JP3094532B2 - Image heating device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a rotating endless film and a deviation control means for controlling the deviation of the film in a direction perpendicular to the moving direction of the film to be within a predetermined range. And an image heating apparatus for heating an image on a recording material by heat from the film side.

[0002]

2. Description of the Related Art An image heating apparatus of the above-described film heating type is known from Japanese Patent Application Laid-Open No. 63-313182, and is an image heating fixing apparatus in an image forming apparatus such as an electrophotographic copying machine, a printer and a facsimile. That is, electrophotography
An image forming process such as an electrostatic recording or a magnetic recording may be directly applied to a surface of a recording material (an electrofax sheet, an electrostatic recording sheet, a transfer material sheet printing paper, etc.) using a toner made of a heat-meltable resin or the like. The present invention can be utilized as an image heating and fixing apparatus for performing a heat fixing process on an unfixed visible image (toner image) formed by an indirect (transfer) method and corresponding to target image information as a fixed image on a recording material carrying the image. 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 linear heating element having a low heat capacity 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, it is possible to shorten a rise time to a predetermined fixing temperature and save power. Since the fixing point and the separation point between the film and the recording material can be set separately, toner offset can be prevented.
It has advantages such as solving various drawbacks of other system devices and 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] In order to control the shift, the ribs and flange members are used to restrict the movement of the film. For example, when the shape of the film-suspending and conveying roller is formed into a crown shape, the film is made of a thin film and is made of a material such as polyimide having low elasticity. In some cases, it is difficult to restrict the shift of the film, and it is difficult to ensure the stable rotation and transport of the film.

In view of the above, a means for detecting a 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.

[0008]

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 above-mentioned film shift control mechanism detects the position of the film shift within a certain range, and reciprocates the film within the range to control the shift of the film. When the speed becomes higher, the frequency of reciprocating motion of the film naturally increases, which causes problems such as damage to the film and generation of wrinkles. In addition, when a film detection failure or a driving means for displacing the film-suspending conveyance roller, for example, a solenoid is used, the driving frequency of the solenoid increases, and the solenoid itself may be heated more than necessary. These condition settings can be optimized in the initial state by component accuracy, adjustment, and the like. However, the above-mentioned film shift speed is an unstable factor because a change in durability or the like is expected.

[0010] Particularly, unlike the general film (belt) conveyance, the present apparatus is a heating apparatus.
Since the temperature reaches about 200 ° C., the normal temperature state means that the initial film shift condition changes due to the coefficient of friction of the film transporting means, the surface of the heating element, and the thermal expansion of parts such as the film transport roller. I have to.

It is also known that in a film heating type heating apparatus, a fluorine-based heat-resistant grease is applied to the inner surface of the film as a lubricant because the film is conveyed while sliding with a fixedly supported heating element. However, since this type of grease viscosity has a large temperature dependency, this point is also a factor that makes the conditions near the film unstable.

When the film is always reciprocated in the same area, the wear of the surface of the heating element, the heating element supporting member, and the film transport means may be reduced.

Accordingly, the present invention relates to a film heating type heating apparatus using an endless film provided with the above-described film shift movement control mechanism, which can cope with the instability of the film shift condition accompanying the endurance of the apparatus. A stable film that prevents film detection errors without causing film damage, wrinkles, etc., even if a change in the film shift speed due to temperature factors and durability changes is provided by providing a means to adjust the film shift change. An object of the present invention is to improve the reliability of an apparatus by enabling a shift control and a film conveyance.

[0014]

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

(1) An endless film which rotates, and a deviation control means for controlling a deviation of the film in a direction perpendicular to a moving direction of the film so as to be within a predetermined range. An image heating apparatus that heats an image on a recording material by heat from the apparatus has a counting unit that counts the progress of durability of the apparatus, and changes the width of a predetermined range by the deviation control unit according to the count value of the counting unit. An image heating apparatus, comprising:

(2) The image heating apparatus according to (1), wherein the counted value is the number of recording materials.

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

(4) The image heating apparatus according to any one of (1) to (3), wherein the counting means is nonvolatile.

<Operation> That is, by switching the film shift movement control range in accordance with the count value of the counting means for counting the progress of the endurance of the apparatus, even if the film shift speed changes due to a temperature factor and a change in the endurance, the film shift speed is changed. Since the film movement distance range of the film reciprocation in the deviation control is variable, the frequency of the film reciprocation control reciprocation can be suppressed to a certain range, thereby preventing excessive stress on the film and eliminating wrinkles and the like. be able to. In addition, erroneous detection of the film and temperature rise of the solenoid can be minimized, and the displacement of the film, the heating element, and the heating element supporting member can be reduced by abrasion of the same part. Life can be extended. It can be implemented without increasing the complexity of the film shift control mechanism,
With respect to an image heating apparatus of a film heating system using an endless film, stable conveyance of the film can be realized, and the reliability of the apparatus can be improved.

[0020]

【Example】

<First Embodiment> (FIGS. 1 to 12) FIG. 1 is a plan view of an example of a heating device according to the present invention,
FIG. 2 is a side view, and FIG. 3 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. 3) The image forming apparatus shown in FIG. 3 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, and is reciprocally driven in the left-right direction 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 downwardly facing 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 light on the original surface of the slit illumination light is sequentially imaged and exposed on the surface of a photosensitive drum 58 which rotates synchronously with the scanning of the original image by an imaging lens (short focus imaging element array) 57.

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, 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 has been 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 position of 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 developed image on the surface of the photosensitive drum 58 is sequentially transferred to the transfer material P 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 transfer, 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 and 2) In FIGS. 1 and 2, reference numerals 13 and 12 denote a pair of left and right endless film driving rollers and a driven roller which also serves as a tension roller, which are disposed substantially in parallel with each other. Reference numeral 11 denotes an endless film suspended and stretched between the two rollers 13 and 12. The drive roller 13 is rotated in a clockwise direction as indicated by an arrow a by a drive system including a drive motor 27. It is rotationally driven at a predetermined peripheral speed in the direction.

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 silicon rubber or the like having good releasability. 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, which has been transported from the transfer section 61 (FIG. 3) to the fixing device 1 by the transport device 65 and carries the unfixed toner image t (heat-fusible toner) on the upper surface, sandwiches the endless film 11. 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. 6) 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,
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. Is shifted to the right or left in the film width direction along the side plate 18 or the side plate 18 or the side plate 19.
In this case, the edge of the film may be rubbed and damaged.

Therefore, in the present embodiment, the driven roller 1
2 is supported on the side plate 18 with a degree of freedom of movement in the front and rear directions of arrows A and B with respect to the side plate 18, and is normally urged to move in the forward direction A by the compression spring 22 as indicated by the solid line. At the first position, it is received by a stopper (not shown), and the plunger of the solenoid 23 is connected. When the energization of the solenoid 23 is turned on, the bearing 20 is pulled in the retreating direction B against the compression spring 22. Then, the position is displaced to the second position indicated by the two-dot chain line.

That is, energization ON / OFF of the solenoid 23
Thus, the degree of parallelism of the driven roller 12 with respect to the driving roller 13 and the heater 14 can be changed.

In this embodiment, when the solenoid 23 is off and the bearing 20 is at the first position shown by the solid line, the rotating film 11
Moves toward the left side in the film width direction, that is, toward the far end side of the rollers 13 and 12 along the length of the suspended tension members 13, 12 and 14 along the length thereof. Is in the second position shown by the two-dot chain line, the rotating film 11 moves to the right in the film width direction, that is, toward the front ends of the rollers 13 and 12, in contrast to the above.

Reference numeral 16 denotes a photo sensor for detecting the position of the film shift. Also, as shown in FIG. 1, the front end 3 of the film 11 is masked as indicated by hatching so as to block the light of the photosensor 16 around the entire edge.

In this embodiment, a photo-interrupter is used as 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 which reflects light. is necessary. Alternatively, the image 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 film edge cleaning member. The film edge is always cleaned so as to prevent erroneous reading when a reflection type sensor is used due to contamination of the film edge or the like. 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. 4 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. 5 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, the film 11 is formed by the arrow a shown in FIG.
The photo sensor 16 is turned to O
N / OFF is repeated, and the ON / OFF cycle ratio (duty) depends on the film position (deviation position).
Ratio) 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. 6, 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 or more in front of the reference position b. At this time, the OFF time of the photo sensor 16 is 0 second.

On the contrary, 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 is
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. 7) FIG. 7 is a schematic diagram of a control system.

Reference numeral 26 denotes a microcomputer to which the photo sensor 16 is connected to an input terminal IN1. A solenoid 23 is connected to the OUT1 terminal. The OUT2 terminal outputs a rotation control signal of the motor 27 for driving the present fixing device.

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

Although not shown, other input and output signal terminals of the copying machine using the present fixing device are provided, and a microcomputer 26 is provided with a copying operation system for 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.

A photosensor 28 described below is connected to the input port IN2 of the microcomputer 26 as means for counting the progress of the device in endurance. (E) Counting Means 28 (FIG. 8) The counting means 28 of this embodiment detects the driving time of the film 11 and counts the degree of endurance of the apparatus.

More specifically, as shown in FIG. 8, a gear 29 coaxially mounted on the film drive shaft rotates the gear associated with the film drive, that is, the drive time of the film via the relay gear 30. The gear 31 is provided.

Reference numeral 32 denotes a light shielding plate coaxially attached to the gear 31. When the film is driven for a predetermined time, the notch 32a of the light shielding plate 32 is positioned on the photo sensor 28, and the optical path of the sensor 28 is opened. The sensor turns on. At this time, the toothless portion 31a of the gear 31 is located at a position corresponding to the gear 30, so that the image of the gear 31 with respect to the relay gear 30 is cut off.
2 does not rotate.

In this embodiment, the film drive time reaches the predetermined time until the sensor of the photo sensor 28 is detected by the sensor ON, that is, during the sensor OFF period, the film shifts in the first shift control range. The shift control is performed, and after the sensor is turned on, the film shift control is performed in the second shift control range.

Here, the first deviation control range and the second deviation control range have a relationship of first deviation control range> second deviation control range.

(F) Control Program (FIGS. 9 to 12) FIGS. 9 to 12 show flowcharts of a film shift movement control program of the fixing device.

This program is also programmed in the above-mentioned built-in ROM in the microcomputer 26, and is called and executed by a main sequence program or the like at regular time intervals or as needed. 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, 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. Step 3 is performed, the solenoid 23 is turned on, and the deviation control is set to the near side.
Move to. In step 2, the front flag is set to 0.
In the case of, since the film has been controlled so as to be shifted to the far side, the process proceeds to step 4 as it is.

At 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).

In 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 process proceeds 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.

Next, at step 6, the sensor 16
If N, the process proceeds to step 8 to reset the value of the error timer to 0, start the measurement, and proceed 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, and if the sensor 16 is turned off, the process proceeds to step 11. Then, the value of the timer 1 is reset to 0 and the measurement is started, and the process 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 27.

In step 27, it is determined whether or not the film driving time detecting sensor 28 is ON. In this embodiment, the first deviation control range is d / 4 to 3d / 4, and the second deviation control range is 2d / 5 to 3d / 5. If the sensor 28 is ON in step 27, the process proceeds to step 28 to perform control in the second shift control range,
If it is not ON, the process proceeds to step 16 to perform control in the first shift control range.

In step 28, the measured value of the timer 1 is 2d
A comparison is made to determine whether or not the time is shorter than / 5 seconds. If the time is shorter, it can be determined that the film 11 is located on the front side of the second shift control range. The approach direction of the film 11 is switched to the back side, the front flag is reset to 0, and the process proceeds to step 20.

If the measured value of the timer 1 is not smaller than 2d / 5 seconds in step 28, the flow shifts to step 29.

In step 29, the value measured by the timer 1 becomes 3
It is comparing whether it is larger than d / 5 seconds,
If it is not larger, the process proceeds to step 20. If it is larger, it can be determined that the film 11 is located on the far side of the second shift control range.
3 is turned on to switch the direction of shifting of the film 11 to the near side, the foreground flag is set to 1, and the routine proceeds to step 20.

In step 16, the measured value of timer 1 is set to d /
A comparison is made as to whether the time is less than 4 seconds. If the time is smaller than 4 seconds, it can be determined that the film 11 is located closer to the front side than the first shift control range. The direction of the approach 11 is switched to the back side, the front flag is reset to 0, and the process 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 larger, the process proceeds to step 20. If it is larger, it can be determined that the film 11 is located farther than the first shift control range.
3 is turned on to switch the direction of shifting of the film 11 to the near side, the foreground 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 described above, the motor 27
In the case of the FF, the process proceeds to step 13, where the measurement of the timer 1 is stopped, the measured value is reset to 0, the solenoid 23 is turned off, and the process returns to step 1.

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 (the copying device in this embodiment), and then goes to step 26 to move to the film 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 from the time of rotation of the motor, and the non-volatile R which stores the shift direction controlled up to that time.
The solenoid 23 is controlled according to the content of AM. Next, when the sensor 16 is ON when the motor is rotating, wait until the sensor 16 is turned OFF, and when the sensor 16 is OFF, wait until the sensor 16 is turned ON and then wait until the sensor 16 is turned OFF. The timing of switching to OFF 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 until the sensor 16 switches from OFF to ON is measured so that the film position is within a predetermined control range corresponding to the film driving time. Controlling.

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

<Second Embodiment> (FIGS. 13 and 14) In this embodiment, the progress of durability of the apparatus is counted by a copy number counter.

That is, as shown in FIGS. 2 and 3, a paper ejection sensor 33 is provided on the transfer material outlet side of the fixing device 1, and the sensor 33 detects that the transfer material has passed through the fixing device, and the signal is output. 13, the microcomputer 26 counts the number of transfer materials that have passed through the fixing device 1.

The count value is a predetermined number, for example, 1
When the number of sheets is smaller than 10,000 sheets, the shift control of the film is controlled in the first shift control range, and after the number of sheets reaches 10,000 or more, the control is performed in the second shift control range (<first shift control range). I have.

In this embodiment, the configuration of the example of the image forming apparatus, the configuration of the fixing device 1, and the configuration of the film shift control mechanism are the same as those in the first embodiment. Except for changing to the step of judging whether or not “counter value> 10,000 sheets”, the other is the same as FIGS. 9 to 12.

That is, in FIG. 10, step 27 is not a step of judging whether or not “counter value> 10,000 sheets”. If the count value is larger than 10,000 sheets, the process shifts to step 28 to set the second shift control range. If the number is smaller than 10,000, the process proceeds to step S16, and the control is performed in the first shift control range.

FIG. 14 shows a subroutine for counting the number of discharged sheets. This subroutine is a program that is called after the transfer material P enters the fixing device 1 and the paper discharge sensor 33 is turned on during the copying operation sequence.

At step 124, the paper discharge sensor 33 is turned on.
-Judge OFF. When the sensor 33 is ON, the process proceeds to step 125.

In step 125, the value of the JAM error timer is checked. This timer is cleared when the transfer material P enters the fixing device 1. When the timer becomes longer than a predetermined time, it is considered that the transfer material has stayed (jammed) in the fixing device 1, and the process proceeds to step 127 to stop the operation.

If the timer value is smaller than the predetermined time, the process returns to step 124. When the sensor 33 is OFF in Step 124, the process proceeds to Step 126. In step 126, in addition to the count value of the number of discharged sheets, the count value is stored in a nonvolatile RAM, and the process exits this subroutine.

The counting of the number of copies is not performed by the paper discharge sensor 33 as in the present embodiment, but may be performed by using a paper feed sensor or a paper path sensor of the transfer material conveying unit.

<Third Embodiment> (FIGS. 15 and 16) In this embodiment, the progress of durability of the apparatus is counted by a film drive time timer.

FIG. 15 is a schematic diagram of the electric control. The film shift control is the same as in the first and second embodiments described above, except that step 27 in FIG. 10 is replaced by a step of determining whether the timer value is equal to or greater than a predetermined value.

As shown in the flow of FIG. 16, the film drive time timer determines whether the motor is on or off, and turns on the motor.
Can be calculated only in the case of (1), and can be performed in the same manner as in the first and second embodiments.

<Fourth Embodiment> (FIGS. 17 to 19) This embodiment is another example of the film position detecting means.

FIG. 17 is a plan view of the fixing device 1 in which an intermediate portion is omitted. Components and portions common to those of the above-described device of FIG. 1 are denoted by the same reference numerals, and the description thereof will not be repeated.

Photosensors 105, 106, 107 and 108 detect the position of the film.

The sensors 107 and 108 are sensors 105
It is installed to detect the film position outside the film detection position of 106. Further, both end portions 3, 3 'of the film 11 are subjected to a masking process so as to block light from the photo sensor.

In this embodiment, a photo-interrupter is used as a photosensor. However, when a reflection-type photosensor is used here, both ends 3.3 of the film 11 are used.
The part 'needs a reflection member treatment to reflect light. Further, in this embodiment, the processing such as masking is performed only on both ends, but it goes without saying that the processing may be performed on the entire film. Alternatively, the image may be read by a photo sensor via a movable piece that moves along the edge of the film.

Reference numerals 101 and 102 denote film edge cleaning members which constantly clean the film edge so as to prevent erroneous reading when a reflection type sensor is used due to contamination of the film edge. is there. In the present embodiment, felt is used, but any type may be used as long as it has a cleaning effect.

The photo sensors 105 and 106 are connected to the side plate 18.
・ Switch the shift control range by moving in the vertical direction to 19. The photo sensors 105 and 106 are connected to the side plates 18.
It is movable along a rail (not shown) provided in a direction perpendicular to 19.

Reference numerals 113 and 114 denote solenoids for moving the photosensors 105 and 106. Photo sensor 105.1 when solenoids 113 and 114 are ON
06 detects the outer film position.

Next, a schematic diagram of the electric control is shown in FIG.
(B). 115 is a microcomputer,
The input terminals IN1, IN2, IN3, and IN4 are connected to the photosensors 105, 106, 107, and 108, respectively.
And a motor rotation control signal for driving the present fixing device is output to OUT1. A solenoid 23 is connected to OUT2.

The sensor 28 is a sensor for detecting the film driving time, and has a configuration as shown in FIG.
Q1 is a driver circuit for driving the solenoids 113 and 114. When the sensor 28 is turned off, the solenoid is turned on.

Although not shown, the microcomputer 115 has terminals for other input and output signals of a copying machine using the fixing device 1. The microcomputer 115 has a built-in ROM, RAM, and the like in which a copying operation sequence program of the copying machine is programmed.

FIG. 19 is a flowchart for controlling the film shift by the microcomputer 115. This is programmed in the built-in ROM of the microcomputer 115 as in the first embodiment, and is executed by being called from a main sequence program or the like at regular time intervals or as needed.

First, after the start, in step 301, it is determined whether or not the motor 27 is ON. If the motor 27 is on, the process proceeds to step 302. If the motor 27 is off, the solenoid in step 308 is turned off without performing the shift control, the back side flag is set, and step 310 is performed.
Exit and return to the main program.

Next, in step 302, it is determined whether or not the film is near. This means that the content of a predetermined address on the RAM in the microcomputer 115 is set as a back side flag, and the state of the memory is 1 or 0.
Have been determined. If the film is moving to the back, that is, if the back flag is 1, the process proceeds to step 303.

In step 303, the sensor 108
Judgment as to whether or not N is made, and the sensor 108 is ON
If not, the process proceeds to step 304. Step 30
In step 4, it is determined whether or not the input port IN1 is ON. If the input port IN1 is ON, the process proceeds to step 305.

In step 305, since the film is approaching the back and the sensor is turned on, the solenoid 23 is turned on so that the film is brought closer to the near side. At the same time, the back flag is reset, and the process proceeds to the exit of step 310. Become.

In step 304, input port IN
If is not ON, the process proceeds to the exit of step 310 as it is.

In step 303, the sensor 108
Is ON, that is, if the film is further moved to the front side even though it is controlled to move to the back side, the process proceeds to step 309, where the film abnormality flag is set, and step 308 is performed. Then, the solenoid 23 is turned off, the back side flag is reset, and the routine proceeds to step 310, where the routine returns to the main sequence.

Similarly, in step 302, when the film is approaching the front side, that is, when the back side flag is “0”, the process proceeds to step 306.

At step 301, the sensor 107
If the sensor 107 is ON, that is, if the film has moved further to the rear side despite the fact that the film is about to move to the near side, the process proceeds to step 309 and the same as described above. And return to the main program.

In step 306, the sensor 10
If 7 is OFF, the process proceeds to step 307 to determine whether the input port IN2 is ON. If the input port IN2 is not ON, the process directly proceeds to step 310 and returns to the main program. If the input port IN2 is ON, the process proceeds to step 200 and the solenoid 23 is turned off to move the film to the back side. At the same time, the back side flag is set, the routine proceeds to step 310, and the program returns to the main program.

As described above, the solenoids 113 and 114 are turned ON or OFF according to the detection signal of the sensor 28.
As a result, the shift control range can be changed according to the film driving time.

The same applies when the signal from the sensor 28 is input to the microcomputer 115 and the solenoids 113 and 114 are driven by the microcomputer. Further, instead of detecting the film driving time by the sensor 28, the sensor 10 is mechanically operated by the gear 31 shown in FIG.
The same is true even if 5.106 is moved.

Further, similarly to the second embodiment, the nonvolatile RA
The same effect can be obtained by calculating the number of sheets discharged by a microcomputer having M and moving the solenoids 113 and 114 based on the count value.

[0126]

As described above, according to the present invention, in a film heating type image heating apparatus using an endless film, the reciprocating movement distance of the film in the film shift control is variable. Due to the grease distribution, etc., it is possible to keep the reciprocation frequency of film deviation control within a certain range even if the film deviation speed changes.
This can prevent excessive stress on the film and eliminate wrinkles and the like. In addition, erroneous detection of the film and temperature rise of the solenoid can be minimized.
Since the sliding wear of the same portion of the heater supporting member is reduced, the life of the entire apparatus can be extended. It can be implemented without increasing the complexity and size of the film shift control mechanism, and can achieve stable film transport for film heating type image heating devices using endless films.
The reliability of the device could 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 schematic configuration diagram of an example of an image forming apparatus using the heating device as a fixing device.

Fig. 4 Outline drawing of endless film

FIG. 5 is a diagram showing a relationship between a film sensor and a film position.

FIG. 6 is a graph showing a relationship between a film position and a film sensor output.

FIG. 7 is a schematic diagram of a control system.

FIG. 8 is a diagram of an example of a unit for counting a film driving time.

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 control program.
Chart

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

FIG. 13 is a schematic diagram of a control system according to a second embodiment.

FIG. 14 is a flowchart of a control program.

FIG. 15 is a schematic diagram of a control system according to a third embodiment.

FIG. 16 is a flowchart of a control program.

FIG. 17 is a partially omitted plan view of an example of a heating device according to a fourth embodiment.

18A and 18B are schematic diagrams of a control system.

FIG. 19 is a flowchart of a control program.

[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 solenoid 26 microcomputer 27 motor 28/33 counting means

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G03G 15/20 G03G 15/16 G03G 15/00 510

Claims (4)

(57) [Claims] 1. A rotating endless film, a shift control means for controlling a shift of the film in a direction perpendicular to a moving direction of the film to be within a predetermined range,
An image heating apparatus for heating an image on a recording material by heat from the film side, comprising counting means for counting the progress of durability of the apparatus; by a predetermined range
An image heating device characterized by changing a width . 2. The image heating apparatus according to claim 1, wherein the count value is the number of recording materials. 3. The image heating apparatus according to claim 1, wherein the count value is an operation time of the apparatus. 4. The image heating apparatus according to claim 1, wherein said counting means is non-volatile.