JP5288264B2 - Paper conveying apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to a sheet conveying apparatus and an image forming apparatus, and more particularly to a sheet conveying apparatus in which a pickup roller is disposed on a swinging holder member and an image forming apparatus including the sheet conveying apparatus.

  In general, as a paper transport device provided in an automatic document feeder (ADF) provided in a copying machine or the like, a pickup roller for taking in a document set on a document tray, and one original from the document taken in by the pickup roller Is provided with a feed roller for feeding the document toward the document conveyance path. In the ADF, a document set on a document tray is conveyed toward a reading unit by a document conveying device including these pickup rollers and feed rollers, and a document image is read at a scanning position.

  In the document conveying device, when picking up a document, the pick roller is moved downward to come into contact with the upper surface of the document bundle to draw the uppermost document, and when the document is not picked up, the pickup roller is moved upward to move the document. Separate from the bundle by a predetermined distance. The operations for contacting and separating the pickup roller are performed using various mechanisms.

  In Patent Document 1, a feed roller that conveys a document, a pickup roller that pre-feeds a document on a document conveyance surface to the feed roller, a support shaft that is rotatably supported by a drive shaft of the feed roller, and the pickup An automatic document feeder comprising: a bracket that rotatably supports a roller; and a spring clutch that is supported by the feed roller drive shaft and that transmits a rotational force of the feed roller drive shaft to the bracket as a rotational force of the bracket. Describes an automatic document feeder having a turning force adding means for applying to the bracket a turning force in a direction opposite to a direction in which a pickup roller is pressed against the document feeding surface.

  Patent Document 2 discloses that the pickup roller can be rotated in the upstream portion of the conveyance path in order to control the time required for the plunger suction and return operation suitable for the operation of the automatic document feeder while reducing the operation noise. The supported pickup arm is swingably provided, and a coil spring is interposed between the rotating body and the pickup arm via a friction plate, so that the rotation of the rotating body is transmitted to the pickup arm. The picked-up roller that is in pressure contact brings the document into the conveyance path, and includes a spring pressure adjusting tool for adjusting the spring pressure by extending or compressing the coil spring according to the type of the document. Have been described.

  Further, in Patent Document 3, in an automatic document feeder that sequentially feeds documents placed on a paper feed tray from the uppermost paper to the transport path using a paper feed unit, poor feeding or separation failure due to differences in the paper thickness of the original. In order to prevent the occurrence of the occurrence of the problem and to enable the reliable retraction to the conveyance path, the connecting mechanism including the support shaft, the lever, and the cam raises and lowers the calling roller, and the spring connects the link of the connecting mechanism. The solenoid is energized to separate the calling roller from the sheet bundle, and the solenoid drives the connecting mechanism to bring the calling roller into contact with the upper surface of the document bundle. It is described that the solenoid is dynamically driven and is driven with different driving duty at the time of solenoid plunger suction and return.

  In the above-described conventional automatic document feeder, the pickup roller is arranged at a raised position so that the document can be set when waiting for paper feeding. The pickup roller driving device is required to be as simple as possible and to be as small as possible on the premise of a stable paper transport operation.

  However, since the one disclosed in Patent Document 1 has one end of a spring clutch provided on the feed roller shaft connected to the pickup holder, the spring clutch is loosened and the spring feeds during the downward movement of pressing against the document conveying surface. The roller rotates idly with respect to the roller shaft, and the holder is pressed against the document with a substantially constant force by the torque generated by the idling. In addition, the spring will be tightened when the pickup roller is raised, so if the holder hits anything, the spring clutch may be damaged. It is necessary to provide a gap between the holder and the upper cover so that the holder does not interfere with the upper cover, which may increase the size of the apparatus.

  In addition, the device described in Patent Document 2 has a configuration in which a coil spring is interposed between a rotating body and a pickup arm via a friction plate, and the driving force to the pickup arm is transmitted by the frictional force so that it is supplied. There is a problem that it is difficult to set the paper pressure.

  Further, the device described in Patent Document 3 has a problem that the raising and lowering of the calling roller is performed by a solenoid and the mechanism is complicated, and the configuration of the entire apparatus including the control mechanism becomes complicated and large, resulting in an increase in cost.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an inexpensive sheet conveying apparatus and image forming apparatus that can stably convey a sheet and have a simple configuration.

The invention of claim 1
A pickup roller that picks up one sheet at a time from the sheet bundle and a feed roller that conveys the picked-up sheet to the next stage, and the pickup roller is rotatably held by a feed roller drive shaft that drives the feed roller In the paper conveying device arranged on the member,
An overall cylindrical coil-shaped wire, and a spring main body portion that is coaxially inserted into the feed roller drive shaft, and two protrusions that project outward from both ends of the coil-shaped wire at a predetermined angle. A spring member having a free end, and changing the rotational sliding resistance between the spring main body and the feed roller drive shaft by changing the angle between the two free ends to change;
One abutting portion disposed on the holder member and capable of abutting on one free end of the spring member when the feed roller driving shaft rotates in the paper conveying direction, and the feed roller driving shaft is configured to convey the paper. A predetermined angle larger than an angle between the one abutting portion and the two free end portions with the feed roller drive shaft as a center, when the other end of the free end portion can be abutted when rotating in the opposite direction. A holder driving member having the other abutting portion arranged at a position sandwiching
A contact position changing member that changes a position of at least one contact portion of the one and other contact portions and changes an angle between the contact portions;
A sheet conveying apparatus comprising:

  According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the holder and the holder driving member are integrally formed.

According to a third aspect of the present invention, in the paper conveying apparatus according to the first or second aspect , the contact position changing member is detachably disposed on the holder member.

According to a fourth aspect of the present invention, in the paper conveying apparatus according to the fourth aspect , the contact position changing member is inserted into the feed roller drive shaft, and the spring member is sandwiched between the holder member and the holder member. It is attached.

According to a fifth aspect of the present invention, in the paper conveying apparatus according to the third or fourth aspect , the contact position changing member is attached to the holder member in a variable position.

According to a sixth aspect of the present invention, there is provided an image forming apparatus comprising the paper conveying device according to any one of the first to fifth aspects.

  According to the paper transport device of the present invention, the swing driving force of the holder member due to the rotation of the feed roller drive shaft is caused by the sliding frictional force between the feed roller shaft and the spring member. Since the swing driving force is controlled when each free end of the spring member comes into contact with the abutting portion, a paper transport device that can stably transport the paper without excessive force is used as another drive source. It is not necessary and can be realized with a simple, small and inexpensive configuration.

2 is a cross-sectional configuration diagram of an automatic document feeder. FIG. It is a perspective view which shows the feed unit used for the automatic document feeder based on an Example. FIG. 3 is an enlarged perspective view of the feed unit shown in FIG. 2. FIG. 3 is a side view of the feed unit shown in FIG. 2. It is a perspective view which shows a spring member. It is a perspective view which shows the feed unit which concerns on a 2nd Example. It is a perspective view which shows the spacer member used for the feed unit shown in FIG. It is a perspective view which shows the feed unit which concerns on the modification of a 2nd Example. It is a perspective view which shows the feed unit which concerns on the other modification of a 2nd Example.

  The paper transport device according to the present invention includes a pickup roller that picks up the paper one by one from the paper bundle and a feed roller that transports the picked-up paper to the next stage, and the pick-up roller drives a feed roller that drives the feed roller. In a paper conveying device arranged on a holder member rotatably held on a shaft, a spring main body portion, which is made of a substantially cylindrical coiled wire material, is coaxially inserted into the feed roller driving shaft, and this coil shape Two free ends projecting from the opposite ends of the wire rod with a predetermined angle therebetween, and being displaced so as to change the angle between the two free ends, the spring body portion and the feed A spring member that changes rotational sliding resistance with the roller shaft; and the feed roller disposed on the holder member One contact portion that can contact one free end of the spring member when the moving shaft rotates in the paper transport direction, and the free when the feed roller drive shaft rotates in the direction opposite to the paper transport direction. The other end disposed at a position sandwiching a predetermined angle larger than the angle between the one abutting portion and the two free ends with the feed roller drive shaft as a center. A holder driving member having a contact portion.

  According to the present invention, the rotational force transmitted to the feed unit is controlled by the spring member inserted into the feed roller drive shaft during forward and reverse rotation of the feed roller drive shaft. An apparatus can be provided.

  In the image forming apparatus according to the present invention, the holder and the holder driving member are integrally formed. The paper conveying apparatus according to the present invention further includes a contact position changing member that changes a position of at least one of the one and other contact portions to change an angle between the contact portions. ing. According to the present invention, it is possible to solve the problem that the angle formed by both free ends of the spring member after assembly varies due to variations in the inner diameter of the spring member and variations in the number of turns (angle), and the spring member cannot be assembled. In addition, the delay angle generated when the feed roller shaft rotates from the state in which the feed roller shaft rotates in the direction in which the pickup roller is pressed against the document to the direction in which the pickup roller is retracted is suppressed to a certain amount. Therefore, it is possible to reduce a delay in operation due to rattling when the feed roller shaft rotates forward and backward.

  In addition, the contact position changing member of the sheet conveying apparatus of the present invention is detachably disposed on the holder member. Further, the contact position changing member of the paper conveying apparatus of the present invention is fitted to the holder member by being inserted into the feed roller drive shaft and sandwiching the spring member with the holder member. According to the present invention, since the spring member is held by the contact position changing member, other parts such as an E-ring are not required, the number of parts can be reduced, and the cost increase can be minimized.

  Further, the contact position changing member of the sheet conveying device of the present invention is attached to the holder member so that the position thereof can be changed. According to the present invention, since the position adjustment of the contact position changing member is accurately performed, it is possible to prevent a delay in the operation at the time of forward and reverse rotation of the feed roller shaft, and it is possible to stabilize and minimize the operation timing. The paper transport time and the first copy time can be shortened. The image forming apparatus according to the present invention includes the sheet conveying device.

  Hereinafter, a paper conveying apparatus according to the present invention will be described. In this embodiment, the sheet conveying apparatus according to the present invention is applied to an automatic document conveying apparatus disposed in an image forming apparatus. FIG. 1 is a sectional view of an automatic document feeder. An automatic document feeder 1 is attached to an upper part of an image reading apparatus 2 such as a copying machine, a facsimile machine, a scanner or the like so as to be opened and closed. The image reading device 2 is provided with a contact glass 3 on its upper surface, and conveys an original by the automatic document conveying device 1 and reads an image of the original conveyed by passing through the contact glass 3. Further, a single-side mode and a double-side mode can be set by an instruction from an operation unit (not shown) of the image reading apparatus 2, and the operation of the automatic document feeder 1 is controlled according to the set mode.

  Next, the automatic document feeder 1 will be specifically described. The automatic document feeder 1 includes a document placing table 5, a pickup roller 7, a document placing sensor 8, a feed roller 9, and a blocking roller 10. The document placing table 5 is used to place and set the document 6, and the document 6 is set in page order with the image surface facing upward. The pickup roller 7 sends the document 6 to a separation unit downstream of the document transport, and is normally disposed at a standby position at a predetermined interval from the document placement table 5. The document placement is that the document 6 is on the document placement table 5. When it is detected by the position sensor 8 and an instruction to start feeding the original is instructed, it is controlled so as to move down to the position where it comes into contact with the upper surface of the original 6 from the standby position.

  Further, the feed roller 9 is rotated clockwise to feed the document 6 on the document table 5. The blocking roller 10 is stopped or rotated in the clockwise direction, so that one by one from the topmost document 6 is sequentially brought about by the frictional action among the documents 6 called by the call pickup roller 7 with the feed roller 9. To separate. The pickup roller 7 and the feed roller 9 are disposed in the holder member 35 to constitute a feed unit 30 and are disposed below the upper cover 34 of the automatic document feeder 1. The feed unit 30 is driven to swing around the axis of the feed roller 9 as indicated by an arrow in the figure. In this swinging operation, when the feed unit 30 swings to the A side in the drawing, a feeding operation is performed, and when the feed unit 30 swings to the B side in the drawing, a retracting operation is performed. Although the configuration using the blocking roller 10 is described in FIG. 1, the same separation effect can be obtained by using a separation pad having a surface that causes friction with the document instead of the blocking roller 10. Can do.

  The automatic document feeder 1 includes a first transport path (A), a paper discharge path (B), a switchback transport path (C), and a switching claw 17. The first transport path (A) is formed between the guides 11 and 11 a and constitutes a path for moving the document 6 separated and transported by the feed roller 9 of the separation unit onto the contact glass 3. The first conveyance path (A) is provided in an arch shape between the separation unit and the contact glass 3 serving as the document reading unit. The document 6 sent out by the feed roller 9 is reversed to contact glass 3. Lead up.

  The paper discharge path (b) is formed between the guides 12 and 12a, and is a path for moving the document 6 conveyed through the contact glass 3 from the first conveyance path (b) to the document discharge port 13. Configure.

  The switchback conveyance path (c) is formed between the guide 16 and the guide 16a and the guide 16a and the switching claw 17 provided below the document placing table 5 and above the document discharge table 14. A path for switching back the document 6 conveyed from the document discharge port 13 of the paper path (b) and guiding it again to the first conveyance path (a) is formed, It is provided above the document discharge table 14.

  The switching claw 17 is provided above the document discharge table 14, and the document 6 discharged from the document discharge port 13 at the end of the discharge path (B) is switched to the document discharge by switching to the dotted line position. When the document 6 is guided to the switchback conveyance path (c) without being loaded on the table 14 and then introduced into the switchback conveyance path (c), the original 6 is switched to the solid line position, thereby being switched to the switchback conveyance path (c). The switched-back document 6 is guided from the rear end to the second transport path (d).

  The second transport path (d) is formed between the guides 18 and 18a, and merges with the first transport path (b) and is switched back by the switchback transport path (c). Is a path for moving the first to the first transport path (A).

  Further, the sheet feed rollers 23, 24, 25 are provided in the vicinity of the document discharge port 13, and the document 6 passing through the discharge path (b) between the sheet feed rollers 23, 24 is supplied to the document discharge table 14 or Transport to switchback transport path (c). Further, the document 6 switched back by the switchback conveyance path (c) between the sheet feed rollers 24 and 25 is conveyed from the switchback conveyance path (c) to the second conveyance path (d).

  Further, a pair of feed rollers 26 and 26a (switchback members) capable of forward and reverse rotation are provided on the switchback conveyance path (c), and the document 6 conveyed into the switchback conveyance path (c) is switched back. Then, the paper is introduced into the path (C), and then reversely rotated to switch back the document 6 from the paper discharge path (B) and transport it to the second transport path (D).

  The sensor 28 is disposed at the exit of the first conveyance path (b) between the roller pair 20, 20 a and the contact glass 3, that is, in the vicinity of the upstream side in the document conveyance direction from the so-called contact glass 3. The sensor 28 reads the document by matching the leading edge of the document with the reading timing.

  Next, the feed unit 30 will be described. 2 is a perspective view showing a feed unit used in the automatic document feeder according to the embodiment, FIG. 3 is an enlarged perspective view of the feed unit shown in FIG. 2, and FIG. 4 is a side view of the feed unit shown in FIG. FIG. 5 is a perspective view showing the spring member. The feed unit 30 is configured so that the pickup roller 7 can be rotationally driven in a holder member 35, and the pickup roller 7 is supported by a feed roller drive shaft 31 via the feed unit 30. Reference numeral 35a denotes a lid member for the holder member 35.

  When the feed unit 30 is swung around the feed roller drive shaft 31 (arrow AB in the figure), the pickup roller 7 supported by the feed unit 30 presses the document 6 on the document table 5, and the document 6 is pre-processed. Feeded. The pre-fed original is separated by the feed roller 9 and the blocking roller 10 and conveyed one by one to the reading unit.

  A substantially semi-cylindrical holder driving member 36 is attached to the holder member 35 so as to cover the lower portion of the feed roller driving shaft 31 at one of the protruding positions of the feed roller driving shaft 31. The holder driving member 36 is formed integrally with the holder member 35. A spring member 32 is arranged inside the holder driving member 36 so as to be coaxial with the feed roller driving shaft 31.

  The spring member 32 includes a cylindrical spring main body portion 32c made of a coiled wire, and two free end portions 32a and 32b formed so as to project a predetermined angle from both ends of the coiled wire rod of the spring main body 32c. It is configured with. The inner diameter of the spring main body 32c is formed slightly smaller than the outer diameter of the feed roller drive shaft 31 when there is no load. By relatively moving the two free ends 32a and 32b in the rotational direction, the spring body 32c is twisted, and the inner diameter of the spring body 32c is changed.

  When installing the spring member 32 on the feed roller drive shaft 31, the free end portions 32a and 32b are rotated to increase the inner diameter of the spring body portion 32c. Therefore, after installation on the feed roller drive shaft 31, the number of turns of the coiled wire rod of the spring body 32c and the relative positions of the free ends 32a and 32b change, and the free end 32a is in the state shown by the solid line. . 5 indicates a state before the spring member 32 is incorporated into the feed roller drive shaft 31, that is, the diameter of the spring main body portion 32c is smaller than that of the feed roller drive shaft 31. . The free ends 32a and 32b are bent so that their tips are substantially circular.

  The holder driving member 36 includes a semi-cylindrical main body portion 36c, and the main body portion 36c is formed with an abutting portion 36a and an abutting portion 36b at an end portion along the generatrix. The spring member 32 is disposed in the spring main body 32c so as to penetrate the feed roller drive shaft 31, and is slidably supported on the feed roller drive shaft 31. As described above, the inner diameter of the spring body 32c of the spring member 32 is set smaller than the outer diameter of the feed roller drive shaft 31, and is set while the free ends 32a and 32b are rotated to increase the inner diameter.

As shown in FIG. 4, in a state of arranging the spring member 32 to the feed roller drive shaft 31, the angle C which two free ends 32a, 32b sandwich the angles D contact portion 36a and the contact portion 36b sandwich It is set smaller. Here, the two angles vary greatly due to an error in the outer diameter of the shaft, an error in the components of the spring itself, and the like, so that the above relationship is established including this variation.

  Next, the operation of this embodiment will be described. In a state where the spring member 32 is disposed in the holder driving member 36, the free end portion 32a of the spring member 32 is disposed on the contact portion 36a side, and the free end portion 32b is disposed on the contact portion 36b side. . When the feed roller 9 rotates in the document conveyance direction (clockwise (B to A in the figure)), the spring member 32 also rotates due to friction between the spring main body 32c and the feed roller drive shaft 31, and the free end 32a is the feed unit 30. The feed unit 30 is rotated in a direction (A direction in the drawing) in which the pickup roller 7 is pressed against the document.

  When the pickup roller 7 abuts against the document surface, a reaction force from the abutting portion 36a of the feed unit 30 is applied to the free end portion 32a of the spring member 32, and the free end portion 32a moves to move the spring main body portion 32c. A force in the direction of opening the inner diameter is applied. Then, the frictional force between the spring member 32 and the feed roller drive shaft 31 is reduced, and the spring member 32 slides and idles with the feed roller drive shaft 31. The torque due to idling at this time becomes the contact force of the pickup roller 7 to the original, and the original set with a predetermined conveyance drag is conveyed. That is, in this example, the torque limiter is configured by the feed roller drive shaft 31, the spring member 32, and the holder drive member 36, and a rotational force exceeding a certain level is not transmitted to the feed unit 30.

  When the feed roller drive shaft 31 is rotated reversely after all the originals are read, the spring member 32 also rotates together, the other free end 32b comes into contact with the contact portion 36b of the holder drive member 36, and the feed unit 30 is moved upward. The pickup roller 7 is moved in the direction of the standby position.

  When the lid 30c, which is the upper surface of the feed unit 30, hits the upper cover 34, the force from the feed unit 30 acts on the free end 32b of the spring member 32, and the force in the direction in which the inner diameter of the spring member opens. Is added, the spring body 32c is expanded, and the spring body 32c slides with the feed roller drive shaft 31. In this state, the drive of the feed roller drive shaft 31 is stopped, and the feed unit 30 stops at the standby position. That is, also in this case, the torque limiter is configured by the feed roller drive shaft 31, the spring member 32, and the holder drive member 36, and a rotational force exceeding a certain level is not transmitted to the feed unit 30.

  Therefore, according to this embodiment, the rotational force transmitted to the feed unit is controlled by the spring member inserted into the feed roller drive shaft when the feed roller drive shaft is rotated forward and backward. A paper conveying apparatus can be provided.

  6 is a perspective view showing a feed unit according to the second embodiment, and FIG. 7 is a perspective view showing a contact position changing member used in the feed unit shown in FIG. In the feed unit 40 according to the present embodiment, one position of the abutting portion where the two free end portions 32a and 32b of the spring member abut is variable. For this reason, in this example, the holder drive member 42 having one contact portion 42b is erected and disposed on the holder member 35, and the position of the contact position changing member 41 having another contact portion 41a is variable. Install in.

  The contact position changing member 41 includes an annular insertion portion 41b inserted into the feed roller drive shaft 31, an extension portion 41c protruding outward from the insertion portion, and the extension portion 41c in the axial direction of the feed roller drive shaft 31. An extending contact portion 41a and a locking portion 41d formed at the tip of the contact portion 41a are provided. Further, in this example, five engagement portions 41 c can be inserted in the side surface portion 33 of the holder member 35 and in the vicinity of the through portion of the feed roller drive shaft 31 for positioning the contact position changing member 41. The blind holes 33a to 33e are opened at equal intervals.

  In the feed unit 40 according to this example, the contact position changing member 41 is inserted into the feed roller drive shaft 31, and a spring member is sandwiched between the holder member 35 and the locking portion 41d is formed into a predetermined locking hole portion. The contact position changing member 41 is fixed to the holder member 35 by insertion.

  According to this example, by changing the mounting position of the contact position changing member 41, the position of the contact portion 41a with which the free end portion 32a of the spring member 32 contacts is changed to a desired position, and the contact portion 41a and The angle between the contact portions 42b (corresponding to the angle D in FIG. 4) can be adjusted. For this reason, the positional relationship between the free end portions 32a and 32b of the spring member 32 and the contact portions 41a and 42b is appropriate regardless of the inner diameter of the spring main body portion 32c of the spring member 32 and the shaft diameter of the feed roller drive shaft 31. Can be.

  Further, according to this embodiment, the spring member 32 is sandwiched between the holder member 35 and the contact position changing member 41 and assembled, so that a holding member such as an E-ring for holding the spring member 32 can be avoided. The number of parts can be reduced.

  FIG. 8 is a perspective view showing a feed unit according to a modification of the second embodiment. In the feed unit 50 according to the present embodiment, the contact position changing member 51 is disposed on the side surface portion 33 of the holder member 35 so that the mounting position is variable. In this example, the holder drive member 52 that forms one contact portion 52b is erected on the holder member 35, and the contact position changing member 51 that forms the other contact portion 51a is variably installed. .

  The contact position changing member 51 includes the contact portion 51a and an annular mounting plate portion 51b that extends from the contact portion 51a and is attached to the side surface portion 33 of the holder member 35 through the feed roller drive shaft 31. ing. A large number of engagement hole portions 53a to 53d are formed in the mounting plate portion 51b at equal angles around a hole portion through which the feed roller drive shaft 31 passes. Further, the side projection 33 of the holder member 35 is formed with an engagement projection (not shown) that is fitted into one of the engagement holes 53a to 53d.

  The contact position changing member 51 may be attached to the side surface portion 33 by attaching the engagement protrusion into the selected engagement hole portion among the engagement hole portions 53a to 53d of the attachment plate portion 51b. Thereby, the angle which the contact part 51a and the contact part 52b pinch | interpose can be set arbitrarily.

  FIG. 9 is a perspective view showing a feed unit according to another modification of the second embodiment. In the feed unit 60 according to the present embodiment, the contact position changing member 61 is disposed on the side surface portion 33 of the holder member 35 so that the mounting position is variable. In this example, the holder drive member 62 having one contact portion 62b is erected and disposed on the holder member 35, and the contact position changing member 61 having another contact portion 61a is variably installed. .

  The contact position changing member 61 includes the contact portion 61a and a mounting plate portion 61b that extends from the contact portion 61a and is attached to the side surface portion 33 of the holder member 35 through the feed roller drive shaft 31. . The mounting plate portion 61b is fixed to the side surface portion 33 by a screw member 63, and an arc-shaped elongated hole 61c concentric with the hole portion is formed in the mounting plate portion 61b.

When attaching the mounting plate portion 61b to the side surface portion 33, the mounting plate portion 61b is disposed at a predetermined position, the screw member 63 is screwed into the side surface portion 33 through the arc-shaped elongated hole 61c, and the mounting plate portion 61b is fixed to 33. In this case, the angle between the contact part 61a and the contact part 62b can be arbitrarily set. According to this example, the attachment plate portion 61 b can be accurately attached to an arbitrary position of the side surface portion 33 of the holder member 35.

1: Automatic document feeder 2: Image reading device 3: Contact glass 5: Document placement table 6: Document 7: Pickup roller 8: Document placement sensor 9: Feed roller 10: Blocking roller 11, 11a: Guides 12, 12a: Guide 13: Document discharge port 14: Document discharge table 16: Guide 16a: Guide 17: Switching claw 18, 18a: Guide 20, 20a: Roller pair 23, 24, 25: Sheet feed roller 24: Sheet feed roller 23, 24, 25: Sheet feed rollers 26, 26a: Feed roller pair 28: Sensor 30: Feed unit 30c: Lid 31: Feed roller drive shaft 32: Spring members 32a, 32b: Free end 32c: Spring main body 33: Side surface Portions 33a to 33e: Locking hole 34: Upper cover 35: Holder member 36: Holder driving member 36a: Abutting portion 36b Contact part 36c: Main body part 40: Feed unit 41: Contact position changing member 41a: Contact part 41b: Insertion part 41c: Extension part 41d: Locking part 42: Holder drive member 42b: Contact part 50: Feed unit 51: Contact position changing member 51a: Contact portion 51b: Mounting plate portion 52: Holder driving member 52b: Contact portions 53a to 53d: Engaging hole portion 60: Feed unit 61: Contact position changing member 61: Mounting portion 61a: Contact part 61b: Mounting plate part 61c: Arc-shaped slot 62: Holder drive member 62b: Contact part 63: Screw member

JP 2000-177861 A JP 2005-194023 A JP 2007-70107 A

Claims (6)

A pickup roller that picks up one sheet at a time from the sheet bundle and a feed roller that conveys the picked-up sheet to the next stage, and the pickup roller is rotatably held by a feed roller drive shaft that drives the feed roller In the paper conveying device arranged on the member,
An overall cylindrical coil-shaped wire, and a spring main body portion that is coaxially inserted into the feed roller drive shaft, and two protrusions that project outward from both ends of the coil-shaped wire at a predetermined angle. A spring member having a free end, and changing the rotational sliding resistance between the spring main body and the feed roller drive shaft by changing the angle between the two free ends to change;
One abutting portion disposed on the holder member and capable of abutting on one free end of the spring member when the feed roller driving shaft rotates in the paper conveying direction, and the feed roller driving shaft is configured to convey the paper. A predetermined angle larger than an angle between the one abutting portion and the two free end portions with the feed roller drive shaft as a center, when the other end of the free end portion can be abutted when rotating in the opposite direction. A holder driving member having the other abutting portion arranged at a position sandwiching
A contact position changing member that changes a position of at least one contact portion of the one and other contact portions and changes an angle between the contact portions;
A sheet conveying apparatus comprising:   The image forming apparatus according to claim 1, wherein the holder and the holder driving member are integrally formed. Before Kise' touch position changing member is a sheet conveying apparatus according to claim 1, wherein the Rukoto is removably disposed in the holder member. The contact position changing member is the feed roller fitted to the drive shaft sheet conveying apparatus according to claim 3, wherein the sandwich is installation on the said holder member between the holder member and the spring member. The contact position changing member is a sheet conveying apparatus according to claim 3 or 4, wherein the attached before the variable position in Kiho holder member. An image forming apparatus comprising: a sheet conveying device according to any one of 請 Motomeko 1 to 5.