JPH09328243A - Skewing straightener and sheet processing unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the driving rollers of respective paired resist rollers accurately alignable with each other without using any highly accurate jigs as well as without any troublesome adjustments, in this skewing straightener with these symmetrically paired resist rollers which straighten any possible skewing state of a document as conveying this document upon holding it between. SOLUTION: Any possible skewing state of a document is corrected as being conveyed in holding it between a symmetrical pair of resist rollers 200 and 20a to be set up at the same position in the conveying direction. When the document skews, a rotational speed of the resist roller pair on one side is increased or decreased for the straightening of skewingness. At this point, each of driving rollers 200A and 201A of these resist rollers 200 and 201 is installed on the same support shaft 206 in a state of being rotatable. In addition, the driving roller 201A rotates on the support shaft 206 by means of drive out of a motor 105 being transmitted via a belt 208.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a skew feeding correction device which is provided in a sheet processing apparatus such as a document reading apparatus and corrects a skewed state of a sheet. The sheet processing apparatus referred to here has a sheet processing means for performing a predetermined process (for example, reading an image, forming an image, etc.) on a sheet (original, paper, etc.) fed one by one. It is a generic term for all devices.

[0002]

2. Description of the Related Art A fed sheet is sent to a sheet processing section in a correct posture without skewing just upstream of a sheet processing section of a sheet processing apparatus such as a document reading device, a copying machine, a printer, a facsimile, etc. Therefore, a skew correction device for correcting the skewed state of the sheet is usually provided.

In a digital type sheet processing apparatus, an active type skew feeding correction apparatus is used which straightens a skewed state while conveying a sheet for the purpose of increasing the number of sheets processed per unit time (throughput). There is.

4 and 5 show the structure of a conventional active-type skew feeding device provided in a digital-type image reading apparatus.

This skew feeding correction device includes a pair of left and right registration rollers (first and second roller pairs) 100 and 101 arranged at the same position in the document conveying direction, and a pair of the registration roller pairs 100 and 101. Left and right document leading edge detecting sensors (first and second sheet leading edge detecting means) 102 composed of transmissive optical sensors arranged at the same position in the downstream document transport direction,
It comprises 103 and the like.

Drive roller 10 of registration roller pair 100
The drive of the drive motor 104 is transmitted to 0A via the drive shaft 111. Further, the drive of the drive motor 105 is transmitted to the drive roller 101A of the registration roller pair 101 via the drive shaft 112. Registration roller pair 100,
The driven rollers 100B and 101B of 101 are adapted to come into contact with the drive rollers 100A and 101A at a predetermined pressure and to be driven to rotate.

Usually, a pair of left and right registration rollers 100, 1
01 is rotating at the same peripheral speed as the conveying roller pair 106 that conveys the document S to the pair of registration rollers 100 and 101.

The document S transported by the transport roller pair 106 is transported downstream by the pair of left and right registration rollers 100 and 101, and the leading edge of the document is detected by the left and right document leading edge detection sensors 102 and 103.

If the leading edge of the document S is simultaneously detected by the left and right document leading edge detection sensors 102 and 103, the document S being conveyed by the pair of left and right registration rollers 100 and 101 is not skewed. However, when the time detected by the left and right document leading edge detection sensors 102 and 103 is different, the document S is skewed.

For example, a pair of left and right registration rollers 100,
When the document S being conveyed by 101 is skewed as shown by the imaginary line in FIG. 4, the document edge detection sensor 103 on the right side is faster than the document edge detection sensor 102 on the left side by a predetermined time. Detect the tip.

The CPU 10 which is a control means for controlling the drive motors 104 and 105 of the pair of left and right registration rollers 100 and 101, the drive motor 107 of the pair of conveyance rollers 100 and the like.
When there is a time difference in the input of the detection signals from the left and right document leading edge detection sensors 102 and 103, 8 determines the tilt direction and the tilt angle of the document leading edge based on this time difference. And
According to the tilted state of the leading edge of the document, the motor control circuit 10
The rotation speed of one of the registration roller pairs 100 and 101 is controlled via 9, 110. For example, when the leading edge of the document S is tilted as shown in the phantom line in FIG. 4, the CPU 1
Reference numeral 08 increases the rotation speed of the drive motor 104 of the left registration roller pair 100 via the motor control circuit 109. By doing this, the pair of left and right registration rollers 10
Based on the difference in the rotational speeds of 0 and 101, the registration roller pair 1
The document S being conveyed by 00 and 101 is rotated in the direction of arrow a and is corrected to the state without the skew shown in the solid line.

As a result, the pair of left and right registration rollers 10
The original S conveyed by 0 and 101 passes on the transparent glass 129 without any skew and the image is read.

[0013]

By the way, in the case of the above-mentioned active type skew correcting device, in order to correct the skewed state of the document S with high accuracy, the pair of left and right registration rollers 10 are used.
0, 101 accuracy, especially drive rollers 100A, 101A
Although the accuracy of alignment between them is very important, in the conventional example, since the drive rollers 100A and 101A are supported by independent drive shafts 111 and 112, respectively, there are the following problems. (1) To accurately align the drive rollers 100A and 101A with each other, a highly accurate jig must be used. (2) After adjustment with a jig, the adjustment may change due to changes over time or external factors. (3) It is difficult to reproduce once the adjustment is wrong.

The present invention has been made in view of the above points, and uses a highly accurate jig to align the driving rollers of the first and second roller pairs for correcting the skewed state of the sheet. It is an object of the present invention to provide a skew straightening device that can be accurately aligned even if it is not used.

[0015]

SUMMARY OF THE INVENTION The present invention has a pair of first and second rollers arranged at the same position in the sheet conveying direction for nipping and conveying a sheet, and the first and second rollers are provided. The present invention relates to a skew feeding correction device that corrects a skewed state of a sheet by changing the transport speed of the first roller pair or the second roller pair while transporting the sheet in pairs.

In order to achieve the above object, the present invention provides that the drive rollers of the first roller pair and the second roller pair are rotatably mounted on the same support shaft. Characterize.

[0017]

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

FIG. 1 and FIG. 2 show the construction of the skew feeding correction device of the present invention. 1 is a plan view and FIG. 2 is a perspective view.

In describing the configuration of the skew feeding correction device of the present invention, the same members and the like as those of the conventional skew feeding correction device (FIGS. 4 and 5) are designated by the same reference numerals and are structurally Descriptions of those that are functionally unchanged will be omitted.

The skew feeding correction portion, which is the main part of the skew feeding correction apparatus, is composed of a pair of left and right registration rollers 200 and 201. The registration roller pair 200, 201 is composed of driving rollers 200A, 201A and driven rollers 200B, 201B which are pressed against the driving rollers 200A, 201A and are driven to rotate. Drive roller 20
0A and 201A are fixed to the image reading apparatus main body 1
Each of them is rotatably mounted independently on a supporting shaft 206 of a book.

A pulley portion 200C is integrally formed on the left driving roller 200A. Drive roller 200
Output shaft 104B of drive motor 104 that transmits drive to A
A pulley 104C is fixed on the top. Pulley 200
Timing belt 207 is provided between C and the pulley 104C.
Drive roller 2 is driven by the motor 104.
Transfer to 00A.

A pulley portion 201C is integrally formed with the right driving roller 201A. Drive roller 201
Output shaft 105 of drive motor 105 that transmits drive to A
A pulley 105C is fixed on B. Pulley 20
The timing belt 20 is provided between the 1C and the pulley 105C.
8 is passed over, and the drive from the motor 105 is transmitted to the drive roller 201A.

FIG. 3 shows the overall construction of an image reading apparatus equipped with the skew feeding correcting apparatus of the present invention. Here, the document S
It will be explained along the flow of.

A plurality of originals S are stacked on the paper feed tray 120 with the image side facing up.

The document S set on the paper feed tray 120 is
The uppermost original is sequentially fed out by the feeding roller 123 that rotates in the clockwise direction.

The originals S fed by the feeding roller 123 are separated one by one by a pair of separating rollers 124 and fed.

The document S fed by the separation roller pair 124 is conveyed by the conveyance roller pairs 125 and 106 to the left and right registration roller pairs 200 and 201 of the skew feeding correcting apparatus of the present invention.
(See FIGS. 1 and 2). At this time, the document S is
It moves along the transport guides 126 and 127.

The original S reaching the pair of left and right registration rollers 200, 201 receives the pair of left and right registration rollers 200, 201.
The sheet 201 is continuously conveyed onto the transparent glass 129 which is the image reading section of the scanner section 128.

The leading edge of the document S that has passed through the nip between the pair of left and right registration rollers 200 and 201 has a leading edge detection sensor 102 for the left and right documents, which is installed in the middle of the pair of left and right registration rollers 200 and 201 and the transparent glass 129. Detected by 103. At this time, if there is a time lag in the input of the detection signals from the sensors 102 and 103, the CPU 108, as described in the above-mentioned conventional example, uses one of the drive motors 104 and 105 of the pair of left and right registration rollers 200 and 201. The rotational speed of is controlled (accelerated or decelerated) to correct the skewed state of the document S.

The original S whose skewed state has been corrected passes on the transparent glass 129. At this time, the document S is illuminated by the illumination lamp 130, and the reflected light thereof is reflected by the mirrors 131, 1
The image is reflected by 32, 133, converged by the lens 134, and forms an image on the CCD sensor 135 as a reading element.

The document S after the image is read is discharged onto the paper discharge tray 137 by the discharge roller pair 136.

[0032]

As described above, in the skew feeding correcting device of the present invention, the drive rollers of the first roller pair and the second roller pair are mounted rotatably on the same support shaft. Therefore, it is possible to accurately align the drive rollers of the first and second roller pairs with each other without using a highly accurate jig and performing complicated adjustment.

[Brief description of drawings]

FIG. 1 is a plan view showing the configuration of a skew feeding correction device of the present invention.

FIG. 2 is a perspective view showing the configuration of a skew feeding correction device of the present invention.

FIG. 3 is a vertical cross-sectional side view showing the overall configuration of an image reading apparatus including the skew feeding correction device of the present invention.

FIG. 4 is a plan view showing a configuration of a skew feeding correction device of a conventional example.

FIG. 5 is a perspective view showing the configuration of a skew feeding correction device of a conventional example.

[Explanation of symbols]

102 Document Edge Detection Sensor (First Sheet Edge Detection Unit) 103 Document Edge Detection Sensor (Second Sheet Edge Detection Unit) 104, 105 Motor 108 CPU (Control Unit) 200 Registration Roller Pair (First Roller Pair) 201 Registration roller pair (second roller pair) 202, 203 Drive roller 206 Support shaft 128 Scanner unit (sheet processing means) S Document (sheet)

Claims (4)

[Claims] 1. A pair of first and second rollers arranged at the same position in the sheet conveying direction for nipping and conveying the sheet,
In a skew feeding correcting device that corrects a skewed state of a sheet by changing a feeding speed of the first roller pair or the second roller pair while feeding the sheet by the first and second roller pairs, A skew feeding correction device, wherein each of the driving rollers of the first roller pair and the second roller pair is rotatably mounted on the same support shaft. 2. The driving from each motor is transmitted to the driving roller of the first roller pair and the driving roller of the second roller pair, and the driving roller of the first roller pair and the second driving roller of the second roller pair are transmitted. The skew correcting device according to claim 1, wherein the driving roller of the pair of rollers rotates on the support shaft. 3. A first and a second sheet leading edge detecting means disposed at the same position downstream of the first roller pair and the second roller pair in the sheet conveying direction to detect the sheet leading edge, and the first and second sheet leading edge detecting means. 2. The control means for controlling the conveying speed of the first roller pair or the second roller pair based on the information from the first and second sheet leading edge detecting means. Skew correction device. 4. The sheet straightening device according to claim 1, and a sheet process for performing a predetermined process on a sheet that has been conveyed with a skewed state corrected by the skew straightening device. A sheet processing apparatus comprising: