JP2005049552A - Fixing device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fixing device which performs successful energy saving fixing. <P>SOLUTION: The fixing device is provided with a fixing belt 22 being a fixing rotary body in which a region irradiated with light generates heat. A light source section 38 is driven and controlled by utilizing image information so that a toner image formed on a recording material S and a heat generation region overlap in a contact region (a nip section 24) of a toner image in the fixing belt 22. Thereby only a toner image part on the recording material S is heated. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fixing device and an image forming apparatus including the same.
[0002]
[Prior art]
Conventionally, demands for resource saving and energy saving have been increasing in order to preserve the global environment. Also in electrophotographic image forming apparatuses, there is an active movement to reduce power consumption in order to save energy. In particular, energy saving is being studied in the field of fixing where power consumption is severe.
[0003]
In a commonly used fixing device, fixing is performed by heating a fixing roller or the like according to the maximum sheet passing size of the device. However, heating over the entire maximum sheet passing width heats a portion where there is no paper, such as small size paper, and wastes power correspondingly. In the case of an image having a small image area, almost all of the blank paper portion is heated, and power is wasted. For this reason, Patent Documents 1, 2, 3, 4 and the like have proposed to save energy by heating only the portion of the paper on which the toner is placed.
[0004]
[Patent Document 1]
JP 2001-343860 A
[Patent Document 2]
JP 2000-338800 A
[Patent Document 3]
JP-A-6-270431
[Patent Document 4]
JP-A-6-095538
[0005]
[Problems to be solved by the invention]
In Patent Document 1, heating for fixing is performed by a contact halogen heater, and energy saving is achieved by changing the heating rate of the contact halogen heater according to image information. However, in this method, in the axial direction of the fixing roller. Is not possible, and there is a problem that in the axial direction of the fixing roller, a wasteful portion is heated and the energy saving effect is reduced accordingly.
[0006]
In Patent Document 2, only an image portion of an unfixed image is fixed by irradiating a laser beam, and toner on the background portion is removed by a cleaning device to prevent background contamination.
However, when a laser is used, a high-energy laser output device is required to melt the toner resin, and there is a problem that the device is large and expensive, and it is difficult to save energy.
[0007]
In Patent Document 3, a toner image is heat-fixed on a transfer paper by a thermal head via a heat-resistant belt. As described above, when the thermal head is brought into contact with the recording paper through the heat-resistant belt, the heat generating element of the thermal head is insufficient in heat to melt the toner resin, and heat is transferred to the recording paper through the heat-resistant belt. Since it is difficult to transmit, the temperature of the thermal head must be raised as much as possible, and there is a problem that it is difficult to save energy.
[0008]
In Patent Document 4, a plurality of heating elements are independently controlled to generate heat within an arbitrary range. Such a heating element has a time lag from when the energization is turned on until it reaches a fixing temperature, and energization time is required in advance, and there is a problem that it is difficult to save energy.
[0009]
An object of the present invention is to provide a fixing device and an image forming apparatus that perform good energy-saving fixing.
[0010]
An object of the present invention is to provide a fixing device and an image forming apparatus that perform good energy-saving fixing while preventing offset using a low-melting toner of about 100 ° C.
[0011]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a fixing device that is rotatably supported and rotationally driven so that a region irradiated with light generates heat, and selectively emits dot-shaped light in the width direction of the fixing rotating member. The fixing rotator using an illuminating light source, a contact means for closely attaching a recording material on which a toner image is formed to the fixing rotator, and image information for forming the toner image on the recording material. And a light irradiation means for driving and controlling the light source unit so that the toner image formed on the recording material and the heat generation area overlap each other in the contact area of the toner image.
Therefore, using the image information, the light source unit irradiates the fixing rotator with dot-like light so that the toner image formed on the recording material and the heat generation area overlap in the contact area of the toner image on the fixing rotator. The light irradiation area of the fixing rotator generates heat, and the toner image comes into contact with the heat generation area, and only the toner image is heated and fixed.
[0012]
According to a second aspect of the present invention, in the fixing device according to the first aspect, the fixing rotator includes an optical semiconductor portion in which a region irradiated with light is in a conductive state and a resistance heating portion in which an energized portion generates heat. Provided in contact arrangement in the radial direction of rotation.
[0013]
Therefore, when a voltage is applied to the fixing rotator, current flows in the radial direction of rotation in the light irradiation region and heat is generated, but heat is not generated outside the light irradiation region.
[0014]
According to a third aspect of the present invention, in the fixing device according to the second aspect, the optical semiconductor unit includes a transparent conductor and an optical semiconductor layer laminated, and the resistance heating unit is in contact with the optical semiconductor layer. A resistance heating layer and a conductor layer are stacked.
[0015]
Therefore, it is possible to reliably apply a voltage to the fixing rotator.
[0016]
According to a fourth aspect of the present invention, in the fixing device according to any one of the first to third aspects, the light source unit is disposed inside the fixing rotating body.
[0017]
Therefore, the space is effectively used. The apparatus is downsized.
[0018]
According to a fifth aspect of the present invention, in the fixing device according to any one of the first to fourth aspects, the fixing rotator is a fixing belt.
[0019]
Therefore, it is possible to easily provide a configuration for heat dissipation and cooling of the fixing rotator.
[0020]
According to a sixth aspect of the present invention, in the fixing device according to the fifth aspect, the contact means includes a pressure belt that faces the fixing belt and sandwiches and conveys the recording material with the fixing belt. In addition, the pressure belt and the fixing belt sandwich and convey the recording material even after the toner image is heated.
[0021]
Therefore, in the toner image after fixing, heat is radiated to the pressure belt and the fixing belt, thereby preventing the toner image from being offset to the fixing belt.
[0022]
According to a seventh aspect of the present invention, in the fixing device according to the sixth aspect, the contact means includes a pressure roller that presses the pressure belt toward the fixing belt.
[0023]
Accordingly, the toner image is sufficiently in close contact with the fixing belt, thereby sufficiently transferring heat to the toner image. Therefore, fixing at a low temperature of about 100 ° C. is possible.
[0024]
According to an eighth aspect of the present invention, in the fixing device according to the sixth or seventh aspect, the pressure belt has elasticity.
[0025]
Therefore, when the recording material is conveyed while being in close contact with the fixing belt, the toner image is prevented from being displaced due to a minute difference in linear velocity.
[0026]
According to a ninth aspect of the present invention, there is provided the fixing device according to any one of the first to eighth aspects, further comprising a cooling unit that cools the fixing rotator after the toner image is heated.
[0027]
Therefore, after the toner is heated, the temperature of the fixing rotator is reset before the light is again irradiated to heat the toner image, and the extra area is prevented from being heated during the next heating of the toner image. Is done. At this time, the toner image of the recording material in close contact with the fixing rotator is also cooled together. Thereby, the offset of the toner image to the fixing rotator is prevented.
[0028]
According to a tenth aspect of the present invention, in the fixing device according to the ninth aspect, the cooling means is a heat pipe.
[0029]
Therefore, the cooling means is realized with a simple configuration.
[0030]
According to an eleventh aspect of the present invention, in the fixing device according to the ninth aspect, the cooling means is a heat sink.
[0031]
Therefore, the cooling means is realized with a simple configuration.
[0032]
According to a twelfth aspect of the present invention, in the image forming apparatus in which a toner image formed on a recording material is fixed by a fixing device to form an image on the recording material, the fixing device is any one of the first to eleventh aspects. Fixing device.
[0033]
Therefore, the same effect as the invention according to any one of claims 1 to 11 is exhibited.
[0034]
DETAILED DESCRIPTION OF THE INVENTION
A first embodiment of the present invention will be described with reference to FIGS. This embodiment is an example applied to a laser printer as an image forming apparatus. FIG. 1 is a schematic diagram showing the internal structure of the laser printer according to the present embodiment.
[0035]
In the apparatus main body 2 of the laser printer 1, an image forming unit 3, an optical writing device 4, a fixing device 5, a paper feeding unit 6, a registration roller 7 and the like are arranged.
[0036]
The image forming unit 3 includes a drum-shaped photosensitive member 11 that is rotationally driven, a charger 12 that is arranged around the photosensitive member 11 in the order of the image forming process, a developing unit 13, a transfer unit 14, a cleaning unit 15, and the like. Yes. In the image forming unit 3, the outer peripheral surface of the photosensitive member 11 is uniformly charged by the charger 12, and the photosensitive member 11 is scanned by scanning the outer peripheral surface of the charged photosensitive member 11 with a scanning line from the optical writing device 4. An electrostatic latent image is formed on the outer peripheral surface of the body 11, and the electrostatic latent image is developed with toner in the developing device 13 to become a toner image. Scanning by the optical writing device 4 is performed based on image information for forming a toner image on the recording material S. Then, the recording material S fed and conveyed from the paper supply unit 6 is temporarily stopped by the registration roller 7 and synchronized with the rotation of the photoconductor 11, that is, the leading edge of the toner image formed on the photoconductor 11 and the recording. The toner image is transferred to the recording material S by the transfer device 14 by being transferred to the transfer position by the registration roller 7 at the timing when the predetermined position of the material S coincides.
[0037]
Next, the fixing device 5 will be described with reference to FIGS. 2 is a schematic view showing the fixing device 5, and FIG. 3 is a schematic sectional view showing a part of the fixing device 5 in an enlarged manner.
[0038]
As shown in FIG. 2, the fixing device 5 is disposed in a fixing case 21 (see FIG. 1), an endless fixing belt 22 that is a rotationally driven fixing rotator, and a fixing belt 22 that is disposed so as to face the fixing belt 22. And an endless pressure belt 23 in close contact with the belt 22. In the fixing device 5, a nip portion 24 is formed by the fixing belt 22 and the pressure belt 23, and the recording material S is nipped and conveyed by the nip portion 24. Here, the nip portion 24 becomes a contact area where the toner image on the recording material S contacts the fixing belt 22.
[0039]
The fixing belt 22 is stretched in a triangular shape by three tension rollers 25, 26, and 27 and is rotatably supported. Then, one of the tension rollers 25, 26, 27 is rotated in the clockwise direction in FIG. 2 by being driven to rotate by the motor 28 (see FIG. 4). Of the fixing belt 22, the fixing belt 22 positioned between the tension rollers 26 and 27 faces the pressure belt 23. Hereinafter, this position is referred to as a facing position. The position between the tension rollers 25 and 26 is on the upstream side of the facing position, and the space between the tension rollers 27 and 25 is on the downstream side of the facing position.
[0040]
As shown in FIG. 3, the fixing belt 22 is configured by sequentially laminating an optical semiconductor layer 30, a resistance heating layer 31, and a conductor layer 32 on a transparent conductor 29 along the radial direction of rotation. Yes. The transparent conductor 29 and the optical semiconductor layer 30 constitute an optical semiconductor portion 33, and the resistance heating layer 31 and the conductor layer 32 constitute a resistance heating portion 34.
[0041]
The optical semiconductor layer 30 is a photosensitive layer having a configuration similar to that of a normal photosensitive layer, and has a high resistance in a dark place and a low resistance in a light irradiation portion irradiated with light. That is, the light irradiation part is conductive and the other part is non-conductive.
[0042]
When the members (on the present embodiment, the optical semiconductor layer 30 and the conductor layer 32) located on both sides of the resistance heating layer 31 are conductive, a circuit through which a current flows is formed. The flowing part generates heat.
[0043]
The fixing belt 22 is connected to a power source 35 between the tension rollers 27 and 25 on the downstream side of the facing position. Specifically, the conductor layer 32 is connected to the negative pole side of the power supply 35 via the belt contact electrode 36, and the transparent conductor 29 is connected to the positive pole side of the power supply 35 via the belt contact electrode 37.
[0044]
The heat generation principle of the fixing belt 22 will be described. First, a voltage is applied by a power source 35 between the transparent conductor 29 and the surface conductor layer 32 in a dark place. Then, light irradiation is performed from the direction of the transparent conductor 29. Here, the inside of the fixing case 21 is a dark place, and the optical semiconductor layer 30 exhibits conductivity only in the light irradiation portion. A current flows through a portion of the resistance heating layer 31 located between the conductive portion and the surface conductive layer 32 to generate heat. In this way, only the light irradiated portion of the resistance heating layer 31 generates heat.
[0045]
The tension roller 26 located on the downstream side of the nip portion 24 incorporates a heat pipe (not shown) as a cooling means, and cools the fixing belt 22 that contacts the tension roller 26.
[0046]
A light source unit 38 is disposed inside the fixing belt 22. Specifically, the light source unit 38 is disposed to face the inner surface of the fixing belt 22 between the tension rollers 25 and 26 on the upstream side of the facing position. The light source unit 38 is an LED array in which a plurality of LEDs are arranged in the entire width direction of the fixing belt 22, and selectively emits dot-shaped light in the width direction of the fixing belt 22.
[0047]
The pressure belt 23 is stretched around a pressure roller 41 and a tension roller 42 and is rotatably supported. The pressure roller 41 is disposed on the upstream side in the transport direction and faces the tension roller 26 via the pressure belt 23 and the fixing belt 22. The pressure roller 41 is urged toward the tension roller 26 by an elastic body (not shown) such as a spring. An elastic layer 41 a having elasticity is formed on the surface portion of the pressure roller 41. The pressure roller 41 and the pressure belt 23 constitute a contact means 43. The tension roller 42 is disposed on the downstream side in the transport direction and faces the tension roller 27 via the pressure belt 23 and the fixing belt 22.
[0048]
In the fixing device 5, as described above, the fixing belt 22 is driven to rotate in the clockwise direction in FIG. 2, so that the pressure belt 23 is rotated by the fixing belt 22 and rotates counterclockwise in FIG. .
[0049]
FIG. 4 is a block diagram showing the electrical connection of each part of the image forming apparatus. The laser printer 1 includes a CPU (Central Processing Unit), a ROM (Read Only Memory) that stores fixed data such as a computer program in advance, and a RAM (Random Access Memory) that functions as a work area that stores various data in a rewritable manner. A main control unit 51 having a computer configuration is provided. The main control unit 51 is connected to the image forming unit 3, the optical writing device 4, the fixing device 5, various motors 52 that drive the paper feeding unit and registration rollers, and the main control unit 51 is connected to the laser printer 1. Each part is driven and controlled.
[0050]
The fixing device 5 includes a CPU (Central Processing Unit), a ROM (Read Only Memory) that stores fixed data such as a computer program in advance, and a RAM (Random Access Memory) that functions as a work area that stores various data in a rewritable manner. A fixing control unit 53 having a computer configuration is provided. The fixing control unit 53 is connected to a motor 28 that rotationally drives the tension roller 25, 26, or 27, a light source unit 38, a power source control unit 54 that controls the power source 35, and the like. 5 is driven and controlled.
[0051]
A fixing operation performed by the fixing device 5 in such a configuration will be described. The fixing control unit 53 drives the motor 28 after receiving a fixing operation start instruction from the main control unit 51. As a result, the fixing belt 22 and the pressure belt 23 rotate. At the same time, the power supply control unit 54 turns on the power supply 35 and applies −300 V to the conductor layer 32 of the fixing belt 22 via the belt contact electrode 36.
[0052]
Then, using the image information, the light source unit 38 is driven and controlled so that the toner image formed on the recording material S and the heat generation region overlap each other in the toner image contact region (nip portion 24) on the fixing belt 22. Specifically, the image information is acquired by receiving it from the main control unit 51. Then, the synchronization signal transmitted from the main control unit 51 when the re-conveyance of the recording material S by the registration roller 7 is started is received and synchronized with the toner image of the recording material S conveyed to the nip portion 24 by the synchronization signal. The portion of the fixing belt 22 that moves to the nip portion 24 is irradiated with light. Here, the function of the light irradiation means is realized.
[0053]
Here, the timing at which the main control unit 51 sends the synchronization signal to the fixing control unit 53 is not limited to the start point of re-conveyance of the recording material S by the registration roller 7 but may be a predetermined point in the image forming operation. . Further, as the synchronization signal, a detection sensor for detecting the recording material S is provided at the entrance of the fixing case 21 of the fixing device 5, and the detection signal output when the detection sensor detects the recording material S is used as the synchronization signal. Also good.
[0054]
As described above, in the fixing belt 22 where light is irradiated only to the region where the toner images overlap, only that portion generates heat. In this state, at the portion of the nip portion 24 where the tension roller 26 and the pressure roller 41 face each other, the heat generating portion of the fixing belt 22 is formed on the toner image of the recording material S conveyed from the transfer device 14 side. The toner image is heated and the toner image is heated. At this time, the toner image is sufficiently adhered to the fixing belt 22 by the pressing by the pressure roller 41, and the heat transfer to the toner image is sufficiently performed. Thereby, fixing at a low temperature of about 100 ° C. is possible. Therefore, a low melting point toner of about 100 ° C. can be used as the toner.
[0055]
After the toner image is fixed in this manner, the recording material S is further conveyed through the nip portion 24 and discharged onto the discharge tray 16. When the recording material S is conveyed after the portion of the nip portion 24 where the tension roller 26 and the pressure roller 41 face each other, in the recording material S and the toner image, the fixing belt 22 and Heat dissipation to the pressure belt 23 is performed. Due to this heat radiation, the toner image is solidified reliably, so that the toner image on the recording material S is prevented from being offset to the fixing belt 22 when separated from the fixing belt 22.
[0056]
The fixing belt 22 after heating the toner image is cooled by a heat pipe through the tension roller 27 and reset in temperature when passing through a portion of the nip portion 24 facing the tension roller 27. This prevents the extra area from being heated at the next heating of the toner image. At this time, the toner image on the recording material S that is in close contact with the fixing belt 22 is also cooled at the same time, thereby reliably preventing the toner image from being offset to the fixing belt 22.
[0057]
Further, in this fixing operation, when the recording material S is conveyed in close contact with the fixing belt 22, the toner image is prevented from being displaced due to a minute linear velocity difference due to the elasticity of the elastic layer 23 a of the pressure belt 23. Has been.
[0058]
As described above, in the present exemplary embodiment, the light source unit 38 (LED array) forms a dot shape so that the toner image and the heat generation region overlap in the contact region (nip portion 24) where the toner image contacts the fixing belt 22. The fixing belt 22 is heated by irradiating light, and the toner image is heated and fixed by the heat. Therefore, the toner image can be heated at the level of one pixel, thereby heating the portion other than the toner image in the recording material S. Therefore, energy saving of the fixing operation is realized.
[0059]
At this time, the fixing belt 22 is irradiated with light to generate heat, and the toner image is heated and fixed by the heat. Therefore, the light source unit 38 does not have to be a high-energy laser output device, such as an LED array. Therefore, energy saving of the fixing operation is realized.
[0060]
In addition, since the fixing belt 22 generates heat and transmits the heat to the toner image, heat can be transmitted more easily than a conventional method in which the toner image is heated by a thermal head via a heat-resistant belt. Energy saving of fixing operation is realized. Further, since no preheating time is required, energy saving of the fixing device 5 is realized.
[0061]
Further, since the light source unit 38 is an LED array, the light source unit 38 can be miniaturized and can be easily arranged on the inner side of the fixing belt 22. Since the light source unit 38 is arranged inside the fixing belt 22, the space is effectively used and the fixing device 5 is downsized.
[0062]
Further, since the cooling means is a heat pipe, the cooling means is realized with a simple configuration.
[0063]
In this embodiment, the laser printer 1 has been described as an example of the image forming apparatus. However, the present invention is not limited to this, and the image forming apparatus may be, for example, a copying machine or a facsimile.
[0064]
Next, a second embodiment of the present invention will be described with reference to FIG. The same parts as those of the first embodiment are denoted by the same reference numerals, and description thereof is also omitted. Here, FIG. 5 is a schematic view showing the fixing device 5 of the present embodiment. In FIG. 5, the power supply 35 relationship is omitted.
[0065]
In the present embodiment, the cooling means is different from the first embodiment. That is, as the cooling means, the heat sink 61 is provided in contact with the inside of the fixing belt 22 between the tension rollers 26 and 27 at the opposite positions, and the tension roller 27 is a normal tension roller having no heat pipe. The heat sink 61 is a metal block having a plurality of fins 61a to increase the surface area.
[0066]
In such a configuration, in the fixing operation, the fixing belt 22 after heating the toner image is cooled by the heat sink 61 and the temperature is reset. As a result, in the next heating of the toner image, it is possible to prevent the excess area from being heated. At this time, the toner image of the recording material S that is in close contact with the fixing belt 22 is also cooled at the same time. This reliably prevents the toner image from being offset on the fixing belt 22.
[0067]
Further, since the cooling means is the heat sink 61, the cooling means is realized with a simple configuration.
[0068]
【The invention's effect】
According to the fixing device of the first aspect of the present invention, a fixing rotator that is rotatably supported and is driven to rotate and generates heat in a region irradiated with light, and a dot-like shape selectively in the width direction of the fixing rotator. The fixing using the light source unit for irradiating light, the contact means for closely attaching the recording material on which the toner image is formed to the fixing rotating body, and the image information for forming the toner image on the recording material A light irradiating means for driving and controlling the light source unit so that the toner image formed on the recording material and the heat generating region overlap each other in the contact area of the toner image on the rotating body. Is not necessary, and the recording material is not heated excessively, so that good energy-saving fixing can be performed.
[0069]
According to a second aspect of the present invention, in the fixing device according to the first aspect, the fixing rotator includes an optical semiconductor portion in which a region irradiated with light is in a conductive state and a resistance heating portion in which a portion that is energized generates heat. Are arranged in contact with each other in the radial direction of rotation so that a voltage can be applied to the fixing rotating body so that a current flows in the radial direction of rotation in the light irradiation region to generate heat, and heat is not generated outside the light irradiation region. Can be.
[0070]
According to a third aspect of the present invention, in the fixing device according to the second aspect, the optical semiconductor unit includes a transparent conductor and an optical semiconductor layer stacked, and the resistance heating unit is formed on the optical semiconductor layer. By laminating the resistance heating layer and the conductor layer that are in contact with each other, it is possible to reliably apply a voltage to the fixing rotator.
[0071]
According to a fourth aspect of the present invention, in the fixing device according to any one of the first to third aspects, since the light source unit is disposed inside the fixing rotating body, space is effectively used. Therefore, the device is miniaturized.
[0072]
According to a fifth aspect of the present invention, in the fixing device according to any one of the first to fourth aspects, the fixing rotator is a fixing belt, so that the structure for radiating and cooling the fixing rotator is provided. It can be easily provided.
[0073]
According to a sixth aspect of the present invention, in the fixing device according to the fifth aspect, the contact means includes a pressure belt that faces the fixing belt and sandwiches and conveys the recording material with the fixing belt. The pressure belt and the fixing belt sandwich and convey the recording material even after the toner image is heated, and in the toner image after fixing, heat is radiated to the pressure belt and the fixing belt. The offset of the toner image to the fixing belt can be prevented.
[0074]
According to a seventh aspect of the present invention, in the fixing device according to the sixth aspect, the contact means includes a pressure roller that presses the pressure belt toward the fixing belt, thereby preventing the fixing belt. The toner image adheres sufficiently, whereby heat can be sufficiently transferred to the toner image, fixing at a low temperature of about 100 ° C. is possible, and a low melting point toner of about 100 ° C. is used. it can.
[0075]
According to an eighth aspect of the present invention, in the fixing device according to the sixth or seventh aspect, the pressure belt has elasticity so that when the recording material is conveyed in close contact with the fixing belt, a minute linear velocity is obtained. It is possible to prevent the toner image from being shifted due to the difference.
[0076]
According to the ninth aspect of the present invention, in the fixing device according to any one of the first to eighth aspects, the toner is heated by including a cooling unit that cools the fixing rotating body after the toner image is heated. After that, the temperature of the fixing rotator is reset before the light is irradiated again for heating the toner image, and it is possible to prevent heating of the extra area when the toner image is heated next time. At this time, the toner image of the recording material that is in close contact with the fixing rotator can be cooled at the same time, thereby preventing the offset of the toner image to the fixing rotator.
[0077]
According to a tenth aspect of the present invention, in the fixing device according to the ninth aspect, since the cooling means is a heat pipe, the cooling means can be realized with a simple configuration.
[0078]
According to the eleventh aspect of the present invention, in the fixing device according to the ninth aspect, the cooling means is a heat sink, so that the cooling means can be realized with a simple configuration.
[0079]
According to a twelfth aspect of the present invention, in the image forming apparatus in which the toner image formed on the recording material is fixed by the fixing device to form an image on the recording material, the fixing device is any one of the first to eleventh aspects. By using the fixing device according to one aspect, it is possible to achieve the same effects as the invention according to any one of claims 1 to 11.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing a laser printer according to a first embodiment of the present invention.
FIG. 2 is a schematic diagram illustrating a fixing device.
FIG. 3 is an enlarged schematic cross-sectional view showing a part of the fixing device.
FIG. 4 is a block diagram illustrating electrical connection of each unit included in the image forming apparatus.
FIG. 5 is a schematic diagram illustrating a fixing device according to a second embodiment of the present invention.
[Explanation of symbols]
1 Laser printer (image forming device)
5 Fixing device
22 Fixing belt (fixing rotating body)
23 Pressure belt
24 Nip (contact area)
29 Transparent conductor
30 Optical semiconductor layer
31 Resistance heating layer
32 Conductor layer
33 Optical Semiconductor Department
34 Resistance heating part
38 Light source
41 Pressure roller
43 Contact means
61 Heat sink (cooling means)
S Recording material

Claims (12)

A fixing rotator that is rotatably supported and rotationally driven and generates heat in an area irradiated with light;
A light source unit that selectively emits dot-shaped light in the width direction of the fixing rotating body;
An adhering means for adhering the recording material on which the toner image is formed to the fixing rotator;
Using the image information for forming the toner image on the recording material, the toner image formed on the recording material and the heat generation area overlap in the contact area of the toner image on the fixing rotating body. And a light irradiation unit that drives and controls the light source unit. 2. The fixing according to claim 1, wherein the fixing rotator includes an optical semiconductor unit in which a region irradiated with light is in a conductive state and a resistance heating unit that generates heat in an energized portion in contact with each other in a radial direction of rotation. apparatus. The optical semiconductor unit includes a transparent conductor and an optical semiconductor layer stacked,
The fixing device according to claim 2, wherein the resistance heating unit includes a resistance heating layer and a conductor layer that are in contact with the optical semiconductor layer. The fixing device according to claim 1, wherein the light source unit is disposed inside the fixing rotator. The fixing device according to claim 1, wherein the fixing rotator is a fixing belt. The contact means includes a pressure belt that faces the fixing belt and sandwiches and conveys the recording material with the fixing belt, and the pressure belt and the fixing belt hold the recording material even after the toner image is heated. The fixing device according to claim 5, wherein the fixing device is nipped and conveyed. The fixing device according to claim 6, wherein the contact means includes a pressure roller that presses the pressure belt toward the fixing belt. The fixing device according to claim 6, wherein the pressure belt has elasticity. The fixing device according to claim 1, further comprising a cooling unit that cools the fixing rotator after heating the toner image. The fixing device according to claim 9, wherein the cooling unit is a heat pipe. The fixing device according to claim 9, wherein the cooling unit is a heat sink. In an image forming apparatus in which a toner image formed on a recording material is fixed by a fixing device to form an image on the recording material.
An image forming apparatus, wherein the fixing device is the fixing device according to claim 1.

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