the sheet feeding tray is large. As a result, the paper separation property deteriorates. As a result, when feeding (feeding) a sheet from the sheet feed tray, misfeeds such as a multi-feed in which a plurality of sheets are overlapped and a delay in sheet conveyance are likely to occur. In particular, in an environment with high humidity, a large adhesion force acts between the sheets, so that double feed and misfeed are likely to occur.

  Therefore, conventionally, a technique has been proposed in which air is blown to the end portion of the paper stored in the paper feed tray to release the close contact between the papers by the flow of air between the papers (for example, Patent Document 1). reference).

JP-A-11-5543

  In general, copy paper or the like is cut into a predetermined size in the manufacturing process. For this reason, fine paper dust adheres to the cut surface of the paper. Therefore, when air is blown onto the edge of the sheet as in the conventional technique, paper dust rises in the sheet feeding tray. The paper dust soared adheres to the lower surface of the top plate covering the upper side of the paper feed tray, and gradually accumulates there. Then, after a certain period of use, the paper dust accumulated so far becomes a lump and falls on the paper due to an impact when the paper supply tray is inserted and the paper feed tray is inserted. In such a case, an image is formed on the paper on which the paper dust is placed, so that an image defect such as a white spot occurs in the paper powder portion.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a paper feeding device capable of preventing the occurrence of image defects due to paper dust.

  The paper feeding device according to the present invention includes a paper feeding tray for storing paper, and paper dust collecting means for collecting paper dust attached to a top plate portion covering the upper side of the paper feeding tray.

  In the paper feeding device according to the present invention, when paper dust that has risen into the paper feeding tray by air blowing or the like adheres to the top plate that covers the top of the paper feeding tray, the paper dust is collected by the paper dust collecting means. By collecting the paper powder, the paper dust collected on the top plate is not agglomerated and dropped on the paper.

  According to the paper feeding device of the present invention, the paper dust attached to the top plate portion is collected by the paper dust collecting means, so that the paper dust collected on the top plate portion does not fall on the paper in the paper feeding tray. The occurrence of image defects due to paper dust can be prevented in advance.

  Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic diagram showing a configuration example of an image forming apparatus to which the present invention is applied. The illustrated image forming apparatus 1 includes a receiving unit 5 connected to an image reading device 2 and an external device (such as a personal computer) 3 via a communication line 4, and an image writing unit based on image data received by the receiving unit 5. 6, an image recording control unit 7 that controls 6, a drum-shaped image carrier (photosensitive drum) 8 on which an electrostatic latent image is written by the image writing unit 6, and a circumferential direction of the image carrier 8. A charging device 9, a developing device 10, a cleaner 11, a transfer roll 12 that transfers the toner image formed on the image carrier 8 to a sheet, a fixing unit 13 that fixes the toner image transferred to the sheet, A discharge roll 14 for discharging the paper on which the toner image has been fixed by the fixing device 13, a discharge tray 15 for receiving the paper discharged by the discharge roll 14, and the opposing positions of the image carrier 8 and the transfer roll 12 (d) A sheet transport unit 16 that transports the sheet toward the sheet position), a plurality of sheet feed trays 17 that store sheets used for image formation in a stacked state, and a sheet supply unit that supplies sheets stored in the sheet feed tray 17. The paper portion 18 and an air blowing portion 19 that blows air to the side end portion of the paper stored in the paper feed tray 17 are provided.

  Among these, the image reading apparatus 2 may exist as a functional unit of the image forming apparatus 1 or may exist as a functional unit separate from the image forming apparatus 1. Further, the paper feed tray 17, the paper feed unit 18, and the air blowing unit 19 constitute a “paper feed device” included in the image forming apparatus 1. Further, the image writing section 6, the image carrier 8, the charger 9, the developing device 10, the transfer roll 12, the fixing device 13 and the like constitute “image forming means” in the present invention.

  FIG. 2 is a schematic side view showing the configuration of the sheet feeding device according to the first embodiment of the present invention. The illustrated sheet feeding device includes a paper dust collecting unit 20 in addition to the sheet feeding tray 17, the sheet feeding unit 18, and the air blowing unit 19 described above. The paper feed tray 17 is provided so as to be able to be taken in and out (inserted / removed) from the apparatus main body of the image forming apparatus 1. The operation of taking in and out the paper feed tray 17 includes an operation of pulling out the paper feed tray 17 from the apparatus main body and an operation of inserting the paper feed tray 17 into the apparatus main body. In addition, the paper tray 17 is inserted and removed when, for example, paper is set, replenished, or replaced with respect to the paper tray 17.

  The paper feed tray 17 is provided with a paper base 22 that supports the paper 21 in a loaded state in a space in which a predetermined number (a plurality of sheets) of paper (paper bundle) can be accommodated. The paper table 22 is supported by an elevating mechanism (not shown) so as to be movable up and down. In this paper feed tray 17, the paper 21 is supported in parallel with the main surface (upper surface) of the paper table 22, so the stacking direction of the paper is perpendicular to the main surface of the paper table 22 (up and down direction in FIG. 2). Become.

  The paper supply unit 18 is disposed on the side where paper is supplied. The paper supply unit 18 supplies the paper 21 stored in the paper supply tray 17 in order from the top, and is configured using a paper supply roll 23. The paper feed roll 23 is configured using, for example, a pickup roll, a feed roll, and a retard roll. The pickup roll abuts on the uppermost surface of the paper 21 stored in the paper feed tray 17 and rotates in this contact state, thereby calling up the paper 21 from the paper feed tray 17. The feed roll feeds the paper 21 called by the pickup roll toward the paper transport unit 16 while being nipped with the retard roll. The retard roll contacts the lower surface side of the paper 21 called between the feed roll (nip position) by the pickup roll, and gives an appropriate frictional resistance (braking force) to the lower paper in this contact state. This prevents paper double feeding.

  The air blowing unit 19 is configured by using a blower such as a blower or a fan, for example, and is mounted on an exterior cover portion on the front side F of the paper feed tray 17. The front side F refers to the side from which the paper feed tray 17 is pulled out in the paper feeding device, and the opposite side is the rear side R. In the image forming apparatus, the side on which the user operating the image forming apparatus stands is the front side F, and the opposite side is the rear side R. The air blowing unit 19 blows air from the direction perpendicular to the paper feeding direction to the side edge of the paper 21 accommodated in the paper feeding tray 17, thereby separating the upper paper 21 by air blow-off. It is a thing to undo the adhesion. The side edge of the paper refers to the edge of the paper that is arranged in the paper feed tray 17 in a direction perpendicular to the paper feed direction. The paper feeding direction is the direction in which the paper moves when the paper is fed by the paper feeding unit 18 in the paper feeding tray 17. In this example, air is blown from the direction orthogonal to the paper feeding direction toward the side edge of the paper 21, but this is not limiting, and the leading edge of the paper 21 from the downstream side in the paper feeding direction is not limited thereto. Air may be blown toward the head.

  The paper dust collecting unit 20 is provided at an end portion on the rear side R of the paper feed tray 17. The paper dust collecting unit 20 moves integrally with the paper feed tray 17 when the user performs an operation to put in and out the paper feed tray 17. The paper dust collecting unit 20 is configured using a cleaning brush 24 and a tray 25. The cleaning brush 24 is elongated in the width direction of the paper feed tray 17 when viewed from the front side F. The cleaning brush 24 serves as a cleaning member for cleaning the top plate portion 26 that covers the upper side of the paper feed tray 17. The hair tip portion of the cleaning brush 24 is disposed in contact with the lower surface of the top plate portion 26. The tray 25 is disposed almost directly below the contact portion between the cleaning brush 24 and the top plate portion 26 in order to receive the paper powder 27 that has been swept away by the cleaning brush 24.

  In the image forming apparatus including the sheet feeding device having the above configuration, when the sheets 21 stored in the sheet feeding tray 17 are sequentially supplied by the sheet feeding unit 18, the uppermost sheet is raised by raising the sheet table 22 prior to the sheet feeding unit 18. The paper 21 is disposed at a predetermined paper feed height (a height that contacts the pickup roll), and air is blown from the air blowing unit 19 toward the side edge of the paper 21. When air flows between the sheets of the uppermost layer by the blowing of air, the adhesion between the sheets is released there. For this reason, the paper can be reliably separated and sent out by the paper feed roll 23.

  Further, when air is blown from the air blowing portion 19 as described above, the paper dust 27 that has risen due to this adheres to the lower surface of the top plate portion 26. For this reason, as the paper feeding operation is repeated many times, the paper dust 27 gradually accumulates on the lower surface of the top plate portion 26. Incidentally, FIG. 2 shows a state in which paper dust 27 is attached to the lower surface of the top plate portion 26 by blowing air, but actually, dust other than paper dust is also added to the top plate portion 26 together with the paper dust 27. It will adhere to the lower surface of.

  On the other hand, in the paper feeding device having the above-described configuration, the paper 21 set in the paper feeding tray 17 is set or replenished, or the paper 21 set in the paper feeding tray 17 is replaced with another paper (for example, paper having a different size). When the user performs an operation of taking in and out the paper feed tray 17 in order to replace it with a paper having a different paper quality, the paper dust collecting unit 20 moves together with the paper feed tray 17. That is, when the operation of pulling out the paper feed tray 17 is performed, the paper dust collecting unit 20 moves to the front side F together with the paper feed tray 17, and when the operation of inserting the paper feed tray 17 is performed, Together, the paper dust collecting unit 20 moves to the rear side R.

  Accordingly, when the paper feed tray 17 is pulled out, the cleaning brush 24 moves to the front side F while stroking the lower surface of the top plate portion 16, and when the paper feed tray 17 is inserted, the cleaning brush 24 is moved to the top plate portion 16. Move to the rear side R while stroking the lower surface. For this reason, the paper dust 27 adhering to the lower surface of the top plate portion 26 is swept away by the cleaning brush 24. Further, the paper powder 27 swept off by the cleaning brush 24 falls into the tray 25. For this reason, the paper dust 27 attached to the lower surface of the top plate portion 26 can be removed by the cleaning brush 24 and collected in the receiving tray 25 by performing the operation of taking in and out the paper feed tray 17. Therefore, the paper dust 27 can be collected by the paper dust collecting unit 20 before the paper dust 27 adhering to the lower surface of the top plate part 26 falls due to the impact of the insertion operation of the paper feed tray 17. For this reason, generation | occurrence | production of the image defect by paper dust can be prevented beforehand.

  Further, as a configuration of the paper dust collecting unit 20, the cleaning brush 24 is detachably attached to the paper feed tray 17 using attachment means such as screws, so that the cleaning brush 24 is replaced with an unused (new) brush from the used brush. Can be replaced. Further, the tray 25 is also detachably attached to the paper feed tray 17 using attachment means such as screwing, so that the tray 25 in which the paper powder 27 is accumulated can be removed and emptied, or a separately prepared empty ( Alternatively, it can be replaced with a new) receiving tray 25.

  Further, as shown in FIG. 3, the paper dust collecting unit 20 is configured so that the posture of the cleaning brush 24 serving as a cleaning member can be changed to two postures, a vertical posture and a horizontal posture, and the top plate portion 26 is cleaned. When the top plate portion 26 is in a vertical posture, the first operation mode (cleaning mode) is set in which the cleaning brush 24 is brought into contact with the lower surface of the top plate portion 26. It is good also as a 2nd operation mode (non-cleaning mode) in which the cleaning brush 24 is separated (retracted) from the lower surface of the top plate portion 26 in a horizontal posture. In this case, the posture change (switching of the operation mode) of the cleaning brush 24 may be performed manually or automatically using a drive source such as a solenoid or a motor.

  When the configuration in which the operation mode (posture) of the cleaning brush 24 can be switched as described above is employed, the posture of the cleaning brush 24 is set to the horizontal posture only when the top plate portion 26 needs to be cleaned by the adhesion of the paper powder 27. By changing from the vertical posture to the vertical posture, the operation mode of the cleaning brush 24 can be switched from the second operation mode to the first operation mode, and the cleaning brush 24 can be brought into contact with the top plate portion 26. For this reason, deformation and wear of the cleaning brush 24 can be reduced as compared with the case where the cleaning brush 24 is always in contact with the top plate portion 26. When cleaning the top plate portion 26 is not necessary, the cleaning brush 24 can be supplied without contacting the top plate portion 26 by maintaining the operation mode of the cleaning brush 24 in the second operation mode (horizontal posture). Since the paper tray 17 can be taken in and out, the operating force required for the paper tray 17 can be reduced.

  FIG. 4A is a schematic perspective view showing a configuration of a paper feeding device according to the second embodiment of the present invention, and FIG. The illustrated sheet feeding device is different from the first embodiment in particular in the configuration of the paper dust collecting unit 20. That is, the cleaning brush 24 and the tray 25 are attached to a support member 28 that spans the width direction of the paper feed tray 17 (direction parallel to the paper feed direction). The support member 28 is guided and supported by a pair of left and right inner guide members 29 in the width direction of the paper feed tray 17 so as to be movable up and down. Each inner guide member 29 is fixed to an end portion on the rear side of the sheet feeding tray 17 with screws or the like.

  In addition, rotating rollers 30 are provided at both ends of the support member 28. The rotating roller 30 is engaged with a guide groove 32 of an outer guide member 31 that forms a pair on the left and right in the width direction of the paper feed tray 17. Each outer guide member 31 is fixed to the apparatus main body frame or the like by screwing or the like. The guide groove 32 is formed by two upper and lower elongated upper guide grooves 32A and a lower guide groove 32B along the loading / unloading direction of the paper feed tray 17. The upper guide groove 32A and the lower guide groove 32B are connected to each other at the front side F end and the rear side R end. A switching gate 33 is provided on the front side F of the guide groove 32. The switching gate 33 is swingably provided inside the outer guide member 31.

  In the image forming apparatus including the sheet feeding device having the above-described configuration, when the sheet feeding tray 17 is inserted and mounted at a predetermined position, an end (around portion) on the rear side R of the guide groove 32 formed in the outer guide member 31. The rotating roller 30 is disposed on the surface. Therefore, in the paper dust collecting unit 20, the support member 28 moves downward while being guided by the pair of left and right inner guide members 29 due to the weight of the cleaning brush 24, the tray 25, the support member 28, and the like. Therefore, the rotary rollers 30 provided at both ends of the support member 28 are in a state of falling into the lower guide groove 32 </ b> B inside the outer guide member 31. Further, in this state, the cleaning brush 24 is separated from the lower surface of the top plate portion 26.

  When the user operates to pull out the paper feed tray 17 from the state in which the paper feed tray 17 is mounted in this manner, the rotary roller 30 moves to the front side F along the lower guide groove 32B together with the paper feed tray 17. To do. For this reason, the cleaning brush 24 is maintained in a state of being separated from the lower surface of the top plate portion 26 (second operation mode) from the start to the end of the drawer operation of the paper feed tray 17. Further, inside the outer guide member 31, the rotating roller 30 contacts the switching gate 33 while the paper feed tray 17 is being pulled out. At this time, the switching gate 33 is once pushed up by the rotating roller 30 and returns to the original state when the rotating roller 30 completely passes (separates from the switching gate 33).

  Thereafter, when the operation of inserting the paper feed tray 17 after completing the replenishment and replacement of the paper is performed, the rotary roller 30 moves together with the paper feed tray 17. At this time, the rotating roller 30 is guided by the switching gate 33 on the front side of the guide groove 32 and guided from the lower guide groove 32B to the upper guide groove 32A, and moves to the rear side R as it is along the upper guide groove 32A. . When the rotary roller 30 is thus engaged with the upper guide groove 32 </ b> A, the cleaning brush 24 comes into contact with the lower surface of the top plate portion 26. For this reason, the cleaning brush 24 is maintained in a state (first operation mode) in contact with the lower surface of the top plate portion 26 from immediately after the insertion operation of the paper feed tray 17 is started until it is finished. Therefore, the paper dust 27 adhering to the lower surface of the top plate portion 26 can be swept off by the cleaning brush 24 and collected in the tray 25.

  Further, by such an operation, the cleaning brush 24 can be brought into contact with the lower surface of the top plate portion 26 only when the paper feed tray 17 is inserted, and the paper powder 27 adhering thereto can be removed by the cleaning brush 24. For this reason, if the cleaning brush 24 is disposed further to the rear side than the rear end of the paper feed tray 17, even if the paper powder 27 that has been swept away by the cleaning brush 24 is missed by the receiving tray 25. The paper powder 27 can be dropped outside the paper feed tray 17. Therefore, it is possible to reliably prevent the paper feed tray 17 and the paper stored in the paper feed tray 17 from becoming dirty due to the fall of the paper powder 27.

  FIG. 5 is a schematic side view showing the configuration of the sheet feeding device according to the third embodiment of the present invention. In the configuration of the illustrated sheet feeding apparatus, of the sheet feeding trays 17-1 and 17-2 arranged in the upper and lower two stages, the upper part of the lower sheet feeding tray 17-1 is the upper sheet feeding tray 17-2. It is covered with a bottom surface (corresponding to the top plate), and paper dust 27 adheres to it. The configuration of the paper dust collecting unit 20 having the cleaning brush 24 and the tray 25 is the same as that in the first embodiment, but the mounting position of the paper dust collecting unit 20 in the tray loading / unloading direction (left and right direction in FIG. 5). Is set to the front side F of the lower paper feed tray 17-1.

  In the image forming apparatus including the sheet feeding device having the above-described configuration, when the upper sheet feeding tray 17-2 is pulled out while the lower sheet feeding tray 17-1 is mounted, the upper sheet feeding tray 17- 2 is moved to the front side F while being stroked by the cleaning brush 24, and when an operation of inserting the upper paper feed tray 17-2 is performed, the bottom surface of the upper paper feed tray 17-2 is moved to the cleaning brush 24. Move to the rear side R while being stroked.

  As a result, when the upper feed tray 17-2 is put in and out, the paper dust 27 adhering to the bottom surface of the upper feed tray 17-2 is swept away by the cleaning brush 24. Further, the paper powder 27 swept off by the cleaning brush 24 falls into the tray 25. For this reason, by performing the operation of taking in and out the upper paper feed tray 17-2, the paper dust 27 adhering to the bottom surface of the paper feed tray 17-2 can be removed by the cleaning brush 24 and collected in the tray 25. Therefore, before the paper dust 27 adhering to the bottom surface portion of the upper paper feed tray 17-2 falls due to an impact caused by the insertion operation of the lower paper feed tray 17-1, the paper dust 27 is removed from the paper dust recovery unit 20. Can be recovered. For this reason, generation | occurrence | production of the image defect by paper dust can be prevented beforehand.

  Although not shown, in the tray loading / unloading direction, when the attachment position of the paper dust collection unit 20 is set at the rear end of the lower paper feed tray 17-1 as in the first embodiment, the upper stage The paper feed 27 attached to the bottom of the upper paper feed tray 17-2 is removed in the same manner as described above by operating the lower paper feed tray 17-1 with the paper feed tray 17-2 attached. It can be removed by the cleaning brush 24 and collected in the tray 25.

  FIG. 6 is a schematic side view showing the configuration of the paper feeding device according to the fourth embodiment of the present invention. In the configuration of the sheet feeding device shown in the figure, the upper portion of the sheet feeding tray 17 is covered with an endless belt member 34. The belt member 34 constitutes a “top plate portion” and has a wide belt structure corresponding to the depth dimension of the paper feed tray 17. The belt member 34 is stretched in a loop by a driving roll 35, a driven roll 36, and a tension roll 37 that constitute a belt driving mechanism. The drive roll 35 rotates the belt member 34 in the direction of the arrow by rotating with a motor (not shown) as a drive source. The driven roll 36 rotates as the belt member 34 travels as the drive roll 35 rotates. The tension roll 37 rotates according to the travel of the belt member 34 while applying a predetermined tension to the belt member 34.

  Further, the paper dust collecting unit 20 is provided in the vicinity of the paper feeding unit 18 and at a position deviated in the horizontal direction from a position directly above the paper feeding tray 17. The paper dust collecting unit 20 includes a cleaning blade (cleaning member) 38 that cleans the belt member 34 that is running by a belt drive mechanism, and a tray 39. Since the cleaning blade 38 has a long plate-like structure that is long in the width direction of the belt member 34 (the axial direction of the driven roll 36), the blade tip portion of the blade is in contact with the belt member 34 wound around the driven roll 36. Is arranged in. The tray 38 is disposed almost directly below the contact portion between the belt member 34 and the cleaning blade 39 in order to receive the paper dust 27 scraped off by the cleaning blade 38.

  In the image forming apparatus including the sheet feeding device having the above-described configuration, the upper side of the sheet feeding tray 17 is covered with the belt member 34. Therefore, the paper powder 27 that has risen by the blowing of air from an air blowing unit (not shown) is removed from the belt member. It adheres to the lower surface of 34 (the surface facing the paper feed tray 17). In removing the paper dust 27, in the paper feeding device configured as described above, the belt member 34 is caused to travel in the direction of the arrow by driving a motor (not shown) to rotate the driving roll 35. As a result, the paper dust 27 adhered to the lower surface of the belt member 34 moves in the direction of the arrow together with the belt member 34. The paper powder 27 is scraped off by the cleaning blade 38 when it has moved to the portion around the driven roll 36. Further, the paper powder 27 scraped off by the cleaning blade 38 falls into the tray 39. Therefore, the paper that has adhered to the lower surface of the belt member 34 by causing the belt member 34 to travel with a predetermined amount, that is, about a half of the circumferential length of the belt member 34 by the rotation of the drive roll 35. The powder 27 can be removed by the cleaning blade 38 and collected in the tray 39.

  Therefore, the running operation of the belt member 24 due to the rotation of the drive roll 35 and the collecting operation of the paper dust collecting unit 20 in conjunction with this are performed at a preset operation start timing, thereby adhering to the lower surface of the belt member 34. The paper powder 27 can be collected by the paper powder collection unit 20 before the paper powder 27 falls due to the impact of the insertion operation of the paper feed tray 17. For this reason, generation | occurrence | production of the image defect by paper dust can be prevented beforehand. Further, if the operation start timing is set at the end of the paper feeding operation or at the time of loading / unloading of the paper feeding tray, the belt driving mechanism can be used without affecting the paper feeding operation in a situation where more paper dust 27 is generated. And the paper dust collection | recovery part 20 can be operated. For this reason, the paper dust 27 can be efficiently recovered by the paper dust recovery unit 20.

  Furthermore, as an additional configuration of the paper dust collecting unit 20, a charging control device (not shown) that charges and gradually charges the belt member 34 can be provided. When such a configuration is adopted, the belt member 34 is charged by the charging control device when the belt driving mechanism and the paper dust collecting unit 20 are not in operation (for example, at the time of paper feeding operation), so that the air is blown up. Since the paper dust 27 is attracted by static electricity due to electrification, the paper dust 27 in the paper feed tray 17 can be positively attached (adsorbed) to the belt member 34. Further, when the belt driving mechanism and the paper dust collecting unit 20 are operated (for example, during a non-paper feeding operation), the belt member 34 is gradually de-energized by the charging control device, so that the paper dust 27 is detached from the belt member 34. Since it is urged by slow electricity, the paper dust 27 adhering to the belt member 34 can be easily scraped off by the cleaning blade 38. Therefore, the collection efficiency of the paper dust 27 by the paper dust collection unit 20 can be further increased. Further, since the amount of paper dust remaining in the paper feed tray 17 can be reduced, it is possible to prevent malfunctions of mechanical parts, sensors, and the like in the paper feed tray 17 caused by dirt due to paper dust.

  FIG. 7 is a cross-sectional view showing a main part of a paper feeding device according to the fifth embodiment of the present invention. In the configuration of the sheet feeding device shown in the figure, a paper dust adsorbing member 40 is provided on the lower surface of the top plate portion 26 that covers the upper side of the sheet feeding tray 17. The paper dust adsorbing member 40 constitutes “paper dust collecting means” in the present invention. The paper dust adsorbing member 40 is formed by laminating a plurality of pressure-sensitive adhesive sheets having the surface on the paper feed tray 17 side as an adhesive surface and the opposite surface as a peeling surface. The paper dust adsorption member 40 is detachably attached to the lower surface of the top plate portion 26 directly or via an attachment plate (not shown).

  In the image forming apparatus including the paper feeding device having the above-described configuration, the paper dust 27 that has risen by the air blowing from the air blowing unit 19 adheres to the adhesive surface of the paper dust absorbing member 40 and is captured there. Therefore, even when an impact due to the insertion operation of the paper feed tray 17 is applied, the paper dust 27 attached to the paper dust suction member 40 does not fall. Moreover, the paper dust 27 adhering to the pressure-sensitive adhesive surface can be collected by removing the pressure-sensitive adhesive sheets forming the paper powder adsorption member 40 one by one. For this reason, it is possible to prevent the occurrence of image defects due to paper dust by peeling off the adhesive sheet at an appropriate timing such as during periodic inspection.

1 is a schematic diagram illustrating a configuration example of an image forming apparatus to which the present invention is applied. 1 is a schematic side view illustrating a configuration of a sheet feeding device according to a first embodiment of the present invention. It is a figure which shows the principal part of the paper feeder which concerns on 1st Embodiment of this invention. It is a figure which shows the structure of the paper feeder which concerns on 2nd Embodiment of this invention. It is a schematic side view which shows the structure of the paper feeder which concerns on 3rd Embodiment of this invention. It is a schematic side view which shows the structure of the paper feeder which concerns on 4th Embodiment of this invention. It is sectional drawing which shows the principal part of the paper feeder which concerns on 5th Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 17 ... Paper feed tray, 18 ... Paper feed part, 19 ... Air blowing part, 20 ... Paper dust collection part, 21 ... Paper, 24 ... Cleaning brush, 25 ... Receptacle, 26 ... Top plate part, 27 ... paper dust, 28 ... support member, 29 ... inner guide member, 30 ... rotary roller, 31 ... outer guide member, 32 ... guide groove, 33 ... switching gate, 34 ... belt member, 35 ... drive roll, 36 ... follower Roll, 37 ... tension roll, 38 ... cleaning blade, 39 ... tray, 40 ... paper powder adsorption member

Claims (15)

A paper tray that contains paper,
A paper dust collecting means for collecting the paper dust adhering to the top plate portion covering the upper side of the paper feed tray. The paper feeding device according to claim 1, further comprising an air blowing unit that blows air onto an end portion of the paper stored in the paper feeding tray. A paper tray that contains paper,
Paper dust collecting means for collecting paper dust attached to the top plate portion covering the upper side of the paper feed tray,
The paper dust collecting means includes a cleaning member for cleaning the top plate portion. The sheet feeding device according to claim 3, wherein the cleaning member cleans the top plate portion when the sheet feeding tray is put in and out. The paper dust collecting means includes a first operation mode in which the cleaning member is in contact with the top plate portion, and a second operation mode in which the cleaning member is separated from the top plate portion. The sheet feeding device according to claim 3. The sheet feeding device according to claim 3, wherein the cleaning member is provided on a rear side of the sheet feeding tray and cleans the top plate portion when the sheet feeding tray is inserted. The sheet feeding device according to claim 3, wherein the top plate portion includes a bottom surface portion of an upper sheet feeding tray disposed on an upper stage of the sheet feeding tray. The top plate portion is constituted by an endless belt member stretched by a belt drive mechanism above the paper feed tray,
The sheet feeding device according to claim 3, wherein the cleaning member cleans the traveling belt member by the belt driving mechanism. The cleaning member is provided on the front side of the paper feed tray in contact with the bottom surface of the upper paper feed tray, and cleans the bottom surface of the upper paper feed tray when the upper paper feed tray is inserted and removed. The paper feeding device according to claim 7. The sheet feeding device according to claim 8, further comprising a charging control device that performs charging and slow charging of the belt member. The paper feeding device according to claim 8, wherein the belt driving mechanism causes the belt member to travel a predetermined amount at a preset operation start timing. The sheet feeding device according to claim 11, wherein the operation start timing is set at the end of the sheet feeding operation or when the sheet feeding tray is pulled out. A paper tray that contains paper,
Paper dust collecting means for collecting paper dust attached to the top plate portion covering the upper side of the paper feed tray,
The paper dust collecting means comprises a paper dust adsorption member provided on the top plate portion. The paper feeder according to claim 13, wherein the paper dust adsorbing member has an adhesive surface on the side of the paper feed tray. A paper tray that contains paper,
Image forming means for forming an image on the paper supplied from the paper feed tray;
An image forming apparatus, comprising: a paper dust collecting unit that collects paper dust attached to a top plate portion covering an upper portion of the paper feed tray.

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