JPH042917Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field This invention relates to a skew correction device for paper fed from an automatic paper feeder for manuscripts, etc. of a copying machine.

Prior Art An automatic document feeder (hereinafter referred to as ADF) is used to improve copying efficiency by eliminating the need to manually feed documents consisting of multiple sheets one by one into the exposure section of a copying machine. It has recently become widely used.

By the way, as one of the devices to correct the skew (skew feeding) of paper ejected into the paper transport path from an automatic paper feeder such as ADF,
The leading edge of the paper collides with a stopper that extends perpendicularly to the paper transport direction so that it can be retracted, and the paper is excessively fed to form a buckling on the paper, and the stiffness of the paper causes the leading edge of the paper to follow the stopper. A device is known that also corrects the skew.

An example of its configuration will be explained with reference to FIG. - A stopper 1 is provided which extends in a direction perpendicular to the conveying direction so as to be retractable. On the upstream side thereof, a roller pair consisting of an insertion drive roller 3 and a pinch roller 4 is provided so as to be able to approach and separate from each other across the paper path. A slack retaining portion 10 is formed between the guide plates 6 and 9 on one side of the paper transport path between the roller pairs 3, 4 and 7, 8 to bulge the transport path outward in the thickness direction. There is. Further, between the stopper 1 and the roller pairs 3 and 4 and between the slack retaining part 10 and the roller pairs 7 and 8,
Paper leading edge detection sensors 5 and 33 are provided.

With the above configuration, as shown in Figure 2, the ADF
The document S discharged from the discharge port C of 30 is conveyed by the pair of rollers 7 and 8, and its tip is detected by the sensor 33, and the signal causes the pair of rollers 3 and 4 to be separated, passes through the slack retaining section, and then the document S is conveyed by the pair of rollers 7 and 8. 3,4
The tip abuts the stopper 1 through the gap. After the leading edge of the sheet contacts the stopper 1, the sheet is still fed by the pair of rollers 7 and 8 for a certain period of time, so that the sheet buckles and sag B as shown in FIG. The roller pair 7, 8 is stopped after a certain period of time has elapsed from the time when the sensor 5 detects the leading edge of the paper. The slack B mentioned above is accommodated in the slack holding section 10. The sagging document tries to stretch by itself, and the leading edge of the paper completely follows the stopper 1 to correct the skew.Then, the pinch roller 4 of the insertion roller pair presses against the drive roller 3 and pinches the document. The posture of the leading edge of the document is maintained, and then the stopper 1 is retracted from the conveyance path. When the paper feed timing comes, the insertion drive roller 3 starts rotating and feeds the paper in the direction A with the skew corrected.

Now, the above-mentioned slack retaining unit 10 can not only accommodate the slack of the paper during skew correction, but also retain the slack at the leading edge of the paper fed from the automatic paper feeder even if the paper is curled. It is necessary to have a function that reliably guides the insertion rollers toward the pair of insertion rollers without getting caught or deviating in the wrong direction. To this end, it is possible to make the curvature of the bulge of the guide plate of the slack retaining section gentler to reduce the protrusion, but in such a case, it may not be possible to accommodate enough slack, or the skew due to the waist of the paper may be corrected. The disadvantage is that the repulsive force cannot be obtained.

In order to improve this drawback, one end of the slack retaining section is fixed to a guide member of the paper conveyance path adjacent to the slack retaining section so as to be in contact with the paper being conveyed in the paper conveying direction. When a sheet of paper is buckled for skew correction by providing one flexible thin plate member that is displaced by
A skew correction device has been proposed that presses and deforms a flexible thin plate member with the outer surface of the sag, and uses the waist of the thin plate member in addition to the waist of the paper as a repulsive force for correcting the skew. .

However, in the above configuration in which one flexible thin plate member is provided in the slack holding section, when backling is formed on the paper for skew correction, the paper thin plate member starts to bulge near the free end, and the paper thin plate member starts to bulge out near the free end. It does not match the sagging curved surface and cannot accommodate a sufficient amount of bending, resulting in the disadvantage that it is difficult to obtain sufficient repulsive force for correcting skew. Furthermore, when curled paper is fed, depending on the position of the free end of the flexible thin plate member, the leading edge of the paper may get caught on the free end of the flexible thin plate member, and the paper may not be guided smoothly.

Purpose The present invention is based on the purpose of this invention.
In view of the above-mentioned problems of the paper skew correction device having the above-mentioned flexible thin plate member, the leading edge of the paper fed from the automatic paper feeder is smoothly guided in a predetermined direction when passing through the slack holding unit. It is an object of the present invention to provide a skew correction device equipped with a sag retaining part that can sufficiently accommodate the sag formed in paper during skew correction and provide sufficient repulsive force for skew correction. .

Configuration In order to achieve the above object, the slack retaining section according to the present invention is fixed with one end thereof in surface contact with the outer surface of the upstream guide member and the inner surface of the downstream guide member in the paper conveyance direction, respectively. When no external force is applied to the other ends, they overlap each other with the upstream side facing inward, forming approximately one plane along the paper conveyance direction, and are elastically displaced outward due to slack in the paper during skew correction. It is composed of two flexible thin plate members.

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 3 shows an embodiment in which the present invention is applied to a slack retaining section of a skew correction device of a document feeder having the above-described configuration. In the figure, the guide plate 6 on the downstream side in the conveyance direction of the document sent out from the ADF 30
One end of Mylar sheets 11 and 12 is bonded to the inner surface of the upstream guide plate 9 and the outer surface of the upstream guide plate 9, respectively. The other ends of the Mylar sheets 11 and 12 are overlapped with each other by an appropriate length so that the upstream sheet is on the inside, forming approximately one plane along the document conveyance direction. The thickness of the Mylar sheets 11 and 12 is set to such a value that, when a document whose leading edge is pressed by a stopper during skew correction becomes sagging, it can be easily pushed outward and bent by the sagging. . Note that the slack retaining section 10 is the cover 1.
0a regulates the limit when the Mylar sheet is pushed and bent due to the slack of the paper, and protects the Mylar sheet.

As described above, this slack retaining portion includes the guide plate 9,
The Mylar sheet 12, the Mylar sheet 11, and the guide plate 6 are successively stacked and connected on the outside and extend along the document transport direction, so that the leading edge of the document sent out from the ADF 30 by the feed rollers 7 and 8 is connected to the guide plate. The sheet is smoothly guided and conveyed toward the pair of insertion rollers 3 and 4 without being caught by the sheets or the joints between sheets. Even if the document is curled, the conveyance direction of the leading edge of the document is regulated by the Mylar sheets 12 and 11, thereby preventing the leading edge of the document from deviating in an undesired direction and getting caught on the cover 10a, resulting in a jam.

When the leading edge of the document collides with the stopper 1 and a slack is formed in the document, the document will be stretched to 2 as shown in FIG.
The mylar sheets 11 and 12 begin to bend easily from the joining position, the mylar sheets 11 and 12 are pushed outward, and the document sag into a generally natural sag shape to accommodate a sufficient amount of sag. the result,
The waist of the Mylar sheet works together with the waist of the original to ensure that the leading edge of the original hits the stopper. When the stopper is removed and the document is sent out by the pair of insertion rollers 3 and 4, and the slack is eliminated, the mylar sheets 11 and 12 return to their original positions due to their flexibility. Note that instead of the slack retaining portion cover 10a, a rod-shaped member or the like may be provided for regulating the amount of displacement of the mylar sheet.

Effects As described above, according to the present invention, when the paper fed from the automatic paper feeder passes through the slack retaining unit, the paper is reliably guided in a predetermined direction with a simple configuration, and when the paper is corrected for skew. The slack of the paper can be sufficiently accommodated, and the skew correction effect can be ensured.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing an example of the configuration of a skew correction device of a paper feeding device to which the present invention is applied, Fig. 2 is a sectional view illustrating its skew correction action, and Fig. 3 is a sag retention according to the present invention. FIG. 4 is a cross-sectional view showing the state of the slack retaining part when paper slack occurs. 1... Stopper, 3, 4... Insertion roller pair,
6, 9...Guide plate, 10...Sag holding part, 1
1, 12...Mylar sheet (flexible thin plate member),
30...Automatic paper feeder.

Claims (1)

[Scope of Claim for Utility Model Registration] A stopper that is provided so as to be inserted into and retracted from the conveyance path of paper sent out from an automatic paper feeder and extends in a direction perpendicular to the paper conveyance direction, and between the stopper and the automatic paper feeder. A pair of insertion rollers are provided so as to be able to approach and separate from each other across the paper path, and the paper is provided in the paper transport path between the pair of insertion rollers and the automatic paper feeder, and is formed by abutting the leading edge of the paper against the above-mentioned stopper. A skewer for a paper feeder having a slack retaining part that accommodates slack in paper and has a flexible thin plate member having one end fixed to a guide member of an adjacent paper conveyance path and elastically displaced by slack in the paper. In the correction device, the flexible thin plate member is fixed with one end in surface contact with the outer surface of the upstream guide member and the inner surface of the downstream guide member of the slack retaining section in the paper conveyance direction, and the flexible thin plate member is fixed with one end in surface contact with each other. The ends overlap each other with no external force applied, with the upstream side facing inside.
A skew correction device comprising two flexible thin plate members that form approximately one plane along the paper conveyance direction and are elastically displaced outward due to sagging of the paper during skew correction.