JP6303639B2 - Sheet feeding apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to an electrostatic adsorption separation type sheet feeding apparatus and an image forming apparatus using the sheet feeding apparatus.

The technical background of the electrostatic adsorption separation method will be described.
Conventionally, as a method of separating stacked sheets such as originals and recording paper at the time of feeding, a separation method using a frictional force and a separation method using air suction are known. However, in the method using the frictional force, since a rubber material or the like is used for the feeding roller, the frictional force changes due to a change with time such as wear, and the separation performance is deteriorated. In addition, when sheets with different (coefficient) friction coefficients or sheets with different friction coefficients are separated at the same time, separation failures such as multiple feeding simultaneously feeding multiple sheets or separation of sheets from stacked sheets occur. Sometimes. Furthermore, since the sheet is separated by applying pressure when the sheet is separated, wrinkles and streaks may occur on the sheet or may become dirty.

  On the other hand, the separation method using air suction is a non-friction separation method that does not depend on the friction coefficient of a roller or a sheet. However, since an air suction blower and an air duct are required, the apparatus becomes large and the air suction sound becomes noise, which is unsuitable as an apparatus used in an office.

In view of this, an electrostatic attraction separation method has been proposed, which is a kind of non-friction separation method, in which an electric field is formed on a dielectric belt, and this is brought into contact with a sheet for adsorption and separation. Details are described in Patent Documents 1 and 2 and the like. This system uses an adsorption belt in which an alternating charge is applied to an endless dielectric belt wound around a plurality of rollers. The suction belt is swung or moved in parallel to come close to or in contact with the sheet, and the uppermost sheet is sucked onto the suction belt. Thereafter, the uppermost sheet is separated by moving the suction belt away from the stacked sheet bundle.
The separation feeding apparatus using the electrostatic adsorption separation system as described above is excellent in that it is free from wear, sheet breakage, noise generation and the like, and can be downsized.

A sheet feeding flow in such an electrostatic adsorption separation method will be described.
As disclosed in the above-described patent document, this separation and feeding apparatus performs separation and feeding by taking the following flow.
(A) The suction belt moves and the uppermost sheet of the laminated sheet group contacts the suction belt surface.
(B) The uppermost sheet is attracted to the belt surface by waiting in a contact state for a predetermined time.
(C) The suction belt moves in a state where the uppermost sheet is sucked and held, and the suction belt and the sheet bundle are separated to the transport position.
(D) The two stretching rollers holding the suction belt are rotated to convey the sheet.
(E) After completion of sheet conveyance, the process returns to A for continuous paper feeding.
In the proposed separation mechanism using the suction belt, separation is ensured by separating the sheet adsorbed on the electrostatic belt by the “belt up and down movement” of C and E in a series of operations, from the sheet bundle. ing.

A conventional example of the separation configuration will be described.
In order to enhance the adsorption and separation of the sheet feeding device using electrostatic force, for example, in the technique disclosed in Patent Document 2, the belt swings so that the belt surface is substantially parallel to the sheet material stacking surface. It is configured to do.
In the technique disclosed in Patent Document 3, the electrostatic attraction means is independently supported by a pair of swing members at a predetermined position in a direction intersecting the feeding direction, thereby increasing the sheet adsorbability.
The technique disclosed in Patent Document 4 is a method in which the uppermost sheet of a sheet bundle is brought into contact with a dielectric for a predetermined time, and then the stacking surface is lowered in a direction away from the dielectric to separate the sheets. In this technique, a method for optimizing the contact time and the descending speed is disclosed.

  Further, in the technique disclosed in Patent Document 5, the pressure contact force between the recording material placed on the paper feed tray and the paper feed roller is adjusted. The structure is such that the pressure of the paper feed roller is released when it is pulled out.

  Further, as a means for moving the endless dielectric belt in the direction of separating in the electrostatic adsorption separation method, as used in the technique disclosed in Patent Document 6, a method of moving the adsorption belt using a solenoid There is. Patent Document 7 proposes a method in which an adsorption / separation unit is rotated around a rotation axis by a rack, a gear, and a motor.

  By the way, if the belt unit is composed of a roller that stretches the belt and a unit that supports them, the belt unit has a certain weight. For this reason, conventionally, the driving load used for swinging the belt unit is reduced by stretching the belt unit with an elastic member. Also, the side fence that regulates the sheet width direction mounted on the sheet stacking tray needs to regulate all the sheet bundles to a predetermined position, so the height direction is installed to a position higher than the top surface of the sheet. Yes. The sheet stacking tray is configured to pull out in a direction perpendicular to the conveyance direction.

  Due to the above configuration, if the tray is pulled out while the belt unit is not sufficiently separated from the suction position or the suction position, the side fence interferes with the belt unit and there is a concern about destruction. There is also concern about damage to the belt surface due to rubbing between the lower surface of the belt and the upper surface of the sheet bundle.

  As a solution to this, it is possible to set the initial position of the belt unit at a position sufficiently away from the suction position by sufficiently increasing the tension of the elastic member that stretches the belt unit. In this case, when the power of the apparatus is cut off, the belt unit is stretched around the elastic member, and the belt unit gradually moves away from the suction position.

  However, the load on the drive source for swinging the belt unit at the time of swing is large. For example, when the drive source is a stepping motor, there is a risk of worst-case stepping out, and a solution has been desired.

A sheet feeding apparatus according to the present invention includes a suction belt disposed to face an upper surface of a stacked sheet bundle, a first stretching roller that stretches the suction belt, and a sheet of the first stretching roller. A suction separation unit having a second stretching roller located on the upstream side in the conveying direction; a stretching roller driving means for rotating the first stretching roller or the second stretching roller; The suction belt is moved between a suction position where the upper sheet is sucked by the suction belt and a separation position separated from the sheet bundle than the suction position, and the suction belt and the sheet bundle are moved. Contact / separation means for transporting the uppermost sheet adsorbed to and separated from the adsorption belt, a stacking tray for the sheet bundle that is detachably attached to an attachment port formed in the apparatus main body, and the contact / separation means The above A force that stretches the contact / separation means on the elastic member in conjunction with the drawer of the stacking tray. Ri is Na large, when the drawer of the loading tray, and having a contact member in contact with the laminate mounting tray to the apparatus main body, and a guide portion for slidably guiding the movement of the support member, the abutment member It has a shaft to be connected, and the shaft is connected to the support member .

  According to the present invention, it is possible to avoid interference with the suction belt and rubbing of the lower surface of the suction belt with the uppermost surface of the sheet bundle when the unit including the suction belt is pulled out.

1 is a schematic view of a gear type sheet separating and feeding device that is an implementation target of the present invention. It is the schematic of the other example of the gear-type sheet | seat separation feeding apparatus used as the implementation object of this invention. It is the schematic which shows the structure of the adsorption | suction belt of the apparatus of FIG. It is the schematic which shows the structure of the charging roller of the apparatus of FIG. 1, and a charging blade. FIG. 3 is a diagram illustrating a main part of an image forming apparatus equipped with a sheet feeding device. It is a figure which similarly shows the flow of sheet feeding operation | movement. 1 is a diagram illustrating a schematic configuration of an image forming apparatus that is mounted with a sheet feeding apparatus and that is an object of implementation of the present invention. In the sheet feeding apparatus according to the embodiment of the present invention, it is a diagram illustrating a state in which the tray is started to be pulled out among the operations when the tray is pulled out. In the sheet feeding apparatus according to the embodiment of the present invention, it is a diagram showing a state in which the tray is being pulled out of the operations when the tray is pulled out. FIG. 5 is a diagram illustrating an operation flow when the tray is pulled out in the sheet feeding device according to the embodiment of the present invention. FIG. 5 is a diagram illustrating an operation flow when the tray is pulled out in the sheet feeding device according to the embodiment of the present invention. FIG. 9 is a cross-sectional view taken along line AA in FIG. 8 showing a state before the tray is pulled out in the sheet feeding device according to the embodiment of the present invention. It is a top view of a paper feed tray. FIG. 9 is a cross-sectional view taken along the line AA in FIG. 8 showing a state after the tray is pulled out in the sheet feeding device according to the embodiment of the present invention. It is a top view of a paper feed tray. FIG. 9 is a side view taken along line BB in FIG. 8 showing a state before the tray is pulled out in the sheet feeding apparatus according to the embodiment of the present invention. FIG. 9 is a plan view conceptually showing a sheet feeding device according to an embodiment of the present invention when viewed from the top surface direction of FIG. 8. It is sectional drawing which follows the AA line of FIG. 8 which shows the state before tray drawing by the adsorption | suction separation unit using the rack and pinion used for the sheet | seat feeding apparatus which concerns on one Embodiment of this invention. FIG. 13B is a plan view of the sheet feeding device in the state of FIG. FIG. 9 is a side view taken along line B-B in FIG. 8, illustrating a state before the tray is pulled out by an adsorption separation unit using a rack and a pinion used in the sheet feeding apparatus according to the embodiment of the present invention. FIG. 14A is a plan view of the sheet feeding apparatus in the state of FIG. 14A, and FIG.

An embodiment of the present invention will be described.
First, the unit configuration will be described with reference to FIGS. In the figure, 1 is a sheet bundle, 1a is the uppermost sheet (also referred to as paper), 1b is a second or lower sheet, 2 is an endless adsorption separation belt made of a dielectric (hereinafter simply referred to as adsorption belt 2 and belt 2). 3 may be described as a dielectric endless belt 2), 3 is a roller electrode, and 4 is an AC power source. Reference numeral 5 denotes a downstream roller which is a belt stretching roller, 6 is also an upstream roller, 7 is a bottom plate, 8 is a bottom plate raising arm, and 9 is a pair of conveying rollers which are paper feed rollers. Further, in the figure, 10 is a downstream guide plate, 11 is a paper feed tray, and 12 is an adsorption separation unit.

    The downstream roller 5 to which the drive is transmitted is held by the adsorption / separation unit 12, and the shaft position is also fixed with respect to the unit. The downstream roller 5 has a small diameter suitable for separating the sheet from the belt 2 by the curvature.

  The belt 2 is disposed to face the upper surface of the sheet bundle 1 and is supported so as to be swingable around the downstream roller 5 as a rotation center. The rotation of the upstream roller 6 is within the movable range of the abutting portion 41 of the upstream roller shaft installed in the adsorption separation unit 12. When the downstream roller 5 comes into contact with the sheet bundle 1 due to the rotation of the adsorption separation unit 12, the lower surface of the belt 2 becomes the upper surface of the sheet bundle by the free rotation operation of the upstream roller 6 regardless of the stop position of the downstream roller 5. Contact with the surface. The configuration in FIG. 2 is basically the same.

The configuration of the belt 2 will be described with reference to FIG.
In the sheet feeding apparatus according to the present embodiment, an endless member wound around a downstream holding roller (hereinafter simply referred to as a downstream roller) 5 and an upstream holding roller (hereinafter simply referred to as an upstream roller) 6 as suction means serving as a pickup member. An adsorption separation belt 2 comprising a belt is used. A housing 20 is installed on the downstream roller 5, and the upstream roller 6 is rotatably supported by a bearing 22 configured to be slidable with respect to the housing 20. And it is urged | biased by the spring 21, and it is comprised so that it may follow with respect to the downstream roller 5 with the belt tension | tensile_strength and the friction of an adsorption | suction separation inner surface. Driving to the rollers 5 and 6 is connected to the downstream roller 5, and the upstream roller 6 is driven via the belt 2.

  Normally, a high conveying force of 5 N or less is not required for feeding sheets and sheets, but in the case of special conditions such as conveying sheets with high adhesion, slip occurs between the belt 2 and the rollers 5 and 6. It can also happen. In that case, slip can be prevented by increasing the friction coefficient of contact between the inner surface of the belt 2 and the rollers 5 and 6. A retaining rib 23 is provided on the inner side of both side edges of the belt 2 and is engaged with both side end surfaces of the rollers 5 and 6 to prevent the belt 2 from shifting.

  The belt 2 is configured as a two-layer belt in which a conductive layer having a resistance of 106 Ωcm or less is formed on the back surface of a polyethylene terephthalate cover having a thickness of about 50 μm having a resistance of 10 表面 8 Ωcm or more by vapor deposition of aluminum. The symbol “^” indicates a power. Further, the downstream roller 5 is provided with a conductive rubber layer having a resistance value of 10 6 Ωcm on the surface. The upstream roller 6 is a metal roller. Both the downstream roller 5 and the upstream roller 6 are grounded. Note that the above is a configuration disclosed in Patent Document 1 as an existing technology.

  In the figure, 13 is a second drive transmission portion (rack), 14 is a unit rotation shaft, 15 is a first drive transmission portion (pinion), 16 is a drive shaft, 20 is a belt housing, 21 is a belt tension compression spring, 22 Is a bearing, and 23 is a detent rib.

A charging operation for generating an adsorption force on the belt 2 and an adsorption principle (the principle of electrostatic adsorption: charging, adsorption, separation) will be described with reference to FIGS.
The configuration of the belt 2 and the charging unit (described later) includes a roller electrode 3 connected to an AC power source 4 so as to come into contact with the belt 2 at a position wound around a downstream roller 5 as a driving roller. Yes. The roller electrode 3 is fixed to the adsorption separation unit 12, and the position with respect to the belt 2 is uniquely determined.

  The downstream roller 5 is intermittently driven in accordance with a paper feed signal by a drive motor. The drive transmission from the drive motor to the downstream roller 5 may be via an electromagnetic clutch.

  The adsorption separation unit 12 is supported so as to be swingable on the upstream side in the sheet conveyance direction, and normally stands by at a standby position where the belt 2 is separated from the sheet. When a paper feed signal is input, first, the downstream roller 5 is driven to rotate. An alternating voltage is applied from the AC power supply 4 via the roller electrode 3 to the belt 2 that has been wound around the rollers 5 and 6 and started to rotate. Then, on the surface of the belt 2, an alternating charge pattern is formed at a pitch (pitch should be about 5 mm to 15 mm) according to the AC power supply frequency and the circumferential speed of the belt 2.

  After charging the belt 2, the belt 2 is brought into contact with the sheet bundle 1. Then, an unequal electric field is formed on the uppermost sheet 1a, which is a dielectric, by the charge pattern on the surface of the belt 2. Due to this unequal electric field, Maxwell's stress acts and only the uppermost sheet 1a is adsorbed and held on the belt 2. Then, as the belt 2 advances, the curvature is separated and fed out in the paper feeding direction, and conveyed to the image forming unit by the guide member 10 and the conveying roller pair 9. The sheet adsorbing force due to the charge pattern acts only on the uppermost sheet 1a and does not act on the second sheet 1b or lower. In this paper feeding method, since the frictional force between the pickup means and the paper is not used, the contact pressure between the belt 2 and the sheet bundle 1 can be made sufficiently small, so that double feeding due to friction does not occur.

  A guide member 10 and a conveyance roller pair 9 are provided on the downstream side of the belt 2 in the sheet feeding direction to guide conveyance of the sheet. The linear speeds of the conveying roller pair 9 and the belt 2 are the same. When the conveying roller pair 9 is intermittently driven at a timing, the belt 2 is also controlled to be intermittently driven. The belt 2 is separated from the sheet bundle 1 before the rear end of the paper 1a reaches the position facing the upstream roller 6 which is a driven roller so that the second paper 1b is not attracted to the belt 2. Further, separation of the sheet from the belt 2 at the downstream roller 5 portion is based on curvature separation. Instead of the AC power source 4, for example, a power source that can be supplied by changing the direct current to high and low potentials may be used. A power supply that supplies a rectangular wave, a sine wave, or the like is also conceivable. For example, a rectangular wave having an amplitude of 4 KV can be applied to the surface of the belt 2.

The charging member will be described with reference to FIG.
In this embodiment, the roller electrode 3 is used as the charging means, but a blade-shaped charging member (charging blade) 40 may be used as shown in FIG. The charging blade 40 can form a charge pattern having a smaller pitch width than the roller-shaped charging member (roller electrode 3). Then, the increase in the suction force with respect to the first sheet (uppermost sheet 1a) of the stacked sheet bundle 1 is accelerated. Further, since the decrease in the attractive force acting on the second and subsequent sheets 1b is accelerated, it is advantageous in that the time required for the separation operation can be shortened.

The belt drive train will be described with reference to FIG.
The downstream roller 5 is a driving roller. A pulley 25 that is fixed so as not to rotate with respect to the downstream roller shaft 5a is provided. In addition, an idler pulley 26 is provided rotatably on the unit rotation shaft 14. The pulley 25 and the idler pulley 26 are connected by a timing belt 28. Even when the unit rotates, the distance from the rotation shaft to the downstream roller 5 that holds the belt does not substantially change, so that the tension of the timing belt 28 is maintained and the drive is transmitted. In the figure, 6a is an upstream roller shaft.

  From the idler pulley 26 to the shaft of the belt drive source motor 24 (the drive source of the belt 2), it is shown in the drawing that it is connected to the motor pulley 27 by a timing belt 29.

A flow of the sheet feeding operation in the configuration shown in FIG. 1 will be described with reference to FIG.
When the paper feeding operation starts, the pinion gear constituting the first drive transmission unit 15 rotates, the adsorption separation unit 12 rises, and stops rising at a predetermined position (A).
Next, when the bottom plate 7 is raised and the sensor 18 detects the sheet surface of the uppermost sheet 1a and comes into contact with the bottom plate 7, the raising of the bottom plate 7 is stopped (B). Here, the belt 2 is charged.
Next, the pinion gear constituting the first drive transmission unit 15 rotates again to lower the adsorption separation unit 12 (C).
Then, the adsorption / separation unit 12 is lowered and stopped at a predetermined position, and waits for a predetermined time (D).
Again, the adsorption separation unit 12 is raised, the rise is stopped at a predetermined position, and the belt 2 is rotated. The sheet adsorbed on the belt 2 is fed. After feeding the sheet, the rotation of the belt 2 is stopped (E). Then, returning to FIG. 2C, the subsequent operations (C) to (E) are repeated.
The flow of the paper feeding operation in the configuration shown in FIG.

  In FIG. 7, reference numeral 50 denotes a main body of an image forming apparatus such as a copying machine, 51 denotes a conveyance path, and 52 denotes a paper feeding unit. The apparatus main body 50 includes a registration roller 53, an image forming unit 54, a fixing unit 55, and a paper discharge roller 56. In the figure, 57 is a paper discharge tray, 58 is a scanner unit, and 59 is an ADF unit. Since these are well-known and well-known structures, description is abbreviate | omitted.

  Hereinafter, a configuration that is a feature of the present invention will be described with reference to FIGS.

<Embodiment 1>
Embodiment 1 of the present invention will be described with reference to FIGS. 8A to 10B.
One end of the elastic member 61 is connected to the rear portion of the bracket 12 b constituting the adsorption / separation unit 12 through the idler pulley 60 and the idler pulley 62, and the other end is connected to the pulley 63 connected to the shaft 65. ing. In the same configuration, the elastic member 74 has one end connected to the rear portion of the bracket 12a constituting the adsorption / separation unit 12 through the idler pulley 73 and the idler pulley 75, and the other end connected to the shaft 64. 76. The balance is maintained at a position where the lower surface of the dielectric endless belt 2 and the upper surface of the sheet bundle 1 are horizontal. In the figure, 72 and 77 are support shafts, 78 is a support member, 79 is a side fence, 80 is a tray, and 81 is a caster.

  The shaft 64 is fastened to an abutting member 66 that abuts on the pushing member 71 connected to the paper feed tray 11. The contact member 66 is rotatably connected to a connecting shaft 68 that is rotatably connected to the connecting member 67 at the other end. The connecting member 67 is rotatably connected to a connecting shaft 69 that is rotatably connected to the connecting member 70 that is fastened to the shaft 65.

  Then, when the paper feed tray 11 is pulled out by the user, the pushing member 71 pushes the contact member 66. As a result, the shaft 64 and the shaft 65 rotate, and the pulleys 63 and 76 wind up the wire connected to the elastic member 61 and the elastic member 74 by the rotation. As a result, the tension force of the elastic members 61 and 74 increases, and the adsorption / separation unit 12 rises (see FIG. 10A). Therefore, as the sheet feeding tray 11 is pulled out, the dielectric endless belt 2 and the adsorption / separation unit 12 rise from the sheet bundle 1 in the separation direction.

  That is, the tension force of the elastic members 61 and 74 is increased in conjunction with the drawer of the paper feed tray 11, and the brackets 12a and 12b, the dielectric endless belt 2 and the like constituting the adsorption separation unit 12 are pulled up, and the side fence 79 Move to a position where it does not interfere with. Thereby, it is possible to avoid interference between the adsorption separation unit 12 and the side fence 79 and rubbing between the uppermost surface of the sheet bundle 1 and the lower surface of the dielectric endless belt 2.

  Since the pull-out force of the paper feed tray 11 is used, a drive source is not required for raising the adsorption separation unit 12 and the like when the paper feed tray 11 is pulled out. In other words, since the movement of the contact member 66 when the paper feed tray 11 is pulled out is converted into the rotation of the shafts 64 and 65, a drive source is not required for raising the adsorption separation unit 12 and the like. Therefore, even if the user pulls out the paper feed tray 11 when the main apparatus is turned off, the suction separation unit 12 and the like can be separated from the sheet bundle 1.

<Embodiment 2>
A second embodiment of the present invention will be described with reference to FIGS. 13A to 14B.
When the user pulls out the paper feed tray 11, the push-out member 71 pushes out the contact member 66, the shafts 64 and 65 rotate, the tension of the elastic members 61 and 74 is increased, and the adsorption / separation unit 12 is pulled up. The configuration is the same as in the first embodiment. The present embodiment is different from the first embodiment in the configuration of lifting the adsorption separation unit 12.

  The elastic member 61 is connected via an idler pulley 60 to a rack 82 engaged with an adsorption / separation unit 12 (rear part) and a pinion gear 83 fastened to a shaft 65. The balance is maintained at a position where the lower surface of the dielectric endless belt 2 and the upper surface of the sheet bundle 1 are horizontal. Similarly, the elastic member 74 is connected via an idler pulley 73 to a rack 84 that is engaged with a suction separation unit 12 (rear part) and a pinion gear 85 that is fastened to the shaft 64. The balance is maintained at a position where the lower surface of the dielectric endless belt 2 and the upper surface of the sheet bundle 1 are horizontal.

  The rack 82 and the pinion gear 83 are supported by holes in the support member 78, and the rack 82 and the pinion gear 83 are configured to slide along the holes when moving. The shaft 64 is fastened to an abutting member 66 that abuts on the pushing member 71 connected to the paper feed tray 11. The contact member 66 is rotatably connected to a connecting shaft 68 that is rotatably connected to the connecting member 67 at the other end. Further, the connecting member 67 is rotatably connected to a connecting shaft 69 that is rotatably connected to the connecting member 70 fastened to the shaft 65.

  Then, when the paper feed tray 11 is pulled out by the user, the pushing member 71 pushes the contact member 66. As a result, the pinion gears 83 and 85 fastened to the shafts 64 and 65 rotate, and the racks 82 and 84 move the elastic members 61 and 74 in the stretching direction. By doing so, the tension force increases and the adsorption separation unit 12 rises. As the paper feed tray 11 is pulled out, the dielectric endless belt 2 and the suction separation unit 12 rise from the sheet bundle 1 in the separation direction.

  That is, also in this embodiment, the tension force of the elastic members 61 and 74 is increased in conjunction with the drawer of the paper feed tray 11, and the brackets 12a and 12b, the dielectric endless belt 2 and the like constituting the adsorption separation unit 12 are pulled up. Then, it is moved to a position where it does not interfere with the side fence 79. This avoids interference between the adsorption separation unit 12 and the side fence 79 and rubbing between the uppermost surface of the sheet bundle 1 and the lower surface of the dielectric endless belt 2.

  The present invention is not limited to the embodiments described above, and many variations are possible by those having ordinary knowledge in the art within the technical idea of the present invention.

1: Sheet bundle (1a: top paper, 1b: next paper)
2: Endless dielectric belt 3: Electrode 4: Power supply 5, 6: Belt tension roller (5: downstream roller, 6: upstream roller)
5a, 6a: Roller shaft 7: Bottom plate 8: Bottom plate raising arm 9: Paper feed roller 10: Downstream guide plate 11: Paper feed tray 12: Adsorption / separation unit 12a, 12b: Adsorption / separation unit bracket 13: Second drive transmission unit (rack)
14: Unit rotation shaft 15: First drive transmission unit (pinion)
16: Drive shaft 17: Drive source (motor)
20: belt housing 21: compression spring for belt tension 22: bearing 23: detent rib 24: belt drive source motor 25: pulley 26: idler pulley 27: motor pulley 28: timing belt 1
29: Timing belt 2
41: Unit abutting section 50: Device main body 51: Transport path 52: Paper feed unit 53: Registration roller 54: Image forming unit 55: Fixing unit 56: Paper discharge roller 57: Paper discharge tray 58: Scanner unit 59: ADF unit 60: pulley 61: elastic member 62: idler pulley 63: idler pulleys 64, 65: shaft 66: abutting member 67: connecting members 68, 69: connecting shaft 70: connecting member 71: push-out member 72: support shaft 73: aridra pulley 74: Elastic member 75: Idler pulley 76: Pulley 77: Support shaft 78: Support member 79: Side fence 80: Tray 81: Caster 82: Rack gear 83: Pinion gear 84: Rack gear 85: Pinion gear

JP-A-5-139548 JP 2010-037047 A Japanese Patent Laid-Open No. 2003-237862 JP 2004-26314 A JP 2010-162333 A Japanese Patent No. 3862577 JP 2010-126317 A

Claims (4)

A suction belt arranged opposite to the upper surface of the stacked sheet bundle,
A first stretching roller that stretches the suction belt; and
A second stretching roller located upstream of the first stretching roller in the sheet conveying direction;
An adsorption separation unit having
A tension roller driving means for rotating the first tension roller or the second tension roller;
The suction belt is moved between a suction position where the uppermost sheet of the sheet bundle is sucked by the suction belt and a separation position which is separated from the sheet bundle than the suction position, and the suction belt Contacting / separating means for contacting and separating the sheet bundle and conveying the uppermost sheet adsorbed to the adsorption belt;
A stacking tray of the sheet bundle that is detachably mounted in a mounting port formed in the apparatus body;
An elastic member that stretches the contacting / separating means away from the sheet bundle;
A support member for supporting the elastic member;
Have
Wherein in conjunction with the withdrawal of the tray the moving means of Ri said resilient to the name large force tension member,
The apparatus main body has a contact member that comes into contact with the stacking tray when the stacking tray is pulled out,
A guide portion for slidably guiding the movement of the support member;
A shaft connected to the contact member;
Connecting the shaft to the support member;
A sheet feeding apparatus characterized by that. A suction belt arranged opposite to the upper surface of the stacked sheet bundle,
A first stretching roller that stretches the suction belt; and
A second stretching roller located upstream of the first stretching roller in the sheet conveying direction;
An adsorption separation unit having
A tension roller driving means for rotating the first tension roller or the second tension roller;
The suction belt is moved between a suction position where the uppermost sheet of the sheet bundle is sucked by the suction belt and a separation position which is separated from the sheet bundle than the suction position, and the suction belt Contacting / separating means for contacting and separating the sheet bundle and conveying the uppermost sheet adsorbed to the adsorption belt;
A stacking tray of the sheet bundle that is detachably mounted in a mounting port formed in the apparatus body;
An elastic member that stretches the contacting / separating means away from the sheet bundle;
A support member for supporting the elastic member;
Have
In conjunction with the drawer of the stacking tray, the force to stretch the contacting / separating means on the elastic member is increased.
The apparatus main body has a contact member that comes into contact with the stacking tray when the stacking tray is pulled out,
A guide portion for slidably guiding the movement of the support member;
A shaft connected to the contact member;
First transmission means coupled to the shaft;
Have
The support member serves as second transmission means that engages with the first transmission means .
A sheet feeding apparatus characterized by that. In the sheet feeding apparatus according to claim 1 or 2,
The support member is the force for stretching the elastic member is larger ing by moving,
A sheet feeding apparatus characterized by that. An image forming apparatus comprising the sheet feeding device according to claim 1.