JP2587040Y2 - Paper skew correction mechanism - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a skew correction mechanism for correcting skew of a sheet when the sheet is fed by rollers or the like.

[0002]

2. Description of the Related Art FIG. 5 is a perspective view of a conventional paper skew correcting mechanism. Reference numeral 1 denotes a sheet, and 2 denotes a conveyance roller. Two conveyance rollers 2 are coaxially provided so as to be positioned on both left and right sides with respect to the conveyance direction of the sheet 1, and are rotated by a driving force from a driving unit (not shown). I do.

[0005] Reference numeral 3 denotes a sheet conveying surface. The conveying roller 2 projects from a hole formed in the sheet conveying surface 3, and its outer peripheral surface is in contact with the sheet 1 on the sheet conveying surface 3. Reference numeral 4 denotes a pinch roller opposed to the transport roller 2, which has an axis parallel to the axis of the transport roller 2 and is rotatably supported by a bracket 5. Reference numeral 6 denotes a shaft to which the bracket 5 is fixed. The shaft 6 has an axis parallel to the axis of the pinch roller 4. When the shaft 6 rotates, the pinch roller 4 conveys an arc around the shaft 6. It moves in a direction approaching or moving away from the roller 2.

[0004] Reference numeral 7 denotes an arm fixed to the end of the shaft 6, and reference numeral 8 denotes a solenoid that rotates the shaft 6 through the arm 7. In a state where the solenoid 8 is not operated and its movable core is released, the pinch roller 4 is pressed against the transport roller 2 by a force of a spring (not shown) with a strong force, and the paper 1 is transported with the pinch roller 4. The paper 1 is conveyed by receiving a strong conveying force by being clamped between the roller 2 and the conveying roller 2 rotating.

When the solenoid 8 is actuated and its movable core is sucked, the shaft 6 rotates, and the pinch roller 4 moves in an arc around the shaft 6 in a direction away from the transport roller 2. As a result, the paper 1
No longer receive the transfer force from A conveying roller 9 has an axis parallel to the axis of the conveying roller 2 and rotates upon receiving a driving force from driving means (not shown). This transport roller 9
Is behind the conveyance roller 2 in the conveyance direction of the paper 1,
Is provided so as to be located at the center of the sheet conveying direction, and projects from a hole formed in the sheet conveying surface 3, and its outer peripheral surface contacts the sheet 1 on the sheet conveying surface 3.

[0006] Reference numeral 10 denotes a slip roller which is disposed to face the transport roller 9.
, And is rotatable with an axis parallel to the axis, and is pressed against the transport roller 9 by a spring or the like (not shown).
The force that presses the slip roller 10 against the transport roller 9 is very weak as compared to the force that presses the pinch roller 4 against the transport roller 2 when the solenoid 8 is released, and the paper 1 moves between the slip roller 10 and the transport roller 9. The sheet 1 is conveyed by receiving a weak conveying force by clamping the sheet 1 and rotating the conveying roller 9.

Reference numeral 11 denotes a passage detection sensor for detecting the passage of the paper 1. The passage detection sensor 11 detects the passage of the paper 1 at a position slightly deviated from the clamp position of the paper 1 by the conveyance roller 9 and the slip roller 10 in the conveyance direction of the paper 1. There is a detection position of the leading edge of the sheet 1. 12a and 12b are skew detection sensors,
These skew detection sensors 12a, 12a, 12a, and 12a are respectively located at positions slightly deviated rearward in the transport direction of the paper 1 from the detection positions of the leading edge of the paper 1 by the passage detection sensor 11 and at the left and right sides in the transport direction of the paper 1. Paper 1 with 12b
There is a tip detection position, and the skew detection sensors 12a and 12b
When the leading end of the sheet 1 is detected in both cases, it is determined that the sheet 1 is not skewed.

Reference numeral 13 denotes a stopper which protrudes from the sheet conveying surface 3 and blocks the conveying path of the sheet 1 immediately after the skew detecting sensors 12a and 12b. The directions protrude from two holes formed in the sheet conveying surface 3 so as to block the conveying path of the sheet 1 on the same line. Thus, when the sheet 1 is conveyed, the leading ends of the left and right sides of the sheet 1 respectively abut against the stopper 13 protruding from the sheet conveying surface 3, and the skew of the sheet 1 is corrected. At the same time, the skew detection sensor 12
The leading ends of the left and right sides of the sheet 1 are detected at a and 12b, and it is determined that the skew of the sheet 1 has been corrected.

Reference numeral 14 denotes a solenoid for moving the stopper 13, and reference numeral 15 denotes a rotatable arm for transmitting the driving force of the solenoid 14 to the stopper 13. The stopper 13 is driven by the solenoid 14 and is perpendicular to the sheet conveying surface 3. When the solenoid 14 is in the released state, the solenoid 14 is retracted to a position where it does not protrude from the sheet conveying surface 3 by the force of a spring (not shown). And when the solenoid 14 operates,
It protrudes vertically from the paper transport surface 3 and blocks the transport path of the paper 1.

Reference numeral 16 denotes a transport roller, which is provided coaxially with two transport rollers 16 located on the left and right sides with respect to the transport direction of the sheet 1, and is rotated by receiving a driving force from a driving means (not shown). . The transport roller 16 is used for the paper transport surface 3.
And the outer peripheral surface thereof is in contact with the sheet 1 on the sheet conveying surface 3.

Reference numeral 17 denotes a pinch roller disposed opposite to the transport roller 16, and is rotatable with an axis parallel to the axis of the transport roller 2. The pinch roller 17 is pressed against the conveying roller 17 with a strong force by a spring or the like (not shown), and clamps the sheet 1 between the pinch roller 17 and the conveying roller 16. Is transported under a strong transport force.

Here, the conveying roller 16 and the pinch roller 1
The position where the sheet 1 is clamped by the position 7 is shifted rearward in the direction in which the sheet 1 is conveyed from the position where the stopper 13 blocks the conveyance path of the sheet 1. When the leading end of the sheet 1 is clamped between the transport roller 16 and the pinch roller 17, the trailing end of the sheet 1 can be clamped between the transport roller 2 and the pinch roller 4. The transport roller 2 and the transport roller 16 in the front-back direction with respect to the transport direction of the sheet
The transport roller 9 and the slip roller 10, the paper detection sensor 11, and the skew detection sensor 12 are provided between the transport roller 2 and the transport roller 16.
a, 12b and a stopper 13 are provided.

Next, the operation of the conventional paper skew correction mechanism will be described. First, the solenoid 8 is in a released state, and in a state where the pinch roller 4 is strongly pressed against the transport roller 2,
The sheet 1 is conveyed under a strong conveying force by the conveying roller 2 and the pinch roller 4, and is conveyed by the conveying roller 9 and the slip roller 1.
Clamped to zero. When the sheet 1 is detected by the passage detection sensor 11, the solenoid 8 operates to retract the pinch roller 4 upward so that the conveying force of the conveying roller 2 is not applied to the sheet 1 and the solenoid 1
The sheet 4 is conveyed by the conveying roller 9 and the slip roller 10 and hits the stopper 13 by operating the sheet 4 and causing the stopper 13 to protrude from the sheet conveying surface 3.

The paper 1 has a transport roller 9 and a slip roller 1
Since the transport force received from 0 is weak, the sheet 1 hits the stopper 13 without breaking or damaging the end face, and the skew is corrected. Skew detection sensors 12a, 12
After detecting that both outputs b have changed and the skew of the sheet 1 has disappeared, the solenoid 8 is released and the pinch roller 4 is pressed against the conveying roller 2 again to clamp the sheet 1 and the solenoid 14 Is released, and the stopper 13 is retracted from the sheet conveying surface 3,
The sheet 1 is conveyed with a strong conveying force to a position where it is clamped by the conveying roller 16 and the pinch roller 17.

[0015]

However, in the above-described conventional skew correcting mechanism, when the skew is corrected by abutting the sheet against the stopper, the conveying roller and the slip for conveying the sheet with a weak conveying force are used. Rollers are required, and usually the paper is transported with a strong transport force, and when the paper is transported by the transport roller and the slip roller to correct the skew, the paper can be retracted so as not to exert the transport force on the paper. Another transport roller and a pinch roller are required, and there is a problem that the structure is complicated and the mechanism becomes large.

The present invention has been made to solve the problem that the structure is complicated and large as described above.
It is an object of the present invention to provide an inexpensive and small paper skew correction mechanism with a simple structure.

[0017]

In order to achieve this object, according to the present invention, the pressing force of the pinch roller in front of the stopper against the transport roller is switched between during the normal transport of the sheet and when the sheet abuts against the stopper. That is, the claims
The invention according to 1 is a stopper that is movable in a direction perpendicular to the paper transport surface, and a drive that moves the stopper from a position that protrudes from the paper transport surface to block the paper transport path and retracts from the paper transport surface. Means, and first detection means for detecting that a sheet has hit a stopper located immediately before the stopper and protruding from the sheet conveying surface;
A pair of left and right conveying rollers positioned in front of the stopper, and a pinch roller opposed to the conveying roller, the pin
Pressing the ninch roller against the transport roller with weak force
First pressing means for applying a force to the pinch roller
Together with the pressing force of the first pressing means.
Pressing the pinch roller against the transport roller with strong force
A second pressing means for applying a pressing force;
With the action or release of the pressing force of the pressing means,
Select the strength of the pressing force of the pinch roller against the transport roller.
Switching means for switching, and second detecting means positioned between the transport roller and the first detecting means for detecting that the paper has approached the stopper. When it is detected, the second pushing is performed by the switching means .
The action of the pressing force of the attaching means is released to weaken the pressing force of the pinch roller, the stopper is moved by the driving means to a position blocking the sheet transport path, and when the sheet is detected by the first detecting means, the switching means is used. Of the second pressing means
It reacted with pressing force by strong pressing force of the pinch roller, in which the control means to retract the stopper from the position obstructing the transport path of the paper is provided by the drive means.

According to a second aspect of the present invention, the sheet strikes a stopper movable in a direction perpendicular to the sheet conveying surface and a stopper located immediately before the stopper and protruding from the sheet conveying surface. a first detecting means for detecting the right and left pair of conveying rollers located in front of the stopper, and a pinch roller opposed to the conveying roller, this
Pressing the pinch roller with a small force on the transport roller
A first pressing hand for applying a pressing force to the pinch roller
Together with the step and the pressing force of the first pressing means
Pressing the pinch roller against the transport roller with strong force
A second pressing means for applying a pressing force;
By the action or release of the pressing force of the pressing means
The strength of the pressing force of the pinch roller against the transport roller
Switching means for switching, and transmitting the driving force of the switching means to the stopper, and interlocking with the switching of the pressing force of the pinch roller, causing the stopper to protrude from the sheet conveying surface to block the sheet conveying path from the position where the sheet is conveyed. Transmitting means for moving the sheet to a position where the sheet is retracted from the conveying roller;
Second detecting means for detecting that the sheet has come close to the stopper is provided between the detecting means and the detecting means, and when the sheet is detected by the second detecting means, the second pressing is performed by the switching means .
When the pressing force of the attaching means is released, the pressing force of the pinch roller is weakened, and the stopper is moved to a position where the sheet conveyance path is interrupted. When the sheet is detected by the first detecting means, the second pressing is performed by the switching means . Pressing force of means
To increase the pressing force of the pinch roller, and to provide a control means for retracting the stopper from a position where the paper path is interrupted .

[0019]

According to the first aspect of the present invention , when the sheet approaches the stopper and is detected by the second detecting means, the switching means controls the pressing force of the second pressing means.
Thereby weakening the pressing force of the pinch roller to release the action, driving hands stage moves the stopper in a position to block the transport path of the paper, abutted against the stopper by transporting the paper with a weak conveying force. When the sheet hits the stopper and is detected by the first detecting means, the switching means switches the second pressing means.
Of the pinch roller to increase the pressing force of the pinch roller, and the driving means retracts the stopper from the position blocking the sheet conveying path, thereby conveying the sheet with a strong conveying force.

Further, in the invention according to claim 2, when the sheet approaches the stopper and is detected by the second detecting means, the switching means releases the action of the pressing force of the second pressing means.
Converting mechanism weaken the pressing force of the pinch roller, stopper moves to a position to block the transport path of the paper the driving force is transmitted to the stopper by the transmission means, abut by conveying the sheet in the stopper with a weak conveying force. When the sheet is detected by the first detection means abuts against the stopper, with switching hands <br/> stage is strongly pressing force of the pressing force to act on the pin <br/> Chirora the second pressing means In conjunction with this, the stopper retracts from the position where the stopper interrupts the sheet conveyance path, and conveys the sheet with a strong conveyance force.

[0021]

An embodiment will be described below with reference to the drawings. FIG. 1 is a perspective view of the paper skew correcting mechanism according to the first embodiment of the present invention. Reference numeral 1 denotes a sheet, and 2 denotes a conveyance roller. Two conveyance rollers 2 are coaxially provided so as to be positioned on both left and right sides with respect to the conveyance direction of the sheet 1, and are rotated by a driving force from a driving unit (not shown). I do.

Reference numeral 3 denotes a sheet conveying surface. The conveying roller 2 projects from a hole formed in the sheet conveying surface 3, and its outer peripheral surface is in contact with the sheet 1 on the sheet conveying surface 3. Reference numeral 18 denotes two pinch rollers arranged to face the transport roller 2, and the pinch roller 18 has an axis parallel to the axis of the transport roller 2 and is rotatably supported by a shaft 19.

Reference numeral 20 denotes a first spring for pressing the pinch roller 18 against the transport roller 2 via a shaft 19;
The two pinch rollers 18 are equally distributed on the transport roller 2 respectively.
Two first springs 20 so as to be pressed against
Are the outer shafts 1 of the two pinch rollers 18 respectively.
Multiplied by nine. The first spring 20 is a weak spring, and the pinch roller 18 is pressed against the conveyance roller 2 by the first spring 20 with a weak force.
The paper 1 is clamped between the pinch roller 18 and the transport roller 2 and the transport roller 2 rotates, whereby the paper 1 is transported by receiving a weak transport force.

Reference numeral 21 denotes a lever which presses the pinch roller 18 against the transport roller 2 via a shaft 19, reference numeral 22 denotes a shaft to which the lever 21 is fixed and which is the center of rotation of the lever 21, and reference numeral 23: A solenoid that rotates through 25 is the arm 2
4 is a second spring that presses the pinch roller 18 against the transport roller 2 via the shaft 19 and the lever 21. The second spring 25 is a stronger spring than the first spring 20. .

In a state where the movable core of the solenoid 23 is released, the shaft 22 rotates under the force of the second spring 25, and the lever 21 comes into contact with the shaft 19, and in addition to the first spring 20, The pinch roller 18 is pressed against the transport roller 2 by the second spring 25. As described above, when the solenoid 23 is not operated, the pinch roller 18 is pressed against the transport roller 2 by the first spring 20 and the second spring 25 with a strong force, and the paper 1 is transported with the pinch roller 18. The paper 1 is clamped between the roller 1 and the paper 1 by rotating the transport roller 2.
Is transported under a strong transport force.

The position where the lever 21 contacts the shaft 19 is located at the center between the pinch rollers 18 so that the force of pressing the right and left pinch rollers 18 against the transport roller 2 by the second spring 25 becomes equal. It is. In a state where the solenoid 23 is operated and its movable core is being sucked, the shaft 22 rotates in the opposite direction to the above, against the second spring 25, and the lever 21 is raised to a position away from the shaft 19, The pinch roller 18 is pressed against the transport roller 2 only by the first spring 20. As described above, when the solenoid 23 is operating, the pinch roller 1 is
8, the paper 1 is clamped between the pinch roller 18 and the transport roller 2 by a weak force, and the paper 1 is transported by receiving the weak transport force by rotating the transport roller 2. Is done.

[0027] 11 is a passage detecting sensor for detecting passage of the sheet 1, the sheet 1 by the conveying roller 2 and the pinch roller 18
To the position Figure in the conveying direction behind the sheet 1 from the clamping position of, there is a detection position of the paper 1 tip by the passage detecting sensor 11. Reference numerals 12a and 12b denote skew detection sensors, which are respectively located at positions slightly deviated rearward in the transport direction of the paper 1 from the detection position of the leading edge of the paper 1 by the passage detection sensor 11, and are capable of detecting the left and right front edges of the paper 1 in the transport direction, respectively. As described above, when the leading edge of the sheet 1 is detected by the skew detecting sensors 12a and 12b, and the leading edge of the sheet 1 is detected by both the skew detecting sensors 12a and 12b, the sheet 1 is not skewed. Is determined.

Reference numeral 13 denotes a stopper which protrudes from the sheet conveying surface 3 and interrupts the conveying path of the sheet 1 immediately after the skew detecting sensors 12a and 12b. The directions protrude from two holes formed in the sheet conveying surface 3 so as to block the conveying path of the sheet 1 on the same line. Thus, when the sheet 1 is conveyed, the leading ends of the left and right sides of the sheet 1 respectively abut against the stopper 13 protruding from the sheet conveying surface 3, and the skew of the sheet 1 is corrected. At the same time, the skew detection sensor 12
The leading ends of the left and right sides of the sheet 1 are detected at a and 12b, and it is determined that the skew of the sheet 1 has been corrected.

Reference numeral 14 denotes a solenoid for moving the stopper 13, and reference numeral 15 denotes a rotatable arm for transmitting the driving force of the solenoid 14 to the stopper 13. The stopper 13 is driven by the solenoid 14 and is perpendicular to the sheet conveying surface 3. When the solenoid 14 is in the released state, the solenoid 14 is retracted to a position where it does not protrude from the sheet conveying surface 3 by the force of a spring (not shown). And when the solenoid 14 operates,
It protrudes vertically from the paper transport surface 3 and blocks the transport path of the paper 1.

Reference numeral 16 denotes a conveying roller, which is provided coaxially with two conveying rollers 16 located on both right and left sides with respect to the conveying direction of the sheet 1, and rotates by receiving a driving force from a driving unit (not shown). . The transport roller 16 is used for the paper transport surface 3.
And the outer peripheral surface thereof is in contact with the sheet 1 on the sheet conveying surface 3.

Reference numeral 17 denotes a pinch roller disposed opposite to the transport roller 16, and is rotatable along an axis parallel to the axis of the transport roller 2. The pinch roller 17 is pressed against the conveying roller 17 with a strong force by a spring or the like (not shown), and clamps the sheet 1 between the pinch roller 17 and the conveying roller 16. Is transported under a strong transport force.

Here, the conveying roller 16 and the pinch roller 1
The position where the sheet 1 is clamped by the position 7 is shifted rearward in the direction in which the sheet 1 is conveyed from the position where the stopper 13 blocks the conveyance path of the sheet 1. When the leading end of the sheet 1 is clamped between the transport roller 16 and the pinch roller 17, the trailing end of the sheet 1 can be clamped between the transport roller 2 and the pinch roller 18. The transport roller 2 and the transport roller 1 in the front-back direction with respect to the transport direction of the paper 1
6 is set, and the paper detection sensor 11 described above is disposed between the transport roller 2 and the transport roller 16.
Skew detection sensors 12a and 12b and a stopper 13 are provided.

FIG. 2 is a block diagram showing a control system of the sheet skew correcting mechanism in the first embodiment. Reference numeral 26 denotes a control unit. The control unit 26
Is detected, the solenoid 14 is actuated and the stopper 13
Is protruded from the sheet conveying surface 3, and the solenoid 23 is operated to move the lever 21 away from the shaft 19 so that the pressing force of the pinch roller 18 is received only from the first spring 20.

The control means 26 controls the skew detection sensor 12
When both a and 12b detect the paper 1, the solenoid 1
4 is released, the stopper 13 is retracted from the sheet conveying surface 3, the driving of the solenoid 23 is released, and the lever 21 is brought into contact with the shaft 19 by the second spring 25 to reduce the pressing force of the pinch roller 18 to the first. Of the second spring 25 in addition to the first spring 20.

FIG. 3 is a flowchart showing the operation of the first embodiment. Hereinafter, the operation of the skew feeding correcting mechanism of the first embodiment will be described. Normally, the solenoid 23 is released, the lever 21 contacts the shaft 19 by the second spring 25, and the pinch roller 18
The paper 1 is pressed against the transport roller 2 by a strong force of the second spring 25 in addition to the transport roller 2 (S1, S2), and is clamped between the transport roller 2 and the pinch roller 18.
Is transported by receiving a strong transport force by the rotation of the transport roller 2 (S3). At this time, the solenoid 14 is also in the released state, and the stopper 13 is retracted to a position where it does not protrude from the sheet conveying surface 3.

When the passage detecting sensor 11 detects the sheet 1 (S4), the solenoid 14 is operated to cause the stopper 13 to protrude from the sheet conveying surface 3 (S5, S6). Further, by operating the solenoid 23 to separate the lever 21 from the shaft 19, the force of the second spring 25 is not applied to the pinch roller 18 (S7, S8), and the pinch is pinched only by a weak pressing force by the first spring 20. As a result, the roller 18 or the transport roller 2 is pressed.
The paper 1 is conveyed with a weak conveyance force, and the leading end thereof is
3, the skew is corrected (S9). here,
As described above, the pressing force of the pinch roller 18 against the conveying roller 2 by the first spring 20 is weak, and the conveying force of the sheet 1 received from the conveying roller 2 and the pinch roller 18 is weak. The skew is corrected by hitting the stopper 13 without being damaged.

After detecting that both the outputs of the skew detection sensors 12a and 12b have changed and the skew of the sheet 1 has been eliminated (S10), the solenoid 14 is released and the stopper 13 is moved from the sheet conveying surface 3 to the stop. Evacuation (S1
1, S12), the solenoid 23 is released. As a result, the lever 21 contacts the shaft 19 by the second spring 25, and the pinch roller 18 is pressed against the transport roller 2 by the strong force of the second spring 25 in addition to the first spring 20 (S13, S14). , Paper 1 clamped between transport roller 2 and pinch roller 18
Is transported again by receiving a strong transport force (S15).

Then, the sheet 1 is clamped by the transport roller 16 and the pinch roller 17 and transported to the next processing system (S16). FIG. 4 is a perspective view of a main part of a paper skew correcting mechanism according to a second embodiment of the present invention. This second embodiment is:
In the first embodiment, the change of the pressing force of the pinch roller 18 and the movement of the stopper 13 are performed by different driving means, respectively, and are performed in conjunction with one driving means.

That is, reference numeral 27 denotes a connection between the arm 24 for rotating the lever 21 and the arm 15 for moving the stopper 13 so that the driving force of the solenoid 23 is
This is the link to communicate to Although not shown in FIG. 3, other components are the same as those in the first embodiment shown in FIG. 1, and the description thereof is omitted here.

By connecting the arm 24 and the arm 15 with the link 27 as described above, the lever 2 receives the force of the second spring 25 when the solenoid 23 is released.
1 is in contact with the shaft 19, the pinch roller 18 is pressed against the transport roller 2 by the first spring 20 and the second spring 25 with a strong force, and the spring 2
The force of No. 5 is transmitted to the arm 15 via the link 27, and the stopper 13 is retracted to a position where the stopper 13 does not protrude from the sheet conveying surface 3.

When the solenoid 23 is in operation, the lever 21 is moved up to a position away from the shaft 19 against the second spring 25, and the pinch roller 18 is moved by the first spring 20 to the transport roller 2. And the driving force of the solenoid 23 is transmitted to the arm 15 via the link 27 to
3 protrudes from the sheet transport surface 3.

The operation of the paper skew correcting mechanism according to the second embodiment will be described below. Normally, the solenoid 23 is in the released state,
The lever 21 is moved by the second spring 25 to the shaft 19.
, The pinch roller 18 is pressed against the transport roller 2 by the strong force of the second spring 25 in addition to the first spring 20, and the paper 1 clamped between the transport roller 2 and the pinch roller 18 is When the transport roller 2 rotates, the transport roller 2 receives a strong transport force and is transported. The stopper 13 is also connected to the second spring 25 via the link 27.
Is retracted to a position where it does not protrude from the sheet transport surface 3.

When the passage detecting sensor 11 detects the sheet 1, the solenoid 23 is operated. The driving force of the solenoid 23 is transmitted to the stopper 13 via the link 27, and the stopper 13 protrudes from the sheet conveying surface 3. When the solenoid 23 is operated, the lever 21 is moved to the shaft 19.
Away from the pinch roller 1
8 and is pressed against the pinch roller 18 or the transport roller 2 only by the weak pressing force of the first spring 14.

Since the pressing force of the pinch roller 18 against the transport roller 2 by the first spring 14 is weak, and the transport force of the sheet 1 received from the transport roller 2 and the pinch roller 18 is weak, the end face of the sheet 1 is broken or damaged. The skewing is corrected by hitting the stopper 13 without any wobbling.
After detecting that both the outputs of the skew detection sensors 12a and 12b have changed and that the skew of the sheet 1 has disappeared, the solenoid 23 is released to release the second spring 2.
5 is transmitted to the stopper 13 via the link 27,
The stopper 13 retreats from the sheet conveying surface 3. When the solenoid 23 is released, the lever 21 comes into contact with the shaft 19 by the second spring 25, and the pinch roller 18 is transported by the second spring 25 in addition to the first spring 20. 2, the sheet 1 is again conveyed by receiving a strong conveying force, and conveyed to a position where it is clamped by the conveying roller 16 and the pinch roller 17.

[0045]

As described in detail above, claim 1
The present invention relates to a driving means for driving a stopper, a first detecting means which is located immediately before the stopper and detects that a sheet has hit the stopper, and a pair of right and left transport rollers which are located before the stopper. When the pinch roller opposed to the conveying roller, the pinch roller conveyor b
Roller with a small force.
Pressing means for acting on the first pressing means
The pinch roller is transported according to the pressing force of the
No. that applies a pressing force to press the roller with strong force
2 pressing means, and pressing of the second pressing means
The pinch roller is conveyed by the action or release of an applied force.
Switching means for switching the strength of the pressing force on the roller;
Second detection means is provided between the transport roller and the first detection means for detecting that the paper has approached the stopper. When the second detection means detects the paper, the switching means detects the paper . Release the action of the pressing force of pressing means 2
Thereby weakening the pressing force of the pinch roller to move the stopper to a position blocking the transportation path of the sheet by the drive means, the pressing force of the second pressing means by the switching means when detecting the sheet by the first detecting means By acting on the pinch roller, the pressing force of the pinch roller is increased, and the stopper is retracted from the position where the sheet conveyance path is interrupted by the driving means.

As a result, it is not necessary to separately provide rollers for transporting the sheet with a weak transport force, which is conventionally required for abutting the sheet against the stopper to correct the skew, thereby simplifying the structure. Therefore, miniaturization and cost reduction of the device can be expected. According to a second aspect of the present invention, there is provided a first detecting unit which is located immediately before a stopper and detects that a sheet has hit the stopper, a pair of right and left transport rollers located before the stopper, and A pinch roller facing the roller, and a conveying roller
To the pinch roller.
First pressing means to be used, and the first pressing hand
Move the pinch roller along with the pressing force of the step
The second to apply the pressing force that presses with strong force
Pressing means and pressing force of the second pressing means
Or release of the pinch roller
Switching means for switching the strength of the pressing force against the
The driving force of the switching means is transmitted to the stopper, and the stopper is protruded from the sheet conveying surface to move from a position to block the sheet conveying path to a position to retract from the sheet conveying surface in conjunction with switching of the pressing force of the pinch roller. And a second detecting unit that is located between the transport roller and the first detecting unit and detects that the sheet has approached the stopper. When the second detecting unit detects the sheet, , Off
The action of the pressing force of the second pressing means by the replacement means .
Release and reduce the pressing force of the pinch roller, and move the stopper to the position where the paper
When the sheet is detected by the first detecting means, the second means is detected by the switching means .
The pressing force of the pressing means is applied to increase the pressing force of the pinch roller, and the stopper is retracted from a position blocking the paper transport path.

[0047] Thus, <br/> cutting conversion of the pressing force of the pinch roller um, by performing in conjunction with movement of the stopper in one drive unit can be further simplified structure, both controlled.

[Brief description of the drawings]

FIG. 1 is a perspective view of a sheet skew correcting mechanism according to a first embodiment of the present invention.

FIG. 2 is a block diagram illustrating a control system of a sheet skew correction mechanism according to the first embodiment.

FIG. 3 is a flowchart showing the operation of the first embodiment.

FIG. 4 is a perspective view of a paper skew correcting mechanism according to a second embodiment of the present invention.

FIG. 5 is a perspective view of a conventional paper skew correction mechanism.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Paper 2 Transport roller 3 Paper transport surface 11 Passage detection sensor 12a, 12b Skew detection sensor 13 Stopper 14 Solenoid 18 Pinch roller 23 Solenoid

Claims (2)

(57) [Scope of request for utility model registration] A stopper movable in a direction perpendicular to the sheet conveying surface; and a driving unit for moving the stopper from a position protruding from the sheet conveying surface to block a sheet conveying path to a position retracting from the sheet conveying surface. A first detecting unit that is positioned immediately before the stopper and detects that a sheet has hit a stopper that protrudes from a sheet conveying surface; a pair of left and right conveying rollers positioned in front of the stopper; and a pinch roller opposed to, press for pressing the pinch roller with a small force to the conveying roller
First pressing for applying a pressing force to the pinch roller
Means and the pressing force of the first pressing means.
Pressing the punch roller against the transport roller with strong force
A second pressing means for applying a force, and an action or solution of the pressing force of the second pressing means.
Pressing force of the pinch roller against the transport roller
Switching means for switching the strength of the sheet, and second detecting means positioned between the transport roller and the first detecting means for detecting that the paper has approached the stopper. When a sheet is detected, the switching means releases the pressing force of the second pressing means to weaken the pressing force of the pinch roller, and the driving means moves the stopper to a position where the paper feeding path is interrupted. Move the first
When the sheet is detected by the detecting means, the second pressing is performed by the switching means .
A sheet skew correction mechanism characterized by comprising control means for increasing the pressing force of the pinch roller by applying the pressing force of the attaching means and retracting the stopper from the position at which the paper conveying path is interrupted by the driving means. 2. A stopper which is movable in a direction perpendicular to the sheet conveying surface, and first detecting means for detecting that the sheet has hit a stopper located immediately before the stopper and protruding from the sheet conveying surface. A pair of right and left transport rollers located in front of the stopper, a pinch roller facing the transport roller, and a push for pressing the pinch roller against the transport roller with a weak force.
First pressing for applying a pressing force to the pinch roller
Means and the pressing force of the first pressing means.
Pressing the punch roller against the transport roller with strong force
A second pressing means for applying a force, and an action or solution of the pressing force of the second pressing means.
Pressing force of the pinch roller against the transport roller
Switching means for switching the strength of the sheet, and transmitting the driving force of the switching means to the stopper, and interlocking with the switching of the pressing force of the pinch roller, the stopper is protruded from the sheet conveyance surface to block the sheet conveyance path from the position. A transmitting means for moving to a position where the sheet is retracted from the sheet conveying surface; and a second detecting means positioned between the conveying roller and the first detecting means for detecting that the sheet has approached the stopper. When the sheet is detected by the second detecting means, the switching means cancels the pressing force of the second pressing means to weaken the pressing force of the pinch roller, and the stopper interrupts the sheet conveying path. And when the first detecting means detects the paper, the switching means causes the second pressing means to move.
A paper skew correcting mechanism, characterized in that control means is provided for increasing the pressing force of the pinch roller by applying the pressing force of (1) and for retracting the stopper from a position blocking the sheet conveyance path.