JP2004107062A - Paper feeding cassette - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paper feeding cassette for precisely restraining a position of a paper and not for generating failure of paper feeding and the like by releasing a lock of a bottom plate and pressing the paper to a paper feeding roller at a timing for starting the rotation of the paper feeding roller after a paper feeding cassette is mounted. <P>SOLUTION: A locked member 5 is hanged to a bottom plate 3 of a paper feeding cassette 1, and locked and held to a locking member 7 at the time of supplementing paper sheets. The paper feeding cassette 1 is mounted to a paper feeding part of an image recording device. When a paper feeding roller 10 is driven, a cam installed to a shaft 11 swings the locking member 7 via a rod 9 and a link 8, so as to detach the bottom plate from a locking position. Because the bottom plate 3 is raised by a spring 6, the paper sheet is brought into contact with the paper feeding roller 10, so as to enable a paper feeding action. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a lock mechanism for a bottom plate of a paper feed cassette, and more particularly to a paper feed device provided with a means for raising the bottom plate at the timing when the paper feed cassette is mounted and the paper feed roller starts rotating.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in an image forming apparatus such as an electrophotographic copying machine or a facsimile machine, a sheet feeding cassette for storing sheets of an arbitrary size is disposed in one or a plurality of sheet feeding units. A plurality of sheets are stacked and stored in the sheet cassette, the bottom plate on which the sheets are placed is raised, and a predetermined pressing force is applied to the sheet rollers against the sheet feeding roller of the sheet feeding unit of the image forming apparatus. To separate the sheets one by one using a sheet separating means such as a separation claw, and feed the sheets toward the image recording unit. A regulating member such as a side guide or an end guide is provided in the sheet accommodating portion of the sheet cassette to regulate a rear end portion and a side surface in a sheet feeding direction, and sheets are set in the sheet cassette. Later, the regulating member is fixed to the regulating position to regulate the paper so as not to be displaced.
[0003]
In the paper feed cassette, the bottom plate on which the paper is placed is provided with a spring at the front end in the paper feed direction, and the front end in the paper feed direction is provided via a hinge provided at an intermediate portion or a rear portion inside the cassette. The sheet is supported so as to swing greatly, and the sheet is lifted and pressed against the sheet feeding roller. In addition, side guides are arranged on both sides of the paper supported by the bottom plate in the paper feeding direction to regulate both sides of the paper. Is provided with a separating claw for locking the corners of the sheet and performing a sheet separating action. Locking means is provided for holding the bottom plate in a depressed position when replenishing the paper in the paper cassette, and while the paper cassette is being mounted on the paper feeding section of the image recording apparatus, The paper is lifted by releasing the lock.
[0004]
[Patent Document 1]
JP-A-2000-62971
[0005]
[Problems to be solved by the invention]
However, the lock mechanism provided in the conventional paper feed cassette is configured to release the lock of the bottom plate at the final stage of mounting the paper feed cassette in the paper feed unit. The insertion operation is continued even after the contact with the paper roller. Therefore, the paper cassette is further moved in the mounting direction while the paper is in contact with the paper feed roller, and the paper is subjected to a shock or the like when the bottom plate is lifted during the movement of the paper cassette. As a result, the corner at the leading end of the sheet on the sheet feeding side may not be accurately locked by the separation claw. Therefore, when the engagement state with the separation claw is not set well, when the paper feed roller is driven to feed the paper, the operation of feeding the paper may not be performed accurately, and the paper feed failure may occur. And often cause jams.
[0006]
According to the present invention, at the timing when the paper feed cassette is mounted and the paper feed roller starts rotating, by unlocking the bottom plate and pressing the paper against the paper feed roller, the position of the paper is accurately regulated, It is an object of the present invention to provide a sheet feeding device that does not cause a sheet feeding failure or the like.
[0007]
[Means for Solving the Problems]
The present invention relates to a paper feeding device provided in an image recording apparatus, and the invention according to claim 1 is directed to a bottom plate that can swing inside a paper feeding cassette, and a lock member that fixes the bottom plate at a lowered position. A paper feeding roller of an image recording apparatus to which the paper feeding cassette is mounted includes a paper feeding roller for feeding out the paper placed on the bottom plate, and the rotation of the paper feeding roller and the locking of the bottom plate. And means for canceling.
[0008]
According to a second aspect of the present invention, the lock member is rotated by rotating a gear of a driving force transmission unit from a driving source to a paper feeding roller in a paper feeding unit of the image recording apparatus to which the paper feeding cassette is mounted. And releasing the lock of the bottom plate.
[0009]
The invention according to claim 3 is characterized in that at the start of the rotation operation of the paper feed roller, the unlocking means of the bottom plate is operated.
[0010]
With the configuration described above, in the paper feed cassette of the present invention, after the paper feed cassette is attached to the paper feed unit of the image recording apparatus, the bottom plate is unlocked and raised. The paper does not move after contacting the paper feed roller. Therefore, the leading end of the sheet placed on the bottom plate does not separate from the separation claw, and the sheet feeding operation can be performed in a good state without disturbing the alignment state of the sheet. It is.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
The sheet cassette of the present invention will be described with reference to the illustrated example. A sheet cassette 1 that accommodates a large number of sheets and is attached to a sheet feeding unit of the image forming apparatus to supply sheets is shown in a plan view of FIG. 1 and a perspective view of FIG. 2 and a side view of FIG. And a so-called universal type paper feed cassette capable of storing paper of an arbitrary size in a paper storage section defined by the frame 2 is illustrated. . A bottom plate 3 for supporting the paper P is swingably supported on the paper feed cassette 1 via hinges 4 and 4, and is raised by a spring 6 arranged at a lower portion on the front end side in the paper feed direction. The paper P is pressed against the paper feed roller 10 with a predetermined pressing force, and the developing roller 10 is rotated to feed the paper.
[0012]
Further, in order to regulate the sheets accommodated in the sheet cassette 1, an end guide 15 for regulating a rear end portion of the sheet feeding side (paper supply direction) and side guides 16 and 16a for regulating both sides of the sheet. Are provided. Each of the three guide members 15 to 16a is provided so as to be guided along a guide member (not described) provided on the bottom plate of the sheet feeding cassette 1, and each of the guide members is located at an arbitrary position. It can be fixed. Two side guides 16 and 16a for regulating both sides in the width direction orthogonal to the sheet feeding direction inside the sheet cassette support separation claws 17 and 17a, respectively. The sheet is separated one by one by a feeding force due to the rotation and friction of the developing roller 10 and a locking action by the separation claws 17 and 17a, and is directed toward a recording unit of an image recording apparatus (not shown). To feed paper.
[0013]
In the paper feeding mechanism disposed in the paper feeding device, the rotating shaft 11 provided with the paper feeding roller 10 is supported via bearings 12 provided on both frames, and is provided at one end of the rotating shaft 11. A toothless gear 21 serving as a roller gear is arranged so as to mesh with the transmission gear 32, and is configured as a drive device 20. In the driving device 20, a disc-shaped regulating member 25 is provided in addition to the toothless gear 21 provided on the rotating shaft 11, and as shown in FIGS. A spring 27a is connected to the pin member 27, and the toothless gear 21 is urged in the rotation direction during paper feeding. The regulating member 25 is provided with a locking groove 26, and a locking claw 29 operated by a solenoid 28 is inserted into the locking groove 26 to hold the toothless gear 21 at the stop position. It is configured to
[0014]
In the driving device 20, when a command for feeding a sheet to the sheet cassette is output, the solenoid 28 is energized to pull the locking claw 29 out of the locking groove 26 to lock the regulating member 25. Is released, so that the toothless gear 21 is in a rotatable state. When the locking by the locking claw 29 is released, the restricting member 25 is rotated by a predetermined angle in the counterclockwise direction in the drawing by the spring 27a, and as shown in FIG. The teeth at the tip end are engaged with the transmission gear 32. Since the transmission gear 32 is constantly rotating, the toothless gear 21 is rotated in the sheet feeding direction by the transmission gear 32, and the sheet feeding operation by the sheet feeding roller 10 is performed. Is rotated once, the locking claw 29 engages with the locking groove 26 of the regulating member 25, and the rotation of the toothless gear 21 is interrupted.
[0015]
In the state where the rotation of the toothless gear 21 is interrupted, the toothless part 23 of the toothless gear 21 is positioned corresponding to the transmission gear 32, so that even if the transmission gear 32 continues to rotate, the toothless gear 21 The gear 21 is held at the stop position, and is held in the positional relationship between the gears 21 and 32 as shown. When the next sheet feed signal is supplied, the solenoid 28 is operated, the locked state by the locking claw 29 is released, the toothless gear 21 is rotated by the spring 27a, and the toothless gear for the transmission gear 32 is rotated. Due to the engagement of 21, the paper feed roller 10 rotates the paper feed roller 1 once to feed the paper from the paper feed cassette.
[0016]
In the example shown in FIGS. 2 and 3, the rotating shaft 11 for driving the paper feed roller 10 is fixed at one end to a toothless gear 21 provided with a toothless part 23. On the upstream side in the rotation direction from the concave portion 23a of the toothless gear 21, a protruding portion 22 having teeth formed on the surface side is provided so as to protrude. The elastic body 24 is inserted into the protruding portion 22 so as to fill the recess 23a inside the protruding portion 22, and the protruding portion 22 is pressed outward from the shaft center side. The drive device 20 is provided so as to exert an action of resisting a force bent to the side 23, but the configuration of the drive device 20 is not particularly limited.
[0017]
In the drive device 20 provided for the paper feed cassette 1, a cam member 13 is provided on a shaft 11 of the paper feed roller 10, and is configured to be rotatable together with the paper feed roller 10. Further, in the sheet cassette 1, a locked member 5 is provided so as to protrude below the bottom plate 3 so as to correspond to the cam member 13, and when the bottom plate 3 is lowered, the locked member 5 5 is provided for locking. The locking member 7 has an actuated rod 9 disposed at a position corresponding to a cam member 13 provided on a shaft 11 of the paper feed roller 10, and connects the rod 9 and the locking member 7 to a link member 8. Is connected.
[0018]
Until the paper is supplied to the paper feed cassette 1 and mounted on the paper feed unit of the image recording apparatus, the bottom plate 3 is kept in a state where the locked member 5 is locked by the locking member 7. Is held at the lowered position while maintaining the posture at the time of placing. Then, when a feed command is input to the image recording apparatus and the feed roller 10 is started to rotate by the driving device 20, the cam member 13 provided on the shaft 11 rotates and presses the rod 9. The locking member 7 is rocked via the link member 8, the locked state of the bottom plate 3 is released, and the bottom plate 3 is rocked upward by the spring 6. Further, since the leading end of the sheet P supported by the bottom plate 3 is locked by the separation claw 17, the sheets are fed one by one by friction with the sheet feeding roller 10. Therefore, when feeding paper from the paper feed cassette 1, the bottom plate can be raised in synchronization with the operation of starting rotation of the paper feed roller 10. Therefore, unlike the conventional paper cassette, the paper does not rise in the middle of the mounting operation, and the paper rises and the paper cassette is further moved while being in contact with the paper feed roller, and the paper is removed. There is no problem such as detachment from the separation claw.
[0019]
In addition to the examples shown in FIGS. 2 and 3, it is also possible to provide locking means for the bottom plate 3 as shown in FIG. 4 or FIG. In the example shown in FIG. 4, a link member 8 is provided so as to protrude from a side portion in the frame of the sheet cassette, and a locking member 7 interlocked with the link member 8 is combined. A cam member 13 is provided on the shaft 11 in the same manner as in the above embodiment. Then, in a state where the frame is mounted on the paper feed unit and positioned, the bottom plate 3 is raised in synchronization with the operation of starting the rotation of the paper feed roller 10, so that the paper is fed to the separation claw. Is accurately locked and held at the tip of the sheet so that the sheet separating operation can be performed satisfactorily.
[0020]
In the example shown in FIG. 5, a cassette gear 33 is protruded from the side of the frame of the paper feed cassette, and the shaft of the cassette gear 33 is provided to extend below the paper storage unit, and a cam member 34 is attached. . Further, a locking member 7 for locking the distal end portion of the bottom plate 3 is swingably provided via a link member 8 and a spring 9a. The driving device 20 disposed in the paper feeding unit of the image recording apparatus includes a driving unit for the paper feeding roller 10 that is driven by a motor 30 via an intermediate gear 31, and a driving device for the cassette gear 33 of the paper feeding cassette. A transmission mechanism from the gear 31 to the transmission gear 32 is provided. Therefore, by mounting the sheet cassette on the sheet feeding section, the transmission gear 32 meshes with the cassette gear 33, and when the motor 30 starts rotating according to the sheet feeding command, the cam member 34 is simultaneously rotated with the rotation of the cassette gear 33. The rotation causes the link member 8 and the locking member 7 to swing, so that the locking with respect to the bottom plate 3 is released, and the paper is raised to the paper feeding position by the spring 6.
[0021]
In the paper feeding device using the paper feeding cassette of the present invention, the relationship between the mounting direction of the paper feeding cassette and the feeding direction of the paper is not particularly defined. In addition, the structure of the locking member for holding the bottom plate at the lowered position and a combination mechanism of a link member and a rod as an interlocking mechanism, or an auxiliary means for swinging the locking member, etc. are appropriately provided. It is possible to combine. Further, the configuration and the like of the cam member provided on the paper feed roller may be made of an arbitrary member corresponding to the locking member, and the paper may be raised in conjunction with the rotation of the shaft of the paper feed roller. It is also possible.
[0022]
【The invention's effect】
In the paper feed cassette of the present invention, since the paper feed cassette of the present invention is configured as described above, after the paper feed cassette is mounted on the paper feed unit of the image recording apparatus, the bottom plate is unlocked and raised. The paper does not move after contacting the paper feed roller. Therefore, the leading end of the sheet placed on the bottom plate does not separate from the separation claw, and the sheet feeding operation can be performed in a good state without disturbing the alignment state of the sheet. It is.
[Brief description of the drawings]
FIG. 1 is a plan view of a paper feed cassette.
FIG. 2 is a perspective view illustrating a relationship between a sheet feeding cassette and a sheet feeding member.
FIG. 3 is an explanatory diagram showing a relationship between a bottom plate and a retaining unit.
FIG. 4 is an explanatory diagram of another embodiment different from FIG. 3;
FIG. 5 is an explanatory view of an embodiment different from FIG. 3;
[Explanation of symbols]
1 paper cassette, 2 frames, 3 bottom plate,
4 hinge, 5 locked member, 6 spring,
7 locking member, 8 link member, 9 rod,
10 paper feed rollers, 11 axes, 12 bearings,
13 cam member, 15 end guide, 16 side guide,
17 separation claw, 20 driving device, 21 toothless gear,
22 projecting part, 23 concave part, 24 elastic body, 25 regulating member,
26 locking groove, 27 pin, 28 solenoid,
29 locking member, 30 motor, 31 intermediate gear,
32 conduction gear, 33 cassette gear, 34 cam member.

Claims (3)

A bottom plate that can swing inside the paper cassette,
A lock member for fixing the bottom plate at a lowered position,
A paper feed roller of an image recording apparatus to which the paper feed cassette is mounted includes a paper feed roller for feeding out the paper placed on the bottom plate,
Means for unlocking the bottom plate at the same time as the rotation of the sheet feeding roller is started. In the paper feeding unit of the image recording apparatus to which the paper feeding cassette is mounted,
2. The sheet feeding device according to claim 1, wherein a lock of the bottom plate is released by rotating a lock member by rotating a gear of a driving force transmission unit from a driving source to the sheet feeding roller. The paper cassette according to claim 1, wherein a lock release unit of the bottom plate is operated at a start of the rotation operation of the paper feed roller.

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