JP3511854B2 - Fixing device - Google Patents

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 and a printer, and more particularly to a belt deviation preventing technique for a fixing device using an endless belt.

[0002]

2. Description of the Related Art Recently, as a fixing device suitable for high-speed and high-quality color electrophotographic copying machines, a so-called belt nip type fixing device in which an endless belt is stretched around a heating roll is proposed by the present applicant. (JP-A-8
-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 pressed against the surface of a heat fixing roll 100. By pressing from the inside of the endless belt 104 by a pressure contact member 105 as shown in FIG. 32, the nip width and pressure contact force between the heat fixing roll 100 and the endless belt 104 are sufficiently secured, and the heat fixing roll 100 is
By rotating the endless belt 104 at a high speed, it is possible to fix a high-quality color image at a high speed.

However, in such a belt nip type fixing device, a plurality of rolls 101, 102, 1 are used.
The endless belt 104 stretched between the rollers 03 rotates at high speed while being pressed against the surface of the heat fixing roll 100 by the pressing member 105. Therefore, the pressure contact member 1
As shown in FIG. 33, the abrasion material 106 partially adheres to the inner surface of the endless belt 104 and the surfaces of the tension rolls 101, 102, 103 in the form of a thin film due to the abrasion of No. 05,
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 becomes the rolls 101, 10 and 10.
2,103 "Belt bias" occurs, which rotates to one side. As described above, when the “belt shift” occurs in the endless belt 104, the end of the endless belt 104 may be worn by contacting another member, and the end of the endless belt 104 may be damaged. I have a problem.

Therefore, as a means for preventing the belt deviation of the fixing device using such an endless belt and the damage of the belt due to the deviation of the belt, forming a roll around the endless belt into a drum shape. In this case, in this case, since the elastic belt and the drum-shaped roll are combined to prevent deviation of the belt by utilizing the change in tension of the elastic belt, heat resistance and heat A fixing device using a non-elastic belt made of a polyimide film or the like cannot provide the effect of preventing the belt deviation from the viewpoint of superiority of characteristics.

Further, as a method of correcting the deviation of the belt, there are 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. In a fixing device that requires the belt to be pressed against a heating roll in order 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. However, a new problem arises in that the cost is significantly increased because

In order to prevent the deviation of the belt without causing such a problem, JP-A-54-69442, JP-A-3-238247, and JP-A-7-2 are used.
As disclosed in Japanese Patent Laid-Open No. 19364 and Japanese Patent Laid-Open No. 8-262903, as shown in FIGS.
In a fixing device or an image forming apparatus that uses a belt to which a load is applied, by axially moving one of the rolls that stretches the belt, the so-called active that corrects the misalignment of the belt A steering system has been proposed.

The copying machine according to the above Japanese Patent Laid-Open No. 54-69442 relates to the prevention of meandering of the endless belt-shaped photoconductor, but the meandering of the endless belt-shaped photoconductor of the copying machine is controlled by swinging the rollers. In the device, 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 a signal from the detecting means are used to move the endless belt-shaped photosensitive member to the moving means. And an electric control circuit that outputs an output signal for a longer time than required for the circuit.

Further, in the belt deviation correcting device according to Japanese Patent Laid-Open No. 3-238247, an endless belt is stretched around at least two rollers, and one of the rollers is the endless belt. The endless belt is supported by a bracket which is rotatable about the center of the length of the endless belt, and the bracket applies tension to the endless belt. It is configured so as to be biased in the direction by a biasing member.

Further, the image fixing device according to the above-mentioned Japanese Patent Laid-Open No. 8-262903 is proposed by the applicant of the present invention. In the same publication, one of a plurality of rolls around which an endless belt is stretched It is disclosed that by arranging the two rolls in a displaceable manner, deviation of the belt can be prevented.

[0011]

However, the above-mentioned prior art has the following problems. That is, the above-mentioned JP-A-54-69442 and JP-A-3
No. 238247, and further Japanese Patent Laid-Open No. 8-262903.
In a fixing device using a belt to which a load is applied, as disclosed in Japanese Unexamined Patent Application Publication No. 2005-242, when one of the rolls for stretching the belt is axially moved, a so-called active steering system is adopted. As described above, when a belt made of an inelastic material is used as the endless belt, and the roll that stretches the endless belt is made of a metal member, the flatness of the endless belt becomes flat when manufacturing the endless belt. 39 cannot be prevented from occurring, and if the endless belt has a flatness variation or waviness, the endless belt will be
As shown in FIG.
However, even if the roll 102 that stretches the belt 104 is axially moved, it is not possible to effectively prevent the deviation of the belt 104.

Further, as disclosed in Japanese Patent Application Laid-Open No. 54-69442, a roll coated with an elastic material is used as a roll for correcting the deviation of the belt, so that the tension between the belt and the roll is uneven. It is also possible to improve the friction resistance and increase the frictional resistance.

However, in the above belt nip type fixing device, in order to improve the fixing property, as shown in FIG. 31, a pressure contact member 105 as shown in FIG. 32 is applied to the heating roll 100 from the inside of the belt 104 with a high load. Since it is necessary to press the belt, a new problem arises that the belt is biased due to uneven 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 deviation of the belt, and wear and sliding resistance of the belt and the pressing member are reduced. Therefore, Japanese Patent Application Laid-Open No. 8-262903 and Japanese Patent Application Laid-Open No. 9-3429 related to the applicant's proposal.
37 and 38 as disclosed in Japanese Patent Publication No.
It has been already proposed by the applicant of the present invention to apply a lubricant to the inner surface of the belt 104 by the application member 108 made of felt or the like as shown in FIG.

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
The contact resistance of No. 4 is significantly reduced, and the endless belt 104
By using a roll coated with an elastic body as the roll 102 for correcting the unevenness of the belt, the effect of improving the uneven tension between the belt and the roll and increasing the frictional resistance cannot be obtained, and an endless body made of a non-elastic body is not obtained. Belt 104
39 is stretched on a roll, as shown in FIG. 39, the belt 104 cannot be stretched (contacted) uniformly due to waviness, undulation, etc., so that the belt may be damaged due to improper straightening of the belt. There was a problem that there was In addition, a polyimide film or the like, which is a hard member and is excellent in heat resistance, is used as the base material of the endless belt 104.
As shown in FIG. 0, when the belt 104 is subjected to meandering control while tension is applied, the belt 104 is rolled at the edge portion of the end of the belt 104 as shown in FIGS. 41 and 42.
There is a problem that the elastic body 102a on the surface of No. 02 bites and wears, causing new fixing stains and belt deviation due to wear powder.

Therefore, the present invention has been made in order to solve the above-mentioned problems of the prior art, and the object thereof is to apply a lubricant to the inner surface of the belt,
By using a roll coated with an elastic body as a roll that corrects the deviation of the belt, it is possible to improve the unevenness of tension between the belt and the roll and increase the frictional resistance. Another object of the present invention is to provide a fixing device which can be prevented.

Another object of the present invention is to effectively wear the elastic body on the roll surface even when a polyimide film which is a hard member and is excellent in 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 stain due to abrasion powder and new belt deviation.

[0018]

That is, according to the invention described in claim 1, an endless belt stretched by a plurality of rolls is brought into pressure contact with the surface of the fixing member, and the fixing member is brought into pressure contact with the endless belt. In a fixing device that performs a fixing process by allowing a transfer material carrying an unfixed toner image to pass through an area, an elastic layer is formed on the surface of at least one of the plurality of rolls around which the endless belt is stretched. Along with coating, unevenness is formed on the surface of the elastic layer , and the at least one roll is further formed.
The elastic layer that is coated on the surface of the
The coating width of the elastic layer so that it does not come into contact with the
Considering the offset of the dress belt, set it narrower than the end
It is a thing.

The invention described in claim 2 is a fixing device.
Ends stretched by multiple rolls on the surface of the member
The fixing belt and the endless bell
Pass through the transfer material bearing the unfixed toner image
The fixing device that performs the fixing process.
A plurality of rolls that stretch the endless belt.
The surface of at least one roll is coated with an elastic layer
At the same time, unevenness is formed on the surface of the elastic layer,
Bullets coated on the surface of the at least one roll
The edge of the endless belt contacts the edge of the elastic layer.
A wear-resistant coating layer is provided over the surrounding area .

Further, the invention according to claim 3 is characterized in that the unevenness formed on the surface of the elastic layer is a groove formed in the elastic layer. Fixing device.

Further, in the invention as set forth in claim 4, the unevenness formed on the surface of the elastic body layer comprises minute unevenness formed by roughening the surface of the elastic body layer. The fixing device according to claim 1 or 2, which is characterized in that.

[0022]

[0023]

[0024]

In the invention described in claim 1, at least one of the plurality of rolls around which the endless belt is stretched is coated with an elastic layer on the surface of the roll, and
Since the unevenness is formed on the surface of the elastic layer, even when the lubricant is applied to the inner surface of the endless belt, the unevenness formed on the elastic layer of the roll surface scrapes off the lubricant. By using a roll coated with an elastic body as a roll for correcting the deviation of the belt, it is possible to obtain an effect of improving tension unevenness between the belt and the roll and increasing frictional resistance. It is possible to reliably prevent the deviation.

In the invention described in claim 2 , the elastic layer coated on the surface of at least one of the plurality of rolls around which the endless belt is stretched does not come into contact with the end of the endless belt. As described above, since the covering width of the elastic body layer is set to be narrower than the end portion in consideration of the deviation of the endless belt, the end portion of the endless belt may contact the elastic body layer coated on the surface of the roll. Without
Even if a hard material such as a polyimide film with excellent heat resistance 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, fixing stains due to abrasion powder and new belt It is possible to reliably prevent the deviation.

Further, in the invention described in claim 3 , the endless belt has an end portion at the end of the elastic layer coated on the surface of at least one of the plurality of rolls around which the endless belt is stretched. Since the abrasion-resistant coating layer is provided over the range in which the parts come into contact with each other, the abrasion-resistant coating layer can prevent abrasion of the elastic layer coated on the surface of the roll. Even when using a polyimide film that is a hard member and has excellent heat resistance as the base material, it is possible to effectively prevent abrasion of the elastic body on the roll surface, and to prevent fixing stains due to abrasion powder and new belt deviation. It can be surely prevented.

[0027]

DETAILED DESCRIPTION OF THE INVENTION

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below based on the illustrated embodiments.

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

In FIG. 2, reference numeral 1 denotes a heat fixing roll. This heat fixing roll 1 is driven by a driving source (not shown) at a predetermined speed along the arrow direction, for example 250.
It is designed to be rotationally driven at a peripheral speed of mm / sec. The heat fixing roll 1 has, for example, an outer diameter of 46 mm,
It is provided with a metal core 2 formed into a cylindrical shape having an inner diameter of 40 mm and a length of 350 mm. As the metal core 2,
For example, one made of aluminum or stainless steel is used. The surface of the metal core 2 is covered with HTV silicon 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. Silicon RTV rubber 4 is dip-coated to a thickness of 50 μm, and the surface of the top coat layer 4 is finished to a state close to a mirror surface. The rubber hardness of the base elastic layer 3 is Te.
1,000 g load according to JIS K6301 by a spring type A hardness tester manufactured by clock.
This is the value of the result of measurement with f added. The metal core 2 may be made of metal having high thermal conductivity other than aluminum, stainless steel, or the like.
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 arranged as a heating source inside the metal core 2, and the heating and fixing roll 1 has a surface temperature of 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 of one end of the heat fixing roll 1. Is
The surface temperature of the heat fixing roll 1 is controlled by a temperature controller (not shown) so that the surface temperature of the heat fixing roll 1 becomes 150 ° C., for example.

Further, the surface of the heat fixing roll 1 has a dimethyl silicone oil viscosity of 1000 as a release agent.
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 housed in the oil pan 8a is supplied and a release agent 8b attached to the surface of the release agent supply roll 8c. It is constituted by a release agent application roll 8d which is supplied and applies the release agent 8b to the surface of the heat fixing roll 1. The release agent supply device 8 includes a release agent coating roll 8d and a release agent supply roll 8 as the heat fixing roll 1 rotates.
When c is driven to rotate, 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 arranged so as to be in pressure contact with 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 peripheral length of 188 mm.
The book rolls 11, 12, and 13 are stretched with a tension of about 8 kg. The above three rolls 11, 12, 13
The diameter of each is, for example, 23 mm, 18 mm, 18
It is set to mm. Also, the above three rolls 11,
Of the rolls 12 and 13, the rolls 11 and 13 are formed of, for example, stainless steel in a cylindrical shape or a cylindrical shape, and serve as a steering roll.
As described in detail later, is formed by covering the surface of a cylindrical or cylindrical member made of metal such as stainless steel with an elastic layer. Further, a pressure contact member 14 for pressing the endless belt 10 against the surface of the heat fixing roll 1 with a predetermined pressure is arranged between the roll 11 and the roll 13. The outlet of the belt nip is the pressure roll 1.
1 is pressure-bonded through 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, strain ε is generated on the surface thereof, and the transfer material 16 can be peeled by its own rigidity. In the figure,
Reference numeral 15 denotes a halogen lamp for heating the endless belt 10, which is disposed inside the stainless steel roll 13 as needed. Reference numeral 16 indicates a transfer material carrying an unfixed toner image 17.

The pressure contact 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 body layer 14b is covered with the low friction layer 14c.
It is configured by coating with, and as shown in FIG.
The compression coil spring 18 arranged on the side of the base plate 14a is pressed against the heat fixing roll 1. As the base plate 14a, for example, one made of stainless steel having a width (belt running direction) of 20 mm, a length (perpendicular to the paper surface) of 320 mm, and a thickness of 5 mm is used. The elastic layer 14b is made of silicone sponge (foam of silicone rubber) having a rubber hardness of 23 ° and has a thickness of 5 mm. The rubber hardness here is
The results are obtained by applying a load of 300 gf using a rubber hardness tester for Asker C type sponge manufactured by Kobunshi Kagaku Kagaku. 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.

Here, the elastic layer 14b is attached to the pressure contact member 14.
By providing, the contact surface of the low friction layer 14c that comes into contact with the endless belt 10 can be aligned with the outer peripheral surface of the heat fixing roll 1. That is, when the pressure contact member 14 is pressed against the heat fixing roll 1 by a load of a certain amount or more, the elastic layer 14b is deformed, and the contact surface of the low friction layer 14c is pressed against the outer peripheral surface of the heat fixing roll 1. It is designed to transform like this. Therefore, the press contact member 1
When 4 is pressed against the heat fixing roll 1 by the compression coil spring 18, the endless belt 10 is pressed against the heat fixing roll 1 without a 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 application member 19 made of felt or the like. The friction coefficient between the endless belt 10 and the pressure contact member 14 is thereby reduced. When the dimethyl silicone oil is applied, the friction coefficient μ2 between the pressure contact 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 sides of the endless belt 10, the endless belt 10 is
With the rotation of the heating and fixing roll 1, it is possible to travel while sliding on the pressure contact member 14.

Further, as shown in FIG. 2, a cleaning device 20 for cleaning the surface of the heat fixing roll 1 is arranged on the surface of the heat fixing roll 1. The cleaning device 20 supplies a cleaning web 20b from a supply roll 20a and presses the cleaning web 20b while winding the cleaning web 20b by a take-up roll 20c rotated by a motor (not shown). Heat fixing roll 1 by roll 20d
The offset toner and the like adhering to the surface of the heat-fixing roll 1 are removed by pressing the surface of the heat-fixing roll 1.

By the way, in this reference example , at least one of a plurality of rolls around which the endless belt is stretched is stretched.
The surface of one roll is covered with the elastic layer, and the surface of the elastic layer is formed with irregularities.

That is, in this reference example , as shown in FIG. 2, the three rolls 1 around which the endless belt 10 is stretched are stretched.
The roll 12, which is arranged at a position apart from the heating and fixing roll 1, among 1, 12, 13 has a function as a steering roll for correcting the deviation of the endless belt 10. This steering roll 12 is, for example, as shown in FIG.
Further, as shown in FIG. 5, when the position of one end is fixed, the other end is rotatably supported along the arrow direction, and when the endless belt 10 is biased,
Belt offset detection means 21 including a micro switch
By detecting the belt deviation, the one end of the steering roll 12 is moved in the direction of the arrow to move the endless belt 10 to the side opposite to the side where the deviation occurs and correct the belt deviation. Is able to.

As shown in FIG. 1, the steering roll 12 has an elastic layer 23 made of silicon rubber, EPDM or the like on the surface of a cylindrical member 22 (or a cylindrical member) made of iron, aluminum or stainless steel. By covering the elastic layer 23 with a spiral groove 24, for example.
Even when a lubricant is applied to the inner surface of the endless belt 10, the retaining 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.
It is configured so that when a deviation occurs in 0, it can be corrected. The coating thickness of the elastic layer 23 is set to, for example, about 0.5 mm, but it goes without saying that it may be set thicker or thinner than this. As shown in FIG. 1, the elastic layer 23 coated on the surface of the steering roll 12 has spiral groove portions 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 scratched, and the steering roll 12
The friction resistance between the endless belt 10 and the endless belt 10 can be improved.

With the above-mentioned structure, in the fixing device according to this reference example , the elastic body is coated as a roll for correcting the deviation of the belt even when the lubricant is applied to the inner surface of the belt as follows. By using the roll,
It is possible to obtain the effects of improving the unevenness of tension between the belt and the roll and increasing the frictional resistance, and it is possible to reliably prevent the belt from being offset.

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

By the way, the endless belt 10 made of a non-elastic material such as the polyimide film is stretched by three rolls 11, 12, and 13 with a large tension, and is strongly pressed against the heat fixing roll 1 by the pressing member 14. It is driven to rotate at high speed while being pressed by 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 remarkably reduced due to the influence of the lubricant as it is, and as a roll 12 that corrects the deviation of the endless belt 10. By using the roll covered with the elastic layer 232, the effect of improving the tension unevenness between the endless belt 10 and the roll 12 and increasing the frictional resistance cannot be obtained, and the endless belt 10 made of the non-elastic body is used for the roll 11 , 12 and 13 cannot be evenly stretched (contacted) due to waviness or undulation of the endless belt 10, so that there is a possibility that the endless belt 10 may be damaged due to improper correction on one side of the belt. is there.

Therefore, in the above-mentioned reference example , when the "belt deviation" occurs in the endless belt 10, the belt deviation detecting means 21 detects this and the three endless belts 10 are stretched. Rolls 11, 1
By appropriately moving the steering roll 12 out of 2 and 13 along the arrow direction shown in FIGS. 4 and 5, it is possible to correct the “belt deviation”.

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 the pressure contact member 14, and the endless belt 10 and the pressure contact member 14 are pressed against each other. 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 roll coated with the elastic layer 23 is used as the steering roll 12 that corrects the deviation of the endless belt 10. There is a fear that the effect of improving the tension unevenness with 12 and the effect of increasing the frictional resistance may not be obtained.

Therefore, in the above-mentioned reference example , by forming a spiral groove 24 in the elastic layer 23 covering the surface of the steering roll 12 as shown in FIG. 1, the inner surface of the endless belt 10 is formed. The oil film of the applied lubricant (oil) can be easily scratched, the frictional resistance between the elastic body layer 23 of the steering roll 12 and the endless belt 10 can be secured, and the steering roll 12 can shift the belt to one side. The steering control can be performed in an extremely stable state without reducing the correction effect, the endless belt 10 can be prevented from being biased or damaged, and the durability of the endless belt 10 can be dramatically improved. Becomes Further, 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. A scraping force acting diagonally can be imparted, and the scraping effect of the oil film of the lubricant (oil) can be enhanced.

6 to 8 show a modified example of the above-mentioned reference example 1, and the steering roll 1 shown in FIG.
No. 2 includes a plurality of grooves formed in parallel with each other at a constant interval so that the groove portion 24 formed in the elastic layer 23 is not spiral and is orthogonal to the axial direction of the steering roll 12. And in this case,
The lubricant can be scraped in the axial direction, and the scraped lubricant can be held by the plurality of groove portions 24 formed so as to be orthogonal to the axial direction, and the lubricant can be prevented from diffusing in the axial direction. As a result, reliable contact between the roll 12 and the belt 10 can be ensured. Steering roll 1 shown in FIG.
In the roll shown in FIG. 6, a plurality of groove portions 24 are formed along the axial direction of the roll 12 at a constant pitch over the entire circumference. In this case, the scraping effect of the lubricant is obtained. improves. The steering roll 12 shown in FIG. 8 is similar to the roll shown in FIG.
One spiral groove portion 24 and another spiral groove portion 24 are formed in the opposite direction at the same pitch in the opposite direction. In this case, lubrication is more effective than the type shown in FIG. The scraping effect of the agent can be further enhanced.

[0048] Reference Example 2 FIG. 9 shows a reference example 2 of the present invention, the reference
The same parts as those in Example 1 will be designated by the same reference numerals and will be described.
In this reference example 2, 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 reference example , as shown in FIG. 9, it is formed by roughening the surface of the elastic layer 23 on the surface of the elastic layer 23 covering the steering roll 12. It is configured to form minute unevenness 25. The minute irregularities 25 on the surface of the steering roll 12 are, for example, the steering roll 1
2 is coated uniformly with the elastic layer 23, and then the surface of the steering roll 12 is coated with the elastic layer 23.
Is cooled by liquid nitrogen or the like to be frozen, and the surface of the frozen elastic body layer 23 having a glass transition temperature or lower is ground by a cutting tool using a lathe or the like, or subjected to polishing or the like to give a predetermined surface. The roughness, for example, the surface roughness Ra is formed to be several μm to several 100 μm. The surface roughness of the surface of the elastic layer 23 may be other than the above values.

In this way, by forming the minute irregularities 23 on the surface of the elastic body layer 21 covering the steering roll 12, the endless belt 10 made of an inelastic body is formed.
When the steering wheel 12 is stretched, the contact (stretching) 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.
Even if the coating is applied, the convex portions 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 guide the excess lubricant in the concave portions of the irregularities 23, thereby ensuring the friction resistance with the endless belt 10. You can
It is possible to reliably prevent the original deviation of the belt.

10 to 11 show a modification of Reference Example 2 described above. In the steering roll 12 shown in FIG. 10, in addition to the elastic layer 23 having minute irregularities 25 on its surface, A groove 24 is formed in a spiral shape on the elastic layer 23, and the groove 2 is formed in the spiral shape.
4 can also scrape off excess lubricant (oil), and the steering roll 12 and the endless belt 10
The steering roll 12 shown in FIG. 11 is configured so that the groove portion 24 formed in the elastic body layer 23 is not spiral-shaped, and the steering roll 12 has a frictional resistance. It is composed of a plurality of groove portions 24 which are formed in parallel with each other at a constant interval so as to be orthogonal to the axial direction of.

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

[0053] Reference Example 3 FIG. 12 shows a reference example 3 of the present invention, the ginseng
The same parts as those in Consideration 1 will be described with the same reference numerals. In Reference Example 3, the shape of the unevenness formed on the elastic layer of the steering roll is different from that in Reference Example 1.

That is, in the fixing device according to the third reference example , as shown in FIG. 12, linear grooves 24 along the axial direction are formed in the elastic layer 23 of the steering roll 12 at a fine pitch over the entire circumference. Has been 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 a roll for correcting the deviation of the belt 12, it is possible to obtain the effects of improving the tension unevenness between the endless belt 10 and the steering roll 12 and increasing the frictional resistance. You can
It is possible to provide a fixing device capable of reliably preventing the belt from being offset.

The rest of the configuration and operation are the same as in the first reference example , so description thereof will be omitted.

[0057] Reference Example 4 FIG. 13 shows a reference example 4 of the present invention, the ginseng
In the reference example 4, the same parts as those in the consideration example 1 are designated by the same reference numerals, and the shapes of the irregularities formed on the elastic layer of the steering roll are different from those of the reference example 1.

That is, in the fixing device according to the fourth reference example , as shown in FIG. 13, the elastic layer 23 covering the surface of the steering roll 12 is formed in a mesh shape having fine cells 25. .

The rest of the configuration and operation are the same as in Reference Example 1, so description thereof will be omitted.

Reference Example 5 FIGS. 14 and 15 show Reference Example 5 of the present invention. The same parts as those of Reference Example 1 are designated by the same reference numerals and will be described. The shape of the unevenness formed on the elastic layer of the steering roll is different from that of Reference Example 1.

That is, as shown in FIGS. 14 and 15, the fixing device according to the reference example 5 is configured so that the minute recesses 30 are formed on the surface of the elastic layer 23 covered by the steering roll 12. This roll 1
Innumerable dents 3 formed on the surface of the elastic layer 23 coated on 2
0 is dented so that it acts like a suction cup and contacts the belt 10. As a method of manufacturing the elastic layer 22 of the steering roll 12 as described above, air bubbles or the like are mixed into the elastic body to be covered, or as shown in FIG. 16, the granular material 31 is mixed into the elastic body 23 to be covered. Examples of the method include removing the particulate matter 31 after shaping, or using a particulate matter (metal) 31 that can be removed with a solvent.

With this structure, even if a lubricant is applied to the inner surface of the endless belt 10, the surface of the elastic body layer 23 covering the steering roll 12 is provided with minute recesses 30, and the same effect as a sucker is provided. As a result, it is possible to more effectively improve the belt offset correction defect due to the slip of the endless belt 10 and the steering roll 12.

The other structure and operation are the same as those of the reference example 1, and the description thereof will be omitted.

Reference Example 6 FIGS. 17 and 18 show Reference Example 6 of the present invention. The same parts as those of Reference Example 1 will be designated by the same reference numerals. The shape of the unevenness formed on the elastic layer of the steering roll is different from that of Reference Example 1.

That is, in the fixing device according to the sixth reference example , as shown in FIGS.
By applying a convexing process to the mold to be coated with 2, the recesses 40 are uniformly formed 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 body layer 23 covered by the steering roll 12 can hold the lubricant to some extent,
It is possible to prevent an increase in contact resistance between the belt 10 and the roll 12 due to excessive scraping of the lubricant.

The rest of the configuration and operation are the same as in the first reference example , so description thereof will be omitted.

Reference Example 7 FIGS. 19 and 20 show Reference Example 7 of the present invention. The same parts as those of Reference Example 1 are designated by the same reference numerals in the following description. The shape of the unevenness formed on the elastic layer of the steering roll is different from that of Reference Example 1.

That is, in the fixing device according to Reference Example 7, as shown in FIGS. 19 and 20, the silicon heat shrinkable tube 50 with holes is used as the 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 formed on the elastic layer 24 of the steering roll 12 by coating the base 22 of the roll 12 with the unevenness 51. Is.

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

The other structure and operation are the same as those in the reference example 1, and therefore their explanations are omitted.

[0071] Example 1 Figures 22 and 23 are those showing a first embodiment of the present invention, when the in Reference Example 1 and the same parts will be denoted by the same reference numerals, in the embodiment 1, Even if a hard material such as a polyimide film with excellent heat resistance 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, fixing stains due to abrasion powder and new belt It is possible to reliably prevent the deviation.

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

Further, in this embodiment, FIG. 24 and FIG.
As shown in, the surface of the elastic body layer 23 covering the surface of the steering roll 12 is covered with the cylindrical member 22 of the roll 12.
By forming the same surface as that of the steering roller 12 covering the elastic layer 23, the covering width of the elastic layer 23 becomes narrower than the range in which the belt meanders (controls) in the axial direction. Even when configured, it is possible to prevent a gap from being formed between the endless belt 10 and the end portion of the steering roll 12. Further, in this embodiment, the edge portion of the endless belt 10 has an edge portion where the belt 10 cuts into the elastic layer 22 of the roll 12,
As shown in FIGS. 26 and 27, the belt 10 is rolled at the edge portion at the end of the belt 10 by covering and reinforcing the wear preventing member 70 made of heat-resistant resin, metal, or the like.
Solving problems such as image stains and belt deviation caused by abrasion powder generated by cutting into the elastic layer 23 of
It is configured so as to have a very stable belt deviation prevention effect and improve reliability. As the wear preventing member 70, for example, as shown in FIG. 28, a heat resistant resin 8 made of polyimide, epoxy resin or the like is used.
Immerse the end of the roll 12 in a container 81 containing 0,
It may be formed by curing the heat resistant resin 80. As the wear preventing member 70, as shown in FIG. 29, a tape or ring 82 made of metal (iron, aluminum, copper), polyimide or the like is formed so as to be fitted into the end portion of the roll 12. Is also good.

In this case, even if the endless belt 10 is controlled to meander, it is possible to prevent the elastic layer 23 covering the surface of the roll 12 from contacting only the inner surface of the belt 10 and contacting the end portions thereof. Even when the hard belt 10 (metal, polyimide, etc.) is stretched, the elastic layer 23 on the surface of the roll 12 due to the biting of the belt edge can be prevented from being worn.

The rest of the configuration and operation are the same as in the first reference example , so description thereof will be omitted.

Second Embodiment FIG. 30 shows a second embodiment of the present invention. The same parts as those of the first embodiment will be designated by the same reference numerals. In this second embodiment , the steering roll 12 will be described. A lubricant (oil) 90 is applied to the inner surface of the endless belt 10 via the 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, the lubricant (oil) stored in the lubricant tank 91 is provided at one end of the groove 24 formed in the elastic layer 23 on the surface of the steering roll 12. 90 is supplied from the supply port 93 by a pump 92 in small amounts, and the lubricant (oil) 90 is evenly applied to the inner surface of the belt 10 through the groove portion 24 on the surface of the steering roll 12 and the surface of the steering roll 12 is covered. Excess 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 structure and operation are the same as those of the first embodiment, and therefore the description thereof is omitted.

[0078]

The present invention has the above-described structure and operation, and 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 deviation of the belt, it is possible to improve the unevenness of tension between the belt and the roll and increase the frictional resistance. It is possible to provide a fixing device which can be prevented.

Further, according to the present invention, even when a polyimide film or the like, which is a hard member and is excellent in 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. Therefore, it is possible to provide the fixing device capable of reliably preventing the fixing stain due to the abrasion powder and the new belt deviation.

[Brief description of drawings]

FIG. 1 is a front view of a principal part showing a reference example 1 of a fixing device according to the present invention.

FIG. 2 is a configuration diagram showing a reference example 1 of a fixing device according to the present invention.

FIG. 3 is a perspective view showing a pressure contact member.

FIG. 4 is a perspective explanatory view showing a state where the endless belt is offset.

FIG. 5 is a perspective explanatory view showing a state where the endless belt is offset.

FIG. 6 is a front configuration diagram showing a modified example of the fixing device according to the first reference example of the present invention.

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

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

FIG. 9 is a front view of the essential part showing a second reference example of the fixing device according to the present invention.

FIG. 10 is a front configuration diagram showing a modified example of the fixing device according to the second reference example of the present invention.

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

FIG. 12 is a reference example 3 of the fixing device according to the present invention.
It is a front view of a main part showing the.

FIG. 13 is a reference example 4 of the fixing device according to the present invention.
It is a front view of a main part showing the.

FIG. 14 is a reference example 5 of the fixing device according to the present invention.
It is a front view of a main part showing the.

15 is a cross-sectional view of the main parts of FIG.

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

FIG. 17 is a reference example 6 of the fixing device according to the present invention.
It is a front view of a main part showing the.

18 is a cross-sectional view of the main parts of FIG.

FIG. 19 is a reference example 7 of the fixing device according to the present invention.
It is a front view of a main part showing the.

20 is a cross-sectional view of the main parts of FIG.

FIG. 21 is an explanatory view showing a method for manufacturing the roll shown in FIG.

FIG. 22 is a first embodiment of the fixing device according to the present invention.
FIG. 3 is a cross-sectional view of the main part showing

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

FIG. 24 is a first embodiment of the fixing device according to the present invention.
FIG. 9 is a cross-sectional view of a main part showing a modified example of FIG.

FIG. 25 is an explanatory diagram of the same modified example.

FIG. 26 is a first embodiment of the fixing device according to the present invention.
It is sectional drawing of the principal part which shows the other modified example.

FIG. 27 is an explanatory diagram of another modification.

FIG. 28 is an explanatory view showing a method for manufacturing the roll shown in FIG. 26.

FIG. 29 is an explanatory diagram showing a method of manufacturing the roll shown in FIG. 26.

FIG. 30 is a second embodiment of the fixing device according to the present invention.
FIG.

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

FIG. 32 is a perspective view showing a pressure contact member.

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

34 (a) and 34 (b) are configuration diagrams respectively showing another conventional fixing device.

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

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

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

FIG. 38 is a perspective view showing a pressure contact member.

FIG. 39 is an explanatory diagram showing a non-uniform contact state between a belt and a roll.

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

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

FIG. 42 is a cross-sectional view of essential parts showing the operation of a conventional fixing device.

[Explanation of symbols]

1 heat fixing roll, 10 endless belt, 11, 13
Roll, 12 steering roll, 14 pressure contact member, 22
A cylindrical member, 23 elastic layers, and 24 groove portions (unevenness).

Claims (4)

(57) [Claims] 1. 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 that performs a fixing process, the surface of at least one of the plurality of rolls around which the endless belt is stretched is covered with an elastic layer, and unevenness is formed on the surface of the elastic layer . In addition, said at least one roll
The elastic layer coated on the surface is the end of the endless belt.
The width of the elastic layer so that it does not touch the end.
A fixing device characterized in that the fixing belt is set to be narrower than an end portion in consideration of deviation of the belt . 2. The surface of the fixing member is covered by a plurality of rolls.
The endless belt stretched over
Bears the unfixed toner image on the pressure contact area between the material and the endless belt
The fixing process is performed by passing the held transfer material.
In the fixing device, the endless belt is stretched.
Surface of at least one roll of the plurality of rolls
The surface of the elastic layer while covering the elastic layer.
Irregularities are formed, and further the on the end of the elastic layer coated on the surface of at least one roll, over a range of the ends of the endless belt are in contact, characterized in that a wear-resistant coating layer And fixing device. 3. The unevenness formed on the surface of the elastic layer,
The fixing device according to claim 1 or 2, wherein the fixing device comprises a groove formed in the elastic layer. 4. The unevenness formed on the surface of the elastic layer,
The fixing device according to claim 1 or 2, wherein the fixing device comprises minute irregularities formed by roughening the surface of the elastic layer.