JPH0541539B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates primarily to a paper supply device used in a double-sided copying machine, and more particularly, to a paper supply device for a copying machine that is capable of reliably refeeding paper that is in a standby state after one side has been copied.

In conventional copying machines that can copy on both sides of paper, the paper that has been copied on one side is kept on standby in the copying machine, and in the next copying process, this paper is fed again and copied, and after copying on both sides is completed. The paper is discharged outside the copying machine, and the copying machine is equipped with a paper feeding device as shown in FIG. 1A, for example. In this feeding device, when paper a, which has been copied on one side, reaches the inlet, pinch roller b is separated by feed roller c to facilitate the entry of paper a. The pinch roller b reaches between the retard roller e and the retard roller e pressed against it, as shown in FIG. However, in the paper supply device having this structure, the pinch roller b is moved up and down each time the paper a is carried in, so the structure is complicated and expensive.

This invention was made with the aim of eliminating this drawback, and is a copying machine that can reliably refeed paper without the need for a pinch roller that moves up and down each time paper is carried in, or a mechanism to drive this. The present invention aims to provide a paper feeding device with a simple configuration.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings shown in FIG. It has a paper tray 2 that is tilted diagonally, and a guide sheet 15 made of a slippery flexible sheet on the upper side of the paper tray 2.
The lower end of the feed roller 3 reaches the vicinity of a feed roller 3 connected to a drive system (not shown) via a one-way clutch 3c. As shown in FIG. 3, the feed roller 3 consists of a cylindrical small-diameter portion 3a and a plurality of large-diameter portions 3b protruding from the small-diameter portion 3a at intervals. A portion 2a of the lower end of the tray 2 has entered. Reference numeral 4 denotes a retard roller provided close to the feed roller 3, which includes a cylindrical small diameter portion 4a and a small diameter portion 4a.
The large diameter portions 4b are located between the large diameter portions 3b of the feed roller 3, and a part of the circumferential surface thereof is located between the large diameter portions 3b of the feed roller 3. It is somewhat protruding in between. Further, the shaft 4c of the retard roller 4 is rotatably supported at the lower part of a housing 6 whose upper end side is swingably supported by a tie bar 5, and a tie plate 7 is provided at the rear of the housing 6. The tie plate 7 is provided with an adjustment screw 8 for adjusting the position of the retard roller 4 in the direction toward and away from the feed roller 3, and a tension spring 9 for biasing the housing 6 in the direction toward the distance from the feed roller 3.

On the other hand, reference numeral 10 denotes an entry guide plate formed of a leaf spring or the like, and a fixed part 11 of the guide plate 11 is provided so that the upper end thereof goes around approximately half the circumference of the feed roller 3.
a, the lower end side of the approach guide plate 10 is curved in an arc shape, and the tip is further divided into each large diameter portion 3b of the feed roller 3,
They are pressed against the circumferential surface of the large diameter portion 3b as shown in FIG. 4, respectively.

Further, the lower end side of the guide plate 11 reaches the conveyance roller 12 after bypassing the lower part of the feed roller 3, and the paper 13 guided by the guide plate 11
The conveying roller 12 increases the speed and conveys to the next process. Note that 14 in the figure is the paper 1 in order to send out the paper 13 in accordance with the copying timing.
This is a paper detector for detecting 3 and temporarily stopping it.

However, the paper 13, which has been copied on one side in the first copying process, is guided by the slope of the paper tray 2 and the guide sheet 15, and falls naturally between them.
The leading edge of the paper 13 is pressed against the feed roller 3 and its peripheral surface by the loading force and the falling force.
It is inserted between the tips of 0. In this state, the sheets 13 are kept on standby for the next copy, and the sheets 13 that have been brought in one after another during this time are transferred to the first sheet 1 as shown in FIG.
3 Deposited on ₁ . Next, when the feed roller 3 is driven via the one-way clutch 3c, the paper ₁₃₁ whose leading edge is stuck is transferred to the feed roller 3.
At the same time, the paper 13 ₂ on top of the paper 13 ₁ is also transported at the same time, but as shown in FIG. 6, when it reaches the retard roller 4, it slowly rotates in the opposite direction to the feed roller 3. The upper paper 13 ₂
is separated from the lower paper 13 ₁ and its conveyance is blocked, so only the lower paper 13 ₁ that is in close contact with the feed roller 3 is guided by the guide plate 11 and conveyed, reaching the conveyance roller 12 (FIG. 7). . The paper 13 that has reached the conveyance roller 12 is accelerated and conveyed out by the conveyance roller 12, which rotates at a faster circumferential speed than the feed roller 3, and at this time, the one-way clutch 3c of the feed roller 3 rotates idly, so that the sheet 13 rotates at the same speed as the conveyance roller 12. The paper 13 is rotated at a speed of 100 to allow the paper 13 to be conveyed at an increased speed. When the trailing end of the paper 13 leaves the feed roller 3 (FIG. 8), the feed roller 3 returns to its original speed, and as the first paper 13 ₁ is carried out, the leading edge is placed between the peripheral surface of the feed roller 3 and the entry guide plate 10. Conveyance of the next sheet of paper 13 ₂ that has entered is started.
The next sheet 13 ₂ is also conveyed together with the upper sheet 13 ₃ as above, but since the upper sheet 13 ₃ is stopped from being conveyed when it reaches the retard roller 4, only the lower sheet 13 is conveyed. , paper 13
When the leading edge of the paper reaches the paper detector 14, it is temporarily stopped until it synchronizes with the next copying timing (FIG. 9). Thereafter, while repeating the above operation, the sheets 13 on the paper tray 2 are sent out one after another, and the uncopied surfaces are copied.

In the above embodiment, the tip of the entry guide plate 10 was structured to be in contact with the circumferential surface of the feed roller 3, but as shown in FIG. A similar effect can be obtained even in a non-contact manner.

Furthermore, it goes without saying that the above-mentioned supply device can be used not only for double-sided copying machines but also for ordinary copying machines.

As described in detail above, this invention utilizes the falling of the paper to insert the leading edge of the paper between the feed roller and the entry guide plate. It is possible to refeed the paper reliably, and it does not require the conventional pinch roller that moves up and down or a complicated mechanism to drive it, so it is easy to manufacture and can be provided at low cost.

[Brief explanation of the drawing]

1A and 1B are explanatory diagrams of a conventional device, FIG. 2 is a side view showing an embodiment of the present invention, FIG. 3 is a front view of a feed roller and a retard roller, and FIG.
The figure is a perspective view of the feed roller and the entrance guide plate, FIGS. 5 to 9 are explanatory diagrams of the operation, and FIG. 10 is an explanatory diagram showing another embodiment. 2 is a paper tray, 3 is a feed roller, 4 is a retard roller, 10 is an entry guide plate, and 15 is a guide sheet.

Claims (1)

[Claims] 1 Above the paper tray 2 which is inclined so that the paper 13 is carried in high and the discharge side is low, the paper tray 2 is made of a flexible sheet and the leading edge is in contact with the upper surface of the paper tray 2. A guide sheet 15 is provided to guide the paper 13 stored on the paper tray 2 so that it falls along the upper surface of the paper tray 2, and a guide sheet 15 is provided on the lower end side of the paper tray 2 to guide the paper 13 stored on the paper tray 2 one by one. Feeding roller 3
A retard roller 4 is provided close to the feed roller 3 to prevent double feeding of the paper 13, and
On the paper input side of the feed roller 3, there is an arcuate approach guide that sequentially retreats the leading edge of the upper paper 13 so that the leading edge of the paper 13 stacked on the paper tray 2 enters the feed roller 3 more than the lower paper 13. A paper supply device for a copying machine including a plate 10.