JPH092691A - Endless film driving gear - Google Patents

Abstract

PURPOSE: To prevent manufacturing in an unstable device of generating a twist of an endless film, b providing a sag detecting means of detecting a sag amount of the endless film in the device having the endless film rotated to be bridged over between at least two suspension wound extending members. CONSTITUTION: An endless film 1 is driven to be rotated among a drive roller 2, film guide member 7 and a heating unit 4. A sag detecting lever 11 is provided with a weight part 12 so as to position the center of gravity of the lever 11 in a left side from a support shaft 10, to always apply rotary moment in the counterclockwise direction by self weight, with a tip end part of a left side arm part always into contact with a film upper surface. When the endless film 1 is sagged due to dispersing accuracy, the detecting lever 11 is placed in a condition shown by a broken line, with a pointer part 13 reading the upper of a scale part 14, and a sagging amount of the film can be confirmed. Accordingly, a proper process, in accordance with a detected sag condition by dispersing part accuracy in the initial assembly step, can be performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an endless film drive device having an endless film (or endless belt) which is stretched between at least two suspension tension members and rotates.

[0002]

2. Description of the Related Art Conventionally, for example, there is a film heating type heating device as a device having an endless film which is stretched between at least two suspension tension members. This heating device is known, for example, from Japanese Patent Laid-Open No. 63-313182.

An embodiment of the heating device is shown in FIG.
The laterally long heating element 4 whose longitudinal direction is perpendicular to the paper surface is, for example, a low heat capacity heater in which an energization resistance heating element pattern is printed on the surface of a ceramic substrate, and is attached to the support stay 4b via a heater holder 4a made of a heat insulating material. It is fixedly installed.

The drive roller 2 and the driven roller (tension roller) 3 are arranged substantially in parallel with the heating body 4 with their both end shaft portions rotatably held between bearings (not shown). The drive roller 2 has, for example, a diameter of 10 to 30 mm,
It has a heat resistant rubber layer on the surface layer. The drive roller 2 is rotationally driven by a rotary drive system including a drive source M.

An endless film 1 suspended and stretched between the above-mentioned driving roller 2, driven roller 3 and heating body 4.
Is a heat-resistant resin film such as polyimide,
Thickness of about 10 to 80 μm, 5 to 20 μm on the outer peripheral surface
And a peripheral length of about 60 to 300 mm.

A pressure roller 5 made of silicon rubber or the like is provided which is in pressure contact with the heating body 4 with the endless film 1 sandwiched therebetween.

When the driving roller 2 is rotationally driven in the clockwise direction shown by the arrow in the drawing, the driving force is transmitted to the endless film 1 by the frictional force between the outer peripheral surface of the driving roller 2 and the inner peripheral surface of the endless film 1, and The endless film 1 is rotationally driven between the three members of the driving roller 2, the driven roller 3, and the heating body 4 in the clockwise direction of the arrow in the figure.

The endless film 1 is pressed against the heating body 4 by the pressure roller 5, and the endless film 1
The inner surface of the rotating body rotates while closely contacting the surface of the heating body 4. The pressure roller 5 rotates following the rotation of the endless film 1.

In a state where the endless film 1 is rotationally driven and the heating body 4 is heated by energization and is controlled to a predetermined temperature, the film 1 at the pressure contact portion (heating nip) N between the heating body 4 and the pressure roller 5 is heated. The heated material P is introduced between the pressure roller 5 and the pressure roller 5, and the pressure contact portion N is nipped and conveyed together with the endless film 1 to transfer the heated material to the endless film 1.
The heat treatment is performed by the heat of the heating body 4 via the.
Numerals 6 and 6 are heated material conveyance guide members before and after the pressure contact portion N.

Such a film heating type heating device is, for example, a copying machine / laser beam printer (LB).
P) In an image forming apparatus such as an electrostatic printer, it can be used as an image heat fixing apparatus for a recording material P as a heated material on which an unfixed toner image to be fixed is formed and carried.

A heating device of a heat roller type, which has been widely used as an image heating and fixing device in an image forming apparatus, has a large heat capacity of the heat roller. Therefore, a wait time for raising the roller to a predetermined fixable temperature. Takes a long time and the image forming apparatus is not used (standby)
Also, electric power must be supplied so as to maintain the start-up temperature, but the film heating type heating device as described above can use both the heating body 4 and the endless film 1 having extremely small heat capacities. Since the temperature rises quickly, even when the temperature of the fixing device is the same as room temperature during standby of the image forming apparatus, the heating member 4 and the endless film 1 can be immediately fixed to a predetermined fixing temperature by energizing the heating member 4. That is, it has excellent quick start performance, and the power consumption of the fixing device during standby can be reduced to zero, power consumption can be reduced, wait time can be shortened, and the temperature inside the image forming apparatus can be suppressed. It has features such as being able to.

[0012]

However, in the above-mentioned conventional example, the endless film 1 which is suspended and stretched between at least two members, that is, the driving roller 2, the driven roller 3 and the heating body 4, is used. In the process of rotation, along with the driving roller 2, the driven roller 3, and the heating body 4, it tends to be slightly or slightly naturally displaced toward one end side or the other end side in the film width direction orthogonal to the film rotation direction.

The factors of the positional deviation due to the displacement of the film toward one side include parallelism and twist between the above-mentioned members on which the endless film 1 is suspended and stretched. To improve the accuracy of these, There is a limit, and it is difficult to prevent the film from moving toward the side by improving the accuracy.

In order to prevent such movement toward the film, a method has been proposed in which the end portion of the endless film is forcibly regulated by a guide. However, the deviation force of the endless film is greater than the strength of the end portion of the endless film. Since it is large, the endless film may be damaged due to durability.

Further, a sensor for detecting the end position of the endless film is provided, and the drive roller 2 is moved in accordance with the deviation.
Although a method of moving the parallel alignment between the driven roller 3 and the driven roller 3 to control the deviation has been proposed, it is not possible to completely control the deviation by changing the surface frictional force (friction coefficient) of the driving roller 2 or the accuracy of the parts. It was difficult.

In such an endless film driving apparatus, in the endless film rotational driving conveyance state, the tension of the endless film portion between the drive roller 2 and the driven roller 3 which is on the downstream side of the drive roller 2 in the endless film conveyance direction. The (tension) becomes lower than the tension of the other endless film portions, and both end portions in the width direction of this endless film portion are likely to sag.

The end portion of this slack endless film is
As shown in FIG. 8, with respect to the shortest (straight line) transport path Z (solid line) of the endless film from the drive roller 2 to the driven roller 3, the transport path X above it (broken line).
Alternatively, although the lower transport path Y (two-dot chain line) is taken, the wrap angle of the slack endless film with respect to the drive roller 2 is smaller than the wrap angle θ ₀ with respect to the drive roller 2 at the center of the endless film. , Θ ₁ when the endless film end takes the above-mentioned orbit X, which is almost the same as the winding angle θ ₀ with respect to the drive roller 2 at the center of the endless film, but the lower orbit Y is taken. In this case, the winding angle becomes θ ₂ and it changes greatly.

Therefore, the wrapping angle of the endless film 1 around the drive roller 2 becomes unstable, the meandering of the endless film occurs, and the conveyance becomes unstable. As a result, wrinkles are likely to occur, the leaning force is increased, and the instability of the leaning control is easily increased.

Therefore, the present invention relates to an apparatus of this type,
It is possible to prevent the production of an unstable device where the endless film shift is unstable, improve the stability of the endless film shift control, and improve the durability of the endless film with a simple configuration. It is intended to improve the stability of the endless film shift control and the reliability of the apparatus.

[0020]

The present invention is an endless film drive device characterized by the following constitutions.

(1) In an apparatus having an endless film that is stretched around at least two suspension tension members, a slack detecting means for detecting the amount of slack of the endless film is provided. Endless film drive.

(2) In an apparatus having an endless film that is stretched around at least two suspension tension members, the slack detecting means for detecting the amount of slack of the endless film and the tension of the endless film are adjusted. Endless film tension adjusting means for controlling the endless film tension adjusting means for controlling the endless film tension adjusting means so as to obtain an appropriate amount of slack based on the amount detected by the slack detecting means. apparatus.

(3) In an endless film driving device having an endless film which is stretched around at least two suspension tension members, a slack detecting means for detecting the amount of slack of the endless film, and the endless film. An endless film driving device comprising: a backing member for an inner surface; and a link mechanism for bringing the backing member into contact with the inner surface of the endless film when the slack detecting means detects a slack.

(4) The endless film driving device as set forth in any one of (1) to (3), wherein the sag detecting means is a swing lever having one end in contact with the endless film.

(5) The endless film drive device according to any one of (1) to (3), wherein the sag detecting means is a non-contact type distance sensor.

(6) A heating member and a pressure member that form a heating nip portion sandwiching the film are provided on the inner surface side and the outer surface side of the endless film, and between the film outer surface and the pressure member of the heating nip portion. The endless film according to any one of (1) to (5), which is a heating device for performing a heat treatment by introducing a material to be heated into the sheet and nipping and conveying the heating nip portion together with the film. Drive.

(7) A heating member and a pressure member that form a heating nip portion sandwiching the film are provided on the inner surface side and the outer surface side of the endless film, and between the film outer surface and the pressure member of the heating nip portion. In addition, an image heat fixing device for introducing a recording sheet carrying an unfixed image and carrying the heating nip portion together with the film by nipping and fixing the unfixed image on the surface of the recording sheet. Do (1)
The endless film drive device according to any one of (1) to (5).

[0028]

[Action]

a) By providing a slack detecting means for detecting the amount of slack of the endless film suspended between at least two suspension tension members, the slack state of the film at the initial assembly stage is caused by variations in the parts precision. Can be detected, and it is possible to prevent the manufacture of a device in which the occurrence of the endless film shift is unstable.

That is, by providing the slack detecting means for the endless film, it is possible to objectively evaluate the slack state of the endless film, and it is possible to detect the slack of the endless film caused by the variation in the parts precision in the initial assembly stage. Performance check at the unit stage,
And quality can be secured.

B) Further, a slack detecting means for detecting the amount of slack of the endless film, and an endless film tension adjusting means for adjusting the tension of the endless film,
By providing the control means that drives the endless film tension adjusting means so that the amount of slack is appropriate based on the amount detected by the slack detecting means, it is possible to increase the latitude and durability due to variations in parts accuracy at the initial assembly stage. It is possible to cope with a changing amount of slack, and it is possible to improve the stability of the endless film deviation control and the durability of the endless film.

C) A slack detecting means for detecting the amount of slack of the endless film, a backing member for the inner surface of the endless film, and the backing member is brought into contact with the inner surface of the endless film when slack is detected by the slack detecting means. By providing the link mechanism, it is possible to realize stable control and quality assurance with a simple configuration without requiring electrical control. That is, with a simple structure, it is possible to improve the stability of the endless film shift control and the reliability of the device.

D) The durability of the endless film can be improved by using a non-contact type sensor as the slack detecting means of the endless film.

[0033]

【Example】

<First Embodiment> (FIGS. 1 and 2) (1) Example of Image Forming Apparatus FIG. 1 shows a schematic view of an example of an image forming apparatus equipped with an endless film driving device according to the present invention as an image heating and fixing device. . The image forming apparatus of this embodiment is a copying machine or a printer using a transfer type electrophotographic process.

Reference numeral 31 is a rotary drum type electrophotographic photosensitive member, which is rotationally driven in the clockwise direction of the arrow at a predetermined process speed (peripheral speed).

Reference numeral 32 denotes a contact charging roller as a photosensitive member charging means, which applies a predetermined charging bias to uniformly charge the surface of the rotating photosensitive member 31 to a predetermined polarity and potential.

The charged surface of the rotary photosensitive member 31 is exposed 33 with desired image information by an image information exposing means (not shown) such as a slit image forming exposing means for a document image and a laser beam scanning exposing means. As a result, an electrostatic latent image corresponding to the target image information is formed on the surface of the rotating photoconductor 31.

The latent image is developed as a toner image by the toner developing device 34.

The toner image is transferred from a paper feeding unit (not shown) to a transfer unit, which is a pressure contact nip between the rotating photoconductor 31 and the transfer roller 35 to which a predetermined transfer bias is applied. It is transferred to the transfer material P as a recording sheet that is conveyed at a timing.

The transfer material P, which has passed through the transfer portion and has received the transfer of the toner image, is separated from the surface of the rotary photosensitive member 31 and is conveyed and introduced into the image heating and fixing device A described in the next item (2). The unfixed toner image is heated and fixed, and is output as a copy or a print.

After the transfer of the toner image onto the transfer material P, the surface of the rotary photoreceptor 31 is cleaned by a cleaning device 36 to remove residual adhered substances such as transfer residual toner, and is repeatedly used for image formation.

(2) Image Heating and Fixing Device A FIG. 2 is a schematic diagram of the structure of the image heating and fixing device A. The image heating and fixing device A of this example is substantially the same device as the film heating type heating device having the rotating endless film shown in FIG. 8, and common components and parts are designated by the same reference numerals and are described again. Is omitted. The same applies to the second to fourth embodiments described later.

In the apparatus of this example, a film guide member 7 is used instead of the driven roller (tension roller) 3 in the apparatus of FIG. This film guide member 7
Is made of, for example, rust-proof sheet metal (zinc-plated steel plate, etc.), and like the heating element 4, has a horizontal length with the direction perpendicular to the paper surface as the length, and is wider than the width of the endless film 1. A spring 8 is stretched between both ends of the film guide member 7 and the immovable member 9 so that the film guide member 7 is always biased in the film tension direction to apply tension to the endless film 1.

As in the apparatus shown in FIG. 8, the endless film 1 is rotationally driven between the driving roller 2, the film guide member 7 and the heating body 4 by the rotational driving of the driving roller 2.

Reference numeral 11 denotes a slack detecting lever which is swingable and rotatable about the support shaft 10. This slack detection lever 11 is
The weight portion 12 is provided so as to correspond to at least one end portion of the film portion between the drive roller 2 and the film guide member 7, and the weight portion 12 is provided so that the center of gravity of the lever 11 is located on the left side of the support shaft 10. The turning moment in the counterclockwise direction always acts on the support shaft 10 due to its own weight, and the tip of the left arm always contacts the upper surface of the film. In addition to its own weight, a tension spring, a torsion coil spring, or the like may be used to constantly apply a counterclockwise turning moment to the detection lever 11. The tip portion of the right arm of the detection lever 11 is a pointer portion 13, and the scale portion 1 attached to the immovable member 1
4 is shown.

Thus, when tension is applied to the endless film 1 and there is no slack, the detection lever 11 is in the rotation angle state as shown by the solid line, and the pointer portion 1 of the detection lever 11 is in the state.
Reference numeral 3 indicates the lower side of the scale portion 14, and the winding angle between the endless film 1 and the driving roller 2 at that time is θ ₁ .

On the other hand, when the endless film 1 is sagging due to variations in the accuracy of the components, the detection lever 11 is in the rotation angle state as shown by the broken line, and the detection lever 1
The pointer portion 13 of 1 indicates the upper side of the scale portion 14, and the winding angle between the endless film 1 and the driving roller 2 at that time is θ.
_{It is 2} .

As can be seen from the figure, θ ₂ > θ
_When the film is slack, the wrap angle of the endless film 1 with respect to the drive roller 2 becomes large.

Since the amount of change in the wrapping angle is the amount of film slack, the amount of film slack can be confirmed by visually checking the scale portion 14. In other words, the wrapping angle can be checked.

As a result, in the initial assembly stage, it becomes possible to detect the slackened state of the film caused by the variation in the parts precision, and appropriate processing is performed in accordance with the detected slackened state, and the occurrence of the endless film deviation is unstable. It is possible to prevent the manufacture of various devices. That is, by providing a slack detecting means for the endless film, it is possible to objectively evaluate the slack state of the endless film, and it is possible to detect the slack of the endless film caused by variations in parts accuracy at the initial assembly stage, and at the unit stage. Performance check and quality assurance can be performed.

Reference numeral 71 is a recording sheet P for the pressure roller 5.
An anti-rolling claw, 72 is a pair of fixing paper discharge rollers.

<Second Embodiment> (FIG. 3) FIG. 3 is a schematic view of the configuration of the image heating and fixing apparatus A of this embodiment.

In this embodiment, the tip of the right arm of the detection lever 11 is the sensor flag section 15.
A sensor unit (photo interrupter or the like) 16 related to the sensor flag unit 15 is attached to a stationary member, and an ON signal is generated when the sensor flag unit 15 enters the sensor unit 16 and an OFF signal is generated when the sensor flag unit 15 is separated. It is composed.

Also, at least one end of the spring 8 on at least one side of the biasing springs 8 at both ends of the film guide member 7 on the side opposite to the film guide member 7 side is a link freely rotatable about the support shaft 40. It is locked to a pin 42 implanted in one arm portion of 41. The other arm of the link 41 is engaged with the advancing / retreating plunger 44 of a solenoid 43, which is fixedly mounted on and supported by the immovable member 9, through a pin 45.

When the energization of the solenoid 43 is OFF, the link 41 is rotated counterclockwise around the support shaft 40 by pulling the spring 8 as shown by the solid line, and the plunger portion 44 of the solenoid 43 is moved from the solenoid 43. It is in a state in which it projects and its tip portion abuts the stationary receiving member 9a as shown by the solid line. In this state, the film guide member 7 is subjected to a predetermined pulling force f ₁ by the spring 8.
And a predetermined tension (appropriate tension) acts on the film 1 by the urging force. This is the first tension state of the film.

When the solenoid 43 is energized,
The plunger portion 44 of the solenoid 43 is the solenoid 43
When the link 41 is pulled in, the link 41 is rotated around the support shaft 40 in the clockwise direction as shown by the chain double-dashed line, as shown by the chain double-dashed line. Will be up. In this state, the film guide member 7 is applied with a tensile biasing force f ₂ (> f ₁ ) stronger than the above-mentioned pulling biasing force f ₁ when the solenoid is OFF, and a strong tension acts on the film 1 by the biasing force. This is the second tension state of the film.

Reference numeral 17 is a control circuit (CPU), and the sensor section 16 is connected to the control circuit 17 via a signal bus 18. A solenoid drive circuit 19 is connected to the control circuit 17 via a signal bus 20.
Is connected to the solenoid 43 via the signal bus 21.

When the slackened state of the endless film 1 is shown by the solid line (at the proper tension), the slackened detection lever 11
Indicates the rotation angle state indicated by the solid line, and the sensor flag unit 15
Is separated from the sensor unit 16, the signal from the sensor flag unit 15 to the control circuit 17 is an OFF signal, there is no output signal from the control circuit 17 to the solenoid drive circuit 19, and therefore the solenoid 43 is in the OFF state. The film 1 is kept in the first tension state and the endless film 1 is given a proper tension.

On the other hand, when the slack state of the endless film 1 is in the two-dot chain line state as shown in the figure, that is, when the endless film 1 is slack, the slack detecting lever 11 is in the two-dot chain line state and the sensor flag Since the section 15 interrupts the sensor section 16, the signal from the sensor flag section 15 to the control circuit 17 is an ON signal, and there is an output signal from the control circuit 17 to the solenoid drive circuit 19. Therefore, the solenoid 43 is in the ON state. The film 1 is further tensioned and is kept in the second tension state. As a result, the endless film 1 is in the state indicated by the solid line, and the slack is eliminated.

Therefore, it becomes possible to deal with the expansion of the latitude due to the variation of the parts accuracy in the initial assembly stage and the amount of slack which changes due to the durability, etc., and the stability of the endless film deviation control and the durability of the endless film can be improved. .

<Third Embodiment> (FIG. 4) FIG. 4 is a schematic view of the configuration of the image heating and fixing apparatus of this embodiment.

In the present embodiment, the distal end portion of the right arm portion of the detection lever 11 is provided with the elongated hole portion 46. 47
Is a slide volume mounted and supported by an immovable member, and a slider pin 47a of this slide volume
And the elongated hole portion 46 of the detection lever 11 are engaged with each other, and the rotational swing of the slack detection lever 11 can be detected in an analog manner by the slide volume 47.
That is, the slide volume 47 outputs an analog signal corresponding to the slack state of the endless film 1 detected by the detection lever 11. The analog output signal is input to the control circuit 17 via the signal bus 48 → A / D converter 49 → digital signal bus 50.

54 is a step motor, 56 is a first gear provided on a rotary shaft 55 of the motor, and 57 is a first gear 5
A second gear meshed with the gear 6, and a lever 58 fixed to a shaft 57a of the second gear 57. Film guide member 7
At least one side of the bias springs 8
The end portion of the side opposite to the film guide member 7 side is locked to a pin 59 planted in the lever 58.

Therefore, the lever 58 swings in accordance with the rotation angle of the step motor 54, whereby the biasing force of the spring 8 changes, and the tension of the endless film 1 can be changed via the film guide member 7. .

The control circuit 17 and the step motor 54 are
They are connected via a signal bus 51, a step motor drive circuit 52, and a signal bus 53.

When the slack state of the endless film 1 is in the solid line state as shown in the figure (at the proper tension), the slack detection lever 11 is in the rotation angle state shown in the solid line, and the value of the slide volume 47 is, for example, In the lowered state (small resistance value), it is input to the control circuit 17, and the step motor 54
Is not driven.

The endless film 1 gradually sags 2
When the state indicated by the dotted chain line is reached, the slide volume 47
Is increased in resistance value and is input to the control circuit 17, and based on the signal, the step motor 54 causes the lever 5 to move.
8 is rotated clockwise, and the tension is properly controlled so that the endless film 1 is in the slack inside state.

<Fourth Embodiment> (FIG. 5) FIG. 5 is a schematic view of the configuration of the image heating and fixing apparatus of this embodiment.

The apparatus according to the present embodiment is different from the apparatus according to the third embodiment in that the contact lever 11 which is a contact type as the slack detecting means for the endless film 1 is replaced by a non-contact type distance sensor 60 (for example, a Sound wave sensor or infrared sensor) is used. The sensor 60 is fixedly supported by the immovable member 9.

The sensor 60 outputs an analog signal corresponding to the detected slackened state of the endless film 1. The analog output signal passes through the signal bus 48 → A / D converter 49 → digital signal bus 50 and the control circuit 1
Enter 7

The other device configuration is the same as that of the third embodiment.

When the slackened state of the endless film 1 is in the solid line state as shown in the figure (at the proper tension), the distance between the endless film 1 and the sensor 60 is short, and the electric resistance value becomes small, for example. It is input to the circuit 17, and the step motor 54 is not driven.

The endless film 1 gradually sags 2
When the state indicated by the dotted chain line is reached, the distance between the endless film 1 and the sensor 60 becomes long and the electric resistance value becomes small and is input to the control circuit 17, and the step motor 54 operates the lever 58 based on the signal. The endless film 1 is driven in a clockwise rotating direction so that the endless film 1 has a proper tension.

By using the non-contact type sensor 60 as the sagging detecting means of the endless film, the durability of the endless film can be improved.

<Fifth Embodiment> (FIG. 6) FIG. 6 shows a fifth embodiment. FIG. 6 is a view showing a cross section in the longitudinal direction of the endless film 1, and at least one end of the endless film 1 is provided with a slack detection lever 11 capable of swinging and rotating about a rotating shaft 10,
The slack detection lever 11 is provided with a weight portion 12 so that its own center of gravity is located on the left side of the rotation center axis 10.
The weight portion 12 urges and contacts the endless film 1 by its own weight. In addition to its own weight, a biasing force may be applied to the detection lever 11 by a tension spring, a torsion coil spring, or the like. A hole 61 is formed on the left side of the detection lever 11, and a link lever 62 is connected so as to engage therewith. One end of the link lever 62 is provided at the hole 63 with the other link lever 64.
The link lever 64 is swingable around the rotary shaft 65. An endless film backing member 65 is provided at the left end of the link lever 64.

By these link mechanisms, when the endless film 1 sags and changes from the solid line state to the two-dot chain line state, the detection lever 11 also changes to the two-dot chain line state, and the link action causes the endless film backing member 65 to move upward. It is possible to regulate the slack of the endless film 1 by moving to. Thereby, the change in the winding angle of the endless film 1 can be reduced.

The slack detecting means 11 and the tension adjusting means 65 are linked by a link mechanism as in the present embodiment, so that electrical control is not required and the control is stabilized and the quality is improved with a simple structure. Securement can be realized. That is, with a simple structure, it is possible to improve the stability of the endless film shift control and the reliability of the device.

Also, the endless film backing member 65
Is controlled by a solenoid, a step motor or the like as shown in FIG. 3, FIG. 4 or FIG. 5, the sag detecting means also uses FIG. 3, FIG. 4 or FIG. Is obtained.

<Others> FIG. 7 shows the heating element 4 and the driving roller 2.
In an apparatus having a structure in which the endless film 1 is suspended and stretched between two members and is driven to rotate, a non-contact type distance sensor 60 is provided as a sag detecting means to electrically detect the amount of sag of the endless film. Then, it is confirmed by an appropriate display means (not shown).

The heating device as the image heating and fixing device of the embodiment is a device for heating the recording material P carrying an image to modify the surface property, a hypothetical fixing device, a sheet-like material being nipped and conveyed and dried. It can be effectively used as a means and a device for heat-treating a material to be heated widely such as a device for laminating.

The heating means of the heating nip portion N may be magnetic induction heating means or the like. In this case, the film 8 itself can be used as a magnetic induction heating member.

The image forming process for the recording material P of the image forming apparatus shown in FIG. 1 is not limited to the transfer type electrophotographic process as in the embodiment, and other known transfer type or direct type image forming principles and processes. Of course, it can be

[0082]

INDUSTRIAL APPLICABILITY As described above, according to the present invention, regarding an apparatus having an endless film which is hung between at least two suspension tension members and rotates, it is possible to manufacture an apparatus in which endless film deviation is unstable. It is possible to improve the stability of the endless film deviation control and the durability of the endless film, and with a simple configuration, it is possible to improve the stability of the endless film deviation control and improve the reliability of the device. And the intended purpose is often achieved.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an example of an image forming apparatus.

FIG. 2 is a schematic configuration diagram of an image heating and fixing device as an endless film driving device of the first embodiment.

FIG. 3 is a schematic configuration diagram of an image heating fixing device as an endless film driving device of a second embodiment.

FIG. 4 is a schematic configuration diagram of an image heating fixing device as an endless film driving device of a third embodiment.

FIG. 5 is a schematic configuration diagram of an image heating fixing device as an endless film driving device of a fourth embodiment.

FIG. 6 is a schematic configuration diagram of an image heating and fixing device as an endless film driving device of a fifth embodiment.

FIG. 7 is a schematic configuration diagram of an image heating fixing device as an endless film driving device of another configuration mode.

FIG. 8 is a schematic configuration diagram of an image heating fixing device as a conventional endless film driving device.

[Explanation of symbols]

 1 Endless Film 2 Driving Roller 4 Heating Body 7 Film Guide Member 8 Pulling Spring 11 Slack Detection Lever 14 Scale 15 Sensor Flag 17 Sensor 17 Control Circuit (CPU) 43 Solenoid 47 Slide Volume 53 Step Motor 60 Non-contact Distance Sensor 62/64 Link member 65 Backing member

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mihoko Sakurai 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Atsushi Nishibata 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Within the corporation

Claims (7)

[Claims] 1. An apparatus having an endless film which is stretched around at least two suspension tension members and rotates, wherein slack detecting means for detecting a slack amount of the endless film is provided. Film drive. 2. An apparatus having an endless film which is stretched between at least two suspension tension members and rotates, wherein a slack detecting unit for detecting a slack amount of the endless film and a tension of the endless film are adjusted. An endless film drive device, comprising: an endless film tension adjusting means; and a control means for driving the endless film tension adjusting means so that an appropriate amount of slack is obtained based on a detection amount from the slack detecting means. . 3. An endless film driving device having an endless film which is stretched between at least two suspension tension members and rotates, wherein a slack detecting means for detecting a slack amount of the endless film, and an inner surface of the endless film. An endless film driving device, comprising: a backing member for the backing member and a link mechanism for bringing the backing member into contact with the inner surface of the endless film when slack is detected by the slack detecting means. 4. The endless film drive device according to claim 1, wherein the sag detecting means is a swing lever having one end in contact with the endless film. 5. The endless film drive device according to claim 1, wherein the slack detecting unit is a non-contact distance sensor. 6. A heating member for forming a heating nip portion sandwiching the film and a pressing member are provided on the inner surface side and the outer surface side of the endless film, and the heating nip portion is provided between the outer surface of the film and the pressing member. The endless film drive according to any one of claims 1 to 5, which is a heating device for introducing a material to be heated and nipping and transporting the heating nip portion together with the film for heat treatment. apparatus. 7. A heating member and a pressing member that form a heating nip portion with the film sandwiched between the inner surface side and the outer surface side of the endless film, and the heating nip portion is provided between the outer surface of the film and the pressing member. An image heat fixing device for introducing a recording sheet carrying an unfixed image and transporting the heating nip portion together with the film by heat-fixing the unfixed image on the recording sheet surface. The endless film drive device according to any one of claims 1 to 5.