Fixing device, image forming apparatus, and heater manufacturing method

Abstract

To provide a fixing device that can improve manufacturing yield of a substrate composed of metal material and can be manufactured at low cost, an image forming apparatus, and a method for manufacturing a heater.SOLUTION: A fixing device (45) comprises: a heater (60) that has a substrate (S) and a resistance heating element (P); and a holder that holds the heater (60). The substrate (S) has a substrate protrusion (ST) that is arranged on one end side in a width direction (SH) orthogonal to a longitudinal direction (LH) and protrudes in the width direction (SH), and a substrate recess (SU) that is arranged on the other end side in the width direction (SH) and is recessed in the width direction (SH) in substantially the same shape as the substrate protrusion (ST). The holder has an engagement part that is engaged with the substrate protrusion (ST) or the substrate recess (SU).SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to a fixing device, an image forming apparatus, and a method for manufacturing a heater. [Background technology]

[0002] Known image forming apparatuses, such as electrophotographic printers, include a fixing device that heats a sheet on which an image is to be formed to fix a developer image. Such fixing devices include a substrate, a heater having a resistance heating element disposed on the substrate, and a holder that holds the heater (see, for example, Patent Document 1 listed below). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-52348 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the fixing device as described above, the heater and the holder are positioned by forming a positioning hole in the substrate and providing a positioning protrusion on the holder that fits into the positioning hole.

[0005] However, in the conventional fixing device described above, the positioning hole is configured as a recess formed so as to be recessed in the width direction of the heater. Therefore, when manufacturing the conventional fixing device by cutting out the substrate from a metal plate or the like, it is necessary to cut out the recessed portion in addition to the rectangular shape that forms the outer shape of the substrate. As a result, the conventional fixing device has problems in that it is not possible to prevent the increase in waste material during the manufacturing of the substrate, which reduces the manufacturing yield and increases the manufacturing cost.

[0006] An object of the present disclosure is to provide a cost-effective fixing device, an image forming apparatus, and a heater manufacturing method that can improve the manufacturing yield of substrates made of metal materials. [Means for solving the problem]

[0007] In order to solve the above problems, a fixing device of a first aspect of the present disclosure includes a substrate made of a metal material, a heater having a resistance heating element arranged on the substrate, and a holder for holding the heater, wherein the substrate is arranged at one end in a width direction perpendicular to the longitudinal direction and has a substrate convex portion that protrudes in the width direction, and a substrate concave portion that is arranged at the other end in the width direction and has approximately the same shape as the substrate convex portion and is concave in the width direction, and the holder has an engaging portion that engages with the substrate convex portion or the substrate concave portion.

[0008] According to the above configuration, the substrate protrusions and the substrate recesses that are recessed in substantially the same shape as the substrate protrusions are respectively arranged on one end side and the other end side in the width direction of the substrate, thereby making it possible to configure an inexpensive fixing device that can suppress an increase in waste material during substrate manufacturing and improve the manufacturing yield of substrates made of metal material.

[0009] A second aspect of the present disclosure is the fixing device of the first aspect, wherein the substrate protrusion and the substrate recess may be disposed at approximately the same position in the longitudinal direction of the substrate.

[0010] According to the above configuration, it is possible to reliably prevent an increase in waste materials during the manufacture of substrates, and to reliably improve the manufacturing yield of substrates made of metal materials.

[0011] A third aspect of the present disclosure is a fixing device of the first or second aspect, wherein the heater has a power supply terminal arranged at one end of the substrate in the longitudinal direction, and a heating pattern that generates heat when power is supplied from the power supply terminal, and on the substrate, the substrate convex portion and the substrate concave portion may be arranged between the power supply terminal and the heating pattern in the longitudinal direction.

[0012] According to the above configuration, it is possible to position the substrate relative to the holder at a position close to the power supply terminal, and even if thermal expansion in the longitudinal direction occurs in the substrate due to heat generation, it is possible to prevent the position of the power supply terminal from shifting.

[0013] A fourth aspect of the present disclosure is the fixing device of the third aspect, wherein the heater has a power supply pattern that electrically connects the power supply terminal and the heating pattern, the width dimension of the power supply pattern is smaller than the width dimension of the heating pattern, and the substrate recess may be arranged within an area in the longitudinal direction where the power supply pattern is formed.

[0014] According to the above configuration, the dimension of the substrate in the width direction can be reduced.

[0015] A fifth aspect of the present disclosure is the fixing device according to any one of the first to fourth aspects, wherein the engagement portion may be a holder recess that can be fitted into the substrate protrusion.

[0016] According to the above configuration, the substrate protrusion is fitted into the holder recess, so that the heater can be positioned relative to the holder in the longitudinal direction.

[0017] A sixth aspect of the present disclosure is the fixing device according to any one of the first to fourth aspects, wherein the engagement portion may be a holder protrusion that can be fitted into the board recess.

[0018] According to the above configuration, the recessed portion of the substrate is fitted into the protruding portion of the holder, thereby enabling the heater to be positioned in the longitudinal direction relative to the holder.

[0019] An image forming apparatus according to a seventh aspect of the present disclosure includes the fixing device according to any one of the first to sixth aspects.

[0020] According to the above configuration, it is possible to configure a low-cost image forming apparatus that can improve the manufacturing yield of substrates made of metal materials.

[0021] An eighth aspect of the present disclosure is a method for manufacturing a heater having a substrate made of a metal material and a resistance heating element arranged on the substrate, the method comprising a manufacturing process for manufacturing a plurality of the substrates from a single metal plate, the manufacturing process including manufacturing the substrates having a substrate convex portion arranged on one end side in a width direction perpendicular to the longitudinal direction of the substrate and protruding in the width direction, and a substrate concave portion arranged on the other end side in the width direction and concave in the width direction with approximately the same shape as the substrate convex portion, wherein in the manufacturing process, the substrate convex portion of one substrate is formed, thereby forming the substrate concave portion of a substrate adjacent to the one substrate.

[0022] According to the above configuration, by forming a substrate convex portion on one substrate, a substrate concave portion can be formed on another substrate adjacent to the one substrate, and an increase in waste material from the metal plate during substrate manufacturing can be suppressed. As a result, it is possible to configure a low-cost heater that can improve the manufacturing yield of substrates made of metal material, and further a low-cost fixing device and a low-cost image forming apparatus using the same. [Effects of the Invention]

[0023] According to one aspect of the present disclosure, it is possible to provide a cost-effective fixing device, an image forming apparatus, and a heater manufacturing method that can improve the manufacturing yield of substrates made of metal materials. [Brief explanation of the drawings]

[0024] [Figure 1] FIG. 1 is a diagram illustrating a schematic configuration of an image forming apparatus according to a first embodiment of the present disclosure. [Figure 2] 2 is a cross-sectional view showing the configuration of a main part of the fixing device shown in FIG. 1. [Figure 3] FIG. 2A is an exploded perspective view illustrating a specific configuration of a heater included in the heating unit, and FIG. 2B is a cross-sectional view showing a cross section of the heater. [Figure 4] FIG. 2 is an enlarged plan view showing the main configuration of the heater. [Figure 5] 5A and 5B are diagrams illustrating the relationship between the heater and a holder included in the heating unit. [Figure 6] FIG. 3 is an enlarged plan view showing an example of the configuration of the main parts of the heater and the holder. [Figure 7] FIG. 4 is a perspective view showing a specific configuration of a connector attached to the heating unit. [Figure 8] 3A to 3C are diagrams illustrating a method for manufacturing the substrate of the heater. DETAILED DESCRIPTION OF THE INVENTION

[0025] [Embodiment 1] A first embodiment of the present disclosure will be described below with reference to Figures 1 to 8. In this embodiment, a laser printer that forms an image on a sheet S1 using toner will be described as an example of an image forming apparatus 1.

[0026] [Configuration of image forming apparatus 1] 1 is a diagram illustrating a schematic configuration of an image forming apparatus 1 according to a first embodiment of the present disclosure. In the following description, a monochrome printer that performs image formation processing for monochrome images is exemplified as the image forming apparatus 1, but the present embodiment is not limited to this, and the image forming apparatus 1 may also be, for example, a color printer that performs image formation processing for full-color images.

[0027] 1, the image forming apparatus 1 includes a housing 2, a paper feed unit 3, an image forming unit 4, a discharge roller 5, a discharge tray 6, and a main motor M. As shown in FIG. 1, the housing 2 forms the outer container of the image forming apparatus 1 and houses the main components of the image forming apparatus 1.

[0028] As shown in Fig. 1, the paper feed unit 3 supplies sheets S1. The paper feed unit 3 includes a paper feed tray 31, a feed roller 32, a pressure plate 33, a transport roller 34, and a registration roller 35. The paper feed tray 31 is a box-shaped member with an open top, and stores a predetermined amount of sheets S1. The sheets S1 are recording media on which an image formation process is performed, and are made of paper, plastic, or the like.

[0029] The feed roller 32 feeds out the sheet S1 stored in the paper feed tray 31. That is, when the sheet S1 is fed out, the sheet S1 on the paper feed tray 31 is brought toward the feed roller 32 by the pressure plate 33, and is fed to the conveyance roller 34 as the feed roller 32 rotates. The conveyance roller 34 conveys the sheet S1 toward the registration roller 35. The registration roller 35 aligns the position of the leading edge of the sheet S1, and then conveys the sheet S1 toward the image forming unit 4.

[0030] The image forming unit 4 forms an image by performing an image forming process on the sheet S1 delivered by the paper feed unit 3. As shown in Fig. 1, the image forming unit 4 includes an exposure unit 41, a transfer unit 42, a charger 43, a developing unit 44, a fixing device 45 of the present disclosure, and a photosensitive drum 46. The exposure unit 41 includes a laser light source (not shown), a polygon mirror 41G, a scanning lens 41L, a polygon motor 41M, and a reflecting mirror 41R.

[0031] The polygon mirror 41G is a rotary polygonal mirror having six reflective surfaces on the side surfaces of a regular hexagonal prism. The polygon mirror 41G deflects the light beam L1 emitted from the laser light source in a direction toward the photosensitive drum 46. The polygon motor 41M is driven by a motor driver (not shown) to rotate the polygon mirror 41G.

[0032] The exposure unit 41 deflects a light beam L1 using a polygon mirror 41G, and emits the light beam L1 from the polygon mirror 41G via a scanning lens 41L and a reflecting mirror 41R onto the surface of the photosensitive drum 46. The exposure unit 41 scans the surface of the photosensitive drum 46 with the light beam L1 to expose the photosensitive drum 46. As a result, an electrostatic latent image that constitutes a toner image (described later) is formed on the photosensitive drum 46. The polygon motor 41M is, for example, a brushless DC motor.

[0033] The transfer unit 42 includes a transfer roller that sandwiches the sheet S1 between itself and the photosensitive drum 46, and transfers the toner image from the photosensitive drum 46 to the sheet S1. The charger 43 includes, for example, a scorotron charger having a charging wire and a grid portion (not shown). In this charger 43, a charging voltage is applied to the charging wire by a high-voltage generating circuit (not shown), and a grid voltage is applied to the grid portion, thereby generating a corona discharge and uniformly charging the surface of the photosensitive drum 46. The developing unit 44 includes a developing roller 44R and a toner cartridge 44A that contains a developer, such as toner.

[0034] In addition to the above description, for example, the transfer device 42 may include a transfer belt instead of the transfer roller. Also, for example, the charger 43 may include a charging roller instead of the scorotron charger.

[0035] In the image forming unit 4, the surface of the photosensitive drum 46 is uniformly charged by the charger 43, and then a light beam L1 from the exposure unit 41 forms an electrostatic latent image based on print data on the surface of the photosensitive drum 46. The developing roller 44R supplies toner from inside the toner cartridge 44A to the surface of the photosensitive drum 46 on which the electrostatic latent image has been formed. This makes the electrostatic latent image visible, and a toner image is formed on the surface of the photosensitive drum 46. Thereafter, a sheet S1 fed from the paper feed unit 3 is transported to a transfer position between the photosensitive drum 46 and the transfer unit 42, whereby the toner image formed on the surface of the photosensitive drum 46 is transferred onto the sheet S1.

[0036] The sheet S1 onto which the toner image has been transferred is transported to the fixing device 45 by the photosensitive drum 46 and the transfer device 42. The fixing device 45 fixes the toner image formed on the sheet S1. Specifically, the fixing device 45 uses heat generated by the heater 60 to thermally fix the toner image on the sheet S1 transported from the photosensitive drum 46 and the transfer device 42. The sheet S1 onto which the toner image has been thermally fixed is discharged onto a discharge tray 6 by discharge rollers 5. The specific configuration of the fixing device 45 in the present embodiment 1 will be described in detail later.

[0037] The main motor M is, for example, a brushless DC motor. A transmission mechanism such as a gear that transmits the rotational force of the main motor M is connected to the main motor M, and the main motor M functions as a power source for each part housed inside the housing 2.

[0038] [Configuration of Fixing Device 45] The fixing device 45 of this embodiment will be specifically described with reference to Fig. 2. Fig. 2 is a cross-sectional view showing the main configuration of the fixing device 45 shown in Fig. 1.

[0039] 2, the fixing device 45 of this embodiment includes a heating unit 51 that contacts the sheet S1 on which the toner image is formed and heats the sheet S1, and a pressure roller 52 that applies pressure to the sheet S1. The heating unit 51 and the pressure roller 52 are pressed against each other by a pressing unit (not shown). In the fixing device 45, the pressing unit is controlled in accordance with instructions from a control unit (not shown), whereby the toner image is fixed to the sheet S1 with a predetermined pressure being applied between the heating unit 51 and the pressure roller 52.

[0040] The heating unit 51 includes a heater 60, a holder 70, a stay 80, and a belt 90. The heater 60 is a heating member configured in a rectangular shape in a plan view. The heater 60 includes a first surface 60A disposed on the pressure roller 52 side and a second surface 60B facing the first surface 60A. The second surface 60B abuts against the holder 70, whereby the heater 60 is supported by the holder 70.

[0041] The holder 70 is made of, for example, a synthetic resin material, and includes a guide surface 70A that guides the belt 90, and a support portion 70B that supports the heater 60. The guide surface 70A guides the belt 90 by contacting the inner circumferential surface 90A of the belt 90. The support portion 70B includes a support surface 70B1 that abuts against and supports the second surface 60B of the heater 60. The stay 80 is a reinforcing member that supports the holder 70, and is formed by bending a plate material that is more rigid than the holder 70, for example, a metal material such as a steel plate, into a generally U-shaped cross section.

[0042] The belt 90 is an endless belt that is heat-resistant and flexible, and includes a base material made of a metal material such as stainless steel, and an insulating layer made of a synthetic resin material such as fluororesin that covers the base material (not shown). The belt 90 accommodates the heater 60, holder 70, and stay 80 therein, and rotates around the heater 60, holder 70, and stay 80. Furthermore, an inner peripheral surface 90A of the belt 90 abuts against the first surface 60A of the heater 60, so that heat from the heater 60 is transferred to the sheet S1 via the belt 90.

[0043] The pressure roller 52 includes a rotating shaft 52A made of a metal material and an elastic layer 52B made of a synthetic rubber material or the like that covers the surface of the rotating shaft 52A. The pressure roller 52 sandwiches the belt 90 between itself and the heater 60, thereby forming a nip portion NP for heating and pressurizing the sheet S1.

[0044] The pressure roller 52 is driven to rotate in a rotation direction R2 by a driving force transmitted from the main motor M. That is, the pressure roller 52 rotates while sandwiching the sheet S1 conveyed in the conveying direction H between the pressure roller 52 and the belt 90, whereby the belt 90 is driven to rotate in the rotation direction R1 by the frictional forces between the pressure roller 52, the belt 90, and the sheet S1. As a result, in the fixing device 45, the sheet S1 on which the toner image has been transferred is conveyed between the heating unit 51 and the pressure roller 52, and the toner image is thermally fixed onto the sheet S1.

[0045] [Configuration of heater 60] Next, the heater 60 will be described in detail with reference to Figures 3 and 4. Figure 3(A) is an exploded perspective view illustrating the specific configuration of the heater 60 included in the heating unit 51, and Figure 3(B) is a cross-sectional view showing a cross section of the heater 60. Figure 4 is an enlarged plan view showing the configuration of the main parts of the heater 60.

[0046] As shown in FIGS. 3A and 3B, the heater 60 includes a first insulating layer Z1 having the second surface 60B, a substrate S laminated on the first insulating layer Z1, a second insulating layer Z2 laminated on the substrate S, a resistance heating element P disposed on the second insulating layer Z2, and a third insulating layer Z3 disposed to cover the resistance heating element P. The first insulating layer Z1, the second insulating layer Z2, and the third insulating layer Z3 are made of an insulator such as a glass material. The third insulating layer Z3 has the first surface 60A, contacts the inner circumferential surface 90A of the belt 90, and also functions as a protective layer to protect the resistance heating element P from contact with the inner circumferential surface 90A.

[0047] The resistance heating element P includes a power supply terminal T having two terminals T1 and T2, a power supply pattern PE having power supply patterns PE1 and PE2 electrically connected to the terminals T1 and T2, and a heating pattern PH electrically connected to the power supply pattern PE. Connectors, which will be described later, are electrically connected to the terminals T1 and T2 of the power supply terminal T, so that power is supplied to the heater 60 via the connectors.

[0048] At least the heating pattern PH of the resistance heating element P is made of a conductive material with excellent heat generation properties, such as a nickel-chromium alloy or an iron-chromium alloy, and the heating pattern PH generates heat in accordance with instructions from the control unit. That is, the current supplied to the heating pattern PH is controlled, and further, the heat generated by the heating pattern PH is increased or decreased, thereby controlling the heating of the belt 90 from the heater 60.

[0049] In addition, the fixing device 45 of this embodiment is provided with a temperature sensor (not shown) that detects the temperature of the heater 60, and the control unit is configured to control the heater 60 using the detection result of the temperature sensor.

[0050] In addition, in the heater 60, a substrate protrusion ST and a substrate recess SU for positioning the heater 60 on the holder 70 are provided on the substrate S in the width direction of the heater 60, i.e., on one end side and the other end side in the width direction of the substrate S, respectively.

[0051] 4, the substrate S has, at one end of the longitudinal direction LH of the substrate S, a substrate protrusion ST that is located on one end side in the width direction SH perpendicular to the longitudinal direction LH of the substrate S and protrudes in the width direction SH, and a substrate recess SU that is located on the other end side in the width direction SH and has substantially the same shape as the substrate protrusion ST and is recessed in the width direction SH. Note that "the substrate protrusion ST and the substrate recess SU have substantially the same shape" does not mean that the substrate protrusion ST and the substrate recess SU are limited to having exactly the same shape.

[0052] Furthermore, on the substrate S, these substrate protrusions ST and substrate recesses SU are provided at approximately the same positions in the longitudinal direction LH of the substrate S. Note that approximately the same positions in the longitudinal direction LH are not limited to being exactly the same positions in the longitudinal direction LH, but may be substantially the same positions.

[0053] In the heater 60, the first insulating layer Z1 has first convex portions Z1T and first concave portions Z1U at positions overlapping the substrate convex portions ST and substrate concave portions SU, respectively. Similarly, the second insulating layer Z2 has second convex portions Z2T and second concave portions Z2U at positions overlapping the substrate convex portions ST and substrate concave portions SU, respectively, and the third insulating layer Z3 has third convex portions Z3T and third concave portions Z3U at positions overlapping the substrate convex portions ST and substrate concave portions SU, respectively.

[0054] The first convex portion Z1T, the second convex portion Z2T, and the third convex portion Z3T are formed at the same position in the stacking direction of the substrate S as the substrate convex portion ST to be superimposed. Furthermore, the first convex portion Z1T, the second convex portion Z2T, and the third convex portion Z3T are formed in substantially the same shape as the substrate convex portion ST or in a shape slightly smaller than that of the substrate convex portion ST, and are configured so that when the substrate convex portion ST is fitted into a holder concave portion described below, they can be fitted into the holder concave portion together with the substrate convex portion ST. Note that "substantially the same shape" only needs to be substantially the same, and is not limited to being exactly the same shape (the same applies to the relationship between the shape of the substrate concave portion SU and the shapes of the first concave portion Z1U, the second concave portion Z2U, and the third concave portion Z3U described below).

[0055] The first recess Z1U, the second recess Z2U, and the third recess Z3U are formed at the same position in the stacking direction of the substrate S as the substrate recess SU to be superimposed. Furthermore, the first recess Z1U, the second recess Z2U, and the third recess Z3U are formed to have substantially the same shape as the substrate recess SU or a slightly larger shape, and are configured so that when the substrate recess SU is fitted into a holder convex portion described below, they can be fitted into the holder convex portion together with the substrate recess SU.

[0056] The substrate S is made of a metal material such as stainless steel. As described above, the substrate S has the substrate protrusions ST and the substrate recesses SU, and therefore, even when manufacturing a plurality of substrates S from a metal plate of the above metal material, it is possible to reduce waste material and improve the manufacturing yield of the substrates S while manufacturing a plurality of substrates S (details will be described later).

[0057] In the above explanation, the heater 60 has been described as having a first insulating layer Z1, a substrate S, a second insulating layer Z2, a resistance heating element P, and a third insulating layer Z3, but the heater 60 of this embodiment is not limited in any way as long as it has a substrate S made of a metal material and a resistance heating element P arranged on the substrate S.

[0058] [Configuration of Main Parts of Fixing Device 45] Next, the configuration of the main parts of the fixing device 45 of this embodiment will be described in detail with reference to Figures 5 to 7. Figure 5 is a diagram illustrating the relationship between the heater 60 and the holder 70 included in the heating unit 51. Figure 6 is an enlarged plan view showing an example of the configuration of the main parts of the heater 60 and the holder 70. Figure 7 is a perspective view showing a specific configuration of the connector 100 attached to the heating unit 51. Note that the third insulating layer Z3 of the heater 60 is omitted from illustration in Figures 5 and 6.

[0059] 5 and 6, in fixing device 45 of this embodiment, holder 70 is provided with holder recesses 70U as engaging portions that can fit into substrate protrusions ST of substrate S. Holder 70 is also provided with holder protrusions 70T as engaging portions that can fit into substrate recesses SU of substrate S. In fixing device 45 of this embodiment, substrate S, and therefore heater 60, and holder 70 are positioned by fitting substrate protrusions ST and substrate recesses SU into holder recesses 70U and holder protrusions 70T, respectively, and heater 60 is held in holder 70.

[0060] 5 and 6, on the substrate S, the substrate protrusion ST and the substrate recess SU are arranged between the power supply terminal T and the heat generation pattern PH in the longitudinal direction LH. Also, as shown in Fig. 6, the power supply pattern PE is configured so that the dimension H1 in the width direction SH is smaller than the dimension H2 in the width direction SH of the heat generation pattern PH. Furthermore, the substrate recess SU is arranged within the region A in which the power supply pattern PE is formed in the longitudinal direction LH.

[0061] 7, the connector 100 includes a connector main body 101 and a pair of clamping portions 102 and 103 that are provided continuously with the connector main body 101 and are formed to sandwich the heater 60 and the holder 70. The clamping portion 102 is provided with two electrodes 104 that are electrically connected to terminals T1 and T2, respectively, of the power supply terminal T of the heater 60 when the connector 100 is attached to the heating unit 51 to sandwich the heater 60 and the holder 70. The connector 100 is configured to supply power to the heater 60 via the electrodes 104.

[0062] [Method for manufacturing substrate S] Next, a method for manufacturing the substrate S of the heater 60 will be specifically described with reference to Fig. 8. Fig. 8 is a diagram showing a method for manufacturing the substrate S of the heater 60.

[0063] As illustrated in Fig. 8, the substrate S of the heater 60 undergoes a manufacturing process in which multiple substrates S are manufactured from a single metal plate MP. In this manufacturing process, the substrates S are manufactured, each having a substrate protrusion ST disposed at one end in a width direction SH perpendicular to the longitudinal direction LH of the substrate S and protruding in the width direction SH, and a substrate recess SU disposed at the other end in the width direction SH and recessed in the width direction SH with substantially the same shape as the substrate protrusion ST. In addition, in the manufacturing process, as shown in Fig. 8, the substrate protrusion ST of one substrate S is formed, thereby forming a substrate recess SU of a substrate S adjacent to the one substrate S.

[0064] As described above, the fixing device 45, image forming apparatus 1, and manufacturing method for heater 60 of this embodiment include a substrate S, a heater 60 having a resistance heating element P, and a holder 70 for holding the heater 60. The substrate S is disposed at one end in a width direction SH perpendicular to the longitudinal direction LH and has a substrate protrusion ST protruding in the width direction SH, and a substrate recess SU disposed at the other end in the width direction SH and recessed in the width direction SH with substantially the same shape as the substrate protrusion ST. The holder 70 has a holder recess 70U and a holder protrusion 70T that fit into the substrate protrusion ST and the substrate recess SU, respectively. As a result, this embodiment can provide a cost-effective fixing device 45, image forming apparatus 1, and manufacturing method for heater 60 that can reduce waste material during manufacturing of the substrate S and improve the manufacturing yield of metal substrates S, as illustrated in FIG. 8 .

[0065] Furthermore, in the substrate S of this embodiment, the substrate protrusions ST and the substrate recesses SU are provided at approximately the same positions in the longitudinal direction LH of the substrate S, which reliably prevents an increase in waste material during the manufacture of the substrate S. As a result, in this embodiment, the manufacturing yield of the substrate S made of a metal material can be reliably improved, and a cost-effective method for manufacturing the fixing device 45, the image forming apparatus 1, and the heater 60 can be easily configured.

[0066] Furthermore, in this embodiment, the heater 60 has a power supply terminal T arranged at one end of the substrate S in the longitudinal direction LH, and a heating pattern PH that generates heat when power is supplied from the power supply terminal T. Furthermore, the substrate protrusion ST and the substrate recess SU are arranged between the power supply terminal T and the heating pattern PH in the longitudinal direction LH. This makes it possible in this embodiment to position the substrate S relative to the holder 70 at a position close to the power supply terminal T, and even if thermal expansion occurs in the substrate S in the longitudinal direction LH due to heat generation, it is possible to prevent the position of the power supply terminal T from shifting.

[0067] In this embodiment, the heater 60 has a power supply pattern PE that electrically connects the power supply terminal T and the heat generation pattern PH. The dimension H1 of the power supply pattern PE in the width direction SH is smaller than the dimension H2 of the heat generation pattern PH in the width direction, and the substrate recess SU is disposed within the region A in the longitudinal direction LH where the power supply pattern PE is formed. This allows the dimension of the substrate S in the width direction SH to be reduced in this embodiment.

[0068] In the above explanation, the holder 70 is described as having a holder recess 70U and a holder protrusion 70T that fit into the substrate protrusion ST and the substrate recess SU, respectively. However, this embodiment is not limited to this, and is not limited in any way as long as the holder 70 is provided with an engaging portion that engages with the substrate protrusion ST or the substrate recess SU of the substrate S.

[0069] Specifically, for example, the holder 70 may be provided with a holder recess 70U that is larger in size than the substrate protrusion ST and does not function as a positioning element. Also, the holder 70 may not be provided with a holder protrusion 70T at a position that fits into the substrate recess SU. However, as in the above embodiment, providing the holder 70 with the holder recess 70U and the holder protrusion 70T that fit into the substrate protrusion ST and the substrate recess SU, respectively, and positioning the holder 70 and the heater 60 is preferable, as this improves the positioning accuracy between the holder 70 and the heater 60.

[0070] Furthermore, in the above explanation, the power supply terminal T and the connector 100 electrically connected thereto are provided at one end of the longitudinal direction LH, but this embodiment is not limited to this, and the power supply terminal T and the connector 100 may be provided at both the one end side and the other end side of the longitudinal direction LH.

[0071] The present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Configurations obtained by appropriately combining the technical means disclosed in the embodiments are also included in the technical scope of the present disclosure. [Explanation of symbols]

[0072] 1. Image forming device 60 Heater S board ST board protrusion SU substrate recess P Resistance heating element 70 Holder 70U holder recess 70T holder protrusion T Power supply terminal PH fever pattern PE power supply pattern LH Longitudinal SH Width direction MP metal plate

Claims

1. A heater having a substrate made of a metal material and a resistance heating element disposed on the substrate; a holder for holding the heater; the substrate has a substrate protrusion disposed at one end side in a width direction perpendicular to the longitudinal direction and protruding in the width direction, and a substrate recess disposed at the other end side in the width direction and recessed in the width direction in substantially the same shape as the substrate protrusion, the holder has an engaging portion that engages with the substrate convex portion or the substrate concave portion, the engaging portion including a holder concave portion that can be fitted into the substrate convex portion and a holder convex portion that can be fitted into the substrate concave portion, In the substrate, the substrate convex portion and the substrate concave portion are arranged at approximately the same position in the longitudinal direction of the substrate, the heater includes a power supply terminal disposed at one end of the substrate in the longitudinal direction, a heat generating pattern that generates heat when power is supplied from the power supply terminal, and a power supply pattern that electrically connects the power supply terminal and the heat generating pattern, the substrate protrusion and the substrate recess are disposed between the power supply terminal and the heat generating pattern in the longitudinal direction; the power supply pattern has a smaller dimension in the width direction than the heat generation pattern; the substrate recess is disposed within a region in the longitudinal direction in which the power supply pattern is formed, a widthwise dimension of each of the power supply patterns being smaller than a widthwise dimension of each of the heat generating patterns;

2. An image forming apparatus comprising the fixing device according to claim 1 .

Images