JPH08169594A - Paper feeder - Google Patents

Abstract

PURPOSE: To provide a paper feeder by which a posture of a paper sheet can be excellently corrected by register rollers. CONSTITUTION: A paper feeder is provided with feed rollers 14 and 15 to feed a paper sheet by advancing it and register rollers 16 and 17 which are arranged on the downstream side in the paper sheet feeding direction to these feed rollers and correct a posture of the paper sheet in the paper sheet feeding direction when tip a of the paper sheet fed by the feed rollers comes into contact with them in a stopping condition, and is provided with a means which retreats the paper sheet by inversely rotating the register rollers and the feed rollers after the paper sheet comes into contact with the register rollers and then advances the paper sheet by normally rotating the register rollers and the feed rollers.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding device provided in a facsimile machine or the like.

[0002]

2. Description of the Related Art In a facsimile apparatus, when image recording is performed using recording paper made of cut paper, a large number of recording papers are stacked and accommodated in a paper feed cassette, and then accommodated in the paper feed cassette. The recording paper is fed out, the fed recording paper is fed toward the image recording unit, and the image recording unit records an image based on the received image signal on the recording paper.

A paper feeding device is provided between the paper feeding / feeding cassette and the image recording unit to feed the recording paper fed from the paper feeding cassette to the image recording unit. This paper feeding device is configured so that a feeding roller that moves the sheet forward and feeds it, and a tip of the sheet fed by the feeding roller that is provided on the downstream side of the feeding roller in the sheet feeding direction are in contact with each other. And a registration roller that is in contact with the sheet and corrects the orientation of the sheet with respect to the sheet feeding direction. The registration roller is configured by combining a pair of rollers, and one roller is pressed by the elastic force of the other roller.

That is, this paper feeding device rotates the feeding roller and the registration roller in the forward rotation direction when feeding the recording paper, and the feeding roller moves the recording paper forward to feed the recording paper.
The rotation of the registration roller is stopped immediately before the leading edge of the fed recording paper reaches the registration roller. The fed recording paper is pressed against the registration rollers.

If the recording paper moves in a posture in which the longitudinal direction of the recording paper is not parallel to the feeding direction of the recording paper and is in an oblique state, the recording paper is moved to the registration roller which has stopped rotating. Since it abuts and the forward movement is blocked, the posture is corrected by shifting from a state oblique to the feeding direction to a state parallel to the feeding direction. Therefore, the registration rollers rotate again in the normal direction to move the recording paper forward toward the image recording unit.

[0006]

However, this conventional sheet feeding device has the following problems. The fed recording paper may be pinched in a gap smaller than the recording paper thickness generated between the pair of registration rollers. Then, when the recording paper is moved forward by the rotation of the feeding roller, the leading edge of the recording paper is displaced in the direction perpendicular to the axis of the registration roller, and the longitudinal direction of the recording paper is fed. Hard to be parallel to the feeding direction.

Further, in order to prevent the recording paper from entering between the pair of registration rollers, when the force applied to one roller to press and contact the other roller is increased, the registration rollers are moved. There is a problem that the load at the time of rotation increases.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a sheet feeding device capable of satisfactorily correcting the posture of a sheet at a registration roller.

[0009]

SUMMARY OF THE INVENTION A paper feeding device of the present invention is provided with a feeding roller for advancing and feeding a sheet, and a feeding roller provided downstream of the feeding roller in the sheet feeding direction and in a stopped state. A registration roller that corrects the orientation of the paper in the paper feeding direction by abutting the leading edge of the paper fed by the feeding roller, and the registration roller and the feeding roller after the paper abuts the registration roller. Is reversely rotated to move the paper backward, and then the registration roller and the feeding roller are normally rotated to move the paper forward.

[0010]

According to the above structure, after the sheet fed by the feeding roller comes into contact with the registration roller, the registration roller and the feeding roller are reversely rotated to move the sheet backward. The sheet sandwiched between the sheets is discharged from the pair of registration rollers. As a result, the front end of the recording paper is displaced along the longitudinal direction of the registration roller, and the posture of the recording paper is corrected so that the longitudinal direction thereof follows the recording paper feeding direction. After that, the registration roller and the feeding roller are rotated in the forward direction to move the sheet forward, so that the longitudinal direction of the recording sheet can be fed along the recording sheet feeding direction.

Therefore, in order to prevent the sheet from entering between the registration rollers, the roller can be satisfactorily corrected in the registration roller, and one roller is pressed into contact with the other roller so that one roller is pressed against the other roller. It is possible to increase the applied force and thereby avoid a situation in which the load when rotating the registration roller increases.

Further, according to the above configuration, since the feeding roller is rotated in the reverse direction when the registration roller is rotated in the reverse direction, the recording sheet moved backward by the reverse rotation of the registration roller stops at the feeding roller and the recording is performed. It is possible to avoid the occurrence of an accident in which the paper is bent between the registration roller and the feeding roller, which hinders the forward movement.

Further, in the above structure, since the feeding roller is rotated in the reverse direction when the registration roller is rotated in the reverse direction, one electric motor is used for both the registration roller and the feeding roller, and this electric motor is used in the reverse rotation. By rotating both rollers in reverse, both rollers can be easily rotated by a simple rotation drive device. On the other hand, if the feed roller is rotated in the forward direction when the registration roller is rotated in the reverse direction, it is necessary to rotate the registration roller and the feed roller separately by independent electric motors. There is a problem in that the structure becomes large-scale and the operations of the registration roller and the feeding roller are likely to be out of synchronization with each other.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. An embodiment in which the present invention is applied to an apparatus for feeding a recording sheet stored in a sheet feeding cassette to an image recording section in a facsimile apparatus will be described with reference to FIG. In FIG. 1, reference numeral 1 denotes a recording paper feed cassette, in which a large number of recording papers P are stacked and accommodated. An image recording unit 2 is provided above the paper feed cassette and records an image on the recording paper P by an electrophotographic method. Reference numeral 3 denotes a photoconductor drum provided in the image recording unit 2, and 4 denotes a transfer roller provided in the image recording unit 2, and the rotating photoconductor drum 3
The recording paper P is fed between the transfer roller 4 and the transfer roller 4 to record an image.

The sheet feeding device of this embodiment is provided between the sheet feeding cassette 1 and the image recording section 2, and feeds the recording sheet P of the sheet feeding cassette 1 to the image recording section 2 through a U-shaped feeding path. It is something to send. In the figure, 11 is a pickup roller, which is supported by the arm 12a and is in contact with the uppermost layer of the recording paper P accommodated in the paper feed cassette 1. Reference numeral 12 is a feed roller provided on the downstream side of the pickup roller in the recording paper feeding direction, and reference numeral 13 is a separation pad provided so as to face the feed roller 12. Reference numerals 14 and 15 denote a pair of intermediate feeding rollers which are provided on the downstream side in the recording paper feeding direction with respect to the feed roller 12 and are in contact with each other. The pickup roller, the feed roller and the intermediate feeding roller constitute a feeding roller.

Reference numerals 16 and 17 denote registration rollers, which are provided downstream of the intermediate feeding rollers 14 and 15 in the recording paper feeding direction. The registration rollers 16 and 17 will be described with reference to FIGS. Reference numeral 18 is a bearing that supports the shaft 16a on which the registration roller 16 is attached, 19 is a bearing that supports the shaft 17a on which the registration roller 17 is attached, 20 is a support member that supports the bearings 18 and 19, and 21 is an elastic force on the bearing 19. An elastic member that is applied to bring the registration roller 17 into contact with the registration roller 16 and is supported by a support member 20 with screws 22.

Next, the rotary drive unit will be described with reference to FIG. Reference numeral 31 is an electric motor, 32 is a gear rotated by the electric motor 32, 34 is a gear transmitted from the gear 32 through the gear 33, 35 and 37 are gears meshing with the gear 34, 39 is the gear 23 and a registration roller described later. It is a clutch that connects and disconnects with the gear 40 for. The clutch 39 includes a portion connected to the gear 23 and a portion connected to the gear 40, and both of these portions are connected or disconnected by electromagnetic action, for example. The rotation drive unit 41 is configured with these components. That is, the rotation of the electric motor 31 is transmitted through the gears 32 and 33 to the gear 3
4 to the gears 35 and 37 and the clutch 39.

Reference numeral 36 is a gear attached to the shaft to which the feed roller 12 is attached and receiving rotation from the gear 35. The feed roller 12 is rotated by a gear 36.
Reference numeral 38 denotes a gear that is attached to the shaft to which the intermediate feeding roller 13 is attached and meshes with the gear 37. Intermediate feeding roller 1
3 is rotated by a gear 38. Reference numeral 40 denotes a gear which is attached to the shaft to which the registration roller 16 is attached and which meshes with the clutch 39. The registration roller 16 is rotated by the gear 40.

In the transmission gears provided from the electric motor 31 to the feed roller 12, the intermediate feeding roller 14 and the registration roller 16, the feed roller 12, the intermediate feeding roller 14 and the registration roller 16 are electric motors. They are combined so as to rotate in the same direction as the rotation direction of 31.

The pickup roller 11 is rotated by the rotation of the gear 36 of the feed roller 12, and the intermediate feeding roller 15 is rotated by the rotation of the gear 37 of the feeding roller 14. The registration roller 17 is configured as the gear 4 of the registration roller 16.
It is rotated by a gear 41 which receives rotation from zero.

Next, the control unit will be described with reference to FIG.

Reference numeral 51 is a control circuit, 52 is a timer, 53 is a sensor for detecting that the leading edge of the recording paper P has passed the intermediate feeding rollers 14, 15, and 54 is an electric motor drive circuit for driving the electric motor 31. The control circuit 51 rotates the electric motor 31 in the forward direction to take out the recording paper P from the paper feed cassette 1, receives a signal from the sensor 53, and contacts the registration rollers 16 and 17 with the leading end of the recording paper P, and then the registration rollers. 16,
17 and the feeding rollers 14 and 15 are rotated in the reverse direction to form the recording paper P.
The electric motor 31 is reversely rotated in order to move the roller backward, and then the registration rollers 16 and 17 and the feeding rollers 14 and 15 are moved.
To rotate the recording paper P forward to move the recording paper P forward.
It is to rotate 2 forward. The control circuit 51 connects and disconnects the clutch 39. The timer 52 measures time each time the control circuit 51 issues a command to drive the electric motor 32, and gives a time instruction to the control circuit 51.

The operation of the sheet feeding device thus configured will be described with reference to the flowchart shown in FIG. First, when the control circuit 51 commands the electric motor drive circuit 54 to drive in the normal rotation, the electric motor 31 is normally rotated by the electric motor drive circuit 54 (in the direction indicated by the solid line arrow in the figure). The rotation of the electric motor 31 is transmitted through the gears described above, and the feed roller 1
2. The intermediate feeding roller 13 and the registration roller 16 are rotated forward (in the direction of the arrow in the figure). The clutch 39 connects the gear 34 and the gear 40. Further, the pickup roller 12 is also normally rotated. The intermediate feeding roller 14 is also rotated together with the intermediate feeding roller 13. The registration roller 17 is also rotated together with the registration roller 18.

As a result, the recording paper P stored in the paper feed cassette 1 is fed to the pickup roller 12, separated one by one by the feed roller 12 and the separation pad 13, and moved forward (S1). Next, the recording paper P is moved forward through the intermediate feeding rollers 14 and 15 and fed to the registration rollers 16 and 17. When the leading edge of the recording paper P passes through the intermediate feeding rollers 14 and 15, the sensor 53 detects it and outputs it to the control circuit 51 (S2).

Then, the control circuit 51 detects the recording paper P by the sensor 53, and after a certain time has passed, that is, the recording paper P.
Immediately before the front end of the clutch is sandwiched between the registration rollers 16 and 17 (SP3), a command to disengage the clutch 39 is output. By the disengagement operation of the clutch 39, the gear 34 and the gear 40 are disengaged, and the electric motor 32 causes the registration roller 1
The rotation transmission to 6 is blocked, and the registration rollers 16 and 17
Stops rotating (SP4). Then, the registration roller 1 in which the front end of the recording paper P that has been moved forward is stopped
Abut on 6,17. In this case, the leading edge of the recording paper P may enter the gap between the registration rollers 16 and 17.

Then, the control circuit 51, after a lapse of a certain time from the stop of the registration rollers (S5), the clutch 39.
Is connected to connect the gear 34 and the gear 40, and a reverse rotation command is output to the electric motor drive circuit 54.
Is rotated in the reverse direction (in the direction of the broken line arrow in the figure). Electric motor 31
Is transmitted through the gears described above, and the feed roller 12, the intermediate feeding roller 14, and the registration roller 1 are rotated.
6 is reversely rotated (in the direction of the broken line arrow in the drawing). The intermediate feeding roller 15 is also rotated reversely together with the intermediate feeding roller 14. The registration roller 17 is also rotated in reverse with the registration roller 16 (S6). Thereby, the registration rollers 16 and 17
The leading end of the recording paper P, which has entered the gap between the registration rollers 16 and 17, is moved backward by the reverse rotation of the registration rollers 16 and 17, and is discharged from the gap between the registration rollers 16 and 17.
The leading edge of the recording paper P is pressed against the registration rollers 16 and 17 along the longitudinal direction thereof. Further, the entire recording paper P is also moved backward by the intermediate feeding rollers 14 and 15 which rotate in reverse.

Therefore, the posture of the recording paper P is corrected so that the longitudinal direction thereof is along the recording paper feeding direction. Further, in order to prevent the sheet from entering between the registration rollers 16 and 17, the force applied to one roller in order to press one roller into contact with the other roller is increased. It is possible to avoid a situation in which the load when rotating 17 is increased.

The recording paper P moved backward by the reverse rotation of the registration rollers 16 and 17 is fed to the feeding rollers 14 and
The recording sheet P stops at 15 and the registration roller 1
It is possible to avoid the occurrence of an accident in which the sheets 6 and 17 and the intermediate feeding rollers 14 and 15 are bent and interfere with the subsequent forward movement. If the feed roller is rotated in the forward direction when the registration roller is rotated in the reverse direction, the recording sheet moved backward by the reverse rotation of the registration roller stops at the feeding roller and the recording sheet is fed to the registration roller. An accident occurs in which it bends between itself and the feed roller, which hinders the forward movement later.

The control circuit 51 controls the registration roller 1
6 and 17 start reversing and after a certain time has passed (S
7), a command to rotate the electric motor 31 forward again is output, and the electric motor drive circuit 54 rotates the electric motor 31 forward. Thereby, the intermediate feeding rollers 14 and 15 and the registration roller 1
The recording paper P is moved forward by the forward rotation of the recording sheets 6 and 17, and the recording paper P is fed to the image recording unit 2 with its longitudinal direction being along the recording paper feeding direction. Will be recorded.

In the present invention, when the registration rollers 16 and 17 are reversely rotated, the feeding roller is reversely rotated. Therefore, one electric motor is used for both the registration rollers 16 and 17 and the feeding rollers 14 and 15, and this electric motor is used. By using the reverse rotation to reversely rotate both rollers, both rollers can be easily rotated by a simple rotation drive device. On the other hand, when the feed rollers 14 and 15 are rotated in the forward direction when the registration rollers 16 and 17 are rotated in the reverse direction, it is necessary to rotate the registration rollers 16 and 17 and the feed rollers 14 and 15 separately by independent electric motors. However, in this case, the structure of the rotation driving device becomes large, and the operations of the registration rollers 16 and 17 and the feeding rollers 14 and 15 are likely to be out of synchronization.

FIG. 5A is a time chart showing the operation of the registration rollers provided in the conventional paper feeding device. In this time chart, the clutch 39 indicates that the clutch is disengaged to stop the rotation of the registration rollers between the time points a and b, and the electric motor 31 is a
It is shown that the positive rotation is continuously made between the time point and the time point b.

FIG. 5B is a time chart showing the operation of the registration rollers provided in the paper feeding device of the present invention.
In this time chart, the clutch 39 indicates that the clutch is disengaged to stop the rotation of the registration rollers between the time points a and b, and the electric motor 31 reversely rotates between the time points b and c. It shows that it is doing.

The present invention is not limited to the above-mentioned embodiments, but can be modified in various ways. For example, in the above-described embodiment, the pickup roller, the feed roller and the intermediate feeding roller constitute the feeding roller, but the feeding roller is not limited to this, and at least a pair of feeding rollers may be provided. Good. The present invention is not limited to the feeding of recording sheets of a facsimile machine, but can be applied to the case of feeding a document.

[0034]

As described above, according to the sheet feeding device of the present invention, after the sheet comes into contact with the registration rollers, the registration roller and the feeding roller are rotated in the reverse direction to move the sheet backward, so that the sheet is moved between the registration rollers. Since the paper sandwiched between the pair of registration rollers is ejected from the pair of registration rollers, the leading edge of the recording paper is displaced along the longitudinal direction of the registration rollers so that the longitudinal direction of the recording paper is aligned with the recording paper feeding direction. The posture is corrected, and then the registration roller and the feeding roller are normally rotated to move the sheet forward, so that the registration roller can satisfactorily correct the posture of the sheet and can be fed.

Further, in order to prevent the sheet from entering between the registration rollers, the force applied to one roller in order to press one roller into contact with the other roller is increased, thereby rotating the registration roller. It is possible to avoid a situation in which the load when doing increases.

Further, since the feeding roller is rotated in the reverse direction when the gist roller is rotated in the reverse direction, the recording sheet moved backward by the reverse rotation of the registration roller stops at the feeding roller and the recording sheet is fed with the registration roller. It is possible to avoid the occurrence of an accident in which the vehicle bends between itself and the roller and interferes with the subsequent forward movement.

In the present invention, since the feeding roller is rotated in the reverse direction when the registration roller is rotated in the reverse direction, one electric motor is used for both the registration roller and the feeding roller, and the reverse rotation of the electric motor is used. By rotating both rollers in reverse, both rollers can be easily rotated by a simple rotation drive device.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of a paper feeding device of a facsimile machine to which an embodiment of the present invention is applied.

FIG. 2 is a side view showing a registration roller provided in the paper feeding device of the embodiment.

FIG. 3 is a perspective view showing a registration roller provided in the paper feeding device of the embodiment.

FIG. 4 is a flowchart showing the operation of the paper feeding device of the embodiment.

FIG. 5A is a time chart showing the operation of a registration roller provided in a conventional paper feeding device. (B) is a time chart showing the operation of the registration rollers provided in the paper feeding device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Paper feed cassette, 2 ... Image recording part, 11 ... Pickup roller, 12 ... Feed roller, 14 ... Feed roller, 15 ... Feed roller, 16 ... Registration roller, 17 ... Registration roller, 31 ... Electric motor, 39 ... clutch.

Claims (1)

[Claims] 1. A feeding roller for moving a sheet forward to feed the sheet, and a feeding roller provided downstream of the feeding roller in the sheet feeding direction with respect to the sheet fed by the feeding roller in a stopped state. A registration roller that abuts the leading end to correct the posture of the paper with respect to the paper feeding direction; and a rotation of the registration roller and the feeding roller in the reverse direction after the paper abuts the registration roller to move the paper backward; A sheet feeding device, comprising: a unit that rotates the registration roller and the feeding roller in a forward direction to move the sheet forward.