JP2003098866A - Image-heating apparatus and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the cost of a fixing unit and improve usability. SOLUTION: A noncontact temperature sensor is attached to a main. An openable and closable shutter is provided in an opening, necessary to be provided in the fixing unit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic induction heating type heating device and an image heating device, and an image forming apparatus such as an electrophotographic device and an electrostatic recording device provided with the image heating device.

[0002]

2. Description of the Related Art For the sake of convenience, an image heating apparatus (fixing apparatus) for heating and fixing a toner image on a recording material in an image forming apparatus such as a copying machine or a printer will be described as an example.

In an image forming apparatus, a material to be recorded (transfer material sheet, electrofax sheet, electrostatic recording paper, OHP sheet, printing) by an appropriate image forming process means such as electrophotographic process, electrostatic recording process, magnetic recording process, etc. A fixing device that heats and fixes an unfixed image (toner image) of the target image information formed and carried on a recording material surface by a transfer method or a direct method on a recording material surface as a permanently fixed image Roller type devices have been widely used. Further, recently, a film heating type device, which is advantageous in saving energy and shortening the wait time, has been put into practical use. Similarly, an electromagnetic induction heating type device has been proposed.

A) Heat roller type fixing device This is basically a pressure contact roller pair of a fixing roller (heating roller) and a pressure roller, and is a mutual pressure contact portion of the roller pair by rotating the roller pair. The recording material on which the unfixed toner image to be image-fixed is formed and carried in the fixing nip portion and is nipped and conveyed, and the unfixed toner image is recorded by the heat of the fixing roller and the pressing force of the fixing nip portion. The material is fixed by heat and pressure on the material surface.

In general, the fixing roller has an aluminum hollow metal roller as a base body (core bar), and a halogen lamp as a heat source is inserted and disposed in the inner space of the fixing roller. The temperature of the halogen lamp is controlled by controlling the energization of the halogen lamp so that the temperature is maintained at a predetermined fixing temperature.

In particular, as a fixing device of an image forming apparatus for forming a full-color image which is required to sufficiently heat and melt up to four toner image layers to mix colors, a core metal of a fixing roller has a high heat capacity. In addition, a rubber elastic layer for wrapping the toner image around the core metal and uniformly melting the toner image is provided, and the toner image is heated through the rubber elastic layer. There is also a structure in which a heat source is also provided in the pressure roller so that the pressure roller can be heated and temperature controlled.

However, in the heat roller type fixing device, even if the halogen lamp which is a heat source is turned on at the same time when the power source of the image forming apparatus is turned on, the heat capacity of the fixing roller is large, so that the fixing roller and the like are completely cooled. It takes a considerable waiting time (wait time) from standing up to the predetermined fixing temperature, and lacks quick startability.
Further, it is necessary to energize the halogen lamp and keep the fixing roller in a predetermined temperature control state even when the image forming apparatus is in the standby state (when the image is not output) so that the image forming operation can be executed at any time. However, there were problems such as large power consumption.

Further, in a fixing device having a particularly large heat capacity such as the fixing device of the above-mentioned full-color image forming apparatus, there is a delay in temperature adjustment and a temperature rise on the surface of the fixing roller, so that fixing failure may occur. Problems such as uneven gloss and offset tend to occur.

B) Film heating type fixing device A film heating type fixing device is disclosed, for example, in JP-A-63-3.
13182, JP-A-2-157878, Kaihei 4-44075, JP-A-4-204980.

That is, a heat resistant film (fixing film) is sandwiched between a ceramic heater as a heating body and a pressure roller as a pressure member to form a nip portion, and the film in the nip portion and the pressure are pressed. A recording material on which an unfixed toner image to be image-fixed is carried between the roller and the recording material is nipped and conveyed together with the film, so that the heat of the ceramic heater is transferred to the recording material through the film at the nip portion. In addition, the unfixed toner image is thermally and pressure-fixed on the surface of the recording material by the pressing force of the nip portion.

This film heating type fixing device can constitute an on-demand type device by using a ceramic heater and a member having a low heat capacity as a film, and a ceramic heater as a heat source only when image formation is performed in the image forming device. It is only necessary to energize the printer to generate heat at a predetermined fixing temperature, the waiting time from the power-on of the image forming apparatus to the image forming executable state is short (quick start property), and the power consumption during standby is also significantly increased. There are advantages such as small size (power saving).

However, it is disadvantageous in terms of heat amount as a full-color image forming apparatus requiring a large amount of heat or a fixing device for high speed models.

C) Electromagnetic induction heating type fixing device Japanese Utility Model Laid-Open No. 51-109736 discloses an induction heating fixing device in which a magnetic flux induces a current in a fixing roller and Joule heat is used to generate heat. This achieves a more efficient fixing process than a heat roller type fixing device using a halogen lamp as a heat source by directly generating heat of the fixing roller by utilizing generation of an induced current.

The fixing process is performed by heating the cylindrical fixing film itself, which is a rotating body of electromagnetic induction heat generation, by the alternating magnetic flux of the exciting coil as the magnetic field generating means.

By heating the portion closer to the material to be heated, the distance required to transfer the heat necessary for melting and fixing the unfixed toner image is shortened as compared with the film heating method. Since the heat response is extremely excellent, the heat taken by the material to be heated can be immediately supplied. Therefore, it is suitable for a full-color image forming apparatus that requires a larger amount of heat.

Since the heat capacity is smaller than that of the heat roller type fixing device, the waiting time from power-on of the image forming device to the image forming executable state is short (quick start property), and power consumption during standby is also large. Can be reduced to

[0017]

Although the above-mentioned fixing devices have different heating systems, the fixing operation is made possible by properly controlling the temperature of the roller or the film to keep it at a predetermined fixing temperature.

Generally, in most cases, the temperature of the fixing roller and the fixing film, which come into contact with the unfixed toner image, is detected and temperature control is performed so as to maintain a predetermined fixing temperature.

During temperature control, it is most accurate to control the heater (halogen lamp, ceramic heater, etc.) or magnetic field generating means based on the temperature of the central portion of the fixing roller or fixing film in the sheet passing area.

However, when a thermistor or the like used as the temperature detecting means is brought into contact with the paper passage area of the fixing roller or the fixing film, the toner adhering to the surface of the fixing roller (or film) during the fixing operation is gradually brought into contact with the thermistor. It accumulates gradually.

When the toner contaminates the surface of the fixing roller (or the film), on the contrary, finally, a blobs stain, which is an image defect in which a stain of the temperature sensor width remains in the fixed image, occurs.

If the fixing device is equipped with a cleaner such as a web, there is no problem, but the structure of the fixing device becomes complicated, which is also disadvantageous in terms of cost.

Therefore, when the cleaner is not provided, it is possible to avoid the blobs stain by the following method.

In the case of a fixing system using a fixing film,
Since the temperature sensor can be structurally arranged inside the film and abutted from the inner surface, it is possible to avoid the image defect.

However, since there is a difference between the temperature of the inner surface of the fixing film and the actual temperature of the surface (outer surface) of the fixing film, the temperature control accuracy deteriorates, causing uneven gloss.

On the other hand, in the case of the heat roller type fixing device,
Since the thickness of the roller including the core metal and the rubber layer is large, it is necessary to contact the temperature sensor from the roller surface.

In order to avoid the above-mentioned blobs stain,
It is conceivable to perform temperature control based on the surface temperature of the fixing roller in the non-sheet passing area, but it is unavoidable that the temperature control accuracy deteriorates, which causes uneven gloss.

When a halogen heater is provided in each of the fixing roller and the pressure roller to heat the material to be heated from above and below, by making the heat capacity of the fixing roller and the pressure roller equal, A means for controlling the temperature based on the central portion of the paper passing area on the surface is also conceivable.

However, in order to equalize the heat capacities of the fixing roller and the pressure roller, it is necessary to make the diameters of the fixing roller and the pressure roller substantially equal to each other, so that the degree of freedom in design becomes very narrow, and the fixing device has a small size. It is also very disadvantageous.

As described above, if it is attempted to avoid the blobs from being smeared by the temperature sensor coming into contact with the sheet passing area on the surface of the fixing roller, the accuracy of temperature control is deteriorated, the degree of freedom in designing the fixing device is increased, and the device is enlarged, and the cost is increased. It was causing bad effects such as ups.

Therefore, it is conceivable to dispose the temperature sensor at a fixed distance from the roller surface without contacting the fixing roller.

In this case, the blobs stain is not generated in principle, but the cost of the non-contact type temperature sensor is higher than that of the contact type.

Among the laser printers, high-speed machines and
In a full-color machine, the life of the main body of the image forming apparatus is set to be long, and a fixing device that is used at high temperature and is heavily worn is generally a replacement part, and needs to be replaced several times before the life of the main body.

As described above, the cost increase of the fixing device which needs to be replaced several times is not preferable because the burden on the user becomes large.

Therefore, it is preferable to dispose a high-cost member on the image forming apparatus main body side as much as possible, but it is necessary to provide an opening at the connecting portion with the non-contact temperature sensor for the purpose of detecting the temperature of the surface of the fixing roller. is there.

There is a possibility that the user may inadvertently touch the high temperature fixing roller through the opening.

Therefore, in the present invention, the temperature control accuracy is improved, the size of the fixing device is reduced, and the cost is reduced without the blobs being contaminated, and the user is prevented from touching the fixing roller at a high temperature so that the fixing device can be attached or detached. The purpose is to improve the workability at the time.

[0038]

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

[1]: An image heating device for heating a material to be heated by heating a rotating body with a heat source or by electromagnetic induction heat generation by the action of a magnetic field of a magnetic field generating means, wherein the image heating device inserts the material to be heated. An image heating apparatus characterized in that it has an opening for exposing the roller surface other than the insertion opening and the paper discharge opening, and the opening has a shutter that can be opened and closed.

[2]: An image forming apparatus wherein the temperature detecting means detects the temperature of the rotating body through the opening of the image heating device and the image heating device is detachable.

[3]: The image heating apparatus and the image forming apparatus described in [1] or [2], wherein the opening of the image heating apparatus is arranged on the front side in the detaching direction.

[4]: The image heating apparatus and the image forming apparatus described in [1] to [3], wherein the shutter is closed in association with the detachment of the image heating apparatus and is opened in association with the mounting. .

[5]: Positioning in which the temperature of the rotating body is detected by the non-contact temperature detecting means, and the supporting member of the non-contact temperature detecting means moves in the attachment / detachment direction of the image heating device and comes into contact with the supporting member. Characterized by having a part [1]
The image heating apparatus and the image forming apparatus described in [4].

<Operation> (1) By disposing a temperature sensor for detecting the surface temperature of the rotating body of the apparatus on the image forming apparatus main body side, the cost of the image heating apparatus as a replacement part can be reduced, and the image heating apparatus can be realized. A shutter that can be opened and closed is provided at the opening of the, and the opening is closed when the image heating device is detached from the main body of the image forming apparatus, so that the user can perform detaching work without worrying about touching the hot rotating body, thus improving workability. To do.

(2) The non-contact temperature sensor arranged on the main body side of the apparatus is arranged at a fixed distance by using positioning with the rotating body of the image heating apparatus to detect the temperature of the fixing roller sheet passing area. The image heating device can be downsized because it can be performed with high accuracy and the degree of freedom in design can be widened. Further, in principle, the blobs are not contaminated and it is not necessary to provide a cleaner, so that the cost can be reduced.

[0046]

BEST MODE FOR CARRYING OUT THE INVENTION [First Embodiment] For convenience of explanation, an image forming apparatus in the following embodiments will be described with reference to an embodiment having a heat roller type fixing device. However, the present invention is not limited to the fixing device of the heat roller system, and can be applied to the above-mentioned film heating system, electromagnetic induction heating system and the like.

(1) Example of image forming apparatus Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 is a schematic view of a cross section of a color laser printer using an electrophotographic process. The color laser printer (image forming apparatus) shown in FIG. 2 uses an intermediate transfer belt as an intermediate transfer member, and a developing unit, an exposing unit, an image carrier (hereinafter referred to as “photosensitive drum”), and a charging unit for each color. ,
Equipped with cleaning means.

The first photosensitive drum 1a in FIG. 2 has an arrow d1.
Image formation exposure optical system, which is uniformly driven by the primary charging roller 3a while being driven to rotate at a predetermined peripheral speed in the direction of, and modulated in accordance with the digital image signal scanned by the laser scanner 5a. First by receiving via
Electrostatic latent image of the color component (here, yellow component) is formed.

Subsequently, the electrostatic latent image is developed by the first color toner (here, yellow toner Y) using the first developing device 2a to obtain a visible image for the first color component. The procedure described above is performed for the second color (magenta), the third color (cyan), and the fourth color (black).

In the first embodiment, the intermediate transfer belt 6 has the same peripheral speed as the photosensitive drum 1a in the direction of the arrow d2. It is driven to rotate.

The transfer of the yellow visible image from the photosensitive drum 1a to the intermediate transfer belt 6 (primary transfer) is carried out by applying a primary transfer bias supplied from a power source S1.

With respect to magenta, cyan and black, a color image is obtained by sequentially superimposing and primary transferring on the intermediate transfer belt 6 using the same means.

The color toner image formed on the intermediate transfer belt 6 is collectively transferred (secondary transfer) onto the heated material P conveyed at the nip portion with the secondary transfer roller 7.
The heated material P to which the color image is secondarily transferred is conveyed to the fixing device 8, and the color image is fixed by heat and pressure in the nip portion (fixing portion) between the fixing roller and the pressure roller.

The fixing device will be described in section (2).

(2) Fixing Device (Heating Unit) 8 FIG. 1 is a schematic cross-sectional view of the fixing device 8 in the first embodiment.

The fixing device 8 in the first embodiment is a heat roller type fixing device.

An aluminum hollow metal roller is used for the fixing roller core 9a, and a halogen lamp 11 as a heat source is inserted and arranged in the inner space thereof.

Silicon rubber is used as the elastic layer 9b on the aluminum cored bar 9a, and the outermost layer is covered with a PFA tube (not shown) as a release layer.

The fixing roller 9 is heated by the heat generated by the halogen lamp 11, and the energization to the halogen lamp 11 is controlled and temperature controlled so that the outer peripheral surface of the fixing roller 9 is maintained at a predetermined fixing temperature.

On the other hand, like the fixing roller 9, the pressure roller 10 is also provided with an elastic layer 10b of silicon rubber on an aluminum core metal 10a and a PFA release layer (not shown) on the outermost layer.

In the fixing device 8 of the first embodiment, only the fixing roller 9 is provided with the halogen heater, and the pressure roller 10 is not heated by the heat source.

When fixing an unfixed image to a recording material, the main problem is the surface temperature of the fixing roller 9, which is the image side, and the fixing roller 9 is effectively heated with a limited electric power. Therefore, only one high-power heater is used on the fixing roller 9 side.

In the fixing device 8 of the first embodiment, the fixing roller 9 and the pressure roller 10 have different outer diameters, and each has a different outer diameter.
φ and 40φ.

The fixing roller 9 has a large diameter in order to provide a longer time to supply the heat deprived of the material to be heated and to secure the nip width, and the pressure roller 10 has a heat capacity of the fixing device 8. A roller having a diameter smaller than that of the fixing roller 9 is used in order to lower the thermal response.

FIG. 4 is a temperature transition in the paper passing area and the non-paper passing area in the fixing roller 9 when ten sheets of A4 size heated material are fed laterally to the fixing device 8.

Dotted line A in FIG. 4 indicates the temperature at which energization to the halogen heater 11 is started in order to maintain a predetermined fixing temperature.

When the temperature of the fixing roller 9 falls below the temperature indicated by the dotted line A, the halogen heater 11 is energized and the fixing roller 9 is heated.

As can be seen from the temperature transition before the sheet is passed in FIG. 4, the temperature distribution in the longitudinal direction of the surface of the fixing roller 9 generally tends to be lower at the ends than at the center.

Further, since the elastic layer does not have good heat conduction in the longitudinal direction, even if heat is taken by the material to be heated and the temperature in the paper passing area is greatly lowered, the temperature does not drop in the non-paper passing portion and the heater is On the contrary, when the light is turned on, the temperature rises in the non-sheet passing portion.

For the above reasons, if the contact type thermistor is brought into contact with the non-sheet passing portion to control the temperature, the following problems occur.

1. Since the halogen heater keeps lighting for a while even after the paper passing area reaches a predetermined fixing temperature at the time of startup, the overshoot becomes large and the fixing device 8
There is a risk of damaging itself.

2. Although the temperature of the sheet passing area is lowered due to the fixing operation, the halogen heater does not turn on and the temperature continues to drop, causing fixing failure.

For this reason, it is necessary to detect the temperature of the sheet passing area on the surface of the fixing roller 9 to control the temperature, and a non-contact type temperature sensor is used to prevent blobs stain.

FIG. 5 shows a comparison of blobs stains, temperature control accuracy, device size and cost for the various configurations described up to now.

As can be seen from FIG. 5, the non-contact type temperature sensor is advantageous for all of the blobs stain, temperature control accuracy and device size.

However, the non-contact type temperature sensor is disadvantageous in cost as compared with the contact type temperature sensor for the reasons described below.

As the non-contact type temperature sensor, there are a radiation temperature sensor utilizing infrared rays, a combination of a plurality of contact type thermistors, and the like, but the former is much more expensive than the latter.

Therefore, in the first embodiment, a combination of a plurality of contact type thermistors is used, and this is used as an example to compare the contact type and the non-contact type in terms of cost.

The non-contact temperature sensor 12 of the first embodiment is composed of two contact type thermistors (thermistor A and thermistor B), and the thermistor A is the fixing roller 9.
The radiant heat from the surface is detected, and the remaining thermistor B is used to detect the temperature of the thermistor A.

Since the non-contact temperature sensor 12 is arranged in the vicinity of the fixing roller 9, the thermistor A itself is also heated to a high temperature, and the output of the thermistor A does not accurately indicate the temperature of the fixing roller which is the object of temperature measurement.

Therefore, the temperature of the thermistor A itself is measured by the thermistor B, and only the radiant heat from the surface of the fixing roller 9 among the outputs of the thermistor A is selected, whereby the surface temperature of the fixing roller 9 can be accurately known.

When the surface temperature of the fixing roller 9 is T _R and the temperature of the thermistor A is T _A , the output temperature T of the thermistor A
_out is represented by the following equation.

T _out = T _R + T _A That is, the output temperature T _out of the thermistor A is a value obtained by adding the temperature T _A of the thermistor A itself to the fixing roller temperature T _R , and T _A in the above formula is seeking T _R as measured by B.

Comparing the non-contact type temperature sensor with a contact type thermistor, the cost of the element itself is simply doubled, and the thermistor B is prevented from being affected by radiation heat from the surface of the fixing roller 9. Therefore, the cost is further increased because the structure becomes complicated.

Here, the life of the color laser printer according to the present embodiment is 1000 K pages for A4 size lateral feed, and the life of the fixing device 8 that is used at high temperature and is severely worn is 100 K pages.

The fixing device 8 will be replaced nine times before the printer body reaches the end of its life.

When the cost of the fixing device 8 which is a replacement part is increased in this way, the user is actually burdened with 10 times the cost.

Therefore, in the first embodiment, the non-contact type thermistor is arranged in the printer body.

As shown in FIG. 2, an opening is provided in the paper feed side cover of the fixing device 8, and a double door 13a and a door 13b are provided so as to close the opening.

This door has a structure in which the fixing device 8 alone is closed by the force of a spring (not shown), and when the fixing device 8 is attached to the printer main body, the non-contact temperature sensor 12 installed in the printer main body. It can be pushed open by.

Further, when the fixing device 8 is detached from the printer main body, the door 13a and the door 13 are restored by the force of the spring.
By closing b, it is possible to prevent the user from accidentally touching the high-temperature fixing roller 9 and improve workability when the fixing device 8 is attached and detached.

In the first embodiment, the non-contact type temperature sensor detects the temperature of the sheet passing area of the fixing roller 9 to prevent blobs from being contaminated and to perform proper temperature control. It was possible to improve the sex.

[Embodiment 2] In this embodiment, Embodiment 1
The same reference numerals are given to the same constituent members and portions as those of FIG.

The fixing device 8 in the image forming apparatus of the second embodiment has substantially the same structure as the fixing device of the first embodiment.

That is, the fixing roller 9 is a heating roller type fixing device of central heating type, and the temperature of the fixing roller 9 is controlled to a predetermined fixing temperature by controlling the energization of the halogen heater with reference to the temperature of the sheet passing area. .

Further, it is the same non-contact temperature sensor as in the first embodiment that detects the temperature of the sheet passing area on the surface of the fixing roller 9.
The fixing device 8 is provided on the main body side for cost reduction. The fixing device 8 has an opening at the joint with the non-contact temperature sensor on the main body side, and is provided with a shutter 14 that can be opened and closed.

The cross section of this opening has a convex shape, so that the non-contact temperature sensor is pressed and positioned.

FIG. 6 shows an enlarged view of the area A1 in FIG.

In the non-contact temperature sensor 15, the thermistor A and the thermistor B described in the first embodiment are arranged on the substrate 15a.

An opening window is opened in the frame 15b containing the base 15a so that radiant heat from the fixing roller 9 reaches the thermistor A on the base 15a.

A temperature measuring device for measuring the temperature of the thermistor A.
The mister B is arranged in a portion of the frame body 15b where there is no opening window so that it is not affected by radiant heat.

The frame body 15b is provided with an elastic member 15 on the printer body.
It is attached via c. The opening of the fixing device 8 and the frame body 15b of the non-contact temperature sensor have a concave shape and a convex shape, respectively, and both are fitted together when the fixing device 8 is mounted.

The frame body 15b has an elastic layer 15c on the printer body.
The elastic layer 15c functions as a kind of damper because it is installed via the fixing roller 9c, and the fixing roller 9 is vibrated by the vibration during the fixing operation.
It is possible to suppress a large change in the distance between the base 15a on which the thermistor A is arranged.

By doing so, the distance between the surface of the fixing roller 9 and the non-contact temperature sensor provided in the printer main body can always be kept constant, and the temperature of the surface of the fixing roller 9 can be measured accurately. it can.

The slide shutter 14 provided at the opening of the fixing device 8 has a mechanism in which it cannot be opened unless the lock switch 16 on the upper part of the fixing device 8 is pressed and attached when it is attached to the printer body.

By locking the slide shutter 14, when the fixing device 8 is detached, the shutter 14 will not open unless the slide shutter 14 is intentionally opened. Therefore, the user directly touches the high-temperature fixing roller 9. You can almost eliminate the possibility.

As a result, workability at the time of attaching and detaching the fixing device 8 can be improved.

In the image forming apparatus of the second embodiment, the non-contact temperature sensor 15 is installed on the printer main body side to realize cost reduction, and the distance between the non-contact temperature sensor 15 and the surface of the fixing roller 9 is guaranteed to ensure accuracy. The temperature of the surface of the fixing roller 9 was well detected, and the temperature control accuracy could be further improved as compared with the first embodiment.

Further, since the slide shutter 14 provided in the opening of the fixing device 8 has a mechanism for locking the fixing device 8 so that it cannot be opened except when the printer body is mounted, the workability when the fixing device 8 is attached and detached is further improved. I was able to raise it.

[0111]

As described above, according to the present invention, in the heating device of the heat roller system, the film heating system and the electromagnetic induction heating system, the image heating device and the image forming apparatus,
The temperature of the roller or film passing area is detected by a non-contact temperature sensor provided on the printer main body side, and the temperature is adjusted to reduce the cost of the fixing device 8 as a replacement part.

Further, it is possible to improve the temperature control accuracy by ensuring the distance from the fixing roller by positioning while preventing the blobs from being contaminated by abutting the temperature sensor.

On the other hand, by opening and closing the opening of the fixing device 8 required for the joint with the non-contact temperature sensor on the main body side, the user can avoid touching the high temperature part carelessly,
It has become possible to improve workability when attaching and detaching the fixing device 8.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional side view of a fixing device according to a first exemplary embodiment.

FIG. 2 is a schematic sectional explanatory view of a color laser printer according to the present invention.

FIG. 3 is a schematic cross-sectional side view of the fixing device according to the second embodiment.

FIG. 4 is a transition of a fixing roller temperature when ten sheets of A4 size heated material are passed through.

FIG. 5: Comparison of fixing device configurations

FIG. 6 is an enlarged view of a temperature sensor joint portion in the fixing device according to the second embodiment.

FIG. 7 is a schematic view of the basic structure of the fixing device according to the present invention when viewed from the paper feeding side.

FIG. 8 is a side view of the fixing device 8 as viewed from the non-driving side.

[Explanation of symbols]

1a, 1b, 1c, 1d Photosensitive drum 2a, 2b, 2c, 2d developing device 3a, 3b, 3c, 3d charging roller 4a, 4b, 4c, 4d cleaning device 5a, 5b, 5c, 5d laser scanner 6 Intermediate transfer belt 7 Secondary transfer roller 8 fixing roller 9 Pressure roller S1, S2, S3, S4 Primary transfer bias voltage source S5 Secondary transfer bias voltage source

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Nana Taki Hideo             Kyano, 3-30-2 Shimomaruko, Ota-ku, Tokyo             Within the corporation (72) Inventor Tetsuya Sano             Kyano, 3-30-2 Shimomaruko, Ota-ku, Tokyo             Within the corporation F term (reference) 2H033 AA21 AA29 AA31 BA06 BA08                       BA25 BA29 BA32 BB18 BB38                       BE06 CA07                 3K059 AB19 AC33 AD04 AD32 AD35

Claims (5)

[Claims] 1. An image heating apparatus for heating a material to be heated by heating a rotating body with a heat source or by electromagnetic induction heat generation by the action of a magnetic field of a magnetic field generating means, wherein the image heating apparatus inserts the material to be heated. An image heating apparatus having an opening and an opening facing the roller surface other than the paper exit, and the opening having an openable shutter. 2. The image forming apparatus, wherein the temperature detecting means detects the temperature of the rotating body through the opening of the image heating device, and the image heating device is detachable. 3. The image heating apparatus and the image forming apparatus according to claim 1, wherein the opening of the image heating apparatus is arranged on the front side in the detaching direction. 4. The image heating apparatus and the image forming apparatus according to claim 1, wherein the shutter is closed in association with separation of the image heating apparatus and opened in association with mounting. 5. A positioning portion for detecting the temperature of the rotating body by a non-contact temperature detecting means, a supporting member of the non-contact temperature detecting means being movable in a detaching direction of the image heating device, and contacting the supporting member. The image heating apparatus and the image forming apparatus according to claim 1, wherein the image heating apparatus and the image forming apparatus have the same.