JP2002031975A - Fixing device and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fixing device and an image forming device by which the necessary heating of a heating roller is performed with high efficiency in temperature distribution controlled in the longitudinal direction of the heating roller and the temperature control of the heating roller is accurately performed. SOLUTION: This fixing device is equipped with the heating roller having a carbon heater lamp inside, and the heating element of the carbon heater lamp is made of carbon material having at least one flat heat radiation surface. The long-length heating element of the carbon heater lamp is held by an attaching member whose turning angle centering an axis elongated in the length direction of the heating roller can be freely adjusted in a state where it is elongated in the length direction. Furthermore, a calorific value in the length direction is different between the end and the center part of the heating element. Then, a temperature detection element is provided at a position opposed to the front of another heat radiation surface of the heating element. The image forming device is equipped with the above-mentioned fixing device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a fixing device and an image forming apparatus.

[0002]

2. Description of the Related Art Generally, in an image forming apparatus of an electrophotographic system, a heater lamp (hereinafter, referred to as a "halogen heater lamp") including a halogen lamp in order to fix an unfixed toner image on a recording material such as transfer paper. .)
Are widely used. The fixing device includes a heating roller provided with a pressure roller and a pressure roller arranged to be pressed against the heating roller.

In such a fixing device, the temperature of the heating roller is maintained in a predetermined temperature range required for fixing (hereinafter, referred to as a "set temperature range"), and the warm-up time is shortened. In addition, it is necessary to use a halogen heater lamp having a high heat output. In some types of fixing devices, a heating roller is provided with a plurality of halogen heater lamps. The lighting state of the halogen heater lamp of the heating roller is controlled to be on / off by appropriate control means, whereby the temperature of the heating roller is controlled.

However, in the fixing device described above, when the halogen heater lamp is turned on, a considerably large rush current flows at the same time as the start of energization, and a large voltage fluctuation occurs in the lighting circuit. There is a problem that flickering ("flicker" felt by humans) occurs in lighting devices and the like connected to a common power supply system.

A halogen heater lamp usually used as a heating source for a heating roller has a heating intensity distribution substantially uniform in all radial directions of the outer peripheral surface, and heats the entire heating roller. However, it is not possible to heat only a required local position, and as a result, a sufficiently high heating efficiency cannot be obtained.

[0006]

DISCLOSURE OF THE INVENTION The present invention has been made based on the above circumstances, and its object is to provide:
An object of the present invention is to provide a fixing device and an image forming apparatus that can perform required heating with high efficiency for a heating roller. Another object of the present invention is to achieve a controlled temperature distribution in the length direction of the heating roller, and to perform the fixing process sufficiently irrespective of the width dimension of the recording material. An object of the present invention is to provide a fixing device and an image forming apparatus. Still another object of the present invention is to be able to accurately detect the temperature state of the heating roller, thereby accurately controlling the temperature of the heating roller, and reliably prevent the heating roller from being overheated. It is an object of the present invention to provide a fixing device and an image forming apparatus that can perform the fixing.

[0007]

A fixing device according to the present invention is a fixing device having a heating roller having a heating source comprising a carbon heater lamp therein, and the carbon heater lamp constituting the heating source is provided with a heating roller. At least one heating element
It is made of a carbon material having two flat heat radiation surfaces.

The fixing device according to the present invention is a fixing device provided with a heating roller having a heating source composed of a carbon heater lamp therein, wherein the carbon heater lamp constituting the heating source has at least one flat heat radiation. A long heating element made of a carbon material having a surface extends in the length direction of the heating roller, and is held by a mounting member whose rotation angle about an axis extending in the length direction is adjustable. It is characterized by being. In this fixing device, at least one end of the carbon heater lamp is provided with a heat radiation surface display member for displaying the front direction of the heat radiation surface of the heating element, and the heat radiation surface display member is held by the mounting member. Is preferred. Further, in this fixing device, it is preferable that the carbon heater lamp is held at an inclined rotation angle such that the front surface of the heat radiating surface of the heating element faces upstream of the fixing area of the heating roller.

The fixing device according to the present invention is a fixing device provided with a heating roller having a heating source comprising a carbon heater lamp therein, wherein the carbon heater lamp constituting the heating source has at least one flat heat radiation. A heating element made of a carbon material having a surface is provided, and a heating value in a length direction of the heating element is different between an end portion and a center portion.

In the above-described fixing device, the heating element of the carbon heater lamp may have different widths in the length direction between the end and the center. The width dimension may be larger than the central part, or the width dimension at both ends of the heating element may be smaller than the central part. Further, the heating element in the carbon heater lamp, the thickness in the length direction thereof can be different at the end and the center, for example, the thickness at both ends of the heating element is larger than the center, or The thickness at both ends of the heating element may be smaller than the center.

The fixing device according to the present invention is a fixing device provided with a heating roller having a heating source comprising a carbon heater lamp therein, wherein the carbon heater lamp constituting the heating source has at least two flat heat radiations. In a state where a long heating element made of a carbon material having a surface extends in the length direction of the heating roller, the heating element is inclined such that the front surface of one heat radiation surface of the heating element faces the position upstream of the fixing area. It is characterized in that a temperature detecting element for controlling the temperature of the heating roller is provided at a position in the heating roller facing the front of the other heat radiation surface of the heating element, which is held at the moving angle.

[0012] An image forming apparatus according to the present invention includes the above-described fixing device.

[0013]

According to the fixing device of the present invention, since the heating source is a carbon heater lamp made of carbon material, a sufficiently large heat effect can be obtained as compared with a halogen heater lamp having the same power consumption. In addition, since the heating of the heating roller is performed with high efficiency, and the resistance value of the carbon heater lamp at a low temperature is large, the rush current at the start of energization is small.

Further, since the heating element of the carbon heater lamp has a heat radiation surface showing high directivity in the heat intensity distribution, it is possible to heat the heating roller at a required local position with high efficiency. ,
The desired fixing can be reliably performed, and the state can be shifted to a state where the fixing process can be performed in a short time.

According to the image forming apparatus of the present invention, since the fixing device is provided, the heating roller can be heated with high efficiency, and the rush current at the start of energization can be reduced. As a result, the intended fixing can be reliably performed, and the degree of flicker can be easily suppressed within a specified range. Also,
Since the state can be shifted to a state where the fixing process can be performed in a short time, the warm-up time can be reduced.

According to the fixing device of the present invention, since the carbon heater lamp is held by the mounting member whose rotation angle of the heating element is adjustable, high directivity can be obtained in the heat generation intensity distribution of the carbon heater lamp. By adjusting the indicated direction, it is possible to reliably heat the required local position on the heating roller with high efficiency, thereby ensuring the intended fixing and also enabling the fixing process in a short time. State. In particular, since the carbon heater lamp is held such that the front surface of the heat radiation surface of the heating element faces the position upstream of the fixing region of the heating roller, the position upstream of the fixing region heated with a large amount of heat is immediately fixed. Since the temperature reaches the area, the temperature of the fixing area is always maintained within the set temperature area, and the fixing process is executed with high efficiency.

According to the image forming apparatus of the present invention, by providing the above-described fixing device, it is possible to reliably perform the intended fixing and to shift to a state where the fixing process can be performed in a short time. Therefore, high operation reliability can be obtained, and the warm-up time can be shortened.

According to the fixing device of the present invention, the heating roller is set with respect to the length direction since the carbon heater lamp has a heating element having different heating values in the length direction at the end portion and the center portion. Since the heating roller is heated with the generated heat distribution, a desired temperature distribution is obtained in the length direction at a required local position of the heating roller. It is done reliably.

According to the image forming apparatus of the present invention, by providing the above-mentioned fixing device, a desired temperature distribution can be obtained in the length direction at a required position of the heating roller, and thereby, for example, a recording material Regardless of the width dimension of
Since the fixing process can be performed sufficiently reliably, high operation reliability can be obtained.

According to the fixing device of the present invention, the temperature detecting element for controlling the temperature of the heating roller is provided at a position on the heating roller facing the front of the other heat radiation surface of the heating element. Since the temperature at the position of the highest temperature in the heating roller heated by the carbon heater lamp is detected, the temperature of the heating roller can be accurately controlled, and the heating roller is surely overheated. Can be prevented.

According to the image forming apparatus of the present invention, the provision of the above-mentioned fixing device enables accurate control of the temperature of the heating roller and ensures that the heating roller is overheated. For example, in the standby mode, adverse effects such as ignition or smoking and damage to other devices do not occur, and high operational reliability can be obtained. Here, the “standby mode” refers to a state in which the main power is turned on but image formation is not performed.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 1 is an explanatory view showing an example of a main part of the configuration of the image forming apparatus of the present invention, and FIG. 2 is a sectional view for explaining an example of the configuration of a fixing device in the image forming apparatus of FIG. The image forming apparatus includes a drum-shaped photoreceptor 11 on which an electrostatic image is formed, a charging unit 12 for charging the photoreceptor 11, and a toner image formed by visualizing the electrostatic image formed on the photoreceptor 11. A developing unit 13 for forming an image; a transfer unit 14 for transferring the toner image formed on the photoconductor 11 to a recording material 25; a separating unit 15 for separating the recording material 25 adhered to the photoconductor 11; And a fixing device 20 for fixing the unfixed toner image transferred to the surface of the fixing device.
In FIG. 1, reference numeral 17 denotes a transport mechanism, and reference numeral 18 denotes a cleaning unit.

The fixing device 20 has a surface on which the unfixed toner image of the recording material 25 is carried (in the drawing, for example, the recording material 25).
And a pressing roller 22 provided so as to be in pressure contact with the heating roller 21. The fixing region (nip portion) is formed by the heating roller 21 and the pressing roller 22. 23 are formed.

The heating roller 21 has a coating layer 211 made of, for example, a fluororesin formed on the surface of a metal core 212. As the fluororesin forming the coating layer 211, for example, PTFE (polytetrafluoroethylene) and PF
A (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer) and the like. Core metal 212
Is not particularly limited, and examples thereof include metals such as aluminum, iron, and copper or alloys thereof.

The pressure roller 22 has a coating layer 221 made of an elastic material formed on the surface of a metal core 222. Coating layer 2
The elastic body constituting the elastic member 21 is not particularly limited, but includes various soft rubbers such as urethane rubber and silicone rubber and sponge rubber.
It is preferable to use silicone rubber and silicone sponge rubber having good heat resistance, such as TV, RTV, and HTV. The material constituting the core bar 222 is not particularly limited, but may be a metal such as aluminum, iron, or copper, or an alloy thereof.

Inside the heating roller 21, a carbon heater lamp 30 whose heating element 31 is made of a carbon material is arranged so as to extend in the longitudinal direction of the heating roller 21, and the heating roller 21 is directly heated by the heating roller 21. The on / off control of the lighting state is performed by control means (not shown) so that the temperature of the outer peripheral surface is maintained in the set temperature range.

As shown in FIG. 3, the carbon heater lamp 30 has a strip-shaped heating element 3 extending along the tube axis in a straight tubular sealing body 32 made of, for example, quartz glass.
1, both ends of the heating element 31 are held by feeding sections (not shown) provided at both ends of the sealing body 32 to form a feeding structure, and hermetically sealed. Has been stopped. Then, for example, argon gas is sealed in the sealing body 32.

The heating element 31 of the carbon heater lamp 30 is a flat plate having two flat heat radiating surfaces 31A and 31B, and the width of the heat radiating surfaces 31A and 31B of the heating element 31 as shown in FIG. The front direction at the center of the direction, that is, the vertical direction at the center in the width direction (vertical direction in FIG. 4)
High heat intensity. In FIG. 4, 3
3 is an isothermal intensity line.

At least one end of the carbon heater lamp 30 is integrally provided with a heat radiating surface display member 40 having a columnar projection 41 having a flat notched surface 41A. 41A has a specific angular relationship with the heat radiation surfaces 31A and 31B of the heating element 31, for example, is in a state of being parallel. And this heat radiation surface display member 4
0 is fixed to the fixing device 20.
Of the carbon heater lamp 30 is held by a mounting member (not shown) provided on the
The rotation angle about the axis extending in the longitudinal direction of the heating roller 21 can be adjusted, so that the carbon heater lamp 30 has a heat radiating surface 31 of the heating element 31.
A and 31B are held in a state where the front faces face the selected direction.

For example, as shown in FIG. 5, the carbon heater lamp 30 is provided with heat radiating surfaces 31A, 31B of a heating element 31.
Vertical plane at the center in the width direction of the heating element 31
Is a reference plane N that includes both the rotation center axis O of the heating roller 21 and the rotation center axis (not shown) of the pressure roller 22. On the other hand, in a state inclined to the upstream side of the fixing region 23, that is, the front surface of the one heat radiation surface 31A faces a position upstream of the fixing region 23 (hereinafter, also referred to as a “specific heated portion”). It is held by a mounting member (not shown) while being adjusted to the inclined rotation angle α.

The rotation angle α of the plane P in the direction of high heat generation of the heating element 31 with respect to the reference plane N in the carbon heater lamp 30 is made different depending on, for example, the set conveying speed of the recording material 25. Specifically, the recording material 25
Is increased as the set conveyance speed increases, and when an image forming command signal is received, a specific heated portion of the heating roller 21 reaches the fixing area 23 at a timing synchronized with the recording material 25. The state is obtained. Here, the rotation angle α of the high heat generation intensity plane P with respect to the reference plane N is preferably, for example, 0 to 90 degrees, and more preferably 5 to 45 degrees.

The above image forming apparatus operates as follows. That is, when the power switch is turned on, the carbon heater lamp 30 is turned on by the heater lamp lighting control circuit (not shown), and the heating roller 21 is heated. As described above, the carbon heater lamp 30 has a high heat intensity in the front direction at the center in the width direction of the heat radiating surfaces 31A and 31B of the heating element 31. Is heated with a high amount of heat and the heating roller 21 rotates, so that the specific heated portion reaches the fixing area 23 and the recording material 2
The fixing process of the toner image formed on the surface 5 is performed.

According to the fixing device 20, since the carbon heater lamp 30 is used as the heating source of the heating roller 21, a sufficiently large heat effect can be obtained as compared with the halogen heater lamp having the same power consumption. A required position of the heating roller 21 can be heated with high efficiency. This is because the carbon heater lamp has a radiation intensity peak at a longer wavelength than the halogen heater lamp, and radiates a heat ray in a wavelength region having a larger heat action to the fixing roller or the recording material 25 with high efficiency. Further, according to the carbon heater lamp, since the resistance value of the heating element 31 at a low temperature is larger than that of the halogen heater lamp, the rush current accompanying the lighting of the carbon heater lamp is small, and a large voltage fluctuation may occur. And therefore does not significantly increase flicker.

The heating element 31 of the carbon heater lamp 30 has the heat radiation surfaces 31A and 31B exhibiting high directivity in the heat intensity distribution, so that the heating roller 21 can be heated at a required local position with high efficiency. As a result, the intended fixing can be reliably performed, and the state can be shifted to a state where the fixing process can be performed in a short time.

Since the carbon heater lamp 30 is held by a mounting member whose rotation angle of the heating element 31 is adjustable, the notch surface 41A of the heat radiation surface display member 40 is connected to the carbon heater lamp 30. By adjusting the rotation angle so as to face the corresponding direction, the heating element 31 is adjusted.
The front direction of the heat radiation surfaces 31A and 31B is adjusted. Therefore, it is possible to obtain a state in which a required local position in the heating roller 21 is reliably heated with high efficiency, and thereby, it is possible to reliably perform an intended fixing and to perform a fixing process in a short time. Can be migrated to.
In particular, since the carbon heater lamp 30 is held so that the front surface of the one heat radiation surface 31A of the heating element 31 faces a specific heated portion of the heating roller, the heat is intensively heated immediately before the fixing region 23. Specific heated parts
Since the temperature immediately reaches the fixing region 23, the temperature of the fixing region 23 can be constantly maintained within the set temperature range, so that the fixing process can be performed with higher efficiency.

According to the image forming apparatus provided with the fixing device 20 as described above, the intended fixing can be reliably performed, and the state can be shifted to a state where the fixing process can be performed in a short time. High operation reliability can be obtained, and the warm-up time can be reduced.

In the fixing device according to the present invention, the heating element of the carbon heater lamp is such that the amount of heat generated in the length direction (the width direction of the conveyed recording material 25) is different between the end and the center. Can be.

FIG. 6 is an explanatory plan view showing an example of the configuration of a carbon heater lamp in which the amount of heat generated in the longitudinal direction of the heating element differs between the end portion and the central portion, together with the heat generation intensity distribution in the length direction. . The heating element 31 of the carbon heater lamp 30 has a different width dimension in the length direction between the end and the center, that is, the one end 3 of the heating element 31.
The width dimension w1 of each of the 5A and the other end 35B is smaller than the width dimension w2 of the central section 36, and the central area A has a relatively large constant width dimension, and the width dimension continuous to the central area A is continuous. An intermediate region B that gradually decreases and an end region C that has a relatively small constant width and is continuous with the intermediate region B. In the figure, 3
Reference numeral 7 denotes a power supply unit.

In the heating element 31, the width dimension w1 of the end area C is smaller than the width dimension w2 of the central area A.
Since the resistance value is large, the end region C has a higher calorific value than the central region A. However, since the heat escapes from the power supply portion 37, the heat generated by the heating element 31 when the carbon heater lamp 30 is turned on is reduced. The calorific value distribution is such that the calorific value of the end region C is lower than that of the central region A. For example, the calorific value in the end region C is 100 to 14 of the calorific value in the central region A.
The size is set to 0%.

In order to manufacture such a heating element 31, for example, cutting, punching, molding or the like can be used.

According to such a fixing device, since the carbon heater lamp 30 has the heating elements 31 having different heating values in the length direction at the end portion and the center portion, the heating roller 21 is moved with respect to the length direction. The heating can be performed according to the heating value distribution set in advance, and a desired temperature distribution controlled in the length direction at a specific heated portion of the heating roller 21 can be obtained. Regardless of the dimension in the direction, the fixing process is performed sufficiently reliably. For example, the shape of the heating element 31 is changed to one end 35A and the other end 35A.
When the width w1 of B is smaller than the width w2 of the central portion 36, both ends 35A, 3A
Since the heat value of 5B is larger than that of the central portion 36, even if the heat escapes from the power supply portions 37 provided at both ends of the heating element 31, the heat roller 21 is controlled in the length direction at a required position of the heating roller 21. A temperature distribution, for example, a uniform temperature distribution is obtained.

As shown in FIG. 7, in the heating element 31 of the carbon heater lamp 30, the width dimension w3 of the one end 35A and the other end 35B may be larger than the width dimension w4 of the central section 36. .

According to the fixing device having such a configuration, the carbon heater lamp 30 is connected to one end 35A and the other end 35A.
By having the heating element 31 in which the width dimension w3 of B is larger than the width dimension w4 of the central section 36, the amount of heat generated at both ends 35A and 35B of the heating element 31 can be suppressed as compared with the central section 36. When the width of the recording material 25 in the heating roller 21 is small, the portion where the recording material 25 passes through the heating roller 21 can be heated so as to have a uniform temperature distribution.
It is possible to prevent a portion through which the air does not pass from being overheated.

Further, a heater lamp group composed of a plurality of carbon heater lamps is used as a heating source of the heating roller,
By appropriately selecting the arrangement and combination of the carbon heater lamps, the heating source may have different heating value distributions in the length direction.

According to the image forming apparatus provided with the fixing device as described above, a desired temperature distribution can be obtained in the longitudinal direction at a required local position of the heating roller 21.
For example, irrespective of the width of the recording material 25, the fixing process can be performed sufficiently reliably, so that high operational reliability can be obtained.

In the fixing device 20 of the present invention, the other heat radiation surface 31 of the heating element 31 of the carbon heater lamp 30
A temperature detecting element for controlling the temperature of the heating roller 21 can be provided at a position facing B.

FIG. 8 is a perspective view showing a heating roller in another example of the fixing device of the present invention, and FIG. 9 is a sectional view for explaining the heating roller shown in FIG. In this fixing device, the carbon heater lamp 30 is in a state where the front surface of one heat radiation surface 31A of the heating element 31 is inclined so as to face a position (a specific heated portion) upstream of the fixing region 23 of the heating roller 21. It is arranged inside the heating roller 21,
The heating roller 21 is provided with temperature detecting elements 51 and 52 for controlling the temperature of the heating roller 21 in contact with or in proximity to a position facing the other heat radiation surface 31B of the heating element 31 of the carbon heater lamp 30. ing.

One temperature detecting element 51 is composed of, for example, a thermistor, detects the temperature of the outer peripheral surface of the heating roller 21, and outputs the obtained temperature data signal to the carbon heater lamp 3.
It has a function of supplying to a control means (not shown) for controlling the lighting state of 0, and the temperature control is performed by the temperature data signal from the temperature detecting element 51 so that the temperature of the heating roller 21 is maintained within a set temperature range. It is for doing. The other temperature detecting element 52 is made of, for example, a thermostat and is connected to a lighting control circuit (not shown) of the carbon heater lamp 30 so that the temperature of the heating roller 21 exceeds a set temperature limit higher than a set temperature range. And a function for forcibly turning off the carbon heater lamp 30 by detecting that the heating roller 21 is not overheated by the temperature data signal from the temperature detecting element 52. It is.

In this fixing device, the heating roller 21
At the same time as the carbon heater lamp 30 is turned on, temperature measurement of the outer peripheral surface of the heating roller 21 is started by the temperature detecting element 51, and the obtained temperature data signal is transmitted to the control means for controlling the lighting state of the carbon heater lamp 30. Supplied. Then, by turning on and off the lighting state of the carbon heater lamp 30 based on the obtained temperature data signal, the temperature of the specific heated portion of the heating roller 21 is maintained within the set temperature range.

According to such a fixing device, the other heat radiation surface 3 of the heating element 31 in the carbon heater lamp 30 is used.
Since the temperature detecting element for controlling the temperature of the heating roller 21 is provided at a position opposed to the heating roller 1B, the temperature of the heating roller 21 at the highest temperature can be detected. The temperature can be accurately controlled, and the heating roller 21 can be reliably prevented from being overheated.

According to the image forming apparatus having such a fixing device, the temperature of the heating roller 21 can be accurately controlled, and the heating roller 21 can be reliably prevented from being overheated. Therefore, in the standby mode, for example, there is no adverse effect such as ignition or smoking, or damage to other devices, and high operational reliability can be obtained.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments.
For example, the number of carbon heater lamps provided as a heating source of the heating roller in the fixing device is not particularly limited, and the carbon heater lamp may be provided at a position close to the pressure roller. Further, a halogen heater lamp may be provided separately from the carbon heater lamp as a heating source of the heating roller.

A heat radiation surface display member for holding the carbon heater lamp at a predetermined rotation angle by the mounting member includes:
The carbon heater lamp is not particularly limited as long as it can recognize the front direction of the heat radiation surface of the heating element in the carbon heater lamp.

The shape of the heating element of the carbon heater lamp is as follows.
The shape is not limited to the shape described above, and may be, for example, a shape in which the width dimension varies stepwise in the length direction.

On the outer peripheral surface of the heating roller, two
Providing one temperature detecting element is not an essential requirement, and a configuration in which one of the temperature detecting elements is provided may be employed.

[0056]

According to the fixing device of the present invention, since the carbon heater lamp is used as the heating source, a sufficiently large heat effect can be obtained as compared with the halogen heater lamp having the same power consumption. Is performed with high efficiency, and the resistance value of the carbon heater lamp at a low temperature is large, so that the rush current at the start of energization is small. In addition, since the heating element of the carbon heater lamp has a heat radiation surface exhibiting high directivity in the heat intensity distribution, heating at a required local position on the heating roller can be performed with high efficiency. Can be reliably performed, and the state can be shifted to a state where the fixing process can be performed in a short time.

According to the image forming apparatus of the present invention, since the above-described fixing device is provided, the heating roller can be heated with high efficiency, and the rush current at the start of energization can be reduced. As a result, the intended fixing can be reliably performed, and the degree of flicker can be easily suppressed within a specified range. Also,
Since the state can be shifted to a state where the fixing process can be performed in a short time, the warm-up time can be reduced.

According to the fixing device of the present invention, since the carbon heater lamp is held by the mounting member whose rotation angle of the heating element is adjustable, high directivity can be obtained in the heat intensity distribution of the carbon heater lamp. By adjusting the indicated direction, the required local position on the heating roller can be reliably heated with high efficiency, and thereby the desired fixing can be reliably performed and the fixing process can be performed in a short time. Can be shifted to a proper state.
In particular, since the carbon heater lamp is held such that the front surface of the heat radiation surface of the heating element faces the position upstream of the fixing region of the heating roller, the position upstream of the fixing region heated with a large amount of heat is immediately fixed. Since the temperature reaches the area, the temperature of the fixing area can be constantly maintained within the set temperature area, and the fixing process can be executed with high efficiency.

According to the image forming apparatus of the present invention, by providing the above-described fixing device, it is possible to reliably perform the intended fixing and to shift to a state where the fixing process can be performed in a short time. Therefore, high operational reliability can be obtained, and the warm-up time can be shortened.

According to the fixing device of the present invention, the heating roller is set with respect to the longitudinal direction because the carbon heater lamp has a heating element having different heating values in the longitudinal direction at the end portion and the central portion. Since the heating roller is heated with the generated heat distribution, a desired temperature distribution can be obtained in the length direction at a required local position of the heating roller, whereby the fixing process can be performed irrespective of the width of the recording material, for example. It can be done reliably.

According to the image forming apparatus of the present invention, by providing the above-described fixing device, a desired temperature distribution can be obtained in the length direction at a required position of the heating roller. Regardless of the width dimension of
Since the fixing process can be performed sufficiently reliably, high operation reliability can be obtained.

According to the fixing device of the present invention, the temperature detecting element for controlling the temperature of the heating roller is provided at a position on the heating roller facing the front of the other heat radiation surface of the heating element. Since the temperature at the position of the highest temperature on the heating roller heated by the carbon heater lamp is detected, the temperature of the heating roller can be accurately controlled and the heating roller can be reliably prevented from being overheated. can do.

According to the image forming apparatus of the present invention, the provision of the above-described fixing device enables accurate control of the temperature of the heating roller and also reliably prevents the heating roller from being overheated. Therefore, in the standby mode, for example, in the standby mode, there is no adverse effect such as ignition or smoking, or damage to other devices, and thus high operational reliability is obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating an example of a main part of a configuration of an image forming apparatus of the present invention.

FIG. 2 is an explanatory cross-sectional view illustrating a configuration example of a fixing device.

FIG. 3 is an explanatory perspective view showing one configuration of one end of a carbon heater lamp.

FIG. 4 is an explanatory diagram showing a heat generation intensity distribution in a width direction of a heating element of the carbon heater lamp in FIG.

FIG. 5 is an enlarged sectional view showing a heating roller in the fixing device of FIG. 2;

FIG. 6 is an explanatory plan view showing an example of the configuration of a carbon heater lamp in which the amount of heat generated in the length direction of the heating element differs between an end portion and a center portion, together with a heat generation intensity distribution in the length direction.

FIG. 7 is an explanatory plan view showing another example of the configuration of the carbon heater lamp in which the amount of heat generation in the length direction of the heating element differs between the end portion and the center portion, together with the heat generation intensity distribution in the length direction.

FIG. 8 is a perspective view showing a heating roller in another configuration example of the fixing device.

FIG. 9 is an explanatory sectional view of the heating roller of FIG. 8;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Photoreceptor 12 Charging part 13 Developing device 14 Transfer part 15 Separation part 17 Transport mechanism 18 Cleaning part 20 Fixing device 21 Heating roller 211 Coating layer 212 Core metal 22 Pressure roller 221 Coating layer 222 Core metal 23 Fixing area (nip part) Reference Signs List 25 recording material 30 carbon heater lamp 31 heating element 31A, 31B heat radiating surface 32 sealing body 33 uniform radiation intensity line 35A one end portion 35B other end portion 36 central portion 37 feeding portion 40 heat emitting surface display member 41 projecting portion 41A cutout surface 51, 52 Temperature detection element P High heat intensity direction plane N Reference plane

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yuji Tamura 2970 Ishikawacho, Hachioji-shi, Tokyo Konica Corporation (72) Inventor Norifumi Sasamoto 2970 Ishikawacho, Hachioji-shi, Tokyo Konica Corporation (72) Invention Person Uma Soma 2970 Ishikawa-cho, Hachioji-shi, Tokyo Konica Corporation F-term (reference) 2H033 AA23 AA24 BA25 BA27 BA32 BB18 BB28 CA07 CA27 3K058 AA02 AA27 AA41 AA73 BA18 CA12 CA23 CA61 CA71 CB02 CE16 DA02

Claims (13)

[Claims] 1. A fixing device provided with a heating roller having a heating source comprising a carbon heater lamp therein, wherein the heating element of the carbon heater lamp constituting the heating source has at least one flat heat radiation surface. A fixing device comprising a carbon material having the following. 2. A fixing device comprising a heating roller having a heating source made of a carbon heater lamp therein, wherein the carbon heater lamp constituting the heating source is a carbon material having at least one flat heat radiation surface. In a state where the long heating element is extended in the length direction of the heating roller, the heating element is held by a mounting member whose rotation angle about an axis extending in the length direction is adjustable. Fixing device. 3. A heat radiation surface display member for displaying the front direction of the heat radiation surface of the heating element is provided at at least one end of the carbon heater lamp, and the heat radiation surface display member is held by a mounting member. 3. The method according to claim 2, wherein
3. The fixing device according to claim 1. 4. The carbon heater lamp is held at an inclined rotation angle such that the front surface of the heat radiating surface of the heating element faces upstream of the fixing area of the heating roller. The fixing device according to claim 2 or 3. 5. A fixing device provided with a heating roller having a heating source formed of a carbon heater lamp therein, wherein the carbon heater lamp forming the heating source has a carbon material having at least one flat heat radiation surface. A fixing device, comprising: a heating element comprising: a heating element having a heating value in a length direction of the heating element which is different between an end portion and a center portion. 6. The fixing device according to claim 5, wherein the heating element of the carbon heater lamp has a width in a length direction different between an end portion and a center portion. 7. The fixing device according to claim 6, wherein the heating element of the carbon heater lamp has a width dimension at both end portions larger than a center portion. 8. The fixing device according to claim 6, wherein the heating element of the carbon heater lamp has a smaller width at both ends than at the center. 9. The fixing device according to claim 5, wherein the heating element of the carbon heater lamp has a thickness in a length direction different between an end portion and a center portion. 10. The fixing device according to claim 9, wherein the heating element of the carbon heater lamp has a greater thickness at both ends than at the center. 11. The fixing device according to claim 9, wherein the heating element of the carbon heater lamp has a thickness at both ends thereof smaller than that at the center. 12. A fixing device provided with a heating roller having a heating source made of a carbon heater lamp therein, wherein the carbon heater lamp constituting the heating source is a carbon material having at least two flat heat radiation surfaces. In a state in which the long heating element is extended in the length direction of the heating roller, the heating element is held at an inclined rotation angle such that the front surface of one heat radiation surface of the heating element faces a position upstream of the fixing region. A fixing device, wherein a temperature detecting element for controlling the temperature of the heating roller is provided at a position of the heating roller facing a front surface of another heat radiation surface of the heating element. 13. An image forming apparatus comprising the fixing device according to claim 1. Description: