JP2887846B2 - Separated sheet feeding device and separated sheet feeding method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a separation sheet feeding device and a separation sheet feeding method in an image forming apparatus.

[Conventional technology]

A separation roller and a separation belt are provided so as to be in pressure contact with the separation roller. The separation roller rotates in the conveyance direction of the document, and the separation belt rotates in the direction opposite to the conveyance direction to separate and feed the paper one by one. Proposed.

[Problems to be solved by the invention]

However, in the separation sheet feeding device using the separation roller and the separation belt, the paper is pressed against the separation roller and the separation belt during the separation sheet feeding. Will stick. In a state where the belt is not operated, the roller and the belt are in pressure contact with each other, so that the belt is in a state of being bonded. For this reason, there is a problem that the separation performance is inferior at the time of the next document feeding, and double feeding is likely to occur.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a separation sheet feeding device and a separation sheet feeding method which can solve the above-mentioned drawbacks of the conventional apparatus and can prevent a decrease in separation sheet feeding performance.

[Means for solving the problem]

The above object has a separation roller and a separation belt disposed so as to be in pressure contact with the separation roller. The separation roller is rotated in the direction in which the document is transported, and the separation belt is rotated in the direction opposite to the transport direction so that the paper is rotated by one. Detecting means for detecting the setting of the document to the separate sheet feeding in a sheet feeding apparatus for separating and feeding sheets one by one;
The first means includes a control means for rotating the separation belt by a predetermined amount when the detection means detects that a document is set other than during the separation sheet feeding.

The object is to separate a document one by one by sliding a separation roller rotating in a document conveying direction and a separation belt rotating in a direction opposite to the separation roller, and setting a document other than during separation and feeding. This is achieved by a second means for rotating the separation belt by a fixed amount when it is performed.

[Action]

According to the first means, the control means rotates the separation belt by a fixed amount when the detection means detects that a document is set other than during the separation and feeding.

According to the second means, the separation roller rotating in the document conveyance direction and the separation belt rotating in the opposite direction to the separation roller are slid in contact with each other to separate the documents one by one, and also at the time other than during separation and feeding. When the document is set, the separation belt is rotated by a fixed amount.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a side sectional view showing the overall configuration of an RDH as an embodiment of the present invention, and FIG. 2 is an enlarged view of a main part thereof. this
The RDH includes a sheet feed table 1 provided in a cover-type case covering a contact glass 101 provided on the top surface of the copying machine main body 100 over a range excluding the left and right ends of the upper portion thereof and a left end in the figure. Contact glass 101 one by one from the bottom of a sheet bundle placed on a sheet feeding table 1 provided in
A paper feed unit 70 composed of a paper feed mechanism for feeding the paper up and a lower running unit slidably contact the entire upper surface of the contact glass 101, and expose the original fed from the paper feed unit to a predetermined original on the contact glass 101. Transport section 71 having a transport belt 12 for transporting the original to a position and discharging the original from the contact glass 101 after exposing the original.
And a reversing unit for reversing the original sent from the transport unit 71
72, and a return unit 73 for returning the document inverted by the reversing unit 72 to a document bundle on the sheet feeding table 1 are provided.

Hereinafter, each of the sheet feeding unit, the conveying unit, the reversing unit, and the return unit will be described in order.

(Sheet Feeding Unit) Side fences 2 are provided on both the left and right sides in the transport direction within the minimum document placing range at the front of the sheet feeding table 1. In the vicinity of the front end in the paper feeding direction of the paper feeding table 1, two call rollers 3a and 3b having a missing circular portion are positioned so that they do not protrude from the original placing surface when the missing circular portion is located above. Are provided before and after.

Above the call roller 3a, there is provided a pressing plate 4 which is driven by a solenoid (not shown) and presses down the leading end of the document at a position shown by a chain line in FIG. 1 to press the call roller 3a. Above the holding plate 4, there is provided a stopper 5 which rotates around the rear end and is displaced between a retracted position shown by a broken line and an operating position shown by a solid line in FIG. In the operating position, the toe of the stopper 5 abuts on the upper surface of the table 1 or the upper surface of the set of originals, and returns to the upper surface of the original bundle on the table 1 from behind by circulating the set claw when setting the original bundle. It has a function to correct the skew by abutting the leading edge of the document.

The document bundle pressed by the pressing roller 4a by the pressing plate 4 is reliably conveyed to the separation unit by the synchronous rotation of the calling rollers 3a and 3b. In FIG. 1, reference numeral 6 denotes a document set sensor, which detects that the document is set on the document bundle table 1, and outputs a call roller 3 based on the detection signal.
The document bundle is conveyed by rotating a and 3b by a fixed amount.

The call rollers 3a and 3b further have a function of reliably feeding the lowest sheet of the document bundle at the above-mentioned position in cooperation with the separation unit including the endless belt 7 and the separation roller 8. The separation roller 8 rotates in the direction in which the document is moved in the transport direction at a speed at which the peripheral speed becomes the document transport speed. On the other hand, the endless belt 7 is pressed against the circumference of the peripheral surface of the separation roller 8 and pressed. The direction opposite to the transport direction (arrow A in FIG. 1)
In the direction indicated by the arrow) at a speed of, for example, about 1/20 of the document conveying speed, the friction coefficient between the separation roller 8 and the document, the friction coefficient between the endless belt 7 and the document, and the By appropriately setting the friction coefficient, the original fed out from under the original stack by the call rollers 3a and 3b can
In the case of a sheet, the sheet is directly conveyed to the pull-out rollers 9 and 10 on the downstream side, and in the case of two or more sheets, only the lowest one sheet is separated and conveyed toward the pull-out rollers 9 and 10.

The separation roller 8 has a built-in one-way clutch.
When the document is conveyed by the pull-out rollers 9 and 10, even if the separation roller 8 is turned off, the document is conveyed and the document conveyance load is reduced.
It can be transported at a predetermined speed. The drive of the separation roller 8 is turned on and off by a clutch (not shown).
When the registration sensor 11 provided at the discharge section from the paper feed section 70 to the transport section 71 detects the leading end of the document, the clutch is turned off and the drive to the separation roller 8 is shut off. The registration sensor 11 also serves as a detection unit for detecting the trailing edge of the document and controlling to stop the document at a predetermined exposure position on the contact glass 101.

The above-mentioned call rollers 3a and 3b, the separation roller 8, and the pull-out roller 9 can be driven by a single motor or by separate motors.

(Conveying Unit) The conveying unit 71 is composed of a single wide conveying belt 12 wound around a pair of rollers 65 and 66, and its lower running part is pressed against the contact glass 101 by a plurality of pressure rollers 13; Paper feed section 7
The original sent from 0 is conveyed to a predetermined exposure position, and the exposed original is sent to the reversing unit 72.

(Reversing Unit) The reversing unit 72 includes a reversing roller 15 provided along a reversing guide, a pressing roller 16 pressed against the reversing roller 15, and a downstream side between a position shown by a solid line and a position shown by a broken line in FIG. A switching claw 14 displaceable therebetween is provided. The switching claw 14 is switched to the position indicated by the broken line in the case of the double-sided original mode. The switching claw 14 is located at the position shown by the solid line in the figure and is discharged to the return portion 73. A reversing sensor 17 is provided between the pressure roller 16 and the switching claw 14 so as to face the reversing roller 15, whereby the drive timing of the transport belt 12 is controlled. The transport belt 12 and the reversing roller 15 are each driven by a single motor (not shown).

(Return Unit) The return unit 73 is a paper discharge unit that can move on the paper feed table 1 in the document transport direction (the left-right direction in FIG. 1).
The document feed path 18 is connected to the rear of the paper discharge unit 18 in the transport direction, expands and contracts in accordance with the movement of the paper discharge unit 18, and forms a document transport path between the paper discharge unit 18 and the upper surface of the paper feed table 1 behind. It is configured to have a guide plate and an intermediate belt 27 for conveying the document discharged from the reversing section 72 to the paper discharge unit 18.

The above-mentioned guide plates are a plurality of (three in this example) guide plates 21, 22,
23, and by moving the paper discharge unit 18,
The overlap of the guide plates 21, 22, and 23 changes so as to expand and contract. The guide plates 21, 22, and 23 are sequentially overlapped outward in the document transport direction so that the front end of the document transported along the transport path is not caught by the overlapping portion of the guide plates. Above each of the guide plates 21, 22, and 23, an outer cover 24, 25, and 26, respectively, has a rear end fixed to a rising portion formed by bending a rear end of each guide plate upward, and is similar to the guide plate. Are provided so as to be able to extend and contract with each other.

FIG. 3 is a control block diagram. 200 is a CPU, 201 is a group of sensors, 202 is a group of loads such as solenoids, 203 is an I / O port, and 204 is a group of motors.

FIG. 4 is a flow chart of the document setting check subroutine, in which the document setting sensor 6 of the document table is ON.
Subtract one from SWTiM. The program is formed by connecting each routine (document set check and the like) as a main routine. In this case, it is decremented each time the document set check routine is executed. When there is no manuscript
SWTiH is set to OFF _H. When the manuscript is placed, SWTiM
<80 _H below sets TDSET becomes a (which by the time the secured until the document is set correctly).

FIG. 5 is a flowchart of a subroutine of the separation belt operation, and shows that when the document set sensor 6 is turned on, the separation belt motor is turned on and the separation belt 7 is rotated by a predetermined amount (for example, 15 mm). That is,
RUN3F is set when the paper feed operation of RDH starts, and reset when the operation is completed. When RUN3F is 0 and TDSET is 0,
When the pressure falls below OBO _H , the separation belt 7 is turned on, and when the pressure falls below 90 _H , the separation belt 7 is turned off. That is, the time from OBO _H of 90 _H, the separation belts 7
Will be turned ON.

When the separation belt 7 is rotated by the document set in this manner, the pressure contact surface between the separation belt 7 and the separation roller 8 changes, so that the influence of adhesion of dirt can be eliminated, and good separation performance can be maintained. .

〔The invention's effect〕

As described above, according to the first and second aspects of the present invention, since the separation belt is rotated by a fixed amount according to the document set, the pressure contact surface between the separation roller and the separation belt changes each time, and good separation performance is obtained. Can be maintained.

[Brief description of the drawings]

1 is a configuration diagram of an automatic document circulating and feeding apparatus according to an embodiment of the present invention, FIG. 2 is an enlarged view of a main part thereof, FIG. 3 is a control block diagram, and FIGS. 4 and 5 are main parts. 9 is a flowchart showing a subroutine of FIG. 6: Document set sensor, 7: Separation belt, 8: Separation roller, 200: CPU.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-13529 (JP, A) JP-A-56-65734 (JP, A) JP-A-61-130531 (JP, U) JP-A-64 50241 (JP, U) Fully open sho 59-33845 (JP, U) (58) Field surveyed (Int. Cl. ⁶ , DB name) B65H 1/00-3/68

Claims (2)

(57) [Claims] An image forming apparatus has a separation roller and a separation belt disposed so as to be in pressure contact with the separation roller. The separation roller is rotated in a direction in which the document is transported, and the separation belt is rotated in a direction opposite to the transport direction to rotate the paper. In a separation sheet feeding device that separates and feeds one sheet at a time,
Detecting means for detecting the setting of the document to the separate sheet feeding; and control means for rotating the separation belt by a fixed amount when the detecting means detects that the document is set other than at the time of the separate sheet feeding. A separation sheet feeding device characterized by the above-mentioned. 2. A separation roller rotating in a document conveying direction and a separation belt rotating in a direction opposite to the separation roller are slid in contact with each other to separate the documents one by one, and the originals are set except when the paper is separated and fed. A separation belt is rotated by a predetermined amount when the separation is performed.