CN219958078U

CN219958078U - Heater and image forming apparatus

Info

Publication number: CN219958078U
Application number: CN202320254836.9U
Authority: CN
Inventors: 上野宏辅; 玉井雅彦; 青野伸二郎; 壷內暁夫; 加藤聡子; 土居昌弘; 大桥刚; 酒井诚
Original assignee: Toshiba Lighting and Technology Corp
Current assignee: Toshiba Lighting and Technology Corp
Priority date: 2022-06-23
Filing date: 2023-02-20
Publication date: 2023-11-03
Anticipated expiration: 2033-02-20
Also published as: JP2024016481A

Abstract

Embodiments of the present utility model relate to a heater capable of suppressing warpage and an image forming apparatus. The heater of the embodiment comprises: a base portion including a metal and extending along a first direction, and having a first face and a second face opposite to the first face; an insulating layer provided on the first surface side of the base; a heating element provided on the insulating layer and extending along the first direction; and a protection part covering the heating element. The peripheral edge of the base portion in a second direction intersecting the first direction extends along a third direction intersecting the first direction and the second direction.

Description

Heater and image forming apparatus

Technical Field

Embodiments of the present utility model relate to a heater and an image forming apparatus.

Background

A heater for fixing toner (toner) is provided in an image forming apparatus such as a copier or a printer. Generally, such heaters have: an elongated base; a heating element provided on one surface of the base and extending in the longitudinal direction of the base; and a protection part covering the heating element.

The base is formed of a material having heat resistance and insulation and high thermal conductivity. The base is formed of ceramic such as alumina. In addition, the surface of the metal plate may be covered with an insulating material, for example, on the base.

The protective portion is formed of a material having heat resistance and insulation, high thermal conductivity, and high chemical stability. For example, the protection portion is formed of ceramic, glass, or the like.

Here, if the material of the base is metal, it is possible to improve the rigidity of the base, reduce the manufacturing cost, or the like. However, if the material of the base is metal, the material of the base is different from the material of the protection portion, and therefore thermal stress is generated due to a difference in thermal expansion coefficient of the material. If thermal stress is generated, the heater is likely to warp. Further, since the thermal expansion coefficient of metal is higher than that of ceramics or the like, thermal stress tends to increase. If the thermal stress increases, the warpage of the heater increases.

If the warpage of the heater increases, the distance between the heater and the heating target may vary, and uneven heating may occur in the heating target.

Therefore, it is desired to develop a technique capable of suppressing warpage of the heater even when the material of the base is metal.

Disclosure of Invention

A heater, comprising: a base portion including a metal and extending along a first direction, and having a first face and a second face opposite to the first face; an insulating layer provided on the first surface side of the base; a heating element provided on the insulating layer and extending along the first direction; and a protection part covering the heating element, wherein the periphery of the base part in a second direction crossing the first direction extends along a third direction crossing the first direction and the second direction.

An image forming apparatus includes the heater.

Drawings

Fig. 1 is a schematic front view for illustrating a heater of the present embodiment.

Fig. 2 is a schematic back view for illustrating the heater.

Fig. 3 is a schematic cross-sectional view of the heater of fig. 1 in the direction of line A-A.

Fig. 4 is a schematic side view of the heater of fig. 1 in the direction of line B-B.

Fig. 5 is a schematic back view for illustrating a base of another embodiment.

Fig. 6 is a schematic cross-sectional view illustrating a convex portion of still another embodiment.

Fig. 7 is a schematic enlarged view of a portion C in fig. 6.

Fig. 8 is a schematic perspective view for illustrating a heater of still another embodiment.

Fig. 9 is a schematic cross-sectional view of the heater of fig. 8 in the direction of line C-C.

Fig. 10 is a schematic perspective view of the base.

Fig. 11 is a schematic cross-sectional view in the direction of line D-D of the base in fig. 10.

Fig. 12 is a schematic perspective view for illustrating a base of still another embodiment.

Fig. 13 is a schematic perspective view for illustrating a base of still another embodiment.

Fig. 14 is a schematic perspective view for illustrating a base of still another embodiment.

Fig. 15 is a schematic perspective view for illustrating a base of still another embodiment.

Fig. 16 is a schematic perspective view for illustrating a base of still another embodiment.

Fig. 17 is a schematic perspective view for illustrating a base of still another embodiment.

Fig. 18 is a schematic perspective view for illustrating a base of still another embodiment.

Fig. 19 is a schematic perspective view for illustrating a base of still another embodiment.

Fig. 20 is a schematic perspective view for illustrating a base of still another embodiment.

Fig. 21 is a schematic perspective view for illustrating a base of still another embodiment.

Fig. 22 is a schematic front view for illustrating a heater of still another embodiment.

Fig. 23 is a schematic enlarged sectional view of the heater in fig. 22 in the direction of the line E-E.

Fig. 24 is a schematic front view for illustrating a heater of still another embodiment.

Fig. 25 is a schematic enlarged sectional view of the heater of fig. 24 in the direction of the F-F line.

Fig. 26 is a schematic diagram for illustrating an image forming apparatus of the present embodiment.

Fig. 27 is a schematic diagram for illustrating the fixing section.

Fig. 28 is a schematic diagram for illustrating a fixing portion of still another embodiment.

Fig. 29 is a schematic view for illustrating a fixing portion of still another embodiment.

Detailed Description

The heater of the embodiment comprises: a base portion including a metal and extending along a first direction, and having a first face and a second face opposite to the first face; an insulating layer provided on the first surface side of the base; a heating element provided on the insulating layer and extending along the first direction; and a protection part covering the heating element. The peripheral edge of the base portion in a second direction intersecting the first direction extends along a third direction intersecting the first direction and the second direction.

Hereinafter, embodiments will be described by way of example with reference to the drawings. In the drawings, the same constituent elements are denoted by the same reference numerals, and detailed description thereof is omitted. In each drawing, arrows X, Y, and Z indicate three directions orthogonal to each other. For example, the long side direction of the base is the X direction, the short side direction (width direction) of the base is the Y direction, and the direction perpendicular to the surface of the base is the Z direction.

(Heater)

Fig. 1 is a schematic front view for illustrating a heater 1 of the present embodiment.

Fig. 1 is a view of the heater 1 from the side where the heat generating portion 20 is provided.

Fig. 2 is a schematic back view for illustrating the heater 1.

Fig. 2 is a view of the heater 1 from the side opposite to the side where the heat generating portion 20 is provided.

Fig. 3 is a schematic cross-sectional view of the heater 1 of fig. 1 in the direction of the line A-A.

Fig. 4 is a schematic side view of the heater 1 in fig. 1 in the direction of line B-B.

As shown in fig. 1 to 4, the heater 1 includes, for example, a base 10, an insulating layer 11, a heat generating portion 20, a wiring portion 30, and a protection portion 40.

The base 10 has a plate shape and includes a surface 10a (corresponding to an example of the first surface) and a surface 10b (corresponding to an example of the second surface) opposite to the surface 10 a. The base 10 has a shape extending along the X direction. The shape of the base 10 viewed from the Z direction is, for example, an elongated rectangle. The thickness of the base 10 (the distance between the surfaces 10a and 10 b) is, for example, about 0.3mm to 1.0 mm. The size of the base 10 in the X direction and the size of the base 10 in the Y direction can be appropriately changed according to the size of the heating target (e.g., paper).

The base 10 is formed of a material having heat resistance and high thermal conductivity. The base 10 may be formed of a metal such as stainless steel or an aluminum alloy.

The thermal conductivity of metal is higher than that of inorganic material such as ceramics. Therefore, if the base 10 is made of metal, the temperature generation in-plane distribution of the heater 1 can be suppressed. In addition, it is possible to improve the rigidity of the base 10, reduce the manufacturing cost, or the like.

The insulating layer 11 is provided on the surface 10a of the base 10 on the side where the heat generating portion 20 is provided. The insulating layer 11 covers the area of the face 10a of the base 10 where the heat generating portion 20 is provided. The insulating layer 11 is formed of a material having heat resistance and insulation properties. The insulating layer 11 may be formed of an inorganic material such as ceramic.

The heat generating portion 20 converts the applied electric power into heat (joule heat). The heat generating portion 20 is provided on the insulating layer 11. The heat generating portion 20 is insulated from the base portion 10 by the insulating layer 11.

The heat generating portion 20 includes, for example, a heat generating body 21 and a heat generating body 22. Further, the case where the heating elements 21 and 22 are provided is exemplified as an example, but the number and size of the heating elements may be appropriately changed according to the size of the base 10, the size of the object to be heated, and the like. In addition, a plurality of heating elements having different lengths, widths, shapes, and the like may be provided. That is, at least one heating element may be provided.

The heating elements 21 and 22 may be arranged at predetermined intervals in the Y direction (the short side direction of the base 10), for example. The heating element 21 and the heating element 22 extend, for example, in the X direction (longitudinal direction of the base 10).

The dimensions (length dimensions) of the heating element 21 and the heating element 22 in the X direction may be substantially the same, for example. In this case, the centers of the heating element 21 and the heating element 22 are preferably located on the straight line 1 a. That is, the heating element 21 and the heating element 22 are each preferably formed to have a shape symmetrical about the straight line 1a as the symmetry axis.

When the heater 1 is mounted to the image forming apparatus 100, for example, the straight line 1a is overlapped with the center line of the conveyance path of the heating target. In this way, even when the dimension of the heating target in the direction orthogonal to the conveying direction changes, the heating target can be heated substantially uniformly.

The resistance values of the heating element 21 and the heating element 22 may be substantially the same or may be different. For example, the resistance values of the heating element 21 and the heating element 22 can be made substantially the same by making the dimensions (length dimensions) of the heating element 21 and the heating element 22 in the X direction, the dimensions (width dimensions) of the heating element 21 and the heating element 22 in the Y direction, and the dimensions (thickness dimensions) of the heating element in the Z direction substantially the same, respectively. Further, by changing at least any one of these dimensions, the resistance values of the heating element 21 and the heating element 22 can be made different. In addition, by changing the materials, the resistance values of the heating element 21 and the heating element 22 can be made different.

The resistance value per unit length of the heating element 21 may be substantially uniform in the X direction. For example, the dimension (width dimension) of the heating element 21 in the Y direction and the dimension (thickness dimension) of the heating element in the Z direction may be substantially constant. The shape of the heating element 21 viewed from the Z direction may be, for example, a substantially rectangular shape extending along the X direction.

The resistance value per unit length of the heating element 22 may be substantially uniform in the X direction. For example, the dimension (width dimension) of the heating element 22 in the Y direction and the dimension (thickness dimension) of the heating element in the Z direction may be substantially constant. The shape of the heating element 22 viewed from the Z direction may be, for example, a substantially rectangular shape extending along the X direction.

For example, ruthenium oxide (RuO) can be used as the heating element 21 and the heating element 22 ₂ ) Silver-palladium (Ag-Pd) alloys, and the like. The heating element 21 and the heating element 22 can be formed by applying a paste material to the insulating layer 11 by a screen printing method or the like, and hardening the paste material by a firing method or the like, for example.

The wiring portion 30 is provided on the insulating layer 11.

The wiring portion 30 includes, for example, a terminal 31, a terminal 32, a wiring 33, a wiring 34, and a wiring 35.

The terminals 31, 32 are provided near one of the ends of the base 10 in the X direction, for example. The terminals 31 and 32 are arranged in the X direction, for example. The terminals 31 and 32 are electrically connected to a power source or the like via connectors, wirings, and the like, for example.

The wiring 33 is provided on the side of the base 10 where the terminal 31 is provided, for example, in the X direction. The wiring 33 extends along the X direction. The wiring 33 is electrically connected to the terminal 31 and the terminal 31-side end of the heating element 21.

The wiring 34 is provided near an end of the base 10 on the opposite side of the side where the terminals 31, 32 are provided, for example, in the X direction. An end of the heating element 21 on the opposite side of the wiring 33 and an end of the heating element 22 on the opposite side of the wiring 35 are electrically connected to the wiring 34.

The wiring 35 is provided on the side of the base 10 where the terminals 32 are provided, for example, in the X direction. The wiring 35 extends along the X direction. The wiring 35 is electrically connected to the terminal 32 and the terminal 32-side end of the heating element 22.

The wiring portion 30 (the terminal 31, the terminal 32, and the wirings 33 to 35) is formed using a material containing silver, copper, or the like, for example. For example, the terminals 31, 32, and the wirings 33 to 35 can be formed by applying a paste material to the insulating layer 11 by a screen printing method or the like and hardening the paste material by a firing method or the like.

The protection portion 40 is provided on the insulating layer 11 and covers the heat generating portion 20 (the heat generating element 21 and the heat generating element 22) and a part of the wiring portion 30 (the wiring 33, the wiring 34, and the wiring 35). In this case, the terminals 31 and 32 of the wiring portion 30 may be exposed from the protection portion 40.

The protection portion 40 extends in the X direction. The protection portion 40 has, for example, a function of insulating a part of the heat generating portion 20 and the wiring portion 30, a function of transmitting heat generated in the heat generating portion 20, and a function of protecting a part of the heat generating portion 20 or the wiring portion 30 from an external force, corrosive gas, or the like. The protection portion 40 is formed of a material having heat resistance and insulation properties and having high chemical stability and thermal conductivity. The protection portion 40 is formed of, for example, ceramic, glass, or the like. In this case, the protective portion 40 may be formed using glass to which a filler containing a material having high thermal conductivity such as alumina is added. The thermal conductivity of the glass to which the filler is added may be, for example, 2[W/(m·k) ] or more.

The heater 1 may further include a detection unit for detecting the temperature of the heat generating unit 20. The detection unit may be, for example, a thermistor (thermistor). The detection portion may be provided at least either one of the side of the base 10 on which the heat generating portion 20 is provided, and the side of the base 10 opposite to the side on which the heat generating portion 20 is provided.

In the case where the detection portion is provided on the side of the base 10 where the heat generating portion 20 is provided (the side of the surface 10a of the base 10), the detection portion and wiring and terminals electrically connected to the detection portion may be provided on the insulating layer 11. The wiring electrically connected to the detection portion may be covered by the protection portion 40. The terminal electrically connected to the detection portion may be exposed from the protection portion 40.

In the case where the detection portion is provided on the opposite side of the base 10 (the side of the surface 10b of the base 10) from the side on which the heat generating portion 20 is provided, an insulating layer may be provided on the surface 10b, and the detection portion, and wiring and terminals electrically connected to the detection portion may be provided on the insulating layer. The insulating layer may be the same as the insulating layer 11 provided on the face 10 a. In addition, the wiring electrically connected to the detection portion may be covered with a protection portion. The terminal electrically connected to the detection portion may be exposed from the protection portion. The protection portion may be provided in the same manner as the protection portion 40 provided on the insulating layer 11.

Here, as described above, the base 10 is formed of a metal such as stainless steel or an aluminum alloy. On the other hand, the protection portion 40 is formed of, for example, ceramics, glass with filler added, or the like. The insulating layer 11 is formed of an inorganic material such as ceramic.

Therefore, the thermal expansion coefficient of the base 10 is different from the thermal expansion coefficient of the protection portion 40 and the insulating layer 11. When the heater 1 is used, if the heat generating portion 20 (the heat generating element 21, the heat generating element 22) generates heat, the base portion 10, the protection portion 40, and the insulating layer 11 are heated. When the protective portion 40 or the insulating layer 11 is calcined in manufacturing the heater 1, the base portion 10, the protective portion 40, and the insulating layer 11 are heated. Therefore, when the heater 1 is used or manufactured, thermal stress is generated due to a difference in thermal expansion coefficient of the material. If thermal stress occurs, the heater 1 may warp.

Further, since the thermal expansion coefficient of metal is higher than that of ceramics or the like, warpage of the heater 1 is liable to increase. In addition, even if the length of the base 10 in the short side direction (width direction: e.g., Y direction) is short, or the length of the base 10 in the long side direction (e.g., X direction) is long, or the thickness of the base 10 is thin, the warpage of the heater 1 is liable to increase.

If the warpage of the heater 1 increases, the distance between the heater 1 and the heating target may be varied, and uneven heating may occur in the heating target.

Thus, the periphery of the base 10 extends in the Z direction. For example, as shown in fig. 2 to 4, the base 10 is provided with a convex portion 10c and a convex portion 10d. The convex portion 10c and the convex portion 10d are provided on the opposite side of the base portion 10 from the side on which the heat generating portion 20 is provided. The convex portion 10c and the convex portion 10d protrude from the surface 10b of the base portion 10. The convex portion 10c and the convex portion 10d may be integrally formed with the base portion 10, for example. The convex portions 10c and 10d may be formed by press forming, bending, or the like, for example.

The convex portion 10c is provided along the periphery of the face 10b of the base portion 10 in the Y direction. The convex portion 10c extends between one end portion and the other end portion of the base portion 10 in the X direction. The distance H between the top of the protruding portion 10c and the surface 10b of the base portion 10 (the height of the protruding portion 10 c) may be, for example, about 0.3mm to 5.0 mm. The thickness T of the protruding portion 10c may be, for example, about 0.3mm to 1.0 mm.

The convex portion 10d is provided along the periphery of the face 10b of the base portion 10 in the X direction. The convex portion 10d extends in the Y direction. As shown in fig. 2 and 4, a gap may be provided between the convex portion 10d and the convex portion 10c. Further, the convex portion 10d may be brought into contact with the convex portion 10c. The distance between the top of the convex portion 10d and the surface 10b of the base portion 10 (the height of the convex portion 10 d) may be the same as or different from the distance H between the top of the convex portion 10c and the surface 10b of the base portion 10. The thickness of the convex portion 10d may be the same as or different from the thickness T of the convex portion 10c, for example.

If the convex portions 10c and 10d are provided, the bending rigidity of the base 10 can be increased. If the bending rigidity of the base 10 increases, even if thermal stress occurs due to a difference in thermal expansion coefficient of the material, the heater 1 can be restrained from warping.

The convex portions 10c illustrated in fig. 2 to 4 are provided at both side end portions of the base 10 in the Y direction. However, in the case where the generated thermal stress is small or the length of the base 10 in the X direction is short, the generated warp is reduced. In the case where the warpage generated is small, the convex portion 10c may be provided at one end portion of the base portion 10 in the Y direction, and the convex portion 10c may not be provided at the other end portion of the base portion 10. If the protruding portion 10c is provided at only one end portion of the base portion 10, the manufacturing cost of the heater 1 can be reduced.

Further, although the case where one convex portion 10c continuously extending in the X direction is provided at the end portion of the base portion 10 in the Y direction is illustrated, the convex portion 10c may be provided in a partial region of the base portion 10 in the X direction, or a plurality of convex portions 10c aligned in the X direction may be provided.

The convex portions 10d illustrated in fig. 2 to 4 are provided at both side end portions of the base 10 in the X direction. However, in the case where the generated thermal stress is small or the length of the base 10 in the Y direction is short, the generated warp is reduced. In the case where the warpage generated is small, the convex portion 10d may be provided at one end portion of the base portion 10 in the X direction, and the convex portion 10d may not be provided at the other end portion of the base portion 10. If the protruding portion 10d is provided only at one end portion of the base portion 10, the manufacturing cost of the heater 1 can be reduced.

Further, although the case where one convex portion 10d continuously extending in the Y direction is provided at the end portion of the base portion 10 in the X direction is illustrated, the convex portion 10d may be provided in a partial region of the base portion 10 in the Y direction or a plurality of convex portions 10d aligned in the Y direction may be provided.

In addition, the length of the base 10 in the X direction is longer than the length of the base 10 in the Y direction. Therefore, the warp of the base 10 in the X direction is larger than the warp of the base 10 in the Y direction.

In this case, the height of the convex portion 10c may be made higher than the height of the convex portion 10d. The thickness of the convex portion 10c may be larger than the thickness of the convex portion 10d. In this way, an increase in warpage of the base 10 in the X direction can be suppressed.

Fig. 5 is a schematic rear view for illustrating a base 10e of another embodiment.

Fig. 5 is a view of the base 10e from the side opposite to the side where the heat generating portion 20 is provided.

The length of the base 10e in the Y direction is shorter than the length of the base 10e in the X direction. Therefore, the warp of the base 10e in the Y direction is smaller than the warp of the base 10e in the X direction.

In this case, as shown in fig. 5, the convex portion 10c may be provided at the end of the base portion 10e in the Y direction, and the convex portion 10d may not be provided at the end of the base portion 10e in the X direction. When the warp of the base 10e is small, the convex portion 10c may be provided at one end portion of the base 10e in the Y direction, and the convex portion 10c may not be provided at the other end portion of the base 10 e.

As described above, the manufacturing cost of the heater 1 can be reduced.

Fig. 6 is a schematic cross-sectional view illustrating a convex portion 10c1 according to still another embodiment.

Fig. 7 is a schematic enlarged view of a portion C in fig. 6.

The convex portion 10c illustrated in fig. 3 and 4 is orthogonal to the surface 10b of the base portion 10.

In contrast, the convex portion 10c1 illustrated in fig. 6 and 7 is inclined with respect to the surface 10b of the base 10. For example, the convex portion 10c1 may incline the convex portion 10 c. The inclination angle θ between the convex portion 10c1 and the surface 10b of the base portion 10 may be, for example, "90 ° < θ+.ltoreq.160°". In addition, in the case of the optical fiber, inclination between the convex portion 10c1 and the face 10b of the base 10 the angle θ may be set to, for example "θ is not less than 20 but not more than 90 °".

If the convex portion 10c1 is inclined with respect to the surface 10b of the base 10, the bending rigidity of the base 10 can be improved, and the increase in the size of the heater 1 in the Z direction can be suppressed. Further, if "20 ° ++.θ < 90 °", the tip of the convex portion 10c1 is located inside the surface 10b of the base portion 10 when viewed from the Z direction, so that the bending rigidity of the base portion 10 can be improved, and the increase in the size of the heater 1 in the Z direction and the Y direction can be suppressed.

The arrangement, number, size, inclination angle θ, etc. of the projections 10c and 10d can be appropriately changed according to the magnitude of the generated thermal stress, warpage, etc. The arrangement, number, size, inclination angle θ, etc. of the protruding portions 10c and 10d can be appropriately determined by performing experiments or simulations, for example.

Fig. 8 is a schematic perspective view for illustrating a heater 12 of still another embodiment.

Fig. 9 is a schematic cross-sectional view in the direction of line C-C of the heater 12 in fig. 8.

Fig. 10 is a schematic perspective view of the base 13.

Fig. 11 is a schematic cross-sectional view in the direction of line D-D of the base 10 in fig. 10.

As shown in fig. 8 and 9, the heater 12 includes, for example, a base 13, an insulating layer 11, a heat generating portion 20, a terminal 36, and a protection portion 40.

As shown in fig. 8 to 11, the base 13 extends in the X direction. The periphery of the base 13 extends in the Z direction. The base 13 has, for example, a first portion 13a, a second portion 13b, and a third portion 13c. The second portion 13b and the third portion 13c are disposed on the same side of the first portion 13a in the Z direction. For example, the first portion 13a, the second portion 13b, and the third portion 13c may be integrally formed.

The first portion 13a is plate-shaped and provided in plurality. The plurality of first portions 13a extend along the X direction and are arranged in the Y direction at predetermined intervals. Although the base 13 illustrated in fig. 8 to 11 is provided with two first portions 13a, three or more first portions 13a may be provided. The number and the interval of the first portions 13a can be appropriately changed according to the size of the heating target, for example.

The plurality of first portions 13a may be disposed at the same position or at different positions in the X direction. The positions of the two first portions 13a illustrated in fig. 8 to 11 in the X direction are the same.

Preferably, the plurality of first portions 13a are each disposed at the same position in the Z direction. In this case, the heat generating portion 20 (the heat generating element 21, the heat generating element 22) is provided on the surface 13a1 of the first portion 13a via the insulating layer 11. Therefore, it is preferable that the faces 13a1 of the plurality of first portions 13a are each provided in the same plane in the Z direction. In this way, the occurrence of uneven heating of the heating object due to the deviation in the distance between the heat generating portion 20 and the heating object can be suppressed.

The first portion 13a is, for example, rectangular in shape as viewed from the Z direction. The size of the first portion 13a in the X direction and the size of the first portion 13a in the Y direction may be appropriately changed according to the size, the number, or the like of the heating elements provided. In this case, the dimensions in the X direction and the dimensions in the Y direction of each of the plurality of first portions 13a may be the same or different. The dimensions in the X direction and the dimensions in the Y direction of the two first portions 13a illustrated in fig. 8 to 11 are the same.

As shown in fig. 10 and 11, in the Y direction, the second portion 13b is provided between the first portion 13a and the first portion 13 a. Therefore, the number of the second portions 13b is one less than the number of the first portions 13 a. The second portion 13b protrudes from a surface 13a2 of the first portion 13a opposite to the surface 13a1 to a side opposite to the surface 13a1. The second portion 13b is disposed on the face 13a2 of the first portion 13 a. The end of the second portion 13b in the Y direction is provided at the periphery of the face 13a2 of the first portion 13a in the Y direction. For example, the second portion 13b has a plate shape and has a shape curved in the Z direction in the vicinity of the end portions on both sides in the Y direction. That is, the second portion 13b intersects the periphery of the first portion 13 a.

The third portion 13c has a plate shape. The third portion 13c is provided at the periphery of the face 13a2 of the first portion 13a on the side opposite to the side where the second portion 13b is provided in the Y direction. That is, in the Y direction, the third portion 13c intersects with the peripheral edge of the first portion 13a on the side opposite to the side on which the second portion 13b is provided. In this case, since the plurality of first portions 13a are arranged in the Y direction, the third portion 13c may be provided at least any one of the two first portions 13a located at both ends in the Y direction. That is, the third portion 13c may be provided with at least one. In the base 13 illustrated in fig. 8 to 11, a third portion 13c is provided in each of two first portions 13a arranged along the Y direction.

The third portion 13c protrudes from the surface 13a2 of the first portion 13a to the side opposite to the surface 13a1 side of the first portion 13 a. As shown in fig. 11, if the angle between the third portion 13c and the face 13a2 of the first portion 13a is set to θ, the angle θ may be set to "20°+.θ+.160°". By setting the angle θ in this way, the bending rigidity of the base 13 can be increased. In this case, if "20+.θ < 90 °" or "90+.θ+.ltoreq.160°", the dimension of the base 13 in the Z direction can be reduced. Further, if "20 ° ++.θ < 90 °", the dimension of the base 13 in the Z direction can be reduced, and the dimension increase of the base 13 in the Y direction can be suppressed.

The dimension Lc (mm) of the third portion 13c in the Z direction may be the same as or different from the dimension Lb (mm) of the second portion 13 b. The base 13 illustrated in fig. 11 is "Lc (mm) > Lb (mm)".

The thickness of the first portion 13a, the thickness of the second portion 13b, and the thickness of the third portion 13c are, for example, about 0.3mm to 1.0 mm. Further, the thickness of the first portion 13a, the thickness of the second portion 13b, and the thickness of the third portion 13c may be the same or different.

The base 13 (the first portion 13a, the second portion 13b, and the third portion 13 c) is formed of a material having heat resistance and high thermal conductivity. The base 13 is formed of a metal such as stainless steel or an aluminum alloy. The base 13 may be formed by plastic working such as bending and pressing, drawing, or the like.

The thermal conductivity of metal is higher than that of inorganic material such as ceramics. Therefore, if the base 13 is made of metal, the temperature generation in-plane distribution of the heater 12 can be suppressed. Further, it is possible to improve the rigidity of the base 13, suppress the occurrence of cracks, defects, and the like, and reduce the manufacturing cost.

Further, details regarding suppression of warpage in the base 13 will be described later.

The insulating layer 11 is provided on the side of the base 13 where the heat generating portion 20 is provided. The insulating layer 11 may be provided at least on the face 13a1 of the first portion 13a of the base 13. In this case, as shown in fig. 8 and 9, the insulating layer 11 may be provided so as to cover the side of the base 13 on which the heat generating portion 20 is provided. If the insulating layer 11 is also provided on the second portion 13b, the bending rigidity of the heater 12 can be improved. Therefore, the heater 12 can be restrained from warping.

The insulating layer 11 can be formed by, for example, applying a paste material to the base 13 by a screen printing method or the like and hardening the paste material by a firing method or the like.

The heat generating portion 20 is provided on the insulating layer 11. The heat generating portion 20 is provided on the first portion 13a of the base 13 via the insulating layer 11, for example. The heat generating portion 20 is insulated from the base portion 13 by the insulating layer 11.

In the case of the heater 12 illustrated in fig. 8 and 9, the heat generating portion 20 has a heat generating body 21 and a heat generating body 22. The heating element 21 and the heating element 22 extend along the X direction (the longitudinal direction of the base 13). The heating element 21 is provided on one of the first portions 13a via the insulating layer 11. The heating element 22 is provided on the other first portion 13a via the insulating layer 11. That is, the heating element 21 and the heating element 22 are provided on the opposite side of the first portion 13a from the side on which the second portion 13b is provided, with the insulating layer 11 interposed therebetween.

Although the case where one heating element is provided in one first portion 13a is illustrated, a plurality of heating elements may be provided in one first portion 13 a. That is, at least one heating element may be provided on one first portion 13 a. In addition, a plurality of heating elements having different sizes, shapes, and the like may be provided in one first portion 13 a.

The dimensions (length dimensions) of the heating element 21 and the heating element 22 in the X direction may be substantially the same, for example. Preferably, the centers of the heating element 21 and the heating element 22 are located on the straight line 12 a. That is, the heating element 21 and the heating element 22 are each preferably formed to have a shape symmetrical about the straight line 12a as the symmetry axis.

When the heater 12 is mounted to the image forming apparatus 100, for example, the straight line 12a is overlapped with the center line of the conveyance path of the heating target. In this way, even if the dimension or position of the heating target in the direction orthogonal to the conveying direction changes, the heating target is easily heated substantially uniformly.

The terminals 36 may be provided in plurality. A plurality of terminals 36 are provided on the insulating layer 11. The plurality of terminals 36 may be provided near the ends of both sides in the X direction of the base 13, for example. As shown in fig. 8, a pair of terminals 36 electrically connected to the end of the heating element 21 and a pair of terminals 36 electrically connected to the end of the heating element 22 may be provided. The plurality of terminals 36 are exposed from the protection portion 40. The plurality of terminals 36 are electrically connected to, for example, a power source via connectors, wirings, and the like.

One of the ends of the heating element 21 and the heating element 22 in the X direction may be electrically connected by one terminal 36, the other terminal 36 may be electrically connected to the other end of the heating element 21 in the X direction, and the other terminal 36 may be electrically connected to the other end of the heating element 22 in the X direction. In this way, the heating element 21 and the heating element 22 can be connected in series.

One of the ends of the heating element 21 and the heating element 22 in the X direction may be electrically connected by one terminal 36, and the other ends of the heating element 21 and the heating element 22 in the X direction may be electrically connected by one terminal 36. In this way, the heating element 21 and the heating element 22 can be connected in parallel.

In addition, a plurality of terminals 36 may be arranged near the end portion of the base 13 on one side in the X direction. In this way, since connectors, wiring, and the like are provided on one side of the heater 12, wiring work is facilitated.

Further, wiring for electrically connecting the terminal 36 to the heating element 21 and the heating element 22 may be provided. If wiring for electrically connecting the terminal 36 to the heating element 21 and the heating element 22 is provided, the terminal 36 can be easily arranged at an arbitrary position.

The terminal 36 and the wiring for electrically connecting the terminal 36 to the heating element 21 and the heating element 22 are formed using a material containing silver, copper, or the like, for example. For example, the terminal 36 and the wiring can be formed by applying a paste material to the insulating layer 11 by a screen printing method or the like and hardening the paste material by a firing method or the like.

The protection portion 40 is provided on the insulating layer 11 and covers the heat generating portion 20 (the heat generating element 21 and the heat generating element 22). As described above, the terminals 36 are exposed from the protection portion 40.

The heater 12 may further include a detection unit for detecting the temperature of the heat generating unit 20. The detection unit may be, for example, a thermistor. The detection portion may be provided at least either one of the side of the base 13 on which the heat generating portion 20 is provided, and the side of the base 13 opposite to the side on which the heat generating portion 20 is provided.

In the case where the detection portion is provided on the side of the base 13 where the heat generating portion 20 is provided, the detection portion and wiring and terminals electrically connected to the detection portion may be provided on the insulating layer 11. The wiring electrically connected to the detection portion may be covered by the protection portion 40. The terminal electrically connected to the detection portion may be exposed from the protection portion 40.

In the case where the detection portion is provided on the opposite side of the base 13 from the side on which the heat generating portion 20 is provided, an insulating layer may be provided on the base 13, and the detection portion and wiring and terminals electrically connected to the detection portion may be provided on the insulating layer. The insulating layer may be set to be the same as the insulating layer 11. The detection portion and the wiring electrically connected to the detection portion may be covered with a protection portion. The terminal electrically connected to the detection portion may be exposed from the protection portion. The protection portion may be the same as the protection portion 40.

Next, suppression of warpage in the base 13 will be described.

As described above, the base 13 is formed of a metal such as stainless steel or an aluminum alloy. On the other hand, the protection portion 40 is formed of, for example, ceramics, glass with filler added, or the like. The insulating layer 11 is formed of an inorganic material such as ceramic.

Therefore, as in the case of the heater 1, thermal stress is generated in the heater 12 due to the difference in the thermal expansion coefficient of the material. If thermal stress is generated, the heater 12 may be warped.

As shown in fig. 8 to 11, the second portion 13b is provided in the base 13 of the present embodiment. The vicinity of the end portions of both sides in the Y direction of the second portion 13b is curved in the Z direction. That is, in the central region in the Y direction of the base 13, an end portion of the second portion 13b intersecting the first portion 13a is provided.

Since the end portion of the second portion 13b intersecting the first portion 13a extends in the X direction, the bending rigidity of the base portion 13 in the X direction can be increased. Therefore, warpage of the base 13 in the X direction can be suppressed.

Further, if the second portion 13b is provided, the bending rigidity of the base portion 13 in the Y direction can be increased. Therefore, warpage of the base 13 in the Y direction can be suppressed.

In addition, a third portion 13c intersecting the first portion 13a is provided in the base portion 13. The third portion 13c extends along the X direction, and thus the bending rigidity of the base portion 13 in the X direction can be increased. Therefore, warpage of the base 13 in the X direction can be suppressed.

Although the third portion 13c continuously extending along the X direction is exemplified above, the third portion 13c may be provided in a partial region of the first portion 13a in the X direction or a plurality of third portions 13c aligned in the X direction when the size of the base portion 13 in the X direction is small or the generated thermal stress is small.

Although the second portions 13b bent in the Z direction are illustrated near the end portions on both sides in the Y direction, the flat plate-shaped second portions 13b intersecting the first portions 13a may be provided when the size of the base portion 13 in the Y direction is small or the thermal stress generated is small. If so, the structure of the second portion 13b can be simplified.

If the number of the third portions 13c is reduced, or the third portions 13c are reduced, or the structure of the second portions 13b is simplified, a reduction in the manufacturing cost of the heater 12 can be achieved.

The number or size of the third portions 13c, the structure of the second portions 13b, and the like can be appropriately determined by performing experiments or simulations to suppress the occurrence of warpage.

As described above, when the heater 12 of the present embodiment is used, warpage of the heater 12 can be suppressed even when the material of the base 13 is a metal.

Fig. 12 to 21 are schematic perspective views illustrating a base portion of a further embodiment.

As shown in fig. 12, the base 50 has a first portion 13a and a second portion 13b. That is, the base 50 omits the third portion 13c from the base 13.

For example, in the case where the size in the X direction or the size in the Y direction of the base is small, or the generated thermal stress is small, the generated warp is reduced. In addition, as described above, the bending rigidity of the base portion increases regardless of whether the second portion 13b or the third portion 13c is provided. Therefore, in the case where the generated warpage is small, either one of the second portion 13b and the third portion 13c may be provided.

In fig. 12, the second portion 13b is provided and the third portion 13c is omitted, but the second portion 13b may be omitted and the third portion 13c may be provided. In the case where the second portion 13b is omitted and the third portion 13c is provided, the third portion 13c may be provided on the peripheral edges of both sides in the Y direction, or the third portion 13c may be provided on the peripheral edge of one side in the Y direction.

Among them, the base 13 described above is preferable in the case where the dimension in the X direction or the dimension in the Y direction of the base is large, the thermal stress generated is large, or the like.

As shown in fig. 13, the base 51 has, for example, a first portion 13a, a second portion 13b1, and a third portion 13c. The second portion 13b provided in the base 50 described above has a shape curved in the Z direction in the vicinity of the end portions of both sides in the Y direction. In contrast, the second portion 13b1 provided in the base 51 has a shape (for example, a V-shaped cross-sectional shape) curved in the Z direction from the center in the Y direction. That is, the ends of the second portion 13b on both sides in the Y direction may be bent toward the first portion 13 a.

As the second portion 13b1 having a shape curved from the center in the Y direction to the Z direction, the bending rigidity of the base 51 can also be increased, and further the bending rigidity of the heater can be increased. Therefore, the heater can be restrained from warping. In addition, the size of the base 51 in the Y direction can be reduced, and further the size of the heater in the Y direction can be reduced.

As shown in fig. 14, the base 52 has, for example, a first portion 13a, a second portion 13b2, and a third portion 13c. The second portion 13b2 is curved in a convex shape to the side opposite to the first portion 13a side. That is, the second portion 13b2 has a shape curved in the Z direction. As the second portion 13b2 having such a shape, the bending rigidity of the base 52 can also be increased, and further the bending rigidity of the heater can be increased. Therefore, the heater can be restrained from warping. In addition, the size of the base 52 in the Y direction can be reduced, and further the size of the heater in the Y direction can be reduced.

As shown in fig. 15 and 16, the base 53 has, for example, a first portion 13a, a second portion 13b3, and a third portion 13c. The positions of the end portions provided on both sides in the X direction of the second portion 13b of the base 50 described above are the same as the positions of the end portions on both sides in the X direction of the first portion 13 a. In contrast, the position of one of the ends in the X direction of the second portion 13b3 provided in the base 53 is the same as the position of one of the ends in the X direction of the first portion 13a, but the position of the other end in the X direction of the second portion 13b3 is located further inside (between the ends in the X direction of the first portion 13 a) than the position of the other end in the X direction of the first portion 13 a. As with the second portion 13b described above, the second portion 13b3 has a shape that is curved in the Z direction in the vicinity of the end portions of both sides in the Y direction, and therefore the bending rigidity of the base 53 can be increased.

Further, in the base 53, the vicinity of the end portion on the one side of one of the first portions 13a is connected to the vicinity of the end portion on the one side of the other first portion 13a, so that the bending rigidity of the first portion 13a can be increased, and further, the bending rigidity of the base 53 can be increased. Therefore, the bending rigidity of the heater increases, and therefore, the heater can be further suppressed from being warped.

As shown in fig. 17, the base 54 has, for example, a first portion 13a, a second portion 13b4, and a third portion 13c. The positions of the end portions of the second portion 13b4 on both sides in the X direction are located further inside (between the end portions of the first portion 13a in the X direction) than the positions of the end portions of the first portion 13a on both sides in the X direction. The second portion 13b4 has a shape that is curved in the Z direction near the end portions of both sides in the Y direction, and therefore the bending rigidity of the base 54 can be increased.

In addition, in the base portion 54, the vicinity of the end portions on both sides of one of the first portions 13a are connected to the vicinity of the end portions on both sides of the other first portion 13a, so that the bending rigidity of the first portion 13a can be further increased, and the bending rigidity of the base portion 54 can be further increased. Therefore, the bending rigidity of the heater increases, and therefore, the heater can be effectively restrained from warping.

As shown in fig. 18, the base 55 has a plurality of second portions 13b4. The plurality of second portions 13b4 may be arranged at predetermined intervals in the X direction. In this way, the first portion 13a arranged in the Y direction can be connected to three or more portions of the first portion 13a, and therefore the rigidity of the first portion 13a can be further increased. Therefore, since the bending rigidity of the base 55 and thus the bending rigidity of the heater are increased, the heater can be more effectively prevented from being warped.

In fig. 15 to 18, the case where the vicinity of the end portions of the second portion on both sides in the Y direction is curved in the Z direction is described, but as described in fig. 13 and 14, the case where the second portion has a shape curved in the Z direction from the center in the Y direction or the case where the second portion has a shape curved in the Z direction is also described.

As shown in fig. 19, the base 56 has three first portions 13a and two second portions 13b. The number of the first portions 13a and the number of the second portions 13b are not limited to the illustrated number. The number of the first portions 13a may be set to three or more, and the number of the second portions 13b may be set to two or more. In this case, as described above, the second portion 13b is provided between the first portion 13a and the first portion 13a in the Y direction. Therefore, the number of the second portions 13b is one less than the number of the first portions 13 a.

If the number of first portions 13a is increased, the number of heating elements arranged in the Y direction can be increased. However, if only the number of first portions 13a is increased, the bending rigidity of the base 56 is reduced. In this case, if the second portions 13b are provided between the first portions 13a and the first portions 13a, the decrease in bending rigidity of the base 56 can be suppressed even if the number of the first portions 13a increases. Therefore, the base 56 of the present embodiment can increase the number of heating elements, and can suppress a decrease in bending rigidity of the base 56. As a result, the heating range by the heater can be enlarged and the occurrence of warpage in the heater can be suppressed.

As shown in fig. 20, the base 57 has three first portions 13a and two second portions 13b1. The number of the first portions 13a and the number of the second portions 13b1 are not limited to the illustrated number. The number of the first portions 13a may be set to three or more, and the number of the second portions 13b1 may be set to two or more. In this case, as described above, the second portion 13b1 is provided between the first portion 13a and the first portion 13a in the Y direction. Therefore, the number of the second portions 13b1 is one less than the number of the first portions 13 a.

As in the case of the base portion 56 described above, if the base portion 57 of the present embodiment is provided, even if the number of the first portions 13a increases, the decrease in bending rigidity of the base portion 57 can be suppressed. Therefore, the number of heating elements can be increased by providing the base 57, and the bending rigidity of the base 57 can be suppressed from decreasing. As a result, the heating range by the heater can be enlarged and the occurrence of warpage in the heater can be suppressed.

As shown in fig. 21, the base 58 has three first portions 13a and two second portions 13b2. The number of the first portions 13a and the number of the second portions 13b2 are not limited to the illustrated number. The number of the first portions 13a may be set to three or more, and the number of the second portions 13b2 may be set to two or more. In this case, as described above, the second portion 13b2 is provided between the first portion 13a and the first portion 13a in the Y direction. Therefore, the number of the second portions 13b2 is one less than the number of the first portions 13 a.

As in the case of the base portion 56 described above, if the base portion 58 of the present embodiment is provided, even if the number of the first portions 13a increases, the decrease in bending rigidity of the base portion 58 can be suppressed. Therefore, the number of heating elements can be increased by providing the base 58, and the bending rigidity of the base 58 can be suppressed from decreasing. As a result, the heating range by the heater can be enlarged and the occurrence of warpage in the heater can be suppressed.

Fig. 22 is a schematic front view for illustrating the heater 14 of still another embodiment.

Fig. 22 is a view of the heater 14 from the side where the heat generating portion 20 is provided.

Fig. 23 is a schematic enlarged sectional view in the direction of line E-E of the heater 14 in fig. 22.

As shown in fig. 22 and 23, the heater 14 includes, for example, a base 15, an insulating layer 11, a heat generating portion 20, a wiring portion 30, and a protection portion 40.

The periphery of the base 15 extends in the Z direction. The base 15 has a plate shape and is curved in the Z direction (thickness direction). The base 15 extends along the X direction. A concave portion 15a1 is provided on the curved outer surface 15a of the base portion 15, which is a convex curved surface. The recess 15a1 is opened in the outer surface 15a such that the center of the outer surface 15a extends in the X direction.

The thickness T of the base 15 is, for example, about 0.3mm to 1.0 mm. The dimension of the base 15 in the X direction can be appropriately changed according to the size of the heating target (e.g., paper). The radius of curvature R of the outer surface 15a in the vicinity of the concave portion 15a1 is, for example, 0.1mm or more. When the radius of curvature R of the outer surface 15a is set in this manner, the object to be heated by the heater 14 is smoothly conveyed. In addition, it is preferable that the connecting portion between the outer surface 15a of the base 15 and the outer surface 40a of the protecting portion 40 is free from a step. In this way, the object to be heated by the heater 14 is conveyed more smoothly.

The base 15 is formed of a material having heat resistance and high thermal conductivity. The base 15 is formed of a metal such as stainless steel or an aluminum alloy. The base 15 may be formed by plastic working such as bending and pressing, drawing, or the like.

The thermal conductivity of metal is higher than that of inorganic material such as ceramics. Therefore, if the base 15 is made of metal, the temperature generation in-plane distribution of the heater 14 can be suppressed. Further, it is possible to improve the rigidity of the base 15, suppress the occurrence of cracks, defects, and the like, and reduce the manufacturing cost.

Further, details regarding suppression of warpage in the base 15 will be described later.

The insulating layer 11 is provided on the bottom surface 15a2 of the recess 15a1 of the base 15. The insulating layer 11 extends along the X direction. The insulating layer 11 covers at least the region of the bottom surface 15a2 of the recess 15a1 where the heat generating portion 20 is provided. The insulating layer 11 can be formed by, for example, applying a paste material to the bottom surface 15a2 of the recess 15a1 by screen printing or the like and hardening the paste material by firing or the like.

The heat generating portion 20 (heat generating element 21, heat generating element 22) is provided on the insulating layer 11. The heat generating portion 20 is insulated from the base portion 15 by the insulating layer 11.

The number and size of the heating elements may be appropriately changed according to the size of the base 15, the size of the heating object, and the like. In addition, a plurality of heating elements having different lengths, widths, shapes, and the like may be provided. That is, at least one heating element may be provided.

The heating elements 21 and 22 may be arranged at predetermined intervals in the Y direction (the short side direction of the insulating layer 11). The heating element 21 and the heating element 22 extend, for example, in the X direction (the longitudinal direction of the insulating layer 11).

The dimensions (length dimensions) of the heating element 21 and the heating element 22 in the X direction may be substantially the same, for example. In this case, the centers of the heating element 21 and the heating element 22 are preferably located on the straight line 14 a. That is, the heating element 21 and the heating element 22 are each preferably formed to have a shape symmetrical about the straight line 14a as the symmetry axis.

When the heater 14 is mounted to the image forming apparatus 100, for example, the straight line 14a is overlapped with the center line of the conveyance path of the heating target. In this way, even when the size or position of the heating target in the direction orthogonal to the conveying direction changes, the heating target can be heated substantially uniformly.

The wiring portion 30 is provided on the insulating layer 11.

The arrangement, shape, material, function, and manufacturing method of the terminal 31, the terminal 32, the wiring 33, the wiring 34, and the wiring 35 can be the same as those in the case of the heater 1 described above.

The heater 14 may further include a detection unit for detecting the temperature of the heat generating unit 20. The detection unit may be, for example, a thermistor. The detection portion may be provided on at least one of the insulating layer 11 and a region of the concave inner surface 15b of the base 15 facing the outer surface 15a, the region facing the insulating layer 11.

Next, suppression of warpage in the base 15 will be described.

As described above, the base 15 is formed of a metal such as stainless steel or an aluminum alloy. On the other hand, the protection portion 40 is formed of, for example, ceramics, glass with filler added, or the like. The insulating layer 11 is formed of an inorganic material such as ceramic.

Therefore, when the heater 14 is used or manufactured, thermal stress is generated due to a difference in thermal expansion coefficient of the material. If thermal stress is generated, the heater 14 may be warped.

However, as shown in fig. 23, the base 15 has a plate shape and a shape curved in the Z direction (thickness direction). When the base 15 having such a shape is provided, the bending rigidity of the base 15 can be increased. If the bending rigidity of the base 15 is increased, even if thermal stress is generated due to a difference in thermal expansion coefficient of the material, the heater 14 can be restrained from being warped.

In addition, a general heater having a flat plate-like base is mounted to a bracket (stand) provided in a fixing portion of the image forming apparatus.

The base 15 has a shape curved in the Z direction (thickness direction), and thus the base 15 can be provided with a function of a stand. Therefore, the heater 14 can be directly used for the fixing portion 200 described later, and thus the bracket can be omitted. If the bracket can be omitted, the structure of the fixing portion 200 can be simplified.

In this case, the dimension L of the base 15 in the Z direction is preferably 1mm or more and 5mm or less. In this way, even if the heater 14 is directly used in the fixing unit 200, the conveyance of the heating target by the heater 14 becomes smooth.

Further, by setting the dimension L of the base 15 in the Z direction in this manner, the bending rigidity of the base 15 can be increased, and therefore, for example, even when the thickness T of the base 15 is set to about 0.3mm to 1.0mm, a sufficient bending rigidity can be obtained with respect to the generated thermal stress.

The dimension W of the base 15 in the Y direction is preferably 4mm or more and 10mm or less. In this way, the bending rigidity of the base 15 can be increased, and therefore, for example, even when the thickness T of the base 15 is set to about 0.3mm to 1.0mm, a sufficient bending rigidity can be obtained with respect to the generated thermal stress.

As described above, if the heater 14 according to the present embodiment is used, even if the material of the base 15 is metal, warpage of the heater 14 can be suppressed, and the structure of the fixing unit 200 can be simplified.

Fig. 24 is a schematic front view for illustrating a heater 16 of still another embodiment.

Fig. 24 is a view of the heater 16 from the side where the heat generating portion 20 is provided.

Fig. 25 is a schematic enlarged sectional view of the heater 16 in fig. 24 in the F-F line direction.

As shown in fig. 24 and 25, the heater 16 includes, for example, a base 60, an insulating layer 11, a heat generating portion 20, a wiring portion 30, a protection portion 40, and a reinforcing portion 70. In addition, a detection unit for detecting the temperature of the heat generating unit 20 may be further provided in the same manner as the heater 1 described above.

Further, the centers of the heating element 21 and the heating element 22 are preferably located on the straight line 16 a. That is, the heating element 21 and the heating element 22 are each preferably formed to have a shape symmetrical about the straight line 16a as the symmetry axis.

When the heater 16 is mounted to the image forming apparatus 100, for example, the straight line 16a is overlapped with the center line of the conveyance path of the heating target. In this way, even when the size or position of the heating target in the direction orthogonal to the conveying direction changes, the heating target can be heated substantially uniformly.

The base 60 has a first portion 61 and a second portion 62. The first portion 61 and the second portion 62 may be integrally formed. The base 60 (the first portion 61 and the second portion 62) may be formed of a metal such as stainless steel or an aluminum alloy, for example. The base 60 may be formed by plastic working such as bending and pressing, drawing, or the like.

The first portion 61 has a plate shape. The first portion 61 extends in the X direction. On the outer surface 61a in the Z direction of the first portion 61, a concave portion 61a1 is provided. The recess 61a1 is open at the outer surface 61 a. In the concave portion 61a1, the center of the outer surface 61a is extended in the X direction. As with the recess 15a1 described above, the insulating layer 11 is provided on the bottom surface 61a2 of the recess 61a1. The insulating layer 11 is provided with a heat generating portion 20, a wiring portion 30, and a protection portion 40. The protection portion 40 covers the heat generating portion 20 (the heat generating element 21 and the heat generating element 22) and a part of the wiring portion 30 (the wiring 33, the wiring 34, and the wiring 35). The terminals 31 and 32 of the wiring portion 30 are exposed from the protection portion 40.

The outer surface 61a of the first portion 61 may be provided with a convexly curved surface. The radius of curvature R1 of the outer surface 61a in the vicinity of the concave portion 61a1 is, for example, 0.1mm or more. By setting the radius of curvature R1 of the outer surface 61a in this manner, the object to be heated by the heater 16 is conveyed smoothly. In addition, it is preferable that the connecting portion between the outer surface 61a of the first portion 61 and the outer surface 40a of the protecting portion 40 has no step. In this way, the object to be heated by the heater 16 is conveyed more smoothly.

The second portion 62 is plate-shaped and provided with a pair. The second portions 62 are provided at respective peripheral edges of both sides in the Y direction of the inner surface 61b of the first portion 61 facing the outer surface 61 a. The second portion 62 protrudes from the inner surface 61b in the Z direction. A pair of second portions 62 face each other.

The dimensions of the base 60 (the first portion 61 and the second portion 62) in the X direction can be appropriately changed according to the size of the heating target.

The thickness T1 of the first portion 61 and the thickness T2 of the second portion 62 are, for example, about 0.3mm to 1.0 mm.

The dimension W1 of the base 60 in the Y direction (the dimension of the first portion 61 in the Y direction) is, for example, about 4mm to 10 mm.

The dimension L1 of the base 60 in the Z direction may be 1mm or more and 5mm or less.

That is, the dimension W1 of the base 60 in the Y direction may be smaller than the dimension W of the base 15 in the Y direction described above. In addition, the dimension L1 in the Z direction of the base 60 may be smaller than the dimension L in the Z direction of the base 15 described above. Thus, miniaturization of the base 60 can be achieved.

However, if the dimension W1 in the Y direction of the base 60 and the dimension L1 in the Z direction of the base 60 are set in this way, the bending rigidity of the base 60 is smaller than that of the base 15.

Therefore, the reinforcing portion 70 is provided in the heater 16.

As shown in fig. 25, the reinforcing portion 70 is provided on the inner surface 61b side of the first portion 61. The reinforcement 70 is disposed between one of the second portions 62 and the other second portion 62. The reinforcement 70 extends along the Z direction. The reinforcement 70 protrudes from the inner surface 61b side of the first portion 61. The reinforcement portion 70 has a plate shape and is curved in the Z direction (thickness direction). For example, the reinforcing portion 70 may have a U-shape when viewed from the X direction. One of the ends of the reinforcement 70 in the Y direction is connected to one of the second portions 62. The other end portion in the Y direction of the reinforcing portion 70 is connected to the other second portion 62. The ends of the reinforcement 70 may be welded or soldered to the second portion 62, or may be attached to the second portion 62 using fastening members such as screws.

The reinforcement 70 is formed of a metal such as stainless steel or an aluminum alloy. The reinforcing portion 70 may be formed by plastic working such as bending and pressing, drawing, or the like.

The thickness of the reinforcing portion 70 may be, for example, 0.3mm or more and 2.0mm or less. The dimension L2 of the reinforcement portion 70 in the Z direction may be, for example, 30mm to 80 mm. The dimension of the reinforcement portion 70 in the X direction may be set to be the same as the dimension of the base portion 60 in the X direction, for example. In addition, a plurality of reinforcing portions 70 may be provided. That is, the reinforcement part 70 may be provided with at least one. In the case where a plurality of reinforcing portions 70 are provided, the plurality of reinforcing portions 70 may be arranged in the X direction at predetermined intervals.

If the reinforcement portion 70 extending in the Z direction is connected to the base portion 60, the bending rigidity can be increased, and therefore, even if the dimension W1 of the base portion 60 in the Y direction and the dimension L1 of the base portion 60 in the Z direction are reduced, the heater 16 can be restrained from being warped.

In addition, the base 60 (first portion 61) having a convex curved surface (outer surface 61 a) may be made to function as a bracket. Therefore, the heater 16 can be directly used for the fixing portions 200a and 200b described later, and therefore, the bracket can be omitted. If the bracket can be omitted, the structures of the fixing portions 200a and 200b can be simplified.

As described above, if the heater 16 according to the present embodiment is used, even if the material of the base 60 is metal, warpage of the heater 16 can be suppressed, and the structures of the fixing portion 200a and the fixing portion 200b can be simplified.

(image Forming apparatus)

In one embodiment of the present utility model, an image forming apparatus 100 including a heater 1 may be provided. The description regarding the heater 1 described above and modifications of the heater 1 (e.g., the heater 12, the heater 14, the heater 16) are applicable to the image forming apparatus 100.

In the following, a case where image forming apparatus 100 is a copier will be described as an example. The image forming apparatus 100 is not limited to a copier, and may be provided with a heater for fixing toner. For example, the image forming apparatus 100 may be a printer or the like.

Fig. 26 is a schematic diagram for illustrating the image forming apparatus 100 of the present embodiment.

Fig. 27 is a schematic diagram for illustrating the fixing portion 200.

As shown in fig. 26, the image forming apparatus 100 includes, for example, a frame 110, an illumination unit 120, an image forming element 130, a photosensitive drum 140, a charging unit 150, a discharging unit 151, a developing unit 160, a cleaner 170, a housing unit 180, a conveying unit 190, a fixing unit 200, and a controller 210.

The frame 110 has a box shape, and houses therein the illumination unit 120, the image forming element 130, the photosensitive drum 140, the charging unit 150, the developing unit 160, the cleaner 170, a part of the housing unit 180, the conveying unit 190, the fixing unit 200, and the controller 210.

A window 111 made of a light-transmitting material such as glass may be provided on the upper surface of the frame 110. An original 500 to be copied is placed on the window 111. In addition, a moving portion that moves the position of the original 500 may be provided.

The illumination section 120 is disposed in the vicinity of the window 111. The illumination unit 120 includes a light source 121 such as a lamp and a reflector 122.

The imaging element 130 is disposed in the vicinity of the window 111.

The photosensitive drum 140 is disposed below the illumination portion 120 and the imaging element 130. The photosensitive drum 140 is rotatably provided. A zinc oxide photosensitive layer or an organic semiconductor photosensitive layer is provided on the surface of the photosensitive drum 140, for example.

The charging portion 150, the discharging portion 151, the developing portion 160, and the cleaner 170 are provided around the photosensitive drum 140.

The storage unit 180 includes, for example, a cassette (cassette) 181 and a tray 182. The cassette 181 is detachably mounted to one of the side portions of the frame 110. The tray 182 is provided at a side portion of the frame 110 opposite to the side where the cartridge 181 is mounted. The cassette 181 accommodates paper 510 (for example, white paper) before copying. The tray 182 accommodates therein a sheet 511 to which a copy image 511a is fixed.

The conveying section 190 is provided below the photosensitive drum 140. The transport section 190 transports the paper 510 between the cassette 181 and the tray 182. The conveying section 190 includes, for example, a guide 191 that supports the conveyed paper 510, and conveying rollers 192 to 194 that convey the paper 510. Further, a motor for rotating the conveying rollers 192 to 194 may be provided in the conveying section 190.

The fixing portion 200 is provided on the downstream side (the tray 182 side) of the photosensitive drum 140.

As shown in fig. 27, the fixing unit 200 includes, for example, a heater 1 (12), a holder 201, a film belt 202, and a pressure roller 203.

The heater 1 (12) is mounted on the conveyance path side of the paper 510 of the holder 201. The heater 1 (12) may be embedded in the holder 201. In this case, the side of the heater 1 (12) on which the protection portion 40 is provided is exposed from the holder 201.

The film tape 202 covers the holder 201 provided with the heater 1 (12). The film tape 202 may contain a resin having heat resistance such as polyimide.

The pressing roller 203 is disposed to face the holder 201. The pressing roller 203 has, for example, a core 203a, a driving shaft 203b, and an elastic portion 203c. The driving shaft 203b protrudes from the end of the core 203a and is connected to a driving device such as a motor. The elastic portion 203c is provided on the outer surface of the core 203 a. The elastic portion 203c is formed of an elastic material having heat resistance. The elastic portion 203c may contain, for example, silicone resin or the like.

The controller 210 is disposed inside the frame 110. The controller 210 includes an arithmetic unit such as a central processing unit (Central Processing Unit, CPU) and a storage unit storing a control program. The arithmetic unit controls the operations of the respective components provided in the image forming apparatus 100 based on the control program stored in the storage unit. The controller 210 may include an operation unit for inputting copying conditions and the like by a user, a display unit for displaying an operation state, abnormal display, and the like.

Further, since known techniques can be applied to control each component provided in the image forming apparatus 100, a detailed description thereof is omitted.

Fig. 28 is a schematic diagram for illustrating a fixing portion 200a of still another embodiment.

As shown in fig. 28, the fixing portion 200a includes, for example, a heater 14, a film belt 202, and a pressure roller 203.

The heater 14 is mounted so that the side where the protection portion 40 is provided faces the pressing roller 203.

Generally, a fixing unit is provided with a heater having a flat plate-shaped base, a bracket to which the flat plate-shaped heater is attached, a film belt, and a pressure roller. As described above, the heater 14 according to the present embodiment can provide the base 15 having a shape curved in the Z direction (thickness direction) with a function as a bracket. Therefore, since the bracket can be omitted, the structure of the fixing portion 200a can be simplified.

Fig. 29 is a schematic diagram for illustrating a fixing portion 200b of still another embodiment.

As shown in fig. 29, the fixing portion 200b includes, for example, a heater 16, a film belt 202, and a pressure roller 203.

The heater 16 is mounted so that the side where the protection portion 40 is provided faces the pressing roller 203. As described above, the heater 16 according to the present embodiment can provide the base 60 (the first portion 61) having the convex curved surface (the outer surface 61 a) with a function as a bracket. Therefore, since the bracket can be omitted, the structure of the fixing portion 200b can be simplified.

Claims

1. A heater, comprising:

a base portion including a metal and extending along a first direction, and having a first face and a second face opposite to the first face;

An insulating layer provided on the first surface side of the base;

a heating element provided on the insulating layer and extending along the first direction; and

a protection part covering the heating element,

the peripheral edge of the base portion in a second direction intersecting the first direction extends along a third direction intersecting the first direction and the second direction.

2. The heater of claim 1, wherein the base is rectangular in shape when viewed from a third direction,

at least any one of four peripheral edges of the rectangle extends along the third direction.

3. The heater according to claim 1 or 2, wherein, in the case where an inclination angle between a peripheral edge of the base portion extending along the third direction and the second face is set to θ, the following formula is satisfied:

θ is more than 90 degrees and less than or equal to 160 degrees or more than 20 degrees and less than or equal to 90 degrees.

4. A heater according to claim 1, wherein,

the base has:

a plurality of first portions arranged at predetermined intervals in the second direction; and

and a second portion disposed between the first portion and the first portion in the second direction and intersecting a peripheral edge of the first portion.

5. The heater of claim 4, wherein the base further has a third portion intersecting a periphery of the first portion on a side opposite to a side on which the second portion is provided in the second direction,

in the third direction, the second portion and the third portion are disposed on the same side of the first portion.

6. The heater of claim 4 or 5, wherein the heat generating body is provided on the insulating layer provided on the first portion.

7. The heater according to claim 4 or 5, wherein end portions of both sides of the second portion in the second direction are bent toward the first portion side, or,

the second portion is curved in a convex shape to a side opposite to the first portion side.

8. The heater of claim 1, wherein the base further has a recess opening at the first face and extending in the first direction,

the first face is a convex curved face,

the insulating layer is arranged on the bottom surface of the concave part.

9. The heater of claim 8, wherein the base has a shape curved toward the third direction,

The recess is open at the curved first face.

10. The heater according to claim 8 or 9, further comprising a reinforcing portion having a plate shape and a shape curved toward the third direction,

an end of the reinforcement portion is connected to a peripheral edge of the base portion extending along the third direction.

11. A heater according to claim 8 or 9, wherein the radius of curvature of the first face in the vicinity of the recess is 0.1mm or more.

12. An image forming apparatus including the heater according to any one of claims 1 to 11.