JPH06312859A - Diagonal feed correcting device for document - Google Patents

Abstract

PURPOSE:To correct diagonally feeding a document with a simple constitution by constituting right/left rollers of a driving roller for conveying a document in a large diameter as compared with central rollers, and bringing driven rollers, cooperated with these right/left rollers, selectively into contact with any of the right/left rollers in accordance with diagonally feeding the document. CONSTITUTION:A drive roller 13 of at least one paired conveying rollers is constituted so that parts 13a, 13i opposed to right/left parts of a document are formed in a large diameter relating to rollers 13b to 13h in a central part. Driven rollers 23a, 23i, opposed to these large diameter parts 13a, 13i, are provided capable of respectively contacting/separating with/from the large diameter parts 13a, 13i, and by bringing any one of the driven rollers 23a, 23i selectively into contact with the one large diameter part, the document is conveyed by right/left different conveying forces, to correct a diagonal feed. Further, driven rollers 23b to 23h in the central part are positioned always into pressure contact relating to the driving rollers 13b to 13h, to further provide a surface of friction coefficient relatively smaller than the driving roller against the document.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for correcting a skew of an original during circulation in an original conveying apparatus such as a copying machine or a printer which circulates and conveys a sheet-like original.

[0002]

2. Description of the Related Art In a circulating type conveying apparatus which repeatedly conveys a document to be copied a predetermined number of times and performs image scanning a predetermined number of times, since the document is repeatedly circulated in the same path,
There is a problem that the document is skewed due to nonuniformity of the diameter of the transport roller and the contact pressure in the circulation path, and the image is scanned while the document is bent. For this reason, conventionally, the guide plate of the U-turn portion of the document forming a part of the document circulation path is moved in the reverse oblique direction corresponding to the skew of the document to reduce the left and right transport path lengths of the document. There has been proposed a device which is modified to correct skewing of a document.

[0003]

According to this conventional apparatus, it is possible to correct the skew of a small original, but in the apparatus for handling a large original, the mechanism for moving the guide is large. In addition, additional means such as positioning of the guide plate is required. Therefore, the present invention is
An object of the present invention is to provide an apparatus capable of correcting skew of a document even with a large document with a simple configuration.

[0004]

In order to solve such a problem, an original skew feeding correction apparatus according to the present invention is provided with a plurality of conveying rollers including a plurality of driving rollers and driven rollers arranged along a conveying path of the original. A pair of rollers and a detector for detecting left and right bending of the document to be conveyed, and at least one roller pair of the pair of conveying rollers has a roller facing the left part and the right part of the document of the driving roller. The driven roller, which is a roller having a large diameter with respect to the roller in the central portion and which opposes the large diameter roller, is provided so as to be able to come into contact with and separate from the large diameter roller respectively, and according to a signal from the skew detector, One of the driven rollers is selectively brought into contact with one of the large-diameter rollers to convey the original document with different left and right conveying forces to correct the skew of the original document.

Further, in particular, the driven roller in the central portion is always in pressure contact with the drive roller, and has a surface having a friction coefficient relatively smaller than that of the drive roller with respect to the original.

[0006]

According to such means, when the document is conveyed normally, that is, when the document is not skewed, the driven rollers opposed to the large-diameter roller are located away from the large-diameter roller on both the left and right sides, and the document is at the center. It is conveyed by a driving roller and a driven roller. If the original is skewed in either the left or right direction, the driven roller facing the large-diameter roller on the side that lags left and right moves so as to contact the drive roller, and the delayed side on the left and right of the original becomes the peripheral speed of the large-diameter roller. The document is conveyed by a dependent feed amount and the skew of the original is corrected. Since the central driven roller that supports the center of the document only supports the document with a relatively small frictional force, it does not become an obstacle when correcting the document by the large-diameter roller.

【Example】

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, reference numerals 11 to 14 denote driving rollers that constitute one of the pair of conveying rollers, and each driving roller has an upper driven roller 21 that constitutes the other of the pair of conveying rollers.
.About.24 and lower driven rollers 31 to 34 are arranged so as to come into contact with each other with an appropriate pressure. Each drive roller 11
Numerals 14 to 14 each have an outer peripheral surface such as rubber having a relatively large frictional force, are connected to an appropriate driving source, rotate at the same speed in the same direction, and are fed between them in cooperation with a driven roller. The incoming original is conveyed at a constant speed. Drive roller 1
1-14 and upper driven rollers 21-
24 and lower driven rollers 31 to 34 are respectively A
It is provided at a position suitable for forming a shortest circulation path when circulating 0, A1, A2, and A3 size originals in the longitudinal direction. Fingers 41 to 44 are provided corresponding to and adjacent to the drive rollers 11 to 14, respectively. Each of the fingers 41 is provided so as to be movable independently of each other, and is normally located at a lower position where it does not obstruct the upper conveyance path 50, but when actuated, it also moves upward so as to cross the upper conveyance path 50 and is conveyed. The advancing direction of the incoming original is changed and the original is guided to the lower conveyance path 60.

A sheet-like original inserted through an original insertion port (not shown) is conveyed to the lower circulation path 60 by the paper feed roller 70, and is conveyed downward by the normally rotating drive rollers 11-14 and lower driven rollers 31-34. It is conveyed so as to cross the document exposure position 80 through the path 60. Original exposure position 8
0 is usually a transparent glass plate, and the original is conveyed (scanned) along the upper surface with the image surface facing downward. As is well known, this original is exposed by an exposure lamp 81, and its light image is formed on a photosensitive drum 83 via a lens 82,
A copy image according to the original is formed by the operation of the well-known image forming means.

The exposed original is U-turned by the original U-turn unit 1 and guided to the upper conveyance path 50. In the case of a single copy, all the fingers 41 to 44 are at positions retracted downward from the upper conveyance path 50, and therefore, the document passes along the upper conveyance path 50 through the driving rollers 11 to 14 and the upper driven rollers 21 to 24. It is conveyed to the outside by the discharge roller 90.

On the other hand, when copying a plurality of sheets from the same original, the originals are circulated. In this case, the size of the conveyed document is detected by a size detection device (not shown) before the document is inserted into the circulation path. As a result, one of the fingers 41 to 44 corresponding to the document size operates in accordance with the detected size signal, and constitutes the shortest circulation path described above. For example, when the same A0 size original is copied a plurality of times, the fingers 41 are actuated in accordance with the detection signal from the size detection device to project into the upper conveyance path 50. As a result, the document scanned by the document exposure position 80 and sent to the upper conveyance path 50 through the U-turn section 1 is transferred to the finger 4
1 is returned to the lower conveyance path 60 side along the drive roller 11 and is conveyed again to the document exposure position 80. This circulation is performed until the set number of copies is completed. When the exposure for the final copy is completed, the finger 41 retracts downward from the upper conveyance path 50, and the document is ejected by the ejection roller 90.

Similarly, for originals of other sizes, the corresponding fingers are activated to effect similar circulation.

When the document is skewed while the document is being circulated, a skew detector 100 is arranged so as to face the lower conveyance path 60 in order to detect this. In the drawing, it is arranged between the lower driven rollers 32 and 33. Detector 1
Reference numeral 00 denotes a series of optical or mechanical sensors that are tandemly arranged at appropriate intervals in the direction orthogonal to the document traveling direction so as to detect the passage of the document on the left and right sides of the leading edge. Then, it is detected whether or not the document is skewed by comparing the left and right passage times of the document. This detector is ineffective in the case of one-sheet copying (without cyclic feeding).

In order to correct the skewed original, at least one of the conveying roller pairs, for example, the driving roller 13 and the driven roller 23 has a structure as shown in FIG. In FIG. 2, the drive roller 13 has a plurality of rollers 13a to 13i fixed to a rotating drive shaft 15. Each roller 13
a to 13i have a surface having a relatively large frictional force such as rubber, and the central rollers 13b to 13h have substantially the same shape and configuration as the coaxial shape.
i is coaxial with the central rollers 13b to 13h, but has a diameter slightly larger than those, for example, 1 to 3 mm larger in diameter. The originals to be conveyed are these drive rollers 13a-13
i and the driven rollers 23a to 23i are conveyed, and the large-diameter rollers 13a and 13i are located opposite to the left and right portions of the document to be conveyed, respectively.

Driven rollers 23b to 23h arranged so as to face the central drive rollers 13b to 13h, respectively.
Consists of coaxial rollers having the same diameter, and has a surface with a relatively small frictional force against a document such as synthetic resin. Each roller 23b
23 h are provided rotatably with respect to their shafts 16, respectively, and the driving roller 1 is provided by a biasing means 17 such as a spring.
3b to 13h are arranged so that they are always in contact with each other by an appropriate pressure.

On the other hand, driven rollers 23a and 23i are provided so as to be able to come into contact with and separate from the large diameter rollers 13a and 13i independently of each other. Driven roller 23a or 23
i indicates that when the original to be conveyed is skewed in either direction, one of the delay sides is selected and the corresponding large-diameter roller 13 is selected.
Contact b or 13i. That is, when the document is normal (the document is not skewed), the driven rollers 23a and 23i are separated from the large-diameter rollers 13a and 13i, and the document is driven by the central driving rollers 13b to 13h and the driven roller 23b that cooperates therewith. 〜23i, it is conveyed at a constant speed.

While the document is being conveyed, the skew detector 10
When the skew feeding of the original is detected by 0, the driven roller 23a or 23i on the left and right sides is moved so as to contact the large diameter roller 13a or 13i. For example, if the right side of the original is skewed so that the right side is delayed, the right driven roller 23i comes into contact with the large diameter roller 13i, and the delayed side of the original is conveyed by the fast feed amount of the large diameter roller 13i. Correct skew. This correction is repeated until the detector 100 confirms the correction of the skew feeding of the document. In addition,
During this correction, as described above, the center driven roller 23b
Since .about.23h is formed by the surface having a relatively small frictional force, slippage occurs between the document and the original, which does not hinder the correction.

3 to 5 show driven rollers 23a and 2a.
3 shows a mechanism for moving 3i in a direction of moving toward and away from the large diameter rollers 13a and 13i. Although the driven roller 23a will be described for the sake of explanation, the driven roller 23i may have the same configuration except that the left and right sides are different. The driven roller 23a is rotatably provided with respect to the support plate 51 by the support shaft 50. The base of the support plate 51 is supported by a shaft 52 so as to be able to pivot in the vertical direction with respect to the fixed portion of the apparatus. As the support plate 51 pivots, the driven roller 23a described above moves with respect to the large diameter roller 13a. Approach and separate. A base portion of a torsion coil spring 58 is arranged around the shaft 52, and the spring 58 moves the driven roller 23a in a direction in which the driven roller 23a contacts the large diameter roller 13a by causing one end of the spring 58 to act on the fixing portion of the device and the other end to act on the support plate 51. Work like. As particularly shown in FIG. 4, a pin 53 is projected from the other end of the support plate 51, and one end of the pin 53 is an engaging hole 57 formed in a moving plate 56 connected to a plunger 55 of a solenoid 54. Located so as to project inside. As shown in FIG. 5, the engagement hole 57 is an elongated hole inclined so as to rise toward the solenoid 54 side. On the other hand, the moving plate 56 is an appropriate guide 5.
The movable plate 56 is guided horizontally by the reference numerals 9 and 61, and acts to move the moving plate 56 in the direction opposite to the solenoid 54 by the action of the tension spring 62 provided on the side opposite to the solenoid 54. is doing.

With such a structure, in a normal state (a state where there is no skew of the document), the solenoid 54 is biased, whereby the moving plate 56 is pulled to the solenoid side against the action of the spring 62, and the engaging hole is formed. The pin 53 located in 57 moves downward according to the shape of the engagement hole. As a result, the support plate 51 pivots to move the driven roller 23a to the large diameter roller 13a.
Pull away from. If skew is detected, the solenoid 54 is deenergized, which causes the moving plate 56 to move to the right side in FIG. 5 by the action of the spring 62, and the driven roller 23a is moved to the large diameter roller via the support plate 51. 13a is contacted. At this time, the driven roller 23a is pressed against the large-diameter roller 13a with an appropriate pressure by the action of the torsion coil spring 13a.

[0019]

As described above, according to the present invention, the left and right rollers of the driving roller for conveying the original are configured to have a larger diameter than the center.
The skew feeding of the document can be corrected by a simple configuration in which the driven roller that cooperates with these is selectively brought into contact with any one of them according to the skew feeding of the document. In addition, since the roller portion that determines the document feed speed directly changes the feed amount of the document left and right, control is easy.

[Brief description of drawings]

FIG. 1 is a schematic view of a document feeder that can incorporate a skew feeding correction device according to the present invention.

FIG. 2 is a principle view of a skew feeding correction device according to the present invention.

FIG. 3 is a side sectional view of a main part of the skew feeding correction device according to the present invention.

FIG. 4 is a top view of the portion of FIG.

5 is a rear view of the portion of FIG.

[Explanation of symbols]

 11-14 Drive roller 21-24 Upper driven roller 31-34 Lower driven roller 50 Upper conveyance path 60 Lower conveyance path

Claims (2)

[Claims] 1. A plurality of conveying roller pairs, each of which is composed of a plurality of driving rollers and driven rollers, arranged along a document conveying path, and a detector for detecting left and right bending of a document to be conveyed. At least one roller pair of the conveying roller pair is a driven roller in which a roller facing the left portion and the right portion of the original of the driving roller is a roller having a larger diameter than the roller in the central portion and facing the large diameter roller. Are provided so as to be able to come into contact with and separate from the large-diameter roller respectively, and one of the driven rollers selectively comes into contact with one of the large-diameter rollers in accordance with a signal from the skew detector, and the left and right sides are different from each other. An original skew feeding correction device, which feeds an original with a feeding force to correct the skew feeding of the original. 2. The driven roller in the central portion is always positioned in pressure contact with the driving roller, and has a surface having a friction coefficient relatively smaller than that of the driving roller with respect to the original. A document skew correction apparatus according to Item 1.