KR20060108296A - Paper feeding apparatus including means for guiding the paper curl - Google Patents

Abstract

Disclosed is a paper sheet feeding apparatus including curl guide means. The paper feed apparatus according to the present invention includes a paper loading stand, a pickup roller, a finger member for generating a curl at the leading end of the paper to prevent the paper from being fed in two or more sheets, and the portion where the curl is generated. And a curl guide means for guiding in the feed direction, wherein the curl guide means presses the curl generating portion in the feed direction of the paper, thereby improving the straightness during paper feeding, and reducing the occurrence of jams or damage to the main body parts of the image forming apparatus.

Kernel guide means, paper feeder, paper stacker, pickup roller, finger member

Description

Paper feeding apparatus including means for guiding the paper curl}

1 is a side cross-sectional view illustrating the operation of the paper feed apparatus according to the present invention.

Figure 2 is a perspective view showing a state before the paper is picked up in the sheet feeding apparatus according to the present invention.

Figure 3 is a perspective view showing a state that the paper is picked up from the paper feeding apparatus according to the present invention.

Figure 4 is a perspective view showing a state that the paper is picked up in the conventional paper feeding apparatus.

<Description of the symbols for the main parts of the drawings>

100 ... Paper loading 110 ... Feed roller

120 Knock-up plate 130 Knock-up spring

140.Finger member 180 ... Pick-up roller

Pick-up roller rotation shaft 200 Paper guide

300 ... Curl 400 ... Guide Roller

P ... paper

The present invention relates to a paper feeder for feeding paper into an image forming apparatus.

Background Art [0002] In general, an image forming apparatus such as a printer or a copying machine includes a sheet feeding apparatus for storing a plurality of sheets of paper, an OHP film, and the like, and sequentially feeding the received sheets into the image forming apparatus main body.

4 shows a conventional paper feeding apparatus. The paper feed apparatus includes a paper loading table 10 for loading paper P, and a pickup roller 18 for picking up the paper P loaded on the paper loading table 10 and feeding it into the image forming apparatus main body. do. The pickup roller 18 is coupled to the pickup roller rotation shaft 19. In order to prevent the paper P from overlapping two or more sheets and being supplied to the main body of the image forming apparatus, a weight feed prevention means is provided. A representative example of the anti-feeding means is a finger member. The finger member 14 press-supports both edges of the paper P tip. When the pick-up roller 18 picks up the paper P, curl 30 is generated at both edges of the front end of the paper P due to the pressing support force of the finger member 14.

When the finger member 14 excessively presses and supports both edges of the front end portion of the paper P, the curl 30 is largely generated in the paper P. In the paper P in which the curl 30 is largely generated, the straightness of the paper P decreases as the tip end thereof is severely curved. When the straightness of the paper P decreases, the paper P may deviate from the normal track, or the paper P may be damaged, such as folding or tearing. The paper P, which deviates from the normal track or is damaged, may be caught by the pick-up roller 18 or other parts connecting parts, resulting in jams or damaging the moving parts of the main body of the image forming apparatus.

SUMMARY OF THE INVENTION The present invention has been made in an effort to improve the above-described problem, and to provide a paper feed apparatus that improves the straightness of the paper leading end where curl occurs, thereby reducing the occurrence of jams and damage to main body parts of the image forming apparatus.

In order to achieve the above object, the paper feeding apparatus according to the present invention,

A paper stack for loading paper;

A pickup roller which rotates and picks up the uppermost sheet of paper stacked on the paper stack and feeds it into the image forming apparatus main body;

A finger member which presses and supports both edge portions of the leading end of the paper to generate curl at the leading end of the picked-up paper, in order to prevent the two or more sheets of paper from being fed over;

Curl guide means for guiding a portion where the curl of the sheet is generated in a feeding direction of the sheet; It includes.

Preferably, the curl guide means comprises a conical guide roller that is in contact with the portion where the curl of the paper is generated.

The guide roller is preferably rotated while pressing the portion where the curl of the paper is generated in the feed direction of the paper.

Hereinafter, with reference to the accompanying drawings, an embodiment according to the present invention will be described in detail. 1 is a side sectional view showing a main part of a paper sheet feeding apparatus according to the present invention.

Referring to this, the paper feeder, the paper loading stand 100 is detachably coupled to the image forming apparatus main body (not shown), the knock-up plate 120 is installed in the paper loading stand 100 to load the paper (P) , A pickup roller 180 which picks up the paper P loaded on the knock-up plate 120 and supplies it to the inside of the image forming apparatus main body, and a feed roller 110 which transfers the paper P picked up by the pickup roller 180. ). The knock-up spring 130 is interposed between the knock-up plate 120 and the paper loading table 100 to press the knock-up plate 120 toward the pickup roller 180. The knock-up plate 120 loaded with the paper P is elastically raised / lowered. The knock-up plate 120 maintains a constant height of the uppermost end of the loaded paper (P) while rising / falling. In one embodiment, the pickup roller 180 is a roller having a locally cut shape such that only a part thereof contacts the paper P. The pickup roller 180 is coupled to the pickup roller rotating shaft 190. The pickup roller 180 has a long radius and a short radius. When the pickup roller 180 rotates, the long radius portion contacts the top edge of the paper P and picks up the paper P, and the short radius portion is spaced apart from the top edge of the paper P. The feed roller 110 includes at least one pair of opposing rollers, and conveys the paper P picked up from the pickup roller 180 into the image forming apparatus main body. A paper guide 200 is provided at the front end of the knock-up plate 120 to guide the picked paper P to the feed roller 110.

The paper sheet feeding apparatus includes a finger member 140 as a sheet feeding prevention means for preventing the feeding of the paper P. The finger member 140 crimps and supports the edges on both sides of the front end of the paper P loaded on the knock-up plate 120. The coefficient of friction between the pickup roller 180 and the sheet P is set to a value larger than the coefficient of friction between the sheet P and the sheet P. FIG. The paper feeding direction of the paper P is the y axis. Since the finger member 140 compresses and supports only both edge portions of the front end portion of the paper P, the y-axis progress is hindered at both edge portions of the front end portion of the paper P. When the pickup roller 180 is rotated, a curl is generated at both edge portions of the front end portion of the paper P due to the friction between the pickup roller 180 and the paper P and the pressing support force of the finger member 140. The curl helps to separate the sheets of paper (P). Only the uppermost sheet of paper P loaded on the knockup plate is separated into sheets.

FIG. 1 shows a paper stacking apparatus 100 having a cassette type coupled to a main body of an image forming apparatus, and shows an embodiment of a paper feeding apparatus provided with a knock-up plate 120 and a finger member 140. . Although not shown, it is possible to implement a paper feed apparatus including an MF (Multi function) paper loading stand that is rotatably coupled to the image forming apparatus main body and loads paper P of various sizes. Even in the MF (Multi function) type paper loading stand, the paper guide device in which the finger member 140 is provided can be implemented with the following guide information.

The curl 300 generated in the sheet P prevents the sheet P from being fed to the image forming apparatus main body by stacking two or more sheets. The pickup roller 180 advances the leading end of the paper P in a straight direction in which the paper P is supplied. In addition to the structure of the finger member 140, the pressing support force of the finger member 140 changes depending on the type of the paper P, the loading state of the paper P, and the like. When the pressing support force of the finger member 140 changes, the size of the curl 300 (Curl) also changes. Even in the same paper feeder, the curl 300 of various sizes may occur depending on the material or thickness of the paper P, the loading state of the paper P, and the like. As the size of the curl 300 increases, the straight performance of the paper P decreases. When the straight performance of the paper P decreases, the paper P not only deviates from the normal orbit, but also breaks the paper P such as folding or tearing. When the curl 300 of a predetermined size or more occurs, a curl guide means for compensating the straight performance of the paper P by pushing the rear portion of the curl 300 in the advancing direction of the paper P is required.

Fig. 2 shows a state before the paper P is picked up in the paper feeding device provided with the curl guide means according to the present invention. 3 shows a state in which the paper P is picked up.

In one embodiment according to the invention, the curl guide means comprises a conical guide roller 400 in contact with the portion where the curl 300 of the paper (P) is generated, the guide roller 400 is the paper It is preferable to rotate while pressing the part in which the curl 300 of (P) generate | occur | produced in the supply direction of the said paper P. FIG.

As shown in FIG. 2, the pickup roller 180 does not contact the uppermost end of the paper P until the paper P is picked up. The conical guide roller 400 is also not in contact with the paper P. The curl 300 does not occur until the pickup roller 180 picks up the paper P. FIG.

As shown in FIG. 3, the pickup roller 180 contacts the uppermost end of the paper P to pick up the paper P while rotating. Due to the friction between the pick-up roller 180 and the paper P and the pressing support force of the finger member 140, the curl 300 is generated at both edges of the paper P. The curl guide means is in contact with the portion where the curl 300 of the paper P is generated. The curl guide means guides the portion where the curl 300 of the paper P is generated in the feeding direction of the paper P. As shown in FIG. Therefore, the curl guide means improves the straightness of the paper P. Since the paper P having improved straightness in the direction in which the paper P is supplied to the image forming apparatus main body is supplied along the normal trajectory, the occurrence of jams and damage to the image forming apparatus main body parts are reduced.

In one embodiment, the curl guide means includes a conical guide roller 400 that rotates while pressing the portion in which the curl 300 of the paper P is generated in the feed direction of the paper P. The embodiment of the curl guide means is not limited thereto, and an elastic brush (not shown) or an elastic link (not shown) that rotates while pressing the portion where the curl 300 of the paper P is generated in the feed direction of the paper P is provided. Various embodiments, such as), are possible.

In one embodiment, the guide roller 400 is preferably coupled to the same axis as the pickup roller 180. A separate rotating member for rotating the guide roller 400 may be provided, but when the guide roller 400 is coupled to the same rotating shaft 190 as the pickup roller 180, the guide roller 400 may be simply driven. have.

In one embodiment, the guide roller 400 is preferably formed integrally on the side of the pickup roller (180). The curl 300 is generated between the finger member 140 and the pickup roller 180. The guide roller 400 is installed between the finger member 140 and the pickup roller 180. The guide roller 400 is conical so as to rotate while pressing the portion where the curl 300 of the paper P is generated in the feeding direction of the paper P. The guide roller 400 is provided at a position in contact with the curl 300. The guide roller 400 may be coupled to the same rotation shaft 190 as the pickup roller 180 as a separate roller, but is preferably integrally formed on the side of the pickup roller 180. The mechanical structure of the upper end of the paper (P) can be simplified, and jams caused by the paper (P) being sandwiched between the guide roller 400 and the pickup roller 180 are prevented. At least one guide roller 400 is preferably provided at every position where the curl 300 is generated.

Compared to the size of the curl 300 generated in the conventional paper feeding device shown in FIG. 4, the paper feeding device of the present invention shown in FIG. 3 generates a relatively small size 300. This is because the guide roller 400 improves the straightness of the paper P while pressing the portion where the curl 300 is generated in the feed direction of the paper P. The occurrence of jams of the paper P or damage to the image forming apparatus body parts are also reduced.

As described above, in the sheet feeding apparatus according to the present invention, the curl guide means presses the curl generating portion in the feed direction of the sheet, thereby improving the straightness during the sheet feeding, and prevents jam or damage to the image forming apparatus main part. Decrease.

Although the present invention has been described with reference to the embodiments shown in the drawings, this is merely exemplary, and those skilled in the art to which the art belongs can make various modifications and other equivalent embodiments therefrom. Will understand. Therefore, the true technical protection scope of the present invention will be defined by the claims below.

Claims (5)

A paper stack for loading paper; A pickup roller which rotates and picks up the uppermost sheet of paper stacked on the paper stack and feeds it into the image forming apparatus main body; A finger member which presses and supports both edge portions of the leading end of the paper to generate curl at the leading end of the picked-up paper, in order to prevent the two or more sheets of paper from being fed over; Curl guide means for guiding a portion where the curl of the sheet is generated in a feeding direction of the sheet; Paper feeder comprising a. The method of claim 1, The curl guide means, And a conical guide roller in contact with the portion where the curl of the paper is generated. The method of claim 2, And the guide roller is coupled to the same shaft as the pickup roller. The method of claim 3, wherein And the guide roller is formed integrally with the side of the pickup roller. The method according to any one of claims 2 to 4, And the guide roller is rotated while pressing the portion where the curl of the paper is generated in the feeding direction of the paper.

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