JP2017105579A - Sheet delivery device, sheet supply device, and image formation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet delivery device which can deal with acceleration of a device delivering and supplying the uppermost sheet more than a conventional technique.SOLUTION: A sheet delivery device 200 makes the surface of a suction belt 2 stretched over a downstream side stretch roller 5 and an upstream side stretch roller 6 electrified by an electrode roller 3, performs electrostatic suction by bringing the electrified surface of the suction belt 2 into contact with the uppermost sheet 1a of a sheet bundle 1, then separates the surface of the suction belt 2 from the sheet bundle 1 and feeds the uppermost sheet 1a toward a conveyance roller pair 9. A separation mechanism 120 for bringing the surface of the suction belt 2 into contact with the sheet bundle 1 or separating the suction belt from the sheet bundle to separate the uppermost sheet 1a from the sheet bundle 1 is configured as follows. The separation mechanism 120 includes a cam 15 and a follower such as a follower roller 13 (follower bearing 13a) moving according to the rotation of the cam 15 in the state of being into contact with the cam 15.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a sheet feeding apparatus, a sheet feeding apparatus having the sheet feeding apparatus, and an image forming apparatus including at least one of them.

  Conventionally, as a sheet feeding device for separating and sending the uppermost sheet from a bundle of sheets such as stacked originals and recording paper, an electric field is formed on the suction belt (charging the suction belt), and the sheet is brought into contact with the sheet for suction. There is known an electrostatic adsorption separation type sheet feeding apparatus that separates and separates.

For example, Patent Document 1 describes an apparatus (image forming apparatus) provided with a sheet feeding apparatus (sheet conveying apparatus) having the following separation mechanism (swing mechanism).
After the uppermost sheet is attracted to the charged suction belt stretched between the upstream tension roller and the downstream tension roller, the suction unit is swung so that the downstream tension roller side rotates upward. And a separation mechanism for separating the sheet bundle excluding the uppermost sheet. Then, the suction belt is moved (rotated) on the surface, and the separated uppermost sheet is sent out toward the nipping and conveying means of the supplying apparatus.

The separation mechanism of the sheet feeding apparatus has a pair of swing members (brackets) that support the suction unit so as to sandwich the suction unit. Further, a swing fulcrum provided further upstream of the upstream tension roller of the pair of swing members in the sheet feeding direction, a fan-shaped rack gear portion and a pinion gear formed on the downstream side of the downstream tension roller in the sheet feeding direction. The gear mechanism which comprises the rack and pinion which consists of is also provided.
The suction unit supported by the swinging member is swung with respect to the sheet bundle by moving the rack gear side of the swinging member up and down by switching the on / off and rotation direction of the drive motor that drives the pinion gear. Hold it possible.

In recent years, even in the electrostatic adsorption separation type sheet feeding apparatus, the speed of separating and feeding the top sheet from the sheet bundle has been increased in response to the demand for speeding up the apparatus such as an image forming apparatus that supplies the top sheet. High speed is desired.
However, in order to oscillate a pair of oscillating members that support the suction unit so as to sandwich the suction unit, in a configuration that switches on / off of a drive motor that drives a pinion gear of a gear mechanism having a rack and pinion and a rotation direction, There are the following problems.

With a drive source such as a drive motor, it takes time to rotate from the stopped state and stop from the rotated state, that is, to turn on / off the drive source and to switch the rotation direction, and thus there is a possibility that the speed of the image forming apparatus cannot be accommodated.
Here, the same problem may occur even in a configuration using a solenoid or the like instead of a gear mechanism having a rack and pinion as a configuration for swinging the pair of swinging members supported so as to sandwich the suction unit.

  In order to solve the above-described problems, the present invention charges the surface of an adsorption belt stretched around a plurality of rollers by a charging unit, and contacts the charged adsorption belt with the uppermost sheet of the sheet bundle. After electrostatic adsorption, the surface of the adsorption belt that electrostatically adsorbs the uppermost sheet is separated from the sheet bundle excluding the uppermost sheet, and the uppermost sheet is sent out to the nipping and conveying means. In the apparatus, separating means for separating the uppermost sheet from the sheet bundle excluding the uppermost sheet by contacting and separating the surface of the suction belt with respect to the sheet bundle is in contact with the cam member and the cam member. And a follower that moves in accordance with the rotation of the cam member.

  According to the present invention, it is possible to provide a sheet feeding apparatus that can cope with a higher speed of the apparatus that feeds and supplies the uppermost sheet than before.

1 is a schematic explanatory diagram of a copying machine according to an embodiment. The perspective view which shows schematic structure of a paper feed part. Explanatory drawing of a paper feed part. Explanatory drawing of the principal part of a suction unit. Explanatory drawing of the drive mechanism which rotationally drives an adsorption belt. The perspective view explanatory drawing of the principal part of an adsorption | suction unit. Explanatory drawing of sheet | seat delivery operation | movement using a sheet delivery apparatus. Explanatory drawing of the control system which concerns on adsorption | suction and separation of a sheet delivery apparatus. An example of a cam rotation operation diagram in a case where the suction unit is raised at a constant speed. Another example of a cam rotation operation diagram when raising the suction unit at a constant speed. 6 is a flowchart related to basic sheet separation and conveyance. 10 is a flowchart of another example related to sheet separation and conveyance.

Hereinafter, an embodiment in which a sheet feeding apparatus to which the present invention is applied is applied to a copying machine (hereinafter referred to as a copying machine 100) which is an electrophotographic image forming apparatus will be described.
Here, it goes without saying that the sheet feeding apparatus according to the present invention is not limited to the image forming apparatus of the present embodiment, and can be widely applied to any image forming apparatus that forms an image on a sheet, such as an inkjet image forming apparatus. . Further, the sheet delivery apparatus according to the present invention can be applied to apparatuses other than the image forming apparatus such as an image reading apparatus that reads an image on a sheet.

FIG. 1 is a schematic explanatory diagram of a copying machine 100 according to the present embodiment.
The copying machine 100 includes an automatic document feeder 59, a document reading unit 58, an image forming unit 50, a paper feeding unit 52, and the like. The automatic document feeder 59 separates documents one by one from a bundle of documents placed on the document tray 59a and automatically feeds them to a contact glass on the document reading unit 58. The document reading unit 58 reads the document conveyed on the contact glass by the automatic document conveying device 59. The image forming unit 50 is an image forming unit that forms an image on a sheet that is a recording material fed from the paper feeding unit 52 based on a document image read by the document reading unit 58. The sheet feeding unit 52 accommodates the sheet bundle 1 in which a plurality of sheets are stacked, and feeds the uppermost sheet 1 a located at the uppermost position from the sheet bundle 1 to the image forming unit 50.

  The image forming unit 50 includes a charging device 62, a developing device 64, a transfer device 54, a photoconductor cleaning device 65, and the like around a photoconductor 61 as a latent image carrier. Further, the image forming unit 50 includes an optical writing unit for irradiating the photoreceptor 61 with the laser light 63, a fixing device 55 for fixing the toner image on the sheet, and the like.

  In the image forming unit 50 configured as described above, as the photosensitive member 61 rotates, the surface of the photosensitive member 61 is first uniformly charged by the charging device 62. Next, a laser beam 63 from an optical writing unit based on image data input from a personal computer, a word processor, or the like, or image data of a document read by the document reading unit 58 is irradiated to cause electrostatic latent image on the photoreceptor 61. Form an image. Thereafter, a toner image is formed on the photosensitive member 61 by making the electrostatic latent image visible by attaching toner with the developing device 64.

  On the other hand, the sheet feeding unit 52 separates and feeds the sheets one by one, conveys the sheets, and abuts against the registration roller 53 to stop. Then, in synchronization with the timing of toner image formation in the image forming unit 50, the sheet abutted and stopped by the registration roller 53 is sent out to the transfer unit where the photoconductor 61 and the transfer device 54 face each other. In the transfer unit, the toner image on the photoconductor 61 is transferred onto the sheet fed from the registration roller 53. After the toner image is fixed by the fixing device 55, the sheet on which the toner image has been transferred is discharged to the discharge tray 57 by the discharge roller pair 56. On the other hand, the surface of the photoconductor 61 after the toner image transfer is cleaned by removing residual toner by the photoconductor cleaning device 65 to prepare for image formation again.

FIG. 2 is a perspective view illustrating a schematic configuration of the paper feeding unit 52.
FIG. 3 is an explanatory diagram of the paper feeding unit 52.
FIG. 4 is an explanatory diagram of a main part of the suction unit 110.
The sheet feeding unit 52 is a topmost sheet that is positioned at the top of the sheet feeding cassette 11 serving as a sheet storage unit for stacking and storing a plurality of sheets and the sheet bundle 1 composed of a plurality of sheets on the sheet feeding cassette 11. And a sheet feeding device 200 that separates and feeds the sheet 1a.

  As shown in FIG. 3, the paper feed cassette 11 has a bottom plate 7 on which a plurality of stacked sheet bundles 1 are stacked. A support member 8 that supports the bottom plate 7 is rotatably mounted between the bottom portion of the paper feed cassette 11 and the bottom plate 7. As shown in FIG. 2, the sheet feeding unit 52 is provided with a sheet detecting unit 140 that detects that the uppermost sheet 1a of the sheet bundle 1 has reached a predetermined position.

  The sheet detection unit 140 includes a filler 144 that is rotatably supported by a shaft 142 provided in the apparatus main body, and a transmission optical sensor 143. When the support member 8 is rotated by the drive motor to raise the bottom plate 7, the sheet bundle 1 stacked on the bottom plate 7 rises and the uppermost sheet 1 a comes into contact with the filler 144. At this time, the light receiving unit 143a of the transmissive optical sensor 143 receives light from the light emitting unit 143b. Further, when the bottom plate 7 is raised, the filler 144 blocks the light of the light emitting unit 143b, and the light receiving unit 143a does not receive the light. Thereby, it is detected that the uppermost sheet 1a of the sheet bundle 1 has reached a predetermined position, and the rotation of the support member 8 is stopped.

  The sheet feeding apparatus 200 includes a suction unit 110, and a separation mechanism (swing means) that separates the uppermost sheet 1a from the sheet bundle 1 except the uppermost sheet 1a by swinging the suction unit 110. (Swinging mechanism) 120 is provided. Further, a drive mechanism 130 for moving the surface of the suction belt 2 is also provided. As shown in FIG. 4, the suction unit 110 includes a suction belt 2 that is stretched between a downstream tension roller 5 and an upstream tension roller 6.

Suction belt ^{2, 1 × 10 8 [Ω ·} cm] and the surface consisting of polyethylene terephthalate 50 [[mu] m] thickness of about having a higher volume resistivity, 1 × 10 6 formed by aluminum vapor deposition ^[Omega · cm] and a conductive layer having a volume resistivity of not more than 2. By making the suction belt 2 have such a two-layer structure, a conductive layer can be used as a grounded counter electrode. Therefore, the electrode roller 3 serving as a charging member for applying a charge to the suction belt 2 is replaced with the suction belt 2. It can be provided anywhere as long as it is in contact with the surface layer. In addition, a rib 23 for stopper is provided on the inner side of both edges in the width direction of the suction belt 2, and both end surfaces of the downstream tension roller 5 and the upstream tension roller 6 are in contact with the rib 23. As a result, the suction belt 2 is prevented from shifting.

The downstream tension roller 5 is provided with a conductive rubber layer having a volume resistivity of 1 × 10 ⁶ [Ω · cm] on the surface, and the upstream tension roller 6 is a metal roller. The downstream tension roller 5 and the upstream tension roller 6 are both grounded.

  The downstream tension roller 5 is a small-diameter roller suitable for separating the sheet from the suction belt 2 by the curvature. That is, by setting the diameter of the downstream tension roller 5 to be small and increasing the curvature, the sheet attracted to the suction belt 2 and sent out is separated from the downstream tension roller 5 and is guided downstream in the sheet conveying direction. It can enter the conveyance path H formed by the member 10.

  Further, as shown in FIG. 4, the downstream shaft 5 a of the downstream tension roller 5 is rotatably supported by the housing 20. The upstream shaft 6 a of the upstream tension roller 6 is rotatably supported by a bearing 22 that is slidably held in the sheet conveyance direction with respect to the housing body 20 a of the housing 20. The bearing 22 is urged to the upstream side in the sheet conveying direction by a spring 21. As a result, the upstream tension roller 6 is urged to the upstream side in the sheet conveying direction, and tension is applied to the suction belt 2.

  The surface of the suction belt 2 facing the sheet bundle 1 is slackened so that the suction belt 2 and the downstream tension roller 5 as a driving roller do not idle. In this way, by loosening the surface of the suction belt 2 facing the sheet bundle 1, even when the uppermost sheet of the sheet bundle has undulations, the adsorption belt 2 can follow the undulations of the uppermost sheet, A contact area between the suction belt 2 and the uppermost sheet can be ensured. As a result, even if the uppermost sheet is wavy, the uppermost sheet can be favorably adsorbed to the adsorption belt 2.

  Usually, even if the tension of the suction belt 2 is 5 [N] or less, the suction belt 2 is driven to rotate without slipping between the downstream tension roller 5 and the upstream tension roller 6 and the suction belt 2, It is possible to convey the uppermost sheet 1a adsorbed to the adsorption belt 2. On the other hand, when a sheet having a special condition such as a sheet having a high adhesion force is conveyed, slip may occur between the downstream tension roller 5 and the upstream tension roller 6 and the suction belt 2. It is done. For this reason, it is preferable to increase the friction coefficient of the surface of the upstream tension roller 6 and the surface of the downstream tension roller 5 with respect to the suction belt 2 so that slip is not easily generated.

FIG. 5 is an explanatory diagram of the drive mechanism 130 that rotationally drives the suction belt 2.
The suction unit 110 has a pair of brackets 12 arranged so as to be sandwiched between the main scanning line direction, that is, the direction substantially parallel to the surface of the uppermost sheet to be fed and the direction substantially perpendicular to the direction of feeding the uppermost sheet. A driven first pulley 26a and a driving second pulley 26b are fixed to one end of the swing shaft 14 that rotatably supports these brackets 12. A driven second pulley 25 is fixed to one end of the downstream tension roller 5, and a driven timing belt 28 is wound around the driven first pulley 26 a and the driven second pulley 25. A drive motor 24 is provided upstream of the swing shaft 14 in the sheet conveyance direction, and a drive first pulley 27 is fixed to the motor shaft 24 a of the drive motor 24. A drive timing belt 29 is wound around the drive first pulley 27 and the drive second pulley 26b.

  When the drive motor 24 is driven, the downstream tension roller 5 is rotationally driven via the drive timing belt 29 and the driven timing belt 28. As a result, the suction belt 2 moves to the surface, and the upstream tension roller 6 is driven to rotate by friction of the inner peripheral surface of the suction belt 2.

  In the present embodiment, the driving force of the driving motor 24 is transmitted to the downstream tension roller 5 by relaying the swing shaft 14 that supports the bracket 12. With this configuration, when the suction unit 110 swings around the swing shaft 14 as will be described later, the distance between the downstream tension roller 5 and the swing shaft 14 does not vary. Therefore, the tension of the driven timing belt 28 is maintained and the driving force can be transmitted to the downstream tension roller 5 satisfactorily.

  The drive mechanism 130 may be configured so that the drive force is transmitted from the drive motor 24 to the upstream tension roller 6, and the upstream tension roller 6 may be used as a drive roller for rotating the suction belt 2.

As shown in FIGS. 2 and 3, on the downstream side in the sheet conveyance direction of the sheet feeding unit 52, a separation mechanism as a separating unit that swings the bracket 12 and separates the uppermost sheet 1 a from the sheet bundle 1. 120 is provided.
The separation mechanism 120 is fixed to the follower roller 13 as a follower and the cam rotation shaft 16 at the upper part near the downstream end of each bracket 12 in the sheet conveyance direction, and pushes down the follower roller 13 that contacts the follower roller 13 downward. And a cam 15 having a contour curve. Further, the separation mechanism 120 includes a swing motor 30, and a motor shaft 30 a of the swing motor 30 is fixed to one end of the cam rotation shaft 16.

  Further, each cam 15 provided corresponding to each bracket 12 is fixed to the same cam rotation shaft 16, and each cam 15 is rotated by rotating the cam rotation shaft 16 by the swing motor 30. be able to. Thereby, the two cams 15 provided at both ends in the belt width direction can be rotationally driven by one swing motor 30, the number of parts can be reduced, and the apparatus can be made inexpensive. Further, the movement of the follower roller 13 rotatably held by the follower bearings 13a provided on the brackets 12 can be synchronized with a simple configuration.

The cam 15 is a plate cam in which the movement of the follower roller 13 and the contour curve of the cam 15 that guides the movement of the follower roller 13 are in the same plane. Rotate around. The follower roller 13 always comes into contact with the cam 15 disposed above by a pulling force that pulls upward of a tension spring 17 that is an urging means provided in the approximate center in the longitudinal direction of each bracket 12. Energized and moves up and down as the cam 15 rotates. Thus, each bracket 12 swings about the swing shaft 14 as the cam 15 rotates.
In the separation mechanism 120 having such a configuration, by driving the swing motor 30, each cam 15 rotates and the follower roller 13 moves up and down, so that each bracket 12 moves relative to the sheet bundle 1. Move in the direction of contact and separation. Thereby, each bracket 12 swings around the swing shaft 14 as a fulcrum.

  Each bracket 12 is connected and fixed by a reinforcing member 70. By connecting and fixing each bracket 12 with the reinforcing member 70, the one bracket 12 and the other bracket 12 can be integrally swung. Accordingly, the suction belt 2 held by each bracket 12 is prevented from being twisted when the bracket is swung, and the uppermost sheet 1a adsorbed to the suction belt 2 is prevented from being separated from the suction belt 2. it can.

  As shown in the perspective view of the main part of the suction unit in FIG. 6, an electrode roller 3 as a charging member for charging the surface of the suction belt 2 is in contact with the surface of the suction belt 2. The electrode roller 3 is connected to a charging power source 4 as voltage applying means for generating an alternating voltage. The charging member is not limited to a roller shape, and may be a blade shape, for example.

Next, a basic sheet feeding operation using the sheet feeding apparatus 200 of the present embodiment will be described with reference to FIG.
7A and 7B are explanatory views of a basic sheet feeding operation using the sheet feeding apparatus 200. FIG. 7A shows a standby state, FIG. 7B shows a sheet feeding signal, and a suction belt. 2 shows a state when charging of 2 is started. Further, FIG. 7C shows a state when the bottom plate 7 on which the sheet bundle is stacked and the lowering of the suction unit 110 are started after the completion of charging, and FIG. 7D shows the rise of the bottom plate 7. The state where the lowering of the suction unit 110 is completed and the uppermost sheet 1a is sucked is shown. FIG. 7E shows a state in which the suction unit 110 is swung to the conveyance position and the uppermost sheet 1a is separated from the sheet bundle 1 and conveyed.

As shown in FIG. 7A, the bottom plate 7 is normally in the lowered position and the suction unit 110 is in the suction position during standby or the like.
First, when a paper feed signal is input, the swing motor 30 is driven to rotate the cam 15 in the clockwise direction in the drawing, the follower roller 13 is raised by the urging force of the tension spring 17, and the swing shaft 14 is moved. The suction unit 110 is swung counterclockwise in the drawing (in a direction away from the sheet bundle 1) as a fulcrum. When the suction unit 110 swings to the transport position shown in FIG. 7B, the drive of the swing motor 30 is stopped.

  As shown in FIG. 7B, when the suction unit 110 stops at the transport position, the drive motor 24 is driven to move the surface of the suction belt 2. Next, an alternating voltage is applied to the suction belt 2 moving on the surface by the charging power source 4 via the electrode roller 3. Thereby, the surface of the suction belt 2 has a positive polarity at a pitch (pitch should be about 2 [mm] to 16 [mm]) according to the AC power supply frequency and the circumferential speed of the suction belt 2. A charging pattern is formed in which charging portions and negative polarity charging portions are alternately arranged in the belt circumferential direction. In addition to alternating current, the charging power source 4 may be one in which direct current is changed to an alternating potential of high and low, such as a rectangular wave and a sine wave. In the present embodiment, a rectangular wave having an amplitude of 4 [kV] is applied to the surface of the suction belt 2.

  When charging to the suction belt 2 is completed, as shown in FIG. 7C, the surface movement of the suction belt 2 is stopped and the bottom plate 7 that has been waiting at the lowered position is started to rise. Before and after this, the oscillating motor 30 is driven to rotate the cam 15 clockwise in the figure, and the follower roller 13 is lowered to rotate the oscillating shaft 14 as a fulcrum in the clockwise direction in the figure ( The suction unit 110 is swung in a direction in the vicinity of the sheet bundle 1.

  When the bottom plate 7 is raised and the suction unit 110 is lowered, the uppermost sheet 1 a of the sheet bundle 1 comes into contact with the upstream tension roller 6 through the suction belt 2. When the bottom plate 7 is further raised and the suction unit 110 is lowered, the upstream tension roller 6 is pushed up by the sheet bundle 1 and hits the lower end surface 41a of the long hole 12a. Moves upward while being guided by the elongated hole 12a. Further, as the bottom plate 7 rises, the filler 144 rotates counterclockwise in the figure. When the uppermost sheet 1a of the sheet bundle 1 comes to a predetermined position, the filler 144 blocks light from the light emitting unit 143b of the transmission optical sensor 143. Thereby, the transmission type optical sensor 143 detects that the uppermost sheet 1a of the sheet bundle 1 has reached a predetermined position, and stops raising the bottom plate 7.

  Further, when the suction unit 110 reaches the suction position, the rotation of the swing motor 30 is stopped. When the swing motor 30 is a stepping motor, the suction unit 110 can be accurately stopped at the suction position by controlling the swing motor 30 based on the rotation angle (number of pulses). When the swing motor 30 is a DC motor, the suction unit 110 can be accurately stopped at the suction position by controlling the swing motor 30 based on the driving time.

  As shown in FIG. 7D, when the rising of the bottom plate 7 is stopped and the lowering (swinging) of the suction unit 110 is stopped, the belt flat portion of the suction belt 2 facing the sheet bundle 1 is moved to the sheet bundle 1. Abuts on the uppermost sheet 1a. When the suction belt 2 comes into contact with the uppermost sheet 1a, Maxwell's stress acts on the dielectric sheet due to an unequal electric field formed by the charging pattern on the surface of the suction belt 2, and the uppermost sheet of the sheet bundle 1 1a is adsorbed to the adsorbing belt 2.

  In the state shown in FIG. 7 (d), when the uppermost sheet 1 a is adsorbed to the adsorbing belt 2, when the uppermost sheet 1 a is adsorbed, the swing motor 30 is driven to rotate the cam 15 clockwise, and the follower roller 13 is moved. Raise. By raising in this way, the suction unit 110 is swung counterclockwise in the figure with the swing shaft 14 as a fulcrum. Then, the downstream tension roller 5 moves together with the bracket 12 in a direction away from the sheet bundle 1.

  On the other hand, the upstream tension roller 6 does not move from the upper surface of the sheet bundle 1 due to its own weight, but moves relative to the bracket 12 in the sheet bundle direction. Thereby, the belt flat portion is separated from the upper surface of the sheet bundle 1 so that the surface portion (belt flat portion) of the suction belt 2 brought into contact with the upper surface of the sheet bundle 1 is inclined with respect to the upper surface of the sheet bundle. As a result, the sheet is bent, and the portion of the uppermost sheet 1 a that is adsorbed to the belt flat portion of the adsorption belt 2 is turned from the upper surface of the sheet bundle 1 as the adsorption belt 2 swings. At this time, the restoring force acts on the sheet adsorbed on the adsorption belt 2, and only the uppermost sheet 1a can be adsorbed on the adsorption belt 2, and the second sheet 1b can be separated by the restoring force of the sheet.

  When the suction unit 110 further rotates counterclockwise in the figure with the swing shaft 14 as a fulcrum, the upstream shaft 6a of the upstream tension roller 6 abuts against the lower end surface 41a of the elongated hole 12a. In this way, when the suction unit 110 is further rotated from the state where the upstream tension roller 6 is in contact with the lower end surface 41a of the long hole 12a, the upstream tension roller 6 also moves together with the bracket 12, and the upstream side The tension roller 6 is separated from the upper surface of the sheet bundle 1.

  As shown in FIG. 7E, when the suction unit 110 reaches the transport position for transporting the sheet, the drive of the swing motor 30 is stopped. Then, the drive motor 24 is driven to move the surface of the suction belt 2 so that the uppermost sheet 1a sucked on the suction belt 2 is transported toward a pair of transport rollers 9 as a nipping and transporting means. When the leading edge of the uppermost sheet 1a electrostatically attracted to the suction belt 2 reaches the winding portion of the downstream tension roller 5 of the suction belt 2, it is separated from the suction belt 2 by curvature separation and guided to the guide member 10. However, it moves toward the conveyance roller pair 9.

  The linear speeds of the conveyance roller pair 9 and the suction belt 2 are set to be substantially the same. When the conveyance roller pair 9 is intermittently driven at a timing, the adsorption belt 2 is also intermittently driven. The drive motor 24 is controlled. Further, the drive of the suction belt 2 may be controlled by providing an electromagnetic clutch in the drive mechanism 130 and controlling the electromagnetic clutch.

  Further, in the present embodiment, the bracket 12 is provided with the elongated hole 12a, and the upstream shaft 6a of the upstream tension roller 6 is held in the elongated hole 12a. That is, the upstream tension roller 6 is configured to be swingable about the downstream tension roller 5 with respect to the bracket 12, and the suction unit 110 is in the feeding position. At this time, there are two configurations: the upstream tension roller 6 is supported so that the inclination angle of the suction belt 2 with respect to the upper surface of the sheet bundle 1 is a predetermined angle (for example, 7.85 °). It only has to be prepared.

The sheet adsorption force due to the charging pattern acts only on the uppermost sheet 1a, and the second sheet 1
Does not work on paper below b. In this paper feeding method, since the frictional force between the pickup means and the sheet is not used, the contact pressure between the suction belt 2 and the sheet bundle 1 can be sufficiently reduced.
Does not cause double feed due to friction. The suction belt 2 is separated from the sheet bundle 1 before the rear end of the uppermost sheet 1 a reaches the position facing the upstream tension roller 6, so that the second sheet 1 b is not sucked by the suction belt 2.

As described above, the basic sheet feeding operation using the sheet feeding apparatus 200 of the present embodiment has been described with reference to FIG. 7, but the sheet feeding operation of the sheet feeding apparatus 200 of the present embodiment is the above-described basic example. It is not limited to.
As will be described in detail later, for example, depending on the shape of the cam 15 and the type of sheet, it is possible to operate as follows. From the standby state shown in FIG. 7 (a), when a paper feed signal is received and the swing motor 30 is driven to start rotating the cam 15 in the clockwise direction in the figure, until the series of paper feed requests is interrupted, the cam It is also possible to continuously feed the paper without stopping the 15 rotational driving.

In this embodiment, as the cam 15 rotates, the suction unit 110 is swung via the bracket 12 by the vertical movement of the follower roller 13 (follower bearing 13a) that moves in contact with the cam 15. I am letting.
As described above, by configuring the separation mechanism 120 included in the sheet feeding apparatus 200, the following effects can be achieved.
The surface of the suction belt 2 can be brought into and out of contact with the sheet bundle 1 by the movement of the follower roller 13 that moves according to the rotation of the cam 15. By making contact and separation in this way, the drive source of the swing motor 30 provided in the separation mechanism 120 can be configured to be continuously driven in one direction when continuous sheets are fed.

As a result, the swing motor 30 rotates from the stopped state and stops from the rotating state, that is, the drive source is turned on, as compared with the conventional configuration using a gear mechanism having a rack and pinion and a separating means having a solenoid or the like.・ The time required for switching off and rotating direction can be shortened.
Further, a cam 15 that guides the movement of the follower roller 13 that controls the movement of the surface of the suction belt 2 so as not to increase the speed fluctuation when the surface of the suction belt 2 is separated from the sheet bundle 1 excluding the uppermost sheet 1a. It is also easy to form a contour curve.
Therefore, it is possible to provide the sheet feeding apparatus 200 that can cope with the higher speed of the copying machine 100 that feeds and supplies the uppermost sheet 1a than before.

Further, the separating means included in the sheet feeding device 200 includes a pair of brackets 12 that are arranged so as to sandwich the suction belt 2 from the main scanning direction and swing about the swing shaft 14. A (follower bearing 13a) is provided in each bracket 12.
By configuring in this way, the following effects can be achieved. The pair of brackets 12 are arranged so as to sandwich the suction belt in a direction parallel to the surface of the uppermost sheet 1a sent out and perpendicular to the direction of sending out 1a, and swing around the swing shaft 14. For this reason, when the suction belt 2 is brought into contact with and separated from the sheet bundle 1, it is possible to prevent the suction belt 2 from being twisted and causing troubles such as a jam when being transferred to the conveying roller pair 9 of the copying machine 100.

The follower roller 13 as a follower included in the sheet feeding apparatus 200 of the present embodiment is composed of a rotating member that is rotatably supported by the follower bearing 13a.
According to this, the following effects can be produced. The contact portion of the follower with the cam member is rubbed and worn by the rotation of the cam member. On the other hand, the follower roller 13, which is a rotating member rotatably supported by the follower bearing 13 a, is brought into contact with the cam 15 as in the sheet feeding device 200 of the present embodiment, whereby the friction of the follower roller 13 is reduced. Thus, the life of the separation mechanism 120 and, by extension, the sheet feeding apparatus 200 can be increased.

Further, both of the swing from the suction position to the feeding position and the swing from the feeding position to the suction position, both the biasing force of the tension spring 17 biasing the follower roller 13 of the cam 15 and the swing motor 30 This can be done by driving force. As a result, the suction unit can be lowered to the suction position faster than the free fall speed of the suction unit 110. Therefore, after the first sheet is conveyed, the suction operation for the next sheet can be started quickly, and the sheet interval can be shortened, so that productivity can be increased.
Here, in the sheet feeding apparatus 200 of the present embodiment, the tension spring 17 is provided as the biasing means in order to maintain the contact state between the cam 15 and the follower roller 13, but the sheet feeding apparatus of the present embodiment. 200 is not limited to such a configuration.
For example, instead of a tension spring, an urging means such as a compression spring that pushes each bracket 12 upward is provided, or a new cam that pushes the follower roller 13 from below is provided in conjunction with the rotation of the cam 15. Also good.

  Further, in the sheet feeding apparatus 200 of the present embodiment, the driving force is transmitted to the suction unit 110 at the downstream end portion in the sheet transport direction that is farthest from the swing shaft 14 that is the swinging fulcrum of the suction unit 110, The suction unit 110 is swung. In this way, by separating the driving force transmission portion from the swing shaft 14, compared to the case where the driving force is transmitted on the support shaft side (upstream side of the suction unit 110 in the sheet conveyance direction) by the lever principle, The adsorption unit 110 can be swung with a small load. Thereby, the enlargement of the swing motor 30 can be avoided, and the enlargement of the apparatus can be suppressed. Further, wear at the contact portion between the cam 15 and the follower roller 13 can be suppressed.

Here, a control system related to adsorption and separation of the sheet delivery apparatus 200 in the sheet delivery apparatus 200 of the present embodiment will be described with reference to FIG.
FIG. 8 is an explanatory diagram of a control system related to the adsorption and separation of the sheet delivery apparatus 200.
The control unit 18 includes a CPU, a RAM, a ROM that stores various programs, and the like, and functions as a charging control unit that controls the charging power supply 4. The control unit 18 also functions as drive motor control means for controlling the drive motor 24 and swing motor control means for controlling the swing motor 30.

  When a paper feed signal is input and the swing motor 30 is driven from the position shown in FIG. 7A to swing the suction unit 110 to the transport position shown in FIG. 7B, the drive motor 24 is driven. The suction belt 2 is moved on the surface. Thereafter, the charging power source 4 is turned on, and an alternating voltage is applied from the electrode roller 3 to the suction belt 2 moving on the surface, thereby forming a charging pattern on the surface of the suction belt 2. Then, the drive motor 24 is stopped and charged at the timing when the leading end of the charging pattern reaches the point where the charging margin α is added to the belt circumferential distance from the charging position by the electrode roller 3 to the leading end position of the sheet bundle 1. Turn off the power supply 4.

  Thereafter, the swing motor 30 is driven to swing the suction unit 110 to the suction position shown in FIG. 7D, wait for a predetermined time, and when the uppermost sheet 1a is sucked to the belt flat portion of the suction belt 2, the swing unit 30 is swung. The moving motor 30 is driven to swing the suction unit 110 to the conveying position shown in FIG. 7E, and the uppermost sheet 1a is turned up from the upper surface of the sheet bundle. In the present embodiment, since the charging pattern is formed over the entire length in the sheet conveying direction of the belt flat portion facing the uppermost sheet 1a of the sheet bundle 1, sufficient sheet adsorption when the uppermost sheet 1a is turned up from the upper surface of the sheet bundle. Power can be exerted, and stable folding operation can be realized.

Here, in the sheet feeding apparatus 200 of the present embodiment, a cam driving unit such as a swing motor 30 that rotationally drives the cam member and a belt driving unit such as a driving motor 24 that moves the surface of the suction belt are separately provided. Provide.
By configuring in this way, the following effects can be achieved. By separating the driving means for the cam 15 and the suction belt 2, the controller 18 can simultaneously perform the contact / separation operation with respect to the sheet bundle 1 on the surface of the suction belt 2 and the conveying operation of the sucked uppermost sheet 1a. For this reason, the contact / separation operation such as the lowering operation is simultaneously performed during the conveying operation of the uppermost sheet 1a, and the productivity of the copying machine 100 can be further increased.

Next, the cam shape of the cam 15 that can be suitably used in the sheet feeding apparatus 200 according to the present embodiment will be described with reference to the drawings.
FIG. 9 is an example of a cam rotation operation diagram when the suction unit 110 is raised at a constant speed, and FIG. 10 is another example of a cam rotation operation diagram when the suction unit 110 is raised at a constant speed.

As described above, in the sheet feeding apparatus 200 according to the present embodiment, the cam 15 receives a paper feed signal from the standby state and starts rotating the cam 15 clockwise in the drawing until a series of paper feed requests is interrupted. It is possible to continuously feed the paper without stopping the rotation driving.
Here, for example, in a sheet feeding apparatus used for a high-speed image forming apparatus of about 80 ppm, the speed of separating the sheets by swinging the suction belt of the suction unit with respect to the sheet bundle is 0.355 seconds (hereinafter, “355 [ ms])). The breakdown is required to be about 127 [ms] for descending, about 100 [ms] for adsorption time, and about 127 [ms] for ascending.
However, in a configuration including a gear mechanism having a rack and pinion, a solenoid, and the like for swinging a pair of swing members that support the conventional suction unit so as to hold the suction unit, the drive source is turned on / off or rotated. It may take about 0.5 seconds to change the direction. For this reason, there existed a possibility that it could not respond to the speed of the apparatus which supplies a sheet | seat.
On the other hand, in the configuration having the cam 15 and the follower roller 13 that moves according to the rotation of the cam 15, the surface of the suction belt 2 is brought into contact with the sheet bundle 1 by the rotation (movement) of the cam 15 in one direction. Can be separated. For this reason, when performing continuous sheet feeding, the swing motor 30 provided in the separation mechanism 120 can be configured to be continuously driven in one direction.

In addition, in the configuration equipped with a conventional gear mechanism having a rack and pinion, a solenoid, etc., it is difficult to adjust the speed when the swinging member is swung to perform the contact / separation operation between the sheet bundle and the suction belt. There was a case where the speed fluctuation inside became large.
In particular, if the speed fluctuation when separating the uppermost sheet from the sheet bundle is large, the adsorbed uppermost sheet may be peeled off from the adsorption belt.
On the other hand, in the configuration having the cam 15 and the follower roller 13 that moves in accordance with the rotation of the cam 15, the surface of the suction belt 2 is moved relative to the sheet bundle 1 by the rotation of the cam 15 in one direction as described above. Can be touched and separated. For this reason, it is easy to stabilize the rotational speed of the cam 15, and by appropriately forming the contour curve of the cam 15 that contacts the follower roller 13, the speed fluctuation when separating the uppermost sheet from the sheet bundle is reduced. You can also.

In order to cope with an increase in the speed of the sheet feeding apparatus, for example, the lowering time, the sucking time, and the rising time of the suction unit 110 according to the productivity of the sheet feeding apparatus as described above are varied. Movement is necessary. And in the structure provided with the cam 15, the descent time of the adsorption | suction unit 110, the adsorption | suction time, and the raise time can be set easily by designing the contour curve of the cam 15 which contacts the follower roller 13 appropriately. .
In order to cope with an increase in the speed of an apparatus for supplying sheets, it is necessary to reduce the speed fluctuation when separating the uppermost sheet from the sheet bundle. And in the structure provided with the cam 15, the speed fluctuation | variation at the time of the raise of the adsorption | suction unit 110 can be easily made small by designing the outline curve of the cam 15 which contacts the follower roller 13 appropriately.
Here, an example of a cam shape that can be suitably used in the sheet feeding apparatus 200 of the present embodiment will be described with reference to FIG.

The cam rotation operation diagram of the cam 15 shown in FIG. 9 is set so that the speed when raising from the suction position to the raising position (conveying position) is substantially constant. Specifically, in the state shown in FIG. 7B, the follower roller 13 is in the raised position until 20 [ms] after the rotation speed of the swing motor 30 reaches a predetermined rotation speed. It has a certain shape. Then, it reaches the suction position from the rising position during 20 to 146 [ms], that is, 126 [ms], and is maintained at the suction position during 146 to 246 [ms], that is, 100 [ms]. The Thereafter, a contour curve of the cam 15 that contacts the follower roller 13 is formed so as to reach the ascending position at a substantially constant speed from 246 to 372 [ms], that is, 126 [ms]. Yes.
That is, in the example shown in FIG. 9, the cam 15 moves the follower roller 13 at a constant speed when the surface of the suction belt 2 is separated from the sheet bundle 1 except the uppermost sheet 1a. The shape has a contour curve that contacts the follower roller 13.

By configuring the cam shape of the cam 15 in this way, the following effects can be achieved. When separating from the sheet bundle 1 (second sheet 1b) excluding the uppermost sheet 1a, the surface of the suction belt 2 can be separated at a constant speed, and the load on the uppermost sheet 1a is reduced. In addition, it is possible to further reduce the speed fluctuation when separating.
Therefore, it is possible to provide the sheet feeding apparatus 200 that can cope with further increase in the speed of the copying machine 100 that feeds and supplies the uppermost sheet 1a. Thereby, it can suppress that a sheet | seat peels at the time of the raise which separates the adsorption belt 2 from the sheet | seat bundle 1. FIG.

Next, another example of the cam shape that can be suitably used in the sheet feeding apparatus 200 of the present embodiment will be described with reference to FIG.
The cam rotation operation diagram of the cam 15 shown in FIG. 10 is similar to the cam rotation operation diagram shown in FIG. 9 so that the speed when raising from the suction position to the raising position (conveying position) is substantially constant. Is set.
In addition, in another example shown in FIG. 10, the surface of the suction belt 2 with respect to the sheet bundle 1 is faster than the moving speed when the surface of the suction belt 2 is separated from the sheet bundle 1 excluding the uppermost sheet 1a. The moving speed when touching is increased. Specifically, in the state shown in FIG. 7B, until 20 [ms] elapses after the rotation speed of the swing motor 30 reaches a predetermined rotation speed, the same as the example shown in FIG. In addition, the follower roller 13 is set in a shape such that it is in the raised position.

However, while the period from the ascending position to the attracting position is only 20 to 106 [ms], that is, only 86 [ms] is required, it reaches the ascending position at substantially constant speed from the attracting position. The time required until this time is between 246 and 372 [ms], that is, 126 [ms]. That is, the moving speed when the surface of the suction belt 2 is brought into contact with the sheet bundle 1 is made faster than the moving speed when the surface of the suction belt 2 is separated from the sheet bundle 1 excluding the uppermost sheet 1a. ing.
By configuring the cam shape of the cam 15 in this way, the following effects can be achieved. By quickly lowering the suction belt 2, the suction time for sucking the uppermost sheet 1 a can be increased (lengthened).
Specifically, in both the examples shown in FIGS. 9 and 10, the time required for the cam 15 to rotate only once is the same at 372 [ms], and in the cam 15 of another example shown in FIG. Compared to the example shown in FIG. 9, the time for adsorption is increased by 40 [ms].

Next, another example of the sheet feeding operation for the second and subsequent sheets in the sheet feeding operation using the sheet feeding apparatus 200 of the present embodiment in the case of continuous side feeding will be described with reference to the drawings.
FIG. 11 is a flowchart relating to basic sheet separation and conveyance, and FIG. 12 is a flowchart of another example relating to sheet separation and conveyance.

  In the flowchart relating to the basic sheet separation and conveyance shown in FIG. 10, first, the suction belt 2 is charged to suck the first sheet (uppermost sheet 1a) (S101). After completion, the lowering operation of the suction unit 110 is performed (S102). When the lowering operation of the suction unit 110 is completed, the suction unit 110 is held at the suction position for a predetermined time, and the process proceeds to a sheet suction operation for sucking the first sheet (S103). Then, when the sheet suction operation is completed after a predetermined time has elapsed, the operation proceeds to a lifting operation of the suction unit 110 for separating the first sheet from the sheet bundle 1 (S104). When the ascending operation is completed and the suction unit 110 reaches the transport position (lift position), the drive motor 24 of the drive mechanism 130 is driven to transfer the first sheet to the transport roller pair 9 of the copier 100. The operation proceeds to the transport operation (S105).

  Thereafter, when the sheet conveying operation of the first sheet is completed, the charging operation of the suction belt 2 for sucking the second sheet (second sheet 1b) is performed similarly to the first sheet. Perform (S111). After this charging operation is completed, the suction unit 110 is lowered (S112). Thereafter, the same operation as the first sheet is repeated until the paper feed signal is interrupted.

On the other hand, in the flowchart of another example shown in FIG. 12, the flow from the transfer of the first sheet to the sheet conveying operation for transferring the first sheet to the conveying roller pair 9 of the copying machine 100 is (S201) to (S205). This is the same as the flow until the first sheet shown is shifted to the sheet conveying operation.
However, the second and subsequent charging operations and the lowering operation of the suction unit 110 are different.
Specifically, the charging operation start (S211) and the lowering operation start of the suction unit 110 (S213) are started substantially simultaneously. The charging operation and the lowering operation of the suction unit 110 are performed in parallel, and after the charging operation is completed (S212), the lowering operation of the suction unit 110 is completed (S214). Subsequent operations are the same as the first operation, that is, the flow described with reference to FIG. 9 except that the charging operation and the lowering operation of the suction unit 110 are similarly performed in parallel.

Based on the follow chart shown in FIG. 12, the sheet feeding operation is performed, and when a plurality of paper feed signals are input, the second and subsequent charging operations and the lowering operation of the suction unit 110 are performed in parallel. Thus, the time required for the sheet feeding operation can be further shortened.
Therefore, the productivity of the copying machine 100 using (comprising) the sheet conveying apparatus of the present embodiment can be further increased.

As described above, the present embodiment has been described with reference to the drawings. However, the specific configuration is not limited to the configuration including the sheet feeding device 200 of the present embodiment described above, and the scope of the present invention is not deviated. Design changes may be made.
For example, the configuration in which the sheet feeding device 200 is provided in the paper feeding unit 52 connected to the image forming unit 50 as illustrated in FIG. 1 has been described. However, the sheet feeding device 200 according to the present embodiment has such a configuration. It is not limited to. For example, the present invention can be applied to a sheet feeding device provided in a sheet feeding device that can be attached to and detached from a device that processes sheets. By providing such a sheet feeding device with a sheet feeding device having any of the above-described configurations, the same effects as those of any of the above-described sheet feeding devices can be achieved.

  Further, not only the copying machine 100 but also any one of the above-described sheet feeding devices or sheet feeding devices can provide an effect similar to that of any of the above-described sheet feeding devices or sheet feeding devices. A forming apparatus can be provided.

What was demonstrated above is an example, and there exists an effect peculiar for every following aspect.
(Aspect A)
The surface of the suction belt such as the suction belt 2 stretched around a plurality of rollers such as the downstream tension roller 5 and the upstream tension roller 6 is charged by the charging means such as the electrode roller 3, and the surface of the charged suction belt is charged. Is brought into contact with the uppermost sheet such as the uppermost sheet 1a of the sheet bundle such as the sheet bundle 1 and electrostatically adsorbed, and then the surface of the adsorbing belt that has electrostatically adsorbed the uppermost sheet is placed on the second sheet 1b. In a sheet delivery apparatus such as a sheet delivery apparatus 200 that sends the uppermost sheet toward a nipping and conveying means such as a pair of conveyance rollers 9, Separation means such as a separation mechanism 120 that separates the uppermost sheet from the sheet bundle excluding the uppermost sheet by bringing the surface into and out of contact with the sheet bundle includes a cam 15 and the like. And arm member, in a state of being in contact with said cam member, and having a follower, such follower rollers 13 which moves in response to rotation of said cam member (follower bearing 13a).

According to this, as described in the present embodiment, the following effects can be achieved.
The movement of a follower that moves in accordance with the rotation of the cam member allows the surface of the suction belt to be brought into contact with and separated from the sheet bundle, and a swinging motor provided in the separating means when performing continuous sheet feeding A cam drive source such as 30 can be configured to continuously drive in one direction.
As a result, the rotation of the drive source such as the drive motor from the stop state and the stop from the rotation state, that is, the drive source of the drive source, compared to the conventional configuration using the separation mechanism having a gear mechanism having a rack and pinion and a solenoid or the like. Time required for switching on / off and rotating direction can be shortened.
In addition, the cam contour curve that guides the movement of the follower is formed to control the movement of the suction belt surface so as not to increase the speed fluctuation when the suction belt surface is separated from the sheet bundle excluding the uppermost sheet. Is also easy.
Therefore, it is possible to provide a sheet feeding apparatus that can cope with higher speeds of apparatuses such as the copying machine 100 that feeds and supplies the uppermost sheet as compared with the prior art.

(Aspect B)
In (Aspect A), the separating means is disposed so as to sandwich the suction belt from a direction substantially parallel to a surface of the uppermost sheet to be sent out and substantially perpendicular to a direction of feeding the uppermost sheet, and is centered on a predetermined center of rotation. A swing member such as a pair of brackets 12 swinging is provided, and the follower is provided in each swing member.

According to this, as described in the present embodiment, the following effects can be achieved.
The pair of oscillating members are arranged so as to sandwich the suction belt in a direction parallel to the surface of the uppermost sheet sent out and perpendicular to the direction of sending out the uppermost sheet, and oscillate around a predetermined rotation center. For this reason, when the suction belt is brought into contact with and separated from the sheet bundle, the suction belt is twisted, and it is possible to suppress the occurrence of problems such as a jam when the sheet is delivered to the nipping / conveying means of the apparatus that supplies the uppermost sheet.

(Aspect C)
In (Aspect A) or (Aspect B), the cam member moves the follower at a constant speed when the surface of the suction belt is separated from the sheet bundle excluding the uppermost sheet. The shape has a contour curve in contact with the follower.
According to this, as described in the present embodiment, the following effects can be achieved.
When separating from the sheet bundle excluding the uppermost sheet, the surface of the suction belt can be separated at a constant speed, the load on the uppermost sheet can be reduced, and the speed fluctuation when separating can be reduced. It can be made even smaller.
Therefore, it is possible to provide a sheet feeding apparatus that can cope with further increase in the speed of the apparatus that feeds and supplies the uppermost sheet. Thereby, it can suppress that a sheet | seat peels at the time of the raise which separates an adsorption | suction belt from a sheet | seat bundle.

(Aspect D)
In any one of (Aspect A) to (Aspect C), cam drive means such as a swing motor 30 that rotationally drives the cam member and belt drive means such as a drive motor 24 that moves the surface of the suction belt are separately provided. It is characterized by providing in.
According to this, as described in the present embodiment, the following effects can be achieved.
By separating the driving means for the cam member and the suction belt, the contact / separation operation with respect to the sheet bundle on the surface of the suction belt and the conveying operation of the sucked uppermost sheet can be performed simultaneously by control means such as the control unit 18. For this reason, it is possible to further increase the productivity of the apparatus for supplying the sheet by simultaneously performing the contact and separation operation such as the lowering operation during the conveying operation of the uppermost sheet.

(Aspect E)
In any one of (Aspect A) to (Aspect D), the follower includes a rotating member rotatably supported by a bearing such as a follower bearing 13a.
According to this, as described in the present embodiment, the following effects can be achieved.
The contact portion of the follower with the cam member is rubbed and worn by the rotation of the cam member, but the friction of the follower can be reduced by bringing the rotation member supported rotatably on the bearing into contact with the cam member. Thus, the life of the separating means and the sheet feeding apparatus can be extended.

(Aspect F)
In any one of (Aspect A) to (Aspect E), the suction belt may be moved with respect to the sheet bundle rather than the moving speed when the surface of the suction belt is separated from the sheet bundle excluding the uppermost sheet. The moving speed when contacting the surface is increased.
According to this, as explained in the present embodiment, the suction time for sucking the uppermost sheet can be increased (lengthened) by quickly lowering the suction belt.

(Aspect G)
The surface of the suction belt stretched around a plurality of rollers is charged by a charging means, and the surface of the charged suction belt is brought into contact with the uppermost sheet of the sheet bundle and electrostatically adsorbed. In the sheet feeding apparatus provided with a sheet feeding device that separates the surface of the sucked belt from the sheet bundle excluding the uppermost sheet and feeds the uppermost sheet toward the nipping and conveying means. As described above, the sheet feeding device according to any one of (Aspect A) to (Aspect F) is provided.
According to this, as described in the present embodiment, the following effects can be achieved.
It is possible to provide a sheet feeding apparatus that can achieve the same effects as the sheet feeding apparatus according to any one of (Aspect A) to (Aspect F).

(Aspect H)
In the image forming apparatus for forming an image on the uppermost sheet sent out from the stacked sheet bundle, any one of (Aspect A) to (Aspect F) is used as a sheet delivery apparatus that sends out the uppermost sheet from the sheet bundle. The sheet supply device of (Aspect G) is provided as a sheet supply device that includes a sheet supply device or that includes a sheet supply device that supplies the uppermost sheet from the sheet bundle.
According to this, as described in the present embodiment, the following effects can be achieved.
It is possible to provide an image forming apparatus that can achieve the same effects as the sheet feeding device according to any one of (Aspect A) to (Aspect F) or the sheet feeding device according to (Aspect G).

DESCRIPTION OF SYMBOLS 1 Sheet bundle 1a Top sheet 1b Second sheet 2 Adsorption belt 3 Electrode roller 4 Charging power source 5 Downstream tension roller 5a Downstream axis 6 Upstream tension roller 6a Upstream axis 7 Bottom plate 8 Support member 9 Conveying roller pair DESCRIPTION OF SYMBOLS 11 Paper feed cassette 12 Bracket 13 Follower roller 13a Follower bearing 14 Oscillation shaft 15 Cam 16 Cam rotation shaft 17 Pulling spring 18 Control part 24 Drive motor 30 Oscillation motor 100 Copying machine 110 Adsorption unit 120 Separation mechanism 130 Drive mechanism 200 Sheet feeding device

JP 2013-249157 A

Claims (8)

The surface of the suction belt stretched around a plurality of rollers is charged by a charging means, and the surface of the charged suction belt is brought into contact with the uppermost sheet of the sheet bundle and electrostatically adsorbed. In the sheet delivery device that separates the surface of the adsorbing belt that has been adsorbed from the sheet bundle excluding the uppermost sheet, and sends the uppermost sheet toward the nipping and conveying means,
Separating means for separating the uppermost sheet from the sheet bundle excluding the uppermost sheet by bringing the surface of the suction belt into contact with or separated from the sheet bundle,
A sheet feeding apparatus comprising: a cam member; and a follower that moves in response to the rotation of the cam member in contact with the cam member. The sheet delivery apparatus according to claim 1, wherein
The separation means is disposed so as to sandwich the suction belt from a direction substantially parallel to a surface of the uppermost sheet to be sent out and substantially perpendicular to a direction of feeding the uppermost sheet, and swings around a predetermined rotation center. Has a rocking member,
The sheet feeding device according to claim 1, wherein the follower is provided on each of the swing members. In the sheet feeding apparatus according to claim 1 or 2,
The cam member has a contour curve that contacts the follower so that the follower moves at a constant speed when the surface of the suction belt is separated from the sheet bundle excluding the uppermost sheet. A sheet feeding device characterized by having a shape. In the sheet feeding apparatus according to any one of claims 1 to 3,
A sheet feeding apparatus comprising: a cam driving unit that rotationally drives the cam member; and a belt driving unit that moves the surface of the suction belt. In the sheet feeding device according to any one of claims 1 to 4,
The follower is composed of a rotating member that is rotatably supported by a bearing. In the sheet feeding apparatus according to any one of claims 1 to 5,
The moving speed when bringing the surface of the suction belt into contact with the sheet bundle is faster than the moving speed when separating the surface of the suction belt with respect to the sheet bundle excluding the uppermost sheet. A sheet feeding apparatus characterized by the above. The surface of the suction belt stretched around a plurality of rollers is charged by a charging means, and the surface of the charged suction belt is brought into contact with the uppermost sheet of the sheet bundle and electrostatically adsorbed. In the sheet supply apparatus provided with a sheet delivery device that separates the surface of the suction belt that has been sucked away from the sheet bundle excluding the uppermost sheet, and sends the uppermost sheet toward the nipping and conveying means,
A sheet feeding apparatus comprising the sheet feeding apparatus according to claim 1 as the sheet feeding apparatus. In an image forming apparatus that forms an image on the uppermost sheet fed from a stacked sheet bundle,
The sheet feeding apparatus according to any one of claims 1 to 6, wherein the sheet feeding apparatus feeds the uppermost sheet from the sheet bundle.
Alternatively, an image forming apparatus comprising the sheet supply device according to claim 7 as a sheet supply device provided with a sheet delivery device that sends out the uppermost sheet from the sheet bundle.

Images