JP2001225973A - Image formation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image formation device allowing the use of various kinds of sheets and capable of reducing the number of parts to miniaturize the device. SOLUTION: A second sheet feeding device B having a second sheet storage part 13 separate from a sheet storage part 10 of a cassette A and a feeding means 15 feeding a sheet S stored in the sheet storage part 13 into a picture image formation part 3 is provided in an end part on pull-out side of the cassette A which stores the sheet S to be fed into the picture image formation part 3 and is mounted in a device main body 41 so as to pull it out freely.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine or a printer, and more particularly to a sheet feeding apparatus for feeding a sheet to an image forming unit.

[0002]

2. Description of the Related Art Conventionally, in an image processing apparatus such as a copying machine or a printer, a sheet on which an image is to be formed is stored in a cassette which is detachably mounted on the apparatus main body, and the sheet is supplied to the apparatus provided in the apparatus main body. There is a configuration in which a sheet is taken out one by one by a feeding mechanism and fed to an image forming unit.

By the way, in the case of an apparatus which is required to use various kinds of sheets, separately from the above-mentioned cassette,
There is a case where a multi-feeding device including a sheet storage unit for storing and storing various types of sheets and a feeding unit for feeding the sheets stacked and stored in the sheet storage unit to the image forming unit is provided.

[0004]

However, in a conventional image forming apparatus having such a multi-feeding apparatus,
The multi-feeding device occupies a large space in the image forming apparatus including the feeding unit, and thus hinders downsizing of the image forming device. Also, the number of parts increases.

In order to reduce the size of the multi-feeding device,
For example, instead of providing the feeding means, a guide member may be provided in a part of the sheet feeding cassette, and sheets may be set one by one on the guide member and fed, that is, so-called manual sheet feeding may be performed. However, with this configuration, only one sheet can be set at a time, and there is a problem in use as an image forming apparatus in a networked environment.

Accordingly, the present invention has been made in view of such circumstances, and provides an image forming apparatus which can use various types of sheets, and which can be reduced in size and number of parts. It is intended for.

[0007]

According to the present invention, there is provided an image forming apparatus wherein a cassette for storing sheets is detachably mounted on an apparatus main body, and sheets are supplied from a cassette to an image forming section by a sheet feeding device to form an image. In the forming apparatus, a second sheet feeding device is provided at an end of the drawer side of the cassette for feeding sheets stored in a second sheet storing unit different from the sheet storing unit of the cassette to the image forming unit. It is characterized by having.

Further, the present invention is characterized in that the second sheet storage section is provided in the cassette.

Further, the present invention is characterized in that the second sheet storage section is provided in the apparatus main body.

Further, the present invention is characterized in that the front second sheet storage portion is provided in the apparatus main body so as to be movable between a position for storing sheets and a standby position for not storing sheets. .

Further, the present invention is characterized in that a drive transmitting means for driving the second sheet feeding apparatus by a driving means provided in the apparatus main body is provided.

In the invention, it is preferable that the second sheet feeding device includes a pickup roller for sending out the sheet, and a lift movable between a position where the sheet is pressed by the pickup roller and a position where the pressing is released. A plate, and rotation of the pickup roller and elevating operation of the elevating plate are performed by driving of the driving means.

Further, in the present invention, the drive transmission means has a gear train on the apparatus main body side and a gear train on the cassette side, and the gear trains are connected according to mounting of the cassette on the apparatus main body. It is characterized by being performed.

Further, the present invention is characterized in that the second sheet feeding device is provided integrally with the cassette.

Further, the present invention is characterized in that the second sheet feeding device is detachably provided on the cassette.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a diagram showing a schematic configuration of a printer which is an example of an image forming apparatus according to a first embodiment of the present invention.

In FIG. 1, reference numeral 40 denotes a printer, 41 denotes a printer main body (hereinafter referred to as a main body) which is an apparatus main body.
, A feeding means C, and a sheet feeding cassette A which is a cassette housed in the main body 41.

The image forming section 3 includes a photosensitive drum 4 which is an image carrier which rotates in the direction of an arrow, and an optical system 5 which forms a latent image by irradiating the drum surface with laser light in accordance with image information. Developing means 6 for developing the latent image into a visible image by toner development
And a transfer roller 7 for transferring the toner image onto the sheet S.

The paper feed cassette A is detachably mounted on the main body 41 and has a cassette tray 10 serving as a sheet storage section for storing and storing sheets S, and a separation claw 12.
And a transport roller 21. Further, at a drawer side end of the sheet cassette A, a multi-sheet feeding device B which is a second sheet feeding device provided with a multi-tray 13 which is a second sheet storage portion different from the cassette tray 10 is provided. Are provided integrally.

The feeding means C includes a cassette tray 10
Roller 11 for feeding out the sheets S stacked and stored in the feeding roller 11
And a drive unit (not shown) for driving the feed roller 11, and the sheet S stored in the cassette tray 10 is provided.
Are picked up by the feeding roller 11 and then separated by the separation claw 12 one by one.
, And fed to the image forming unit 3 via the registration roller 1.

On the other hand, the multi-feeding device B integrated with the cassette tray 10 is a pickup roller 15 serving as a feeding means for feeding out the sheets S stacked on the multi-tray 13 to be loaded while regulating the sheets S in the width direction. And a separation pad 16 for separating the sheets S sent by the pickup roller 15 one by one, and a transport roller 22. The sheets S stacked on the multi-tray 13 are conveyed by the conveyance rollers 22 while being separated one by one by the cooperation of the pickup roller 15 and the separation pad 16, and are fed to the image forming unit 3 via the registration rollers 1. It is supposed to be.

Next, the printer 40 thus configured
Will be described.

At the time of image formation, first, the surface of the photosensitive drum 4 rotating in the direction of the arrow is uniformly charged, and thereafter, the charged drum surface is irradiated with laser light according to image information by the optical system 5. The surface of the drum is exposed to form a latent image, and the latent image is developed into a visible image by developing the toner with developing means 6.

Next, by applying a bias voltage to the transfer roller 7, the visualized toner image is transferred from the cassette tray 10 by the feed roller 11, the transport roller 21, and the registration roller 1, or Multi-tray 13 to pick-up roller 15, transport roller 2
2 and the sheet S conveyed by the registration roller 1. Then, after transferring the toner image in this manner,
The sheet S is conveyed to the fixing unit 8, and after the toner image is heated and fixed on the sheet S by the fixing unit 8, the sheet S is discharged by a discharge roller 9 to a sheet discharge unit 42 provided on the upper surface of the main body 41.

The sheet cassette A is detachable as described above. When the sheets S are stored in the cassette tray 10, the sheet cassette A is pulled out from the main body in the direction of the arrow in FIG. After the sheets S are stored, the sheet feeding cassette A is pushed into the main body 41.

Incidentally, the pickup roller 15 and the transport roller 22 of the multi-feeding device B are driven by driving means provided on the main body 41. By providing the driving means for driving the multi-feeding device B in the main body 41 as described above, in other words, by not providing the driving means in the multi-feeding device B, the multi-feeding device B and the Paper cassette A equipped with
Can be reduced in size, and the printer itself can be further reduced in size.

On the other hand, FIG. 3 is a diagram showing a configuration of a drive section (drive transmission means) for driving the multi-feeding device B by a drive means provided in the apparatus main body. In the present embodiment, the driving unit is configured to also drive the transport roller 21 provided in the sheet cassette A.

In the figure, reference numeral 71 denotes a motor as a driving source, 70a and 70b denote transmission gears, 72 denotes a connection gear, and 73
Is a passive gear provided on the paper cassette A. When the paper cassette A is mounted on the main body 41, the passive gear 73 provided on the paper cassette A is connected to the coupling gear 72 on the main body side as shown in FIG. It is designed to engage. Thus, the rotation of the motor 71 is transmitted to the passive gear 73 via the transmission gears 70a and 70b and the connection gear 72.

Here, the driving gear 7 for driving the transport roller 21 provided in the sheet cassette A is provided on the passive gear 73.
When the motor 71 rotates when the sheet feeding cassette A is mounted, the conveying roller 21 is driven, and when the sheet S stored in the cassette tray 10 is sent out, the sheet S is sent out from the feeding roller 11. The conveyed sheet S can be conveyed toward the registration roller 1.

On the other hand, a driving gear 77 for driving the conveying roller 22 on the multi-feeding device side is meshed with the passive gear 73. When the motor 71 rotates, the conveying roller 22 is driven, and When sending out the sheet S stored in the tray 13, the sheet S sent from the pickup roller 15 can be conveyed toward the registration roller 1.

The rotation of the drive gear 77 is transmitted to a pickup drive gear 79 for driving the pickup roller 15 via an idler gear 78 for adjusting the rotation direction.

Here, the pickup driving gear 79
The toothless drive gear 79a fixed to the rotation shaft 80 of the pickup roller 15 and having a toothless portion 79d as shown in FIG. The gear 79a includes a toothless clutch gear 79b which is urged in the rotational direction with respect to the gear 79a and has a toothless portion 79d and a claw shape 79c for controlling the rotation of the pickup drive gear 79.

Further, in FIG.
The arm 82 is swingably attached to the rotating shaft 73a. On one side of the arm 82, a claw portion 82a that is engaged with a claw shape 79c of a pickup drive gear 79 (a toothless clutch gear 79b) is provided. Is formed.

Then, as shown in FIG.
By locking a in the claw shape 79c of the pickup drive gear 79, the rotation of the pickup drive gear 79 is restricted. In the figure, reference numeral 83 denotes a tension spring, which causes the arm 82 to move the claw portion 82 a to the pickup driving gear 7.
It is urged in the direction of locking with the nine claw shapes 79c.

Here, when the rotation is restricted by the arm 82, the toothless portion 79d of the pickup drive gear 79 is at a position facing the idler gear 78. Therefore, in this state, even if the idler gear 78 rotates together with the drive gear 77, the pickup drive gear 79 does not rotate.

On the other hand, as will be described later, the other end 82b of the arm 82 is pressed by a solenoid (not shown) or the like, and the arm 82 swings counterclockwise while resisting the spring force of the tension spring 83. The claw portion 82 a of 82 comes off the claw shape 79 c of the pickup drive gear 79.

Then, the claw portion 82 of the arm 82 is
When a is disengaged, the toothless clutch gear 79b is rotated by the force of the coil spring 81 which has been contracted, and meshes with the idler gear 78. Thus, the rotation of the idler gear 78 is transmitted to the toothless clutch gear 79b, and the toothless clutch gear 79b rotates.

Further, as described above, the toothless clutch gear 79
When b rotates, the coil spring 81 expands, whereby the rotation of the toothless clutch gear 79b is transmitted to the toothless drive gear 79a, and the pickup drive gear 79 rotates, whereby the rotation shaft on which the pickup roller 15 is fixed is rotated. 80
Will rotate.

Here, a cam 85 for controlling an elevating plate 84 for pressing the sheet S stacked on the multi-tray 13 against the pickup roller 15 is provided on the rotating shaft 80 of the pickup roller 15 as shown in FIG. Installed. Therefore, when the pickup roller 15 is rotated by the rotation of the rotation shaft 80, the elevation plate 84 is raised by the action of the cam 85 attached to the rotation shaft 80 and the interlocking plate 86 that transmits the movement of the cam 85 to the elevation plate 84. The sheet S stacked on the multi-tray 13 is pressed by the pickup roller 15.

By the way, when the pickup driving gear 79 rotates about one rotation, the toothless portion 79d of the toothless driving gear 79a comes to face the idler gear 78, whereby the rotation of the idler gear 78 rotates.
Will not be transmitted.

However, when the pickup roller 15 rotates, the pressing force of the elevating plate 84 and the interlocking plate 8
6 and the force of the return damper 87 are applied from below, so that even if the rotation of the idler gear 78 is no longer transmitted, the rotating shaft 80 presses the lifting plate 84 transmitted via the cam 85. , Interlocking plate 86 and return damper 8
7 to rotate.

In the present embodiment, the force acting on the other end 82b of the arm 82 before the rotation shaft 80 starts rotating by the force transmitted through the cam 85 as described above. As a result, the claw portion 82a of the arm 82 returns to the position where the claw shape 79c of the pickup drive gear 79 (the toothless clutch gear 79b) is locked by the bias of the tension spring 83. ing.

As a result, after the rotation of the idler gear 78 is no longer transmitted, the pickup roller 15 is rotated by the rotating shaft 80 rotated by the force transmitted through the cam 85.
Is rotated, the claw shape 79c of the pickup drive gear 79 is changed to the claw portion 82a of the arm 82 as shown in FIG.
And the rotation of the pickup driving gear 79 is regulated.

Next, the printer 40 constructed as described above is used.
The sheet feeding operation using the multi-feeding device B will be described.

After the paper cassette A is mounted on the main body 41,
When the motor 71 rotates, the rotation of the motor 71 is reduced by the transmission gears 70a and 70b and the connecting gear 72, and then the passive gear 73 on the sheet cassette side meshed with the connecting gear 72 rotating in the direction of the arrow shown in FIG. Is transmitted to As a result, the passive gear 73 and the drive gears 75 and 77 meshed with the passive gear 73 rotate, and the transport roller 21 that transports the sheet S of the cassette tray 10 and the transport roller 22 on the multi-feed device start rotating. .

Here, when the sheet S stored in the cassette tray 10 is fed, the arm 82 biased by the tension spring 83 as shown in FIG.
Is locked to the claw shape 79c of the pickup drive gear 79 (the toothless clutch gear 79b), so that the rotation of the pickup drive gear 79 is restricted. At this time, the toothless portion 79d of the pickup drive gear 79 is located at a position facing the idler gear 78 as shown in FIG.

Therefore, even if the driving gear 77 rotates and the idler gear 78 meshing with the driving gear 77 rotates, the idler gear 78 and the pickup driving gear 79 rotate.
Never mesh with. Thus, the drive is not transmitted to the pickup drive gear 79, and the pickup roller 15 does not rotate.

On the other hand, when feeding the sheet S from the multi-feeding device B, a solenoid (not shown) provided on the main body 41 operates according to a sheet feeding instruction from a main body control unit (not shown), as shown in FIG. The force in the direction of the arrow is applied to the end 82b of the arm 82, and the arm 82
It swings counterclockwise around 3a. As a result, the claw portion 82a of the arm 82 is
Then, the toothless clutch gear 79b is rotated by the force of the coil spring 81 and meshes with the idler gear 78.

Further, when the idler gear 78 and the missing tooth clutch gear 79b mesh with each other by the rotation of the missing tooth clutch gear 79b, the rotating shaft 80 to which the pickup roller 15 is fixed rotates, and the pickup roller 15 rotates. I do. When the rotating shaft 80 rotates in this manner, the elevating plate 84 moves by the action of the cam 85 and the interlocking plate 86 attached to the rotating shaft 80.

As a result, the sheets S stacked on the multi-tray 13 are pressed by the pickup roller 15, and when the pickup roller 15 rotates in this state, the sheet S is taken out and cooperated with the separation pad 16. The sheets are separated one by one by the action and sent to the transport roller 22.

After feeding the sheet S in this way,
The pickup drive gear 79 rotates by the rotation of the idler gear 78 and the force transmitted via the cam 85. Thereafter, the claw shape 79c is locked to the claw portion 82a of the arm 82, which has already returned to the position shown in FIG. 4 by the urging force of the tension spring 83, and the toothless portion 79d is rotated to a position facing the idler gear 78. By doing
The rotation of the pickup drive gear 79 is restricted. With such a series of operations, the intermittent rotation operation of the pickup roller 15 of the multi-feeding device B becomes possible.

By the way, as described above, the main body 4
By driving the pickup roller 15 and the transport roller 22 of the multi-feeding device B by the drive unit provided in the unit 1, all electrical connections such as solenoids used for rotation control are also performed in the main body. By eliminating the need for an electrical connection between the main body 41 and the paper cassette A in this manner, the structure of the paper cassette A can be simplified even when the multi-feeding device B is provided. And the number of parts can be reduced.

Further, by not providing the driving means in the multi-feeding device B, the multi-feeding device B and the sheet cassette A having the same can be downsized as described above. The size of the printer itself can be reduced.

On the other hand, in this embodiment, as shown in FIG. 7, the frame A1 of the sheet cassette A has a monocoque structure made of a single molding material so as to integrate the sheet cassette A and the multi-feeding device B. It has become. By integrating the sheet cassette A and the multi-feeding device B in this manner, the number of components can be reduced, and the cost can be reduced.

The configuration of the sheet feeding cassette A is not limited to the one shown in the figure, and for example, as shown in FIG.
1 and the frames A1 and B1 may be integrated by fastening means such as screws.

By dividing the frames A1 and B1 in this way, that is, by providing the multi-feeding device B in the sheet cassette A in a detachable manner,
The paper cassette A can be diverted to a cassette that requires only a sheet storage unit (cassette tray 10) such as an optional paper cassette, and the number of types of parts can be reduced.
The space for unnecessary functions can be reduced.

Further, as a configuration of the sheet feeding cassette A, as shown in FIG. 9, the multi-tray 13 of the multi-feeding device B is provided on the main body 41 so as to be rotatable (movable).
The multi-tray 13 may be used by rotating it downward only when is used.

With this configuration, when the multi-feeding device B is not used, the multi-tray 13 can be stored in the main body, and the space can be saved. By not providing the multi-tray 13 in the sheet cassette A, the sheet cassette A can be reduced in weight.

[0060]

As described above, by providing the sheet feeding device in the cassette which is detachably mounted on the apparatus main body as in the present invention, it is possible to use many types of sheets and to use the sheet feeding device. Even when a feeding device is provided, the size of the device can be reduced and the number of parts can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a schematic configuration of a printer as an example of an image forming apparatus according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a state in which a paper cassette of the printer is pulled out.

FIG. 3 is a diagram illustrating a configuration of a driving unit that drives a multi-feeding device provided in the paper feed cassette.

FIG. 4 is a diagram showing a state when the multi-feeding device of the driving unit is not used.

FIG. 5 is a side sectional view of the multi-feeding device.

FIG. 6 is a diagram showing a state when the multi-feeding device of the driving unit is used.

FIG. 7 is a diagram illustrating a configuration of the paper feed cassette.

FIG. 8 is a diagram illustrating another configuration of the paper feed cassette.

FIG. 9 is a diagram illustrating another configuration of the paper feed cassette.

[Explanation of symbols]

 3 Image Forming Unit 10 Cassette Tray 11 Feed Roller 13 Multi Tray 15 Pickup Roller 40 Printer 41 Printer Main Body 71 Motor 72 Drive Gear 73 Passive Gear 78 Idler Gear 79 Pickup Drive Gear A Paper Cassette B Multi Feeder C Feeder Throw S sheet

Claims (9)

[Claims] 1. An image forming apparatus in which a cassette for storing sheets is detachably mounted on an apparatus main body and sheets are supplied from a cassette to an image forming section by a sheet feeding device to form an image, wherein the cassette is pulled out. An image forming apparatus, wherein a second sheet feeding device for feeding a sheet stored in a second sheet storing section different from the sheet storing section of the cassette to the image forming section is provided at a side end portion. apparatus. 2. The image forming apparatus according to claim 1, wherein said second sheet storage portion is provided in said cassette. 3. The image forming apparatus according to claim 1, wherein said second sheet storage portion is provided in said apparatus main body. 4. The apparatus body according to claim 3, wherein the second sheet storage portion is movably provided between a position for storing sheets and a standby position for not storing sheets.
The image forming apparatus as described in the above. 5. The image forming apparatus according to claim 1, further comprising a drive transmitting unit for driving the second sheet feeding device by a driving unit provided in the apparatus main body. 6. The second sheet feeding device includes a pickup roller for feeding a sheet, and an elevating plate movable between a position where the sheet is pressed by the pickup roller and a position where the pressing is released. 6. The image forming apparatus according to claim 5, wherein the drive unit drives the pickup roller to rotate and move the lift plate up and down. 7. The drive transmission means has a gear train on the apparatus main body side and a gear train on the cassette side, and the gear train is connected in accordance with mounting of the cassette on the apparatus main body. The image forming apparatus according to claim 5, wherein: 8. The image forming apparatus according to claim 1, wherein the second sheet feeding device is provided integrally with the cassette. 9. The image forming apparatus according to claim 1, wherein the second sheet feeding device is detachably provided on the cassette.