JPH0214270B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a paper feeding device that is mainly used in a double-sided copying machine and feeds stacked sheets of paper that have been copied on one side and are in a standby state one by one.

In order to make double-sided copying possible, a special tray for double-sided copying is required to temporarily store sheets of paper in the machine so that the paper that has been single-sided copied can be copied again.

An example of this will be explained with reference to FIG.
It is deposited and stored in. When the one-sided copying completed paper has been stored, the pressing member 5 is activated with a signal to start copying on the second side.
is pressed onto the paper, applying appropriate pressure between it and the auxiliary roller 4, and rotating the auxiliary roller 4 and feed roller 2 in the paper feeding direction and the separation roller 3 in the opposite direction, the stacked paper 7 is 1 piece of paper from the position
The second side of the sheet is fed to the copying section.

In this type of paper feeding device, due to the influence of static electricity and curling of the paper, the leading edge of the paper at the lowest position may be fed more easily than the leading edge of the papers stacked above it, as shown in Figure 2. When the roller 2 is housed at a position away from the front side in the feeding direction, as shown in FIG.
The paper above the paper at the lowest position is sent out by the feed roller 2 first, making it extremely easy to send double feeding.

The present invention has been made in consideration of the above-mentioned problems, and it is an object of the present invention to provide a paper feeding device for a copying machine that can reliably prevent double feeding due to the above-mentioned poor storage configuration.

The configuration will be explained below based on the embodiment shown in FIG. 4 and below. In this embodiment, the same constituent members as those of the conventional example are given the same reference numerals as those shown in the drawings showing the conventional example, and the explanation thereof will be omitted.

After passing through the conveyance roller 6, the single-sided copy paper passes through the conveyance paddle 8 and the guide member 10, and is deposited on the double-sided copy tray 1. The paper at this time is detected by the photo sensor 11. Photo sensor 1 after completion of deposition
The pressing member 5 controlled by the detection operation in step 1 moves downward onto the paper, thereby applying appropriate pressure between the auxiliary roller 4 and the paper, and rotating the auxiliary roller 4, the feed roller 2, and the separating roller 3. As a result, the stacked papers are fed one by one starting from the lowest one.

A photo sensor 9 is provided at an exit portion on the feeding direction side of the nip portion between the feeding roller 2 and the separating roller 3 of the sheet feeding device configured as described above.

Then, after the leading edge of the first sheet of paper on the double-sided copying tray 1 is detected by the photo sensor 11 on the entrance side, an electromagnetic clutch (not shown) is turned on until the leading edge of the first sheet of paper is detected by the photo sensor 9 on the exit side, and the feed roller 2 separates the paper. By rotating the roller 3 and auxiliary roller 4,
The first sheet of paper is stopped with its leading edge past the nip between the feed roller 2 and the sorting roller 3, and the leading edge of the second and subsequent sheets of paper is in front of the leading edge of the first sheet of paper. You will no longer be detained in a state where you are exposed. The accommodation state at this time is shown in FIG. In addition, when the first sheet of paper is moving in the tray 1 toward the photo sensor 9 on the exit side, the pressing member 5
When the first sheet of paper is lowered, the first sheet of paper is more reliably conveyed to the position of the photo sensor 9 on the exit side by the auxiliary roller 4.

With the above configuration, when the first sheet of paper stored in the double-sided copying tray 1 is fed out, the second or more sheets of paper are prevented from being fed out at the same time, and double feeding that results in poor accommodation is reliably prevented. Ru.

As another example of application, for example, as shown in FIG. 6, the length of the paper stored in the duplex copying tray 1 is short, and the second paper falls near the rear end of the paper, causing the first If there is a possibility that the leading edge of the second sheet will hit the rear end of the first sheet when the paper advances to the position of the photo sensor 9 on the exit side, resulting in a storage failure, then when storing the first sheet, the feed roller 2 is left in a stopped state, and after the leading edge of the second sheet is detected by the photo sensor 11 on the entrance side, if the feed roller 2 and the sorting roller 3 are rotated at a certain timing, the first sheet will be transferred to the exit. It is stopped at a predetermined position by the photo sensor 9 on the side, and the second sheet does not advance beyond the nip of the feed roller 2 and the separating roller 3 due to the separating action of the separating roller 3, and when the third sheet is received. Moreover, the leading end of the sheet does not abut against the trailing end of the second sheet of paper, thereby preventing storage failure. Further, when the second sheet is completely accommodated and the feed roller 2 rotates, the pressing member 5 is lowered and the first sheet is conveyed by the force of the auxiliary roller 4, thereby ensuring that the first sheet reaches the photo sensor 9. The pressing member 5 is raised at an appropriate timing that does not interfere with the storage of the third sheet of paper.

The present invention is as described above, and the paper feed of a copying machine is provided in which a nip is formed by a feeding roller and a separating roller at the tip of an intermediate tray such as a double-sided copying tray that receives sheets that are sequentially fed. In the apparatus, a detection means such as a photo sensor is provided at the entrance of the intermediate tray and at the exit of the nip between the feed roller and the separation roller in the feeding direction, respectively;
The drive unit for the feed roller and the separation roller drives the feed roller and the separation roller after the detection means on the entrance side detects the leading edge of the first sheet of paper until the detection means on the exit side detects this. Since the paper feeding device of the copying machine is constructed by connecting the drive means as described above, 1.
The first sheet of paper can be stopped with its leading edge protruding from the nip between the feed roller 2 and the sorting roller 3 in the feeding direction, and therefore the second and subsequent sheets can be reliably separated by the sorting roller 3. Yes, double-sided copy tray 1
It is possible to reliably prevent double feeding due to poor storage configuration in the intermediate tray.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the general configuration of a paper feeding device of a copying machine, Figs. 2 and 3 are enlarged explanatory diagrams of its main parts, Fig. 4 is an explanatory diagram of the configuration of the present invention, and Fig. 5 is an illustration of the operation. An explanatory diagram, FIG. 6, is an explanatory diagram showing another application example. 1 is a double-sided copying tray, 2 is a feeding roller, 3 is a sorting roller, 4 is an auxiliary roller, 5 is a pressing member,
9 and 11 are photo sensors.

Claims (1)

[Claims] 1. In a copying machine paper feeding device in which a nip is formed by a feeding roller and a sorting roller and is provided at the tip of an intermediate tray such as a double-sided copying tray that receives sheets that are successively fed, the entrance of the intermediate tray is Department and
A detection means such as a photo sensor is provided on the exit side of the nip between the feed roller and the separation roller in the feeding direction, and one detection means on the entrance side is provided in the drive section of the feed roller and separation roller. A paper feeding device for a copying machine, characterized in that a driving means is connected to drive a feed roller and a separating roller after detecting the leading edge of the paper until the detecting means on the exit side detects this.