JP2014051333A - Sheet separation and transport device and image forming apparatus - Google Patents

Abstract

There is provided a sheet separating and conveying device capable of stabilizing a sheet conveying property by lifting a suction and separating unit that adsorbs and separates a sheet to an endless belt with static electricity horizontally without unevenness.
SOLUTION: A dielectric belt (endless belt 2) for attracting and holding the uppermost sheet material of a sheet bundle 1 by using electrostatic force, and rotating the uppermost sheet material from the second and subsequent sheet materials. An adsorbing / separating unit 15 is provided that rotates about 16 and separates. Wires 20 are attached to both ends of the adsorption / separation unit 20 in the sheet material conveyance direction downstream of the center and in a direction perpendicular to the sheet material conveyance direction, and have pulleys 22 and 23 around which the wire 20 is wound. A configuration in which the adsorption / separation unit 15 is rotated by adjusting the winding amount of the wire 20 so that the tension of the wire 20 does not act on the adsorption / separation unit 15 when the adsorption / separation unit 15 contacts the uppermost sheet material. And
[Selection] Figure 3

Description

  The present invention relates to a sheet separation / conveyance apparatus and an image forming apparatus, and more particularly, to a sheet separation / conveyance apparatus that uses static electricity to attract and separate a sheet on a non-circular belt, and the sheet separation / conveyance apparatus. The present invention relates to an image forming apparatus including an electrophotographic copying machine, a facsimile apparatus, a printer apparatus, and the like.

  An endless dielectric belt that attracts and holds the sheet material located at the top of the laminated sheet group using electrostatic force as a sheet separating and conveying device that uses static electricity to attract and separate the sheet on a belt. And a sheet separating and conveying apparatus having a structure for separating and separating the second and subsequent sheets of the sheet bundle in which the uppermost sheet material is laminated, using a gear and a drive on both sides of the suction separating unit. A structure that rotates is known. However, in this configuration, there is a problem that the adsorption / separation unit may not be able to be lifted horizontally due to unevenness of the gear backlash.

  In Patent Document 1, it is possible to increase the feeding speed by ensuring a stable separation and feeding function for feeding the stacked objects one by one from the surface while having a wide range of freedom of selection of the objects. An object of the present invention is to provide an apparatus for feeding an object to be laminated, in which the object to be laminated laminated on a receiving member is separated one by one from the object at the surface position and fed one by one. An electrostatic adsorption belt that is stretched over a roller and covered with a plurality of electrodes with an insulating layer, connected to the plurality of electrodes, induces surface polarization on the surface of the object by applying a voltage, and surface polarization by cutting off the applied voltage Electrostatic attraction control circuit for returning to an original state without any object, an object feeding mechanism for feeding out a feeding object electrostatically attracted to a belt holding surface of the electrostatic attraction belt by belt rotation, and the belt holding surface A relative distance adjusting mechanism that adjusts the relative distance between the stacked objects to bring the belt holding surface and the stacked objects close to or in contact at the time of suction, and separates the belt holding surface from the stacked objects at the time of feeding. An apparatus for feeding a stacked object is disclosed. However, even the invention disclosed in Patent Document 1 cannot solve the problem that the adsorption separation unit may not be lifted horizontally.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a sheet separating and conveying apparatus and an image forming apparatus having a configuration capable of lifting a suction separating unit horizontally.

  The sheet separating and conveying apparatus of the present invention has an endless dielectric belt that attracts and holds the sheet material positioned at the uppermost part of the stacked sheet bundle using electrostatic force, and rotates around a rotation axis. In the sheet separating and conveying apparatus provided with the adsorption separating unit for separating the uppermost sheet material from the second and subsequent sheets of the sheet bundle, a string-like rigid body is centered in the sheet material conveying direction of the adsorption separating unit. A drive source for winding up the string-like rigid body, a shaft connected to the drive source, and the string-like rigid body on the shaft; The adsorption separation unit is rotated by adjusting the amount of winding of the string-like rigid body, and the adsorption separation unit and the uppermost sheet material are in contact with each other. Even tension shaped for rigid body and having a structure that does not act with respect to the adsorptive separation unit.

  According to the present invention, it is possible to lift the adsorption / separation unit horizontally without left-right bias and to stabilize paper transportability.

The perspective view which shows the structure of one Embodiment of the sheet separation conveyance apparatus of this invention. Diagram showing wire floating prevention configuration The figure shown about a structure and operation | movement of the adsorption separation unit used with the sheet separation conveyance apparatus which concerns on Embodiment 1 of this invention. FIG. 3 is a view corresponding to FIG. 3 illustrating a sheet separating and conveying apparatus according to the second embodiment of the present invention. 1 is a diagram illustrating a configuration of an example of an image forming apparatus that is an object of the present invention. Conceptual cross-sectional view for explaining the configuration and operation of a sheet separating and conveying apparatus using an adsorption separating unit

  In the embodiment of the present invention, when a gear and a drive source are used for the rotation operation of the adsorption / separation unit, the rotation operation of the adsorption / separation unit becomes uneven due to the backlash of the gears on both sides. The adsorption / separation unit is lifted by a string-like rigid body (a non-stretchable linear body made of metal wire, resin wire, etc.), and the adsorption / separation unit is rotated by adjusting the amount of winding. It can be lifted evenly from side to side. Since the amount of winding of the string-like rigid body is adjusted, it is possible to perform fine position adjustment that cannot be adjusted due to the influence of gear backlash. Further, there is a problem of the strength of the gear when the heavy adsorption / separation unit is rotated. However, in the configuration in which the entire adsorption unit is lifted by a string-like rigid body, it is not necessary to consider the strength problem.

<Embodiment 1>
FIG. 5 is a diagram illustrating the configuration of an example of an image forming apparatus that is an object of the present invention. Note that the image forming apparatus to be implemented in the present invention is not limited to the one shown in the figure, and the image forming apparatus such as a copying machine, a facsimile apparatus, an apparatus having a function of a multifunction machine having a copying function and a facsimile function, etc. Various devices that perform the above are targeted.

  In FIG. 5, a copying machine 100 as an example of an image forming apparatus separates a document from a document bundle placed on a document tray 110a and automatically feeds the document to a contact glass on a document reading unit 120. An apparatus 110, a document reading unit 120 that reads a document conveyed on the contact glass by the automatic document conveyance device 110, and an image read by the document reading unit 120 on a sheet material fed from the sheet feeding unit 130. An image forming unit (image forming unit) 140 to be formed and a sheet bundle 1 in which a plurality of sheet materials are stacked, and the sheet material 1a positioned at the top of the sheet bundle 1 is fed to the image forming unit 140. A paper feed unit 130 is provided. In this embodiment, the image forming unit 140 and the paper feeding unit 130 can be divided, but a configuration other than that may be used.

  The sheet feeding unit 130 separates a sheet feeding cassette 150 as a sheet stacking member on which a plurality of sheet materials 1 a are stacked, and a sheet material positioned at the uppermost position from the plurality of sheet materials 1 a on the sheet feeding cassette 150. And a sheet separating and feeding device 160 to be conveyed.

  The sheet material 1 a separated and fed by the sheet separating and feeding device 160 is transported on the transport path 170, and the sheet material 1 a transported on the transport path 170 is transported by the transport roller pair 180. Then, the toner image formed in the image forming unit 140 is transferred by the transfer roller 190, this toner image is thermally transferred by the fixing device 200, and discharged to the discharge tray 220 by the discharge roller pair 210.

  The image forming unit 140 includes four image forming units 230 (230Y (yellow), 230C (cyan), 230M (magenta), 230BK (black)), an intermediate transfer belt 240 that is a transfer belt, and an exposure device 250. It is configured.

  The exposure apparatus 250 converts color-separated image data input from a personal computer, a word processor, or the like, or image data of an original read by the original reading unit 120 into a signal for driving a light source, and accordingly, each laser light source unit. The semiconductor laser is driven to emit a light beam.

  The image forming units 230Y, 230C, 230M, and 230BK form images of different colors (toner images), and the image forming units 230Y, 230C, 230M, and 230BK are rotated in the clockwise direction. The image forming apparatus includes a photosensitive member 260 (260Y, 260C, 260M, and 260BK) that is an image carrier, a charging unit 270, a developing unit 280, a cleaning unit 290, and the like disposed around the photosensitive member 260.

  The photoreceptor 260 is formed in a cylindrical shape and is driven to rotate by a drive source (not shown). A photosensitive layer is provided on the outer peripheral surface portion of the photoconductor 260, and a light beam indicated by a broken line emitted from the exposure device 250 is spot-irradiated on the outer peripheral surface of the photoconductor 260. An electrostatic latent image corresponding to the image information is written.

  The charging unit 270 charges the outer peripheral surface of the photoconductor 260 in a uniform manner, and a contact type is used for the photoconductor 260. The developing unit 280 supplies toner to the photosensitive member 260, and the supplied toner adheres to the electrostatic latent image written on the outer peripheral surface of the photosensitive member 260, whereby the electrostatic latent image on the photosensitive member 260 is changed. A toner image is visualized, and a non-contact type is used for the photoreceptor 260.

  The cleaning unit 290 cleans residual toner adhering to the outer peripheral surface of the photoconductor 260 and employs a brush contact type in which a brush contacts the outer peripheral surface of the photoconductor 260.

  The intermediate transfer belt 240 is composed of an endless belt formed using a resin film or rubber as a base, and the toner image formed on the photosensitive member 260 is transferred to the intermediate transfer belt 240. The toner image is transferred to the sheet material 1 a by the transfer roller 190.

  FIG. 6 is a conceptual cross-sectional view for explaining the configuration and operation of the sheet separating and conveying apparatus using the adsorption separating unit 15. A roller electrode 3 connected to an AC power supply 4 is provided so as to contact an endless belt (hereinafter referred to as an endless belt) 2 at a position wound around the driving roller 5. The roller electrode 3 is fixed to a member (hereinafter referred to as a unit main body) 15a constituting the adsorption / separation unit 15, and the position with respect to the endless belt 2 is uniquely determined. The unit main body 15a pivotally supports the unit main body 15a so as to be rotatable about the rotation shaft 16 in the vertical direction in the figure.

  On the downstream side in the sheet feeding direction of the endless belt 2 (on the right side in FIG. 6), a guide member 10 and a conveyance roller for guiding conveyance of the sheet material from a bundle of sheet materials (hereinafter referred to as a sheet bundle) 1. A pair 12 is provided. Further, ribs (not shown) for stoppering are provided inside both side edges of the endless belt 2, and the rollers 5 and 6 of the endless belt 2 are engaged with both side ends of the driving roller 5 and the driven roller 6. This prevents misalignment in the axial direction. The drive roller 5 is intermittently driven according to a paper feed signal sent via an electromagnetic clutch (not shown) by a drive motor (not shown).

  The adsorption separation unit 15 normally stands by in a state shown in FIG. 3B described later. When a paper feed signal is input, the electromagnetic clutch is first engaged, and the driving roller 5 is driven to rotate. The movement (circumferential movement) is started in a state where it is hung around. An alternating voltage is applied to the endless belt 2 from the AC power source 4 via the roller electrode 3, and the surface of the endless belt 2 has a pitch (pitch is, for example, 5 mm to 5 mm) according to the AC power source frequency and the belt circumferential speed. An alternating charge pattern is formed.

  After the endless belt 2 is charged, the arms 8 and 8 rotate to push the bottom plate 7 horizontally, and before and after that, the adsorption separation unit 15 moves downward and moves to the state shown in FIG. . The bottom plate 7 moves up and stops after its position is detected by a sensor which will be described later.

  Maxwell's stress acts on the uppermost sheet material 1a of the sheet bundle 1 which is a dielectric material due to an unequal electric field formed by the charge pattern on the surface of the endless belt 2, and only the uppermost sheet material 1a Adsorbed and held on the endless belt 2, the curvature is separated from the endless belt 2 as the endless belt 2 advances, and is fed out in the paper feeding direction, and is conveyed to the image forming unit 140 by the guide member 10 and the conveyance roller 9. .

  The sheet material adsorbing force due to the charge pattern basically acts only on the uppermost sheet material 1a and does not act on the second sheet material 1b or lower. In this paper feeding method, since the frictional force between the pickup means and the sheet material is not used, the contact pressure between the endless belt 2 and the sheet bundle 1 can be made sufficiently small. Therefore, double feed due to friction does not occur.

  The linear speeds of the conveying roller pair 12 and the endless belt 2 are set to be the same. When the conveying roller pair 12 is intermittently driven at a timing, the endless belt 2 is also controlled to be intermittently driven. The endless belt 2 is separated from the sheet bundle 1 before the rear end of the uppermost sheet material 1a reaches the position facing the driven roller 6 so that the second sheet material 1b is not attracted to the endless belt 2. Yes. Further, separation of the sheet material from the endless belt 2 at the portion of the driving roller 5 is based on curvature separation as described above. The power source to be applied to the roller electrode 3 may be one in which the direct current is changed to a high and low alternating potential in addition to the alternating current, and a rectangular wave, a sine wave, and the like may be considered. In the present embodiment, it is assumed that a rectangular wave having an amplitude of 4 KV is applied to the surface of the endless belt 2.

  FIG. 1 is a perspective view showing the configuration of an embodiment of the sheet separating and conveying apparatus of the present invention. In the sheet adsorbing / separating apparatus of the present embodiment, an adsorbing / separating unit 15, a string-like rigid body (wire or the like) 20 that lifts the adsorbing / separating unit 15, a pulley 22 around which the string-like rigid body is wound, a pulley 23 around which a wire is wound, and a wire floating The wire guide 24 and the drive source (stepping motor) 21 are configured to prevent the above. In the following description, the rigid body 20 such as a wire will be described as the wire 20.

  The place where the wire 20 is attached to the adsorption / separation unit 15 is downstream of the center of the adsorption / separation unit 15 in the conveyance direction of the sheet bundle 1 (the direction from the left to the right in FIG. 1). As a result, the rotation operation can be performed around the rotation shaft 16.

  The rotational operation amount of the adsorption separation unit 15 is adjusted by the winding amount of the wire 20. Note that the winding amount of the wire 20 is adjusted by the rotation amount of the stepping motor 21. The wires 20 are provided at both ends of the adsorption / separation unit 15, and by making the wire winding amounts coincide with each other, the adsorption / separation unit 15 is not inclined left and right (in the depth direction of the paper surface in FIG. 1) with respect to the conveyance direction of the sheet bundle 1. Can be lifted. Furthermore, by having the stepping motor 21 for winding the wire on each of the left and right sides, it is possible to further reduce the twist when lifting the adsorption separation unit 15. Further, by adopting a configuration in which the wire 20 can be slackened, even when several sheets of the sheet bundle 1 are conveyed, even if the leading end position of the stacked sheet bundle 1 slightly changes, the stacked sheet bundle 1 The suction separation unit 15 can be stably brought into contact with the first sheet.

  FIG. 2 is a diagram showing a structure for preventing the wire 20 from floating, and is a perspective view of a portion indicated by a rectangular chain line in FIG. In the sheet adsorbing / separating apparatus of this embodiment, the wire 20 as a string-like rigid body is wound around a pulley 23 between the adsorbing / separating unit 15 and the pulley 22. A cylindrical wire guide 24 is provided in the vicinity of the pulley 23. By passing the wire 20 through the pulley, the wire 20 is prevented from being detached from the pulley 22 and the pulley 23 even if the wire 20 is slack (FIG. 2A). ). However, the wire guide 24 does not need to be cylindrical, and as a cheaper configuration example, for example, as shown in FIG. 2B, the wire guide 25 may be configured by combining flat plate-like support members. As shown in FIG. 2C, the wire guides 24 may be provided at a plurality of locations (two locations in the figure). In that case, the configuration is not limited to the configuration in which the wire guides 24 are provided in the vicinity of the pulley 23 as in the example of FIG.

  FIG. 3 is a diagram showing the configuration and operation of the adsorption separation unit 15 which is an electrostatic adsorption unit. 3 shows a configuration in which two wire guides 24 are provided near the pulley 23 as in the example of FIG. 2C, the configuration of the adsorption separation unit in the present invention is not limited to this example.

  In the suction separation unit 15 of the present embodiment, as described above, the suction means serving as a pickup member is wound around the driving roller 5 that holds the downstream side in the sheet conveyance direction and the driven roller 6 that holds the upstream side. An endless belt 2 is used. Driving to the rollers 5 and 6 is connected to the driving roller 5, and the driven roller 6 is configured to be driven via a belt, and the driven roller 6 is urged by, for example, a spring (not shown) and the endless belt 2. The tension is applied to.

  The endless belt 2 is made of a dielectric material having a resistance of 10 抵抗 8 Ωcm or more, for example, a film of polyethylene terephthalate having a thickness of about 100 μm. The driving roller 5 is preferably provided with a conductive rubber layer having a resistance value of about 10 6 Ωcm on the surface, and the driven roller 6 is preferably a metal roller. Both the driving roller 5 and the driven roller 6 are grounded. The driving roller 5 is preferably of a small diameter suitable for separating one uppermost sheet material of the sheet bundle 1 from the endless belt 2 by the curvature.

  In the endless belt 2, the driven roller 6 is rotatable about the drive roller 5 as an axis. Therefore, an arc-shaped groove 29 is formed in the holding member 28, and the adsorption / separation unit 15 can rotate around the rotation shaft 16, and the wire 20 is fixed to both ends of the shaft of the drive roller 5. It can be rotated by a wire winding means provided with a stepping motor 21 for winding the wire.

  When adsorbing the sheet, the adsorbing / separating unit 15 is in the state shown in FIG. 3A, and the endless belt 2 is in contact with the upper surface of the uppermost sheet material 1a of the sheet bundle 1 at the position of the driving roller 5 and adsorbing and separating. The unit 20 stops in a state where the wire 20 hanging from the unit 15 is slack. At this time, the driven roller 6 receives a force in the push-up direction by the uppermost sheet material 1a, and the upper surface of the uppermost sheet material 1a on the outer peripheral surface of the endless belt 2 comes into contact.

  By waiting for a predetermined time in this state and adsorbing the uppermost sheet material 1 a to the endless belt 2, the adsorption separation unit 15 is rotated upward in the figure around the rotation shaft 16 to raise the endless belt 2. The uppermost sheet material 1 a is separated from the sheet bundle 1. By slacking the wire 20 when the sheet material is attracted, the outer peripheral surface of the endless belt 2 is brought into contact with the sheet bundle 1 in a stable state even when the leading end position of the stacked sheet bundle 1 changes minutely. Thereby increasing the adsorptivity of the sheet material.

  If the wire 20 is stopped while being slackened, the inertial force may cause the wire 20 to flutter and come off the pulley 22 or the pulley 23. However, by providing the wire guide 24, the fluttering of the wire 20 is suppressed. It is possible to prevent the wire 20 from coming off.

<Embodiment 2>
FIG. 4 is a view corresponding to FIG. 3 showing the sheet separating and conveying apparatus according to the second embodiment of the present invention, and a view showing a form in which the support structure of the wire 20 is different. As described above, the driven roller 6 of the endless belt 2 can rotate about the shaft (rotating shaft 16) of the driving roller 5 as an axis. That is, the adsorption separation unit 15 is configured to rotate around the rotation shaft 16. A stopper 27 is bonded to the end portion of the wire 20 as a portion to be hooked to the adsorption / separation unit 15, and the stopper 27 is hooked to both ends of the adsorption / separation unit 15 on the downstream side in the sheet material conveyance direction. As a part, there is provided a through hole 26 shaped so that the wire 20 passes but the retaining 27 does not pass.

  When adsorbing the sheet material, as shown in FIG. 4A, the adsorbing / separating unit 15 causes the endless belt 2 to contact the upper surface of the uppermost sheet material 1a, and the through hole 26 and the retaining member 27 are separated from each other. The wire 20 is stopped in a state where the tension becomes 0 or less.

  After waiting for a predetermined time in the state of FIG. 4 (A) and adsorbing the uppermost sheet material 1a to the endless belt 2, when the wire 20 is wound up, as shown in FIG. 27 is caught in the through hole 26 of the adsorption separation unit 15. Then, the adsorption / separation unit 15 is lifted.

  In the configuration shown in FIG. 3, it is necessary to secure a space for absorbing the deflection of the wire 20 around the wire 20, but in the present embodiment, the space around the through hole 26 of the adsorption separation unit 15 is prevented from being removed. It is only necessary to secure a space that takes into account the amount of separation from the space 27 (a space that is considerably smaller than the configuration of FIG. 3).

  The present invention is not limited to the embodiments described above, and many modifications can be made by those having ordinary knowledge in the art within the technical idea of the present invention.

1: Sheet bundle 1a, 1b: Sheet material 2: Endless belt 3: Roller electrode 4: AC power supply 5: Driving roller 6: Driven roller 7: Bottom plate 8: Arm 9: Conveying roller 10: Guide member 15: Adsorption separation unit 15a : Unit body 16: Rotating shaft 20: Wire 21: Stepping motor 22: Pulley 23: Pulleys 24 and 25: Wire guide 26: Through hole 27: Stopper 28: Holding member 29: Groove 100: Copying machine

JP 2010-126317 A

Claims (7)

The sheet material positioned at the uppermost part of the stacked sheet bundle has an endless dielectric belt that attracts and holds the sheet material by using electrostatic force, and the uppermost sheet material is moved to the center by rotating about a rotation axis. In a sheet separating and conveying apparatus provided with an adsorption separation unit that separates the second and subsequent sheets of a bundle,
A string-like rigid body is provided at both ends in the direction perpendicular to the sheet material conveyance direction on the downstream side of the center in the sheet material conveyance direction of the adsorption separation unit,
A drive source for winding up the string-like rigid body, a shaft connected to the drive source, a pulley that winds the string-like rigid body on the shaft, and adjusting a winding amount of the string-like rigid body, The adsorbing / separating unit is rotated so that the tension of the string-like rigid body does not act on the adsorbing / separating unit when the adsorbing / separating unit and the uppermost sheet material come into contact with each other. Sheet separating and conveying device. The sheet separating and conveying apparatus according to claim 1,
A sheet separating and conveying apparatus comprising a guide member for restricting movement of the string-like rigid body in a plane perpendicular to a longitudinal direction between the pulley and the suction separating unit. In the sheet separating and conveying apparatus according to claim 1 or 2,
The attachment part between the adsorption separation unit and the string-like rigid body includes a latch part provided on the string-like rigid body, and a latching part provided on the adsorption separation unit for latching the latch part. Consists of
A sheet separating and conveying apparatus, wherein the hooking portion and the hooked portion are brought into contact with each other by rolling up the string-like rigid body, and the suction separation unit is rotated. In the sheet separating and conveying apparatus according to any one of claims 1 to 3,
The latching portion is a retaining provided at an end of the string-like rigid body, and the latched portion is a through hole having a shape that allows the string-shaped rigid body to pass therethrough but does not allow the retaining member to pass. A sheet separating and conveying apparatus.   5. The sheet separating and conveying apparatus according to claim 1, wherein a drive source is connected to each of the string-like rigid bodies installed at both ends of the adsorption and separating unit.   6. The sheet separating / conveying apparatus according to claim 1, wherein at least one guide member is disposed at an intermediate portion of each of the string-like rigid bodies. An image forming apparatus comprising the sheet separating and conveying apparatus according to claim 1.