JP2008201508A - Sheet material supply device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet material supply device capable of stably delivering a sheet material for a long period by preventing coiling around a roller material, while neutralizing charges, even when electric charges are generated on the surface of the thin sheet material by an electrostatic order with an abutting roller made of a rubber material. <P>SOLUTION: A metal thin wire member neutralizing charges by corona discharging on a sliding contact surface with the sheet material by being electrically conducted with a device grounding end is attachably/detachably provided on a guide surface of the sheet material in the vicinity of a pickup roller and a separation roller. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a sheet material supply apparatus that continuously supplies a sheet material into an apparatus main body such as an image forming apparatus or an image reading apparatus.

  A conventional sheet material supply device is in contact with a pickup roller that feeds a stacked sheet material in order to continuously supply the sheet material one by one into an apparatus main body such as an image forming apparatus or an image reading apparatus. The separation roller and the retard roller have a separation mechanism for rolling the sheet material. In this separation mechanism, the pickup roller is brought into contact with the sheet material with a predetermined load, and the sheet material is fed out one by one by the rotation of the pickup roller and is fed into the apparatus main body such as an image forming apparatus or an image reading apparatus. Rollers (hereinafter referred to as roller materials) used for feeding and separating the pick-up roller, etc., use a rubber material having a large coefficient of friction with normal paper. The rollers are negatively charged, the sheet material made of paper is positively charged, and these positive and negative charges are attracted to each other, so the sheet material is attracted to the peripheral surface of the roller, and the sheet material is peeled off from the roller material. There was a problem of becoming difficult.

Therefore, in a recent sheet material supply apparatus, the edge of the conductive static elimination sheet, which is partially grounded, is disposed close to the peripheral surface of the paper feed roller or the vicinity of the paper passing portion that starts to peel from the paper feed roller. There has been proposed an attempt to remove the charged electric charge.
JP-A-11-005347

  In general, in a so-called self-discharge type static elimination means that discharges a grounded conductor (hereinafter referred to as a grounded conductor) close to a charged object, its static elimination capability is determined by the distance between the charged body and the ground conductor. Therefore, a sufficient charge eliminating effect cannot be obtained unless the charged body and the grounded conductor are placed very close to each other. The charge removal of the sheet material in a general self-discharge type static eliminator such as a static eliminator brush is based on so-called corona discharge that occurs when the accumulation of charges induced by the approach of a charged object to a thin wire metal exceeds a certain amount. The charge of the charged object is electrically neutralized, and the ground conductor is in contact with the charged object.

  In the charge removal method shown in (Patent Document 1), the edge of the conductive charge-eliminating sheet is disposed close to the peripheral surface of the roller or the vicinity of the paper passing portion that begins to peel off from the paper feed roller, and the charged body and the ground Since there is a space between the conductor, the charge removal performance is lowered.

  That is, if the edge of the conductive sheet is arranged at the peeling position from the roller peripheral surface so as to contact the sheet material to be fed out, the charge eliminating effect is improved, but the leading end of the sheet material to be brought into contact with the conductive sheet. As a result, jamming is induced and a predetermined space is required, so that more effective charge removal is difficult.

  Further, for example, when used for a device that feeds a sheet material made of a fixed-size sheet having a constant thickness at a relatively low speed, such as a serial printer, as shown in (Patent Document 1), the sheet is a roller material with its own rigidity. Therefore, the peeling position is stable and the distance from the conductive sheet is also stable.

  However, when the sheet material to be fed is thin, the sheet material is attracted to the roller by the attractive force between the electric charges, and therefore, the peeling position from the roller material is shifted to the downstream side in the rotation direction of the roller material, and the conductive materials arranged close to each other. The distance from the conductive sheet material is also reduced, and the risk of contact with the conductive sheet material is also increased.

  In addition, when the charge charge is not sufficiently neutralized, the sheet material is weak and does not easily peel off from the roller by its own rigidity alone, so there is little contact with the edge of the roller exposure hole on the sheet material guide surface. There is also a problem that jams occur.

  Furthermore, when the sheet material is fed out continuously and at high speed, even if the sheet material is discharged while being in contact with the ground conductor, the fed sheet material wears the ground conductor, and the life of the ground conductor is shortened. There is also a problem.

  Therefore, in the present invention, even when the sheet material to be fed is thin and fed at a high speed, the electric charge generated on the surface of the sheet material is surely removed, and stable feeding that is less likely to cause jamming is enabled. An object of the present invention is to provide a sheet material supply device that can be easily and inexpensively replaced even when the ground conductor is worn.

  In order to solve the above-described problems, a sheet material supply device according to the present invention includes a pickup roller that feeds stacked sheet materials and a sheet material guide surface in the vicinity of a separation roller that is disposed downstream in the feeding direction of the pickup roller. The means is detachably arranged, and in order to further enhance the charge removal effect, the charge removal means is a brushed metal wire or a brush-like metal wire.

  According to the present invention, by contacting a grounding conductor made of a fine metal wire that is likely to cause corona discharge to the sheet material being conveyed, the charge generated on the surface of the sheet material is neutralized and reliably eliminated, Even when the fine metal wire of the grounding conductor is worn due to sliding contact with the sheet material, the grounding conductor can be detachably disposed on the apparatus body to facilitate replacement. .

  According to a first aspect of the present invention, a pickup roller that feeds the laminated sheet material, a separation roller that is disposed downstream of the pickup roller in the feeding direction and rotates in the direction of feeding the sheet material, and a predetermined pressing force applied to the separation roller And a retard roller supported so as not to rotate so as to prevent the sheet material from entering through a predetermined idling load, or to rotate in a direction to return the sheet material via a predetermined idling load. Static electricity removing means, that is, an installation conductive body, which is grounded to the sheet material guide surface in the vicinity of the pickup roller or separation roller of the material supply device, is detachably disposed, and the ground conductive material by sliding contact with the fed sheet material is provided. It can be easily exchanged for wear.

  According to the second aspect of the present invention, when the charge eliminating means is made of a brushed metal thin wire and is in sliding contact with the charged sheet material, the sheet material is efficiently charged by corona discharge between the metal thin wire and the sheet material. It is to be summed up.

  According to the third aspect of the present invention, when the charge eliminating means is made of a brush-like fine metal wire and is in sliding contact with the charged sheet material, the sheet material is efficiently charged by corona discharge between the fine metal wire and the sheet material. It is to be summed up.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a cross-sectional view of a sheet material supply apparatus according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of a main part of a pickup roller module, and FIG. 3 is a ground conductor mounted on a sheet material guide surface of a lower housing of the pickup roller module FIG. 4 is a perspective view of a state where the installation conductor on the sheet material guide surface of the lower housing of the pickup roller module is removed, and FIG. 5 is a perspective view of the ground conductor.

  In FIG. 1, a sheet material supply apparatus according to an embodiment of the present invention continuously supplies sheet materials S one by one into an apparatus main body such as an image forming apparatus or an image reading apparatus. , A hopper 1 that can be moved up and down, a pickup roller 2 that contacts the sheet material S on the hopper 1 and feeds the sheet material one by one, and a separation roller 3 that conveys the sheet material S fed by the pickup roller 2 in the feeding direction. And a retard roller 4 which is brought into pressure contact with the separation roller with a predetermined idling load at a predetermined pressure and imparts a rolling effect to the fed sheet material S.

  The pickup roller 2, the separation roller 3, and the retard roller 4 are individually connected to driving sources and can be driven independently. Further, the pickup roller 2 and the separation roller 3 are equipped with one-way clutches that rotate (idle) in the transport direction with respect to the respective drive shafts and lock in the reverse direction.

  In FIG. 5, the ground conductor 20 is formed of a thin metal plate, and can be detachably attached to the lower housing 7 of FIG. That is, an elastic engagement tongue 20a is formed at one end of the ground conductor 20, and a mounting tongue 20b is formed at the other end. In FIG. 4, the mounting tongue portion 20 b of FIG. 5 is inserted into the ground conductor mounting hole 23 of the lower housing 7, and the elastic engagement tongue portion 20 a is inserted into the ground conductor engagement hole 24 of the lower housing 7.

  As shown in FIG. 2, a conductive member that conducts to an installation end of a device (not shown) is disposed at a position in contact with the elastic engagement tongue 20a of the ground conductor engagement hole 24 of FIG. With the elastic engagement 20, the ground conductor 20 is detachably attached to the lower housing 7 and is electrically grounded to the apparatus ground end.

  Further, as shown in FIG. 5, a sheet-like raised or brush-like metal thin wire member 21 is bonded to the surface of the installation conductor 20 that is in sliding contact with the sheet material by a conductive adhesive. As described above, the conductive member 22 electrically connected to the ground terminal of the apparatus main body is disposed at the position where the ground conductor 20 of the lower housing 7 of FIG. As a result, the conductive member 22 is electrically connected to the device ground terminal.

  In FIG. 1, a hopper 1 is configured to be substantially parallel movable (up and down) in a vertical direction by a pressing mechanism such as a pantograph-like link (not shown) or a cam (not shown), and a sheet material S is placed on the upper surface. It is a configuration that can be placed. The hopper 1 moves up and down in the vertical direction. When the sheet material S is fed, the hopper 1 is raised until the sheet material S comes into contact with the pickup roller 2, and the sheet material S is directed toward the inside of the apparatus by the rotation of the pickup roller 2 in the arrow direction. Pull out. The separation roller 3 is rotationally driven in the direction of the arrow, and the retard roller 4 is pressed against the separation roller 3 with a predetermined idling load.

  At this time, the retard roller 4 may be rotated in a direction to return to the sheet material feeding direction via a predetermined idling load.

  When the sheet material S is fed out by the pickup roller 2, the pickup roller 2 is a rubber material, so that the electric charge according to the electrostatic ranking with the sheet material S is brought into contact with the peripheral surface of the pickup roller 2 and the roller of the sheet material S. Occurs on the surface.

  On the other hand, the contact surface of the sheet material S with the pickup roller 2 is in contact with the ground conductor 20 formed with the metal thin wire member 22 on the sliding contact surface. As described above, the charged electric charges are neutralized by corona discharge with the fine metal wires.

  Accordingly, the mutual suction force does not act between the sheet material S and the pickup roller 2, and even a thin sheet material having weak stiffness can be peeled off from the roller by its own rigidity and smoothly conveyed downstream. it can.

  Similarly, a charged charge is also generated between the separation roller 3 and the sheet material S. However, since the ground conductor 20 is also in the vicinity of the separation roller 4, the charge is neutralized as described above, The sheet material S is not attracted to the separation roller 4.

  When the sheet material S is fed out at a high speed, the fine metal wire on the surface of the ground conductor 20 is worn, but since it is attached to the lower housing 7 by meshing attachment, it can be easily attached and detached, and the ground conductor is used as a replacement part. If provided, it is possible to recover the static elimination effect even after the fine metal wires are worn.

  That is, in the sheet material supply apparatus according to the present embodiment, a grounded static eliminating means, that is, an installation conductive body, is detachably disposed on the sheet material guide surface in the vicinity of the pickup roller or the separation roller, so that the sheet material supply device can be stably provided over a long period of time. It is possible to neutralize the charge generated by the electrostatic ranking with the roller material, and even when a thin sheet material is fed out at a high speed, it is possible to carry out a stable feeding without jamming.

  The sheet material supply apparatus of the present invention is useful as an apparatus for continuously supplying a sheet material into an apparatus main body such as an image forming apparatus or an image reading apparatus. In particular, the present invention is suitable as a sheet material supply device that enables the sheet material to be fed out to be thin and to neutralize the charged charge even when the sheet material is adsorbed to the roller material by charging, thereby enabling stable feeding without jamming. .

Sectional drawing of the sheet material supply apparatus in embodiment of this invention Cross section of the main part of the pickup roller module The perspective view of the state in which the ground conductor of the sheet material guide surface of the lower housing of the pickup roller module is mounted The perspective view of the state where the installation conductor of the sheet material guide surface of the lower housing of the pickup roller module is removed Perspective view of grounding conductor

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hopper 2 Pickup roller 3 Separation roller 4 Retard roller 7 Lower housing 20 Grounding conductor 20a Elastic engagement tongue part of grounding conductor 20b Grounding conductor mounting tongue part 21 Metal wire member 22 Conductive member 23 Grounding conductor mounting hole 24 Grounding Conductor engagement hole S Sheet material

Claims (3)

A pickup roller for feeding out the laminated sheet material;
A separation roller disposed downstream of the pickup roller in the feeding direction and rotating the sheet material in the feeding direction;
Abuts against the separation roller with a predetermined pressing force, and rotates in a direction to return the sheet material through a predetermined idling load, or supports non-rotatably to prevent entry of the sheet material through a predetermined idling load. A retard roller, and
On the sheet material guide surface in the vicinity of the pickup roller or the separation roller,
A sheet material supply apparatus, wherein a grounded static elimination means is detachably disposed. 2. The sheet material supply apparatus according to claim 1, wherein the static eliminating unit is made of a brushed metal fine wire. 2. The sheet material supply apparatus according to claim 1, wherein the static eliminating unit is made of a brush-like fine metal wire.

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