JPS6341335A - Conveying method for sheet material - Google Patents

Abstract

PURPOSE:To convey a sheet material being placed in a condition with no generation of position displacement or the like to a copying part, by releasing a retard roller from being pressed to come into contact with a feed roller thereafter pressing only a separating auxiliary member to come into contact with the feed roller. CONSTITUTION:Conveyance is started by paired resist rollers 21, and a retard roller 15 is released from being pressed to come into contact with a feed roller 7 during the time just before a loop condition is eliminated. Thereafter only a separating auxiliary member 26 is placed in a condition that it is lightly pressed to come into contact with the feed roller 7, and transfer paper P, being placed in a condition of receiving almost no conveying load, is appropriately conveyed to a copying part by the paired resist rollers 21. And during this time, the transfer paper P after the second sheet in a double-feed condition, even if it tends to be placed between the feed roller 7 and the separating auxiliary member 26 by the drawing action, is effectively separated by the separating auxiliary member 26.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Industrial Application Field The present invention relates to a method for conveying sheet materials such as transfer paper. Concerning a method for separating and conveying sheet materials.

(B) Conventional technology Conventionally, in copying machines, etc., devices for producing and feeding transfer paper, etc. using retard rollers are known, and they are generally used to feed transfer paper, etc., at the top of a large number of sheets of transfer paper stored in a paper feed cassette. A pickup roller that sequentially sends out the transfer paper by pressing against the pickup roller, a feed roller installed downstream of the pickup roller, and a constant torque applied in the opposite direction to the paper feeding direction through the torque IJE screw that presses against the feed roller. The retard roller is provided with a retard roller, and a pair of registration rollers are arranged further downstream and separated by a predetermined pressure.

When conveying the transfer paper, the difference between the frictional force between the feed roller and retard roller and the transfer paper and the frictional force between the transfer paper is used to properly maintain the gap between the feed roller and the retard roller. When a sheet of transfer paper is fed, the retard roller is forcibly rotated in the paper feeding direction by the conveyance force of the feed roller, and a predetermined loop is formed in the direction of the stopped registration roller pair. If the transfer paper is double-fed between the feed roller and the retard roller, the retard roller rotates in the anti-feeding direction to feed the second and subsequent transfer papers in the anti-feed direction. While returning to the direction side, only the first sheet of transfer paper is conveyed by the feed roller toward the pair of registration rollers as described above. Next, when the rotation of the feed roller is stopped and at the same time conveyance by the pair of registration rollers is started,
Under proper conveyance conditions, the feed roller and retard roller that are in pressure contact with each other move together in the paper feeding direction as soon as the loop of the transfer paper is released, and as the transfer paper is moved by the pair of registration rollers. The transfer paper is conveyed toward the transfer section while being rotated systematically, and in the above-mentioned double feeding state, only the first transfer paper is transported while the retard roller is functioning to return the second and subsequent sheets. The image is transported toward the transfer section.

→ Problems to be Solved by the Invention By the way, in the transfer paper transport method using the above-described transport device, the retard roller is always in pressure contact with the feed roller, so the transfer paper is transported to the transfer section by the registration roller pair. If the retard roller is working to prevent electrical transmission until the trailing edge of the transfer paper passes between the feed roller and the retard roller, the torque limit of the retard roller may cause the transfer paper to be conveyed. In addition, during proper conveyance when the retard roller does not prevent double feeding, the above-mentioned conveyance load is constantly applied to the conveyed transfer paper. In addition, there is a drawback in that the conveyed transfer paper may be misaligned, elongated, etc., and as a result, the image completed on the transfer paper may be misaligned, disturbed, shrunk, etc.

(b) Means for solving the problem The present invention aims to solve the above-mentioned problems,
Before the sheet material such as transfer paper that has reached the pair of registration rollers and formed a loop starts to be conveyed by the pair of registration rollers and the loop is eliminated, the pressing contact between the feed roller and the retard roller is released, The present invention is characterized in that only the separation assisting member is then pressed into contact with the feed roller.

(Rhinoceros) Effect By adopting the above means, conveyance by the pair of registration rollers is started, and even if the loop state of the sheet material disappears,
C! - The material is lightly held by the feed roller that idles as it moves and the separation auxiliary member that lightly contacts the feed roller, and is properly transported to the transfer section by the pair of registration rollers with almost no transport load. Ru.

At that time, even if the second and subsequent sheets of transfer paper in a multi-fed state try to enter between the feed roller and the separation assisting member, they are effectively separated by the separation action of the separation assisting member.

(F) Embodiments Hereinafter, embodiments in which the present invention is embodied in a copying machine will be described with reference to the drawings.

A copying machine to which the present invention is applied has a box-shaped device main body, as well as a general copying machine, and has a transfer section inside thereof, and
The upper part is equipped with a document mounting table made of a transparent material such as glass, and one side thereof is equipped with a paper feed section, and the other side is equipped with a transfer paper receiver for aSWi copying transfer paper. Has a stand.

As shown in FIG. 1, a paper feed cassette 2 containing a large number of transfer papers P is disposed in the paper feed section 1. The uppermost transfer paper P is maintained at a predetermined height by means for detecting the height of the transfer paper P (not shown). The uppermost transfer paper P is brought into contact with the pickup roller 6 with a predetermined pressing force near its tip, and is fed toward the feed roller 7 side, that is, to the left, by the clockwise rotation of the pickup roller 6. There is. The pickup roller 6 is driven by a drive means (not shown) via an arm 9 to a shaft 10,
It is connected to the feed roller 7 which is rotationally driven in a clockwise direction via a one-way clutch 11, and is rotated in synchronization with the feed roller via a gear train, etc. Basically, the transfer paper P is The tension spring 12 transfers the paper during feeding until it is sent to the feed roller 7.
When the transfer paper P starts to be fed by the feed roller 7, the arm 9 resists the spring 12 and is moved toward the shaft 10 by the solenoid 13.
By being rotated counterclockwise around , it is separated from the transfer paper P. A retard roller 15 is disposed opposite the feed roller 7, and the feed roller 15 is driven by a drive (not shown) provided on the shaft 16 at the end of an arm member 17 that swings about a shaft 16. The shaft 19 is rotated by means of a gear train or the like, and is further rotated clockwise with a constant torque via a torque limiter 20, as shown in FIG. Then, due to the conveying action of the feed roller 7, the leading edge of the transfer paper P is kept stationary by the pair of registration rollers 2.
1 and until a predetermined loop is formed in the transfer paper P in the conveyance path 22, the retard roller 15
is pressed against the feed roller 7 by the tension spring 23 with a predetermined pressing force, but from the time when the loop is formed and the rotational drive of the feed roller 7 is stopped, the transfer is then performed by the registration roller pair 21. After the conveyance of the paper P starts and until the loop state of the transfer paper P disappears, the arm member 17 is pulled by the solenoid 25 against the spring 23 and rotated clockwise, so that the retard roller 15 is adapted to be released from the press contact state with the feed roller 7. and,
As shown in FIG. 2, the feed roller 15 is divided into two parts so as to be in pressure contact with each other at both ends of the feed roller 7, and a separation auxiliary member such as a friction pad is provided between the two parts. 26 is, for example, a spring 27
, an extremely small contact force is applied to the feed roller 7 by the arm member 30 rotating around the shaft 29, that is, while the transfer paper P is being transported by the registration roller pair 21, one sheet of the transfer paper P is being transported. The paper is brought into contact with the feed roller 7 with a light force that is enough to prevent the second and subsequent transfer papers from being dragged by the rear end of the transfer paper P and being conveyed downstream from the feed roller 7. It has become.

Since this embodiment has the above-described configuration, when the paper feeding operation is started, the uppermost one of the many transfer papers P comes into pressure contact with the rotating pickup roller 6, as shown in FIG. As a result, the transfer paper P is separated from the lower transfer paper P and conveyance is started. At this time, a certain torque is applied to the retard roller 15 in the counter-feeding direction as shown by the dotted line arrow, but it comes into contact with the feed roller 7 and is forcibly rotated in the paper feeding direction as shown by the solid line arrow. Next, as shown in (b), the separated transfer paper P is held between the feed roller 7 and the retard roller 15 and conveyed toward the registration roller pair 21. At this time, the retard roller 15 is forced to move counterclockwise (as shown by the solid line arrow) against a constant torque in the counter-feeding direction, as shown by the dotted line arrow, due to the am force with the transfer paper P conveyed by the feed roller 7. Then, the above (a
), for example, if two sheets of transfer paper P are fed in an overlapping state between the feed roller 7 and the retard roller 15, the frictional force between the transfer sheets 2 is small, so that the upper transfer paper P is transported in the paper feeding direction by the frictional force caused by contact with the feed roller 7, and the lower transfer paper P is pulled back by a constant torque in the counter-feeding direction by the frictional force caused by the contact with the feed roller 15. is repeated, (c
), double feeding is prevented. Then (d)
After the leading edge of the transferred transfer paper P collides with the registration roller pair 21 which is still in a stationary state, a predetermined slack or loop is formed in the transfer paper P as shown by the two-dot chain line due to the conveying action of the feed roller rough. At this point, the rotational drive of the feed roller 7 is stopped. At this time, as shown in (d), the pickup roller 6 is rotated upward and released from contact with the transfer paper P. However, if the timing of this contact release is early, the above ((d)) It suffices to do this before the loop is resolved in step b) or at the latest in step (d), which will be described later. However, when the length of the transfer paper P in the feeding direction is relatively short, in order to prevent the next transfer paper P from being fed, the rear end of the previous transfer paper P is Pick up roller 6 before passing through
Of course, it is necessary to release the contact between the transfer IP and the transfer IP.

Second, during this period, the retard roller 15 (rolling double feed prevention effect) is performed in exactly the same manner as the above-mentioned operation.

Then, as shown in (e), conveyance by the pair of registration rollers 21 is started, and the pressing contact of the retard roller 15 with the feed roller 7 is released just before the loop state is canceled.

The ideal timing for releasing the pressure contact of the retard roller 15 with the feed roller 7 is immediately before the loop state is eliminated, but there is no problem even if the timing is immediately before the loop is eliminated. After that, only the separation auxiliary member 26 is lightly pressed and contacted by the feed roller 7, and the transfer paper P+ is properly conveyed to the transfer section by the pair of registration rollers 26- with almost no conveyance load. be done. During this time, the second and subsequent sheets of transfer paper P in the double-feed state try to enter between the feed roller 7 and the separation assisting member 26 due to the pulling action of the transfer paper P that is being conveyed by the pair of registration rollers 21. However, since no other conveying action is acting on them, they are effectively separated by the separation assisting member 26.

Note that in the above embodiment, the separation auxiliary member 26 was described as being in constant pressure contact with the feed roller 7;
The separation auxiliary member 26 is connected to the retard roller 1 by an appropriate mechanism.
It may be configured such that when the feed roller 5 is released from the feed roller 7, the feed roller 7 is pressed against the feed roller 7.

Next, FIG. 4 shows another embodiment in which a part of the structure of the retard roller and the separation assisting member has been changed. The separation auxiliary members 26', 26', which are divided into two parts on both sides of the retard roller 15', are configured to press into or release the narrow retard roller 15' from the feed roller 7. It is configured to contact both ends. It should be noted that in this embodiment as well, the conveyance action for the transfer paper P and the double-feed prevention action are the same as in the above-mentioned embodiment, so the operations related to this embodiment will be omitted below.

(G) As described in detail, according to the present invention, a feed roller,
In a sheet material conveying system that includes a retard roller that is pressed into contact with the roller and is driven via a torque limiter, and a register roller pair, the feed roller and retard roller are moved after the sheet material reaches the registration roller pair. Since the sheet material is conveyed by canceling the pressing contact with the feed roller, and then only the separation auxiliary member comes into pressing contact with the feed roller, the conveyance load is hardly applied to the sheet material when the sheet material is conveyed by the pair of registration rollers. As a result, the sheet material is transported to the transfer section with high precision and stability without any positional deviation or stretching, and as a result, the completed image is positioned on the sheet material.
Extremely high quality image formation is achieved without disturbance, shrinkage, etc.

Furthermore, the time during which the feed roller and retard roller are in pressure contact is shortened, and wear and the like of the fractionation roller is reduced, making it possible to prolong the life of the copying machine and the like.

[Brief explanation of drawings]

FIG. 1 is a sectional side view of a main part of an embodiment in which the present invention is applied to a paper feed section of a copying machine, FIG. 2 is a sectional view taken along line XX in FIG. 1, and FIG.
a) to (e) are explanatory diagrams of the paper feeding operation, and FIG. 4 is a sectional view corresponding to FIG. 2 of another embodiment. 7...Feed roller, 11...One-way clutch, 15...Retard roller, 20.I
・Lux limiter, 21 ・Registration roller pair,
26... Separation auxiliary member, P... Sheet material (transfer paper).

Claims (1)

[Claims] (1) a feed roller, a retard roller that is in pressure contact with the feed roller and is driven via a torque limiter;
and a sheet material conveyance system including a pair of registration rollers, after the sheet material reaches the pair of registration rollers, the pressing contact between the feed roller and the retard roller is released, and then only the separation auxiliary member presses the feed roller. A method of transporting sheet materials in contact with each other.