JPH09185280A - Roller, fixing heater, fixing device and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a roller which is facilitated in the attachment of a rotary shaft, free to automatically align and capable of improving close contactness with a pressure roller, without requiring advanced working and assembling accuracy by providing attaching fixtures which support the rotary shaft, so that it passes through the center axis of a base body, have heat resistance and are free to elastically deform. SOLUTION: In the roller 11 for a fixing heater, a roller base body 12 as a straight cylindrical base body is made of a heat-resistant insulating material. A pair of left and right fixtures 14a and 14b for fixedly holding both end parts of the rotary shaft 13 passing through the center axis of the roller base body 12, not to rotate the rotary shaft 13 are attached not to be rotated, in the roller base body 12. The respective attaching fixtures 14a and 14b are made of for instance, phosphor bronze having the heat resistance, spring and elasticity and boss parts 15 through which the rotary shaft 13 is inserted and which fix the rotary shaft 13, not to rotate it and plural arms 16 radially extended out are integrally formed. Thus, for the roller base body 12 and the attaching fixtures 14a and 14b, working with high accuracy is unnecessitated and the workability of working and assembling is facilitated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roller-type fixing heater suitable for use in small equipment such as office automation equipment, household electric equipment and precision manufacturing equipment, and a copying machine equipped with this fixing heater. The present invention relates to a fixing device used for fixing a toner such as a facsimile and an image forming apparatus using the fixing device.

[0002]

2. Description of the Related Art Generally, in an electronic copying machine, a copy sheet on which a toner image is formed is passed between a fixing heater and a pressure roller while directly or indirectly through a heat-resistant sheet while pressing the fixing sheet. It is equipped with a fixing device that heats, melts, and fixes the toner on the copy paper by the heating of.

FIG. 12 shows a conventional fixing device of this type.
The roller 1 is configured as shown in FIG.

The roller 1 has a cylindrical base body 2 made of a heat-resistant electrically insulating material such as ceramics and has a cylindrical base body 2 at both axially open ends.
3b are respectively inserted and fixed, and further, the rotary shaft 4 passing through the central axis of the roller base 2 is inserted into the central holes of the end plugs 3a and 3b, and the rotary shaft 4 is inserted through the insertion portion. The rotation shaft 4 is concentrically attached to the roller base 2 by being fixed so as not to rotate. Both outer ends of the rotary shaft 4 are rotatably supported by bearings (not shown).

By forming a resistance heating element (not shown) and a pair of electrodes electrically connected to both ends of the roller heating element on the outer peripheral surface of the roller base 2 in an annular shape by thick film printing or the like. It is designed to be a roller type fixing heater.

[0006]

However, in such a conventional roller 1, the pair of end plugs 3a and 3b for fixing the rotary shaft 4 to the roller base 2 and the roller base 2 are both made of a material having high rigidity. Therefore, once the centering is performed, the positional relationship between the roller base 2 and the rotary shaft 4 is fixed, and the centering cannot be performed.

Further, when the rotating shaft 4 and the central axis of the roller base body 2 are deviated from each other, the roller base body 2 is eccentrically rotated and the rotation becomes unsmooth. Familiarity becomes poor and the contact pressure between the two becomes uneven in the axial direction. For this reason, uneven heating may occur, and uneven fixing may occur.

Therefore, conventionally, the circularity of the roller base 2 must be processed with high precision, and the rotary shaft 4 must be concentrically mounted on the roller base 2 with high precision. For this reason, there is a problem in that workability and assembling workability are low and the manufacturing cost is high.

By the way, Japanese Patent Laid-Open No. 57-189170 describes that both ends of a thin-walled heating roller are made of elastic members. However, since this is a thin-walled cylinder, elastic deformation is possible. When the heating roller and the pressure roller are brought into pressure contact with each other, the heating roller and the elastic members at both ends of the heating roller are elastically deformed together to improve the adhesion with both rollers. The centering of the rotary shaft 4 is not adjustable. Further, this heating source is a lamp, which is different from the resistance heating element made of thick film printing or the like.

Therefore, an object of the present invention is to easily attach the rotary shaft of the roller and to perform self-alignment, to easily improve the adhesion with the pressure roller, and to perform high-level processing and assembly. An object of the present invention is to provide an inexpensive roller, a fixing heater, a fixing device, and an image forming apparatus that do not require application accuracy.

[0011]

A roller according to a first aspect of the present invention comprises a cylindrical roller base body having at least an outer surface formed of a heat-resistant electric insulating layer; and extending outward from both axial ends of the roller base body. And a rotation shaft that holds the rotation shaft so that it does not rotate, and when the roller shaft is attached to the rotation shaft, the rotation shaft is supported so as to pass on the central axis of the base body. And a member;

In the present invention, the roller substrate is, for example, alumina (Al ₂ O ₃ ) or mullite (3Al ₂ O ₃ ·.
It may be made of 2SiO ₂ ) ceramics, or may be made of a metal straight barrel having a heat-resistant electric insulating layer on its outer surface. The mounting member that attaches the rotary shaft to the roller base is
Any material can be used as long as it has heat resistance, elasticity, and elasticity and can be elastically deformed. For example, there is a leaf spring made of phosphor bronze.

According to the present invention, since the rotary shaft is attached to the roller base by the elastically deformable mounting member, the rotary shaft may be displaced from the central axis of the roller base due to the low circularity accuracy of the roller base. If there is a deviation, the mounting member receives the external force that attempts to restore the deviation and is elastically deformed during rotation, so that the rotation axis can be automatically aligned with the central axis of the roller base body.

For this reason, since the roller base body and the mounting member do not require high-precision machining and assembly, workability of machining and assembly is facilitated, and the machining cost can be reduced. It is possible to improve the adhesion to the pressure roller with which the roller base body is in contact. Further, even if the resistance heating element expands and contracts due to repeated energization heating, the expansion and contraction can be absorbed by the mounting member having heat resistance and elasticity, so that the adhesion between the roller and the pressure roller is improved. It is possible to prevent the fluctuation, and it is possible to prevent the fixing force of the mounting member from being lowered and dropping from the roller base body.

According to another aspect of the roller of the present invention, the mounting member includes an insertion support portion which is fixed to and supports the rotation shaft by inserting the rotation shaft into the insertion hole on the center axis of the roller base so as not to rotate; An elastically deformable fixing portion that is connected to the insertion supporting portion to fix the insertion supporting portion in the roller base; and a locking portion that is formed in the fixing portion and is positioned at the mounting position on the inner peripheral surface of the roller base. And a lock portion. The locking portion may have any shape as long as it can lock the attachment member.

According to the present invention, the mounting member is inserted from the opening end of the roller base body, and is simply pushed until the locking portion is locked in the locking portion of the inner peripheral surface of the roller base body. It can be installed accurately and easily at the mounting position. By locking each locking portion of each mounting member to each locking portion of the roller base body, it is possible to prevent each mounting member from rotating the locking portion within the roller base body. Moreover,
Since the mounting member itself is elastically deformable, the mounting member can be elastically contracted and easily and quickly inserted into the roller base body, and its assembling property can be improved.

According to a third aspect of the present invention, the fixed portion is configured so as to radially extend outward from the insertion support portion in the radial direction.

According to the present invention, since there is a gap between the radial portions that are adjacent to each other in the circumferential direction of the mounting member, each radial portion can be elastically deformed toward this gap side. Therefore, the radial elastic deformation amount can be increased.
As a result, the amount of automatic alignment of the rotary shaft can be further increased.

According to another aspect of the roller of the present invention, the mounting member has a fixed portion which is externally fitted and fixed to both axial end portions of the roller base body, respectively. An insertion support portion that is inserted into the insertion hole on the central axis of the and fixed and supported so as not to rotate.

According to the present invention, the rotary shaft can be easily and quickly attached to the roller base body by simply pushing the fixed portion of the attachment member into both ends of the opening of the roller base body and externally fitting it.

The roller of claim 5 is characterized in that the rotating shaft and at least one mounting member are electrically conductive.

According to a sixth aspect of the roller, the mounting member is electrically conductive, and two electrically conductive rotary shafts divided at both axial ends of the roller base are fixed so as not to rotate. It is characterized by

The rotary shaft may be one, or may be divided into two, as long as it can extend outward from both ends of the roller base.

The fixing heater according to claim 7 is the roller according to any one of claims 1 to 4, a resistance heating element formed on at least the outer surface of the roller base, and substantially concentric with at least the outer surface of the roller base. And a pair of electrodes that are formed into a shape and are electrically connected to the resistance heating element.

In the present claim and the following claims, the resistance heating element is mainly formed of a silver-palladium (Ag.Pd) alloy, a nickel-tin (Ni.Sn) alloy, or the like, and is formed in an annular band shape by thick film printing or the like. It

The electrode is silver or silver / platinum (Ag / Pt)
It is formed in a ring shape by thick film printing using a good conductor such as an alloy or silver / palladium (Ag / Pd) alloy.

The outer surfaces of these electrodes and the resistance heating element are almost entirely covered with a glassy overcoat layer,
Mechanical improvements such as wear resistance and impact resistance, corrosion protection from sulfidation and oxidation, and electrical insulation of the pressure roller and the like may be achieved.

According to the fixing heater of the present invention,
The roller according to any one of 1 to 4 is provided, and since these rollers have the function of automatically aligning the rotating shaft, the adhesion with the pressure roller can be constantly improved. For this reason, it is possible to prevent uneven heating and eventually uneven fixing. In addition, substantially the same operational effects as those of the invention according to any one of claims 1 to 4 can be obtained.

A fixing device according to an eighth aspect of the present invention includes: the roller according to the fifth aspect; a resistance heating element formed on at least an outer surface of the roller base; and a resistance formed by being formed substantially concentrically on at least the outer surface of the roller. A pair of electrodes electrically connected to one end of the heating element; a through hole formed in the roller to penetrate the inside and outside of the roller in the radial direction and electrically connect one conductive mounting member to the resistance heating element. And; are provided.

According to the present invention, since the roller having the self-centering function according to the fifth invention is provided, it is possible to obtain substantially the same operational effect as the present invention.

According to a ninth aspect of the present invention, there is provided a fixing device including: the roller according to the sixth aspect; a resistance heating element formed on at least an outer surface of the roller base body; A through hole formed with a conductor for electrically connecting the conductive mounting member to the resistance heating element.

According to the present invention, since the roller having the self-centering function according to the sixth invention is provided, it is possible to obtain substantially the same operational effect as the present invention.

According to a tenth aspect of the present invention, there is provided the fixing heater device according to the eighth or ninth aspect, wherein the fixing heater is arranged so as to face the fixing heater and presses the fixing heater, and heat from the fixing heater is applied to the image on the fixing target. And a pressure roller that acts on the toner forming the sheet and conveys the fixing target.

According to an eleventh aspect of the present invention, there is provided the fixing device according to the tenth aspect, wherein toner is attached to the electrostatic latent image formed on the medium to form a reverse image, and the reverse image is transferred to a fixing target. And means for forming a predetermined image.

Therefore, the fixing device according to claim 10,
The image forming apparatus according to claim 11 has the respective inventions described above, and therefore has substantially the same operational effect.

[0036]

FIG. 1 is a block diagram showing an embodiment of the present invention.
This will be described with reference to FIG. In addition, in FIGS.
The same or corresponding parts are designated by the same reference numerals.

FIG. 1 is a vertical sectional view of a roller for a fixing heater according to a first embodiment of the present invention, and FIG. 2 is a right side view of FIG. 1. In these drawings, the roller 11 for the fixing heater is heat-resistant. Electrically insulating material such as alumina (Al
₂ O ₃ ) or mullite (3Al ₂ O ₃ · 2SiO ₂ )
For example, a roller base 12 which is a body body of a cylindrical body having a straight body is formed of ceramics.

Inside the roller base body 12, a pair of left and right fittings 14a and 14b in the figure for firmly holding the both ends of the rotary shaft 13 passing on the central axis thereof so as not to rotate are attached so as not to rotate. doing.

As shown in FIG. 2, each of the fixtures 14a, 14b
Is a heat resistant, springy and elastic material such as phosphor bronze, which is inserted through the rotary shaft 13 and fixed so as not to rotate, and a radial direction outward from the boss portion 15. The plurality of extending arms 16 are formed integrally or integrally.

Each arm 16 is formed so that its tip portion 16a is slightly curved inward, so that it can be easily inserted inward from the opening end of the roller base body 12. Further, as shown in FIG. The outer surface of the roller base 12 has a plurality of engaging recesses 1 for positioning formed on the inner peripheral surfaces of both ends thereof.
Engaging protrusions 16b that engage with the inside of 2a are provided in a protruding manner.

Therefore, according to this embodiment, after the rotary shaft 13 is attached to the pair of attachments 14a and 14b, the pair of attachments 14 is inserted into the roller base body 12 from its opening end.
a and 14b are elastically contracted and inserted, and each arm 16
Of the engaging convex portion 16b of the engaging concave portion 12a in the roller base 12.
By pushing it in until it engages,
4b can be easily and quickly attached to a predetermined attachment position in the roller base 12, and the rotary shaft 13 can be attached to the roller base 12. In addition, by fitting the respective engaging protrusions 16b of the respective fittings 14a and 14b into the engaging recesses 12 of the roller base 12, the respective fittings 14
It is possible to position the mounting positions of a and 14b and prevent the mounting tools 14a and 14b from rotating in the roller base body 12.

After mounting the respective attachments 14a and 14b on the roller base 12, the rotary shaft 13 is attached to the roller base 12.
It is possible to perform centering at the same time so as to coincide with the central axis of. Moreover, since the respective attachments 14a and 14b are elastically deformable, the center axes of the rotary shaft 13 and the roller base 12 are displaced from each other because the roundness accuracy of the roller base 12 is very low. If the two outer ends of the rotary shaft 13 are rotatably supported by a pair of bearings (not shown),
An external force for returning to the central axis acts on each of the fixtures 14a and 14b, and the respective external forces of the fixtures 14a and 14b elastically deform by this external force so that the rotary shaft 13 is automatically centered. can do.

Therefore, the roller base 12 and each mounting tool 1
Since it is not necessary to process 4a and 14b with high precision, it is possible to reduce the manufacturing cost and improve the assembly workability.

Further, since the respective attachments 14a, 14b have heat resistance and elasticity, they are less likely to be deteriorated by the heating of the resistance heating element formed on the outer peripheral surface of the roller base 12, and the heating and stopping thereof are not required. Since the expansion and contraction that accompany it can be absorbed by elastic deformation, it is possible to prevent the attachments 14a, 14b from falling off the roller base 12 in advance.

Furthermore, since each arm 16 of each of the attachments 14a and 14b extends radially outward, there is a gap between adjacent arms 16 in the circumferential direction, and the arm 16 can be elastically deformed toward this gap. Therefore, the amount of elastic deformation can be increased. Therefore, the amount of automatic alignment of the rotary shaft 13 can be increased.

FIG. 3 is a vertical cross-sectional view of the second embodiment of the present invention, which is characterized in that the pair of fittings 14a, 14b are replaced with bifurcated fittings 17a, 17b.

The bifurcated fittings 17a and 17b are provided on the rotary shaft 13.
On the inner and outer both sides of the boss portion 18 for holding the roller base 12 on the central axis,
19b are provided respectively. Each inner arm 1
The engaging recess 1 of the roller base 12 is provided only on the outer surface of the tip portion of 9a.
An engagement protrusion 20 that engages with 2a is provided. This is because the engaging protrusions 20 are also provided on the outer arms 19b and the engaging recesses 12b that engage with the engaging protrusions 20 are provided on the roller base body 12 when the forked attachments 17a and 17b are inserted into the roller base body 12. , The engaging protrusion of the inner arm 19a is the outer engaging recess 12
This is because it is inserted into b and further insertion is impossible.

According to the bifurcated attachments 17a and 17b, the arms 19a and 19b are provided on both inner and outer sides thereof, so that the holding strength of the rotary shaft 13 can be increased and stabilized.

FIG. 4 is a longitudinal sectional view of a third embodiment of the present invention, in which the pair of fittings 14a, 14b are replaced with, for example, three rubber fittings 21, 22, 23. There are features. Each of these rubber fittings 21, 22, and 23 is formed of a heat resistant rubber such as silicon into a cylindrical body that is tightly inserted and fixed at both end portions of the roller base 12 and an intermediate portion thereof so as not to rotate. Insertion holes 21a, 2 for inserting the rotary shaft 13 on the central axis of the roller base 12 are provided in the shaft center portion.
2a and 23a are respectively formed, and these insertion holes 21a to
The rotation shaft 13 is fixed to 23a so as not to rotate.

Therefore, according to this embodiment, each of the rubber fittings 21 to 23 also causes the respective fittings 14a, 14a to
b, 17a, and 17b have the function of automatically aligning the rotary shaft 13, and the shapes of the rubber fittings 21 to 23 are simple, so that the manufacturing is easy and the mass productivity can be improved. it can.

FIG. 5 (A) is a longitudinal sectional view of an essential part of the fourth embodiment of the present invention, and FIG. 5 (B) is a right side view of FIG. 5 (A). It is characterized in that it is held and fixed by 24.

The cap-like fitting 24 is formed of a bottomed cylindrical shape that is fitted and fixed to both ends of the roller base 12 so as not to rotate by phosphor bronze or the like having heat resistance and springiness, and its inner surface. Each of them has an annular fitting groove 24a into which both ends of the roller base 12 are tightly fitted.

Further, an insertion hole 24b for inserting the rotary shaft 13 is bored in the axial center portion of the cap-shaped fixture 24, and the rotary shaft 13 is fixed so as not to rotate in the insertion hole 24b. This cap-shaped attachment 24 also has the function of automatically aligning the rotary shaft 13 as in the above embodiments.

FIG. 6 is a vertical cross-sectional view of a main part of a fifth embodiment of the present invention, which is characterized in that the rotary shaft 13 is held and fixed by a lid-like attachment 25.

The lid-like attachment 25 is formed of, for example, phosphor bronze into a bottomed cylindrical shape which is externally fitted and fixed to both ends of the roller base 12, and the inside of an insertion hole 25a into which the rotary shaft 13 is inserted is curved in an arc shape. The rotating shaft 13 is elastically deformably held by the plurality of curved portions 25b.

Therefore, the lid-like attachment 25 also has a function of automatically aligning the rotary shaft 13.

FIG. 7 is a vertical sectional view of a fixing heater according to a sixth embodiment of the present invention. The fixing heater 26 is a fixing heater roller according to any one of the above embodiments, for example, 1
1 (see FIG. 1) on the substantially outer peripheral surface other than both end portions of the roller base body 12 of FIG. 1, for example, a film shape mainly composed of silver / palladium (Ag / Pd) alloy or nickel / tin (Ni / Sn) alloy. The resistance heating element 27 is formed in an annular band shape by thick film printing or the like.

Further, silver or a silver / platinum (Ag / Pd) alloy,
A pair of left and right annular strip electrodes 28a and 28b made of a good conductor film of silver / palladium alloy (Ag / Ρd) or the like is formed by thick film printing. The inner ends of the electrodes 28a and 28b partially overlap with both ends of the resistance heating element 27 in the vertical direction, for example, and are electrically connected to each other over the entire circumference to supply power to the resistance heating element 27. It is like this.

The electrodes 28a and 28b are integrally connected to both axial ends of the roller base 12 and the inner peripheral side thereof. The entire outer peripheral surface of the resistance heating element 27 is entirely covered with a vitreous overcoat layer 29 to improve mechanical strength such as abrasion resistance and impact resistance, and corrosion resistance protection from sulfidation and oxidation. It is electrically insulated from the pressure roller and the like. However, as shown in FIG. 8, the overcoat layer 29 may be omitted, or the roller base 12 may be formed by coating the entire peripheral surface of a metal pipe (not shown) with a ceramic layer.

Then, as shown in FIG. 7, a pair of electrodes 28
Power supply means 3 for applying a predetermined voltage to a and 28b to supply power
0 is provided. As the power feeding means, the electrodes 28a, 28
There is a strip-shaped power supply body, a power supply brush, or the like that slides on the outer peripheral surface of b and is electrically connected.

FIG. 8 is a vertical cross-sectional view of the seventh embodiment of the present invention, in which the fixing heater 31 has a rotary shaft 13 extending in the axial direction.
The parts 13a and 13b are provided with conductivity, and each of these minor axes 1
3a, 13b two inside and outside one set of fittings 32, 33, 3
4, 35 are attached to the roller base body 12 and, at the same time, the resistance heating elements 27 are connected to the conductive minor shafts 13a and 13b.
It is characterized in that a power supply means 36 for supplying power to

Each of the fittings 32 to 35 is formed into a columnar body which is inserted and fixed in the roller base body 12 by phosphor bronze or the like having heat resistance, conductivity and spring property, and each of the minor shafts 13a and 13b is attached to the roller base body 12. Insertion hole 32a that can be inserted on the central axis,
33a, 34a, 35a are respectively inserted, and the short shafts 13, 13b are fixed so as not to rotate in the insertion holes 32a-35a.

The inner peripheral surface of the roller base body 12 in contact with the outer peripheral surfaces of the outer mounting members 33 and 35 penetrates radially outward and is electrically connected to the inner peripheral surface of the resistance heating element 27. Through holes 37 and 38 are provided respectively.

Therefore, power is supplied from the power supply means 36 to the resistance heating element 27 through the short shafts 13a and 13b, the outer attachments 33 and 35, and the through holes 37 and 38 in this order.

FIG. 9 is a vertical cross-sectional view of an eighth embodiment of the present invention. This fixing heater 39 has a fixture 40 having heat resistance and electrical insulation, and a fixture 4 having heat resistance and conductivity.
1 holds one long rotating shaft 13c having conductivity, and the annular electrode 4 on one end side of the roller base 12
2 and that the power supply means 43 for supplying power to the resistance heating element 27 is provided from one end of the conductive rotating shaft 13c on the electrode 42 side.

Then, the inner peripheral surface of the roller base 12 which contacts the outer peripheral surface of the conductive mounting member 41 penetrates in the radial direction of the roller base 12 and electrically contacts the inner peripheral surface of the resistance heating element 27. Through holes 44 are provided.

Therefore, the power is fed from the power feeding means 43 through the electrode 42 on the one hand and the conductive rotary shaft 13c, the conductive fitting 41 and the through hole 44 on the other hand in this order to the resistance heating element 2.
Powered to 7. According to this, power can be supplied from one side having the electrode 42.

FIG. 10 shows the configuration of an embodiment of an electronic copying machine 51 which is a kind of image forming apparatus according to the ninth embodiment of the present invention. The copying machine 51 is provided in a housing 52, and a cassette. An image forming unit 54 that draws in the copy paper P in 53 and forms a toner image corresponding to the image of the original document (not shown), and a fixing device 55 that fixes the toner image on the copy paper P are built-in.

The fixing device 55 is constructed, for example, as shown in FIG. 11, and faces the pressure roller 56 so as to face the fixing device 2.
6, 31, and 39, for example, 26 are juxtaposed, and both outer ends of the rotary shaft 13 of the fixing device 26 are rotatably supported by bearings (not shown). It is elastically pressed against the silicone rubber layer 57 of the pressure roller 56.

The fixing device 26 includes a pair of electrodes 28.
The resistance heating element 27 generates heat by being energized through a pair of power feeding brushes (not shown) of the power feeding means 30 having elasticity, which is made of a phosphor bronze plate slidably contacting the outer peripheral surfaces of a and 28b, and the overcoat layer is formed. 29. Therefore, the outer surface of the surface glass coat layer 29 and the pressure roller 5 are
The unfixed toner image T can be fused and fixed on the copy paper P by pinching the copy paper P on which the toner image T is formed with the silicone rubber layer 57 of 6 and heating by the fixing heater. .

Since the fixing device 26 is provided with the roller base 12 having the function of automatically aligning the rotary shaft 13,
The adhesiveness between the fixing heater and the pressure roller 56 can be constantly enhanced constantly, and substantially the same effect as that of the fixing heater including the roller base 12 can be obtained.

[0072]

As described above, according to claim 1 of the present application, since the rotary shaft is mounted on the roller base by the elastically deformable mounting member, the accuracy of the roundness of the roller base is low. If the rotation axis is deviated from the center axis of the roller base by the mounting member, the mounting member receives the elastic force to rotate and automatically deforms the rotation axis to the center axis of the roller base. Can be aligned.

For this reason, since the roller base and the mounting member do not require high-precision processing and assembly, workability of processing and assembly is facilitated, and the processing cost can be reduced and the roller It is possible to improve the adhesion to the pressure roller with which the base body is in contact. Further, even if the resistance heating element expands and contracts due to repeated energization heating, the expansion and contraction can be absorbed by the mounting member having heat resistance and elasticity, so that the degree of adhesion between the roller and the pressure roller can be improved. It is possible to prevent the fluctuation, and it is also possible to prevent the fixing force of the mounting member from being lowered and dropping from the roller base body.

According to the second aspect of the invention, the mounting member is inserted from the opening end of the roller base body and is simply pushed until the locking portion is locked in the locking portion of the inner peripheral surface of the roller base body. Can be accurately and easily attached to a predetermined attachment position. By locking each locking portion of each mounting member to each locking portion of the roller base body, it is possible to prevent each mounting member from rotating the locking portion within the roller base body.
Moreover, since the mounting member itself is elastically deformable, the mounting member can be elastically contracted and easily and quickly inserted into the roller base body, and its assembling property can be improved.

According to the third aspect of the invention, since there is a gap between the radial portions that are adjacent to each other in the circumferential direction of the mounting member, each radial portion can be elastically deformed toward the gap side. Therefore, the radial elastic deformation amount can be increased. As a result, the amount of automatic alignment of the rotary shaft can be further increased.

According to the fourth aspect of the present invention, the rotary shaft can be easily and quickly attached to the roller base by simply pushing the fixing portion of the attachment member into both ends of the opening of the roller base and externally fitting it.

According to the fifth and sixth aspects of the present invention, one rotary shaft may be used, or the rotary shaft may be divided into two, as long as it can extend outward from both ends of the roller base.

According to the fixing heater of claim 7, claim 1
To the roller base of the invention described in any one of
Since these roller bases have a function of automatically adjusting the axis of rotation, the adhesion with the pressure roller can be constantly improved.
For this reason, it is possible to prevent uneven heating and eventually uneven fixing. In addition, substantially the same operational effects as those of the invention according to any one of claims 1 to 4 can be obtained.

According to the invention of claim 8, since the roller having the self-aligning function of claim 5 is provided, it is possible to obtain substantially the same operational effect as the invention having this substrate.

According to the invention of claim 9, since it has the roller having the self-centering function of claim 6, it is possible to obtain substantially the same operational effect as the invention having this roller.

A fixing device according to claim 10 and claim 11
The described image forming apparatus has the above-described inventions as appropriate, and therefore has substantially the same operational effects.

[Brief description of the drawings]

FIG. 1 is a vertical cross-sectional view of a fixing heater roller according to a first embodiment of the present invention.

FIG. 2 is a right side view of FIG.

FIG. 3 is a vertical cross-sectional view of a fixing heater roller according to a second embodiment of the present invention.

FIG. 4 is a vertical cross-sectional view of a fixing heater roller according to a third embodiment of the present invention.

5A is a longitudinal sectional view of a main part of a fixing heater roller according to a fourth embodiment of the present invention, and FIG. 5B is a right side view of FIG. 5A.

FIG. 6 is a vertical cross-sectional view of a main part of a fixing heater roller according to a fifth embodiment of the present invention.

FIG. 7 is a longitudinal cross-sectional view of a main part of a fixing heater according to a sixth embodiment of the present invention.

FIG. 8 is a longitudinal cross-sectional view of a main part of a fixing heater according to a seventh embodiment of the present invention.

FIG. 9 is a vertical cross-sectional view of a main part of a fixing heater according to an eighth embodiment of the present invention.

10 is an overall configuration diagram of an image forming apparatus including the fixing heater shown in FIG.

11 is an enlarged view of a main part of the fixing device shown in FIG.

FIG. 12 is a vertical sectional view of a conventional fixing heater roller.

[Explanation of symbols]

 11 Roller for Fixing Heater 12 Roller Base 12a Engagement Recess (Locking Part) 13 Rotation Shafts 13a, 13b Minor Shaft of Rotation Shaft 13c Conductive Rotation Shafts 14a, 14b Attachment (Attachment Member) 15, 18 Boss 15 Arm ( Radial part) 17a, 17b Bifurcated fitting 19a Inner arm 19b Outer arm 20 Engagement convex part (locking part) 21,22,23 Rubber fitting 21a, 22a, 23a Insertion hole 24 Cap fitting 24b Fitting groove 25 Lid-like fittings 26, 31, 39 Fixing heater 27 Resistance heating elements 28a, 28b Pair of annular electrodes 29 Glass coat layer 30, 36, 43 Power feeding means 33, 35, 41 Conductive fittings 32, 34, 40 Electrical insulation Mounting fixture 37, 38, 44 Through hole 51 Electronic copying machine (image forming apparatus) 52 Housing 53 Cassette 54 Image formation 55 fixing device 56 the pressure roller 57 the silicone rubber layer P copy sheet Τ toner image

Claims (11)

[Claims] 1. A cylindrical roller base body having at least an outer surface formed of a heat-resistant electrical insulating layer; rotating shafts extending outward from both axial ends of the roller base body; and a rotating shaft which does not rotate. And a heat-resistant elastically deformable mounting member for supporting the rotary shaft so as to pass on the central axis of the base body while being attached to the roller base body. And Laura. 2. A mounting member, and an insertion support portion for fixing and supporting the rotation shaft by inserting the rotation shaft into the insertion hole on the central axis of the roller base body so as not to rotate; and integrally connecting to the insertion support portion. An elastically deformable fixing part for fixing the insertion support part in the roller base; a locking part formed on the fixing part and locked by a positioning locking part at the mounting position on the inner peripheral surface of the roller base; The roller according to claim 1, further comprising: 3. The roller according to claim 2, wherein the fixing portion is configured to extend radially outward from the insertion support portion in the radial direction. 4. The mounting member includes a fixed portion which is fitted and fixed to both axial end portions of the roller base body, respectively; and a rotary shaft is integrally formed with the fixed portion so that the rotary shaft is inserted on the central axis of the roller base body. The roller according to claim 1, further comprising: an insertion support portion that is inserted into the hole and fixed and supported so as not to rotate. 5. The roller according to claim 1, wherein the rotating shaft and the at least one mounting member are electrically conductive. 6. The mounting member is electrically conductive and has a structure in which two conductive rotating shafts divided at both axial ends of the roller base are fixed so as not to rotate. The roller according to any one of claims 1 to 4. 7. The roller according to claim 1, a resistance heating element formed on at least an outer surface of the roller base body, and a resistance formed substantially concentrically on at least the outer surface of the roller base body. A fixing heater comprising: a pair of electrodes electrically connected to a heating element. 8. The roller according to claim 5; a resistance heating element formed on at least an outer surface of the roller base; and a concentric shape formed on at least an outer surface of the roller base at one end of the resistance heating element. An electrode electrically connected; and a through hole formed with a conductor penetrating radially inside and outside the roller base body to electrically connect one conductive mounting member to the resistance heating element. A fixing heater characterized in that 9. The roller according to claim 6 ,; a resistance heating element formed on at least an outer surface of the roller base; and a resistance heating element having a conductive mounting member at least at both ends thereof penetrating radially inside and outside the roller base. And a through hole formed with a conductor electrically connected to the fixing heater. 10. The fixing heater according to claim 8 or 9, wherein the fixing heater faces the fixing heater and is in pressure contact with the fixing heater, and heat from the fixing heater forms an image on a fixing target. And a pressure roller that conveys the material to be fixed and that is applied to the fixing device. 11. The fixing device according to claim 10, wherein toner is attached to the electrostatic latent image formed on the medium to form a reverse image, and the reverse image is transferred to a fixing target to form a predetermined image. An image forming apparatus comprising: a forming unit;