JP2020007151A - Sheet transfer device and image reading device - Google Patents

Abstract

To provide a sheet transfer device that enhances jam processing property and an image reading device equipped therewith.SOLUTION: The sheet transfer device comprises: a first driving source; a first driving unit including a first roller that transports a sheet and driven by the driving force of the first driving source; a second driving source; a second driving unit including a second roller that transfers a sheet and driven by the driving force of the second driving source; an operating part manually operated to rotate; and a switching part for switching between a first condition where the first driving unit and the second driving unit are not connected and a second condition where the first driving unit and the second driving unit are connected. In the second condition, the rotation of the operating part is transmitted to the first driving unit, causing the first roller to rotate, and the rotation of the operating part is transmitted to the second driving unit, causing the second roller to rotate.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a sheet conveying device for conveying a sheet and an image reading device including the same.

  2. Description of the Related Art Generally, an image reading apparatus including an automatic document feeder (hereinafter, referred to as an ADF) for feeding a document placed on a document tray and a reading unit for reading an image of a sheet fed by the ADF is known. Have been. When a sheet is jammed in the ADF when the ADF conveys the sheet, it is necessary to remove the jammed sheet.

  Conventionally, in order to remove a jammed sheet, an ADF provided with a jam release dial for manually feeding the sheet to a position where the sheet can be grasped and pulled out has been proposed (see Patent Document 1). In this ADF, as shown in FIG. 14, timing pulleys 244, 252, and 272 are fixed to drive shafts 240, 250, and 270 of first to third transport rollers 24, 25, and 27 that transport a sheet. A timing belt 98 is wound around the timing pulleys 244, 252, and 272.

  A gear 253 formed integrally with the timing pulley 252 is connected to a surface platen roller gear 262 for transmitting drive to the surface reading platen roller 26 via an idler gear 99. The tension is applied to the timing belt 98 by the pulley 152 of the jam release dial 15. By rotating the jam release dial 15, the first to third transport rollers 24, 25, 27 and the platen roller 26 for surface reading can be manually rotated via the timing belt 98 to perform the jam processing. In addition, by driving a motor (not shown), in addition to the first to third transport rollers 24, 25, and 27 and the platen roller 26 for reading the front surface, the paper feed roller, the registration roller, and the platen roller for reading the back surface are driven. be able to.

JP 2010-041464 A

  By the way, in the automatic document feeder described in Patent Document 1, during normal sheet conveyance, all rollers in the automatic document feeder are driven by driving a motor. However, when a plurality of rollers in the automatic document feeder are configured to be driven by a plurality of motors, for example, a roller driven by one motor and a roller driven by another motor are mutually driven. Not transmitted. For this reason, there is a problem that the number of rollers that can be driven by the jam clearing dial is reduced, and the jam clearability is reduced.

  SUMMARY OF THE INVENTION It is an object of the present invention to provide a sheet conveying apparatus having improved jam clearance and an image reading apparatus having the same.

  According to the present invention, in a sheet conveying apparatus, a first driving unit includes a first driving source, a first roller for conveying a sheet, and is driven by a driving force of the first driving source; a second driving source; A second drive unit that includes a second roller that conveys the first drive unit, a second drive unit that is driven by the drive force of the second drive source, an operation unit that is manually operated and rotates, the first drive unit and the second drive unit, And a switching state for switching between a first state in which the first drive unit and the second drive unit are connected to each other, and a rotation of the operation unit in the second state. Is transmitted to the first drive unit to rotate the first roller, and the rotation of the operation unit is transmitted to the second drive unit to rotate the second roller.

  ADVANTAGE OF THE INVENTION According to this invention, jam handling property can be improved.

FIG. 1 is an overall view illustrating a printer according to an embodiment. FIG. 2 is a perspective view showing the image reading device. FIG. 2 is a cross-sectional view illustrating the image reading device. FIG. 3 is a perspective view showing the image reading apparatus with a cover member in an open state. FIG. 2 is a perspective view showing the image reading apparatus with an ADF opened. (A) is a perspective view showing a drive transmission configuration in an unconnected state, and (b) is a view for explaining a state of transmission of rotation input from a first motor and a second motor. (A) is a perspective view showing a drive transmission configuration in a connected state, and (b) is a diagram for explaining a state of transmission of rotation input from a jam processing dial. FIG. 4A is a side view showing the positions of a second platen glass and a shading plate when reading a document, and FIG. 4B is a side view showing the positions of the second platen glass and a shading plate when performing shading correction. FIG. 4 is a perspective view showing a configuration for moving a second platen glass and a shading plate. (A) is sectional drawing which shows the glass holder located in a normal position, (b) is sectional drawing which shows the glass holder in the middle of moving from a normal position to a shading position. (C) is a cross-sectional view showing the glass holder located at the shading position, and (d) is a cross-sectional view showing the glass holder moving from the shading position to the normal position. FIG. 4 is a perspective view showing a switching unit. Sectional drawing which shows the switching means of a cover member in a closed state. Sectional drawing which shows the switching means of a cover member in an open state. FIG. 9 is a schematic diagram showing a drive transmission configuration of a conventional ADF. FIG. 7 illustrates a modification of the present embodiment.

[overall structure]
The printer 200 as the image forming apparatus according to the present embodiment is an electrophotographic laser beam printer. As shown in FIG. 1, the printer 200 includes a printer main body 202 and an image reading device 201 mounted on the upper part of the printer main body 202.

  The printer main body 202 has an image forming unit 205 that forms an image on a sheet, and a cassette 203 that stores sheets fed to the image forming unit 205. Is provided with a discharge tray 204 from which is discharged. The sheets stored in the cassette 203 are fed by a feeding roller (not shown) or the like. The image forming unit 205 includes a laser writing unit, an electrophotographic processing unit, a fixing unit, and the like (not shown), and forms an image on a sheet fed from the cassette 203 by a conventionally known electrophotographic method.

[Image reading device]
Next, the image reading device 201 will be described in detail. As shown in FIGS. 2 and 3, the image reading apparatus 201 includes an automatic document feeder (hereinafter, referred to as an ADF) 301 that feeds a document G stacked on a document tray 304 and discharges the document G to a document discharge tray 305. Have. The image reading apparatus 201 includes a reading unit 302 that reads a document G conveyed by an ADF 301 as a sheet conveying apparatus. As shown in FIG. 5, the ADF 301 is rotatably supported by the reading unit 302 by hinges 306 so that a document table glass 413 described later can be opened. In this embodiment, a sheet includes a recording material on which an image is formed by the image forming unit 205 and a document from which an image is read by the image reading device 201. The document may be blank, or an image may be formed on one or both sides.

  As shown in FIG. 3, the ADF 301 includes a pickup roller 71, a separation roller pair 72, a plurality of conveyance roller pairs 402, 403, 405, 407, and 409, a registration roller pair 404, and a discharge roller pair 410; have. Further, the ADF 301 includes a first platen roller 406 disposed to face the first platen glass 411, a second platen roller 408 disposed to face the second platen glass 412, and a second reading as a reading unit. 415.

  The reading unit 302 has a first platen glass 411, a document table glass 413 capable of supporting a document G, and a first reading unit 414. The first reading unit 414 as a reading unit is It is configured to be movable in the direction (arrow T direction). The first reading unit 414 and the second reading unit 415 include a light source, a photoelectric conversion element, and the like (not shown), and a CCD sensor, a CMOS sensor, or the like can be applied to the photoelectric conversion element. The light emitted from the light source is reflected by the original G, and the reflected light from the original G is incident on the photoelectric conversion element. The photoelectric conversion element can obtain an image of the document G as image information by photoelectrically converting the reflected light from the document G.

  The first platen glass 411 and the second platen glass 412 are formed of a transparent member such as a glass that transmits light. A mode in which the document conveyed by the ADF 301 is read is referred to as "flow reading", and a mode in which the document is positioned on the platen glass 413 and the first reading unit 414 is read in the sub-scanning direction is referred to as fixed reading.

  In the case of fixed reading, the user opens the ADF 301 and places a document on the platen glass 413. Then, the user operates the operation panel (not shown) to start fixed reading by the image reading device 201. When the fixed reading is started, the first reading unit 414 moves in the sub-scanning direction between the position indicated by the solid line and the position indicated by the broken line in FIG. Can be

  In the case of the drift reading, the user places the document G on the document tray 304 and operates the operation panel to start the drift reading by the image reading apparatus 201. At this time, the first reading unit 414 reads an image while stopped at a position below the first platen glass 411 as indicated by a solid line in FIG. The document G placed on the document tray 304 is fed to the upstream transport path R1 by the pickup roller 71, and is separated one by one by the separation roller pair 72. Then, the document G passing through the upstream conveyance path R1 is conveyed to the first platen glass 411 arranged on the downstream conveyance path R2 by the conveyance roller pair 405 while the skew is corrected by the registration roller pair 404.

  While the original G is being guided by the first platen roller 406, an image of the first surface (front surface) is read by the first reading unit 414 via the first platen glass 411. The document G from which the image has been read by the first reading unit 414 is conveyed to the discharge roller pair 410 by the conveyance roller pairs 407 and 409, and is discharged out of the apparatus by the discharge roller pair 410. The document G discharged outside the apparatus is stacked on a document discharge tray 305. When an image on the second surface (back surface) of the document is also read, the document on which the image on the first surface is read by the first reading unit 414 is guided by the second platen roller 408 while holding the second platen glass 412. Then, the image of the second surface is read by the second reading unit 415.

  By the way, in order to read the image of the original G by the flow reading, it is necessary to pass through the transport path inside the ADF 301 as described above. When the document G stays, that is, is jammed for some reason when passing through the transport path, it is necessary to perform a jam process for removing the jammed document G. For example, as shown in FIG. 4, in the jam processing, a user opens a cover member 56 supported by a main body 57 as an apparatus main body of the ADF 301 so as to be openable and closable. The cover member 56 opens and closes with respect to the main body 57 around the opening and closing shaft 55 as shown in FIG.

  Here, as shown in FIG. 4, the main body 57 has a first transport guide 74, and the cover member 56 has a second transport guide 75. When the cover member 56 is in a closed state (closed position) with respect to the main body 57, the second transport guide 75 faces the first transport guide 74, and the upstream as a transport path together with the first transport guide 74. A transport path R1 is formed. When the cover member 56 is in an open state (open position) with respect to the main body 57, the upstream transport path R1 is opened as shown in FIG. That is, the cover member 56 is configured to be displaceable between a closed state and an open state. When the cover member 56 is opened by the user and the upstream transport path R1 is opened, the document G jammed in the upstream transport path R1 can be removed.

  Also, for example, as shown in FIG. 5, the ADF 301 is opened to the reading unit 302 by the user in the jam processing. As a result, the original G that has jammed in the vicinity of the first platen glass 411 or the first platen roller 406 can be accessed, and the original G can be removed.

  However, if the document G is jammed at a position where it cannot be accessed even when the cover member 56 or the ADF 301 is opened, the document G cannot be jammed by these methods. In particular, when the original G is a small-sized original such as a business card, and the paper jams on the downstream transport path R2 as a transport path provided downstream of the upstream transport path R1 in the original transport direction, the original G is jammed. It is difficult. For this reason, as shown in FIG. 4, the main body 57 is provided with a jam processing dial 48 as an operation unit which is manually operated and rotated by a user. When the user manually rotates the jam processing dial 48, the rotation is transmitted to each transport roller. Then, the document G in the downstream transport path R2 can be manually transported to a position where the user can access.

  The jam processing dial 48 is covered by a cover member 56 in a closed state as shown in FIG. 2, and is exposed when the cover member 56 is opened as shown in FIG. For this reason, unless the cover member 56 is opened, the user cannot access the jam clearing dial 48, thereby preventing the jam clearing dial 48 from being operated by mistake.

[Drive transmission configuration]
Next, a configuration for transmitting drive to each roller in the present embodiment will be described with reference to FIGS. 6A to 7B. As shown in FIG. 6A, the ADF 301 has a first drive unit DR1 and a second drive unit DR2. The first drive unit DR1 driven by the drive from the first motor 40 as the first drive source includes a first rotation shaft 42, a second rotation shaft 43, and a first rotation shaft 42 that drives the first motor 40. And a timing belt 80 that transmits the signal to the second rotation shaft 43.

  The first rotation shaft 42 rotatably supports a first conveyance roller 405 a as a first roller that is a driving roller of the conveyance roller pair 405, and the second rotation shaft 43 includes a driving roller of the conveyance roller pair 407. A certain second transport roller 407a is rotatably supported. A first gear 49 is provided at one end of the second rotating shaft 43. The first platen roller 406, the second platen roller 408, and the transport roller pair 409 shown in FIG. 3 are also driven by the first motor 40 by a drive transmission mechanism (not shown). The first transport roller 405a and the second transport roller 407a each constitute a first transport unit that is driven by the first motor 40 and transports a document.

  The second drive unit DR2 driven by the drive from the second motor 41 as a second drive source includes a third rotation shaft 44 as a rotation shaft, a second gear 51 meshable with the first gear 49, A gear pulley 54 as a third gear meshing with the second gear 51 and an output shaft 46 are provided. A discharge roller 410a, which is a driving roller of the discharge roller pair 410, is rotatably supported on the third rotating shaft 44. The discharge roller 410a forms a second roller. A plurality of first transport rollers 405a, second transport rollers 407a, and discharge rollers 410a are provided in the axial direction, respectively.

  On the third rotating shaft 44, a dial pulley 81, a connecting pulley 82, and a reverse rotation gear 83 are rotatably supported. A first one-way clutch 84 as a one-way clutch is provided between the dial pulley 81 and the third rotary shaft 44, and a second one-way clutch 85 is provided between the reverse rotation gear 83 and the third rotary shaft 44. Is provided. Note that the first one-way clutch 84 may be provided between the jam processing dial 48 and the third rotation shaft 44, and the second one-way clutch 85 is provided between the output shaft 46 and the third rotation shaft 44. What is necessary is just to be provided.

  A timing belt 86 as a first transmission unit is wound around a pulley provided integrally with the dial pulley 81 and the jam processing dial 48, and rotation of the jam processing dial 48 is performed via the timing belt 86 via a dial pulley. 81. A timing belt 87 as a second transmission unit is wound around the connection pulley 82 and the gear pulley 54, and rotation of the connection pulley 82 is transmitted to the gear pulley 54 via the timing belt 87. The gear pulley 54 has a pulley and a gear formed integrally on the same axis, and the gear of the gear pulley 54 always meshes with the second gear 51. The rotation of the reverse rotation gear 83 is transmitted to the output shaft 46 by the gear train GT.

  A tension pulley 88 is provided at one end of the output shaft 46 so as to be rotatable relative to the output shaft 46, and the tension pulley 88 is in contact with the timing belt 87 so as to apply tension. Further, the tension pulley 88 is rotated by the timing belt 87, but the rotation of the tension pulley 88 is not transmitted to the output shaft 46. Thus, by arranging the tension pulley 88 and the output shaft 46 so as to overlap the timing belt 87 in the radial direction, the size of the second drive unit DR2 can be reduced.

  Here, the direction in which the document G is transported toward the document discharge tray 305 is the document transport direction, and the rotation of each roller or the transport of the document G in the document transport direction is normal rotation, in the direction opposite to the document transport direction. The rotation when the original G is conveyed is referred to as reverse rotation. The forward rotation direction is a first direction, and the reverse rotation direction is a second direction opposite to the first direction. The first one-way clutch 84 does not transmit the forward rotation of the third rotating shaft 44 to the jam processing dial 48, but transmits the reverse rotation of the third rotating shaft 44 to the jam processing dial 48. Further, the first one-way clutch 84 transmits the forward rotation of the jam processing dial 48 to the third rotation shaft 44 and does not transmit the reverse rotation of the jam processing dial 48 to the third rotation shaft 44. On the other hand, the second one-way clutch 85 does not transmit the forward rotation of the third rotation shaft 44 to the output shaft 46, but transmits the reverse rotation of the third rotation shaft 44 to the output shaft 46.

  Here, the first one-way clutches 84 and 85, the reverse gear 83, and the gear train GT are referred to as a reverse drive unit 45, and the gear pulley 54 and the second gear 51 are referred to as a jam processing drive unit 47 (see FIG. 7A).

  FIG. 6B illustrates a state in which the first gear 49 and the second gear 51 are separated from each other, that is, a non-connection state as a first state in which the first drive unit DR1 and the second drive unit DR2 are not drive-connected. FIG. 7B shows a connection state as a state where the first gear 49 and the second gear 51 are meshed, that is, a second state in which the first drive unit DR1 and the second drive unit DR2 are drivingly connected. In FIGS. 6B and 7B, forward rotation is indicated by a solid arrow, and reverse rotation is indicated by a dashed arrow.

  When a copy job or the like is executed, as shown in FIG. 6B, the first motor 40 and the second motor 41 rotate in the non-connected state. Then, the transport roller pairs 405, 407, 409, the first platen roller 406, the second platen roller 408, and the discharge roller pair 410 including the first transport roller 405a, the second transport roller 407a, and the discharge roller 410a rotate forward. As a result, the document G is transported in the document transport direction.

  On the other hand, when the jam processing dial 48 is rotated to perform normal rotation in order to perform the jam processing in the connected state, the normal rotation of the reverse rotation driving unit 45 causes the jam processing driving unit 47 to rotate as shown in FIG. Via the first transport roller 405a and the second transport roller 407a. Therefore, the pair of transport rollers 405, 407, and 409, the first platen roller 406, the second platen roller 408, and the pair of discharge rollers 410 including the first transport roller 405a, the second transport roller 407a, and the discharge roller 410a rotate forward. The original is transported in the original transport direction.

[Shading correction]
Next, shading correction according to the present embodiment will be described with reference to FIGS. 8 to 10D. Shading correction refers to correcting unevenness in density level caused by the influence of the characteristics of the photoelectric conversion element of the reading unit and the lens aberration in order to keep the reading accuracy of the image constant. Shading correction is performed periodically before reading a document.

  As shown in FIG. 8A, a shading plate 416 is attached to the second platen glass 412, and the shading plate 416 is a white reference member having a white surface. The second reading unit 415 (see FIG. 3) starts the second platen glass 412 at the reading position RD and reads the image of the document. The second reading unit 415 is fixed to the ADF 301 and does not move. In a normal copy job, the shading plate 416 is located at a position shifted from the reading position RD, and does not hinder reading of a document.

  On the other hand, when performing shading correction, the second platen glass 412 and the shading plate 416 move in the direction of arrow B, and as shown in FIG. 8B, the shading plate 416 is located at a position overlapping the reading position RD. I do. Then, the shading plate 416 is read by the second reading unit 415 as a white reference. That is, the shading plate 416 functions as a white reference at the time of shading correction.

  Next, a configuration for moving the second platen glass 412 and the shading plate 416 in the direction of arrow B will be described. As shown in FIG. 9, pins 171e, 171e are provided in the main body 57 of the ADF 301, and the pins 171e, 171e are respectively engaged with long holes 171d, 171d formed in the glass holder 171a. The glass holder 171a holds the second platen glass 412, and at least the upper part of the second platen glass 412 is formed of glass so that light from the second reading unit 415 can be transmitted.

  A long hole 171d2 is formed on the downstream side of the glass holder 171a in the document conveying direction, and a cam shaft 182a to which drive is transmitted from the output shaft 46 (see FIG. 6A) is formed in the long hole 171d2. Is penetrating. A cam 182 which is an eccentric cam is fixed to both ends of the cam shaft 182a, and the cam 182 is in contact with the first contact portion 171b and the second contact portion 171c of the glass holder 171a. The first contact portion 171b and the second contact portion 171c face each other with the cam 182 interposed therebetween.

  FIG. 10 is a diagram viewed from the direction of arrow E in FIG. 9, and is a cross-sectional view illustrating the glass holder 171 a that moves between (a) to (d) in accordance with the phase of the cam 182. FIG. 10A is a cross-sectional view showing a glass holder 171a located at a normal position where a document is read, and FIG. 10C shows the glass holder 171a located at a shading position where shading correction is performed. It is sectional drawing. FIG. 10B is a cross-sectional view showing the glass holder 171a on the way from the normal position to the shading position, and FIG. 10D is a cross-sectional view showing the glass holder 171a on the way from the shading position to the normal position. FIG.

  As shown in FIG. 10A, when the glass holder 171a is located at the normal position, the shading plate 416 attached to the second platen glass 412 is shifted from the reading position RD of the second reading unit 415. It is located in. As shown in FIG. 10B, when the output shaft 46 (see FIG. 6A) is rotated in the reverse direction and the cam 182 rotates in the direction of arrow A, the movement of the cam 182 causes the first contact portion 171b and the second contact portion 171b to move. The glass holder 171a moves in the direction of arrow B by following the contact portion 171c. That is, the cam 182 moves the shading plate 416 moving integrally with the glass holder 171a in the direction of arrow B.

  When the cam 182 further rotates in the direction of arrow A, as shown in FIG. 10C, the glass holder 171a further moves in the direction of arrow B, and the shading plate 416 is moved to a position overlapping the reading position RD of the second reading unit 415. To position. In this state, the second reading unit 415 reads the shading plate 416 as a white reference. Thereafter, when the cam 182 further rotates in the direction of arrow A, the glass holder 171a moves in the direction of arrow C opposite to the direction of arrow B, as shown in FIG. When the cam 182 further rotates in the direction of arrow A, as shown in FIG. 10A, the glass holder 171a further moves in the direction of arrow B, and the glass holder 171a returns to the normal position.

  By the way, as shown in FIG. 6B, when the first motor unit DR1 and the second drive unit DR2 are not connected and the second motor 41 rotates in the reverse direction, the discharge roller 410a, the jam processing dial 48, and the output shaft 46 Is reversed. When performing the shading correction, for example, only the second motor 41 is rotated in a reverse state with the first motor 40 stopped. Thereby, the output shaft 46 is reversed, and the shading correction can be performed by moving the shading plate 416 together with the glass holder 171a as described above. Then, after the second motor 41 is further rotated in the reverse direction to return the glass holder 171a to the normal position, by rotating the first motor 40 and the second motor 41 in the normal direction, a copy job with high reading accuracy can be performed. . The second motor 41 is composed of, for example, a stepping motor.

[Switching means]
Next, the switching unit 90 for switching the connection state and the non-connection state between the first drive unit DR1 and the second drive unit DR2 will be described with reference to FIGS. As shown in FIG. 11, the switching unit 90 has one end connected to the interlocking member 50 rotatably supported on the main body 57 of the ADF 301 about the rotation fulcrum C1, and one end to the hook F of the main body 57. A compression spring 52 for urging the interlocking member 50. The interlocking member 50 rotatably supports the gear pulley 54 about the rotation fulcrum C1, and rotatably and swingably supports the second gear 51 meshing with the gear pulley 54. Since the interlocking member 50 and the gear pulley 54 both rotate about the rotation fulcrum C1, the gear pulley 54 and the second gear 51 are always meshed even when the interlocking member 50 turns. The compression spring 52 as an urging member urges the interlocking member 50 in a direction in which the second gear 51 approaches the first gear 49.

  As shown in FIG. 12, the cover member 56 has a projection 53 projecting downward and capable of pressing the interlocking member 50. When the cover member 56 is in the closed state, the protrusion 53 of the cover member 56 presses the interlocking member 50 downward against the urging force of the compression spring 52. At this time, the interlocking member 50 is located at the separated position for holding the second gear 51 in a state of being separated from the first gear 49. Therefore, when the cover member 56 is in the closed state, the first drive unit DR1 and the second drive unit DR2 are in a non-connection state in which the drive connection is not performed.

  As shown in FIG. 13, when the cover member 56 is opened around the opening / closing shaft 55 by the user, the protrusion 53 separates from the interlocking member 50, and the interlocking member 50 is turned by the urging force of the compression spring 52. Rotate clockwise. Then, the interlocking member 50 is located at a meshing position for holding the second gear 51 in a state meshed with the first gear 49. For this reason, when the cover member 56 is in the open state, the first drive unit DR1 and the second drive unit DR2 are connected to be driven and connected.

  As described above, the switching unit 90 disconnects the first drive unit DR1 and the second drive unit DR2 when the cover member 56 is in the closed state, and connects the first drive unit DR1 and the second drive unit DR2 when the cover member 56 is in the open state. To When the cover member 56 is displaced from the open state to the closed state, the interlocking member 50 is pressed by the projection 53 of the cover member 56 against the urging force of the compression spring 52 from the engagement position to the separation position. Is done. Further, when the cover member 56 is displaced from the closed state to the open state, the interlocking member 50 moves to the meshing position by the urging force of the compression spring 52.

  As described above, in the present embodiment, the first drive unit DR1 and the second drive unit DR2 having different drive sources are provided. Then, in the normal state in which the jam processing is not performed, the cover member 56 is in the closed state, and the first drive unit DR1 and the second drive unit DR2 are in a non-connected state in which the drive is not connected. For this reason, for example, even if the first motor 40 and the second motor 41 are rotated forward to convey the document G in a copy job, the driving forces of the first motor 40 and the second motor 41 do not merge. And gears are not damaged. The shading correction can be performed by reversing only the second motor 41, but at this time, the driving force of the second motor 41 is not transmitted to the first drive unit DR1, and the load of the second motor 41 is reduced. Can be reduced.

  In addition, when the cover member 56 is opened to perform the jam clearance and the cover member 56 is opened, the first drive unit DR1 and the second drive unit DR2 are connected to be driven and connected. In this state, when the user rotates the jam processing dial 48 forward, all the rollers connected to the first drive unit DR1 and the second drive unit DR2 can be rotated forward. More specifically, the transport roller pairs 405, 407, and 409, the first platen roller 406, the second platen roller 408, and the discharge roller pair 410 are rotated forward, and the document G is transported to a position accessible by the user to perform the jam processing. be able to. When performing jam processing by the jam processing dial 48, it is advantageous that as many rollers as possible are drivingly connected to the jam processing dial 48. In the present embodiment, even if the document G is jammed in the downstream conveyance path R2 located at a position deep in the main body 57, the document G can be conveyed without any problem and the jam can be cleared, thereby improving the jam removability. .

  Further, since the driving sources are divided into the first motor 40 and the second motor 41, it is possible to secure the torque required for conveying the document G, and to reduce the size of each motor. In the present embodiment, the protrusion 53 is provided on the cover member 56, but the present invention is not limited to this, and the interlocking member 50 may be pressed by the smooth surface of the cover member 56.

  Further, in the present embodiment, the jam processing dial 48 is configured to transmit the drive to the third rotation shaft 44 of the second drive unit DR2 by the timing belt 87, but is not limited thereto. For example, the jam processing dial 48 may be configured to transmit the drive to the first rotation shaft 42 or the second rotation shaft 43 of the first drive unit DR1. That is, the jam processing dial 48 only needs to be configured to be able to transmit a driving force to at least one of the first drive unit DR1 and the second drive unit DR2 by rotating.

  In the present embodiment, the cam 182 is fixed to the cam shaft 182a to which the drive is transmitted from the output shaft 46. However, the present invention is not limited to this, and the cam 182 may be fixed to the output shaft 46.

  In the present embodiment, the transport roller pairs 405, 407, 408, and 409, the first platen roller 406, and the second platen roller 408 are driven in the first drive unit DR1, and the discharge roller pair 410 in the second drive unit DR2. Is being driven. However, the present invention is not limited to this, and which roller is driven by which drive unit may be freely set.

  Further, in any of the above-described embodiments, the description has been made using the electrophotographic printer 200, but the present invention is not limited to this. For example, the present invention can be applied to an ink jet type image forming apparatus that forms an image on a sheet by discharging ink liquid from a nozzle. Further, the first drive unit DR1 and the second drive unit DR2 of the present embodiment are provided in the ADF 301, but are not limited to this. For example, the present invention is applied to any drive unit of the printer main body 202. You may.

  Further, in the present embodiment, an example has been described in which the first drive unit DR1 and the second drive unit DR2 are connected in accordance with the operation of opening the cover member 56. However, the first drive unit DR1 and the second drive unit DR2 may be linked to each other by a user's operation of moving a member different from the cover member 56 as in the following modified example (FIG. 15A ) (B)).

  15A and 15B, the lever 61 is rotatable around a fulcrum 61A. The movable gear 51A is rotatably supported by a lever 61. FIG. 15A shows a state in which the gear 51A is separated from the gear pulley 54 of the second drive unit DR2 and the first gear 49 of the first drive unit DR1. FIG. 15B shows a state in which the gear 51A meshes with the gear pulley 54 of the second drive unit DR2 and the gear 51A meshes with the first gear 49 of the first drive unit DR1.

  A tension spring 63 is attached to the lever 61. The extension spring 63 urges the attachment portion 61B with the lever 61 downward. In FIG. 15A, the rotation of the lever 61 in the clockwise direction due to the force of the tension spring 63 is stopped by the stopper 62. When a jam occurs, the user operates the distal end portion 61C of the lever 61 before operating the jam processing dial 48. That is, when the user moves the distal end 61C of the lever 61 to the left in FIG. 15A, the state is switched to the state in FIG. 15B.

  In FIG. 15B, the first drive unit DR1 and the second drive unit DR2 are connected by a gear 51A. When the jam processing is completed, the user operates the distal end portion 61C of the lever 61 so as to switch to the state shown in FIG. As shown in the modified example of FIGS. 15A and 15B, the gear 51A that moves to connect the first drive unit DR1 and the second drive unit DR2 is not connected to the first drive unit DR1. And the second drive unit DR2.

  Here, a mode in which the user manually moves the lever 61 has been described as an example, but a solenoid may be connected to the lever 61 and the lever 61 may be moved by the solenoid. When using a solenoid, for example, the following configuration may be used. When a jam occurs, the solenoid is driven to change from the state of FIG. 15A to the state of FIG. 15B. Then, after the jam has been cleared and before the sheet is fed, the driving of the solenoid may be released and the state shown in FIG. 15A may be changed by the force of the spring. In any of the embodiments described above, the rotation of the dial is transmitted to the first drive unit DR1 and the second drive unit DR2, so that the jam clearance can be improved.

  40: first drive source (first motor) / 41: second drive source (second motor) / 44: rotating shaft (third rotating shaft) / 48: operating unit (jam processing dial) / 49: first gear / 50: interlocking member / 51: second gear / 52: urging member (compression spring) / 53: projection / 54: third gear (gear pulley) / 56: cover member / 84: one-way clutch (first one-way clutch) ) / 86: first transmission unit (timing belt) / 87: second transmission unit (timing belt) / 90: switching unit / 182: cam / 201: image reading device / 301: sheet transport device (ADF) / 405a: First roller (first transport roller) / 410a: second roller (discharge roller) / 414, 415: reading unit (first reading unit, second reading unit) / 416: white reference member (shading plate) / C1: Rotating fulcrum / DR : The first drive unit / DR2: second drive unit / R2: conveying path (downstream transport path)

Claims (12)

A first driving source;
A first drive unit that includes a first roller that conveys a sheet and is driven by a driving force of the first drive source;
A second drive source;
A second drive unit that includes a second roller that conveys a sheet, and is driven by a driving force of the second drive source;
An operation unit which is manually operated and rotated,
A switching unit configured to switch between a first state in which the first drive unit and the second drive unit are not connected and a second state in which the first drive unit and the second drive unit are connected; ,
In the second state, the rotation of the operation unit is transmitted to the first drive unit to rotate the first roller, and the rotation of the operation unit is transmitted to the second drive unit to rotate the second roller. Do
A sheet conveying device, characterized in that: A cover member that can be located at a closed position when the first roller and the second roller convey a sheet so as to pass through a conveyance path, and an open position where the conveyance path is opened,
The switching unit switches from the first state to the second state in accordance with the movement of the cover member from the closed position to the open position.
The sheet conveying device according to claim 1, wherein: The first drive unit has a first gear driven together with the first roller,
The second drive unit has a second gear driven together with the second roller,
The switching unit has an interlocking member that interlocks with the cover member and supports the second gear rotatably and swingably,
The interlocking member holds the second gear in a state separated from the first gear when the cover member is at the closed position, and holds the second gear when the cover member is at the open position. Is held in mesh with the first gear,
The sheet conveying device according to claim 2, wherein: The switching unit includes an urging member that urges the interlocking member to a meshing position where the second gear and the first gear mesh with each other,
The interlocking member is moved by the cover member from the meshing position against the urging force of the urging member when the cover member moves from the open position to the closed position, and the cover member is closed. When moving from the position to the open position, move to the meshing position by the urging force of the urging member,
The sheet conveying device according to claim 3, wherein: The cover member has a protrusion capable of pressing the interlocking member,
The sheet conveying device according to claim 4, wherein: The interlocking member is supported rotatably about a pivot point,
The second drive unit rotates around the rotation fulcrum by the driving force of the second drive source, and has a third gear that can mesh with the second gear.
The sheet conveying device according to any one of claims 3 to 5, wherein: The second roller discharges the sheet outside the machine,
The second drive unit includes:
A rotating shaft rotatable in a first direction and a second direction opposite to the first direction by the second drive source and rotatably supporting the second roller;
A first transmission unit that can transmit rotation of the operation unit to the rotation shaft;
A second transmission unit capable of transmitting the rotation of the rotation shaft to the third gear.
The sheet conveying device according to claim 6, wherein: When the rotating shaft rotates in the second direction, the second roller discharges the sheet outside the machine,
The second drive unit is provided between the rotation shaft and the operation unit, transmits rotation of the rotation shaft in the second direction to the operation unit, and controls rotation of the rotation shaft in the first direction. Having a one-way clutch that does not transmit to the operation unit,
The sheet conveying device according to claim 7, wherein: The operation unit is covered by the cover member located at the closed position, and is exposed when the cover member is located at the open position.
The sheet conveying device according to claim 2, wherein The switching unit includes a movable gear,
In the first state, the gear is located at a position where at least one of the first drive unit and the second drive unit is disconnected from the gear.
In the second state, the gear is located at a position where the gear is connected to the first drive unit and the gear is connected to the second drive unit.
The sheet conveying device according to claim 1, wherein: A sheet conveying device according to claim 1,
A reading unit that reads an image of a sheet conveyed by the first roller and the second roller,
An image reading apparatus, comprising: A white reference member that functions as a white reference at the time of shading correction of the reading unit,
A cam that is rotated by rotation from the second drive source transmitted by the second drive unit, and moves the white reference member.
The image reading device according to claim 11, wherein:

Images