JP2000198593A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control the feed speed of continuous paper stably by setting the tension that acts on it in dependence on its thickness, material, roulettes and the like. SOLUTION: A plate 310 consists of an L-cross-sectioned plate member extending in a direction orthogonal to the feed direction of continuous paper 10. The plate 310 is urged clockwise on a pivot 312C by an urging means 320 that also urges a swing arm 315 counterclockwise about a pivot 315C. Rotation of a cam driving shaft 340A controls the position of the swing arm 315 between a first swing position indicated by the continuous line and a second swing position indicated by the alternate long and two short dashes line, with the result that an accordingly boosted or reduced urging force the urging member 320 applies to the plate 310 increases or decreases the tension a side edge 312D of an upper plate 312 gives to the continuous paper 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic image forming apparatus for forming an image on continuous paper.

[0002]

2. Description of the Related Art An electrophotographic image forming apparatus includes an image forming unit that draws a latent image on a photosensitive drum, develops the latent image with toner, and transfers the developed toner image from the photosensitive drum to paper. A fixing unit that heats and pressurizes the toner image transferred to the sheet to fix the toner image on the sheet. When the image forming apparatus is to form an image on continuous paper, the paper is placed on a transport path between the image forming section and the fixing section, at a position abutting on the lower surface of the paper passing through the transport path. A displacement member urged in a direction abutting on the lower surface of the sheet while being supported so as to be displaceable in a thickness direction of the sheet, and the fixing unit according to the displacement amount of the displacement member, that is, the amount of slack of the sheet, In some cases, the amount of slack of a sheet in a transport path between an image forming unit and a fixing unit is adjusted to a predetermined range by adjusting a transport speed. Such a displacement member extends in the width direction of the continuous paper orthogonal to the transport direction of the continuous paper, is supported so as to be displaceable in the thickness direction of the continuous paper, and passes through a transport path between the image forming unit and the fixing unit. It is urged by an urging means such as a coil spring so as to contact the lower surface of the continuous paper. In the continuous paper, feed holes are formed at predetermined intervals on both sides in the width direction, and perforations are formed at predetermined lengths, such as perforations, for cutting the continuous paper into predetermined lengths. A transport means such as a tractor that fits in a continuous paper feed hole and applies a transport force to the continuous paper is provided at a location upstream of the image forming unit.

[0003]

In the above-described image forming apparatus for adjusting the conveying speed according to the displacement amount of the displacement member, when the continuous paper is thin and its stiffness is weak, the tension applied to the continuous paper by the displacement member is reduced. If it is too strong, there is a problem that the continuous paper is strongly pulled toward the downstream side in the transport direction, and the feed holes of the continuous paper come off the tractor, causing a transport failure. Conversely, when the continuous paper is thick and strong, if the tension applied to the continuous paper by the displacement member is too weak, the folds of the mountain fold and the valley fold may be formed at the folds at the perforations of the continuous paper. Alternately, the displacement member flaps up and down at the fold of the continuous paper, making it impossible to accurately detect the amount of slack in the continuous paper, making the adjustment of the transport speed unstable. Such flutter also causes a so-called skew, in which the conveying direction of the continuous paper is inclined. Therefore, when using continuous paper having different thicknesses in one image forming apparatus, that is, different stiffness,
If the strength of the tension applied to the continuous paper by the displacement member is set to an appropriate value corresponding to the continuous paper of a specific thickness, when a continuous paper having a thickness different from the specific thickness is used, However, the above-described problem may occur. The present invention has been devised in view of the above circumstances, and an object of the present invention is to apply tension to continuous paper to the thickness, material,
An object of the present invention is to provide an image forming apparatus capable of stably controlling the transport speed of continuous paper by making settings corresponding to perforations and the like.

[0004]

In order to achieve the above object, the present invention is characterized in that the image forming apparatus is provided with a tension setting mechanism for setting tension applied to the continuous paper by the displacement member at different stages. I do. In the present invention, an appropriate tension corresponding to the thickness, material, perforation, etc. of the continuous paper is applied to the continuous paper by the tension setting mechanism.

[0005]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram showing a main part of the image forming apparatus according to the first embodiment, FIG. 2 is a front view showing a configuration of a fixing unit, a sheet conveyance speed detection unit, and a paper discharge unit, and FIG.
Is a plan view showing a state viewed from the direction of arrow A, and FIG. 4 is a block diagram showing a configuration of a control circuit in the image forming apparatus according to the first embodiment.

Referring to FIG. 1, the configuration of the image forming apparatus according to the first embodiment will be described. The image forming apparatus includes a tractor 1
00, an image forming unit 200, a conveying speed detecting unit 300, a fixing unit 400, a paper discharging unit 500, and the like. In this embodiment, the paper on which an image is formed is continuous paper 10 having a constant width, and feed holes are formed at regular intervals on both side edges of the continuous paper 10 in the width direction. Each time a perforated line or the like is formed to cut the continuous paper into a certain length. Incidentally, as such continuous paper, besides ordinary high-quality paper, bond paper, card paper, label paper, film and the like are used. The continuous paper 10 supplied from the right side (upstream in the transport direction) of the tractor 100 in FIG.
0, conveying speed detecting unit 300, fixing unit 400, paper discharging unit 50
0 is sequentially discharged to the outside of the apparatus.

The tractor 100 includes pulleys 102 and 104 disposed below the left and right side edges in the width direction of the continuous paper 10 and are spaced from each other in the transport direction of the continuous paper 10. Belt 106 wrapped around 104
And a paper pressing plate 108 extending to the opposite side of the belt 106 with the continuous paper 10 interposed therebetween. The belt 106 has pins 106 that are fitted into feed holes formed on both side edges in the width direction of the continuous paper 10 to apply a conveying force to the continuous paper 10.
A are provided at intervals in the extending direction of the belt 106. The paper holding plate 108 has a feed hole for the continuous paper
The upper surface of the continuous paper 10 is held so as not to separate from the sheet 06A.

The image forming section 200 is disposed downstream of the tractor 100 in the transport direction, extends in a direction perpendicular to the transport direction of the continuous paper 10, and rotates so that the photosensitive surface contacts the upper surface of the continuous paper 10. , A charging unit 220, an exposure unit 230, a development unit 240, and a transfer unit 250 that are arranged in a process order at a portion surrounding a photosensitive surface formed on the outer periphery of the photosensitive drum 210. , A cleaning unit 260 and a charge removing unit 270. The charging unit 220 charges the photosensitive surface of the photosensitive drum 210, the exposure unit 230 draws a latent image on the charged photosensitive surface, and the developing unit 240 applies a toner to the latent image formed on the photosensitive surface. The transfer unit 250 transfers the toner image formed on the photosensitive surface to the continuous paper 10, and the cleaning unit 260 removes the toner remaining on the photosensitive surface. The charge removing section 270 removes the charge on the photosensitive surface. At the transfer unit 250, the continuous paper 10 is attracted to the photosensitive surface of the charged photosensitive drum 210 by the action of static electricity, so that the continuous paper 10 is rotated from the photosensitive drum 210 rotating along the transport direction of the continuous paper 10. A transfer force is applied in the transfer direction.

The conveying speed detecting unit 300 extends in the width direction orthogonal to the conveying direction of the continuous paper 10, is supported so as to be displaceable in the thickness direction of the continuous paper 10, and has the image forming unit 200 and the fixing unit 4.
And a plate 310 that is urged to abut one surface of the continuous paper 10 passing through the transport path 600 during the period 00 and applies tension to the continuous paper 10 on the transport path 600. The continuous paper 1 generated due to a difference between the transport speed of the continuous paper 10 at the location of the image forming unit 200 and the transport speed of the continuous paper 10 at the location of the fixing unit 400 based on the amount.
It is configured to detect a slack amount of zero. Details of the configuration of the transport speed detecting unit 300 will be described later.

The fixing unit 400 is provided at a position downstream of the conveying speed detecting unit 300 in the conveying direction, extends in a direction perpendicular to the conveying direction of the continuous paper 10, and fixes the upper and lower surfaces of the sheet to each other. The heat roller 410 and the press roller 420 are provided so as to be sandwiched between the rollers. Heat roller 410
Inside, a halogen lamp 412 as a heat source is provided extending in the axial direction of the heat roller 410. At both ends of the shaft of the press roller 420, the press roller 42
A pressing mechanism 430 for pressing the outer peripheral surface of the heat roller 410 to the outer peripheral surface of the heat roller 410 is provided. A guide plate 450 for guiding the continuous paper 10 to the press contact point 440 is provided upstream of the press contact point 440 between the press roller 420 and the heat roller 410 in the transport direction. Are arranged so as to extend in a direction orthogonal to the transport direction. The continuous paper 10 is fixed to the fixing unit 4.
00, the pressure contact point 44 of the press roller 420
At the time of passing through 0, a conveying force is applied by the heat roller 410 that is driven to rotate.

The paper discharge unit 500 is disposed at a position downstream of the fixing unit 400 in the transport direction, extends in a direction perpendicular to the transport direction of the continuous paper 10, and is driven to rotate by a discharge roller 502.
And a discharge roller 504 rotatably supported and pressed against the discharge roller 502. The continuous paper 10 is provided with a conveying force toward the downstream side in the conveying direction by passing through the press-contact portions of the rotating discharge rollers 502 and 504, and is discharged from a discharge port (not shown).

Next, with reference to FIGS. 2 and 3, the configurations of the transport speed detecting unit 300 and the fixing unit 400 will be described in detail. The transport speed detection unit 300 includes a plate 310 (corresponding to a displacement member in the claims), a swing arm 315, a biasing unit 320, and transmission optical sensors 330A and 330B (corresponding to a displacement amount detection unit in the claims). ), A cam 340 and the like.

The plate 310 is formed of a plate-like member extending in a direction perpendicular to the direction of transport of the continuous paper 10 and having an L-shaped cross section. The plate 310 has an upper plate 312 that is wide in the direction perpendicular to the longitudinal direction and faces the lower surface of the continuous paper 10 and a lower plate 314 that is narrow in the direction perpendicular to the longitudinal direction and is not facing the lower surface of the continuous paper 10. are doing. On the upper plate 312, a slope 312D1 is formed at a side edge 312D on the opposite side to the portion connected to the lower plate 314, the slope being inclined downward toward the side edge. From both longitudinal edges of the upper plate 312, bent pieces 312A are erected downward, and bearing holes 312B are formed through these two bent pieces 312A, respectively. In these two bearing holes 312B, two support shafts fixed to a portion of the frame 1000 erected from the bottom of the image forming apparatus erected at a position sandwiching the plate 310 at both ends in its extending direction. 312C are inserted respectively,
The plate 310 is swingably supported by a support shaft 312C.

The lower plate 314 and the support shaft 312 are located at a position near one end of the lower plate 314 in the longitudinal direction.
A detection plate 314A extending in a direction orthogonal to C is provided upright toward the downstream side in the transport direction. Below the detection plate 314A, a mounting portion 1006 fixed to the standing piece 1004 of the bottom frame 1002 of the image forming apparatus and extending in the horizontal direction is arranged at a distance from the detection plate 314A. I have. In the mounting portion 1006, transmission type optical sensors 330A and 330B for detecting the swinging position of the sensing end 314A1 extending downward from the sensing plate 314A are provided at different positions in the swinging direction of the sensing piece 314A. Installed.

A mounting piece 1006A is erected from a side edge near the center of the plate 310 in the longitudinal direction of the mounting portion 1006, and a support shaft 315C extending in a direction parallel to the shaft 312C is mounted on the mounting piece 1006A. The upper part 315A of the swing arm 315 is rotatably supported by the support shaft 315C. And this swing arm 3
A biasing means comprising a coil spring is provided between a hole 315B provided at a lower portion of the lower plate 15 and a hole 314B provided at a position slightly closer to one end than the center in the longitudinal direction of the lower plate 314. 320 are stretched.

Both ends of a cam drive shaft 340A extending in a direction parallel to the support shaft 315C are rotatably supported on the frame 1000, and the cam 340 is fixed to an intermediate portion of the cam drive shaft 340A. . A cam surface 340B is provided on the outer peripheral surface of the cam 340 and abuts against the outer peripheral surface of a columnar post 315D protruding from one surface of the swing arm 315. The cam surface 340B is moved from the cam drive shaft 340A. Is changed along the circumferential direction of the cam drive shaft 340A.

A gear 340C is fixed to one end of the cam drive shaft 340A at a position outside the frame 1000. The gear 340C is connected to a cam drive motor 722 (FIG. 1) via a gear train (not shown). The rotation driving force from 4) is transmitted. According to the above configuration,
A biasing means 320 is stretched between the hole 315B of the swing arm 315 and the hole 314B of the lower plate 314 of the plate 310. Therefore, in FIG. 2, the plate 310 is urged clockwise about the support shaft 312C by the urging means 320, and the swing arm 315 is rotated.
Is urged in a counterclockwise direction (corresponding to one swing direction in the claims) around the support shaft 315C.

For this reason, the swing arm 315 moves the post 31 of the swing arm 315 by the urging force of the urging means 320.
5D contacts the cam surface 340B of the cam 340 provided in the counterclockwise direction of the swing arm 315, whereby the swing limit position of the swing arm 315 in the counterclockwise direction is regulated. That is, the swing arm 315 and the cam 340
This constitutes a swing limit position setting means for regulating the swing limit position of the swing arm 315 in one swing direction.

Then, the cam drive shaft 340A rotates and the cam surface 34 with which the post 315D of the swing arm 315 abuts.
By changing the position of 0B, the swing limit position of the swing arm 315 is adjusted between the first swing position shown by the solid line in FIG. 2 and the second swing position shown by the two-dot chain line. I have. When the swing arm 315 swings between the first and second swing positions about the support shaft 315C, the swing arm 315
Hole 315B and the lower plate 31 of the plate 310
4, the distance from the hole 314B changes, and the urging force of the urging means 320 changes. For example, if the swing arm 315 is in the first swing position, the distance between the hole 315B of the swing arm 315 and the hole 314B of the lower plate 314 of the plate 310 increases, and the urging means 320 is deformed in the extension direction. By doing so, the biasing force becomes stronger. On the other hand, the swing arm 315
Is in the second swing position, the hole 31 of the swing arm 315
5B and the hole 3 in the lower plate 314 of the plate 310
As the distance from the urging means 14B is reduced and the urging means 320 is deformed in the shortening direction, the urging force becomes weak.

For this reason, the biasing force acting on the plate 310 in the clockwise direction about the support shaft 312C increases and decreases,
The tension applied to the continuous paper 10 that the side edge 312D of the upper plate 312 contacts with the upper plate 312 increases or decreases. Then, the control unit 710 in FIG. 4 described later controls the cam drive motor 722 to change the rotational position of the cam 440 and change the rotational position of the cam 440 to the side edge 312 of the upper plate 312 of the plate 310.
The tension applied to the continuous paper 10 by D is increased or decreased. Details of this operation will be described later.

According to the above configuration, the image forming section 2
If the continuous paper 10 slacks too much on the conveyance path 600 between the fixing unit 400 and the fixing unit 400, the plate 310
The detection plate 314A swings clockwise around the center C.
In the detection end 314A1, the transmission type optical sensor 330A is turned on (detection light transmission state), and the transmission type optical sensor 330B
Is turned off (the detection light is not transmitted). Further, the transport path 60 between the image forming unit 200 and the fixing unit 400
If the continuous paper 10 is too tense on the
10 swings counterclockwise around the support shaft 312C, the detection end 314A1 of the detection plate 314A turns off the transmission type optical sensor 330A (detection light non-transmission state) and turns the transmission type optical sensor 330B on. Move so as to be on (detection light transmission state). Further, the image forming unit 200 and the fixing unit 40
When the continuous paper 10 is in a proper tension state on the conveyance path 600 during the period 0, the plate 310 is swung to a position intermediate between the two states, and the detection end 314 of the detection plate 314A is detected.
A1 is held at a position where both of the transmission optical sensors 330A and 330B are turned off (the detection light is not transmitted).

Then, a control unit 710 in FIG.
By controlling the rotation speed of the heat roller 410 of the fixing unit 400 described below based on the detection operation of the transmission optical sensors 330A and 330B, the continuous paper 10 on the conveyance path 600 between the image forming unit 200 and the fixing unit 400 is controlled. The slack amount is set to be within a predetermined range. Details of this operation will be described later.

The fixing section 400 includes a heat roller 410 and a press roller 420. Press roller 420
Is configured to be pressed against the heat roller 410 by the pressing mechanism 430. Inside the heat roller 410, two halogen lamps 412 constituting a heater are provided.
A and 412B are disposed in a state of extending in the axial direction of the heat roller 410. A gear 414 is provided at an end of the heat roller 410, and the gear 414 has a frame 101 erected from the bottom frame 1002.
Gear 416 rotatably supported between 0, 1012
A and a rotary drive force from a motor (not shown) are transmitted through a gear train including 416B. Inside the press roller 420, a shaft 422 extending in the axial direction of the press roller 420 is provided so as to penetrate therethrough. The shaft 422 is supported by bearings 420 provided at both ends of the press roller 420. The press roller 420 is rotatably supported on the shaft 422.

The pressing mechanism 430 includes a swing plate 432, a biasing member 434, and a locking portion 436. Rocking plate 432
The recess 432 </ b> A is disposed opposite to a position sandwiching both ends of the press roller 420 and abuts and supports the outer peripheral surface of the shaft 422 protruding from both ends of the press roller 420.
have. A support shaft 432B extending in a direction parallel to the support shaft 422 protrudes from a frame 1008 erected on the opposite side to the press roller 420 with each swing plate 432 interposed therebetween. 432B corresponds to each rocking plate 43
Each of the rocking plates 432 is inserted into a bearing hole 432 </ b> C provided at a position near the transport speed detecting unit 300 on the upper part of the second plate 2.
Are swingably supported in a plane orthogonal to the shaft 422 of the press roller 420.

Further, a bearing hole 432 at the upper part of the rocking plate 432 is provided.
A rectangular notch is formed at a location opposite to C.
The frame 1008 includes an upper edge 43 of the rectangular cutout.
A stopper 432E is provided at a position where it comes into contact with the 2D, and regulates the swing range of the swing plate 432. Rocking plate 4
The engagement piece 432F is provided at a position below the 32 bearing holes 432C.
Extends downward.

The frame 1003 fixed to the bottom frame 1002 at a distance from the bottom frame 1002 is provided with a locking portion 436 at a distance from the locking piece 432F. The locking portion 436 includes a fixing plate 436A fixed to the frame 1003, and a screw portion 436B that is screwed to the fixing plate 436A and rotated to move in a direction of coming and coming from the locking piece 432F. ing. An urging member 434 composed of a coil spring is stretched between the locking piece 432F and the screw portion 436B of the locking portion 436. Therefore, the swinging plate 432 is provided with the urging member 434.
Thus, the pressure roller 420 is urged to swing upward around the support shaft 432B, that is, in a direction in which the press roller 420 is pressed against the heat roller 410. Then, by rotating the screw portion 436B, the screw portion 436B is rotated.
The distance between the locking member 432F and the urging member 434 is adjusted.
Is configured to be able to adjust the urging force.

Next, the configuration of the control circuit will be described with reference to the block diagram of FIG. The control circuit 700 includes the control unit 7
10, a cam motor drive unit 720, a transport motor drive unit 730, a print control unit 740, an operation input unit 750, and the like. The control unit 710 is configured by a microcomputer or the like, and includes a CPU 712, a ROM 714 storing a control program for the CPU, a RAM 716 providing a working area, an interface unit 718 for transmitting and receiving signals to and from each unit described below, and the like. ing. The interface unit 718 includes the transmission type optical sensor 33.
0A and 330B, and these transmission-type optical sensors 33
In addition to inputting the detection signals input from 0A and 330B, it is connected to the cam motor driving means 720, the transport motor driving means 730, and the printing control means 740, and is configured to output control signals to these. Further, it is configured to input an operation signal input from the operation input unit 750.

The cam motor driving means 720 controls the rotation of a cam driving motor 722 for applying a rotational driving force to the cam driving shaft 340A. Transport motor driving means 73
Numeral 0 controls the driving of a plurality of motors (not shown) that apply a driving force for transporting the continuous paper 10 to the tractor 100, the photosensitive drum 210, the heat roller 410, and the paper discharge unit 500. The control unit 710 is configured to control the transport motor driving unit 730 to individually control the transport speed of continuous paper by the tractor 100, the photosensitive drum 210, the heat roller 410, and the paper discharge unit 500. ing. The print control unit 740 includes the image forming unit 200
To control the operation related to image formation by. The operation input unit 750 includes, for example, an operation input panel provided in the image forming apparatus. The operation input unit 750 generates an operation signal based on an operation for specifying the thickness of the continuous paper and outputs the operation signal to the interface unit 718 as described later. It is configured to be.

Next, the operation of adjusting the urging force on the plate 310 by the transport speed detecting unit 300 will be described with reference to FIGS. First, the operation input unit 750
Then, the thickness of the continuous paper 10 is specified and input. To specify the thickness, for example, one of two stages of thick mouth and thin mouth is selected and input. The operation input unit 750 generates an operation signal corresponding to the specified thickness and inputs the generated operation signal to the control unit 710 via the interface unit 718. The control unit 710 drives the cam motor 722 by controlling the cam motor driving means 720 based on the input operation signal, and the cam driving shaft 34
OA is rotated by a predetermined amount to rotate the cam 340 to a predetermined position.

When the operation signal input to the control unit 710 corresponds to the thick mouth, the control unit 710 controls the swing arm 315 to swing to the first swing position shown by the solid line in FIG. Next, the rotation of the cam 340 is controlled. Therefore, the urging force applied to the plate 310 by the urging means 320 is strong, and the tension applied to the continuous paper 10 from the plate 310 is set to be strong. On the other hand, the control unit 710
When the operation signal input thereto corresponds to a thin mouth, the rotation of the cam 340 is adjusted so that the swing arm 315 is swung to the second swing position shown by the solid line in FIG. Control. Therefore, the urging force applied to the plate 310 by the urging means 320 is weak, and the tension applied to the continuous paper 10 from the plate 310 is set to be weak.

Therefore, when the thickness of the continuous paper 10 is small, the tension applied from the plate 310 to the continuous paper 10 becomes weaker, so that the feed hole of the continuous paper 10 comes off from the tractor 100 while the continuous paper 10 is being conveyed. Transport failure is prevented. When the thickness of the continuous paper 10 is large, the tension applied from the plate 310 to the continuous paper 10 is increased.
10 is prevented from fluttering. That is, continuous paper 1
0 to the continuous paper 10 by the plate 310 corresponding to the thickness of
Can be set to an appropriate value.

The adjustment of the biasing force by the biasing means 320 is not limited to the two steps described above, but is performed by the cam 340.
Of course, by adjusting the rotational position of the continuous paper 10, it is possible to adjust the continuous paper 10 according to the thickness of the continuous paper 10 to be used. The applied tension can be set in multiple stages.

In the first embodiment described above, the biasing force setting means for setting the biasing force of the biasing means 320 to different stages by the swinging position setting means constituted by the swinging arm 315 and the cam 340 is provided. It is configured. The urging force setting means and the urging means 320 constitute a tension setting mechanism for setting the tension applied to the continuous paper 10 at different stages.

Next, with reference to FIG. 2, FIG. 3, and FIG. 4, a description will be given of the control operation of the continuous paper transport speed performed based on the detection operation of the transmission optical sensors 330A and 330B. The control unit 710 controls the rotation speed of the heat roller 410 of the fixing unit 400 as described below, so that the amount of slack of the continuous paper 10 on the transport path 600 between the image forming unit 200 and the fixing unit 400 is predetermined. It is within the range. That is, when the continuous paper 10 is excessively slack and the transmission type optical sensor 330A is turned on and the transmission type optical sensor 330B is turned off, the control unit 710 controls the transport motor driving unit 7
30, the rotation speed of the heat roller 410 of the fixing unit 400 is increased, and the heat roller 410 is rotated.
Is increased in comparison with the transport speed (corresponding to the rotation speed of the photosensitive drum 210) at the location of the image forming unit 200, thereby removing excess slack of the continuous paper 10 and returning the continuous paper 10 to an appropriate tension state. Conversely, if the continuous paper 10 is too tense and the transmission optical sensor 330A is turned off and the transmission optical sensor 330B is turned on, the control unit 710
Controls the transport motor driving unit 730 to reduce the rotation speed of the heat roller 410 of the fixing unit 400 and reduce the transport speed at the location of the heat roller 410 to the transport speed at the location of the image forming unit 200 (the photosensitive drum 210 (Corresponding to the rotation speed of the continuous paper 10), the excessive tension of the continuous paper 10 is relaxed to return to an appropriate tension state.

As described above, the tension applied from the plate 310 to the continuous paper 10 in accordance with the thickness of the continuous paper 10 is set to an appropriate value corresponding to the thickness of the continuous paper 10.
Even if the thickness of the continuous paper 10 is large, the plate 310
The fixing unit 40 does not flutter at the position of the zero perforation.
Control of the transport speed of the continuous paper 10 by 0 can be stably performed. Further, since the continuous paper 10 does not flutter, it is possible to prevent the occurrence of skew in which the transport direction of the continuous paper is inclined. In addition, the transmission type optical sensors 330A and 330B
The control unit 710 that controls the transport speed at the location of the heat roller 410 based on the on / off operation of the image forming unit 200 constitutes the transport speed adjusting means in the claims.

Next, a second embodiment will be described with reference to FIGS. FIG. 5 is a front view illustrating the configuration of a fixing unit, a sheet conveyance speed detecting unit, and a paper discharging unit of the image forming apparatus according to the second embodiment. FIG. 6 is a diagram illustrating a control circuit of the image forming apparatus according to the second embodiment. FIG. 3 is a block diagram illustrating a configuration. 5 and 6 showing the first embodiment,
The same parts as those in FIG. 4 are denoted by the same reference numerals, and description thereof will be omitted. As shown in FIG. 5, in the second embodiment, a solenoid 316 is used to set the urging force of the urging member 320 connected to the plate 310 at different stages. The solenoid 316 is connected to the solenoid body 316.
A and a rod 316B. The solenoid body 316A is fixed to the frame 1004 and the mounting portion 1
Mounting portion 1006 extending vertically downward from the edge of 006
It is attached to A. One end of the urging means 320 is connected to the hole 316B1 formed at the tip of the rod 316B.

When a current is supplied to the solenoid main body 316A by the solenoid driving means 725 shown in FIG. 6 to operate it, the rod 316B is attracted by the solenoid main body 316A and is located at the first position shown by a solid line in FIG. When the supply of current to the solenoid is stopped and becomes inactive, the rod 316B is projected outward by the urging force of the urging member incorporated in the solenoid main body 316A so that the rod 316B is located at the second position indicated by the two-dot chain line in FIG. Is configured.

As shown in FIG. 6, the solenoid driving means 7
25 controls the operation of the solenoid 316 based on a control signal from the interface unit 718. Therefore, as in the case of the first embodiment, the operation input means 7
When the thickness of the continuous paper 10 is specified from 50 and input to the control unit 710, the control unit 710
By controlling the solenoid 25 to activate and deactivate the solenoid 316, the rod 316B is positioned at the first and second positions. When the rod 316B is located at the first and second positions, the distance between the hole 316B1 of the rod 316B and the hole 314B of the lower plate 314 of the plate 310 changes, and the urging force of the urging means 320 changes. That is, the rod 31
6B is in the first position, the rod 316
The distance between the hole 316B1 of B and the hole 314B of the lower plate 314 of the plate 310 increases, and the urging means 320
Is deformed in the extension direction, the urging force applied by the urging means 320 to the plate 310 becomes strong, and the plate 3
The tension applied to the continuous paper 10 from 10 becomes stronger. On the other hand, when the rod 316B is located at the second position, the hole 316B1 of the rod 316B and the plate 31
0, the distance between the lower plate 314 and the hole 314B is reduced, and the urging means 320 is deformed in the shortening direction, so that the urging force given to the plate 310 by the urging means 320 becomes weak. The applied tension is weaker.

Therefore, also in the second embodiment, the tension applied to the continuous paper 10 by the side edge 312D of the upper plate 312 of the plate 310 can be increased or decreased by operating or not operating the solenoid 316. Thus, the same operation and effect as those of the first embodiment can be obtained. In the second embodiment, the plate 310
Of tension applied to the continuous paper 10 from the solenoid 31
6 is limited to two stages corresponding to the operation and non-operation of the first embodiment, but only the solenoid 316 is required for adjusting the urging force of the urging means 320, and the number of parts is the same as that of the first embodiment. There is an advantage that the manufacturing cost is low and the manufacturing cost is low. In the second embodiment, an urging force setting unit that sets the urging force of the urging unit 320 to a different stage by the solenoid 316 is configured. And
The continuous paper 1 is set by the urging force setting means and the urging means 320.
A tension setting mechanism for setting the tension applied to 0 to different stages is configured.

Next, a third embodiment will be described with reference to FIGS. FIG. 7 is a front view illustrating a configuration of a fixing unit, a sheet conveying speed detecting unit, and a sheet discharging unit of the image forming apparatus according to the third embodiment, and FIG. 8 is a plan view as viewed in the direction of arrow B in FIG. 7 and 8, the same parts as those in FIGS. 2 and 3 showing the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

First, the configuration of the image forming apparatus according to the second embodiment, which is different from that of the first embodiment, will be described with reference to FIGS. As shown in FIGS. 7 and 8, in the third embodiment, the swing arm 370 is swung by rotating the cam 360 by the rotational driving force of the operation knob 356 that is manually rotated, thereby causing the plate 310 to move. The configuration is such that the urging force of the connected urging member 320 is set at different stages.

A cam drive shaft 350 extending in a direction parallel to the width direction of the continuous paper 10 extends between the mounting portion 1006A and the frame 1000. Cam drive shaft 350
The bearing hole 3 is provided in the mounting portion 1006A and the frame 1000 at one end 350A and the other end 350B.
52 and 354 are rotatably supported. An operation knob 356 is fixed to a portion 350C of the other end 350B that extends to the outside of the frame 1000. A cam 360 is fixed to one end portion 350A of the cam drive shaft 350, and an outer peripheral surface of the cam 360 has a cam surface 36 which contacts an upper edge 370A of a swing arm 370 described later.
0A is provided, and the cam surface 360A is configured such that the radial distance from the cam drive shaft 350 changes along the circumferential direction of the cam drive shaft 350.

A support shaft 372 extending in a direction parallel to the cam drive shaft 350 protrudes from the mounting portion 1006A. The support shaft 372 is inserted into a hole 370B provided at one end of the swing arm 370. And the swing arm 370 is connected to the support shaft 37.
2 for swinging support. Swing arm 37
A hole 370C is provided at the other end of the zero, and one end of the urging means 320 is connected to the hole 370C.

According to the above configuration, the hole 370C of the swing arm 370 and the lower plate 314 of the plate 310
A biasing means 320 is stretched between the hole 314B and the hole 314B. Therefore, in FIG. 7, the plate 310 is urged clockwise about the support shaft 312C by the urging means 320, and the swing arm 370 is rotated counterclockwise about the support shaft 372 (claims). (Corresponding to one of the swing directions). Therefore, the swing arm 3
70 is the swing arm 3 by the urging force of the urging means 320.
The upper edge 370A of the abutment 70 comes into contact with the cam surface 360A of the cam 360 provided in the counterclockwise direction of the swing arm 370, whereby the swing limit position of the swing arm 370 in the counterclockwise direction is regulated. ing. That is, the swing arm 370 and the cam 360 constitute swing limit position setting means for regulating the swing limit position of the swing arm 370 in one swing direction.

Then, the cam drive shaft 350 rotates and the cam surface 360 against which the upper edge 370A of the swing arm 370 contacts.
By changing the position of A, the swing arm 370 is adjusted between a first swing position shown by a solid line in FIG. 7 and a second swing position shown by a two-dot chain line. Swing arm 3
When 70 swings about the support shaft 372 between the first and second swing positions, the distance between the hole 370C of the swing arm 370 and the hole 314B of the lower plate 314 of the plate 310 changes. The urging force of the urging means 320 changes. For example, if the swing arm 370 is at the first swing position, the distance between the hole 370C of the swing arm 370 and the hole 314B of the lower plate 314 of the plate 310 increases, and the urging means 320 is deformed in the extension direction. By doing so, the biasing force becomes stronger. On the other hand, if the swing arm 370 is at the second swing position, the hole 370C of the swing arm 370 and the plate 31
When the distance between the zero lower plate 314 and the hole 314B is reduced and the urging means 320 is deformed in the shortening direction, the urging force becomes weak.

For this reason, the clockwise urging force acting on the support shaft 312C acting on the plate 310 increases and decreases, and the tension applied to the continuous paper 10 by the side edge 312D of the upper plate 312 increases and decreases. become. Therefore, by rotating the operation knob 356 to position the swing arm 370 in the first and second swing positions, the tension applied to the continuous paper 10 by the side edge 312D of the upper plate 312 of the plate 310 is continuously increased. Paper thickness, material,
It can be increased or decreased according to the perforation or the like, and the same operation and effect as those of the first and second embodiments can be obtained.

The control circuit according to the third embodiment has a structure similar to that shown in FIGS. 4 and 6 showing the control circuits according to the first and second embodiments. And a cam motor driving means for driving the solenoid and the solenoid driving means. That is, the third embodiment has an advantage that the number of parts is small and the manufacturing cost is low as compared with the configurations of the first and second embodiments.

Also, in the third embodiment, similarly to the first embodiment, the adjustment of the biasing force by the biasing means 320 is not limited to the above-described two steps. It is needless to say that the rotational position can be adjusted in multiple stages by adjusting the rotational position. In this case, the tension applied to the continuous paper 10 is increased in accordance with the thickness, material, perforation, etc. of the continuous paper 10 to be used. Can be set in stages. In the third embodiment described above, the biasing force setting means for setting the biasing force of the biasing means 320 to different stages by the swinging position setting means constituted by the swinging arm 370 and the cam 360 is configured. I have. The urging force setting means and the urging means 320 constitute a tension setting mechanism for setting the tension applied to the continuous paper 10 at different stages.

[0049]

As is clear from the above description, the present invention
An image forming unit that draws a latent image on a photosensitive drum, develops the latent image with toner, and transfers the developed toner image from the photosensitive drum to continuous paper, and a fixing unit that fixes the toner image transferred to the continuous paper And a lower portion of the continuous paper that is supported to be displaceable in a thickness direction of the continuous paper at a position where the lower portion of the continuous paper passes through a conveyance path between the image forming unit and the fixing unit. A displacement member biased in a contacting direction,
Displacement amount detecting means for detecting a displacement amount of the displacement member, and a conveying speed of the continuous paper on a conveying path between the image forming unit and the fixing unit corresponding to the displacement amount detected by the displacement amount detecting unit And a conveyance speed adjusting means for adjusting the slack amount of the continuous paper on the conveyance path to be within a predetermined range, wherein the tension applied to the continuous paper by the displacement member is changed at different stages. The configuration was provided with a tension setting mechanism for setting. Therefore, by setting appropriate tension corresponding to the thickness, material, perforation, etc. of the continuous paper to the continuous paper by the displacement member, it is possible to prevent the continuous paper from being disturbed, and to prevent the continuous member from being disturbed. By accurately detecting the amount of slack in the continuous paper, the control of the transport speed can be stabilized.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating a main part of an image forming apparatus according to a first embodiment.

FIG. 2 is a front view illustrating a configuration of a fixing unit, a sheet conveying speed detecting unit, and a sheet discharging unit of the image forming apparatus according to the first embodiment.

FIG. 3 is a plan view showing a state in which FIG. 2 is viewed from an arrow A direction.

FIG. 4 is a block diagram illustrating a configuration of a control circuit of the image forming apparatus according to the first embodiment.

FIG. 5 is a front view illustrating a configuration of a fixing unit, a sheet conveying speed detecting unit, and a sheet discharging unit of the image forming apparatus according to the second embodiment.

FIG. 6 is a block diagram illustrating a configuration of a control circuit in an image forming apparatus according to a second embodiment.

FIG. 7 is a front view illustrating a configuration of a fixing unit, a sheet conveyance speed detecting unit, and a sheet discharging unit of an image forming apparatus according to a third embodiment.

FIG. 8 is a plan view as seen from the direction of arrow B in FIG. 7;

[Explanation of symbols]

Reference Signs List 10 continuous paper 200 image forming section 310 plate (displacement member) 315 swing arm 316 solenoid 320 biasing means 330A, 330B transmission type optical sensor (displacement amount detecting means) 340 cam 360 cam 370 swing arm 400 fixing section 410 heat roller 420 press roller 710 control unit (transport speed adjusting means)

Claims (16)

[Claims] An image forming section for drawing a latent image on a photosensitive drum, developing the latent image with toner, and transferring the developed toner image from the photosensitive drum to continuous paper; and a toner transferred to the continuous paper. A fixing section for fixing an image, and a continuous section in a state where the section is supported so as to be displaceable in a thickness direction of the continuous sheet at a position abutting on a lower surface of the continuous sheet passing through a conveyance path between the image forming section and the fixing section A displacement member urged in a direction in which the displacement member is in contact with the lower surface of the paper, a displacement amount detecting means for detecting a displacement amount of the displacement member, and the image forming corresponding to the displacement amount detected by the displacement amount detecting means An image forming apparatus comprising: a conveyance speed adjusting unit configured to adjust a conveyance speed of the continuous paper on a conveyance path between a fixing unit and the fixing unit so that a slack amount of the continuous paper on the conveyance path is within a predetermined range. The displacement section With a tension setting mechanism for setting the different stages of the tension applied to the continuous paper by, that the image forming apparatus according to claim. 2. The apparatus according to claim 1, wherein the displacement member is rotatably supported by a support shaft extending in a width direction of the continuous paper orthogonal to a transport direction of the continuous paper. Image forming device. 3. The tension setting mechanism includes: urging means for urging the displacement member; and urging force setting means for setting the urging force of the urging means to different stages. 2. The image forming apparatus according to 1. 4. The displacement member is rotatably supported by a support shaft extending in a width direction of the continuous paper orthogonal to a direction in which the continuous paper is conveyed. The image forming apparatus according to claim 3, wherein one end is connected. 5. The setting of the urging force of the urging means to different stages by the urging force setting means is performed by changing a distance between one end and the other end of the urging means. Item 5. The image forming apparatus according to Item 4. 6. The other end of the biasing means is connected to a swing arm provided to be swingable, and the swing arm is biased in one swing direction by the biasing means. A swinging position for limiting a limit swinging position of the swinging arm in the one swinging direction, the swinging arm being provided with a cam abutting on the swinging arm in one swinging direction of the swinging arm; 6. The image forming apparatus according to claim 5, wherein a setting unit is configured, and the urging force setting unit is configured by the swing position setting unit. 7. The cam has a cam surface in contact with the swing arm, and is configured such that a limit swing position of the swing arm is adjusted by rotation of the cam. The image forming apparatus according to claim 6. 8. The image forming apparatus according to claim 7, wherein the cam is rotated by a rotational driving force of a motor. 9. The image forming apparatus according to claim 7, wherein the rotation of the cam is performed by a rotational driving force of an operation knob rotated by a manual operation. 10. The urging force setting means includes a solenoid having a solenoid main body and a rod projecting into and out of the solenoid main body, and the other end of the urging means is connected to the rod. The image forming apparatus according to claim 5, wherein: 11. The fixing unit includes a heat roller extending in a width direction of the continuous paper and a press roller pressed against the heat roller. Configured to pass,
11. The method according to claim 1, wherein adjusting the transport speed of the continuous paper by the transport speed adjusting unit is performed by adjusting a rotation speed of the heat roller or the press roller. 12. Image forming device. 12. The image forming apparatus according to claim 1, wherein said urging means is constituted by a coil spring. 13. The continuous paper according to claim 1, wherein the continuous paper has a constant width, and feed holes are formed at regular intervals on both side edges in the width direction of the continuous paper. The image forming apparatus according to claim 1. 14. The continuous paper is formed of perforations and the like at predetermined lengths, and cut lines are formed for breaking the continuous paper to a predetermined length. The image forming apparatus as described in the above. 15. The paper according to claim 1, wherein, in addition to the normal high-quality paper used as the continuous paper, a bond paper, card paper, label paper, film or the like is used. Image forming device. 16. The apparatus according to claim 1, wherein the tension applied to the continuous paper by the displacement member is set to be adjusted in two or three or more stages.
The image forming apparatus according to claim 1.