JPH06199448A - Sheet transport device - Google Patents

Abstract

PURPOSE:To secure a sheet conveyor that is able to set a sheet in the delivery direction in an accurate manner. CONSTITUTION:An auxiliary roller 17 is installed at the upstream of a main roller 5, and this roller 17 is made so as to energize a transferal force in the forward feeding direction to a sheet tip at the time of sheet feeding back by a reverse rotation of the main roller 5. With this constitution, the sheet tip is measured up to a bus bar of the main roller 5 in a highly accurate manner, and further sheet conveyance is made achievable up to the specified printing position so accurately by means of the normal rotation of this main roller 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device such as a printer, a typewriter, a copying machine, and a fax machine for transporting a sheet (recording paper, document paper) to a recording section or a reading section. The present invention relates to a device that can feed with high accuracy in a direction perpendicular to a busbar without skewing.

[0002]

2. Description of the Related Art As shown in FIG. 11, in a recording apparatus 150 such as a conventional typewriter, when a sheet P is set in the apparatus, the sheet P is placed on a sheet feed tray 151 provided obliquely and a platen knob 152 is set. When the sheet P is once turned into the platen 153, and then the platen knob 152 is reversed, the sheet P is disengaged from the meshing portion of the platen 153 and the pinch roller 155. 153 stays along the meshing part of the pinch roller 155. Next, when the platen knob 152 is rotated in the normal direction, the sheet P moves to the platen 153.
Is reliably conveyed in the direction perpendicular to the mother paper. The above method is a method that has been often used from the past.

Next, in Japanese Examined Patent Publication No. 62-3826, as shown in FIG. 12, a pickup roller 1 of a sheet feeding device is used.
The sheet P fed from 61 to the drive roller 162 is passed until the sheet P passes through the meshing portion of the drive roller.
By reversely feeding the sheet P and bending the sheet P between the pickup roller 161 and the drive roller 162,
The leading edge of the sheet P is brought into contact with the meshing portion of the drive roller 162, and then the drive roller 1
A method is proposed in which the sheet 62 is rotated forward and the sheet P is fed out.

[0004]

However, as shown in FIG.
In the prior art example, when the sheet P stays in the meshing portion of the platen 153 and the pinch roller 155 and then re-enters the meshing portion of the platen 153 by rotating the knob 152 in the forward direction, the tip of the sheet P meshes with the platen 153. Since the force for pressing the sheet P must depend on the weight of the sheet P, when the sheet feeding direction becomes nearly horizontal, the force for pressing the sheet P against the meshing portion of the platen 153 does not work and the sheet P cannot re-enter. There was a big drawback.

In the conventional example of FIG. 12, the drive roller 16
The force for pressing the sheet front end to the meshing portion of 2 uses the repulsive force of the sheet P by bending the sheet P, so that the sheet feeding direction is not selected, but it is assumed that the sheet P is bent. Since the sheet P to be used is thick and difficult to bend, it cannot be used. In addition, the space and passage length for bending the sheet P must be sufficiently prepared, and the size of the apparatus is small. It was difficult to make it.

The present invention is a sheet conveying apparatus capable of accurately feeding a sheet in the sheet feeding direction even when the sheet insertion direction is skewed and a thick sheet is fed. It is intended to provide.

[0007]

The present invention is a sheet (P)
A main roller (5) and a pressing means (9) for conveying the sheet, and an auxiliary roller (17) arranged on the upstream side of the main roller (5).
And the auxiliary roller (17) biases a transfer force in the forward feeding direction to the front end of the sheet (P) when the sheet (P) is fed backward by the reverse rotation of the main roller (5). When feeding, the left and right ends of the sheet (P) pass the contact position between the main roller (5) and the pressing means (9) by a predetermined amount, and then the main roller (5) is reversed by a predetermined amount. The left and right ends of the sheet (P) can be pulled out from the contact position, and at the same time, the left and right ends of the sheet (P) are retained along the contact position by the transfer force of the auxiliary roller (5) in the forward feeding direction. After that, it has a control means (24) for controlling the main roller (5) and the auxiliary roller (17) so that the main roller (5) is rotated forward by a predetermined amount and the sheet (P) is sent to the printing position. And

[0008]

According to the present invention, the auxiliary roller (1) is provided on the upstream side of the main roller (5) and the pressing means (9) and the main roller (5).
7) is provided so that the auxiliary roller (17) biases the transfer force in the forward feeding direction to the leading end of the sheet (P) when the sheet (P) is fed back by the reverse rotation of the main roller (5). When the sheet is fed, the left and right ends of the sheet (P) pass the contact position between the main roller (5) and the pressing means (9) by a predetermined amount, and then the main roller (5) is reversed by a predetermined amount. At the same time as the left and right ends of the sheet (P) are pulled out from the contact position, the right and left ends of the sheet (P) are retained along the contact position by the forward transfer force of the auxiliary roller (5), By providing the means (18) for feeding the sheet (P) to the printing position by rotating the main roller (5) forward by a predetermined amount, it is possible to convey the sheet (P) in any feeding direction and to make it thick. The bus bar of the main roller (5) even if the sheet (P) is hard to bend Transportation of high precision perpendicular direction is possible in.

[0009]

1 and 2 show a first embodiment of the present invention, FIG. 1 is a sectional view of the present apparatus, and FIG. 2 is a schematic view showing a sheet conveying mechanism of the present apparatus.

In FIG. 1, the outside of the apparatus main body 1 is composed of a cover 2 and a paper feed tray 3, the cover 2 is provided with a paper feed opening 2a and a paper ejection opening 12b, and the feed base 3 is provided with a paper guide 3a. ing. The sheet R is inserted from the paper feed port 2a and discharged from the paper discharge port 2b.

Inside a plurality of side plates 4 provided in the apparatus 1, a main roller 5 for conveying a sheet, a support shaft 6 to which the main roller 5 is fixed, and a guide plate 7 for guiding the sheet. A sensor S1 provided in the hole of the guide plate,
A platen 8 for holding the printing position of the sheet, a holding plate 9 to which a rotational force is applied in the direction of the main roller 5 by a spring 10 around a fulcrum 9a, and a sheet attached to the free end of the holding plate 9 A pressing roller 11 for bringing the main roller 5 into contact with the main roller 5, a carriage 13 guided by a plurality of guide shafts 12 and movable in the width direction of the sheet, and mounted on the carriage 13 to correspond to image information. A recording head 14 for printing is provided.

The means for abutting the sheet on the main roller 5 may have a structure in which the presser plate 9 and the presser roller 11 provided at the free end of the presser plate 9 are provided. Further, a thin plate having a spring property such as stainless steel may be used as the pressing plate without the pressing roller.

Further, in the apparatus body 1, a support shaft 15, a ring 16 fixed to the support shaft 15, and the ring 16 are provided.
16a and 16b that are erected on the peripheral surface of the auxiliary roller 17, the auxiliary roller 17 that is rotatably mounted on the support shaft and that has the pin 17a on its side surface, and the end portions are connected to the pins 16a and 17a. Spring 18, a pinch roller 20 that is pressed against the auxiliary roller 17 while being axially supported by a spring plate 19, and a sensor S disposed near the paper feed port 2a.
Two are provided. The surface of the auxiliary roller 17 is made of a material having a high friction property such as rubber.

In FIG. 2, the motor M1 is a motor gear 2
The main roller pair 5 is rotated based on the control signal of the controller 24 as a control device via the first and second stage gears 22 and the main roller gear 23 fixed to the shaft 6.

The rotation of the motor M1 includes a gear 25 and a gear 26 which are connected to the main roller gear, and a one-way clutch 28.
Is transmitted to the shaft 15 via.

The one-way clutch 28 transmits the rotation of the gear 27 in the direction of arrow 30 to the shaft 15 which is interlocked with the rotation of the main roller in the direction of arrow 29, which is the forward feed of the sheet P. The rotation of the gear 27 in the direction of arrow 32, which is interlocked with the rotation of the sheet P in the direction of backward feeding in the direction of arrow 31, is not transmitted to the shaft 15.

The ratchet wheel 33 fixed to the support shaft 15 and having saw teeth formed on the outer circumference of the ratchet lever 34 is rotated counterclockwise by the urging force of the spring 35 about the shaft 34a. The tip is in contact.
The ratchet lever 34 is provided on the ratchet wheel 3
3 is allowed to rotate in the direction of arrow 30, but is prevented from rotating in the direction of arrow 32.

The plunger 36 is the controller 24.
By moving the movable rod 37 upward based on the control signal of, the ratchet lever 34, which is in contact with the bent portion at the lower end of the movable rod 37, is rotated clockwise about the shaft 34d against the force of the spring 35. So that the ratchet wheel 3
The ratchet wheel 33 can be rotated clockwise by disengaging the meshing with the tooth portion 3. <Operation of First Embodiment> Next, referring to FIGS.
The sheet conveying operation of the embodiment apparatus will be described.

When the sheet P is inserted from the sheet feeding port 2a along the sheet feeding table 3 and the sheet guide 3a, the sensor S2 detects the leading edge of the sheet. Based on the detection, the controller 24 activates the motor M1 to rotate the main roller 5 in the direction of the arrow 29 which is the sheet forward feeding direction.

The rotation of the main roller 5 is performed by the gear 23 and the gear 2.
5, transmitted to the gear 27 through the gear 26 as rotation in the direction of arrow 30.

When the gear 27 rotates in the direction of arrow 30, the one-way clutch 28 connects the gear 27 and the support shaft 15, so that the support shaft 15 also rotates in the same direction. The rotation of the support shaft 15 causes the ring 16 fixed to the support shaft 15, the pin 16a provided on the peripheral surface of the ring 16, the pin 17a provided on the side surface of the auxiliary roller 17, and the end portion to be a pin. 16
It is transmitted to the auxiliary roller 17 via the spring 18 connected to a and 17a, and the auxiliary roller 17 also rotates in the direction of arrow 30.

The pin 17a is always in contact with the pin 16b by a predetermined force by the spring 18 during the rotation. By the rotation of the auxiliary roller in the direction of arrow 30, the sheet P is conveyed to the back of the apparatus, and the leading edge of the sheet is detected by the sensor S1.
Is detected, the controller 24 controls the motor M1 to send out the sheet front end only by the length L shown in FIG. The protrusion length N from the contact position between the main roller 5 and the pressing roller 11 to the leading end of the sheet will be described with reference to FIG.

FIG. 9 is a schematic view of the sheet conveying portion of the apparatus 1 shown in FIG. 1 as viewed from above.

When the sheet P is conveyed obliquely like P1, the left and right protrusion lengths N differ from each other to a left protrusion length T and a right protrusion length U, resulting in a difference of TU = W.

Assuming that the difference of W is a skew amount, when the amount of W is large, the amount of the protrusion length N needs to be increased accordingly, but the amount is limited due to the size of the sheet feeding port 2a. Need to be provided.

The sheet side end regulating means 3a, 3b are effective means for regulating the amount of W. If the maximum skew amount W is 3 mm and the margin such as slip between the sheet P and each conveying roller is 2 mm, the protrusion length N is N = 3 + 2 = 5.

From the state in which the leading edge of the sheet is projected by N, the main roller 5 is rotated by the control of the controller 24 as indicated by the arrow in the sheet reverse feeding direction.

At least the amount of rotation of the main roller 5 is preferably at least the protrusion length N, for example, a transport length corresponding to about 2 × N to 3 × N.

The gear 27 rotates in the direction of arrow 32 in conjunction with the rotation of the main roller 5 in the direction of arrow 31, but this rotation is not transmitted to the support shaft 15 by the action of the one-way clutch 32.

Following the reverse movement of the sheet P, the auxiliary roller 17 rotates in the direction of arrow 32. Meanwhile, pin 17
a also rotates, but the support shaft 15 is the ratchet wheel 3
3, by the action of the ratchet lever 34, the arrow 32
Since the rotation in the direction is blocked, the pin 16a does not rotate, and the rotation of the auxiliary roller 17 is performed while the spring 18 extends. The pulling force of the spring 18 acts so as to rotate the auxiliary roller 17 in the direction of the arrow 30, so that the auxiliary roller 17 constantly applies a transfer force in the forward feeding direction to the sheet during this time. Further, since the plurality of auxiliary rollers 17 are independently rotatably fitted to the support shaft 15, they are independent of each other even if the amount of movement of the sheet in the backward feeding direction varies depending on the position in the sheet. And respond.

In FIG. 9, when the sheet P is fed back from the state of P1, the right end protruding length U is fed to the contact position first, but when it goes out of the contact position of the main roller 5 and the pressing roller 11, it is further exceeded. Does not retreat. At the same time, the left end is fed backward, but since U <T, it is placed at the right end and fed to the contact position, and the left and right leading ends of the sheet P stay along the contact position and enter the state of P2. The biasing force of the spring 18 is set so that the leading end of the sheet does not bend in the state of P2. When the controller 24 rotates the main roller 5 by a predetermined amount in the direction of arrow 29, with the state of P2 as the start position for sheet cueing, the transfer force of the auxiliary roller 17 in the forward feeding direction causes the left and right leading ends of the sheet P to contact the sheet. After passing through the contact position along the position, it is accurately conveyed to the print recording position of the recording head 14 without skew.

Next, based on the print signal, the sheets P are successively fed in the forward direction by a predetermined amount, the carriage 13 reciprocates in the sheet width direction, and printing is performed by the recording head 14. When printing is performed again in a special printing mode during printing, for example, when returning to the preceding printing area and printing is performed again, the controller 24 causes the plunger 36 to work to enable the ratchet wheel 33 to rotate in the direction of the arrow 32. At the same time, in order to return the sheet P to the preceding printing position, when the main roller 5 is rotated in the direction of the arrow 31 by a predetermined amount, the auxiliary roller 17 follows the backward feeding movement of the sheet P without generating a shifting force in the forward feeding direction. The sheet P is conveyed with the conveyance accuracy of the main roller 5. Thereafter, when the main roller 5 rotates in the forward feeding direction, the controller 24 stops the operation of the plunger and returns it to the original state.

As another method of controlling the plunger 37, when the sheet P reaches the printing position of the recording head 14, the plunger 36 is driven to lift the lever 34, and the operation of the plunger 36 is stopped as described above. There is also a method of performing it when the recording operation of the sheet P is completed.

When the sensor S1 detects the trailing edge of the sheet P, the main roller 5 feeds a predetermined amount of sheet for printing under the control of the controller 24.

After the last sheet feeding is completed, the main roller 5 performs a predetermined amount of sheet discharging rotation to discharge the sheet 2
The sheet is discharged from b.

The controller 24 rotates the main roller 5 even if there is no sheet trailing edge detection signal from the sensor S1 when the total sheet feed amount for printing stored in advance according to an instruction from the computer is reached. Then, the sheet is discharged.

The controller 24 sets the apparatus 1 to the initial state when the signal of the sensor S1 is the signal of no paper after the sheet discharging operation by the main roller 5. On the other hand, when the signal is a signal indicating that paper is present, it is determined that a sheet conveyance failure has occurred, and a warning is given by a display means, an acoustic means, or the like.

A second embodiment will be described with reference to FIGS. 3 and 4.

FIG. 3 is a sectional view of this apparatus, and FIG. 4 is a schematic view showing a sheet conveying mechanism of this apparatus. In FIGS. 3 and 4, members having the same shapes and functions as those shown in FIGS. 1 and 2 are designated by the same reference numerals.

In FIG. 3, the outside of the apparatus main body 1 is composed of a cover 2 and a paper feed tray 3, and the cover 2 has a paper feed port 2a.
A paper guide 3a is provided on the paper feed table 3 with a paper discharge port 2b. The sheet P is inserted from the paper feed port 2a and discharged from the paper discharge port 2b. Inside the plurality of side plates 40,
A main roller 5 that conveys the sheet P, a support shaft 6 to which the main roller 5 is fixed, and a guide plate 7 that guides the sheet.
The sensor S1 provided in the hole of the guide plate 7, the platen 8 for holding the printing position of the sheet, and the spring 10 centering around the fulcrum 9a, and the pressing force applied to the main roller 5 in the direction of the main roller 5. A plate 9, a pressing roller 11 attached to the free end of the pressing plate 9 for contacting the sheet with the main roller 5, and a carriage 13 which is guided by a plurality of guide shafts 12 and is movable in the width direction of the sheet. And this carriage 1
The recording head 14 is mounted on the printer No. 3 and prints according to print information.

Further, in the apparatus body 1, a long hole 40a provided in the side plate 40 is movably supported like a support shaft 41a shown by a dotted line. A support shaft 41, an auxiliary roller 42 fixed to the support shaft and having a surface made of a material having high friction such as rubber, and a predetermined amount of force applied to the auxiliary roller 42 by a biasing force of a spring 44 about the support shaft 43a. Contacting with pressure,
Moreover, the guide plate 43 whose contact surface is made of a slippery material
A sensor S2 is provided in the hole of the guide plate 43 near the insertion opening 2a.

In FIG. 4, the motor M1 is a motor gear 2
The main roller position 5 is rotated based on a control signal from the controller 24 via the first and second stage gears 22 and the main roller gear 23 fixed to the shaft 6.

The rotation of the motor M1 is performed by the main roller gear 2
It is transmitted to the shaft 41 via the one-way clutch 28 and the gear 25 and the gear 26 that are connected to the gear 3.

The one-way clutch 28 transmits the rotation of the gear 27 in the direction of arrow 30 to the shaft 45, but does not transmit the rotation of the gear 27 in the direction of arrow 32.

The shaft 45 and the support shaft 41 are connected to each other via a universal joint 46 that flexibly transmits rotation.

A plurality of free rollers 47 are rotatably fitted on the support shaft 41.

A spring 48 whose end portion is connected to one end portion 41a of the support shaft 41 and a spring hooking portion 40b provided on the side plate 40 is provided with a support shaft 41 which extends along the elongated hole 40a. The movement in the direction close to the roller 5 is urged.

On the outer periphery of the ratchet wheel 33 fixed to the shaft 45 and having saw teeth formed on the outer periphery thereof, the tip of the ratchet lever 34, which is rotated counterclockwise by the urging force of the spring 35 about the shaft 34a, is provided. Abutting. The ratchet lever 34 allows the ratchet wheel 33 to rotate in the direction of arrow 30, but prevents the ratchet wheel 33 from rotating in the direction of arrow 32.

The plunger 36 is the controller 24.
The movable rod 37 is moved upward based on the control signal of. The ratchet lever 34, which comes into contact with the bent portion provided at the lower end of the movable rod 37 by the movement, is rotated clockwise around the shaft 43a and escapes from the meshing portion of the ratchet wheel 33. It is possible to rotate in 32 directions. <Operation of Second Embodiment> Next, referring to FIGS.
The sheet conveying operation of the embodiment apparatus will be described.

When the sheet P is inserted from the paper feed port 2a along the feeding table 3 and the paper guide 3a, the sensor S2 detects the front end of the sheet, and the controller 24 causes the motor M1 to detect the leading edge.
Is started to rotate the main roller 5 in the direction of arrow 29.

The rotation of the main roller 5 is performed by the gear 23 and the gear 2.
5. The gear 27 is rotated in the direction of arrow 30 through the gear 26.

When the gear 27 rotates in the direction of arrow 30, since the one-way clutch 28 connects the gear 27 and the shaft 45, the support shaft 41 also rotates in the direction of arrow 30 via the universal joint 46. The sheet P sandwiched between the auxiliary roller 42 fixed to the support shaft 41 and the guide plate 43 is sent to the main roller 5 by the rotation of the auxiliary roller 42. The free roller 47 follows the movement of the sheet P and guides the sheet while pressing the floating of the sheet P.
When the sensor S1 detects the leading edge of the sheet P, the controller 24 controls the motor M1 to feed the sheet L by the length L.

Next, when the controller 24 rotates the main roller 5 in the direction of the arrow 31 by a predetermined amount, the sheet P is rotated.
The auxiliary roller 42 tries to rotate in the direction of the arrow 32 as the ratchet lever 34 moves.
Therefore, the auxiliary roller 4 cannot rotate because
2 is moved in a direction away from the roller 5 while tensioning the spring 48 while the rotation is stopped. The auxiliary roller 42
Continues to give the sheet P a moving force in the forward feeding direction by the tension force during the movement operation.

When the left and right ends of the sheet P move back and forth to move out of the contact position between the main roller 5 and the pressing roller 11 during the reverse rotation of the main roller 5, the left and right ends of the sheet P move to the auxiliary roller 42. The force stays along the contact position. The biasing force of the spring 48 is set so that the leading end of the sheet is not bent by the transition force.

When the main roller 5 is rotated in the forward feeding direction by a predetermined amount after the main roller 5 is rotated in the forward direction by a predetermined amount after the reverse rotation by a predetermined amount, the left and right ends of the sheet P are moved by the auxiliary roller 42. The transitional force passes the contact position along the contact position, and further, the recording head 14 is fed to the print recording position without skew and with high accuracy.
After that, the operations from the completion of printing to the subsequent discharge of the sheet are the same as those in the first embodiment, and the description thereof will be omitted.

A third embodiment will be described with reference to FIGS.

FIG. 5 is a sectional view of the present apparatus, and FIG. 6 is a schematic view showing a sheet conveying mechanism of the present apparatus. In FIGS. 5 and 6, members having the same shape and function as those shown in FIGS. 1 and 2 are designated by the same reference numerals.

In FIG. 5, the outside of the apparatus main body 1 is composed of a cover 2 and a paper feed tray 3. The cover 2 is provided with a paper feed opening 2a and a paper exit 2b, and the paper feed tray 3 is provided with a paper guide 3a. ing. The sheet P is inserted from the paper feed 2a and ejected from the paper ejection port 2b. Inside the plurality of side plates 50, a main roller 5 that discharges the sheet, a support shaft 6 to which the main roller is fixed, a guide member 51 that guides the sheet,
The sensor S1 provided in the hole of the guide plate 51, the platen 8 for holding the printing position of the sheet, and the pressing plate 9 which is given a turning force in the direction of the main roller 5 by the spring 10 around the fulcrum 9a. And a pressing roller 1 which is attached to the free end of the pressing plate 9 to bring the sheet into contact with the main roller 5.
1, a carriage 13 guided by a plurality of guide shafts 12 and movable in the width direction of the sheet, and the carriage 13
Is equipped with a recording head 14 for printing according to image information.

Further, in the apparatus main body 1, a lever 54 is provided which is rotated counterclockwise about the pin 52 by the biasing force of a spring 53, and one end of the lever 54 is rotatably supported. The shaft 55 is supported, the auxiliary roller 56 fixed to the shaft 55, and the end of the side plate 50 are axially supported. A shaft 57, an auxiliary roller 58 fixed to the shaft 57, and a sensor S2 arranged near the insertion port 2a are provided.

In FIG. 6, the motor M1 rotates the main roller 5 based on a control signal from the controller 24 via the motor gear 21, the two-stage gear 22, and the main roller gear 23 fixed to the shaft 6.

The rotation of the motor M1 is performed by the main roller gear 2
3 through the gear 59 meshing with the gear 60 and the gear 6
It is transmitted to 1.

The one-way clutch 62 transmits the rotation of the gear 60 in the direction of the arrow 63 to the shaft 55, but does not transmit the rotation in the opposite direction.

The one-way clutch 64 transmits the rotation of the gear 61 in the direction of arrow 65 to the shaft 57, but does not transmit the rotation in the opposite direction.

The other end of the shaft 55 is rotatably supported by the lever 68, which is rotated counterclockwise by the urging force of the spring 67 about the rotation shaft 66 of the gear 59. Therefore, the axial length between the gear 59 and the gear 60 is kept constant even if the levers 54 and 68 rotate.

When the main roller 5 rotates in the direction of arrow 29, the gear 64 rotates in the direction of arrow 65 via the gears 23 and 59. This rotation is transmitted to the shaft 5 via the one-way clutch 64.
7, the auxiliary roller 58 also rotates in the direction of arrow 65. On the other hand, the rotation of the gear 60 in the same direction as that of the gear 64 is disengaged by the one-way clutch 62, so that the shaft 55 does not rotate, but the sheet P is sandwiched (the same even when there is no sheet) to the auxiliary roller 58 by a spring. 13, the spring 67 contacts the auxiliary roller 5 with a predetermined pressing force.
6 rotates in the direction of arrow 63 following the rotation of the auxiliary roller 58 in the direction of arrow 65. The rotation of the plurality of auxiliary rollers gives the sheet P a transfer force in the forward feeding direction.

When the main roller 5 rotates in the direction of arrow 31, the gear 60 rotates in the direction of arrow 63. This rotation is transmitted to the shaft 55 via the one-way clutch 62, and the auxiliary roller 56 also rotates in the direction of arrow 63.

On the other hand, the rotation of the gear 64 in the same direction as the gear 60 is interrupted by the clutch 64, so the shaft 57 does not rotate, but the auxiliary roller 58 follows the rotation of the roller 56 and rotates in the direction of arrow 65. To do. The rotation of the plurality of auxiliary rollers gives the sheet P a transfer force in the forward feeding direction.

The plurality of free rollers 69 rotatably fitted to the shaft 55 and the plurality of free rollers 70 rotatably fitted to the shaft 57 so as to face the free rollers 69 are arranged so as to press the rising of the sheet P and Rotates freely according to movement.

The plunger 36 moves the movable member 37 upward in response to the control signal from the controller. By this movement, the lower end of the movable member 37 contacts the lower surface of the tip of the lever 68, and the lever 68 and the lever 54 rotate clockwise. By this rotation, the auxiliary rollers 56 and 58 are separated from each other, so that the sheet P is moved only by the conveying force of the main roller. <Operation of Third Embodiment> Next, referring to FIGS.
The sheet conveying operation of the carrying device will be described.

When the sheet P is inserted from the paper feed port 2a along the feeding table 3 and the paper guide 3a, the sensor S2 detects the leading edge of the sheet, and the controller 24 activates the motor M1 to cause the main roller 5 to move. Rotate in the direction of arrow 29.

The rotation of the main roller 5 is performed by the gear 23, the gear 59, the gear 61, the one-way clutch 64, and the support shaft 57.
The auxiliary roller 58 is rotated in the direction of arrow 65 through.
The rotation of the auxiliary roller 58 conveys the leading edge of the sheet P toward the main roller 5. When the sensor S1 detects the leading edge of the sheet during the conveyance, the controller 24 controls the motor M1 to feed the sheet by the length L. During the rotation of the auxiliary roller 58, the auxiliary roller 56 follows the rotation of the auxiliary roller 58 through the sheet P and follows the arrow 63.
Rotate in the direction.

Next, when the controller 24 rotates the main roller 5 in the direction of arrow 31 by a predetermined amount, the rotation of the gear 60 in the direction of arrow 63 passes through the clutch 62 and the auxiliary roller 5 is rotated.
6, the auxiliary roller 56 also rotates in the same direction, so that the rotation gives a transfer force T to the sheet P in the forward feeding direction. While the auxiliary roller 56 is rotating, the auxiliary roller 58 is rotated in the direction of arrow 65 following the rotation of the auxiliary roller 56 via the sheet P.

When the left and right front ends of the sheet P move forward and backward and pass through the contact position between the main roller 5 and the pressing roller 11 during the reverse rotation of the main roller 5, the front end of the sheet is moved by the transfer force of the auxiliary roller 56. Stay along the contact position.

The biasing forces of the spring 13 and the spring 67 are set so that the leading edge of the sheet is not bent by the shifting force.

When the main roller 5 rotates a predetermined amount in the forward feeding direction with the above-mentioned state as the start position for sheet cueing after the predetermined amount of reverse rotation, the left and right ends of the sheet P are moved by the auxiliary roller 56. By the transitional force, it passes through the contact position along the contact position and is fed to the print recording position of the recording head 14 without skew and with high accuracy.

After that, the operations from the completion of printing to the subsequent discharge of the sheet are the same as those in the first embodiment, and the description thereof will be omitted.

A fourth embodiment will be described with reference to FIGS. 7 and 8. FIG. 8 is a sectional view of the apparatus, and FIG. 7 is a schematic view showing a sheet feeding mechanism of the apparatus and a sheet feeding mechanism. In FIGS. 8 and 7, members having the same shapes and functions as those shown in FIGS. 1 and 2 are designated by the same reference numerals.

In FIG. 8, reference numeral 71 is a main body cover 71a.
Is a paper exit.

In the main body cover 71, a plurality of sheets K
A paper support 73 for holding the rear end of the sheet, a pressure plate 74 rotatably supported by a shaft 74a on the hopper 72, a paper feed roller 76 having a half-moon-shaped cross section, and Paper feed roller 76
Support shaft 75 to which is firmly attached and the pressure plate 7
4 is provided with a separating claw 78.

Further, the auxiliary roller 80 that conveys the sheets that have been separated and fed one by one by the rotation of the paper feed roller 76 and the separation claw 78, and the support shaft 79 to which the auxiliary roller is fixed, A pinch roller 82 that is pressed against the auxiliary roller 80 while being supported by a spring plate 81;
A guide plate 83 that guides the sheet, a sensor S1 that detects the movement of the sheet, a platen 8 that holds the printing position of the sheet, a main roller 5 that conveys the sheet, and a support shaft 6 to which the main roller is fixed. And the spring 1 around the fulcrum 9a
0, a pressing plate 9 is applied with a turning force in the direction of the main roller 5, a pressing roller 11 attached to the free end of the pressing plate 9 to bring a sheet into contact with the main roller 5, and a plurality of guides. A carriage 13 guided by the shaft 12 and movable in the width direction of the sheet, and a recording head 14 mounted on the carriage 13 for performing printing in accordance with image information.

The surface of the auxiliary roller 80 is made of a material having a high friction property such as rubber.

In FIG. 7, the motor M1 is the motor gear 2
The main roller 5 is rotated based on a control signal from the controller 84 via the first and second stage gears 22 and the main roller gear 23 fixed to the shaft 6.

The controller 84 also controls the motor M2, and the rotation of the motor M2 is transmitted to the paper feed roller gear 88 by the motor gear 85, the gear 86, and the intermediate gear 87.

The paper feed roller gear 88 is rotatably mounted on the shaft 75.

The rotation of the paper feed roller gear 88 is transmitted to the paper feed roller 76 via the one-rotation spring clutch 89 and the support shaft 75.

FIG. 10 is a sectional view of the one-rotation spring clutch 89. Inside the cam ring 99, a spring 96 and a bin 9 are provided.
8, a cylinder 97 fixed to the shaft 75 is provided. The spring 96 is wound around the boss portion of the paper feed gear 88 and the cylinder 97. Further, one end 96a of the spring 96 is connected to the cam ring 99 and the other end 96b is connected to the cylinder 97.

In the above structure, when the tip end of the lever 91 is caught by the projection 99a of the cam ring 99 during the rotation of the support shaft 75 due to the rotation of the feed gear 88 in the direction of arrow 92, the rotation of the cam ring 99 is stopped. To do. On the other hand, the rotation of the support shaft 75 connected to the cam ring 99, the spring 96 and the cylinder 97 is also stopped. Since the rotation of the end portion 96a of the spring 96 is also stopped by the stop, the winding force of the spring 96 around the boss portion of the paper feed gear 88 is loosened, and only the paper feed gear 88 continues to rotate.

On the other hand, when the feed gear 88 is rotated by a predetermined amount in the direction of arrow 93 by the motor M2, the tip of the lever 91 is disengaged from the protrusion 99a, so that the spring 96 is tightened and the feed gear 88 and the support shaft 75 are connected. And then arrow 92
The paper feed roller is also rotated by the rotation in the direction.

The roller 84 rotatably provided on the shaft 79 guides the sheet K by the conveying roller 5 while following the movement of the sheet K. <Operation of Fourth Embodiment> Next, the sheet conveying operation of the apparatus according to the fourth embodiment will be described with reference to FIGS. 7 and 8.

In response to the paper feed command from the host computer, the controller 84 rotates the motor M1 to rotate the main roller 5 in the direction of arrow 29. At the same time, the controller 84 rotates the motor M2 to move the paper feed gear 88 to the arrow 9
When the lever 91 is rotated by a predetermined amount in the three directions, the tip of the lever 91 is disengaged from the protruding portion 99a and the spring 96 is tightened.
Rotation of the paper feed roller 76 is transmitted to the paper feed roller 76.
Also begins to turn toward arrow 92. When the maximum radius portion of the sheet feeding roller 75 contacts the upper surface of the plurality of sheets K, the sheet K
The upper surface paper is moved in the direction of the separation claw 78, and only one sheet is separated by the claw 78, and the separated sheet is conveyed in the direction of the main roller 5 by the paper feed roller 76 and the auxiliary roller 80.

When the sensor S1 detects the leading edge of the sheet K, the controller 84 controls the amount of rotation of the motor M1 to feed the leading edge of the sheet by the length L shown in FIG. The amount N of protrusion of the leading edge of the sheet has been described in detail in the description of the first embodiment, and thus the description thereof is omitted.

Next, the controller 84 reversely rotates the motor M1 to rotate the main roller 5 in the direction of arrow 31 by a predetermined amount to move the sheet K in the reverse feeding direction. At the same time, the controller 84 rotates the motor M2 to rotate the auxiliary roller 80 in the direction of arrow 94, and gives the sheet K a transfer force in the forward feeding direction.

There are the following two methods for the auxiliary roller 80 to apply the transfer force to the sheet K.

The first method sets the peripheral speed of rotation of the auxiliary roller 80 to a normal peripheral speed. On the other hand, if the spring force of the spring plate 81 that applies the pressing force to the pinch roller 79 that presses the sheet K against the auxiliary roller 80 is made as small as possible within the range that satisfies the forward direction conveyance force, the surface of the sheet K is changed to the auxiliary direction. The roller 80 slips and gives a positive direction transfer force to the sheet K.

When a sheet having a low surface hardness is used by the above method, the slip may scrape the surface of the sheet to cause scratches.

As a means for preventing the occurrence of the scratches, if the controller 84 controls the motor M2 to reduce the rotational peripheral speed of the auxiliary roller 80, the peripheral surface of the auxiliary roller 80 slips on the sheet surface. By reducing the thickness, the force for scraping the surface of the sheet is weakened, and therefore the occurrence of the scratches can be prevented.

Next, the second method in which the auxiliary roller 80 applies the transfer force to the sheet K is to rotate the main roller 5 in the direction of the arrow 31 to move the sheet K in the reverse feeding direction. Motor M so as to rotate in the direction opposite to the arrow 94 while being driven while applying a transfer force in the forward feeding direction to the sheet.
2 is controlled.

According to the above method, the rotational force in the forward feeding direction given to the sheet K by the auxiliary roller 80 by the motor M2 is given to the motor M2 so that it becomes smaller than the rotational force given to the auxiliary roller 80 by the sheet K at the time of backward feeding. The controller 84 controls the current or the voltage or both the current and the voltage.

When the leading edge of the sheet passes through the contact position between the main roller 5 and the pressing roller 11 due to the rotation of the main roller 5 in the direction of the arrow 31, even if there is a time lag between the leading edge of the sheet and the trailing edge of the sheet, the auxiliary roller 80 Since the transfer force is applied to the sheet K at substantially the center of the sheet, when the sheet K exits the entire width of the leading edge of the sheet K, the sheet K is entirely rotated around the contact point of the auxiliary roller 80, and the transfer force causes the sheet K to move. Since the leading edge of the sheet is pressed against the contact position between the main roller 5 and the pressing roller 11, the sheet stays along the contact position.

When the main roller 5 is rotated in the direction of arrow 29 by a predetermined amount from the above state, the right and left ends of the sheet K are moved along the contact position by the transfer force of the auxiliary roller 80 in the forward feeding direction. In this state, it passes through the contact position and is conveyed to the print position of the recording head 14 with high accuracy without skew.

Next, based on the print signal, the sheet K is fed by the main roller 5 in the forward feeding direction by a predetermined amount, and then the carriage 1 is moved.
3 is reciprocated in the sheet width direction, and printing is performed by the recording head 14.

While the sheet K is being conveyed by the main roller 5,
Although the motor M2 is stopped, the one-way clutch 95 allows the auxiliary roller 80 to freely rotate in the direction of arrow 94, and the auxiliary roller 80 follows the movement of the main roller 5 in the forward direction of the sheet K. Therefore, the auxiliary roller 80 does not impose a load on the conveying force of the main roller 5, and thus the main roller 5 can feed the sheet with high accuracy.

In the above-mentioned embodiment, the device for applying the transfer force to the sheet by the auxiliary roller 80 has been described. However, the auxiliary roller 80 and the pinch roller 82 are omitted, and the paper feeding roller 76 has the same function and function as the auxiliary roller 80. The same effect can be obtained by performing the operation.

As described above in detail, in the apparatus of the present invention, the auxiliary roller is provided on the upstream side of the main roller, and the auxiliary roller shifts to the forward end of the sheet in the forward feeding direction when the sheet is reversely fed by the reverse rotation of the main roller. By urging the force, the leading edge of the sheet follows the generatrix of the main roller with high accuracy, and while maintaining the above state, the main roller can be rotated normally to reach a predetermined printing position. Thus, it is possible to provide an extremely excellent sheet conveying device capable of conveying sheets.

The same effect can be obtained by applying the functions and operations of the main roller and the auxiliary roller in the embodiment of the present invention to a registration roller used in a printing apparatus such as a copying machine.

[0106]

As described above, according to the present invention, the main roller and the pressing means and the auxiliary roller are provided on the upstream side of the main roller, and the auxiliary roller reversely feeds the sheet by reversing the main roller. At this time, a transfer force in the forward feeding direction is always applied to the leading end of the sheet. And when feeding
After the left and right ends of the sheet have passed the contact position between the main roller and the pressing means by a predetermined amount, the main roller is reversed by a predetermined amount to move the left and right ends of the sheet out of the contact position, and at the same time, the auxiliary roller Since the right and left leading ends of the sheet are retained along the contact position by the positive direction transition force, and then the main roller is rotated forward by a predetermined amount to feed the sheet to the printing position, the sheet feeding direction is set. It is possible to carry out any transport, and it is possible to transport a sheet that is thick and difficult to bend in a direction perpendicular to the generatrix of the main roller.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view of a recording apparatus to which a first exemplary embodiment of a sheet conveying apparatus according to the present invention is applied.

FIG. 2 is a perspective view of the sheet conveying device section.

FIG. 3 is a vertical cross-sectional side view of a recording apparatus to which a second embodiment of the sheet conveying apparatus of the invention is applied.

FIG. 4 is a perspective view of the sheet conveying device section.

FIG. 5 is a vertical sectional side view of a recording apparatus to which a third embodiment of the sheet conveying apparatus of the invention is applied.

FIG. 6 is a perspective view of the sheet conveying device section.

FIG. 7 is a perspective view of a sheet conveying device according to a fourth embodiment of the present invention.

FIG. 8 is a vertical cross-sectional side view of a recording apparatus to which the sheet conveying apparatus is also applied.

FIG. 9 is a plan view of a sheet and a sheet feeding unit according to the present invention.

FIG. 10 is a vertical sectional side view of the spring clutch portion.

FIG. 11 is a perspective view of a recording apparatus to which a conventional sheet conveying apparatus is applied.

FIG. 12 is a side view showing a main part of another conventional sheet conveying device.

[Explanation of symbols]

 P sheet M1, M2 motor 1 recording device 5 main roller 9 pressing plate (pressing means) 16 ring 17 auxiliary roller 18 spring member 24 controller (control means) 42 auxiliary roller 48 spring member 56, 58 auxiliary roller 80 auxiliary roller 84 controller ( Control means) 89 1 rotation spring clutch

Claims (5)

[Claims] 1. A main roller for conveying a sheet, a pressing means, and an auxiliary roller arranged on the upstream side of the main roller, wherein the auxiliary roller is used to reversely feed the sheet by reversing the main roller. , A forward force is applied to the leading end of the sheet, and at the time of feeding, the left and right leading ends of the sheet pass the contact position between the main roller and the pressing unit by a predetermined amount, and then the main roller is moved. The left and right ends of the sheet can be slipped out of the contact position by reversing them by a predetermined amount, and at the same time, the left and right ends of the sheet are retained along the contact position by the transfer force of the auxiliary roller in the forward feeding direction. A sheet conveying device, comprising: a control unit that controls the main roller and the auxiliary roller so as to forwardly rotate a sheet by a predetermined amount and feed the sheet to a printing position. 2. The sheet conveying apparatus according to claim 1, wherein the urging force applied to the leading edge of the sheet by the auxiliary roller is generated by a spring member that connects the auxiliary roller to a driving unit of the auxiliary roller. 3. A biasing force applied to the sheet front end by the auxiliary roller makes at least one end of a support shaft to which the auxiliary roller is fixed movable, and a spring exerting a biasing force in a direction to prevent the movement. The sheet conveying device according to claim 1, wherein the sheet conveying device is generated by a member. 4. The sheet conveying apparatus according to claim 1, wherein the biasing force applied to the front end of the sheet by the auxiliary roller is generated by the auxiliary roller slipping on the sheet surface. 5. The sheet conveying apparatus according to claim 1, wherein the urging force applied to the leading edge of the sheet by the auxiliary roller is generated by a rotational force of a motor that drives the auxiliary roller.