JP2024002032A - Heater and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heater capable of suppressing warpage of a heater even if a substrate material is metal and an image forming apparatus.

SOLUTION: A heater 1 includes a substrate 10 that includes metal and has a shape extending on one side, an insulating layer 11 provided on a first surface of the substrate, heating elements 21, 22 provided on the insulating layer and extending in the longitudinal direction of the substrate, a protective portion 40 covering the heating elements, and at least one convex part 10c provided along the peripheral part of a second surface of the substrate, opposing the first surface.

SELECTED DRAWING: Figure 3

COPYRIGHT: (C)2024,JPO&INPIT

Description

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

Image forming apparatuses such as copying machines and printers are provided with heaters for fixing toner. Generally, such a heater includes an elongated substrate, a heating element provided on one surface of the substrate and extending in the longitudinal direction of the substrate, and a protection part that covers the heating element.

The substrate is made of a material that is heat resistant, insulative, and has high thermal conductivity. The substrate is made of ceramics such as aluminum oxide, for example. Further, the substrate may be, for example, a metal plate whose surface is coated with an insulating material.
The protective portion is made of a material that has heat resistance and insulation properties, high thermal conductivity, and high chemical stability. For example, the protection part is formed from ceramics, glass, or the like.

Here, if the material of the substrate is metal, it is possible to improve the rigidity of the substrate and reduce manufacturing costs. However, if the material of the substrate is metal, the material of the substrate and the material of the protective portion are different, and thermal stress is generated due to the difference in coefficient of thermal expansion of the materials. When thermal stress occurs, the heater is likely to warp. Furthermore, since the coefficient of thermal expansion of metal is higher than that of ceramics, etc., thermal stress tends to increase. As the thermal stress increases, the warpage of the heater increases.

If the warpage of the heater increases, the distance between the heater and the object to be heated may vary, which may cause uneven heating of the object.
Therefore, it has been desired to develop a technology that can suppress the occurrence of warpage in the heater even when the material of the substrate is metal.

Japanese Patent Application Publication No. 2007-240606

An object of the present invention is to provide a heater and an image forming apparatus that can suppress warping of the heater even when the material of the substrate is metal.

The heater according to the embodiment includes: a substrate including metal and having a shape extending in one direction; an insulating layer provided on a first surface of the substrate; and a substrate provided on the insulating layer and extending in the longitudinal direction of the substrate. A heating element that extends; a protective part that covers the heating element; and at least one convex part provided along a periphery of a second surface of the substrate opposite to the first surface. .

According to the embodiments of the present invention, it is possible to provide a heater and an image forming apparatus that can suppress warping of the heater even when the material of the substrate is metal.

FIG. 2 is a schematic front view for illustrating a heater according to the present embodiment. FIG. 3 is a schematic rear view for illustrating a heater. 2 is a schematic cross-sectional view of the heater in the direction of line AA in FIG. 1. FIG. FIG. 2 is a schematic side view of the heater in the direction of line BB in FIG. 1. FIG. FIG. 7 is a schematic back view for illustrating a substrate according to another embodiment. FIG. 7 is a schematic cross-sectional view for illustrating a convex portion according to another embodiment. 7 is a schematic enlarged view of section C in FIG. 6. FIG. FIG. 1 is a schematic diagram illustrating an image forming apparatus according to an embodiment. FIG. 3 is a schematic diagram for illustrating a fixing section.

Hereinafter, embodiments will be illustrated with reference to the drawings. Note that in each drawing, similar components are denoted by the same reference numerals, and detailed explanations are omitted as appropriate. Further, arrows X, Y, and Z in each drawing represent three directions orthogonal to each other. For example, the longitudinal direction of the substrate is the X direction, the lateral direction (width direction) of the substrate is the Y direction, and the direction perpendicular to the surface of the substrate is the Z direction.

(heater)
FIG. 1 is a schematic front view illustrating a heater 1 according to the present embodiment.
Note that FIG. 1 is a diagram of the heater 1 viewed from the side where the heat generating section 20 is provided.
FIG. 2 is a schematic rear view illustrating the heater 1. As shown in FIG.
Note that FIG. 2 is a diagram of the heater 1 viewed from the opposite side to the side where the heat generating section 20 is provided.
FIG. 3 is a schematic cross-sectional view of the heater 1 in the direction of line AA in FIG.
FIG. 4 is a schematic side view of the heater 1 in the direction of line BB in FIG.

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

The substrate 10 has a plate shape and has a surface 10a (corresponding to an example of a first surface) and a surface 10b (corresponding to an example of a second surface) opposite to the surface 10a. The substrate 10 has a shape extending in the X direction. The shape of the substrate 10 when viewed from the Z direction is, for example, a long rectangle. The thickness of the substrate 10 is, for example, about 0.5 mm to 1.0 mm. The dimensions of the substrate 10 in the X direction and the dimensions of the substrate 10 in the Y direction can be changed as appropriate depending on the size of the object to be heated (for example, paper).

The substrate 10 is made of a material that is heat resistant and has high thermal conductivity. The substrate 10 can be made of metal such as stainless steel or aluminum alloy, for example.

The thermal conductivity of metals is higher than that of inorganic materials such as ceramics. Therefore, if the substrate 10 is made of metal, it is possible to suppress the in-plane temperature distribution of the heater 1 from occurring. Furthermore, it is possible to improve the rigidity of the substrate 10 and reduce manufacturing costs.

The insulating layer 11 is provided on the surface 10a of the substrate 10 on the side where the heat generating section 20 is provided. The insulating layer 11 covers a region of the surface 10a of the substrate 10 where the heat generating section 20 is provided. The insulating layer 11 is formed from a material having heat resistance and insulating properties. The insulating layer 11 can be formed from an inorganic material such as ceramics, for example.

The heat generating section 20 converts the applied electric power into heat (Joule heat). The heat generating section 20 is provided on the insulating layer 11. The heat generating section 20 and the substrate 10 are insulated by an insulating layer 11.
The heat generating section 20 includes, for example, a heat generating body 21 and a heat generating body 22. Note that, as an example, a case where the heating elements 21 and 22 are provided is illustrated, but the number and size of the heating elements may be changed as appropriate depending on the size of the substrate 10, the size of the object to be heated, etc. Can be done. Moreover, it is also possible to provide a plurality of types of heating elements having different lengths, widths, shapes, etc. That is, at least one heating element may be provided.

The heating element 21 and the heating element 22 can be arranged side by side at a predetermined interval in the Y direction (the lateral direction of the substrate 10), for example. The heating element 21 and the heating element 22 extend, for example, in the X direction (the longitudinal direction of the substrate 10).

The dimensions (length dimensions) in the X direction of the heating element 21 and the heating element 22 can be, for example, substantially the same. In this case, it is preferable that the centers of the heating elements 21 and 22 are located on the straight line 1a. That is, it is preferable that each of the heating element 21 and the heating element 22 has a shape that is line symmetrical with respect to the straight line 1a as an axis of symmetry.

When attaching the heater 1 to the image forming apparatus 100, for example, the straight line 1a is arranged to overlap the center line of the conveyance path of the object to be heated. In this way, even if the dimensions of the object to be heated in the direction orthogonal to the conveyance direction change, the object to be heated can be heated substantially uniformly.

The electrical resistance values of the heating element 21 and the heating element 22 can be approximately the same or different. For example, by making the dimensions in the X direction (length dimension), the dimension in the Y direction (width dimension), and the dimension in the Z direction (thickness dimension) of the heating elements 21 and 22 substantially the same, the heating elements The electrical resistance values of the heating element 21 and the heating element 22 can be made to be approximately the same. Further, by changing at least one of these dimensions, the electrical resistance values of the heating element 21 and the heating element 22 can be made to be different. Further, by changing the material, the electrical resistance values of the heating element 21 and the heating element 22 can be made to be different.

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

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

The heating element 21 and the heating element 22 can be formed using, for example, ruthenium oxide (RuO ₂ ), a silver-palladium (Ag-Pd) alloy, or the like. The heating element 21 and the heating element 22 can be formed, for example, by applying a paste-like material onto the insulating layer 11 using a screen printing method or the like and hardening it using a baking method or the like.

The wiring section 30 is provided on the insulating layer 11.
The wiring section 30 includes, for example, a terminal 31, a terminal 32, a wiring 33, a wiring 34, and a wiring 35.

The terminals 31 and 32 are provided, for example, near one end of the substrate 10 in the X direction. For example, the terminals 31 and 32 are arranged side by side in the X direction. The terminals 31 and 32 are electrically connected to, for example, a power source via a connector, wiring, or the like.

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

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

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

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

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

The protection part 40 extends in the X direction. The protection part 40 has, for example, a function of insulating the heat generating part 20 and a part of the wiring part 30, a function of transmitting the heat generated in the heat generating part 20, and a function of protecting the heat generating part 20 and the wiring part 30 from external force, corrosive gas, etc. It has the function of protecting a part of the The protection part 40 is made of a material that has heat resistance and insulation properties, and has high chemical stability and thermal conductivity. The protection portion 40 is made of, for example, ceramics or glass. In this case, the protective portion 40 can also be formed using glass to which a filler containing a material with high thermal conductivity such as aluminum oxide is added. The thermal conductivity of the filler-added glass can be, for example, 2 [W/(m·K)] or more.

Further, the heater 1 can further be provided with a detection section that detects the temperature of the heat generating section 20. The detection unit can be, for example, a thermistor. The detection section can be provided on at least one of the side of the substrate 10 where the heat generating section 20 is provided, and the side of the substrate 10 opposite to the side where the heat generating section 20 is provided.

When the detection section is provided on the side of the substrate 10 where the heat generating section 20 is provided (the surface 10a side of the substrate 10), the detection section and the wiring and terminals electrically connected to the detection section are covered with an insulating layer. 11. The wiring electrically connected to the detection section can be covered by the protection section 40. A terminal electrically connected to the detection section can be exposed from the protection section 40.

When the detection section is provided on the side of the substrate 10 opposite to the side on which the heat generating section 20 is provided (on the surface 10b side of the substrate 10), an insulating layer is provided on the surface 10b, and the detection section and the detection section Wiring and terminals electrically connected to the insulating layer can be provided on the insulating layer. The insulating layer can be similar to the insulating layer 11 provided on the surface 10a. Furthermore, the wiring electrically connected to the detection section can be covered by the protection section. A terminal electrically connected to the detection section can be exposed from the protection section. The protective portion can be similar to the protective portion 40 provided on the insulating layer 11.

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

Therefore, the coefficient of thermal expansion of the substrate 10 is different from the coefficients of thermal expansion of the protective portion 40 and the insulating layer 11. Further, when the heater 1 is used, when the heat generating section 20 (heat generating elements 21 and 22) is made to generate heat, the substrate 10, the protection section 40, and the insulating layer 11 are heated. When the protective portion 40 and the insulating layer 11 are fired during manufacturing of the heater 1, the substrate 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 the difference in the coefficient of thermal expansion of the materials. When thermal stress occurs, there is a risk that the heater 1 will warp.

Further, since the coefficient of thermal expansion of metal is higher than that of ceramics, etc., the heater 1 tends to warp more easily. In addition, the length of the substrate 10 in the lateral direction (width direction: for example, the Y direction) may be short, the length of the substrate 10 in the longitudinal direction (for example, the X direction) may be long, or the thickness of the substrate 10 may be thin. Even if the heater 1 is bent, the warpage of the heater 1 tends to increase.
When the warpage of the heater 1 becomes large, the distance between the heater 1 and the object to be heated may vary, which may cause uneven heating of the object to be heated.

Therefore, as shown in FIGS. 2 to 4, the substrate 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 substrate 10 to the side where the heat generating portion 20 is provided. The convex portion 10c and the convex portion 10d protrude from the surface 10b of the substrate 10. The convex portion 10c and the convex portion 10d can be formed integrally with the substrate 10, for example. The convex portion 10c and the convex portion 10d can be formed by, for example, press molding or bending.

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

The convex portion 10d is provided along the periphery of the surface 10b of the substrate 10 in the X direction. The convex portion 10d extends in the Y direction. As shown in FIGS. 2 and 4, a gap can be provided between the convex portion 10d and the convex portion 10c. Further, the convex portion 10d and the convex portion 10c may be in contact with each other. The distance between the top of the projection 10d and the surface 10b of the substrate 10 (the height of the projection 10d) is the same as the distance H between the top of the projection 10c and the surface 10b of the substrate 10. You can also make it different. The thickness of the convex portion 10d can be, for example, the same as the thickness T of the convex portion 10c, or can be different.

If the convex portions 10c and 10d are provided, the bending rigidity of the substrate 10 can be increased. If the bending rigidity of the substrate 10 is increased, even if thermal stress is generated due to a difference in the coefficient of thermal expansion of the materials, it is possible to suppress the generation of warpage in the heater 1.

The convex portions 10c illustrated in FIGS. 2 to 4 are provided at both ends of the substrate 10 in the Y direction. However, when the generated thermal stress is small or the length of the substrate 10 in the X direction is short, the generated warp becomes small. If the warpage that occurs is small, the protrusion 10c may be provided at one end of the substrate 10 in the Y direction, and the protrusion 10c may not be provided at the other end of the substrate 10. By providing the convex portion 10c only at one end of the substrate 10, the manufacturing cost of the heater 1 can be reduced.

Moreover, although the case where one convex part 10c extending continuously in the X direction is provided at the end of the substrate 10 in the Y direction is illustrated, the convex part 10c is provided in a part of the region of the substrate 10 in the X direction. Or, it is also possible to provide a plurality of convex portions 10c lined up in the X direction.

The convex portions 10d illustrated in FIGS. 2 to 4 are provided at both ends of the substrate 10 in the X direction. However, when the generated thermal stress is small or the length of the substrate 10 in the Y direction is short, the generated warp becomes small. If the warpage that occurs is small, the protrusion 10d may be provided at one end of the substrate 10 in the X direction, and the protrusion 10d may not be provided at the other end of the substrate 10. If the convex portion 10d is provided only at one end of the substrate 10, the manufacturing cost of the heater 1 can be reduced.

Further, although the case where one convex portion 10d extending continuously in the Y direction is provided at the end of the substrate 10 in the X direction is illustrated, the convex portion 10d is provided in a part of the region of the substrate 10 in the Y direction. Or, it is also possible to provide a plurality of convex portions 10d lined up in the Y direction.

Further, the length of the substrate 10 in the X direction is longer than the length of the substrate 10 in the Y direction. Therefore, the warpage of the substrate 10 in the X direction is greater than the warpage of the substrate 10 in the Y direction.
In this case, the height of the convex portion 10c can be made higher than the height of the convex portion 10d. The thickness of the protrusion 10c can also be made thicker than the thickness of the protrusion 10d. By doing so, it is possible to suppress the warpage of the substrate 10 from increasing in the X direction.

FIG. 5 is a schematic rear view illustrating a substrate 10e according to another embodiment.
Note that FIG. 5 is a view of the substrate 10e viewed from the opposite side to the side where the heat generating section 20 is provided. The length of the substrate 10e in the Y direction is shorter than the length of the substrate 10e in the X direction. Therefore, the warpage of the substrate 10e in the Y direction is smaller than the warp of the substrate 10e in the X direction.

In such a case, as shown in FIG. 5, a protrusion 10c should be provided at the end of the substrate 10e in the Y direction, but a protrusion 10d should not be provided at the end of the substrate 10e in the X direction. Can be done. Note that if the warpage of the substrate 10e is small, the protrusion 10c may be provided at one end of the substrate 10e in the Y direction, and the protrusion 10c may not be provided at the other end of the substrate 10e. .
By doing so, the manufacturing cost of the heater 1 can be reduced.

FIG. 6 is a schematic cross-sectional view for illustrating a convex portion 10c1 according to another embodiment.
FIG. 7 is a schematic enlarged view of section C in FIG. 6.
The convex portion 10c illustrated in FIGS. 3 and 4 is perpendicular to the surface 10b of the substrate 10.
On the other hand, the convex portion 10c1 illustrated in FIGS. 6 and 7 is inclined with respect to the surface 10b of the substrate 10. For example, the convex portion 10c1 can be formed by tilting the convex portion 10c. The inclination angle θ between the convex portion 10c1 and the surface 10b of the substrate 10 can be, for example, “90°<θ≦160°”. Further, the inclination angle θ between the convex portion 10c1 and the surface 10b of the substrate 10 can be set to, for example, “20°≦θ<90°”.

If the convex portion 10c1 is inclined with respect to the surface 10b of the substrate 10, it is possible to improve the bending rigidity of the substrate 10 and to prevent the size of the heater 1 in the Z direction from increasing. Further, if "20°≦θ<90°", the tip of the convex portion 10c1 is located inside the surface 10b of the substrate 10 when viewed from the Z direction, so that the bending rigidity of the substrate 10 is improved. At the same time, it is possible to suppress the dimensions of the heater 1 in the Z direction and the Y direction from increasing.

The arrangement, number, dimensions, inclination angle θ, etc. of the convex portions 10c and 10d can be changed as appropriate depending on the generated thermal stress and the magnitude of warpage. The arrangement, number, dimensions, inclination angle θ, etc. of the convex portion 10c and the convex portion 10d can be appropriately determined by, for example, experimenting or simulation.

(Image forming device)
In one embodiment of the present invention, an image forming apparatus 100 including a heater 1 can be provided. The above description of the heater 1 and the modified examples of the heater 1 (for example, the arrangement, number, dimensions, inclination angle θ, etc. of the above-described convex portions 10c and 10d) are applicable to the image forming apparatus 100. Can be done.

Further, in the following, a case where the image forming apparatus 100 is a copying machine will be described as an example. However, the image forming apparatus 100 is not limited to a copying machine, and may be any apparatus provided with a heater for fixing toner. For example, the image forming apparatus 100 can also be a printer.

FIG. 8 is a schematic diagram illustrating the image forming apparatus 100 according to the present embodiment.
FIG. 9 is a schematic diagram illustrating the fixing section 200.
As shown in FIG. 8, the image forming apparatus 100 includes, for example, a frame 110, a lighting section 120, an imaging element 130, a photosensitive drum 140, a charging section 150, a discharging section 151, a developing section 160, a cleaner 170, a storage section 180, It has a transport section 190, a fixing section 200, and a controller 210.

The frame 110 has a box shape, and includes an illumination section 120, an imaging element 130, a photosensitive drum 140, a charging section 150, a developing section 160, a cleaner 170, a part of the storage section 180, a transport section 190, and a fixing section. 200 and a controller 210 are housed therein.
A window 111 made of a transparent material such as glass can be provided on the upper surface of the frame 110. A document 500 to be copied is placed on the window 111 . Further, a moving unit that moves the position of the original 500 can be provided.

The lighting section 120 is provided near the window 111. The illumination unit 120 includes, for example, a light source 121 such as a lamp, and a reflecting mirror 122.
The imaging element 130 is provided near the window 111.
The photosensitive drum 140 is provided below the illumination section 120 and the imaging element 130. Photosensitive drum 140 is rotatably provided. For example, a zinc oxide photosensitive layer or an organic semiconductor photosensitive layer is provided on the surface of the photosensitive drum 140.
The charging section 150, the discharging section 151, the developing section 160, and the cleaner 170 are provided around the photosensitive drum 140.

The storage unit 180 includes, for example, a cassette 181 and a tray 182. Cassette 181 is removably attached to one side of frame 110. The tray 182 is provided on the side of the frame 110 opposite to the side to which the cassette 181 is attached. The cassette 181 stores paper 510 (for example, blank paper) before being copied. The tray 182 stores the paper 511 on which the copied image 511a is fixed.

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

The fixing unit 200 is provided downstream of the photosensitive drum 140 (on the tray 182 side).
As shown in FIG. 9, the fixing unit 200 includes, for example, a heater 1, a stay 201, a film belt 202, and a pressure roller 203.
The heater 1 is attached to the stay 201 on the paper 510 transport line side. The heater 1 can be embedded in the stay 201. In this case, the side of the heater 1 on which the protective portion 40 is provided is exposed from the stay 201.

The film belt 202 covers the stay 201 on which the heater 1 is provided. The film belt 202 can include, for example, a heat-resistant resin such as polyimide.

Pressure roller 203 is provided to face stay 201 . The pressure roller 203 includes, for example, a core metal 203a, a drive shaft 203b, and an elastic portion 203c. The drive shaft 203b protrudes from the end of the core metal 203a and is connected to a drive device such as a motor. The elastic portion 203c is provided on the outer surface of the core bar 203a. The elastic portion 203c is made of a heat-resistant elastic material. The elastic portion 203c may include, for example, silicone resin.

Controller 210 is provided inside frame 110. The controller 210 includes, for example, a calculation unit such as a CPU (Central Processing Unit), and a storage unit in which a control program is stored. The calculation unit controls the operation of each element provided in the image forming apparatus 100 based on a control program stored in the storage unit. Further, the controller 210 can also include an operation section through which the user inputs copying conditions and the like, a display section that displays operating status, abnormality display, and the like.
Note that since known techniques can be applied to control each element provided in the image forming apparatus 100, detailed explanation will be omitted.

Although several embodiments of the present invention have been illustrated above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, changes, etc. can be made without departing from the gist of the invention. These embodiments and their modifications are included within the scope and gist of the invention, as well as within the scope of the invention described in the claims and its equivalents. Further, each of the embodiments described above can be implemented in combination with each other.

Additional notes regarding the above-described embodiments will be shown below.

(Additional note 1)
a substrate containing metal and having a shape extending in one direction;
an insulating layer provided on a first surface of the substrate;
a heating element provided on the insulating layer and extending in the longitudinal direction of the substrate;
a protective part that covers the heating element;
at least one convex portion provided along a periphery of a second surface of the substrate opposite to the first surface;
Heater equipped with.

(Additional note 2)
The heater according to supplementary note 1, wherein the convex portion extends in the longitudinal direction of the substrate.

(Additional note 3)
The heater according to supplementary note 1 or 2, which satisfies the following formula, where θ is an inclination angle between the convex portion and the second surface.
90°<θ≦160°, or 20°≦θ<90°

(Additional note 4)
The heater according to any one of Supplementary Notes 1 to 3, wherein the convex portion is formed integrally with the substrate.

(Appendix 5)
An image forming apparatus comprising the heater according to any one of Supplementary Notes 1 to 4.

1 heater, 10 substrate, 10a surface, 10b surface, 10c convex part, 10c1 convex part, 10d convex part, 10e substrate, 11 insulating layer, 20 heat generating part, 21 heating element, 22 heating element, 30 wiring part, 40 protection part , 100 image forming apparatus, 200 fixing unit, θ inclination angle

Claims (5)

a substrate containing metal and having a shape extending in one direction;
an insulating layer provided on a first surface of the substrate;
a heating element provided on the insulating layer and extending in the longitudinal direction of the substrate;
a protective part that covers the heating element;
at least one convex portion provided along a periphery of a second surface of the substrate opposite to the first surface;
Heater equipped with. The heater according to claim 1, wherein the convex portion extends in the longitudinal direction of the substrate. The heater according to claim 1 or 2, which satisfies the following equation, where θ is an inclination angle between the convex portion and the second surface.
90°<θ≦160°, or 20°≦θ<90° The heater according to claim 1 or 2, wherein the convex portion is formed integrally with the substrate. An image forming apparatus comprising the heater according to claim 1.

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