JPH05162401A - Device for feeding and holding recording paper for image-forming apparatus - Google Patents

Abstract

PURPOSE:To make position of holding recording paper with a clamper constantly correct in a simple construction for an image-forming apparatus equipped with paired rollers for clamping the recording paper without the need for providing a highly accurate course for feeding the recording paper. CONSTITUTION:The image-forming apparatus as decribed in the title is so constructed that paired rollers 80 for holding recording paper 4 and for driving the paper in the direction of vertical scanning are made up in a structure in which an upper roller 81 having smooth surface and a lower roller 82 whose surface is made of rubber are arranged vertically so that each of the rollers are pressed against each other, and is also constructed so that the recording paper 4, driven and carried by a platen roller 34, is controlled by a thermal transfer head 50 in the direction of proceeding and is fed through a carriage passage that touches the circumferential face of the upper roller 81 on the side closer to its rotation center than the contact point of the upper and the lower rollers 81 and 82 of the paired holding rollers 80.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus for moving a recording sheet in one direction for forming an image on the recording sheet by using a pair of rollers movably driven. The present invention relates to a recording paper supply and holding structure of an image forming apparatus, which holds the front end of the sheet and scans and drives it.

[0002]

2. Description of the Related Art As one of recording (image forming) systems in image forming apparatuses such as printers and facsimiles, a recording head movable in the width direction of the recording sheet or recording over the entire width direction of the recording sheet is performed. Some include a recording head in which elements are arranged, and an image is formed while moving a recording paper in a moving direction of the recording head or in a direction orthogonal to the element arrangement direction. That is, the main scanning is performed by the recording head or the like, and the sub scanning is performed by moving the recording paper.

As a recording paper moving / conveying structure in an image forming apparatus for performing sub-scanning by moving the recording paper as described above, a holding means (clamper) capable of holding the leading end of the recording paper is moved in the scanning direction of the recording paper. There is a configuration in which the recording paper is moved and driven by holding the leading edge of the recording paper with the clamper and moving the recording paper. Since this configuration can accurately manage the movement of the recording paper at the time of image formation, it is particularly suitable for a color image forming apparatus that needs to form an image a plurality of times on the same recording paper. As a configuration of this clamper, the applicant of the present invention has proposed a configuration in which a roller pair in which roller members are arranged in pressure contact with each other is configured to form a clamper, and a recording paper is held by being held between the roller pairs. According to this structure, the recording paper can be held in the clamper or discharged after the image formation is completed by rotating the roller member, and the structure can be simplified.

[0004]

By the way, the recording paper is
It is desired that the recording paper is conveyed from the recording paper accommodating portion toward the clamper by the conveying means, and the clamper accurately grasps the predetermined position of the tip end portion thereof. For this reason, it is necessary to provide a transport mechanism and a control configuration capable of managing the transport by the transport means with high accuracy and always stopping the transport at a position where the relative position to the clamper is correct. When the clamper is composed of the roller pair as described above, in order to accurately hold the holding position of the recording paper by the roller pair (clamper), the recording paper supply path is set so that the leading end of the recording paper is relative to the roller pair. It is necessary to configure the rollers so that they are parallel to each other and move toward the pressure contact portion of the roller member, and to accurately carry the recording paper. However, depending on the configuration of the recording paper supply path, due to factors such as the difference in rigidity peculiar to each recording paper and curl, the paper is always supplied in a state (posture) parallel to the roller pair toward the pressure contact portion of the roller member. It was difficult to do so, and the complexity of the configuration was unavoidable.

[0005]

SUMMARY OF THE INVENTION In view of the above circumstances, the present invention is an image forming apparatus in which a clamper is composed of a roller pair, and does not require an accurate recording paper supply path, but has a simple structure and a holding position by the roller pair. It is an object of the present invention to provide a recording paper supply and holding structure for an image forming apparatus, which can accurately keep the temperature constant.

[0006]

In order to achieve the above object, the recording paper feeding and holding structure of the image forming apparatus according to the present invention uses a movement of the recording paper to scan in one direction for forming an image on the recording paper. In the image forming apparatus, a pair of rollers, in which roller members are arranged in pressure contact with each other in the vertical direction, bite and hold the recording sheet, and the recording sheet is driven to scan and move by the movement of the roller pair. The surface of one roller member of the pair is made smooth, and the leading end of the recording paper guided toward the roller pair by the recording paper path regulating means has a smoother surface than the pressure contact portion of the roller pair. It is set so as to contact the peripheral surface on the side. Further, after the recording paper feeding means for feeding the recording paper toward the roller pair conveys the recording paper until the leading end of the recording paper comes into contact with the contact point of the roller pair, the roller pair is rotationally driven by a predetermined angle to feed the recording paper. Configured to hold.

[0007]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a schematic configuration diagram corresponding to a vertical section of an image forming apparatus to which an embodiment of a recording paper supply and holding structure of the image forming apparatus according to the present invention is applied. The illustrated image forming apparatus 1 is a so-called color image forming apparatus, and a plurality of times (magenta, cyan, yellow, black of magenta, cyan, yellow, and black are printed on the same recording paper based on image information separated into three colors of red, blue, and green. A color image is formed by performing image formation four times). The illustrated device 1 includes a recording paper cassette 2 in which recording papers 4 ... Are accommodated in a lower portion of one end (the left end in the drawing).
Is provided with a detachable paper feed section 10, a paper discharge tray 3 is provided above the paper feed section 10, and recording paper 4 accommodated in a recording paper cassette 2 is introduced from the paper feed section 10. , Is conveyed to the end side opposite to the paper feeding section 10 and inverted to the upper side, and the sublimation dye of the ink ribbon 63 is transferred by the thermal transfer head 50 described later to form an image, and the image is formed on the paper discharge tray 3. It is supposed to be discharged.

The paper feed section 10 is provided with an opening into which the recording paper cassette 2 can be inserted, and the recording paper is introduced above the front end of the recording paper cassette 2 inserted into the opening. A roller 11 is provided, and at a position adjacent to the front end of the recording paper cassette 2, an introducing roller pair 12 in which the rollers are arranged in pressure contact with each other is provided. The recording paper introduction roller 11 and the introduction roller pair 12 are rotationally driven by a drive motor 6 not shown in FIG. 1 as shown in FIG. 2 which is a block diagram of a recording paper conveyance drive system, and the drive motor 6 is associated with the image forming apparatus. 1
Drive control is performed by the control device 5 of FIG.

A conveying roller pair 31 having rollers arranged in pressure contact with each other is provided in front of the introducing roller pair 12 in the conveying direction of the recording sheet (on the right side in the drawing), and further forward of the conveying roller pair 31 in the recording sheet conveying direction. A guide arm 20 having an arc-shaped guide portion 21 is pivotally supported at a substantially central portion thereof, and an outer peripheral surface of the guide arm 20 is formed of an elastic member such as rubber having a predetermined elasticity on a substantially upper side thereof. A platen roller 34 is provided. The conveying roller pair 31 and the platen roller 34 are connected to a drive motor 7 not shown in FIG. 1 as shown in the block diagram of FIG. 2 and are rotationally driven in both forward and reverse directions by the drive motor 7. The drive of the image forming apparatus 1 is controlled by the controller. Further, a friction clutch that idles at a torque of a predetermined value or more is provided in the path of the rotational driving force transmission to the platen roller 34. Between the introduction roller pair 12 and the conveying roller pair 31, and between the conveying roller pair 31 and the guide arm 20, recording paper guide plates 35 for supporting the recording paper to be conveyed are arranged, and respectively. The recording paper support plates 36 are disposed substantially in parallel with each other above the recording paper introduction roller 11 and above.

The lower end of the guide arm 20 is connected by a spring 32 to the lower end of an operating arm 33 pivotally supported by a pin 13 on the right side of the guide arm 20 in the figure, and the spring 32 elastically returns. By the force, the guide arm 20 is biased counterclockwise in the figure and the operation arm 33 is biased clockwise in the clockwise direction. Operation arm 33
The rocking of the roller is such that a rotatable roller-like cam follower 33A provided at the upper end of the roller comes into contact with the outer peripheral cam surface of the roller pressing cam 42 fixed to the cam shaft 43 arranged substantially above the operation arm 33. On the other hand, the swing of the guide arm 20 is restricted by the pinch roller 22 rotatably provided at the upper end of the guide arm 20 coming into contact with the platen roller 34 laterally in the horizontal direction. The contact portion of the cam follower 33A of the operation arm 33 on the surface rotates the cam shaft 43 (rotation of the roller pressure contact cam 42).
The displacement amount of the spring 32 changes due to the displacement of the spring 32, and thus the pressure contact force of the pinch roller 22 to the platen roller 34 changes. With the pinch roller 22 in contact with the platen roller 34, the guide arm 20 is in a substantially vertical state, and the lower end of the guide portion 21 is located in the conveyance path of the recording paper conveyed by the conveyance roller pair 31.

At the end of the recording paper support plate 36 facing the guide portion 21 of the guide arm 20, a recording paper retreat restricting member 37 formed of an elastic member is mounted. The distal end of the guide portion 21 is in contact with the guide portion 21 and is directed obliquely upward toward the guide portion 21. Further, the guide arm 20 is provided with a limit switch 9 by projecting the sensor arm from the guide surface of the guide portion 21, and the detection signal of the limit switch 9 is input to the control device 5 as shown in the block diagram of FIG. It has become so. As a result, the control device 5 can grasp the leading end position of the recording paper by operating the sensor arm of the limit switch 9 for the recording paper conveyed and supplied.

Above the platen roller 34, there is provided a thermal transfer head 50 in which a thermal head array 51 extending across the width of the recording paper is supported by a head frame 52.
The thermal transfer head 50 is pivotally supported by a pivot shaft 53 at substantially the center of a head frame 52, and a cam follower 54 is attached to an end of the thermal transfer head 50 opposite to the thermal head array 51 sandwiching the pivot shaft 53. And the cam follower 5
4 comes into contact with the outer peripheral cam surface of the head operation cam 41 fixed to the same cam shaft 43 as the above-mentioned roller pressure contact cam 42 is mounted, and rotation of the head operation cam 41 (that is, cam shaft 43
The rotation of the outer peripheral cam surface is followed by a swing operation.

The head operation cam 41 has its outer peripheral cam surface formed in three steps with different radii within a predetermined angle range, and the thermal head array 51 is mounted on the platen by the thermal head array 51 with the cam follower 54 corresponding to the cam surface having the largest diameter. The thermal head array 51 is positioned slightly above the platen roller 34 in a state of being in contact with the upper side of the roller 34 with a predetermined pressing force and corresponding to the second-stage medium-diameter cam surface. And the thermal head array 51 has a space between the outer periphery of the platen roller 34 and the thermal head array 51. Further, in the state corresponding to the cam surface having the smallest diameter, the thermal transfer head 50 swings largely clockwise and the thermal head array is moved. 51 is at a retracted position that is largely separated from the platen roller 34.

An ink ribbon reel 61 on the delivery side is arranged below the thermal transfer head 50, and an ink ribbon on the take-up side is arranged at a position substantially symmetrical to the ink ribbon reel 61 on the delivery side with the platen roller 34 interposed therebetween. A reel 62 is arranged. The ink ribbon reel 61 on the delivery side is wound with an ink ribbon 63 in which ribbons of each color to be transferred are sequentially connected by one page (one sheet) of recording paper, and the ink ribbon 63 on the take-up side is wound. It is adapted to be wound up on the ink ribbon reel 62. During image formation with the thermal transfer head 50 at the transfer operation position, the ink ribbon 63 overlaps the recording paper and is sandwiched between the platen roller 34 and the thermal head array 51 (the recording paper is placed on the platen roller 34 side with the ink ribbon 63). 6
3 is sandwiched between the thermal head array 51 side) and the ink ribbon reel 61 on the sending side in synchronization with the movement of the recording paper.
The ink ribbon reel 62 on the take-up side is taken up.

Platen roller 34 and thermal transfer head 50
On the left side in the figure, a pair of left and right widthwise guide shafts 90 supported by a chassis (not shown) of the apparatus and horizontally arranged in the front-rear direction are used to show a side view thereof and a side end portion in FIG. A clamper 70 showing a plan view is provided so as to be slidably movable. The clamper 70 is a sectional view taken along the line AA in FIG. 3, and FIG. 6 is a sectional view taken along the line BB in FIG.
As shown in FIG. 7 which is a C sectional view and FIG. 8 which is a DD sectional view of FIG. 4, a lower roller 81, which is a roller member, is provided by a frame 71 in which side plates 72 are vertically bent at both ends in the width direction.
Is rotatably supported, and an upper roller 82, which is a roller member supported by one end of an arm 74 pivotably supported by a side plate 72 by a shaft 73, is provided between the other end of the arm 73 and the frame 71. The lower roller 81 is disposed in pressure contact with the upper side of the lower roller 81 by the urging force of the spring 75 connected therebetween.
1 and an upper roller 82, and a holding roller pair 80. The vertical position of the platen roller 34 is set so that the horizontal tangent line on the upper side of the platen roller 34 is the pressure contact position of both rollers of the holding roller pair 80.

The lower roller 81 is a so-called rubber roller in which a rubber layer having a predetermined thickness is formed on the outer circumference of a core metal, and the upper roller 8
2 has a smooth outer peripheral surface and is made of stainless steel. The gear 81 is attached to one shaft end of the lower roller 81.
A is fixed, and the gear 81A meshes with an idle gear 76 rotatably supported by side plates 72 at horizontally adjacent positions. The idle gear 76 is attached to an idle shaft 77 rotatably supported by the chassis 71. A two-stage gear 77B having a small outside diameter is fixed to an end portion of the idle shaft 77, which meshes with the fixed idle gear 77A, and projects outward from the side plate 72 of the idle shaft 77. A gear 78 rotatably supported by the side plate 72 is adjacently engaged with the lower roller 81 by rotating and driving either the two-stage gear 77B or the gear 78 exposed laterally. Idle gear 77A, idle gear 76,
It is adapted to be rotationally driven via a gear 81A.

A one-way clutch 81B serving as a rotation direction restricting means is externally mounted on the end of the lower roller 81 on the side opposite to the side where the gear 81A is mounted, and a frame 71 is formed by bending on the outer periphery of the one-way clutch 81B. The engaging claw 71A is engaged, and is rotatable in the direction (clockwise in FIG. 7) in which the recording paper is bitten and held by the action of the one-way clutch 81B and is rotated in the opposite direction (counterclockwise). It is impossible. At one shaft end of the upper roller 82,
Similar to the lower roller 81, a one-way clutch 82A serving as a rotation direction restricting means is externally mounted, and a locking pawl 74A formed by bending an arm 74 is engaged with the outer periphery of the one-way clutch 82A. Thus, the recording paper is rotatable in the direction in which the recording paper is bitten and held (clockwise in FIG. 7) and is not rotatable in the opposite direction (counterclockwise). In other words, both the upper roller 82 and the lower roller 81 rotate in the direction in which the recording paper is held between the rollers 81 and 82 (equal to the direction in which the held recording paper is conveyed to the discharge side). It is possible and non-rotatable in the opposite direction.

Holding arms 91 and 92 are fixed to the outer surfaces of the left and right side plates 72, respectively, and one of the holding arms 91 (front side in FIG. 2) is horizontally (front side).
The guide groove 91A that is opened to the
2, guide grooves 92A that open downward are formed respectively,
The guide shaft 90 is slidably fitted in both the guide grooves 91A and 92A, and the clamper 70 is attached to the guide shaft 90.
Is movably supported along the guide shaft 90. Further, the holding arms 91 and 92 are provided with engaging portions 91B and 92B in a protruding manner, and the movement driving belt 100 is clipped to the engaging portions 91B and 92B by a clip 93.
It is fixed so that it cannot move relative to it.

The moving drive belt 100 is an endless belt, which is wound around pulleys so as to have a track parallel to a guide shaft (not shown), and is driven to rotate by driving means (not shown). The clamper 70 is driven to move left and right in the figure along the guide shaft 90, and the clamper 70 is located at the right side end in the figure adjacent to the platen roller 34 and the thermal transfer head 50 and the left side end in the figure. It can be located at the paper position.

The portions of the clamper 70 corresponding to the front and rear ends (paper feeding position and paper discharging position) of the stroke along the guide shaft 90 are rotationally driven by the pulse motor 8 shown in the block diagram of FIG. 2, respectively. Clamper drive gears (not shown) are arranged, and each of the clamper drive gears has a two-stage gear 77B at the paper feed position and a gear 78 at the paper discharge position.
Are engaged with each other, and the lower roller 81 is rotationally driven counterclockwise in the drawing by the rotation of the clamper drive gear. That is, when the clamper 70 is located at the sheet feeding position and the sheet discharging position, the lower roller 81 can be driven to rotate. Further, on the left side of the clamper 70 at the paper discharge position in the drawing, a pair of paper discharge rollers 38 in which rollers are arranged in pressure contact with each other are arranged.
Is provided.

The image forming apparatus having the above-described structure is controlled by the control device and operates as follows to form an image. First, from the standby state shown in FIG. 1, the head operation cam 41 and the roller pressure contact cam 42 are rotated by the rotation of the cam shaft 43, so that the thermal transfer head 50 is slightly moved from the transfer operation position by the thermal head array 51 as shown in FIG. The recording paper introduction roller 1 is set to the paper feeding position located above.
The recording paper 4 accommodated in the recording paper cassette 2 is introduced into the apparatus 1 by driving 1 and is conveyed by driving the pair of introducing rollers 12 and the pair of conveying rollers 31. At this time, the clamper 70 is in the sheet feeding position.

The leading edge of the recording paper 4 is a guide arm 20.
Is guided by the circular arc-shaped guide portion 21 and deforms the recording paper retreat restricting member 37 while being bent and conveyed upward, and is caught between the platen roller 34 and the pinch roller 22.
It is conveyed by the rotation of the platen roller 34 which is driven to rotate counterclockwise in the figure. During this conveyance, the limit switch 9 is operated to grasp the tip position thereof. Then, as shown in a partially enlarged view in FIG. 10, the thermal transfer head 50 comes into contact with the lower surface of the thermal transfer head 50, which is located at a sheet feeding position with a space between the platen roller 34 and the outer periphery thereof, and is regulated by the thermal transfer head 50. To the clamper 70 located at. At this time, the recording paper 4 moves upward from the horizontal tangential direction of the platen roller 34 due to its rigidity, but does not face upward from the rotation center of the upper roller 82 due to the position setting of the thermal transfer head 50. There is.

The leading edge of the recording paper 4 is the upper roller 82.
Of the recording paper, which abuts on the outer peripheral surface between the contact point (pressing contact portion) with the lower roller 81 and the center of rotation, and abuts on the outer peripheral surface of the upper roller 82, slides on the outer peripheral surface of the upper roller 82. It goes to the contact point between the roller 82 and the lower roller 81. That is, the upper roller 82 guides the recording paper 4 on its peripheral surface, and correctly guides the leading end thereof to the pressure contact portions of the upper and lower rollers 81, 82. The leading edge of the recording paper 4 reaches the pressure contact portion between the upper and lower rollers 81 and 82 of the support roller pair 80 of the clamper 70, and is conveyed until the slack is generated between the clamper 70 and the platen roller 34 as shown in FIG. The conveyance by 34 is stopped, and the leading end of the recording paper 4 is thus supported by the support roller pair 80.
When the recording paper 4 is brought into contact with the pressure contact parts of the upper and lower rollers 81 and 82, the front end of the recording paper 4 becomes parallel to the support roller pair 80, and when the recording paper 4 is inclined, its posture is corrected. The recording paper 4 by the platen roller 34 until this stop
The conveyance amount of is controlled based on the position of the recording paper 4 grasped by operating the limit switch 9, and the recording paper 4 may be loosened, so that highly accurate control is not required.
Further, even if the platen roller 34 is continuously driven to rotate, the friction clutch provided in the drive system works to stop the conveyance.

Next, the lower roller 81 is rotated counterclockwise in the figure by a predetermined amount (predetermined angle), whereby the recording paper 4 is caught between the upper and lower rollers 81 and 82, and the recording paper 4 is moved from the front end to a predetermined position. The leading end of the recording paper 4 is held by the support roller pair 80 in a state where the position corresponds to the pressure contact portion of the upper and lower rollers 81, 82 (FIG. 12). That is, when the lower roller 81 is rotationally driven to bite the recording paper 4, the leading end of the recording paper 4 is surely brought into contact with the pressure contact portion of the upper and lower rollers 81 and 82. By rotating, the recording paper 4 is immediately and surely bitten,
By controlling the rotation angle of the lower roller 81, the bite amount can be accurately managed.

Thereafter, the thermal transfer head 50 is moved to the transfer operation position by the rotation of the head operation cam 41, and the clamper 7 is moved.
0 is moved to the left side in the drawing to drive the recording paper 4, the ink ribbon 63 is wound in synchronization with the movement of the recording paper 4, and an image is formed (transferred) on the recording paper 4 by the thermal head array 51. ) Is performed (FIG. 13). At this time, the platen roller 34 is not rotationally driven, but is rotated following the movement of the recording paper 4 by the action of the friction clutch provided in the drive system described above.
4 does not hinder the movement of the recording paper 4. However, tension is generated on the recording paper 4 due to the rotation resistance of the platen roller 34 and the frictional resistance with the thermal head array 51, and this causes a tension in the direction opposite to the paper feeding or discharging direction of the recording paper 4 held by the clamper 70. The lower roller 81 and the upper roller 82 of the holding roller pair 80 of the clamper 70 cannot be rotated in that direction by the one-way clutches 81A and 82A, respectively, as described above. The lower roller 81 and the upper roller 82 do not rotate and the holding position of the recording paper 4 by the clamper 70 does not shift.

Since this embodiment is a color image forming apparatus, this transfer process is carried out four times for magenta, cyan, yellow and black as described above. That is, after the first transfer process is completed, the clamper 70 is returned to the paper feeding position (the recording paper 4), and further, the clamper 70 is driven to the left side in the drawing (the recording paper 4 is driven to move). ) The next transfer process is performed, and thereafter, this process is repeated a predetermined number of times. When the clamper 70 is returned to the paper feeding position, the platen roller 34 is rotationally driven in the opposite direction (clockwise direction in the figure) to the above-mentioned holding of the recording paper 4 by the clamper 70 (at the time of paper feeding). Even when the clamper 70 is fed back to the paper feed position, the recording paper is driven by the driving force of the platen roller 34 to the clamper 70 in the direction opposite to the paper feeding or discharging direction (right side in the drawing). Although tension acts in the direction of moving the lower roller 81 to the upper roller 82, the one-way clutches 81A and 82A of the clamper 70 prevent the lower roller 81 and the upper roller 82 from rotating in that direction.
The holding position of the clamper 70 does not shift. still,
At the time of this backward feeding, the trailing edge of the recording paper 4 is the recording paper retreat regulating member 37.
By this, the retreat path is changed so that it does not reach the recording paper support plate 36 and returns to the paper feed section 10 side as shown in FIG.

The clamper 70 is at the paper discharge position in the state where the transfer process of the predetermined number of times is completed (transfer of all colors is completed),
Here, the lower roller 81 of the clamper 70 is rotated counterclockwise in the figure, and the recording sheet 4 held by the pair of support rollers 80 is conveyed to the sheet discharge side (left side in the figure) as shown in FIG. The recording paper 4 sent from the clamper 70 is conveyed by the paper discharge roller pair 38 and discharged onto the paper discharge tray 3.

[0028]

As described above, according to the recording paper feeding and holding structure of the image forming apparatus according to the present invention, one roller member of the roller pair is formed to have a smooth surface and the recording paper feeding path is formed. By arranging the roller member pressure contact portion of the roller pair toward the roller member side having a smooth surface,
The roller member having a smooth surface functions as a guide member for introducing the recording paper into the roller pair, and the recording paper can be reliably guided between the roller pair without requiring a complicated guide structure.
In addition, the leading edge of the recording paper comes into contact with the pressure contact portion of the roller pair to make it loose, and the roller pair is rotated from that state to bite the recording paper, so that the orientation of the recording paper is parallel to the roller pair. In addition, the holding position from the leading end can be accurately controlled by the rotation amount of the roller pair, and the holding position of the recording paper can be highly accurate with a simple configuration.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram corresponding to a vertical section of an image forming apparatus to which an embodiment of a recording paper supply and holding structure of the image forming apparatus according to the present invention is applied.

FIG. 2 is a block diagram showing a control configuration of a recording paper transportation system.

FIG. 3 is a side view of a clamper portion.

FIG. 4 is a partial plan view of a side end portion of a clamper portion.

5 is a sectional view taken along line AA of FIG.

6 is a sectional view taken along line BB of FIG.

7 is a sectional view taken along line CC of FIG.

FIG. 8 is a sectional view taken along line DD of FIG.

FIG. 9 is an explanatory diagram of an operation during image formation.

FIG. 10 is a partially enlarged view of the recording paper supplied to the clamper.

FIG. 11 is a partially enlarged view of the recording paper supplied to the clamper.

FIG. 12 is an explanatory diagram of an operation during image formation.

FIG. 13 is an explanatory diagram of an operation during image formation.

FIG. 14 is an explanatory diagram of an operation during image formation.

FIG. 15 is an explanatory diagram of an operation during image formation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus 4 ... Recording paper 34 ... Platen roller (recording paper supply means) 70 ... Clamper 80 ... Holding roller pair (roller pair) 81 ... Upper roller (roller member) 82 ... Lower roller (roller member)

Claims (2)

[Claims] 1. An image forming apparatus for performing unidirectional scanning for forming an image on a recording paper by moving the recording paper, wherein a roller member is arranged so that a roller member is arranged in pressure contact with each other to bite the recording paper. In an image forming apparatus which holds and holds the recording paper in a scanning manner to scan and drive the recording paper by the movement of the roller pair, one roller member of the roller pair has a smooth surface, and the recording paper path regulating means is used to The leading end of the recording paper guided toward the roller pair is set so as to abut on the peripheral surface of the roller member whose surface is smoother than the pressure contact portion of the roller pair on the rotation center side. Recording paper supply and holding structure of forming device. 2. The recording paper feeding means for feeding the recording paper toward the roller pair conveys the recording paper until the leading end of the recording paper comes into contact with the contact point of the roller pair, and then the roller pair rotates by a predetermined angle. The recording paper feeding and holding structure of the image forming apparatus according to claim 1, wherein the recording paper feeding and holding structure is configured to be driven to hold the recording paper.