JPS5926851A - Paper feed device - Google Patents

Abstract

PURPOSE:To automatically correct the paper skew by adjusting the tension of a spring applying a proper pressing force between paper feed rollers in response to the oblique direction of the paper in a paper feed device of a facsimile, etc. CONSTITUTION:If the paper is fed under a state that the tension of a spring 10 is stronger than that of a spring 13, the paper 7 is skewed by a partial pressure in the direction of an arrow 16 and a photosensor 21 is turned off. As a result, a motor 18 is rotated clockwise by some angle by a control section 24 to lower the position of a screw 19, and the pressing force between rollers 4, 6 is weakened near the spring 10. Accordingly, the paper 7 is moved in the direction of an arrow 17 to correct the paper skew. On the contrary, if the paper is fed when the tension of the spring is weaker than that of the spring 13, the paper 7 is skewed by a partial pressure in the direction of the arrow 17 and a photosensor 23 is turned off, the motor 18 is rotated counter-clockwise by some angle to raise the position of the screw 19, thus strengthening the tension of the spring 10, the pressing force between the rollers 4, 6 is strengthened near the spring 10, and the paper is moved in the direction of the arrow 16 to correct the skew.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a paper feeding mechanism for a facsimile, copying machine, or printer, and more particularly to a paper feeding device that sandwiches paper between rollers that are pressed against each other and rotates the rollers to feed the paper. .

In the conventional paper feeding mechanism shown in FIG. 1, a pulley 2 attached to the shaft of a motor 1 and a pulley 3 attached to the shaft of a roller 4 are connected by a belt 5, and the roller 4 is rotated by the motor 1. Also, the bearings 8 and 11 of the roller 4 and the roller 6
The bearings 9 and 12 are attracted to each other by springs 10 and 13, and the rollers 4 and 5 are pressed against each other with an appropriate pressure (・), so when the roller 4 rotates, the roller 6 also rotates. When the motor 1 rotates in the direction of the arrow 14 with the paper 7 sandwiched between the rollers 4 and 6, the paper 7 is fed in the direction of the arrow 15.

However, in such a paper feeding mechanism, if there is a difference in the tension between the springs 10 and 13, the pressure force between the rollers 4 and 6 becomes uneven due to the closed space, causing the paper to skew. For example, if the tension of the spring 1o is stronger than the tension of the spring 13, the pressure force between the rollers 4 and 6 will be stronger near the spring 10 and weaker near the spring 13. The diameter of each of the 6 contact points is 10
It becomes smaller near the spring 13 and becomes larger near the spring 13, so when the paper is fed, a partial pressure is generated in the direction of the arrow 16, causing the paper 7 to travel obliquely. On the other hand, if the tension of the spring 10 is weaker than the tension of the spring 13 (.), a partial pressure is generated in the direction of 17, causing the paper 7 to travel obliquely.

As explained above, the conventional paper feeding mechanism has (1) and (5) problems that cause problems such as skewed feeding and paper jams.

SUMMARY OF THE INVENTION An object of the present invention is to provide a paper feeding device that automatically corrects the skew of paper that occurs due to the above-mentioned reasons.

According to the present invention, the paper feeding mechanism that feeds the paper by sandwiching the paper between one or more pairs of rollers that are pressed against each other and rotating the rollers has a paper feeding mechanism that feeds the paper by rotating the rollers. means for detecting skewing of paper due to partial pressure; and means for automatically adjusting the tension of a spring that draws both ends of the rollers together to apply an appropriate pressure between the rollers in accordance with the skewing direction of the paper. A paper feeding device including the following is obtained.

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 2 shows an embodiment of the present invention.

In the figure, 4 and 6 are rollers, 7 is paper, and 8,9111.
12 is a roller bearing, and 10.13 is a spring that draws the two rollers together. Also, 20, 22 is the coming of light, 21, 2
3 is an optical sensor, and there is 7J of paper between the light source 20 and the optical sensor 21.
At 1, the optical sensor 21 detects the light emitted from the light source 20 and turns on. However, if there is paper between the light source 20 and the light guide 21, the paper blocks the light, so the optical sensor 21 is turned on. OF
It becomes F state.

The same applies to the light source 22 and the optical sensor 23. The optical sensors 21 and 23 are connected to the control unit 24, and the control unit 24 sends signals to the motor and drive unit 25 to control the direction and amount of rotation of the motor 18 according to the 0N10FF state of the optical sensors 21 and 23. Rotate it. That is, the control unit 24 controls the motor 18 to rotate by a certain angle clockwise when the optical sensor 21 is turned off, and to rotate the motor 18 by a certain angle counterclockwise when the optical sensor 23 turns off. . For example, spring 10
If the tension of Rotate motor 8 clockwise by a certain angle and tighten screw 1.
9 is lowered, and the pressing force between the roller 4 and the row 26 is weakened near the spring 10. Therefore, the paper 7 moves in the direction of the arrow 17 to correct the skew. Conversely, when the tension of the spring 10 is weaker than the tension of the spring 13, when the paper is fed, the paper 7 moves obliquely due to the partial pressure in the direction of the arrow 17, and the optical sensor 23 turns off. As a result, the control unit 24 controls the motor 8
By rotating the screw 19 counterclockwise by a certain angle, the position of the screw 19 is raised and the tension of the spring 10 is increased. Therefore, the pressing force between the rollers 4 and 6 becomes stronger near the spring 10, and the paper moves in the direction of the arrow 16 to correct the skew.

As explained above, according to the present invention, even if skew occurs due to uneven pressure force of paper feeding rollers, the skew is detected and automatically adjusted by adjusting the pressure force of the rollers. Lines can be corrected and problems such as paper jams can be prevented.

[Brief explanation of drawings]

FIG. 1 is a schematic perspective view of a paper feeding mechanism of a conventional facsimile, copying machine, or printer, and FIG. 2 is a plan view showing an embodiment of the paper feeding mechanism of the present invention. 1... Roller rotation motor, 2, 3...
・Pulley, 4.6...Roller, 5...
Belt, 7... Paper, 8.9, 11.12...
...Bearing, 10.13...Spring, 14...
...Motor rotation direction, 15...Paper feeding direction, 16,17...Partial pressure, 18...Control motor, 19...Screw , 20.22...
...Light source, 21°23...Light sensor, 24.
...Control unit, 25...Motor drive unit.

Claims (1)

[Claims] A paper feeding device such as a facsimile, copying machine, or printer that sandwiches paper between a pair or a pair of rollers that press against each other, rotates the rollers, and feeds the paper using the frictional force generated between the rollers and the paper. A means for detecting the skew of the paper due to a partial force in the direction of the roller axis generated by paper feeding, and a means for detecting the skew of the paper due to the partial pressure in the direction of the roller axis, and a means for detecting the skew of the paper by drawing the both end shafts of the rollers together and applying the tension of a spring to apply an appropriate pressing force between the rollers. and means for automatically adjusting according to the line direction.