Patent Publication Number: US-2023152737-A1

Title: Heating device

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2021-184695, filed on Nov. 12, 2021, the entire contents of which are incorporated herein by reference. 
     FIELD 
     Embodiments described herein relate to a heating device. 
     BACKGROUND 
     A heating device includes a tubular body, a heater, a power supply unit, and a support member. The tubular body is formed in a tubular shape. The heater is disposed inside the tubular body. The heater has an axial direction of the tubular body as a longitudinal direction. The heater has its first surface side being in contact with an inner peripheral surface of the tubular body. The heater generates heat by energization. The power supply unit supplies power to the heater. The support member supports the heater. The tubular body slides on the first surface of the heater. In order to prevent wear and damage to the first surface of the heater, a disposition of the heater may be changed with respect to the tubular body. When the disposition of the heater is changed, disposition of the power supply unit may also be changed. Depending upon the disposition of the heater and the power supply unit, the support member may be complicated. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic configuration diagram of an image forming apparatus according to an embodiment; 
         FIG.  2    is a hardware configuration diagram of the image forming apparatus; 
         FIG.  3    is an XZ cross-sectional view of a heating device; 
         FIG.  4    is a plan view of a heater; 
         FIG.  5    is a cross-sectional view taken along a line V-V in  FIG.  4   ; 
         FIG.  6    is a diagram illustrating disposition of a thermostat unit and a first temperature detection unit; 
         FIG.  7    is an electric circuit diagram of the heating device; 
         FIG.  8    is a diagram illustrating disposition of the heater and a heat equalizing member; 
         FIG.  9    is a diagram of the heating device as viewed from a rear side; 
         FIG.  10    is a perspective view illustrating mounting states of the heater, a support member, and power supply connectors; 
         FIG.  11    is a perspective view of the support member; 
         FIG.  12    is a plan view including a front side end portion of the support member; 
         FIG.  13    is a cross-sectional view taken along a line XIII-XIII in  FIG.  12   ; 
         FIG.  14    is a plan view including a rear side end portion of the support member; 
         FIG.  15    is a cross-sectional view taken along a line XV-XV in  FIG.  14   ; 
         FIG.  16    is a diagram illustrating an example of a method for mounting the heater; 
         FIG.  17    is a diagram illustrating the example of the method, following  FIG.  16   ; 
         FIG.  18    is a diagram illustrating the example of the method, following  FIG.  17   ; 
         FIG.  19    is a perspective view including the rear side end portion of the support member, as viewed from an arrow XIX in  FIG.  16   ; 
         FIG.  20    is a perspective view including a cross section taken along a line XX-XX in  FIG.  19   ; 
         FIG.  21    is a perspective view including the front side end portion of the support member, as viewed from an arrow XXI in  FIG.  16   ; 
         FIG.  22    is a perspective view including the rear side end portion of the support member, as viewed from an arrow XXII in  FIG.  17   ; 
         FIG.  23    is a perspective view including a cross section taken along a line XXIII-XXIII in  FIG.  22   ; and 
         FIG.  24    is a perspective view including the front side end portion of the support member, as viewed from an arrow XXIV in  FIG.  17   . 
     
    
    
     DETAILED DESCRIPTION 
     In general, according to one embodiment, a heating device capable of preventing complication of a support member is provided. 
     A heater assembly according to an embodiment includes a tubular body, a heater, and a support member. The tubular body is formed in a tubular shape and has a length that extends longitudinally. The heater is received within the tubular body. The heater provides thermal energy in response to being electrically energized. The heater includes a first surface side extending laterally and longitudinally along an inner peripheral surface of the tubular body. The heater includes n electrical contact, through which electrical energy is supplied to the heater. The support member is coupled to the heater and extends longitudinally. The support member defines an opening that exposes the electrical contact. The support member is configured to bend to facilitate coupling the heater to the support member. 
     Hereinafter, a heating device (e.g., a heater assembly) according to an embodiment will be described with reference to the drawings.  FIG.  1    is a schematic diagram of an image forming apparatus according to the embodiment. As illustrated in  FIG.  1   , an image forming apparatus  1  includes a housing  10 , a scanner unit  2  (e.g., a scanner), an image forming unit  3  (e.g., a printer), a sheet supply unit  4 , a conveying unit  5  (e.g., a conveyor), a sheet discharge tray  7 , a reversing unit  9 , a control panel  8  (e.g., a user interface), and a control unit  6  (e.g., a controller). The image forming apparatus  1  forms an image on a sheet-shaped recording medium (hereinafter, referred to as a “sheet”) such as a piece of paper. 
     The housing  10  forms an outer shape of the image forming apparatus  1 . The housing  10  accommodates components of the image forming apparatus  1 . The scanner unit  2  reads image information of an object to be copied based on brightness and darkness of light, and generates an image signal. The scanner unit  2  outputs the generated image signal to the image forming unit  3 . 
     The image forming unit  3  forms an output image by a recording material such as a toner based on an image signal received from the scanner unit  2  or an image signal received from the outside. Hereinafter, the output image is referred to as a toner image. The image forming unit  3  transfers the toner image to a surface of a sheet S. The image forming unit  3  applies heat and pressure to the toner image on the surface of the sheet S to fix the toner image on the sheet S. The image forming unit  3  forms an image on the sheet S. 
     The sheet supply unit  4  supplies sheets S one by one to the conveying unit  5  according to a timing when the image forming unit  3  forms the toner image. The sheet supply unit  4  includes a sheet accommodation unit  20  (e.g., a tray) and a pickup roller  21 . The sheet accommodation unit  20  stores sheets S of a predetermined size and a predetermined type. The pickup roller  21  takes out the sheets S one by one from the sheet accommodation unit  20 . The pickup roller  21  supplies the taken-out sheets S to the conveying unit  5 . 
     The conveying unit  5  conveys the sheet S supplied from the sheet supply unit  4  to the image forming unit  3 . The conveying unit  5  includes conveying rollers  23  and registration rollers  24 . The conveying rollers  23  convey the sheet S supplied from the pickup roller  21  to the registration rollers  24 . The conveying rollers  23  abut a tip of the sheet S in a conveying direction against nips of the registration rollers  24 . The registration rollers  24  adjust a position of the tip of the sheet S in the conveying direction by bending the sheet S at the nip. The registration rollers  24  convey the sheet S according to a timing when the image forming unit  3  transfers the toner image to the sheet S. 
     The image forming unit  3  will be described. The image forming unit  3  includes a plurality of image forming portions  25 , a laser scanning unit  26 , an intermediate transfer belt  27 , a transfer unit  28 , and a heating device  30  (e.g., a heater assembly). Each image forming portion  25  includes a photoreceptor drum  29  (e.g., a photosensitive element). The image forming portion  25  forms, on the photoreceptor drum  29 , a toner image corresponding to the image signal from the scanner unit  2  or the outside. The plurality of image forming portions  25  form toner images using a yellow toner, a magenta toner, a cyan toner, and a black toner, respectively. 
     A charger, a developing device, and the like are disposed around the photoreceptor drum  29 . The charger charges a surface of the photoreceptor drum  29 . The developing device accommodates a developer including a yellow toner, a magenta toner, a cyan toner, and a black toner. The developing device develops an electrostatic latent image on the photoreceptor drum  29 . As a result, a toner image using a toner of each color is formed on the photoreceptor drum  29 . 
     The laser scanning unit  26  scans the charged photoreceptor drum  29  with a series of laser beams L to expose the photoreceptor drum  29 . The laser scanning unit  26  exposes colors on the photoreceptor drums  29  of the image forming portions  25  with different laser beams LY, LM, LC, and LK, respectively. Accordingly, the laser scanning unit  26  forms an electrostatic latent image on the photoreceptor drums  29 . 
     The toner image formed on the surface of the photoreceptor drum  29  is primarily transferred to the intermediate transfer belt  27 . The transfer unit  28  transfers, to the surface of the sheet S at a secondary transfer position, the toner image primarily transferred to the intermediate transfer belt  27 . The heating device  30  applies heat and pressure to the toner image transferred to the sheet S to fix the toner image to the sheet S. The heating device  30  functions as a fixing device (e.g., a fixer) that fixes the toner image to the sheet S. 
     The reversing unit  9  reverses the sheet S in order to form an image on a back surface of the sheet S. The reversing unit  9  reverses front and back surfaces of the sheet S discharged from the heating device  30  by switchback. The reversing unit  9  conveys the reversed sheet S toward the registration rollers  24 . The sheet discharge tray  7  is loaded with the discharged sheet S on which the image is formed. The control panel  8  is a part of an input unit that inputs information for an operator to operate the image forming apparatus  1 . The control panel  8  includes a touch panel and various hard keys. The control panel  8  may provide information to the operator (e.g., through representation on the touch panel). The control unit  6  controls each unit of the image forming apparatus  1 . 
       FIG.  2    is a hardware configuration diagram of the image forming apparatus  1  according to the embodiment. The image forming apparatus  1  includes a central processing unit (CPU)  91  (e.g., a processor), a memory  92 , an auxiliary storage device  93 , and the like. The CPU  91 , the memory  92 , the auxiliary storage device  93 , and the like are connected by a bus, respectively. The image forming apparatus  1  executes various programs. The image forming apparatus  1  functions as an apparatus including the scanner unit  2 , the image forming unit  3 , the sheet supply unit  4 , the conveying unit  5 , the reversing unit  9 , the control panel  8 , and a communication unit  90  by executing the programs. 
     The CPU  91  functions as the control unit  6  by executing programs stored in the memory  92  and the auxiliary storage device  93 . The control unit  6  controls operation of each functional unit of the image forming apparatus  1 . The auxiliary storage device  93  is formed by using a storage device such as a magnetic hard disk device or a semiconductor storage device. The auxiliary storage device  93  stores information. The communication unit  90  includes a communication interface (e.g., a network interface) for connecting an own device to an external device. The communication unit  90  communicates with the external device via the communication interface. 
     The heating device  30  will be described in detail.  FIG.  3    is an XZ cross-sectional view of the heating device  30  according to the embodiment. As illustrated in  FIG.  3   , the heating device  30  includes a pressure roller  31  and a heating mechanism  35  (e.g., a heater). 
     The pressure roller  31  forms a nip N with the heating mechanism  35 . The pressure roller  31  applies pressure to a toner image T on a sheet S that entered the nip N. The pressure roller  31  rotates on its axis to convey the sheet S. The pressure roller  31  includes a core metal  32  (e.g., a metallic core), an elastic layer  33  (e.g., a middle layer), and a release layer  34  (e.g., an outer layer). 
     The core metal  32  is formed in a cylindrical, columnar shape by a metal material such as stainless steel. Both end portions of the core metal  32  in an axial direction are rotatably supported. The core metal  32  is rotationally driven by a motor (e.g., an electric motor). The core metal  32  is in contact with a cam member. The cam member enables the core metal  32  to move toward and away from the heating mechanism  35  by rotating. 
     The elastic layer  33  is formed of an elastic material (e.g., a resilient material) such as silicone rubber. The elastic layer  33  is formed on an outer peripheral surface of the core metal  32  with a constant thickness. The release layer  34  is formed of a resin material such as tetrafluoroethylene or perfluoroalkyl vinyl ether copolymer (PFA). The release layer  34  is formed on an outer peripheral surface of the elastic layer  33 . 
     A hardness of an outer peripheral surface of the pressure roller  31  is preferably 40° to 70° under a load of 9.8 N as measured by an ASKER-C hardness meter. Accordingly, an area of the nip N is ensured. Moreover, durability of the pressure roller  31  is ensured. 
     The pressure roller  31  can move toward and away from the heating mechanism  35  by rotation of the cam member. When the pressure roller  31  moves toward the heating mechanism  35  and is pressed by a pressure spring, the nip N is formed. On the other hand, when jam of the sheet S occurs in the heating device  30 , the sheet S can be removed by moving the pressure roller  31  away from the heating mechanism  35 . In a state in which a tubular body  36  stops rotating, such as during sleep, plastic deformation of the tubular body  36  is prevented by moving the pressure roller  31  away from the heating mechanism  35 . 
     The pressure roller  31  is rotationally driven by the motor and rotates about its axis (e.g., a central longitudinal axis of rotation). When the pressure roller  31  rotates about its axis in a state in which the nip N is formed, the tubular body  36  of the heating mechanism  35  is driven to rotate. The pressure roller  31  rotates about its axis in a state in which the sheet S is disposed on the nip N, thereby conveying the sheet S in a conveying direction W. 
     The heating mechanism  35  applies heat to the toner image T on the sheet S that entered the nip N. The heating mechanism  35  includes the tubular body  36 , a heater  37 , a heat equalizing member  46 , a support member  38 , a stay  39 , a thermostat unit  40  (e.g., a thermostat), a first temperature detection member  41  (e.g., a first temperature sensor), and a second temperature detection member  42  (e.g., a second temperature sensor). 
     Hereinafter, an XYZ coordinate system may be used to describe a configuration of the heating device  30 . In the embodiment, an X direction, a Y direction, and a Z direction are defined as follows. The X direction corresponds to a direction along a lateral direction of the heater  37 . The Y direction corresponds to a direction along a longitudinal direction of the heater  37  (e.g., an axial direction of the tubular body, along a length of the tubular body). In the present embodiment, the Y direction is orthogonal to the conveying direction W of the sheet S. The Z direction corresponds to a direction orthogonal to the X direction and the Y direction (e.g., a vertical direction or orthogonal direction). Hereinafter, in the X direction, one side is referred to as +X side and the other side is referred to as −X side. In the Y direction, one side is referred to as +Y side, and the other side is referred to as −Y side. In the Z direction, one side is referred to as +Z side, and the other side is referred to as −Z side. 
     The tubular body  36  is formed in a tubular shape by a film or the like. The tubular body  36  has an endless (e.g., continuous) peripheral surface. The tubular body  36  is flexible. The tubular body  36  forms the nip N between the tubular body  36  and the pressure roller  31 . The tubular body  36  fixes, at the nip N, the toner image T on the sheet S. The tubular body  36  is an endless belt (e.g., a fixing belt) of the heating device  30 . 
     The tubular body  36  includes a base layer, an elastic layer, and a release layer in this order from an inner peripheral side (e.g., the base layer is the innermost layer). The base layer is formed of a material such as polyimide resin. The base layer is in a tubular shape extending in the Y direction. The elastic layer is laminated and disposed on an outer peripheral surface of the base layer. The elastic layer is formed of an elastic material such as silicone rubber. The release layer is laminated and disposed on an outer peripheral surface of the elastic layer. The release layer is formed of a material such as PFA resin. 
     The heater  37  is disposed inside the tubular body  36 . The heater  37  faces a heated region  361 , which is a part of the tubular body  36  in a circumferential direction. The heater  37  heats the heated region  361 . The heater  37  is disposed inside a portion where the tubular body  36  faces the pressure roller  31  so as to face the nip N. 
     A lubricant is applied to an inner peripheral surface of the tubular body  36 . The heater  37  is in contact with the inner peripheral surface of the tubular body  36  through the lubricant. When the heater  37  generates heat, a viscosity of the lubricant decreases. Accordingly, slidability between the heater  37  and the tubular body  36  is ensured. The tubular body  36  slides on a surface (a +Z side surface) of the heater  37  while being in contact with the heater  37  on one surface. 
     The heat equalizing member  46  (e.g., a heat spreader) is formed of a metal material such as copper or aluminum. Thermal conductivity of the heat equalizing member  46  is higher than thermal conductivity of a substrate  50  of the heater  37 . A length of the heat equalizing member  46  in the X direction is equal to a length of the substrate  50  of the heater  37  in the X direction. A length of the heat equalizing member  46  in the Y direction is shorter than a length of the substrate  50  of the heater  37  in the Y direction. The heat equalizing member  46  is disposed in contact with the −Z side surface of the heater  37 . The heat equalizing member  46  averages a temperature distribution of the heater  37 . 
     The support member  38  (e.g., a support) is formed of a resin material such as a liquid crystal polymer. The support member  38  is disposed so as to cover −Z side and both sides in the X direction of the heat equalizing member  46 . The support member  38  supports the heater  37  through the heat equalizing member  46 . Round chamfers are formed at both end portions of the support member  38  in the X direction. The support member  38  supports the inner peripheral surface of the tubular body  36  at both end portions of the heater  37  in the X direction. 
     The stay  39  (e.g., a frame, a chassis, etc.) is formed of a steel plate material or the like. A cross section of the stay  39  along an XZ plane is formed in a U shape. The stay  39  is mounted on the −Z side of the support member  38  such that a U-shaped opening portion is blocked by the support member  38 . The stay  39  extends in the Y direction. Both end portions of the stay  39  in the Y direction are fixed to the housing  10  of the image forming apparatus  1 . Therefore, the heating mechanism  35  is supported by the image forming apparatus  1 . The stay  39  improves (e.g., increases) bending rigidity of the heating mechanism  35 . Flanges  49  that restrict movement of the tubular body  36  in the Y direction are mounted near both end portions of the stay  39  in the Y direction. 
       FIG.  4    is a plan view of the heater  37  according to the embodiment.  FIG.  5    is a cross-sectional view taken along a line V-V in  FIG.  4   . As illustrated in  FIG.  4   , the heater  37  includes the substrate  50 , a heat generating member  51 , and a wiring set  52  (e.g., a wiring harness). In  FIG.  4   , the substrate  50  is indicated by a two-dot chain line. 
     The substrate  50  is formed of a metal material such as stainless steel or a ceramic material such as aluminum nitride. The substrate  50  is formed in a rectangular plate shape along the Y direction. The substrate  50  is disposed on an inner side (the −Z side) of the tubular body  36  in a radial direction. The substrate  50  has the axial direction of the tubular body  36  as a longitudinal direction. 
     As illustrated in  FIG.  5   , the substrate  50  has a first surface  501  and a second surface  502  facing opposite directions to each other. The first surface  501  (e.g., a bottom surface) is a surface facing the +Z side. The second surface  502  (e.g., a top surface) is a surface facing the −Z side. A first protective layer  56  made of a glass material or the like is formed on the first surface  501  of the substrate  50 . In the heater  37  according to the embodiment, the first surface  501  side of the substrate  50  is in contact with the inner peripheral surface of the tubular body  36 . The first protective layer  56  has a surface facing the +Z side. The surface of the first protective layer  56  is a surface on a side where the heater  37  is in contact with the inner peripheral surface of the tubular body  36 . The surface of the first protective layer  56  corresponds to a first surface  371  of the heater  37 . 
     An insulating layer  55  made of a glass material or the like is formed on the second surface  502  of the substrate  50 . The heat generating member  51  and the wiring set  52  are disposed on the substrate  50  through the insulating layer  55  (e.g., the insulating layer  55  extends between (a) the heat generating member  51  and the wiring set  52  and (b) the substrate  50 ). The heat generating member  51  and the wiring set  52  are provided on a −Z side surface of the insulating layer  55 . The heat generating member  51  and the wiring set  52  are covered with a second protective layer  57  made of a glass material or the like. The second protective layer  57  has a surface facing the −Z side. The surface of the second protective layer  57  corresponds to a second surface  372  opposite to the first surface  371  of the heater  37 . 
     As illustrated in  FIG.  4   , the heat generating member  51  includes a first heat generating portion  511  and second heat generating portions  512 . The first heat generating portion  511  and the second heat generating portions  512  are formed of a temperature coefficient of resistance (TCR) material. For example, the first heat generating portion  511  and the second heat generating portions  512  are formed of a silver-palladium alloy or the like. 
     The first heat generating portion  511  according to the embodiment includes a central heating element  513 . The central heating element  513  is disposed at a central portion of the substrate  50  in the longitudinal direction (the Y direction). An outer shape of the central heating element  513  is a rectangular shape having long sides along the Y direction and short sides along the X direction. The central heating element  513  is disposed along the longitudinal direction of the substrate  50 . 
     The second heat generating portions  512  according to the embodiment respectively include a first end portion heating element  514  and a second end portion heating element  515 . The first end portion heating element  514  and the second end portion heating element  515  are disposed at end portions of the substrate  50  in the longitudinal direction (the Y direction). Outer shapes of the first end portion heating element  514  and the second end portion heating element  515  are each a rectangular shape having long sides along the Y direction and short sides along the X direction. Dimensions of the first end portion heating element  514  and the second end portion heating element  515  in the Y direction are smaller than a dimension of the central heating element  513  in the Y direction. Dimensions of the first end portion heating element  514  and the second end portion heating element  515  in the X direction are equal to a dimension of the central heating element  513  in the X direction. 
     The first end portion heating element  514  is disposed on an end portion of the substrate  50  in the +Y side of the longitudinal direction (the Y direction). The second end portion heating element  515  is disposed on an end portion of the substrate  50  in the −Y side of the longitudinal direction (the Y direction). The first end portion heating element  514  is disposed on the +Y side with respect to the central heating element  513 . The second end portion heating element  515  is disposed on the −Y side with respect to the central heating element  513 . The first end portion heating element  514  and the second end portion heating element  515  are located on an outer side (the +Y side or the −Y side) of the substrate  50  in the longitudinal direction with respect to the central heating element  513 . 
     The wiring set  52  is made of a metal material such as silver. The wiring set  52  includes a central contact  521 , a central wiring  522 , an end portion contact  523 , a first end portion wiring  524 , a second end portion wiring  525 , a common contact  526 , and a common wiring  527 . The central contact  521 , the end portion contact  523 , and the common contact  526  correspond to power supply units (e.g., electrical contacts) that supply power to the heater  37 . 
     The central contact  521  is disposed on the −Y side with respect to the heat generating member  51 . The central contact  521  supplies electric power (i.e., electrical energy) to the central heating element  513  via the central wiring  522 . The central wiring  522  is disposed on the +X side of the heat generating member  51 . The central wiring  522  connects an end side of the central heating element  513  on the +X side to the central contact  521 . 
     The end portion contact  523  is disposed on the −Y side with respect to the central contact  521 . The end portion contact  523  supplies electric power to the end portion heating elements  514  and  515  via the end portion wirings  524  and  525 . The first end portion wiring  524  is disposed on the +X side of the central wiring  522 , which is the +X side of the heat generating member  51 . The first end portion wiring  524  connects an end side of the first end portion heating element  514  on the +X side to an end portion of the end portion contact  523  on the +X side. The second end portion wiring  525  is disposed on the +X side of the heat generating member  51 , which is the −X side of the central wiring  522 . The second end portion wiring  525  connects an end side of the second end portion heating element  515  on the +X side to an end portion of the end portion contact  523  on the −X side. 
     The common contact  526  is disposed on the +Y side with respect to the heat generating member  51 . The common wiring  527  is disposed on the −X side of the heat generating member  51 . The common wiring  527  connects end sides of the central heating element  513 , the first end portion heating element  514 , and the second end portion heating element  515  on the −X side to the common contact  526 . 
     In the present embodiment, the heat generating member  51  generates heat by energization (e.g., when electrically energized through a resistive heating process in which the application of electrical energy causes the heating elements to generate or provide thermal energy). An electric resistance value of the central heating element  513  is smaller than electric resistance values of the first end portion heating element  514  and the second end portion heating element  515 . In the present embodiment, a narrow sheet having a width in the Y direction smaller than a predetermined width passes through a central portion of the heating device  30  in the Y direction. In this case, the control unit  6  causes only the central heating element  513  to generate heat. On the other hand, when a wide sheet having a width in the Y direction larger than the predetermined width is used, the control unit  6  causes the entire heat generating member  51  to generate heat. That is, when the wide sheet is used, the control unit  6  causes the central heating element  513 , the first end portion heating element  514 , and the second end portion heating element  515  to generate heat. In the present embodiment, heat generation of the central heating element  513 , the first end portion heating element  514 , and the second end portion heating element  515  can be controlled independently of each other. In the present embodiment, the heat generation of the first end portion heating element  514  and the second end portion heating element  515  is controlled in the same manner. 
     As illustrated in  FIG.  3   , the thermostat unit  40  and the first temperature detection member  41  are disposed on the −Z side of the heater  37  with the heat equalizing member  46  interposed therebetween. For example, the first temperature detection member  41  is a thermistor. The thermostat unit  40  and the first temperature detection member  41  are mounted and supported on a −Z side surface of the support member  38 . Temperature sensing elements of the thermostat unit  40  and the first temperature detection member  41  are in contact with the heat equalizing member  46  through a hole or passage penetrating the support member  38  in the Z direction. The thermostat unit  40  and the first temperature detection member  41  measure a temperature of the heater  37  via the heat equalizing member  46 . 
       FIG.  6    is a diagram illustrating disposition of the thermostat unit  40  and the first temperature detection unit  41 .  FIG.  6    corresponds to a plan view of the thermostat unit  40  and the first temperature detection unit  41  as viewed from the −Z side. In  FIG.  6   , illustration of the support member  38  is omitted. The following descriptions regarding the disposition of the thermostat unit  40  and the first temperature detection unit  41  are descriptions of disposition of the respective temperature sensing elements. 
     As illustrated in  FIG.  6   , the first temperature detection member  41  includes a central heater thermometer  411  and an end portion heater thermometer  412 . The central heater thermometer  411  and the end portion heater thermometer  412  are disposed apart from each other in the Y direction. The central heater thermometer  411  and the end portion heater thermometer  412  are disposed within a range of the heat generating member  51  in the Y direction. The central heater thermometer  411  and the end portion heater thermometer  412  are disposed at the center of the heat generating member  51  in the X direction. As viewed from the Z direction, the central heater thermometer  411  and the end portion heater thermometer  412  overlap with at least a part of the heat generating member  51 . 
     The central heater thermometer  411  measures a temperature of the central heating element  513 . The central heater thermometer  411  is disposed within a range of the central heating element  513 . As viewed from the Z direction, the central heater thermometer  411  overlaps with the central heating element  513 . 
     The end portion heater thermometer  412  measures a temperature of the second end portion heating element  515 . Since the heat generation of the first end portion heating element  514  and the second end portion heating element  515  is controlled in the same manner by the control unit  6 , a temperature of the first end portion heating element  514  and a temperature of the second end portion heating element  515  are equal to each other. The end portion heater thermometer  412  is disposed within a range of the second end portion heating element  515 . As viewed from the Z direction, the end portion heater thermometer  412  overlaps with the second end portion heating element  515 . An end portion heater thermometer that measures the temperature of the first end portion heating element  514  may be provided separately from the end portion heater thermometer  412 . 
     When a temperature of the heater  37  detected or sensed through the heat equalizing member  46  exceeds a predetermined temperature, the thermostat unit  40  cuts off energization of the heat generating member  51 . The thermostat unit  40  includes a central thermostat  401  and an end portion thermostat  402 . The thermostat unit  40  is also disposed in the same manner as the first temperature detection member  41  described above. 
     When the temperature of the central heating element  513  exceeds a predetermined temperature, the central thermostat  401  cuts off the energization of the heat generating member  51 . The central thermostat  401  is disposed within the range of the central heating element  513 . As viewed from the Z direction, the central thermostat  401  overlaps with the central heating element  513 . 
     When the temperature of the first end portion heating element  514  exceeds a predetermined temperature, the end portion thermostat  402  cuts off the energization of the heat generating member  51 . Since heat generation of the first end portion heating element  514  and the second end portion heating element  515  are controlled in the same manner, the temperature of the first end portion heating element  514  and the temperature of the second end portion heating element  515  are equal to each other. The end portion thermostat  402  is disposed within a range of the first end portion heating element  514 . As viewed from the Z direction, the end portion thermostat  402  overlaps with the first end portion heating element  514 . 
     In the heater  37  according to the present embodiment, the central heater thermometer  411  and the central thermostat  401  are disposed within the range of the central heating element  513 , thereby controlling the temperature of the central heating element  513 . In the heater  37  according to the present embodiment, the end portion thermostat  402  and the end portion heater thermometer  412  are disposed within the ranges of the first end portion heating element  514  and the second end portion heating element  515 , respectively, thereby controlling the temperatures of the first end portion heating element  514  and the second end portion heating element  515 . 
     As illustrated in  FIG.  3   , the second temperature detection member  42  is disposed on the +X side inside the tubular body  36 . The second temperature detection member  42  measures a temperature of the tubular body  36  by being in contact with the inner peripheral surface of the tubular body  36 . The second temperature detection member  42  corresponds to a belt thermometer that measures a temperature of the fixing belt serving as the tubular body  36 . 
       FIG.  7    is an electric circuit diagram of the heating device  30  according to the embodiment. In  FIG.  7   , the plan view illustrated in  FIG.  6    is disposed on a lower side of a paper sheet, and the plan view illustrated in  FIG.  4    is disposed on an upper side of the paper sheet. In addition, in  FIG.  7   , the second temperature detection member  42  is illustrated together with the cross section of the tubular body  36  in an upper side of the lower plan view. The second temperature detection member  42  includes a central belt thermometer  421  and an end portion belt thermometer  422 . 
     The central belt thermometer  421  is in contact with a central portion of the tubular body  36  in the Y direction. The central belt thermometer  421  is in contact with the tubular body  36  within a range of the central heating element  513  in the Y direction. The central belt thermometer  421  measures a temperature of the central portion of the tubular body  36  in the Y direction. 
     The end portion belt thermometer  422  is in contact with an end portion of the tubular body  36  on the −Y side. The end portion belt thermometer  422  is in contact with the tubular body  36  within a range of the second end portion heating element  515  in the Y direction. The end belt thermometer  422  measures a temperature of the end portion of the tubular body  36  on the −Y side. As described above, the heat generation of the first end portion heating element  514  and the second end portion heating element  515  are controlled in the same manner. In the present embodiment, the temperature of the end portion on the −Y side and the temperature of the end portion on the +Y side of the tubular body  36  are equal to each other. 
     A power supply  70  (e.g., a supply of alternating current electrical energy) is connected to the central contact  521  via a central triac  71 . The power supply  70  is connected to the end portion contact  523  via an end portion triac  72 . Control units  6  control an ON/OFF state of the central triac  71  and the end portion triac  72  independently of each other. 
     When the control unit  6  turns on the central triac  71 , the power supply  70  energizes the central heating element  513 . Accordingly, the central heating element  513  generates heat (e.g., thermal energy). When the control unit  6  turns on the end portion triac  72 , the power supply  70  energizes the first end portion heating element  514  and the second end portion heating element  515 . Accordingly, the first end portion heating element  514  and the second end portion heating element  515  generate heat. As described above, the heat generation of (a) the central heating element  513  and (b) the first end portion heating element  514  and the second end portion heating element  515  are controlled independently of each other. The central heating element  513 , the first end portion heating element  514 , and the second end portion heating element  515  are connected in parallel with respect to the power supply  70 . 
     The power supply  70  is connected to the common contact  526  via the central thermostat  401  and the end portion thermostat  402 . The central thermostat  401  and the end portion thermostat  402  are connected in series. When the temperature of the central heating element  513  rises abnormally, a temperature detected by the central thermostat  401  exceeds a predetermined temperature. In this case, the central thermostat  401  cuts off energization of the power supply  70  to the entire heat generating member  51 . 
     When the temperature of the first end portion heating element  514  rises abnormally, a temperature detected by the end portion thermostat  402  exceeds a predetermined temperature. In this case, the end portion thermostat  402  cuts off the energization of the power supply  70  to the entire heat generating member  51 . As described above, the heat generation of the first end portion heating element  514  and the second end portion heating element  515  are controlled in the same manner. Therefore, when the temperature of the second end portion heating element  515  rises abnormally, the temperature of the first end portion heating element  514  also rises in the same manner. Therefore, also when the temperature of the second end portion heating element  515  rises abnormally, the end portion thermostat  402  cuts off the energization of the power supply  70  to the entire heat generating member  51  in the same manner. 
     The control unit  6  acquires the temperature of the central heating element  513  by the central heater thermometer  411 . The control unit  6  acquires the temperature of the second end portion heating element  515  by the end portion heater thermometer  412 . The temperature of the second end portion heating element  515  is equal to the temperature of the first end portion heating element  514 . The control units  6  measure the temperature of the heat generating member  51  by the heater thermometers  411  and  412  when the heating device  30  is started (e.g., warmed up) and when the heating device  30  returns from a pause state (e.g., a sleep state). 
     If at least one of the temperature of the central heating element  513  and the temperature of the second end portion heating element  515  is lower than a predetermined temperature when the heating device  30  is started or when the heating device  30  returns from the pause state, the control unit  6  causes the heat generating member  51  to generate heat for only a short time. Thereafter, the control unit  6  starts rotation of the pressure roller  31 . Due to the heat generation of the heat generating member  51 , the viscosity of the lubricant applied to the inner peripheral surface of the tubular body  36  decreases. As a result, slidability between the heater  37  and the tubular body  36  at a start of the rotation of the pressure roller  31  is ensured. 
     The control unit  6  acquires the temperature of the central portion of the tubular body  36  in the Y direction by the central belt thermometer  421 . The control unit  6  acquires the temperature of the end portion of the tubular body  36  on the −Y side by the end portion belt thermometer  422 . The temperature of the end portion of the tubular body  36  on the −Y side is equal to the temperature of the end portion of the tubular body  36  on the +Y side. During operation of the heating device  30 , the control units  6  acquire the temperatures of the central portion and the end portion of the tubular body  36  in the Y direction. 
     The control units  6  execute phase control or wave number control on the electric power to be supplied to the heat generating member  51  by the central triac  71  and the end portion triac  72 . The control unit  6  controls the energization of the central heating element  513  based on the temperature of the central portion of the tubular body  36  in the Y direction. The control units  6  control the energizations of the first end portion heating element  514  and the second end portion heating element  515  based on the temperature of the end portion of the tubular body  36  in the Y direction. 
       FIG.  8    is a diagram illustrating a disposition of the heater  37  and the heat equalizing member  46  according to the embodiment. As illustrated in  FIG.  8   , the heat equalizing member  46  has a concave portion  461  on an outer surface facing the heater  37  side. The concave portion  461  is formed in the Y direction so as to include a range in which the substrate  50  of the heater  37  is disposed. The concave portion  461  penetrates the heat equalizing member  46  in the Y direction. The concave portion  461  is not in contact with the heater  37 . On the other hand, each of both sides of the heat equalizing member  46  in the X direction with respect to the concave portion  461  are in contact with the heater  37 . In the present embodiment, each of both side portions of the heat equalizing member  46  in the X direction with respect to the concave portion  461  are in contact with the −Z side surface (the second surface  372  of the heater  37 ) of the second protective layer  57 . 
     When printing is started in the image forming apparatus  1 , the heat generating member  51  raises the temperature of the tubular body  36  to a fixing temperature. When the heat generating member  51  generates heat from a room temperature, for example, temperature distribution of the heat generating member  51  is highest at a center of the heat generating member  51  in the X direction. The temperature distribution of the heat generating member  51  decreases as a distance from the center of the heat generating member  51  in the X direction increases. As described above, the temperature distribution of the heat generating member  51  has a chevron shape having a temperature peak position. The temperature peak position of the heat generating member  51  is the center of the heat generating member  51  in the X direction. The concave portion  461  of the heat equalizing member  46  is formed so as to cover the center of the heat generating member  51  in the X direction. 
     Next, the support member  38  according to the embodiment will be described in detail.  FIG.  9    is a diagram of the heating device  30  according to the embodiment as viewed from a rear side of the image forming apparatus  1 .  FIG.  10    is a perspective view illustrating mounting states of the heater  37 , the support member  38 , and power supply connectors  101  according to the embodiment.  FIG.  11    is a perspective view of the support member  38  according to the embodiment. In  FIGS.  9  and  10   , the heater  37  is illustrated by dot hatching. 
     As illustrated in  FIG.  10   , the support member  38  has the Y direction (the axial direction of the tubular body  36 ) as the longitudinal direction. The support member  38  supports the attached heater  37  by being bent relative to the heater  37 . In the present embodiment, the heater  37  is attached to the support member  38  by bending the support member  38  with respect to the heater  37 . The support member  38  supports the heater  37  attached as described above. As illustrated in  FIG.  9   , an opening portion  59  for exposing the power supply unit is formed in the support member  38 . As illustrated in  FIG.  11   , the support member  38  is formed of a single member that is continuous in the longitudinal direction of the support member  38 . 
     An amount of deformation of the support member  38  in a direction intersecting the longitudinal direction and a lateral direction in a state in which the heater  37  is attached to the support member  38  is larger than an amount of deformation of the heater  37  in a direction intersecting the longitudinal direction and the lateral direction. The state in which the heater  37  is attached to the support member  38  corresponds to the mounting state of the heater  37  illustrated in  FIG.  10   . The amount of deformation of the support member  38  in the direction intersecting the longitudinal direction and the lateral direction corresponds to an amount of deformation of the support member  38  in the Z direction. The amount of deformation of the heater  37  in the direction intersecting the longitudinal direction and the lateral direction corresponds to an amount of deformation of the heater  37  in a thickness direction (the Z direction). In the present embodiment, the amount of deformation of the support member  38  in the Z direction in the mounting state of the heater  37  is larger than the amount of deformation of the heater  37  in the Z direction. For example, the amount of deformation of the support member  38  in the Z direction is set to a size that allows the heater  37  to be attached by bending only the support member  38  with respect to the heater  37 . For example, the amount of deformation of the support member  38  in the Z direction may be larger than the amount of deformation of the heater  37  in a thickness direction (the Z direction) of the substrate  50 . 
     As illustrated in  FIG.  11   , the support member  38  includes a support portion main body  60 , first contact portions  61 , second contact portions  62 , and third contact portions  63 . In the support portion main body  60 , opening portions  59  are formed on end portion sides of the support member  38  in the longitudinal direction. The opening portions  59  are open to the −Z side of the support member  38 . The support portion main body  60  is in contact with the second surface  372  side opposite to the first surface  371  side of the heater  37 . In the present embodiment, the support portion main body  60  is in contact with the second surface  372  (a surface of the second protective layer  57 ) of the heater  37  via the heat equalizing member  46 . 
     The support portion main body  60  includes a first support portion  601 , second support portions  602 , third support portions  603 , and fourth support portions  604 . The first support portion  601  has a longitudinal direction defined along the Y direction (the axial direction of the tubular body  36 ) as a longitudinal direction. The first support portion  601  faces the heat equalizing member  46 . The first support portion  601  supports the second surface  372  of the heater  37  through the heat equalizing member  46 . 
     The second support portions  602  are disposed at end portions of the first support portion  601  in the longitudinal direction. The second support portions  602  are in contact with end portions of the heat equalizing member  46  in the longitudinal direction. The second support portions  602  protrude to the +Z side from the end portions of the first support portion  601  in the longitudinal direction. 
     As illustrated in  FIG.  13   , the second support portion  602  includes a guide surface  620  that guides the heater  37 . The guide surface  620  includes a first inclined surface  621  and a second inclined surface  622  that are inclined with respect to the first support portion  601  in the longitudinal direction. In the cross-sectional view of  FIG.  13   , the first inclined surface  621  is inclined such that the first inclined surface  621  is located on the −Z side from an inner end in the Y direction of a +Z side surface of the second support portion  602  toward an inner side in the Y direction. In the cross-sectional view of  FIG.  13   , the second inclined surface  622  is inclined such that the second inclined surface  622  is located on the −Z side from an outer end in the Y direction of the +Z side surface of the second support portion  602  toward an outer side in the Y direction. 
     As illustrated in  FIG.  11   , the third support portions  603  are disposed at end portions of the first support portion  601  in the X direction (the lateral direction). The third support portions  603  are disposed on both sides of the first support portion  601  in the lateral direction. The third support portions  603  are in contact with the end portion of the heat equalizing member  46  in the Z direction (the lateral direction). The third support portions  603  support the end portions of the heater  37  in the lateral direction together with the heat equalizing member  46 . 
     The fourth support portions  604  are provided in the third support portions  603 . The plurality of fourth support portions  604  are disposed at intervals in the longitudinal direction of the first support portion  601 . The fourth support portions  604  are provided on the third support portions  603  on each of both sides in the X direction. The fourth support portions  604  are in contact with the inner peripheral surface of the tubular body  36 . Round chamfers are formed at outer end portions of the fourth support portions  604  in the X direction. The fourth support portions  604  support the inner peripheral surface of the tubular body  36  on the outer side of the heater  37  in the X direction. 
     The first contact portion  61  is disposed via a gap  69  that opens to allow the heater  37  to be movable in the axial direction with respect to the support portion main body  60 . The first contact portion  61  is in contact with the first surface  371  of the heater  37 . The gap  69  is formed between the second support portion  602  and the first contact portion  61 . 
     The second contact portions  62  are disposed via the opening portions  59  with respect to the support portion main body  60 . The second contact portions  62  are in contact with end portions of the heater  37  in the longitudinal direction. 
     The third contact portion  63  is disposed between the first contact portion  61  and the second contact portion  62  in the longitudinal direction of the support member  38 . The third contact portion  63  is in contact with each end portion of the heater  37  in the lateral direction. 
     In the present embodiment, the first contact portions  61 , the second contact portions  62 , and the third contact portions  63  are respectively disposed on both sides of the support member  38  in the longitudinal direction. One side (the +Y side) of the support member  38  in the longitudinal direction corresponds to a front side of the image forming apparatus  1 . The other side (the −Y side) of the support member  38  in the longitudinal direction corresponds to a rear side of the image forming apparatus  1 . Hereinafter, the first contact portion  61 , the second contact portion  62 , and the third contact portion  63  disposed on the front side of the image forming apparatus  1  are referred to as a first front side contact portion  81 , a second front side contact portion  82 , and a third front side contact portion  83 , respectively. Hereinafter, the first contact portion  61 , the second contact portion  62 , and the third contact portion  63  disposed on the rear side of the image forming apparatus  1  are referred to as a first rear side contact portion  84 , a second rear side contact portion  85 , and a third rear side contact portion  86 , respectively. 
     As illustrated in  FIG.  12   , the first front side contact portion  81  includes a first front side wall portion  811 , a second front side wall portion  812 , a third front side wall portion  813 , and a fourth front side wall portion  814 . The first front side wall portion  811  faces the first surface  371  of the heater  37  on the +Y side end side of the heater  37 . 
     The second front side wall portion  812  is disposed at an end portion (the +Y side end portion) of the first front side wall portion  811  opposite to the first support portion  601 . As illustrated in  FIG.  13   , the second front side wall portion  812  protrudes to the −Z side from the +Y side end portion of the first front side wall portion  811 . As illustrated in  FIG.  12   , the second front side wall portion  812  extends in the X direction of the first front side wall portion  811 . 
     The third front side wall portion  813  is disposed between the +Y side end portion of the support portion main body  60  and the second front side wall portion  812 . As illustrated in  FIG.  13   , the third front side wall portion  813  protrudes to the −Z side from a back surface (a −Z side surface) of the first front side wall portion  811 . As illustrated in  FIG.  12   , the third front side wall portion  813  extends in the X direction of the first front side wall portion  811 . The third front side wall portion  813  is in contact with the first surface  371  of the heater  37  on the +Y side end side of the heater  37 . 
     The fourth front side wall  814  is disposed between the second front side wall portion  812  and the third front side wall portion  813 . As illustrated in  FIG.  13   , the fourth front side wall portion  814  protrudes to the −Z side from the back surface of the first front side wall portion  811 . As illustrated in  FIG.  12   , the fourth front side wall portion  814  extends in the X direction of the first front side wall portion  811 . The fourth front side wall portion  814  extends substantially parallel to the third front side wall portion  813 . As illustrated in  FIG.  13   , a thickness of the fourth front side wall portion  814  in the Z direction is larger than a thickness of the third front side wall portion  813  in the Z direction. The thickness of the fourth front side wall portion  814  in the Z direction is larger than a thickness of the heater  37  in the Z direction. 
     The second front side contact portion  82  is in contact with the +Y side end portion of the heater  37  in the longitudinal direction. The second front side contact portion  82  is disposed on an inner side portion of the fourth front side wall portion  814  in the Y direction. As illustrated in  FIG.  12   , the second front side contact portion  82  protrudes to the −Y side from a central portion of the fourth front side wall portion  814  in the X direction. In the plan view of  FIG.  12   , an outer shape of a portion in which the second front side contact portion  82  and the fourth front side wall portion  814  are combined is a T-shape. The second front side contact portion  82  is in contact with a central portion in the X direction on a +Y side end edge of the heater  37  in the longitudinal direction. As illustrated in  FIG.  13   , a thickness of the second front side contact portion  82  in the Z direction is the same as the thickness of the fourth front side wall portion  814  in the Z direction. The thickness of the second front side contact portion  82  in the Z direction is larger than the thickness of the heater  37  in the Z direction. 
     The third front side contact portion  83  is in contact with the end portion of the heater  37  in the lateral direction on the +Y side end side of the heater  37 . As illustrated in  FIG.  12   , the third front side contact portion  83  is disposed at an end portion of the third front side wall portion  813  in the X direction. As illustrated in  FIG.  13   , the third front side contact portion  83  protrudes to the −Z side from the end portion of the third front side wall portion  813  in the X direction. A thickness of the third front side contact portion  83  in the Z direction is substantially the same as the thickness of the heater  37  in the Z direction. 
     As illustrated in  FIG.  14   , the first rear side contact portion  84  includes a first rear side wall portion  841 , a second rear side wall portion  842 , a third rear side wall portion  843 , and a fourth rear side wall portion  844 . The first rear side wall portion  841  faces the first surface  371  of the heater  37  on the −Y side end side of the heater  37 . 
     As illustrated in  FIG.  15   , the first rear side wall portion  841  includes a guide surface  840  that guides the heater  37 . The guide surface  840  is formed in a portion of the first rear side wall portion  841  facing the gap  69 . The guide surface  840  is inclined with respect to the first support portion  601  in the longitudinal direction. In the cross-sectional view of  FIG.  15   , the guide surface  840  is inclined such that the guide surface  840  is located on the −Z side from the −Z side end portion of the +Y side surface of the first rear side wall portion  841  toward the −Y side. In the cross-sectional view of  FIG.  15   , the guide surface  840  of the first rear side wall portion  841  is substantially parallel to the second inclined surface  622  of the second support portion  602 . 
     The second rear side wall portion  842  is disposed at an end portion (the −Y side end portion) of the first rear side wall portion  841  opposite to the first support portion  601 . The second rear side wall portion  842  protrudes to the −Z side from the −Y side end portion of the first rear side wall portion  841 . A convex portion  845  that protrudes to the −Z side with respect to the second rear side wall portion  842  is provided at an end portion of the second rear side wall portion  842  in the X direction. As illustrated in  FIG.  14   , a pair of convex portions  845  are disposed at an interval in the X direction. The disposition interval of the pair of convex portions  845  is large enough to move the heater  37  in the axial direction. The interval between the pair of convex portions  845  in the X direction is larger than a length of the heater  37  in the X direction. 
     The third rear side wall portion  843  is disposed between the −Y side end portion of the support portion main body  60  and the second rear side wall portion  842 . As illustrated in  FIG.  15   , the third rear side wall portion  843  protrudes to the −Z side from the back surface (the −Z side surface) of the first rear side wall portion  841 . As illustrated in  FIG.  14   , the third rear side wall portion  843  extends in the X direction of the first rear side wall portion  841 . The third rear side wall portion  843  is in contact with the first surface  371  of the heater  37  on the −Y side end side of the heater  37 . 
     The fourth rear side wall portion  844  is disposed between the second rear side wall portion  842  and the third rear side wall portion  843 . The fourth rear side wall portion  844  protrudes to the −Z side from the back surface of the first rear side wall portion  841 . The fourth rear side wall portion  844  extends in the X direction of the first rear side wall portion  841 . The fourth rear side wall portion  844  extends substantially parallel to the third rear side wall portion  843 . A thickness of the fourth rear side wall portion  844  in the Z direction is the same as a thickness of the third rear side wall portion  843  in the Z direction. The fourth rear side wall portion  844  is in contact with the first surface  371  of the heater  37  on the −Y side end side of the heater  37 . 
     The second rear side contact portion  85  is in contact with the −Y side end portion of the heater  37  in the longitudinal direction. The second rear side contact portion  85  is disposed at a position overlapping with the second rear side wall portion  842  as viewed from the Z direction. The second rear side contact portion  85  protrudes to the +Y side from the central portion of the second rear side wall portion  842  in the X direction. The second rear side contact portion  85  is in contact with a central portion in the X direction on a −Y side end edge of the heater  37  in the longitudinal direction. As illustrated in  FIG.  15   , a thickness of the second rear side contact portion  85  in the Z direction is larger than a thickness of the second rear side wall portion  842  in the Z direction. The thickness of the second rear side contact portion  85  in the Z direction is larger than the thickness of the heater  37  in the Z direction. The thickness of the second rear side contact portion  85  in the Z direction may be smaller than the thickness of the second front side contact portion  82  in the Z direction. 
     The third rear side contact portion  86  is in contact with the end portion of the heater  37  in the lateral direction on the −Y side end side of the heater  37 . As illustrated in  FIG.  14   , the third rear side contact portion  86  is disposed at an end portion of each of the third rear side wall portion  843  and the fourth rear side wall portion  844  in the X direction. As illustrated in  FIG.  15   , the third rear side contact portion  86  protrudes to the −Z side from the end portion of each of the third rear side wall portion  843  and the fourth rear side wall portion  844  in the X direction. A thickness of the third rear side contact portion  86  in the Z direction is substantially the same as the thickness of the heater  37  in the Z direction. 
     Next, an example of a method for mounting the heater  37  will be described.  FIG.  16    is a diagram illustrating an example of the method for mounting the heater according to the embodiment.  FIG.  17    is a diagram illustrating the example of the method for mounting the heater according to the embodiment, following  FIG.  16   .  FIG.  18    is a diagram illustrating the example of the method for mounting the heater according to the embodiment, following  FIG.  17   .  FIGS.  16 - 18    may represent consecutive steps of the method for mounting the heater according to the embodiment. 
     As illustrated in  FIG.  16   , first, the −Y side end portion of the heater  37  is obliquely inserted into the gap  69  on the rear side. For example, the heater  37  is moved in a direction of an arrow HA in a state in which the support member  38  is along the Y direction. In the present embodiment, the heating device  30  is assembled by inclining the heater  37  and bending the support member  38  (e.g., from an unbent or resting configuration to a bent configuration). In this case, the −Y side end portion of the heater  37  is inserted by bending the support member  38  away from the heater  37  such that the −Y side end portion of the heater  37  is not caught by the second support portion  602  on the rear side of the support member  38 . 
     For example, when the −Y side end portion of the heater  37  is inserted into the gap  69  on the rear side, the guide surfaces  620  and  840  on the rear side may be used. As illustrated in  FIG.  20   , the second surface  372  on the −Y side end side of the heater  37  may be along the second inclined surface  622  (the guide surface  620 ) of the second support portion  602  on the rear side. Alternatively, the first surface  371  on the −Y side end side of the heater  37  may be along the guide surface  840  of the first rear side wall portion  841 . As a result, the −Y side end portion of the heater  37  can smoothly pass through the gap  69  on the rear side while the bending of the support member  38  is reduced as much as possible. 
     As illustrated in  FIG.  19   , the −Y side end portion of the heater  37  passes through the gap  69  on the rear side, and then passes through between the pair of convex portions  845 . As a result, the −Y side end portion of the heater  37  protrudes to the −Y side with respect to the second rear side wall portion  842 . In this case, the −Y side end portion of the heater  37  may be inserted using the bending of the support member  38  such that the −Y side end portion of the heater  37  is not caught by the second rear side contact portion  85  of the support member  38 . 
     For example, the thickness of the second rear side contact portion  85  in the Z direction may be set such that the second rear side contact portion  85  does not overlap with a movement trajectory of the heater  37  when the −Y side end portion of the heater  37  passes through the gap  69  on the rear side. As illustrated in  FIG.  15   , for example, the thickness of the second rear side contact portion  85  in the Z direction may be smaller than the thickness in the Z direction of the third rear side contact portion  86  located on the +Y side with respect to the second rear side contact portion  85 . Accordingly, the −Y side end portion of the heater  37  can protrude to the −Y side with respect to the second rear side wall portion  842  while the bending of the support member  38  is reduced as much as possible. 
     For example, when the −Y side end portion of the heater  37  protrudes further to the −Y side with respect to the second rear side wall portion  842 , the −Y side end portion of the heater  37  may protrudes to a position illustrated in  FIG.  16   . As illustrated in  FIG.  16   , the −Y side end portion of the heater  37  may protrude to the −Y side with respect to the second rear side wall portion  842  until the +Y side end portion of the heater  37  is located on the −Y side with respect to the −Y side end portion of the first front side contact portion  81 . Accordingly, in a next step, the +Y side end portion of the heater  37  can be inserted into the gap  69  on the front side while the bending of the support member  38  is reduced as much as possible. 
     As illustrated in  FIG.  21   , in a state in which the +Y side end portion of the heater  37  is located on the −Y side with respect to the −Y side end portion of the first front side contact portion  81 , the heater  37  is inclined with respect to the support member  38  in the longitudinal direction. In the state illustrated in  FIG.  21   , the +Y side end portion of the heater  37  is located on the +Z side with respect to the first front side contact portion  81 . 
     Next, the +Y side end portion of the heater  37  is inserted into the gap  69  on the front side. For example, first, the +Y side end portion of the heater  37  is moved to the −Z side in a state in which the −Y side end portion of the heater  37  protrudes to the −Y side with respect to the second rear side wall portion  842 . For example, the heater  37  is moved in the direction of the arrow HA in  FIG.  16   , and then is moved in a direction of an arrow HB. The heat equalizing member  46  is mounted in advance on the support member  38 . The heat equalizing member  46  is disposed in advance between the second support portion  602  on the front side and the second support portion  602  on the rear side. 
     For example, when moving the +Y side end portion of the heater  37  to the −Z side, the +Y side end portion of the heater  37  may be moved until the second surface  372  of the heater  37  comes into contact with the +Z side end portion of the heat equalizing member  46 . For example, the +Y side end portion of the heater  37  may be moved to the −Z side until the heater  37  overlaps with the gap  69  on the front side as viewed from the Y direction. Accordingly, the +Y side end portion of the heater  37  can be inserted into the gap  69  on the front side while the bending of the support member  38  is reduced as much as possible. 
     Next, the +Y side end portion of the heater  37  is inserted into the gap  69  on the front side by moving the heater  37  to the +Y side. For example, after the heater  37  is moved in the direction of the arrow HB in  FIG.  16   , the heater  37  is moved in a direction of an arrow HC. In this case, the heater  37  is inserted by bending the support member  38  such that the +Y side end portion of the heater  37  is not caught by the second support portion  602  on the front side. 
     For example, when the +Y side end portion of the heater  37  is inserted into the gap  69  on the front side, the guide surface  620  on the front side may be used. For example, the second surface  372  of the heater  37  on the +Y side end side of the heater  37  may be along the first inclined surface  621  (e.g., of the guide surface  620 ) of the second support portion  602  on the front side. The first inclined surface  621  may facilitate aligning the +Y side end of the heater  37  with the gap  69  in the Z direction. As a result, the +Y side end portion of the heater  37  can smoothly pass through the gap  69  on the front side while the bending of the support member  38  is reduced as much as possible. 
     After the +Y side end portion of the heater  37  is inserted into the gap  69  on the front side, the heater  37  is further moved to the +Y side. Next, the +Y side end portion of the heater  37  is brought into contact with the second front side contact portion  82 . As a result, as illustrated in  FIG.  17   , the heater  37  is mounted on the support member  38 . As illustrated in  FIG.  24   , in a state in which the heater  37  is mounted, since the +Y side end portion of the heater  37  is in contact with the second front side contact portion  82 , the movement of the heater  37  to the +Y side is restricted. 
     In the state in which the heater  37  is mounted, the first surface  371  on the +Y side end side of the heater  37  is in contact with the third front side wall portion  813 . Therefore, movement of the heater  37  to the +Z side is restricted by the third front side wall portion  813 . In the state in which the heater  37  is mounted, the second surface  372  on the +Y side end side of the heater  37  is in contact with the second support portion  602  on the front side. Therefore, movement of the heater  37  to the −Z side is restricted by the second support portion  602  on the front side. In the state in which the heater  37  is mounted, an end portion of the heater  37  in the lateral direction on the +Y side end side is in contact with the third front side contact portion  83 . Therefore, movement of the heater  37  in the X direction is restricted by the third front side contact portion  83 . 
     For example, the third front side contact portion  83  may be disposed at both end portions of the third front side wall portion  813  in the X direction. As a result, in the state in which the heater  37  is mounted, both end portions of the heater  37  in the lateral direction on the +Y side end side are in contact with the third front side contact portion  83  on both sides in the X direction. Therefore, the movement of the heater  37  to both sides in the X direction (+X side and −X side) is restricted by the third front side contact portion  83 . 
     As illustrated in  FIG.  22   , in the state in which the heater  37  is mounted, the −Y side end portion of the heater  37  is in contact with the second rear side contact portion  85 . As a result, movement of the heater  37  to the −Y side is restricted. As illustrated in  FIG.  23   , in the state in which the heater  37  is mounted, the first surface  371  on the −Y side end side of the heater  37  is in contact with each of the third rear side wall portion  843  and the fourth rear side wall portion  844 . Therefore, the movement of the heater  37  to the +Z side is restricted by the third rear side wall portion  843  and the fourth rear side wall portion  844 . In the state in which the heater  37  is mounted, the second surface  372  on the −Y side end side of the heater  37  is in contact with the second support portion  602  on the rear side. Therefore, movement of the heater  37  to the −Z side is restricted by the second support portion  602  on the rear side. In the state in which the heater  37  is mounted, an end portion of the heater  37  in the lateral direction on the −Y side end side is in contact with the third rear side contact portion  86 . Therefore, the movement of the heater  37  in the X direction is restricted by the third rear side contact portion  86 . 
     For example, the third rear side contact portions  86  may be disposed at both end portions of each of the third rear side wall portion  843  and the fourth rear side wall portion  844  in the X direction. As a result, in the state in which the heater  37  is mounted, both end portions of the heater  37  in the lateral direction on the −Y side end side are in contact with the third rear side contact portions  86  on both sides in the X direction. Therefore, the movement of the heater  37  to both sides in the X direction (+X side and −X side) is restricted by the third rear side contact portions  86 . 
     In the state in which the heater  37  is mounted, the power supply units  521 ,  523 , and  526  are located in the opening portions  59 . Therefore, the power supply units  521 ,  523 , and  526  are exposed to the −Z side. As illustrated in  FIG.  24   , in the state in which the heater  37  is mounted, the common contact  526  is exposed to the −Z side on the +Y side end side of the heater  37 . In the state in which the heater  37  is mounted, the common contact  526  overlaps with the third front side wall portion  813  as viewed from the Z direction. 
     As illustrated in  FIG.  23   , in the state in which the heater  37  is mounted, the central contact  521  and the end portion contact  523  are exposed to the −Z side on the −Y side end side of the heater  37 . In the state in which the heater  37  is mounted, the central contact  521  overlaps with the third rear side wall portion  843  as viewed from the Z direction. In the state in which the heater  37  is mounted, the end portion contact  523  overlaps with the fourth rear side wall portion  844  as viewed from the Z direction. Accordingly, the support member  38  provides support directly beneath each of the contacts in the Z direction, minimizing deflection of the heater  37  and associated stresses on the heater  37  caused by the contact forces of the power supply connectors  101  in the Z direction. 
     As illustrated in  FIG.  18   , next, the power supply connectors  101  are connected to the power supply units  521 ,  523 , and  526  of the heater  37 . Hereinafter, a unit (an assembly) in the state in which the heater  37  is mounted on the support member  38  is referred to as a mounting unit  100 . Each of the power supply connectors  101  is formed with an insertion hole  110  (e.g., a slot, a groove, a passage, etc.) that opens in the X direction so as to allow an outer portion of the mounting unit  100  in the Y direction to be inserted therethrough. 
     Each power supply connector  101  includes a first connector wall portion  111  and a second connector wall portion  112  that face each other across the insertion hole  110 . The first connector wall portion  111  is in contact with the +Z side surface of the first contact portion  61  of the mounting unit  100 . The second connector wall portion  112  includes terminal portions connected to the power supply units  521 ,  523 , and  526 . The terminal portions are biased to the +Z side toward the power supply units  521 ,  523 , and  526  by a biasing member such as a leaf spring. 
     The power supply connectors  101  are attached to both sides of the mounting unit  100  in the longitudinal direction. Hereinafter, the power supply connector  101  attached to one side (the front side of the image forming apparatus  1 ) in the longitudinal direction of the mounting unit  100  is referred to as a front side power supply connector  121 . Hereinafter, the power supply connector  101  attached to the other side (the rear side of the image forming apparatus  1 ) in the longitudinal direction of the mounting unit  100  is referred to as a rear side power supply connector  122 . 
     For example, first, the rear side power supply connector  122  is attached to the −Y side of the mounting unit  100 . For example, the rear side power supply connector  122  is moved in a direction of an arrow CA in  FIG.  18   . As a result, the −Y side end portion of the mounting unit  100  is inserted into the insertion hole  110  of the rear side power supply connector  122 . As illustrated in  FIG.  9   , the first rear side contact portion  84  of the mounting unit  100  has a shape curved toward the +Z side. Therefore, the −Y side end portion of the mounting unit  100  can be smoothly inserted into the insertion hole  110  of the rear side power supply connector  122 . 
     Two terminal portions are provided corresponding to the two power supply units  521  and  523 . The terminal portion corresponding to the (one) power supply unit  521  is guided along the third rear side wall portion  843  via the heater  37 . The terminal portion corresponding to the (other) power supply unit  523  is guided along the fourth rear side wall portion  844  via the heater  37 . Accordingly, the −Y side end portion of the mounting unit  100  can be smoothly inserted into the insertion hole  110  of the rear side power supply connector  122 . 
     In the present embodiment, the pair of convex portions  845  are provided at the end portions of the second rear side wall portion  842  in the X direction. In a state in which the rear side power supply connector  122  is attached, the pair of convex portions  845  may be in contact with the −Y side surface of the rear side power supply connector  122 . Accordingly, positional deviation of the rear side power supply connector  122  to the −Y side can be avoided. 
     Next, the front side power supply connector  121  is attached to the +Y side of the mounting unit  100 . For example, the front side power supply connector  121  is moved in a direction of an arrow CB in  FIG.  18   . As a result, the +Y side end portion of the mounting unit  100  is inserted into the insertion hole  110  of the front side power supply connector  121 . The first front side contact portion  81  of the mounting unit  100  has a shape curved toward the +Z side in the same manner as the first rear side contact portion  84 . Therefore, the +Y side end portion of the mounting unit  100  can be smoothly inserted into the insertion hole  110  of the front side power supply connector  121 . 
     The front side power supply connector  121  has two terminal portions in the same manner as the rear side power supply connector  122 . One terminal portion corresponding to the power supply unit  526  is guided along the third front side wall portion  813  via the heater  37 . The other terminal portion is directly guided along the fourth front side wall portion  814 . Accordingly, the +Y side end portion of the mounting unit  100  can be smoothly inserted into the insertion hole  110  of the front side power supply connector  121 . 
     In the present embodiment, the second front side wall portion  812  is provided at the +Y side end portion of the first front side wall portion  811 . In a state in which the front side power supply connector  121  is attached, the second front side wall portion  812  may be in contact with the +Y side surface of the front side power supply connector  121 . Accordingly, positional deviation of the front side power supply connector  121  to the +Y side can be avoided. 
     Through the above steps, the power supply connectors  101  can be connected to the power supply units  521 ,  523 , and  526  of the heater  37  in the mounting unit  100 . For example, the power supply connector  101  may be of a lock type that is locked at a connection position by a lock pin or the like. For example, the power supply connector  101  may have a configuration in which the power supply connector  101  is unlocked by pressing a switch. For example, the power supply connector  101  may have a configuration in which when the power supply connector  101  is unlocked, the pair of connector wall portions  111  and  112  are opened. 
     As described above, the heating device  30  according to the embodiment includes the tubular body  36 , the heater  37 , the power supply units  521 ,  523 , and  526 , and the support member  38 . The tubular body  36  is formed in a tubular shape. The heater  37  is disposed inside the tubular body  36 . The heater  37  has the axial direction of the tubular body  36  as the longitudinal direction. The heater  37  is in contact with the inner peripheral surface of the tubular body  36  on the first surface side  371 . The heater  37  generates heat by energization. The power supply units  521 ,  523 , and  526  supply power to the heater  37 . The opening portions  59  for exposing the power supply units  521 ,  523 , and  526  are formed in the support member  38 . The support member  38  has the axial direction as the longitudinal direction. The support member  38  supports the attached heater  37  by being bent relative to the heater  37 . The above configuration exhibits the following effects. The heater  37  can be attached to the support member  38  by bending the support member  38  relative to the heater  37 . The support member  38  can support the heater  37  attached as described above. Therefore, complication of the support member  38  can be prevented. 
     When the tubular body  36  slides on the first surface  371  of the heater  37 , in order to prevent wear or damage to the first surface  371  of the heater  37 , the disposition of the heater  37  may be changed with respect to the tubular body  36 . When the disposition of the heater  37  is changed, the disposition of the power supply units  521 ,  523 , and  526  may be changed. Depending on the disposition of the heater  37  and the power supply units  521 ,  523 , and  526 , the support member  38  may be complicated. For example, a structure is provided in which the support member  38  is divided into a plurality of members and the divided plurality of members are combined to support the heater  37 . However, when the support member  38  is divided into a plurality of members, the number of components increases, and the support member  38  is complicated. On the other hand, according to the embodiment, since the support member  38  is formed of one single member that is continuous in the longitudinal direction of the support member  38 , the increase in the number of components can be prevented. Therefore, the complication of the support member  38  due to the increase in the number of components can be prevented. 
     The amount of deformation of the support member  38  in the direction intersecting the longitudinal direction and the lateral direction in the state in which the heater  37  is attached to the support member  38  is larger than the amount of deformation of the heater  37  in the direction intersecting the longitudinal direction and the lateral direction. The above configuration exhibits the following effects. The heater  37  can be attached to the support member  38  by largely bending the support member  38  with respect to the heater  37 . Therefore, excessive deformation of the heater  37  can be avoided when mounting the heater  37 . Therefore, cracking, damage, or the like due to the deformation of the heater  37  can be prevented. 
     The support member  38  includes the support portion main body  60  and the first contact portion  61 . In the support portion main body  60 , the opening portions  59  are formed on the end portion sides of the support member  38  in the longitudinal direction. The support portion main body  60  is in contact with the second surface  372  side opposite to the first surface  371  side of the heater  37 . The first contact portion  61  is disposed via the gap  69  that opens to allow the heater  37  to move in the axial direction with respect to the support portion main body  60 . The first contact portion  61  is in contact with the first surface  371  side of the heater  37 . The above configuration exhibits the following effects. The support portion main body  60  is in contact with the second surface  372  side of the heater  37 , so that the movement of the heater  37  to the second surface  372  side can be restricted. The first contact portion  61  is in contact with the first surface  371  side of the heater  37 , so that the movement of the heater  37  to the first surface  371  side can be restricted. Therefore, positional deviations of the heater  37  to the first surface  371  side and the second surface  372  side (Z direction) can be prevented. 
     The support member  38  further includes the second contact portions  62  disposed with respect to the support portion main body  60  via the opening portions  59 . The second contact portions  62  are in contact with the end portions of the heater  37  in the longitudinal direction. The above configuration exhibits the following effects. The second contact portions  62  are in contact with the end portions of the heater  37  in the longitudinal direction, so that the movement of the heater  37  in the longitudinal direction can be restricted. Therefore, positional deviation of the heater  37  in the longitudinal direction (Y direction) can be prevented. 
     The first contact portions  61  and the second contact portions  62  are disposed on both sides of the support member  38  in the longitudinal direction. The above configuration exhibits the following effects. The first contact portions  61  are in contact with the first surface  371  of the heater  37  on both sides of the support member  38  in the longitudinal direction, so that the movement of the heater  37  to both sides in the longitudinal direction toward the first surface  371  can be restricted. The second contact portions  62  are in contact with the end portions of the heater  37  in the longitudinal direction on both sides of the support member  38  in the longitudinal direction, so that the movement of the heater  37  to both sides in the longitudinal direction can be restricted. Therefore, positional deviation of the heater  37  toward the first surface  371  and positional deviation of the heater  37  in the longitudinal direction can be more effectively prevented. 
     The power supply units  521 ,  523 , and  526  are disposed on the second surface  372  side opposite to the first surface  371  side of the heater  37 , the first surface  371  being in contact with the inner peripheral surface of the tubular body  36 . The above configuration exhibits the following effects. The tubular body  36  slides on the first surface  371  side of the heater  37 . The power supply units  521 ,  523 , and  526  are disposed on a side (the second surface  372  side) opposite to a side on which the heater  37  slides. Therefore, wear and damage to the power supply units  521 ,  523 , and  526  can be prevented. 
     The heat equalizing member  46  has the concave portion  461  on the outer surface facing the heater  37 . The above configuration exhibits the following effects. Since the concave portion  461  is not in contact with the heater  37 , most of heat generated by the heat generating member  51  is transmitted to the tubular body  36  without being transmitted to the heat equalizing member  46 . Since the tubular body  36  is efficiently heated, a time before the printing is started can be shortened. A reset time of the image forming apparatus  1  can be reduced or prevented from becoming long. 
     The concave portion  461  penetrates the heat equalizing member  46  in the Y direction, thereby exhibiting the following effects. The heat generated by the heat generating member  51  is transmitted to the tubular body  36  without being transmitted to the heat equalizing member  46  at any position in the Y direction. Since the tubular body  36  is further efficiently heated, a time before the printing is started can be further shortened. 
     Next, a modification of the embodiment will be described. In the heating device according to the embodiment, the heater can be attached to the support member by bending the support member with respect to the heater. Alternatively, in the heating device, the heater may be attached to the support member by bending the heater with respect to the support member. For example, the heating device may include a support member to which the heater can be attached by bending the support member relative to the heater. For example, a mode in which the heater and the support member are bent can be changed according to the required specifications. 
     The amount of deformation of the support member in the direction intersecting the longitudinal direction and the lateral direction in the state in which the heater is attached to the support member according to the embodiment is larger than the amount of deformation of the heater in the direction intersecting the longitudinal direction and the lateral direction. On the other hand, the amount of deformation of the support member in the direction intersecting the longitudinal direction and the lateral direction in the state in which the heater is attached to the support member may be equal to or less than the amount of deformation of the heater in the direction intersecting the longitudinal direction and the lateral direction. For example, modes of the amounts of deformation of the heater and the support member in the state in which the heater is attached to the support member can be changed according to the required specifications. 
     The support member according to the embodiment includes the support portion main body in which the opening portion is formed on the end portion side in the longitudinal direction of the support member, the support portion main body being in contact with the second surface side opposite to the first surface side of the heater. On the other hand, the support member may not include a support portion main body. For example, the support member may include a contact member that is in contact with the second surface side of the heater, separately from the support portion main body. For example, a configuration mode of the support member can be changed according to the required specifications. 
     The support member according to the embodiment includes the first contact portion that is disposed via the gap, which opens so as to allow the heater to move in the axial direction with respect to the support portion main body, and is in contact with the first surface side of the heater. However, the support member may not include the first contact portion. For example, the support member may include a contact member that is in contact with the first surface side of the heater, separately from the first contact portion. For example, a configuration mode of the support member can be changed according to the required specifications. 
     The support member according to the embodiment includes the second contact portion that is disposed via the opening portion with respect to the support portion main body and is in contact with the end portion of the heater in the longitudinal direction. However, the support member may not include the second contact portion. For example, the support member may include a contact member that is in contact with the end portion of the heater in the longitudinal direction, separately from the second contact portion. For example, a configuration mode of the support member can be changed according to the required specifications. 
     The first contact portions and the second contact portions according to the embodiment are disposed on both sides of the support member in the longitudinal direction. Alternatively, the first contact portions and the second contact portions may not be disposed on both sides of the support member in the longitudinal direction. For example, the first contact portion and the second contact portion may be disposed only on one side of the support member in the longitudinal direction. For example, a disposition mode of the first contact portion and the second contact portion can be changed according to the required specifications. 
     The power supply units according to the embodiment are disposed on the second surface side opposite to the first surface side of the heater, the first surface side being in contact with the inner peripheral surface of the tubular body. Alternatively, the power supply units may be disposed on the first surface side of the heater that is in contact with the inner peripheral surface of the tubular body. For example, a disposition mode of the power supply units can be changed according to the required specifications. 
     The heat equalizing member according to the embodiment has the concave portion on the outer surface facing the heater side. Alternatively, the heat equalizing member may not have a concave portion on the outer surface facing the heater side. For example, the heat equalizing member may be formed in a flat plate shape that has the axial direction of the tubular body as a longitudinal direction. For example, a mode of the heat equalizing member can be changed according to the required specifications. 
     The heater according to the embodiment is disposed inside the portion where the tubular body faces a pressure member so as to face the nip. However, the heater may not be disposed to face the nip. For example, the heater may face a region to be heated that is a part of the tubular body in the circumferential direction. For example, a disposition mode of the heater can be changed according to the required specifications. 
     In the method for mounting the heater according to the embodiment, first, the −Y side end portion of the heater is obliquely inserted into the gap on the rear side. Alternatively, in the method for mounting the heater, first, the +Y side end portion of the heater may be obliquely inserted into the gap on the front side. For example, a method for mounting the heater can be changed according to the required specifications. 
     According to at least one of the embodiments described above, the support member can support the attached heater by being bent relative to the heater. Therefore, complication of the support member can be prevented. 
     While certain embodiments have been described, these embodiments have been presented as examples and are not intended to limit the scope of the disclosure. These embodiments can be implemented in various other forms, and various omissions, substitutions, and changes can be made without departing from the gist of the disclosure. The accompanying claims and their equivalents are intended to cover these embodiments or modifications as would fall within the scope and spirit of the exemplary embodiments described herein.