JP3063308B2 - 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. An image heating and fixing device that heats and fixes an unfixed visible image (toner image) corresponding to target image information formed as a permanent fixed image on a recording material carrying the image by a transfer or direct method. Can be used. 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] Regarding the image fixing apparatus of the film heating type, there are a hot roller type, a hot plate type, a flash fixing type,
In comparison with other thermal fixing devices such as oven fixing method. 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.

As a cause of the displacement, there are parallelism and twist of two or more rollers which apply tension by suspending the film. However, there is a limit to improving the accuracy of these rollers. It is very difficult to prevent the film from shifting only by improving the accuracy.

For example, when the film is restricted by a rib or a flange member or the shape of the film-suspending conveying roller is made into a crown shape, for example, the film is a thin film and the material is less elastic. In the case of polyimide or the like, it is difficult to control the shift of the film, and it is difficult to ensure the stable rotation and transportability of the film.

Therefore, when a thin heat-resistant sheet having a film thickness of less than 100 μm is used as the film deviation control means, at least one roller shaft among the film suspension rollers that apply tension to the endless film is used. The endless film is displaced so that the direction of the endless film can be switched. At the same time, a sensor for detecting the position of the endless film is provided to control the endless film.

That is, when it is detected that the shift of the film to one side in the width direction has reached a predetermined limit position, the film is shifted to the other side in the width direction of the film, which is the return direction. Activating the means for displacing the rollers, and conversely, when it is detected that the shift of the film to the other side in the width direction has reached a predetermined limit position, the shift of the film is shifted in one direction in the film width direction, which is the return direction. By providing a film shift movement control mechanism configured to actuate the means for displacing the roller to change to the side, the shift movement in the film width direction during the rotation driving process of the endless film is within a predetermined fixed range. An inward reciprocation control is performed by controlling the reciprocating movement.

[0010]

However, a heating device of a film heating type using an endless film provided with the above-described film-shifting movement control mechanism also has a problem in controlling the film-shifting with the endurance of the device. There is qualitative.

That is, the film shift control mechanism adjusts the direction of the film shift in the forward direction under a certain condition.
In the initial state, a certain reciprocating movement can be guaranteed in the initial state with a certain degree of component accuracy or initial adjustment, but the long-term operation causes wear on the inner surface of the film, the conveying means, and the surface of the heating element, and the friction coefficient is reduced. Or the accuracy of the tension adjustment of the endless film occurs.

Further, since the film is conveyed while rubbing the fixedly supported low heat capacity heating element, a fluorine-based heat-resistant grease may be lubricated on the inner surface of the film for the purpose of preventing vibration at the rubbing portion and reducing torque. In this case, if the viscosity of the grease has temperature dependency, the grace application state changes over time.

[0013] These factors cause the aging condition of the film shift condition to change over time. In the worst case, the shift control becomes impossible. As a result, the film shifts to one side, which has a bad effect such as breakage of the machine. Also.

Accordingly, the present invention relates to a film heating type heating apparatus using an endless film, which is provided with the above-described film shift movement control mechanism, in response to a change in the film shift condition accompanying the endurance of the apparatus. , By providing means for changing the amount of displacement of the transport means that controls the film deviation, it is possible to maintain stable film deviation control and film transport irrespective of the endurance progress of the device, and improve the reliability of the device. The purpose is to let them.

[0015]

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

(1) A rotating endless film
In the direction perpendicular to the direction of film movement.
Shift control means for controlling shift of the system,
Image heating that heats the image on the recording material with heat from the lum side
The device has a counting means for counting the endurance progress of the device.
Then, in accordance with the count value of the counting means, the deviation control means
Image characterized by controlling the shift speed of the film due to
Heating equipment.

(2) The image heating apparatus according to (1) , wherein the counted value is an operation time of the apparatus.

(3) The count value is the number of recording materials.
The image heating apparatus according to (1), wherein:

(4) The counting means is non-volatile
Image heating according to any one of (1) to (3),
apparatus.

[0020]

In other words, by having means for changing the shift speed of the film shift control in accordance with the count value (integral value) of the counting means (endurance integration means) for counting the running progress of the apparatus,
The shift speed appears due to the aging of the endless film, etc., and even though the film shift direction is switched by the control means, the film does not shift in one direction and becomes uncontrollable, and the film shift direction is memorized. In addition to the shift control having a non-volatile means, stable film shift control can be performed for a long period of time.

This makes it possible to prevent the apparatus from being damaged, and at the same time, to control the deviation even if the speed difference due to the deviation direction of the endless film becomes large due to long-time use. This also has the effect of eliminating the need for precision and increasing the design margin.

Further, the mechanism for controlling the movement of the film shift is complicated.
This method can be implemented without increasing the size, and a film heating type heating device using an endless film can realize long-term stable conveyance of a film as described above, and can improve the reliability of the device.

[0023]

【Example】

<First Embodiment> (FIGS. 1 to 12) 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 platen glass disposed on the upper plate 51 of the copier housing 50, and is driven to reciprocate in the left-right direction by a driving 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.

Then, the downward illumination light of the original surface of the slit illumination light is sequentially imaged and exposed by an imaging 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 positive or negative charging process by a discharger 59 and then subjected to the above-mentioned image forming exposure, whereby 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 the 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 and a driven roller which also serves 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 which is 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 silicon rubber or the like having good releasability, and a biasing portion (not shown) sandwiching the film portion of the endless film 11 between the heater 14 and the descending side. 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 carrying the unfixed toner image t (heat-fusible toner) on the upper surface of the transfer material P conveyed from the transfer section 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-Side Movement Control Mechanism The drive roller 13 and the driven roller 12 of the endless film 11 are supported between the front side plate 19 and the rear side plate 18 of the fixing device 1 as shown in FIG. It is arranged. 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,
Unless the accuracy in the (Y-axis direction, Z-axis direction) is set to ± 0, when the drive roller 13 is driven to rotate the film 11 in the direction of arrow a, the film 11 Due to the positional relationship (variation in the X, Y, and Z axes) of the three members of the rollers 13 and 12 and the heater 14, the length of the rollers 13 and 12 is longer than the initial position of the film 11 shown by the solid line in FIG. Of the film in the width direction of the film along the right side (the back side direction C of the apparatus) or the left side (the front side direction B of the apparatus), and the edge of the film is rubbed against the side plate 18 or the side plate 19 to be damaged. Become.

Therefore, in this embodiment, the driven roller 1
The bearing 21 on the front side of FIG.
.The bearing 2 has a degree of freedom of movement in the vertical direction of Q.
The parallelism of the driven roller 12 with respect to the driving roller 13 can be changed by vertically moving P · Q by the fork arm 24 that is directly driven to swing vertically by the stepping motor 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.

Numeral 16 denotes a photo sensor for detecting the position of the shift of the film. 1 and 3
As shown in the figure, the front end 3 (shaded area) of the film 11 is masked so as to block the light of the photosensor 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 portion 3 of the film 11 is treated with a reflection member which 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, 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 3, which is always cleaned to prevent erroneous reading when a reflection type sensor is used, for example, due to contamination of the film end. Is what it is. 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 stepping motor 23 is connected to the output terminal OUT1.
Is connected. The output terminal OUT2 outputs a rotation control signal of the motor 27 for driving 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.

(E) Control Program (FIGS. 9 to 13) FIGS. 9 to 13 show 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 as needed by a main sequence program or the like. It has become.

First, after the start, in step 1 (FIG. 9), it is determined whether or not the motor 27 is ON. If the motor 27 is on, the process proceeds to step 2, and if the motor 27 is off, the process returns to step 1 and waits until the motor 27 is turned on.

Next, in step 2, an initial operation of the stepping motor 23 for deviation control is performed. In the initial operation, the stepping motor 23 is rotated counterclockwise,
The driven roller 12 is rotated until the front end thereof reaches a predetermined lowermost position. Thereafter, the position of the driven roller 12 is controlled by the stepping motor 23 based on the number of pulses from the position where the lower limit is set to the zero point. Next, the routine proceeds to step 101.

In step 101, it is determined whether or not the film has been controlled so as to approach the front side. This means that the content of a predetermined address in the nonvolatile RAM in the microcomputer 26 is set as a near side flag, and when the state of the memory is 1, that is, when the memory has been controlled to the near side, the step is performed. In step 103, a pulse is given to the stepping motor 23 to a position where the driven roller 12 is higher than the center position by a displacement amount.

In this embodiment, the middle point of the driven roller 12 is a position 50 pulses above the above-mentioned zero point, and the amount of displacement depends on the integral value of the operation time of the driving roller 13 as shown in FIG. The time integration value is set and stored in a non-volatile RAM that does not disappear even when the power is turned off. The position of the driven roller 12 at this time is stored in the RAM.

Conversely, when the foreground flag is 0, step 10
2 is executed, and a pulse is applied to the stepping motor 23 until the driven roller 12 becomes lower than the center position by the amount of displacement, and the position of the driven roller 12 at this time is stored in the RAM.
Save it inside.

In step 4, it is determined whether or not the sensor 16 is off. If the sensor 16 is on, the process proceeds to step 8, 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 6, it is determined whether or not the sensor 16 is ON. If not, the process proceeds to step 7.

In step 7, an error check routine is executed, and the process returns to step 6.

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. 10).

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 this routine.

If the sensor 16 is ON in step 6, the process proceeds to step 8, resets the value of the error timer to 0, starts measurement, and proceeds to step 9.

In step 9, it is determined whether or not the sensor 16 is OFF. If the sensor 16 is not OFF, the process proceeds to step 10 to execute an error check routine, and returns to step 9. If the sensor 16 is turned off, the process proceeds to step 9. The process proceeds to step 11, resets the value of the timer 1 to 0, starts measurement, and proceeds to step 12 (FIG. 10).

In step 12, it is determined whether or not the motor 27 is ON. If the motor 27 is ON, the process proceeds to step 14.

At step 14, it is determined whether or not the sensor 16 is ON.
The process proceeds to step 5 to execute an error check routine, and returns to step 14. If it is ON, the process proceeds to step 16.

In step 16, the measured value of timer 1 is set to d /
If it is smaller than 4 seconds, it can be determined that the film 11 is located on the near side.
A pulse is given so that 3 is at the position of [50-displacement amount], the approach direction of the film 11 is switched to the back side, the front flag is reset to 0, and the routine proceeds to step 20.

If the measured value of the timer 1 is not smaller than d / 4 seconds in step 16, the process proceeds to step 18.

At step 18, the measured value of the timer 1 becomes 3
It is comparing whether it is larger than d / 4 seconds,
If it is not large, the process proceeds to step 20. If it is large, it can be determined that the film 11 is located on the back side. Therefore, the process proceeds to step 19 and a pulse is given so that the stepping motor 23 is at the position of [50 + displacement amount]. Film 11
Is switched to the near side, the near flag is set to 1, and the routine proceeds to step 20.

In step 20, the value of the error timer is reset to 0 and measurement is started, and the process proceeds to step 21.

In step 21, it is determined whether or not the sensor 16 is OFF. If the sensor 16 is not OFF, the process proceeds to step 22, executes an error check routine, and returns to step 21.

In step 21, the sensor 16
In the case of FF, the process proceeds to step 23, where the value of the timer 1 is reset to 0, measurement is started, and the process returns to step 12.

In step 12, the motor 27 is turned off.
In the case of (1), the process proceeds to step S13. First, the measurement of the timer 1 is stopped, the measured value is reset to 0, then all the phase excitations of the stepping motor 23 are turned off, and the process returns to step S1.

The driving of the stepping motor 23 is R
This is performed for the current position of the driven roller 12 in the AM.
For example, when the current position is shifted to the position of 70 pulses at the position of 30 pulses, the stepping motor 23 is rotated clockwise by 40 pulses, and the current position is shifted to the position of 10 pulses at the position of 30 pulses. Sometimes, it is rotated counterclockwise by 20 pulses.

FIG. 12 shows a flowchart of a film abnormality processing program which is a part of the main program. Here, it is determined in step 24 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 24, the flow goes to step 25 to turn off all the outputs of all the devices (copying device in this embodiment). An abnormality is displayed and the step 26 is set as a permanent loop so that the main program cannot be executed.

As described above, the endless film 11 of the present fixing device starts with the non-volatile R which stores the shift direction which has been controlled before that time.
The stepping motor 23 is controlled according to the content of AM. Next, when the sensor 16 is ON during the rotation of the motor,
The output of the film position sensor 16 is changed from ON to OFF by waiting until the FF is turned off, and when the sensor 16 is OFF, waits until the sensor 16 is turned ON and then turns OFF.
The timing of switching to is detected, and the initial setting ends. Then, the position of the film 11 is detected only by measuring the OFF time of the sensor 16 until the sensor 16 switches from OFF to ON.

Thereafter, the OFF time of the sensor 16 from the timing when the sensor 16 switches from ON to OFF to the time from OFF to ON is measured, and the film position is controlled so as to be within a predetermined control range according to the driving time of the film. The control is performed while changing the amount of displacement of the driven roller 12 according to the integral value of the operation time of the film drive motor.

In this embodiment, a transmission type photo sensor is used as the sensor 16. However, it goes without saying that the same applies when a sensor such as a micro switch or a reflection type photo sensor is used.

<Embodiment 2> (FIGS. 14 to 16) In FIG. 14, the fork lever 24 is freely swingable in the vertical direction U and D about the support shaft 24a. The driven roller 12 is engaged with the side bearing 21 by switching the fork lever 24 up and down rotation U / D.
This is the same as in the above-described first embodiment in that the film 11 is switched in the direction B / C (FIGS. 1 and 3) by the vertical movement P · Q on the front side of FIG.

The fork lever 24 is always urged to rotate in the downward rotation direction D (counterclockwise) by the tension spring 32, and the lower rotation limit of the lever 24 is opposite to the fork lever side of the fork lever 24. It is regulated by the upper stopper blade 1a which interferes with the rear end of the side lever.

Reference numeral 33 denotes a solenoid for rotating the fork lever 24 in the upward rotation direction U (clockwise) against the tension spring 32. The upper rotation limit of the lever 24 by the solenoid is a fork portion of the fork lever 24. It is regulated by the lower stopper blade 1b which interferes with the lever rear end on the side opposite to the side. Therefore, the displacement range of the deviation control is defined by the interval between the upper and lower stopper blades 1a and 1b.

The upper and lower stopper blades 1 a and 1 b are vertically movable along the guide member 2. The upper stopper blade 1a moves upward along the guide member 2 when the upper screw rod 7a is rotated forward. The thread of the upper threaded rod 7a is terminated immediately before it is not necessary for the upper stopper blade 1a to move upward any further. The lower stopper blade 1b moves down along the guide member 2 when the lower screw bar 7b is rotated forward. The thread of the lower screw bar 7b is terminated immediately before the lower stopper blade 1b does not move down any further.

Reference numeral 10 denotes a gear connected to the film drive roller 13 by transmission means such as a gear train or a pulley (not shown). The gear rotates in a direction indicated by an arrow at a predetermined low speed in conjunction with the drive of the film 11. .

The rotation of the gear 10 is transmitted to the lower screw 7b via the worm gear 6 → the transmission gear 5 → the lower gear train 9 (9a ・ 9b), and the lower screw 7b is gradually rotated forward. Accordingly, the lower stopper blade 1b gradually moves down along the guide member 2.

The rotation of the gear 10 is performed by the worm gear 6 → the transmission gear 5 → the gear 9a → the connecting rod 9c → the upper gear train 8.
(8a, 8b, 8c) is transmitted to the upper screw rod 7a, and the upper screw rod 7a is rotated forward little by little, so that the upper stopper blade 1a is gradually moved upward along the guide member 2. To go.

Accordingly, the interval between the upper and lower stopper blades 1a and 1b increases in accordance with the driving time of the film 11, that is, the driving time of the apparatus, that is, the vertical rotation angle of the fork lever 24 increases, and the durability of the apparatus increases. Correspondingly, the displacement range of the deviation control of the film 11 is changed.

The upper and lower gear trains 8 (8a and 8b), 9
The ratio of the gear ratios (9a, 9b, 9c) is set so as to prevent the shift speed from largely changing depending on the shift direction due to the aging of the endless film or the like. Is gone. The range in which the upper and lower stopper blades 1a and 1b can move depends on the service life of the fixing device and the solenoid 33.
Of each gear to obtain a predetermined tooth value and the required number of gears.

FIGS. 15 and 16 correspond to FIGS. 9 and 10 of the film shift control program of the first embodiment. Therefore, the flow chart of the program in this embodiment is shown in FIGS. In the order shown in FIG. 12, the rough procedure is performed according to the first embodiment.

As described above, the rotation of the gear 10 proceeds during the operation time of the fixing device, and the displacement range of the shift control can be changed according to the integration of the operation time of the fixing device. The same effect can be obtained.

Further, this embodiment is characterized in that the operation of changing the shift speed of the shift control in accordance with the integrated value of the operation time of the machine is not performed by software at all, but only by mechanical means such as gears. is there.

<Third Embodiment> (FIG. 17) This embodiment is different from the second embodiment in that the gear 10 is rotated by one pitch for each sheet of paper conveyed to the apparatus. It was done.

30 is ON only once by transporting one sheet of paper
When the switch 30 is depressed by the switch which is turned off by the conveyance of one sheet, the gear 10 advances by one pitch. A leaf spring 31 is provided so that the gear 10 does not rotate in the reverse direction.

As described above, the rotation of the gear 10 proceeds in accordance with the number of copies made, and the upper and lower stopper blades 1 in accordance with the durability of the apparatus as in the second embodiment.
The interval between a and 1b increases, and according to the number of copies,
That is, it is possible to change the control range of the film shift control according to the durability of the apparatus. Therefore, it is clear that the same effect as in the second embodiment can be expected.

In this embodiment, the number of copies is detected by a microcomputer and stored in a nonvolatile RAM.
0 may be driven by a stepping motor controlled by a microcomputer.

[0102]

As described above, according to the present invention, rotation is achieved.
Endless film and the direction of movement of this film
A deviation control hand that controls the deviation of the film in the orthogonal direction
And a step on the recording material by heat from the film side.
With regard to the image heating device that heats the image , the shift speed appears due to the aging of the endless film, etc.,
Despite switching the film shift direction by the control means, the film will not be shifted in one direction and become uncontrollable. Over a stable film shift control.

As a result, it is possible to prevent damage to the apparatus, and at the same time, it is possible to control the shift even if the speed difference due to the shift direction of the endless film becomes large due to long-time use, thereby adjusting the tension of the endless film. This also has the effect of eliminating the need for precision and increasing the design margin.

Further, the film-side movement control mechanism is complicated.
It can be performed without increasing the size, and the rotating end
Perpendicular to the moving direction of the film
Deviation control means for controlling the deviation of the film in the direction.
Having an image on a recording material by heat from the film side.
With respect to the image heating device to be heated , long-term stable conveyance of the film can be realized, and the reliability of the device can be improved.

[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 a flowchart of a film shift movement control program.

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

FIG. 14 is a schematic diagram of a film shift control mechanism according to a second embodiment.

FIG. 15 is a flowchart of a film shift movement control program.

FIG. 16 is a flowchart of a film shift movement control program.

FIG. 17 is a main part view of a film shift movement control mechanism according to a third embodiment.

[Explanation of symbols]

 Reference Signs List 11 endless film 12 driven roller 13 drive roller 14 fixing heater 15 pressure roller 16 photosensor 23 stepping motor 24 fork lever 26 microcomputer 27 motor

Claims (4)

(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
And a counting means for counting the endurance progress of the apparatus.
Film shift by the shift control means according to the count value of the step
An image heating apparatus characterized by controlling a shift speed. 2. The image heating apparatus according to claim 1, wherein the count value is an operation time of the apparatus. 3. The method according to claim 2, wherein the counted value is the number of recording materials.
The image heating apparatus according to claim 1, wherein 4. The method according to claim 1, wherein said counting means is non-volatile.
The image heating device according to claim 1, wherein