JP2001043966A - Heating device, heat fixing device and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably feed a film by mounting a structural body for supporting a heating film at a side opposite to a nip part in the width direction of the heating film, and providing a sliding member for controlling an end part of the heating film at an end of the structural body. SOLUTION: Slidable end guides 5a, 5b are rotatably fitted to spring holders 4a, 4b fixed to both ends of a stay 2, and a pressure roller 6 is rotatably fixed to a frame 7 through bearings 9a, 9b. The pressure roller 6 is rotated by transmitting the driving force transmitted from a driving source of an image forming device body to a gear 11. A film 1 contacted with the pressure roller 6 is driven while guided by the end guides 5a, 5b with the frictional force. The magnetic force is produced when the high frequency bias is applied from an excitation circuit of the image forming device body, whereby a heating layer of the film 1 is heated by the electromagnetic induction, and a member to be heated is guided to a nip part to fix an unfixed image.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating process in which a nip formed at a pressure contact portion between a heat-resistant heating film (hereinafter abbreviated as "film") and a pressing member is passed through a member to be heated. The present invention relates to a heating device for performing the heating, a heating fixing device using the heating device as a heat source, and an image forming apparatus such as a copying machine or a printer to which the heating fixing device is applied.

[0002]

2. Description of the Related Art As a conventional heating device, a) a film including a heat generating layer which generates heat by electromagnetic induction by the action of a magnetic field, and a pressing member which presses against the film to form a nip portion therebetween. B) a heating element fixed to the holder, a film whose inner surface is driven in pressure contact with the heating element, and a nip portion formed by pressing the film against the heating element, and the nip portion is formed at the nip portion. In general, a member having a pressurizing member for subjecting a member to be heated conveyed to the outer surface of the film to heat treatment by heat from the heating body is used.

[0003]

However, the above-mentioned conventional heating apparatus has a problem that the type using a plurality of rollers has a large number of parts, so that the apparatus becomes large and the cost increases. Further, a type in which a cylindrical guide member formed of a resin or the like also serves as a structure is advantageous for miniaturization and cost reduction, but due to the warp and strength of the resin, the longitudinal direction (the member to be heated) In order to obtain a stable nip in the width direction, there is a problem in that the length is limited, and the pressing force is also limited by the strength of the heater and the like and the guide strength.

In order to regulate the film, a fixed resin member or the like for regulating the width direction of the film is installed at the end of the film. However, since the fixed member slides with the end of the film, There is a problem that this may cause breakage of the film or the like and significantly reduce the durability of the film.

When the guide member also serves as a structure,
Because of the above-mentioned strength, it is necessary to have a certain size not only in the longitudinal direction but also in the transport direction. The resistance caused an increase in the torque of the device. Further, it has been confirmed from the results of experiments that the size of the contact area between the guide member and the film affects the temperature uniformity and the efficiency particularly when electromagnetic induction heating is used.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and a structure is provided in a longitudinal direction (a width direction of a member to be heated) at a nip-facing portion in a film, and the nip portion is formed. It is an object of the present invention to obtain a heating device which transmits a pressing force of the film directly through the structure and which is provided with a sliding member at the end of the structure to regulate the end of the film, thereby enabling stable feeding of the film.

Further, a heat fixing device capable of performing stable heat fixing of a toner image using the heating device as a heat source, and a high quality image free from image unevenness can be formed by applying the heat fixing device. An object is to obtain an image forming apparatus.

[0008]

According to the present invention, there is provided a heating apparatus, a heat fixing apparatus, and an image forming apparatus having the following components.

(1) A heat-resistant heating film including a heat-generating layer which is movable along the holder surface and generates electromagnetic induction by the action of a magnetic field, and a nip portion is formed between the two by pressing against the heating film. A heating member for heating the member to be heated by passing the member to be heated through the nip portion, wherein the structure supporting the heating film on the side opposite to the nip portion has a width of the heating film. A heating device, comprising: a sliding member disposed in the direction of the body and regulating an end of the heating film at an end of the structure.

(2) A heating element fixed to the holder, a heat-resistant heating film whose inner surface is driven by being pressed against the heating element, and a nip formed by pressing the heating film against the heating element. A heating member that passes the heated member through the nip portion to perform heat treatment, wherein the heating body is configured to support the heating element on a side of the heating body opposite to the nip portion. And placed in the width direction of the
A heating device, wherein a sliding member for regulating an end of the heating film is provided at an end of the structure.

(3) The sliding member for regulating the end of the heating film is rotatably held at the end of the structure, and rotates with the rotation of the heating film. The heating device according to (2).

(4) The heating member is a recording material carrying an unfixed image, and the heat source for heating and fixing the unfixed image on the recording material is any one of (1) to (3). A heating fixing device comprising the heating device according to claim 1.

(5) An image forming apparatus having image forming means for forming and carrying an unfixed toner image on a recording material, and fixing means for heating and fixing the unfixed toner image formed and carried on the recording material to the recording material. The image forming apparatus according to claim 1, further comprising a heat fixing device according to (4) as the fixing unit.

[0014]

An embodiment of the present invention will be described below with reference to the accompanying drawings.

Embodiment 1 1 to 4 show a heating device according to Embodiment 1 of the present invention. In each of the drawings, a stay 2 as a structure is disposed inside a film 1, and an exciting core is provided for the stay 2. 12. The film guide 3 holding the exciting coil 13 is fixed. Spring halters 4a and 4b are fixed to both ends of the stay 2. End guides 5a and 5b as sliding members are rotatably fitted in the spring halters 4a and 4b, respectively. The pressure roller 6 has bearings 9a and 9b.
And is rotatably fixed to the frame 7 via.

The spring halter 4a fixed to the stay 2
4b, while holding the film 1 and the end guides 5a and 5b, the grooves 4c and 4d of the spring halter 4a and 4b enter the notches 7a and 7b of the frame 7, and are supported so as to be able to move up and down. The pressure springs 8a and 8b are set between the spring halters 4a and 4b and the frame 7, and the film 1 is held between the pressure rollers 6 by the pressure springs 8a and 8b.
It is pressurized by the action of b and is fixed by the top plate 10. A gear 11 for driving transmission is provided at the end of the pressure roller.
Has been fixed. As shown in FIG. 4, the structure of the film 1 includes a release layer 1a, an elastic layer 1b, and a heat generating layer 1c.

The pressure roller 6 is rotated by transmitting a driving force transmitted from a driving source (not shown) of an image forming apparatus main body (not shown) to the gear 11. The film 1 that comes into contact with the pressure roller 6 follows while being guided by the end guides 5a and 5b by frictional force.

On the other hand, an excitation circuit (not shown) of the image forming apparatus main body (not shown) is connected to an excitation coil 13, and generates a magnetic force by applying a high-frequency bias from the excitation circuit. By the action of the magnetic force, an induced current (eddy current) is generated in the heat generating layer (ferromagnetic conductive layer) 1c of the film 1, and the film 1 enters an electromagnetic induction heat generating state.

From this state, the member to be heated P is conveyed and introduced into the nip N between the film 1 and the pressure roller 6,
Heat from the film 1 that has undergone electromagnetic induction and heat is applied by the pressing force of the pressure springs 8a and 8b, and an unfixed image is fixed on the member P to be heated.

Embodiment 2 5 to 7 show a heating device according to a second embodiment of the present invention. In each figure, a stay 2 is provided inside a film 1 and a film guide holding a heater 14 for the stay 2 is shown. 3 is fixed. Spring halter 4 at both ends of stay 2
a, 4b are fixed. This spring halter 4a, 4
End guides 5a and 5b are rotatably fitted in each of b. The pressure roller 6 has bearings 9a and 9
It is rotatably fixed to the frame 7 via b.

The spring holder 4a fixed to the stay 2
4b, the grooves 4c and 4d of the spring holders 4a and 4b enter the cutouts 7a and 7b of the frame 7 while holding the film 1 and the end guides 5a and 5b, and are held so as to be able to move up and down. With the pressure springs 8a, 8b set between the spring holders 4a, 4b and the frame 7, the film is pressed between the film 1 and the pressure roller 6 by the action of the pressure springs 8a, 8b and fixed by the top plate 10. I have.

A gear 11 for power transmission is fixed to the end of the pressure roller. The pressure roller 6 rotates when a driving force is transmitted to a gear 11 from a driving source (not shown) of an image forming apparatus main body (not shown). The film 1 that comes into contact with the pressure roller 6 is driven while being guided by the end guides 5a and 5b together with the end guides 5a and 5b by frictional force.

On the other hand, the heater 14 is heated by the power supplied from the power supply of the image forming apparatus main body (not shown). From this state, pressure and heat are applied when the heated member P is transported and introduced into the nip N between the film 1 and the pressure roller 6, and the unfixed image is fixed on the heated member P.

Embodiment 3 FIG. FIG. 8 is a schematic sectional view of a heat fixing device according to Embodiment 3 of the present invention using the heating device of Embodiment 1 or 2 as a heat source.

As shown in FIG. 8, the heat fixing device 100
Includes a heater 21, a heater holder 22 that supports the heater 21 and guides a cylindrical film 23,
A pressure roller 24 made of heat-resistant rubber, a pressing member 25 for pressing the heater holder 22 toward the pressure roller 24, and the like are provided. The film 23 receives a frictional force by the rotation of the pressure roller 24 and is rotated and conveyed along the heater holder 22. Then, the sheet P on which the unfixed toner image t is formed on the surface is
When the nip N formed by the heater 21 and the pressure roller 24 is conveyed while being heated while being pressed to a total pressure of about 4 to 40 kgf, the toner image t is fixed on the sheet P. You. Usually, this film 23 has a film thickness of 100 μm or less, such as a polyimide or other film having a thickness of 100 μm or less, made of PTFE, P
It is composed of a composite film coated with FA and FEP as a release layer.

On the other hand, the heater 21 is made of aluminum nitride (A
The heating element 21b is formed on one surface of a heater substrate 21a having LN) as a base material, and a temperature detecting element 21c is arranged on the opposite surface, and the temperature of the fixing device is controlled by this temperature detection. ing. Also, the heater 21
Is made of a thermoplastic resin having good moldability, for example, a liquid crystal polymer.

As described above, according to the third embodiment, by having the heating device shown in the first embodiment as a heat source, there is no trouble caused by the heater spot.
Stable heat fixing can be performed.

Embodiment 4 FIG. 9 is a schematic diagram showing an example of an image forming apparatus provided with a heat fixing device according to Embodiment 3 of the present invention. This image forming apparatus is a laser beam printer using an electrophotographic process. Reference numeral 51 denotes a housing; and 52, an electrophotographic photosensitive drum as an image holding body. The photosensitive drum 52 is driven to rotate at a predetermined peripheral speed (process speed) in a clockwise direction indicated by an arrow. Then, the photosensitive drum 52 is rotated by the charging roller 53
Is primary-charged uniformly to a predetermined polarity and potential, and modulated on the charged surface in accordance with a time-series electric digital pixel signal of target image information output by a laser scanning exposure device (laser beam scanner) 54. Laser light L
, An electrostatic latent image corresponding to the target image information is formed on the peripheral surface of the drum. The latent image is stored in the developing device 5
5, the toner image is developed, and the toner image reaches a transfer nip portion N between the photosensitive drum 52 and the transfer roller 56.

On the other hand, the recording material P in the paper feed cassette 58 is conveyed one by one by the paper feed roller 57,
Through the transfer nip N at a predetermined timing, and an electric field having a polarity opposite to that of the toner is applied from the back surface of the recording material P by the transfer roller 56, so that the toner image of the photosensitive drum 52 is applied to the surface of the recording material P. Transcribed.

Upon receiving the transfer of the toner image, the transfer nip N
Is separated from the surface of the photosensitive drum 52, guided to the conveyance guide 60, enters the heat fixing device 100 of the present invention shown in FIG. 7, and passes through the fixing nip N as described above. The toner image is heated and fixed, and is discharged out of the apparatus through the sheet path 62. The surface of the photosensitive drum 52 after the transfer of the toner image onto the recording material P is cleaned by the cleaning device 63 and is repeatedly provided for image formation.

As described above, according to the third embodiment, a stable fixing operation can be performed, and a high-quality image can be formed.

[0032]

As described above, according to the present invention, the structure is disposed in the longitudinal direction (the width direction of the member to be heated) at the nip-facing portion in the film, and the pressure applied to the nip is directly reduced. Since a sliding member (bearing member) is provided at the end of the structure to regulate the end of the film while receiving by this structure, it is difficult to secure a stable nip in the conventional film fixing system. Accordingly, it has become possible to provide a film heating apparatus which has many advantages such as shortening of warm-up time, power saving, and improvement of responsiveness.

At the same time, it is possible to reduce the sliding resistance at the end of the film and at the same time the contact resistance with the guide member, so that it is possible to suppress an increase in the torque of the device caused by the lengthening. At the same time, the load on the film end was reduced by reducing the sliding resistance at the film end, and as a result, the durability of the film was greatly improved.

Further, in the heating device according to the first aspect of the present invention, which employs an electromagnetic induction heating method, in addition to the above-mentioned effects, a heating device such as a fixing device used in a color image forming apparatus which needs to secure a large amount of heat is required. However, the present invention is applicable regardless of the size of the recording material.

Further, since this heating device is constituted as a heat source, a heating and fixing device capable of performing stable heating and fixing can be obtained, and a high quality image without image unevenness can be obtained by applying the heating and fixing device. There are effects such as that an image forming apparatus for forming can be obtained.

[Brief description of the drawings]

FIG. 1 is a front view showing a heating device according to Embodiment 1 of the present invention.

FIG. 2 is an exploded perspective view of the heating device according to the first embodiment.

FIG. 3 is a side view of the heating device according to the first embodiment.

FIG. 4 is a cross-sectional side view of a film applied to the heating device according to the first embodiment.

FIG. 5 is a front view showing a heating device according to a second embodiment of the present invention.

FIG. 6 is an exploded perspective view of the heating device according to the second embodiment.

FIG. 7 is a side view of a heating device according to a second embodiment.

FIG. 8 is a schematic sectional view of a heat fixing device according to Embodiment 3 of the present invention.

FIG. 9 is a schematic diagram illustrating an image forming apparatus according to a fourth embodiment.

[Explanation of symbols]

1 film, 2 stays, 3 film guide, 4
Spring halter, 5 end guide, 6 pressure roller, 5
2 photosensitive drum (image forming means), 53 charging roller (image forming means), 54 laser scanning exposure device (image forming means), 5
5 developing device (image forming means), 100 heat fixing device.

Claims (5)

[Claims] 1. A heat-resistant heating film including a heat-generating layer movable along a holder surface and generating electromagnetic induction by the action of a magnetic field, and a nip portion formed therebetween by pressing against the heating film. A heating member having a pressure member and heating the member to be heated by passing the member through the nip portion, wherein a structure supporting the heating film on a side opposite to the nip portion is formed in a width direction of the heating film. And a sliding member disposed at an end of the structure for regulating an end of the heating film. 2. A heating body fixed to a holder, a heat-resistant heating film whose inner surface is driven by being pressed against said heating body, and a nip portion formed by pressing said heating film against said heating body. A heating device having a pressing member to be formed, and a heating member that passes through the nip portion and performs a heat treatment.
A structure for supporting the heating element is provided in the width direction of the heating film on a side of the heating element opposite to the nip portion, and a slide for regulating an end of the heating film at an end of the structure. A heating device comprising a member. 3. A sliding member for regulating an end of a heating film is rotatably held at an end of the structure, and rotates with the rotation of the heating film. Item 3. The heating device according to Item 2. 4. The heating member according to claim 1, wherein the member to be heated is a recording material carrying an unfixed image, and a heat source for heating and fixing the unfixed image on the recording material. A heating fixing device comprising the heating device of (1). 5. An image forming apparatus comprising: image forming means for forming and carrying an unfixed toner image on a recording material; and fixing means for heating and fixing the unfixed toner image formed and carried on the recording material to the recording material. 5. The fixing device according to claim 4, wherein
An image forming apparatus comprising the heat fixing device according to any one of the preceding claims.