JP2001213534A - Sheet feeder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet feeder capable of precisely setting a sheet on a designated location. SOLUTION: A guide member 62 is attached in adjacent to a cut-out surface 69 of a semicircular roller 60 retractably around a pin 65 and in such a condition of retaining a guide surface 63 in a space K. Moreover, a stopper member 50 is provided in downstream side of the guide surface 63 in a sheet conveying direction. An end of the sheet P comes into contact with the stopper part 51. The sheet P, therefore is appropriately set.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feeder for an image forming apparatus such as a copying machine, a facsimile machine, and a printer, and more particularly, to a paper feeder suitable for a stack bypass using a half moon roller, an automatic document feeder, and the like. It relates to a paper device.

[0002]

2. Description of the Related Art A paper feeder using a half moon roller is known as one type of a paper feeder in a stack bypass provided in an image forming apparatus such as a copying machine, a facsimile machine, a printer or the like. I have. The paper feeding device using the half-moon roller includes a paper feeding unit using the half-moon roller and a separating unit using a torque limiter or the like, and the half-moon roller usually has a cut portion of the half-moon roller positioned below. (See FIG. 1), a plurality of sheets can be set. When feeding the paper, the uppermost sheet is fed by one rotation of the half-moon roller, but in order to prevent the so-called double feed in which the second and subsequent sheets from the top are fed at the same time,
By rotating the separation roller provided with the torque limiter in the same direction as the half-moon roller, the uppermost sheet and the second and subsequent sheets are separated, and only the uppermost sheet is fed. Further, when the semi-circular roller rotates in a state where no paper is set, that is, when a non-feeding state occurs, the separating roller is provided with a torque limiter so that the separating roller follows the semi-circular roller and rotates in a direction opposite to the semi-circular roller. It is supposed to.

Generally, in a half-moon roller type paper feeder having the above-described configuration, when a plurality of sheets are set, or when additional sheets are added on the set sheets, the sheets are moved to a predetermined position. Is not set in the paper feeder, and several sheets from the uppermost sheet go deeper into the paper feeding unit, and there is a problem that the paper cannot be fed properly.

As a means for solving this, as shown in FIG. 5, a pin 33 is provided near the cutout portion 30a of the meniscus roller 30.
The guide member 31 is provided rotatably with the fulcrum as a fulcrum, and the guide surface 31a of the guide member 31 is located in the space K between the half-moon roller 30 and the separation roller 40.
1 is known so that it does not rotate clockwise from the state shown in FIG. According to this, when the sheet P is set, the sheet P is set at a predetermined position along the guide surface 31a of the guide member 31.

[0005]

However, even in the above-described paper feeder in which the guide member is provided on the half-moon roller, it is set even though it is set properly by an operator, for example. Conventionally, the guide member rotates counterclockwise if you try to insert the paper further while moving the paper back and forth without feeling, and several sheets from the top move deeper than the paper feed unit. In some cases, the problem has not been solved.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a paper feeder that can be accurately set at a predetermined position.

[0007]

According to another aspect of the present invention, there is provided a paper feeder, comprising: an apparatus main body; and a paper feeder provided in the apparatus main body and capable of feeding sheets one by one. Unit, a paper feeding unit opening into which the leading end of the paper can be inserted so that the leading end of the paper is located in the paper feeding unit, and a paper mounting table provided in the paper feeding unit opening for placing paper to be conveyed. The paper feeding unit rotates the half-moon roller and a guide member provided on the half-moon roller so that the sheet is guided to an appropriate position when the sheet is placed on the paper mounting table. And a separating unit for separating the uppermost sheet and the second sheet when feeding the sheet on the sheet mounting table. Insert the stopper member into the half-roller so that the leading edge of the paper is properly positioned when A sheet feeding apparatus, characterized in that digit.

According to the above means, when setting a plurality of sheets or adding sheets, even if the operator tries to insert the sheet to the inside of the sheet feeding section, the operator is caught by the stopper member and the sheet is not inserted into the sheet feeding section. Therefore, it is possible to prevent paper from being set on the paper, thereby enabling proper paper feeding.

[0009]

FIG. 1 shows a general image forming apparatus using a half-moon roller. An original mounting table 2 is provided on an upper portion of the image forming apparatus 1 as an apparatus main body.
Is scanned by the optical system 3, an electrostatic latent image is formed on the photoconductor 4, and the electrostatic latent image is formed as a toner image by the developing device 5. On the other hand, the paper placed on the paper loading table 8 provided in the paper feeding section opening 81 is
Only the uppermost sheet is fed by the feed roller 6 and the separation roller 7, and the registration roller pair 9 synchronizes so that the toner image on the photoconductor 4 is transferred onto the sheet. The toner image on the photoconductor 4 is transferred to a sheet by the transfer device 10. The sheet on which the toner image has been transferred is further conveyed to the downstream side, the toner image is fixed on the sheet by the fixing device 11, and is discharged to the sheet discharge tray 13 by the discharge roller pair 12.

FIGS. 2 and 3 show only the sheet feeding device according to the present invention. FIG. 2 shows a normal state, and FIG. 3 shows a state in which the half-moon roller has rotated half a turn. 2 and 3
The detailed configuration of the present invention will be described with reference to FIG.

Referring to FIG. 2, a sheet mounting table 21 provided with a width adjusting mechanism from the upstream side in the sheet conveying direction, a lift plate 22 for moving the leading end of the sheet upward during sheet feeding, and a half moon roller 60 as sheet feeding means. Separating rollers 70 as separating means are configured as a pair of upper and lower rollers, and further arranged on the downstream side are upper and lower guide plates 61 and 71. The separation roller 70 is attached to a torque limiter (not shown).

The half-moon roller 60 is driven by a driving means (not shown) from the shaft 6.
The control unit (not shown) is controlled to rotate once to feed one sheet. The separation roller 70 is also rotated by the drive from the drive unit. Half Moon Roller 6
0 is a normal position in the state shown in FIG. 2, in which the half-moon roller 60 and the separation roller 70 are in a non-contact state,
A space K is formed. A guide member 62 is mounted near the cutout surface 69 of the half-roller 60 so as to be rotatable about the pin 65 and to position the guide surface 63 in the space K. Further, a stopper portion 64 is provided on the downstream side of the guide surface in the sheet conveyance direction, and a protrusion 66 is provided so that the guide member 62 does not rotate clockwise from the state shown in FIG. Therefore, when the paper P is set along the guide surface 63 of the guide member 62, the leading end of the paper P comes into contact with the stopper portion 64, and the paper P is set at an appropriate position.

However, even if the operator adopts the above configuration, the stopper member 50 is provided on the half-moon roller 60 on the assumption that the sheet is set further back and forth while moving the sheet forward and backward. The stopper member 5
Numeral 0 is provided on the downstream side in the transport direction of the guide member 62 provided on the half-moon roller 60 so as to be rotatable around the pin 55. The stopper member 50 is provided with a stopper portion 51 so that the sheet P does not pass through the stopper member 50.
A guide portion 52 is provided so as to properly abut on 1, and the stopper portion 51 and the guide portion 52 are exposed to the transport path. Further, even when the sheet P is set, that is, even when the leading end of the sheet P comes into contact with the stopper portion 51, the protrusion 53 provided on the half-moon roller 60 is prevented from rotating clockwise about the pin 55. The projection 54 of the stopper member 50 is in contact with the projection 54.

A lift plate 22 is provided on the downstream side of the paper mounting table 21 in the paper transport direction. When feeding paper, a lifting / lowering means (not shown) is operated by a signal from a control means (not shown). The leading end of the sheet P thus lifted rises to the state shown in FIG. Reference numeral 23 denotes a sheet leading end contact member provided on the downstream side in the transport direction of the lift plate 22 and on the upstream side in the transport direction of the separation roller 70 so that the leading ends of the set sheets P are aligned. Upper and lower guide plates 61 and 71 are provided on the downstream side in the transport direction of the upper and lower roller pairs of the half-moon roller 60 and the separation roller 70, respectively, and further downstream, the paper fed by the paper feeding means is provided. An unillustrated feed roller pair for transporting the sheet to the downstream side in the transport direction is provided.

Next, the operation of the present invention will be described with reference to FIGS. FIG. 2 shows a normal state, in which the operator sets the paper P in this state. More specifically, the operator sets the sheet P on the sheet mounting table 21. At this time, the leading edge of the sheet P is the top of the sheet P to be set and the leading ends of several sheets from the top are the guide surfaces of the guide member 62. Guided to the proper position by 63. The lower sheet P is set to an appropriate position by the sheet aligning member 23. On the other hand, the top and several sheets P from the top are also set to appropriate positions by the stopper portions 64 of the guide members 62. However, even if the guide member 62 rotates counterclockwise to insert the paper P further back and forth to insert it further back, even if the paper P is inserted further beyond the guide member 62, the stopper member 50 Stopper part 5
1, the sheet P is always set at an appropriate position.

As described above, when the sheet P properly set on the sheet mounting table 21 is instructed to be fed from the sheet mounting table 21, the control means (not shown) first raises the tip of the lift plate 22 so as to raise it. The lifting means (not shown) is operated, and then the driving means (not shown) is operated so that the half-moon roller 60 makes one rotation in the direction shown by A in FIG. 2 and at the same time the separation roller 70 also rotates in the direction shown by B in FIG. As a result, the sheet P is sorted, and only the uppermost sheet P is fed. FIG. 3 is a view showing a state in which paper is being fed, and shows a state where the half-moon roller 60 has rotated half a turn. The guide member 62 is brought into the state shown in FIG. 3 by its own weight around the pin 65, but its rotation is prevented by the rotation preventing member 67 so that the guide member 62 does not rotate any more. Further, the stopper member 50 is brought into the state shown in FIG. 3 by its own weight around the pin 55, but the stopper member 50 is prevented from rotating further by the pin 66.
Is prevented from rotating. Therefore, FIG.
If the half-roller 60 further rotates half a turn from this state, the guide member 62 and the stopper member 50 return to the normal state from the direction D shown in FIG. If it is from the E direction, the protrusion 66
This is because it is impossible to return to a normal state because of the presence of the 53.

Further, the stopper member 50 is separated from the separation roller 70.
There are the following effects as a result of the provision on the downstream side. That is, as shown in FIG. 4, after the sheet P is separated by the separation roller 70 at the time of sheet feeding, the leading end of the next sheet to be fed may reach the separation roller 70. In this state, when the operator replenishes the paper on the paper mounting table, the paper whose leading end has reached the separation roller 70 is pushed downstream in the transport direction by the paper when the replenishment is performed. Part 5
Although it moves slightly downstream by 1, it is held at an appropriate position, so that there is no inconvenience in the next sheet feeding.

Further, when there is no paper P on the paper mounting table 21 and a paper feeding operation is performed, that is, when the half-moon roller 60 and the separation roller 70 rotate, the separation roller 70 is attached to the torque limiter. Then, torque is applied to the separation roller 70 due to the rotation of the half-moon roller 60 in the direction A, and the separation roller 70 rotates in the direction indicated by C in FIG. That is, the separation roller 70 follows the half-moon roller 60. Therefore, half moon roller 60
There is no fear of abrasion on the surface of the roller and the surface of the separation roller 70.

In the above embodiment, an example of application to a stack bypass has been described. However, the present invention is not limited to this, and can be applied to an automatic document feeder. In addition, an example in which a separation roller is attached to a torque limiter as a separation unit has been described, but the present invention is not limited to this, and any known separation unit used in combination with a half-moon roller can be applied. is there.

In the above-described embodiment, the stopper portion 64 is provided on the guide member 62. Alternatively, the guide member 62 may be a conventional guide member shown in FIG. 5, that is, a guide member having no stopper portion. The invention is not limited to this.

[0021]

As described above, according to the present invention, even when an operator attempts to insert a sheet to the back of the sheet feeding section when setting a plurality of sheets or adding sheets, the guide member is provided. It is possible to prevent the paper from being set in the back of the paper feeding section by being caught by the stopper section of the paper feeding section, thereby enabling proper paper feeding.

[0022]

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a general image forming apparatus.

FIG. 2 is a view showing a sheet feeding device according to the present invention (half-moon roller is in a normal state).

FIG. 3 is a diagram illustrating a sheet feeding device according to the present invention (a state in which a half-moon roller has rotated half a turn).

FIG. 4 is a diagram illustrating a paper feeding state according to the present invention.

FIG. 5 is a diagram showing a conventional sheet feeding device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 21 ... Paper mounting table 50 ... Stopper member 51 ... Stopper part 60 ... Half moon roller 62 ... Guide member 63 ... Guide surface 64 ... Stopper part 70 ... Separation roller

Claims (1)

[Claims] An apparatus main body and a sheet provided on the apparatus main body are provided with one sheet.
A paper feed unit capable of feeding sheets one by one, a paper feed unit opening into which the leading edge of the paper can be inserted so that the leading edge of the paper is located in the paper feed unit, and a sheet to be conveyed provided in the paper feed unit opening. The paper feeding unit is provided on the half-moon roller so that the paper is guided to an appropriate position when the paper is placed on the half-moon roller and the paper mounting table. A sheet feeding means comprising a guide member and a drive unit for rotating the half-moon roller, and a separating means for separating the top sheet and the second sheet when feeding the sheet on the sheet mounting table, A paper feeding device, characterized in that a stopper member is provided on a half-moon roller so that the leading edge of the paper is properly positioned when the leading edge of the paper is inserted into the paper feeding unit opening.