JP2002018786A - Sheet material carrying device and sheet material cutting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cut a paper sheet by a cutter so that a cut end of the paper sheet does not become oblique. SOLUTION: The paper sheet P sandwiched and stopped between nip rollers 26 and 27 and carrier rollers 47 and 48 is cut by the cutter 50. At this time, tensile force trying to pull the paper sheet P in the cutting part side is generated by cutting time resistance of a rotary blade 58. Thus, when there exists rotational looseness in the nip rollers 26 and 27 and the carrier rollers 47 and 48, the paper sheet moves to the cutting part side by a rotational looseness quantity, and the cut end becomes oblique. However, the nip rollers 26 and 27 and the carrier rollers 47 and 48 eliminate a backlash in the direction for rotating the rollers by the tensile force so that the rollers do not rotate by the tensile force. Thus, the paper sheet is not obliquely cut.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet conveying apparatus provided with a cutter for cutting a sheet conveyed by a conveying roller in a direction perpendicular to the conveying direction, and a method for cutting the sheet.

[0002]

2. Description of the Related Art A thermal transfer type image forming apparatus for thermally transferring an image exposed on a photosensitive material to paper is usually drawn out of a magazine by a predetermined length and cut to expose a sheet-shaped photosensitive material. Send to the department.

[0003] Then, after water is applied to the photosensitive material on which an image has been exposed in the exposure unit, the transfer material is superimposed on paper as an image receiving material, wound around a heat drum, and pressed against the heat drum with an endless belt for a predetermined time. The image is thermally transferred from the photosensitive material to paper.

As shown in FIG. 11, a paper P is stored in a magazine 90 in a state of being wound up in a roll shape. The paper P pulled out of the magazine 90 by the pull-out roller 92 is nipped and conveyed by the conveying roller 94 to the transfer unit side. Then, the paper P pulled out by a predetermined length is cut by the cutter 96 in a state where the paper P is pinched and stopped by the pull-out roller 92 and the conveyance roller 94, and then conveyed to the transfer unit.

[0005] By the way, a torque is normally transmitted from the motor to the pull-out roller 92 and the transport roller 94 by a gear mechanism. Then, in order to transmit torque to the gear mechanism, as shown in FIG.
However, if the drive gear 98 is stopped in a state where the torque is transmitted (in the direction indicated by the solid arrow in FIG. 13), an inconvenience as shown in FIG. 12 occurs.

That is, when the cutter 96 cuts the paper, a tensile force is generated at the cut portion of the paper due to the cutting resistance. Therefore, the driven gear 100 of the pull-out roller 92 holding the paper P rotates by the amount of the backlash (in the direction indicated by the dashed arrow in FIG. 13), and the paper P is sent out to the cutter 96 side (the arrow in FIG. 12 indicates). direction).

As a result, the cut edge E of the paper (the edge portion of the paper) becomes oblique rather than orthogonal to the paper transport direction, and the commercial value of the finished print decreases.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above circumstances, and has as its object to cut a paper with a cutter so that a cut edge of the paper is not inclined.

[0009]

According to the first aspect of the present invention, the sheet material stopped and held between the rollers for conveyance is cut by a cutter. At this time, a tensile force for pulling the sheet material toward the cut portion is generated due to resistance at the time of cutting of the cutter. For this reason, if there is a backlash in the rollers holding the sheet material, the paper moves toward the cutting section by the amount of the backlash, and the cut becomes oblique.
In the present invention, since the backlash of the roller is prevented by the backlash prevention means, the cut edge of the paper does not become oblique.

According to a second aspect of the present invention, the backlash preventing means is an electromagnetic clutch which is attached to the rotating shaft of the roller and locks the rotating shaft when the cutter is cut. As described above, by directly locking the rotation axis of the roller, the rotation of the roller due to the tensile force generated on the paper is prevented.

According to a third aspect of the present invention, the backlash preventing means removes backlash in the direction in which the roller rotates due to the pulling force, of the backlash of the driving force transmission gear mechanism to the roller.

That is, before the paper is cut by the cutter, the driving gear of the driving force transmission gear mechanism is reversed by the amount corresponding to the backlash, so that the backlash in the direction in which the roller rotates due to the pulling force is eliminated, and the rotational play of the roller is reduced. Can be prevented.

According to a fourth aspect of the present invention, there is provided a sheet material cutting method in which a sheet material is conveyed to a predetermined position by a conveying means and cut by a cutter in a direction perpendicular to the conveying direction. Then, the transport means is locked so that the transport means is not pulled in by the tensile force acting on the sheet material when the cutter is cut.

[0014]

FIG. 1 shows an image forming apparatus 10 provided with a sheet material conveying device 11 according to the present embodiment. (Image Forming Apparatus) The supply reel 2 is provided on the photosensitive material magazine 18 disposed below the housing 16 of the image forming apparatus 10.
The photosensitive material 12 wound around 0 is set. The supply reel 20 is rotated by driving means (not shown) to unwind the photosensitive material 12.

The leading end of the photosensitive material 12 is nipped by a draw-out roller 22 provided at a mounting opening of the photosensitive material magazine 18. The pull-out roller 22 pulls out the photosensitive material 12 under predetermined conditions and sends out the photosensitive material 12 to the guide plate 24, or a buffer (indicated by a two-dot chain line) under predetermined conditions.
To form

The photosensitive material 12 that has passed through the guide plate 24 is
The image is wound around the exposure drum 14 and an image is exposed by the scanning head 28. As described above, the photosensitive material 12 is wound around the exposure drum 14 and exposed to light, whereby the photosensitive material 1 is exposed.
No wrinkles or the like occur in the width direction of No. 2, and the flatness of the exposed surface can be ensured.

The photosensitive material 12 to which the image has been exposed is sandwiched between a support table 34 and a pressure plate 36, and water is applied by a water-absorbing coating member 40 (such as a sponge) provided in a coating tank 38.

The photosensitive material 12 coated with water is wound around a heat drum 42 having a built-in halogen lamp by tension rollers 44 and 46 at a constant pressure. The wound photosensitive material 12 is superposed from above on a paper P described later while being heated, and transfers an image.

Next, the photosensitive material 12 on which the image has been transferred is taken up on a waste reel 30. Thus, the photosensitive material 1
2 is cut from the supply reel 20 to the waste reel 30 without cutting.
The photosensitive material 12 itself functions as a timing belt for applying a constant pressure to the paper P.

On the other hand, the paper P wound around the supply reel 12 is set in the receiving material magazine 32 arranged above the housing 16. The paper P is pulled out by the nip rollers 26 and 27, cut by a cutter 50 to a predetermined length, guided by conveyance rollers 47 and 48 and a guide plate 49, and is superposed on the photosensitive material 12 while being superposed on the photosensitive material 12. Can be wrapped around.

The paper P on which the image has been transferred from the photosensitive material 12 is peeled off from the heat drum 42 by a peeling claw (not shown), guided by the transport roller 13 and the guide plate 15 and reaches the tray 17. (Cutter) As shown in FIG. 2 and FIG.
Is guided by a guide rail 52 in a direction perpendicular to the paper P transport direction (paper width direction). The guide rail 52 has a plate-shaped fixed blade 5 having a length exceeding the width of the roll paper P stored in the receiving magazine 32.
4 are attached.

On the fixed blade 54, a guide rail 5
The paper P is sent from the elongated slit formed in FIG. An upper housing 60 that houses the rotary blade 58 (single blade type) in a partially exposed state is located above the fixed blade 54.

Both ends of the rotary shaft 62 of the rotary blade 58 are rotatably supported by bearings 64 and 66, and the bearing 64 is attached to a cantilever plate 68. A coil spring 59 is mounted between the plate 68 and the disk 61 to urge the rotary blade 58 toward the fixed blade 54.
Thereby, the side surface of the rotary blade 58 is pressed against the cutting point of the fixed blade 54. Therefore, when the rotary blade 58 moves along the fixed blade 54 while rotating, the rotary blade 58 rotates due to friction, and the paper P is cut at the cutting point.

On the other hand, a disk 70 is coaxially fixed to the rotary shaft 62 of the rotary blade 58. A groove 72 is formed on the outer peripheral surface of the disk 70, and the O-ring 7
4 are attached. The O-ring 74 runs on the upper surface of the fixed blade 54 while rotating while the O-ring 74 is slightly pressed.

A slider 76 is arranged on the lower surface of the fixed blade 54 so as to face the O-ring 74. The slider 76 is connected to the upper housing 60 by a connecting plate 78, and slides on the lower surface of the fixed blade 54 to move the O-ring 7.
4, the vertical movement of the rotary blade 58 with respect to the fixed blade 54 is restricted with the fixed blade 54 interposed therebetween.

A wire 80 is fixed to the slider 76. The wire 80 is endless and is wound around pulleys arranged at both ends of the guide rail 52. The torque of the stepping motor is transmitted to the pulley via a speed reducer.

In this configuration, when the paper P reaches the cutting position, the stepping motor rotates forward at the timing described later, and the upper housing 60 moves along with the slider 76 along the fixed blade 54. At this time, the rotary blade 58 cuts the paper P in the width direction at a cutting point with the fixed blade 54. By reversing the stepping motor, the upper housing 60 is pulled back together with the slider 76 and stands by at the standby position.

The lower housing 8 is connected to the connecting plate 78.
2 is fixed and moves integrally with the upper housing 60. In the lower housing 82, a metal receiving roller 84 is supported by a rotating shaft 88. Receiving roller 8
A groove 86 is formed on the outer peripheral surface of the rotary blade 4, and the cutting edge of the rotary blade 58 enters the groove 86. That is, in this embodiment, the rotary blade 58 and the receiving roller 8 as a receiving member are used.
4 moves integrally to generate sagging P1 at the cut portion of the paper P, thereby suppressing the occurrence of kebabachi. (Sheet Conveying Apparatus) As shown in FIGS. 4 and 5, an end of a rotating shaft 104 of a nip roller 26 provided at an outlet 102 of a receiving magazine 32 is provided with a first driven gear 10.
6 is attached. When the receiving material magazine 32 is set in the storage portion 108, the first driven gear 106 meshes with a first transmission gear 110 provided on the housing side and a driving gear 114 rotated by a stepping motor 112, respectively. I have.

At this time, the nip roller 26 nips the paper P drawn out from the drawer 102 between the nip roller 27 and the nip roller 27 provided in the housing 16. By rotating the first driven gear 106 in the counterclockwise direction in FIG. 5, the paper P is conveyed in the direction of the arrow (toward the cutter 50).

On the other hand, transport rollers 48 and 47 are located downstream of the nip rollers 26 and 27 with the cutter 50 therebetween.
Are arranged, and the paper P is nipped and conveyed to the heat drum 42 side. A second driven gear 118 is attached to an end of the rotation shaft 116 of the transport roller 48, and meshes with a second transmission gear 120 to which a driving force is transmitted from the first transmission gear 110 by a gear group 122.

That is, the driving force of the stepping motor 112 is controlled by the driving gear 114, the first driven gear 106, the first transmission gear 110, the gear group 122, and the second transmission gear 120.
Through to the second driven gear 118. The gear ratio between the first driven gear 106 and the second driven gear 118 is set so that the rotation speed of the second driven gear 118 is slightly increased.
It is adjusted so that no slack occurs.

Here, the cutting start timing of the cutter will be described.

As shown in FIG. 6, the paper P as a sheet material is pulled out from the drawer opening 102 of the receiving material magazine 32 by the nip rollers 26 and 27, and when the transport length reaches a predetermined length, the stepping motor 112 is stopped. The upstream and downstream sides of the paper P are sandwiched between the nip rollers 26 and 27 and the transport rollers 48 and 47.

At this time, as shown in FIG. 9A, between the driving gear 114 and the first driven gear 106, the first driven gear 106 is turned clockwise (A) while the driving gear 114 is stopped. Backlash R that can rotate in the direction (see FIG. 6). In addition, a backlash occurs between the second transmission gear 120 and the second driven gear 118 such that the second driven gear 118 can rotate counterclockwise while the second transmission gear 120 is stopped.

Here, the stepping motor 112 is inverted by a predetermined pulse, and the drive gear 114 is rotated counterclockwise (in the direction indicated by the broken line in FIG. 9B) and then stopped. Accordingly, as shown in FIGS. 7 and 9B,
The backlash R that allows the first driven gear 106 to rotate in the counterclockwise direction is eliminated, and the second transmission gear 120 does not rotate. Therefore, the second driven gear 118 cannot rotate clockwise without change.

In this state, when the paper P is cut by the cutter 50 as shown in FIG. 8, a cutting resistance is generated at the cutting portion. A tensile force is generated in the direction of arrow C. However, since the first driven gear 106 is locked by the drive gear 114 and the second driven gear 118 is locked by the second transmission gear 120, the nip rollers 26 and 27 and the transport roller 48 that hold the paper P are , 47 do not rotate.

Therefore, since the paper P does not move toward the rotary blade 58 of the cutter 50 at the beginning of cutting the paper P, the paper P is not cut diagonally.

In this embodiment, a method for removing backlash of the gear mechanism is employed in order to construct an economical paper transport device. As shown in FIG.
Electromagnetic clutches 128 are attached to the rotating shaft 104 of the nip roller 26 and the rotating shaft 116 of the transport roller 48, respectively.
A configuration in which the locks 4 and 116 are locked may be employed.

[0039]

According to the present invention, the cut edge of the paper does not become skewed.

[Brief description of the drawings]

FIG. 1 is a side view illustrating an image forming apparatus provided with a sheet material conveying device according to an embodiment.

FIG. 2 is a cross-sectional perspective view of a cutter of the sheet conveying apparatus according to the embodiment.

FIG. 3 is a sectional view of a cutter of the sheet conveying apparatus according to the embodiment.

FIG. 4 is a perspective view showing a receiving material magazine of the sheet material conveying device according to the present embodiment.

FIG. 5 is a side view showing a gear mechanism of the sheet conveying apparatus according to the embodiment.

FIG. 6 is a side view showing a meshing state of a gear mechanism of the sheet conveying apparatus according to the embodiment.

FIG. 7 is a side view showing a meshing state of a gear mechanism of the sheet conveying apparatus according to the embodiment.

FIG. 8 is a side view illustrating a meshing state of a gear mechanism of the sheet conveying apparatus according to the exemplary embodiment.

FIG. 9 is an enlarged view showing a meshing portion of a gear mechanism of the sheet conveying apparatus according to the embodiment.

FIG. 10 is a side view illustrating a gear mechanism of a sheet material conveying device according to another embodiment.

FIG. 11 is a conceptual diagram showing a conventional receiving magazine.

FIG. 12 is a perspective view showing a state where paper is cut by a conventional cutter.

FIG. 13 is an enlarged view showing a meshing state of a conventional gear mechanism.

[Explanation of symbols]

 26 Nip Roller (Roller) 27 Nip Roller (Roller) 47 Transport Roller (Roller) 48 Transport Roller (Roller) 58 Rotary Blade (Cutter) 106 First Follower Gear 112 Stepping Motor (Rotation Prevention Means) 114 Drive Gear 128 Electromagnetic Clutch

Claims (4)

[Claims] 1. A sheet material transport device in which a cutter for cutting a sheet material held and stopped between rollers for conveyance is disposed, wherein the roller is formed by a tensile force applied to the sheet material when the cutter is cut. A sheet material transporting device having a backlash preventing means for preventing the backlash of the sheet. 2. The sheet material conveying apparatus according to claim 1, wherein the backlash preventing means is an electromagnetic clutch attached to a rotating shaft of the roller and locking the rotating shaft when the cutter is cut. 3. The backlash preventing means removes backlash in a direction in which the roller rotates due to a pulling force of the sheet material, among backlashes of a driving force transmission gear mechanism to the roller. Item 2. The sheet material conveying device according to Item 1. 4. A method for cutting a sheet material, wherein the sheet material is conveyed to a predetermined position by a conveying means and cut by a cutter in a direction perpendicular to the conveying direction. A method for cutting a sheet material, wherein the transporting means is locked so that the transporting means is not drawn into the cutter side.