JP3412890B2 - Endless film shift prevention mechanism - Google Patents

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. The present invention relates to a mechanism (a shift movement restricting mechanism, a shift movement control mechanism) for preventing a shift movement along a suspension tension member in a film width direction (film rotation axis direction) orthogonal to a film rotation direction.

[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.

Reference numeral 4 is a horizontally long heating element whose longitudinal direction is perpendicular to the plane of the paper, for example, a low heat capacity heater in which a current-carrying resistance heating element pattern is printed on the surface of a ceramic substrate, and a heater holder 4a made of a heat insulating material is interposed therebetween. Is fixedly provided on the support stay 4b.

Numerals 2 and 3 are a drive roller and a driven roller (tension roller), which are rotatably held at their both end shafts between bearings (not shown) and are arranged substantially parallel to the heating body 4. . The drive roller 2 has, for example, a diameter of 10 to 30.
mm, having a heat resistant rubber layer on the surface. M is a drive source of the rotary drive system of the drive roller 2.

Reference numeral 1 designates the driving roller 2 and the driven roller 3 described above.
It is an endless film suspended and stretched between three members of the heating body 4. This endless film 1 is, for example, a heat-resistant resin film such as polyimide, has a thickness of about 10 to 80 μm, has a fluorine-based release layer of 5 to 20 μm on the outer peripheral surface, and has a perimeter of about 60 to 300 mm. Is.

Reference numeral 5 denotes a pressure roller made of silicon rubber or the like, which is made to sandwich the film 1 and is pressed against the heating body 4.

When the driving roller 2 is rotationally driven in the clockwise direction shown by the arrow, 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, The endless film 1 is rotationally driven between the driving roller 2, the driven roller 3, and the heating body 4 in the clockwise direction indicated by the arrow.

The film 1 is pressed against the heating element 4 by the pressure roller 5, and the inner surface of the film 1 comes into close contact with the surface of the heating element 4 and rotates while sliding. Pressure roller 5
Rotates following the rotation of the film 1.

In a state where the endless film 1 is rotationally driven and the heating element 4 is heated by energization and is controlled to a predetermined temperature, the film 1 at the pressure contact portion (heating portion) N between the heating element 4 and the pressure roller 5 is controlled. A material P to be heated is introduced between the pressure roller 5 and the pressure roller 5, and the pressure contact portion N is conveyed together with the film 1 to heat the material P to be heated by the heat of the heating body 4 through the film 1. Is. Reference numeral 20 is a conveyance guide member for the material P to be heated.

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 heating and fixing device for a recording material P as a heated material on which an unfixed toner image to be fixed is formed and carried, and a recording material carrying an image is heated. It can be effectively used as a means and a device for widely heating a material to be heated such as a device for modifying the surface property, a device for hypothetical attachment, and the like.

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 the film 1 having a very small heat capacity can be used and the temperature rises quickly, even if the temperature of the fixing device is the same as the room temperature when the image forming apparatus is in standby, The heating element 4 and the film 1 immediately rise to a predetermined fixing temperature by energization, that is, they have an excellent quick start property and are in standby. The power consumption of the fixing device can be zero, it is possible to shorten the power saving-wait time,
Further, the image forming apparatus has a feature that it can suppress the temperature rise inside the apparatus.

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 an endless film 1 which is suspended between two or more members 2, 3 and 4 and rotates, the member in which the endless film suspends and stretches the endless film during the rotation process of the endless film 1. Along the 2/3 or 4 direction, one side or the other side in the film width direction that is orthogonal to the film rotation direction tends to naturally shift to a larger or smaller size.

The factors that cause the positional deviation due to the film shift toward one side include parallelism and twisting between the members 2, 3 and 4 that suspend the endless film 1.
There is a limit to improving the accuracy of these, and it is difficult to prevent the film from moving toward the above-mentioned position only by improving the accuracy.

As one of means for preventing or controlling the deviation of the film, there is provided a film deviation detection ring for the end of the film at one end of a member on which an endless film is suspended. Linear movement of the rotational force (rotation torque) due to the sliding movement force of the rotating film that acts on the deviation detection ring according to the width of the film edge that is applied to the deviation detection ring, which changes with the deviation of the film in the rotation process. There is a method in which the film deviation is controlled by moving the film suspension member to a relatively balanced position after the conversion.

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 bearing (not shown), and a shaft portion 3a on the front end side is a swing bearing. It is supported to rotate freely.

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 film 1 is stretched, and the rocking bearing 7 side of the driven roller 3 is biased in the lifting direction. As described above, the pulling spring 10 urges the pull-up spring.

Reference numeral 6 denotes a shaft portion 3 of the driven roller 3 on the side of the rocking bearing 7.
It is a ring as a film deviation detection member which is concentrically and freely provided in a. The inner end surface of the ring 6 is substantially in contact with the end surface of the driven roller 3 on the front end side, and has the same diameter as the driven roller. On the outer end surface of the ring 6, a cylindrical control belt winding portion 11 having an outer diameter smaller than the diameter of the driven roller 3 is provided integrally with the ring 6 and concentrically with the shaft 3a. The ring 6 is in a state in which the film portion on the front end side of the film 1 suspended by the driven roller 3 is hooked.

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 winding direction of the control belt 9 with respect to the winding portion 11 is the direction in which the control belt 9 is wound into the winding portion 11 by the rotational torque due to the sliding friction of the ring 6 with the rotating film 1.

Next, the operation will be described.

[0021]. In the rotation driving process of the endless film 1, the film 1 moves in the direction B of the innermost end in the film width direction.
When the applied width (applied amount) W of the film 1 to the ring 6 on the front end side is small, the frictional force between the rotating film 1 and the ring 6 is small, and therefore the rotational torque T acting on the ring 6 is also small. small.

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
Becomes larger, the front end side of the driven roller 3 hits and is received by the upper limit stopper member 13 as shown by the solid line in FIG. 9A, and further pulling is prevented.

That is, the front end side of the driven roller 3 is displaced upward U by using the bearing on the rear end side as a fulcrum, and the displacement causes the driven roller 3 to be twisted in the front and rear sides with respect to the axes of the driving roller 2 and the heating body 4. Occurs.

In this state, the rotary film 1 returns to and moves in the film width direction front end side direction A, which is opposite to the film width direction back end side direction B.

[0025]. With the return movement of the film 1 in the direction A, the width W of the film 1 applied to the ring 6 increases, and the frictional force between the film 1 and the ring 6 increases.
Therefore, the rotational torque T acting on the ring 6 also becomes large.

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 force becomes 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 and is displaced downward D.

When the rotational torque T of the ring 6 increases and the pull-down force on the front end side of the driven roller 3 due to the control belt winding of the winding portion 11 continues to be larger than the pull-up force F by the tension spring 10, the driven roller 3 is driven. The front end side of the roller 3 hits and is received by the lower limit stopper member 12 as shown by the solid line in FIG. 9B, and is prevented from further pulling down.

That is, the front end side of the driven roller 3 is displaced downward D by using the bearing on the rear end side as a fulcrum, and the 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. A twist opposite to the case of 9 (a) occurs.

In this state, the rotary film 1 returns to and moves in the direction B of the film width direction, which is the direction opposite to the direction A of the film width direction on the front end side.

.. With the return movement of the film 1 in the direction B, the width W of the film 1 applied to the ring 6 decreases, and the frictional force between the film 1 and the ring 6 decreases, so that the rotational torque T acting on the ring 6 also decreases. Become.

Due to the decrease in the rotational torque T, the control belt take-up force of the take-up unit 11 is reduced, and the tension spring 10 is stronger than the pull-down force of the take-up unit 11 on the front end side of the driven roller 3 due to the control belt take-up. When the pulling force F due to becomes larger, the control belt 9 causes the winding portion 11 to
While being rewound from, the front end side of the driven roller 3 is pulled up against the tension spring 10 and is displaced upward U.

When the rotation torque T of the ring 6 decreases and the pulling force F by the tension spring 10 continues to be larger than the pulling force on the front end side of the driven roller 3 due to the control belt winding of the winding portion 11, the driven roller continues. The front end side of No. 3 is the upper limit stopper member 13 as shown by the solid line in FIG.
It will be accepted and will be blocked from further pulling.

In this state, the rotating film 1 returns and moves in the direction B on the innermost side in the film width direction.

That is, the ring 6 is subjected to a rotational torque T due to the frictional force with the rotating film 1, and the rotational torque T varies depending on the magnitude of the film engaging width W with respect to the ring 6, and the ring 6 increases as the film engaging width W increases. The rotational torque T of becomes larger and the control belt winding force of the winding portion 11 increases.

Due to the magnitude relationship between the winding force and the pulling force F of the tension spring 10, the front side of the driven roller 3 is displaced up and down U and D, whereby the deviation directions A and B of the rotating film 1 are controlled. is there.

Thus, the U above the front end of the driven roller 3
Tension spring 1 in the downward displacement process or downward D displacement process.
There are times when the driven roller front end side pulling force F due to 0 and the driven roller front end side pulling down force due to the control belt winding force of the winding portion 11 are balanced. At this time, the driven roller 3 remains stationary at a position closer to the rotating film 1 and the film 1 stops rotating and rotates at a fixed position.

When the above two forces are not balanced, the front end side of the driven roller 3 moves up and down U and D within a regulated range between the upper limit stopper 13 and the lower limit stopper 12,
The rotating film 1 also rotates while reciprocating in the directions A and B within a certain range.

[0038]

However, in the above-described conventional endless film shift control mechanism, the ring 6 is used.
Due to the rotation, the force for pulling down the front end side of the driven roller 3 changes depending on the vertical displacement position of the end portion of the driven roller. Therefore, there were the following problems.

(1) The vertical displacement movement of the end portion of the driven roller becomes unstable, and the reliability of stable film deviation control is low.

(2) In a fixing device which requires a high process speed and durability, the force of the roller end portion balances out, the roller end portion remains stationary, and the endless film rotates at a certain position. At this time, the edge of the paper hits a certain position on the film, and the coat layer on the surface of the film is scraped off. Or, the inner surface of the endless film is rubbed and scraped off with the heating element and the like, which causes image deterioration and at the same time reduces the durability of the endless film.

(3) The process speed is not so high, and in the fixing device which is required to be smaller than the durability, the force of the roller end portion does not balance and the roller end portion reciprocates to make an endless film. When the film reciprocates within a certain range and rotates, the film reciprocates,
A ring longer than that range is required, which is against the miniaturization.

Therefore, an object of the present invention is to solve the above-mentioned problems in this type of endless film shift control mechanism.

[0043]

SUMMARY OF THE INVENTION The present invention is an endless film shift control mechanism having the following structure.

[0044] (1) an endless film which is rotated is stretched between at least two suspension KaiCho portion material, set only by rotatably supported on at least one end of at least one film suspension KaiCho portion material, endless A rotatable movable member that rotates due to the frictional force generated when the edge of the film is applied.
And one end of the film suspension tension member is moved.
Connected to the movable member and the rotatable movable member,
It has a drive transmission part that transmits rolling force to the moving member, and can rotate
Rotated by frictional force between the member and the multiplied Tsu and has a film part to it
And the film suspended KaiCho portion Zaitan part displacing means for positional displacement of the end of the full Irumu suspension KaiCho portion material in a predetermined direction is converted into linear motion the rotary motion when rotation torque is applied to the movable member, A mechanism to prevent the endless film from slipping
The moving member in accordance with the rotational position of the rotatable movable member.
Position the end of the film suspension tension member in the
Rotation torque is changed by changing the radius of rotation of the motion transmitting part in the circumferential direction.
Position the end of the film suspension tension member in the specified direction.
An endless film deviation prevention mechanism, characterized in that a driving force of a moving member to be placed and displaced is changed according to a displacement position of an end portion of a film suspension tension member.

[0045] (2) full Irumu suspension KaiCho portion material end reciprocates in a predetermined direction, and wherein the reciprocating close motion Rie down dress film by the round-trip motion within a certain range
(1) The endless film deviation prevention mechanism described in (1) .

(3) The film suspension tension member provided with the film deviation detecting member is a roller, and the film deviation detecting member is a ring member rotatable independently of the rollers. The endless film deviation prevention mechanism according to (1) or (2).

(4) A device having an endless film which is suspended and stretched between at least two film suspension tension members, has a fixed heating body, and the heating body and at least one film suspension tension. A heat-resistant endless film which is stretched between the mounting member and the rotating member, and a pressing member which holds the recording material in close contact with the heating body via the film and conveys the recording material by heating the heating body. The endless film deviation prevention mechanism according to any one of (1) to (3) , which is a fixing device that heats and fixes an image on the recording material by applying it to the recording material via a film.

[0048]

In other words, as described above, the moving member is the rotatable movable member.
The end of the film suspension tension member at a position according to the rotation position of
In addition to the position, change the radius of rotation of the drive transmission in the circumferential direction.
By changing the rotating torque, the film suspension tension member
Driven by a moving member that displaces the end in a predetermined direction
Force is changed depending on the displacement position of the end of the film suspension tension member
Depending on the structure, the end of the film suspension tension member can be stationary or reciprocated, and by stably moving the end of the film suspension tension member, stable endless film deviation control is possible. can do.

[0049]

【Example】

<Embodiment 1> (FIG. 1) This embodiment is carried out in the film heating type image heating and fixing device of FIG. 6, and the endless film deviation prevention mechanism is the same as in FIG. Since it is the same as that of FIG. 9, the repetitive description will be omitted.

That is, in this embodiment, as shown in FIG. 1, the shape of the control belt winding portion 11 of the ring 6 as the film deviation detecting member is such that the diameter r of the winding portion increases as the driven roller 3 lowers, and The diameter r of the winding portion becomes smaller as the driven roller 3 goes up.

As a result, the force of lowering the driven roller 3 by the rotation of the ring 6 becomes larger as the winding portion diameter r becomes smaller. That is, the force F for raising the driven roller 3 by the tension spring 10 while the driven roller 3 is lowered and the force for lowering the driven roller 3 by the rotation torque T of the ring 6 are balanced, and the driven roller 3 hits the lower stopper member 12 before hitting the film. It stops at the equilibrium position closer to.

On the contrary, as the driven roller 3 rises, the force for lowering the driven roller 3 increases, so the force F for raising the driven roller 3 by the tension spring 10 and the rotational torque T of the ring 6.
As a result, the force of lowering the driven roller 3 is balanced, and the driven roller 3 stops at a position closer to the film before hitting the upper stopper member 13.

By stabilizing the force acting on the driven roller 3 in this way, even if the position of the driven roller 3 closer to the film 1 is slightly deviated, the driven roller 3 remains stationary at the current balanced position.

<Embodiment 2> (FIG. 2) This embodiment is also carried out in the image heating fixing apparatus of the film heating system shown in FIG. 6, and the endless film shift prevention mechanism is the same except for the following points. Since it is the same as that of FIGS. 7 to 9, its repetitive description will be omitted.

In this embodiment, as shown in FIG. 2, the shape of the control belt winding portion 11 of the ring 6 is opposite to that of the first embodiment, and the diameter r of the winding portion becomes smaller as the driven roller 3 goes down. On the contrary, the diameter r of the winding portion increases as the driven roller 3 rises.

As a result, the force for lowering the driven roller 3 by the rotating torque T of the ring 6 becomes larger as the winding portion diameter r becomes smaller. That is, as the driven roller 3 lowers, the force for lowering the driven roller 3 increases, so that the driven roller 3 lowers until it hits the lower stopper member 12.

On the contrary, as the driven roller 3 rises, the force for lowering the driven roller 3 becomes smaller, so that the driven roller 3 rises until it hits the upper stopper member 13.

As a result, the driven roller 3 does not stop at the equilibrium position near the film 1 but reciprocates up and down within the range regulated by the two stopper members. Therefore, the film 1 rotates while reciprocating within a certain range.

<Embodiment 3> (FIG. 3) This embodiment is also carried out in the image heating fixing apparatus of the film heating system shown in FIG. 6, and the endless film deviation prevention mechanism is the same except for the following points. Since it is the same as that of FIGS. 7 to 9, its repetitive description will be omitted.

In this embodiment, as shown in FIG. 3, a tough filamentous member 9A was used instead of the control belt. Further, although the winding portion 11 has a cylindrical shape, a member such as a pin 14 is erected on the outer side of the winding portion 11 to cause the thread-like member 9A instead of the control belt to interfere with the winding portion 11, thereby achieving the same operation as that of the winding portion 11 of the second embodiment. It was made.

In Examples 1 to 3, the ring 6 as the film deviation detecting member is provided at one end of the rotating driven roller 3 as the film suspension tension member.
You may provide on both ends. The ring 6 may be a tapered ring whose diameter increases toward the outer end.
The driven roller 3 as the film tension member may be a film sliding member having a semicircular shape or the like. The ring 6 may be provided on a film suspension tension member other than the driven roller 3, for example, the drive roller 2. When the rotation angle of the ring 6 is small, a part of the ring 6 may be a cylinder instead of a cylinder.

In the embodiment, the control belt 9 or the thread member 9A is used as a member for converting the rotational force of the ring 6 into the substantially vertical displacement of the driven roller 3 as a film suspension tension member. The cam may be displaced by bringing it into contact with a fixed cam follower using a cam integrated with the ring.

FIG. 4 shows a film heating system in which a heat-resistant endless film 1 is suspended and stretched between two members of a driving roller 2 and a heating body 4 and the driving roller 2 is rotated to drive the film 1 to rotate. This is a heating device, which is provided with a film deviation preventing mechanism on one end side of the driving roller 2 as in the case of the driven roller 3 of the above embodiment. However, in the case of this example, when the roller end portion is lowered, the film approaches in that direction. Therefore, the directions of the pulling force by the ring rotation torque T and the pulling force by the spring 10 are reversed.
That is, the roller end portion is pulled up by the ring rotation torque T and lowered by the tension spring 10.

In FIG. 5, for example, the heating device having the film deviation preventing mechanism of the first embodiment described above is used as the image heating and fixing device 20.
1 shows a schematic configuration of an example of an image forming apparatus in which 0 is incorporated. The image forming apparatus of this embodiment is a reciprocating platen type, a rotary drum type, a transfer type, and a process cartridge attaching / detaching type electrophotographic copying apparatus.

Reference numeral 100 denotes an apparatus casing, 101 denotes a reciprocating type document placing table made of a transparent plate member such as a glass plate disposed on an upper surface plate 102 of the apparatus casing, and the apparatus casing upper surface plate 102.
The upper part is driven to reciprocate rightward and leftward in the drawing at predetermined speeds.

Reference numeral G denotes an original, which is placed on the upper surface of the original placing table 101 according to a predetermined placement reference with the image surface side to be copied facing downward, and by placing the original pressing plate 103 on the original and pressing it. Set.

Reference numeral 104 denotes a slit opening serving as a document illuminating section which is opened on the surface of the machine top 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.

The downward image surface of the document G placed and set on the document placing table 101 successively passes through the position of the slit opening 104 from the right side to the left side in the forward movement process of the document placing table 101 to the right. In the course of the passage, the light from the lamp 105 is received through the slit opening 104 and the transparent original placing table 101 to be illuminated and scanned, and the reflected light on the original surface of the illumination scanning light is reflected on the surface of the photosensitive drum 107 by the image element array 106. The image is exposed to light.

The photosensitive drum 107 is coated with a photosensitive layer such as a zinc oxide photosensitive layer or an organic semiconductor photosensitive layer, and is rotated in a clockwise direction indicated by an arrow 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 an image is formed on the surface of the photosensitive drum 107. An electrostatic latent image corresponding to the exposed original image is sequentially formed.

The 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 as the visualized image is provided with a transfer discharger 111 as a transfer portion. It moves to the part.

Reference numeral S denotes a cassette in which transfer material sheets P as recording materials are stacked and accommodated. The sheets in the cassette are fed and fed one by one by the rotation of the feeding roller 112, and then the drum 107 is fed by the registration rollers 113. When the leading edge of the upper toner image forming portion reaches the portion of the transfer discharger 111, the leading edge of the transfer material sheet P also reaches the position between the transfer discharger 111 and the photosensitive drum 107, and the timing is adjusted so that they coincide with each other. It is then delivered synchronously.

Then, the toner image on the side of the photosensitive drum 107 is sequentially transferred onto the surface of the fed sheet by the transfer discharger 111.

The sheet to which the toner image has been transferred 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-mentioned image heating and fixing device 200 by the conveying device 114 and carried thereon. The heat-fixed toner image is fixed to the discharge roller 1 as an image-formed product (copy).
Then, the sheet is discharged onto the sheet discharge tray 117 outside the machine through the sheet feeding unit 16.

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.

The PC is a process cartridge which is attached / detached to / from the cartridge attaching / detaching portion 120 in the apparatus main body 100.
In the case of the present example, the apparatus main body 10 including the four process devices of the photosensitive drum 107 as an image bearing member, the charging device 109, the developing device 110, and the cleaning device 118 together.
It is detachable and replaceable with respect to 0.

[0076]

As described above, the moving member is rotatable.
Film suspension tension member at a position according to the rotational position of the moving member
The radius of rotation of the drive transmission part is measured along with the position of the end.
By changing the rotation torque by changing the direction,
With a moving member that displaces the end of the installation member in a predetermined direction.
Drive force depending on the displacement position of the end of the film suspension tension member
With the changing structure, it is possible to stably move the end portion of the film suspension tension member, and the end portion of the film suspension tension member can be stationary or reciprocated. Therefore, the endless film can be rotated at a fixed position or can be rotated while reciprocating within a fixed range.

[0077] Thus the process speed is high, the durability is required, the fixing device of the film heating type, according Kamitan portion during sheet passing by reciprocally closer motion endless film within a certain range of the coating layer of the film It is possible to prevent image deterioration due to abrasion and abrasion of the inner surface of the film due to the heater portion and the like, and at the same time improve the durability of the film.

Further, the process speed is not so fast, and in a low-speed small-sized fixing device which is required to be downsized, the endless film is moved by rotating the endless film at a fixed position, so that the length over the range is reached. The ring, which used to be required, can be shortened, and a smaller fixing device can be realized.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of the shape and operation of a control belt winding portion of a film shift prevention mechanism of the first embodiment.

FIG. 2 is an explanatory view of the shape and operation of a control belt winding section of the film shift prevention mechanism of the second embodiment.

FIG. 3 is an explanatory diagram of a configuration and an operation of a control thread-like member winding portion of the film deviation prevention mechanism according to the third embodiment.

FIG. 4 is a schematic configuration diagram of another example of a film heating type heating device.

FIG. 5 is a schematic configuration diagram of an example of an image forming apparatus.

FIG. 6 is a schematic configuration diagram of an example of a film heating type heating device.

FIG. 7 is a front view of a film deviation prevention mechanism portion.

FIG. 8 is a perspective view of a film shift prevention mechanism portion.

9 (a) and 9 (b) are operation explanatory views of a film deviation prevention mechanism.

[Explanation of symbols]

1 Endless film 2 drive roller 3 Driven roller 4 Heating body (heater part) 5 pressure roller 6 ring (film shift detection member) 9 Control belt Ten tension springs 11 Winding part 12 Lower limit stopper member 13 Upper limit stopper member 14 pin

Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G03G 15/20 101 B65H 23/032

Claims (4)

(57) [Claims] 1. An endless film which is suspended between at least two suspension tension members and rotates , and at least 1.
One of the settings by rotatably supported on at least one end portion of the film suspension KaiCho portion material only, and the rotatable member which is rotated by frictional force generated by the end of the endless film is applied,
A moving part for moving one end of the film suspension tension member
Rotational force of the rotary movable member connected to the material and the rotary movable member
And a drive transmission unit that transmits the
Rotatable by a frictional force between it and Tsu hanging film portion and
The rotary motion film is converted into linear movement to position moving the end of the full Irumu suspension KaiCho portion material in a predetermined direction the suspension KaiCho portion Zaitan unit displacement means when the rotational torque is applied to the member
With the endless film deviation prevention mechanism
The moving member to a position that corresponds to the rotating position of the rotatable movable member.
In addition to positioning the end of the rum suspension tension member, the drive transmission unit
Changing the rotation torque by changing the radius of rotation of
Position displacement of the end of the film suspension tension member in the specified direction.
An endless film deviation prevention mechanism characterized in that the driving force of the moving member to be changed is changed according to the displacement position of the end portion of the film suspension tension member. 2. A claim that full Irumu suspension KaiCho portion material end reciprocates in a predetermined direction, and wherein the reciprocating close motion within a certain range Rie down dress film by the round-trip motion
The endless film deviation prevention mechanism described in 1 . 3. 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 mechanism for preventing deviation of the endless film according to claim 1 or 2. 4. 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 member via the film and conveys the recording material by heating the heating member. The endless film deviation prevention mechanism according to any one of claims 1 to 3 , wherein the fixing device is a fixing device that heats and fixes an image on the recording material by applying the recording material to the recording material through the fixing device.