Paper-feeding device of image forming equipment

Abstract

A paper-feeding apparatus of an image forming apparatus, having a driving motor, at least one first drive roller positioned downstream in a paper pickup direction of a pickup roller, at least one second drive roller disposed to press the sheet of paper with a predetermined pressure against the first drive roller, and a drive roller power transmitter transmitting a power of the driving motor to the first drive roller, to allow the pickup roller and the first and the second rollers to be respectively driven in the paper pickup direction and a paper feeding direction during the pickup of paper, and to transmit the power of the driving motor to the second drive roller, to allow only the first and the second rollers to be driven in the paper feeding direction during the line feeding of paper, and thus prevent paper feed troubles such as paper jamming and paper skewing.

Description

technical field [0001] The present invention relates to a paper feeding device of an image forming apparatus such as a copying machine, a printer, and a facsimile machine, and more particularly to a paper feeding device of an image forming apparatus that avoids, for example, It is difficult to feed paper due to paper jams and skewed paper, and improve the paper feeding accuracy of the paper feed roller. Background technique [0002] Image forming apparatuses such as copiers, printers, and facsimile machines are generally provided with a paper feeding device that feeds sheets of paper to the image forming unit. [0003] As shown in Figures 1 and 2, this paper supply device 10 includes: a paper cassette 20 for stacking paper sheets P; a frame 11 for mounting and dismounting the paper cassette 20 thereon; a pick-up unit 30, which is relatively Since the paper cassette 20 is installed on the frame 11 and picks up the sheets P one by one; Page P. [0004] The pickup unit 30 in...

AI Technical Summary

Problems solved by technology

[0015] However, in the conventional sheet feeding device 10, since the pickup roller assembly 31 and the drive roller gear set have first and second one-way power transmissions, respectively, the supply roller is driven by the supply roller driving motor to supply the paper sheet after the sheet is picked up. When paper is fed, the feed roller is susceptible to the pulling force of the first one-way power transmitter of the pickup roller assembly 31 and the second power transmitter of the drive roller gear set, respectively, corresponding to the idling pickup roller 34 and drive roller 41, And the gravity of the pickup roller assembly 31 and the pressure acting on the sheet P between the driving roller and the auxiliary driving rollers 41, 42

[0016] This resistance acting on the supply roller not only reduces the paper feeding accuracy of the supply roller, but in the worst case can also cause the paper to be skewed or jammed

[0017] In addition, in the conventional sheet feeding device 10, due to gravity and the like by the pickup roller assembly 31, the vector of the force acting on the sheet P is different from the rotational force acting on the sheet P by the pickup roller 34 during paper pickup. The vector of the power is reversed, so there is a problem that the rotational resultant force of the pickup roller 34 decreases during sheet pickup, and therefore, the paper pickup efficiency of the pickup roller 34 decreases.

[0018] If the paper pickup efficiency of the pickup roller 34 is lowered, troubles such as the sheet P not being picked up or the sheet jamming may occur

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