JP4952523B2 - Paper feeding device and image forming apparatus - Google Patents

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 by the sucking and transporting means and transported. When the uppermost sheet is sucked by the suction conveyance means, 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.

By the way, the air blowing section from the side is arranged so that the vertical center of the air blowing port is substantially on the upper surface of the sheet bundle, so that the upper end of the air blowing port is above the upper surface of the sheet bundle. In addition, the sheet feeding device places a bundle of sheets on a drawer-type sheet feeding tray, and when feeding sheets, pulls out the sheet feeding tray and supplies sheets. The side regulating member having a blower opening from the side is attached to the paper feed tray, and the sheet suction conveyance unit is attached to the image forming apparatus main body. For this reason, when the paper feed tray is pulled out for the purpose of paper supply or the like, if the air blowing part protrudes upward from the upper surface of the paper bundle, it cannot move due to interference with the sheet adsorbing and conveying means. In Patent Document 2, in order to avoid such a situation, the air blowing section from the side is provided near the rear end of the sheet bundle so as not to interfere with the sheet suction and conveyance means.
Japanese Patent No. 3870178 Japanese Patent No. 3911405

  However, in the configuration of Patent Document 2, since there is no air blown from the side just below the sheet suction conveyance unit, the paper cannot be sufficiently separated. In addition, when the paper size is small, there is a problem that the side air blowing unit may not be used.

  The present invention solves such a problem, and a side air blowing section can be provided directly below the sheet suction conveyance means, and the side regulating member is attached to the sheet suction when the paper feed tray is pulled out. It is an object of the present invention to provide a sheet feeding device that does not interfere with the sheet suction conveyance unit even when passing under the unit, and an image forming apparatus including the sheet feeding device.

In order to achieve the above object, a sheet feeding device according to the present invention stacks a bundle of sheets composed of a plurality of sheets and feeds a sheet tray that can be pulled out in a direction intersecting the sheet conveying direction.
A first air blowing section including an air guide path having an air blowing port for blowing air to a side end of the sheet bundle loaded on the sheet feeding tray;
Elevating means for elevating and lowering the air guide path;
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;
A control unit for controlling the lifting means to raise and lower the air guide path;
The a, the a and the suction conveying portion the blowing port, have a portion overlapping on the paper transport direction,
The raising / lowering means is a blower fan provided in the first blower unit, and the wind guide path is raised by the wind pressure when the blower fan blows air, and when the blower is stopped, the wind guide path is lowered by its own weight. It is characterized by.

  The first blower unit may have a blower fan, and the control unit may control the air volume of the blower fan. Furthermore, the control unit may be configured to be able to control the lifting / lowering means even during paper feeding.

  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.

  By blowing air from the side surface of the sheet bundle in the first air blowing unit, air can be sent to the sheet directly below the suction conveyance unit, and the sheets can be reliably separated one by one. Also, when pulling out the paper feed tray such as when replenishing paper, the sheet suction / conveying means and the air blowing port can be pulled out without interfering with each other by lowering the air guide path or the air blowing port. .

  As a result, it is possible to feed a coated paper or the like in a high-humidity environment with high adhesion without causing double feeding. In addition, an image forming apparatus including a paper feeding device can prevent double feeding regardless of the type of paper, and can form an image on a paper in an image forming unit.

  When the air guide path is moved up and down by the wind pressure of the blower fan, the structure of the lifting and lowering unit becomes simple, and the sheet feeding device can be manufactured at low cost.

  By making it possible to control the air volume of the blower fan, it is possible to blow air in accordance with the quality of the paper and to further increase the reliability of paper feeding.

  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 conveyed by the paper feed unit, and one or both images of the document d are 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 and upside down in the reverse paper discharge unit 17 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 feed 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 that blows air on the upper part of the paper P from the blower ports 44 on both sides orthogonal to the direction in which the paper P is withdrawn. 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.

  FIGS. 6A and 6B are views of the first air blowing unit 40, in which the air blowing port 44 is in the raised position, with FIG. 6A being a front view and FIG. 6B being a right side view. FIGS. 7A and 7B are views of the first air blower 40. FIG. 7A is a front view and FIG. 7B is a right side view with the blower port 44 in the lowered position.

  The entire first air blowing unit 40 is disposed in the side portion regulating member 41. The air blowing port 44 is an opening on the outlet side of the cylindrical air guide passage 43, and the direction of the air blowing port 44 and the inlet side opening is substantially perpendicular. The air guide path 43 is slidably fitted on the opening end of the blower fan 42 on the inlet side. The air blown upward by the blower fan 42 is turned 90 ° in the air guide path 43 and blown out in the horizontal direction.

  The air guide path 43 can be moved up and down by the lifting means 47, and the air blowing port 44 opens at the upper end of the side portion regulating member 41. It is desirable that the height of the uppermost sheet P be approximately at the center between the upper end 44a and the lower end 44b of the blower port 44 when the blower port 44 is lifted by the lifting means 47. When the air guide path 43 is lowered by the elevating means 47, the side portion regulating member 41 and the upper end surface of the air guide path 43 are made lower than the lower surface of the suction conveyance unit 60. In the embodiment, as shown in FIG. 7, the height is made the same as the surface 41b on the downstream side of the side portion regulating member 41, but the side portion regulating member 41 moves even if it is above the surface 41b. If it does, it should just not interfere with adsorption conveyance part 60. Further, as the lifting / lowering means 47, driving means such as a solenoid and a motor can be used. In the embodiment of the present invention, a solenoid is used.

  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.

  When the first air blowing unit 40 is driven and the air guide path 43 is raised by the lifting and lowering means 47, air is blown out from the air blowing port 44 to the lower part of the suction conveyance unit 60, and air is blown to several sheets above the stacked paper P. Is sprayed. 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 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 sheet P, the uppermost sheet P of the sheet bundle advances in the direction of the arrow X shown in the figure and is sent to the image forming apparatus main body A.

  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 plate-like shutter that is the shielding member 45 is pivotally supported by the shaft 46 and is opened and closed by the solenoid SOL. The control unit controls the elevating means 47 to elevate and lower the air guide path 43 at a desired timing, and controls the shielding member 45 so as to be openable and closable so that air blowing by the first air blowing unit 40 is turned on (blowing) and off ( Control to switch to (stop).

  FIG. 8 is a cross-sectional view showing a sheet suction and conveyance process by the first blower 40 and the second blower 50.

  FIG. 8A 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 air blower V <b> 2 (the illustrated white arrow) blown up by the second air blower 50 blows the vicinity of the front bottom of the suction belt 63.

  FIG. 8B 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 paper P1 becomes too large and damages the paper or the plurality of papers P float 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.

  FIG. 9 is a block diagram illustrating a configuration of control of the paper feeding device, and FIG. 10 is a timing chart illustrating 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, and the raising / lowering means 47 are controlled.

  When a sheet bundle is set in the sheet feed tray 31 and sheet feed start information is input to the control unit, the lifting / lowering means 47 ascends the air guide path 43 and the first blowing unit 40 starts blowing. When the upper part of the sheet bundle is blown up and the suction detection sensor PSl detects that the suction belt 63 of the suction conveyance unit 60 sucks the paper P1, the control unit controls the shielding member 45 to control the first blower unit 40. Switch the implementation of air spraying to non.

  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. 10, for the first sheet P1, when the suction detection sensor PS1 is on and the feed sensor PS2 is off 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 above is a standard timing, and it is desirable to obtain an optimal timing according to the paper size and quality, store it in the control unit, and control based on the stored data.

  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. The lifting / lowering means 47 can also move up and down the air guide path 43 depending on the paper feeding state during paper feeding. The specific sheet P, the optimum air volume, the timing for raising and lowering the air guide path 43, and the like are stored in the control unit of the image forming apparatus, similarly to the timing for opening and closing the shielding member 45 described above. 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 or the air outlet 44 is lowered to the lowered position by the elevating means 47. 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 elevating means 47 is operated by the control unit so as to satisfy such a condition. In the embodiment, a solenoid is used as the lifting means 47, but it may be lifted and lowered by a motor or the like.

  Normally, when the paper feed tray 31 is pulled out, the first air blowing unit 40 stops air blowing because the image forming apparatus is stopped. Therefore, as an example, when the 1st ventilation part 40 is blowing, it exists in a raise position, and when it stops blowing, you may control to maintain the lowered position. As one of such configurations, it is possible to adopt a configuration in which the air guide path 43 is lightened and fitted so as to be lifted and lowered by a light force, and is lifted and lowered by the wind pressure of the blower fan 42.

  As described above, according to the embodiment of the present invention, the air blowing port 44 and the suction conveyance unit 60 are arranged so as to overlap at least partially in the paper conveyance direction (arrow X), and thus are small. Even the size paper P can be separated one by one. In addition, since the sheets immediately below the suction conveyance unit 60 are separated one by one by the wind from the air blowing port 44, the adsorption conveyance unit 60 can easily adsorb only the uppermost sheet P.

  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. The figure which shows the 1st ventilation part which has a ventilation port in a raise position. The figure which shows the 1st ventilation part which has a ventilation port in a lowered position. Sectional drawing which shows the adsorption | suction conveyance process of the paper by a 1st ventilation part and a 2nd ventilation part. 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 44 Air outlet 45 Shield member 47 (of the air guide path) Lifting means 50 Second air blower 51 Air blower fan 52 Guide plate 53 Air blower 60 Adsorption transport part 63 Adsorption belt 64 Suction part 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 (4)

A paper tray that stacks a stack of paper sheets and that can be pulled out in a direction that intersects the paper transport direction;
A first air blowing section including an air guide path having an air blowing port for blowing air to a side end of the sheet bundle loaded on the sheet feeding tray;
Elevating means for elevating and lowering the air guide path;
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;
A control unit for controlling the elevating means to raise and lower the air guide path;
The a, the a and the suction conveying portion the blowing port, have a portion overlapping on the paper transport direction,
The raising / lowering means is a blower fan provided in the first blower unit, and the wind guide path is raised by the wind pressure when the blower fan blows air, and when the blower is stopped, the wind guide path is lowered by its own weight. A paper feeder characterized by. 2. The sheet feeding device according to claim 1 , wherein the first blowing unit includes a blowing fan, and the control unit controls an air volume of the blowing fan. Wherein the control unit is, the sheet feeding apparatus according to claim 1 or claim 2, wherein the lifting means can also be controlled sheet feeding in the paper a. An image forming unit for forming a toner image on the image carrier;
A transfer unit for transferring a toner image on the image carrier to paper;
A paper feeding device for transporting the paper to the transfer unit;
A fixing device that heats and fixes the paper on which the toner image is formed, and
Image forming apparatus, wherein the sheet feeding device is a paper feeding device according to any one of claims 1 to 3.

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