JPH0640106A - Recording paper scanning travel mechanism in image forming device - Google Patents

Abstract

PURPOSE:To obtain a recording paper scanning travel mechanism which can be simplified in structure in an image forming device. CONSTITUTION:A clamper 70 having paired support rollers 80 consisting of an upper roller 81 and a lower roller 82 vertically disposed in pressure contact with each other is supported movably along a guide shaft 90. The leading end of recording paper is clamped between the paired support rollers 80 to be supported. In this construction, the sub-scanning of the recording paper at the time of image forming is conducted by traveling the clamper 70 along the guide shaft 90.

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 holding the leading edge of the recording sheet. The present invention relates to a recording paper scanning movement mechanism in an image forming apparatus that is driven to perform scanning movement.

[0002]

2. Description of the Related Art As one of recording (image forming) methods in image forming apparatuses such as copying machines, printers, and facsimiles, a recording head movable in the width direction of the recording paper or the entire width direction of the recording paper is provided. There is a recording head in which recording elements are arranged, and an image is formed while moving the recording paper in the moving direction of the recording head or in the direction orthogonal to the element arrangement direction. That is, the main scanning is performed by the recording head, and the sub-scanning is performed by moving the recording paper. As a moving / conveying structure of the recording paper in the image forming apparatus which performs the sub-scanning by the movement of the recording paper, a holding means (clamper) capable of holding the leading end of the recording paper is provided so as to be movable in the scanning direction of the recording paper. There is a configuration in which the recording paper is moved and driven by holding and moving the leading end of the recording paper with the clamper. According to this configuration, since the movement management of the recording paper can be accurately performed, it is often used especially in a color image forming apparatus which needs to form an image a plurality of times on the same recording paper.

[0003]

However, in the conventional structure as described above, a paper discharge conveying means for discharging the recording paper is provided separately from the clamper, and when the paper is discharged after the image formation is completed, the clamper is used. It is necessary to release the holding of the recording paper by means of (1) and drive the recording paper to be discharged by the discharge conveying means, which complicates the structure.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances and provides a recording paper scanning movement mechanism in an image forming apparatus which can be simplified in structure.

[0005]

In order to achieve the above object, the recording paper scanning movement mechanism in the image forming apparatus according to the present invention moves the recording paper by scanning in one direction for forming an image on the recording paper. In the image forming apparatus, the holding member movable in the scanning direction of the recording paper holds the leading edge of the recording paper and drives the recording paper to scan and move. The roller members are arranged in pressure contact with each other. A pair of rollers is provided so as to be movable in the scanning direction of the recording paper, and the recording paper is held by engaging the recording paper between the pair of rollers, and the held recording paper is scanned and driven by the movement. A recording paper scanning movement mechanism in an image forming apparatus characterized in that. According to this configuration, the recording sheet can be held and the sheet can be discharged after the image formation is completed by rotating the roller member, and the configuration can be simplified.

[0006]

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 longitudinal section of an image forming apparatus to which an embodiment of a recording paper scanning movement mechanism in 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 is a plurality of times (magenta, cyan, yellow, black of magenta, cyan, yellow, black) on the same recording paper based on image information that is color-separated into three colors of red, blue and green. A color image is formed by performing image formation four times).

At the lower part of one end (left end in the figure) of the apparatus 1, there is provided a paper feed section 10 to which a recording paper cassette 2 accommodating the recording paper 4 is detachable, and a paper feed section 10 is ejected above the paper feed section 10. A paper tray 3 is provided, and the recording paper 4 accommodated in the recording paper cassette 2 is introduced from the paper feeding unit 10 and the paper feeding unit 10
The thermal transfer head 50, which will be described later, transfers the sublimation dye of the ink ribbon 63 to form an image, and the image is formed and discharged onto the discharge tray 3. ing. The paper feed unit 10 is formed with an opening into which the recording paper cassette 2 can be inserted, and the recording paper introducing roller 11 is provided above the front end of the recording paper cassette 2 when the recording paper cassette 2 is inserted into the opening. Further, an introduction roller pair 12 is provided at a position adjacent to the front end of the recording paper cassette 2 so that the rollers are arranged in pressure contact with each other in the vertical direction.

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 (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 arcuate guide portion 21 is pivotally supported at a substantially central portion thereof, and a platen roller 34 is provided substantially above the guide arm 20. The lower end of the guide arm 20 is connected via a spring 32 to the lower end of an operation arm 33 that is rockably operated by a cam 41 provided at the right end of the device 1 in the drawing.
The return force of the spring 32 urges it to swing counterclockwise in the figure. A pinch roller 2 is provided on the upper end of the guide arm 20.
2 is rotatably provided, and this pinch roller 22
Is pressed against the horizontal direction of the platen roller 34 by the urging force of the guide arm 20 by the spring 32, and in this state, the guide arm 20 is in a substantially vertical state.
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.

A recording paper guide plate 3 for supporting the recording paper conveyed between the introducing roller pair 12 and the conveying roller pair 31 and between the conveying roller pair 31 and the guide arm 20.
5 are arranged, and the upper side of each of them and the recording paper introducing roller 1
1 above the recording paper support plate 3 in parallel with each other at a predetermined interval.
6 are provided. Guide part 2 of the guide arm 20
A recording paper retreat restricting member 37 formed of an elastic member is attached to an end of the recording paper retreat plate 36 opposed to the recording paper supporting plate 36, and the recording paper retreat restricting member 37 is directed obliquely upward toward the guide portion 21. , Its tip is provided in contact with the guide portion 21.

A thermal transfer head 50 having a thermal head array 51 extending in the width direction of the recording paper is provided above the platen roller 34. The thermal transfer head 50 is pivotally supported by a pivot shaft 52 at substantially the center thereof, and a cam follower 53 is attached to an end portion on the opposite side of the thermal head array 51 with the pivot shaft 52 interposed therebetween. The cam follower 53 comes into contact with the outer peripheral cam surface of the head operation cam 42 fixed to the same cam shaft 43 as the above-mentioned cam 41 is mounted, and the rotation of the head operation cam 42 (that is, the cam shaft 4).
(3 rotation), the outer peripheral cam surface is displaced to follow the displacement. By swinging counterclockwise in the figure, the thermal head array 51 can be positioned at the transfer action position facing the upper side of the platen roller 34 as shown by the solid line in the figure, and swings clockwise in the figure. Thus, the thermal head array 51 can be positioned at a retracted position separated from the platen roller 34 by a predetermined distance as shown by an imaginary line in the figure.
Although not shown, the thermal transfer head 50 is also located at the paper feed position where the thermal head array 51 is located slightly above the transfer operation position (the thermal head array 51 is located slightly above the platen roller 34). It can be located.

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 disposed 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 respective colors 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 around the ink ribbon reel 62. At the time of image formation with the thermal transfer head 50 at the transfer operation position, the ink ribbon 63 is sandwiched between the platen roller 34 and the thermal head array 51 in a superposed state with the recording paper (the recording paper is the ink on the platen roller 34 side). The ribbon 63 is sandwiched between the thermal head array 51 side) and the ink ribbon reel 6 on the sending side in synchronization with the movement of the recording paper.
The ink ribbon reel 62 on the take-up side is wound up from 1.

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 the side view in FIG. 2 and the 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 of FIG. 4, FIG. 4 is a sectional view taken along the line BB of FIG. 2, and FIG.
As shown in FIG. 6 which is a C sectional view and FIG. 7 which is a DD sectional view of FIG. 3, a rubber layer having a predetermined thickness is formed on the surface by a frame 71 in which side plates 72 are vertically bent at both ends in the width direction. The lower roller 81 formed with is rotatably supported and
An upper roller 82 supported at one end of an arm 74 pivotally supported by a side plate 72 by a shaft 73 is connected to a spring 75 connected between the other end of the arm 73 and the frame 71.
The support roller pair 80, which is arranged in pressure contact with the upper side of the lower roller 81 by the urging force of the lower roller 81 and includes the lower roller 81 and the upper roller 82.
It is configured with.

A gear 81A is provided on one shaft end of the lower roller 81.
Is fixed, the gear 81A meshes with an idle gear 76 rotatably supported by side plates 72 at horizontally adjacent positions, and the idle gear 76 is fixed to an idle shaft 77 rotatably supported by the chassis 71. Idol Gear 7
7A, and a two-stage gear 77B having a small outside diameter is fixed to an end portion of the idle shaft 77 protruding outward from the side plate 72,
A gear 78 rotatably supported by the side plate 72 is horizontally adjacent to the small-diameter gear of the two-stage gear 77B and engages either the two-stage gear 77B or the gear 78 exposed laterally. By being rotationally driven, the lower roller 81 is rotationally driven via the idle shaft 77, the idle gear 77A, the idle gear 76, and the gear 81A. or,
At the end of the lower roller 81 opposite to the side where the gear 81A is mounted,
The one-way clutch 81B is externally mounted, and the outer surface of the one-way clutch 81B is engaged with a locking claw 71A that is formed by bending the frame 71. The one-way clutch 81B can rotate clockwise in FIG. 7 by the action of the one-way clutch 81B. Therefore, it cannot rotate counterclockwise.

The lower roller 8 is attached to one axial end of the upper roller 82.
As in the case of 1, the one-way clutch 81A is externally mounted, and the engaging pawl 74A formed by bending the arm 74 is engaged with the outer periphery of the one-way clutch 81A, and the action of the one-way clutch 81A causes counterclockwise rotation in FIG. Is rotatable but not clockwise. In other words, the upper roller 82 and the lower roller 81 both eject the recording paper sandwiched between the rollers 81 and 82 on the paper discharge side (see FIG. 2).
It can be rotated in the direction of conveyance to the middle left side and cannot be rotated on the opposite side.

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) in the horizontal direction.
The guide groove 91A which is opened to the
2 are formed with guide grooves 92A that open downward,
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. In addition, the holding arms 91 and 92 have engaging portions 91B,
92B is provided in a protruding manner, and the movable drive belt 100 is fixed to the engaging portions 91B, 92B by a clip 93 so as not to be relatively movable.

The moving drive belt 100 is an endless belt, and as shown by the chain double-dashed line in FIG. 8 showing the drive path, the pulley 101, so that it has a track parallel to the guide shaft.
It is linked among 10, 103, 104, 105 and 106. The pulley 102 is rotatably driven by a drive motor (not shown) capable of rotating in the forward and reverse directions, and the clamper 70 is driven by a predetermined stroke along the guide shaft 90 by the circling drive of the moving drive belt 100 by the rotational drive of the pulley 102. A sheet feeding position located at the right end in the figure adjacent to the platen roller 34 and the thermal transfer head 50,
It can be positioned at the paper discharge position at the left end in the figure. As shown in FIG. 9, the clamper drive gears 301 and 301 are provided at the portions corresponding to the front and rear ends (feed position and discharge position) of the stroke of the clamper 70 along the guide shaft 90, respectively.
302 is provided.

Pulleys 201 and 202 are coaxially fixed to the two drive gears 301 and 302, respectively, and the pulleys 201, 202, 203, 204, and 202, as shown by the alternate long and short dash line in FIG.
205, 206 and 207 are synchronously rotated by a rotary drive belt 200 linked to each other, and
Gear 3 meshed with one clamper drive gear 301
A drive motor (not shown) capable of rotating in the normal and reverse directions is used to rotate the motor. The clamper drive gears 301 and 302 include the clamper drive gears 301 and 3 respectively.
A gear 304, which is rotatably and pivotally attached to an arm 310 pivotally supported by a rotation shaft of 02, meshes with the gear 304, and the gear 304 is a so-called planetary gear with respect to the clamper drive gears 301 and 302.

The arm 310 has a substantially U-shaped cross section and is provided so as to sandwich the clamper drive gears 301 and 302. The gear 304 is pivotally supported at the tip of one arm and the end of the other arm. The stopper protrusion 311 is bent outward, and the stopper protrusion 311 is inserted into a swing angle regulation hole 321 formed in a bracket 320 supporting the outer ends of the rotary shafts of the clamper drive gears 301 and 302, and the arm 310 is inserted. Is swingable within the swing angle regulation hole 321 within a range in which the stopper protrusion 311 can move. Here, the swing range of the gear 304 is such that, on the right side of the drawing, when the clamper 70 is located at the right side sheet feeding position, the arm 310 swings to the right side of the drawing and the gear 30.
4 is a predetermined position away from the two-stage gear 77B of the clamper 70, and a retracted position in which the two are out of mesh with each other, and the arm 310 swings counterclockwise in the drawing from the retracted position, and the gear 304 causes the two-stage gear of the clamper 70 to move. 77B and the position where it meshes with 77B. On the left side of the drawing, when the clamper 70 is positioned at the left end of the drawing, the arm 310 swings to the left side of the drawing and the gear 304 is spaced from the gear 78 of the clamper 70 by a predetermined distance. It can be located at a retracted position where they are not meshed with each other and a position where the arm 310 swings clockwise in the drawing to mesh with the gear 78 of the clamper 70.

Both the paper feed side arm 310 and the paper discharge side arm 310 are oscillated by the urging means (not shown) toward the retreat side, and the clamper 70 is immediately fed while the clamper 70 is positioned on the paper feed side and the paper discharge side. The paper-side and paper-delivery-side gears 304 are prevented from meshing with the two-stage gear 77B or the gear 78 of the clamper 70. On the left side of the clamper 70 at the paper discharge position in the figure, a paper discharge roller pair 38 in which rollers are arranged in pressure contact with each other is provided.

Thus, the image forming apparatus constructed as described above operates as follows to form an image. First, as shown in FIG. 10, the recording paper 4 accommodated in the recording paper cassette 2 is introduced into the apparatus 1 by driving the recording paper introducing roller 11, and is conveyed by driving the introducing roller pair 12 and the conveying roller pair 31. . At this time, the clamper 70 is at the paper feed position, and the thermal transfer head 50 is at the paper feed position, although not shown, in which the thermal head array 51 is located slightly above the transfer operation position. The leading edge of the recording paper 4 is guided by the arcuate guide portion 21 of the guide arm 20 to deform the recording paper retreat restricting member 37 while being bent and conveyed upward, between the platen roller 34 and the pinch roller 22. It is bitten in, conveyed by the rotation of the platen roller 34, guided by the thermal transfer head 50, and headed to the pressing portion of the upper and lower rollers 81 of the clamper 70 at the sheet feeding position.

Here, the clamper drive gear 301 is driven to rotate counterclockwise in the figure, and the clamper drive gear 301 is rotated.
Rotation causes the arm 310 to oscillate counterclockwise in the figure, the gear 304 meshes with the two-stage gear 77B of the clamper 70, and the two-stage gear 77B is rotationally driven. As a result, the lower roller 81 moves counterclockwise in the figure. The upper and lower rollers 81 are driven to rotate around
The recording paper 4 is bitten in the meantime, and the driving is stopped in a state where the amount of biting is predetermined. As a result, the leading end of the recording paper 4 is held by the support roller pair 80 of the clamper 70 (FIG. 11).

After that, the thermal transfer head 50 is brought to the transfer operation position by the rotation of the head operation cam 42, and the clamper 70 is driven to move to the left side in the drawing by the rotational driving of the moving drive belt 100 in the counterclockwise direction in the drawing. 4 is moved and driven, the ink ribbon 63 is wound up 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 (FIG. 1).
2). 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 completion of the first transfer process, the clamper 70 (recording paper 4) is returned to the paper feeding position by the reverse rotation (clockwise rotation) of the moving drive belt 100, and the moving drive belt 100 is further moved. In the figure, the clamper 70 is driven to move to the left side in the figure by the counterclockwise orbital drive (the recording sheet 4 is moved and driven) to perform the next transfer step, and thereafter, this step is repeated a predetermined number of times. It is what is done.

When the clamper 70 is returned to the paper feeding position, the trailing end of the recording paper 4 is changed by the recording paper retreat restricting member 37, and the recording paper supporting plate 36 is provided as shown in FIG.
It is designed so that it does not return to the side of the sheet feeding unit 10 when it reaches the top. 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), and the clamper drive gear 301 is in the opposite direction to that at the time of paper feeding as shown in FIG. It is rotationally driven in the (clockwise) direction, whereby the movable drive belt 100 is circumferentially driven in the clockwise direction, the clamper drive gear 302 is rotationally driven, and the arm 31 is rotated.
0 swings clockwise in the figure, and the gear 304 moves the clamper 70.
The lower roller 81 is rotated in the counterclockwise direction in the figure by meshing with the gear 78, and the recording paper 4 gripped by the pair of support rollers 80 is conveyed to the discharge side (left side in the figure).
The recording paper 4 delivered from the clamper 70 is conveyed by the paper ejection roller pair 38 and ejected onto the paper ejection tray 3.

[0024]

As described above, according to the recording paper scanning / moving mechanism in the image forming apparatus of the present invention, the leading end of the recording paper is nipped by the roller pair in which the roller members are arranged in pressure contact with each other. Since the recording paper gripped by the movement is configured to scan and drive, by rotating the roller member of the roller pair, the recording paper can be held and the paper ejection drive can be performed after the image formation is completed. Can be converted.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram corresponding to a longitudinal section of an image forming apparatus to which an embodiment of a recording paper scanning movement mechanism in an image forming apparatus according to the present invention is applied.

FIG. 2 is a side view of a clamper part.

FIG. 3 is a partial plan view of a side end portion of a clamper portion.

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

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

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

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

FIG. 8 is a schematic configuration diagram of a moving drive system of the clamper and a rotary drive system of the clamper.

FIG. 9 is an explanatory diagram of a rotary drive transmission system of a clamper.

FIG. 10 is an explanatory diagram of an operation during image formation.

FIG. 11 is an explanatory diagram of an operation during image formation.

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.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus 4 ... Recording paper 80 ... Support roller pair (roller pair) 81 ... Upper roller (roller member) 82 ... Lower roller (roller member)

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H04N 1/034 9070-5C

Claims (1)

[Claims] 1. An image forming apparatus for performing one-directional scanning for forming an image on a recording sheet by moving the recording sheet, wherein the recording sheet is moved by a holding means movable in the scanning direction of the recording sheet. In a device that scans and drives the recording paper while supporting the leading edge, a roller pair in which roller members are arranged in pressure contact with each other is provided movably in the scanning direction of the recording paper, and recording is performed between the roller pair. A recording paper scanning / moving mechanism in an image forming apparatus, characterized in that the recording paper is held by being bitten into the paper, and the recording paper held by the movement is scanned and driven.