JP2518073Y2 - Paper feeder - Google Patents

Description

[Detailed Description of the Invention] Industrial field of use The present invention blows air to the leading end of the stacked sheets to separate them from each other, and sucks the bottom sheet by a negative pressure suction section. The present invention relates to a sheet feeding device used in a copying machine, a printer, or the like, which conveys and feeds a sheet through a guide member provided on the downstream side of the negative pressure suction portion in the sheet feeding direction.

2. Description of the Related Art As a sheet feeding device used in a copying machine or the like, air is blown to a stacked sheet bundle, the sheet is floated by the air knife, and the sheet is separated by utilizing its deformation resistance,
There is a type in which the lower sheets stacked are attracted to a conveyor belt by negative pressure and sequentially fed. Conventionally, in such a device, the face curl of the sheet front end is promoted by the air knife, and when the sheet leaves the suction part and enters the guide member provided on the downstream side, the tip curl part comes into contact with the guide member. , I couldn't guide and the seat sometimes buckled. Such a problem occurs depending on the stiffness of the seat, but occurs when the contact angle of the leading end of the seat with the guide member is about 45 ° or more.

In order to prevent this, as shown in FIGS. 3 (a) and 3 (b), the guide member 7 is of a type in which the central portion of the guide member is projected and the left and right sides are retracted, and the both ends of the curled sheet are guided in a squeezing manner. Is known, but it was insufficient to prevent the above problems.

DISCLOSURE OF THE INVENTION Problem to be Solved by the Invention The present invention solves the above problems in the prior art, and provides a sheet feeding device capable of feeding a sheet well without buckling of the sheet in the guide member. And

Means for Solving the Problems In order to solve the above problems, the invention of claim 1 blows air to the leading end of the stacked sheets on the feeding side to separate the sheets from each other, and the negative pressure is applied to the bottom sheet. In a sheet feeding device that conveys while sucking by a suction unit and feeds through a guide member provided on the downstream side of the negative pressure suction unit in the sheet feeding direction, the sheet feeding device that is fed to the inlet of the guide member It is characterized in that a rotating body for guiding the leading end of the lower sheet is provided.

According to a second aspect of the present invention, air is blown to the leading end of the transfer sheet stacked on the intermediate tray for re-feeding to separate the transfer sheets, and the bottom transfer sheet is sucked by the negative pressure suction unit. In a sheet feeding device that conveys the sheet while sucking the sheet through a guide member provided on the downstream side of the negative pressure suction portion in the transfer sheet feeding direction, the transfer sheet is retracted before being stacked on the intermediate tray. It is characterized in that there is provided a pressing member which is located at a position and which is moved to a position where it presses the transfer papers separated by air blowing from the top after being loaded.

According to the first aspect of the invention, since the rotating body for guiding the leading end of the lowermost sheet fed to the guide member inlet is provided, the leading end of the curled sheet is pressed by the rotation of the rotating body, and the curl is reduced. The formed sheet is introduced into the guide member.

According to the second aspect of the present invention, since the transfer paper separated by the air knife is pressed from above after the transfer paper is stacked, the curl amount of the transfer paper promoted by the air knife can be reduced.

Embodiment Hereinafter, the present invention will be described in detail with reference to an embodiment shown in the drawings.

The sheet feeding device shown in FIG. 1 is used, for example, in a double-sided copying machine as an intermediate tray for re-feeding a transfer sheet after being copied on one side, which is an example of a sheet.

The transfer paper P is sequentially discharged by the discharge roller 1, the rear ends thereof are aligned by the end fence 2 and stacked on the bottom of the tray, and the transfer paper P is floated by the air knife blown from the air knife device 3 and separated from each other.

An upper end of the transfer sheet P on the feeding side is provided with a rotatable sheet front end guide plate 4, one end side of which is pivotally supported, and a guide plate is provided after the final transfer sheet P is discharged and stacked. Four
A solenoid (not shown) for rotating is driven, and the guide plate 4 is rotated to press the transfer paper P from above, and regulate the face curl of the tip portion caused by the air knife.

The rotational position of the sheet leading end guide plate 4 is set sufficiently higher than the height at which the sheets are stacked, and is set at a position that does not prevent the transfer sheet P from being lifted by the air knife.

In this state, the lowermost transfer paper P is sucked onto the conveyor belt 6 by the suction air of the vacuum tank 5 which is a suction unit and separated from the upper transfer paper, and the conveyor belt 6 is driven by a driving device (not shown) by a paper feed signal. When driven in the counterclockwise direction, the sheet is conveyed in the feeding direction on the left side in the drawing, guided by the guide plate 7 as a guide member, and fed from the conveying roller 8 to the image forming unit (not shown).

In this case, since the transfer paper P is pressed by the paper leading end guide plate 4 and curling is suppressed, the transfer paper P with a small curl
Will be sent to the guide plate 7, and the transfer paper P will not be buckled because it is not guided in the guide plate.

 Next, the embodiment shown in FIG. 2 will be described.

In the present embodiment, a brush roller 4a, which is an example of a rotating body, is provided at the entrance of the guide plate 7 instead of the paper leading end guide plate 4 shown in FIG. The configuration of other parts is the same as that of FIG.

When the lowermost sheet of the stacked transfer sheets P is conveyed by the conveyor belt 6, the front end of the face-curled transfer sheet P is
It hits the outer peripheral portion of the rotating pig roller 4a, is guided by this and is directed downward, the face curl is corrected, and it is introduced into the guide plate 7. As a result, it is possible to prevent the transfer paper P from buckling in the guide plate 7 and causing a defective guide.

Since the brush roller 4a guides the transfer paper P, the peripheral speed of the outer periphery of the brush roller 4a is set to be higher than at least the speed of the belt 6, which is the speed at which the transfer paper P is conveyed. It is set to an appropriate speed in consideration of the sheath diameter and the like.

If the brush roller 4a is made of a conductive material, static electricity generated during stacking of the transfer paper P and during feeding and separation can be removed, and the effect of improving the separability of the paper occurs.

In the above embodiments, the brush roller is used as the rotating body, but a sheet having a constant incident angle with respect to the surface of the rotating body such as a guide plate-shaped member or a roller having a recess for guiding the sheet in the width direction is used. Anything can be used as long as it can be conveyed in the circumferential direction when the tip portion abuts.

As described above, according to the invention of claim 1, the face curl generated on the seat is reduced and guided to the guide member, and according to the invention of claim 2, the face curl of the seat is suppressed by the pressing member. By restricting the occurrence of the occurrence of defects, it is possible to prevent defective guides in the guide member and buckling of the sheet.

[Brief description of drawings]

1 and 2 are explanatory views of a sheet feeding device according to an embodiment of the present invention, FIG. 3 (a) is a plan view showing an example of a guide member of a conventional sheet feeding device, and FIG. 3 (b) is It is the sectional view on the AA line. 3 ... Air knife device 4 ... Paper tip guide plate (pressing member) 4a ... Brush roller (rotating body) 5 ... Vacuum tank (negative pressure suction part) 6 ... Conveying belt 7 ... Guide plate (guide member) )

Claims (2)

(57) [Scope of utility model registration request] 1. A sheet feeding device for feeding a stack of sheets, wherein air is blown to the leading end of the feeding side to separate the sheets from each other and the lowermost sheet is conveyed while being sucked by a negative pressure suction section. In a sheet feeding device that feeds through a guide member provided on the downstream side in the feeding direction, a rotating body that guides a leading end portion of the lowermost sheet that is fed is provided at an inlet portion of the guide member. Paper feeding device. 2. A sheet of transfer paper stacked on an intermediate tray for re-feeding is blown with air to separate the transfer sheets, and the bottom transfer sheet is sucked by a negative pressure suction section. In a paper feeding device that conveys the transfer paper through a guide member provided on the downstream side of the negative pressure suction portion in the transfer paper feeding direction, the transfer paper is moved to a retracted position before being stacked on the intermediate tray. A sheet feeding device provided with a holding member that moves to a position where the transfer sheets separated by being blown with air are pressed from the top after being stacked.