JP3109294B2 - Paper tray - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding tray mounted on a sheet feeding section of an image forming apparatus, and more particularly, to a case where a bottom plate on which sheets are placed is configured to be swingable. The present invention relates to a device that can prevent the end of a sheet from being displaced from the front wall inside the tray due to movement, and can accurately position the leading end of the sheet.

[0002]

2. Description of the Related Art In an image forming apparatus such as an electrophotographic copying machine or a printer, a plurality of paper storage devices such as a paper supply tray and a paper supply cassette are mounted on a paper supply unit, and the paper storage devices are mounted on the paper storage devices. In general, a mechanism for storing sheets of different sizes to feed sheets of a required size corresponding to the size of a document is generally used. Devices such as the paper feed tray and the paper feed cassette include those that can store sheets of a fixed size and those that can store sheets of any size. Then, in a state where a large number of sheets can be stored in any of the sheet storage devices, and the sheet storage device is set in the sheet feeding unit, the sheet is pushed up toward the roller device of the sheet feeding device, and the roller member is rotated. Thus, the sheet can be sent out.

[0003] Among the sheet storage devices, for a sheet feeding cassette, for example, a device as disclosed in Japanese Patent Application Laid-Open No. 60-171936 is used. The conventional paper feed cassette is configured as shown in FIG. 4, in which a bottom plate 31 for placing paper is swingable via a hinge 32 inside the paper feed cassette 30. A mechanism for pushing up the bottom plate 31 by means of a spring 33. Further, snubbers 34 are provided on both sides of the leading end on the sheet feeding side with respect to the paper P placed on the bottom plate, and a separating action is performed in a state where the corners of the leading end of the paper are locked by the snubber. I am giving it. The paper feed roller 5 disposed with respect to the paper feed cassette is provided with a half-moon-shaped roller member with respect to the drive shaft 6. The arc portion of rubs against the paper and gives the effect of feeding the paper, and by the cooperation of the snubber,
It is possible to perform a sorting action on paper.

However, as described above, when sheets are placed on the bottom plate and the bottom plate is configured to be swingable, if the number of sheets placed on the bottom plate is large, However, there is a problem that the position of the sheet changes following the swing of the bottom plate. For example, when the bottom plate is swung through a hinge, the sheet supported by the bottom plate may be displaced, and the leading end of the sheet may retreat from the position regulated by the snubber. When the leading end of the sheet is displaced rearward, there is a problem in that when feeding the sheet, a delay occurs in the time required for the sheet to reach a predetermined position after driving the sheet feeding roller. In the case where such a delay occurs in the sheet feeding timing, there may be a case where the conveyance of the sheet in the sheet conveyance path and the control of the recording of the image and the like may be hindered.

[0005] As described above, the occurrence of paper misalignment due to the swinging of the bottom plate can be explained by the actual disclosure of Japanese Patent Application Laid-Open No. 56-1622.
It is described in Japanese Patent Publication No. 52 and the like. For example, in the paper feed tray 40 shown in FIG. 5, a bottom plate 41 for supporting the paper is arranged, the rear end of the paper is regulated by an end guide 48, and a snubber is provided corresponding to the front end of the paper. 47 are provided. In the paper feed tray, a side plate 45 supporting a snubber is provided via a hinge 46 so as to be swingable separately from a bottom plate, and the bottom plate 41 is raised by a spring 43 using a push-up arm 42. Thus, the upper surface of the paper is brought into contact with the paper feed roller at a predetermined pressure.

A paper feed tray 40 as shown in FIG.
, When the leading end of the sheet P is locked to the snubber and the trailing end is regulated by the end guide 48, the bottom plate 41 is raised using the push-up arm 42 when the sheet P is set in the sheet feeding section of the image forming apparatus. The action takes place. By the operation of raising the bottom plate, a bending action is applied to the entirety of the sheet P, and as a result, a gap of the interval A is formed between the snubber and the leading end of the sheet, A problem occurs in that a gap having a distance B is formed between the end guide and the end guide. Therefore, if a gap is formed in the snubber portion among the gaps formed before and after the sheet, the timing at which the sheet is fed is delayed. In addition, if a gap is formed between the end guide and the end guide, there is a problem that the sheet positioning operation is not performed accurately and the separating operation by the snubber is hindered.

Therefore, in the conventional paper feed tray, an interlocking mechanism between the bottom plate and the end guide is formed.
By moving the end guide in accordance with the operation of swinging the bottom plate, a mechanism is configured such that the sheet is accurately held between the snubber and the end guide. By accurately positioning the paper in the paper feed tray, a delay in paper feed timing can be prevented.

[0008]

However, in the conventional paper storage device, even when an interlocking mechanism between the bottom plate and the end guide is formed, the moving distance of the end guide is defined by the size of the bottom plate. There is a problem that a difference occurs in the moving distance of the end guide between the case where the bottom plate is configured as a large one and the one where the bottom plate is small. Further, since the moving distance of the end guide is also defined by the position of the hinge of the bottom plate, in a tray having a configuration in which the swing center of the bottom plate is not provided at a position sufficiently higher than the horizontal portion of the bottom plate, There is a problem that the moving distance of the end guide cannot be sufficiently obtained.

Further, when the interlocking mechanism between the bottom plate and the end guide is configured, there is a problem that the configuration tends to be complicated, and it is necessary to configure each coupling mechanism in accordance with the size of the paper to be stored. There is. Therefore, even when a large number of paper feed trays are used, it is difficult to share the components of the paper feed trays, and there remains a major problem in terms of parts management in addition to a problem in manufacturing. .

[0010]

SUMMARY OF THE INVENTION The object of the present invention is to solve the problem of the conventional paper feed tray as described above, and to operate an interlocking mechanism between a bottom plate and an end guide via a drive shaft for swinging the bottom plate. The present invention is to provide an apparatus that can accurately set an operation of positioning a leading end of a sheet by restricting a movement amount of an end guide in response to a sheet shift caused by swinging of a bottom plate. The purpose is.

[0011]

According to the present invention, there is provided a bottom plate for supporting a sheet inside a tray, an end guide which can be arranged at an arbitrary position for regulating a rear end of the sheet, and a rocking mechanism for the bottom plate. The present invention relates to a paper feed tray provided with a push-up arm for causing the sheet to move. According to a first aspect of the present invention, an interlocking member is disposed between a drive shaft supporting a push-up arm for swinging the bottom plate and the end guide, so as to follow the swing of the bottom plate. And moving the end guide. According to a second aspect of the present invention, a cam-shaped member is provided on a drive shaft of the push-up arm, a wire wound around the cam-shaped member is connected to an end guide and moved, and after a sheet rocked by the bottom plate, The end is regulated.

As described above, by connecting the end guide to the shaft of the push-up arm for swinging the bottom plate via the interlocking member, the end guide can be adjusted in accordance with the amount of sheet displacement caused by the swing of the bottom plate. , The moving amount of the end guide can be set. Then, regardless of the size of the paper accommodated in the paper feed tray, it is possible to prevent the leading end of the paper from being displaced due to the swing of the bottom plate. Further, the moving amount of the end guide is not affected by the length of the bottom plate in the sheet feeding direction or the like, and the rear end of the sheet can be regulated by the end guide. Therefore, in the apparatus according to the present invention, the position of the leading edge of the sheet can be accurately determined, and the leading edge of the sheet does not shift, and the feeding timing can be accurately set.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The paper feed tray of the present invention will be described with reference to the illustrated example. The paper feed tray 10 shown in FIG. 1 is positioned with respect to the paper feed device 1 arranged in the paper feed unit, and feeds the paper P placed on the bottom plate 11 to the nudger roller 2.
, And the sheet sent out by the roller 2 is
A mechanism for feeding the paper toward the image recording unit while separating between the paper feed roller 3 and the retard roller 4 is configured.
In the paper feed tray 10, a bottom plate 11 for supporting the paper is swingably provided via a hinge 12,
A push-up arm 17 for swinging the bottom plate 11 is provided fixed to the drive shaft 15. The drive shaft 15 is connected to a drive mechanism (not shown) disposed in the paper feed unit for driving. The drive shaft 15 swings the bottom plate 11 with the paper feed tray attached to the paper feed unit. To raise the paper toward the paper feed roller.

In the paper feed tray 10 of the present invention, an end guide 13 is disposed to regulate the rear end of the paper P, and a connecting bar member 18 is provided between the end guide 13 and the drive shaft 15. Attached. In order to attach the connection bar member 18 to the drive shaft 15, a link member 16 is provided for the drive shaft 15, and attachment portions on both sides of the link member 16 are configured to be swingable with each other. Then, as shown in FIG. 2, the end guide 13 is moved to the sheet feeding side by driving the driving shaft 15 and moving the end of the bottom plate 11 on the sheet feeding side via the push-up arm 17. , So that the sheet P is not displaced.

The interval of the movement of the end guide 13 is set so as to correspond to the length of the displacement of the sheet when the bottom plate is swung. In addition, the shape of the link member 16 disposed between the drive shaft 15 and the connection bar member 18 and the position of the connection portion can be appropriately set. In the paper feed tray of the present invention configured as shown in FIG. 1, as the paper is fed out and the remaining amount decreases,
As the swing angle of the bottom plate increases, and the swing angle of the bottom plate increases, the distance by which the end guide is moved to the paper feed side increases. Further, when pulling out the paper feed tray from the paper feed unit, the drive shaft is first disconnected from the drive unit of the main body, and the end guide is returned to the position where it is retracted in accordance with the operation of lowering the bottom plate.

As shown in FIG. 1, in addition to using a connection bar member for connecting the bottom plate and the end guide, the paper feed tray of the present invention comprises an interlocking mechanism as shown in FIG. Can also. In the example shown in FIG. 3, the push-up arm 17 is attached to the drive shaft, and the cam member 20 is fixed. A wire 21 is connected between the cam member 20 fixed to the drive shaft 15 and the end guide 13 to form an interlocking mechanism between the lifting arm and the end guide. In the above embodiment, the wire 2
One end of the wire is wound around the cam member 20, and the other end of the wire is fixed to a mounting member provided below the end guide. Further, in order to return the end guide 13, a spring 22 is disposed between the spring 22 and the rear frame of the tray so that the end guide can be retracted when the lifting arm is returned.

As described above, the cam member 20 and the wire 2
1 to form an interlocking mechanism between the bottom plate and the end guide. In the paper feed tray, the drive shaft 15 is driven to raise the bottom plate 11 via the push-up arm 17 so that the sheet Can be positioned at the sheet feeding position. Further, the end guide is advanced in the sheet feeding direction following the operation of raising the sheet, whereby the action of positioning the sheet can be satisfactorily exhibited. Further, when the paper tray is pulled out of the paper feeding unit, the pressing by the push-up arm is released, and the bottom plate is lowered by the weight of the paper, but the end guide is pulled toward the rear by the spring, so that the original is returned. Will be returned to the position. Then, as shown in FIG. 1, when the leading end of the sheet descends together with the bottom plate 11 and the rear end moves toward the rear of the tray, the position of the trailing end of the sheet is determined. Stopped.

Further, as shown in the embodiment, when the end guide is movably connected to the drive shaft for swinging the bottom plate through a connecting bar member or a wire, the fixed size is obtained. The mechanism of the present invention can be applied only to a tray capable of storing the sheets.
However, for example, in the example shown in FIG. 1 described above, a connecting member corresponding to the paper size is disposed on the connecting bar member 18 so that a pin member that can be inserted and removed between the end guide 13 and the connecting bar member 18 is provided. It is also possible to configure a mechanism for connecting via a. When the position at which the end guide is attached to the connection bar member is configured to be variable, the end guide moving mechanism of the present invention can be applied to a universal type tray or the like as it is. Becomes possible.

In order to drive the drive shaft 15 with respect to the interlocking mechanism of the present invention configured as described above, for example, the drive shaft is engaged with a paper feed unit on which a paper feed tray is mounted. Means for driving the drive shaft in a state where the members are arranged and the sheet feeding tray is set at a predetermined position can be used. In order to drive the drive shaft, any drive force transmission mechanism can be used. Further, the paper feed tray of the present invention is provided for the paper feed unit of the image forming apparatus.
It can be easily applied to an apparatus provided with a mechanism for attaching and detaching a tray from the front side of the apparatus main body.

[0020]

As described above, according to the paper feed tray of the present invention, the end guide is connected to the axis of the push-up arm for swinging the bottom plate via the interlocking member, thereby enabling the bottom plate to be rotated. The amount of movement of the end guide can be set according to the amount of deviation of the sheet due to the swing. Then, regardless of the size of the paper accommodated in the paper feed tray, it is possible to prevent the leading end of the paper from being displaced due to the swing of the bottom plate. Further, the moving amount of the end guide is not affected by the length of the bottom plate in the sheet feeding direction or the like, and the rear end of the sheet can be regulated by the end guide. Therefore, in the apparatus according to the present invention, the position of the leading edge of the sheet can be accurately determined, and the leading edge of the sheet does not shift, and the feeding timing can be accurately set.

[Brief description of the drawings]

FIG. 1 is a side view showing a configuration of a sheet feeding tray of the present invention.

FIG. 2 is an explanatory diagram of a state where a bottom plate of a tray is raised.

FIG. 3 is an explanatory view of another embodiment of the present invention.

FIG. 4 is a side view showing a configuration of a conventional paper feed tray.

FIG. 5 is an explanatory diagram showing a configuration of another conventional paper feed tray.

[Explanation of symbols]

Reference Signs List 1 paper feeder, 10 paper feed tray, 11 bottom plate, 13 end guide, 15 drive shaft, 16 link member, 17 push-up arm, 1
8 Connection bar member, 20 cam member, 21 wire, 30 paper cassette, 31 bottom plate, 40 paper tray, 41 bottom plate, 47 snubber, 48 end guide.

Claims (2)

(57) [Claims] 1. A bottom plate that supports a sheet inside a tray, an end guide that regulates a rear end of the sheet and can be arranged at an arbitrary position, and a push-up arm that swings the bottom plate. In the paper feed tray provided, an interlocking member is arranged between a drive shaft that supports a push-up arm for swinging the bottom plate and the end guide, and the swing member follows the swing of the bottom plate. A paper feed tray characterized by moving an end guide. 2. A cam-shaped member is provided on a drive shaft of the push-up arm, a wire wound around the cam-shaped member is connected to an end guide and moved, and a rear end portion of a sheet rocked by the bottom plate 2. The method according to claim 1, wherein
Paper tray described in.