JP3070187B2 - Image heating device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotating endless shape.
And the direction perpendicular to the direction of movement of this film
Deviation control means for controlling the deviation of the film toward the
Then, the image on the recording material is added by the heat from the film side.
The present invention relates to a heating device for heating an image .

[0002]

2. Description of the Related Art A heating apparatus of the above-mentioned film heating type is known from Japanese Patent Application Laid-Open No. 63-313182, and is an image heating and fixing apparatus in an image forming apparatus such as an electrophotographic copying machine, a printer and a facsimile. That is, electrophotography
Indirectly to the surface of recording material (transfer material sheet, electrostatic recording sheet, electrofax sheet, printing paper, etc.) using toner made of resin which can be heated and melted by image forming process means such as electrostatic recording and magnetic recording. It can be used as an image heating / fixing apparatus that heats and fixes an unfixed visible image (toner image) corresponding to target image information as a fixed image on a recording material carrying the image, which is formed by a (transfer) method or a direct method. . Further, for example, it can be used as a device for heating a recording material carrying an image to improve the surface properties such as gloss, or a device for performing a temporary deposition process.

[0003] As for the film heating type fixing device, in comparison with other heat fixing type devices such as a heat roller type, a hot plate type, a flash fixing type and an oven fixing type. Since a low heat capacity linear heating element can be used as the heating element, and a thin film having a thickness of, for example, about 40 μm can be used as the heating element, the rise time to a predetermined fixing temperature can be reduced, and power can be saved. Since the fixing point and the separation point between the film and the recording material can be set separately, toner offset can be prevented, and other advantages such as solving various drawbacks of other system devices can be solved, which is effective. .

[0004] As described above, an endless type film can be used to rotate and drive the film to be used repeatedly, or an endless roll-wound film can be used by running out. it can.

[0005] In a film heating type heating device using an endless type film, the film moves and moves in the width direction (direction perpendicular to the film rotation direction) during the rotation driving process of the film. Actions are taken to restrict movement.

[0006] The cause of the film misalignment is the parallelism and twist of two or more rollers that apply tension to the film. However, there is a limit to improving these accuracy. It is very difficult to prevent the film from shifting.

For this reason, at least one of a plurality of rollers that apply tension to the endless film is formed into a crank shape, or the end of the endless film is restricted by attaching a brim to both ends of the roller. However, when the film is a thin film and the material is polyimide or the like having low elasticity, it is difficult to control the shift of the film, and it is difficult to secure the stable rotation and transportability of the film.

In view of the above, a means for detecting the shift position of the film is provided, and when it is detected that the shift to one side in the width direction of the film has reached a predetermined limit position, the shift of the film in the return direction is detected. Activating the means for displacing the film suspension conveyance roller so as to change to the other side in the film width direction, and when it is detected that the shift of the film to the other side in the width direction has reached the predetermined limit position, By providing a film shift control mechanism configured to actuate a means for displacing the film suspension transport roller so as to change the film shift to one side in the film width direction that is the return direction, the rotation drive of the endless film In the process, a shift movement control process is performed in which the shift movement in the film width direction is controlled by reciprocating infinitely within a predetermined range.

[0009]

However, a heating device of the film heating type using an endless film provided with the above-mentioned film shift movement control mechanism also has a film shift control instability due to a temperature factor or durability change. is there.

In other words, the above-mentioned shift control means switches the shift direction of the film between the forward and reverse directions under certain conditions, and in the initial state, the reciprocation of the shift is guaranteed by a certain degree of component accuracy or initial adjustment. However, when some external condition is applied, the film does not shift in a predetermined direction even if the conveying means is displaced. In other words, when the film runs backward or moves rapidly at a rapid speed, stable running of the film cannot be realized, for example, skewing of the recording material and wrinkling of the film occur.

As the above-mentioned external conditions, the influence on heat is the most important, and it is not necessary to consider an extreme temperature difference in general film conveyance. In this state, the temperature of each component rises to about 150 ° C. to 200 ° C. The rise in temperature naturally changes (generally reduces) the friction coefficient of the conveying means and the surface of the heating element, and the initial reciprocating reciprocation condition may be lost.

In addition, there is a temperature distribution in the heating element itself, the size of the recording material to be passed, and the temperature rise of the non-sheet passing portion based on one side. When the transfer means is heated, the transfer means also has a temperature gradient, causing a difference in thermal expansion in the longitudinal direction, and as a result, a shift due to a transfer speed difference.

[0013] Further, due to the durability, the friction coefficient changes due to wear of the inner surface of the film, the conveying means, and the surface of the heating element.

Further, in the film heating type fixing device, since the film is conveyed while rubbing the fixedly supported low heat capacity heating element, fluorine-based heat-resistant grease is applied to the film for the purpose of preventing vibration at the rubbing portion and reducing torque. The inner surface may be lubricated. In this case, since the grease viscosity has temperature dependency, and the grace application state after the initial and after the durability changes, this also causes a change in the film deviation condition, which affects the deviation control described above. Become.

The present invention is to solve the above problems. That is, by providing a means for adjusting a change in the film shift speed due to a change in the size of the material to be heated passed through the apparatus, a stable film shift control and a film transporter capable of constantly transporting the film are provided. The purpose is to provide.

[0016]

According to the present invention, there is provided an image heating apparatus having the following constitution.

A rotating endless film, and
Film shift in the direction perpendicular to the direction of film movement
Deviation control means for controlling the
Image heating device that heats the image on the recording material
There are, in the direction orthogonal to the moving direction of the film
A detecting means for detecting the width of the recording material;
Of the film by the shift control means according to the detection width of
An image heating apparatus characterized by controlling a shift speed.

<Operation> That is, the detection width from the detection means for detecting the width of the recording material
The film shift speed is controlled according to the width of the recording material, even if the size of the introduced recording material changes and the film shift speed changes .
Rukoto can be enabled the stable nearest Ri control.

Further, since the amount of displacement can be set according to the situation, excessive stress is not applied to the film, and film damage can be minimized.

The present invention can be easily implemented without increasing the size and complexity of the structure as the film deviation control means, and is a very effective means for stably transporting a thin film in a film heating type heating device.

[0021]

【Example】

<First Embodiment> (FIGS. 1 to 13) FIG. 1 is a partially omitted plan view of an example of a heating device according to the present invention, FIG.
Is a perspective view, and FIG. 4 is a schematic configuration diagram of an example of an image forming apparatus in which the heating device is incorporated as a fixing device.

(A) Configuration of Example of Image Forming Apparatus (FIG. 4) The image forming apparatus shown in FIG. 4 is an electrophotographic copying machine of a platen reciprocating type, a rotating drum type, and a transfer type.・ Since the image forming process and the like belong to the public domain, only a brief explanation will be given.

Reference numeral 52 denotes a reciprocating original table glass disposed on the upper plate 51 of the copier housing 50, which is driven to reciprocate in the left and right directions by a drive mechanism (not shown). The original 53 is placed at a predetermined position on the upper surface of the original platen glass 52 with the image surface to be copied facing downward, and is held down by the original pressing plate 54 and set.

The downward image surface of the set original 53 undergoes slit illumination scanning by sequentially passing through the illuminating section 55 during the forward or backward movement of the original table glass 52. Reference numeral 56 denotes an illumination light source.

The downward illumination of the slit illumination light reflected from the original surface is sequentially imaged and exposed on an image forming lens (short focus imaging element array) 57 on the surface of a photosensitive drum 58 which rotates synchronously with the scanning of the original image.

The photosensitive drum 58 is subjected to a uniform charging process, positive or negative, by the discharger 59 and then subjected to the above-mentioned image forming exposure, so that an electrostatic latent image corresponding to the original image is sequentially formed on the peripheral surface of the drum. Is formed.

Next, the photosensitive drum 58 on which the latent image is formed
The surface sequentially passes the position of the developing device 60 and undergoes sequential development of the latent image. The developed image on the surface of the photosensitive drum 58 reaches the transfer discharger 61 by the subsequent rotation of the photosensitive drum.

On the other hand, the transfer material P
Is fed into the copying machine by the paper feed roller 63, and the leading end is received at the nip portion of the registration roller pair 64 which is in a rotation stopped state at that time. Here, the photosensitive drum 5
The rotation of the registration roller pair 64 is started at a predetermined timing synchronized with the rotation of the rotation of the transfer roller 8, whereby the transfer material P is guided by the guide member and fed toward the photosensitive drum 58, and is transferred to the photosensitive drum 58. The developing image on the surface of the photosensitive drum 58 is sequentially transferred onto the transfer material P by being introduced into the transfer section between the discharge units 61 for use.

The copy material P having received the image transfer is a photosensitive drum 58
The transfer device 6 is sequentially separated from the surface by a separation unit (not shown).
5, the image is introduced into the fixing device 1, and the image is fixed.
It is discharged to 7.

After the image is transferred, the surface of the photosensitive drum 58 is cleaned by a cleaning device 68 and repeatedly used for image formation.

(B) Fixing device 1 (FIGS. 1 to 3) Reference numerals 13 and 12 denote a pair of left and right endless film drive rollers disposed substantially in parallel with each other, and a driven roller also serving as a tension roller. An endless film stretched and stretched between 12, and the drive roller 13 is driven to rotate clockwise as shown by an arrow a by a drive system (not shown) including a drive motor 27 (FIG. 2); It is rotationally driven at a predetermined peripheral speed in a clockwise direction. 22
FIG. 1 shows a compression spring that biases the driven roller 12 as a tension roller.

The film 11 is a heat-resistant film having a total thickness of 100 μm, more preferably less than 40 μm. In this embodiment, an endless film having a thickness of about 20 μm such as polyimide, polyetherimide, PES, PFA or the like as a base film and a release layer of PTFE or the like coated on the image contact surface by about 10 μm.

Reference numeral 14 denotes a heating element fixedly disposed (fixed and supported by a fixing device) on the inner surface of the descending film portion of the endless film 11 described above. This heating element is a film 11
Is a low-heat-capacity linear heating element (hereinafter, referred to as a heater) having a length in the direction intersecting the surface movement direction, that is, the film width direction, and generates heat when energized.

Reference numeral 15 denotes a pressure roller having a rubber elastic layer of silicone rubber or the like having good releasability, and a biasing portion (not shown) sandwiching the film portion on the lower side of the endless film 11 between the heater 14 and the pressure roller. By means, for example, total pressure 4-5kg
, And rotates in the film moving direction in the forward direction at the same peripheral speed as the film speed as the film moves.

The transfer material P carried on the upper surface of the unfixed toner image t (heat-fusible toner) conveyed from the transfer unit 61 (FIG. 4) to the fixing device 1 by the conveyance device 65 with the endless film 11 interposed therebetween. The unfixed image surface enters between the film 11 and the pressure roller 15 of the pressure contact portion (fixing nip portion) N formed by the heater 14 and the pressure roller 15 so that the unfixed image surface becomes the transfer material P.
At a speed substantially the same as the transport speed of the film 11, and passes through the fixing nip N while receiving the clamping pressure in a state of being overlapped with the film 11 in a plane moving state in the same direction. In this process, the toner image bearing surface of the transfer material P is heated by receiving the heat of the heater 14 via the film 11, and the toner image t is completely softened and melted at least in the surface layer portion, and is thermally fixed to the transfer material P surface. . The transfer material P that has passed through the fixing nip portion N is separated from the surface of the film 11 at the curvature of the film 11 along the roller 13 when the transfer material P passes through the position of the film drive roller 13.

(C) Film shift control mechanism (FIG. 1)
FIG. 3) The drive roller 13 and the driven roller 12 of the endless film 11 are disposed between the front side plate 19 and the rear side plate 18 of the fixing device 1 as shown in FIG. 21
Reference numeral 20 denotes a front end bearing and a rear end bearing of the driven roller 12.

Here, the driving roller 13, the driven roller 12,
The parallelism of the heater 14 and the pressure roller 15 (X-axis direction,
When the drive roller 13 is driven (Y-axis direction, Z-axis direction) to rotate the film 11 in the direction indicated by the arrow a, the film 11 is rotated by the rollers 13 and 12 and the heater Due to the positional relationship of the three members (variation in each direction of the X, Y, and Z axes), the initial position of the film 11 indicated by the solid line in FIG. A shift occurs to the rear side direction C) or to the left side (front side direction B of the apparatus), so that the end of the film rubs against the side plate 18 or the side plate 19 and is damaged.

In this embodiment, the bearing 21 on the front side of the driven roller 12 has a degree of freedom of movement in the vertical direction indicated by arrows P and Q in FIG. The degree of parallelism of the driven roller 12 with respect to the driving roller 13 can be changed by vertically moving P · Q by a fork arm 24 that is directly driven to vertically swing and rotate by 23.

When the stepping motor 23 rotates clockwise, that is, when the arm 24 rotates clockwise U, the front end of the driven roller 12 is displaced in the direction of arrow P. When the front end of the driven roller 12 is lifted in the direction indicated by the arrow P, the film 11 is set to shift in the direction indicated by the arrow B on the front side. Conversely, the stepping motor 23 rotates counterclockwise,
Is rotated in the counterclockwise direction D, so that the front end of the driven roller 12 is lowered, so that the film 11 is shifted in the direction of the arrow C on the back side.

In this embodiment, the stepping motor 23 is rotated clockwise in accordance with the output of a transfer material size detecting means, which will be described later, which detects the size of the transfer material as the material to be heated introduced into the apparatus. So that the film 11 is set so as to be closer to the front side of the apparatus in FIG. 1, and conversely, the stepping motor 23 is rotated counterclockwise to lower the driven roller 12 downward. Thus, the film 11 is set so as to approach the back side of the apparatus. At this time, by controlling the number of drive pulses applied to the stepping motor 23, the amount of inclination of the driven roller 12 can be changed, and the speed of the endless film 11 can be varied.

Reference numeral 16 denotes a photosensor for detecting the position of the shift of the film. 1 and 3
As shown in the figure, the front end 3 of the film 11 (shaded portion)
Is masked so as to block the light of the photo sensor 16 around the entire edge.

In this embodiment, a photo-interrupter is used for the photosensor 16. However, when a reflection-type photosensor is used here, the end 3 of the film 11 is treated with a reflection member that reflects light. is necessary. Alternatively, the position of the film may be read by a photo sensor via a movable piece that moves along the edge of the film 11.

In this embodiment, the processing such as masking is performed only on one end of the film 11, but it goes without saying that the processing may be performed on the entire film.

Reference numeral 4 denotes a cleaning member for the film end portion 3. The film end portion 3 is always cleaned so as to prevent erroneous reading when a reflection type sensor is used, for example, due to contamination of the film end portion. Is what you are doing. In the present embodiment, felt is used, but any type may be used as long as it has a cleaning effect.

FIG. 5 shows the outer shape of the film 11. This film is an endless belt as described above, and its diameter is φM. Also, as shown in the figure, film 1
One end (the front end) of 1 is cut diagonally,
Let the length of the longest part be Lmax and the length of the shortest part be Lm
If in, the dimension of the obliquely cut portion (oblique cut portion) of the film 11 is obtained by Lmax-Lmin, and is set to ΔL (the oblique cut amount of the film) here. The oblique cut portion is arranged on the front side of the main fixing device as shown in FIG. 1 so that the photo sensor 16 detects the position of the film 11.

FIG. 6 is a detailed view of the positional relationship between the photo sensor 16 and the film 11. In this embodiment, the photo sensor 1
A transmission type photo-interrupter is used for 6 and its detection position is indicated by b. This is film 11
Is on the back side of the position b, the photo sensor 16 is ON
In the case of being on the near side of the position b, the switch is turned off. Further, the oblique cut portion of the film 11 is configured to be at the position of the detection position b.

That is, as the film 11 rotates in the direction of arrow a, the photosensor 16 repeats ON / OFF, and the ON / OFF cycle ratio (duty ratio) depends on the film position (deviation position). Will be variable.

The film position shown in FIG.
6 represents a reference position where the center of the oblique cut portion of the film 11 is located at the detection position b. The film position and OFF of the photo sensor 16 are centered on the reference position of the film.
The relationship of time is shown in the graph of FIG.

As shown in FIG. 7, when the film 11 is at the reference position b, the OFF time of the photosensor 16 is c seconds, and the film 11 is located at least ΔL / 2 and closer to the near side than the reference position b. At this time, the OFF time of the photo sensor 16 is 0 second.

Conversely, when the film 11 is located at least ΔL / 2 behind the reference position b, the photo sensor 16 is kept off.

Here, the OF in the case where the shift position of the film 11 is immediately before the position where the photo sensor 16 is kept turned off.
The F time is d seconds, which can be considered to be substantially the same as the time for the film 11 to make one round, and the OFF time c seconds at the reference position b is the center of the film oblique cut portion. The time is almost half of d seconds.

(D) Film-Side Movement Control Circuit (FIG. 8) FIG. 8 is a schematic diagram of a control system.

Reference numeral 26 denotes a microcomputer, and the photo sensor 16 is connected to the input terminal IN1. A solenoid 23 is connected to the OUT1 terminal. An OUT2 terminal outputs a rotation control signal of the motor 27 that also drives the fixing device.

A +5 V power supply is connected to the VDD terminal.
The GND terminal is connected to the ground.

Although not shown, a terminal for other input signals and output signals of the copying machine using the present fixing device is provided, and the microcomputer 26 has a copying operation of the copying machine. A built-in non-volatile RAM, which retains its stored contents even when power supply to the microcomputer 26 is cut off, together with a ROM and a RAM in which a can program and the like are programmed.

The switches SW1 to SW4 for detecting the code of the sheet cassette mounted on the image forming apparatus are connected to the input ports IN2 to IN5 of the microcomputer 26. When this switch is selectively pressed and turned on by a claw on the loading paper cassette described below, information on the size of the transfer material contained in the cassette (that is, information on the width of the transfer material) is input to the microcomputer 26. I do.

(E) Transfer Material Size Detecting Means (FIG. 9) FIG. 9 is a view of the paper feed cassette 62 viewed from the rear. When paper is set in the cassette, the claw 7 behind the paper feed cassette is used.
1 is set to a predetermined value corresponding to the size of the accommodated paper, and the paper feed cassette 62 is mounted on the image forming apparatus.
Is selectively turned on by the claw 71, so that the cassette 6
2 can be detected. In the case of FIG. 9, when the claw 71 is on, it becomes "1" at the input ports IN2 to IN5 of the microcomputer 26, and when it is not on, it becomes "0". For example, if the 4-bit signal is “0110”, it is determined that A4 size paper is in the cassette 62.

(F) Control Program (FIGS. 10 to 13) FIGS. 10 to 13 are flowcharts of a film shift movement control program of the fixing device.

This program is also programmed in the built-in ROM in the microcomputer 26, and is called and executed at regular time intervals or by a main sequence program or the like as needed. It has become.

First, after the start, in step 1, it is determined whether or not the sheet cassette 62 is mounted on the image forming apparatus main body. If so, the paper size data is transferred to the microcomputer, and the process proceeds to step S2. If not, return to step 1 and wait until mounted.

In step 2, the motor 27 is turned on.
It is determined whether or not it is. Here Motor 2
If the switch 7 is ON, the process proceeds to step 3 and the motor 2
If 7 is OFF, return to step 2 and motor 27 is ON
You will have to wait until you do.

Next, in step 3, it is determined whether or not the film has been controlled so as to approach the front side or the back side. This is the aforementioned microcomputer.
If a predetermined content on the non-volatile RAM in the data 26 is set as a basic position flag, and the state of the memory is 1, that is, if the memory has been controlled to be closer to the near side or the far side, the process proceeds to step 4. The process proceeds to return the stepping motor 23 to the basic position, reset the basic position flag, and proceed to step 5. In step 3, the basic position flag is set to 0.
In the case of (1), the stepping motor 23 is at the basic position, so that the routine proceeds to step 5 as it is.

In step 5, it is determined whether or not the sensor 16 is OFF. If the sensor 16 is ON, the process proceeds to step 9, and if it is OFF, the process proceeds to step 5.

In step 5, the value of the error timer is reset to 0, measurement is started, and the process proceeds to step 6.

In step 7, it is determined whether or not the sensor 16 is ON.
Move to.

In step 8, an error check routine is executed, and the process returns to step 7.

Here, the contents of the error check routine will be described with reference to FIG.
It is determined whether or not 7 is ON. If ON, the process proceeds to step S2.
Move to (FIG. 11).

At step S2, it is determined whether or not the error timer value is greater than d seconds. If the error timer value is less than d seconds, the routine goes to the exit of this routine. If the error timer value is greater than d seconds in step S2, step S
It will shift to 3. In step S3, an error flag is set, and the routine goes to the exit of the routine.

In step 7, if the sensor 16 is ON, the process proceeds to step 9 to reset the value of the error timer to 0, start measurement, and proceed to step 10.

In step 10, it is determined whether or not the sensor 16 is OFF. If the sensor 16 is not OFF, the process proceeds to step 11 to execute an error check routine, and returns to step 10. If the sensor 16 is turned off, The process proceeds to step 12, resets the value of the timer 1 to 0, starts measurement, and proceeds to step 13 (FIG. 11).

In step 13, it is determined whether or not the motor 27 is ON.
Move to.

At step 15, it is determined whether or not the sensor 16 is ON. If the sensor 16 is not ON, the process proceeds to step 16 to execute an error check routine and returns to step 15, and if ON, the process proceeds to step 17. I do.

At step 17, a comparison is made as to whether the value measured by the timer 1 is smaller than 1/4 d second.
If it is smaller here, it can be determined that the film 11 is located on the near side, so that the process proceeds to step 18 and the stepping motor 23 is rotated clockwise from the basic position by a predetermined pulse according to the sheet feeding size, and The direction is switched to the back side, the basic position flag is set to 1, and the routine proceeds to step 21.

If it is determined in step 17 that the measured value of the timer 1 is not smaller than 1/4 d second, the process proceeds to step 19
Move to.

In step 19, it is determined whether or not the measured value of the timer 1 is greater than 3/4 dsec. If not, the process proceeds to step 21; Because it can be determined that it was located,
The process proceeds to step 20, and the stepping motor 23 is rotated counterclockwise by a predetermined pulse corresponding to the paper feed size to switch the approach direction of the film 11 to the near side, the basic position flag is set to 1, and the process proceeds to step 21. .

At step 21, the value of the error timer is reset to 0 and measurement is started.
Move to.

At step 22, the sensor 16 is turned off.
If it is not OFF, the process proceeds to step 23, executes an error check routine, and returns to step 22. In step 22, the sensor 1
If 6 is OFF, the process proceeds to step 24, where the value of the timer 1 is reset to 0, measurement is started, and the process returns to step 13.

If the motor 27 is turned off in the above-described step 13, the process proceeds to step 14, where the timer 1
Is stopped, the measured value is reset to 0, the stepping motor is returned to the basic position, the basic position flag is reset to 0, and the process returns to step 1.

FIG. 13 shows a flowchart of a film abnormality processing program which is a part of the main program. Here, it is determined in step 25 whether or not the error flag is set. If the error flag is not set, the process proceeds to the exit and the next main sequence program is executed.

If the error flag is set in step 25, the process proceeds to step 26, in which all outputs of all devices (copying device in this embodiment) are turned off, and then to step 27, the film An error is displayed and the step 27 is set as a permanent loop so that the main program cannot be executed.

As described above, in the conventional deviation control, when the sheet is fed on one side basis, the film is less likely to shift in the direction of the paper passing portion in the longitudinal direction of the driven roller. By varying the shift speed, stable film shift control can be performed.

In this embodiment, the transmission type photosensor is used as the sensor 16, but it goes without saying that the same applies to the case where a sensor such as a microswitch or a reflection type photosensor is used.

<Second Embodiment> (FIGS. 14 and 15) FIG.
4A shows a manual tray portion of the image forming apparatus of the manual paper feed type. The transfer material P is placed on the manual feed tray 80 by inserting the leading end of the transfer material P into the nip portion between the feed roller 81 and the tray 80. The paper feed roller 81 is driven to rotate by the paper feed start signal, and the transfer material P on the tray 80 is fed into the apparatus, and is fed to the image transfer unit via the registration roller 64.

Reference numerals 82 and 83 denote optical sensor arrays as paper size detecting means disposed downstream of the paper feed roller 81 in the transfer material feeding direction. FIG. 14B is a perspective view of the optical sensor array portion.

Reference numeral 82 denotes an LED array as a light emitting side;
Denotes a phototransistor array on the light receiving side, which is arranged to face each other. The transfer material P fed from above the tray 80 by the paper feed roller 81 is
And the phototransistor array 83, the portion through which the paper (transfer material) passes during the passing process is where the light emission of the LED array 82 to the phototransistor array 83 on the light receiving side is blocked, and the portion that does not pass through is LED
The detection signal obtained from the phototransistor that has received the array light and received the light is a paper size detection microcomputer 84 shown in FIG.
Through the input ports IN2 to IN2 of the microcomputer 26.
It is output to IN5 as a 4-bit signal.

Therefore, the same operation as in the first embodiment can be performed, and the same effect can be obtained. The optical sensor arrays 82 and 83 may be provided anywhere in the paper transport section from the paper feed section to the entrance of the fixing device.

<Third Embodiment> (FIGS. 16 and 17) This embodiment is still another embodiment of the paper size detecting means.

FIG. 16A shows a manual paper feed type image forming apparatus similar to that shown in FIG.
As paper size detecting means in a direction downstream feeding the transfer material feeding than 1, and Tsumearei 86 arranged claws 85 ₁ ... 85 ₆ of retractable ((b) is a perspective view thereof), is opposed to this Tsumearei 86 A paper holder 88 is arranged. Claw array 8
The 6 are arranged a photo-interrupter 87 ₁ ... 87 ₆ respectively corresponding to Kakuka倒claws 85 ₁ ... 85 _6.

The transfer material P fed from the tray 80 by the paper feed roller 81 passes between the claw array 86 and the paper retainer 88, and passes through the transfer material passage portion according to the width of the fed transfer material P. The claws 85 ₁ … 85 ₆ are selectively collapsed, and the photo-interrupters 87 ₁ … 87 ₆ corresponding to the claws that have fallen.
((C) → (d)), and its signal is
Is input to the microcomputer 26 via the paper size detection microcomputer 84 to detect the paper size.

Therefore, the same operation as in the first embodiment can be performed, and the same effect can be obtained. In addition, the sensor 8 of the present embodiment
6.88 may be provided anywhere in the paper transport section from the paper feed section to the entrance of the fixing device.

[0091]

As described above, according to the present invention, the recording material
The width of the film according to the detection width from the detection means that detects the width
Since the shift speed is controlled, even if the introduced recording material changes size and the film shift speed changes, the width of the recording material
The shift speed of the film can be controlled accordingly, and stable shift control has become possible.

In the present invention, as the deviation control, the structure becomes complicated,
It can be easily carried out without increasing the size, and is an extremely effective means for long-term stable transport of a thin film in this type of heating device.

[Brief description of the drawings]

FIG. 1 is a partially omitted plan view of an example of a heating device according to the present invention.

[Fig. 2] Side view

FIG. 3 is a perspective view

FIG. 4 is a schematic configuration diagram of an example of an image forming apparatus using the heating device as a fixing device.

FIG. 5 is an outline drawing of an endless film.

FIG. 6 is a relationship diagram between a film sensor and a film position.

FIG. 7 is a graph showing a relationship between a film position and a film sensor output.

FIG. 8 is a schematic diagram of a control system.

FIG. 9 is an explanatory diagram of a paper feed cassette and a paper size detecting unit.

FIG. 10 is a flowchart of a film shift movement control program.

FIG. 11 is a flowchart of a film shift movement control program.

FIG. 12 is a flowchart of a film shift control program.
Chart

FIG. 13 is a flowchart of a film shift control program.
Chart

14A is a partial view of a manual sheet feeding type image forming apparatus provided with a paper size detecting unit according to the second embodiment, and FIG. 14B is a perspective view of the paper size detecting unit.

FIG. 15 is a schematic diagram of a control system.

16A is a partial view of a manual sheet feeding type image forming apparatus provided with a paper size detecting unit according to the third embodiment, FIG. 16B is a perspective view of a claw array of the paper size detecting unit,
(C) is a state diagram of the paper size detection unit before the paper passes, (d)
Is the state diagram during paper passage

FIG. 17 is a schematic diagram of a control system.

[Explanation of symbols]

 Reference Signs List 11 endless film fixing sheet 12 driven roller 13 drive roller 14 fixing heater 15 pressure roller 16 photosensor 23 stepping motor 26/56 microcomputer 27 motor 71 / SW1 to SW4 paper size detecting means 82/83 paper size detecting means 86/88 Paper size detection means

Continuation of the front page (56) References JP-A-2-285379 (JP, A) JP-A-2-259788 (JP, A) JP-A-3-14477 (JP, A) (58) Fields investigated (Int .Cl. ⁷ , DB name) G03G 15/20

Claims (1)

(57) [Claims] A rotating endless film;
Film in a direction perpendicular to the direction of film movement
Deviation control means for controlling the displacement of the film.
Image heating device that heats the image on the recording material with heat from
Oite, the recording material in the direction orthogonal to the moving direction of the film
Detection means for detecting the width of the
The shift speed of the film by the shift control means according to the known width
An image heating device characterized by controlling the degree.