JP2003195666A - Belt and fixing belt or fixing device furnished with fixing belt consisting of this belt and image forming device furnished with this fixing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a belt which prevents the occurrence of coiling round of a sheet material, prevents the adhesion of paper powder and the like at a low cost and has high fixing quality, a fixing device of a low cost and small size which is furnished with this belt and is highly durable without using a coating application material, separating pawl, etc., surely prevents the occurrence of coiling round of the sheet, is high in a fixing speed and is suppressed in the fluctuation in the speed within a fixing nip and an image forming device which is furnished with the fixing device and can form the color image of high quality at a low cost and high speed by preventing the occurrence of the image disturbance of an abnormal image by the fluctuation in the speed of the fixing nip. <P>SOLUTION: The belt consists of a base body 1, an intermediate layer 2 consisting of a heat resistant elastic material having hardness of ≤30° in a hardness meter of JIS-A and a front layer 3 consisting of a fluororesin material. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a belt, a fixing device equipped with the belt, and an image forming apparatus equipped with the fixing device. More specifically, the invention relates to a belt for mounting and conveying a sheet material to be heated or pressed. An image is formed by transferring a toner image formed by using an electrophotographic method and a fixing device having the belt for heating and fixing an object to be heated on a conveyed sheet material, and then fixing the toner image. The present invention relates to an image forming apparatus including a fixing device such as a copying machine, a printer, a facsimile machine, or a complex machine of these.

[0002]

2. Description of the Related Art In a conventional belt, a fixing device equipped with the belt, and an image forming apparatus equipped with the fixing device, in an electrophotographic copying machine, a printer, a facsimile machine, etc., a laser is used as a photoreceptor of an image carrier. A fixing device that irradiates light to draw an electrostatic latent image, transfers it as a toner image on a transfer material sheet material by a developing unit, mounts this sheet material on a belt, and heats and melts it while applying pressure An image is formed by the included image forming apparatus. FIG. 19
21 to 21 are configuration diagrams of a conventional fixing device and a main part thereof, and the fixing device 110 is a sheet material (S) of a recording medium carrying a toner image of a toner (t) of an object to be heated which is an unfixed image. Via a belt 113 for endless heating and fixing which is stretched around the fixing roller 111 and the conveying roller 112, and a nip between the fixing roller 111 and the pressure roller 114 ( The unfixed image is heat-fixed to the sheet material (S) of the recording medium by heating and pressurizing the toner (t) in the N) portion to heat and fuse the toner (t). Here, the fixing roller 111 has a cored bar 111a in the center, and in order to make the nip width sufficiently wide on its outer periphery, a heat insulating material made of a soft and heat-resistant material, for example, foamed silicone rubber or the like. It has an elastic member. Belt 113 for heat fixing
As the base 113a, a thin endless belt made of nickel, heat-resistant resin polyimide, etc., carbon steel, stainless steel, etc. is used, and the surface layer 113c is a heat-resistant release layer made of fluorine resin or silicon. It has a two-layer structure covered with rubber or the like (see FIG. 20). Surface layer 113
The silicone rubber layer of c is a JIS-A hardness meter and preferably has a rubber hardness of 25 to 65 degrees and a thickness of 100 μm to 300 μm in order to obtain good fixability and thermal response. The endless belt 113 for heat fixing is formed by a nickel electroforming method or a polyimide molding method and has no belt seam. However, in such an endless belt for heat fixing, the width of the nip (N) portion is narrow and the fixing temperature becomes unstable at the time of high-speed fixing, and the width of the nip (N) portion is made sufficiently wide. For this reason, the diameter of the fixing roller becomes large and the separability deteriorates, causing wrapping.Because an endless belt for heat fixing that does not have a belt seam is used, the cost is high and paper dust etc. also adhere. The fixing quality was also poor.
The pressure roller 114 has a two-layer structure in which a surface layer 114c of a cored bar 114a made of aluminum, stainless steel, carbon steel or the like has a heat-resistant release layer such as fluororesin or silicone rubber (see FIG. 21). Here, the core metal 11
There is also a case where 4a is hollow and has a halogen heater or the like as a heat source therein. The transport roller 112 is a thin-walled roller having a hollow metal cylinder made of aluminum, carbon steel, stainless steel, or the like. Further, the heating means 11 is provided in the conveying roller 112.
It is equipped with a 2b halogen heater and the like. Originally, such a heating type fixing device 110 using the belt 113 is used.
Has a short rise time, has an effect of preventing the belt offset of the toner (t), and is oil-less, or even a small amount of oil can be applied, which is a resource saving.

A fixing device is also known in which the hardness of the elastic body of the pressure roller is set to be 20 to 30 degrees higher than the hardness of the elastic body of the heating roller by a JIS-A hardness meter (Japanese Patent Laid-Open No. 2000-2000). -See the publication such as 338811). As a result, the nip shape becomes convex and the peeling angle of the transfer material from the heating roller can be increased, and the separation performance is improved. However, under the condition that a large amount of toner of each color is attached, it is difficult to reliably separate the toner due to the effect of the nip shape. In particular, under severe conditions of oillessness and high linear velocity, it is difficult to separate the transfer material without a separating means such as a separating claw that abuts the fixing roller. It is also known to arrange a fixing separation claw for separating the recording medium in a non-contact manner with the surface of the fixing roller (see Japanese Patent Laid-Open No. 8-166738). However, since the fixing roller and the pressure roller have the same structure, the nip shape is flat and the peeling angle with respect to the fixing roller is small. Therefore, it is necessary to accurately adjust the distance between the separation claw and the fixing roller. Further, since a space adjusting mechanism or the like is required, the number of parts of the separating claw increases, resulting in cost increase. Further, even in such a method, it is difficult to secure the separation performance corresponding to each paper type without applying oil. A fixed fixing member for pressurizing the nip by pressing it against the fixing roller via the pressure belt to fix the part of the fixing member is bite into the fixing roller via the belt at the nip outlet separating part to form a distortion. With the aim of improving the separability by the minute slip effect between the belt and the fixing roller due to such distortion, the belt is set freely on the fixing member for pressure, there is no belt tension means, and the free belt nip method is also available. It is publicly known (see JP-A-11-133776, etc.). Since the separation performance is not sufficient even with such a method, the separation means is provided to assist the separation,
It was a factor of cost increase.

A fixing method and a fixing device including a belt heat storage step, a heat and pressure step of fixing using only the heat storage energy and then radiating a toner image, and a sheet peeling step of a portion separated from the fixing stage are also known. There is (JP-A-9
-See the publication such as No. 73243). However, since only the belt is preheated by the heat storage means to be fixed and driven by the pressure roller drive and / or the belt drive means, the heating temperature is lowered, high-speed fixing is difficult, and the number of parts is large and large. Was the cost. The pressure roller having an elastic layer, the roller on the advancing direction side and the roller on the front side are pressed against each other via a belt to form a fixing nip, and the roller pressure on the advancing direction side is made larger than the roller pressure on the front side. A belt fixing device is also known (see Japanese Patent Laid-Open No. 9-90787 and the like). However, it is driven by the transport roller on the fixing belt side. There is a risk of image distortion due to speed fluctuations occurring in the fixing nip due to the fixing belt slipping. A conventional belt, a fixing device including the belt, and an image forming apparatus including the fixing device pass through a nip formed by pressure contact between a fixing member and a pressure member, so that the transfer material is not fixed on the sheet. The toner image is fixed by heating and pressurizing The toner of the heated body is melted in the nip, so the toner that is the heated body becomes an adhesive and the transfer material is wrapped around without being separated from the fixing member. In order to prevent so-called wrapping, the surface layer of the fixing member is made of a material such as fluororesin having a good releasability. For example, in a full-color copying machine or the like of an image forming apparatus, it is necessary to mix toners, which are four colors of yellow, magenta, cyan, and black, which are objects to be heated in a molten state. Since the toner was completely melted in the nip, winding of the transfer material was further generated. Usually, the mold releasability is secured by applying silicone oil as a mold release agent.

As the separating means, a plurality of claws are installed in the axial direction of the fixing member so as to lightly contact the surface of the fixing member by an elastic body such as a spring. The transfer material is separated by the nail and is carried out along the separation guide. Separation is ensured by touching the claws, but the fixing member is worn or scratched,
The toner and oil scraped off with a nail adheres to the transfer material as dirt, resulting in poor image quality. On the other hand, in the oilless fixing, (1) stains due to the adhesion of oil to the transfer paper are eliminated. (2) Maintenance is free because there is no oil supply. (3) There is an advantage that the oil application member is eliminated and the cost is reduced. However, in the oilless fixing, the margin was narrower and the problem became tighter compared to the oil application. or,
As a problem peculiar to belt fixing, a slight misalignment of toner occurs before the unfixed toner, which is a heated object, is fused and fixed on the transfer paper of the sheet in the fixing nip, which is caused by the speed fluctuation generated in the fixing nip. The image disturbance of the abnormal image that occurred is occurring. The cause of this image disturbance is the toner position deviation due to the speed variation caused by the belt slip, the elastic deformation due to the pressure contact between the rollers, and the like. A heating type fixing device that uses a belt has a short rise time and has an effect of preventing belt offset of the toner to be heated, and it is possible to apply oilless or even a small amount of oil. Compared with oil application, the margin is narrower and more severe.If you use a separation claw of the separation means or a separation guide plate, separation will be reliable, but wear and scratches on the fixing member will reduce durability, and The image quality was also deteriorated because the toner and oil scraped off adhered to the transfer material as dirt. Further, a main problem of a belt used for high-speed color fixing, a fixing device including the belt, and an image forming apparatus including the fixing device is that a sheet material of recording paper is wound around the belt during separation. . When the speed is increased, the nip width capable of fixing is maintained, so that the roller diameter becomes large and it becomes difficult to separate the curvature. Further, since the sheet material of the recording paper is conveyed along the belt, the higher the linear velocity, the less the time margin for the recording paper to be separated from the fixing belt, and the easier the winding. Therefore, in the conventional belt, the fixing device equipped with the belt, and the image forming apparatus equipped with the fixing device, sheet wrapping occurs in the fixing belt, the endless belt becomes expensive, and paper dust and the like adhere to the belt. The fixing quality will also deteriorate, and if a separation claw or separation guide plate of separation means for preventing wrapping is used, wrapping will be prevented reliably, but the durability will deteriorate due to wear or scratches, and scraping will be done with a nail. In addition, toner and oil adhere to the transfer material as dirt, which lowers the image quality. The fixing speed is low to prevent wrapping, and the object to be heated is inside the fixing nip due to speed fluctuations that occur within the fixing nip. Before the toner is fused and fixed on the transfer paper of the sheet, the image quality of the formed image is deteriorated due to the image disturbance of the abnormal image caused by the minute positional deviation of the toner to be heated. It says failure has occurred.

[0006]

Therefore, the object of the present invention is to solve such a problem. That is, it is possible to prevent the occurrence of wrapping of the sheet material at a low cost and to prevent the adhesion of paper powder and the like, and the fixing quality is high, and the durability is excellent without using the coating material or the separating claws. A fixing device equipped with a low-cost and small belt that reliably prevents the occurrence of the toner, has a high fixing speed, and suppresses the speed fluctuation in the fixing nip, and an image disturbance of an abnormal image due to the speed fluctuation in the fixing nip. An object of the present invention is to provide an image forming apparatus including a fixing device that can prevent the occurrence of high-speed color images at low cost and can form high quality images.

[0007]

In order to achieve the above object, the present invention according to claim 1 is a belt for mounting and conveying a sheet material to be heated or pressed, wherein the substrate and the hardness are JI.
The most main feature is that the belt is composed of an intermediate layer made of a heat-resistant elastic material having a hardness of S-A of 30 degrees or less and a surface layer made of a fluororesin material. According to the present invention of claim 2, in the belt according to claim 1, the surface hardness is JI.
The main feature is that the belt has an S-A hardness meter of 70 degrees or more. According to a third aspect of the present invention, in the belt according to the first or second aspect, the base body is a belt including a joint portion in which an end portion of a sheet-like thin plate-shaped member and both end portions of the other end portion are joined. It is a characteristic. According to a fourth aspect of the present invention, in the belt according to the third aspect, the step difference between the ends of the sheet-shaped thin plate-shaped member at the joining portion and the other end of the sheet-shaped thin-plate-shaped member is made equal to the thickness of the sheet-shaped thin plate-shaped member. 1/1
The main feature is that the belt is 0 or less. According to a fifth aspect of the present invention, in the belt according to the first, second, third or fourth aspect, the thickness of the rubber of the heat resistant elastic material of the intermediate layer is 1
The main feature is that the belt has a diameter of 00 μm to 300 μm. The present invention according to claim 6 relates to claims 1, 2 and
In the belt described in 3, 4, or 5, the main feature is that the surface layer is a belt in which the thickness of the fluororesin material is 5 μm to 30 μm. The present invention according to claim 7 provides the belt according to claim 1, 2, 3, 4, 5 or 6.
The main feature of the surface layer is a belt formed by coating a fluororesin tube material. According to the present invention of claim 8, in a fixing device for heating and fixing an object to be heated on a conveyed sheet material with a fixing belt, a fixing roller rotatably supported, and a fixing roller rotatably supported to generate heat. A fixing belt which is stretched around a conveying roller and rotates, and a first fixing nip portion is formed on the upstream side of a sheet material which is pressed by the fixing belt and conveyed to the fixing roller. A roller, a pressure roller, and a second fixing nip portion for continuously enlarging the fixing nip width to the first fixing nip portion. The second fixing nip portion is formed on the fixing belt. The most main feature is that it is a fixing device including a fixing nip portion forming means.
A ninth aspect of the present invention is characterized in that, in the fixing device according to the eighth aspect, the fixing belt is the fixing device that is the belt according to any one of the first to seventh aspects. .

According to a tenth aspect of the present invention, in the fixing device according to the eighth or ninth aspect, the first fixing nip portion is the second fixing nip portion.
The main feature is that the fixing device has a larger pressing force than the fixing nip portion. The present invention according to claim 11 is characterized in that, in the fixing device according to claim 8, 9 or 10, the fixing roller is a fixing device having a curvature smaller than that of the second fixing nip portion forming means. According to a twelfth aspect of the present invention, in the fixing device according to the eighth, ninth, tenth or eleventh aspect, the conveying roller is on the inner peripheral surface of the fixing belt,
The main feature of the fixing device is a fixing device including a tension applying unit that applies a tension to the fixing belt. According to a thirteenth aspect of the present invention, in the fixing device according to the twelfth aspect, the tension applying unit has a fixing belt tension of 1 (kg / one side) or more,
The main feature of the fixing device is that it is 3 (kg / one side) or less. The present invention according to claim 14 relates to claims 8 and 9,
In the fixing device described in 10, 11, 12 or 13,
The main feature of the carrying roller is that it is a fixing device arranged in the vertical direction with respect to the second fixing nip portion forming means or on the downstream side in the carrying direction of the sheet material. According to a fifteenth aspect of the present invention, in the fixing device according to any one of the eighth to fourteenth aspects, the pressure roller is a fixing device having a surface hardness of 70 degrees or more as measured by a JIS-A hardness meter. The main feature is that there is. According to a sixteenth aspect of the present invention, in the fixing device according to any one of the eighth to fifteenth aspects, the pressure roller includes a core metal, an intermediate layer made of a heat resistant elastic material, and a surface layer made of a fluorine resin material. The main feature is that it is a fixing device. A seventeenth aspect of the present invention is characterized in that, in the fixing device according to the sixteenth aspect, the surface layer made of a fluorine resin material is a fixing device made of a fluorine resin tube material. The present invention of claim 18 is the fixing device according to any one of claims 8 to 17, wherein the pressure roller has a rubber thickness of 0.5 made of a heat resistant elastic material.
The main feature of the fixing device is that the intermediate layer has a hardness of not less than 30 mm and a hardness of JIS-A of 30 degrees or less, and a surface layer made of a fluorine resin layer having a thickness of 5 μm to 30 μm. A nineteenth aspect of the present invention is the fixing device according to any one of the eighth to eighteenth aspects, in which the second nip portion forming means is a second belt which is rotatably supported by stretching the fixing belt.
The main feature is that the image forming apparatus is a nip portion forming roller.

According to a twentieth aspect of the present invention, in the fixing device according to the nineteenth aspect, the second nip portion forming roller is
The main feature of the fixing device is that it also serves as a conveyance roller. The present invention of claim 21 is characterized in that, in the fixing device according to claim 19 or 20, the second nip portion forming roller is a fixing device having a diameter of 10 mm or more and 20 mm or less. According to a twenty-second aspect of the present invention, in the fixing device according to any one of the eighth to twenty-first aspects, a second nip portion forming means and a second pressure roller for applying pressure via a fixing belt are used. The main feature of the fixing device is that the fixing nip portion has a flat shape or a concave shape in the conveying direction of the sheet conveyed from the pressure roller. The present invention according to claim 23 relates to claims 19 to 22.
In the fixing device described in any one of the above items, the driving unit that rotationally drives the pressure roller also rotationally drives the second fixing nip portion forming roller so that the peripheral speeds of the fixing belt and the pressure roller become equal to each other. Its main feature is that it is a fixing device. According to a twenty-fourth aspect of the present invention, in the fixing device according to any one of the eighth to twenty-second aspects, the driving unit that rotationally drives the pressure roller also rotationally drives the conveyance roller to fix the fixing belt and the pressure roller. The main feature is that the fixing device has the same peripheral speed. A twenty-fifth aspect of the present invention is the fixing device according to any one of the eighth to twenty-second aspects, in which the driving unit that rotationally drives the pressure roller and the driving unit that rotationally drives the conveyance roller that stretches the fixing belt. And the drive control means for making the peripheral speeds of the fixing belt and the pressure roller equal to each other. According to a twenty-sixth aspect of the present invention, in the fixing device according to any one of the eighth to twenty-second aspects, a drive control unit that adjusts a rotation speed of a drive unit that rotationally drives the pressure roller and a fixing belt are stretched. Drive control means for adjusting the rotation speed of the drive means for rotationally driving the conveying roller to
The main feature of the fixing device is that the peripheral speeds of the fixing belt and the pressure roller are equal.

The present invention according to claim 27 relates to claims 19 and 2.
In the fixing device described in 0, 21, 22, 23, 24, 25, or 26, the main feature is that the fixing roller and the second fixing nip portion forming roller are fixing devices having the same configuration and the same shape. To do. According to a twenty-eighth aspect of the present invention, in the fixing device according to the nineteenth, twenty-second, twenty-two, twenty-two, twenty-three, twenty-fourth, twenty-fifth, twenty-six or twenty-seventh aspect, the fixing roller and the second fixing nip portion forming roller have the same diameter, The main feature is that the fixing device has the same surface hardness and the same pressing force as the pressure roller via the fixing belt. The present invention according to claim 29 is the fixing device according to any one of claims 8 to 28, wherein any one of a fixing roller and a pressure roller arranged to face the fixing roller via a fixing belt and press the fixing roller. The main feature of the fixing device is that one has a crown shape and the other has an inverted crown shape. The present invention according to claim 30 provides the fixing device according to any one of claims 19 to 29,
Of the pressure roller formed by pressing the second fixing nip portion forming roller and the fixing roller opposite to each other via the fixing belt, one of them has a crown shape and the other has a reverse crown shape. The main feature. According to a thirty-first aspect of the present invention, in the fixing device according to any one of the nineteenth to twenty-eighth aspects, the second fixing nip portion forming roller has a rigid crown shape and the pressure roller has a straight shape. The main feature is that it is a device. According to a thirty-second aspect of the present invention, in an image forming apparatus for forming an image by transferring a toner image formed by using an electrophotographic method to a transfer target and then fixing the image, a rotatably held image carrier, Charging means for charging the image carrier, latent image forming means for forming an electrostatic latent image on the image carrier charged by the charging means, and electrostatic latent image formed by the latent image forming means. Developing means for developing a toner image by attaching toner, and transfer means for transferring the toner image visualized by the developing means onto a sheet material,
The image forming apparatus is characterized in that it is an image forming apparatus including the fixing device according to any one of claims 8 to 31 for fixing the toner image formed on the sheet material by the transfer means).

[0011]

According to the first aspect of the present invention, there is provided a fixing device having a belt and a fixing belt having the above-described structure, or a fixing belt including the fixing belt, and an image forming apparatus having the fixing device. 30 with A hardness tester
(EN) A belt having an intermediate layer made of a heat-resisting elastic material and having a surface layer made of a fluororesin material, the surface layer of which is made of a fluororesin material. According to the second aspect, it is possible to provide a belt having a surface hardness of 70 degrees or more as measured by a JIS-A hardness meter. In the third aspect, the base body can provide a belt in which the end portions of the sheet-shaped thin plate-shaped member and the both end portions of the other end portion are joined at the joint portions. According to a fourth aspect of the present invention, there is provided a belt in which a step between the ends of the sheet-shaped thin plate-shaped member and the other end of the joined portion that are abutted with each other is 1/10 or less of the thickness of the sheet-shaped thin-plate-shaped member. To be able to. According to the fifth aspect, it is possible to provide a belt in which the rubber of the heat resistant elastic material of the intermediate layer has a thickness of 100 μm to 300 μm. According to claim 6, the surface layer has a thickness of the fluororesin material of 5 μm to 30 μm.
To be able to provide a belt that According to the present invention, the surface layer can be provided with a belt coated with a fluororesin tube material. In claim 8, the upstream side of the sheet material that is conveyed by pressure with a fixing roller that is rotatably supported and a conveying roller that is rotatably supported and generates heat and that is pressed by a fixing belt that is rotated and conveyed with the fixing roller. A pressure roller that forms the first fixing nip portion and is driven to rotate by heat, and a second fixing nip portion that continuously expands the fixing nip width to the first fixing nip portion, at least for winding the sheet material. (EN) A fixing device for forming a fixing belt can be provided by means of a second fixing nip portion forming means having a curvature equal to or greater than the prevention curvature. In a ninth aspect, the fixing belt can provide a fixing device including the belt according to any one of the first to seventh aspects.

According to the tenth aspect of the present invention, it is possible to provide a fixing device in which the first fixing nip portion has a larger pressing force than the second fixing nip portion. In the eleventh aspect, the fixing roller can provide a fixing device having a curvature smaller than that of the second fixing nip portion forming means. According to the twelfth aspect of the present invention, the conveying roller is provided on the inner peripheral surface of the fixing belt, and it is possible to provide a fixing device that applies tension to the fixing belt by the tension applying means. In claim 13, the tension of the fixing belt is 1 (kg / one side) or more and 3 (k) by the tension applying means.
g / one side) It is possible to provide a fixing device having the following. According to the fourteenth aspect of the present invention, it is possible to provide a fixing device in which the conveying roller is arranged in the direction perpendicular to the second fixing nip portion forming means or on the downstream side in the sheet material conveying direction. According to the fifteenth aspect, it is possible to provide a fixing device in which the surface hardness of the pressure roller has a rigidity of 70 degrees or more as measured by the JIS-A hardness meter. According to the sixteenth aspect of the present invention, it is possible to provide the fixing device in which the pressure roller includes the core metal, the intermediate layer made of the heat resistant elastic material, and the surface layer made of the fluorine resin material.
In the seventeenth aspect of the present invention, the surface layer made of the fluorine resin material makes it possible to provide a fixing device made of the fluorine resin tube material. 19. The pressure roller according to claim 18, wherein the pressure roller is made of a heat-resistant elastic material and has a thickness of 0.5 mm or more and a hardness of JIS-A hardness meter of 30 degrees or less, and a fluorine resin having a thickness of 5 μm to 30 μm. (EN) Provided is a fixing device including a surface layer including layers.
According to the nineteenth aspect, it is possible to provide a fixing device in which the second nip portion forming roller of the second nip portion forming means rotatably supported stretches the fixing belt.

In the twentieth aspect, the second nip portion forming roller can provide a fixing device which also serves as a conveying roller. In the twenty-first aspect, the second nip portion forming roller can provide a fixing device having a diameter of 10 mm or more and 20 mm or less.
In claim 22, the second fixing nip portion formed by the second nip portion forming means and the pressure roller that applies pressure via the fixing belt has a flat shape, or the sheet material is conveyed from the pressure roller. (EN) Provided is a fixing device having a concave shape in a direction. In claim 23,
The driving means for rotationally driving the pressure roller also rotationally drives the second fixing nip portion forming roller so as to provide a fixing device that equalizes the peripheral speeds of the fixing belt and the pressure roller. According to the twenty-fourth aspect of the present invention, the driving means for rotationally driving the pressure roller can also rotationally drive the conveying roller to provide a fixing device that equalizes the peripheral speeds of the fixing belt and the pressure roller. In the twenty-fifth aspect of the present invention, it comprises a driving means for rotating the pressure roller and a driving means for rotating the conveying roller stretching the fixing belt, and the drive control means makes the peripheral speeds of the fixing belt and the pressure roller equal. To be able to provide a fixing device that does so. According to a twenty-sixth aspect of the present invention, there are provided a drive control means for adjusting the rotation speed of the drive means for rotationally driving the pressure roller, and a drive control means for adjusting the rotation speed of the drive means for rotationally driving the conveying roller for stretching the fixing belt. Therefore, it is possible to provide a fixing device that makes the peripheral speeds of the fixing belt and the pressure roller equal to each other.

In claim 27, the fixing roller and the second
It is possible to provide a fixing device in which the fixing nip portion forming rollers have the same configuration and the same shape. Claim 2
In No. 8, it is possible to provide a fixing device in which the fixing roller and the second fixing nip portion forming roller have the same diameter, the same surface hardness, and the same pressing force as the pressure roller via the fixing belt. According to a twenty-ninth aspect, it is possible to provide a fixing device in which one of the pressure rollers, which is arranged to face the fixing roller via a fixing belt and is pressed, has a crown shape and the other has an inverted crown shape. To 31. A fixing device according to claim 30, wherein one of the pressure rollers, which is arranged to face the second fixing nip portion forming roller via the fixing belt and is pressed, has a crown shape and the other has an inverted crown shape. To be able to provide. In the thirty-first aspect, it is possible to provide a fixing device in which the second fixing nip portion forming roller has a rigid crown shape and the pressure roller has a straight shape. The toner according to claim 32, wherein the electrostatic latent image formed by the latent image forming means for forming an electrostatic latent image on the image bearing body charged by the charging means for charging the rotatably held image bearing body 32. The toner image formed on the sheet material by the transfer means for transferring the toner image visualized by the developing means for adhering the toner to the sheet material according to any one of claims 8 to 31. (EN) Provided is an image forming apparatus that fixes with a fixing device.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described in detail with reference to the drawings. 1 and 2, the belt 0 on which the sheet material to be heated or pressed is placed and conveyed is
The above surface layer of a high release material having a low surface energy, which comprises a substrate 1, an intermediate layer 2 made of a heat-resistant elastic material having a hardness of 30 degrees or less as measured by a JIS-A hardness meter, and a surface layer 3 made of a fluororesin material. 3 and the above-mentioned intermediate layer 2 of heat resistant elastic material to reduce the surface hardness and improve the releasability, so that the sheet material (S) is prevented from being wound and the fixing quality is high. Further, the belt 0 and the pressure roller 14 (not shown)
In addition, it is possible to perform oilless double-sided fixing without image stains due to offset toner or paper dust. The belt 0 has a thickness of the surface layer 3 of 5 μm to 30 μm.
Fluorocarbon resin material, the thickness of the rubber of the intermediate layer 2 is 100
μm to 300 μm, made of soft heat-resistant elastic material whose rubber hardness is less than 30 degrees by JIS-A hardness tester, lowering surface hardness and improving releasability to prevent sheet material from winding and fixing quality. It has become possible to raise even higher. When the belt 0 is used as the fixing belt 13 (not shown), the rubber thickness of the intermediate layer 2 is 1
If it is less than 00 μm, it becomes difficult to uniformly fix an unfixed image, and a partial gloss unevenness such as a satin finish or a citron skin, 30
When the thickness is 0 μm or more, the fixing temperature does not follow the speed, and the temperature of the fixing belt 13 during continuous sheet feeding decreases. When the fixing belt 13 (not shown), which is the belt 0, is used in the fixing device 10 (not shown), it is possible to prevent the recording paper of the sheet material (S) from being wrapped around and the deterioration of the image quality due to the improved releasability. Even if there is unevenness on the surface, it is now possible to obtain uniform high-quality fixing without uneven glossiness or offset due to unevenness on the surface.

The larger the surface hardness of the fixing belt 13, the smaller the amount of paper dust adhered (see FIG. 2). As a substitute characteristic of the amount of paper dust adhered, O due to paper dust adhered on the OHP recording paper
The decrease in HP translucency was measured with a turbidimeter. The larger the turbidity (%) value, the larger the amount of paper dust adhered, and the permissible value of the amount of paper powder adhered is 2% or less, which causes no problem. Therefore, the fixing belt 1
No. 3 has a three-layer structure and the surface hardness is 70 degrees or more on the JIS-A hardness meter, and the amount of paper dust adhered is small. The fixing belt 13 is formed by covering and adhering the surface layer 3 with a fluorine resin tube material. Therefore, the sheet material (S) is further prevented from being wound around, and the fixing belt 13 is caused by adhesion of offset toner or paper powder. Oilless double-sided fixing without image stains is possible, and durability that can withstand repeated bending operations due to rotation is also improved. Furthermore, it has excellent abrasion resistance, good surface roughness accuracy, and gloss on the image surface, and it eliminates the drawbacks of the conventional coating method and coating method of the fluorine resin material. For example, in the coating method, after the fluororesin powder having a thickness of 10 μm to 20 μm is electrostatically coated, the adhesive force of the coating layer is strengthened and the surface is smoothed in a firing process. On the other hand, in the method of coating the surface layer 3 with a pre-molded fluorine resin tube material having a thickness of 30 μm to 70 μm using a heat resistant adhesive,
As the characteristics of the molded product, the surface roughness accuracy is good, a uniform and high-gloss image is obtained, and the abrasion resistance is also good. That is, in terms of surface roughness, the average surface roughness is Ra for the fluorine resin tube material: about 0.1 μm, and the coating method is 0.2 to 0.6 μm. In terms of durability, the amount of paper abrasion is less, and the amount of the fluorine resin tube material is about half that of the painting method. Regarding the body 1, the polyimide belt is more durable than the metal belt.

In FIG. 3, the base body 1 of the belt 0 is shown.
Is the end 1b and the other end 1c of the sheet-shaped thin plate member 1a
Since both ends of the fixing belt 1 are joined together by the joining portion 1d to form an endless shape, the fixing belt 1 is attached to the fixing device 10 (not shown).
When used as No. 3, the sheet material (S) can be prevented from being wrapped around, and the cost is low. The fixing belt 13
Is a step (G) at both ends of the joining portion 1d where the end portion 1b and the other end portion 1c of the sheet-shaped thin plate member 1a are butted.
Is 1 / th of the thickness (T) of the sheet-shaped thin plate-shaped member 1a.
Since it is formed with 10 or less, horizontal stripes do not occur in the formed image after fixing by the fixing device 10 in the image forming apparatus 20 (not shown). The fixing belt 13 has a three-layer belt structure, and the thickness of the rubber layer of the heat-resistant elastic material, which is the intermediate layer 2, is 150 μm, and the step is preferably 10 μm or less.
In the current prototype manufacturing, a step difference of 2 μm or less is realized. Even if there is a step in the joining portion 1d as described above, in the case of the three-layer belt structure like the fixing belt 13, the intermediate layer 2
The level difference (G) is absorbed by the elastic effect of, and the level difference (G) cannot be confirmed on the surface. The endless belt with a seam by such a construction method has an advantage that the labor cost is lower than that of a seamless seamless belt without a seam, and a low-cost fixing belt 13 can be provided. The endless belt is, of course, a seamless belt without joints, joined by an adhesive of a heat-resistant resin sheet such as polyimide, or an ultra-thin plate of stainless steel or iron-based material with a thickness of 100 μm. By the following precision butt technology, for example, processing method by welding,
It also includes manufactured seams.

In FIGS. 4 to 7, a fixing device 10 for fixing toner by heating a toner (t) on a conveyed sheet material (S) by a fixing belt 13 is a fixing roller rotatably supported. 11 and a fixing belt 13 that is rotatably supported by the fixing roller 11 and that is stretched and rotated by the conveying roller 12 that is heated by the heating means 12b to generate heat, or
The fixing belt 13 and the fixing belt 13 contacting the outer peripheral surface,
Alternatively, the heating means 14e that forms the first fixing nip portion (N1) on the upstream side of the sheet material (S) that is conveyed by pressing with the fixing belt 13 and the fixing roller 11 is heated to generate heat and the driving means 14d. Pressure roller 1 driven to rotate by
4, the pressure roller 14 and the first fixing nip portion (N1) are formed on the fixing belt 13 or at least the second fixing nip portion (N2) for continuously expanding the fixing nip width. The second fixing nip portion forming roller 15a of the second fixing nip portion forming means 15 having a curvature equal to or larger than the curvature that prevents the sheet material (S) from being wrapped around, and is used for separating the curvature without using a coating material, a separating claw, or the like. By this, the durability is further improved, the occurrence of wrapping of the sheet material (S) is further reliably prevented, the fixing temperature is further stabilized, the fixing nip width is expanded, the fixing speed is further increased, and the speed fluctuation in the fixing nip is suppressed. Furthermore, it is low cost and small.

The arrow A shown in the figure for the recording sheet of the sheet material (S)
First fixing nip portion (N1) on the upstream side in the transport direction
The entrance of the fixing belt 13 or the fixing roller 11 via the fixing belt 13, the driving means 14d, and
Rigid pressure roller 1 provided with the heating means 14e
And the fixing belt 13 or the fixing belt 13 comes into contact with the pressure roller 14 and the pressure roller 14 and the fixing belt 13 or the fixing belt 13. Between the recording sheet of the sheet material (S) and the first fixing nip portion (N1) on the downstream side of the conveying direction of the recording sheet of the sheet material (S) in the direction of arrow A in the figure. The outlet of the second fixing nip portion (N2) is a fixing belt 13 or, via the fixing belt 13,
A second fixing nip portion forming unit 15 having a curvature of at least equal to or greater than the curvature for preventing the recording material sheet S from being wrapped around.
Second fixing nip portion forming roller 15a and pressure roller 1
No. 2 continued to the first fixing nip (N1) by No. 4
Of the fixing nip portion (N2) is formed,
Fixing roller 11 and second fixing nip portion forming means 1
Of the second fixing nip portion forming roller 15a and the pressure roller 14 of No. 5, at least the fixing roller 11 has an elastic layer, and further in the fixing step, it is on the upstream side in the conveying direction in the direction of arrow A in the drawing. At the front of the entrance of the first fixing nip portion (N1), the temperature of the fixing belt 13 or the fixing belt 13 is set to a softening point temperature of the toner (t) or more, that is, a so-called fixable toner temperature, and the separation is performed. In the process, the recording sheet of the sheet material (S) is not wrapped around the fixing belt 13 or the fixing belt 13. The fixing roller 11 has a cored bar 11a at the center and a first fixing nip portion (N
In order to make the width of 1) sufficiently wide, it is provided with a heat-resistant elastic member made of a soft heat-resistant material such as foamed silicone rubber. The thickness of the fixing roller 11 is 15% to 20% of the diameter of the fixing roller 11, which is a sufficient thickness. In order to improve the releasability of the transfer sheet of the sheet material (S) from the fixing belt 13 or the fixing belt 13, the fixing nip portions (N1, N2) face downward. That is, the hardness of the pressure roller 14 is increased, and the thickness of the release layer of the surface layer 14c of the pressure roller 14 is set to the pressure roller 1
Assuming that the diameter of No. 4 is less than 7%, the hardness is 20 Hs according to the JIS-A hardness meter. Since the pressure roller 14 is used as a driving roller, its rigidity is important, and the fact that the peripheral speed does not fluctuate due to thermal expansion or pressure deformation is an image disturbance phenomenon. It is necessary as a method for preventing the occurrence of an abnormal image caused by a slight positional deviation of the toner (t) before the toner (t) is fused and fixed on the recording sheet of the sheet material (S). In order to reduce the speed fluctuation of the pressure roller 14 and suppress the occurrence of abnormal images,
The larger the surface hardness, the better, and there is no problem if the JIS-A hardness meter has a hardness of 70 degrees or more.

The second fixing nip portion forming means 15 may be a fixing member (not shown), but a second fixing nip portion forming roller 15a is preferable in order to suppress speed fluctuations due to slips and the like. If the curvature (1 / radius) is large, it is possible to improve the separation performance by the curvature separation. As a result, the recording sheet of the sheet material (S) is prevented from being wound around without the need to bring the separation claw of the separation means, the separation guide plate, or the like into contact with the fixing belt 13 or the fixing belt 13. That is, self-separation is possible. Further, in the fixing step, the fixing of the unfixed toner (t) to the sheet material (S) onto the recording paper is sufficiently performed without causing cold offset and deterioration of the fixing property. The image distortion as described above does not occur. Not only the fixing temperature but also the fixing conditions in the fixing process
The width of the fixing nip portion (N) and the fixing pressure are also important. Like the fixing device 10, the width of the fixing nip portion (N) that expands by continuously forming the second fixing nip portion (N2) in the first fixing nip portion (N1) and the fixing pressure is larger. On the other hand, in the separating step, the fixing member (not shown) of the second fixing nip portion forming means 15 and the second fixing nip portion forming roller 15a have a large curvature (1 / radius) and a small diameter. Separability improves. From the above description, it is inevitable that the relationship between the diameter and pressure of each roller in the fixing step and the separating step is as follows, and the diameter of the fixing roller 11> the second fixing nip portion forming means 15 is illustrated. Not fixing member or second fixing nip portion forming roller 15a
, The curvature of the fixing roller 11 (1 / radius) <the curvature (1 / radius) of the fixing member (not shown) of the second fixing nip portion forming means 15 and the second fixing nip portion forming roller 15a, the fixing roller 11 Pressure (Vitality of the first fixing nip portion (N1))> Pressure of a fixing member (not shown) of the second fixing nip portion forming means 15 or the second fixing nip portion forming roller 15a (second fixing nip portion (N2) It is desirable for the formation of a high-quality color image at low cost by preventing wrapping and preventing the occurrence of image disturbance of an abnormal image due to speed fluctuations in the fixing nip.

The separable curvature of the fixing member (not shown) of the second fixing nip portion forming means 15 and the second fixing nip portion forming roller 15a which prevent separation of the sheet material (S) from winding is the sheet material (S). Recording paper of the second fixing nip (N
At the exit of 2), in order to separate from the fixing belt 13 or the fixing belt 13, the separation moment (M1) of the recording sheet of the sheet material (S)> toner (t) / fixing belt 13 or the fixing belt There is a relation of the adhesion moment (M2) of the interface of 13. Second fixing nip portion forming means 1
5, the curvature (1 / radius) of the fixing member (not shown) and the second fixing nip portion forming roller 15a, the bending rigidity of the recording sheet of the sheet material (S), the toner (t) / fixing belt 13, or
The releasing factor of the fixing belt 13 is a main factor, but as a factor that can be controllably realized, a fixing member (not shown) of the second fixing nip portion forming unit 15 or the second fixing nip portion forming roller 15a is used. The curvature (1 / radius) of is important. Experiments have shown that the greater the curvature (1 / radius) of the fixing member (not shown) of the second fixing nip forming means 15 and the second fixing nip forming roller 15a, the smaller the diameter, the more the effect of curvature separation can be obtained. Has been verified by (Fig. 5
See). The diameter of the second fixing nip portion forming roller 15a of the second fixing nip portion forming means 15 is 10 mm or more, 2
By setting it to 0 mm or less, preferably 16 mm or less, it is possible to more reliably prevent the occurrence of wrapping of the recording material of the sheet material (S).

In the fixing device 10, the diameter of the fixing member (not shown) of the second fixing nip portion forming means 15 and the second fixing nip portion forming roller 15a is small, that is, the diameter is 20 m.
Separability was good at m or less, and the effect of curvature separation was verified (see FIG. 5). In the fixing device 10, the set fixing temperature is 160 ° C., and the abnormal image generation temperature such as hot offset is 180 ° C. or higher. Therefore, the recording sheet of the sheet material (S) is not wrapped in the fixing temperature range. Further, a fixing member (not shown) of the second fixing nip portion forming means 15 or a second fixing nip portion forming roller 15a.
In order to prevent abnormal images such as wrinkles on the recording sheet of the sheet material (S) and uneven image gloss due to the bending deformation of the roller that occurs when the fixing belt 13 is pressed against the pressure roller 14 via the fixing belt 13. Therefore, even if the fixing member (not shown) of the second fixing nip portion forming means 15 or the second fixing nip portion forming roller 15a is made of an iron-based metal material, the diameter is required to be 10 mm or more. Further, in the fixing device 10, the bending deformation amount of the fixing member (not shown) of the second fixing nip portion forming means 15 or the second fixing nip portion forming roller 15a, which is an iron-based metallic material, is about 0.3 mm or less. But,
This is a condition for obtaining a good image without wrinkles and uneven gloss. At this time, the usable second fixing nip portion forming means 1
The lower limit of the diameter of the fixing member 5 and the second fixing nip portion forming roller 15a (not shown) is about 10 mm.
Since the pressure roller 14 has rigidity and is rotationally driven by the driving unit 14d, the fixing belt 13 or the fixing belt 1
Compared with the method of driving the roller that stretches 3 the effect of preventing the fluctuation of the speed in the fixing nip (N) and the stable conveyance of the recording sheet of the sheet material (S) without wrinkling and the image disturbance There is. Fixing device 10 in image forming apparatus 20
Forms a continuous second fixing nip portion (N2) in the first fixing nip portion (N1) to expand the range of the fixing nip portion (N), and at the same time, the heating means 1 is provided in the conveying roller 12.
2b is arranged to heat not only the pressure roller 14
The heater of the heating means 14e is also provided in the inside so that the fixing temperature can be stabilized in a small size. In particular, in the image forming apparatus 20 described above, the fixing temperature does not decrease even during continuous high-speed paper feeding, a stable fixed toner image with little gloss variation can be obtained, and color images can be developed at high speed. became.

The fixing belt 13 or the fixing belt 13 and the pressure roller 14 can reach a predetermined temperature quickly, and high-speed start-up is also possible. In addition, the second nip portion forming roller 1
5a is the same as when the conveyance roller 12 is also used. Further, the fixing belt 1 has a small number of parts, is small, and is low in cost.
3 or the fixing device 10 including the fixing belt 13 can be provided (see FIG. 7). Since the pressure roller 14 is composed of the core metal 14a of the roller, the intermediate layer 14b having the heat resistant elastic material, and the surface layer 14c having the fluororesin material, the occurrence of the wrapping of the recording sheet of the sheet material (S). Prevent (see FIG. 6). Further, oilless double-sided fixing without image stains caused by the adherence of offset toner or paper powder on the pressure roller 14 has become possible.
The pressure roller 14 has a thickness of the intermediate layer 14b of 0.5 mm.
As described above, the heat-resistant elastic material having a rubber hardness of 30 degrees or less as measured by the JIS-A hardness meter and the surface layer 14c having a thickness of 5 μm to 30 μm
It is made of a fluorine resin material of μm. As a result, the surface layer 14c and the elastic layer of the high release material having a low surface energy are provided on the intermediate layer 14b to reduce the surface hardness, so that the releasability is improved and the recording sheet wraps around the recording sheet (S). It is now possible to prevent image quality deterioration. The pressure roller 14 has a surface hardness of 75 degrees when the thickness of the intermediate layer 14b of the elastic body provided on the core metal 14a is 1 mm and the rubber hardness is 30 degrees or less by JIS-A hardness meter. Is no problem. Since the surface layer 14c of the pressure roller 14 is formed by covering and adhering the fluorine resin tube material, the sheet material (S) is prevented from being wound around the recording paper, and the image due to the offset toner or paper dust is adhered. It also enables oilless double-sided fixing without dirt. Furthermore, it has excellent abrasion resistance, good surface roughness accuracy, and gloss on the image surface, and it eliminates the drawbacks of the conventional coating method and coating method of the fluorine resin material. For example, the coating method has a thickness of 10 μm.
After the electrostatic coating of the fluorine resin powder of about 20 μm, the adhesive force of the coat layer is strengthened and the surface is smoothed in the firing step. Compared with that, the pre-molded thickness is 30 μm to 70
In the method in which the surface layer 3 is coated with a μm fluororesin tube material using a heat-resistant adhesive, the characteristics of the molded product are that the surface roughness accuracy is good, a uniform and high-gloss image is obtained, and the abrasion resistance is high. Wearability is also good. That is, in terms of surface roughness, the average surface roughness is Ra for the fluororesin tube material; about 0.1 μm, and the coating method is 0.2 μm to 0.6 μm.

In FIG. 8, the fixing device 10 is provided on the fixing belt 13 or on the inner peripheral surface of the fixing belt 13, and the fixing belt 13 or the tension applying means 12 for the fixing belt 13 is provided.
The conveying roller 12 having a has a direction substantially perpendicular to a fixing member (not shown) of the second fixing nip portion forming unit 15 or the second fixing nip portion forming roller 15a or a recording material of a sheet material (S). The fixing belt 1 is arranged on the downstream side in the conveying direction in the direction of the arrow (A) shown in the drawing, so that the occurrence of the wrapping of the recording sheet of the sheet material (S) can be more reliably prevented.
3, or the fixing device 10 including the fixing belt 13 can be provided. In the fixing device 10, the pressure roller 14 is on the driving side, and the fixing belt 13 or the fixing belt 13 is on the driven side. In such a configuration, the second
From the fixing nip portion (N2) of the conveyance roller 1
The fixing belt 13 moving in the direction 2 or the fixing belt 13 is loosened and loosened. As a result, the fixing member (not shown) of the second fixing nip portion forming unit 15 or the fixing belt 13 of the second fixing nip portion forming roller 15a or the fixing belt 13 has a weak adhesiveness, and the second fixing nip portion is weak. (N
In order to prevent the fixing belt 13 or the diameter of the fixing belt 13 from bulging to reduce the curvature (1 / radius) at the exit separating portion of 2), the separating roller is prevented from being deteriorated. The fixing belt 1 is applied by the tension applying means 12a.
3, or tension is applied in the direction in which the fixing belt 13 is stretched. However, the fixing belt 13 or the fixing belt 13
However, in order to wrap around the fixing member (not shown) of the second fixing nip portion forming means 15 and the second fixing nip portion forming roller 15a sufficiently closely, the fixing belt 13 or the inner peripheral surface of the fixing belt 13 should be used. A fixing member (not shown) of the second fixing nip portion forming means 15 or the second fixing nip portion forming roller 15
By reducing the frictional force between a and the fixing belt 13, or
It is necessary to increase the tension of the fixing belt 13.

As one of the methods, the fixing belt 13,
Alternatively, the contact surface between the inner peripheral surface of the fixing belt 13 and a fixing member (not shown) of the second fixing nip portion forming means 15 or the second fixing nip portion forming roller 15a is reduced to fix the fixing belt 1
3, or the wrapping angle of the second fixing nip portion forming means 15 of the fixing belt 13 around the fixing member (not shown) or the second fixing nip portion forming roller 15a may be reduced. On the contrary, when the conveyance roller 12 is arranged on the fixing belt 13 or on the upstream side with respect to the fixing belt 13, the fixing belt 13 or the fixing belt 13 or even if tension is applied to the fixing belt 13. The close wrapping property of the second fixing nip portion forming means 15 of the fixing belt 13 around the fixing member (not shown) or the second fixing nip portion forming roller 15a is not good. That is, the conveying roller 12 is in a direction substantially perpendicular to a fixing member (not shown) of the second fixing nip portion forming means 15 and the second fixing nip portion forming roller 15a, or a recording sheet of a sheet material (S). The fixing belt 13 or the second fixing nip portion forming means 15 of the fixing belt 13 is provided on the downstream side in the conveying direction of the arrow (A) direction in the figure.
Adhesiveness to the fixing member (not shown) and the second fixing nip portion forming roller 15a is good, and the occurrence of wrapping of the recording material of the sheet material (S) can be prevented more reliably. The fixing belt 13 or the tension of the fixing belt 13 for improving the adhesion is approximately 1 (kg / one side) to 3 (kg / one side).
It is desirable that the range is one side). Further, 1 (kg / one side) is preferable in terms of good adhesion, and 3 (kg / one side) or less is preferable in terms of preventing belt deformation due to tensile strength.

In FIG. 9 or 10, the fixing device 10 is used.
Is the second fixing formed by the second fixing nip portion forming roller 15a of the second fixing nip portion forming means 15 and the fixing belt 13 or the pressure roller 14 which is in pressure contact with the fixing belt 13 therebetween. The shape of the nip portion (N2) is a concave shape of a concave nip (see FIG. 9) formed in the direction in which the recording sheet of the sheet material (S) moves away from the pressure roller 14 or a substantially flat linear nip. The flat shape (see FIG. 10) prevents the recording sheet of the sheet material (S) from being wrapped around, and particularly, the fixing belt 13 or the fixing belt 13
A fixing belt 13 for preventing double-sided fixing by preventing the occurrence of wrapping around and the winding around the pressure roller 14,
Alternatively, the fixing device 10 including the fixing belt 13 can be provided. In the fixing device 10, at the time of one-sided fixing, if the diameter of the second fixing nip portion forming roller 15a of the second fixing nip portion forming means 15 is small at the outlet separating portion of the second fixing nip portion (N2). ,
The shape of the second fixing nip portion (N2) is the fixing belt 13,
Alternatively, the curvature separation is possible even in the concave shape of the concave nip formed in the direction in which the recording sheet of the sheet material (S) approaches the fixing belt 13. On the other hand, at the time of double-sided fixing, the concave shape of the concave nip or the flat shape of the straight nip of the substantially flat nip causes a curvature (a recording sheet of the sheet material (S) does not wind around the pressure roller 14 ( 1 / radius (r)) and the separation angle (θ1, θ2).

In FIG. 11, the fixing device 10 has a driving means 14d for rotating the pressure roller 14 having rigidity.
Also rotationally drives the fixing belt 13 or the second fixing nip portion forming roller 15a that stretches the fixing belt 13,
The fixing belt 13, or the fixing belt 13 and the pressure roller 1
The peripheral speeds of 4 are made equal. Particularly, a fixing nip portion (N) is generated between the fixing belt 13 or the fixing belt 13 and the pressure roller 14 due to a difference in peripheral speed due to the slip of the fixing belt 13 or the fixing belt 13.
It prevents the occurrence of image distortion inside. The driving means 14d
The rotational driving of the fixing belt 13 or the fixing belt 13 and the fixing roller 13 or the pressure roller 14 that presses the fixing belt 13 to form the fixing nip portion (N) is applied to each rotating body. By adding the fixing belt 13, it is possible to prevent the fixing belt 13 or the fixing belt 13 from slipping. Further, by setting the conditions such that the peripheral speed of the fixing belt 13 or the peripheral speed of the fixing belt 13 and the peripheral speed of the pressure roller 14 are substantially the same in the range where the image disturbance does not occur, for example, Fusing roller 1
By setting the diameter and the rotation speed of the first fixing nip portion forming roller 15a and the pressure roller 14 to be the same, it is possible to prevent the occurrence of image distortion.
3, or the fixing device 10 including the fixing belt 13 can be provided.

In FIG. 12, the fixing device 10 has a driving means 14d for rotationally driving the pressure roller 14 having rigidity.
Is the fixing belt 13 or the inner surface of the fixing belt 13, and the rigid conveying roller 12 having the tension applying means 12a is also rotationally driven to fix the fixing belt 13 or the fixing belt 13 and the pressure roller. The circumferential speeds of 14 are made equal. In particular, the fixing belt 13 or the fixing belt 13
The pressure roller 14 prevents the image disturbance in the fixing belt 13 or in the fixing nip portion (N) that occurs when a peripheral speed difference occurs including the slip of the fixing belt 13. By the driving means 14d, the fixing belt 13,
Or, the rotational driving of the fixing belt 13 and the fixing belt 13,
Alternatively, the fixing belt 13 or the fixing belt 13 is provided by applying rotational drive of the pressure roller 14 that presses against the fixing belt 13 to form a fixing nip portion to each rotating body.
It is possible to prevent the occurrence of slip. For example, the fixing belt 13 or the fixing belt 13 and the pressure roller 14 have substantially the same peripheral speed and a peripheral speed difference in a range where image disturbance does not occur. 13 or by setting the diameter and the number of rotations of the conveying roller 12 and the pressure roller 14 around which the fixing belt 13 is stretched to be the same, it becomes possible to prevent the occurrence of image distortion.
Further, the reason why the conveying roller 12 among the fixing belt 13 or each roller wound around the fixing belt 13 is driven by the driving means 14d is that, on the contrary, another roller, that is, the fixing belt 13 or It is preferable to use the fixing roller 11 formed of a fixing elastic body that is pressed against the fixing belt 13 to form the fixing nip portion (N) or the second fixing nip portion forming roller 15a as the driving roller. This is because it is not preferable because it is difficult to suppress the speed fluctuation, and the image to be formed is directly adversely affected.

In FIG. 13, the fixing device 10 includes a driving means 14d for rotatively driving the pressure roller 14 and a fixing belt 13, or a driving means 13a for rotatively driving the conveying roller 12 stretching the fixing belt 13. The belt drive control means 16a of the drive control means 16 makes the peripheral speeds of the fixing belt 13 or the fixing belt 13 and the pressure roller 14 equal to each other.
3 or the image disturbance in the fixing nip portion (N) that occurs in the state where the peripheral speed difference occurs between the fixing belt 13 and the pressure roller 14 including the fixing belt 13 or the slip of the fixing belt 13. It is designed to prevent the occurrence. Further, under the condition that the peripheral speed of the fixing belt 13 or the peripheral speed of the fixing belt 13 and the peripheral speed of the pressure roller 14 are substantially the same and there is a peripheral speed difference in a range where image disturbance does not occur, the drive control means 16 operates. The belt drive control means 16a drives the fixing belt 13 or the fixing belt 13 at a predetermined speed. The belt drive control means 16a of the drive control means 16 is preset by feeding back the speed read by the fixing belt 13 or the speed detecting means 16a ₁ for detecting the speed of the fixing belt 13, for example. compared computing speed value as a reference in the comparison operation unit 16a _2, the control given to the drive means 13a instructions for eliminating the difference between the readings to the reference value. In FIG. 14, the fixing device 10 includes the driving unit 14d that rotationally drives the pressure roller 14 and the driving unit 13a that rotationally drives the fixing belt 13 or the transport roller 12 that stretches the fixing belt 13. The fixing belt 1 is provided by the belt drive control means 16a and the pressure roller drive control means 16b of the drive control means 16.
3, or the fixing belt 13 and the pressure roller 14 are made to have the same peripheral speed, and in particular, the fixing belt 13 or
The fixing belt 1 is provided between the fixing belt 13 and the pressure roller 14.
3 or the occurrence of image disturbance in the fixing nip portion (N) that occurs when a peripheral speed difference occurs including the slip of the fixing belt 13 is prevented. Further, under the condition that the peripheral speed of the fixing belt 13 or the peripheral speed of the fixing belt 13 and the peripheral speed of the pressure roller 14 are substantially the same and there is a peripheral speed difference in a range where image disturbance does not occur, the drive control means 16 operates. The fixing belt 13 or the fixing belt 13 is controlled by the belt driving control means 16a and the pressure roller driving control means 16b.
Is controlled to a predetermined speed. The belt drive control means 16a and the pressure roller drive control means 16b of the drive control means 16 are, for example, the fixing belt 13 or the speed detection means 16a ₁ for detecting the speed of the fixing belt 13 and the pressure roller 14. The speed read by the speed detecting means 16b _{1 for} detecting the speed is fed back, and the reference speed value set in advance is compared with the comparison calculating means 16a ₂ and the comparison calculating means 16b ₂ to obtain the reference value. On the other hand, a control for giving a command for eliminating the difference between the read values to the driving means 13a and the driving means 14d is performed.

In FIG. 15, in the fixing device 10, the fixing roller 11 and the second fixing nip portion forming roller 15a have the same configuration and the same shape, and have substantially the same diameter and substantially the same surface hardness, and the fixing belt. 13, or the pressure applied to the pressure roller 14 via the fixing belt 13 is set to have substantially the same set value, and in particular, the fixing belt 13 or the fixing belt 13
The pressure roller 14 and the pressure roller 14 are configured to prevent the image disturbance in the fixing belt 13 or in the fixing nip that occurs in the state where the peripheral speed difference including the slip of the fixing belt 13 occurs. The first fixing nip portion (N1) and the second fixing nip portion (N2) have the same fixing conditions such as nip width, pressure, and temperature, and under the fixing condition, in the fixing nip portion (N). Since the speed fluctuation of is not likely to occur, the image is not disturbed. In the fixing device 10, the fixing belt 1
3 or the first fixing nip portion (N
The difference between the inlet temperature of 1) and the outlet temperature of the second fixing nip portion (N2) is about 5 ° C., and there is almost no difference. In FIG.
The fixing device 10 includes a pressure roller 14, a fixing belt 13,
Alternatively, either one of the fixing roller 11 and the second fixing nip portion forming roller 15a of the second fixing nip portion forming means 15 which are arranged in pressure contact with each other via the fixing belt 13 is illustrated. In the case of, the fixing roller 11 or the second fixing nip portion forming roller 15a has a crown shape in which the outer shape of the central portion in the longitudinal direction is larger than the outer shapes of both ends, and in the other case, the pressure roller 14 is reversed. By having a crown shape, the occurrence of wrapping of the recording material of the sheet material (S) is further reliably prevented. Sheet material (S)
When the sheet material (S) is separated, the sheet material (S) is deformed so as to follow the shapes of the second fixing nip portion forming roller 15a and the pressure roller 14, and the sheet material (S) is slightly bent, The bending rigidity of the sheet material (S) at the time of separation increases, the winding moment of the separation moment increases, and the occurrence of winding is prevented. Further, as another effect, the nip width of the separating portion can be made constant in the roller longitudinal direction, and it is possible to suppress the occurrence of image gloss unevenness caused by the uneven nip width.

In the fixing device 10 shown in FIG. 17, the second fixing nip portion forming roller 15a has a crown shape in which the outer shape of the central portion in the longitudinal direction having rigidity is larger than the outer shape of both ends, and the pressure roller 14 is used. Is a straight shape, and the sheet material (S) is used as the second fixing nip portion forming roller 15a and the pressure roller 14 when the recording sheet of the sheet material (S) is separated.
The sheet material (S) is deformed so as to conform to the shape of (1) and a slight elasticity is given to the sheet material (S). As a result, the bending rigidity of the sheet material (S) at the time of separation increases, the separation moment and the winding moment increase, and the occurrence of winding is further reliably prevented.
Only the second fixing nip portion forming roller 15a has a crown shape, which simplifies the structure. Pressure roller 14
Since it has an ordinary straight shape, the cost can be reduced. In FIG. 18, an image forming apparatus 20 that forms an image by transferring a toner image formed by using an electrophotographic method to a sheet material (S) of a transfer target and then fixing the image is rotatably held. A body 21, a charging unit 22 for charging the image carrier 21, and a latent image forming unit 2 for forming an electrostatic latent image on the image carrier 21 charged by the charging unit 22.
3, a developing means 24 for adhering toner (t) to the electrostatic latent image formed by the latent image forming means 23 to make it visible, and a toner image visualized by the developing means 24 for sheet material. The transfer device 25 transfers the image to (S) and the fixing device 10 that fixes the toner image formed on the sheet material (S) by the transfer device 25. It is also possible to prevent the occurrence and to form a high-quality high-speed color image at low cost. An image forming apparatus 20 equipped with a fixing device 10 is a 4-photoreceptor belt 1-pass type full-color image forming apparatus for a recording system of 4 image stations, and is illustrated with a sheet material (S) placed thereon. The image forming process means 50 is arranged along the rotation direction of the conveyance belt 26 that rotates in the counterclockwise conveyance direction indicated by the arrow (B). Between the fixing means 10 and the registration roller pair 28 of the paper feeding means 27, below the conveyor belt 26, the image forming process is performed in order from the upstream side in the rotating direction of the conveyor belt 26. As means 50, a first image station 51 is provided with an image forming process consisting of the cyan photoconductor belt 21a of the image carrier 21, and a second image station 52 is provided with the image carrier 2.
1, the image forming process of the magenta photoconductor belt 21b, the image forming process of the yellow photoconductor belt 21c of the image carrier 21 on the third image station 53, and the image carrying process of the fourth image station 54 on the fourth image station 54. The image forming process including the black photosensitive belt 21d of the body 21 is further provided with the fixing unit 10 and the like.

Focusing on the first image station 51, the image forming process is in accordance with a general electrostatic recording system, and the cyan of the charging means 22 arranged in the plurality of image forming areas in the dark is arranged. The cyan photoreceptor belt 21 of the image carrier 21 uniformly charged by the charger 22a.
An electrostatic latent image of a predetermined color is written on a by the cyan light writing unit 23a of the latent image forming means 23, and the electrostatic latent image is visualized by the cyan developing device 24a of the developing means 24, and the cyan image is formed. The toner image is transferred to the sheet material (S) conveyed by the conveyor belt 26 by the cyan transfer device 25a of the transfer means 25 arranged in the plurality of image forming areas 4, and the image bearing after transfer is performed. Residual toner adhering to the cyan photoconductor belt 21a of the body 21 is removed by the cyan cleaning means 29a of the cleaning means 29 arranged in the plurality of image forming areas to be prepared for the next step. Next, in the second image station 52, similarly, the image carrier 2 uniformly charged by the magenta charger 22b of the charging means 22 arranged in the plurality of image forming areas in the dark.
An electrostatic latent image of a predetermined color is written on the magenta photosensitive belt 21b of No. 1 by the magenta light writing unit 23b of the latent image forming means 23, and the electrostatic latent image is arranged in the plurality of image forming areas 4. Further, the magenta developing device 24b of the developing means 24 visualizes the magenta toner image, and the magenta toner image is transferred to the conveyor belt 26 by the magenta transfer device 25b of the transferring means 25 arranged in the plurality of image forming areas 4. Sheet material (S) that is placed and conveyed
After the transfer, the residual toner attached to the magenta photosensitive belt 21b of the image carrier 21 after the transfer is removed by the cleaning unit 2 arranged in the plurality of image forming areas.
It is removed by the cyan cleaning means 29a of No. 9 and is prepared for the next step.

Similarly, in the third image station 53, the image carrier 21 is uniformly charged by the yellow charger 22c of the charging means 20 arranged in the plurality of image forming areas in the dark. An electrostatic latent image of a predetermined color is written on the yellow photoconductor belt 21c by the yellow light writing unit 23c of the latent image forming means 23, and the electrostatic latent image is arranged in the plurality of image forming areas 4. The yellow toner image is visualized by the yellow-developing device 24c of the developing device 24, and the yellow toner image is transferred to the conveyor belt 26 by the yellow transferring device 25c of the transferring device 25 arranged in the plurality of image forming areas 4. Residual toner that is transferred to a sheet material (S) that is placed and conveyed and that is attached to the yellow photoconductor belt 21c that is the image carrier 21 after the transfer. Is adapted to be provided in the next step is removed by the yellow cleaning unit 29c of the cleaning means 29 disposed in the plurality of image forming region is.

In the fourth image station 54, similarly, the image carrier 21 is uniformly charged by the black charger 22d of the charging means 22 arranged in the plurality of image forming areas in the dark. An electrostatic latent image of a predetermined color is written on the black photoconductor belt 21d by the black light writing unit 23d of the latent image forming means 23, and the electrostatic latent image is developed in the plurality of image forming areas. The black developing device 24d of the means 24 visualizes the black toner image, and the black toner image is placed on the conveyor belt 26 by the black transferring device 25d of the transferring means 25 arranged in the plurality of image forming areas. The residual toner transferred to the conveyed sheet material (S) and adhered to the black photosensitive belt 21d which is the image carrier 21 after the transfer is Serial provided are removed by the cleaning means 29 disposed in a plurality of image forming region to the next step, by being sequentially superimposed transfer, so that the can to form a full color image. After the final transfer, the fixing unit 10 fixes the full-color toner image carried on the sheet material (S), which is placed and conveyed on the conveyor belt 26, to fix the full-color toner image on the sheet material (S). Get the final image. Therefore, the fixing device 10
In the fixing device 10, it is possible to prevent the sheet material (S) from wrapping around, to prevent the image disturbance of the abnormal image due to the speed fluctuation in the fixing nip, and to form a high-quality color image at a low cost. The image forming apparatus 20 including
Can be provided. Incidentally, the charging means 22 and the transfer means 2 in the image forming apparatus 20.
5, the cleaning means 29, etc.,
The configuration and materials are not particularly limited. For example, even in the case of cleaning-less, only the cleaning means 29 is deleted and the other concepts and configurations are the same.

[0035]

Since the present invention is configured as described above, according to the invention of claim 1, a surface layer of a high mold release material having a low surface energy and a soft heat resistant elastic material are provided in the intermediate layer. By lowering the surface hardness and improving the releasability, it is possible to prevent the occurrence of wrapping of the sheet material and provide a belt with high fixing quality. According to the invention of claim 2, the surface layer of the high mold release material having a low surface energy and the soft heat resistant elastic material are provided in the intermediate layer to prevent the sheet material from being wrapped around by improving the mold release property, and the amount of the paper dust attached It is now possible to provide belts with low fixing quality. According to the third aspect of the present invention, the surface layer of the high release material having a low surface energy and the soft heat resistant elastic material are provided in the intermediate layer to reduce the surface hardness and prevent the sheet material from being wrapped around by improving the release property. When used in a fixing device of an image forming apparatus, it is possible to provide a belt with high fixing quality and low cost. According to the invention of claim 4, the surface layer of the high mold release material having a low surface energy and the soft heat resistant elastic material are provided in the intermediate layer to reduce the surface hardness to prevent the sheet material from being wrapped around by improving the mold release property. When used in a fixing device of an image forming apparatus, it is possible to provide a low-cost belt that prevents lateral stripes in a formed image after fixing and has high fixing quality. According to the invention of claim 5, the surface layer of the high mold release material having a low surface energy and the soft heat resistant elastic material are provided in the intermediate layer to reduce the surface hardness to prevent the sheet material from being wound around by improving the mold release property. When used in the fixing device of the image forming apparatus, the unfixed image is uniformly fixed, there is no partial gloss unevenness like satin or citron skin, the fixing temperature has speed followability, and the temperature during continuous paper feeding is high. It is now possible to provide a belt with high fixing quality without deterioration.

According to the invention of claim 6, the surface layer of the high mold release material having a low surface energy and the soft heat resistant elastic material are provided in the intermediate layer to reduce the surface hardness to improve the mold release property and thereby the wrapping of the sheet material occurs. When used in the fixing device of the image forming apparatus, the unfixed image is uniformly fixed, there is no partial gloss unevenness like satin or citron skin, and there is a speed followability of the fixing temperature during continuous paper feeding. It is now possible to provide a belt with high fixing quality without lowering the temperature. According to the invention of claim 7, the surface layer of the high release material having a low surface energy and the soft heat resistant elastic material are provided in the intermediate layer to reduce the surface hardness to further improve the release property, thereby further preventing the occurrence of wrapping of the sheet material. If it is used in a fixing device of an image forming apparatus, oilless double-sided fixing without image stains caused by the adherence of offset toner or paper dust is possible, and durability that can withstand repeated bending operation due to rotation is also improved, and abrasion resistance It is now possible to provide a belt that is excellent in surface roughness accuracy, has a good image surface gloss, and has a high fixing quality.
According to the invention of claim 8, the durability is excellent due to the curvature separation without using a coating material or a separating claw, so that the sheet material is reliably prevented from being wound, the fixing temperature is stable, and the fixing nip width is expanded. As a result, it is possible to provide a fixing device equipped with a small belt at a low cost, which has a high fixing speed and suppresses the speed fluctuation in the fixing nip. According to the invention of claim 9, the durability is further excellent by the curvature separation without using a coating material, a separating claw, etc., and the occurrence of wrapping of the sheet material is further reliably prevented, and the fixing temperature is further stable, and the fixing nip width. Therefore, it has become possible to provide a fixing device equipped with a small belt at a lower cost, in which the fixing speed is further increased and the speed fluctuation in the fixing nip is suppressed. According to the invention of claim 10, the durability is excellent due to the curvature separation without using a coating material, a separating claw, etc., and the occurrence of winding of the sheet material is further reliably prevented, the fixing temperature is stable, and the fixing nip width is expanded. As a result, it is possible to provide a fixing device equipped with a small belt at a low cost, which has a higher fixing speed and further suppresses speed fluctuations in the fixing nip.

According to the eleventh aspect of the present invention, the durability is excellent due to the curvature separation without using a coating material, a separating claw or the like, and the sheet material is more reliably prevented from being wrapped around, so that the fixing temperature is stable and the fixing nip is stable. It has become possible to provide a fixing device equipped with a low-cost and small belt in which the width is expanded, the fixing speed is further increased, and the speed fluctuation in the fixing nip is further suppressed. According to the invention of claim 12, the durability is excellent due to the curvature separation without using a coating material or a separating claw, so that the sheet material is more reliably prevented from being wound, the fixing temperature is stable, and the fixing nip width is expanded. As a result, it is possible to provide a fixing device equipped with a small belt at a low cost, which has a high fixing speed and suppresses the speed fluctuation in the fixing nip. According to the invention of claim 13, the second fixing belt is provided.
Adhesion to the fixing nip forming means is good, there is no belt deformation due to tensile strength, and durability is excellent due to curvature separation without the use of coating materials or separation claws, and the occurrence of wrapping of the sheet material is further reliably prevented. Thus, it has become possible to provide a fixing device equipped with a small belt at a low cost, which has a stable fixing temperature, a wide fixing nip width, a high fixing speed, and a speed variation in the fixing nip is suppressed. Claim 1
According to the invention of 4, the adhesion of the fixing belt to the second fixing nip portion forming means is good, and the durability is excellent due to the curvature separation without using a coating material, separation claws, etc. Further, it is possible to provide a fixing device equipped with a small belt at a low cost, which is further surely prevented, the fixing temperature is stable, the fixing nip width is expanded, the fixing speed is high, and the speed fluctuation in the fixing nip is suppressed. It became so. Claim 1
According to the fifth aspect of the invention, the durability is excellent due to the curvature separation without using a coating material or a separating claw, so that the sheet material is reliably prevented from being wrapped around, the fixing temperature is stable, and the fixing nip width is widened and fixed. It is possible to provide a fixing device equipped with a small belt, which has a high speed, further suppresses the speed fluctuation in the fixing nip, prevents the occurrence of abnormal images, has a small amount of paper dust adhesion, and is low in cost. It was

According to the sixteenth aspect of the present invention, the durability is excellent due to the curvature separation without using a coating material, a separating claw, etc., and the sheet material is more reliably prevented from being wrapped around, and the fixing temperature is stable, and the fixing nip is stable. It has become possible to provide a fixing device equipped with a low-cost and small belt in which the width is expanded, the fixing speed is high, and the speed fluctuation in the fixing nip is suppressed. According to the seventeenth aspect of the invention, it is possible to perform oilless double-sided fixing without image stains caused by the adherence of offset toner or paper dust, and excellent durability due to curvature separation without using a coating material or separation claws. To provide a fixing device equipped with a low-cost and small belt in which the fixing temperature is stable, the fixing nip width is widened, the fixing speed is high, and the speed fluctuation in the fixing nip is suppressed. I was able to do it. According to the eighteenth aspect of the present invention, it is possible to prevent the image quality from being deteriorated, and the durability is excellent due to the curvature separation without using a coating material, a separation claw, or the like, and the occurrence of wrapping of the sheet material is further reliably prevented and fixed. It has become possible to provide a fixing device equipped with a small belt that is stable in temperature, the fixing nip width is widened, the fixing speed is high, and speed fluctuations in the fixing nip are suppressed, and that is small in cost.
According to the invention of claim 19, the durability is excellent due to the curvature separation without the use of a coating material, separation claws or the like, and the occurrence of wrapping of the sheet material is further reliably prevented, the fixing temperature is stable, and the fixing nip width is expanded. As a result, it is possible to provide a fixing device equipped with a small belt at a low cost, which has a high fixing speed and further suppresses the speed fluctuation in the fixing nip. According to the invention of claim 20, the number of parts is small, the durability is excellent by the curvature separation without using a coating material, separation claws and the like, and the occurrence of wrapping of the sheet material is further reliably prevented, and the fixing temperature is stable. It has become possible to provide a fixing device equipped with a belt of a smaller size and a lower cost, in which the fixing nip width is expanded, the fixing speed is high, and the speed fluctuation in the fixing nip is further suppressed.

According to the twenty-first aspect of the present invention, the durability is excellent by the curvature separation without using a coating material, a separating claw, etc., and the sheet material is more reliably prevented from wrapping, so that the fixing temperature is stable and the fixing nip is stable. It has become possible to provide a fixing device equipped with a small belt at a low cost in which the width is expanded, the fixing speed is high, and the speed fluctuation in the fixing nip is further suppressed. According to the invention of claim 22, double-sided fixing is also possible, and the durability is excellent due to the curvature separation without using a coating material, separation claws, etc., and the occurrence of wrapping of the sheet material is further reliably prevented, and the fixing temperature is increased. It has become possible to provide a fixing device including a small belt that is stable, has a wide fixing nip width, has a high fixing speed, and suppresses speed fluctuations in the fixing nip. According to the invention of claim 23, the occurrence of image distortion is prevented, the durability is excellent by the curvature separation without using a coating material, separation claws, etc., and the occurrence of wrapping of the sheet material is further reliably prevented and fixed. It has become possible to provide a fixing device equipped with a small belt which is stable in temperature, the fixing nip width is widened, the fixing speed is high, and the speed fluctuation in the fixing nip is further suppressed, at a low cost. According to the invention of claim 24, the occurrence of image distortion is prevented, and the durability is excellent by the curvature separation without using a coating material, separation claws, etc., and the occurrence of wrapping of the sheet material is further reliably prevented and fixed. It has become possible to provide a fixing device equipped with a small belt which is stable in temperature, the fixing nip width is widened, the fixing speed is high, and the speed fluctuation in the fixing nip is further suppressed, at a low cost. According to the invention of claim 25, the occurrence of image distortion is prevented, the durability is excellent by the curvature separation without using a coating material, separation claws, etc., and the occurrence of wrapping of the sheet material is further reliably prevented and fixed. It has become possible to provide a fixing device equipped with a small belt which is stable in temperature, the fixing nip width is widened, the fixing speed is high, and the speed fluctuation in the fixing nip is further suppressed, at a low cost. According to the invention of claim 26, the occurrence of image distortion is prevented, the durability is excellent due to the curvature separation without using a coating material, separation claws, etc., and the occurrence of wrapping of the sheet material is further reliably prevented and fixed. It has become possible to provide a fixing device equipped with a small belt that is stable in temperature, the fixing nip width is widened, the fixing speed is high, and the speed fluctuation in the fixing nip is further suppressed, at a low cost.

According to the twenty-seventh aspect of the present invention, the occurrence of image distortion is prevented, and the durability is excellent by the curvature separation without the use of a coating material or separation claws, and the occurrence of wrapping of the sheet material is more reliably prevented. Thus, it is possible to provide a fixing device equipped with a small belt at a low cost, in which the fixing temperature is more stable, the fixing nip width is expanded, the fixing speed is high, and the speed fluctuation in the fixing nip is further suppressed. became. Claim 29
According to the invention, the occurrence of image gloss unevenness is suppressed, the durability is excellent due to the curvature separation without the use of a coating material or separating claws, etc., and the occurrence of sheet material wrapping is further reliably prevented, and the fixing temperature is stable. Thus, it has become possible to provide a fixing device equipped with a small belt which is low in cost, in which the fixing nip width is expanded, the fixing speed is high, and the speed fluctuation in the fixing nip is suppressed. According to the invention of claim 30, image gloss unevenness is generated, and the durability is excellent by curvature separation without using a coating material, separation claws or the like, and the occurrence of wrapping of the sheet material is further reliably prevented and fixed. It has become possible to provide a fixing device equipped with a small belt that is stable in temperature, the fixing nip width is widened, the fixing speed is high, and speed fluctuations in the fixing nip are suppressed, and that is small in cost. According to the invention of claim 31, the durability is excellent by the curvature separation without using a coating material or separation claws, and the occurrence of sheet material wrapping is further reliably prevented, the fixing temperature is stable, and the fixing nip width is expanded. As a result, it is possible to provide a fixing device equipped with a small belt which has a high fixing speed and further suppresses the speed fluctuation in the fixing nip, and which has a small cost. According to the thirty-second aspect of the invention, there is provided an image forming apparatus including a fixing device capable of preventing the occurrence of the image disturbance of the abnormal image due to the speed fluctuation in the fixing nip and forming the high-quality color image at a low cost. It is now possible to provide.

[Brief description of drawings]

FIG. 1 is a partially enlarged view illustrating a main part of a belt according to an exemplary embodiment of the present invention.

FIG. 2 is a graph showing characteristics of turbidity (%) and surface hardness (degree) of a belt showing an embodiment of the present invention.

FIG. 3 is an enlarged view illustrating a state of another main portion of the belt according to the embodiment of the present invention.

FIG. 4 is an explanatory diagram illustrating a main part of a fixing device including a fixing belt or a fixing belt including the fixing belt according to an exemplary embodiment of the present invention.

FIG. 5 is a second fixing device including a fixing belt or a fixing belt including the fixing belt according to an embodiment of the present invention.
FIG. 3 is a graph diagram illustrating characteristics of a second nip portion forming roller of the fixing nip portion forming unit, winding occurrence temperature (° C.), and speed (mm / s).

FIG. 6 is an explanatory diagram illustrating another main part of the fixing device including the fixing belt or the fixing belt including the fixing belt according to the embodiment of the present invention.

FIG. 7 is an explanatory diagram illustrating a main part of a fixing belt including a fixing belt or a fixing belt including the fixing belt according to another exemplary embodiment of the present invention.

FIG. 8 is an explanatory diagram illustrating a main part of a fixing belt including a fixing belt or a fixing belt including the fixing belt according to another exemplary embodiment of the present invention.

FIG. 9 is an explanatory diagram illustrating another main part of the fixing device including the fixing belt or the fixing belt including the fixing belt according to the embodiment of the invention.

FIG. 10 is an explanatory diagram illustrating a main part of a fixing belt including a fixing belt or a fixing belt including the fixing belt according to another exemplary embodiment of the present invention.

FIG. 11 is an explanatory diagram illustrating a main portion of a fixing belt including a fixing belt or a fixing belt including the fixing belt according to another exemplary embodiment of the present invention.

FIG. 12 is an explanatory diagram illustrating a main part of a fixing belt including a fixing belt or a fixing belt including the fixing belt according to another exemplary embodiment of the present invention.

FIG. 13 is an explanatory diagram illustrating a main portion of a fixing belt including a fixing belt or a fixing belt including the fixing belt according to another exemplary embodiment of the present invention.

FIG. 14 is an explanatory diagram illustrating a main part of a fixing belt including a fixing belt or a fixing belt including the fixing belt according to another exemplary embodiment of the present invention.

FIG. 15 is an explanatory diagram illustrating a main part of a fixing belt including a fixing belt or a fixing belt including the fixing belt according to another exemplary embodiment of the present invention.

FIG. 16 is an explanatory diagram illustrating a main part of a fixing belt including a fixing belt or a fixing belt including the fixing belt according to another exemplary embodiment of the present invention.

FIG. 17 is an explanatory diagram illustrating a main portion of a fixing belt including a fixing belt or a fixing belt including the fixing belt according to another exemplary embodiment of the present invention.

FIG. 18 is an explanatory diagram illustrating an image forming apparatus including a fixing device according to an exemplary embodiment of the present invention.

FIG. 19 is an explanatory diagram illustrating a main part of a conventional fixing device.

FIG. 20 is an enlarged view illustrating a main part of a conventional fixing belt.

FIG. 21 is an enlarged view illustrating a main part of a conventional pressure roller.

[Explanation of symbols]

0 belt 1 base body, 1a sheet-shaped thin plate-shaped member, 1b end portion,
1c Other end part, 1d Bonding part 2 Intermediate layer 3 Surface layer 10 Fixing device 11 Fixing roller, 11a Core metal 12 Conveying roller, 12a Tension applying means, 12b Heating means 13 Fixing belt, 13a Driving means 14, Pressure roller, 14a Core metal , 14b Intermediate layer, 1
4c surface layer, 14d drive means, 14e heating means 15 second fixing nip portion forming means, 15a second fixing nip portion forming roller 16 drive control means, 16a belt drive control means, 1a
6a ₁ speed detection means, 16a ₂ comparison calculation means, 16a
b pressure lower drive control means, 16b ₁ speed detection means, 16b ₂ comparison calculation means 20 image forming apparatus 21 image carrier, 21a cyan photosensitive belt, 21b
Magenta photoconductor belt, 21c yellow photoconductor belt, 21d black photoconductor belt 22 charging means, 22a cyan charger, 22b magenta charger, 22c yellow charger, 22d black charger 23 latent image forming means, 23a cyan light writing unit , 23b magenta light writing unit, 23c yellow light writing unit, 23d black light writing unit 24 developing means, 24a cyan developing device, 24b magenta developing device, 24c yellow developing device, 24d black developing device 25 transfer means, 25a cyan transferring device, 25b Magenta transfer device, 25c Yellow transfer device, 25d Black transfer device 26 Conveyor belt 27 Paper feeding means 28 Registration roller pair 29 Cleaning means, 29a Cyan cleaning means, 29b Magenta cleaning means, 2 c Yellow cleaning means, 29d Black cleaning means 50 Image forming process means 51 First image station 52 Second image station 53 Third image station 54 Fourth image station 110 Fixing device 111 Fixing roller 111a Core bar 112 Conveying roller , 112b heating means 113 belt, 113a substrate, 113c surface layer 114 pressure roller, 114a core metal, 114c surface layer

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kiyoshi Oshima             1-3-3 Nakamagome, Ota-ku, Tokyo Stocks             Company Ricoh (72) Inventor Jun Yura             1-3-3 Nakamagome, Ota-ku, Tokyo Stocks             Company Ricoh (72) Inventor Satoshi Baba             1-3-3 Nakamagome, Ota-ku, Tokyo Stocks             Company Ricoh (72) Inventor Takashi Fujita             1-3-3 Nakamagome, Ota-ku, Tokyo Stocks             Company Ricoh (72) Inventor Hirokazu Ikegami             1-3-3 Nakamagome, Ota-ku, Tokyo Stocks             Company Ricoh F term (reference) 2H033 AA09 AA25 BA11 BA25 BA30                       BB03 BB04 BB06 BB18 BB29                       BB30 BB33 BB34 BB37 BB39                       CA04 CA07 CA13 CA30 CA36                 2H072 CA05 JA03 JC02 JC06                 3F024 AA07 BA05 CA04 CA08                 3F049 BA12 DA04 LA02 LA05 LA07                       LB03

Claims (32)

[Claims] 1. A belt for carrying and transporting a sheet material to be heated or pressed, a substrate, an intermediate layer made of a heat-resistant elastic material having a hardness of 30 degrees or less as measured by a JIS-A hardness meter, and a fluororesin material. A belt characterized by comprising a surface layer made of. 2. The belt according to claim 1, wherein the surface hardness is 70 degrees or more as measured by a JIS-A hardness meter. 3. The belt according to claim 1 or 2, wherein the base body is composed of a joint portion in which an end portion of the sheet-shaped thin plate-shaped member and both end portions of the other end portion are joined. 4. The belt according to claim 3, wherein the step difference between the ends of the sheet-shaped thin plate-shaped member at the joint and the other end of the joined portion is 1/10 of the thickness of the sheet-shaped thin-plate-shaped member. A belt characterized in that: 5. The belt according to claim 1, 2, 3 or 4, wherein the rubber of the heat resistant elastic material of the intermediate layer has a thickness of 100.
A belt having a size of from μm to 300 μm. 6. The belt according to claim 1, 2, 3, 4 or 5, wherein the surface layer has a thickness of a fluororesin material of 5 μm.
A belt having a thickness of 30 to 30 μm. 7. The belt according to claim 1, 2, 3, 4, 5 or 6, wherein the surface layer is coated with a fluororesin tube material. 8. A fixing device for heating and fixing an object to be heated on a conveyed sheet material with a fixing belt, and a fixing roller rotatably supported, and a conveying roller rotatably supported by the fixing roller to generate heat. A fixing belt which is stretched and rotated around the fixing belt; a pressure roller which heats and drives to form a first fixing nip portion on the upstream side of a sheet material which is pressed through the fixing belt and conveyed with the fixing roller; A second fixing nip portion that forms a second fixing nip portion that continuously enlarges the fixing nip width on the fixing belt between the pressure roller and the first fixing nip portion. A fixing device comprising a forming unit. 9. The fixing device according to claim 8, wherein the fixing belt is the belt according to any one of claims 1 to 7. 10. The fixing device according to claim 8 or 9, wherein the first fixing nip portion has a larger pressing force than the second fixing nip portion. 11. The fixing device according to claim 8, 9 or 10, wherein the fixing roller has a curvature smaller than that of the second fixing nip portion forming means. 12. The fixing device according to claim 8, 9, 10 or 11, wherein the conveying roller is provided on the inner peripheral surface of the fixing belt and includes a tension applying means for applying tension to the fixing belt. And fixing device. 13. The fixing device according to claim 12, wherein the tension applying means has a fixing belt tension of 1 (kg /
A fixing device, characterized in that it is not less than one side) and not more than 3 (kg / one side). 14. The fixing device according to claim 8, 9, 10, 11, 12 or 13, wherein the conveying roller is downstream from a direction perpendicular to the second fixing nip portion forming means or a sheet material conveying direction. A fixing device characterized by being arranged on the side. 15. The fixing device according to claim 8, wherein the pressure roller has a surface hardness of JIS.
A fixing device having a hardness of 70 degrees or more as measured by a hardness meter A. 16. The fixing device according to claim 8, wherein the pressure roller includes a core metal, an intermediate layer made of a heat resistant elastic material, and a surface layer made of a fluorine resin material. Characterizing fixing device. 17. The fixing device according to claim 16, wherein the surface layer made of a fluorine resin material is made of a fluorine resin tube material. 18. The fixing device according to claim 8, wherein the pressure roller has a rubber made of a heat resistant elastic material having a thickness of 0.5 mm or more and a hardness of JIS-A. And an intermediate layer of 30 degrees or less and a thickness of 5 μm to 30
A fixing device comprising a surface layer made of a fluorine resin layer of μm. 19. The fixing device according to claim 8, wherein the second nip portion forming means forms a second nip portion which is rotatably supported by stretching the fixing belt. A fixing device characterized by being a roller. 20. The fixing device according to claim 19, wherein the second nip portion forming roller also serves as a conveying roller. 21. The fixing device according to claim 19, wherein the second nip portion forming roller has a diameter of 10 m.
A fixing device having a length of m or more and 20 mm or less. 22. The fixing device according to claim 8, wherein the second fixing nip portion is formed by a second nip portion forming unit and a pressure roller that applies pressure via a fixing belt. The fixing device has a flat shape or a concave shape in the conveying direction of the sheet material conveyed from the pressure roller. 23. The fixing device according to claim 19, wherein the driving unit that rotationally drives the pressure roller also rotationally drives the second fixing nip portion forming roller to form a fixing belt. A fixing device characterized in that the peripheral speeds of the pressure rollers are equalized. 24. The fixing device according to claim 8, wherein the driving unit that rotationally drives the pressure roller also rotationally drives the conveying roller, and the peripheral speeds of the fixing belt and the pressure roller. The fixing device is characterized in that 25. The fixing device according to claim 8, further comprising: a driving unit that rotationally drives the pressure roller, a driving unit that rotationally drives a conveying roller that stretches the fixing belt, and the fixing unit. A fixing device comprising drive control means for making the peripheral speeds of the belt and the pressure roller equal. 26. The fixing device according to claim 8, wherein a drive control unit that adjusts a rotation speed of a drive unit that rotationally drives the pressure roller, and a conveyance roller that stretches the fixing belt. And a drive control unit that adjusts the rotation speed of a drive unit that rotationally drives the fixing device, and the fixing belt and the pressure roller have the same peripheral speed. 27. Claims 19, 20, 21, 22, 2
The fixing device described in 3, 24, 25, or 26 is characterized in that the fixing roller and the second fixing nip portion forming roller have the same configuration and the same shape. 28. Claims 19, 20, 21, 22, 2
In the fixing device described in 3, 24, 25, 26 or 27, the fixing roller and the second fixing nip portion forming roller have the same diameter, the same surface hardness, and the same pressing force as the pressure roller through the fixing belt. A fixing device characterized by the above. 29. The fixing device according to claim 8, wherein any one of a pressure roller formed by pressing the fixing roller and a fixing belt so as to face each other via a fixing belt is a crown. A fixing device having a shape and the other being an inverted crown shape. 30. The fixing device according to claim 19, wherein the second fixing nip portion forming roller faces the second fixing nip portion forming roller and is pressed against the second fixing nip portion forming roller. A fixing device, wherein one of them has a crown shape and the other has an inverted crown shape. 31. The fixing device according to any one of claims 19 to 28, wherein the second fixing nip portion forming roller has a rigid crown shape and the pressure roller has a straight shape. Fixing device. 32. In an image forming apparatus for forming an image by transferring a toner image formed by using an electrophotographic method to a transfer target, and fixing the image, a rotatable image carrier and the image carrier. Charging means for charging the body, latent image forming means for forming an electrostatic latent image on the image carrier charged by the charging means, and toner adhered to the electrostatic latent image formed by the latent image forming means 9. A developing means for developing the toner image by means of the above, a transferring means for transferring the toner image visualized by the developing means onto a sheet material, and a toner image formed on the sheet material by the transferring means. 32. An image forming apparatus comprising the fixing device according to any one of 1 to 31.