JPH08127449A - Drive device for endless film - Google Patents

Abstract

PURPOSE: To perform stable control of gathering-aside without lowering and instability of rotation torque due to peeling-off of a film by a method wherein a gathering-aside preventing mechanism for an endless film is arranged at one end of a film stretching- around member and a film position detecting means is arranged at the other end part. CONSTITUTION: A heating body 4 is arranged inside an endless film 1 around a drive roller 2 and a driven roller 3 and in a position where the heating body is positioned facing a pressure roller 5 with a paper sheet P nipped therebetween. A gathering-aside preventing mechanism for a film having a rotary ring 6 located concentrically to the driven roller 3 is disposed on the end side, situated this side, of the film 1. Further, a film position detecting means 30 is provided to detect a gathering-aside amount of the film 1 when the film 1 is run in the direction of an arrow mark through energization of the drive roller 2. A absolute value of a gathering-aside amount of the film 1 is detected from a ratio between an ON-time in which a light shielding plate 31c passes a light running from the light emission part of a sensor 32 to a light receiving part and an OFF-time in which light is shielded and the occurrence of gathering-aside exceeding a specified amount is displaced by a display device 35.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus having an endless film (or an endless belt member) which is hung between at least two suspension tension members to rotate, and the film is formed during the rotation process of the endless film. Driving an endless film equipped with a mechanism (deviation movement regulation mechanism, deviation movement control mechanism) that prevents the film from moving along the suspension tension member in the film width direction (the film rotation axis direction) intersecting the film rotation direction. Regarding the device.

[0002]

2. Description of the Related Art As a device having an endless film which is stretched around at least two suspension tension members, there is, for example, a film heating type heating device. This heating device is known, for example, from Japanese Patent Laid-Open No. 63-313182. One 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 supported via a heater holder 4a made of a heat insulating material. It is fixedly provided on the stay 4b.

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 source M of the rotary drive system of the drive roller 2 is provided.

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 heating element 4 with the endless film 1 sandwiched therebetween.
A pressure roller 5 made of silicone rubber or the like is disposed in pressure contact with.

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 element 4 by the pressure roller 5, and the inner surface of the endless film 1 is rotated while being in close contact with the surface of the heating element 4 and sliding. 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 element 4 generates heat by energization and is controlled to a predetermined temperature, the endless film of the pressure contact portion (heating portion) N between the heating element 4 and the pressure roller 5 is controlled. 1 to be heated between the pressure roller 5 and the pressure roller 5, the endless film 1 is sandwiched and conveyed with the pressure contact portion N, and the material to be heated P is heated by the heat of the heating body 4 through the endless film 1. It is something to process. The conveyance guide member 20 for the material to be heated P is the pressure contact portion N.
It is a guide member for the front and rear heated materials P.

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, an image heat fixing device for a recording material P as a heated material on which an unfixed toner image to be fixed is carried and a recording material P carrying an image
A device that heats the surface to modify the surface property, a device that is supposed to wear, etc.
It can be effectively used as a means / apparatus for widely heating materials to be heated.

The heating roller type heating device which has been widely used as an image heating and fixing device in an image forming apparatus has a large heat capacity of the heating roller. Therefore, a weight for raising the roller to a predetermined fixing temperature is used. It takes a long time, and electric power must be supplied so as to maintain the startup temperature even when the image forming apparatus is not in use (during standby). However, the film heating type heating apparatus as described above uses the heating element 4 Since both endless films 1 having a very small heat capacity can be used and 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 element The heating element 4 and the endless film 1 immediately rise to a predetermined fixing possible temperature by energization, that is, they have excellent quick start properties. , The power consumption of the fixing device during standby can be zero, it has a power saving, it is possible to shorten the wait time, also features such as the internal temperature of the image forming apparatus the unit can also be suppressed.

By the way, as in the film heating type heating device or the image heating and fixing device of the above example, at least 2
In an apparatus having one or more members, that is, the endless film 1 which is suspended between the driving roller 2, the driven roller 3, and the heating body 4 and rotates, the endless film 1 is rotated in the course of rotation of the endless film 1. A driving roller 2 and a driven roller 3 in which an endless film 1 is suspended and stretched,
In addition, along with the heating element 4, it tends to naturally move toward the one end side or the other end side in the film width direction orthogonal to the film rotation direction to a greater or lesser degree.

The factors causing the positional deviation due to the displacement of the film toward one side include parallelism and twisting between the above-mentioned members that suspend the endless film 1 in a suspended manner, but there is a limit to improving the accuracy of these. However, it is difficult to prevent the above-mentioned movement toward the film only by improving the accuracy.

As one of means for preventing or controlling the deviation of the endless film 1, the film deviation detection in which the end of the endless film 1 is applied to one end of a member on which the endless film 1 is suspended and stretched is detected. A ring is provided, and the sliding movement of the endless film that acts on the deviation detection ring according to the width of the edge of the film with respect to the deviation detection ring, which changes with the deviation movement of the endless film 1 during the rotation process of the endless film 1. There is a method in which a film deviation is controlled by converting a rotational force (rotational torque) by a force into a linear motion and moving the film suspension tension member relatively to a balanced position.

Specific examples are shown in FIGS. This example is applied to the film heating type heating device shown in FIG.

The driven roller 3, which is one of the film suspension tension members, has a shaft portion on the rear end side rotatably supported by a universal bearing (not shown), and the shaft portion 3a on the front end side swings. Bearing 7
It is rotatably supported by.

The rocking bearing 7 is biased by a pressing spring 8 so as to bias the driven roller 3 in the direction in which the endless film 1 is stretched, and the rocking bearing 7 of the driven roller 3 is also biased.
A pulling spring 10 pulls up and biases the side so that it is biased in the lifting direction.

A ring 6 as a film deviation detection member is rotatably and concentrically fitted to a shaft portion 3a of the driven roller 3 on the side of the rocking bearing 7. The end surface 6a of the ring 6 (the side closer to the center in the width direction crossing the running direction of the endless film 1) is in contact with the end surface of the driven roller 3 on the front end side, and is substantially the same as the driven roller 3. Of diameter.
A cylindrical control belt winding portion 11 having an outer diameter smaller than that of the driven roller 3 is provided on the front end surface of the ring 6 integrally with the ring 6 and concentrically with the shaft 3a. The ring 6 is in a state in which the edge portion on the front end side of the endless film 1 suspended by the driven roller 3 is engaged.

One end 9a is fixed to the outer surface of the control belt winding section 11, and the other end 9b is locked to a stationary locking section 21 (for example, a side plate (not shown)) below the control belt winding section 11. A control belt 9 is provided. The control belt 9 is a member that is flexible and has a small tensile elongation. Further, the control belt 9 is wound around the winding portion 11 in a direction in which the ring 6 is wound into the winding portion 11 by a rotational torque generated by sliding contact with the endless film 1.

Next, the operation will be described. When the drive source M is energized and the drive roller 2 rotates, the endless film 1 is moved to the position shown in FIG.
At the time of traveling in the arrow direction, the driven roller 3 is driven to be wound, and the ring 6 and the endless film 1 slide.

During the rotational driving process of the endless film 1, the endless film 1 moves toward the rear end side direction B in the film width direction, and the width (amount of contact) W of the endless film 1 with respect to the ring 6 on the front end side is small. Then, the frictional force between the endless film 1 and the ring 6 becomes small, so that the rotational torque T acting on the ring 6 also decreases.

Therefore, the tension spring 1 is stronger than the control belt winding force of the winding portion 11 due to the rotation torque T.
A force F that pulls up the front end side of the driven roller 3 by 0
Is larger, the front end side of the driven roller 3 is displaced upwards U by using the free bearing on the rear end side as a fulcrum, and this displacement causes the driven roller 3 to move forward and rearward with respect to the axes of the driving roller 2 and the heating body 4. Twist occurs. By this, the drive roller 2,
The peripheral length of the endless film 1 to be wound around the driven roller 3 and the heating body 4 increases on the front end side of the driven roller 3, and as the endless film 1 moves in the rear end side direction B, the endless film 1 moves. The force that moves to the far end side decreases and becomes 0, and the endless film 1 goes too far to the far end side due to inertia, so a force that returns to the front end side of the endless film 1 occurs, and the endless film 1 has the above film width. The direction B of the film width direction, which is the opposite direction to the direction B of the rear end side of the direction, returns to the direction A of the front end side of the film width direction. Even when the oscillating bearing 7 hits the upper limit stopper member 13 shown by the solid line in FIG. 6 when the endless film 1 moves too far to the rear end side, the endless film 1 similarly returns to the front end side direction A and moves. To do.

With the return movement of the endless film 1 in the front end side direction A, the width W of the endless film 1 applied to the ring 6 increases, and the frictional force between the endless film 1 and the ring 6 increases. The rotational torque T that acts also increases.

As the rotational torque T increases, the control belt winding force of the winding portion 11 increases, and the pulling force of the control roller winding of the winding portion 11 on the front end side of the driven roller 3 is caused by the tension spring 10. When the pulling force F is larger than the pulling force F, the control belt 9 is wound around the winding portion 11, and the front end side of the driven roller 3 is pulled down against the tension spring 10 around the universal bearing on the back end side. It is displaced to the lower LW.

Due to the displacement of the driven roller 3 to the lower side LW, the driven roller 3 is twisted in the front and back with respect to the axes of the driving roller 2 and the heating body 4, which is the reverse of the state of FIG. As a result, the circumference of the endless film 1 to be wound around the driving roller 2, the driven roller 3, and the heating body 4 becomes shorter on the front end side of the driven roller 3, and the endless film 1 moves to the front end side. As it moves, the force to move to the front end side of the endless film 1 decreases and 0
Since the endless film 1 goes too far to the front end side due to inertia, a force toward the back end side of the endless film 1 is generated, and the endless film 1 is in a direction opposite to the front end side direction A in the film width direction. It moves back in the widthwise direction B on the far end side. Even when the rocking bearing 7 hits the lower limit stopper member 12 shown by the solid line in FIG. 7 when the endless film 1 moves too far to the front end side, the endless film 1 similarly moves toward the rear end side direction B. To do.

That is, the ring 6 is the endless film 1.
Rotational torque T is applied due to the frictional force with
Changes and the larger the film width W, the more ring 6
The rotational torque T of becomes larger and the force of winding the control belt 9 of the winding portion 11 increases.

The front side of the driven roller 3 is displaced up and down by U and LW depending on the magnitude relationship between the force for winding the control belt 9 and the pulling force F of the tension spring 10, so that the directions A and B of the rotating film 1 deviate. It is controlled.

Thus, the U above the front end side of the driven roller 3
In the process of displacing to the lower side or the process of displacing to the lower LW, the pull-up force F of the driven roller on the front end side by the tension spring 10 and the pull-down force of the driven roller on the front end side by the force of winding the control belt 9 of the winding portion 11 are balanced. There are times At this time, the driven roller 3 remains stationary at a position closer to the endless film 1 and the endless film 1 stops moving and rotates at a fixed position.

As described above, the present construction is a method for automatically shifting the endless film to control the shift using the shift of the endless film. However, if the user uses the device abnormally, for example, when the entire device is placed on an uneven surface and the heating device is distorted, the endless film may slip to the end of the roller without being able to control the deviation. there were. In addition, if the user mistakenly passes the paper to a position that is largely deviated from the designated reference position, the temperature distribution inside the device may change significantly, and as a result, deviation control may become impossible. . In such a case, the device itself is not a malfunction, and if the user uses it normally, the original operation can be expected.
Therefore, a means for detecting the position of the endless film is provided so as to display a warning to the user when the position of the endless film is abnormal. As the detection method, since the endless film does not necessarily have a light-shielding color, stable detection cannot be performed by non-contact optical detection, and therefore detection is performed using a contact lever. In particular, in order to detect the absolute position of the endless film, it is effective to detect it by cutting the end face of the endless film obliquely. By doing so, the absolute amount of the shift amount of the endless film can be obtained from the ratio of the time when the lever is displaced and the time when the lever is not displaced by the running of the endless film. Conventionally, the endless film deviation detecting means is disposed on the same side as the deviation control mechanism provided with the ring.

[0030]

However, if the ring and the endless film position detecting means are arranged on the same side, the following disadvantages occur. (1) In the case of the detection method in which the end portion of the endless film is obliquely cut and the absolute position of the endless film is always grasped, the width W of the endless film applied to the ring does not change even if the position of the entire endless film does not change. It will change greatly in the cycle of 1 round. For this reason, the obtained rotation torque T greatly changes in one turn of the endless film, and the driven roller 3 largely moves up and down. As a result, not only the operation becomes unstable, but also the image may be disturbed. (2) Even if the end portion of the endless film is not cut obliquely, the levers are in contact with the end surface of the endless film, so that some curling occurs at the edge of the endless film. In that case, since the contact force of the endless film with the ring becomes small, the frictional force decreases and the rotation torque T also decreases. As a result, the driven roller 3 cannot be lowered for the full stroke, and as a result, the deviation control capability may decrease.

It is an object of the present invention to provide an endless film driving device which is not affected by the film deviation detection device with respect to the endless film deviation prevention mechanism.

[0032]

SUMMARY OF THE INVENTION A first invention of the present invention is an apparatus having an endless film which is hung between at least two suspension tension members to rotate, wherein at least one film tension tension member is provided. A film shift detection member, which is rotatably supported at one end, and which has an end of the endless film, and is connected to the film shift detection member. When the rotational torque is applied by the frictional force with the applied endless film portion, the rotational movement of the film deviation detection member is converted into a linear movement to displace the end portion of the film suspension tension member in a predetermined direction. A film position detecting hand is provided near the other end of the film suspending / stretching member. We were provided a driving apparatus of an endless film characterized.

In a second aspect of the present invention, the film suspension tension member provided with the film deviation detection member is a roller, and the film deviation detection member is a ring member rotatable independently of the rollers. The drive device for an endless film according to the first invention is characterized in that

According to a third aspect of the present invention, an apparatus having an endless film which is stretched and rotated between at least two film suspension tension members is fixed to a heating body, and at least one of the heating body and the heating body is fixed. A heat-resistant endless film that is stretched and rotated between two film suspension tension members,
The recording material has a pressurizing member that is in close contact with the heating body via the endless film and is conveyed, and heat of the heating body is applied to the recording material via the endless film to heat an image on the recording material. The endless film driving device according to the first or second invention is a fixing device for fixing.

[0035]

Embodiments of the present invention will be described below with reference to the drawings.

[Embodiment 1] This embodiment is carried out in the film heating type image heating and fixing device shown in FIG.
The endless film deviation prevention mechanism is the same as that shown in FIGS.

In the first embodiment, as shown in FIG. 1, one end of the endless film 1 provided with a ring 6 between the driving roller 2 and the driven roller 3 at a position close to the driven roller 3 and an end opposite to the one end. The film position detection means 30 is provided on the side (the rear end side) so that the end of the endless film 1 on the side of the ring 6 coincides with the traveling direction.
The film position detection means 30 includes a detection lever 31 and a sensor 3.
2, consisting of a sensor holder 33.

End portion 1a on the far end side of the endless film 1
Is cut obliquely to the running direction of the endless film 1 when detecting the absolute position of the endless film 1, and is parallel to the running direction of the endless film 1 when detecting the relative position to the film position detecting means 30. . The end portion 1a is cut such that the width of the endless film 1 is the smallest at one location of the endless film 1 and the width is the largest at the other location, and the width gradually changes between the smallest width portion and the largest width portion. It is supposed to do.

The detection lever 31 has a stylus 31a with which the end 1a on the far end side of the endless film 1 comes into contact with the tip of the arm 31b. The base of the arm 31b is rotatably mounted on a fixed vertical shaft 33a provided on the sensor holder 33. It is supported. The arm 31b is biased by a spring (not shown) toward the end portion 1a on the rear end side of the endless film 1. A fan-shaped light-shielding plate 31c is attached to the root of the arm 31b with the center of the vertical shaft 33a as the center.

The sensor 32 has a light emitting portion and a light receiving portion with the edge of the arc portion of the light shielding plate 31c in between. Sensor 32
Is fixed to the sensor holder 33, and the sensor holder 33 is fixed to a stationary portion, for example, a side plate (not shown) of the heat fixing device.

The signal detected by the sensor 32 is sent to the controller 34.
Sent to. End portion 1a on the far end side of the endless film 1
Is cut obliquely with respect to the running direction of the endless film 1, the control device 34 determines from the ratio of the time when the sensor 32 during one rotation of the endless film 1 receives the light and the time when the sensor 32 does not receive the light. The absolute value of the deviation amount of 1 is calculated. Further, when the end portion 1a on the far end side of the endless film 1 is parallel to the running direction of the endless film 1, the light from the light emitting portion of the sensor 32 passes through the arc of the light shielding plate 31c and reaches the light receiving portion. A large number of holes are provided along the arc, and the light receiving section sends the received light as pulses to the control device 34. Alternatively, the light shielding plate 31c is an arc-shaped magnetic scale, for example, and the sensor 32 reads the magnetic scale. Alternatively, the scale may be optically read. When the end portion 1a on the rear end side of the latter endless film 1 is parallel to the traveling direction of the endless film 1, the control device 34 reads the position of the endless film 1 with respect to the film position detection means 30.

The control device 34 drives the display device 35 to display when the amount of deviation of the endless film 1 exceeds the specified value as described above. Alternatively, at the same time when the apparatus is stopped, it is displayed on the display device 35 that the endless film 1 is excessively close.

Next, the operation of the above configuration will be described.

When the endless film 1 travels in the direction of the arrow in FIG. 1 due to the urging of the drive roller 2, the front side deviation control mechanism has already acted as if it were full, and the endless film 1 travels at a fixed position. When the device is placed in a place where twisting occurs as described above, or when the device is placed obliquely, the amount of shift of the endless film 1 increases despite the function of the above-described shift control mechanism. When the end portion 1a on the far end side of the endless film 1 is obliquely cut, the film position detection means 30 causes the detection lever 31 during one rotation of the endless film 1 to move at a certain angle about the vertical axis 33a. It reciprocates, and the shading plate 31c is the sensor 3
The position where the light from the light emitting part 2 to the light receiving part is blocked,
The position where light is transmitted to the light receiving portion through this light is set. Since the ratio of the ON time for transmitting the light and the OFF time for blocking the light depends on the position of the end portion 1a on the back end side of the endless film 1,
The absolute value of the shift amount of the endless film 1 can be detected from the on / off time ratio. This deviation amount is determined by the control device 34.
Is calculated, and when the amount exceeds the specified amount, it is displayed on the display device 35. Alternatively, the device is stopped at the same time.

End portion 1a on the far end side of the endless film 1
If it is not cut diagonally, Star Rice 31a
The position of the light shielding plate 31c is determined by the position of
Is a circular arc scale, the scale of the scale read by the sensor 32 is sent to the control device 34, whereby the deviation amount of the endless film 1 is calculated and displayed on the display device 35 when the deviation amount exceeds the specified amount. Alternatively, the device is stopped at the same time.

Since the position of the end portion 1a on the back end side of the endless film 1 is detected in this manner, the end portion on the front end side of the endless film 1 is located at the end portion of the endless film 1.
Since the film position detecting means 30 does not come into contact with the end portion on the front end side, the end portion does not turn over, and the endless film deviation prevention mechanism operates by the film position detecting means. You can't be made inaccurate.

[Embodiment 2] FIG. 2 shows a schematic structure of an example of an image forming apparatus in which a heating device having the film driving device of the above-described Embodiment 1 is incorporated as an image heating and fixing device 200. The image forming apparatus of this example is a reciprocating platen type, a rotary drum type, a transfer type, and a process cartridge attaching / detaching type electrophotographic copying apparatus.

The reciprocating type document placing table 101 made of a transparent plate member such as a glass plate disposed on the upper surface plate 102 of the apparatus main body 100 has predetermined upper and lower surfaces on the upper surface plate 102 in the drawing. It is reciprocally driven at a speed.

The original G is set by placing the original G on the upper surface of the original placing table 101 according to a predetermined placing standard with the image side to be copied facing downward, and pressing the original pressure plate 103 to cover it. It

A slit opening 10 serving as a document illuminating section which is opened on the surface of the upper surface plate 102 with the direction perpendicular to the reciprocating direction of the document placing table 101 (direction perpendicular to the paper surface) as the longitudinal direction.
4 is provided.

The downward image surface of the document G placed and set on the document placing table 101 sequentially passes through the position of the slit opening 104 from the right side to the left side in the reciprocating movement of the document placing table 101 to the right. Iki, lamp 1 in the process of passing
The slit opening 104 for the light of 05 and the transparent document placing table 1
The light is received and scanned through 01 to be illuminated and scanned, and the reflected light of the illumination scanning light from the original is image-wise exposed on the surface of the photosensitive drum 107 by the image element array 106.

The photosensitive drum 107 is coated with a photosensitive layer such as a zinc oxide photosensitive layer and an organic semiconductor photosensitive layer, and is rotated in a clockwise direction indicated by an arrow in the figure at a predetermined peripheral speed around a central support shaft 108, and the rotation thereof is performed. In the process, a uniform charging process of positive polarity or negative polarity is performed by the charger 109, and the uniformly charged surface is subjected to the image formation exposure (slit exposure) of the original image, so that the surface of the photosensitive drum 107 is imaged. An electrostatic latent image corresponding to the exposed original image is sequentially formed.

This electrostatic latent image is sequentially visualized by the developing device 110 with toner made of resin or the like that is softened and melted by heating, and the toner image which is the visualized image is arranged at a portion where the transfer discharger 111 as a transfer portion is provided. Shift to.

The recording material P in the cassette S in which the recording material P is stacked and accommodated is fed out and fed one by one by the rotation of the feeding roller 112, and then the front end of the toner image on the photosensitive drum 107 is transferred by the registration roller 113. When the recording material P reaches the position of the discharger 111, the leading edge of the recording material P also reaches the position between the transfer discharger 111 and the photosensitive drum 107, and is fed in a timed manner so that they coincide with each other.

Then, the image on the photosensitive drum 107 side is sequentially transferred onto the surface of the recording material P by the transfer discharger 111.

Recording material P which has received the toner image transfer at the transfer portion
Is sequentially separated from the surface of the photosensitive drum 107 by a separating means (not shown), and is guided to the above-described image heating and fixing device 200 by the conveying device 114 to be subjected to heat fixing of the unfixed toner image carried thereon, and an image formed object ( As a copy), it is discharged onto the discharge tray 117 outside the machine through the discharge roller 116.

The surface of the photosensitive drum 107 after the image transfer is subjected to removal of adhered contaminants such as transfer residual toner by the cleaning device 118, and is repeatedly used for image formation.

Cartridge attaching / detaching portion 1 in the apparatus main body 100
The process cartridge PC that is attached to and detached from the image forming apparatus 20 includes a photosensitive drum 107 as an image carrier, a charger 109, and a developing device 1.
10. The four process devices of the cleaning device 118 are included and can be attached to and detached from the apparatus main body 100 in a batch.

[0059]

According to the first aspect of the present invention, an endless film deviation prevention mechanism is provided at one end of a film suspension tension member, and a film position detection means is provided at the other end of the film suspension tension member. Stable deviation control is now possible without lowering the rotational torque from the ring due to curling and causing instability. In addition, by cutting the endless film diagonally and detecting it, it has become possible to always grasp the absolute position of the film.

The second invention of the present invention is suitable for application to the one in which a roller is used as a film deviation detection member at one end of the film suspension tension member in the first invention.

A third invention of the present invention is the heating body according to the first or second invention, wherein an apparatus having an endless film which is suspended between at least two film suspension tension members and is rotated is fixed. And a heat-resistant endless film which is stretched and rotated between the heating body and at least one film suspension tensioning member, and a recording material is brought into close contact with the heating body through the endless film and is nipped and conveyed. Since the fixing device has a pressing member for applying heat of a heating body to the recording material via the endless film to heat and fix the image on the recording material, the traveling of the endless film is stable, The fixing position in the width direction of the recording material becomes constant, and the recording material passes through while maintaining a constant position in the width direction during the fixing operation, and even if the endless film shifts excessively,
There is an effect that can be grasped.

[Brief description of drawings]

FIG. 1 is a perspective view of a drive device for an endless film embodying the present invention.

FIG. 2 is a schematic vertical sectional view of an example of an image forming apparatus embodying the present invention.

FIG. 3 is a vertical cross-sectional view showing a schematic configuration of an example of a film heating type heating device.

FIG. 4 is a front view of a film shift prevention mechanism portion.

FIG. 5 is a perspective view of a film shift prevention mechanism portion.

FIG. 6 is a perspective view showing the operation of FIG.

FIG. 7 is a perspective view showing the operation of FIG.

[Explanation of symbols]

 1 Endless Film 2 Drive Roller 3 Driven Roller 4 Heater (Heater Part) 5 Pressure Roller 6 Ring (Film Deviation Detection Member) 9 Control Belt 10 Tension Spring 12 Lower Limit Stopper Member 13 Upper Limit Stopper Member 30 Film Position Detection Means

Claims (3)

[Claims] 1. An apparatus having an endless film which is stretched between at least two suspension tension members, and is provided rotatably supported at one end of at least one film tension tension member. The endless film is rotated by a frictional force between the film deviation detection member and the film deviation detection member, which is connected to the film deviation detection member, and the film deviation detection member is engaged by the endless film with the endless film portion applied to the film deviation detection member. A film suspension tensioning member end portion displacement means for converting the rotational movement of the film deviation detection member into a linear movement when a torque is applied to displace the end portion of the film suspension tensioning member in a predetermined direction. An endless film having a film position detecting means provided near the other end of the film suspension tension member. Sfilm drive. 2. The film suspension tension member provided with the film deviation detection member is a roller, and the film deviation detection member is a ring member rotatable independently of the rollers. The drive device for the endless film according to claim 1. 3. An apparatus having an endless film suspended and stretched between at least two film suspension tension members, a fixed heating element, and the heating element and at least one film suspension tension element. A heat-resistant endless film that is stretched between the member and the rotating member, and a pressing member that holds the recording material in close contact with the heating body via the endless film and conveys the recording material. 3. A fixing device, which is applied to the recording material through an endless film to heat and fix the image on the recording material.
The endless film driving device described in 1.