PAPER FEEDING DEVICE FOR PRINTER

Abstract

Provided is a paper feeding device for a printer that is capable of absorbing an impact occurring when a rear end of paper escapes from the outer peripheral surface of a pickup roller and thus comes into contact with a bottom surface of a paper stacking part. The paper feeding device for a printer includes: a paper stacking part for stackedly accommodating at least one or more sheets of paper therein; a pickup roller protruding from a bottom surface of the paper stacking part to feed the paper forward; and buffers linearly protruding from the bottom surface of the paper stacking part to absorb the impact occurring when the rear end of the paper escapes from the outer peripheral surface of the pickup roller and then comes into contact with the bottom surface of the paper stacking part.

Claims

1. A paper feeding device for a printer, comprising: a paper stacking part for stackedly accommodating at least one or more sheets of paper therein; a pickup roller protruding from a bottom surface of the paper stacking part to feed the paper forward; and buffers linearly protruding from the bottom surface of the paper stacking part to absorb an impact occurring when the rear end of the paper escapes from the outer peripheral surface of the pickup roller and then comes into contact with the bottom surface of the paper stacking part.

2. The paper feeding device according to claim 1, wherein each buffer protrudes from the bottom surface of the paper stacking part in a paper feed direction and a protruding thickness of the buffer is lower than the highest point of the pickup roller.

3. The paper feeding device according to claim 2, wherein each buffer comprises a first tapered portion gradually decreased in the protruding thickness toward the front side thereof so that as the paper is fed forward, the rear end of the paper is close to the bottom surface of the paper stacking part.

4. The paper feeding device according to claim 3, wherein each buffer comprises a second tapered portion gradually decreased in the protruding thickness toward the rear side thereof.

5. The paper feeding device according to claim 4, wherein an inclination of the second tapered portion is lower than an inclination of the first tapered portion.

6. The paper feeding device according to claim 4, wherein each buffer comprises a flatten portion formed between the first tapered portion and the second tapered portion in such a manner as to be constant in the protruding thickness.

7. The paper feeding device according to claim 1, wherein the buffers are formed on the outsides of both ends of the pickup roller.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0037] FIGS. 1 and 2 show a conventional portable photo printer.

[0038] FIG. 3 shows paper feeding processes of the conventional portable photo printer.

[0039] FIGS. 4 to 6 show a paper feeding device for a printer according to the present invention.

[0040] FIGS. 7 to 9 show paper feeding processes to the printer in the paper feeding device according to the present invention.

[0041] FIGS. 10 to 12 show various examples of a buffer in the paper feeding device according to the present invention.

MODE FOR INVENTION

[0042] Hereinafter, an explanation on a configuration and an operation of a paper feeding device for a printer according to the present invention will be in detail given with reference to the attached drawing.

[0043] As shown in FIGS. 4 and 5, a paper feeding device 1 for a printer according to the present invention includes a paper stacking part 10, a pickup roller R1, pressurizing means (not shown), and buffers 20.

[0044] The paper stacking part 10 provides a space in which at least one or more sheets of paper are accommodatedly stacked up and down onto each other.

[0045] The pickup roller R1 is configured to allow a portion of a top peripheral surface thereof to protrude from a bottom surface 11 of the paper stacking part 10 to forward feed the paper coming into close contact with the protruding top peripheral surface thereof. In detail, the top peripheral surface of the pickup roller R1 comes into contact with the paper located at the lowermost position among the stacked paper, and if the pickup roller R1 rotates, in this state, it can feed the paper located at the lowermost position forward.

[0046] The pressurizing means is adapted to allow the paper to be brought into close contact with the pickup roller R1 so that the pickup roller R1 and the paper rub against each other to feed the paper, without any slipping. The pressurizing means can be utilized with the paper pressurizing member 120 as known means, as shown in FIG. 1.

[0047] Particularly, the paper feeding device 1 according to the present invention is provided with the buffers 20 that are adapted to absorb an impact occurring when the rear end of the paper escapes from the protruding top peripheral surface of the pickup roller R1 and then comes into contact with the bottom surface 11 of the paper stacking part 10. In more detail, the buffers 20 are adapted to allow the rear end of the paper to be separated from the outer peripheral surface of the pickup roller R1 and to slowly fall downward on the bottom surface 11, thereby softening the impact occurring at that time.

[0048] Now, an explanation on the configuration and operation of the buffers 20 will be in detail given with reference to FIGS. 5 and 6.

[0049] As shown, each buffer 20 linearly protrudes from the bottom surface 11 of the paper stacking part 10. Further, the buffers 20 are formed on the outsides of both ends of the pickup roller R1 in such a manner as to be parallel with each other.

[0050] Also, the protruding thickness of the buffer 20 is lower than the highest point of the pickup roller R1.

[0051] Furthermore, the buffer 20 has a first tapered portion 21 gradually decreased in the protruding thickness toward the front side thereof. The highest point 21a of the first tapered portion 21 is lower than the peak of the pickup roller R1, and the lowest point 21b thereof is equal to the bottom surface 11. The first tapered portion 21 receives the rear end of the paper from the pickup roller R1 and slowly moves the paper to the bottom surface 11 of the paper stacking part 10, thereby minimizing the impact transferred to the rear end of the paper. According to the present invention, the highest point 21a of the first tapered portion 21 is formed located in a direction of 10 to 12 o'clock.

[0052] Moreover, the buffer 20 has a second tapered portion 23 gradually decreased in the protruding thickness toward the rear side thereof. The second tapered portion 23 is adapted to minimize a portion with which the paper comes into contact, thereby reducing the load occurring upon paper feeding.

[0053] Further, the buffer 20 has a flatten portion 22 formed between the first tapered portion 21 and the second tapered portion 23 in such a manner as to be constant in the protruding thickness from the bottom surface 11.

[0054] On the other hand, an inclination of the second tapered portion 23 is lower than an inclination of the first tapered portion 21. In detail, an absolute value of the inclination of the second tapered portion 23 is smaller than an absolute value of the inclination of the first tapered portion 21.

[0055] Next, an explanation on an operating state of the paper feeding device 1 according to the present invention will be given with reference to FIGS. 7 and 9.

[0056] As shown in FIG. 7, first, a portion of the top peripheral surface of the pickup roller R1 protrudes from the bottom surface 11 of the paper stacking part 10, and a plurality of paper sheets are stacked on the top peripheral surface of the pickup roller R1. Further, the paper pressurizing member 120 pressurizes the top of the stacked paper downward.

[0057] In this state, if the pickup roller R1 rotates in a counterclockwise direction, the paper P1, which is located at the lowermost position among the stacked paper, that is, comes into close contact with the pickup roller R1, is moved along the outer peripheral surface of the pickup roller R1 and is thus fed forward. As a result, the rear end of the paper P1 passes over the peak R1 and slowly falls downward. In this process, by the way, the rear end of the paper P1 comes into contact with the highest points 21a of the buffers 20 (See FIG. 8).

[0058] Next, the rear end of the paper P1 is separated from the outer peripheral surface of the pickup roller R1 and comes into contact with the first tapered portions 21 of the buffers 20, so that the rear end of the paper P1 is gently moved along the inclined surface of the first tapered portions 21 and slowly approaches the bottom surface 11 (See FIG. 9).

[0059] Under the above-mentioned processes, until the rear end of the paper P1 separated from the outer peripheral surface of the pickup roller R1 comes into contact with the bottom surface 11 of the paper stacking part 11, the rear end of the paper P1 is slowly moved along the first tapered portions 21 of the buffers 20, thereby minimizing the impact occurring during the movement.

[0060] Accordingly, the impact applied to the rear end of the paper is absorbed to in advance prevent the impact from being transferred to the front end of the paper on which images are being formed.

[0061] According to the present invention, the buffers 20 may be changed into various forms. For example, as shown in FIG. 10, the buffers 20 may be replaced with buffers 30 each having a first tapered portion 31 gradually decreased in the protruding thickness toward the front side thereof and a flatten portion extended flattenly from the first tapered portion 31 in such a manner as to have the protruding thickness equal to the highest point 31a of the first tapered portion 31.

[0062] On the other hand, the buffers 20 may be replaced with buffers 40 each having a first tapered portion 41 gradually decreased in the protruding thickness toward the front side thereof and a second tapered portion 42 gradually decreased in the protruding thickness toward the rear side thereof in such a manner as to be adjacent to the first tapered portion 41, without having any flatten portion (See FIG. 11)

[0063] Further, the buffers 20 may be replaced with buffers 50 each having a first tapered portion 51 gradually decreased in the protruding thickness toward the front side thereof and a flatten portion 52 extended flattenly from the first tapered portion 51, without having any second tapered portion (See FIG. 12).