JPH11147624A - Paper feeder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make surely delivering possible of paper in a normal condition, prevent generation or the like of a diagonal feed and a jam of this paper, by generating a pressure, at which a pickup roller is brought into pressure contact with an upper surface of the paper, equalized in a right/left side of the pickup roller. SOLUTION: A paper feeder is constituted by a separate roller 3, a pair of arms 4, 5 mounted able to swivel in a drive shaft 2 of the separate roller 3, a pickup roller 6 supported between the arms 4, 5, and a pulling spring 32 for energizing upward the pickup roller 6 in almost the center between the arms 4, 5. An upper end part of this pulling spring 32 is mounted in a shaft 62 in parallel to the pickup roller 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feeder for separating stacked paper sheets one by one from an upper layer and conveying the separated paper sheets to a feed roller on the lower side of the conveyance. The paper is inserted into the nip and the arm is rotated downward to press the pickup roller against the upper surface of the paper, the paper is inserted into the nip of the feed roller, and the arm is raised to push the pickup roller against the paper. The present invention relates to a structure of a sheet feeding device for releasing contact.

[0002]

2. Description of the Related Art Conventionally, a separate roller rotatably supported by a drive shaft, a retard roller pressed against the roller, an arm rotatably supported by the drive shaft, and a pickup supported by the arm There has been proposed a supply device including a roller, an urging means for urging the pickup roller upward, and a clutch member for transmitting a driving force from a drive shaft to a separate roller and a pickup roller. And an automatic document feeder mounted on a facsimile machine. In such a supply device, one end of the pickup roller is supported by the arm. However, in a structure in which the pickup roller is supported in a so-called cantilever manner, the axis of the pickup roller swings, and the pickup roller is rotated by the paper. Was not pressed uniformly. To cope with this problem, there has been proposed a supply device having a structure for supporting both ends of the pickup roller.

A sheet feeder having a structure for supporting both ends of a pickup roller has a structure as shown in FIGS. 7 and 8, for example. That is, a separate roller 3 is rotatably fitted to the drive shaft 2, and the outer peripheral portion of the separate roller 3 is made of rubber, soft synthetic resin, or the like.
The separate roller 3 is in pressure contact with a retard roller (not shown). A clutch 7 is formed at one end of the separate roller 3, and the driving force from the drive shaft 2 is transmitted to the separate roller 3 by the clutch 7. The clutch unit 7 is configured as a one-way clutch in which the driving force is transmitted only in the direction from the drive shaft 2 to the separate roller 3. An arm 5 is rotatably fitted to one end of the separate roller 3.

On the other hand, the other end of the separate roller 3
A first gear 12 driven by the drive shaft 2 via the clutch unit 7 is provided, and an arm 74 is rotatably fitted to the drive shaft 2 outside the first gear 12. The other end of the rotating shaft 15 is supported by the tip of the arm 74, and one end of the rotating shaft is supported by the tip of the arm 5. A pickup roller 6 whose outer peripheral portion is made of rubber, soft synthetic resin, or the like is rotatably fitted on the rotation shaft 15.

The drive shaft 2 and the rotary shaft 15 of the arm 74
A second gear 14 is rotatably supported between the first gear 12 and the first gear 12. The rotation of the second gear 14 is restricted by the torque limiter 21 formed between the arm 74 and the second gear 14. Further, a third gear 16 meshing with the second gear 14 is externally fitted to the rotating shaft 15, and the rotation of the first gear 12 is transmitted to the pickup roller 6 via the second gear 14 and the third gear 16. It is configured as follows. An arm spring 65 is interposed between an arm 74 that supports the pickup roller 6 and a shaft 62 provided horizontally above the arm 74, and the arm spring 65 urges the pickup roller 6 upward. ing.

In the paper feeder 71 configured as described above, when the drive shaft 2 is driven to rotate, the rotation is transmitted to the separate roller 3 and the first gear 12 via the clutch 7. As a result, the first gear 12 rotates,
Since the rotation of the second gear 14 meshed with the first gear 12 is restricted by the urging force of the torque limiter 21, the arm 74 resists the urging force of the arm spring 65 with the rotation of the first gear 12. To rotate downward. By the turning operation of the arm 74, the rotating shaft 15 supported by the arm 74 and the arm 5 connected to the arm 74 by the rotating shaft 15 rotate integrally. That is, the supply device is configured such that when the drive shaft 2 rotates in one direction, the pickup roller 6 rotates downward with the rotation. Then, the pickup roller 6 rotated downward
When is pressed against the paper surface, the rotation is stopped and the rotation is started, and the paper is fed to the nip portion between the separate roller 3 and the retard roller.

When the fed sheet is transported at a high speed by a further downstream feed roller, the separate roller is pulled in a direction of increasing the rotation speed by the transported sheet. When the rotation speed of the separate roller is increased to be in an overfeed state, the clutch portion 7 which is a one-way clutch is in a disconnected state, and the drive shaft 2
Is not transmitted to the separation roller 3 and the pickup roller 6. Further, the downward turning power to the arm 74 is cut off, and the pickup roller 6 is turned upward by the urging force of the arm spring 65.

[0008]

In the paper feeder 71 constructed as described above, the pickup roller 6 whose both ends are supported by the arms 74.5 is attached upward by an arm spring 65 attached to the arm 74. When the sheet feeding device 71 is operated, the up-down rotation operation is repeatedly performed. When the pickup roller 6 feeds out the sheet, the pickup roller 6 rotates downward against the urging force of the arm spring 65, and presses and rotates on the upper surface of the sheet to feed out the uppermost sheet. . In this case, both ends of the pickup roller 6 are supported by arms 74.5 so that the pickup roller 6 is pressed against the upper surface of the sheet with a uniform pressure.

However, since only the arm 74 of the pickup roller 6 is urged upward by the arm spring 65, the axis of the pickup roller 6 swings, and the pressure for pressing against the upper surface of the sheet differs between the left and right sides. There was a case. As a result, the pickup roller 6 is in a so-called one-sided contact state with respect to the sheet, so that the sheet is not properly fed, and a problem such as skew of the sheet or occurrence of jam occurs.

[0010]

The present invention uses the following means in order to solve the above-mentioned problems in the paper feeding apparatus. That is, according to the first aspect of the present invention, the paper feeding device includes a separate roller, a pair of arms attached to the drive shaft of the separate roller so as to be vertically swingable, and a pickup roller supported between the arms. And an urging means for urging the pickup roller upward substantially at the center between the arms.

Further, in the present invention, the upper end of the urging means is attached to a support member parallel to the pickup roller.

According to the third aspect of the present invention, the paper feeder is applied to a document separation paper feeder of an automatic document feeder.

[0013]

Embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a side sectional view showing an automatic document feeder equipped with the sheet feeding device of the present invention, FIG. 2 is a plan sectional view showing the sheet feeding device of the present invention, FIG. 3 is the same side view, and FIG. 5, FIG. 5 is a front view, FIG. 6 is a view showing a mounting position of a lower end portion of an urging means for urging the pickup roller upward, FIG. 7 is a side view showing a conventional paper feeder, and FIG.
Is a plan view of the same.

An automatic document feeder equipped with the paper feeder of the present invention will be described. FIG. 1 shows an example in which the sheet feeder of the present invention is mounted as a document separation sheet feeder in an automatic document feeder of an image processing apparatus. At the top of the image processing apparatus, a supply tray 47 which is continuous with the document placing plate 37 is provided in an inclined state, and a discharge tray 48 is provided below the supply tray 47.
Is arranged. The image processing apparatus includes a stationary document placing surface 51 below the discharge tray 48 and a reading unit 52 that the optical reading device scans below the stationary document placing surface 51.
Is provided. Further, the image processing apparatus includes a recording paper transport mechanism, and includes a recording unit 53 that performs recording on the recording paper based on information read by the original in the reading unit 52 or based on received information. , Below the reading unit 52.

Sheets of paper 54 stacked on the supply tray 47 are separated one by one from the upper layer side and fed out into an automatic document feeder 55. The fed sheet 54 is conveyed in the automatic document feeder 55 and is read by the reading unit 5.
After the content is read by the second reading device, the document is discharged to the discharge tray 48.

A paper feeder 1 is provided in the automatic document feeder 55. The paper feeder 1 is provided with a separate roller 3 rotatable by a drive shaft 2 and a retard roller which is pressed against the separate roller 3. A roller 33, an arm 4 pivotally supported by the drive shaft 2, and a pickup roller 6 rotatably supported at the distal end of the arm 4 via a rotation shaft 15 and the like. . A tension spring 32 is interposed between the pickup roller 6 and the casing 31 of the automatic document feeder 55, and the lower end of the tension spring 32 is attached to a bracket 61 attached to the rotating shaft 15. The upper end is locked by a shaft 62 fixed to the casing 31. The shaft 62 is a support member parallel to the pickup roller 6. And the pickup roller 6 is
When the paper feeding device 1 is in the stopped state, the paper feeding device 1 is configured to be rotated upward by the urging force of the tension spring 32 and to be located at the standby position 56. That is, the tension spring 32 is an urging means for urging the pickup roller 6 upward.

The automatic document feeder 55 includes a document placing plate 37
When the detection means (not shown) detects that the sheets 54 are stacked on the sheet, the drive motor (not shown) is started to drive the drive shaft 2, the retard roller 33, the feed roller 34, and the discharge roller 36. When the drive shaft 2 is driven to rotate, the separation roller 3 is driven by the rotation of the drive shaft 2.
Are rotated in the direction of the arrow in FIG. 1 and the pickup roller 6 is rotated downward against the urging force of the tension spring 32. Pickup roller 6
Is rotated to the operating position 57 and pressed against the uppermost surface of the sheet 54, the pickup roller 6 stops rotating and starts rotating in the direction of the arrow. Then, the rotation of the pickup roller 6 causes one of the uppermost layers of the paper 54 to be fed out between the separate roller 3 on the downstream side and the retard roller 33.

The fed paper 54 is sent out to the transport path 45 by the separate roller 3 and the retard roller 33, reaches the feed roller 34, and is further transported by the feed roller 34. Feed roller 34
Is rotated so that the separation roller 3 and the retard roller 33 convey the paper 54 at a speed higher than the speed at which the paper 54 is conveyed. Therefore, when the paper 54 is conveyed by the feed roller 34, the separation roller No. 3 is pulled by the paper 54 in the direction in which the number of rotations increases. When the number of rotations of the separate roller 3 increases, the state in which the separation roller 3 is rotated downward is released, and the pickup roller 6 is pulled by the tension spring 32.
Is configured to return to the standby position 56 by the urging force.

The paper 54 conveyed by the feed roller 34 passes over the original reading surface 35, and at this time, a reading unit 52
The contents are read by an optical reading device in the inside, and then discharged to a discharge tray 48 by a discharge roller 36. Also,
When the rear end of the paper 54 conveyed at a high speed by the feed roller 34 is conveyed downstream of the separation roller 3 and the retard roller 33, the separation roller 3 returns to the speed driven by the drive shaft 2 and the pickup roller 6
Is rotated downward again to feed out the paper 54 stacked on the supply tray 47 again, and thereafter the above operation is repeated.
When all the sheets 54 stacked on the supply tray 47 are fed out and discharged to the discharge tray 48, the automatic document feeder 55 stops its operation.

Next, the paper feeder 1 mounted on the automatic document feeder 55 configured as described above will be described. In FIG. 2, a separate roller 3 is rotatably fitted to the drive shaft 2 via an inner cylinder 11. The separate roller 3 has a separate roller body 19 made of rubber, a soft synthetic resin, or the like, which is press-fitted to a separate roller core 18 rotatably fitted to the inner cylinder 11. And the separate roller body 19 are integrally rotated. The separate roller 3 is in pressure contact with the retard roller 33.

One end of the inner cylinder 11 protrudes outside the one end of the separate roller core 18, and furthermore,
A drive-side cylinder 26 is disposed outside one end of the inner cylinder 11. The drive-side cylinder 26 is externally fitted to the drive shaft 2, and is fixed by a fixing pin 25 in the rotation direction of the drive shaft 2 so as to rotate integrally with the drive shaft 2.

A spring clutch 27 is fitted around one end of the separate roller core 18, one end of the inner cylinder 11, and the outer periphery of the drive-side cylinder 26, and one end of each of these separate roller cores 18. , One end of the inner cylinder 11, the drive-side cylinder 26, and the spring clutch 27 constitute the clutch unit 7. The clutch portion 7 is configured as a one-way clutch in which the direction of transmission of the driving force from the drive shaft 2 is only the direction from the drive-side cylinder 26 to the separate roller core 18 and the inner cylinder 11.

The driving force from the driving shaft 2 is
Is transmitted to the separate roller core 18 and the inner cylinder 11 through the spring clutch 27.
Is wound so that the roller core 1 is tight.
8, the inner cylinder 11, and the driving cylinder 26 are configured to rotate integrally. That is, the separate roller 3
Is driven by the drive shaft 2 via the clutch unit 7. Conversely, when the driving force from the drive shaft 2 is interrupted and is not transmitted to the separate roller core 18 and the inner cylindrical body 11, that is, as described above, the rotational speed when the separate roller 3 is driven by the drive shaft 2 When the motor is rotating at a higher speed, the spring clutch 27 is loosened, and the spring clutch 27 slides with respect to the separate roller core 18, the inner cylinder 11, and the drive-side cylinder 26, and the drive shaft 2. The driving force from the separate roller core 18
And is not transmitted to the inner cylinder 11.

At the other end of the separate roller core 18, a large-diameter portion 44 is formed inwardly of the portion where the spring clutch 27 is externally fitted. The arm 5 is rotatably fitted between the fitting portion and the large diameter portion 44.

On the other hand, at the other end of the separate roller 3, the other end of the inner cylindrical body 11 protrudes outward of the separate roller 3, and the other end of the inner cylindrical body 11
Is attached. The first gear 12 includes an inner cylinder 11
It is configured so as to be able to rotate integrally with it. Outside the first gear 12, the arm 4 is rotatably fitted to the drive shaft 2. The other end of the rotating shaft 15 is rotatably supported at the tip of the arm 4, and one end of the rotating shaft 15 is rotatably supported by the tip of the arm 5. A pickup roller 6 configured by press-fitting a roller body 20 formed of rubber, soft synthetic resin, or the like to a cylindrical body 17 is rotatably fitted on the rotating shaft 15.

The other end of the connecting shaft 13 is fixed between the drive shaft 2 and the rotating shaft 15 in the arm 4.
The second gear 14 is rotatably supported on the second gear 14.
Are meshed with the first gear 12. One end of the connecting shaft 13 on the side opposite to the side on which the second gear 14 is provided is connected to the arm 5. The arm 4 and the arm 5 rotate integrally by being connected by the connection shaft 13 and the rotation shaft 15,
Thus, the pickup roller 6 can rotate smoothly while maintaining a state parallel to the drive shaft 2.

The rotation of the second gear 14 is restricted by a torque limiter 21 formed between the arm 4 and the second gear 14. The torque limiter 21
Is a pressure receiving plate portion 41 formed on the second gear 14 and the arm 4
And a second spring 14, a biasing plate 23 biased by the coil spring 22 toward the pressure receiving plate portion 41, and a biasing plate 23 between the pressure receiving plate portion 41 and the biasing plate 23. And a slip adjusting plate 24 made of felt or the like. When the second gear 14 receives a rotational driving force from the drive shaft 2 via the first gear 12 in a state where the rotation is prevented by the torque limiter 21, the second gear 14 rotates so as to revolve around the first gear 12. Then, the arm 4 is rotated. Further, the second gear 14 rotates when it receives a torque larger than the torque limiter 21 from the first gear 12 with the stop of the rotation operation of the arm 4.

A third gear 16 is rotatably supported on the rotating shaft 15 via the clutch 10, and the third gear 16 meshes with the second gear 14. The clutch 10 provided between the third gear 16 and the rotary shaft 15 applies the driving force from the drive shaft 2 to the first gear 1.
When the rotation of the third gear 16 transmitted via the second gear 14 and the second gear 14 is transmitted to the rotation shaft 15 and the pickup roller 6 rotates at a speed higher than the rotation speed by the driving force from the drive shaft 2. Is configured as a one-way clutch that blocks transmission of rotation from the rotating shaft 15 that rotates integrally with the pickup roller 6 to the third gear 16. Thereby, the pickup roller 6 can rotate at a higher speed than the rotation speed of the third gear 16 when the paper 54 is conveyed at a high speed by the feed roller 34 and is in an overfeed state.

On the arm 5 side of the rotating shaft 15, a torque limiter 9 is formed. The torque limiter 9 includes a drive-side cylinder 28 fixed to the rotating shaft 15, and a coil spring 29 that is fitted to the drive-side cylinder 28 and the end of the cylinder 17 on the arm 5 side. . The coil spring 29 tightens the drive-side cylinder 28 and the cylinder 17 when the load on the pickup roller 6 is not so large, for example, when the pickup roller 6 is pressed against the paper 54 to be fed out. The rotation of 15 is transmitted to the pickup roller 6. Conversely, when the pickup roller 6 is stopped due to a large load, such as when the pickup roller 6 is pressed against the fixed surface, the coil spring 29 is loosened,
The coil spring 29 and the drive-side cylinder 28 slide, and the rotating shaft 15 is configured to idle with respect to the pickup roller 6.

As shown in FIGS. 3 to 5, a bracket 61 is attached to the rotating shaft 15. The bracket 61 is formed of, for example, a plate-like member that is long in the left and right directions, and has both ends thereof bent downward to form a substantially “U” shape. The bracket 61 is attached to the rotating shaft 15 by these two end portions. A locking portion 63 is formed on the upper surface of the horizontal portion of the bracket 61 located above the pickup roller 6, and the lower end of the tension spring 32 is locked to the locking portion 63. The upper end of the tension spring 32 is locked to the shaft 62. The shaft 62 is fixed to the casing 31 of the automatic document feeder 55 so as to be rotatable, and is provided laterally so that the drive shaft 2 and the rotation shaft 15 are parallel to the axis. The upper end of the tension spring 32
The shaft 62 is locked at a position vertically above the locking portion 63.

As shown in FIG. 6, the tension spring 3
The locking portion 63 of the bracket 61 to which the lower end portion of the bracket 2 is locked is a dimension 66 from the locking portion 63 to the arm 4.
And the dimension 66 from the locking portion 63 to the arm 5 are substantially equal. That is, the locking portion 63 is disposed at a substantially central portion between the arm 4 and the arm 5 in the axial direction of the rotation shaft 15.

As described above, the tension spring 32 is disposed substantially at the center between the arm 4 and the arm 5 to urge the pickup roller 6 upward, whereby the arm 4 side of the pickup roller 6 and the arm 4 The upward biasing force applied to the fifth side can be equalized. Further, since the upper end of the extension spring 32 is engaged with a portion of the shaft 62 located vertically above the engagement portion 63, the urging force of the extension spring 32 acts directly upward, and the arms 4 and 5 and the No tensile stress is applied to the pickup roller 6 in the left-right direction. Further, since the upper end of the extension spring 32 is slidably engaged in the axial direction of the shaft 62, the position of the engagement portion 63 at which the lower end of the extension spring 32 is engaged is determined by the axis of the shaft 62. Direction, that is, even in the left-right direction, the upper end of the tension spring 32 is always located directly above the locking portion 63 due to the urging force of the tension spring 32.

The lower end of the tension spring 32 is
The tension spring 32 may be attached to a portion of the connection shaft 13 which is located at a substantially central portion between the arm 4 and the arm 5, and the tension spring 32 is provided between the arm 4 side and the arm 5 side of the pickup roller 6. It is only necessary to mount at a position where the upward biasing force applied to the upper surface becomes equal. Further, the upper end of the extension spring 32 may be attached to a locking member or the like formed at a portion located immediately above the locking portion 63 of the casing 31 of the sheet feeding device 1. That is, the upper end of the tension spring 32 may be attached to a member located immediately above the locking portion 63.

The operation of feeding the paper 54 by the paper feeder 1 configured as described above will be described. As described above, when the drive shaft 2 is rotationally driven by the drive motor, the spring clutch 27 of the clutch unit 7 operates in the tightening direction, and the drive force of the drive shaft 2 is applied by the clutch unit 7 to the separate roller 3 and the first roller 3. The power is transmitted to the gear 12. The second gear 14 meshing with the first gear 12 does not rotate because the rotation is restricted by the torque limiter 21, and the first gear 1
2, the arm 4 supporting the second gear 14 rotates together with the arm 5 downward. With this rotation, the pickup arm 6 is moved to the standby position 5.
6 rotates downward against the urging force of the tension spring 32. When the pickup arm 6 turned downward reaches the operating position 57 and comes into pressure contact with the upper surface of the sheet 54, the turning operation of the pickup arm 6 stops.

When the rotation is stopped, a torque larger than the torque limited by the torque limiter 21 is transmitted from the first gear 12 to the second gear 14, and the second gear 14 rotates. Driving force is transmitted to the pickup roller 6 via the three gears 16, the clutch 10, and the torque limiter 9. Due to the rotation of the pickup roller 6,
One of the uppermost layers of the paper 54 to which the pickup roller 6 is pressed is placed on the downstream side of the separate roller 3 and the retard roller 3.
3 between.

As described above, when the fed sheet 54 is conveyed at a high speed by the further downstream feed roller 34, the separate roller 3 is pulled by the conveyed sheet 54 in the direction of increasing the rotation speed. . When the rotation speed of the separate roller 3 becomes high and the overfeed state occurs, the rotation of the separate roller core 18 of the clutch unit 7, which is a one-way clutch, becomes faster than the rotation of the drive side cylinder 26, and the spring clutch 27
Is loosened and becomes a cutoff state. In this state, the driving force of the drive shaft 2 is not transmitted to the separation roller 3 and the pickup roller 6, and the separation roller 3 and the pickup roller 6 are idle and rotate at the same speed as the paper 54 conveyed at high speed. I do. Further, the power for turning the arms 4 and 5 downward is cut off, and the arms 4 and 5 are rotated upward by the urging force of the tension spring 32 and return to the standby position 56.

Thereafter, when the rear end of the paper 54 conveyed at a high speed is conveyed downstream from the separation roller 3 and the retard roller 33, the separation roller 3 returns to the speed driven by the drive shaft 2, and the pickup roller 6 is rotated downward again to feed out the sheets 54 stacked on the supply tray 47 again, and thereafter, the above operation is repeated.

As described above, the pick-up roller 6 whose both ends are supported by the arms 4 and 5 repeatedly moves up and down when the paper feeder 1 is operated.
7 and the paper 54 stacked on the supply tray 47 are fed out. That is, when the pickup roller 6 feeds out the paper 54, the pickup roller 6 rotates downward against the urging force of the tension spring 32, rotates while pressing against the upper surface of the paper 54, and moves to the uppermost layer. Is fed out.

As described above, when the pickup roller 6 is rotated downward and pressed against the upper surface of the sheet 54, the pickup roller 6
However, since the tension spring 32 is disposed at a substantially central portion between the arm 4 and the arm 5, the tension spring 32 is arranged at the arm 4 side and the arm 5 side of the pickup roller 6, that is, the pickup roller The upward biasing force acting on the left and right sides of 6 becomes equal. As a result, the pressure of the pickup roller 6 pressing against the upper surface of the sheet becomes equal between the arm 4 side and the arm 5 side, and the sheet 54 can be reliably fed out in a normal state. Generation can be prevented.

[0040]

According to the present invention, the following effects can be obtained by employing the above-described configuration in the paper feeding apparatus. First, since the sheet feeding device is configured as in claim 1, when the pickup roller rotates downward and presses against the upper surface of the sheet, the upward urging force acting on the left side and right side of the pickup roller is reduced. Become equal. As a result, the pressure of the pickup roller pressing against the upper surface of the sheet becomes equal between the left side and the right side of the pickup roller, and the sheet can be reliably fed in a normal state, and skew of the sheet, occurrence of a jam, etc. Could be prevented.

Further, the lower end of the urging means may be attached to the sheet feeding device at a position substantially at the center of the two arms in the axial direction of the drive shaft. Is attached to a member disposed vertically above the mounting position of the lower end of the urging means, so that the urging force of the tension spring acts immediately above and a tensile stress is applied to the arm and the pickup roller in the left-right direction. There is no.
As a result, the pickup roller can be pressed against the upper surface of the paper only by a downward pressing force, and the paper is reliably fed out in a normal state, thereby preventing skew of the paper and occurrence of a jam. We were able to.

Further, as set forth in claim 3, the paper feeding device is
Since it was applied to the document separation and feeding device of the automatic document feeder,
When a document is automatically fed by the automatic document feeder, the document can be prevented from skewing or jamming, and the document can be fed reliably.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing an automatic document feeder equipped with a paper feeder of the present invention.

FIG. 2 is a plan sectional view showing a sheet feeding device of the present invention.

FIG. 3 is a side view of the same.

FIG. 4 is a plan view of the same.

FIG. 5 is a front view of the same.

FIG. 6 is a diagram showing a mounting position of a lower end portion of an urging means for urging the pickup roller upward.

FIG. 7 is a side view showing a conventional sheet feeding device.

FIG. 8 is a plan view of the same.

[Description of Signs] 1 Paper feeder 2 Drive shaft 3 Separate roller 4.5 Arm 6 Pickup roller 7 Clutch 15 Rotation shaft 27 Spring clutch 32 Tension spring (biasing means) 61 Bracket 62 Shaft (support member) 63 Lock Part 66 Dimensions from arm (4.5) to locking part

Claims (3)

[Claims] A separate roller, a pair of arms attached to a drive shaft of the separate roller so as to be vertically swingable, a pickup roller supported between the arms,
A sheet feeding device comprising: urging means for urging the pickup roller upward substantially at the center between the arms. 2. The sheet feeding device according to claim 1, wherein an upper end of the urging means is attached to a support member parallel to the pickup roller. 3. The sheet feeding device according to claim 1, wherein the sheet feeding device is applied to a document separation sheet feeding device of an automatic document feeder.