Heating device

Abstract

To provide a heating device that can prevent complication of a support member.SOLUTION: A heating device of an embodiment has a cylindrical body, a heater, a power supply unit, a support member, and a soaking member. The cylindrical body is formed into a cylindrical shape. The heater is arranged inside the cylindrical body. The heater has an axial direction of the cylindrical body as a longitudinal direction. The heater is in contact, on its first surface, with an inner peripheral surface of the cylindrical body. The heater generates heat upon energization. The power supply unit supplies power to the heater. The support member is formed with an opening to expose the power supply unit. The support member has the axial direction as a longitudinal direction. The support member is attached by being bent relative to the heater and supports the heater. The soaking member is in contact with a second surface of the heater on the opposite side of the first surface. The soaking member equalizes the temperature distribution of the heater. The soaking member has a recess in an outer surface directed toward the heater.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] SUMMARY OF THE INVENTION An embodiment of the present invention relates to a heating device. [Background technology]

[0002] The heating device comprises a cylindrical body, a heater, a power supply unit, and a support member. The cylindrical body is formed in the cylindrical body. The heater is disposed inside the cylindrical body. The axial direction of the heater is the longitudinal direction. A first surface of the heater contacts the inner circumferential surface of the cylindrical body. The heater generates heat when electricity is applied. The power supply unit supplies electricity to the heater. The support member supports the heater. The cylindrical body slides on the first surface of the heater. In order to suppress wear and damage to the first surface of the heater, the position of the heater relative to the cylindrical body may be changed. Changing the position of the heater may change the position of the power supply unit. Depending on the position of the heater and the power supply unit, the support member may become complicated. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-75597 Summary of the Invention [Problem to be solved by the invention]

[0004] The problem to be solved by the present invention is to provide a heating device that can suppress the complexity of the support member. [Means for solving the problem]

[0005] The heating device of the embodiment has a cylindrical body, a heater, a power supply unit, a support member, and a heat-equalizing member. The cylindrical body is formed in a cylindrical shape. The heater is disposed inside the cylindrical body. The heater has a longitudinal direction in the axial direction of the cylindrical body. A first surface side of the heater contacts the inner peripheral surface of the cylindrical body. The heater generates heat when current is applied. The power supply unit supplies power to the heater. The support member has an opening that exposes the power supply unit. The longitudinal direction of the support member is the axial direction. The support member supports the attached heater by bending it relative to the heater. The heat-equalizing member contacts a second surface side of the heater opposite the first surface side. The heat-equalizing member equalizes the temperature distribution of the heater. The heat-equalizing member has a recess on its outer surface facing the heater. [Brief explanation of the drawings]

[0006] [Figure 1] 1 is a schematic diagram of an image forming apparatus according to an embodiment. [Figure 2] FIG. 1 is a diagram illustrating a hardware configuration of an image forming apparatus according to an embodiment. [Figure 3] FIG. 2 is an XZ cross-sectional view of the heating device according to the embodiment. [Figure 4] FIG. [Figure 5] VV cross section of Figure 4. [Figure 6] FIG. 3 is an explanatory diagram illustrating the arrangement of a thermostat unit and a first temperature detection unit according to the embodiment. [Figure 7] FIG. 2 is an electrical circuit diagram of the heating device according to the embodiment. [Figure 8] FIG. 3 is an explanatory diagram illustrating the arrangement of a heater and a heat equalizing member according to the embodiment. [Figure 9] FIG. 2 is a diagram illustrating the heating device of the embodiment as viewed from the rear side of the image forming apparatus. [Figure 10] FIG. 2 is a perspective view showing a state in which a heater, a support member, and a power supply connector are mounted according to the embodiment. [Figure 11] FIG. [Figure 12] FIG. 4 is a plan view including a front end portion of the support member according to the embodiment. [Figure 13] XIII-XIII cross section of Figure 12. [Figure 14] FIG. 4 is a plan view including a rear end portion of the support member according to the embodiment. [Figure 15] Cross-sectional view of XV-XV in Figure 14. [Figure 16] FIG. 4 is an explanatory diagram of an example of a mounting method of a heater according to an embodiment. [Figure 17] 17 is an explanatory diagram of an example of a mounting method of the heater according to the embodiment, following FIG. 16. [Figure 18] 18 is an explanatory diagram of an example of a mounting method of the heater according to the embodiment, following FIG. 17. [Figure 19] 19 is a perspective view including a rear end portion of the support member of the embodiment, as viewed from the arrow XIX in FIG. 16. [Figure 20] FIG. 20 is a perspective view including a cross section taken along the line XX-XX in FIG. 19 . [Figure 21] 17 is a perspective view including a front end portion of the support member of the embodiment, as viewed from the arrow XXI in FIG. 16. [Figure 22] 18 is a perspective view including a rear end portion of the support member of the embodiment, as seen from the arrow XXII in FIG. 17. [Figure 23] FIG. 23 is a perspective view including a cross section taken along line XXIII-XXIII of FIG. 22. [Figure 24] 18 is a perspective view including a front end portion of the support member of the embodiment, as seen from the arrow XXIV in FIG. 17. DETAILED DESCRIPTION OF THE INVENTION

[0007] Hereinafter, a heating device 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 an embodiment. 1, the image forming apparatus 1 includes a housing 10, a scanner section 2, an image forming unit 3, a sheet supply section 4, a conveyance section 5, a paper discharge tray 7, a reversing unit 9, a control panel 8, and a control section 6. The image forming apparatus 1 forms an image on a sheet-like recording medium such as paper (hereinafter referred to as a "sheet").

[0008] The housing 10 forms the outer shape of the image forming apparatus 1. The housing 10 accommodates the components of the image forming apparatus 1. The scanner unit 2 reads image information of the object to be copied as light and darkness, and generates an image signal. The scanner unit 2 outputs the generated image signal to the image forming unit 3.

[0009] The image forming unit 3 forms an output image using a recording material such as toner based on an image signal received from the scanner unit 2 or an image signal received from an external source. Hereinafter, the output image will be referred to as a toner image. The image forming unit 3 transfers the toner image onto the surface of the 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 to the sheet S. The image forming unit 3 forms an image on the sheet S.

[0010] The sheet supply section 4 supplies the sheets S one by one to the conveyance section 5 in synchronization with the timing at which the image forming unit 3 forms a toner image. The sheet supply section 4 includes a sheet storage section 20 and a pickup roller . The sheet storage section 20 stores sheets S of a predetermined size and type. The pickup roller 21 picks up the sheets S one by one from the sheet storage unit 20. The pickup roller 21 supplies the picked-up sheets S to the conveying unit 5.

[0011] The conveying section 5 conveys the sheet S supplied from the sheet supplying section 4 to the image forming unit 3. The conveying section 5 includes a conveying roller 23 and a registration roller 24. The conveying roller 23 conveys the sheet S supplied from the pickup roller 21 to the registration roller 24. The conveying roller 23 abuts the leading edge of the sheet S in the conveying direction against the nip of the registration roller 24. The registration rollers 24 bend the sheet S at the nip, thereby adjusting the position of the leading edge of the sheet S in the conveying direction. The registration rollers 24 convey the sheet S in accordance with the timing at which the image forming unit 3 transfers a toner image onto the sheet S.

[0012] The image forming unit 3 will now be described. The image forming unit 3 includes a plurality of image forming sections 25, a laser scanning unit 26, an intermediate transfer belt 27, a transfer section 28, and a heating device 30. The image forming unit 25 has a photosensitive drum 29. The image forming unit 25 forms a toner image on the photosensitive drum 29 in response to an image signal from the scanner unit 2 or an external device. The multiple image forming units 25 form toner images using yellow, magenta, cyan, and black toner, respectively.

[0013] A charger, a developer, and the like are arranged around the photosensitive drum 29. The charger charges the surface of the photosensitive drum 29. The developer contains developer containing yellow, magenta, cyan, and black toner. The developer develops the electrostatic latent image on the photosensitive drum 29. As a result, a toner image made of toner of each color is formed on the photosensitive drum 29.

[0014] The laser scanning unit 26 scans the charged photosensitive drum 29 with laser light L to expose the photosensitive drum 29. The laser scanning unit 26 exposes the photosensitive drum 29 of the image forming unit 25 for each color with separate laser light LY, LM, LC, and LK. In this way, the laser scanning unit 26 forms an electrostatic latent image on the photosensitive drum 29.

[0015] The toner image on the surface of the photosensitive drum 29 is primarily transferred onto the intermediate transfer belt 27 . The transfer unit 28 transfers the toner image that has been primarily transferred onto the intermediate transfer belt 27 onto the surface of the sheet S at the secondary transfer position. The heating device 30 applies heat and pressure to the toner image transferred to the sheet S, thereby fixing the toner image to the sheet S. The heating device 30 functions as a fixing device that fixes the toner image to the sheet S.

[0016] The reversing unit 9 reverses the sheet S to form an image on the back side of the sheet S. The reversing unit 9 reverses the sheet S discharged from the heating device 30 by a switchback. The reversing unit 9 conveys the reversed sheet S toward the registration rollers 24. The sheet discharge tray 7 holds the sheet S on which an image has been formed and discharged. The control panel 8 is a part of an input unit through which an operator inputs information for operating the image forming apparatus 1. The control panel 8 has a touch panel and various hard keys. The control unit 6 controls each unit of the image forming apparatus 1.

[0017] 2 is a diagram showing the hardware configuration of an image forming apparatus 1 according to an embodiment. The image forming apparatus 1 includes a CPU (Central Processing Unit) 91, 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 to each other via a bus. The image forming apparatus 1 executes various programs. By executing the programs, the image forming apparatus 1 functions as a device including a scanner section 2, an image forming unit 3, a sheet supply section 4, a conveyance section 5, a reversing unit 9, a control panel 8, and a communication section 90.

[0018] 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 the operation of each functional unit of the image forming apparatus 1. The auxiliary storage device 93 is configured using a storage device such as a magnetic hard disk device, a semiconductor storage device, etc. The auxiliary storage device 93 stores information. The communication unit 90 includes a communication interface for connecting the device to an external device, and communicates with the external device via the communication interface.

[0019] The heating device 30 will now be described in detail. 3 is an XZ cross-sectional view of the heating device 30 according to the embodiment. As shown in FIG.

[0020] The pressure roller 31 forms a nip N between itself and the heating mechanism 35. The pressure roller 31 applies pressure to the toner image T on the sheet S that has entered the nip N. The pressure roller 31 rotates to transport the sheet S. The pressure roller 31 has a core metal 32, an elastic layer 33, and a release layer 34.

[0021] The core 32 is formed into a cylindrical shape from a metal material such as stainless steel. Both axial ends of the core 32 are rotatably supported. The core 32 is driven to rotate by a motor. The core 32 abuts against a cam member. The cam member rotates to move the core 32 toward and away from the heating mechanism 35.

[0022] The elastic layer 33 is made of an elastic material such as silicone rubber, etc. The elastic layer 33 is formed on the outer circumferential surface of the core metal 32 with a constant thickness. The release layer 34 is formed on the outer peripheral surface of the elastic layer 33 and is made of a resin material such as PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer).

[0023] The hardness of the 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 tester. This ensures the area of ​​the nip N. In addition, the durability of the pressure roller 31 is ensured.

[0024] The pressure roller 31 can move toward and away from the heating mechanism 35 by the rotation of a cam member. When the pressure roller 31 is brought close to the heating mechanism 35 and pressed by a pressure spring, a nip N is formed. On the other hand, if a sheet S jams in the heating device 30, the sheet S can be removed by moving the pressure roller 31 away from the heating mechanism 35. When the cylindrical body 36 is stopped from rotating, such as during sleep mode, plastic deformation of the cylindrical body 36 is prevented by moving the pressure roller 31 away from the heating mechanism 35.

[0025] The pressure roller 31 is driven to rotate by a motor. When the pressure roller 31 rotates with the nip N formed, the cylindrical body 36 of the heating mechanism 35 rotates accordingly. The pressure roller 31 rotates with the sheet S disposed in the nip N, thereby conveying the sheet S in the conveying direction W.

[0026] The heating mechanism 35 heats the toner image T on the sheet S that has entered the nip N. The heating mechanism 35 has a cylindrical body 36, a heater 37, a heat equalizing member 46, a support member 38, a stay 39, a thermostat unit 40, a first temperature detection member 41, and a second temperature detection member 42.

[0027] Hereinafter, an XYZ coordinate system may be used to explain the configuration of the heating device 30. In this embodiment, the X, Y, and Z directions are defined as follows: The X direction corresponds to the direction along the short side of the heater 37. The Y direction corresponds to the direction along the long side of the heater 37 (the axial direction of the cylindrical body). In this embodiment, the Y direction is perpendicular to the conveying direction W of the sheet S. The Z direction corresponds to the direction perpendicular to the X and Y directions. Hereinafter, in the X direction, one side will be referred to as the +X side and the other side as the -X side. In the Y direction, one side will be referred to as the +Y side and the other side as the -Y side. In the Z direction, one side will be referred to as the +Z side and the other side as the -Z side.

[0028] The cylindrical body 36 is formed into a cylindrical shape using a film or the like. The cylindrical body 36 has an endless circumferential surface. The cylindrical body 36 is flexible. The cylindrical body 36 forms a nip N between itself and the pressure roller 31. The cylindrical body 36 fixes the toner image T to the sheet S at the nip N. The cylindrical body 36 is an endless belt (fixing belt) of the heating device 30.

[0029] The cylindrical body 36 has, in order from the inner periphery, a base layer, an elastic layer, and a release layer. The base layer is made of a material such as polyimide resin. The base layer is cylindrical and extends in the Y direction. The elastic layer is laminated on the outer periphery of the base layer. The elastic layer is made of an elastic material such as silicone rubber. The release layer is laminated on the outer periphery of the elastic layer. The release layer is made of a material such as PFA resin.

[0030] The heater 37 is disposed inside the cylindrical body 36. The heater 37 faces a heated region 361, which is a part of the cylindrical body 36 in the circumferential direction. The heater 37 heats the heated region 361. The heater 37 is disposed inside the part of the cylindrical body 36 that faces the pressure roller 31, facing the nip N.

[0031] A lubricant is applied to the inner circumferential surface of the cylindrical body 36. The heater 37 contacts the inner circumferential surface of the cylindrical body 36 via the lubricant. When the heater 37 generates heat, the viscosity of the lubricant decreases. This ensures the sliding properties between the heater 37 and the cylindrical body 36. The cylindrical body 36 slides on the surface of the heater 37 (the surface on the +Z side) while contacting the heater 37 with one surface.

[0032] The temperature equalizing member 46 is made of a metal material such as copper or aluminum. The thermal conductivity of the temperature equalizing member 46 is higher than the thermal conductivity of the substrate 50 of the heater 37. The length of the temperature equalizing member 46 in the X direction is equal to the length of the substrate 50 of the heater 37 in the X direction. The length of the temperature equalizing member 46 in the Y direction is shorter than the length of the substrate 50 of the heater 37 in the Y direction. The temperature equalizing member 46 is disposed in contact with the -Z side surface of the heater 37. The temperature equalizing member 46 equalizes the temperature distribution of the heater 37.

[0033] The support member 38 is made of a resin material such as a liquid crystal polymer. The support member 38 is arranged to cover the -Z side and both sides in the X direction of the heat equalizing member 46. The support member 38 supports the heater 37 via the heat equalizing member 46. Both ends of the support member 38 in the X direction are rounded and chamfered. The support member 38 supports the inner circumferential surface of the cylindrical body 36 at both ends of the heater 37 in the X direction.

[0034] The stay 39 is made of a steel plate material or the like. The cross section of the stay 39 taken along the XZ plane is formed into a U-shape. The stay 39 is attached to the -Z side of the support member 38 so that the opening of the U is closed by the support member 38. The stay 39 extends in the Y direction. Both ends of the stay 39 in the Y direction are fixed to the housing 10 of the image forming apparatus 1. This supports the heating mechanism 35 on the image forming apparatus 1. The stay 39 improves the bending rigidity of the heating mechanism 35. Flanges 49 that limit movement of the cylindrical body 36 in the Y direction are attached to the vicinity of both ends of the stay 39 in the Y direction.

[0035] 4 is a plan view of the heater 37 according to the embodiment, and FIG. 5 is a cross-sectional view taken along line VV of FIG. As shown in Fig. 4, the heater 37 has a substrate 50, a heat generating member 51, and a wiring set 52. In Fig. 4, the substrate 50 is indicated by a two-dot chain line.

[0036] The substrate 50 is made of a metal material such as stainless steel or a ceramic material such as aluminum nitride. The substrate 50 is formed in the shape of a rectangular plate extending along the Y direction. The substrate 50 is disposed on the radially inner side (-Z side) of the cylindrical body 36. The longitudinal direction of the substrate 50 is the axial direction of the cylindrical body 36.

[0037] As shown in FIG. 5 , the substrate 50 has a first surface 501 and a second surface 502 facing in opposite directions. The first surface 501 faces the +Z side. The second surface 502 faces 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 of this embodiment, the first surface 501 side of the substrate 50 abuts against the inner circumferential surface of the cylindrical body 36. The first protective layer 56 has a surface facing the +Z side. The surface of the first protective layer 56 is the surface of the heater 37 that contacts the inner circumferential surface of the cylindrical body 36. The surface of the first protective layer 56 corresponds to the first surface 371 of the heater 37.

[0038] 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 via the insulating layer 55. The heat-generating member 51 and the wiring set 52 are provided on the -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.

[0039] 4, the heat generating member 51 has a first heat generating portion 511 and a second heat generating portion 512. The first heat generating portion 511 and the second heat generating portion 512 are made of a TCR (temperature coefficient of resistance) material. For example, the first heat generating portion 511 and the second heat generating portion 512 are made of a silver-palladium alloy or the like.

[0040] The first heat generating portion 511 of the embodiment includes a central heat generating element 513. The central heat generating element 513 is disposed in the center of the longitudinal direction (Y direction) of the substrate 50. The central heat generating element 513 has an outer shape that is rectangular with its long side aligned along the Y direction and its short side aligned along the X direction. The central heat generating element 513 is disposed along the longitudinal direction of the substrate 50.

[0041] The second heating section 512 of the embodiment includes a first end heating element 514 and a second end heating element 515. The first end heating element 514 and the second end heating element 515 are arranged at the ends of the substrate 50 in the longitudinal direction (Y direction). The first end heating element 514 and the second end heating element 515 have a rectangular outer shape with a long side along the Y direction and a short side along the X direction. The Y direction dimensions of the first end heating element 514 and the second end heating element 515 are smaller than the Y direction dimension of the central heating element 513. The X direction dimensions of the first end heating element 514 and the second end heating element 515 are equal to the X direction dimension of the central heating element 513.

[0042] The first end heating element 514 is disposed at the end on the +Y side in the longitudinal direction (Y direction) of the substrate 50. The second end heating element 515 is disposed at the end on the -Y side in the longitudinal direction (Y direction) of the substrate 50. The first end heating element 514 is disposed on the +Y side of the central heating element 513. The second end heating element 515 is disposed on the -Y side of the central heating element 513. The first end heating element 514 and the second end heating element 515 are located outside the central heating element 513 in the longitudinal direction of the substrate 50 (on the +Y side or -Y side).

[0043] The wiring set 52 is made of a metal material such as silver, and includes a center contact 521, a center wiring 522, an end contact 523, a first end wiring 524, a second end wiring 525, a common contact 526, and a common wiring 527. The center contact 521, the end contact 523, and the common contact 526 correspond to a power supply unit that supplies power to the heater 37.

[0044] The central contact point 521 is disposed on the −Y side of the heat generating member 51. The central contact point 521 supplies power 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 the end edge on the +X side of the central heat generating element 513 and the central contact point 521.

[0045] The end contact 523 is disposed on the −Y side of the central contact 521. The end contact 523 supplies power to the end heating elements 514 and 515 via end wiring 524 and 525. The first end wiring 524 is disposed on the +X side of the heat generating member 51, and on the +X side of the central wiring 522. The first end wiring 524 connects the end edge on the +X side of the first end heating element 514 and the end of the end contact 523 on the +X side. The second end wiring 525 is disposed on the +X side of the heat generating member 51 and on the -X side of the central wiring 522. The second end wiring 525 connects the end edge on the +X side of the second end heating element 515 and the end of the end contact 523 on the -X side.

[0046] The common contact point 526 is disposed on the +Y side of 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 the −X side edges of the central heating element 513, the first end heating element 514, and the second end heating element 515 to the common contact 526.

[0047] In this embodiment, the heat-generating member 51 generates heat when electricity is applied. The electrical resistance of the central heating element 513 is smaller than the electrical resistances of the first end heating element 514 and the second end heating element 515. In this embodiment, a narrow sheet whose width in the Y direction is smaller than a predetermined width passes through the center 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, in the case of a wide sheet whose width in the Y direction is larger than the predetermined width, the control unit 6 causes the entire heat-generating member 51 to generate heat. That is, in the case of a wide sheet, the control unit 6 causes the central heating element 513, the first end heating element 514, and the second end heating element 515 to generate heat. In this embodiment, the heat generation of the central heating element 513, the first end heating element 514, and the second end heating element 515 can be controlled independently of each other. In this embodiment, the heat generation of the first end heating element 514 and the second end heating element 515 is controlled in the same manner.

[0048] As shown in Fig. 3, the thermostat unit 40 and the first temperature detecting member 41 are disposed on the -Z side of the heater 37, sandwiching the heat equalizing member 46 therebetween. For example, the first temperature detecting member 41 is a thermistor. The thermostat unit 40 and the first temperature detecting member 41 are attached to and supported on the -Z side surface of the support member 38. The temperature sensing elements of the thermostat unit 40 and the first temperature detecting member 41 pass through holes that penetrate the support member 38 in the Z direction and come into contact with the heat equalizing member 46. The thermostat unit 40 and the first temperature detecting member 41 measure the temperature of the heater 37 via the heat equalizing member 46.

[0049] Fig. 6 is an explanatory diagram of the arrangement 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, the support member 38 is not shown. The following explanation of the arrangement of the thermostat unit 40 and the first temperature detection unit 41 explains the arrangement of the respective temperature-sensing elements.

[0050] 6, the first temperature detection member 41 includes a central heater thermometer 411 and an end heater thermometer 412. The central heater thermometer 411 and the end heater thermometer 412 are arranged at an interval from each other in the Y direction. The central heater thermometer 411 and the end heater thermometer 412 are arranged within the Y-direction range of the heat-generating member 51. The central heater thermometer 411 and the end heater thermometer 412 are arranged at the center of the heat-generating member 51 in the X direction. When viewed from the Z direction, the central heater thermometer 411 and the end heater thermometer 412 overlap with at least a portion of the heat-generating member 51.

[0051] The central heater thermometer 411 measures the temperature of the central heating element 513. The central heater thermometer 411 is disposed within the range of the central heating element 513. When viewed from the Z direction, the central heater thermometer 411 overlaps with the central heating element 513.

[0052] The end heater thermometer 412 measures the temperature of the second end heating element 515. Because the heat generation of the first end heating element 514 and the second end heating element 515 is controlled in the same way by the control unit 6, the temperature of the first end heating element 514 and the temperature of the second end heating element 515 are equal to each other. The end heater thermometer 412 is disposed within the range of the second end heating element 515. When viewed from the Z direction, the end heater thermometer 412 overlaps with the second end heating element 515. Note that an end heater thermometer that measures the temperature of the first end heating element 514 may be provided separately from the end heater thermometer 412.

[0053] The thermostat unit 40 cuts off the power supply to the heat-generating member 51 when the temperature of the heater 37 detected via the heat-equalizing member 46 exceeds a predetermined temperature. The thermostat unit 40 includes a central thermostat 401 and an end thermostat 402. The thermostat unit 40 is also arranged in the same manner as the first temperature detection member 41 described above.

[0054] The central thermostat 401 cuts off the power supply to the heat-generating member 51 when the temperature of the central heating element 513 exceeds a predetermined temperature. The central thermostat 401 is disposed within the range of the central heating element 513. When viewed from the Z direction, the central thermostat 401 overlaps with the central heating element 513.

[0055] The end thermostat 402 cuts off the power supply to the heat-generating member 51 when the temperature of the first end heating element 514 exceeds a predetermined temperature. Because the heat generation of the first end heating element 514 and the second end heating element 515 is controlled in the same way, the temperature of the first end heating element 514 and the temperature of the second end heating element 515 are equal to each other. The end thermostat 402 is disposed within the range of the first end heating element 514. When viewed from the Z direction, the end thermostat 402 overlaps with the first end heating element 514.

[0056] In the heater 37 of this embodiment, the central heater thermometer 411 and the central thermostat 401 are arranged within the range of the central heating element 513, thereby controlling the temperature of the central heating element 513. In the heater 37 of this embodiment, the end thermostat 402 and the end heater thermometer 412 are arranged within the ranges of the first end heating element 514 and the second end heating element 515, thereby controlling the temperatures of the first end heating element 514 and the second end heating element 515.

[0057] 3, the second temperature detecting member 42 is disposed on the +X side inside the cylindrical body 36. The second temperature detecting member 42 measures the temperature of the cylindrical body 36 by contacting the inner circumferential surface of the cylindrical body 36. The second temperature detecting member 42 corresponds to a belt thermometer that measures the temperature of the fixing belt serving as the cylindrical body 36.

[0058] Fig. 7 is an electrical circuit diagram of the heating device 30 of this embodiment. In Fig. 7, the plan view of Fig. 6 is arranged at the bottom of the page, and the plan view of Fig. 4 is arranged at the top of the page. Fig. 7 also shows the second temperature detecting member 42 together with a cross section of the cylindrical body 36 above the bottom plan view. The second temperature detecting member 42 includes a center belt thermometer 421 and an end belt thermometer 422.

[0059] The central belt thermometer 421 contacts the central portion in the Y direction of the cylindrical body 36. The central belt thermometer 421 contacts the cylindrical body 36 within the Y direction range of the central heating element 513. The central belt thermometer 421 measures the temperature of the central portion in the Y direction of the cylindrical body 36.

[0060] The end belt thermometer 422 contacts the end of the cylindrical body 36 on the -Y side. The end belt thermometer 422 contacts the cylindrical body 36 within the Y-direction range of the second end heating element 515. The end belt thermometer 422 measures the temperature of the end of the cylindrical body 36 on the -Y side. As described above, the heat generation of the first end heating element 514 and the second end heating element 515 is controlled in the same way. In this embodiment, the temperature of the end of the cylindrical body 36 on the -Y side and the temperature of the end of the cylindrical body 36 on the +Y side are equal to each other.

[0061] The power supply 70 is connected to the center contact 521 via the center triac 71. The power supply 70 is connected to the end contact 523 via the end triac 72. The control unit 6 controls the ON / OFF of the center triac 71 and the end triac 72 independently of each other.

[0062] When the control unit 6 turns on the center triac 71, electricity is passed from the power supply 70 to the center heating element 513. As a result, the center heating element 513 generates heat. When the control unit 6 turns on the end triac 72, electricity is passed from the power supply 70 to the first end heating element 514 and the second end heating element 515. As a result, the first end heating element 514 and the second end heating element 515 generate heat. As described above, the heat generation of the center heating element 513, the first end heating element 514, and the second end heating element 515 is controlled independently of each other. The center heating element 513, the first end heating element 514, and the second end heating element 515 are connected in parallel to the power supply 70.

[0063] The power supply 70 is connected to the common contact 526 via the central thermostat 401 and the end thermostat 402. The central thermostat 401 and the end thermostat 402 are connected in series. When the temperature of the central heating element 513 rises abnormally, the temperature detected by the central thermostat 401 exceeds a predetermined temperature. At this time, the central thermostat 401 cuts off the power supply 70 to the entire heating member 51.

[0064] If the temperature of the first end heating element 514 rises abnormally, the temperature detected by the end thermostat 402 exceeds a predetermined temperature. At this time, the end thermostat 402 cuts off the power supply 70 to the entire heat-generating member 51. As described above, the heat generation of the first end heating element 514 and the second end heating element 515 is controlled in the same way. Therefore, when the temperature of the second end heating element 515 rises abnormally, the temperature of the first end heating element 514 also rises similarly. Therefore, if the temperature of the second end heating element 515 rises abnormally, the end thermostat 402 similarly cuts off the power supply 70 to the entire heat-generating member 51.

[0065] The control unit 6 acquires the temperature of the central heating element 513 using the central heater thermometer 411. The control unit 6 acquires the temperature of the second end heating element 515 using the end heater thermometer 412. The temperature of the second end heating element 515 is equal to the temperature of the first end heating element 514. The control unit 6 measures the temperature of the heat-generating member 51 using the heater thermometers 411, 412 when the heating device 30 is started (during warming up) and when it returns from a temporary pause state (sleep state).

[0066] When the heating device 30 is started or returns from a paused state, if the temperature of at least one of the central heating element 513 or the second end heating element 515 is lower than a predetermined temperature, the control unit 6 causes the heating element 51 to heat for a short period of time. Thereafter, the control unit 6 starts the rotation of the pressure roller 31. The heat generated by the heating element 51 reduces the viscosity of the lubricant applied to the inner circumferential surface of the cylindrical body 36. This ensures slidability between the heater 37 and the cylindrical body 36 when the pressure roller 31 starts to rotate.

[0067] The control unit 6 acquires the temperature of the center in the Y direction of the cylindrical body 36 using the center belt thermometer 421. The control unit 6 acquires the temperature of the end on the -Y side of the cylindrical body 36 using the end belt thermometer 422. The temperature of the end on the -Y side of the cylindrical body 36 is equivalent to the temperature of the end on the +Y side of the cylindrical body 36. The control unit 6 acquires the temperatures of the center and end in the Y direction of the cylindrical body 36 when the heating device 30 is operating.

[0068] The control unit 6 performs phase control or wave number control on the power supplied to the heat-generating member 51 using the center triac 71 and the end triac 72. The control unit 6 controls the power supplied to the center heating element 513 based on the temperature of the center in the Y direction of the cylindrical body 36. The control unit 6 controls the power supplied to the first end heating element 514 and the second end heating element 515 based on the temperature of the end parts in the Y direction of the cylindrical body 36.

[0069] FIG. 8 is an explanatory diagram of the arrangement of the heater 37 and the heat equalizing member 46 according to the embodiment. As shown in FIG. 8 , the temperature equalizing member 46 has a recess 461 on its outer surface facing the heater 37. The recess 461 is formed in the Y direction to include the area in which the substrate 50 of the heater 37 is disposed. The recess 461 penetrates the temperature equalizing member 46 in the Y direction. The recess 461 is not in contact with the heater 37. On the other hand, both sides of the temperature equalizing member 46 in the X direction relative to the recess 461 are in contact with the heater 37. In this embodiment, both sides of the temperature equalizing member 46 in the X direction relative to the recess 461 are in contact with the -Z side surface of the second protective layer 57 (the second surface 372 of the heater 37).

[0070] When printing begins in the image forming apparatus 1, the heat-generating member 51 raises the temperature of the cylindrical body 36 to the fixing temperature. When the heat-generating member 51 generates heat from room temperature, for example, the temperature distribution of the heat-generating member 51 is highest at the center of the heat-generating member 51 in the X direction. The temperature distribution of the heat-generating member 51 decreases as the distance from the center of the heat-generating member 51 in the X direction increases. In this way, the temperature distribution of the heat-generating member 51 has a mountain-like shape with 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 recess 461 of the heat-equalizing member 46 is formed to cover the center of the heat-generating member 51 in the X direction.

[0071] Next, the support member 38 of the embodiment will be described in detail. Fig. 9 is a view of the heating device 30 of the embodiment as seen from the rear side of the image forming apparatus 1. Fig. 10 is a perspective view showing the mounting state of the heater 37, support member 38, and power supply connector 101 of the embodiment. Fig. 11 is a perspective view of the support member 38 of the embodiment. In Figs. 9 and 10, the heater 37 is indicated by dot hatching.

[0072] As shown in FIG. 10, the Y direction (the axial direction of the cylindrical body 36) is the longitudinal direction of the support member 38. The support member 38 supports the attached heater 37 by bending it relative to the heater 37. In this embodiment, the heater 37 is attached to the support member 38 by bending the support member 38 relative to the heater 37. The support member 38 supports the heater 37 attached in this manner. As shown in FIG. 9, an opening 59 is formed in the support member 38 to expose the power supply portion. As shown in FIG. 11, the support member 38 is formed from a single member that is continuous in the longitudinal direction of the support member 38.

[0073] The amount of deformation in the direction intersecting the longitudinal and lateral directions of the support member 38 when the heater 37 is attached to the support member 38 is greater than the amount of deformation in the direction intersecting the longitudinal and lateral directions of the heater 37. The state in which the heater 37 is attached to the support member 38 corresponds to the mounted state of the heater 37 shown in FIG. 10. The amount of deformation in the direction intersecting the longitudinal and lateral directions of the support member 38 corresponds to the amount of deformation in the Z direction of the support member 38. The amount of deformation in the direction intersecting the longitudinal and lateral directions of the heater 37 corresponds to the amount of deformation in the thickness direction (Z direction) of the heater 37. In this embodiment, the amount of deformation in the Z direction of the support member 38 when the heater 37 is mounted is greater than the amount of deformation in the Z direction of the heater 37. For example, the amount of deformation in the Z direction of the support member 38 is set to a size that allows the heater 37 to be mounted by deflecting only the support member 38 relative to the heater 37. For example, the deformation amount of the support member 38 in the Z direction may be set larger than the deformation amount of the heater 37 in the thickness direction of the substrate 50 (Z direction).

[0074] As shown in FIG. 11, the support member 38 includes a support body 60, a first contact portion 61, a second contact portion 62, and a third contact portion 63. The support body 60 has an opening 59 formed on the longitudinal end side of the support member 38. The opening 59 is open on the -Z side of the support member 38. The support body 60 abuts against the second surface 372 side of the heater 37, which is opposite to the first surface 371 side. In this embodiment, the support body 60 abuts against the second surface 372 of the heater 37 (the surface of the second protective film 57) via the heat equalizing member 46.

[0075] The support body 60 includes a first support portion 601 , a second support portion 602 , a third support portion 603 , and a fourth support portion 604 . The first support portion 601 has a longitudinal direction in the Y direction (the axial direction of the cylindrical body 36). 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 via the heat equalizing member 46.

[0076] The second support portion 602 is disposed at the longitudinal end of the first support portion 601. The second support portion 602 abuts against the longitudinal end of the heat equalizing member 46. The second support portion 602 protrudes from the longitudinal end of the first support portion 601 to the +Z side.

[0077] As shown in FIG. 13 , the second support portion 602 has 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 longitudinal direction of the first support portion 601. In the cross-sectional view of FIG. 13 , the first inclined surface 621 is inclined to be positioned on the -Z side as it moves inward in the Y direction from the inner end of the +Z side surface of the second support portion 602 in the Y direction. In the cross-sectional view of FIG. 13 , the second inclined surface 622 is inclined to be positioned on the -Z side as it moves outward in the Y direction from the outer end of the +Z side surface of the second support portion 602 in the Y direction.

[0078] 11, the third support portion 603 is disposed at the end of the first support portion 601 in the X direction (short side direction). The third support portion 603 is disposed on both sides of the first support portion 601 in the short side direction. The third support portion 603 abuts against the end of the heat equalizing member 46 in the Z direction (short side direction). The third support portion 603 supports the end of the heater 37 in the short side direction together with the heat equalizing member 46.

[0079] The fourth support portion 604 is provided on the third support portion 603. A plurality of fourth support portions 604 are arranged at intervals in the longitudinal direction of the first support portion 601. A fourth support portion 604 is provided on each of the third support portions 603 on both sides in the X direction. The fourth support portion 604 abuts against the inner circumferential surface of the cylindrical body 36. A rounded chamfer is formed on the outer end portion of the fourth support portion 604 in the X direction. The fourth support portion 604 supports the inner circumferential surface of the cylindrical body 36 on the outer side of the heater 37 in the X direction.

[0080] The first contact portion 61 is disposed with a gap 69 interposed therebetween, which allows the heater 37 to move axially relative to the support portion main body 60. The first contact portion 61 contacts a first surface 371 of the heater 37. The gap 69 is formed between the second support portion 602 and the first contact portion 61.

[0081] The second contact portion 62 is disposed on the support portion main body 60 via the opening 59. The second contact portion 62 comes into contact with an end portion of the heater 37 in the longitudinal direction.

[0082] 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 comes into contact with an end portion of the heater 37 in the lateral direction.

[0083] In this embodiment, the first contact portion 61, the second contact portion 62, and the third contact portion 63 are arranged on both longitudinal sides of the support member 38. One longitudinal side (+Y side) of the support member 38 corresponds to the front side of the image forming apparatus 1. The other longitudinal side (-Y side) of the support member 38 corresponds to the 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 arranged on the front side of the image forming apparatus 1 will be referred to as the first front-side contact portion 81, the second front-side contact portion 82, and the third front-side contact portion 83, respectively. Hereinafter, the first contact portion 61, the second contact portion 62, and the third contact portion 63 arranged on the rear side of the image forming apparatus 1 will be referred to as the first rear-side contact portion 84, the second rear-side contact portion 85, and the third rear-side contact portion 86, respectively.

[0084] As shown in FIG. 12, the first front 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 sidewall portion 811 faces the first surface 371 of the heater 37 at the +Y side end of the heater 37.

[0085] The second front side wall portion 812 is disposed at the end (+Y side end) of the first front side wall portion 811 opposite to the first support portion 601. As shown in Fig. 13, the second front side wall portion 812 protrudes to the -Z side from the +Y side end of the first front side wall portion 811. As shown in Fig. 12, the second front side wall portion 812 extends across the first front side wall portion 811 in the X direction.

[0086] The third front sidewall 813 is disposed between the +Y side end of the support body 60 and the second front sidewall 812. As shown in FIG. 13, the third front sidewall 813 protrudes to the -Z side from the rear surface (the -Z side surface) of the first front sidewall 811. As shown in FIG. 12, the third front sidewall 813 extends in the X direction across the first front sidewall 811. The third front sidewall 813 abuts against the first surface 371 of the heater 37 at the +Y side end of the heater 37.

[0087] The fourth front sidewall 814 is disposed between the second front sidewall 812 and the third front sidewall 813. As shown in FIG. 13, the fourth front sidewall 814 protrudes from the rear surface of the first front sidewall 811 toward the -Z side. As shown in FIG. 12, the fourth front sidewall 814 extends in the X direction across the first front sidewall 811. The fourth front sidewall 814 extends approximately parallel to the third front sidewall 813. As shown in FIG. 13, the thickness of the fourth front sidewall 814 in the Z direction is greater than the thickness of the third front sidewall 813 in the Z direction. The thickness of the fourth front sidewall 814 in the Z direction is greater than the thickness of the heater 37 in the Z direction.

[0088] The second front-side contact portion 82 contacts the +Y-side longitudinal end of the heater 37. The second front-side contact portion 82 is disposed on the inner side in the Y direction of the fourth front sidewall portion 814. As shown in FIG. 12, the second front-side contact portion 82 protrudes from the X-direction center of the fourth front sidewall portion 814 to the -Y side. In the plan view of FIG. 12, the outer shape of the combined second front-side contact portion 82 and the fourth front sidewall portion 814 is T-shaped. The second front-side contact portion 82 contacts the X-direction center of the +Y-side longitudinal edge of the heater 37. As shown in FIG. 13, the Z-direction thickness of the second front-side contact portion 82 is the same as the Z-direction thickness of the fourth front sidewall portion 814. The Z-direction thickness of the second front-side contact portion 82 is greater than the Z-direction thickness of the heater 37.

[0089] The third front-side contact portion 83 contacts the short-side end portion of the heater 37 at the +Y end of the heater 37. As shown in FIG. 12, the third front-side contact portion 83 is disposed at the X-direction end portion of the third front sidewall portion 813. As shown in FIG. 13, the third front-side contact portion 83 protrudes from the X-direction end portion of the third front sidewall portion 813 to the -Z side. The Z-direction thickness of the third front-side contact portion 83 is approximately the same as the Z-direction thickness of the heater 37.

[0090] As shown in FIG. 14, the first rear contact portion 84 includes a first rear sidewall portion 841 , a second rear sidewall portion 842 , a third rear sidewall portion 843 , and a fourth rear sidewall portion 844 . The first rear sidewall portion 841 faces the first surface 371 of the heater 37 on the −Y side end side of the heater 37.

[0091] As shown in FIG. 15 , the first rear sidewall portion 841 has a guide surface 840 that guides the heater 37. The guide surface 840 is formed on a portion of the first rear sidewall portion 841 that faces the gap 69. The guide surface 840 is inclined with respect to the longitudinal direction of the first support portion 601. In the cross-sectional view of FIG. 15 , the guide surface 840 is inclined so as to be positioned on the -Z side as it moves from the -Z side end of the +Y side surface of the first rear sidewall portion 841 toward the -Y side. In the cross-sectional view of FIG. 15 , the guide surface 840 of the first rear sidewall portion 841 is substantially parallel to the second inclined surface 622 of the second support portion 602.

[0092] The second rear sidewall 842 is disposed at the end (-Y side end) of the first rear sidewall 841 opposite to the first support portion 601. The second rear sidewall 842 protrudes from the -Y side end of the first rear sidewall 841 toward the -Z side. A protrusion 845 that protrudes further toward the -Z side than the second rear sidewall 842 is provided at the X direction end of the second rear sidewall 842. As shown in FIG. 14 , a pair of protrusions 845 are disposed with a gap in the X direction. The gap between the pair of protrusions 845 is large enough to allow the heater 37 to move in the axial direction. The gap in the X direction between the pair of protrusions 845 is larger than the length of the heater 37 in the X direction.

[0093] The third rear sidewall 843 is disposed between the -Y side end of the support body 60 and the second rear sidewall 842. As shown in FIG. 15, the third rear sidewall 843 protrudes to the -Z side from the rear surface (the -Z side surface) of the first rear sidewall 841. As shown in FIG. 14, the third rear sidewall 843 extends in the X direction across the first rear sidewall 841. The third rear sidewall 843 abuts against the first surface 371 of the heater 37 at the -Y side end of the heater 37.

[0094] The fourth rear sidewall portion 844 is disposed between the second rear sidewall portion 842 and the third rear sidewall portion 843. The fourth rear sidewall portion 844 protrudes from the rear surface of the first rear sidewall portion 841 to the -Z side. The fourth rear sidewall portion 844 extends in the X direction across the first rear sidewall portion 841. The fourth rear sidewall portion 844 extends approximately parallel to the third rear sidewall portion 843. The thickness in the Z direction of the fourth rear sidewall portion 844 is the same as the thickness in the Z direction of the third rear sidewall portion 843. The fourth rear sidewall portion 844 abuts against the first surface 371 of the heater 37 at the -Y side end of the heater 37.

[0095] The second rear-side contact portion 85 contacts the -Y-side longitudinal end of the heater 37. The second rear-side contact portion 85 is disposed at a position overlapping with the second rear sidewall portion 842 when viewed from the Z direction. The second rear-side contact portion 85 protrudes from the X-direction central portion of the second rear sidewall portion 842 to the +Y side. The second rear-side contact portion 85 contacts the X-direction central portion of the -Y-side longitudinal edge of the heater 37. As shown in FIG. 15 , the Z-direction thickness of the second rear-side contact portion 85 is thicker than the Z-direction thickness of the second rear sidewall portion 842. The Z-direction thickness of the second rear-side contact portion 85 is thicker than the Z-direction thickness of the heater 37. The Z-direction thickness of the second rear-side contact portion 85 may be thinner than the Z-direction thickness of the second front-side contact portion 82.

[0096] The third rear-side contact portion 86 contacts the short-side end portion of the heater 37 on the -Y side end of the heater 37. As shown in Fig. 14, the third rear-side contact portion 86 is disposed at each of the X-direction ends of the third rear sidewall portion 843 and the fourth rear sidewall portion 844. As shown in Fig. 15, the third rear-side contact portion 86 protrudes to the -Z side from each of the X-direction ends of the third rear sidewall portion 843 and the fourth rear sidewall portion 844. The Z-direction thickness of the third rear-side contact portion 86 is substantially the same as the Z-direction thickness of the heater 37.

[0097] Next, an example of a method for mounting the heater 37 will be described. Fig. 16 is an explanatory diagram of an example of a method for mounting a heater according to an embodiment. Fig. 17 is an explanatory diagram of an example of a method for mounting a heater according to an embodiment, following Fig. 16. Fig. 18 is an explanatory diagram of an example of a method for mounting a heater according to an embodiment, following Fig. 17.

[0098] As shown in Figure 16, first, the -Y side end of the heater 37 is inserted obliquely into the gap 69 on the rear side. For example, with the support member 38 aligned in the Y direction, the heater 37 is moved in the direction of arrow HA. In this embodiment, the heater 37 is tilted and the bending of the support member 38 is utilized to assemble the heating device 30. At this time, the bending of the support member 38 is utilized to insert the -Y side end of the heater 37 so that it does not get caught on the second support portion 602 on the rear side of the support member 38.

[0099] For example, when inserting the -Y side end of heater 37 into rear-side gap 69, rear-side guide surfaces 620, 840 may be used. As shown in Fig. 20, second surface 372 at the -Y side end of heater 37 may be aligned with second inclined surface 622 (guide surface 620) of second rear support portion 602. Alternatively, first surface 371 at the -Y side end of heater 37 may be aligned with guide surface 840 of first rear sidewall portion 841. This allows the -Y side end of heater 37 to be smoothly passed through rear-side gap 69 while minimizing deflection of support member 38.

[0100] 19 , the -Y side end of the heater 37 is passed through the rear-side gap 69 and then passed between the pair of protrusions 845. This causes the -Y side end of the heater 37 to protrude further to the -Y side than the second rear sidewall portion 842. At this time, it is preferable to use the flexure of the support member 38 to insert the -Y side end of the heater 37 so that it does not get caught on the second rear-side abutment portion 85 of the support member 38.

[0101] For example, the Z-direction thickness of the second rear-side contact portion 85 may be set so that the second rear-side contact portion 85 does not overlap the movement trajectory of the heater 37 when the -Y-side end of the heater 37 passes through the rear-side gap 69. As shown in Fig. 15, for example, the Z-direction thickness of the second rear-side contact portion 85 may be set thinner than the Z-direction thickness of the third rear-side contact portion 86 that is located on the +Y side of the second rear-side contact portion 85. This allows the -Y-side end of the heater 37 to protrude further to the -Y side than the second rear sidewall portion 842 while reducing the deflection of the support member 38 as much as possible.

[0102] For example, when the -Y side end of the heater 37 is caused to protrude further toward the -Y side than the second rear sidewall portion 842, it is preferable that it protrude to the position shown in Fig. 16. As shown in Fig. 16, it is preferable that the +Y side end of the heater 37 protrude further toward the -Y side than the second rear sidewall portion 842 until it is positioned further toward the -Y side than the -Y side end of the first front-side abutment portion 81. This makes it possible, in the next step, to insert the +Y side end of the heater 37 into the front-side gap 69 while minimizing deflection of the support member 38.

[0103] 21, when the +Y side end of the heater 37 is located on the -Y side of the -Y side end of the first front-side contact portion 81, the heater 37 is inclined with respect to the longitudinal direction of the support member 38. In the state shown in FIG. 21, the +Y side end of the heater 37 is located on the +Z side of the first front-side contact portion 81.

[0104] Next, the +Y side end of the heater 37 is inserted into the front-side gap 69. For example, first, with the -Y side end of the heater 37 protruding further to the -Y side than the second rear sidewall portion 842, the +Y side end of the heater 37 is moved toward the -Z side. For example, the heater 37 is moved in the direction of arrow HA in FIG. 16 , and then moved in the direction of arrow HB. A heat equalizing member 46 is mounted in advance on the support member 38. The heat equalizing member 46 is disposed in advance between the front-side second support portion 602 and the rear-side second support portion 602.

[0105] For example, when moving the +Y side end of the heater 37 toward the -Z side, it is advisable to move it until the second surface 372 of the heater 37 abuts the +Z side end of the heat equalizing member 46. For example, it is advisable to move the +Y side end of the heater 37 toward the -Z side until the heater 37 overlaps with the front-side gap 69 when viewed from the Y direction. This allows the +Y side end of the heater 37 to be inserted into the front-side gap 69 while minimizing the deflection of the support member 38.

[0106] Next, the heater 37 is moved to the +Y side, thereby inserting the +Y side end of the heater 37 into the gap 69 on the front side. For example, the heater 37 is moved in the direction of arrow HB in FIG. 16 , and then moved in the direction of arrow HC. At this time, the +Y side end of the heater 37 is inserted by utilizing the flexure of the support member 38 so that it does not get caught on the second support portion 602 on the front side.

[0107] For example, when inserting the +Y side end of the heater 37 into the front-side gap 69, it is preferable to use the front-side guide surface 620. For example, it is preferable to align the second surface 372 of the heater 37 on the +Y side end side of the heater 37 with the first inclined surface 621 (guide surface 620) of the front-side second support portion 602. This allows the +Y side end of the heater 37 to be smoothly passed through the front-side gap 69 while minimizing deflection of the support member 38.

[0108] After the +Y side end of the heater 37 is inserted into the front-side gap 69, the heater 37 is further moved toward the +Y side. Next, the +Y side end of the heater 37 is brought into contact with the second front-side contact portion 82. This allows the heater 37 to be mounted on the support member 38, as shown in FIG. 17. As shown in FIG. 24, in the mounted state of the heater 37, the +Y side end of the heater 37 is in contact with the second front-side contact portion 82, so that movement of the heater 37 toward the +Y side is restricted.

[0109] When the heater 37 is mounted, the first surface 371 at the +Y side end of the heater 37 abuts against the third front sidewall portion 813. Therefore, the third front sidewall portion 813 restricts the movement of the heater 37 toward the +Z side. When the heater 37 is mounted, the second surface 372 at the +Y side end of the heater 37 abuts against the front-side second support portion 602. Therefore, the front-side second support portion 602 restricts the heater 37 from moving toward the -Z side. When the heater 37 is mounted, the end of the heater 37 in the short direction on the +Y side abuts against the third front abutment portion 83. Therefore, the third front abutment portion 83 restricts the movement of the heater 37 in the X direction.

[0110] For example, the third front contact portions 83 may be disposed at both X-direction ends of the third front sidewall portion 813. As a result, when the heater 37 is mounted, both short-side ends on the +Y side of the heater 37 abut against the third front contact portions 83 on both X-direction sides. Therefore, the third front contact portions 83 limit the movement of the heater 37 to both X-direction sides (+X side and -X side).

[0111] 22, when the heater 37 is mounted, the -Y side end of the heater 37 abuts against the second rear abutment portion 85. This limits the movement of the heater 37 toward the -Y side. 23 , when the heater 37 is mounted, the first surface 371 at the −Y side end of the heater 37 abuts against each of the third rear sidewall portion 843 and the fourth rear sidewall portion 844. Therefore, the third rear sidewall portion 843 and the fourth rear sidewall portion 844 restrict movement of the heater 37 toward the +Z side. When the heater 37 is mounted, the second surface 372 at the -Y side end of the heater 37 abuts against the rear-side second support portion 602. Therefore, movement of the heater 37 toward the -Z side is restricted by the rear-side second support portion 602. When the heater 37 is mounted, the end of the heater 37 in the short direction on the -Y side abuts against the third rear abutment portion 86. Therefore, the third rear abutment portion 86 restricts the movement of the heater 37 in the X direction.

[0112] For example, the third rear contact portions 86 may be disposed at both X-direction ends of the third rear sidewall portion 843 and the fourth rear sidewall portion 844. As a result, when the heater 37 is mounted, both short-side ends on the -Y side of the heater 37 abut against the third rear contact portions 86 on both X-direction sides. Therefore, the third rear contact portions 86 limit the movement of the heater 37 to both X-direction sides (the +X side and the -X side).

[0113] When heater 37 is mounted, power supply parts 521, 523, and 526 are located in opening 59. Therefore, power supply parts 521, 523, and 526 are exposed on the −Z side. 24, when the heater 37 is mounted, the common contact 526 is exposed to the -Z side at the +Y end of the heater 37. When the heater 37 is mounted, the common contact 526 overlaps with the third front side wall portion 813 when viewed from the Z direction.

[0114] 23 , when the heater 37 is mounted, the central contact 521 and the end contact 523 are exposed to the -Z side at the -Y end of the heater 37. When the heater 37 is mounted, the central contact 521 overlaps with the third rear sidewall 843 when viewed from the Z direction. When the heater 37 is mounted, the end contact 523 overlaps with the fourth rear sidewall 844 when viewed from the Z direction.

[0115] 18, next, the power supply connector 101 is connected to the power supply portions 521, 523, and 526 of the heater 37. Hereinafter, the unit (assembly) in which the heater 37 is mounted on the support member 38 is referred to as the mounting unit 100. The power supply connector 101 has an insertion hole 110 that opens in the X direction and allows the outer portion of the mounting unit 100 in the Y direction to be inserted therethrough.

[0116] The power feeding connector 101 includes a first connector wall 111 and a second connector wall 112 that face each other across the insertion opening 110. The first connector wall 111 abuts against the +Z side surface of the first abutment portion 61 of the mounting unit 100. The second connector wall 112 has terminal portions that connect to the power feeding portions 521, 523, and 526. The terminal portions are biased toward the +Z side toward the power feeding portions 521, 523, and 526 by a biasing member such as a leaf spring.

[0117] The power supply connectors 101 are attached to both longitudinal sides of the mounting unit 100. Hereinafter, the power supply connector 101 attached to one longitudinal side of the mounting unit 100 (the front side of the image forming apparatus 1) will be referred to as the front-side power supply connector 121. Hereinafter, the power supply connector 101 attached to the other longitudinal side of the mounting unit 100 (the rear side of the image forming apparatus 1) will be referred to as the rear-side power supply connector 122.

[0118] 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 the direction of arrow CA in FIG. 18 . This allows the -Y side end of the mounting unit 100 to be inserted into the insertion opening 110 of the rear-side power supply connector 122. As shown in FIG. 9 , the first rear-side abutment portion 84 of the mounting unit 100 has a shape that curves toward the +Z side. This allows the -Y side end of the mounting unit 100 to be smoothly inserted into the insertion opening 110 of the rear-side power supply connector 122.

[0119] Two terminal portions are provided corresponding to the two power supply portions 521, 523. The terminal portion corresponding to one power supply portion 521 is guided along the third rear side wall portion 843 via the heater 37. The terminal portion corresponding to the other power supply portion 523 is guided along the fourth rear side wall portion 844 via the heater 37. This allows the -Y side end portion of the mounting unit 100 to be smoothly inserted into the insertion opening 110 of the rear-side power supply connector 122.

[0120] In this embodiment, a pair of protrusions 845 is provided on an end portion in the X direction of the second rear side wall portion 842. When the rear power supply connector 122 is attached, the pair of protrusions 845 may abut on a surface on the -Y side of the rear power supply connector 122. This can prevent the rear power supply connector 122 from shifting in position to the -Y side.

[0121] 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 the direction of arrow CB in FIG. 18 . This allows the +Y side end of the mounting unit 100 to be inserted into the insertion opening 110 of the front-side power supply connector 121. The first front-side abutment portion 81 of the mounting unit 100 has a shape that curves toward the +Z side, similar to the first rear-side abutment portion 84. This allows the +Y side end of the mounting unit 100 to be smoothly inserted into the insertion opening 110 of the front-side power supply connector 121.

[0122] The front-side power supply connector 121 has two terminals, similar to the rear-side power supply connector 122. One terminal, which corresponds to the power supply portion 526, is guided along the third front side wall 813 via the heater 37. The other terminal is guided directly along the fourth front side wall 814. This allows the +Y side end of the mounting unit 100 to be smoothly inserted into the insertion opening 110 of the front-side power supply connector 121.

[0123] In this embodiment, a second front side wall 812 is provided at the +Y side end of the first front side wall 811. When the front power supply connector 121 is attached, the second front side wall 812 may abut against the +Y side surface of the front power supply connector 121. This can prevent the front power supply connector 121 from shifting toward the +Y side.

[0124] Through the above steps, the power feed connector 101 can be connected to the power feed portions 521, 523, and 526 of the heater 37 in the mounting unit 100. For example, the power feed connector 101 may be of a locking type that is locked in the connected position by a lock pin or the like. For example, the power feed connector 101 may be configured to be unlocked by pressing a switch. For example, the pair of connector walls 111 and 112 may be configured to open when the power feed connector 101 is unlocked.

[0125] As described above, the heating device 30 of the embodiment includes the cylindrical body 36, the heater 37, the power supply units 521, 523, and 526, and the support member 38. The cylindrical body 36 is formed in a cylindrical shape. The heater 37 is disposed inside the cylindrical body 36. The axial direction of the cylindrical body 36 is the longitudinal direction of the heater 37. The first surface 371 of the heater 37 contacts the inner circumferential surface of the cylindrical body 36. The heater 37 generates heat when power is applied. The power supply units 521, 523, and 526 supply power to the heater 37. The support member 38 has openings 59 that expose the power supply units 521, 523, and 526. The axial direction of the support member 38 is the longitudinal direction. The support member 38 supports the attached heater 37 by being bent relative to the heater 37. The above configuration provides 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 in this manner. Therefore, the support member 38 can be prevented from becoming too complicated. Incidentally, when the cylindrical body 36 slides on the first surface 371 of the heater 37, the arrangement of the heater 37 relative to the cylindrical body 36 may be changed to prevent wear or damage to the first surface 371 of the heater 37. Changing the arrangement of the heater 37 may also change the arrangement of the power supply units 521, 523, and 526. Depending on the arrangement of the heater 37 and the power supply units 521, 523, and 526, the support member 38 may become complicated. For example, there is a structure in which the support member 38 is divided into multiple members and the divided members are combined to support the heater 37. However, dividing the support member 38 into multiple members increases the number of parts and makes the support member 38 more complicated. In contrast, according to the embodiment, it is possible to prevent an increase in the number of parts because the support member 38 is formed from a single member that is continuous in the longitudinal direction of the support member 38. Therefore, it is possible to prevent the support member 38 from becoming complicated due to an increase in the number of parts.

[0126] When the heater 37 is attached to the support member 38, the amount of deformation in a direction intersecting the longitudinal and lateral directions of the support member 38 is greater than the amount of deformation in a direction intersecting the longitudinal and lateral directions of the heater 37. The above-described configuration provides the following effects. The heater 37 can be attached to the support member 38 by bending the support member 38 significantly relative to the heater 37. This makes it possible to avoid excessive deformation of the heater 37 when mounting the heater 37. This makes it possible to prevent cracks, breakage, and the like caused by deformation of the heater 37.

[0127] The support member 38 includes a support body 60 and a first contact portion 61. The support body 60 has an opening 59 formed on the longitudinal end side of the support member 38. The support body 60 contacts the second surface 372 side of the heater 37, which is opposite to the first surface 371 side. The first contact portion 61 is disposed relative to the support body 60 via a gap 69 that opens to allow the heater 37 to move axially. The first contact portion 61 contacts the first surface 371 side of the heater 37. The above configuration provides the following effects. The support portion main body 60 abuts against the second surface 372 side of the heater 37, thereby restricting movement of the heater 37 toward the second surface 372 side. The first abutment portion 61 abuts against the first surface 371 side of the heater 37, thereby restricting movement of the heater 37 toward the first surface 371 side. Therefore, it is possible to suppress positional deviation of the heater 37 toward the first surface 371 side and the second surface 372 side (Z direction).

[0128] The support member 38 further includes a second contact portion 62 that is disposed on the support body 60 via the opening 59. The second contact portion 62 contacts an end portion in the longitudinal direction of the heater 37. The above-described configuration provides the following effects. The second contact portion 62 contacts the longitudinal end of the heater 37, thereby restricting longitudinal movement of the heater 37. This makes it possible to prevent the heater 37 from being displaced in the longitudinal direction (Y direction).

[0129] The first contact portion 61 and the second contact portion 62 are disposed on both sides in the longitudinal direction of the support member 38. The above configuration provides the following effects. The first contact portions 61 contact the first surface 371 of the heater 37 on both longitudinal sides of the support member 38, thereby restricting movement of both longitudinal side portions of the heater 37 toward the first surface 371. The second contact portions 62 contact the longitudinal ends of the heater 37 on both longitudinal sides of the support member 38, thereby restricting movement of the heater 37 to both longitudinal sides. Therefore, it is possible to more effectively restrict misalignment of the heater 37 toward the first surface 371 and misalignment of the heater 37 in the longitudinal direction.

[0130] Power supply portions 521, 523, and 526 are arranged on second surface 372 of heater 37, opposite first surface 371 that contacts the inner circumferential surface of cylindrical body 36. The above configuration provides the following effects. Cylindrical body 36 slides on first surface 371 side of heater 37. Power supply parts 521, 523, 526 are arranged on the opposite side (second surface 372 side) from the side on which heater 37 slides. Therefore, wear and damage to power supply parts 521, 523, 526 can be suppressed.

[0131] The temperature equalizing member 46 has a recess 461 on the outer surface facing the heater 37. The above-described configuration provides the following effects. Because the recess 461 does not contact the heater 37, most of the heat generated by the heat-generating member 51 is transferred to the cylindrical body 36, rather than to the heat-equalizing member 46. Because the cylindrical body 36 is heated efficiently, the time until printing starts can be shortened. This can prevent the recovery time of the image forming apparatus 1 from becoming long.

[0132] The recesses 461 penetrate the temperature equalizing member 46 in the Y direction, thereby achieving the following effects. The heat generated by the heat-generating member 51 is transferred to the cylindrical body 36, regardless of the position in the Y direction, without being transferred to the heat-equalizing member 46. Because the cylindrical body 36 is heated more efficiently, the time until printing starts can be further reduced.

[0133] Next, a modification of the embodiment will be described. In the heating device of the embodiment, the heater can be attached to the support member by bending the support member relative to the heater. Alternatively, the heating device may be able to attach the heater to the support member by bending the heater relative to the support member. For example, the heating device may include a support member that can be bent relative to the heater to attach the heater. For example, the manner in which the heater and the support member are bent can be changed depending on the required specifications.

[0134] In the embodiment, when the heater is attached to the support member, the amount of deformation of the support member in a direction intersecting the longitudinal and lateral directions is greater than the amount of deformation of the heater in a direction intersecting the longitudinal and lateral directions. On the other hand, when the heater is attached to the support member, the amount of deformation of the support member in a direction intersecting the longitudinal and lateral directions may be less than or equal to the amount of deformation of the heater in a direction intersecting the longitudinal and lateral directions. For example, the amount of deformation of the support member and the heater when the heater is attached to the support member can be changed according to the required specifications.

[0135] The support member of the embodiment has an opening formed at an end of the support member in the longitudinal direction and includes a support body that abuts against the second surface of the heater, opposite the first surface. However, the support member does not necessarily have to include a support body. For example, the support member may include an abutment member that abuts against the second surface of the heater, separate from the support body. For example, the configuration of the support member can be changed depending on the required specifications.

[0136] The support member of the embodiment is disposed relative to the support body via a gap that allows the heater to move axially, and includes a first contact portion that contacts the first surface of the heater. However, the support member does not necessarily have to include the first contact portion. For example, the support member may include a contact member that contacts the first surface of the heater, separate from the first contact portion. For example, the configuration of the support member can be changed depending on the required specifications.

[0137] The support member of the embodiment includes a second contact portion that is disposed on the support body through the opening and contacts the longitudinal end of the heater. However, the support member does not necessarily have to include the second contact portion. For example, the support member may include a contact member that contacts the longitudinal end of the heater, separate from the second contact portion. For example, the configuration of the support member can be changed depending on the required specifications.

[0138] In the embodiment, the first and second contact portions are disposed on both longitudinal sides of the support member. However, the first and second contact portions do not have to be disposed on both longitudinal sides of the support member. For example, the first and second contact portions may be disposed on only one longitudinal side of the support member. For example, the arrangement of the first and second contact portions can be changed depending on the required specifications.

[0139] In the embodiment, the power supply unit is disposed on the second surface of the heater, opposite to the first surface that contacts the inner circumferential surface of the cylindrical body. Alternatively, the power supply unit may be disposed on the first surface of the heater that contacts the inner circumferential surface of the cylindrical body. For example, the arrangement of the power supply unit can be changed depending on the required specifications.

[0140] The heat spreader in the embodiment has a recess on the outer surface facing the heater. However, the heat spreader does not necessarily have to have a recess on the outer surface facing the heater. For example, the heat spreader may be formed in a flat plate shape with the axial direction of the cylindrical body as the longitudinal direction. For example, the shape of the heat spreader can be changed depending on the required specifications.

[0141] In the embodiment, the heater is disposed facing the nip inside the portion of the cylindrical body facing the pressure member. However, the heater does not have to be disposed facing the nip. For example, the heater may be disposed facing a heated area that is a portion of the cylindrical body in the circumferential direction. For example, the heater arrangement can be changed depending on the required specifications.

[0142] In the heater mounting method of the embodiment, the -Y side end of the heater is first inserted obliquely into the gap on the rear side. Alternatively, the heater may be mounted by first inserting the +Y side end of the heater obliquely into the gap on the front side. For example, the heater mounting method can be changed depending on the required specifications.

[0143] According to at least one of the embodiments described above, the heater can be supported by bending the support member relative to the heater, thereby preventing the support member from becoming complicated.

[0144] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, as well as within the scope of the invention described in the claims and their equivalents. [Explanation of symbols]

[0145] 30...heating device, 36...cylindrical body, 37...heater, 38...support member, 59...opening, 60...support body, 61...first contact portion, 62...second contact portion, 69...gap, 81...first front contact portion (first contact portion), 82...second front contact portion (contact portion), 84...first rear contact portion (first contact portion), 85...second rear contact portion (second contact portion), 371...first surface of heater, 372...second surface of heater, 521...center contact portion (power supply portion), 523...end contact portion (power supply portion), 526...common contact portion (power supply portion)

Claims

1. A cylindrical body formed in a cylindrical shape; a heater that is disposed inside the cylindrical body, has a longitudinal direction in the axial direction of the cylindrical body, has a first surface side in contact with an inner circumferential surface of the cylindrical body, and generates heat when energized; a power supply unit that supplies power to the heater; a support member having an opening for exposing the power supply portion, the support member having a longitudinal direction in the axial direction and supporting the heater by being deflected relative to the heater; a heat equalizing member that contacts a second surface side of the heater opposite to the first surface side and equalizes the temperature distribution of the heater, The temperature equalizing member has a recess on its outer surface facing the heater. heating device.

2. When the heater is attached to the support member, the amount of deformation of the support member in a direction intersecting the longitudinal and lateral directions is greater than the amount of deformation of the heater in a direction intersecting the longitudinal and lateral directions. The heating device according to claim 1 .

3. The support member is a support body, the opening of which is formed on an end portion of the support member in a longitudinal direction and which abuts against a second surface of the heater opposite to the first surface; a first contact portion that is disposed with respect to the support portion main body via a gap that allows the heater to move in the axial direction and that contacts the first surface side of the heater; The heating device according to claim 1 or 2.

4. The support member is a second contact portion that is disposed on the support body via the opening and contacts an end portion of the heater in the longitudinal direction; The heating device according to claim 3 .

5. The first contact portion and the second contact portion are disposed on both sides of the support member in the longitudinal direction. The heating device according to claim 4.

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