JPH09235049A - Skew correction device on medium carrying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To certainly correct skew and to carry out smooth carriage. SOLUTION: A sheet 14 is carried in the arrow C direction 10 a carrying passage 2 by a carrier roller 5, and inclination is confirmed by sensors 13A, 13B for inclination detection provided in the front of the carrying passage 2. Thereafter, rollers 10A, 10B for inclination correction to rotate in D-E, F-G directions orthogonal with the carrier direction C are provided. Additionally, sensors 12A, 12B for inclination detection positioned on a line on the side of the carrying passage 2 in the F, D direction corresponding to the rollers 10A, 10B and in the C direction are provided. Rotation of the rollers 10A and 190B is stopped by detection of a side end 14a of the sheet 14 by the sensor 12B as well as detection of the side end 14a of the sheet 14 by the sensor 12A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a skew feeding correcting device in a medium conveying device which is provided in various recording devices and which conveys a medium consisting of sheets, cards, and other sheets one by one by a conveying roller.

[0002]

2. Description of the Related Art Generally, a medium conveying device of this type is provided with a plurality of pairs of conveying rollers composed of driving rollers and driven rollers which are in contact with each other. The paper is conveyed by the frictional force between them. In the medium transporting device having such a structure, the frictional force between the transporting roller group and the sheet causes a difference in frictional force with the sheet due to wear of the roller or dust adhering to the roller. A skew feeding device is provided for correcting skew of the sheet such that the sheet is skewed and conveyed.

FIG. 4 and FIG. 5 show a skew feeding correcting device in a conventional medium conveying device, and FIG.
FIG. 5 is a configuration diagram viewed from the front. A skew feeding correction device in a conventional medium transport device will be described based on these drawings. Reference numeral 2 denotes a paper transport path having a slit-shaped cross section, and 3 and 3 denote drive rollers whose upper ends face the paper transport path 2, and are driven by a drive mechanism whose drive source is a motor (not shown). The drive shaft 4 is fixed to the rotating drive shaft 4, and two pairs (a pair on the rear side is not shown) are provided in the front and rear directions along the sheet conveying direction (direction of arrow C in the drawing).

Reference numeral 5 is a driven roller which is in contact with the driving roller 3 and forms a conveying roller pair 8 together with the driving roller 3, and a bracket 6 fixed to a support shaft 7 which is horizontally mounted on a frame (not shown). It is rotatably supported by.
Reference numeral 20 denotes a reference wall formed on one side of the paper transport path 2 by a surface parallel to the C direction for transporting the paper 14, and 21 is inclined from the C direction for transporting the paper 14 to the reference wall 20 side by an angle α. The skew roller is rotatably disposed.
The skew rollers 21 are provided in a pair (the lower side is not shown) so as to be in contact with each other with the sheet conveyance path 2 interposed therebetween, and are rotated by a drive source (not shown).

In such a structure, the sheet 14 in the sheet conveying path 2 is nipped by the driving roller 3 and the driven roller 5 that follows the rotation of the driving roller 3 and conveyed in the direction of arrow C in the figure. At this time, the skew roller 21 is also rotationally driven, so that the sheet 14 is conveyed also in the direction of the arrow H, and the one side edge 14a comes into contact with the reference wall 20 to cause the one side edge 14 to come into contact.
Since a is conveyed in the direction of arrow C while pressing a against the reference wall 20, skewing is corrected.

[0006]

In the above-described conventional medium conveying device, the sheet 14 is formed by the driving roller 3 and the driven roller 5.
While the sheet is sandwiched and conveyed in the direction of arrow C, the skew roller 21 also conveys the sheet in the direction of arrow H. Therefore, the sheet 14 is not bent due to the thickness of the sheet 14, the inclination angle α of the skew roller 21, the conveying speed, or the like. There were problems such as occurrence and skew not being corrected sufficiently. Also,
Since the paper 14 is conveyed while being pressed against the reference wall 20, there is a problem that a paper having a small thickness easily causes a paper jam and the friction with the reference wall 20 prevents the paper from being smoothly conveyed.

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a skew feeding correcting device in a medium feeding apparatus which can correct skew feeding surely and smoothly. To provide.

[0008]

In order to achieve this object, the skew feeding correcting device in the medium carrying device according to the present invention is provided so as to carry the medium in the carrying path and to contact and separate from the medium. A conveyance roller, at least two skew correction sensors provided on the side of the conveyance path along the conveyance direction to detect the side edge of the medium, and the conveyance rollers provided corresponding to each of these sensors. While away from the medium,
Each of the sensors includes at least two skew correction rollers that laterally feed the medium toward the sensor until the side edge of the medium is detected. Therefore, the skew of the medium with respect to the transport direction is corrected by rotationally driving the two skew correction rollers according to the detection of the corresponding sensor, and then the medium is transported by the transport rollers.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram viewed from above the skew feeding correction device in a medium transport device according to the present invention, and FIG. 2 is a configuration diagram viewed from the front for explaining the same operation. b) shows a state of correcting skew,
FIG. 3 is a flow chart for explaining the same operation. In these figures, the same or similar members described in the prior art shown in FIGS. 4 and 5 described above are designated by the same reference numerals, and detailed description thereof will be omitted.

In the present invention, the support shaft 7 is supported so as to be movable up and down, and the driven roller 5 forming the transport roller 8 can be brought into contact with and separated from the drive roller 3. In FIG. 2, 9A and 9B are drive rollers driven by a drive source (not shown).
A driven roller 10 that faces A and 9B with the transport path 2 in between.
A and 10B form a transverse feed roller pair 11A and 11B. The transverse feed roller pairs 11A and 11B are arranged so that the direction of rotation is orthogonal to the transport direction C, that is, the directions of arrows D-E and F-G in the figure. The driven rollers 10A and 10B can move up and down so as to come into contact with and separate from the drive rollers 9A and 9B.

Denoted at 12A and 12B are skew detection sensors which are arranged laterally of the transport path 2 so as to sandwich the transport path 2 between a light emitting element and a light receiving element, each of which is a driven roller 10A as shown in FIG. , 10B in the directions of arrows D and F,
Further, it is located along the same direction as the transport direction C. 13
A and 13B are sensors for skew check, which are arranged in front of the transport path 2 so as to sandwich the light-emitting element and the light-receiving element in the transport path 2, and are located on a line orthogonal to the transport direction C.

Next, the operation of correcting the skew of the medium in the medium transporting device constructed as described above will be described. FIG.
As shown in (a), the transverse feed roller pair 11
The driven rollers 10A and 10B of A and 11B are moved upward by a driving means (not shown) and are retreated from the transport path 2. In such a state, the sheet 14 conveyed in the direction of arrow C in the figure by the pair of conveying rollers 8 on the conveying path 2.
However, if the sheet is skewed as shown by the chain double-dashed line in FIG. 1, the upper edge 14b of the sheet 14 is not detected by the skew checking sensors 13A and 13B at the same time, and therefore, in step 101 in FIG.
The skew is detected at.

When skew is detected in step 101, the pair of transport rollers 8 reversely rotate in step 102 to transport the paper 14 in the direction opposite to the arrow C direction. In step 103, as shown in FIG. 2B, the driven roller 5 of the transport roller pair 8 moves upward and the lateral feed roller pair 1
The driven rollers 10A and 10B of 1A and 11B move downward to contact the driving rollers 9A and 9B to sandwich the sheet 14, and the two driving rollers 9A and 9B of the lateral feed roller pairs 11A and 11B both rotate forward. To do.

As a result of this driving, as shown in FIG. 1, the paper 14 is fed horizontally in the same D and F directions as the upper and lower parts. In step 104, the upper or lower part of the paper 14 is a sensor 12A for skew detection. Alternatively, it is detected by the sensor 12B. Here, in step 105, when the upper portion of the side edge 14a of the sheet 14 is detected by the skew detection sensor 12A as indicated by the one-dot chain line in FIG. 1, in step 108, the driving roller of the transverse feed roller pair 11A is detected. 9
A stops rotating, and only the drive roller 9B rotates forward.

If, in step 105, the sensor 12
If A does not turn on, in step 106, the drive roller 9B of the transverse feed roller pair 11B stops rotating,
Only the drive roller 9A rotates normally. If the skew detection sensor 12A is turned on in step 107 or the skew detection sensor 12B is turned on in step 109, both lateral feed roller pairs 11A,
The drive rollers 9A and 9B of 11B rotate in the reverse direction, and the paper 14
Both the upper part and the lower part of the are fed in the same arrow E and G directions.

In step 111, if there is a difference in the detection time of the side edge 14a of the sheet 14 between the skew detection sensors 12A and 12B, it is determined that the skew of the sheet 14 has not been completely corrected, Returning to step 103, the correction operation described above is repeated again. In step 111,
The side edge 1 of the paper 14 is detected by the skew detection sensors 12A and 12B.
When there is no difference in the detection time of 4a, it is determined that the skew correction by the skew detection sensors 12A and 12B is completed.

In that case, as shown in FIG.
The driven rollers 10A, 1 of the transverse feed roller pair 11A, 11B
0B moves upward, and the driven roller 5 of the transport roller 8 moves downward to come into contact with the drive roller 3 and the paper 1
4, the paper 14 is conveyed by the conveyance roller 8 in the direction C in the figure. A skew occurs while the front end 14b of the sheet 14 is conveyed to the skew confirmation sensors 13A and 13B, and at step 101, the skew confirmation sensors 13A and 1B.
When the skew of the sheet 14 is detected by 3B, the process returns to step 102 and the above-described correction operation is repeated again. When the skew feeding is not detected in step 101, the printing operation is performed in step 112.

As described above, the skew detection sensor 12A,
Since the skew of the paper 14 is corrected by detecting 12B and the lateral feed of the lateral feed rollers 11A and 11B, it is not necessary to press the paper against the reference wall as in the conventional case. Paper 1 without friction with reference wall
The transportation of 4 becomes smooth. In addition, by determining the difference between the skew detection sensors 12A and 12B in step 111, skew correction is reliably performed.

In the present embodiment, the pair of transverse feed rollers 11A and 11B for skew correction and the sensor 12 for skew detection are used.
Two A and 12B are provided, but three or more may be provided to accommodate various sizes of the paper 14. Further, the skew check sensors 13A and 13B are used to detect the skew at the beginning and the end of conveyance, but the steps 101 and 102 are performed.
Is omitted and the sensor 12
The skew feeding may be detected by A and 12B, and in that case, the skew checking sensors 13A and 13B may not be provided.

[0020]

As described above, according to the present invention, the conveyance roller that conveys the medium in the conveyance path and is provided so as to be able to come in contact with and separate from the medium, and to the side of the conveyance path along the conveyance direction. Each of the sensors is provided with at least two skew detection sensors provided for detecting a side edge of the medium, and each of the sensors is provided corresponding to each of the sensors while the conveyance roller is separated from the medium. Since at least two skew correction rollers for laterally feeding the medium to the sensor side are provided until the side edge of the sheet is detected, the medium is not pressed against the reference wall as in the conventional case. There is no clogging or friction with the reference wall, and the medium can be transported smoothly. Further, since the skew detecting sensor can detect the skew a plurality of times and the skew correcting roller can correct the skew, the skew can be surely corrected.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a skew feeding correcting device as seen from above in a medium carrying device according to the present invention.

2A and 2B are configuration diagrams seen from the front for explaining a skew correcting operation of a skew feeding correcting device in a medium feeding device according to the present invention, in which FIG. 2A shows a feeding state, and FIG. Shows the state to correct.

FIG. 3 is a flow chart for explaining a skew correcting operation of a skew correcting device in the medium carrying device according to the present invention.

FIG. 4 is a configuration view of a skew feeding correcting device in a conventional medium conveying device as viewed from above.

FIG. 5 is a configuration diagram of a skew feeding correction device in a conventional medium transport device as viewed from the front.

[Explanation of symbols]

2 ... Conveying path, 8 ... Conveying roller, 11A, 11B ... Transverse feeding roller, 12A, 12B ... Oblique detection sensor, 13
A, 13B ... Sensor for skew check, 14 ... Paper.

Claims (1)

[Claims] 1. A conveyance roller which conveys a medium in a conveyance path and is provided so as to be capable of coming into contact with and separated from the medium, and at least 2 which is provided on a side of the conveyance path along a conveyance direction to detect a side edge of the medium. The sensors for detecting the skew feeding and the conveying rollers which are provided corresponding to the respective sensors and are separated from the medium allow the medium to move to the sensor side until each of the sensors detects the side edge of the medium. A skew correcting device in a medium conveying device, comprising: at least two skew correcting rollers for feeding.