JP2009120284A - Paper feeder and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paper feeder in which paper is not laterally moved even if receiving air blow parts from the side above a paper bundle and also provide an image forming device having the paper feeder. <P>SOLUTION: This paper feeder includes a feed tray on which a paper bundle can be placed, the first air blow part 40 having an air blow hole 44 for blowing air to the side end of the paper bundle, a swing plate 48 rotatably attached to the air blow hole, the second air blow part 50 for blowing air to the end of the paper bundle in the paper feeding direction, and a sucking/feeding part 60 for sucking the uppermost paper among the paper bundle by the suction of air and feeding the paper. When air is not blown from the air blow hole 44, the height of the end of the swing plate 48 is equal to or lower than the height of feeding of the paper bundle. When air blows from the air blow hole 44, the end of the swing plate 48 is generally equal to or higher than the feeding surface of the sucking/feeding part 60. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  INDUSTRIAL APPLICABILITY The present invention reviews paper feeding devices used in image forming apparatuses such as copying machines, printers, facsimiles, printing machines, and multi-function machines, and in particular, ensures that paper with strong adhesion between papers such as coated paper is used. The present invention relates to a sheet feeding device capable of separating and feeding one sheet at a time.

  The image forming apparatus is provided with a paper feeding device that feeds one sheet at a time from a bundle of stacked sheets by a paper feeding roller or the like. In such a sheet feeding device, if a plurality of sheets are double fed, it may cause a paper jam. Further, if the conveying force is small, misfeeding is likely to occur. For this reason, a device has been devised that can reliably feed one by one. That is, misfeeds are prevented by reliably feeding out the uppermost sheet of the stacked sheets by increasing the coefficient of friction between the sheet feeding roller and the sheet. Further, in order to prevent two or more sheets from being sent out, only the uppermost sheet is sent out by pushing back the second and subsequent plates by rolling with a rolling roller, padding or separation claw. .

  This method is effective as long as only ordinary plain paper is used. However, recently, the use of copying machines and printers has been expanded, and various types of paper such as coated paper have been used. Among these sheets, the adhesion between the sheets when stacked is strong, and it may be difficult to reliably prevent double feeding with the above-described sheet feeding device.

  Therefore, there is a method in which a blower opening is provided on the side in the feeding direction of the stacked sheets, air is blown from the blower opening toward a plurality of upper sheets of the stacked sheets, and air is passed between the sheets to separate them. Proposed.

  However, the coated paper has a characteristic that the sheets are strongly adhered to each other in a high humidity environment. A bundle of sheets that are in close contact with each other becomes a heavy lump at a low wind speed, and when the air is blown from the side, the adhesion does not peel off and the sheet cannot be lifted.

  In order to solve this, it is conceivable to increase the blowing of air to float the paper, but even if the air flow is strengthened, the paper is only pushed up greatly, and the separation of each sheet is not improved. .

  Therefore, in Patent Document 1, a sheet suction conveyance unit that sucks and conveys one sheet at a time from the sheet bundle supported by the sheet stacking unit, and a blower that blows air from the front of the sheet feeding direction to the top of the sheet bundle. The structure which provided the part is proposed. By blowing air from the front of the sheet bundle, several sheets at the top of the sheet bundle are lifted, and only the uppermost sheet is sucked and transported by the suction transport unit. When the uppermost sheet is sucked by the suction conveyance unit, the air from the front acts to separate the second and subsequent sheets.

  In general, paper feeding using such a suction means tends to be larger than roller paper feeding, but has excellent paper feeding performance. This is because it is not frictional separation, and is not affected by wear or slip, is stable in the long term, and is relatively unaffected by paper conditions such as paper type.

However, separation is insufficient when the air is blown only from the front of the sheet bundle. Therefore, in Patent Document 2, the air outlet is formed in the side regulating member that positions the both side surfaces of the sheet bundle. A configuration has been proposed in which air is blown from the side of a bundle of sheets through the blower opening. Paper separation is improved by blowing air from the front and side.
Japanese Patent No. 3870178 Japanese Patent No. 3911405

  However, in the method of blowing the air from the side of the sheet bundle as in the configuration of Patent Document 2, the sheet that has been lifted by the air moves in a direction perpendicular to the transport direction (the width direction of the sheet) and the paper feed is poor. There is a problem of causing.

  The present invention solves such a problem. A sheet feeding device in which a sheet does not move in the width direction even when receiving air blow from the side, and an image forming apparatus including the sheet feeding device are provided. It is intended to provide.

  In order to achieve the above object, a sheet feeding device according to the present invention is provided at a sheet feeding tray capable of stacking a sheet bundle composed of a plurality of sheets, and at both ends of the sheet bundle stacked on the sheet feeding tray. A first air blower having an air blowing port for blowing air to a side end of the paper bundle, a swinging plate rotatably provided at each air blowing port, and a paper carrying direction of the paper bundle from the front in the paper carrying direction A second air blowing unit that blows air to the tip of the paper, and an adsorption conveyance unit that adsorbs and conveys the uppermost sheet of the bundle of sheets stacked on the sheet feeding tray one by one by suction of air, In the state where no air is blown out from the air outlet, the tip of the swing plate is lowered downward, and the height of the plate tip is equal to or lower than the sheet feeding height of the sheet bundle, Air blowout from the air vent In one state, the swinging plate is rotated in the direction of plate edge is raised upward, the height of the plate tip, is characterized in that approximately the same or higher than the position and the conveying surface of the suction conveyance unit.

  The rocking plate has a stopper for limiting a rotation angle when rotating in the direction in which the plate tip is raised upward, and the rotation angle when stopped by the stopper is within 45 ° with respect to the horizontal. Or the swing plate is configured to rotate by the air blowing pressure of the first air blower, the length of the swing plate is substantially the same as the length of the blower in the transport direction, The swing plate may be made of a flexible synthetic resin, or may have a structure in which the suction conveyance unit and the air blowing port overlap with each other in the paper conveyance direction.

  In order to achieve the above object, an image forming apparatus of the present invention includes an image forming unit that forms a toner image on an image carrier, a transfer unit that transfers a toner image on the image carrier to paper, and the transfer A sheet feeding device that conveys the sheet and a fixing device that heats and fixes the sheet on which the toner image is formed, and the sheet feeding device is any one of the sheet feeding devices described above. It is characterized by.

  Air is blown from the left and right side surfaces of the sheet bundle at the blower opening of the first blower. Several sheets at the top of the stacked sheet bundle are blown up and separated one by one. There is an oscillating plate at the air outlet, and when the air is blown, the tip of the oscillating plate rises upward and the tip of the plate is at the same level as or higher than the transfer surface of the suction transfer unit. . The plurality of sheets blown up are captured inside the swing plates on both the left and right sides. Due to the suction force of the suction conveyance unit, the uppermost sheet is sucked by the upper suction conveyance unit. The top sheet and the other sheets are separated by the air from the second blower. Since the suction force does not work on the second and subsequent sheets, they remain captured between the swing plates on both sides and do not come out of the swing plates. Accordingly, it is possible to prevent the deviation of the paper in the horizontal direction (width direction). When the blowout of air from the air blowing port of the second air blowing unit stops, the second and subsequent sheets descend on the sheet bundle to prepare for the next sheet supply.

  As described above, the sheet that is lifted by blowing air from the blower opening is restricted from moving in the horizontal direction by the swing plates on both sides, and does not move in the horizontal direction (width direction).

  When the rotation angle that rises above the rocking plate is within 45 ° with respect to the horizontal, the rocking plate is not caught and can rotate smoothly.

  Since the swing plate is rotated by the blow-out pressure of the air from the first air blowing section, it is not necessary to provide a separate swing mechanism for the swing plate, and the configuration can be simplified.

  If the swing plate is made of a flexible synthetic resin, the swing plate can be easily rotated by the air blowing pressure, and the swing plate can be bent, so that the swing plate becomes an obstacle when paper is supplied. Absent.

  If the suction conveyance unit and the air blowing port have a portion that overlaps in the paper conveyance direction, lateral movement of the small size paper can be suppressed by the swing plate.

  Embodiments of the present invention will be described below with reference to the drawings, but the present invention is not limited to the embodiments described below.

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

[Image forming apparatus]
FIG. 1 is an overall configuration diagram of an image forming apparatus including an image forming apparatus main body A, an image reading apparatus SC, an automatic document feeder DF, and a large capacity sheet feeding apparatus LT.

  The image forming apparatus main body A shown in the figure includes an image forming unit including a photosensitive member 1 that is an image carrier, a charging unit 2, an exposure unit 3, a developing unit 4, a transfer unit 5, a cleaning unit 6, and the like, a fixing unit 7, and a sheet. And a transport unit.

  The paper transport unit includes a paper feed cassette 10, a first paper feed unit 11, a second paper feed unit 12, a paper discharge unit 14, a transport path switching unit 15, a circulation refeed unit 16, and a reverse paper discharge unit 17. Has been.

  The document d placed on the document table of the automatic document feeder DF is transported by the paper feed unit, and an image on one or both sides of the document d is exposed by the optical system of the image reading device SC and read by the image sensor CCD. . The analog signal photoelectrically converted by the image sensor CCD is subjected to analog processing, A / D conversion, shade ink correction, image compression processing, and the like in the image processing unit 20 and then sent to the exposure device 3.

  In the image forming unit, processes such as charging, exposure, development, transfer, separation, and cleaning are performed.

  In the image forming unit, the surface of the photoreceptor 1 is charged by the charging unit 2, an electrostatic latent image is formed by laser light irradiation from the exposure device 3, and the electrostatic latent image is visualized by the developing device 4, and toner Become a statue. Next, the paper P stored in the paper feed cassette 10 is conveyed from the first paper feed unit 11. The paper P is conveyed in synchronism with the toner image by the second paper feeding unit 12 composed of registration rollers. Thereafter, the paper P is fixed by the fixing device 7 after the toner image is transferred by the transfer unit 5.

  The paper P after fixing is discharged out of the apparatus by the paper discharge unit 14. On the other hand, the toner remaining on the photosensitive member 1 is removed by the cleaning unit 6. In the case of duplex copying, the paper P on which the image is formed on the first surface is sent to the circulation refeed unit 16 and reversed, and after the image is formed again on the second surface in the image forming unit, the paper discharge unit 14 is formed. Is discharged out of the apparatus. In the case of reverse paper discharge, the paper P branched from the normal paper discharge path is switched back in the reverse paper discharge unit 17 and turned upside down, and then discharged out of the apparatus by the paper discharge unit 14.

  A large-capacity paper feeding device LT which is a paper feeding device of the present invention is connected to the image forming apparatus main body A. The paper feeding device LT includes a paper feeding device main body 30, a first air blowing unit 40, a second air blowing unit 50, a suction conveyance unit 60, and the like. Are fed one by one.

  The sheet feeder main body 30 includes a sheet feed tray 31, a leading end regulating member 32, a trailing end regulating member 33, and a guide rail 34. The paper feed trays 31 are configured in three stages, and each paper feed tray 31 is configured to be drawable from the paper feed device LT by a guide rail 34. The maximum paper supply amount of the paper supply device LT is about 10300 sheets.

  2 is a perspective view showing a main part of the paper feeding device LT of the present invention, FIG. 3 is a front sectional view of the paper feeding device LT, FIG. 4 is a plan view thereof, and FIG.

  In these drawings, the stacked sheets P are placed on the sheet feeding tray 31 and accommodated so as to be lifted and lowered by a mechanism (not shown). The side restricting member 41 is movable in the paper width direction, and lightly presses on both sides of the paper P in accordance with the paper width of the stacked paper P to restrict both side positions of the paper P. The side regulating member 41 has a step at the top, the upstream surface 41a in the sheet P feeding direction is high, and the downstream surface 41b is low. Although not shown, a support member that supports the upper end of the side regulating member 41 is attached to the upstream surface 41a. The downstream surface 41b overlaps a suction conveyance unit 60, which will be described later, in the paper conveyance direction (arrow X direction in FIG. 2). When the paper feed tray 31 is pulled out in the direction of the arrow Y in FIG. 2 during paper feeding, the downstream surface 41 b can pass under the suction conveyance unit 60.

  The leading edge regulating member 32 regulates the leading edge position in the transport direction of the paper P. The rear end regulating member 33 is movable in the transport direction of the paper P and restricts the rear end position in the transport direction of the paper P.

  As shown in FIG. 3, the rear end regulating member 33 is provided with a height detection sensor PS3 for detecting the height of the uppermost sheet P.

  In order to maintain the height of the sheet bundle loaded on the sheet feeding tray 31 at an optimum height for blowing air and blowing the sheet P, the control unit shown in FIG. Based on the detection result of PS3, a lifting motor (not shown) is driven to perform control to raise the paper feed tray 31.

  As shown in FIG. 3, a suction conveyance unit 60 is disposed in the vicinity of the leading end of the paper P in the feeding direction. The suction conveyance unit 60 includes a suction belt 63 that rotates by winding a large roller 61 connected to a drive source and two small rollers 62. The suction belt 63 has a large number of small-diameter through holes. A suction device 64 is disposed inside the suction belt 63 and transports the paper P while sucking it through the suction belt 63.

  As shown in FIGS. 2 and 5, the first blower 40 that blows air on the upper side of the paper P stacked in the paper feed tray 31 from the side perpendicular to the conveyance direction of the paper P is provided on both sides of the paper feed tray 31. Placed on the surface. The first blower 40 has a blower fan 42 and an air guide path 43 connected to the blower outlet of the blower fan 42. The air guide path 43 is configured to be lifted and lowered by lifting means (not shown). When the air guide path 43 rises, a blower port 44 is formed at the front end in a direction orthogonal to the transport direction of the paper P. Air is blown onto the upper portion of the paper P from the blower port 44. The blower port 44 is disposed on the downstream surface 41 b of the side regulating member 41 so as to at least partially overlap the suction conveyance unit 60 in the paper conveyance direction (arrow X). That is, as shown in FIG. 3, the tip side portion of the air blowing port 44 is drawn under the suction belt 63.

  Since the 1st ventilation part 40 is attached in the side part regulation member 41, even when the size of the paper P is changed, the 1st ventilation part 40 also moves variously by moving the side part regulation member 41 It will be possible. In addition, although the 1st ventilation part 40 is provided in the both sides of the paper P in this Example, only one side may be sufficient.

  The first air blowing unit 40 is driven, the air guide path 43 is raised, air is blown out from the air blowing port 44 to the lower portion of the suction conveyance unit 60, and air is blown onto several sheets on the upper side of the stacked sheets P. Air is blown from one end of the paper P through the paper to the other end. As a result, the upper several sheets of the paper P are separated one by one. The suction conveyance unit 60 sucks only the uppermost paper P from the paper P thus separated.

  The suction detection sensor PSl disposed in the vicinity of the suction surface of the suction belt 63 detects that the uppermost surface of the paper P is sucked by the suction belt 63. The suction belt 63 starts to rotate and starts to convey the paper P.

  A feed sensor PS2 disposed in the vicinity of the suction belt 63 on the downstream side of the sheet feeding direction of the sheet feeding tray 31 detects the passage of the sheet P to be fed.

  A second air blower 50 is fixed to the paper feeder main body 30 in the vicinity of the tip of the suction belt 63 on the downstream side of the paper feed tray 31 in the paper transport direction. The 2nd ventilation part 50 is comprised by the ventilation fan 42 grade | etc.,. Note that the second blower unit 50 may be attached to the sheet feeder main body 30 so as to blow air to the leading end portion of the sheet bundle via a duct.

  The blower fan 51 of the second blower unit 50 is attached with the blower port 53 facing upward. The air blown upward is changed in direction by the guide plate 52, blown obliquely upward from the blower port 53, and blown to the vicinity of the suction belt 63 of the suction conveyance unit 60.

  The driving of the second air blowing unit 50 is controlled according to the type of the paper P. In other words, OHP film, trace paper, coated paper with a smooth surface, paper with perforations and lines, etc., and paper with offset printing applied with dusting air. To ensure separation.

  When the suction belt 63 continues to rotate while sucking the paper P, the uppermost paper P of the paper bundle advances in the direction of the arrow X shown in the figure, is nipped by the paper feed roller 65, and is sent to the image forming apparatus main body A. Is done.

  As shown in FIGS. 2 and 3, the air inlet of the first blower 40 is shielded by a shielding member 45 and can be opened and closed. That is, the shielding member 45 formed of a plate-like shutter is pivotally supported by the shaft 46 and is opened and closed by the solenoid SOL. The control means controls the shielding member 45 to be freely opened and closed so as to switch the air blowing by the first blowing unit 40 between ON (blowing) and OFF (stop).

  FIG. 6 is a cross-sectional view illustrating a sheet suction conveyance process by the first blower 40 and the second blower 50.

  FIG. 6A shows a sheet adsorption process. By the first air blow V1 (the white arrow in the figure) blown up by the first air blower 40, a small number of sheets P on the upper layer of the sheet bundle stacked on the sheet feed tray 31 are lifted against the weight of the sheets. Then, it is adsorbed by the intake air V3 (open arrow in the figure) due to the negative pressure of the adsorption belt 63. The second blower V <b> 2 (the white arrow in the figure) blown up by the second blower 50 blows near the front bottom of the suction belt 63.

  FIG. 6B shows a paper separation process. When a small number of upper layers of the sheet bundle are adsorbed by the adsorbing belt 63, the shielding member 45 shields the air inlet of the first air blowing unit 40 and stops air blowing. Then, the air blown only by the second blower 50 passes between the uppermost sheet P1 and the lower sheet P2. The uppermost sheet P1 is adsorbed by the intake air V3 of the adsorbing and conveying unit 60, and is separated from the sheet P of the sheet bundle excluding the uppermost sheet P1. The sheet P2 below the separated uppermost sheet P1 descends in the direction of the arrow due to the weight of the sheet P2, and is accommodated on the sheet P.

  By repeating the air blowing of the first air blowing unit 40 and the second air blowing unit 50 in this way, the floating of the several sheets P2 on the upper part of the sheet bundle spreads over almost the entire surface of the air blowing ports 44 and 53, and the gap between each sheet Are almost the same interval. And air passes through this gap. As a result, the separation of the paper P1 is improved and the paper P1 is easily sent out. As a result, the problem that the floating of the sheet P1 becomes too large and damages the sheet, or a plurality of sheets are floated together and cannot be separated is solved.

  After the separation of the paper P1 from the paper P2, the driving unit (not shown) of the suction conveyance unit 60 starts driving, and the single sheet P1 sucked by the suction belt 63 is conveyed.

  In the above configuration, when the air is blown from the air blowing port 44 of the first air blowing unit 40, the paper P may move not only upward but also laterally, which may cause a paper feed failure. In order to solve this problem, the present invention uses a swing plate described below.

  7A and 7B are views showing the swing plate of the present invention, in which FIG. 7A is a view of the swing plate being lowered, and FIG. 7B is a view of the swing plate being raised.

  A swing plate 48 is located near the upper end of the air outlet 44. The swing plate 48 is rotatable about a rotation shaft 48 a, and both ends of the rotation shaft 48 a are fixed to the side wall of the air guide path 43. The rocking plate 48 is made of an elastic L-shaped material such as plastic. When air blows out from the air blowing port 44, the long side faces upward as shown in FIG. When the balloon stops, the long side faces downward as shown in (a) from the balance between the long side and the short side.

  At the upper end of the air outlet 44, there is a stopper portion 43a for limiting the rotation angle of the swing plate 48. The stopper portion 43 a is an opening edge of the air guide path 43. When the air is blown out from the blower port 44, the swing plate 48 is rotated by the wind pressure, and the long side faces upward, the position where the long side contacts the stopper portion 43a is the upper limit. At this time, the angle θ with the horizontal is set to 45 ° or less. If the angle θ exceeds 45 ° at this time, it will catch on the paper P and the like, and even if the blowing of air is stopped, it cannot return from the state (b) to the state (a).

  Further, when air is blown into the state (b), the long-side tip 48b is substantially the same height as the lower surface 60a of the suction conveyance unit 60 (same as the lower surface of the suction belt 63) or higher than the lower surface 60a. It is trying to become. This is because when the difference between the height of the long-side tip 48b and the height of the lower surface 60a of the suction conveyance unit 60 increases, the paper P moves laterally beyond the swing plate 48 when air is blown. .

  When the air blowing is stopped and the state (a) is reached, the long-side tip 48b comes into contact with the upper surface of the sheet bundle. When there is no sheet bundle, the height is lower than the height of the upper surface of the sheet bundle.

  Next, the operation of the swing plate 48 will be described. When air is blown out from the blower opening 44, several sheets on the sheet bundle P are blown up. At the same time, air is blown between the sheets P and P to separate them one by one. The swing plate 48 also has a long side facing upward as shown in FIG. The several sheets blown up are captured between the left and right swing plates 48 and 48, and cannot move outward. The center of the uppermost sheet P1 is sucked by the lower surface 60a of the suction conveyance unit 60 and becomes the same height as the lower surface 60a. Since the suction force is not applied to the second and subsequent sheets P2, P3 and below, the sheet is captured between the left and right swing plates 48, 48.

  When the blowout of air from the air outlet 44 of the first air blowing unit 40 stops and the air from the second air blowing unit 50 is blown from the front of the paper P, the first sheet adsorbed by the suction conveyance unit 60 P1 is separated from the second and subsequent sheets P2, P3. The sheets P2 and P3 and thereafter are lowered and overlapped on the sheet bundle to prepare for the next sheet feeding.

  In the above embodiment, the swing plate 48 is rotated by blowing air from the air outlet 44, but may be rotated using a solenoid, a motor, or the like.

  FIG. 8 is a block diagram showing a configuration of control of the paper feeding device, and FIG. 9 is a timing chart showing control of the paper feeding device. The control unit is composed of a computer, in which data of paper size and paper type (coated paper, thick letter, OHP film, glossy paper, etc.) are input, and a paper adsorption detection sensor PS1, feed sensor PS2, paper An on / off signal is input from the height detection sensor PS3. Moreover, based on these information, the 1st ventilation part 40, the 2nd ventilation part 50, the paper adsorption | suction conveyance part 60, the shielding member 45, etc. are controlled.

  When a sheet bundle is set in the sheet feeding tray 31 and sheet feeding start information is input to the control unit, an elevator unit (not shown) ascends the air guide path 43 and the first blowing unit 40 starts blowing. Several sheets at the top of the sheet bundle are blown up, and the swing plate 48 is in the state shown in FIG. 7B and restricts the movement of the sheet P in the width direction. When the suction detection sensor PSl detects that the suction belt 63 of the suction conveyance unit 60 has sucked the uppermost sheet P1, the control unit controls the shielding member 45 so that the first air blowing unit 40 does not perform the air blowing. Switch. The swing plate 48 is in the state shown in FIG.

  That is, the control unit detects that the sheet P1 is adsorbed by the adsorption conveyance unit 60 after the adsorption detection sensor PSl (see FIG. 2) disposed in the vicinity of the adsorption belt 63 detects the sheet P1 by the adsorption conveyance unit 60. During the time until the start of the delivery, the air inlet of the first air blowing unit 40 is shielded by the shielding member 45 so as not to perform the air blowing.

  Further, the shielding member 45 is moved only when the suction detection sensor PS1 detects the suction of the paper P1 and when the feed sensor PS2 does not detect the paper P1, that is, before the paper P1 is sent out. Air is blown in the open state.

  The shielding time of the shielding member 45 may not be exactly the same as the above timing. However, if the shielding time is limited to the moment when the feeding of the paper P1 is started, the shielding time becomes extremely short, and the separation effect of the paper P1 is obtained. Absent. Further, if the shielding member 45 is always shielded when the suction detection sensor PS1 detects the suction of the paper P1, the paper P1 may not be attracted to the suction belt 63 due to insufficient push-up by air, and a paper feeding failure may occur. That is, a paper feed failure occurs even if the shielding time is too long or too short. As the best timing, as shown in FIG. 9, for the first sheet P1, when the suction detection sensor PS1 is on and the feed sensor PS2 is off and in a state before the start of feeding, the solenoid SOL Is turned on and the shielding member 45 is closed. When the feed sensor PS2 is on, the shielding member 45 is opened.

  When the second sheet P2 is discharged and the suction detection sensor PS1 is switched from on to off, and the feed sensor PS2 is turned off and a predetermined time has elapsed, the suction detection sensor PS1 is turned on again by the third sheet P and the solenoid SOL is turned on. Is turned on and the shielding member 45 is closed.

  The blower fan 42 can be controlled in rotation by the control unit, and can control the air volume based on the size, paper quality, basis weight, and the like of the paper P, and blow the optimum air volume. Further, the air guide path 43 can be moved up and down depending on the sheet feeding state during sheet feeding. The specific sheet P and the optimum air volume, the opening / closing timing of the shielding member 45, the raising / lowering timing of the air guide path 43, and the like are stored in the control unit of the image forming apparatus. The size, quality, and the like of the paper P stored in the paper feed tray 31 can be stored by being input through the operation unit. By doing in this way, it becomes possible for the control unit to make settings so that spraying can always be performed according to the paper quality.

  When the paper P is replenished, the paper feed tray 31 is pulled out from the paper feed device LT by the guide rail 34. At this time, if the air guide path 43 is raised, it interferes with the suction belt 63 of the suction conveyance unit 60. Therefore, when the paper feed tray 31 is pulled out, the air guide path 43 and the air blowing port 44 are lowered to the lowered position. The lowering position of the air blowing port 44 may be a height at which the air guide path 43 does not interfere with the suction conveyance unit 60 when the paper feed tray 31 is pulled out, and is necessarily lower than the downstream surface 41b of the side portion regulating member 41. There is no need to do this, and it may be higher than the downstream surface 41b.

  As described above, the air guide path 43 needs to be in the raised position when the first air blowing section 40 is blowing air, and in the lowered position when the paper feed tray 31 is pulled out. The lifting means (not shown) is operated by the control unit so as to satisfy such conditions. Solenoid SOL, a motor, etc. can be used as a raising / lowering means.

  As described above, according to this example, the air blowing port 44 and the suction conveyance unit 60 are arranged so that at least a part thereof overlaps in the paper conveyance direction (arrow X). Even P can be separated one by one, and the movement in the left-right direction can also be suppressed.

  Since the swing plate 48 suppresses the lateral movement of the paper P, it is more effective to come into contact with a portion having a long length in the transport direction of the paper P. For such a reason, it is desirable that the swing plate 48 be as long as the length (in the transport direction) of the air blowing port 44. However, at least two short parts that are spaced apart in the transport direction may be provided, or may be spaced apart over the entire length of the air blowing port 44. The length of the short side in the conveyance direction may be the same as the long side, but may be provided only at both ends of the long side.

  Although the large-capacity sheet feeding apparatus LT connected to the image forming apparatus main body A has been described as the sheet feeding apparatus of the present invention, the present invention is also applicable to the sheet feeding cassette 10 disposed in the image forming apparatus main body A. .

1 is an overall configuration diagram of an image forming apparatus including an image forming apparatus main body, an image reading apparatus, an automatic document feeder, and a large capacity paper feeding apparatus. The perspective view which shows the principal part of the paper feeder of this invention. FIG. 3 is a front sectional view of the sheet feeding device. The top view of a paper feeder. The side view of a paper feeder. Sectional drawing which shows the adsorption | suction conveyance process of the paper by a 1st ventilation part and a 2nd ventilation part. It is a figure which shows a rocking | fluctuation plate, (a) is a figure of the state in which the rocking | fluctuation plate is falling, (b) is a figure in the state in which the rocking | fluctuation plate is rising. FIG. 3 is a block diagram illustrating a control configuration of a sheet feeding device. 6 is a timing chart showing control of the paper feeding device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Charging part 3 Exposure apparatus 4 Developing apparatus 5 Transfer part 6 Cleaning part 7 Fixing apparatus 30 Paper feed apparatus main body 31 Paper feed tray 32 Front end regulation member 33 Rear end regulation member 40 1st ventilation part 41 Side part regulation member 42 Blower fan 43 Air guide path 43a (Oscillating plate) stopper 44 Blower port 45 Shield member 48 Oscillating plate 50 Second blower unit 51 Blower fan 53 Blower port 60 Adsorption conveyance unit 63 Adsorption belt 64 Suction unit A Image forming apparatus main body LT Paper feeder P, P1, P2 Paper PSl Adsorption detection sensor PS2 Feed sensor SOL Solenoid Vl First blow V2 Second blow V3 Intake

Claims (7)

A paper feed tray on which a stack of paper sheets can be stacked,
A first air blower provided on both ends of the sheet bundle stacked on the sheet feed tray and having a blower opening for blowing air to the side edge of the sheet bundle;
A swing plate provided rotatably at each of the air blowing ports;
A second air blower that blows air from the front in the paper transport direction to the front end of the paper bundle in the paper transport direction;
An adsorbing and conveying unit that adsorbs and conveys the uppermost sheets of the sheet bundle stacked on the sheet feeding tray one by one by air suction;
In the state where no air is blown out from the blower opening, the swing plate has a plate tip lowered downward, and the plate tip height is equal to or lower than the sheet feed height of the sheet bundle. In the state where air is blown out from the air outlet, the swinging plate rotates in the direction in which the plate tip rises upward, and the height of the plate tip is substantially the same as the conveyance surface of the suction conveyance unit. A paper feeder characterized by a higher position.   The rocking plate has a stopper for limiting the rotation angle when rotating in the direction in which the plate tip is raised upward, and the rotation angle when stopped by the stopper is within 45 ° with respect to the horizontal. The paper feeding device according to claim 1, wherein   The sheet feeding device according to claim 1, wherein the swing plate is rotated by an air blowing pressure of the first air blowing unit.   4. The sheet feeding device according to claim 1, wherein a length of the swinging plate is substantially the same as a length of the air blowing port in a conveying direction. 5.   The sheet feeding device according to claim 1, wherein the swing plate is made of a flexible synthetic resin.   The sheet feeding device according to claim 1, wherein the suction conveyance unit and the air blowing port have a portion overlapping in the sheet conveyance direction. An image forming unit for forming a toner image on the image carrier;
A transfer unit for transferring the toner image on the image carrier to paper;
A paper feeding device that conveys the paper to the transfer unit;
A fixing device that heats and fixes the paper on which the toner image is formed,
An image forming apparatus, wherein the paper feeding device is the paper feeding device according to claim 1.

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