JPH0553463A - Fixing device - Google Patents

Abstract

PURPOSE:To keep the temperature nearly constant over the whole width of a fixing roller even if the temperature condition in the axial direction of the fixing roller is changed. CONSTITUTION:A fixing roller 13 is divided into nearly equal heating regions A, B on the right and left in the axial direction, high-temperature heating sections 15a, 16a of heaters 15, 16 are provided in the whole heating region of the fixing roller 13, and two temperature sensors 17, 18 detecting the surface temperature of the heating regions A, B are provided on the fixing roller 13. Even if dispersion occurs on the surface temperature of the fixing roller 13, the heating regions A, B can be kept at the preset temperature.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention sandwiches and conveys a transfer material carrying an unfixed toner image by a fixing roller and a pressure roller brought into pressure contact with the fixing roller. The present invention relates to a fixing device adapted to fuse and fix to a sheet.

[0002]

2. Description of the Related Art A fixing device of the above type is well known and is provided with a copying machine, a printer, a facsimile or the like. In this type of fixing device, a heating member having a variable heating amount is provided, the surface temperature of the fixing roller is detected by a temperature detecting means, and the heating amount of the heating member is changed according to the signal to change the surface temperature of the fixing roller. The temperature is controlled so as to be maintained at a predetermined set temperature. That is, if the surface temperature of the fixing roller is lower than the set temperature, the power supply to the heating member is turned on, and if the surface temperature is higher than the set temperature, ON / OFF control is performed to turn it off, or the amount of power supply to the heating member is controlled. The temperature control in this case is controlled by the signal from a temperature sensor such as a thermistor that is in contact with or close to the surface of the fixing roller.
The surface temperature of the fixing roller is detected at one place.

[0003]

However, the surface temperature of the fixing roller depends on the flow of air inside and outside the apparatus, the operating environment,
It is often possible that the temperature condition does not become constant over the entire width in the axial direction due to the size of the paper to be passed, variations between the machines, and the like. For this reason, the surface temperature of the fixing roller in the vicinity of the temperature detection means is controlled to a predetermined set temperature, but the predetermined set temperature may not be maintained at a location apart from the temperature detection means. Then, in such a state, there is a problem that the fixing property varies, and it is difficult to obtain stable and good fixing.

The present invention solves the above-mentioned conventional problems,
An object of the present invention is to provide a fixing device that can maintain a substantially constant temperature over the entire width of the fixing roller even if the temperature conditions in the axial direction of the fixing roller are different.

[0005]

The structure of the present invention for achieving the above object is as follows. (1) Fixing by which a transfer material carrying an unfixed toner image is nipped and conveyed by a fixing roller and a pressure roller pressed against the fixing roller, and the unfixed toner image is melted and fixed on the transfer material at that time. In the apparatus, a plurality of heating members provided with a high temperature heating unit at a position corresponding to at least one heating region with respect to a plurality of heating regions divided in the axial direction of the fixing roller, and respective high temperatures of the heating members. Detects the fixing roller surface temperature in the area corresponding to the heating unit,
At least one temperature sensing means for each heating element,
A temperature control device for controlling the surface temperature of the fixing roller in response to a signal from the temperature detecting means, and a plurality of heating members are arranged so that the high temperature heating portion exists in the entire heating region of the fixing roller. A fixing device characterized by being installed.

(2) The heating area is divided into two in the axial direction of the fixing roller, and the heating member is provided with a high temperature heating portion at a position corresponding to one heating area and corresponds to the other heating area. There are two high temperature heating parts provided at the positions to be heated, and the temperature detecting means detects the fixing roller surface temperature in one heating area and the fixing roller surface temperature in the other heating area. The thing is that it is provided.

(3) The heating area is divided into three in the axial direction of the fixing roller, and the heating member is provided with high temperature heating portions at positions corresponding to the heating areas on both sides and corresponds to the central heating area. There are two high temperature heating parts provided at the heating position, and the temperature detecting means detects the fixing roller surface temperature in one heating area and the fixing roller surface temperature in the central heating area. What is done is to be provided.

(4) The heating area is divided into three in the axial direction of the fixing roller, and the heating member is provided with a high temperature heating portion at a position corresponding to one side heating area and a central heating area. There are provided three high temperature heating units at corresponding positions and one having the high temperature heating unit at a position corresponding to the heating region of the other side of the heating member, and the temperature detecting means is provided on one side. One for detecting the fixing roller surface temperature in the heating area, one for detecting the fixing roller surface temperature in the central heating area, and one for detecting the fixing roller surface temperature in the other heating area are provided.

(5) The heating region is divided into three in the axial direction of the fixing roller, and the heating member is provided with high temperature heating portions at positions corresponding to the heating regions on both sides and corresponds to the central heating region. There are two high temperature heating parts provided at the heating position, and the temperature detecting means detects the fixing roller surface temperature in one heating area and the fixing roller surface temperature in the central heating area. The temperature control device changes the set temperature of the heating member provided with high temperature heating parts on both sides according to the size of the transfer material to be passed.

(6) The heating area is divided into three in the axial direction of the fixing roller, and the heating member is provided with high temperature heating portions at positions corresponding to the heating areas on both sides and corresponds to the central heating area. There are two high temperature heating parts provided at the heating position, and the temperature detecting means detects the fixing roller surface temperature in one heating area and the fixing roller surface temperature in the central heating area. The temperature control device changes the set temperature of the heating member having the high temperature heating portions on both sides to a high temperature during warming up.

(7) The transfer material carrying the unfixed toner image is nipped and conveyed by the fixing roller and the pressure roller pressed against the fixing roller, and the unfixed toner image is fused and fixed on the transfer material at that time. In the fixing device described above, there is provided an air flow forming means for forming an air flow flowing from one side to the other side in the axial direction of the fixing roller through the fixing device, and a heating member for heating the fixing roller. The light distribution in the axial direction of the fixing roller is set to be higher on the windward side and lower on the leeward side.

(8) The transfer material carrying the unfixed toner image is nipped and conveyed by the fixing roller and the pressure roller pressed against the fixing roller, and at this time, the unfixed toner image is fused and fixed on the transfer material. In the fixing device described above, an air flow that flows from one to the other in the axial direction of the fixing roller by passing through the fixing device by covering the fixing roller and the pressure roller with a double cover of an outer cover and an inner cover. An air flow forming means for forming the fixing roller and a heating member for heating the fixing roller are provided, and the light distribution of the heating member in the axial direction of the fixing roller is set to be higher on the windward side and lower on the leeward side. And the airflow passing through the fixing device passes through the fixing device after passing between the outer cover and the inner cover.

[0013]

According to the above configuration (1), the plurality of heating members are provided with the high-temperature heating section at a position corresponding to at least one heating region for the heating region divided into a plurality in the axial direction of the fixing roller. And the high-temperature heating section is arranged so as to exist over substantially the entire width area of the fixing roller, and the temperature detection means detects the surface temperature of the fixing roller in the area corresponding to each high-temperature heating section of the heating member. Since the temperature control device is controlled, it is possible to control so as to keep the temperature substantially constant over the entire width of the fixing roller.

According to the above configuration (2), the heating region is divided into two in the axial direction of the fixing roller, and the heating member is provided with a high temperature heating portion at a position corresponding to one heating region and the other. Two parts, one having a high temperature heating part at a position corresponding to the heating region, are provided, and the temperature detecting means detects the surface temperature of the fixing roller in one heating region and the surface of the fixing roller in the other heating region. Since the one for detecting the temperature is provided, the surface temperatures of the two heating regions of the fixing roller can be equalized.

According to the above configuration (3), the heating region is divided into three in the axial direction of the fixing roller, and the heating member is provided with high temperature heating portions at positions corresponding to the heating regions on both sides and the central portion. Two parts are provided, one having a high temperature heating part at a position corresponding to the heating area, and the temperature detecting means detects the surface temperature of the fixing roller in one heating area and the other surface of the fixing roller in the central heating area. Since the one for detecting the temperature is provided, the surface temperatures of the three heating regions of the fixing roller can be equalized.

According to the above construction (4), the heating region is divided into three in the axial direction of the fixing roller, and the heating member is provided with a high temperature heating portion at a position corresponding to one heating region and the center. There are provided three high temperature heating parts at positions corresponding to the heating regions of the above, and three heating members provided at the positions corresponding to the heating regions on the other side. Since one for detecting the fixing roller surface temperature in the heating area on the side, one for detecting the fixing roller surface temperature in the central heating area, and one for detecting the fixing roller surface temperature in the heating area on the other side are provided, The surface temperatures of the three heating regions of the fixing roller can be made uniform.

According to the above configuration (5), the heating region is divided into three in the axial direction of the fixing roller, and the heating member is provided with high temperature heating portions at positions corresponding to the heating regions on both sides and the center. , A high-temperature heating section is provided at a position corresponding to the heating area of the fixing roller, and the temperature detecting means detects the surface temperature of the fixing roller in one heating area and the fixing roller in the central heating area. There is a device that detects the surface temperature, and the temperature control device changes the set temperature of the heating member that has high temperature heating parts on both sides according to the size of the transfer material to be passed, so extra power consumption Can save

According to the above configuration (6), the heating region is divided into three in the axial direction of the fixing roller, and the heating member is provided with high temperature heating portions at positions corresponding to the heating regions on both sides and the center. , A high-temperature heating section is provided at a position corresponding to the heating area of the fixing roller, and the temperature detecting means detects the surface temperature of the fixing roller in one heating area and the fixing roller in the central heating area. The temperature control device changes the set temperature of the heating member provided with the high temperature heating parts on both sides to a high temperature at the time of warming up, so that the warming up time can be shortened.

According to the above construction (7), the air flow forming means for forming an air flow that flows through the fixing device from one side to the other side in the axial direction of the fixing roller, and the heating member for heating the fixing roller. Since the light distribution of the heating member in the axial direction of the fixing roller is set to be higher on the windward side and lower on the leeward side, even if the temperature conditions in the axial direction of the fixing roller due to the air flow are different, fixing is performed. A substantially constant temperature can be maintained over the entire width of the roller.

According to the above construction (8), the fixing roller and the pressure roller are covered by the double cover of the outer cover and the inner cover, pass through the inside of the fixing device, and from one side to the other side in the axial direction of the fixing roller. An air flow forming unit that forms a flowing air flow and a heating member that heats the fixing roller are provided, and the light distribution of the heating member in the axial direction of the fixing roller is higher on the windward side and lower on the leeward side. And the air flow passing through the fixing device passes through the fixing device after passing between the outer cover and the inner cover, the difference in the temperature condition in the axial direction of the fixing roller due to the air flow can be reduced and the thermal efficiency can be improved. Can be good.

[0021]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a laser printer equipped with a fixing device according to the present invention. In FIG. 1, reference numeral 1 is an exposure optical device that projects a laser beam based on an image signal, and 2 is an image forming unit. The image forming unit 2 includes a photoconductor belt 3, a charger 4 that charges the photoconductor belt 3, and a developing device that develops an electrostatic latent image formed by projecting the laser light 5 by the post-charging exposure optical device 1. 6, a transfer charger 9 for transferring the toner image after development onto a recording paper as a transfer material, which is fed from the paper feeding device 7 by a registration roller 8 at a timing, and a fixing device 10 for fixing the recording paper after the transfer. ,
The cleaning device 11 cleans the photoconductor belt 3 after transfer. The recording paper image-formed by the image forming unit 2 is ejected to the paper ejection unit 12.

The fixing device 10 has a fixing roller 13 and a pressure roller 14 which is in pressure contact with the fixing roller 13, and the fixing device 10 of this embodiment has a structure as shown in FIG. The fixing roller 13 contains two heaters 15 and 16 as heating members. In addition, the fixing roller 13
Is divided into heating regions A and B which are divided into two substantially right and left in the axial direction, and the heater 15 is shown in FIG.
As shown in, the high temperature heating unit 15a is provided at the position corresponding to the left heating region A, and the low temperature heating unit 15b is provided at the position corresponding to the right heating region B. On the other hand, the heater 1
As shown in FIG. 2C, 6 has a low temperature heating section 16b at a position corresponding to the left heating area A and a high temperature heating section 16a at a position corresponding to the right heating area B. Therefore, the high temperature heating parts 15a and 16a of the heaters 15 and 16 are present in the entire heating region of the fixing roller 13, and the surface temperature of the fixing roller 13 is approximately the high temperature heating part 1 of the heaters 15 and 16.
It is heated to a predetermined set temperature by 5a and 16a.

The fixing roller 13 is provided with two temperature sensors 17 and 18 as temperature detecting means for detecting the surface temperature of the heating regions A and B so as to be arranged close to or in contact with the fixing roller 13. This temperature sensor 17,1
As shown in FIG. 2A, the temperature detection signal of No. 8 is output to the temperature controller 19, and the temperature controller 19 controls ON / OFF of the heaters 15 and 16 to fix the fixing roller 1.
The surface temperature of No. 3 is maintained at a predetermined set temperature.

In the thus constructed fixing device 10, the heating regions A and B of the fixing roller 13 are different from each other in the temperature sensor 1.
The heaters 15 and 16 are detected by the sensors 7 and 18, and the heaters 15 and 16 are individually turned on and off by the temperature control device 19. Therefore, as shown in Table 1, if the heating areas A and B are both below the set temperature, the heaters 15 and 16 are turned on. If the heating area A is below the set temperature and the heating area B is above the set temperature, the heater 15 is turned on.
Is turned on and the heater 16 is turned off. If the heating area A is equal to or higher than the set temperature and the heating area B is equal to or lower than the set temperature, the heater 15 is turned on.
Is turned off and the heater 16 is turned on, and if both are above the set temperature, the heaters 15 and 16 are turned off.

[0025]

[Table 1]

Thus, the heating area A of the fixing roller 13,
Since B can be controlled separately, the surface temperature of the fixing roller 13 depends on the flow of air inside and outside the apparatus, the usage environment, the size of the paper to be passed,
Even if variations occur in the axial direction of the fixing roller 13 due to variations between machines, the heating regions A and B
Can be maintained at the set temperature, and good fixing can be obtained.

FIG. 4 is an explanatory view showing another embodiment of the present invention, in which the fixing roller 13 is 3 in the axial direction.
Although divided into divided heating areas A, B, and C, there are two heaters 21 and 22. The heater 21 is provided at a position where the high temperature heating part 21a corresponds to the heating regions A and C, and the heater 22 is provided at a position where the high temperature heating part 22a corresponds to the heating region B.

The thus constructed fixing device 10 detects the surface temperatures of the heating regions A and B of the fixing roller 13 so as to detect
Separate temperature sensors 23 and 24 are provided, and the heaters 21 and 22 are individually turned on / off by the temperature control device 25 according to signals from the temperature sensors 23 and 24. Therefore, if the heating regions A and B are both below the set temperature, the heaters 21 and 22 are turned on, and the heating region A is below the set temperature.
If the heating area B is equal to or higher than the set temperature, the heater 21 is turned on and the heater 22 is turned off, and the heating area A is equal to or higher than the set temperature.
If the heating area B is below the set temperature, the heater 21 is turned off.
Then, the heater 22 is turned on, and if both are above the set temperature,
The heaters 21 and 22 are turned off.

Thus, the heating area A of the fixing roller 13,
Since B can be controlled separately, the surface temperature of the fixing roller 13 depends on the flow of air inside and outside the apparatus, the usage environment, the size of the paper to be passed,
Even if variations occur in the axial direction of the fixing roller 13 due to variations between machines, the heating regions A and C on both sides and the heating region B at the center can be maintained at the set temperatures, and good fixing can be obtained. .. For example, when a small size of recording paper is continuously passed, the surface temperature of the central portion through which the recording paper passes decreases, but at this time, the heater 21 is turned off and the heater 22 is turned off.
Should turn on.

FIG. 5 is an explanatory view showing another embodiment of the present invention, in which the fixing roller 13 is divided into heating regions A, B and C which are divided into three substantially equal parts in the axial direction, and the heater 31 is also provided. , 32, 33 are provided. These heaters 3
1, 32, 33 are high temperature heating parts 31a, 32a, 3
The positions of 3a are provided at the positions corresponding to the heating regions A, B, and C, respectively.

The thus configured fixing device 10 is provided with separate temperature sensors 34, 35 and 36 so as to detect the surface temperatures of the heating regions A, B and C of the fixing roller 13, respectively. , 35, and 36, the temperature controller controls the heaters 31, 32, and 33 to be turned on separately.
N / OFF control.

Thus, the heating area A of the fixing roller 13
Since B and C can be controlled separately, the surface temperature of the fixing roller 13 is increased in the axial direction of the fixing roller 13 due to the flow of air inside and outside the apparatus, the usage environment, the size of the paper to be passed, the variation between the machines, and the like. Even if there are variations, the heating areas A, B, C can be maintained at the set temperature, and good fixing can be obtained.

By the way, the length of the fixing roller 13 in the axial direction is formed to be slightly longer than the width of the maximum size recording paper to be fed, and it is necessary to keep the entire width at the set temperature necessary for fixing. When passing recording paper of a size, it is sufficient to keep the temperature of only that portion at the set temperature.

Therefore, in the embodiment shown in FIG. 4, when a small-sized recording paper which can pass through the heating area B is selected, the set temperature of the heating areas A and C heated by the heater 21 is lowered. By doing so, not only extra power consumption can be saved, but also temperature rise in the printer can be suppressed.

The main switch (not shown) is turned on.
It is demanded that the warming-up time for the fixing roller 13 to rise to the set temperature when the machine is started immediately after the operation be shortened as much as possible.

Therefore, since the temperature rise of the fixing roller 13 is delayed in both side regions than in the central region, the heater 2 of the embodiment shown in FIG. 4 only during warming up.
1 is changed so as to raise the set temperature of the heating regions A and C to be heated. With this structure, the warm-up time can be shortened.

By the way, as shown in FIG. 6, the laser printer is provided with a cooling fan 40 as an air flow forming means in order to prevent the temperature inside the machine from rising. The cooling fan 40 allows the heat of the fixing device 10 to flow into the machine. It is placed so that it does not exist. Therefore, the cover 4 of the fixing device 10
An air flow is formed in 1. When this air flow flows in the axial direction of the fixing roller 13 as shown by the arrow, a temperature difference occurs between the windward side and the leeward side.

Therefore, as shown in FIG. 6, one heater 4
When No. 5 is provided, the light distribution of the heater 45 in the axial direction of the fixing roller 13 is preset so that the windward is high and the leeward is low. By setting in this way, it is possible to correct the temperature difference between the windward side and the leeward side by the cooling fan 40 and equalize the entire heating region of the fixing roller 13.

Further, in order to correct the temperature difference between the leeward and the leeward due to the air flow and equalize the entire heating area of the fixing roller 13, the embodiment shown in FIG. 3 or 5 can be applied. In this case, since the heating regions on both sides in the axial direction of the fixing roller 13 are heated by different heaters, by making the set temperature of the windward heater higher than the set temperature of the leeward heater, the windward by the air flow is increased. The temperature difference between the leeward and the leeward can be corrected, and the entire heating region of the fixing roller 13 can be equalized.

FIG. 7 is a modified example of FIG. 6, in which the fixing device 1
In the case of 0, the cover 41 has a double structure of the inner cover 42 and the outer cover 43, and cools between the pair of the fixing roller 13 and the pressure roller 14 and the inner cover 42, and between the inner cover 42 and the outer cover 43. A flow path is formed through which the air flow due to the suction force of the fan 40 passes. In this case, the air flows between the pair of the fixing roller 13 and the pressure roller 14 and the inner cover 42 from right to left in the drawing. On the other hand, between the inner cover 42 and the outer cover 43, the side cover 44 on the cooling fan 40 side is attached to the outer cover 43.
The air flows from the left to the right in the drawing by making it slightly larger than the outer shape of the cross section and forming the inflow port 46 in that portion.

In the thus configured fixing device 10, the air flow due to the suction force of the cooling fan 40 passing in the vicinity thereof is separated from the cooling fan 40 directly into the inflow port 46. The airflow entering the inflow port 46 passes between the inner cover 42 and the outer cover 43, passes between the pair of the fixing roller 13 and the pressure roller 14 and the inner cover 42, and is cooled by the cooling fan 40. Exhausted to. At this time, the area around the fixing roller 13 is shown in FIG.
Similarly to the above, air flows in the axial direction of the fixing roller 13, so that when one heater 45 is provided, the light distribution of the heater 45 in the axial direction of the fixing roller 13 is set so that the windward is higher and the leeward is lower. Set in advance. When the heating region is heated by different heaters, the set temperature of the windward heater is set higher than the set temperature of the leeward heater.

Thus, the temperature difference between the leeward and the leeward due to the air flow can be corrected and the entire heating region of the fixing roller 13 can be equalized. However, in this embodiment, the air flow passing around the fixing roller 13 covers the inner cover. It is warmed by passing between the outer cover 42 and the outer cover 43, and the difference in temperature between the windward side and the leeward side due to the air flow is small, and the thermal efficiency can be improved.

[0043]

According to the structure of the first aspect, the plurality of heating members are arranged such that the high-temperature heating portions thereof are present over substantially the entire width region of the fixing roller, and the high-temperature heating portions of the heating members correspond to the respective high-temperature heating portions. The temperature control device controls the temperature control device by detecting the temperature of the fixing roller surface in the fixed area, so that the fixing roller can be maintained at the predetermined set temperature over the entire width of the fixing roller even if the temperature conditions in the axial direction of the fixing roller are different. Can be controlled.

According to the second aspect of the present invention, the two heating members are arranged such that the high temperature heating portion thereof exists in the heating region divided into two parts of the fixing roller, and the temperature detecting means has one heating region. Since the one for detecting the surface temperature of the fixing roller and the one for detecting the surface temperature of the fixing roller in the other heating area are provided, the surface temperatures of the two heating areas of the fixing roller can be held uniformly.

According to the third aspect of the present invention, the two heating members are arranged such that the high temperature heating portions thereof are present on both sides and in the center of the heating region divided into three parts of the fixing roller, and the temperature detecting means. Since one for detecting the fixing roller surface temperature in the one heating area and one for detecting the fixing roller surface temperature in the central heating area are provided, the surface temperatures of the three heating areas of the fixing roller are equalized. Can be held.

According to the structure of claim 4, the three heating members are arranged such that the high-temperature heating parts thereof are present in the heating region divided into three parts of the fixing roller, and the temperature detecting means heats one side. Since one for detecting the surface temperature of the fixing roller in the area, one for detecting the surface temperature of the fixing roller in the central heating area, and one for detecting the surface temperature of the fixing roller in the other heating area are provided. The surface temperatures of the three heating regions can be kept uniform.

According to the fifth aspect of the present invention, the two heating members are arranged such that the high temperature heating portions thereof are present on both sides and in the center of the heating region divided into three parts of the fixing roller, and the temperature detecting means. Is provided with one that detects the surface temperature of the fixing roller in one heating area and one that detects the surface temperature of the fixing roller in the central heating area.The temperature control device depends on the size of the transfer material to be passed. Since it is changed so as to lower the set temperature of the heating member provided with the high temperature heating portions on both sides, unnecessary power consumption can be saved.

According to the sixth aspect of the present invention, the two heating members are arranged such that the high temperature heating portions thereof are present on both sides and in the center of the heating region divided into three parts of the fixing roller, and the temperature detecting means. Is provided with one that detects the surface temperature of the fixing roller in one heating area and one that detects the surface temperature of the fixing roller in the central heating area.The temperature control device has high temperature heating parts on both sides during warming up. Since the set temperature of the heating member is changed to a high temperature, the warm-up time can be shortened.

According to the structure of claim 7, even if the condition of the surface temperature in the axial direction differs depending on the airflow flowing from one side to the other side in the axial direction of the fixing roller, the light distribution in the axial direction of the fixing roller of the heating member. Since the distribution is set to be higher on the windward side and lower on the leeward side, it is possible to maintain a substantially constant temperature over the entire width of the fixing roller.

According to the structure of claim 8, even if there is air flowing from one side to the other side in the axial direction of the fixing roller,
The light distribution in the axial direction of the fixing roller of the heating member is set to be higher on the windward side and lower on the leeward side, so that the air flow passing through the fixing device passes through between the outer cover and the inner cover, Since the air flows, the difference in temperature condition in the axial direction of the fixing roller due to the air flow can be reduced, and the air flowing in the axial direction of the fixing roller can be warmed, so that the thermal efficiency can be improved.

[Brief description of drawings]

FIG. 1 is a schematic explanatory diagram of a laser printer including a fixing device according to the present invention.

2A is an explanatory view of a fixing roller, and FIG. 2B is a heater 1.
5 is a light distribution distribution map of FIG. 5, and (c) is a light distribution distribution map of the heater 16.

3A is an explanatory view of a fixing roller, and FIG. 3B is a heater 2.
1 is a light distribution distribution map of FIG. 1, and (c) is a light distribution distribution map of the heater 22.

4A is an explanatory view of a fixing roller, and FIG. 4B is a heater 3.
1, the light distribution map of (c) is the light distribution map of the heater 33,
(D) is a light distribution distribution diagram of the heater 32.

FIG. 5 is an explanatory diagram showing another embodiment of the present invention.

FIG. 6 is an explanatory diagram showing a modified example of the embodiment of FIG.

[Explanation of symbols]

10 Fixing Device 13 Fixing Roller 14 Pressure Roller 15, 16, 21, 21, 22, 31, 32, 33, 45 Heater 15a, 16a, 21a, 22a, 31a, 32a, 3
3a High temperature heating part 15b, 16b Low temperature heating part 17, 18, 23, 24, 34, 35, 36 Temperature sensor 19, 25, 37 Temperature control device 41 Cover 42 Inner cover 43 Outer cover A, B, C Heating area

Claims (8)

[Claims] 1. A transfer material carrying an unfixed toner image is nipped and conveyed by a fixing roller and a pressure roller pressed against the fixing roller, and the unfixed toner image is melted and fixed on the transfer material at that time. In the fixing device described above, a plurality of heating members provided with a high-temperature heating unit at a position corresponding to at least one heating region for a plurality of heating regions divided in the axial direction of the fixing roller, and each of the heating members. Temperature controller for detecting the surface temperature of the fixing roller in a region corresponding to the high temperature heating section of the fixing roller, and controlling the surface temperature of the fixing roller by at least one temperature detecting unit for each heating member and a signal of the temperature detecting unit. And a plurality of heating members are arranged so that the high-temperature heating unit is present in the entire heating region of the fixing roller. 2. The heating area is divided into two in the axial direction of the fixing roller, and the heating member is provided with a high temperature heating portion at a position corresponding to one heating area and corresponds to the other heating area. Two units, one having a high-temperature heating unit at a position, are provided, and the temperature detecting means detects the surface temperature of the fixing roller in one heating region and the temperature of the fixing roller in the other heating region. The fixing device according to claim 1, further comprising: 3. The heating region is divided into three in the axial direction of the fixing roller, and the heating member is provided with high temperature heating portions at positions corresponding to the heating regions on both sides and corresponds to the central heating region. Two of them are provided, one having a high temperature heating portion at a position, and the temperature detecting means detects the surface temperature of the fixing roller in one heating area and the temperature of the fixing roller in the central heating area. The fixing device according to claim 1, wherein the fixing device is provided. 4. The heating area is divided into three in the axial direction of the fixing roller, and the heating member is provided with a high temperature heating portion at a position corresponding to one side heating area and corresponds to a central heating area. There are three high temperature heating parts provided at positions where the heating member is provided and one where the heating member is provided at a position corresponding to the heating region on the other side. One for detecting the fixing roller surface temperature in the area, one for detecting the fixing roller surface temperature in the central heating area, and one for detecting the fixing roller surface temperature in the heating area on the other side are provided. The fixing device according to claim 1. 5. The heating region is divided into three in the axial direction of the fixing roller, and the heating member is provided with high temperature heating portions at positions corresponding to the heating regions on both sides and corresponds to the central heating region. Two of them are provided, one having a high temperature heating portion at a position, and the temperature detecting means detects the surface temperature of the fixing roller in one heating area and the temperature of the fixing roller in the central heating area. 4. The temperature control device changes the set temperature of a heating member having high temperature heating parts on both sides according to the size of the transfer material to be passed. Fixing device. 6. The heating region is divided into three in the axial direction of the fixing roller, and the heating member is provided with high temperature heating portions at positions corresponding to the heating regions on both sides and corresponds to the central heating region. Two of them are provided, one having a high temperature heating portion at a position, and the temperature detecting means detects the surface temperature of the fixing roller in one heating area and the temperature of the fixing roller in the central heating area. 6. The fixing device according to claim 3, wherein the temperature control device changes the set temperature of the heating member provided with high temperature heating portions on both sides to a high temperature during warming up. 7. A transfer material carrying an unfixed toner image is nipped and conveyed by a fixing roller and a pressure roller pressed against the fixing roller, and the unfixed toner image is fused and fixed on the transfer material at that time. In the fixing device described above, an air flow forming unit that forms an air flow that flows from one side to the other side of the fixing roller in the axial direction of the fixing roller and a heating member that heats the fixing roller are provided. The fixing device is characterized in that the light distribution in the axial direction of the fixing roller is set to be higher on the windward side and lower on the leeward side. 8. A transfer material carrying an unfixed toner image is nipped and conveyed by a fixing roller and a pressure roller pressed against the fixing roller, and the unfixed toner image is fused and fixed on the transfer material at that time. In the fixing device described above, an air flow that flows from one to the other in the axial direction of the fixing roller is formed by passing through the fixing device by covering the fixing roller and the pressure roller with a double cover of an outer cover and an inner cover. Having an air flow forming means for heating and a heating member for heating the fixing roller,
The distribution of light distribution in the axial direction of the fixing roller of the heating member is set to be higher on the windward side and lower on the leeward side, and that the air flow passing through the fixing device passes between the outer cover and the inner cover. A fixing device characterized by passing through the inside of the fixing device.