JP2000159366A - Cut paper conveying apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cut paper conveying apparatus releasing the pressure contact of a frictional separating pad with a hopping roller when necessary. SOLUTION: A frictional separating piece 7 to which a frictional separating pad 10 pressed into contact with a hopping roller 5 is secured is rotatable about a fulcrum 6. The frictional separating pad 10 is pressed into contact with the hopping roller 5 by a coil spring 11. An approximately L-shaped lever 16 is vertically movably provided in front of and beneath the frictional separating piece 7 and the end of the horizontal part of the lever 16 enters an annular part 9 formed on each side of the frictional separating piece 7. The lever 6 is energized upward by a coil spring 19. The lever 16 is pressed downward to engage its end with the annular part 9 to rotate the frictional separating piece 7 downward.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transport device for transporting cut sheets, which is provided in a printing apparatus or the like that uses cut sheets as a print medium, and in particular, feeds and transfers stacked cut sheets one by one. The present invention relates to a cut sheet transport device.

[0002]

2. Description of the Related Art Conventionally, in a page printer for printing on cut sheet paper, a plurality of printing papers are stacked and stored in a paper hopper section, and the stored paper is pressed against a feeding roller and this feeding roller. The sheet is separated one by one and fed out from the paper hopper by the separation pad. The fed sheet is transported to a printing unit by a transport roller provided in a transport path, where printing is performed on the sheet, and when printing is completed, the sheet is discharged out of the apparatus.

[0003]

When the apparatus is stopped while the cut sheet is being held between the separation pad and the feed roller due to some trouble while the cut sheet is being conveyed, the separation pad is moved to the feed roller. Since it is always in pressure contact, it is difficult to extract the sandwiched cut sheet from between the separation pad and the feed roller. In the case of a page printer, the image forming unit is detachable from the apparatus main body,
Even if the image forming unit is removed from the apparatus main body when removing the jammed cut sheet, it is difficult to grasp the jam sheet by hand, especially when the separation pad is at the deepest part of the apparatus. Furthermore, when the feed roller is connected to the drive shaft that transmits the rotation of the motor, it is more difficult to remove the interposed cut sheet from between the separation pad and the feed roller because the feed roller does not rotate freely. become.

Further, since the separation pad is always in pressure contact with the hopping roller, traces of the separation pad remain on the cut sheet sandwiched between the separation pad and the hopping roller. Furthermore, if the cut sheet that has passed between the separation pad and the hopping roller is transferred by the transfer roller, the cut sheet is transferred while being pressed against the separation pad and the hopping roller for a while. If the force between the separation pad and the hopping roller for holding the cut sheet becomes larger than the conveyance force of the conveyance roller, the conveyance roller may slip,
It causes printing trouble such as paper jam and image shrinkage.

That is, it is required that the pressing force of the separation pad against the hopping roller be released as required.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is directed to a single sheet feeder in which a plurality of cut sheets are fed one by one by a hopping roller and a separation pad pressed against the hopping roller. In the vote paper transport device, a separating means for separating the separation pad from the hopping roller is provided. The separation means is driven by rotating a motor for rotating the hopping roller in a direction opposite to the direction in which the cut sheet is fed, so as to separate the separation pad from the hopping roller.

Further, the present invention is characterized in that the transmission of the driving force of the motor to the hopping roller is canceled by rotating the motor for driving the hopping roller in the direction opposite to the direction in which the cut sheet is fed.

Further, the present invention is characterized in that a separating means is provided for separating the separation pad from the hopping roller with the rotation of the conveying roller at which the leading end of the fed cut-out sheet has reached.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. Elements common to the drawings are assigned the same reference numerals. FIG. 1 is a cutaway perspective view showing a cut-sheet paper transport device according to a first embodiment of the present invention. In the first embodiment, a transport device in an electrophotographic printing apparatus will be described as an example of a cut sheet transport device.

In FIG. 1, a printing apparatus 1 has a frame 2, on which a sheet reversing guide 3 is fixed and a shaft 4 is rotatably supported. A hopping roller 5 is fixed to the shaft 4 at a position substantially at the center of the printing paper width. The fulcrum 6 is on the paper reversing guide 3
A friction separating piece 7 rotatably supported on the center of the shaft is mounted opposite to the hopping roller 5. Friction separation piece 7
Has a planar main body portion 8 and annular portions 9 formed on both sides of the main body portion 8 so as to face downward. A friction separation pad 10 is fixed to the hopping roller 5 side of the main body 8.
A coil spring 11 is disposed below the main body 8 of the friction separating piece 7, and the coil spring 11 urges the friction separating piece 7 upward.

A plurality of printing papers 13 are stored in a paper hopper 12 in a stacked manner. A leaf spring (not shown) is provided below the leading end of the printing paper 13, and the top of the printing paper 13 is pressed against the hopping roller 5 by the leaf spring. A driving force transmission mechanism composed of a gear (not shown) is connected to the shaft 4 via a one-way bearing, and the driving force is obtained from a motor (not shown) serving as a driving source.

A transfer roller 14 is rotatably disposed above the printing paper 13, and furthermore, an image fixing unit 1 is located behind the transfer roller 14.
5 are provided. FIG. 1 shows a state where the image forming unit is removed. The image forming unit is detachably provided on the frame 2, and when the paper is jammed or the image forming unit is replaced, the image forming unit is removed.

A lever 16 is provided in front of the hopping roller 5 and the friction separating piece 7. The lever 16 has a substantially L-shape, and is supported by a guide member (not shown) so as to be vertically movable. The plane portion of the lever 16 is a forked arm 17, and the tip side of the arm 17 enters below the main body 8 of the friction separating piece 7, and the arm 1
A protruding portion 18 protruding left and right from the front end of 7 is formed. The projecting portion 18 enters the annular portion 9 of the friction separating piece 7. The coil spring 11 provided at the lower part of the main body 8 of the friction separating piece 7 is located in a notch between the arms 17 that are forked. A coil spring 19 is provided below the lever 16.
Is provided to urge the lever 6 upward.

When the lever 16 is pushed down, the projection 18 engages with the annular portion 9 to lower the friction separating piece 7 and the friction separating pad 10
Move away from The projection 18 of the lever 16 is attached to the frictional separating piece 7 so as not to hinder the sheet separation during the normal sheet feeding operation.
The biasing force of the coil spring 19 is adjusted so as to be maintained at a position where it does not come into contact with the periphery of the annular portion 9.

When the printing apparatus 1 detects any trouble during printing, for example, occurrence of a paper jam, the motor as a driving source is stopped immediately to prevent the apparatus 1 from being destroyed.
In this case, if the paper 13 is being conveyed, the motor stops while being sandwiched between the hopping roller 5 and the friction separation pad 10 pressed against the hopping roller 5. Since the drive of the hopping roller 5 is generally transmitted by reducing the rotation of the motor,
Although the rotation of the motor is stopped, the hopping roller 5 is substantially locked in at least one direction due to inertia or the like while the rotation of the motor is stopped though the one-way bearing.

In order to remove the held paper, the operator opens a cover (not shown) of the printing apparatus 1, removes the image forming unit, and facilitates the removal of the paper. In this state, the operator pushes down the lever 16 downward. As a result, the projecting portion 18 of the lever 16 engages with the annular portion 9 and urges the friction separating piece 7 downward. As a result, the friction separating piece 7 rotates about the fulcrum 6 at the end of the main body 8,
Descends. When the main body 8 is lowered, the friction separation pad 10 is separated from the hopping roller 5. As a result, the jammed sheet 13 is released from being pinched by the friction separation pad 10 and the hopping roller 5, and the operator can easily remove the sheet 13.

As described above, in the first embodiment, the removal of the jammed paper sandwiched between the friction separation pad 10 and the hopping roller 5 is facilitated by one operation of pressing down the lever 16, and the paper jam or the like is eliminated. Therefore, the operation for restoring the printing apparatus 1 when the failure described above occurs is simplified, and the time for restoring is also shortened.

Next, a second embodiment of the present invention will be described. FIG. 2 is a cutaway perspective view showing a cut-sheet paper transport device according to a second embodiment of the present invention. Also in the second embodiment, a transport device in an electrophotographic printing device will be described as an example of a cut sheet transport device.

In FIG. 2, the printing device 21 is a frame 2
A sheet reversing guide 3 is fixed to the frame 2 and a shaft 4 is rotatably supported. A hopping roller 5 is fixed to the shaft 4 at a position substantially at the center of the printing paper width. A friction separating piece 7 rotatably supported on a fulcrum 6 is attached to the sheet reversing guide 3 so as to face the hopping roller 5.

The friction separating piece 7 is composed of a flat main body 8 and the device 2.
1 has a protruding portion 22 extending in a plane in the inward direction. The fulcrum 6 is provided between the main body 8 and the protrusion 22,
When the protruding portion 22 is pushed upward, the main body 8 is lowered downward. A friction separation pad 10 is fixed to the hopping roller 5 side of the main body 8. A coil spring 11 is disposed below the main body 8 of the friction separating piece 7, and the coil spring 11 urges the main body 8 upward.

A plurality of printing papers 13 are stacked and stored in the paper hopper 12. A leaf spring (not shown) is provided below the leading end of the printing paper 13, and the top of the printing paper 13 is pressed against the hopping roller 5 by the leaf spring. A gear 23 is mounted on the shaft 4 via a one-way bearing 24.
Transmits the rotational force to the shaft 4 only when the gear 23 rotates in the direction of arrow A.

The gear 23 meshes with the gear 25, and the gear 25
Further mesh with the gear train 26. Power is transmitted to the gear train 26 from a motor (not shown). A shaft 27 is fixed to the shaft of the gear 25, and the shaft 27 is rotatably supported by the frame 2. A cam 29 is mounted on the shaft 27 via a one-way bearing 28.

The one-way bearing 28 acts to transmit the rotational force to the cam 29 only when the gear 25 is rotated in the direction of arrow B. The cam 29 has a projection 30, and a tension spring 31 is locked to the projection 30. The tension spring 31 pulls the projection 30 so that the projection 30 of the cam 29 faces the front of the device 21.

In this state, the projection 30 is located below the projection 22 of the friction separating piece 7. When the gear 25 rotates in the direction of arrow B, a rotational force in the same direction is transmitted to the cam 29 by the shaft 27 and the one-way bearing 28, and the protrusion 30 rotates upward. When the protrusion 30 rotates upward, the protrusion 30 contacts the protrusion 22 of the friction separating piece 7 and pushes up the protrusion 22. Thereby, the main body 8 of the friction separating piece 7 is separated from the hopping roller 5.

Further, as in the first embodiment, a transfer roller 14 is rotatably disposed above the printing paper 13.
Further, an image fixing unit 15 is provided on the back side.
FIG. 2 shows a state in which the image forming unit is detached. The image forming unit is detachably provided on the frame 2, and the image forming unit is detached when a paper jam occurs or the image forming unit is replaced.

FIG. 3 is a block diagram showing a control system according to the second embodiment. In FIG. 3, a control unit 32 controls the entire operation of the printing apparatus 21, and is configured by a microprocessor or the like. The control unit 32 includes a motor driving unit 33
Are connected, and a motor 34 is connected to the motor driving unit 33. The motor 34 applies a rotational force to the gear train 26 shown in FIG. The motor 34 rotates in both directions.

The controller 32 includes a jam detection sensor 35.
The reset button 36 is connected, and the jam detection sensor 35 detects a jam of the sheet during printing, and transmits a detection signal to the control unit 32. The reset button 36 is provided inside the printing apparatus 21 and is depressed in conjunction with an opening / closing operation of a cover (not shown) accompanying removal of the jammed paper.

Next, the operation of the second embodiment will be described.
In the normal printing state of the printing device 21, the motor 34
Rotates the gear 23 in the direction of arrow A,
Is transmitted to the shaft 4 by the one-way bearing 24, and the hopping roller 5 rotates in the same direction as the shaft 4 to feed out the printing paper 13. At this time, the gear 25 is rotating in the direction opposite to the arrow B direction, and the shaft 27 rotates with the gear 25.
Therefore, the rotational force is not transmitted to the cam 29.

If any trouble, for example, occurrence of paper jam during printing is detected, the jam detection sensor 35 detects the trouble. When receiving the jam detection signal from the jam detection sensor 35, the control unit 32 stops the motor 34.

In this case, if the paper 13 is being conveyed, the hopping roller 5 and the friction separating pad 10 pressed against the hopping roller 5 are pressed.
Then, the motor 34 stops in the state of being sandwiched. The hopping roller 5 is substantially locked in at least one direction by the action of the one-way bearing 24.

Here, the control section 32 rotates the motor 34 by a predetermined number of rotations in a direction opposite to the rotation direction during normal printing. Accordingly, the gear 25 rotates in the direction of arrow B, and the cam 29 also rotates in the same direction via the shaft 27 and the one-way bearing 28. The rotation of the cam 29 causes the protrusion 30 to rotate upward, and the protrusion 30 comes into contact with the protrusion 22 of the friction separating piece 7 to push up the protrusion 22. As a result, the friction separating piece 7 rotates about the fulcrum 6, and the main body 8 of the friction separating piece 7 separates from the hopping roller 5.

In order to remove the pinched paper, the operator opens the cover (not shown) of the printing device 21, removes the image forming unit, and facilitates the removal of the paper. At this time, the friction separating pad 10 has already
, The jammed paper 13 is released from being pinched by the friction separation pad 10 and the hopping roller 5, and the operator can easily remove the jammed paper 13.

When the motor 34 is rotated in the direction opposite to the direction during printing, the gear 23 rotates in the direction opposite to the direction of arrow A, but the rotation of the gear 23 is not transmitted to the shaft 4 by the action of the one-way bearing 24.

After the jammed paper 13 is removed, the reset button 36 is pressed by closing the cover. Upon receiving this press signal, the control unit 32 rotates the motor 34 by a predetermined amount in the same direction as during normal printing. As a result, the cam 29 returns to the original position shown by 2 by the action of the tension spring 31, and the friction separating piece 7 also returns to the original position by the action of the coil spring 11, so that the friction separating pad 10 is pressed against the hopping roller 5.

As described above, in the second embodiment, when a paper jam occurs, the friction separation pad 10 is automatically separated from the hopping roller 5, so that the removal of the jammed paper is performed in the first embodiment. It becomes easier than in the embodiment.

Next, a third embodiment will be described. FIG. 4 is a cutaway perspective view showing a cut-sheet paper transport device according to the third embodiment. Also in the third embodiment, a description will be given of a transport device in an electrophotographic printing device as an example of a cut sheet transport device.

In FIG. 4, the printing device 41 is a frame 2
A sheet reversing guide 3 is fixed to the frame 2 and a shaft 4 is rotatably supported. A hopping roller 5 is fixed to the shaft 4 at a position substantially at the center of the printing paper width. A friction separating piece 7 rotatably supported on a fulcrum 6 is attached to the sheet reversing guide 3 so as to face the hopping roller 5. A friction separation pad 10 is fixed to the friction separating piece 7 on the hopping roller 5 side. A coil spring 11 is provided below the friction separating piece 7.
The coil spring 11 urges the friction separating piece 7 upward, and presses the friction separating pad 10 against the hopping roller 5.

A gear 42 is attached to the shaft 4, and the gear 42 meshes with the gear 43, and the gear 43 further meshes with the planetary gear 44. A groove 45 is formed in the center of the planetary gear 44, and a shaft 46 is fitted into the groove 45. The shaft 46 is movable in the groove 45. Planetary gear 4
4 meshes with the idle gear 47, and the planetary gear 44 moves in the direction of arrow C or the direction of arrow C 'along the shaft 46 depending on the rotation direction of the idle gear 47. The planetary gear 44 separates from the gear 43 by moving in the direction of arrow C ′. The idle gear 47 obtains a driving force from a motor described later.

FIG. 5 is a block diagram showing a main part of the third embodiment. In FIG. 5, the control unit 52 is a printing device 4
1 controls the entire operation and is constituted by a microprocessor or the like. A motor drive unit 53 is connected to the control unit 52, and a motor 54 is connected to the motor drive unit 53. The motor 54 applies a rotational force to the idle gear 47 shown in FIG. The motor 54 rotates in both directions. Further, a jam detection sensor 55 is connected to the control unit 52, and the jam detection sensor 55 detects a jam of a sheet during printing, and transmits a detection signal to the control unit 52.

Next, the operation of the second embodiment will be described.
In the normal printing state of the printing device 41, the motor 54
Rotates the idle gear 47 in the direction of arrow D,
The planetary gear 44 rotates at a position indicated by a solid line in FIG. The planetary gear 44 meshes with the gear 43, and the rotation of the planetary gear 44 is transmitted to the gear 42 and the shaft 4 via the gear 43, and the hopping roller 5 rotates in the same direction as the shaft 4 to feed out the printing paper 13. .

When any trouble, for example, occurrence of paper jam during printing is detected, the jam detection sensor 55 detects the trouble. When receiving the jam detection signal from the jam detection sensor 55, the control unit 52 stops the motor 54. In this case, if the paper 13 is being conveyed, the motor 34 stops while being sandwiched between the hopping roller 5 and the friction separation pad 10 pressed against the hopping roller 5. The hopping roller 5 is substantially locked in at least one direction.

Here, the control unit 52 rotates the motor 54 by a predetermined number of rotations in a direction opposite to the rotation direction during normal printing. As a result, the idle gear 47 rotates in the direction opposite to the direction of the arrow D, and the planetary gear 44 moves along the axis 46 along the arrow C ′.
In the direction to the position shown by the dotted line, and separates from the gear 43.

When the planetary gear 44 moves, the gear 43, the gear 42 and the hopping roller 5 are in a free state. In this state, the friction separating piece 7 and the hopping roller 5 are not separated from each other, but can be easily rotated because the hopping roller 5 is not locked.

In order to remove the paper sandwiched between the friction separating piece 7 and the hopping roller 5, the operator opens a cover (not shown) of the printing apparatus 1, removes the image forming unit, and facilitates the removal of the paper. At this time, since the hopping roller 5 is already free, the jammed sheet 13 can be easily removed from between the friction separation pad 10 and the hopping roller 5.

After the jammed sheet 13 is removed, the control unit 52 rotates the motor 54 by a predetermined amount in the same direction as during normal printing. This causes the idle roller 47 to move in the direction of arrow D.
, The planetary gear 44 moves in the direction of arrow C and meshes with the gear 43.

As described above, in the third embodiment, when a paper jam occurs, the transmission of the driving force from the motor 54 to the hopping roller 5 is released, so that the hopping roller 5 can be freely rotated. In addition, the jam separation sheet 10 can easily remove jammed paper from between the hopping rollers 5. At this time, there is no need to operate the lever as in the first embodiment or to attach a one-way bearing as in the second embodiment.

The transmission of the driving force to the hopping roller 5 can be canceled regardless of the length of the sheet or the length of the transport path. That is, for example, when the paper is fed by a so-called half-moon-shaped roller, by giving a predetermined relationship between the length from the half-moon-shaped roller to a transport roller located downstream thereof and the diameter of the half-moon-shaped roller, When the fed sheet is conveyed by the conveying roller, the load on the sheet is removed by setting the notch of the half-moon-shaped roller to the sheet side, but in the third embodiment, the hopping roller 5 is used. The transmission of the driving force to the hopping roller 5 can be canceled regardless of the diameter, the transport path length, and the paper length set.

Next, a fourth embodiment of the present invention will be described. FIG. 6 is a side view showing a cut-sheet paper conveying device according to the fourth embodiment, and FIG. 7 is a perspective view showing a main part of the cut-sheet paper conveying device according to the fourth embodiment.

In FIGS. 6 and 7, the cut sheet transport device 6
1 has a detachable paper cassette 62 which slides in the direction of arrow E shown in FIG. A plurality of printing papers 63 are stacked in the paper cassette 62. The loaded printing paper 63 is urged upward by a coil spring 64,
The leading end of the uppermost sheet 63 is in pressure contact with a regulating member pivotally supported near the hopping roller 65. The paper cassette 62 is mounted with an inclination such that the printing paper 63 can slide freely forward by its own weight.

The hopping roller 65 is formed concentrically at substantially the center of a support shaft 66 which is rotatably supported by a frame (not shown).
7 is included and acts to drive the hopping roller 65 only when the support shaft 66 is rotated in the direction of arrow A. The outer peripheral surface 68 of the hopping roller 65 is covered with a friction member formed of a material having a relatively high coefficient of friction so that the hopping roller 65 can be fed without causing slippage between the hopping roller 65 and the printing paper 63.

A drive gear 70 including a one-way bearing 69 is fixed to one end 66a of the support shaft 66. The drive gear 70 meshes with the transmission gear 71 and the drive gear 72, and the one-way bearing 69
Acts so as to transmit the rotation of the drive gear 70 to the support shaft 66 only when rotates in the direction of arrow F.

Slip clutches 73 and 74 are provided on both sides of the support shaft 66 located outside the sheet width.
Slip clutches 73 and 74 have cams 75 and 76, respectively.
Is fixed. The cams 75 and 76 are provided outside the width of the printing paper and have protrusions 75a and 76a, respectively, and the protrusions 75a and 76a have tension springs 77 and 78, respectively.
Is locked. The extension springs 77 and 78 are
a, 76a are always urged downward, and the other ends of the tension springs 77, 78 are locked to a frame (not shown).

The slip clutches 73 and 74 rotate the cams 75 and 76 when the support shaft 66 rotates in the direction of arrow A, and pull the cams 75 and 76 to positions where the protrusions 75a and 76a of the cams 75 and 76 are separated from a cam follower described later. The shaft is rotated against the urging force of the springs 77 and 78, and abuts against a stopper (not shown) formed on the frame to maintain the position while the support shaft 66 is rotating in the direction of arrow A. . When the support shaft 66 rotates in the direction opposite to the direction of the arrow A, the slip clutches 73 and 74 use the cams 75 and 76 to rotate the support shaft 66.
Do not communicate to

The friction separating pad 79 is fixed to the friction separating piece 80. A compression spring 82 is provided below the frictional separation piece 80.
The frictional separation pad 79 is pressed against the hopping roller 65 by the compression spring 82. The friction separation pad 79 is stronger than the frictional force between the printing papers 63,
The hopping roller 65 has a frictional force weaker than the frictional force of the frictional member 68.

On the left and right sides of the friction separating piece 80, arms 83 are provided.
A cam follower 85 is formed integrally with the friction separating piece 80 so as to extend substantially below the support shaft 66 to the outside of the printing paper width. , 86 are formed. The cam followers 85 and 86 are provided with protrusions 75a and 76a of the cams 75 and 76, respectively.
Is formed at a position where it abuts. Cam follower 85,
The friction separating pad 79 is adjusted so as to be separated from the hopping roller 65 when the top of 86 comes into contact with the tips of the protruding portions 75a and 76a.

Support members 87 and 88 are provided upright on the arms 83 and 84 in the vicinity of the frictional separating pieces 80, and the support members 87 and 88 respectively have substantially L-shaped paper regulating members 89 and 9 respectively.
0 is swingably mounted. Paper regulating member 89,
Holes 91, 92 are provided in arms 83, 84 below 90, respectively.
Are formed in the holes 91 and 92 from below.
94 can be projected. The protrusions 93 and 94 are holes 9
1 and 92, the sheet regulating members 89 and 9
The central portions 89a and 90a of the 0 are pushed up. Protrusion 93,
Reference numeral 94 is formed on a frame (not shown).

The paper regulating members 89, 90 are provided within the width of the printing paper, and are loaded on the paper cassette 62 by rotating in the direction of arrow G with the friction separating pad 79 being separated from the hopping roller 65. Printing paper 6
3 is pressed. When the friction separating pad 79 is pressed against the hopping roller 65, the paper regulating member 8
Reference numerals 9 and 90 are retracted to positions where the feeding of the printing paper 63 is not hindered.

The paper transport roller 96 includes a driving roller 97 and a driven roller 98. The driving roller 97 is driven to rotate by a driving gear 72 including a one-way bearing 99, and the driven roller 98 is pressed against the driving roller 97 by pressing means (not shown). The one-way bearing 99 acts to transmit the rotation of the drive gear 72 to the drive roller 97 only when the transmission gear 71 is rotated in the direction of arrow B '.

Hopping roller 65 and sheet transport roller 9
A paper detection sensor 100 is provided on the paper travel path near the paper transport roller 96 between the paper detection rollers 100. The paper detection sensor 100 detects that the leading end of the printing paper 63 has reached, and transmits a detection signal to a control unit (not shown).

FIG. 8 is a block diagram showing a control system according to the fourth embodiment. In FIG. 8, a control unit 101 controls the entire operation of the printing apparatus, and includes a microprocessor and the like. The control unit 101 includes a motor driving unit 10
2 is connected, and a motor 103 is connected to the motor drive unit 102. The motor 103 rotates in both directions, as shown in FIG.
The transmission gear 71 shown in FIG. The control unit 10
1 is connected to a sheet detection sensor 100, which detects the leading edge of the sheet during printing and sends a detection signal to the control unit 101.

Next, the operation of the fourth embodiment will be described.
In a state before the printing apparatus starts the printing operation, the protruding portions 75a, 76a of the cams 75, 76 are urged downward by the tensile force of the tension springs 77, 78, and the cam followers 85,
86 is pushed down. As a result, the friction separation pad 79 is in a state of being separated from the hopping roller 65. At this time, the paper regulating members 89 and 90 are pushed up by the projections 93 and 94, and press the leading end of the printing paper 63 loaded in the paper cassette 62 as shown in FIG.

When the printing operation is started by the control unit 101, the motor 103 is driven to rotate, and the transmission gear 71 rotates in the direction of arrow F. This rotation is transmitted to the support shaft 66 via the gear 70 and the one-way bearing 69, and further transmitted via the one-way bearing 67 to the hopping roller 6.
5 and rotate in the direction of arrow A.

When the support shaft 66 rotates in the direction of arrow A,
The cams 85, 86 are operated by the action of the slip clutches 73, 74.
Rotate in the same direction against the tensile force of the tension springs 77 and 78. When the cams 85 and 86 rotate, the cam followers 85 and 86 follow the rotation of the cams 85 and 86 by the action of the compression springs 82. However, the friction separation pad 79 abuts on the hopping roller 65 and cannot follow any further.
5 and 86 are separated from the cam followers 85 and 86 and abut against a stopper (not shown) to maintain the position.

When the arms 83 and 84 rise, the protrusions 93 and 94 come out of the holes 91 and 92, and the sheet regulating members 89 and 90 rotate in the direction opposite to the arrow G direction. Release the pressure and retreat. Printing paper 63
Is released, the printing paper 63 slides down by its own weight in the direction of the hopping roller 65, and the top end of the printing paper 63 contacts the rotating hopping roller 65, and the topmost printing paper 63 contacts the rotating hopping roller 65. The printing sheets 63 are separated by the friction separating pad 79 and fed out.

When the leading end of the fed printing paper 63 is detected by the paper detection sensor 100, a detection signal is sent to the control unit 1
01, the control unit 101 rotates the motor 103 by a predetermined amount from that point and stops it. As a result, the hopping roller 65 rotates by a predetermined angle, and the printing paper 6
The leading end of the roller 3 is brought into contact with the contact portion between the driving roller 97 and the driven roller 98, and is conveyed until it has a slight bending.

While the support shaft 66 is rotating, the slip clutches 73 and 74 move the cams 75 and 76 to the protruding portions 75a and 76.
a is kept at the retracted position, and the friction separation pad 79 keeps pressing against the hopping roller 65, but when the rotation of the support shaft 66 stops, the cams 75, 76 move in the direction of arrow A by the tensile force of the tension springs 77, 78. Rotating in the opposite direction, the projections 75a, 76a push down the cam followers 85, 86. As a result, the friction separating pad 79 is separated from the hopping roller 65, and the sheet regulating members 89 and 90 are rotated in the direction of arrow G by the projections 93 and 94, and the paper excluding the one sheet of printing paper 63 already fed out. The leading end of the printing paper 63 in the cassette 62 is pressed. The printing paper 63 in the paper cassette 62 is held at a position where its leading end does not come into contact with the hopping roller 65. In addition, it is possible to prevent the second and subsequent print sheets from being fed following the topmost print sheet 63 fed out at this time.

Next, the control unit 101 rotates the motor 103 in the reverse direction, and rotates the transmission gear 71 in the direction of arrow F '.
At this time, the gear 70 rotates, but the one-way bearing 69 does not rotate the support shaft 66. Therefore, the cams 75 and 76 maintain the state shown in FIG. 7, and the friction separation pad 79 maintains the state separated from the hopping roller 65.

The rotation of the transmission gear 71 is transmitted to the drive gear 72 via the gear 70. The rotation of the driving gear 72 is transmitted to the driving roller 97 by the action of the one-way bearing 99, and the driving roller 97 and the driven roller 98 pressed against the driving roller 97 rotate in the arrow H direction. As a result, the first print sheet 63 that has been in contact between the driving roller 97 and the driven roller 98 is restarted to be conveyed, and is conveyed to a printing process unit (not shown) on the downstream side in the conveying direction.

At this time, since the first printing paper 63 is not pressed against the friction separation pad 79 and the hopping roller 65, the friction separation pad 79 and the hopping roller 6 are not pressed.
No load is exerted from 5 on the transport. Note that the hopping roller 65 rotates along with the transported printing paper 63, but this rotation does not apply a load to the printing paper 63.

As described above, according to the fourth embodiment,
One sheet of printing paper 63 is fed out, and the paper transport rollers 96
When the paper is conveyed, the friction separating pad 79 is separated from the hopping roller 65, so that no load is applied to the conveyed printing paper 63, and therefore, the paper conveyance roller 96 slides on the printing paper 63. ,
Alternatively, no image shrinkage or paper jam occurs.
Also, there is no possibility that the printing paper 63 is left with marks such as scratches due to frictional stress.

Next, a fifth embodiment will be described. FIG. 9 is a perspective view showing a cut-sheet paper transport device according to the fifth embodiment. In FIG. 9, the cut-sheet paper transport device 111 has a detachable paper cassette 62, and a plurality of print papers 63 are stacked in the paper cassette 62. The loaded printing paper 63 is urged upward by a coil spring 64, and the leading end of the uppermost paper 63 is
Is pressed against. The paper cassette 62 holds the printing paper 6 under its own weight.
3 is mounted with an inclination such that it can slide freely forward.

The hopping roller 65 is formed concentrically at a substantially central portion of a support shaft 66 rotatably supported by a frame (not shown). Outer peripheral surface 6 of hopping roller 65
Numeral 8 is coated with a friction member formed of a material having a relatively high coefficient of friction so that feeding can be performed without causing slippage between the printing paper 63 and the printing paper 63.

A drive gear 70 including a one-way bearing 69 is fixed to one end 66a of the support shaft 66. The drive gear 70 meshes with the transmission gear 71 and the drive gear 72, and the one-way bearing 69
Acts so as to transmit the rotation of the drive gear 70 to the support shaft 66 only when rotates in the direction of arrow F.

The friction separating pad 79 is fixed to the friction separating piece 80. A compression spring 82 is provided below the frictional separation piece 80.
The frictional separation pad 79 is pressed against the hopping roller 65 by the compression spring 82. The friction separation pad 79 is stronger than the frictional force between the printing papers 63,
The hopping roller 65 has a frictional force weaker than the frictional force of the frictional member 68.

Arms 83 are provided on both left and right sides of the friction separating piece 80.
A friction follower 84 is formed integrally with the friction separating piece 80 so as to extend substantially below the support shaft 66 to the outside of the width of the printing paper. , 113 are formed.

Support members 87 and 88 are provided upright on the arms 83 and 84 in the vicinity of the friction separating pieces 80. The support members 87 and 88 are respectively provided with substantially L-shaped sheet regulating members 89 and 9 respectively.
0 is swingably mounted. Paper regulating member 89,
Holes 91, 92 are provided in arms 83, 84 below 90, respectively.
Are formed in the holes 91 and 92 from below.
94 can be projected. The protrusions 93 and 94 are holes 9
1 and 92, the sheet regulating members 89 and 9
The central portions 89a and 90a of the 0 are pushed up. Protrusion 93,
Reference numeral 94 is formed on a frame (not shown).

The paper regulating members 89 and 90 are provided within the width of the printing paper, and are loaded on the paper cassette 62 by rotating in the direction of arrow G with the friction separating pad 79 being separated from the hopping roller 65. Printing paper 6
3 is pressed. When the friction separating pad 79 is pressed against the hopping roller 65, the paper regulating member 8
Reference numerals 9 and 90 are retracted to positions where the feeding of the printing paper 63 is not hindered.

The paper transport roller 96 includes a driving roller 97 and a driven roller 98. The driving roller 97 is driven to rotate by a driving gear 72 including a one-way bearing 99, and the driven roller 98 is pressed against the driving roller 97 by pressing means (not shown). The one-way bearing 99 acts to transmit the rotation of the drive gear 72 to the drive roller 97 only when the transmission gear 71 is rotated in the direction of arrow F '.

A slip clutch 1 as a driving force transmitting means is provided on the support shaft 114 of the driving roller 97 outside the printing paper width.
15 and 116 are disposed on both sides, and the slip clutch 11 is provided.
Cams 117 and 118 are fixed to 5 and 116, respectively. The cams 117 and 118 each have a protrusion 117
a, 118a, and tension springs 119, 120 are locked to the projections 117a, 118a, respectively. The other ends of the tension springs 119 and 120 are locked to a frame (not shown).
17a and 118a are pulled obliquely upward.

The cam followers 112 and 113
7 and 118 are formed at positions where they come into contact with the protruding portions 117a and 118a. When the tops of the cam followers 112 and 113 come into contact with the tips of the protrusions 117a and 118a, the friction separating pad 79 is adjusted so as to be separated from the hopping roller 65.

Hopping roller 65 and sheet transport roller 9
6, a paper detection sensor 100 is provided on the paper traveling path close to the paper transport roller 96. The paper detection sensor 100 detects that the leading end of the printing paper 63 has reached, and transmits a detection signal to a control unit (not shown).

Next, the operation of the fifth embodiment will be described.
In a state before the printing apparatus starts the printing operation, the cams 117 and 118 are extended by the tension of the tension springs 119 and 120.
Of the cam followers 112, 1
13, the friction separation pad 79 is in pressure contact with the hopping roller 65. At this time, the paper regulating members 89 and 90 are at the positions shown in FIG. 9 and are retracted from the leading end of the printing paper 63 loaded in the paper cassette 62.

When the printing operation is started, a motor (not shown) is driven to rotate, and the transmission gear 71 rotates in the direction of arrow F. This rotation is performed by the gear 70 and the one-way bearing 6.
9 and transmitted to a hopping roller 65 via a one-way bearing 67,
It rotates in the direction of arrow A. By this rotation, the uppermost sheet of printing paper 63 is separated by the friction separating pad 79 and fed out.

When the leading edge of the fed printing paper 63 is detected by the paper detection sensor 100, the motor is rotated by a predetermined amount and stopped from that point. As a result, the hopping roller 65 rotates by a predetermined angle, and the printing paper 63
Is brought into contact with the contact portion between the driving roller 97 and the driven roller 98 and is conveyed until the tip of the roller has a slight bending. Thereby, the skew of the printing paper 63 is corrected.

Next, a control unit (not shown) rotates the motor in the reverse direction, and rotates the transmission gear 71 in the direction of arrow F '. At this time, the gear 70 rotates, but the one-way bearing 6
9 does not rotate the support shaft 66. Drive gear 7
2 is transmitted to the support shaft 114 by the action of the one-way bearing 99, and the drive roller 97 rotates in the direction of arrow H. When the driving roller 97 rotates, the driven roller 98 also rotates, so that the printing paper 63 is conveyed.

When the support shaft 114 rotates in the direction of the arrow H, the tension spring 1 is actuated by the action of the slip clutches 115 and 116.
The cams 117 and 118 also rotate in the same direction against the pulling forces of 19 and 120. By the rotation of the cams 117 and 118,
The protrusions 117a and 118a are the cam followers 112,
Press down 113. As a result, the arms 83 and 84 are pushed down, and the friction separating pad 79 is moved to the hopping roller 65.
Keep away from

The paper regulating members 89 and 90 are
The print paper 63 is rotated in the direction of arrow G by 3 and 94, and presses the leading edge of the print paper 63 in the paper cassette 62 except for the one print paper 63 already fed. The printing paper 63 in the paper cassette 62 is held at a position where its leading end does not come into contact with the hopping roller 65.

While the transmission gear 71 is rotating in the direction of arrow F ′, the friction portion separation pad 79 is
Away from The printing paper 63 is transported by the paper transport roller 96.
, The control unit (not shown) stops the rotation of the motor. When the rotation of the motor is stopped, the rotation of the support shaft 114 is stopped, and the cams 11 are moved by the tension of the tension springs 119 and 120 by the action of the slip clutches 115 and 116.
7, 118 rotate in the direction opposite to the arrow H direction. As a result, the protrusions 117a and 118a move rearward and separate from the cam followers 112 and 113. As a result, the cam followers 112 and 113, that is, the arms 83 and 84 rise by the urging force of the coil spring 82, and the friction separating pad 79 comes into pressure contact with the hopping roller 65, and the paper regulating members 89 and 90
Is retracted to the retracted position.

Therefore, 1
Even when the conveyance of the printing paper 63 is completed and the next conveyance paper 63 is continuously conveyed, the friction separating pad 79 is already in contact with the hopping roller 65 when the motor starts rotating.
, And the sheet regulating members 89 and 90 are retracted, so that the feeding of the printing sheet 63 can be started immediately.

As described above, according to the fifth embodiment,
Since the pressure contact between the hopping roller 65 and the friction separation pad 79 is released only while the printing paper 63 is being transported by the paper transport roller 96, a load is not applied to the printing paper 63 transported by the paper transport roller 96. Therefore, no slippage of the paper transport roller 96 with respect to the printing paper 63, no image shrinkage, and no paper jam occurs. Also, there is no possibility that the printing paper 63 is left with marks such as scratches due to frictional stress.

Further, in the fifth embodiment, the printing paper 6
3 is already started when the feeding of the friction separation pad 7 is started.
9 is in pressure contact with the hopping roller 65, so that the printing paper 63 can be continuously conveyed without causing a time loss.

In the printing apparatus, there is not only a sheet conveying apparatus, but also an apparatus which carries out a conveying or printing process by holding a printing sheet by an elastic roller in each step of a printing process of the main body. The transfer roller unit and the fixing roller unit correspond to these. The mechanism of the present invention is applied to such a roller unit, and the elastic roller of each process is attached only during the operation of each process, that is, while driving some drive shaft. By being configured to be biased, it is possible to prevent deformation of the contact portion of the elastic roller due to constant bias and transfer of components to the contact partner. For example, it is possible to prevent the backup roller, which is always in pressure contact with the transfer roller and the fixing roller, from being deformed and the components from being transferred.

[0093]

As described above in detail, according to the present invention, the separation pad is separated from the hopping roller by operating the separation means manually or by rotation of a motor, or when a paper jam or the like occurs. Since the rotation of the hopping roller is free, the jammed sheet can be easily removed.

When the printing paper is transported by the transport roller downstream of the hopping roller in the transport direction, the printing paper is not pinched by the hopping roller and the separation pad. Accordingly, it is possible to prevent the occurrence of an obstacle such as paper jam or image shrinkage.

[Brief description of the drawings]

FIG. 1 is a cutaway perspective view showing a cut-sheet paper transport device according to a first embodiment.

FIG. 2 is a cutaway perspective view showing a cut-sheet paper transport device according to a second embodiment.

FIG. 3 is a block diagram illustrating a control system according to a second embodiment.

FIG. 4 is a cutaway perspective view showing a cut-sheet paper transport device according to a third embodiment.

FIG. 5 is a block diagram illustrating a control system according to a third embodiment.

FIG. 6 is a side view illustrating a cut-sheet paper transport device according to a fourth embodiment.

FIG. 7 is a perspective view illustrating a cut-sheet paper transport device according to a fourth embodiment.

FIG. 8 is a block diagram illustrating a control system according to a fourth embodiment.

FIG. 9 is a perspective view showing a cut-sheet paper transport device according to a fifth embodiment.

[Description of Signs] 1 Single-sheet transport device 5, 65 Hopping roller 7 Friction separation piece 10 Friction separation pad 13, 63 Printing paper 16 Lever 29 Cam 44 Planetary gear 75, 76, 117, 118 Cam 85, 86, 112, 113 Cam follower 89, 90 Paper regulating member 96 Paper transport roller 100 Paper detection sensor

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3F343 FA02 FC01 GA03 GB01 GC01 GD01 HA12 HB01 HD07 HD09 HD10 HD18 JA01 JD03 JD08 JD33 JD35 KB04 KB05 LA04 LA15 LC11 LC20 LC22 LD26 MA03 MA13 MA14 MA15 MA56 MB03 MB14 MC19 MC20

Claims (6)

[Claims] 1. A cut-sheet transporting apparatus for feeding and transporting a plurality of stacked cut-sheets one by one by a hopping roller and a separation pad pressed against the hopping roller, wherein the separation pad is separated from the hopping roller. A cut-sheet paper transport device comprising a separating means. 2. The hopping roller is rotatably driven by a motor, and the separation means is driven by rotating the motor in a direction opposite to the direction in which the cut sheet is fed, thereby separating the separation pad from the hopping roller. The cut-sheet paper conveying device described in the above. 3. A cut-sheet paper transport device for feeding and transporting a plurality of stacked cut-sheet papers one by one by a hopping roller and a separation pad pressed against the hopping roller, wherein a motor for rotating and driving the hopping roller is provided. A cut sheet transporting device, wherein the transfer of the driving force of the motor to the hopping roller is canceled by rotating in a direction opposite to the direction of feeding the cut sheet. 4. A cut-sheet paper transport device in which a plurality of stacked cut-sheet papers are fed out one by one by a hopping roller and a separation pad pressed against the hopping roller, and then fed by a feed roller. A cut-sheet paper conveying device, further comprising a separation unit that separates the separation pad from the hopping roller with the rotation of the conveyance roller when the leading end of the paper has reached. 5. The cut-sheet transporting device according to claim 4, further comprising a regulating member for preventing the second and subsequent cut-sheets from moving as the separation pad is separated from the hopping roller. 6. The cut-sheet paper conveying device according to claim 4, wherein said separating means does not separate the separation pad before feeding out the cut-sheet paper, but separates the separation pad with the start of rotation of the conveying roller.