JP2017223882A - Image heating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image heating device capable of suppressing abrasion of a conductive part electrically connecting the external surface and the internal surface of a heating rotary part and suppressing the damage of the heating rotary part.SOLUTION: In an image heating device for heating a recording material P which carries an image T by a nip part N, a cylindrical heating rotary body 1 includes: a heating body 1d heated by conduction; a cylindrical base material 1c for holding the heating body; and conductive bodies 1a, 1b which are conductive bodies conductive to the heating body and provided on an external surface and an internal surface of the base material. An end surface in the longitudinal direction of the heating rotary body is smooth. The base material is provided with a hole 1g which penetrates from the external surface to the internal surface of the base material. An internal part of the hole has a conductive part 1f electrically connecting a conductor provided on the external surface and the internal surface of the base material in the internal part of the hole.SELECTED DRAWING: Figure 4

Description

  The present invention relates to an image heating apparatus suitable for use as a fixing device mounted on an image forming apparatus such as an electrophotographic copying machine or an electrophotographic printer.

  2. Description of the Related Art A film heating type device is known as a fixing device mounted on an electrophotographic copying machine or printer. This type of fixing device includes a cylindrical film having a heating element that generates heat when energized, a holder that supports the film, and a flange that restricts movement of the film in the longitudinal direction. Furthermore, it has a power supply electrode that supplies power to the heating element, and a pressure roller that forms a nip portion with the film sandwiched between the holder and the holder. The recording material carrying the unfixed toner image is heated while being conveyed in the nip portion, whereby the toner image is fixed on the recording material.

  Since this fixing device has a small heat capacity of the film, it has a merit that the time from when the power is turned on until it can be fixed is short, and the power consumption is also small.

  Patent Document 1 discloses an apparatus to which the above-described film heating type fixing device is applied. FIG. 10 is a partial cross-sectional perspective view showing the structure of the characteristic part of the fixing device of Patent Document 1.

  In Patent Document 1, in the longitudinal direction Y of the cylindrical belt 154, heat generating patterns 158 and 156 are provided on the inner surface and the outer surface of the insulating layer 155 of the belt, respectively. Then, in the longitudinal direction Y of the belt 154, a notch E is provided at the end of the insulating layer 155, and the end 156c of the heat generation pattern 156 on the outer surface side of the insulating layer is connected to the inner side heat generation pattern via the folded portion 156d in the notch. 158 is electrically connected. Further, the power supply member 170a is brought into contact with the heat generation pattern 156 on the outer surface side, and the power supply member 170b is brought into contact with the heat generation pattern 156 on the inner surface side, thereby enabling power supply to each heat generation pattern.

  The pressure roller 160 and the pressure roller 150 provided inside the belt 154 form a nip portion N with the belt 154 with the belt 154 interposed therebetween.

Japanese Patent Laying-Open No. 2015-4716

  The following problems arise when the configuration of the belt of Patent Document 1 is applied to a cylindrical film. The film is a member that rotates following the rotation of the pressure roller. If a biasing force continues to be applied to the film in the longitudinal direction of the film, the folded portion of the heating element (hereinafter referred to as the conductive portion) is formed in the notch, so that the conductive portion does not contact the flange and is conductive. Wear of the part can be suppressed. However, since the end portion of the film repeats sliding contact with the flange, the film may be torn and damaged starting from the notch.

  It is an object of the present invention to provide an image heating apparatus capable of achieving both suppression of wear of a conductive portion that electrically connects an outer surface and an inner surface of a heating rotator and suppression of breakage of the heating rotator. To do.

In order to achieve the above object, an image heating apparatus according to the present invention includes:
A cylindrical heating rotator, a support member that supports the heating rotator, a regulating member that restricts the movement of the heating rotator in the longitudinal direction, and a nip portion that forms the nip portion with the support member sandwiching the heating rotator In the image heating apparatus that heats a recording material that carries an image at the nip portion, the heating rotator includes a heating element that generates heat when energized, and a cylinder that holds the heating element. A conductive material for energizing the heating element and provided on the outer surface and the inner surface of the substrate, and the end surface in the longitudinal direction of the heating rotator is smooth, The substrate is provided with a hole penetrating from the outer surface to the inner surface of the substrate, and has a conductive portion that electrically connects a conductor provided on the outer surface and the inner surface of the substrate inside the hole. And

  According to the present invention, it is possible to provide an image heating apparatus capable of achieving both suppression of wear of a conductive portion that electrically connects a conductor on an outer surface and an inner surface of a heating rotator and suppression of breakage of the heating rotator. it can.

1 is a longitudinal sectional view of a fixing device according to a first embodiment. FIG. 3 is a diagram when the fixing device according to the first exemplary embodiment is viewed from the upstream side in the conveyance direction of the recording material. 1 is a cross-sectional view of a fixing device according to a first embodiment. FIG. 6 is a diagram for explaining a film configuration of a fixing device according to the first embodiment. FIG. 6 is a diagram for explaining a film configuration of a fixing device according to a second embodiment. FIG. 6 is a diagram for explaining a film configuration of a fixing device according to a third embodiment. FIG. 6 is a diagram for explaining a film configuration of a fixing device according to a fourth embodiment. FIG. 6 is a diagram for explaining a film configuration of a fixing device according to a fifth embodiment. FIG. 6 is a diagram for explaining a film configuration of a fixing device according to a sixth embodiment. FIG. 10 is a partial cross-sectional perspective view showing the configuration of the characteristic part of the fixing device of Patent Document 1.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Although the preferred embodiment of the present invention is an example of the best embodiment of the present invention, the present invention is not limited by the following examples, and various other configurations are possible within the scope of the idea of the present invention. It is possible to replace with the configuration of

[Example 1]
The fixing device (image heating device) of this embodiment will be described with reference to FIGS. The fixing device shown in this embodiment is mounted on an image forming apparatus (not shown) such as an electrophotographic copying machine or a printer, and is unfixed toner formed on a recording material in an image forming unit of the image forming apparatus. An apparatus for heat-fixing an image on a recording material.

(1) Configuration of Fixing Device (Image Heating Device) 10 FIG. 1 is a longitudinal sectional view of a fixing device 10 according to this embodiment. FIG. 2 is a diagram when the fixing device 10 is viewed from the upstream side in the conveyance direction of the recording material P. FIG. FIG. 3 is a cross-sectional view of the fixing device 10 with the flange 5 removed.

  A fixing device 10 shown in this embodiment includes a flexible cylindrical film (heating rotator) 1, a holder (support member) 2, a pressure roller (pressure rotator) 3, and a power supply electrode 4. And having. Further, the fixing device 10 includes a flange (regulating member) 5, a stay (pressure member) 6, a temperature detection element 7, and springs (biasing members) 8 and 9.

  The film 1 has an outer diameter of 18 mm. The length of the direction (hereinafter referred to as the longitudinal direction) Y (see FIG. 2) orthogonal to the conveying direction of the recording material P of the film 1 is 250 mm. In the longitudinal direction Y, a heat generating layer (heating element) 1d (see FIG. 4) that generates heat by energization is provided in a passage region (see FIGS. 2 and 3) through which the recording material P of the film 1 passes. The layer structure of the film 1 will be described in detail later.

  The pressure roller 3 includes a metal core 31 having an outer diameter of 10 mm, an elastic layer 32 provided on the outer peripheral surface of the metal core, and a release layer 33 provided on the outer peripheral surface of the elastic layer. As the elastic layer, silicone rubber having a film thickness of 4 mm is used. As the release layer 33, PFA having a film thickness of 30 μm is used. The outer diameter of the pressure roller 3 is 18 mm. Further, in the roller portion composed of the elastic layer 32 and the release layer 33 of the pressure roller 3, the hardness under an Asker C-type hardness meter 9.8N (1 kgf) load is 40 degrees. In the longitudinal direction Y, both ends of the cored bar 31 are rotatably held by a frame (not shown) of the fixing device 10 via a bearing.

  The holder 2 inserted into the film 1 is formed using a heat resistant resin such as a liquid crystal polymer. The length of the holder 2 in the longitudinal direction Y is 250 mm. The holder 2 supports the film by the arcuate surface 2a on the pressure roller 3 side of the holder being pressed against a part of the inner peripheral surface (inner surface) of the film 1 as described later.

  The stay 6 is made of a gin-coated steel plate having a U-shaped cross section. The stay 6 is inserted into the film 1 and disposed on the flat surface 2 b opposite to the arcuate surface 2 a of the holder 2.

  Each flange 5 held by the frame and fitted to both ends of the film 1 has a regulating surface 5a facing the end surface 1a of the film 1 with a predetermined gap. When the force is continuously applied to the film 1 and the film moves in the longitudinal direction Y, the end surface 1a of the film slides into contact with the regulating surface 5a of the flange 5 on the side of the film movement, thereby causing the film 1 to move in the longitudinal direction of the film. Movement is restricted.

  Each flange 5 is pressed by a spring 8 in a direction perpendicular to the generatrix direction of the film 1, whereby the stay 6 presses the holder 2 and presses the arcuate surface 2 a of the holder against the inner surface of the film 1. As a result, the elastic layer 32 of the pressure roller 3 is elastically deformed to form a nip portion N having a predetermined width between the outer peripheral surface (surface) of the film 1 and the outer peripheral surface (surface) of the pressure roller 3.

  The spring 8 is a compression coil spring made of SUS material. The pressure applied to the flange 5 by the spring 8 was 160N.

  As shown in FIG. 3, in the longitudinal direction Y, concave portions 2 c are provided at both ends of the holder 2 at positions 15 mm inside from both ends of the holder. In each recess 2c, a feeding electrode 4 made of an aluminum material in a rectangular parallelepiped shape is fitted from the arcuate surface 2a side of the holder 2. The dimensions of the feeding electrode 4 are 5 mm in the longitudinal direction Y, 3 mm in the conveyance direction of the recording material P, and 1 mm in height.

  Each power supply electrode 4 is pressed into contact with the conductive layer (conductor) 1a (see FIG. 4) on the inner surface of the film 1 by a spring 9 provided on the power supply electrode 4 inside the recess 2c. The pressure applied to the power supply electrode 4 by the spring 9 was about 5N. Each power supply electrode 4 is supplied with power from an AC power source V via a power supply cable c1 (see FIG. 2) drawn from a through hole 2d provided in communication with the recess 2c in the holder 2.

(2) Heat Fixing Processing Operation The pressure roller 3 is rotated in the arrow direction (see FIG. 1) by driving the motor M and rotating the gear G. The film 1 rotates in the direction of the arrow (see FIG. 1) following the rotation of the pressure roller 3 while the film inner surface slides on the arcuate surface 2 a of the holder 2 and the feeding electrode 4. In order to improve the slidability, 200 mg of heat-resistant grease mainly composed of fluorine oil and PTFE is applied to the inner surface of the film 1.

  Power is supplied to the conductive layer 1a of the film 1 from the AC power source V through the power supply electrode 4, whereby the heat generation layer 1d generates heat and the film rapidly rises in temperature. The temperature of the film 1 is detected by a temperature detection element 7 (see FIG. 2) brought into contact with the inner surface of the film. The control unit 20 controls the power supply control unit 21 so as to maintain the temperature of the film 1 at a predetermined temperature control temperature (target temperature) based on the detected temperature from the temperature detecting element 7.

  The recording material P carrying the unfixed toner image T is heated while being conveyed in the nip portion N, whereby the toner image is fixed on the recording material.

(3) Configuration of Film 1 The configuration of the film 1 will be described with reference to FIG.

  4A is a diagram showing a positional relationship among the film 1, the feeding electrode 4 and the pressure roller 3, FIG. 4B is a development view of the inner surface of the film showing the contact position of the feeding electrode 4, and FIG. (B) A1-A1 cross-section arrow view, (d) is a B1-B1 cross-section arrow view of (b).

  The film 1 has a heat generating layer 1d that generates heat when energized, and a cylindrical base layer (base material) 1c that holds the heat generating layer. The heat generating layer 1d is provided on the outer peripheral surface (outer surface) of the base layer 1c. The film 1 has conductive layers 1a and 1b for energizing the heat generating layer 1d on the inner peripheral surface (inner surface) and outer peripheral surface of the base layer 1c. The conductive layer 1b is bonded to the heat generating layer 1d. Furthermore, the film 1 has a release layer 1e as an outermost layer on the outer peripheral surface (surface) of the heat generating layer 1d on the outer peripheral surface side (outer surface side) of the base layer 1c and the outer peripheral surface (surface) of the conductive layer 1b. That is, the basic configuration of the film 1 is a three-layer configuration including a base layer 1c, a heat generating layer 1d, and a release layer 1e.

  The base layer 1c has one hole 1g at both ends in the longitudinal direction Y. Specifically, at a position 5 mm inside the end surface 1a1 in the longitudinal direction Y of the base layer 1c, a hole 1g having a perfectly circular outer diameter of 0.3 mm that penetrates from the outer surface to the inner surface of the base layer at one location in the circumferential direction of the base layer. Is formed by laser treatment. That is, in the longitudinal direction Y, one hole 1g is provided inside the both ends of the base layer 1c.

  The formation of the hole 1g is not limited to laser processing. You may form the hole 1g in the base layer 1c using a perfect circle punching die. As another method, when forming the base layer 1c and the heat generating layer 1d, a perfectly circular hole 1g may be formed in the base layer in advance using an etching process or a mask process.

  The flexible film 1 may repeatedly bend in a crown shape or a reverse crown shape in the longitudinal direction Y during the rotation of the film. Therefore, depending on the shape of the hole 1g, the film 1 may be cracked starting from the hole. By making the shape of the hole 1g into a shape having no corners such as a perfect circle compared to a shape having corners such as a rhombus or a quadrangle, the generation of cracks starting from the holes can be suppressed.

  In addition, although the diameter of the hole 1g is 0.3 mm, it is preferable to select a hole having a smaller diameter in order to increase the strength required for the film 1. On the other hand, when the electrical resistance values of the conductive layers 1a and 1b are high, it is desirable to select a hole having a large diameter. Specifically, it is desirable to select a range of 0.01 to 1 mm for the diameter of the hole 1g. In view of the balance between the strength of the film 1 and the electrical resistance values of the conductive layers 1a and 1b, it is desirable to set the diameter of the hole 1g.

  At both ends in the longitudinal direction Y of the base layer 1c, conductive layers 1a and 1b are respectively formed at a film thickness of 10 μm on the inner peripheral surface and the outer peripheral surface of the base layer over a position 15 mm inside from the end surface 1a1 of the base layer. Yes. Conductive layer 1b is joined to heat generating layer 1d. A conductive portion 1f is provided on the inner surface of the hole 1g to electrically connect the conductive layer 1a on the inner peripheral surface of the base layer 1c and the conductive layer 1b on the outer peripheral surface. The conductive portion 1f formed on the inner surface of the hole 1g has a thickness of 10 μm.

A polyimide-based silver paste having a volume resistivity of 2.0 × 10 ⁻⁶ [Ω · m] is used as each of the conductive layers 1a and 1b and the conductive portion 1f. A region extending 15 mm from both ends of the base layer 1c is dipped with a polyimide silver paste material, and the film thicknesses of the conductive layers 1a and 1b and the conductive portion 1f are controlled and applied by the dipping speed. After application to the base layer 1c, the polyimide silver paste is fixed to the base layer 1c by putting it in a thermostatic bath at 200 ° C. and baking it.

  Each feeding electrode 4 is in contact with the conductive layer 1a on the inner peripheral surface side (inner surface side) of the base layer at a position 15 mm inside from the end surface 1a1 in the longitudinal direction Y of the base layer 1c. When electric power is supplied from the AC power source V (see FIG. 2) via the feeding electrode 4, a conductive path is formed in the order of the conductive layer 1a, the conductive portion 1f on the inner surface of the hole 1g, the conductive layer 1b, and the heat generating layer 1d.

An insulating polyimide film with a thickness of 50 μm is used as the base layer 1c. As the heat generating layer 1d, polyimide having a film thickness of 10 μm to which carbon black as a conductive filler is added is used. The volume resistivity of the heat generating layer 1d is 1.0 × 10 ⁻⁴ [Ω · m], and the actual resistance value between both ends of the heat generating layer in the longitudinal direction Y is about 40Ω. PFA having a film thickness of 30 μm is used as the release layer 1e.

(4) Effect In order to confirm the effect of the fixing device 10 of this embodiment, the fixing device was operated under the following conditions. The operating conditions are an AC power supply of 100 V, an evaluation environmental temperature of 23 ° C., a humidity of 50%, a rotation speed of the pressure roller 3 of 100 mm / sec, a temperature adjustment temperature of 180 ° C., and a rotation temperature adjustment operation of 100 hours. Under the operating conditions, the presence or absence of wear of the conductive portion 1f on the inner surface of the hole 1g that electrically connects the conductive layers 1a and 1b of the film 1 and the presence or absence of damage to the film were confirmed.

(4-1) Abrasion The pressure applied by the spring 8 is as high as 160 N, and a load of about 10 N at maximum is applied to the film 1 in the longitudinal direction Y as the shifting force with the rotation of the pressure roller 3. May move in the longitudinal direction. In that case, the end face 1a of the film is in sliding contact with the restriction surface 5a of the flange, but the conductive portion 1f is provided on the inner surface of the hole 1g arranged on the inner side of the end face of the film (end face 1c1 of the base layer 1c). The wear of the conductive part was confirmed, but there was no wear of the conductive part.

(4-2) Regarding damage The end face 1a of the film 1 is smooth. Therefore, even if the end surface 1a of the film 1 is in sliding contact with the regulating surface 5a of the flange 5, it is difficult to receive local stress concentration or strain. For the above reasons, there was no occurrence of damage such as the end surface 1a of the film 1 turning over or the film 1 tearing from the end surface 1a.

  In the fixing device of this embodiment, the end surface 1a of the film 1 is smooth, and the conductive portion 1f that electrically connects the conductive layers 1a and 1b on the film inner surface and the film outer surface is disposed on the inner side of the film end surface. It is possible to achieve both suppression of abrasion of the conductive portion and suppression of damage to the film.

[Example 2]
Another example of the fixing device 10 will be described. The fixing device 10 of this embodiment is characterized in that the inside of one hole 1g of the film 1 is filled with a conductive portion 1f. Except for this feature, the configuration is the same as that of the fixing device 10 of the first embodiment.

  The configuration of the film 1 will be described with reference to FIG.

  5A is a diagram showing a positional relationship among the film 1, the feeding electrode 4 and the pressure roller 3, FIG. 5B is a development view of the inner surface of the film showing the contact position of the feeding electrode 4, and FIG. (B) A2-A2 cross section arrow view, (d) is a B2-B2 cross section arrow view of (b).

  In the film 1, the inside of the hole 1g of the film is filled with the conductive portion 1f (see FIG. 5D).

  Also in the fixing device 10 of the present embodiment, the end surface 1a of the film 1 is smooth, and the conductive portion 1f that electrically connects the conductive layers 1a and 1b on the inner surface of the film and the outer surface of the film is disposed inside the end surface of the film. Therefore, the same effect as in the first embodiment can be obtained.

[Example 3]
Another example of the fixing device 10 will be described. The fixing device 10 of this embodiment is characterized in that a conductive layer 1 f is provided on the inner surface of a plurality of holes 1 g of the film 1. Except for this feature, the configuration is the same as that of the fixing device 10 of the first embodiment.

  The configuration of the film 1 will be described with reference to FIG.

  6A is a diagram showing a positional relationship among the film 1, the feeding electrode 4 and the pressure roller 3, FIG. 6B is a development view of the inner surface of the film showing the contact position of the feeding electrode 4, and FIG. (B) A3-A3 cross-sectional arrow view, (d) is a B2-B2 cross-sectional arrow view of (b).

  The base layer 1c has ten holes 1g at both ends in the longitudinal direction Y. Specifically, at a position 5 mm inside the end surface 1a1 in the longitudinal direction Y of the base layer 1c, 10 g of circular holes 1g having an outer diameter of 0.3 mm are formed at equal intervals in the circumferential direction of the base layer. (See FIG. 6 (b)). That is, in the longitudinal direction Y, a plurality of holes 1g are provided inside both ends of the base layer 1c. When these holes 1g are connected by a straight line L1, the intervals between adjacent holes are equal.

  A conductive portion 1f is formed on the inner surface of each hole 1g (see FIG. 6D). When power is supplied from the AC power supply V through the power supply electrode 4, a conductive path is formed in the order of the conductive layer 1a, the conductive portion 1f on the inner surface of each hole 1g, the conductive layer 1b, and the heat generating layer 1d.

  Also in the fixing device 10 of the present embodiment, the end surface 1a of the film 1 is smooth, and the conductive portion 1f that electrically connects the conductive layers 1a and 1b on the inner surface of the film and the outer surface of the film is disposed inside the end surface of the film. Therefore, the same effect as in the first embodiment can be obtained.

  A specific effect of the fixing device 10 of this embodiment will be described.

  Since the film 1 has the conductive paths formed by the conductive portions 1f on the inner surface of the hole 1g at a plurality of positions corresponding to the number of holes, the amount of current flowing per one conductive path can be reduced. The amount of electric power generated in the conductive portion 1f on the inner surface of the hole 1g is expressed by the product of the square of the current value and the electric resistance value of the conductive layer on the inner surface of the hole. That is, according to the configuration of the present embodiment, the amount of power flowing per 1 g of hole can be reduced.

  In particular, when a material having a high electrical resistance value (for example, the same material as the heat generating layer used in Example 1) is selected for the conductive portion 1f on the inner surface of the hole 1g, the amount of power per 1g of the hole increases, Excessive heat is generated due to power concentration in the conductive portion 1f. In such a case, by providing a plurality of holes 1g as in the present embodiment, the amount of power flowing per hole 1g can be reduced, and excessive heat generation at the conductive portion 1f on the inner surface of the hole can be suppressed.

  Moreover, when the distance between the holes 1g in the circumferential direction of the base layer 1c is made non-uniform, there are places where the distance between the holes is long or short. The closer the distance between two adjacent holes 1g, the lower the strength between the two holes. When the film 1 receives a biasing force in the longitudinal direction Y, if there is a portion that is weak even partially, there is a risk that the film will be recessed starting from that portion. In order not to make a locally weak portion, it is desirable that the intervals between the plurality of holes 1g are equal and the intervals between the holes are long.

  Since the intervals between the plurality of holes 1g are equal, the distance between the holes with respect to the feeding electrode 4 is substantially equal when the film 1 is rotated. Therefore, the electrical resistance in the conductive path from the feeding electrode 4 to the conductive layer 1b on the outer peripheral surface of the film can be set substantially equal. That is, there is an effect that unevenness of electric power and unevenness of heat generation hardly occur due to the rotation of the film 1.

[Example 4]
Another example of the fixing device 10 will be described. The fixing device 10 according to the present embodiment is characterized in that the number of the plurality of holes 1g included in the film 1 is increased as compared with the third embodiment, and the conductive portion 1f is provided on the inner surface of each hole 1g. Except for this feature, the configuration is the same as that of the fixing device 10 of the first embodiment.

  The configuration of the film 1 will be described with reference to FIG.

  7A is a diagram showing a positional relationship among the film 1, the feeding electrode 4 and the pressure roller 3, FIG. 7B is a development view of the inner surface of the film showing the contact position of the feeding electrode 4, and FIG. (B) A4-A4 cross section arrow view, (d) is a B4-B4 cross section arrow view of (b).

  The base layer 1c has 40 holes 1g at both ends in the longitudinal direction Y. Specifically, a perfect circle having an outer diameter of 0.3 mm is provided at 10 positions in the circumferential direction of the base layer at each of the first position and the second position on the inner side of the end surface 1a1 in the longitudinal direction Y of the base layer 1c. Shaped holes 1g are formed at equal intervals (see FIG. 7B). That is, in the longitudinal direction Y, a plurality of holes 1g are provided inside both ends of the base layer 1c. When these holes 1g are connected by a straight line L2, the intervals between adjacent holes are equal.

  A conductive portion 1f is formed on the inner surface of each hole 1g (see FIG. 7D). When power is supplied from the AC power supply V through the power supply electrode 4, a conductive path is formed in the order of the conductive layer 1a, the conductive portion 1f on the inner surface of each hole 1g, the conductive layer 1b, and the heat generating layer 1d.

  Also in the fixing device 10 of this embodiment, the end surface 1a of the film 1 is smooth, and the conductive layer 1f that electrically connects the conductive layers 1a and 1b on the inner surface of the film and the outer surface of the film is disposed on the inner side of the end surface of the film. Therefore, the same effect as in Example 1 can be obtained.

  Since the film 1 of this example has 40 holes 1g formed at both ends in the longitudinal direction Y of the base layer 1c, the longitudinal dimension of the film needs to be about 100 mm longer than that of Example 3. Therefore, the fixing device 10 using the film 1 of the present embodiment causes an increase in size as compared with the fixing device using the film 1 of the third embodiment, but has the following specific effects.

  Since the film 1 of this example has more holes 1g than in Example 3, the amount of power flowing per 1g of hole can be further reduced compared to the film 1 of Example 3, and the conductive portion on the inner surface of the hole. The occurrence of excessive heat generation at 1f can be suppressed. Furthermore, it is not possible to make a locally weak portion on the film 1, and it is possible to reduce a risk that the film is recessed.

[Example 5]
Another example of the fixing device 10 will be described. The fixing device 10 of this embodiment is characterized in that a plurality of holes 1g of the film 1 are arranged obliquely with respect to the circumferential direction of the film, and a conductive portion 1f is provided on the inner surface of each hole. Except for this feature, the configuration is the same as that of the fixing device 10 of the first embodiment.

  The configuration of the film 1 will be described with reference to FIG.

  8A is a diagram showing a positional relationship among the film 1, the feeding electrode 4 and the pressure roller 3, FIG. 8B is a development view of the inner surface of the film showing the contact position of the feeding electrode 4, and FIG. (B) A5-A5 cross-section arrow view, (d) is a B5-B5 cross-section arrow view of (b).

  The base layer 1c has 20 holes 1g at both ends in the longitudinal direction Y. Specifically, at a position 5 mm inside the end surface 1a1 in the longitudinal direction Y of the base layer 1c, 10 g of circular holes 1g having an outer diameter of 0.3 mm are formed at equal intervals in the circumferential direction of the base layer. (See FIG. 8 (b)). The plurality of holes 1g are disposed obliquely with respect to the circumferential direction of the base layer 1c. That is, in the longitudinal direction Y, a plurality of holes 1g are provided inside both ends of the base layer 1c. When these holes 1g are connected by a straight line L3, the intervals between adjacent holes are equal.

  A conductive portion 1f is formed on the inner surface of each hole 1g (see FIG. 8D). When power is supplied from the AC power supply V through the power supply electrode 4, a conductive path is formed in the order of the conductive layer 1a, the conductive portion 1f on the inner surface of each hole 1g, the conductive layer 1b, and the heat generating layer 1d.

  Also in the fixing device 10 of the present embodiment, the end surface 1a of the film 1 is smooth, and the conductive portion 1f that electrically connects the conductive layers 1a and 1b on the inner surface of the film and the outer surface of the film is disposed inside the end surface of the film. Therefore, the same effect as in Example 1 can be obtained.

  A specific effect of the fixing device 10 of this embodiment will be described.

  Since the plurality of holes 1g are arranged obliquely with respect to the circumferential direction of the base layer 1c, the inter-hole distance can be increased as compared with the third embodiment. Therefore, the location where weak intensity | strength cannot be made locally on the film 1, and risks, such as a film dent, can be reduced. That is, the effect of suppressing the strength reduction of the film 1 is even greater. Further, it is possible to reduce the amount of electric power flowing per 1 g of the hole, and to suppress the occurrence of excessive heat generation at the conductive portion 1 f on the inner surface of the hole.

[Example 6]
Another example of the fixing device 10 will be described. The fixing device 10 of this embodiment is characterized in that a plurality of holes 1g of the film 1 are arranged obliquely with respect to the circumferential direction of the film, and the inside of each hole is completely filled with a conductive portion 1f. Except for this feature, the configuration is the same as that of the fixing device 10 of the first embodiment.

  The configuration of the film 1 will be described with reference to FIG.

  In FIG. 9, (a) is a diagram showing the positional relationship between the film 1, the feeding electrode 4 and the pressure roller 3, (b) is a development view of the inner surface of the film showing the contact position of the feeding electrode 4, and (c). (B) A6-A6 cross-section arrow view, (d) is a B6-B6 cross-section arrow view of (b).

  The base layer 1c has 20 holes 1g at both ends in the longitudinal direction Y. Specifically, at a position 5 mm inside from the end face 1a1 in the longitudinal direction Y of the base layer 1c, 10 g of circular holes 1g having an outer diameter of 0.2 mm are formed at equal intervals in the circumferential direction of the base layer. (See FIG. 9B). The plurality of holes 1g are disposed obliquely with respect to the circumferential direction of the base layer 1c. That is, in the longitudinal direction Y, a plurality of holes 1g are provided inside both ends of the base layer 1c. When these holes 1g are connected by a straight line L4, the intervals between adjacent holes are equal.

  The inside of each hole 1g is filled with the conductive portion 1f (see FIG. 9D). When electric power is supplied from the AC power supply V through the feeding electrode 4, a conductive path is formed in the order of the conductive layer 1a, the conductive portion 1f of each hole 1g, the conductive layer 1b, and the heat generating layer 1d.

  Also in the fixing device 10 of the present embodiment, the end surface 1a of the film 1 is smooth, and the conductive portion 1f that electrically connects the conductive layers 1a and 1b on the inner surface of the film and the outer surface of the film is disposed inside the end surface of the film. Therefore, the same effect as in Example 1 can be obtained.

  A specific effect of the fixing device 10 of this embodiment will be described.

  The film 1 of this example forms the conductive portion 1f by filling holes formed in the base layer with the polyimide-based silver paste (conductive material) when forming the holes 1g in the base layer 1c. Therefore, compared with Example 3, Example 4, and Example 5 which have a hole with the center of hole 1f opened, the degree of strength reduction is very low. Furthermore, since the conductive portion 1f is based on a resin made of the same material as the polyimide that is the material of the base layer 1c, it exhibits a bending performance equivalent to that of the base layer. Further, since the inside of the hole 1g is filled with the conductive portion 1f, the amount of electric power generated per 1g of the hole can be further reduced, and the generation of excessive heat in the conductive portion on the inner surface of the hole can be suppressed.

  Moreover, since the film 1 of a present Example has the small fall of the intensity | strength by the hole 1g as mentioned above, when priority is given to electric power reduction, the one where the outer diameter of a hole is large is effective. However, the dipping method is selected for the formation of the conductive portion 1f in the present embodiment, and the hole can be filled by one dipping only when the outer diameter is 0.2 mm or less. Therefore, in this embodiment, the hole 1g having an outer diameter of 0.2 mm is selected. Of course, it is possible to further increase the outer diameter if labor is added to the process of forming the conductive portion of the hole 1g.

  In the film 1 of this example, although the hole 1g having an outer diameter of 0.2 mm is selected so as to maximize the reduction in electric energy, the inside of the hole is completely filled with a conductive material, so that the outer diameter is 0.1 mm or less. Even if it exists, the electric energy equivalent to or more than the film 1 of Example 5 can be reduced.

[Other embodiments]
The image heating apparatus according to the present invention is not limited to use as the fixing apparatus of the embodiment. It can also be used effectively as an image heating apparatus for modifying the glossiness of an image once fixed on a recording material (fixed image) or an assumed image (semi-fixed image).

1 cylindrical film, 1a, 1b conductive layer, 1c base layer, 1d heat generating layer, 1g hole, 1f conductive portion, 2 holder, 3 pressure roller, 5 flange, N nip portion, P recording material

Claims (6)

A cylindrical heating rotator, a support member that supports the heating rotator, a regulating member that restricts the movement of the heating rotator in the longitudinal direction, and a nip portion that forms the nip portion with the support member sandwiching the heating rotator An image heating apparatus that heats a recording material that carries an image at the nip portion.
The heating rotator is a heating element that generates heat when energized, a cylindrical base material that holds the heating element, and a conductor that supplies power to the heating element, and is provided on the outer surface and the inner surface of the base material. An end surface in the longitudinal direction of the heating rotator is smooth, and the base material is provided with a hole penetrating from the outer surface to the inner surface of the base material. An image heating apparatus having a conductive portion for electrically connecting a conductor provided on an outer surface and an inner surface.   2. The image heating apparatus according to claim 1, wherein one hole is provided inside the both ends of the base material in a longitudinal direction of the heating rotating body.   The image heating apparatus according to claim 2, wherein the inside of the hole is filled with the conductive portion.   2. The image heating apparatus according to claim 1, wherein a plurality of the holes are provided inside both ends of the base material in a longitudinal direction of the heating rotating body.   The image heating apparatus according to claim 4, wherein when the plurality of holes are connected by a straight line, the intervals between the plurality of holes are equal.   6. The image heating apparatus according to claim 4, wherein the inside of the plurality of holes is filled with the conductive portion.