JP2732467B2 - Paper feed mechanism for printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Overview] Regarding a paper feed mechanism of a printer device, it is intended to prevent interlayer displacement occurring at the time of paper feed when printing a plurality of copy papers in a superimposed manner, and to enable stable paper feed. A mechanism for engaging the paper feed hole and transporting the paper, a platen and a pair of pinch rollers are sequentially arranged, and the continuous paper is pushed and transported by the mechanism for transporting the paper. Then, in a paper feed mechanism for transporting the sheet by pinching rollers after printing on the platen, a rotational driving force is applied to both of the pair of pinch rollers, and the feed amount of the platen side roller is adjusted to the opposite side of the platen. It is configured to be larger than the feed amount of the roller.

[Industrial applications]

 The present invention relates to a paper feed mechanism of a printer.

[Conventional technology]

As shown in FIG. 3A, a paper feed mechanism of a conventional printer device includes a sprocket 1 and a platen 2.
And a bail roller 3 pressed against the platen, wherein the continuous paper 4 sent from the sprocket 1 is conveyed while being held between the platen 2 and the bail roller 3 which are over-fed with respect to the sprocket 1. As shown in FIG. 3 (b), the system includes a sprocket 1, a platen 2, and a pair of pinch rollers 5, 6, and overfeeds the continuous form paper 4 sent from the sprocket 1 to the sprocket 1. And the like, which are conveyed while being pinched by two pinch rollers 5, 6 driven in this manner.

[Problems to be solved by the invention]

In the above-mentioned conventional paper feed mechanism, at the time of paper feeding when a plurality of copy papers are overlapped and printed, as shown in FIG. 4, the upper paper 4 'is shifted ahead of the lower paper 4 "with respect to the platen 2 as shown in FIG. This occurs particularly when the holding force between the sheets is weak, such as when a plurality of sheets are stapled.

This shift between the sheets causes an interlayer shift on the printing surface, and the printing position shifts, which is not preferable. Further, when the interlayer shift further proceeds, the pin and the hole of the paper become poorly fitted at the sprocket, and the paper comes off from the pin, causing a problem such as a jam.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above-described problems, and an object of the present invention is to provide a paper feeding mechanism of a printer device that prevents a layer shift that occurs during paper feeding and enables stable paper feeding.

[Means for solving the problem]

 FIG. 1 is a diagram illustrating the principle of the present invention.

In FIG. 1, reference numeral 1 denotes a sprocket as a mechanism for engaging the paper feed hole and transferring the paper, 2 denotes a platen, 5 and 6 denote pinch rollers, and 7 denotes a print head, which is conveyed from the sprocket 1. The printed paper 4 is printed by the print head 7 on the platen 2 and then the arrow P
Discharged in the direction. At this time, the sprocket 1, the pinch roller 5 on the platen side, and the pinch roller 6 on the side opposite to the platen
C <b <a, where c, a, and b are the paper feed amounts of
Set as

(Operation)

For the feed amount c of the sprocket 1, the pinch rollers 5, 6
By increasing the feed amounts a and b, the slack of the paper between the sprocket 1 and the pinch rollers 5 and 6 is eliminated, and the feed amount a of the pinch roller 5 on the platen side and the pinch roller 6 on the opposite side to the platen are increased. By reducing the feed amount b, it is possible to prevent the outer sheet from preceding the inner sheet with respect to the platen 2.

Embodiment FIG. 2 is a diagram showing an embodiment of the present invention.

In this embodiment, as shown in the figure, a sprocket 1, a platen 2, and a pair of pinch rollers 5, 6 are sequentially arranged in the paper transport direction. The sprocket 1 is a small gear driven by a drive motor (not shown). 8 through a large gear 9, a small gear 10 coaxial with the large gear, and an intermediate gear 11, and are driven clockwise by a gear 12 coaxial with the sprocket 1 as shown by an arrow.
The platen 2 is rotated counterclockwise from a small gear 8 by a gear 13 coaxial with the platen 2 through a large gear 9 and a small gear 10, as shown by an arrow. Further, the pinch rollers 5 and 6 are moved from the gear 13 of the platen 2 to the intermediate pinion 14 via the intermediate gear 14 by the gears 15 and 16 so that the pinch roller 5 inside (as viewed from the paper 4) is counterclockwise and the outer pinch roller 6 Are driven to rotate clockwise, respectively. And a gear train composed of gears 8, 9, 10, 11, 12 and gears 8, 9, 10, 13,
The gear train is set so that c <b <a when the paper feed amount of the sprocket 1 is c, the paper feed amount of the pinch roller 5 is a, and the paper feed amount of the pinch roller 6 is b. Have been.

In this embodiment configured as described above, the paper feed amounts a and b of the pinch rollers 5 and 6 are compared with the paper feed amount c of the sprocket 1.
Is increased, the slack of the sheet between the sprocket 1 and the pinch rollers 5 and 6 is eliminated, and the sheet feed amount b of the pinch roller 6 is reduced with respect to the sheet feed amount a of the pinch roller 5 so that the platen 2 The outer paper can be prevented from leading.

〔The invention's effect〕

As described above, according to the present invention, by changing the paper feed amount of the pair of pinch rollers and making the paper feed amount of the inner pinch roller larger than the paper feed amount of the outer pinch roller with respect to the platen, a plurality of sheets can be obtained. When printing the copy paper, the paper can be stably fed by preventing the interlayer slippage even for the paper having a weak holding force between the papers, such as a paper stapler.

[Brief description of the drawings]

 FIG. 1 is a view for explaining the principle of the present invention, FIG. 2 is a view showing an embodiment of the present invention, FIG. 3 is a view showing a paper feed mechanism of a conventional printer device, and FIG. It is a figure for explaining. In the figure, 1 indicates a sprocket, 2 indicates a platen, 4 indicates paper, 5 and 6 indicate pinch rollers, and 7 indicates a print head.

Continuing on the front page (72) Inventor Mitsuru Inomata 1015 Uedanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Prefecture Inside Fujitsu Limited (72) Inventor Hiroyuki Okitsu 1015-Ueodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Fujitsu Limited (56) Reference Literature Japanese Utility Model Showa 60-101162 (JP, U) Japanese Utility Model Showa 63-43751 (JP, U) Japanese Utility Model 1-93455 (JP, U) Japanese Utility Model 2-48346 (JP, U) Japanese Utility Model Sho 59- 16198 (JP, Y2)

Claims (1)

(57) [Claims] A mechanism (1) for engaging a paper feed hole and transporting the paper, a platen (2), and a pair of pinch rollers (5, 6) are sequentially arranged, and are connected to each other. The book paper (4) is pushed and transported by the mechanism (1) for transporting the paper,
In a paper feed mechanism for transporting the paper (4) between the pinch rollers (5, 6) after printing on the platen (2), a rotational driving force is applied to both of the pair of pinch rollers (5, 6). A paper feed mechanism for a printer, wherein the feed amount of the roller (5) on the platen side is made larger than the feed amount of the roller (6) on the opposite side to the platen.