JP4124754B2 - Image reading apparatus and image forming apparatus - Google Patents

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus and an image forming apparatus, and more particularly, to an image reading apparatus including a document transport unit that is mounted on an image forming apparatus main body including an image reading unit so as to be vertically rotatable using an opening / closing means. The present invention relates to an image forming apparatus.

  FIG. 1 is a diagram illustrating an example of an image forming apparatus using a sheet-through type automatic document feeder. In the figure, reference numeral 50 denotes an image forming apparatus such as a copy or printer. In this image forming apparatus 50, an image reading device 52 is provided above the image forming apparatus main body 51. The image reading apparatus includes a document conveying unit 60 and an image reading unit 70, and the document conveying unit 60 is configured to be openable / closable with an opening / closing means such as a hinge as an axis with respect to the image reading unit.

  That is, such an image forming apparatus is configured to be openable and closable so that one original or a thick original can be read on the contact glass of the image reading unit 70. In addition, when placing a thick document such as a book and reading it, the automatic document feed unit moves upward from the normal position so that the thick document can be pressed, and is almost parallel to the contact glass 54. There is also a configuration that enables this.

  In recent years, with the adoption of a color scanner, electrical noise generated from the scanner may increase. As a countermeasure against this, there has been proposed an apparatus in which the document transport unit and the image reading unit are electrically connected.

  In Patent Document 1, a document cover provided with a document conveying device is provided on a copying machine main body so as to be freely opened and closed by a hinge, a hinge side electrode is provided on a hinge mounting portion, and a mounting portion provided on the copying machine main body is inserted. A body-side electrode that is in contact with and connected to the hinge-side electrode of the mounting portion when the mounting portion is mounted is provided on the mounting body having a concave portion.

  Patent Document 2 has a configuration in which a document reader is connected to an apparatus main body with a flexible wiring board provided with a ground portion, and radio noise is released from the ground portion of the flexible wiring board to the apparatus main body. is there.

JP 2001-154289 A JP 2002-209061 A

  However, since the electrical connection described in Patent Document 1 is performed at a sliding portion, there are cases where a good connection cannot be obtained or resistance due to secular change occurs. In addition, since the ground plate is brought into contact with the document conveying unit, when the document conveying unit is attached to the image reading unit, particularly in a large-sized machine, the force of the hinge of the document conveying unit is large. Distortion may occur and may affect reading performance.

  Moreover, the thing of patent document 2 has a problem that there exists a possibility that a flexible wiring board may be bent by many years of use and may be disconnected.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and is an original reading apparatus that can withstand long-term use, reliably connect an original conveying unit and an image reading unit, and remove electric noise. An object of the present invention is to provide an image forming apparatus.

According to a first aspect of the present invention, there is provided an image reading apparatus including a document conveying unit mounted on a main body of an image forming apparatus including an image reading unit so as to be vertically rotatable using an opening / closing means. A conductive member that electrically connects the original conveying unit and the reading unit when the original conveying unit is closed, and at least one of the original conveying unit and the image reading unit is formed of a conductive elastic member. It is characterized by that.

According to a second aspect of the present invention, in the image reading apparatus according to the first aspect, the conductive elastic member has a material and shape that does not cause a mark or a scratch on the original document sandwiched between the conductive members when the conductive elastic member is closed by the opening / closing means. It is characterized by that.

According to a third aspect of the present invention, in the image reading apparatus according to the first or second aspect, the elastic member is disposed at a position closer to the opening / closing fulcrum than the center of gravity of the document conveying unit.

According to a fourth aspect of the present invention, in the image reading apparatus according to any one of the first to third aspects, a step is provided between a mounting surface to which the elastic member is mounted and a surface adjacent to the mounting surface. Features.

According to a fifth aspect of the present invention, in the image reading apparatus according to any one of the first to fourth aspects, the elastic member is formed of a thin metal plate.

According to a sixth aspect of the present invention, in the image reading apparatus according to any one of the first to fifth aspects, the elastic member is formed of a conductive resin.

  According to the present invention, when the document transport unit is in the closed state, the document transport unit and the image reading unit can be reliably electrically connected, and electrical noise can be removed.

  The best mode for carrying out the present invention will be described below with reference to the embodiments shown in the drawings.

  In the following description, common parts are denoted by common reference numerals. 1 is a perspective view showing an example of an image forming apparatus using a sheet-through type automatic document feeder to which the present invention is applied, and FIG. 2 is a cross-sectional view showing an image reading apparatus of the image forming apparatus according to the embodiment. 3 is an enlarged perspective view showing a state when the document transport unit of the image forming apparatus according to the embodiment is opened, and FIG. 4 is a front view showing a state when the document transport unit of the image forming apparatus according to the embodiment is closed. FIG. 5 is a block diagram illustrating a control system of the image forming apparatus according to the embodiment.

  The image forming apparatus according to the present embodiment reads an image while conveying a document to be read to a fixed reading unit and conveying it at a predetermined speed. As shown in FIG. 1, the image forming apparatus according to the present example includes a document setting unit A for setting a double-sided original document bundle to be read, and a separation feeding unit that separates and feeds originals one by one from the set double-sided document bundle. Part B, a resist part C for primary abutting and aligning the surface of the fed document, and a function for pulling out and transporting the aligned document, and turning the conveyed document so that the document surface is on the reading side (downward) A turn part D that conveys the document toward the image, a reading and reading conveyance part E that reads the image of the document from below the contact glass, a switchback part F that reverses the front and back of the document after reading, and a switchback part F An intermediate conveyance unit G for returning the switched-back document to the registration unit C again, a switchback unit H for waiting the temporary document after reading the back side of the document from the turn unit D by the reading / conveying unit E again, A reverse discharge section I that reverses the original from the back section H and discharges it outside the apparatus, a paper discharge section J that stacks and holds the originals after reading, driving sections 101 to 105 that drive these conveying operations, and a series of And a controller unit 100 for controlling the operation.

  The original bundle 1 to be read is set on the original table 2 including the movable original table 3 with the original surface facing upward. Further, the width direction of the document bundle 1 is positioned in a direction perpendicular to the conveyance direction by a side guide (not shown). The document set is detected by the set filler 4 and the set sensor 5 and transmitted to the main body control unit 111 by the I / F 107.

  Further, an outline of the length of the document in the conveyance direction is determined by a document length detection sensor 30 or 31 (a reflective sensor or an actuator type sensor that can detect even one document) provided on the document table surface. The (At least a sensor arrangement that can determine whether the document size is vertical or horizontal is required.) The movable document table 3 is configured to be moved up and down in the directions a and b shown in the drawing by a bottom plate raising motor 105. When the set filler 4 and the set sensor 5 detect that a document is set, the bottom plate raising motor 105 is operated. The movable original table 3 is raised so that the uppermost surface of the original bundle contacts with the pickup roller 7 by normal rotation.

  The pickup roller 7 is moved by the pickup motor 101 in the c and d directions shown in the figure by the cam mechanism, and the movable document table 3 is raised and pushed by the upper surface of the document on the movable document table 3 to be raised in the c direction. The upper limit can be detected by the detection sensor 8. When the print key is pressed from the main body operation unit 108 and a document feed signal is transmitted from the main body control unit 111 to the controller unit 100 via the I / F 107, the pickup roller 7 rolls by the forward rotation of the paper feed motor 102. Rotation is driven to pick up several (ideally one) originals on the original table 2. The direction of rotation of this roller is the direction in which the uppermost document is conveyed to the paper feed port.

  The paper feeding belt 9 is driven in the paper feeding direction by the normal rotation of 102, and the reverse roller 10 is driven to rotate in the reverse direction to the paper feeding by the normal rotation of the 102 to separate the uppermost original from the original under it, and Only the upper document can be fed.

  The reverse roller 10 is in contact with the paper feed belt 9 at a predetermined pressure, and when it is in direct contact with the paper feed belt 9 or in contact with the original 1 sheet, the reverse roller 10 is counterclockwise as the paper feed belt 9 rotates. In the unlikely event that two or more originals enter between the paper feeding belt 9 and the reverse roller 10, the rotational force is set to be lower than the torque of the torque limiter. It rotates in the clockwise direction, which is the driving direction, and works to push back excess originals, thereby preventing double feeding.

  The original separated by the action of the paper feeding belt 9 and the reverse roller 10 is further fed by the paper feeding belt 9, and the leading edge is detected by the abutting sensor 11 and further abuts against the pull-out roller 12 which is stopped. Thereafter, the sheet feeding motor 102 is stopped in a state in which it is fed by a predetermined amount from the detection of the abutting sensor 11 and is pressed against the pull-out roller 12 with a predetermined amount of deflection. As a result, the driving of the paper feed belt 9 is stopped.

  At this time, by rotating the pickup motor 101, the pickup roller is retracted from the upper surface of the document and the document is fed only by the conveying force of the paper feed belt, whereby the leading edge of the document enters the nip of the pair of upper and lower rollers of the pull-out roller 12, Tip alignment (skew correction) is performed. The pull-out roller 12 has the skew correction function and is a roller for conveying the skew-corrected document after separation to the intermediate roller 14 and is driven by the reverse rotation of the paper feed motor 102. At this time (when the paper feed motor 102 is reversely rotated), the pull-out roller 12 and the intermediate roller 14 are driven, but the pickup roller 7 and the paper feed belt 9 are not driven.

  A plurality of document width sensors 13 are arranged in the depth direction and detect the size in the width direction perpendicular to the conveyance direction of the document conveyed by the pull-out roller 12. Further, the length of the document in the conveyance direction is detected from the motor pulse by reading the leading and trailing edges of the document with the abutment sensor 11. When the document is transported from the registration section C to the turn section D by driving the pull-out roller 12 and the intermediate roller 14, the transport speed at the registration section C is set higher than the transport speed at the reading and reading transport section E. Thus, the processing time for sending the document to the reading unit is shortened.

  When the leading edge of the document is detected by the reading entrance sensor 15, at the same time as starting the deceleration to make the document conveying speed the same as the reading conveying speed before the leading edge of the document enters the nip between the upper and lower roller pairs of the entrance roller 16, The reading motor 103 is driven to rotate forward to drive the inlet roller 16, the second inlet rollers 34 and 35, the conveying belt driving roller 36, and the reading outlet roller 21.

  When the registration sensor 17 detects the leading edge of the document, the registration sensor 17 decelerates over a predetermined conveyance distance, temporarily stops before the reading position sensor 20, and transmits a registration stop signal to the main body control unit 111 via the I / F 107. Subsequently, when a reading start signal is received from the main body control unit 111, the document whose registration has been stopped is transported at an increased speed so as to rise to a predetermined transport speed until the leading end of the document reaches the reading position.

  At the timing when the leading edge of the document detected by the pulse count of the reading motor reaches the reading section, the gate signal indicating the effective image area in the sub-scanning direction on the first surface is sent to the main body control section 111 by the first reading section. Sent until is removed. In the case of single-sided document reading, the document that has passed through the reading and reading conveyance unit E is conveyed to the paper discharge unit J through the reverse paper discharge unit I. At this time, when the leading edge of the original is detected by the paper discharge sensor 24, the paper discharge motor 104 is driven to rotate forward to rotate the paper discharge roller 28 counterclockwise. Further, the discharge motor drive speed is reduced immediately before the trailing edge of the original comes out of the nip of the pair of upper and lower rollers of the discharge roller 28 by the discharge motor pulse count from the detection of the leading edge of the original by the discharge sensor 22. Control is performed so that the document discharged onto the tray 29 does not jump out.

  In the case of double-sided original reading, after the leading edge of the original is detected by the paper discharge sensor 22, the switching claw 37 is lowered by a solenoid (not shown) by the pulse count of the reading motor (arrow j). The upper reversing roller 32 is rotated counterclockwise by an upper reversing motor (not shown). The switching claw 30 is raised (arrow i) at the timing when the trailing edge of the document leaves the paper discharge sensor 22 and then exits the paper discharge roller 28 with a predetermined pulse count, and the upper reverse roller 32 is rotated clockwise to perform intermediate conveyance. Transport to part G. The intermediate transport roller 33 is driven clockwise by the reverse rotation of the paper feed motor.

  Even if the leading edge of the document reaches the pull-out roller 12, the abutting correction is not performed, and the pull-out roller 12 and the intermediate roller 14 are driven to carry to the entrance roller 16. At this time, in order to shorten the processing time, the conveying speed is set to be higher than the conveying speed in the reading and conveying section E as in the case of the surface. In the case of the back side, since the leading edge alignment (skew correction) is performed at the entrance roller nip, when the leading edge of the document is detected by the reading inlet sensor 15, the document conveyance speed is reduced and a predetermined number of pulse counts is reached after the leading edge of the document reaches the nip. Transport and align tip (skew correction). After aligning the tips (skew correction), the reading motor 103 is driven forward to drive the entrance roller 16, the second entrance rollers 34 and 35, the transport belt drive roller 36, the transport belt 37, and the read exit roller 21. .

  When the registration sensor 17 detects the leading edge of the document, the registration sensor 17 decelerates over a predetermined conveyance distance, temporarily stops before the reading position 20, and transmits a registration stop signal to the main body control unit 111 via the I / F 107. Subsequently, when a reading start signal is received from the main body control unit 111, the document whose registration has been stopped is transported at an increased speed so as to rise to a predetermined transport speed until the leading end of the document reaches the reading position.

  At the timing when the leading edge of the document detected by the pulse count of the reading motor reaches the reading section, the gate signal indicating the effective image area in the sub-scanning direction on the first surface is sent to the main body control section 111 by the first reading section. Sent until is removed.

  At the timing when the leading edge of the document detected by the pulse count of the reading motor reaches the reading section, the gate signal indicating the effective image area in the sub-scanning direction on the first surface is sent to the main body control section 111 by the first reading section. Sent until is removed.

  In the case of single-sided original reading, the original that has passed through the reading conveyance unit E is conveyed to the paper discharge unit J through the reverse paper discharge unit I. At this time, when the leading edge of the original is detected by the paper discharge sensor 24, the paper discharge motor 104 is driven to rotate forward to rotate the paper discharge roller 28 counterclockwise. Further, the discharge motor drive speed is reduced immediately before the trailing edge of the original comes out of the nip of the pair of upper and lower rollers of the discharge roller 28 by the discharge motor pulse count from the detection of the leading edge of the original by the discharge sensor 22. Control is performed so that the document discharged onto the tray 29 does not jump out.

  In the case of double-sided original reading, the paper discharge sensor 22 detects the leading edge of the original and then the switching claw 38 is lowered by a solenoid (not shown) by the pulse count of the reading motor (arrow j). The upper reversing roller 32 is rotated counterclockwise by an upper reversing motor (not shown). The switching claw 38 is raised (arrow i) at the timing when the trailing edge of the original leaves the paper ejection sensor 22 and then exits the paper ejection roller 28 by a predetermined pulse count, and the upper reverse roller 32 is rotated clockwise to perform intermediate conveyance. Transport to part G. The intermediate transport roller 33 is driven clockwise by the reverse rotation of the paper feed motor. Even if the leading edge of the document reaches the pull-out roller 12, the abutting correction is not performed, and the pull-out roller 12 and the intermediate roller 14 are driven to carry to the entrance roller 16.

  At this time, in order to shorten the processing time, the conveying speed is set to be higher than the conveying speed in the reading and conveying section E as in the case of the surface. In the case of the back side, leading edge alignment (skew correction) is performed at the nip of the entrance roller 16, so when the leading edge of the document is detected by the reading inlet sensor 15, the document transport speed is reduced and a predetermined pulse is reached after the leading edge of the document reaches the nip. Carries the count number and aligns the tip (skew correction). After aligning the tips (skew correction), the reading motor 103 is driven forward to drive the inlet roller 16, the second inlet rollers 34 and 35, the conveying belt driving roller 36, and the reading outlet roller 21.

  When the registration sensor 17 detects the leading edge of the document, the registration sensor 17 decelerates over a predetermined conveyance distance, temporarily stops before the reading position 20, and transmits a registration stop signal to the main body control unit 111 via the I / F 107. Subsequently, when a reading start signal is received from the main body control unit 111, the document whose registration has been stopped is transported at an increased speed so as to rise to a predetermined transport speed until the leading end of the document reaches the reading position.

  At the timing when the leading edge of the document detected by the pulse count of the reading motor reaches the reading section, the gate signal indicating the effective image area in the sub-scanning direction on the first surface is sent to the main body control section 111 by the first reading section. Sent until is removed. In the case of double-sided original reading, the lower inversion switching claws 23 and 24 are switched (arrows f and g) after the leading edge of the original passes the registration sensor 17 and a predetermined pulse count elapses (arrows f and g). Thus, the document which has been rotated counterclockwise and has passed through the reading / reading conveyance unit E is started to be conveyed to the switchback unit H.

  After a predetermined pulse count has elapsed after the discharge sensor 22 detects the trailing edge of this document, the lower inversion switching claws 23 and 24 are switched by a solenoid (not shown) (arrow e, h) to invert the next document (surface-read document). It is conveyed to the paper discharge unit I. After the leading edge of the next original is detected by the paper discharge sensor 22, the switching claw 30 is lowered by a solenoid (not shown) according to the pulse count of the reading motor (arrow j), the original discharged from the paper discharge roller 28 is scooped, and the upper reverse roller 32 is moved. It is rotated counterclockwise by an upper reversing motor (not shown) and conveyed to the switchback portion F. At this time, the switching claw 30 is raised at the timing of exiting the ejection roller 28 after a predetermined pulse count has elapsed after the trailing edge of the next original that has finished reading the front image has exited the ejection sensor 22, but is inverted at the same timing. The roller 25 is driven clockwise to discharge to the paper discharge unit J.

  In this example, as shown in FIGS. 3 and 4, the image forming apparatus 50 is configured such that the document conveying unit 60 and the image reading unit 70 can be opened and closed by a hinge 206. Further, an electrode 202 which is a conductive member is provided on the upper surface of the image forming apparatus 50 and outside the contact glass 54, and the original document transport unit 60 is closed in the lower surface of the document transport unit 60. In this case, a conductive elastic member 201 which is a conductive member is provided at a location where the electrode 202 comes into contact. By bringing these electrodes 202 into contact with the conductive elastic member 201, the document conveying unit 60 and the image reading unit 70 are electrically connected, and noise can be prevented.

The conductive elastic member 201 is a box-shaped member formed by elastically deforming a metal plate, and is guided by the guide recess 203 to be elastically deformed. Further, the guide recess 203 has a step between its bottom surface 204 and its peripheral surface 205. This step can also be formed by drawing metal or attaching another member. In this example, the provision of the guide recess 203 can alleviate the mechanical impact on the conductive elastic member 201 when the document transport unit 60 is closed, and prevent the conductive elastic member 201 from being damaged or dropped. Can do.

  Further, in this example, when the document transport unit is in the closed state, a large document or the like may be caught, so that the contact portion of the conductive elastic member 201 with the electrode 202 has no protrusion or roughness so that the document is not damaged. It has no flat shape.

  Further, in this example, the conductive elastic member 201 is disposed at a position closer to the hinge 206 than the center of gravity g of the document conveying unit 60. For this reason, when the document conveying unit 60 is closed, it is possible to prevent the document conveying unit 60 from being lifted by a pressing force based on the elasticity of the conductive elastic member 201.

  In the above example, the conductive elastic member is described as a box member formed of a metal plate member, but the shape is not limited to a box shape. Further, the material may be any material as long as it has conductivity and elasticity, such as conductive synthetic resin, conductive rubber and other conductive composite members in addition to metal.

1 is a perspective view showing an example of an image forming apparatus using a sheet-through type automatic document feeder to which the present invention is applied. 1 is a cross-sectional view illustrating an image reading device of an image forming apparatus according to an embodiment. FIG. 3 is an enlarged perspective view illustrating a state when the document transport unit of the image forming apparatus according to the embodiment is opened. FIG. 3 is a front view illustrating a state when the document transport unit of the image forming apparatus according to the embodiment is closed. FIG. 3 is a block diagram illustrating a control system of the image forming apparatus according to the embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Document bundle 2 Document table 3 Movable document table 4 Set filler 5 Set sensor 7 Pickup roller 8 Table rise detection sensor 9 Paper feed belt 10 Reverse roller 11 Contact sensor 12 Pull-out roller 13 Document width sensor 14 Intermediate roller 15 Entrance sensor 16 Entrance roller 17 Registration sensor 20 Reading position sensor 21 Exit roller 22 Paper discharge sensor 23, 24 Switching claw 24 Paper discharge sensor 25 Lower reversing roller 28 Paper discharge roller 29 Paper discharge tray 30 Document length detection sensor 31 Document length detection sensor 32 Upper reverse Roller 33 Intermediate transport roller 34 Entrance roller 35 Entrance roller 36 Transport belt drive roller 37 Transport belt 38 Switching claw 50 Image forming apparatus 51 Image forming apparatus main body 52 Image reading apparatus 54 Contact glass 60 Document transport unit 70 Image reading Knit 100 controller unit 101 through 105 drive unit 101 pickup motor 102 feed motor 103 motor 104 discharge motor 105 the bottom plate lifting motor 107 I / F
108 Main body operation unit 111 Main body control unit 201 Elastic electrode 202 Electrode 203 Guide recess 204 Bottom surface 205 Peripheral surface 206 Hinge A Document setting unit B Separation feeding unit C Registration unit D Turn unit E Reading conveyance unit F Switchback unit G Intermediate conveyance unit H Switchback part I Reversed paper discharge part J Paper discharge part g Center of gravity

Claims (6)

In an image reading apparatus provided with a document conveying unit mounted on an image forming apparatus main body provided with an image reading unit so as to be vertically rotatable using an opening / closing means,
A conductive member that electrically connects the document conveying unit and the reading unit when the document conveying unit is closed is provided in the document conveying unit and the reading unit,
An image characterized in that at least one of the conductive member of the document conveying unit and the image reading unit is formed of a conductive elastic member, and the elastic member is disposed at a position closer to the opening / closing fulcrum than the center of gravity of the document conveying unit. Reader. The image reading apparatus according to claim 1 , wherein a step is provided between an attachment surface to which the elastic member is attached and a surface adjacent to the attachment surface . The elastic member includes an image reading apparatus according to claim 1 or 2, characterized in that it is formed of sheet metal. 3. The image reading apparatus according to claim 1 , wherein the elastic member is made of a conductive synthetic resin . An image forming apparatus characterized by using any of the image reading apparatus of claims 1 to 4. A separation unit that separates the bundle of documents one by one, a conveyance unit that conveys the separated document to the reading unit, a reading unit that reads the conveyed document with a fixed CCD or the like, and a reading unit disposed on the reading unit An image forming apparatus main body provided with guide means, driving means for driving the conveying means, and opening / closing means for the reading unit of the document conveying unit;
A reading and conveying unit configured to convey the document onto the image reading unit; and an automatic document feeder provided on the image forming apparatus main body, the stacking unit configured to stack the document read by the image reading unit. In the image forming apparatus,
A conductive member that electrically connects the document conveying unit and the reading unit when the document conveying unit is closed is provided in the document conveying unit and the reading unit,
An image characterized in that at least one of the conductive member of the document transport unit and the image reading unit is formed of a conductive elastic member, and the elastic member is disposed at a position closer to the opening / closing fulcrum than the center of gravity of the document transport unit. Reader.

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