JPH1179465A - Paper feeder and image forming device having paper feeder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the exertion of influence on recording performance without interposing a clutch in a driving part in recording operation by moving at least one among first and second gears to receive the transmission of driving, and cutting off the transmission of driving to a carrying roller. SOLUTION: Rotation is transmitted to a carrying gear 13 (a first gear) integrally constituted with a carrying roller 6 through a connecting gear (a second gear) from a motor gear 11. The rotation is transmitted to a paper feeding gear through a planetary gear rotatably supported by an intermediate gear and a pendulum arm from the connecting gear. Here, when a carriage 5b moves to a paper feeding position 5B, a contact projection 5d of the carriage 5b contacts with a large gear part 12a of the connecting gear, and moves the connecting gear in the arrow B direction against energizing force of a spring 19, and meshing of a small gear part 12b and the carrying gear 13 separates, and the rotation is not transmitted. When the carriage 5b returns to a standby position, the connecting gear meshes with the carrying gear 13 by energizing force of the spring 19, and the transmission of the rotation is restored.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image input / output device such as a copying machine, a laser beam printer, an ink jet printer, a facsimile, a scanner, and the like, and a sheet feeding device in other sheet material using devices.

[0002] Sheet materials include, for example, transfer materials, recording paper, printing paper, OHP paper, manuscripts, envelopes, postcards, cards, films and the like. The material is not limited to paper, but may be plastic, metal, cloth, or the like.

[0003]

2. Description of the Related Art FIG. 9 shows a conventional paper feeder.

[0006] Reference numeral 61 denotes recording paper stacked in a cassette 62, which is fed by a paper feeding roller 63 and fed to a recording unit 64 including a recording head 64 a and the like.
Reference numeral 65 denotes a transport roller which transports the recording paper 61 in the recording unit 64 by nipping the resist rollers 66 disposed opposite to each other.

Reference numeral 67 denotes a motor for driving the paper feed roller 63 and the transport roller 65. The rotation of the motor is carried out from the motor gear 68 via a paper feed connection gear 69 and a paper feed gear 70.
The rotation is transmitted from the motor gear 68 to the conveyance gear 72 via the conveyance connection gear 71.

The paper feed gear 70 is provided with a one-way clutch 73 composed of, for example, a spring. The rotation of the paper feed gear 70 is transmitted to the paper feed roller 63 in only one direction, and is rotated in the other direction. Is not transmitted. Here, when the paper feed gear 70 rotates clockwise (in the direction of the dashed arrow in the figure), the one-way clutch 73 is locked and the paper feed roller 63 is rotated.
Rotates integrally with the sheet feeding gear 70 in the same direction, and when the sheet feeding gear 70 rotates counterclockwise, the one-way clutch 73 is released, the sheet feeding roller 63 is stopped, and the sheet feeding is stopped. The gear 70 idles.

[0007] A similar one-way clutch 74 is also provided on the transport gear 72, and the rotation of the transport gear 72 is transmitted to the transport roller 65 only in one direction, and the rotation in the other direction is not transmitted. Here, when the transport gear 72 rotates in the counterclockwise direction (the direction of the solid arrow in the drawing), the one-way clutch 74 locks, and the transport roller 65 rotates integrally with the transport gear 72 in the same direction. When the transport gear 72 rotates clockwise, the one-way clutch 74 becomes free, the transport roller 65 stops, and the transport gear 72 idles.

In the operation of the above configuration, first, when the motor gear 68 rotates clockwise, the paper feed roller 63 rotates and the transport roller 65 stops. Therefore, the recording paper 61 is fed out, conveyed downstream, and enters the nip portion between the conveyance roller 65 and the registration roller 66. At this time, since the conveyance roller 65 has stopped rotating, the skew of the leading end of the recording paper is corrected in the nip portion, and a so-called contact registration operation is performed.

Thereafter, when the motor gear 68 rotates counterclockwise, the paper feed roller 63 stops, and the transport roller 65 rotates, so that the recording paper 61 is further transported downstream. An image is formed.

[0010]

The above-mentioned prior art has a configuration in which the driving source of the roller is a single motor and the abutting registration operation is realized. However, there is a disadvantage that the presence of the clutch in the drive path of the transport roller 65 adversely affects the recording paper transport accuracy in the recording unit.

That is, for example, in the case of a so-called spring clutch in which a clutch is wound by a spring, the friction on the inner peripheral surface of the spring is not stabilized, and a slip occurs between the transport gear 72 and the transport roller 65, and the transport roller Unevenness occurs in the rotation of 65. In particular, in an ink jet recording apparatus that performs recording by transporting a sheet by a recording width every time an image of a predetermined width is recorded by carriage scanning, rotation unevenness of the transporting roller may cause unevenness in image joining or double writing. And the image quality was significantly impaired.

Further, if a dedicated motor is provided for each of the transport roller and the paper feed roller, no clutch is required, but the use of two expensive motors significantly increases the product cost.

The same applies to a scanner in which the recording section 64 is replaced with an image reading section, and the unevenness of rotation of the transport roller by the clutch significantly reduces the quality of the input image.

As described above, in the prior art, there is no paper feeder of the image input / output device which can perform the registration operation without affecting the recording and reading performance and can be realized at low cost.

The present invention has been made in view of the above problems.

It is an object of the present invention to (1) realize a sheet feeding device which can perform a resist operation without affecting the transport performance and is low in cost. (2) Even if the paper feeding device of (1) is applied to an image forming apparatus or a reading device, the above-mentioned paper feeding device is realized. (3) To realize a sheet feeding device of a reading device that can perform a registration operation without affecting reading performance and is inexpensive. (4) Even if the reading device of (3) is composed of an optical sensor and a roller, the above-mentioned paper feeding device is realized. (5) A paper feeder is realized without being limited to the configuration of the recording device of (1) and the reader of (3).

[0017]

SUMMARY OF THE INVENTION The present invention comprises a transport roller for transporting a sheet, a feed roller for feeding a sheet from a bundle of stacked sheets to the transport roller, the transport roller and the feed roller. A single drive source for driving the drive source, clutch means for selectively transmitting the drive of the drive source to the feed roller, and a first gear receiving drive transmission for rotating the transport roller; A second gear meshing with the first gear to transmit the drive of the drive source, and transmitting at least one of the first or second gear to transmit the drive to the transport roller. And a disconnecting means for disconnecting the sheet.

[0018]

Next, an embodiment of a sheet feeding apparatus to which the above-described means is applied will be described.

[First Embodiment] FIG. 1 is a schematic sectional view showing the structure of an ink jet printer to which a paper feeder according to the present invention is applied. 2 and 3 are plan views of the ink jet printer. 4 to 7 are explanatory diagrams of the driving unit.

First, the configuration will be described.

Reference numeral 1 denotes a recording sheet constituting a sheet bundle stacked on the middle plate 3 in the feeder 2, which is fed by a feeding roller or a sheet feeding roller 4 and has a recording head 5a.
The paper is fed to the recording unit 5 including Paper feed roller 4
Has a small diameter portion that does not contact the sheet bundle in a predetermined angle range θ. Reference numeral 6 denotes a transport roller which transports the recording paper 1 in the recording unit 5 by nipping the resist roller 7 disposed opposite thereto.

The recording unit 5 is a so-called ink jet printer, and performs scanning in which a carriage 5b carrying a head 5a moves along a carriage guide 5c. The head 5a, which moves integrally with the carriage 5, ejects ink according to image data to form an image.

Further, a guide wedge-shaped recording paper entry path is formed upstream of the transport roller 6 by the guide pairs 8a and 8b.

The recording paper 1 on which the image has been formed is discharged out of the apparatus by a discharge roller pair 9. Reference numeral 20 denotes an edge sensor for detecting the leading end of the recording paper 1.

Next, the drive transmitting portion of the paper feed roller 4 and the transport roller 6 will be described with reference to FIGS.

Reference numeral 10 denotes a motor as a drive source for driving the paper feed roller 4 and the transport roller 6. The rotation of the motor 10 is carried out from a motor gear 11 via a connecting gear 12 as a second gear. The rotation is transmitted to a transfer gear 13 as a first gear integrally formed with the transfer gear 6. A feed gear 17 composed of a toothless gear having a toothless toothless portion is provided from the coupling gear 12 via an intermediate gear 14 and planetary gears 16a and 16b rotatably supported by a pendulum arm 15. The rotation is transmitted to. The pendulum arm 15 is swingably supported coaxially with the rotation axis of the intermediate gear 14.

These intermediate gear 14, pendulum arm 15,
The planetary gears 16a and 16b and the feed gear 17 constitute clutch means.

Here, as shown in FIG. 2, the connecting gear 12 rotates about a shaft 18 and moves in a direction orthogonal to the rotating direction of the gear (direction along the shaft 18; hereinafter, axial direction). The compression spring 19 urges the compression spring 19 in one direction (the direction of arrow A in FIG. 2). Further, the motor gear 11 always meshes with the large tooth portion 12a of the connecting gear 12 to transmit rotation.

On the other hand, as shown in FIG. 2, when the carriage 5b is at the standby position 5A, the urging force of the spring 19 causes
The connecting gear 12 moves in the direction of arrow A, meshes with the small tooth portion 12b and the conveying gear 13, and can transmit the rotation of the motor gear 11 to the connecting gear 12.

When the carriage moves to the paper feed position 5B as shown in FIG. 3, the contact protrusion 5d of the carriage 5b
Comes into contact with the large gear portion 12a of the connecting gear 12, moves the connecting gear 12 in the direction of arrow B against the urging force of the spring 19, and the meshing between the small tooth portion 12b and the conveying gear 13 is released, and the rotation transmission is performed. Not done. Further, when the carriage 5b returns to the standby position 5A again, the connecting gear 12 is engaged with the transport gear 13 again by the urging force of the spring 19, and the rotation transmission is restored.

As described above, the carriage 5 and the spring 19 constitute a connecting / disconnecting means for connecting / disconnecting the drive transmission of the transport roller.

On the other hand, the connecting gear 12a and the intermediate gear 14, and the intermediate gear 14 and the planetary gears 16a and 16b,
The meshing rotation is constantly transmitted. Also, the planetary gear 16b
Engages with and separates from the paper feed gear 17 by the rotation of the pendulum arm 15.

As shown in FIG. 2, when the carriage 5b is in the standby position 5A and the motor gear 11 is rotated counterclockwise by the motor 10 as shown in FIG. 4, each gear is indicated by an arrow in FIG. To rotate the pendulum arm 1
4 rotates counterclockwise in FIG. 4 by the rotational force of the intermediate gear 14, and is at the position shown in FIG. 4, that is, the position where the engagement between the planetary gear 16b and the paper feed gear 17 is released. At this time, since the transport gear 13 rotates counterclockwise, the transport roller 6 rotates in a direction for transporting the recording paper in a predetermined direction.

The sheet feed gear 17 has a tooth portion 17a and a toothless portion 17b. In a standby state, the tooth portion of the intermediate gear 14 is located at a position facing the toothless portion 17b.
Is not transmitted to the feed gear 17.

On the other hand, as shown in FIG. 3, when the carriage 5b moves to the paper feed position 5B, the pendulum arm 15
It comes into contact with the cam surface formed on the carriage 5b and rotates clockwise to the position shown in FIG. 5, that is, the position where the planetary gear 16b and the paper feed gear 17 mesh. When the feed gear 17 is directly engaged with the intermediate gear 14 by being rotated by the planetary gear 16b, the feed gear 17 continues to rotate until the toothless portion 17b faces the intermediate gear 14. That is, the carriage 5b, the planetary gear 1
6b and the like constitute trigger means for rotating the sheet feeding gear 17 one rotation.

The operations such as the driving of the motor, the driving of the carriage, and the detection of the sensor are controlled and operated at a predetermined timing by a control unit (not shown).

Next, the operation of the above configuration will be described with reference to FIG.

First, when the sheet feeding operation is started at time t1 from the standby state in FIG. 4, the carriage 5 moves from the standby position in FIG. 2 to the sheet feeding position in FIG. Thereby,
The carriage 5 contacts the connecting gear 12 and the pendulum arm 15. Therefore, the connecting gear 12 moves in the direction of arrow B in FIG. 3 and releases the engagement with the transport gear 13. Also,
As shown in FIG. 5, the pendulum arm 15 rotates clockwise about the shaft 14a, and the planetary gear 16b meshes with the paper feed gear 17.

Next, when the motor 10 rotates counterclockwise at the time t2, first, the planetary gear 16b and the paper feed gear 17 mesh with each other, and the rotation is transmitted from the planetary gear 16b to the paper feed gear 17 so that the rotation is transmitted. The paper feed roller 4 rotates (FIG. 5), and the recording paper 1 is fed. The rotation of the paper feed gear 17 causes the toothless portion 17b to move as shown in FIG. 6, so that the intermediate gear 14 and the paper feed gear 17a mesh with each other, and the drive is transmitted. At this time, the transport roller 6 is stopped.

When the recording paper 1 is conveyed by a predetermined amount, at time t3
In, the leading end reaches the edge sensor 20, the transport amount is counted from the leading edge detection by the edge sensor 20, and a predetermined amount of resist transport is performed. Due to this resist conveyance, the leading end of the recording paper 1 is curved in a state where it is abutted on the nip between the stopped conveyance roller 6 and the registration roller 7, and skew is corrected, so-called abutting registration operation is performed.

Next, at time t4, the carriage 5b moves from the sheet feeding position in FIG. 3 to the standby position in FIG. As a result, the carriage 5b is separated from the connecting gear 12 and the pendulum arm 15, so that the connecting gear 12 moves in the direction of arrow A in FIG.

As shown in FIG. 6, the planetary gear 16 is released from meshing with the paper feed gear 17, but the intermediate gear 14 is meshed with the paper feed gear 17, and the rotation is also transmitted to the paper feed gear 17 (see FIG. 6). (FIG. 7). Therefore, the transport roller 6 rotates together with the paper feed roller 4, and sends the recording paper 1 to the recording unit 5.

Thereafter, the sheet feeding gear 17 is moved to the toothless portion 17.
Stop rotation when it rotates to the position b (Fig.
Four). Thus, the paper feeding operation is completed, and thereafter, image formation is performed by a predetermined recording method.

As described above, according to the present invention, despite the fact that the paper feed roller and the transport roller are driven by one common motor, the transport roller is stopped without interposing a rotational clutch. In addition, the paper feed roller can be rotated while performing stable butting registration. further,
It is possible to configure a gear transmission training in which a clutch is not interposed in the drive path for transmitting the rotation of the motor during the recording operation to the transport roller and the gear always engages, thereby improving the rotational accuracy of the transport roller and improving the quality of the recorded image. Furthermore, the rotation of the motor may be one direction, and complicated control such as forward / reverse control is not required.
Significant cost reduction can be realized by combining the configuration with no clutch and one motor.

[Second Embodiment] In the above-described embodiment,
Although the recording apparatus is configured as a sheet feeding apparatus in the inkjet recording apparatus, it is needless to say that the recording apparatus may be configured as a sheet feeding apparatus in a reading apparatus in which an optical sensor such as a so-called contact sensor is used.

[Third Embodiment] In the above-described embodiment,
Although the connecting gear is moved by moving the carriage, the connecting gear may be moved using a plunger, a motor, or the like.

The transfer gear may be moved while the position of the connecting gear is fixed.

[0048]

【The invention's effect】

(1) Since the clutch is not interposed in the drive unit during the recording operation, the recording performance is not affected, and a stable resist operation can be performed with the abutting resist, and the cost can be reduced without increasing the number of motors. Thus, it is possible to realize a sheet feeding device applicable to a recording device and the like. (2) Even if the recording device of (1) is a serial printer, the above-described paper feeding device can be realized. In particular, it is possible to eliminate image deterioration at the joint of recorded images. (3) Since no clutch is interposed in the drive unit during the recording operation, the reading performance is not affected, and a stable resist operation can be performed with the butting resist, and at low cost without increasing the number of motors. And a paper feeder for a reading device. (4) Even if the reading device of (3) is composed of an optical sensor and a roller, the above-mentioned paper feeding device is realized. (5) A paper feeder is realized without being limited to the configuration of the recording device of (1) and the reader of (3).

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing the structure of an ink jet printer to which a paper feeding device according to the present invention is applied.

FIG. 2 is a plan view of the inkjet printer.

FIG. 3 is a plan view of the ink jet printer.

FIG. 4 is an explanatory diagram of an operation of a driving unit of the inkjet printer.

FIG. 5 is an explanatory diagram of an operation of a driving unit of the inkjet printer.

FIG. 6 is an explanatory diagram of an operation of a driving unit of the inkjet printer.

FIG. 7 is an explanatory diagram of an operation of a driving unit of the inkjet printer.

FIG. 8 is a time chart illustrating an operation of the ink jet printer.

FIG. 9 is a schematic sectional view showing the structure of a conventional ink jet printer.

[Explanation of symbols]

 Reference Signs List 4 paper feed roller 5a recording head 5b carriage 6 transport roller 10 motor 12 connecting gear

Claims (9)

[Claims] A feed roller for feeding a sheet from a stack of stacked sheets to the feed roller; a single drive source for driving the feed roller and the feed roller; A clutch means for selectively transmitting the drive of the drive source to the feed roller; a first gear receiving drive transmission for rotating the transport roller; and a drive meshing with the first gear. A second gear for transmitting the drive of the source, and disconnecting / disconnecting means for cutting off the transmission of the drive to the transport roller by moving at least one of the first and second gears. A sheet feeding device characterized by the above-mentioned. 2. The feeding roller has a small-diameter portion that does not come into contact with the sheet bundle in a predetermined angle range, and the clutch means starts feeding the drive when the small-diameter portion contacts the sheet bundle. The sheet feeding device according to claim 1, wherein the sheet feeding device is stopped by being rotated until the sheet is opposed to the sheet feeding device. 3. The toothless gear having a toothless portion that rotates synchronously with the feed roller and has no toothless portion, and a drive gear that transmits the drive of the drive source to the toothless gear. 3. The trigger device according to claim 2, further comprising: a trigger unit configured to rotate the missing tooth gear so that the missing gear and the driving gear mesh with each other by rotating the missing tooth gear from a state where the missing tooth portion of the missing gear faces the driving gear. Paper feeder. 4. The trigger means includes a planetary gear that rotates under the drive of the drive gear, and selectively meshes with the toothless gear to rotate the toothless gear until it meshes with the drive gear. The paper feeding device according to claim 3, wherein 5. A recording head for recording on a sheet conveyed by the conveyance roller, and a carriage for movably supporting the recording head, the carriage being in contact with an arm for supporting the planetary gear. The image forming apparatus according to claim 4, further comprising a cam surface that moves the planetary gear to a position where the planetary gear contacts the toothless gear. 6. A driving means for driving the carriage,
The image forming apparatus according to claim 5, further comprising: a control unit that controls the driving unit so as to move the planetary gear to a position where the planetary gear contacts the toothless gear. 7. The image forming apparatus according to claim 1, further comprising a recording unit configured to perform recording on a sheet conveyed by the conveyance roller. 8. The recording means has a recording head and a carriage movably supporting the recording head, and the connecting / disconnecting means is provided on the carriage, and the first or second moving means is moved by the carriage. The image forming apparatus according to claim 7, further comprising a contact portion that contacts and pushes the gear. 9. A driving unit for driving the carriage,
The image forming apparatus according to claim 8, further comprising control means for controlling the driving means so as to move the first or second gear.