JPH1124458A - Fixing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fixing device where effects such as the improvement of the laying unevenness of a belt and a roll and the increase of frictional resistance are obtained and the bias of the belt is surely prevented by using the roll coated with an elastic body as the roll straightening the bias of the belt even in the case of applying lubricant on the inner surface of the belt. SOLUTION: An endless belt laid over by plural rolls is brought into press- contact with the surface of a fixing member, and a transfer material carrying an unfixed toner image at a press-contact part between the fixing member and the endless belt passes, so that fixing processing is performed at the fixing device. In this case, an elastic body layer is applied to the surface of at least one roll out of the plural rolls laying over the endless belt, and also unevenness 24 is formed on the surface of the elastic body layer 23.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing device used in an image forming apparatus such as an electrophotographic copying machine or a printer, and more particularly to a technique for preventing a belt from shifting in a fixing device using an endless belt.

[0002]

2. Description of the Related Art Recently, a so-called belt nip type fixing device in which an endless belt is stretched around a heating roll as a fixing device suitable for a high-speed, high-quality color electrophotographic copying machine or the like has been proposed by the present applicant. (Japanese Unexamined Patent Application Publication No.
-262903 and JP-A-9-34291).

In this belt nip type fixing device, for example, as shown in FIG. 31, an endless belt 104 stretched between a plurality of rolls 101, 102 and 103 is brought into pressure contact with the surface of a heat fixing roll 100, and By pressing from the inside of the endless belt 104 with a pressing member 105 as shown in FIG. 32, the nip width and the pressing force between the heat fixing roll 100 and the endless belt 104 are sufficiently ensured, and the heat fixing roll 100
By rotating the endless belt 104 at a high speed, a high-speed and high-quality color image can be fixed.

However, in such a belt nip type fixing device, a plurality of rolls 101, 102, 1
The endless belt 104 stretched between the rollers 03 rotates at a high speed while being pressed against the surface of the heat fixing roll 100 by the pressing member 105. Therefore, the pressing member 1
As shown in FIG. 33, the wear object 106 partially adheres to the inner surface of the endless belt 104 and the surfaces of the stretching rolls 101, 102, and 103 as a thin film due to the wear of the endless belt 104.
Due to variations in the sliding resistance of the belt 104 in the axial direction and the frictional resistance between the steering roll 12 and the belt 104, the endless belt 104
2, 103 "Belt offset" occurs, in which one side rotates in one direction. As described above, when “belt shift” occurs in the endless belt 104, the end of the endless belt 104 comes into contact with another member and is worn, and there is a possibility that the end of the endless belt 104 may be damaged. Has problems.

Therefore, as a means for preventing the belt bias of the fixing device using such an endless belt and the damage of the belt due to the belt bias, a roll for stretching the endless belt is formed in a drum shape. In this case, it is considered that in this case, by combining the elastic belt and the drum-shaped roll, the belt bias is prevented by utilizing the change in the tension of the elastic belt, so that heat resistance and heat In the fixing device using an inelastic belt such as a polyimide film, the effect of preventing the belt from being shifted cannot be obtained from the viewpoint of the superiority of the characteristics.

Further, as a method of correcting the deviation of the belt, a method of providing an edge guide at the end of the roll, a method of providing a rib at the end of the belt, and the like can be cited. In a fixing device that needs to press the belt against the heating roll to obtain sufficient fixing pressure, the load on the belt increases, and the end of the belt may be damaged or special processing may be applied to the end of the belt. , A new problem arises in that the cost is greatly increased.

In order to prevent the belt from shifting without causing such a problem, Japanese Patent Application Laid-Open Nos. 54-69442, 3-238247, and 7-2
As disclosed in JP 19364 and JP-A-8-262903, as shown in FIGS.
In a fixing device or an image forming apparatus using a belt to which a load is applied, one of the rolls on which the belt is stretched is axially moved to correct the deviation of the belt if it is so-called active. A steering method has been proposed.

The copying machine disclosed in Japanese Patent Application Laid-Open No. 54-69442 relates to the prevention of meandering of an endless belt-like photosensitive member. The meandering of the endless belt-like photosensitive member of the copying machine is controlled by swinging rollers. An electric detecting means for detecting the deviation of the belt, a means for horizontally rotating a control roller for controlling the deviation of the belt, and an endless belt-shaped photosensitive member which is moved to the moving means by a signal from the detecting means. And an electric control circuit that outputs an output signal for a longer time than required for the circumference.

Further, in the belt shift correcting device according to Japanese Patent Application Laid-Open No. 3-238247, an endless belt is stretched over at least two or more rollers, and one of the rollers is connected to the endless belt. The endless belt is supported by a bracket which is rotatable in a direction in which the endless belt is stretched, and the bracket applies tension to the endless belt. It is configured to be urged by an urging member in the direction.

Further, the image fixing apparatus according to the above-mentioned Japanese Patent Application Laid-Open No. 8-262903 is based on the proposal of the present applicant. It is disclosed that by displacing the two rolls, the belt can be prevented from being shifted.

[0011]

However, the prior art described above has the following problems. That is, Japanese Patent Application Laid-Open No. Sho 54-69442 and
JP-A-238247 and JP-A-8-262903.
In a fixing device using a belt to which a load is applied, a so-called active steering system in which one of the rolls stretching the belt is axially moved, as disclosed in As described above, when a belt made of an inelastic body is used as the endless belt, and the roll for stretching the endless belt is formed of a metal member, the flatness of the endless belt is reduced in the manufacture of the endless belt. 39 cannot be prevented from occurring, and if the endless belt has unevenness in flatness or undulation, FIG.
As shown in FIG.
However, there is a problem that the belt 104 cannot be effectively prevented from biasing even if the roll 102 on which the belt 104 is stretched is axially moved even when the roller 102 does not contact uniformly along the axial direction.

Further, as disclosed in Japanese Patent Application Laid-Open No. Sho 54-69442, a roll coated with an elastic body is used as a roll for correcting the deviation of the belt. It is also conceivable to improve the friction and increase the frictional resistance.

However, in the belt nip type fixing device, in order to improve the fixing property, as shown in FIG. 31, a pressing member 105 as shown in FIG. It is necessary to press, and a new problem arises in that the belt is biased due to non-uniformity of contact friction (see FIG. 33) due to friction between the pressure contact member 105 and the belt 104.

In order to solve such a problem, a roll coated with an elastic body is used as a roll for correcting the deviation of the belt, and wear and sliding resistance of the belt and the pressing member are reduced. For this reason, Japanese Patent Application Laid-Open Nos. 8-262903 and 9-3429, which are proposed by the present applicant, are disclosed.
37 and FIG. 38, as disclosed in
As shown in (1), applying the lubricant to the inner surface of the belt 104 by an application member 108 made of felt or the like has already been proposed by the present applicant.

However, as disclosed in JP-A-8-262903 and JP-A-9-34291, when a lubricant is applied to the inner surface of the belt, the steering roll is affected by the lubricant. 102 and belt 10
4, the contact resistance of the endless belt 104
By using a roll coated with an elastic body as the roll 102 for correcting the deviation of the belt, the effect of improving the stretch unevenness of the belt and the roll and increasing the frictional resistance is not obtained, and the endless endless belt made of an inelastic body is used. Belt 104
When the belt is stretched over a roll, as shown in FIG. 39, the belt 104 cannot be stretched (contacted) evenly due to waving or undulation of the belt 104, and there is a possibility that the belt may be damaged due to poor correction of the deviation of the belt. There was a problem that there is. Further, a polyimide film or the like which is a hard member and has excellent heat resistance is used as a base material of the endless belt 104, and FIG.
As shown in FIG. 4, when the meandering control is performed with tension applied to the belt 104, the belt 104 is rolled at the edge of the end of the belt 104 as shown in FIGS.
There is a problem that the elastic body 102a on the surface 02 wears and is worn away, causing new fixing dirt and belt deviation due to abrasion powder.

In view of the above, the present invention has been made to solve the above-mentioned problems of the prior art, and an object thereof is to solve the problem even when a lubricant is applied to the inner surface of the belt.
By using a roll coated with an elastic body as a roll that corrects the belt bias, it is possible to obtain the effects of improving the stretch unevenness between the belt and the roll and increasing the frictional resistance, and ensuring the belt bias. It is another object of the present invention to provide a fixing device that can prevent the above problem.

It is another object of the present invention to effectively reduce the abrasion of the elastic material on the roll surface even when a hard member made of a polyimide film having excellent heat resistance is used as the base material of the endless belt. It is an object of the present invention to provide a fixing device capable of reliably preventing fixing dirt and new belt deviation due to abrasion powder.

[0018]

According to the first aspect of the present invention, an endless belt stretched by a plurality of rolls is brought into pressure contact with the surface of a fixing member, and the endless belt is brought into pressure contact with the fixing member. In a fixing device that performs a fixing process by passing a transfer material carrying an unfixed toner image through a portion, an elastic layer is formed on a surface of at least one of a plurality of rolls on which the endless belt is stretched. In addition to coating, the surface of the elastic layer is formed with irregularities.

According to a second aspect of the present invention, an endless belt stretched by a plurality of rolls is pressed against the surface of the heat fixing roll by being pressed from the inside of the endless belt by a pressing member. By applying a lubricant to the inner surface of the endless belt and tilting the rotation axis of one of the plurality of rolls stretching the endless belt to correct the bias of the endless belt. In the fixing device configured as described above, the surface of the steering roll is covered with an elastic layer, and irregularities are formed on the surface of the elastic layer.

Further, according to a third aspect of the present invention, the unevenness formed on the surface of the elastic layer comprises a groove formed in the elastic layer. Fixing device.

According to a fourth aspect of the present invention, the unevenness formed on the surface of the elastic layer is formed of minute unevenness formed by roughening the surface of the elastic layer. The fixing device according to claim 1, wherein the fixing device is a fixing device.

Further, in the invention described in claim 5, the elastic layer covering the surface of at least one of the plurality of rolls stretching the endless belt contacts the end of the endless belt. The coating width of the elastic body layer is set to be narrower than an end portion of the endless belt in consideration of the deviation of the endless belt so as not to cause the offset.
The fixing device according to any one of the above.

According to a sixth aspect of the present invention, an end of the endless belt is provided at an end of the elastic layer covering the surface of at least one of the plurality of rolls on which the endless belt is stretched. The fixing device according to any one of claims 1 to 4, wherein a wear-resistant coating layer is provided over a range where the portions contact.

[0024]

According to the first aspect of the present invention, at least one of the plurality of rolls on which the endless belt is stretched is coated with an elastic layer on the surface thereof.
Since the unevenness is formed on the surface of the elastic layer, even when a lubricant is applied to the inner surface of the endless belt, the lubricant is scraped off by the unevenness formed on the elastic layer on the roll surface. By using a roll coated with an elastic body as a roll that corrects the bias of the belt, it is possible to obtain the effect of improving the unevenness in tension between the belt and the roll and increasing the frictional resistance, Deviation can be reliably prevented.

Further, according to the invention described in claim 5, the elastic layer coated on the surface of at least one of the plurality of rolls on which the endless belt is stretched does not contact the end of the endless belt. As described above, since the coating width of the elastic layer is set to be smaller than the end in consideration of the offset of the endless belt, the end of the endless belt may come into contact with the elastic layer coated on the surface of the roll. Not
Even when a hard material such as a polyimide film with excellent heat resistance is used as the base material of the endless belt, the abrasion of the elastic body on the roll surface can be effectively prevented, and the fixing dirt due to abrasion powder and a new belt Bias can be reliably prevented.

[0026] Further, according to the invention described in claim 6, the endless belt includes an end portion of the endless belt, the end portion of the elastic layer covering the surface of at least one of the plurality of rolls on which the endless belt is stretched. Since the wear-resistant coating layer is provided over the area where the parts contact, the wear-resistant coating layer can prevent the elastic layer coated on the surface of the roll from being worn, and the endless belt of the endless belt can be prevented. Even when using a hard material such as a polyimide film with excellent heat resistance as the base material, it is possible to effectively prevent the abrasion of the elastic body on the roll surface, and to prevent fixing dirt and new belt deviation due to abrasion powder. It can be reliably prevented.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on the illustrated embodiment.

FIG. 2 is a block diagram showing one embodiment of the fixing device according to the present invention.

In FIG. 2, reference numeral 1 denotes a heating / fixing roll. The heating / fixing roll 1 is driven by a driving source (not shown) at a predetermined speed, eg, 250, in the direction of the arrow.
It is driven to rotate at a peripheral speed of mm / sec. The heat fixing roll 1 has, for example, an outer diameter of 46 mm,
A metal core 2 formed in a cylindrical shape with an inner diameter of 40 mm and a length of 350 mm is provided.
For example, a material made of aluminum, stainless steel, or the like is used. The surface of the metal core 2 is coated with an HTV silicone rubber (rubber hardness: 45 degrees) as an elastic layer 3 to a thickness of 2 mm, and the surface of the elastic layer 3 is further covered with a top coat layer. 4, a silicon RTV rubber is dip-coated to a thickness of 50 μm, and the surface of the top coat layer 4 is finished in a state close to a mirror state. The rubber hardness of the base elastic layer 3 is Te.
According to JIS K6301, a load of 1,000 g is measured by a spring type A hardness tester manufactured by Clock Inc.
This is the value of the result of measurement with f added. The metal core 2 may be made of a metal having high thermal conductivity other than aluminum or stainless steel.
As the top coat layer 4, another material can be used as long as it is an elastic body having high heat resistance.

A halogen lamp 5 having an output of 400 W is disposed as a heating source inside the metal core 2 so that the surface temperature of the heat fixing roll 1 is controlled to a predetermined temperature by the halogen lamp 5. It is designed to be heated from the inside. The surface temperature of the heat-fixing roll 1 is detected by a temperature sensor 6 that contacts the surface of the central portion of the heat-fixing roll 1 and a temperature sensor 7 that contacts the surface of the non-sheet passing portion at one end of the heat-fixing roll 1. And
It is configured to be controlled by a temperature controller (not shown) so that the surface temperature of the heat fixing roll 1 becomes, for example, 150 ° C.

Further, a dimethyl silicone oil having a viscosity of 1000
cs (trade name "KF-96": manufactured by Shin-Etsu Chemical Co., Ltd.)
Are uniformly supplied by the release agent supply device 8. The release agent supply device 8 includes a release agent supply roll 8c to which the release agent 8b accommodated in the oil pan 8a is supplied, and a release agent 8b attached to the surface of the release agent supply roll 8c. And a release agent application roll 8d that applies the release agent 8b to the surface of the heat fixing roll 1 and is supplied thereto. The release agent supply device 8 is configured to rotate the heating / fixing roll 1 to rotate the release agent application roll 8 d and the release agent supply roll 8.
As the roller c rotates, the release agent 8b is applied and supplied to the surface of the heat fixing roll 1.

On the surface of the heat fixing roll 1,
A heat-resistant endless belt 10 is disposed so as to be in pressure contact over a predetermined nip width. The endless belt 10 is formed of, for example, a polyimide film having a thickness of 75 μm, a width of 300 mm, and a circumference of 188 mm.
It is stretched by the rolls 11, 12, and 13 with a tension of about 8 kg. The above three rolls 11, 12, 13
Are, for example, 23 mm, 18 mm and 18 mm, respectively.
mm. Also, the three rolls 11,
Of the rolls 12 and 13, the rolls 11 and 13 are formed of, for example, stainless steel or the like in a cylindrical or columnar shape, and function as a steering roll.
As described in detail below, is formed by covering the surface of a cylindrical or columnar member made of metal such as stainless steel with an elastic layer. Further, between the roll 11 and the roll 13, a pressing member 14 for pressing the endless belt 10 against the surface of the heat fixing roll 1 with a predetermined pressure is disposed. The outlet of the belt nip is a pressure roll 1
1 is pressure-bonded via the belt 10 with a load of about 20 kgf. For this reason, the elastic layer 3 of the heat fixing roll 1 is deformed, distortion ε is generated on the surface thereof, and the transfer material 16 can be peeled off by its own rigidity. In the figure,
Reference numeral 15 denotes a halogen lamp for heating the endless belt 10 which is disposed as needed inside the stainless steel roll 13. Reference numeral 16 denotes a transfer material carrying an unfixed toner image 17.

The pressing member 14 is, as shown in FIG.
The elastic layer 14b is laminated on the surface of the base plate 14a, and the surface of the elastic layer 14b is
As shown in FIG. 2,
It is pressed toward the heat fixing roll 1 by a compression coil spring 18 disposed on the base plate 14a side. As the base plate 14a, for example, a stainless steel plate having a width (the running direction of the belt) of 20 mm, a length (a direction perpendicular to the paper surface) of 320 mm, and a thickness of 5 mm is used. The elastic layer 14b is made of a silicone sponge (silicone rubber foam) having a rubber hardness of 23 ° and has a thickness of 5 mm. Here, the rubber hardness is
This is the result of measurement with a load of 300 gf applied by a rubber hardness meter for sponge of Asker C type manufactured by Kobunshi Kagaku KK. Further, as the low friction layer 14c, "FGF-400-4" (trade name) manufactured by Chuko Kasei, which is a glass fiber sheet impregnated with polytetrafluoroethylene, is used.

The pressing member 14 is provided with an elastic layer 14b.
Is provided, the contact surface of the low friction layer 14 c that contacts the endless belt 10 can be aligned with the outer peripheral surface of the heat fixing roll 1. That is, when the pressing member 14 is pressed toward the heat fixing roll 1 by a load equal to or more than a certain value, the elastic layer 14b is deformed, and the contact surface of the low friction layer 14c is pressed along the outer peripheral surface of the heat fixing roll 1. It is designed to be deformed as follows. Therefore, the pressing member 1
When the compression coil spring 18 presses the endless belt 4 against the heat fixing roll 1, the endless belt 10 is pressed against the heat fixing roll 1 without any gap.

On the inner surface of the endless belt 10, dimethyl silicone oil having a viscosity of 1000 cs (trade name "KF-96" manufactured by Shin-Etsu Chemical Co., Ltd.) is applied by a lubricant applying member 19 made of felt or the like. As a result, the coefficient of friction between the endless belt 10 and the pressing member 14 is reduced. When dimethyl silicone oil is applied, the friction coefficient μ2 between the pressing member 14 and the endless belt 10 is smaller than the friction coefficient μ1 between the endless belt 10 and the heat fixing roll 1. Thus, by setting the friction coefficient on both surfaces of the endless belt 10, the endless belt 10
It is possible to travel while sliding on the pressure contact member 14 with the rotation of the heat fixing roll 1.

Further, a cleaning device 20 for cleaning the surface of the heat-fixing roll 1 is disposed on the surface of the heat-fixing roll 1 as shown in FIG. The cleaning device 20 supplies the cleaning web 20b from the supply roll 20a, and presses the cleaning web 20b into contact with the cleaning web 20b while the cleaning web 20b is wound by a winding roll 20c that is rotated by a motor (not shown). Heat fixing roll 1 by roll 20d
By pressing against the surface of the fixing roller 1, offset toner and the like adhering to the surface of the heat fixing roll 1 are removed.

By the way, in this embodiment, at least one of a plurality of rolls for stretching the endless belt is used.
The surface of one roll is covered with an elastic layer, and the surface of the elastic layer is formed with irregularities.

That is, in this embodiment, as shown in FIG. 2, three rolls 1 for stretching an endless belt 10 are used.
Of the rolls 1, 12, and 13, the roll 12 disposed at a position distant from the heat fixing roll 1 has a function as a steering roll for correcting the bias of the endless belt 10. This steering roll 12 is, for example, shown in FIG.
As shown in FIG. 5 and FIG. 5, when the position of the one end is fixed, the other end is pivotally supported so as to be movable in the direction of the arrow, and when the endless belt 10 is shifted,
Belt shift detecting means 21 composed of a micro switch or the like
The endless belt 10 is moved to the side opposite to the side where the deviation has occurred by moving the one end of the steering roll 12 in the direction of the arrow by detecting the deviation of the belt, thereby correcting the deviation of the belt. You can do it.

As shown in FIG. 1, the steering roll 12 has an elastic layer 23 made of silicon rubber, EPDM, or the like on a surface of a columnar member 22 (may be a cylindrical member) made of iron, aluminum, or stainless steel. Is coated to a thickness of, for example, about 0.5 mm, and a spiral groove 24 is formed in the elastic body layer 23.
Even when a lubricant is applied to the inner surface of the endless belt 10, the holding property of the lubricant and the steering effect are maintained, and the slip of the steering roll 12 and the endless belt 10 due to the lubricant is prevented.
In the case where a deviation occurs in 0, the deviation can be corrected. The coating thickness of the elastic layer 23 is set to, for example, about 0.5 mm. Needless to say, the coating thickness may be set to be thicker or thinner. As shown in FIG. 1, the elastic layer 23 coated on the surface of the steering roll 12 has a spiral groove 24 formed at a predetermined pitch.
The oil film of the lubricant (oil) applied to the inner surface of the endless belt 10 is easily scraped, and the steering roll 12
The frictional resistance between the belt and the endless belt 10 can be improved.

In the fixing device according to the present embodiment, even when the lubricant is applied to the inner surface of the belt, an elastic body is coated as a roll for correcting the deviation of the belt as described below. By using roles,
It is possible to obtain the effects of improving the stretching unevenness between the belt and the roll and increasing the frictional resistance, and it is possible to reliably prevent the belt from being biased.

That is, in the fixing device configured as described above, as shown in FIG. 2, the heating / fixing roll 1 is driven to rotate at a predetermined speed by a driving source (not shown).
Endless belt 10 pressed against heat fixing roll 1
Is driven to rotate, and the heat-fixing roll 1 is heated to a predetermined temperature by a halogen lamp 5 disposed inside. Then, the fixing device heats the unfixed toner image 17 on the transfer material 16 by passing the transfer material 16 carrying the unfixed toner image 17 through the nip portion between the heat fixing roll 1 and the endless belt 10. The image is fixed by pressure and pressure to form a permanent image.

The endless belt 10 made of an inelastic body such as the above-mentioned polyimide film is stretched with a large tension by three rolls 11, 12, and 13. It is driven and rotated at high speed while being pressed against pressure. for that reason,
When a lubricant is applied to the inner surface of the endless belt 10, the contact resistance between the steering roll 12 and the endless belt 10 is significantly reduced due to the effect of the lubricant as it is, and the roll 12 corrects the bias of the endless belt 10. By using a roll coated with the elastic layer 232, the effect of improving the stretch unevenness of the endless belt 10 and the roll 12 and increasing the frictional resistance cannot be obtained, and the endless belt 10 made of an inelastic body can be rolled up by the roll 11 , 12 and 13, the endless belt 10 cannot be evenly stretched (contacted) due to undulation or undulation of the endless belt 10. Therefore, there is a possibility that the endless belt 10 may be damaged due to poor correction of the deviation of the belt. is there.

Therefore, in the above embodiment, when "belt deviation" occurs in the endless belt 10, this is detected by the belt deviation detecting means 21 and the three belts for stretching the endless belt 10 are detected. Roll 11, 1
By appropriately moving the steering roll 12 in the directions indicated by arrows in FIGS. 4 and 5, the "belt shift" can be corrected.

At this time, as shown in FIG. 2, the endless belt 10 is pressed against the surface of the heat fixing roll 1 with a large load by a pressing member 14, and the endless belt 10 is pressed against the pressing member 14 by pressing. In order to prevent the endless belt 10 and the like from being worn, a lubricant (oil) is applied to the inner surface of the endless belt 10. As described above, when the lubricant is applied to the inner surface of the endless belt 10, the endless belt 10 and the steering roll are formed by using a roll coated with the elastic layer 23 as the steering roll 12 for correcting the bias of the endless belt 10. There is a possibility that the effect of improving the stretch unevenness and the frictional resistance with respect to No. 12 may not be obtained.

Therefore, in the above-described embodiment, as shown in FIG. 1, a spiral groove 24 is formed in the elastic layer 23 coated on the surface of the steering roll 12, so that the inner surface of the endless belt 10 is formed. The oil film of the applied lubricant (oil) can be easily scraped, and the frictional resistance between the elastic layer 23 of the steering roll 12 and the endless belt 10 can be secured. It is possible to control the steering in an extremely stable state without reducing the correction effect, to prevent the endless belt 10 from being shifted or damaged, and to dramatically improve the durability of the endless belt 10. Becomes When the spiral groove 24 is formed in the elastic layer 23 on the surface of the steering roll 12, the lubricant (oil) applied to the inner surface of the endless belt 10 by the spiral groove 24 is applied in the axial direction. An obliquely acting scraping force can be provided, and the effect of scraping the oil film of the lubricant (oil) can be enhanced.

FIGS. 6 to 8 show a modification of the first embodiment. The steering roll 1 shown in FIG.
Reference numeral 2 denotes a plurality of grooves formed in parallel with each other at regular intervals so that the grooves 24 formed in the elastic layer 23 are not spiral but perpendicular to the axial direction of the steering roll 12. In this case,
By scraping the lubricant in the axial direction, the scraped lubricant can be held by the plurality of grooves 24 formed so as to be orthogonal to the axial direction, and the lubricant is prevented from diffusing in the axial direction. Thus, reliable contact between the roll 12 and the belt 10 can be ensured. Steering roll 1 shown in FIG.
In the roll 2 shown in FIG. 6, a plurality of grooves 24 along the axial direction of the roll 12 are further formed at a constant pitch over the entire circumference. In this case, the effect of scraping off the lubricant is obtained. improves. The steering roll 12 shown in FIG. 8 is different from the roll shown in FIG.
Is formed with one spiral groove 24 on the surface and another spiral groove 24 at the same pitch in the opposite direction. In this case, the lubrication is better than that of the type shown in FIG. The scraping effect of the agent can be further enhanced.

Second Embodiment FIG. 9 shows a second embodiment of the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals and described.
In the second embodiment, the unevenness formed on the surface of the elastic layer of the steering roll is constituted by minute unevenness formed by roughening the surface of the elastic layer.

That is, in the fixing device according to the second embodiment, as shown in FIG. 9, the surface of the elastic layer 23 coated on the steering roll 12 is formed by roughening the surface of the elastic layer 23. It is configured to form minute irregularities 25. The minute irregularities 25 on the surface of the steering roll 12
2 is uniformly coated with the elastic layer 23, and then the elastic layer 23 is coated on the surface of the steering roll 12.
Is cooled by liquid nitrogen or the like to freeze it, and the surface of the elastic layer 23 having a temperature equal to or lower than the frozen glass transition temperature is ground by a cutting tool using a lathe or the like, or is polished to obtain a predetermined surface. The roughness, for example, the surface roughness Ra is formed to be several μm to several hundred μm. The surface roughness of the surface of the elastic layer 23 may be other than the above value.

As described above, by forming the fine irregularities 23 on the surface of the elastic layer 21 coated on the steering roll 12, the endless belt 10 made of an inelastic body is formed.
In the case where the endless belt 10 is stretched, the contact (stretch) unevenness between the steering roll 12 and the endless belt 10 is improved, and a lubricant (oil) is applied to the inner surface of the endless belt 10.
Is applied, the projections of the irregularities 23 on the surface of the steering roll 12 make point contact with the inner surface of the endless belt 10, and extra lubricant is guided by the concaves of the irregularities 23, thereby ensuring friction resistance with the endless belt 10. Can be
It is possible to reliably prevent the original belt from shifting.

FIGS. 10 to 11 show a modification of the second embodiment. The steering roll 12 shown in FIG. 10 has a structure in which the elastic layer 23 has minute irregularities 25 on the surface. A groove 24 is formed in the elastic layer 23 in a spiral shape.
4 can also scrape off excess lubricant (oil), and the steering roll 12 and the endless belt 10
The inner surface of the steering roll 12 is configured so that frictional resistance acts reliably. In the steering roll 12 shown in FIG. 11, the groove 24 formed in the elastic layer 23 has a spiral shape, And a plurality of grooves 24 formed at regular intervals and parallel to each other so as to be orthogonal to the axial direction.

The other configuration and operation are the same as those of the first embodiment, and the description thereof will be omitted.

Third Embodiment FIG. 12 shows a third embodiment of the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals. The shape of the unevenness formed on the elastic layer is different from that of the first embodiment.

That is, in the fixing device according to the third embodiment, as shown in FIG. 12, linear grooves 24 extending along the axial direction are formed in the elastic layer 23 of the steering roll 12 at a fine pitch over the entire circumference. Is formed.

With this configuration, even when the inner surface of the endless belt 10 is coated with a lubricant,
By using the roll 12 coated with the elastic layer 23 as the roll for correcting the deviation of the belt 12, it is possible to obtain the effects of improving the stretch unevenness of the endless belt 10 and the steering roll 12 and increasing the frictional resistance. Can,
It is possible to provide a fixing device that can surely prevent the belt from shifting.

The other configuration and operation are the same as those of the first embodiment, and the description thereof will be omitted.

Fourth Embodiment FIG. 13 shows a fourth embodiment of the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals. The shape of the unevenness formed on the elastic layer is different from that of the first embodiment.

That is, in the fixing device according to the fourth embodiment, as shown in FIG. 13, the elastic layer 23 coated on the surface of the steering roll 12 is formed in a mesh shape having fine grids 25. .

The other configuration and operation are the same as those of the first embodiment, and the description thereof will be omitted.

Fifth Embodiment FIGS. 14 and 15 show a fifth embodiment of the present invention. The same parts as those in the first embodiment will be denoted by the same reference numerals. The shape of the unevenness formed on the elastic layer of the steering roll is different from that of the first embodiment.

That is, in the fixing device according to the fifth embodiment, as shown in FIGS. 14 and 15, a minute recess 30 is formed on the surface of the elastic layer 23 coated on the steering roll 12. This roll 1
Countless dents 3 provided on the surface of the elastic layer 23 coated
The dents are formed so that 0 acts like a suction cup and comes into contact with the belt 10. Such a method of manufacturing the elastic layer 22 of the steering roll 12 includes mixing air bubbles or the like into the elastic body to be coated, or mixing the granular material 31 into the elastic body 23 to be coated as shown in FIG. After shaping, the granular material 31 is removed, or a granular material (metal) 31 that can be removed with a solvent is used.

With such a configuration, even when a lubricant is applied to the inner surface of the endless belt 10, a minute recess 30 is formed on the surface of the elastic layer 23 coated on the steering roll 12, thereby obtaining the same effect as the suction cup. As a result, it is possible to more effectively improve the correction of belt misalignment due to slippage of the endless belt 10 and the steering roll 12.

The other constructions and operations are the same as those of the first embodiment, and the description is omitted.

Sixth Embodiment FIGS. 17 and 18 show a sixth embodiment of the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals. The shape of the unevenness formed on the elastic layer of the steering roll is different from that of the first embodiment.

That is, in the fixing device according to the sixth embodiment, as shown in FIGS.
The mold to be covered with the roller 2 is subjected to a convex working so that the recess 40 is formed uniformly on the surface of the elastic layer 23 covered with the roll. In this case, since the recess 40 on the surface of the elastic layer 23 covered by the steering roll 12 can hold the lubricant to some extent,
An increase in contact resistance between the belt 10 and the roll 12 due to excessive scraping of the lubricant can be prevented.

The other constructions and operations are the same as those in the first embodiment, and the description thereof will be omitted.

Seventh Embodiment FIGS. 19 and 20 show a seventh embodiment of the present invention. The same parts as those in the first embodiment will be denoted by the same reference numerals. The shape of the unevenness formed on the elastic layer of the steering roll is different from that of the first embodiment.

That is, in the fixing device according to the seventh embodiment, as shown in FIGS. 19 and 20, a silicon heat-shrinkable tube 50 with a hole is used as an elastic layer coated on the surface of the steering roll 12. As shown in FIG. 21, the silicon heat-shrinkable tube 50 in which the holes 51 are formed is coated on the base 22 of the roll 12 so that the unevenness 51 is formed on the elastic layer 24 of the steering roll 12. It is.

In this case, the steering roll can be easily manufactured.

The other constructions and operations are the same as those in the first embodiment, and a description thereof will be omitted.

Eighth Embodiment FIGS. 22 and 23 show an eighth embodiment of the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals. Even when a hard material such as a polyimide film with excellent heat resistance is used as the base material of the endless belt, the abrasion of the elastic body on the roll surface can be effectively prevented, and the fixing dirt due to abrasion powder and a new belt Deviation can be reliably prevented.

That is, in the fixing device according to the eighth embodiment, as shown in FIGS. 22 and 23, the steering roll 12 covered with the elastic layer 23 is moved more than the range in which the belt meanders (controls) in the axial direction. The configuration is such that the coating width of the elastic layer 23 is reduced. In FIG. 22, reference numeral 60 denotes an elastic layer made of silicon rubber or the like coated on the surface of the endless belt 10.

In this embodiment, FIGS. 24 and 25
As shown in FIG. 3, the surface of the elastic layer 23 covering the surface of the steering roll 12 is
By forming the same surface as above, the steering roll 12 covered with the elastic layer 23 is formed so that the coating width of the elastic layer 23 is smaller than the range in which the belt meanders (controls) in the axial direction. Even with this configuration, it is possible to prevent a gap from being generated between the endless belt 10 and the end of the steering roll 12. Furthermore, in this embodiment, the belt 10 is cut into the elastic layer 22 of the roll 12 at the edge of the end of the endless belt 10,
As shown in FIGS. 26 and 27, the belt 10 is rolled at the edge of the belt 10 by coating and reinforcing a wear-resistant member 70 made of a heat-resistant resin, metal, or the like.
To solve problems such as image contamination and belt deviation due to abrasion powder generated by biting into the elastic layer 23 of
The belt is configured to have a very stable belt shift preventing effect and improve reliability. As the wear prevention member 70, for example, as shown in FIG. 28, a heat-resistant resin 8 made of polyimide, epoxy resin or the like is used.
0, the end of the roll 12 is immersed in a container 81,
It may be formed by curing the heat resistant resin 80. Further, as shown in FIG. 29, the abrasion prevention member 70 is formed by fitting a tape or a ring 82 of metal (iron, aluminum, copper) or polyimide to the end of the roll 12. Is also good.

In this case, even if the endless belt 10 is controlled in a meandering manner, the elastic layer 23 coated on the surface of the roll 12 contacts only the inner surface of the belt 10 and prevents the elastic layer 23 from contacting the end. Even if a hard belt 10 (metal, polyimide, or the like) is stretched, abrasion of the elastic layer 23 on the surface of the roll 12 due to biting of the belt edge can be prevented.

The other structure and operation are the same as those of the first embodiment, and the description thereof will be omitted.

Ninth Embodiment FIG. 30 shows a ninth embodiment of the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals. A lubricant (oil) 90 is applied to the inner surface of the endless belt 10 via a groove 24 formed in the elastic layer 23 on the surface. That is, in the fixing device according to this embodiment, as shown in FIG. 30, a lubricant (oil) contained in a lubricant tank 91 is provided at one end of a groove 24 formed in an elastic layer 23 on the surface of the steering roll 12. 90 is supplied by a pump 92 from a supply port 93 little by little, and a lubricant (oil) 90 is uniformly applied to the inner surface of the belt 10 through the groove 24 on the surface of the steering roll 12, and the surface of the steering roll 12 is An extra lubricant (oil) 90 is collected in a lubricant tank 91 from the other end of the groove 24 formed in the elastic layer 23.

The other constructions and operations are the same as those of the first embodiment, and a description thereof will be omitted.

[0078]

The present invention has the above-described structure and operation. Even when a lubricant is applied to the inner surface of the belt,
By using a roll coated with an elastic body as a roll that corrects the belt bias, it is possible to obtain the effects of improving the stretch unevenness between the belt and the roll and increasing the frictional resistance, and ensuring the belt bias. It is possible to provide a fixing device which can prevent the fixing device from being damaged.

Further, according to the present invention, even when a rigid member having excellent heat resistance such as a polyimide film is used as the base material of the endless belt, it is possible to effectively prevent abrasion of the elastic body on the roll surface. Thus, it is possible to provide a fixing device capable of reliably preventing fixing dirt and new belt deviation due to abrasion powder.

[Brief description of the drawings]

FIG. 1 is a front configuration diagram of a main part showing a fixing device according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram illustrating a fixing device according to a first embodiment of the present invention.

FIG. 3 is a perspective view showing a pressing member.

FIG. 4 is a perspective explanatory view showing a state in which the endless belt is biased.

FIG. 5 is a perspective explanatory view showing a state in which the endless belt is biased.

FIG. 6 is a front configuration diagram illustrating a modification of the fixing device according to the first embodiment of the present invention.

FIG. 7 is a front configuration diagram showing another modified example of the fixing device according to the first embodiment of the present invention.

FIG. 8 is a front configuration diagram showing still another modified example of the fixing device according to the first embodiment of the present invention.

FIG. 9 is a front configuration diagram of a main part of a fixing device according to a second embodiment of the present invention.

FIG. 10 is a front configuration diagram showing a modification of the fixing device according to the second embodiment of the present invention.

FIG. 11 is a front configuration diagram showing another modified example of the fixing device according to the second embodiment of the present invention.

FIG. 12 is a front configuration diagram of a main part of a fixing device according to a third embodiment of the present invention.

FIG. 13 is a front configuration diagram of a main part of a fixing device according to a fourth embodiment of the present invention.

FIG. 14 is a front configuration diagram of a main part showing a fixing device according to a fifth embodiment of the present invention.

FIG. 15 is a sectional view of a main part of FIG.

FIG. 16 is an explanatory diagram showing a method of manufacturing the roll shown in FIG.

FIG. 17 is a front view of a main part of a fixing device according to a sixth embodiment of the present invention.

FIG. 18 is a sectional view of a main part of FIG.

FIG. 19 is a front configuration diagram of a main part showing a fixing device according to a seventh embodiment of the present invention.

FIG. 20 is a sectional view of a main part of FIG. 19;

FIG. 21 is an explanatory diagram showing a method of manufacturing the roll shown in FIG.

FIG. 22 is a sectional view of a main part showing Embodiment 8 of the fixing device according to the present invention.

FIG. 23 is an explanatory diagram of the eighth embodiment.

FIG. 24 is a cross-sectional view of a main part showing a modification of the eighth embodiment of the fixing device according to the present invention.

FIG. 25 is an explanatory diagram of the modification.

FIG. 26 is a sectional view of a main part showing another modification of the fixing device according to the eighth embodiment of the present invention.

FIG. 27 is an explanatory diagram of another modification.

FIG. 28 is an explanatory diagram showing a method of manufacturing the roll shown in FIG.

FIG. 29 is an explanatory diagram showing a method of manufacturing the roll shown in FIG.

FIG. 30 is an explanatory view showing a main part of a fixing device according to a ninth embodiment of the present invention.

FIG. 31 is a configuration diagram showing a conventional fixing device.

FIG. 32 is a perspective view showing a pressing member.

FIG. 33 is an explanatory diagram showing an attached matter attached to the surfaces of the belt and the roll.

FIGS. 34A and 34B are configuration diagrams showing other conventional fixing devices, respectively.

FIG. 35 is a configuration diagram showing another conventional image forming apparatus.

FIG. 36 is a configuration diagram showing another conventional fixing device.

FIG. 37 is a configuration diagram showing another conventional fixing device.

FIG. 38 is a perspective view showing a pressing member.

FIG. 39 is an explanatory diagram showing an uneven contact state between the belt and the roll.

FIG. 40 is an explanatory diagram showing the operation of a conventional fixing device.

FIG. 41 is an explanatory diagram showing the operation of a conventional fixing device.

FIG. 42 is a cross-sectional view of a main part showing an operation of a conventional fixing device.

[Explanation of symbols]

1 heat fixing roll, 10 endless belt, 11,
13 rolls, 12 steering rolls, 14 pressure contact members, 22 cylindrical members, 23 elastic layers, 24 grooves (irregularities).

Claims (6)

[Claims] An endless belt stretched by a plurality of rolls is brought into pressure contact with the surface of a fixing member, and a transfer material carrying an unfixed toner image is passed through a pressure contact portion between the fixing member and the endless belt. In a fixing device for performing a fixing process, at least one of a plurality of rolls on which the endless belt is stretched is coated with an elastic body layer, and irregularities are formed on the surface of the elastic body layer. A fixing device. 2. An endless belt stretched by a plurality of rolls on the surface of a heat fixing roll is pressed by being pressed from the inside of the endless belt by a pressing member, and a lubricant is applied to an inner surface of the endless belt. In the fixing device, one of a plurality of rolls for applying and stretching the endless belt is configured to correct a bias of the endless belt by inclining a rotation axis of the steering roll. A fixing device, wherein an elastic layer is coated on a surface of a steering roll, and irregularities are formed on a surface of the elastic layer. 3. The fixing device according to claim 1, wherein the unevenness formed on the surface of the elastic layer comprises a groove formed in the elastic layer. 4. The method according to claim 1, wherein the unevenness formed on the surface of the elastic layer comprises minute unevenness formed by roughening the surface of the elastic layer.
The fixing device as described in the above. 5. The coating of the elastic layer so that the elastic layer coated on the surface of at least one of the rolls stretching the endless belt does not contact the end of the endless belt. The fixing device according to any one of claims 1 to 4, wherein the width is set to be narrower than an end of the endless belt in consideration of an offset. 6. Abrasion resistance over a range in which the end of the endless belt contacts the end of the elastic layer coated on the surface of at least one of the plurality of rolls on which the endless belt is stretched. The fixing device according to any one of claims 1 to 4, further comprising a coating layer having a characteristic property.