JP3415600B2 - Automatic sheet feeder - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic sheet feeding device used for image reading of a copying machine, a facsimile machine or the like, and for sheet conveyance. In the present specification, the “sheet” is an original such as a paper or a film on which an image to be read is recorded, a paper on which the read image is formed,
The concept includes both.

[0002]

2. Description of the Related Art In a copying machine or a facsimile machine, a document automatic reading device for automatically feeding a document or a sheet is used to read a document or form an image as follows. When the start operation is performed, the lift plate on which the seat is placed rises, and the seat
It comes into contact with the rotating feed roller. As a result, the sheet is pulled out and conveyed by the middle-feeding conveyance roller or the like in the conveyance path and reaches the image reading position or the image forming position.
After image reading or image formation, the sheet is continuously conveyed,
It is discharged by the discharge roller.

Rotational drive of the forward feed roller, the middle feed roller, etc. is performed by a drive motor that rotates in one direction.

[0004]

The object of the invention is to be Solved However, the vertical movement of the front Symbol lift plate, but the rotation of the drive motor is performed by changing the vertical movement by the cam, since the drive motor does not rotate only in one direction, the solenoid It is used to turn on / off the transmission of rotational force from the drive motor to the cam. Therefore, a complicated mechanism is required, which contributes to the high cost.

[0005] Therefore, an object of the present invention to realize a sheet automatic feeder capable of vertically moving the lift plate with easy single configuration.

[0006]

Sheet automatic feeder SUMMARY and effects of the invention of the Invention The present invention comprises a forward and reverse rotatable rotating means, shea
Lift that moves up and down the tip of the sheet placed on the table.
The lift plate is lifted in conjunction with the rotation of the plate and the rotating means in one direction.
Drives in the ascending direction and interlocks with the reverse rotation of the rotating means.
The cam that drives the lift plate in the downward direction and turn the cam.
When the moving position reaches the upper limit position of the lift plate
Rotation of the cam in one direction
Position reaches the lower limit position of the lift plate,
A rotation regulating means for idling further rotation in the opposite direction,
When transporting the leading edge of the sheet to the specified position on the transport path,
Rotate the tumbling means in the one direction to move the leading edge of the sheet
When transporting downstream from the specified position of
Control means for rotating the means in the opposite direction,
The rotation restricting means is fitted on the center axis of the cam that is biased
Is fixed to the cam and the other end is free to contact the coil spring and the cam.
First fixing pin that regulates cam rotation by touching
And the reverse of the cam by contacting the free end of the coil spring.
A second fixing pin for restricting rotation in the direction.
(Claim 1). With this configuration, the seat base
Lift the lift plate to the upper limit when removing
You can Rotation means rotation to feed the sheet
Even if it continues, the lift plate has an upper limit because there is a rotation restriction means.
It stays stopped in position. Is the tip of the sheet in place?
When transporting downstream from the
Can be lowered to. At this time, the rotation means
Even if it keeps rolling, the lift plate is
It does not rise and remains stopped at the lower limit position. Shi
Therefore, with a simple configuration that does not use a solenoid, lift
The vertical movement of the board can be controlled.

In the automatic sheet feeding device according to claim 1,
Placed in front of the image reading position or image forming position.
And the resist roller that was placed upstream of the resist roller.
Transport roller and one-way rotation of rotating means to the transport roller
The first directional rotation transmission that transmits and reverse rotation is idling
Rotate the member and the rotating means in the opposite direction to the resist roller.
Second directional rotation transmission that transmits and rotates in one direction idle
Further comprising a member, wherein the predetermined position of the transport path is
It may be the position of the tokoro (claim 2). According to the above configuration, when the front end of the sheet is conveyed to the position of the registration roller, the conveyance roller rotates, but the registration roller does not rotate. Therefore, the front end of the sheet is applied to the registration roller to correct the posture of the sheet. be able to. When the leading edge of the sheet is conveyed downstream from the registration rollers, the registration rollers are rotationally driven. At this time, since the transport roller can freely rotate, even if the sheet is sandwiched, it continues to rotate due to the frictional force with the sheet. Therefore, the sheet is conveyed smoothly.

As described above, the rotating means capable of rotating in the normal and reverse directions,
By adopting the first and second directional rotation transmitting members, it is possible to correct the posture of the sheet with a simple configuration by temporarily stopping the sheet before the image reading position or the image forming position . 3. The automatic sheet feeding device according to claim 2, wherein the transport rollers include a pre-feed transport roller that takes out the sheet from the sheet table and a middle-feed transport roller that transports the taken sheet. The transmission member is
Rotation means for transmitting the rotation in one direction to the middle feed conveyance roller, and provided with connection means for connecting the rotation of the middle feed conveyance roller and the rotation of the front feed conveyance roller, and the connection means and the front feed conveyance roller. In between, the rotation of the rotating means is transmitted in one direction,
You may provide the 3rd directional rotation transmission member which idles rotation of a reverse direction (Claim 3 ).

With this structure, when the front end of the sheet is conveyed downstream from the registration rollers and the front feed roller and the middle feed roller sandwich the sheet, both of them rotate in one direction. , It does not hinder the conveyance of the sheet. When the trailing edge of the sheet leaves the forward-feeding transport roller and the medium-feeding transport roller is in a state of sandwiching the sheet, the forward-feeding transport roller is the medium-feeding transport roller because of the third directional rotation transmission member. Even if is rotated, it does not rotate in conjunction with this. Therefore, the next sheet is not taken out. The next sheet is taken out when the rotating means starts rotating in the opposite direction.

[0010]

[0011]

[0012]

[0013]

[0014]

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the accompanying drawings, taking an automatic document feeder for conveying a document to a document reading section as an example. Figure 1
It is a cross-sectional view showing an internal configuration of the automatic document feeder.
The automatic document feeder includes a document tray 1 for accumulating documents 10.
1. An openable and closable upper cover 14 including a middle feed conveyance roller 12 and a front feed conveyance roller 13, a lift plate (not shown) that lifts the leading edge of the original 10 at the time of feeding, and a sensor for detecting the leading edge of the original 10. 46, the registration rollers 16 that align the originals 10 by being pressed against the leading edge of the originals 10, and then send the originals 10 to the reading position of the image detection unit 18, the contact glass plate 17 immediately above the image detection unit 18, the contact glass plate It has a reading guide 19 for preventing the original 10 guided to 17 from floating, a discharge roller 20 for discharging the read original 10, a sensor 47 for detecting the rear end of the original 10, and the like.

More specifically, the upper cover 14 includes
A front feed transport roller 13 and a middle feed transport roller 12 are provided and connected to each other by a belt 21. The separation roller 45 is adapted to abut on the middle feed transport roller 12.
With the upper cover 14 closed, the lower surface portion 22 of the upper cover 14 and the curved plate 23 of the main body of the automatic document feeder,
Form a paper feed path. At the tip of this paper feed path, the sensor 4
6. A resist roller 16 and a play roller 24 in contact therewith are arranged.

The detection signal of the sensor 46 is used to set the switching point of the rotation direction of the drive motor, which will be described later. The detection method of the sensor 46 may be any method as long as it is a known method such as a contact method or an optical method. At the tip of the resist roller 16, a paper feed path for guiding the original 10 to the contact glass plate 17 is formed by a paper guide 25 and the reading guide 19.

Further, the paper feed path for guiding the original 10 that has passed the reading position is provided with the reading guide 19 and the paper guide 26.
It is formed by and. At the tip of this paper feed path, there are provided a discharge roller 20 that interlocks with the registration roller 16 by a belt, and a sensor 47 that detects the rear end of the document 10. Next, the structure of the gear that drives the rollers will be described. 2 and 3 are configuration diagrams of gears. A drive motor such as a stepping motor that rotates in the forward and reverse directions is provided, and a gear (referred to as a drive gear) 30 is attached to the shaft thereof. A first gear 31 meshes with the drive gear 30, and a first 'gear 31a that rotates together with the first gear 31
The second gear 32 is meshed. The rotation of the second gear is transmitted to the fourth gear 34 via the third gear 33. Fourth
An eccentric circular cam 41 is attached to the gear 34, and the eccentric cam 41 is in contact with the lever 15 connected to the lift plate. The lever 15 and the lift plate are biased in a lifting direction by a spring (not shown).

Further, the second gear 32 has the upper cover 14
In the closed state, it meshes with the fifth gear 35 with a one-way clutch connected to the medium feed roller 12. Further, the 1 ′ ′ gear 31 a is interlocked with the seventh gear 37 with the one-way clutch 38 mounted on the registration roller 16 via the sixth gear 36. Reference numerals 43 and 44 are fixing pins that regulate the rotation angle range of the eccentric cam 41. Figure 4
FIG. 7 is a perspective view of the registration roller 16 and a seventh gear 37 with a one-way clutch 38 attached to the registration roller 16. The one-way clutch 38 is interposed between the registration roller shaft 16 a and the seventh gear 37. One way clutch 38
Any known structure can be adopted as the above (for example, "TOK one-way clutch" manufactured by Tok Bearing Co., Ltd.).

FIG. 5 is a perspective view showing the fourth gear 34 and the eccentric cam 41 attached thereto, and FIG. 6 is a side view. A columnar protrusion 34a is erected from the center of the fourth gear 34, and this is inserted into the inner cylinder portion of a cylinder 41a erected from the eccentric center of the eccentric cam 41. Furthermore, the cylinder 4
A coil spring 42 having a rectangular cross section is fitted in the outer periphery of 1a in a close contact state. One end 42a of the coil spring 42 is fixed to the eccentric cam 41, and the other end 42b is free.

When the fourth gear is rotated in the direction of arrow B or C, the fourth gear 34 and the eccentric cam 41 rotate together due to friction within a certain rotation angle due to the close contact force of the coil spring 42. However, when the fourth gear 34 is rotated in the arrow B direction by a certain angle or more, the eccentric cam 41 contacts the fixing pin 43. Coil spring 4 even if the rotating force works more
When 2 is loosened, the 4th gear becomes idle.

When the fourth gear is rotated in the direction of arrow C by a certain angle or more, the other end 42b of the coil spring 42 comes into contact with the fixed pin 44. Coil spring 4 even if the rotating force works more
2 is loosened and the fourth gear 34 comes to idle. 7 and 8 are perspective views of the middle feed transport roller 12 and the front feed transport roller 13 as viewed from below. Medium feed transport roller 12
A pulley 12b is integrally rotatably mounted on the shaft 12a, and a belt 21 is hung on the pulley 12b.
On the outer periphery of the pulley 12b, a medium feed roller 12 is mounted via a one-way clutch 12c. The rotatable direction of the one-way clutch 12c is the direction D in which the original 10 is conveyed, as shown in FIG.

A simple one-way clutch as shown in the figure is adopted between the pulley 13b of the forward feed roller 13 and the forward feed roller 13. This simple one-way clutch includes a half cylinder 13c formed on an end surface of a pulley 13b and a slope 1 that contacts the half cylinder 13c.
The intermediate rotating body 51 in which a cylinder having 3d is formed is used. The intermediate rotating body 51 can freely move in the rotation axis direction.

FIG. 9 is a perspective view of the intermediate rotating body 51.
It shows a state in which the end surface of the cylinder 13d is obliquely cut over a half circumference or more. Even if the shaft of the middle feed conveyance roller 12 rotates in the direction of arrow E shown in FIG. 7, the middle feed conveyance roller 12 does not rotate because of the one-way clutch 12c. Further, although the pulley 13b rotates in the arrow F direction through the belt 21, the semi-cylindrical 13c formed on the end surface of the pulley 13b does not push out the intermediate rotating body 51. Therefore, the teeth of the intermediate rotator 51 do not mesh with the teeth of the forward feed transport roller 13, and the forward feed transport roller 13 also does not rotate.

However, the shaft 12a of the intermediate feed roller 12
Is rotated in the direction of the arrow D shown in FIG. 8, the one-way clutch 12c is engaged and the middle feed roller 12 is rotated. Further, the pulley 13b rotates in the direction of arrow G through the belt 21, but the semi-cylindrical 13c formed on the end surface of the pulley 13b pushes out the intermediate rotating body 51 along the slope to move the teeth of the intermediate rotating body 51 Transport roller 13
Mesh with the teeth of. For this purpose, the forward feed roller 13
Rotates in the direction G of pulling out the original 10.

The overall operation will be described below. As shown in FIG. 2, when the drive motor rotates counterclockwise (CCW), the gear rotates in the direction of each arrow shown in FIG. With the rotation of the fourth gear 34, the eccentric cam 41 also rotates in the direction of pulling up the abutting lever 15. Therefore, the lever moves upward and the leading edge of the document 10 is lifted. In addition, the eccentric cam 41 is the fixing pin 43 described above.
When it hits, the eccentric cam 41 does not rotate any further, so
The eccentric cam 41 does not push down the lever 15 again.

On the other hand, the middle feed transport roller 12 rotates together with the fifth gear 35, and the front feed transport roller 13 also rotates accordingly. Therefore, the forward feed conveyance roller 13 pulls out the front end of the lifted document 10 and feeds it to the middle feed conveyance roller 12. The middle feed transport roller 12 sets the top original to 1
Separate and transport only one sheet. The conveyed document reaches the registration roller 16, but the registration roller 16 is not rotated due to the action of the one-way clutch 38 as described above, so the document is stopped by the registration roller 16.
At this time, the trailing edge of the document is pushed out by the middle feed transport roller 12, so that the orientation of the document is corrected by the registration roller 16.

The original reaching the registration roller 16 is detected by the sensor 46. In association with the detection of the sensor 46, the drive motor changes the rotation direction to the clockwise direction (CW). As shown in FIG. 3, each gear rotates. As the fourth gear 34 rotates, the eccentric cam 41 rotates in the direction in which the abutting lever 15 is pushed down. Therefore, the lever moves downward and the leading edge of the document 10 is lowered. When the coil spring 42 hits the fixing pin 44 described above, the eccentric cam 41 does not rotate any more, and therefore the eccentric cam 41 does not return the lever 15 again.

The intermediate feed roller 12 does not receive a rotational force due to the action of the one-way clutch 12c and is in a freely rotating state. The forward feed roller 13 is also in a freely rotating state because of the simple one-way clutch described above. At this time, since the middle feed conveyance roller 12 and the front feed conveyance roller 13 are not interlocked, as shown in FIG. 7, even if the middle feed conveyance roller 12 is dragged to the rear end of the document and rotated, the front feed conveyance roller 12 is rotated. The roller 13 is not rotated by this and the original is not pulled out.

On the other hand, the registration roller 16 starts rotating when the one-way clutch 38 is engaged,
The document stopped by is conveyed toward the reading position. Then, the document is read by the image detection unit 18 at the reading position, further conveyed, and discharged by the discharge roller 2
Reach 0. The document passes through the discharge roller 20, and the sensor 4
When 7 detects the trailing edge of the original, the drive motor is rotated counterclockwise (CCW) to start feeding the next original.

FIG. 10 is a block diagram showing the structure of the control unit for driving the drive motor. A central processing unit 61, a main memory 62, an external memory 63 such as a hard disk, an interface 64, etc. are connected via a bus, and the above-mentioned sensors 46, 47 and the motor driver 65 are connected to the interface 64. External memory 63
Stores a program for detecting the leading edge of the document using the sensor 46 and a program for detecting the trailing edge of the document using the sensor 47.

At the start of paper feeding, the central processing unit 61 sends a command signal to the motor driver 65 to rotate the drive motor in the counterclockwise direction (CCW) to start feeding the original. When the sensor 46 detects the leading edge of the document 10, FIG.
As described with reference to FIG. 3, by sending a command signal to the motor driver 65, the drive motor is reversed in the clockwise direction (CW). After that, when the trailing edge of the original is detected using the sensor 47, the drive motor is reversed in the counterclockwise direction (CCW) to start feeding the next original. As described above, a predetermined number of document images can be read.

Although the embodiments of the present invention have been described above, the embodiments of the present invention are not limited to the above-mentioned embodiments. For example, although the above-described embodiments are related to the automatic document feeder, the present invention can be similarly applied to an automatic paper feeder that automatically conveys a sheet to the image forming unit. Other various modifications can be made within the scope of the present invention.

[Brief description of drawings]

FIG. 1 is a sectional view showing an internal configuration of an automatic document feeder according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of gears for explaining transmission of rotation when the drive motor rotates counterclockwise.

FIG. 3 is a configuration diagram of gears for explaining rotation transmission when a drive motor rotates clockwise.

FIG. 4 is a perspective view of a registration roller 16 and a gear 37 with a one-way clutch 38 attached thereto.

5 is a perspective view showing a gear 34 and an eccentric cam 41 attached to the gear 34. FIG.

6 is a side view showing a gear 34 and an eccentric cam 41 attached to the gear 34. FIG.

FIG. 7 is a perspective view of the middle feed transport roller 12, the front feed transport roller 13, and the belt 21 connecting these when the drive motor rotates clockwise as seen from below.

FIG. 8 is a perspective view of the middle feed conveyance roller 12, the front feed conveyance roller 13, and a belt 21 connecting these when the drive motor rotates counterclockwise as seen from below.

9 is a perspective view of an intermediate rotating body 51. FIG.

FIG. 10 is a block diagram showing a configuration of a control unit that drives a drive motor.

[Explanation of symbols]

10 manuscripts 11 Document tray 12 Medium feed roller 12c one-way clutch 13 Forward feed roller 13b pulley 13c half cylinder 13d slope 14 Top cover 16 Resist roller 17 Contact glass plate 18 Image detector 19 Reading Guide 20 discharge rollers 21 belt 24 Play roller 30 drive gear 31st gear 31a 1'gear 32 2nd gear 33 3rd gear 34 4th gear 35 fifth gear with one-way clutch 36 6th gear 37th gear 38 one-way clutch 41 Eccentric cam 42 coil spring 43,44 fixed pin 45 separation roller 46 sensors 47 sensor 51 Intermediate rotating body 61 Central processing unit 65 motor driver

Front page continued (72) Inventor Hiroyuki Harada 1-2-2 Tamatsukuri, Chuo-ku, Osaka City, Osaka Prefecture Kyocera Mita Co., Ltd. (72) Hiroshi Wada 1-2-2 Tamatsukuri, Chuo-ku, Osaka City, Osaka Kyoto Within Ceramita Co., Ltd. (72) Inventor Takuya Eto 1-2-2 Tamatsukuri, Chuo-ku, Osaka-shi, Osaka Within Kyocera Mita Co., Ltd. (56) Reference JP-A-6-144613 (JP, A) JP-A-6- 16261 (JP, A) JP 61-27840 (JP, A) Actual development 59-64 834 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) B65H 1/24 B65H 9 /14

Claims (3)

(57) [Claims] 1. A rotating means capable of rotating in the normal and reverse directions, a lift plate for vertically moving a leading end portion of a sheet placed on a seat base, and a lift plate for raising the lift plate in association with one direction rotation of the rotating means. A cam that is driven to drive the lift plate in a downward direction in conjunction with the reverse rotation of the rotating means, and when the rotational position of the cam reaches a position corresponding to the upper limit position of the lift plate, a further one Rotation of the cam when the rotational position of the cam reaches the position corresponding to the lower limit position of the lift plate, the rotation regulating means for idling further rotation in the opposite direction, and the leading edge of the sheet to the predetermined position of the conveyance path. when conveyed to the position rotates the rotating means in the one direction, when conveyed to the downstream tip of the sheet from the predetermined position of the transport path is closed and a control means for rotating the rotating unit in the opposite direction , The rotation restricting means is Fitted into the central axis
A coil spring with one end fixed to the cam and the other end free,
Fixed to restrict rotation of the cam by abutting against the
By contacting the pin and the free end of the coil spring, the cam
And a second fixing pin for restricting rotation of the sheet in the opposite direction . 2. An arrangement is provided in front of the image reading position or the image forming position.
The resist roller placed, the transfer roller arranged upstream of the resist roller, and the rotation of the rotating means in one direction are transmitted to the transfer roller, and the reverse direction is applied.
Rotation of the first directional rotation transmitting member for idling and rotation of the rotating means in the opposite direction to the registration roller,
The rotation in the direction is caused by a second directional rotation transmission member that idles.
Further, the predetermined position of the transport path is a position of the registration roller.
The automatic sheet feeder according to claim 1. 3. The transport roller comprises a pre-feed transport roller for taking out a sheet from a sheet table and a middle feed transport roller for transporting the taken-out sheet, and the first directional rotation transmitting member is a rotating means. Is for transmitting the rotation in one direction to the middle feed conveyance roller, and a connecting means for connecting the rotation of the middle feed conveyance roller and the rotation of the front feed conveyance roller is provided, and between the connection means and the front feed conveyance roller. 3. The automatic sheet feeding device according to claim 2, further comprising a third directional rotation transmitting member that transmits the rotation in one direction of the rotating means and idles the rotation in the opposite direction.