JP2966164B2 - Locking device for paper cassette - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001]

[0002]

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

[0003]

[0002]

[0004]

2. Description of the Related Art For example, in an electrophotographic copying machine, a latent image formed on a photosensitive drum is developed with toner,
The visible image is transferred to transfer paper (plain paper) conveyed to the transfer position in a timely manner, and the transferred image is fixed by a fixing device. Normally, several tens of the same size paper are set in a tray-shaped container called a cassette. A plurality of cassettes of this type having different accommodation paper sizes are prepared and can be simultaneously loaded into the copying machine main body.

[0005]

[0003] From the loaded cassette, only one sheet is fed by a sheet feed roller from the uppermost surface to a transfer section in response to one copy operation, and is conveyed to a registration roller for timing. You. Note that there are cassettes loaded from the side of the copier main body and cassettes loaded from the front.

[0006]

When a cassette is loaded from the front of the apparatus main body, there are many machines for pulling out the cassette during paper feeding. If the cassette is pulled out during paper feeding, the transfer paper remains in the paper feeding unit, causing a paper jam or a paper tear, making it very difficult to remove the paper. Also, since the transfer paper is pressed by the paper feed roller, a thrust force acts on the paper feed roller,
There is a risk of breaking the feed roller. Therefore, there is provided a lock mechanism for energizing the solenoid during paper feeding and locking the cassette so that the cassette cannot be pulled out.

[0007]

[0005]

[0008]

However, in the above-described lock mechanism, the solenoid always operates during paper feeding, so that the life of the solenoid is shortened and the period for performing the lock function is shortened.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a sheet cassette locking device that can lock a sheet cassette during sheet feeding with a simple configuration.

[0010]

[0006]

[0011]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a paper feed cassette capable of storing a large number of transfer sheets of the same size and being detachable from an image forming apparatus main body. Detecting means for detecting that an obstacle has entered or contacted the handle during operation, and a solenoid which is excited based on a detection signal of the detecting means;
A configuration in which the solenoid is used as a drive source to provide a locking member that regulates the movement of the sheet cassette, or the sheet is rotated in conjunction with the sheet fed from the sheet cassette passing through the transport guide. A configuration is provided in which a rotation member and a lock member that regulates the movement of the paper feed cassette in conjunction with the rotation of the lock member are provided.

[0012]

[0007]

[0013]

According to the above-mentioned means, a detection signal is generated when an obstacle enters or comes into contact with the handle during the copying operation, whereby the solenoid is excited, the locking member is rotated, and the paper feeding cassette is rotated. Lock movement against. As a result, it is possible to prevent the sheet cassette from being pulled out during the copying operation while extending the life of the solenoid.

According to the other means, when the paper fed from the paper feed cassette passes through the inside of the conveyance guide, one end of the rotating member protruding into the passage is pushed and moved by the leading end of the paper. The lock member, which moves in conjunction with this rotation, locks the paper cassette and regulates its movement.
Therefore, it is possible to prevent the paper feed cassette from being pulled out during the paper feed operation with a simple configuration.

[0015]

[0008]

[0016]

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

FIG. 1 is a block diagram showing one embodiment of a sheet cassette locking device according to the present invention.

[0018]

A solenoid switching signal output circuit 2 is connected to an optical sensor 1 for detecting that a hand or the like has been inserted into a handle portion of the sheet cassette. A solenoid drive circuit 3 is connected to the solenoid switching signal output circuit 2,
Further, a solenoid 4 serving as a load is connected to the solenoid drive circuit 3. At one end of the armature of the solenoid 4, one end of a filler 5 as an engaging member having a substantially L-shape and having a fulcrum 6 at the center is fixed. In order to rotate the filler 5 counterclockwise against the driving force of the solenoid 4 (the force for rotating the filler 5 clockwise), the armature of the solenoid 4 is opposite to the fulcrum 6 from the engaging position of the armature. The one end of the spring 7 is engaged on the filler 5 at the position of. The other end of the spring 7 is fixed to the main body rib 8. The bent end portion 5a of the filler 5 engages with a claw 9 provided to protrude from the end of the sheet cassette (in FIG. 1, the sheet cassette is completely pushed in) when the solenoid 4 is operated. I do.

[0019]

FIG. 2 is a plan view showing a schematic configuration of the sheet cassette. The paper feeding cassette 10 has a handle 11 on the front surface, and a claw 9 is provided on one side end of a rear portion.

[0020]

FIG. 3 is a perspective view showing the detailed structure of the handle of the paper feed cassette 10. As shown in FIG. A light emitting element 1a is attached to one side wall in the handle 11, and a light receiving element 1a is mounted on the other side wall in the handle 11 to receive light from the light emitting element 1a.
b is attached. The light sensor 1 is constituted by the light emitting element 1a and the light receiving element 1b.

[0021]

In the above configuration, when the hand 12 (or an obstacle) is inserted into the handle 11 after the copy switch is pressed, the light from the light emitting element 1a is interrupted on the way, and the output signal of the light receiving element 1b is output. Disappears. This disappearance of the output signal is detected by the solenoid switching signal output circuit 2, and based on this detection, the solenoid drive circuit 3 starts energizing the solenoid 4. As a result, the armature is drawn into the solenoid 4, and the filler 5 rotates from the dotted line position to the solid line position against the urging force of the spring 7.
Then, the leading end portion 5a of the filler 5 comes into contact with the claw 9, and the drawer of the paper feed cassette 10 is locked.

[0022]

When the hand 12 (or obstacle) is not inserted into the handle 11, the solenoid 4 is not excited, so that the filler 5 is urged by the spring 7 and is at the dotted line position. For this reason, the claw 9 does not come into contact with the distal end portion 5a, and the sheet cassette 10 is in a state where it can be freely removed. However, since no hand is inserted, a physical pulling force is applied to the sheet cassette 10. It does not move even during paper feeding.

[0023]

FIG. 4 is a sectional view showing a second embodiment of the present invention, and FIG. 5 is a sectional view taken along line AA 'of FIG. 4 showing details of a door portion. In this embodiment, the optical sensor 1
Although the illustration of the control system for driving the solenoid based on the output of FIG. 1 and the illustration of the lock mechanism are omitted, the same configuration is required.

[0024]

The handle 11 has a horizontally long opening in the front, and this opening is formed in a horizontal L-shaped cross section. Further, a groove 13 for sensor installation communicating with the internal space is formed above the entrance of the opening. This groove 13
A door 14 is provided to be openable and closable facing the inner wall of the installation surface, and its upper end is hinged and is always urged by a torsion spring 15 so as to be at a dotted line position. At the lower end of the door 14, a shielding plate 16 that can be inserted into the groove 13 is vertically attached to the door 14. Groove 13
The light-emitting element 1a and the light-receiving element 1b of the optical sensor 1 are attached to both sides of the inner wall facing the shield plate 16 of FIG.

[0025]

4 and 5, when no hand (or obstacle) is inserted into the handle 11,
Due to the urging force of the torsion spring 15, the door 14 is at the position indicated by the dotted line in FIG. Therefore, the output light of the light emitting element 1a reaches the light receiving element 1b without being interrupted. As described above, the solenoid 4 is not excited, and the tip 5a of the filler 5 is not locked to the claw 9, and the locking operation is not performed. Not done.

[0026]

On the other hand, an obstacle (for example, a hand)
Is inserted, and when the fingertip of the finger pulls the door 14 in the direction of arrow B to pull out the sheet cassette 10, the shielding plate 16 enters the groove 13 and blocks light from the light emitting element 1a.
As a result, the detection output of the light receiving element 1b disappears, the solenoid switching signal output circuit 2 and the solenoid drive circuit 3 operate, the solenoid 4 is excited, and the filler 5 rotates from the dotted line position to the solid line position. As a result, the tip 5a of the filler 5 is locked by the claw 9, and the drawer of the sheet cassette 10 is locked.

[0027]

Although FIGS. 4 and 5 show a combination of the optical sensor 1 and the shielding plate 16, it is also possible to use a mechanical on / off means such as a micro switch instead of the optical sensor 1. .

[0028]

FIG. 6 is a front sectional view showing a third embodiment of the present invention. In the present embodiment, the paper feed cassette is attached to and detached from the main body in the length direction in the above embodiment, but is attached and detached in the width direction.

[0029]

A slit 17 is provided on the back of the sheet cassette 10.
Is formed, and one end (18b) can be inserted into the slit 17 so that the filler 18 is supported by the fulcrum 19 in the sheet feeding table 20.
It is supported by. A large number of transfer papers 22 are stored in the paper supply cassette 10, and a paper supply roller 23 is in contact with the uppermost paper. Transport guide plates 24 and 25 are disposed at the position where the uppermost sheet is carried out, and relay rollers 26a and 26b for transporting the transfer sheet to the registration position are disposed at the ends thereof. The filler 18 is used for the spring 2
7 is urged in a counterclockwise direction. Therefore,
Filler 1 is provided at the center of the paper path by the conveyance guide plate.
The upper end portion 18a (rotating member) of the sheet 8 is always in the state of entering, and when the fed transfer sheet passes, the transfer sheet is turned to the chain line position against the spring 27. Further, the optical sensor 1 is disposed at the lower end of the filler 18, and the lower end 18b of the filler 18 is provided between the light emitting element 1a and the light receiving element 1b.
(Lock member) can pass through.

[0030]

As shown in the side view of FIG. 7, the paper feed cassette 10 is inserted into the main body from the direction of arrow C. Then, the paper feed roller 23 rotates in a state where the transfer paper is loaded to the innermost portion, and when the transfer paper on the uppermost surface is fed, the transport guide plates 24 and 2 are transferred.
In the process of passing the inside of the sheet 5, the leading end of the sheet contacts the leading end 18 a of the filler 18. Further, in the process of moving the sheet, the leading end of the sheet keeps pushing the leading end portion 18a, so that the filler 18 continues to rotate from the solid line position to the chain line position. At the stage when the filler 18 is rotated to the dashed line position, the lower end 18
b enters the slit 17 as shown in FIG. In this state, if the user attempts to pull out the sheet cassette 10 in the direction of arrow D, the lower end portion 18b of the filler 18 is inserted into the slit 17 and locked in the direction perpendicular to the drawing direction. Can not do. Therefore, the sheet cassette 10 is not pulled out during sheet feeding.

[0031]

On the other hand, when the sheet is not fed, the filler 18 is at the solid line position and the lower end 18b is completely separated from the side of the sheet cassette 10, so that the lock is released and the sheet is freely fed. The paper cassette 10 can be pulled out.

[0032]

As is apparent from the above description, it is desirable that the upper end 18a of the filler 18 be located on the center line of the paper path formed by the transport guide plates 24 and 25. However, when it is difficult to separate the upper end portion 18a and the lower end portion 18b from each other in distance, as shown in FIG.

[0033]

FIG. 9 is a front sectional view showing a fourth embodiment of the present invention. In the present embodiment, the same reference numerals are used for those having the same members or the same functions as those of the above-described embodiments, and thus the duplicated description will be omitted.

[0034]

This embodiment is characterized in that the lock mechanism is divided into two parts. A lock member 29 having a claw 28 is disposed so as to face the slit 17, and the lower end of the lever-shaped filler 30 is attached to the claw 28. It is locked. The center of the filler 30 is rotatably supported by a shaft 31, and the upper end protrudes into a passage formed by the transport guide plates 24 and 25. The lock member 29 is always urged by a spring 32 in a direction away from the paper feed cassette 10.

[0035]

In this embodiment, normally, as shown in FIG.
7, and the filler 30 is in the upright position. In this state, when the transfer paper is fed from inside the paper feed cassette 10, the leading end of the paper pushes the upper end of the filler 30 in the process of transferring the transfer paper through the transport guide plates 24 and 25. As a result, the filler 30 rotates as shown in FIG. 10, the lower end of the filler 30 pushes the claw 28 to the left in the figure, and the lock member 29 moves to the left in the figure against the spring 32, The left end of the lock member 29 fits into the slit 17. At this time, even if the user attempts to pull out the sheet cassette 10, the lock member 29 is locked by the engagement of the slit 17, and the sheet cassette 10 cannot be removed from the main body.

[0036]

FIG. 11 is a block diagram showing a display control system in the embodiment shown in FIGS. A control unit 33 is connected to the optical sensor 1 (detection unit), and a display unit 34 is connected to the control unit 33. The display unit 34 is provided on the console 37 as shown in FIG. 12, and includes a symbol mark 35 indicating a paper jam and a display graphic 36 indicating a paper jam location.

[0037]

In such a configuration, when the leading end of the transfer sheet pushes down the filler 30, the optical sensor 1 generates a detection signal. This detection signal disappears when the transfer sheet has passed over the filler 30. However, if a paper jam occurs for some reason and the sheet passing is stopped halfway, the detection signal remains output. Therefore, when the control unit 33 determines that this signal has continued for a certain period of time or more, the control unit 33 turns on the symbol mark 35 and the display graphic 36 of the display unit 34 to give a warning.

[0038]

In the third and fourth embodiments,
Although the filler is inserted into the slit 17, the present invention can also be achieved by providing a concave portion in the paper feed cassette 10 or providing a projection (in this case, shortening the length of the filler) instead of the slit. It is.

[0039]

[0028]

[0040]

Since the present invention is constituted as described above, the following effects can be obtained.

In the paper feed cassette locking device according to the present invention, in the paper feed cassette capable of storing a large number of transfer sheets of the same size and detachably attached to the main body of the image forming apparatus, the paper feed cassette is provided with a handle during image forming operation. Detecting means for detecting that an obstacle has entered or contacted, a solenoid which is excited based on a detection signal of the detecting means, and a locking member which regulates the movement of the sheet cassette by using the solenoid as a driving source. Since the paper feed cassette is provided, the lock of the paper feed cassette is performed only when necessary or at the time of paper feed, and the life of the solenoid can be extended.

In the paper feed cassette locking device according to the second aspect, in the paper feed cassette capable of storing a large number of transfer sheets of the same size and being detachable from the image forming apparatus main body, paper is fed from the paper feed cassette. A rotating member that rotates in conjunction with the paper passing through the conveyance guide and a lock member that regulates the movement of the sheet cassette in conjunction with the rotation of the lock member. In addition, it is possible to prevent the sheet cassette from being pulled out during the sheet feeding operation with a simple configuration without separately providing a driving source for locking.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a sheet cassette locking device according to the present invention.

FIG. 2 is a plan view illustrating a schematic configuration of a sheet feeding cassette.

FIG. 3 is a perspective view illustrating a detailed configuration of a handle portion of the sheet cassette.

FIG. 4 is a sectional view showing a second embodiment of the present invention.

FIG. 5 is a cross-sectional view taken along the line AA ′ of FIG. 4 showing details of a door unit.

FIG. 6 is a front sectional view showing a third embodiment of the present invention.

FIG. 7 is an explanatory view showing a cassette attaching / detaching operation of the embodiment of FIG. 6;

FIG. 8 is a perspective view showing another configuration example of the filler in FIG.

FIG. 9 is a front sectional view showing a fourth embodiment of the present invention.

FIG. 10 is a front sectional view showing the locked state of the embodiment of FIG. 9;

FIG. 11 is a block diagram showing a display control system in the embodiment of FIGS. 6 and 7;

FIG. 12 is a plan view showing details of a display unit in FIG. 11;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical sensor 1a Light emitting element 1b Light receiving element 2 Solenoid switching signal output circuit 3 Solenoid drive circuit 4 Solenoid 5 Filler 7 Spring 9 Claw 10 Paper feed cassette 11 Handle 13 Groove 14 Door 16 Shielding plate 17 Slit 18 Filler 18a Upper end 18b Lower end REFERENCE SIGNS LIST 20 paper feed table 24, 25 transport guide plate 27 spring 28 claw 29 lock member 30 filler 31 shaft 32 spring 33 control unit 34 display unit 35 symbol mark 36 display figure

Claims (2)

(57) [Claims] In a sheet cassette capable of storing a large number of transfer sheets of the same size and detachably attached to an image forming apparatus main body, it is detected that an obstacle enters or comes into contact with a handle during an image forming operation. A sheet feeding cassette, comprising: a detecting unit; a solenoid that is excited based on a detection signal of the detecting unit; and a locking member that controls movement of the sheet feeding cassette by using the solenoid as a driving source. Locking device. 2. In a sheet cassette capable of storing a large number of transfer sheets of the same size and detachable from an image forming apparatus main body, a sheet fed from the sheet cassette passes through a transport guide. A rotating member that rotates in conjunction with the
A lock member for regulating movement of the sheet cassette in conjunction with rotation of the lock member.