JPH07129004A - Heating device and image forming device - Google Patents

Abstract

PURPOSE:To make it compatible to attain the high-speed rise of the temperature and improve a fixing performance just after the rise as to an image thermal fixing device, and also, to prolong the life of the device by satisfactorily securing the nip width of a press-contact nip part between a heating part and a pressurizing part and also satisfactorily reducing the heat capacity, as to a heating device for guiding a material to be heated into the mutual press-contact nip part between the heating part equipped with a heat generating body and the pressurizing part which is press-contacted with the heating part so that the material to be heated may be held and carried by them and may be heat- treated. CONSTITUTION:The pressurizing part 23 is provided with an endless, or ended heat-resistant film material 24 which can rotate, or travel forward in the direction of holding and carrying the material to be heated P at the press-contact nip part N and the pressurizing member 26 for pressurizing the film material 24 to the heating part 10 by a prescribed pressure and made of a heat-resistant elastic body, and the material to be heated P is guided into the press-contact nip part N between the heating part 10 and the film material 24 of the pressurizing part 23.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention introduces a material to be heated into a mutual pressure contact nip portion between a heating portion having a heating element and a pressure portion pressed against the heating portion, and nipping and conveying the material to be heated. The present invention relates to a heating device that heats a material.

Further, the present invention relates to an image forming apparatus provided with the heating device as an image heating and fixing device.

[0003]

2. Description of the Related Art A heating device for introducing a material to be heated into a mutual pressure contact nip portion between a heating portion having a heating element and a pressure portion pressed against the heating portion and nipping and transporting the material to be heated. As a specific example of the above, for example, an image heating fixing device such as a heat roller system or a film heating system incorporated in an image forming apparatus such as an electrophotographic copying machine / printer or an electrostatic recording device can be mentioned. The image heating and fixing device will be described below as an example.

FIG. 12 is a schematic cross-sectional view showing a schematic structure of an example of a heat roller type image heating and fixing device.

Reference numeral 10 is a fixing roller (heat roller, heat roller) as a heating portion, and 20 is a pressure roller as a pressure portion, which are arranged in parallel vertically and are in pressure contact with each other so that both ends of the device frame 30 are in contact with each other. A slide bearing (not shown) is rotatably attached and held between the side plates.

The fixing roller 10 is provided with a release layer 12 such as PFA or PTFE formed on the surface of a hollow aluminum cored bar 11, and a halogen heater 13 as a heating element (heat source) is inserted in the hollow of the roller. A temperature sensitive element 14 such as a thermistor is brought into contact with the roller surface.

The pressure roller 20 comprises a cored bar 21 and a heat-resistant elastic layer 22 made of silicon rubber or the like and formed concentrically with the cored bar 21 in a roller shape. A pressing spring (not shown) is pressed against the lower surface of the roller 10 with a predetermined pressing force to form a pressure contact nip portion (fixing nip portion) N having a predetermined width between the fixing roller 10 and the pressure roller 20. is there.

The fixing roller 10 is rotationally driven by a drive system (not shown) in a clockwise direction a as shown by an arrow at a predetermined peripheral speed,
The pressure roller 20 rotates following the fixing roller 10.

The halogen heater 13 of the fixing roller 10 is energized from an AC energizing circuit (not shown) to heat the halogen heater 13 to heat the fixing roller 10, and the surface temperature of the fixing roller 10 is the temperature sensitive element 14. Is detected by the halogen heater 1 so that the detected temperature information is fed back to a control unit (main body control CPU) not shown so that the detected temperature output of the temperature sensitive element 14 becomes a predetermined constant value.
The energization to 3 is controlled. That is, the energization of the halogen heater 13 is controlled so that the surface temperature of the fixing roller 10 is maintained at a predetermined fixing temperature.

Thus, the fixing roller 10 and the pressure roller 20
While the fixing roller 10 is rotated and the fixing roller 10 is temperature-controlled to a predetermined fixing temperature, an unfixed toner image T is formed and carried from an unillustrated image forming mechanism section A side as a material to be heated. The recording material P is conveyed and introduced into the apparatus from the inlet guide 31, enters the fixing nip portion N of the fixing roller 10 and the pressure roller 20, and is nipped and conveyed between the rollers 10 and 20, At the fixing nip portion N, the unfixed toner image T on the recording material P is fixed on the surface of the recording material P as a permanently fixed image by heat and pressure. The recording material P that has undergone the image heating and fixing process exits the apparatus and is output as an image formed product (copy, print).

FIG. 13 is a schematic cross-sectional view showing a schematic structure of an example of a film heating type image heating and fixing device. The same components and parts as those of the apparatus of FIG. 12 described above are designated by the same reference numerals, and repeated description will be omitted.

In the image heating fixing apparatus of the film heating type, the material to be heated is brought into close contact with the surface of the heating element (heating element, heater) through the heat resistant film material and is conveyed together with the heat resistant film material. It is a device based on a configuration for applying heat of a heating element to a material to be heated through a heat resistant film material,
JP-A-63-313182, JP-A-2-1578
78, JP-A-4-44075 to 44083, 20.
It is disclosed in Japanese Patent Publication Nos. 4980-204984.

The apparatus shown in FIG. 13 is disclosed in JP-A-4-44075-4.
This is a so-called tensionless type film heating system device disclosed in Japanese Patent No. 4083, and includes a heating element 15 and a film inner surface guide member 16 holding the heating element 15 on the lower surface.
A heating unit 10 having a cylindrical (endless belt) heat-resistant film material (fixing film) 17 loosely fitted on a film inner surface guide member 16 including the heating element 15 as a basic constituent member; Heating element 1 with 17 in between
It has a pressure roller 20 as a pressure unit that is in pressure contact with 5.

The heating element 15 is, for example, an elongated flat plate having a low heat capacity and having a longitudinal direction perpendicular to the rotation direction a of the cylindrical fixing film material 17 or the conveyance direction of the recording material P as a heating material. It is a ceramic heater.

The film inner surface guide member 16 is made of a heat-resistant resin material or the like having a longitudinal direction perpendicular to the rotation direction a of the cylindrical fixing film material 17 or the conveyance direction of the recording material P as a material to be heated. It is a gutter-shaped horizontally long member having a substantially semicircular cross section, and both ends thereof are fixedly supported between the side plates of the apparatus frame 30. The heating element 15 is fitted in a groove formed along the length of the film inner surface guide member 16 at a substantially central portion of the lower surface thereof, and is attached and held by a heat resistant adhesive.

The ceramic heater 15 as a heating element is energized by an AC energizing circuit (not shown) between energizing electrodes (not shown) at both ends of the ceramic heater 15 to raise the temperature in the effective length region, and a temperature sensing element such as a thermistor (not shown) is exposed. The element detects the heater temperature, and the detected temperature information is fed back to a controller (not shown) to control the energization of the heater 15 so that the detected temperature output of the temperature sensitive element becomes a predetermined constant value. That is, the energization of the heater 15 is controlled so that the temperature of the heater 15 is maintained at a predetermined fixing temperature.

The fixing film 17 is, for example, a heat-resistant film material having a thickness of about 50 μm and a polyimide film as a base material and a release layer such as PFA provided on the outer surface.

Like the pressure roller 20 of the apparatus shown in FIG. 12, the pressure roller 20 comprises a cored bar 21 and a heat resistant elastic layer 22 made of silicon rubber or the like. The outer surface is coated with FEP as a surface layer.

A fixing film 17 is sandwiched between the pressure roller 20 and a ceramic heater 15 serving as a heating element, and a pressure spring (not shown) presses the pressure roller 20 with a predetermined pressing force to form a pressure contact nip portion (fixing nip). Part) N is formed.

The pressure roller 20 is rotationally driven in the counterclockwise direction indicated by the arrow by a drive system (not shown), and the rotary pressure roller 2 is rotated.
The rotational force acts on the cylindrical fixing film 17 due to the frictional force between 0 and the outer surface of the fixing film 17, and the inner surface of the fixing film 17 in the fixing nip portion N slides in close contact with the surface of the heater 15 and the fixing film 17 moves. Film inner surface guide member 1
6 is rotated in the clockwise direction a as indicated by the arrow.

The film inner surface guide member 16 functions to facilitate the rotation of the fixing film 17, and regulates the movement of the rotating fixing film 17 in the circumferential direction and the longitudinal direction to prevent unnecessary turbulence of the film. Prevents leaning.

In this state, the fixing film 17 is rotated by the rotation of the pressure roller 20 and the temperature of the ceramic heater 15 as a heating element is controlled to a predetermined fixing temperature. A recording material P as a material to be heated on which an unfixed toner image T has been formed and carried is conveyed from the image forming mechanism section A side and introduced into the apparatus from an inlet guide 31, and a heater 15 is pressed with a film 17 interposed therebetween. Roller 20
The recording material P enters between the film 17 and the pressure roller 20 in the fixing nip portion N formed between the recording material P and the pressure fixing roller 20, and adheres to the outer surface of the rotary fixing film 17 together with the film 17 and the fixing nip portion. N is nipped and conveyed, so that the heater 15
Is applied to the recording material P via the film 17, and the unfixed toner image T on the recording material P is heated and fixed on the surface of the recording material P. The recording material P that has passed through the fixing nip portion N is separated from the surface of the film 17 and discharged and conveyed.

[0023]

In the heat roller type apparatus shown in FIG. 12, the heat capacity of the fixing roller 10 as the heating section and the pressure roller 20 as the pressing section is large, so that the apparatus is kept at room temperature. It takes time to rise to a predetermined temperature from time to time, and lacks quick startability.

Therefore, this device is roughly divided into 2
The device temperature is controlled in two temperature control modes. One is "printing temperature control" that maintains the device temperature at a predetermined fixing temperature when performing the fixing operation, and the other is to print the device temperature in the device standby state in order to have a quick start property. It is a "standby temperature control" in which the temperature is kept lower than the temperature control temperature.

However, in the general use of the image forming apparatus, the time is longer when the image forming apparatus is in the standby state than when the image forming apparatus is performing the printing operation, and the recent trend is as follows. From the viewpoint of energy saving, it is considered that the energy for keeping the fixing device in the high temperature state in the standby state is useless, so that the heater 13 is not energized when it is not used, or the standby temperature is extremely low. It is suggested to set to.

Also in this case, as a means for providing the quick start property as much as possible, for example,
The thickness of the fixing roller 10 as a heating unit is made as thin as possible, or the outer diameter of the pressure roller 20 as a pressure unit is made as small as possible to reduce the heat capacity of both rollers 10 and 20 as much as possible. It is conceivable that the rise of the device temperature can be accelerated by increasing the output of the heater 13, but in practice, there is a limit to such treatment, and it is difficult to provide a satisfactory quick start property.

In this respect, in the case of the film heating type apparatus as shown in FIG. 13, a low heat capacity heater can be used as the heating element 15 which is a constituent member of the heating section, and a thin film having a low heat capacity can be used as the film 17. Thus, the device is capable of shortening the wait time (quick start property), saving power, suppressing the temperature rise inside the machine, etc., and is significantly superior to the heat roller type device.

However, even in the case of this film heating type apparatus, even if the temperature rising characteristic of the heating unit side is improved by reducing the heat capacity of the heating unit side, the temperature of the entire pressing unit side must be raised at the same time. In that case, the so-called “morning one” improvement cannot be expected.

This is because when the printing operation is performed when the temperature of the pressure roller 20 on the pressure section side is low, the amount of heat taken from the heating section side to the pressure roller 20 side becomes large, and the recording material to be image-fixed. This is because P cannot obtain sufficient heat.

On the other hand, in order to improve the initial fixing performance, it is effective to idle the apparatus and warm the pressure roller 20 for a certain period of time until the printable temperature is reached. The temperature rise slowed down and it took a long time.

From the above, in order to provide a quick start property in the heat roller type device and to improve the fixability in the morning in the film heating type device, the heat capacity of the pressurizing unit side should be as small as possible. Although it is effective to make the pressure roller 20 as small as possible, in order to reduce the heat capacity of the pressure roller 20 which is the pressure portion, specifically, the outer diameter of the roller is reduced to reduce the weight.

In this case, even if the outer diameter of the pressure roller 20 is reduced, it is necessary to secure the pressure contact nip portion N having a sufficient nip width in order to obtain a sufficient fixing property. It was also necessary to reduce the hardness of the roller 20.

If a single layer roller of silicon solid rubber or sponge is used as the pressure roller 20, ASKER
It is also possible to manufacture a low hardness roller having a -C hardness of 30 ° or less. If this is the case, it is expected that the pressure roller 20 can have a smaller diameter and a lower hardness. It is not suitable for a pressure roller of a fixing device that requires a long life.

When the roller surface is coated with a PFA tube in order to prevent dirt from adhering to the roller and improve the durability, a considerable amount of the PFA tube itself is formed when the roller is molded. Since the elastic layer is tightened because the molding is performed under tension, the hardness becomes higher by 15 ° or more as compared with the single-layer roller that does not cover the PFA tube. In order to secure a sufficient nip width, there is a limit to the reduction of the diameter of the roller, and it is the current situation that the diameter cannot be reduced enough to dramatically reduce the heat capacity.

Therefore, in the present invention, in this kind of heating device, the constitution of the pressurizing portion is devised so that the nip width of the pressure contact nip portion with the heating portion can be sufficiently secured and the heat capacity can be sufficiently lowered. It is an object of the present invention to provide a device that enables a rapid rise of the device temperature and, in the image heating and fixing device, an improvement in the fixing performance immediately after the rise, and a long life of the device.

[0036]

The present invention is a heating device and an image forming apparatus characterized by the following configurations.

(1) A material to be heated is introduced into a mutual pressure contact nip portion between a heating portion having a heating element and a pressure portion which is in pressure contact with the heating portion, and is nipped and conveyed to heat the material to be heated. A heating device, wherein the pressurizing section is an endless or endless heat-resistant film material capable of rotating or traveling in the forward direction in the sandwiching and conveying direction of the material to be heated in the press-contact nip portion, and the heat-resistant film material. The heating part is provided with a pressing member made of a heat-resistant elastic body for pressurizing the heating part with a predetermined pressure, and the heating part of the pressing nip part formed between the heating part and the heat resistant part of the pressing part. A heating device, wherein a material to be heated is introduced between the material and a heat-resistant film material, and the material is sandwiched and conveyed to heat the material to be heated.

(2) The pressing member made of the heat-resistant elastic body is a rotatable roller body (1)
The heating device according to.

(3) The pressing member made of the heat-resistant elastic body is a non-rotating fixed member, and the contact surface with the heat-resistant film material has low friction. Heating device.

(4) The heat-resistant film material is a rotatable endless belt-shaped film, and a guide member for guiding the rotation of the film material is provided inside the film material, and the pressure member. The heating device according to (1).

(5) The heating device according to (3) or (4), wherein the pressing member is fixed to the guide member.

(6) The heating apparatus according to (1), wherein the pressure member is driven to rotate, and the heat-resistant film material is rotated or conveyed by the rotational force thereof.

(7) The heat-resistant film material is a rotatable endless belt-shaped film, and a part of the circumference of the film material is always rotatably conveyed without tension. Heating device.

(8) The heating device according to (1), wherein the heating section is a rotating body having a heating element therein.

(9) The heating device according to (1) or (8), wherein the heating section is a rotary heat roller.

(10) The heating section includes a fixed heating element,
It is sandwiched between the heating element and the pressurizing section, and is an endless or endless type capable of rotating or traveling while being in close contact with the surface of the heating element in the press-contact nip portion in the forward direction in which the material to be heated is nipped and conveyed. Having a heat-resistant film material, the material to be heated is introduced between the heat-resistant film material on the heating portion side of the pressure contact nip and the heat-resistant film material on the pressure portion side, and is nipped and conveyed to be heated. The heating device according to (1), characterized in that the material is heat-treated.

(11) The heating device according to (10), wherein the heat-resistant film material on the heating section side is rotated or transported by the rotational force of the pressing member on the pressing section side.

(12) The heat-resistant film material on the heating portion side is a rotatable endless belt-shaped film, and a part of the circumference of the film material is always rotatably conveyed without tension (10). ) The heating device described in.

(13) An image heating fixing device in which the material to be heated is a recording material supporting an unfixed developer image to be image-fixed, and the unfixed developer image is heat-fixed on the recording material. The heating device according to any one of (1) to (12), characterized in that.

(14) An image characterized by including the heating device according to any one of (1) to (13) as an image heating fixing device for heating and fixing an unfixed developer image on a recording material. Forming equipment.

[0051]

Since the pressing member comes into contact with the heating unit or the introduced material to be heated through the film member (pressing film member) on the pressing unit side and does not come into direct contact with them, Since the durability of the pressure member is prevented from being deteriorated due to dirt, and the apparent hardness of the pressure member through the pressure film material is smaller than that of the pressure member coated with the PFA tube, the hardness increase is small. As the pressurizing member, it is possible to use a low-hardness member having a small diameter to reduce the heat capacity and capable of ensuring a sufficient width of the pressure contact nip portion without any trouble.

Therefore, the pressurizing portion is secured to the heating portion, a sufficient nip width of the press contact nip portion is secured, and the heat capacity is sufficiently lowered so that the apparatus temperature rises at a high speed and the image heating and fixing apparatus is not provided. It is possible to achieve both improvement of the fixing performance immediately after the start-up (fixing performance in the morning), and extension of the life of the device.

[0053]

【Example】

<Embodiment 1> (FIGS. 1 to 6) FIG. 1 is a cross-sectional model view showing a schematic configuration of a heating device (image heating and fixing device) of the present embodiment, and FIG.
The same components and parts as those of the apparatus shown in FIG. 12 are designated by the same reference numerals, and the repeated description will be omitted.

In the apparatus of this embodiment, the heating section 10 is a fixing roller (heat roller). Reference numerals 24, 25, and 26 are a pressure film material, a pressure film guide, and a pressure roller that configure the pressure unit 23, respectively.

The pressure film guide 25 is a heat resistant mold member, and both ends of the pressure film guide 25 are side plates 32 of the apparatus frame 30.
-It is fixedly supported between 32.

The pressure film material 24 is a cylindrical heat resistant film loosely fitted on the pressure film guide 25.

As the pressure film material 24, a heat resistant film similar to the fixing film in the film heating type heating device can be used. For example, as shown in the layer structure model diagram in FIG. 3, a heat resistant resin film base material layer 24a such as polyimide or PFA and a PTF formed on the outer surface thereof.
It is a composite layer film material including a releasable layer 24b such as E or PFA. In this example, when PFA is used as the film base layer 24a, the monolayer film can be used as it is.

The pressure roller 26 is inserted through the inside of the cylindrical pressure film material 24, and the shaft portions at both ends are supported between the side plates 32 of the apparatus frame 30 via bearings 26c and 26c.

The pressure roller 26 comprises a core metal 26a and a heat-resistant elastic layer 26b concentric with the core metal.
Roller hardness 3 using silicon solid rubber, silicon sponge, fluororubber, etc. as the heat resistant elastic layer 26b
A very soft grade of about 5 ° (ASKER-C, 500 gf load) or less is used.

The bearings 26c, 26c are attached to the side plates 32, 32 of the apparatus frame 30 with freedom of movement only in the vertical direction.
c and the lug portions 2 at both ends of the pressure film guide 25.
5a and 25a are compressed by pressure springs 27 and 27, and are urged upward, whereby the pressure roller 26 is pressed against the lower surface of the fixing roller 10 as a heating unit. The pressure film material 24 is sandwiched between the fixing roller 10 and the pressure roller 26 to form a pressure contact nip portion (fixing nip portion) N having a predetermined width.

Reference numerals 11a and 11a are bearings of the fixing roller 10. The fixing roller 10 is rotationally driven in a clockwise direction a in FIG. 1 at a predetermined peripheral speed by a driving unit (not shown). Further, the temperature control system (not shown) including the temperature detecting element 14 controls the energization of the halogen heater 13 as a heating element to control the surface temperature to a predetermined fixing temperature.

As the fixing roller 10 is driven to rotate, the cylindrical pressure film material 24 is driven by the rotational force acting on the pressure contact nip portion N with the fixing roller 10 due to the frictional force between the fixing roller 10 and the film outer surface. Rotate. Pressure roller 26
Also, the cylindrical pressure film material 24 rotates following the driven rotation.

The pressure film guide 25 is the film 2
Rotating film 24, which facilitates rotation of 4
The movement of the film in the circumferential direction and the longitudinal direction of the film is regulated to prevent the film from moving unnecessarily and moving unnecessarily.

Then, the recording material P as the material to be heated on which the unfixed toner image T is formed and carried is conveyed from the side of the image forming mechanism A (not shown) and introduced into the apparatus from the inlet guide 31. The recording material P enters between the fixing roller 10 and the pressure film material 24 in the fixing nip portion N formed between the fixing roller 10 and the pressure roller 26 with the pressure film material 24 sandwiched therebetween and is fixed. By being nipped and conveyed through the nip portion N, the unfixed toner image T is heat-fixed to the recording material P.

In the apparatus of this embodiment, the pressure roller 26 is
The fixing roller 10 as a heating portion and the introduced recording material P as a heated material come into contact with each other through the pressure film material 26 and do not come into direct contact therewith, so that the durability is deteriorated due to the contamination of the roller. The pressure film material 24 is not tensioned and is used in a tension-free state.
The apparent hardness of the pressure roller 26 through 4 is 2-3 degrees.
Since the hardness of the pressure roller 26 is small and the hardness increase is small as compared with the hardness increase of 15 ° or more in the case of the PFA tube covering roller described above, the pressure roller 26 has a smaller diameter to reduce the heat capacity and the pressure contact nip portion N. It is possible to use a low-hardness roller that can secure a sufficient width without any hindrance.

Therefore, the pressing unit 23 is applied to the heating unit 10.
By ensuring a sufficient nip width of the pressure contact nip portion N and further sufficiently lowering the heat capacity, it is possible to achieve both a rapid rise of the apparatus temperature and an improvement in the fixing performance immediately after the rise (fixing performance in the morning). In addition, the life of the device can be extended.

The test results of the device of this embodiment and the conventional device are shown below.

.. Device of this Example (FIGS. 1 and 2) a. Fixing roller 10 outer diameter φ: 20 mm, wall thickness t: 0.8 mm, length 260 m
30 μm of PFA coating surface layer 12 on the surface of the aluminum hollow roller 11 of m. Halogen heater 13; 100 V / 400 W Temperature control temperature during printing: 185 ° C. Temperature control temperature during standby: 175 ° C.

B. Pressure film material 24 Base material 24a; 40 μm (made of polyimide), surface layer 24b;
PFA coating 10 μm (including primer layer), film outer diameter; φ20 mm, film width; 230 mm.

C. Pressure roller 26 outer diameter φ; 10 mm, core metal 26a diameter φ; 5 mm, elastic layer; silicone sponge, roller hardness; 25 ° (ASKE
RC, 500gf load), roller rubber length: 225m
m.

D. Pressing force / nip width Total pressure: 5 kgf, width of nip portion N: 2.8 mm.

E. Process speed: 50 mm / se
c.

F. Recording material (transfer material) P; PLOVE
R BOND 75 g / m ² .

G. Evaluation mode No pre-multi-rotation (pre-multi-rotation: operation of rotating the device to heat the pressure roller 26 in a predetermined temperature range during standby), inputting a voltage of 100 V, and continuously 20 immediately after the fixing temperature reaches after the power is turned on. Sheet passing.

.. Conventional device 1 (FIG. 12) a. The same as the fixing roller 10a, the same as the halogen heater 13, the print temperature control temperature, and the stamper temperature control temperature a.

B. Pressure roller 20 outer diameter φ; 20 mm, core bar 21 diameter φ; 9 mm, elastic layer 2
2; Silicon sponge, outer periphery covered with 50 μm thick PFA tube, roller hardness: 42 ° (ASKER-C, 5
00 gf load).

C. Applied pressure / nip width Total load: 8 kgf, width of nip part N: 2.8 mm.

D. Process speed / transfer material P / evaluation mode Same as e, f, and g.

.. Conventional device 2 Same as the configuration.

However, in the evaluation mode, the pre-rotation is performed, and the fixing roller temperature is set to 1 in order to warm the pressure roller 20.
Roller pair 10 between 50 ° C and 175 ° C
・ Turn 20 times.

.. Experimental results a. Wait time The time from turning on the power to reaching the standby temperature was defined as the wait time, and the measurement was performed for the equipment. The results are shown in Table 1 (room temperature 20
°).

Table 1 Device wait time (sec). Example apparatus (without multiple rotation before) 29. Conventional device 1 (without multiple rotation before) 29. Conventional device 2 (with multiple rotations before) 39 From the above results, the conventional device 2 has the worst wait time because heat is taken away by the pressure roller 20 due to multiple rotations before. On the other hand, the conventional device 1 of the embodiment and the conventional device 1 can reduce the wait time by about 10 seconds as compared with the conventional device 2.

B. Fixability Figure 4 shows the fixability immediately after the system goes into standby.
Is.

In this result, the fixing device of Example 1 has the best fixing property, and the fixing device 2 of Conventional Example (with multi-rotation before) has almost the same fixing property. However, in the conventional device 1 (without multiple rotation before), the fixing property is considerably deteriorated.

In this result, the reason why the fixing device of Example 1 has good fixability without multiple pre-rotation is that the heat capacity on the pressurizing side is small and it quickly warms up. The cause is that the pressure roller 20 is not sufficiently warm.

Further, in any of the apparatuses, the fixing property is improved as the number of passed sheets is increased, because the pressure roller is warmed.

The fixing property in this test is defined as follows.

[0088]

[Equation 1] Image density was measured with a Mach beth densitometer.
The rubbing of the image is 22.5 x 22.5 mm on the bottom,
A weight having a weight of 200 gf is used, and Silbon C is sandwiched on the bottom surface thereof, and the image is rubbed. Rubbing is 1 sec per round trip
Calls shall be made in 5 round trips.

From the above measurement results of the wait time and the fixability, it can be seen that the apparatus of this embodiment makes it possible to reduce the wait time and improve the fixability at the same time.

C. Thickness of Pressure Film Material 24 and Hardness of Pressure Roller 26 In this example, the thickness of the pressure film material 24 used and the roller hardness of the pressure roller 26 are shown in FIG. The nip width in FIG. 5 is the one when the roller hardness of the pressure film material 24 and the pressure roller 26 is changed in the apparatus of this embodiment.

A suitable thickness of the pressure film material 24 (including the surface releasable layer) is 100 μm or less, and the pressure roller hardness is 35 ° (ASKER-C, 500 gf load).
The following are considered suitable.

D. Regarding Nip Width On the other hand, FIG. 6 shows the result of observing the change in fixing property when the nip width is changed in the apparatus of this embodiment. The fixability here represents the worst fixability of 20 sheets.

It can be seen that a nip width of at least about 1.8 mm is required to secure a fixing property of about 20%.

<Embodiment 2> (FIGS. 7 and 8) FIG. 7 is a schematic cross-sectional view showing the schematic configuration of the apparatus of this embodiment, and FIG. 8 is a vertical cross-sectional view.

The apparatus of this embodiment is the same as the apparatus of the first embodiment (FIGS. 1 and 2) in place of the pressure roller 20 which is the pressure unit in the film heating type image heating and fixing apparatus of FIG. The pressurizing unit 23 (24 to 27) is applied.

In the apparatus of this embodiment, the pressure roller 26 of the pressure unit 23 is rotationally driven, so that the pressure film material 24 and the fixing film 17 on the heating unit 10 side are rotated in a predetermined direction.

In order to ensure the rotation of the fixing film 17, in the apparatus of this embodiment, both end portions of the pressure roller 26 are exposed to both sides of the pressure film material 24, and the outer peripheral surface of the exposed portion is fixed. The outer surfaces of both ends of the film 17 are in direct contact with each other.

The fixing film 17 uses, for example, a polyimide resin as a heat resistant base material, and has PFA or PTF on its surface layer.
A release layer such as E having a thickness of about 50 μm is used.

The apparatus of this embodiment is composed of the heating element 15 of the heating section 10.
Since the heat capacity around the film inner surface guide member 16 is originally much smaller than that of the heat roller system, and as described above, the heat capacity on the pressurizing section 23 side is also small, the rise time is almost neglected. Since it is possible, it takes about 0 sec.

Moreover, since the pressurizing portion 23 having a small heat capacity is sufficiently warmed by the time the recording material P reaches the fixing nip portion N, sufficient fixing ability can be obtained. <Embodiment 3> (FIG. 9) FIG. 9 is a schematic cross-sectional view showing the schematic configuration of the device of this embodiment.

The apparatus of this embodiment is similar to the apparatus of the first embodiment (FIGS. 1 and 2) except that the pressure roller 26 of the pressure unit 23 is used.
Is changed to a non-rotating fixed pressurizing member 26A, and is otherwise similar to the first embodiment.

The fixed pressure member 26A is a slender heat-resistant elastic member having a semi-cylindrical cross section fixed to the upper surface of the pressure film guide 25 along its length.

The pressure film guide 25 is attached to the apparatus frame 3
When assembled between the side plates 32 of No. 0, the pressure member 26A is pressed against the lower surface of the fixing roller 10 as a pressure portion against the elasticity by sandwiching the pressure film material 24, and the pressure is applied. The elastic reaction force of the member 26A can obtain a predetermined pressing force and a predetermined nip width in the pressure contact nip portion N.

The fixed pressure member 26A is made of a heat-resistant elastic material, and the surface of the pressure film material 24 in contact with the inner surface has low friction.

Specifically, the material used as a simple substance is, for example, a non-woven fabric of PTFE (trade name: Nomex).
The pad member is a porous member made of PTFE (trade name: Fluoropore) or the like.

When the elastic body and the function of low surface friction are separated, silicon elastic rubber, silicon sponge, fluororubber or the like is used as the elastic layer, and the surface thereof is PF.
It can be used by covering it with A tape or Kapton tape.

The pressure member 26A has a hardness of 35 ° (ASK) as in the pressure roller 26 of the apparatus of the first embodiment.
ER-C, 500 gf load) or less is desirable. Further, the pressure film material 24 preferably has a thickness of 100 μm or less.

The pressure film material 24 is driven to rotate while the inner surface slides on the surface of the pressure member 26A as the fixing roller 10 is driven to rotate.

By using the pressure member 26A as a fixing member of a heat-resistant elastic body as in the apparatus of this embodiment, the structure can be made simpler than the case of using a roller type pressure member, and the pressure can be increased. Since the heat capacity on the side of the portion 23 can be further reduced, the wait time can be further shortened and the fixability can be improved in the morning.

<Embodiment 4> (FIG. 10) FIGS. 10 (a), (b), and (c) show other structural examples of the film heating type heating device.

In the case of (a), the first film suspension roller 41, the second film suspension roller (tension roller) 42, and the ceramic heater 15 as a heating element fixedly supported by the heater support member 43. An endless belt-shaped heat-resistant film material (fixing film) 17 is suspended and stretched between three members 41, 22, and 15 which are parallel to each other to form a heating unit 10, and the fixing film 17 of the heating unit 10 is sandwiched. The device of Example 1 is brought into pressure contact with the heater 15 with the device (FIGS. 1 and 2).
The heating unit 23 similar to the above is provided.

The fixing film 17 is rotatively conveyed a by rotating the first film suspension roller 41. The pressure film material 24 rotates following the rotation of the fixing film 17.

In the case of (b), an endless belt-shaped fixing film 17 is suspended and stretched between the heater 15 and the two members 15 and 44 of one film suspending roller 44 to form the heating unit 10. Heater 1 sandwiching 10 fixing films 17
5, the heating unit 23 similar to that of the apparatus of Example 1 (FIGS. 1 and 2) is arranged.

The fixing film 17 is attached to the film suspension roller 4
By the rotation drive of No. 4, it is rotated and conveyed a. The pressure film material 24 rotates following the rotation of the fixing film 17.

In the case of (c), the fixing film 17 is not an endless belt-shaped one, but a long end film wound in a roll is used.
Side to the winding shaft 46 side via the heater 15 to form the heating unit 10, and the fixing film 1 of the heating unit 10
7 is sandwiched and pressed against the heater 15, and the heating unit 23 similar to that of the apparatus of Embodiment 1 (FIGS. 1 and 2) is arranged.

The fixing film 17 is run and conveyed to the winding shaft 46 side. The pressure film material 24 is the fixing film 17
It rotates following the running of.

In the above devices (a), (b), and (c), the pressurizing unit 23 can be the heating unit 23 of the device of the third embodiment (FIG. 9).

The pressure film material 24 of the heating section 23 is
Like the fixing film 17 of the heating unit 10 of the apparatus of (a), (b), and (c), a structure in which an endless belt-shaped film is suspended and stretched and rotated, or a long film wound in a roll is used. It is also possible to have a structure in which an end film is run, and in this case as well, the pressing member 26 through the film is used.
The apparent increase in hardness of 26A is smaller than that of the pressure member coated with the PFA tube, and the same effect as that of the apparatus of Example 1 can be obtained.

<Fifth Embodiment> (FIG. 11) FIG. 11 shows a schematic structure of an example of an image forming apparatus incorporating the image heating and fixing device 50 as the heating device of the heating system of the first embodiment. 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 is an apparatus casing, 101 is 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.
The upper part is driven to reciprocate to the right a and the left a'in the drawing at a predetermined speed.

Reference numeral G denotes an original document, which is placed on the upper surface of the original document table 101 with the image surface side to be copied facing downward according to a predetermined placement standard, and the original document pressure plate 103 is covered and pressed down. Set.

Reference numeral 104 denotes a slit opening serving as a document illuminating section that 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 sequentially moves the slit openings 104 from the right side to the left side in the forward movement process of the document placing table 101 to the right a. The light L of the lamp 105 is passed through the slit opening 104 and the transparent original placing table 101 to be illuminated and scanned in the passing process, and the original surface reflected light of the illumination scanning light is reflected by the image element array 106 by the photosensitive drum. Image formation exposure is performed on the 107th surface.

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 b at a predetermined peripheral speed around the central support shaft 108. During the rotation process, the charging device 109 receives a uniform positive or negative charging process, 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 formed. An electrostatic latent image corresponding to the image-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 which is softened and melted by heating, and the toner image as the visualized image is provided with the 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 housed, the sheets in the cassette are fed out and fed one by one by the rotation of the feeding roller 112, and then the drum is moved by the registration rollers 113. When the leading edge of the toner image forming portion on 107 reaches the portion of the transfer discharger 111, the leading edge of the transfer material sheet P also arrives at the position between the transfer discharger 111 and the photosensitive drum 107 so that they both coincide with each other. It is returned and is synchronously fed.

Then, the toner image on the side of the photosensitive drum 107 is sequentially transferred to 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 separation means (not shown), and is guided to the fixing device 50 by the conveying device 114 and carried on the unfixed toner. The image is heated and fixed, and is discharged as an image-formed product (copy) 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.

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.

[0131]

As described above, according to the present invention, the material to be heated is introduced into the mutual pressure contact nip portion between the heating portion having the heating element and the pressure portion pressed against the heating portion to be nipped and conveyed. For a heating device that heat-treats the material to be heated, a sufficient nip width of the pressure contact nip portion between the heating portion and the pressure portion is ensured, and further, the heat capacity of the pressure portion is sufficiently reduced so that the device temperature rises quickly. In the image heating and fixing device, it is possible to improve the fixing performance immediately after the start-up, and it is possible to extend the life of the device.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing a schematic configuration of a heating device (image heating and fixing device) according to a first embodiment.

[Figure 2] Vertical section model

[Fig. 3] Layer structure model diagram of a composite layer type pressure film material

FIG. 4 is a graph showing the result of a comparative experiment regarding fixing property.

FIG. 5 is a graph showing changes in the nip amount when the thickness of the pressure film material and the hardness of the pressure roller are changed.

FIG. 6 is a graph showing the relationship between the nip width and the fixing property.

FIG. 7 is a cross-sectional model view showing a schematic configuration of the device of Example 2.

[Fig. 8] Vertical section model diagram

FIG. 9 is a schematic cross-sectional view showing the schematic configuration of the device of Example 2.

10 (a), (b), and (c) are schematic views of another example of the configuration of the film heating type heating device.

FIG. 11 is a schematic configuration diagram of an example of an image forming apparatus.

FIG. 12 is a schematic cross-sectional view showing a schematic configuration of an example of a heating device of a heat roller system.

FIG. 13 is a schematic cross-sectional view showing a schematic configuration of an example of a film heating type heating device.

[Explanation of symbols]

10 Heat roller (fixing roller) as a heating unit,
Alternatively, the fixing fill mechanism section 20/23, a pressure roller as a pressure section, or the pressure film mechanism section 13/15, a halogen heater or a ceramic heater as a heating element 14 a temperature detecting element (thermistor) 16/25, a film inner surface guide Member 17 Fixing film 24 Pressure film material 26 / 26A Pressure roller or fixed pressure member N Pressure contact nip part (fixing nip part) P Heated material (recording material, transfer material) T Toner image

Front Page Continuation (72) Inventor Satoru Izawa 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Takahiro Inoue 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (14)

[Claims] 1. A heating method in which a material to be heated is introduced into a mutual pressure contact nip portion between a heating portion having a heating element and a pressure portion pressed against the heating portion and is nipped and conveyed to heat the material to be heated. The device is a device, wherein the pressurizing section is an endless or endless heat-resistant film material capable of rotating or traveling in the forward direction in the sandwiching and conveying direction of the material to be heated in the pressure contact nip portion, and the heat-resistant film material. The heating unit is provided with a pressure member made of a heat-resistant elastic body that pressurizes at a predetermined pressure, and the heat resistance of the heating unit and the pressure unit of the pressure contact nip formed between the heating unit and the pressure unit. A heating device, wherein a material to be heated is introduced between the material and a film material, and the material is sandwiched and conveyed to heat the material to be heated. 2. The heating device according to claim 1, wherein the pressing member made of the heat resistant elastic body is a rotatable roller body. 3. The heating according to claim 1, wherein the pressure member made of the heat-resistant elastic body is a non-rotating fixed member, and the contact surface with the heat-resistant film material has low friction. apparatus. 4. The heat-resistant film material is a rotatable endless belt-shaped film, and is provided with a guide member for guiding the rotation of the film material inside the film material, and the pressing member. The heating device according to claim 1. 5. The heating device according to claim 3, wherein the pressing member is fixed to the guide member. 6. The heating device according to claim 1, wherein the pressure member is rotationally driven, and the heat-resistant film material is rotated or transported by the rotational force thereof. 7. The heat-resistant film material is a rotatable endless belt-shaped film, and a part of the circumference of the film material is always rotatably conveyed in a tension-free manner. Heating device. 8. The heating device according to claim 1, wherein the heating unit is a rotating body having a heating element therein. 9. The heating device according to claim 1, wherein the heating unit is a rotary heat roller. 10. The heating portion is sandwiched between a fixed heating element and the heating element and the pressing portion, and in the press contact nip portion, the heating portion is brought into close contact with the heating element surface in the forward direction in the sandwiching and conveying direction of the material to be heated. A heat-resistant film material having an endless or endless heat-resistant film material that can be rotated or transported while sliding, and a heat-resistant film material on the heating part side of the pressure contact nip part, and a heat-resistant film material on the pressure part side. The heating device according to claim 1, wherein the material to be heated is introduced into the space between the two to be sandwiched and conveyed to heat the material to be heated. 11. The heating device according to claim 10, wherein the heat-resistant film material on the heating section side is rotated or conveyed by rotation by the rotational force of the pressing member on the pressing section side. 12. The heat-resistant film material on the heating section side is a rotatable endless belt-like film, and a part of the circumference of the film material is always rotatably conveyed without tension. The heating device according to. 13. An image heating fixing device for heating an unfixed developer image to be fixed on the recording material, the image heating fixing device heating and fixing the unfixed developer image on the recording material. The heating device according to any one of claims 1 to 12, characterized in that. 14. An image forming apparatus comprising the heating device according to any one of claims 1 to 13 as an image heating fixing device for heating and fixing an unfixed developer image on a recording material. .