Image heating device and image forming apparatus

Abstract

An image heating apparatus includes a heater including a substrate whose longitudinal direction is arranged in a direction orthogonal to a direction in which a recording material is conveyed, a heat generating element provided in the substrate, and an electrode configured to supply electric power to the heat generating element, and a terminal electrically connected to the electrode, in which an image formed on the recording material is heated by heat from the heater. An electrically conductive intermediate member is provided between the terminal and the electrode, the electrically conductive intermediate member includes at least one layer, a first fixing region in which the electrode and the intermediate member are fixed, and a second fixing region in which the terminal and the intermediate member are fixed are offset from each other in the longitudinal direction.

Description

[0001] This invention is a divisional application of the invention patent application filed on December 11, 2019, with application number "201911262426.3" and title "Image Heating Apparatus and Image Forming Apparatus". Technical Field

[0002] This invention relates to image forming apparatuses based on electrophotographic or electrostatic recording methods, such as printers, copiers, and multifunctional devices having the functions of these devices. The invention also relates to an image heating apparatus, such as a fixing device or gloss application device installed in an image forming apparatus, which enhances the gloss of a toner image by reheating the toner image fixed on a recording material. Background Technology

[0003] Film-heated image heating devices are known to be used as image heating devices, such as fixing units installed in electrophotographic image forming apparatuses. The image heating device includes an annular strip of heat-resistant film (also called a fixing film), a heater in contact with the inner surface of the film, a heater holder for holding the heater, and a pressure roller for forming a clamping portion via the film and the heater. In the image heating device, as the recording material carrying the toner image is heated and conveyed in the clamping portion, the toner image is fixed onto the recording material. Because film-heated image heating devices have a low heat capacity, they can save electricity and reduce waiting time (which allows for rapid start-up).

[0004] The substrate of the terminal heater is provided with a heating element and electrodes electrically connected to the heating element. A connector for power supply is connected to the electrodes. Japanese Patent Application Publication No. 1992-351877 discloses a technology that improves the reliability of the power supply part (the connection between the electrodes and terminals) in high-temperature environments by ultrasonically bonding the electrodes on the substrate and the terminals of the connector.

[0005] Patent Document 1: Japanese Patent Application Publication No. 1992-351877 Summary of the Invention

[0006] During the use of the image heating device, thermal stress is repeatedly generated in the feed section as the temperature rises and falls. More specifically, when the heater substrate thermally expands according to the linear coefficient of thermal expansion of the substrate material, the electrodes also thermally expand to a similar degree. The terminals also thermally expand according to the linear coefficient of thermal expansion of their materials. In the device disclosed in Japanese Patent Application Publication No. 1992-351877, when the linear coefficients of thermal expansion of the substrate and the terminals are significantly different, large thermal stress is generated in the power supply section of the ultrasonic bonding due to the difference in the amount of thermal expansion of these components. When thermal stress is repeatedly generated, the terminals may disconnect from the substrate. In addition, when the substrate is made of ceramic, which is a so-called brittle material, and the terminals are metal, the linear coefficient of thermal expansion of the metal is greater than that of the ceramic. Therefore, during the thermal expansion of the substrate and the terminals, a force is applied in the direction that causes the ceramic to be stretched. As a result, fatigue may accumulate at the ceramic, which may shorten the service life of the substrate.

[0007] In view of the foregoing, the object of the present invention is to reduce the thermal stress repeatedly generated at the power supply part and improve the reliability of the device.

[0008] This application relates to an image heating device, which includes:

[0009] A heater, comprising: a substrate having a longitudinal direction orthogonal to the direction of conveying recording material; a heating element disposed in the substrate; and electrodes configured to supply power to the heating element; and

[0010] Terminals, which are electrically connected to the electrodes,

[0011] in,

[0012] The image heating device heats the image formed on the recording material using heat from the heater.

[0013] A conductive intermediate component is disposed between the terminal and the electrode, the conductive intermediate component comprising at least one layer.

[0014] The electrode and the intermediate component are fixed to each other, the terminal and the intermediate component are fixed to each other, and

[0015] The first fixing region where the electrode and the intermediate component are fixed and the second fixing region where the terminal and the intermediate component are fixed are offset from each other in the longitudinal direction.

[0016] The image heating device according to the invention can operate under reduced thermal stress and allows for improved component reliability, wherein the thermal stress is caused by the difference between the linear expansion coefficients of the terminals using intermediate components.

[0017] Other features of the invention will become apparent from the following description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0018] Figure 1A and Figure 1B This is a perspective cross-sectional view of the power supply structure according to the first embodiment of the present invention, taken along the longitudinal direction.

[0019] Figure 2 The overall structure of the image forming apparatus according to the first embodiment is shown.

[0020] Figure 3 This is a cross-sectional view of the fixing device according to the first embodiment, taken along the direction used for conveying recording material.

[0021] Figure 4 This is a central cross-sectional view of the heater according to the first embodiment.

[0022] Figures 5A to 5E The structure of the heater and heater holder according to the first embodiment is shown.

[0023] Figure 6A and Figure 6B This is an overall diagram of the power supply structure according to the first embodiment.

[0024] Figures 7A to 7C This is a view showing the deformation of the electrical supply structure according to the first embodiment caused by thermal expansion.

[0025] Figures 8A to 8C This is a view used to illustrate a method of manufacturing an electrical supply structure according to the first embodiment.

[0026] Figure 9 This is a cross-sectional view of the power supply structure according to the second embodiment of the present invention.

[0027] Figure 10 This is a cross-sectional view of the power supply structure according to the third embodiment of the present invention.

[0028] Figure 11 This is a cross-sectional view of another power supply configuration according to the third embodiment.

[0029] Figure 12A and Figure 12B This is an overall diagram of the power supply structure according to the fourth embodiment of the present invention. Detailed Implementation

[0030] Embodiments of the invention will be described with reference to the accompanying drawings. It should be noted that the dimensions, materials, shapes, and relative arrangements of the components described below in the various embodiments should be appropriately modified according to the construction of the device to which the invention is applied or the various conditions under which the invention is applied; therefore, the following embodiments are not intended to limit the scope of the invention.

[0031] First Embodiment

[0032] In the following description, an electrophotographic image forming apparatus (hereinafter referred to as an image forming apparatus) will be described, which includes a fixing device according to a first embodiment of the present invention. Figure 2 This is a schematic cross-sectional view of an exemplary image forming apparatus 1 according to the first embodiment.

[0033] 1. Overall structure of the image forming apparatus

[0034] Reference Figure 2 The overall structure of the image forming apparatus according to this embodiment is described. The image forming apparatus 1 according to this embodiment is a laser beam printer.

[0035] The image forming apparatus 1 includes a recording material feeding unit and an image forming unit. The recording material feeding unit includes a cartridge 2 and a paper feed roller 3. The paper feed roller 3 picks up the recording material P loaded in the cartridge 2 page by page from the topmost recording material P and conveys the recording material to a clamping section formed by a resisting roller 4 and a roller 5. The orientation of the recording material P is adjusted by the resisting roller 4 and roller 5, and then the recording material is conveyed to the image forming unit.

[0036] The image forming unit includes: a drum-shaped electrophotographic photosensitive component (hereinafter referred to as a photosensitive drum) 6, which serves as an image carrier; a charger 7, which charges the photosensitive drum 6; a developer 8, which develops the latent image on the photosensitive drum 6 with toner; and a cleaner 9, which removes residual toner from the photosensitive drum 6. The photosensitive drum 6 is driven to rotate in the direction indicated by the arrow in the figure. The charger 7 uniformly charges the circumferential surface of the photosensitive drum 6. A laser scanner 10 is provided above the image forming unit (on the upper part of the paper) as an exposure unit to form an electrostatic latent image on the photosensitive drum 6 by irradiating the charged photosensitive drum 6 with a laser beam based on image information. The electrostatic latent image is developed into a toner image by the developer 8. The developed toner image is transferred to the recording material P by a transfer unit 12 formed by a transfer roller 11 and the photosensitive drum 6.

[0037] The recording material P, on which the toner image is transferred, is conveyed to the fixing device (image heating device) 13, which is a fixing unit (image heating unit). The fixing device 13 heats the toner image on the recording material P and fixes it onto the recording material P. The recording material P, which has passed through the fixing device 13, is discharged by the discharge roller pair 14 to the recording material loading unit 15 in the upper part of the image forming apparatus 1.

[0038] 2. Fixing device

[0039] The fixing device 13 according to this embodiment will now be described.

[0040] Figure 3 This is a cross-sectional view of the fixing device 13. The fixing device 13 includes a tubular heating film 23 and a pressure roller 16. In this device, the pressure roller 16 is rotated by the power of an electric motor (not shown), and the heating film 23 is rotated by the conveying force of the pressure roller 16. The fixing device 13 includes a heater 70 as a heating member, a heater holder 17 as a holding member for holding the heater 70, and a pressure support member 20 for reinforcing the heater holder 17. The pressure roller 16 is a pressure member, which includes a spindle portion 18 and a heat-resistant elastic layer 19. The heater holder 17, the heater 70, and the pressure support member 20 are disposed in the internal space of the heating film 23. The heater holder 17 is biased toward the pressure roller 16 by the pressure support member 20, for example by a spring (not shown). When the pressure roller 16 abuts against the heating film 23, a fixing clamping portion N for conveying the recording material P is formed between the heating film 23 and the pressure roller 16. The heater 70 is in contact with the inner surface of the heating film 23. Therefore, when the pressure roller 16 rotates, the heating film 23 rotates, and at the same time, the inner surface of the heating film 23 slides on the heater 70.

[0041] The recording material P, on which the toner image T is carried, is conveyed by the fixing clamping part N. During the conveying process, heat from the heating film 23 heated by the heater 70 and pressure from the fixing clamping part N are applied to the recording material P, and the toner image T is fixed onto the recording material P.

[0042] 3. Heater and heater holder

[0043] The heater 70 and the heater retainer 17 will now be described. Figure 4 This is a central cross-sectional view of heater 70 along the longitudinal direction. Figures 5A to 5E This is a plan view showing the structure of heater 70 and heater holder 17. Figure 4 Is it along the indication Figures 5A to 5E The dashed line at the transport reference position X0 in the figure shows the cross-sectional view of heater 70 when heater 70 is cut off. Figure 5A and Figure 5BThis is a view of the heater 70 as seen from the rear surface layer 73. Figure 5A This is a view of the heater 70 as seen from the top of the protective glass 80, and... Figure 5B This is a view of the heater 70 with the protective glass 80 removed. Figure 5C and Figure 5D This is a view of the heater 70 as seen from the sliding surface layer 72. Figure 5D This is a view of the heater 70 as seen from the top of the protective glass 81, and... Figure 5C This is a view showing the heater 70 with the protective glass 81 removed. Figures 5A to 5E In the diagram, arrow F on the left indicates the direction of transporting recording material P.

[0044] like Figure 4 As shown, the heater 70 has a layered structure that produces a sliding surface layer 72, a substrate 71, and a rear surface layer 73. Here, the sliding surface of the heater 70 is the surface that contacts the inner surface of the heating film 23. In the clamping portion N, the inner surface of the heating film 23 contacts the heater 70, more specifically, the sliding surface of the heater 70, and the outer surface of the heating film 23 contacts the pressure roller 16. The heating film 23 slides while being held between the sliding surface of the heater 70 and the pressure roller 16. The substrate 71 is configured such that the direction orthogonal to the direction used for conveying the recording material P in the clamping portion N is the longitudinal direction of the substrate 71.

[0045] exist Figure 4 In the sliding surface layer 72, a thermistor T1 serving as a temperature sensing unit and conductors 78a to 78d are disposed. Heating elements 74a and 74b, conductors 75a to 75c, and a power electrode 76a are disposed on the rear surface layer 73. In the rear surface layer 73, heating element 74a is disposed upstream in the direction for conveying the recording material P, and heating element 74b is disposed downstream in the conveying direction. Conductors 75a and 75b are disposed at positions that sandwich heating element 74a, and conductors 75a and 75c are similarly disposed at positions that sandwich heating element 74b.

[0046] When power is supplied to heating element 74a through conductors 75a and 75b, heating element 74a generates heat. Similarly, when power is supplied to heating element 74b through conductors 75a and 75c, heating element 74b generates heat. A protective glass 80 is provided to cover heating elements 74a and 74b, as well as conductors 75a to 75c, and to expose electrode 76a.

[0047] like Figure 5BAs shown, seven heating blocks Z1 to Z7 are disposed on the rear surface layer 73 of the heater 70. Each heating block includes an upstream conductor 75b in the conveying direction for conveying the recording material P, a downstream conductor 75c in the conveying direction, and a conductor 75a sandwiched between conductors 75b and 75c. Each heating block includes a heating element 74a upstream in the conveying direction for conveying the recording material P and a heating element 74b downstream in the conveying direction. Electrodes 76a to 76e are electrically connected to the conductor 75a in each heating block.

[0048] like Figure 5A As shown, a protective glass 80 is disposed on the heater 70, except at the position overlapping with electrodes 76a to 76i. Therefore, power supply terminals (described below) extending from the back of the heater 70 can be connected to electrodes 76a to 76i. It should be noted that in the heater 70 according to this embodiment, heating blocks Z2 and Z3 are driven by a common switch (such as a triac switching element) to always heat simultaneously. Heating blocks Z4 and Z5 are also driven by a common switch to always heat simultaneously. Heating blocks Z6 and Z7 are also driven by a common switch to always heat simultaneously. Only heating block Z1 is driven independently. In this way, power can be supplied to the heating blocks independently via terminals and electrodes, and this allows for independent control of the heating of the heating blocks. In this way, multiple heating blocks are provided, thereby forming four heating distributions, as shown in regions 1 to 4. According to this embodiment, region 1 is provided for A5 sheet, region 2 for B5 sheet, region 3 for A4 sheet, and region 4 for letter paper.

[0049] Since the seven heating elements are independently controlled, the heating elements used for power supply can be selected according to the size of the recording material P, thus preventing excessive heat generation in areas where the recording material P does not pass through. It should be noted that the number of heating elements and the width of the heating elements in the direction orthogonal to the transport direction of the recording material P are not limited to a single combination. Figures 5A to 5E Those described. According to this embodiment, an electrode group including electrodes 76g and 76f is formed at the end of the heater 70 on the left side of the figure, and an electrode group including electrodes 76h and 76i is formed at the end of the heater 70 on the right side of the figure. In the longitudinal direction of the heater 70, electrodes 76a to 76e are disposed within the range of the clamping portion N, while electrodes 76f to 76i are disposed outside the range of the clamping portion N.

[0050] like Figure 5CAs shown, the sliding surface layer 72 of the heater 70 is provided with thermistors T1 to T7 and thermistors T1a, T1b, T2a, T3a, T4a, T5a and t2 to t7 configured to detect the temperature of the heating element of the heater 70. Thermistors T1 to T7 are mainly used to control the temperature of the heating element. In the following text, thermistors T1 to T7 are referred to as temperature control thermistors T1 to T7.

[0051] Thermistors T1a, T1b, T2a, T3a, T4a, and T5a are thermistors configured to detect the temperature at the ends of the heating blocks. Hereinafter, thermistors T1a, T1b, T2a, T3a, T4a, and T5a will be referred to as end thermistors T1a, T1b, T2a, T3a, T4a, and T5a. The end thermistors T1a, T1b, T2a, T3a, T4a, and T5a are each positioned relative to the transport reference position X0, closer to the end of a corresponding heating block, except that the widths of heating blocks Z6 and Z7 at the opposite ends are smaller than the widths of the other heating blocks. The heating areas in heating blocks Z6 and Z7 have relatively small widths, therefore no end thermistors are provided for these blocks.

[0052] Thermistors t2 to t7 are provided as auxiliary components. If the temperature control thermistor or the end thermistor fails, thermistors t2 to t7 can be used to detect the temperature of the heating block. Hereinafter, thermistors t2 to t7 are also referred to as sub-thermistors. Sub-thermistors t2 to t7 are provided in the longitudinal direction of heater 70 at positions corresponding to the temperature control thermistors T2 to T7. Thermistors T1 to T7 and end thermistors T1a, T1b, T2a, T3a, Ta, T4a, and T5a each have one energized end connected to the common conductor 78a and another end connected to conductor 78b or 78e. Sub-thermistors t2 to t7 each have one end connected to the common conductor 78c and another end connected to the common conductor 78d. Conductors 78a to 78d extend in the longitudinal direction of heater 70 to opposite ends of heater 70.

[0053] like Figure 5D As shown, the thermistor and conductors 78a to 78d are covered with protective glass 81, except for the two opposite ends of conductors 78a to 78d in the longitudinal direction of heater 70. The portions of conductors 78a to 78d that are not covered by protective glass 81 and are exposed form electrode sets 79a and 79b for the thermistor.

[0054] In this way, using the heater 70 according to this embodiment, the heating blocks Z1 to Z7 can be independently controlled while the temperature of the heating blocks is being detected. Therefore, a fixing device can be provided that is capable of forming a heat distribution suitable for the dimensions of the recording material P being conveyed to the fixing clamping portion N. Although a sub-thermistor is provided in the description of the embodiment, the heater 70 can be configured to not have a sub-thermistor. The presence of the sub-thermistor allows for more complex and precise control.

[0055] like Figure 5E As shown, the heater holder 17 has openings 82a to 82i corresponding to electrodes 76a to 76i. Terminals are provided in the space between the pressure support 20 and the heater holder 17 for electrical connection to electrodes 76a to 76e. Connectors 300 are connected to electrodes 76f to 76i located at the longitudinal ends of the heater 70. Resilient terminals 302 are provided in the housing 301 of each connector 300, and the terminals 302 resiliently contact electrodes 76f to 76i.

[0056] 4. Power supply structure

[0057] Figure 6A and Figure 6B This is an overall view showing the relationship between the heater 70, the heater holder 17, and the power supply terminal 200. Figure 1 is a perspective view of the terminal 200.

[0058] like Figure 6A As shown, according to this embodiment, two types of power supply structures are used as power supply structures for the heating blocks Z1 to Z7 of the heater 70. In the first type of power supply structure, a single-layer flat intermediate member 100 and terminals 200 are placed sequentially on each other to overlap with electrodes 76a to 76e, the single-layer flat intermediate member being conductive. Electrodes 76a to 76e are electrically connected to the intermediate member 100 and to the terminals 200. Clamping portions 201 are provided at each terminal 200 to block the bundle (cable) (not shown) electrically connected to the terminal 200.

[0059] In the second type of power supply configuration, as described above, electrodes 76f to 76i and a power source (not shown) are connected via connector 300. Connector 300 is positioned on heater holder 17 along the width direction of heater 70 while heater 70 is held in place by heater holder. Terminals 302, disposed in housing 301 of connector 300, elastically deform according to the thickness of heater 70. The reaction force caused by the deformation of terminals 302 provides electrical contact between connector 300 and electrodes 75f to 76i. According to this embodiment, terminals 302 generate pressure to be applied to connector 300, but depending on the thickness of heater 70, spacers can be placed on the sliding surface layer 72 side. The presence of spacers makes the pressure applied by terminals 302 to connector 300 more uniform, and the electrical connection between connector 300 and electrodes 75f to 76i more stable.

[0060] Figure 6B The assembly state is shown. Figure 6A The electrical supply configuration is as follows. As described above, electrodes 76a to 76e are electrically connected to the intermediate member 100 and terminals 200 at locations provided in openings 82a to 82e in the heater holder 17. The orientations of the multiple terminals 200 are not identical. The terminals 200 are arranged in different directions such that the bundle of wires (not shown) connected to the terminals 200 can be distributed to two opposite ends of the heater holder 17 in the longitudinal direction. This provides the advantageous effect of reducing the cross-sectional area of ​​the pressure support 20 and the heater holder 17. The heating film 23 can also have a reduced diameter. The connector 300, as another electrical supply configuration, also provides the advantageous effect of allowing electrical contact between the terminals 302 and electrodes 76f to 76i through openings 82f to 82i.

[0061] Now, refer to Figure 1A The power supply structure provided in heater 70 is described in detail. Figure 1A The diagram shows the state in which the electrode 76e shown in Figure 6 is positioned in the heater 70. It should be noted that electrodes 76a to 76d are aligned with... Figure 1A The same arrangement is shown in heater 70.

[0062] like Figure 1A As shown, terminal 200 is provided with a positioning portion 202 and a rotation stop 203. The positioning portion 202 has a hole through which a positioning boss 21 provided in the heater holder 17 is inserted. The rotation stop 203 has a recess that fits into a rotation stop boss 22 provided in the heater holder 17. When the positioning portion 202 is inserted into the positioning boss 21 and the rotation stop boss 22 is fitted to the rotation stop 203, a push nut 303 is fitted to the positioning boss 21, thereby fixing terminal 200 to heater holder 17.

[0063] Terminal 200 has a deformable portion 204 and a connecting portion 205. The deformable portion 204 absorbs the relative displacement difference due to thermal expansion between heater holder 17 and heater 70. More specifically, heater holder 17 is made of heat-resistant resin, and heater 70 is made of ceramic. The coefficient of linear expansion of the heat-resistant resin (liquid crystal polymer) is about 10 to 100 × 10⁻⁶. -6 At / ℃, the linear expansion coefficient of ceramics is approximately 0.1 to 10 × 10⁻⁶. -6 / ℃.

[0064] The changes in the deformed portion 204 and the mating portion 205 associated with the thermal expansion of the heater holder 17 and the heater 70 will be described. First, when the heater 70 generates heat, the temperature of the heater 70 rises before the temperature of the heater holder 17 rises. In other words, in the initial stage of heat generation by the heater 70, the thermal expansion of the heater 70 is primarily near the transport reference position X0. As a result, the deformed portion 204 hardly moves along the expansion direction, but the mating portion 205 of the terminal 200 moves along... Figure 1A The deformed portion 204 moves in the direction indicated by the arrow (the "direction of thermal expansion" in the figure). As a result, the deformed portion 204 is in a state as if it were contracting in the longitudinal direction of the heater 70. As the heater 70 continues to generate heat, the heater holder 17 also has an increased temperature and thermally expands near the transport reference position X0. Depending on the temperature of the heater holder 17, the displacement of the heater holder 17 caused by thermal expansion may become greater than the displacement of the heater 70. Therefore, when the displacement of the heater holder 17 caused by thermal expansion is greater than the displacement of the heater 70 caused by thermal expansion, the positioning boss 21 for the heater holder 17 also displaces in the direction indicated by the arrow. In this way, the deformed portion 204 of the terminal 200 absorbs the relative displacement difference of thermal expansion between the heater holder 17 and the heater 70.

[0065] The engagement portion 205 of terminal 200 is electrically bonded to intermediate member 100 in a face-to-face manner. Intermediate member 100 is electrically bonded to electrode 76e of heater 70 on a surface opposite to the surface of engagement portion 205 bonded to terminal 200. Terminal 200 and intermediate member 100 are arranged to remain in contact with heating elements 74a and 74b of heater 70. This prevents heat loss from heating elements 74a and 74b by terminals 200 and intermediate member 100, and also prevents uneven fixing of the recording material in the longitudinal direction of heater 70.

[0066] Now, refer to Figure 1BThe process for combining the various parts of the electrical structure of the heater 70 is described in detail. First, in the bonding region 400, the bonding portion 205 of the terminal 200 and the intermediate member 100 are electrically bonded by laser bonding. According to this embodiment, the bonding region 400 is a single region. Then, the intermediate member 100 and the electrode 76e are electrically bonded by ultrasonic bonding in bonding regions 401 and 402. According to this embodiment, bonding regions 401 and 402 are two regions arranged side by side in the longitudinal direction of the heater 70. It should be noted that the number and shape of the bonding in bonding regions 400, 401, and 402 can be arbitrary. At least two bonding regions 401 and 402 are examples of a first fixed region between the electrode and the intermediate member. The bonding region 400 is an example of a second fixed region between the terminal and the intermediate member disposed between the two first fixed regions.

[0067] According to this embodiment, a mating region 400 is provided in the longitudinal direction of the heater 70, such that this region is sandwiched between mating regions 401 and 402. (Refer to...) Figure 7A Describe the arrangement of the joint areas 400, 401 and 402. Figure 7A An example of the deformation state associated with the thermal expansion of each part of the electrical structure according to this embodiment is shown. According to this embodiment, the terminal 200 is made of phosphor bronze, the same material used for springs, and has a thickness of 0.1 mm to 1 mm. The sheet-like intermediate member 100 is made of pure copper and has a thickness of 0.01 mm to 0.1 mm. The linear expansion coefficient of phosphor bronze is approximately 18.2 × 10⁻⁶. -6 / ℃, while the linear expansion coefficient of pure copper is approximately 17.7×10. -6 / ℃. The elongation at break of phosphor bronze is about 10% to 20%, while that of pure copper is at least about 35%. The Young's modulus of the ceramic heater 70 is about 280 GPa to 400 GPa, the Young's modulus of the phosphor bronze terminal 200 is about 98 GPa, and the Young's modulus of the intermediate member 100 made of pure copper is about 118 GPa. The electrode 76e of the heater 70 is thinner than the heater 70 and has physical properties such as Young's modulus and coefficient of linear expansion, which are the same as those of the heater 70.

[0068] refer to Figure 7A This will describe the deformation caused by the thermal expansion of each part due to the heat generated by the heater 70. When the heater 70 generates heat, the heater 70, terminal 200, and intermediate member 100 thermally expand and deform, such as Figure 7AAs shown. More specifically, in the joining regions 401 and 402 where the electrode 76e and the intermediate member 100 are joined, the electrode 76e and the intermediate member 100 deform as the heater 70 deforms. This is because the heater 70 has a greater thickness and Young's modulus than the intermediate member 100, causing the intermediate member 100 to deform according to the deformation of the heater 70. However, it should be noted that the electrode 76e and the intermediate member 100 are not joined between the joining regions 401 and 402. The intermediate member 100 has a greater coefficient of linear expansion than the heater 70. Therefore, this is attributed to the heater 70 in the longitudinal direction ( Figure 7A The extension length of the intermediate member 100 (in the left-right direction on the surface of the sheet) is greater than the extension length of the heater 70, which causes the intermediate member 100 to bend in the joint area 400, such as Figure 7A As shown. It should be noted that the material of the intermediate member 100 is selected such that the intermediate member can extend without breaking even when bending causes deformation.

[0069] In the joint region 400 where the terminal 200 and the intermediate member 100 are joined, the terminal 200 and the intermediate member 100 deform by thermal expansion to have equal deformation amounts. This is because the linear expansion coefficients of the terminal 200 and the intermediate member 100 are equal. The deformation of the terminal 200 and the intermediate member 100 can reduce the stress attributable to the thermal expansion induced in each of the joint regions 400, 401, and 402. This is because the stresses generated in the joint regions 400, 401, and 402 are independent of each other and do not reinforce each other. In particular, since the ceramic heater 70 is made of a so-called brittle material, it is desirable to reduce the stress generated in the joint regions 401 and 402.

[0070] Now, refer to Figure 7B and Figure 7C The example description in the example is as follows: Figure 7A The arrangement of the joint areas 400, 401, and 402 shown provides advantageous effects. Figure 7B In the example shown, the engagement between electrode 76e and intermediate member 100 is located in an engagement region 403. An engagement region 404 between terminal 200 and intermediate member 100 is also provided opposite to engagement region 403, with intermediate member 100 located therebetween.

[0071] exist Figure 7B In the example shown, in the longitudinal direction of the heater, the mating regions 403 and 404 are arranged over approximately the entire length of the intermediate member 100. Therefore, with... Figure 7ACompared to the situation shown, when the heater 70 deforms due to thermal expansion, not only the intermediate member 100 but also the terminal 200 may easily follow suit due to the deformation caused by the thermal expansion of the heater 70. Therefore, the stress on the joint region 403 caused by the deformation of the heater 70 due to thermal expansion also affects the stress generated in the joint region 404 between the joint terminal 200 and the intermediate member 100. As a result, the stress generated in the joint region 403 between the joint electrode 76e and the intermediate member 100 is greater than that generated in the joint region 404 between the intermediate member 100 and the intermediate member 76e. Figure 7A The stress generated in the joint areas 401 and 402 in the example.

[0072] exist Figure 7C In the example shown, two engagement regions 406 and 407 are provided between terminal 200 and intermediate member 100. An engagement region 405 connecting electrode 76e and intermediate member 100 is provided between engagement regions 406 and 407 in the longitudinal direction of heater 70.

[0073] exist Figure 7C In the example shown, when the heater 70 deforms due to thermal expansion, the bonding region 405 where the electrode 76e and the intermediate member 100 are joined follows the deformation of the heater 70. In other words, for the deformation of the intermediate member 100 in the bonding region 405, the deformation following the deformation of the heater 70 caused by thermal expansion is dominant compared to the deformation of the intermediate member 100 caused by thermal expansion based on material properties. As a result, the amount of deformation of the intermediate member 100 caused by thermal expansion in the longitudinal direction of the heater 70 is less than the amount of deformation of the intermediate member 100 that would be caused by the thermal expansion of the intermediate member 100 itself. Therefore, the difference between the amount of deformation of the intermediate member 100 caused by thermal expansion and the amount of deformation of the terminal 200 caused by thermal expansion should be greater than [the difference between the two]. Figure 7A As shown in the diagram, with the increase in deformation difference, the deformation of terminal 200 is greater than the deformation of intermediate member 100 in mating regions 406 and 407, such as... Figure 7C As shown, terminal 200 ultimately bends away from heater 70. This not only results in stress being applied to mating regions 406 and 407, but also increases the stress applied to mating region 405 due to the intermediate member 100 being pulled toward terminal 200. More specifically, the stress generated in mating region 405 is affected not only by the stress caused by the relative difference in the amount of deformation due to thermal expansion between electrode 76e and intermediate member 100, but also by the stress caused by the relative difference in the amount of deformation due to thermal expansion between terminal 200 and intermediate member 100.

[0074] exist Figure 7AIn the example shown, in the power supply configuration for electrodes 76a to 76e of the heater 70, an intermediate member 100 is disposed between the terminal 200 and the electrode 76e to reduce the thermal expansion effect of the heater 70. In this way, the thermal stress repeatedly generated in the power supply configuration during operation of the image forming apparatus 1 can be reduced, thereby improving the reliability of the power supply configuration. Therefore, with Figure 7B and Figure 7C Compared to the configuration shown, the junction area disposed between the electrode 76e, the intermediate member 100, and the terminal 200 is more preferably as shown. Figure 7A The configuration shown is as shown.

[0075] According to this embodiment, pure copper is used as the material of the intermediate component 100. However, any other material can be used as the material of the intermediate component 100 if the conductor can absorb the effects of deformation caused by the thermal expansion of the heater 70. Therefore, various materials can be used for the intermediate component 100 if the Young's modulus of the conductor is less than that of the heater 70 and the elongation at break of the conductor is greater than that of the heater 70. According to this embodiment, the connection between the terminal 200 and the wire bundle is blocked by the clamping portion 201, so the thickness of the terminal 200 is ideally set such that the wire bundle leads do not separate from the clamping portion 201. Ideally, the thickness of the terminal 200 is also set considering the connection strength between the terminal 200 and the wire bundle in the clamping portion 201, the assembly of the power supply structure, and the absorption of the relative displacement difference due to thermal expansion between the heater holder 17 and the heater 70. Furthermore, since the terminal 200 has a certain thickness, it is expected that the positioning and fixing of the various components (including the terminal 200) in the power supply structure during assembly will be easier.

[0076] 5. Manufacturing method

[0077] Now, refer to Figure 8A , Figure 8B and Figure 8C A method for manufacturing a power supply structure according to this embodiment is described. Figure 8A , Figure 8B and Figure 8C The manufacturing method shown produces a product for use in manufacturing ... Figure 6A The electrode 76e shown is configured for power supply. First, as... Figure 8A As shown, the intermediate member 100 is disposed on the electrode 76e of the heater 70 such that the member does not contact the heating elements 74a and 74b. Then, the welding head 304 for ultrasonic bonding is pressed against the intermediate member 100 from above. The vibrational energy of a vibrator (not shown) is then transferred to the welding head 304, and the electrode 76e and the intermediate member 100 are bonded by frictional heat generated at their interface. Then, as... Figure 8BAs shown, the heater holder 17 is mounted on the heater 70, and the heater holder 17 and the heater 70 are bonded together using a moisture-curable silicone-based adhesive. Figure 8C As shown, the positioning portion 202 of the terminal 200 is placed via the positioning boss 21 of the heater holder 17. The rotation stop 203 of the terminal 200 is fitted to the rotation stop boss 22 of the heater holder 17. The push nut 303 is fitted to the positioning boss 21, and the terminal 200 is secured to the heater holder 17. Figure 8C As shown, a laser beam is irradiated from above by a laser bonding device 305 on the bonding portion 205 of the terminal 200 to bond the bonding portion 205 of the terminal 200 and the intermediate member 100.

[0078] In the above manufacturing method, the electrode 76e and the intermediate member 100 can be bonded by ultrasonic bonding, so that the load on the heater 70 can be minimized during bonding. The terminal 200 is positioned by the positioning boss 21 and the rotation stop boss 22 of the heater holder 17. Therefore, the heater holder 17 is provided on the heater 70 before bonding the joint portion 205 of the terminal 200 to the intermediate member 100. When ultrasonic bonding is used to bond the joint portion 205 and the intermediate member 100, the welding head 304 can contact the joint portion 205 of the terminal 200. As a result, when the vibration energy is transmitted to the welding head 304 as it contacts the heater holder 17 or the terminal 200, the vibration energy is transmitted to the heater holder 17 or the terminal 200, and this may damage the heater holder 17 or the terminal 200.

[0079] According to this embodiment, a laser bonding device 305 capable of non-contact bonding between the joining portion 205 and the intermediate member 100 can be used, enabling bonding even in an opening 82e located in a confined space, without applying a load to a member that is not the bonding target. Simultaneously, in laser bonding, the laser beam can penetrate the joining portion 205. However, the intermediate member 100 is disposed on the electrode 76e of the heater 70. In this way, even when the laser beam passes through the joining portion 205, the intermediate member 100 also acts as a protective member to protect the heater 70 from the influence of the laser beam, thereby reducing the load on the heater 70 caused by the laser beam.

[0080] According to this embodiment, the joining regions 400 and 401 and 402 are arranged such that they do not overlap when viewed in a direction perpendicular to the flat surface portion of the intermediate member 100. The positional arrangement of the joining regions 400, 401, and 402 is also advantageous in the aforementioned manufacturing method. More specifically, when the electrode 76e and the intermediate member 100 are joined, a joining mark is left on the upper surface of the intermediate member 100 at the portion opposite to the joining regions 401 and 402. However, in the joining region 400, which does not overlap with the joining regions 401 and 402, there is no such process mark on the upper surface of the intermediate member 100. Therefore, the portion of the upper surface of the intermediate member 100 to become the joining region 400 is formed as a smooth surface. Therefore, since the joining between the intermediate member 100 and the terminal 200 can be performed on the smooth surface of the intermediate member 100, a stable joining can be achieved in ultrasonic joining.

[0081] According to this embodiment, ultrasonic bonding and laser bonding are used in the method of manufacturing the electrical structure, but the types of bonding are not limited to these. If a strong bond can be formed between the two components to be joined, the components can be joined on a flat-to-flat basis, for example, by bonding, welding, pressure welding, brazing, or conductive adhesive. In particular, the various bonding methods described above are preferably methods for fixing electrodes and intermediate components. At the same time, intermediate components and terminals can be fixed by any of the bonding methods and connection methods, which insert the components into each other, for example, by pressure fit, shrink fit, and clamping instead of bonding. In this way, electrodes and intermediate components are preferably joined by, for example, bonding, welding, pressure welding, brazing, or conductive adhesive, while intermediate components and terminals can be fixed by bonding or connecting (e.g., by pressure fit, shrink fit, or clamping).

[0082] According to this embodiment, the joining regions 400, 401, and 402 are arranged so that they do not overlap each other in a direction perpendicular to the flat surface portion of the intermediate member 100. However, if these regions are displaced from each other in the longitudinal direction of the heater 70 when viewed from a direction perpendicular to the flat surface portion of the intermediate member 100, the same advantageous effects as described above can be expected even if there are some overlapping regions.

[0083] To achieve a stable bond with intermediate component 100 and terminal 200, an electroplating process can be performed on these components. When electroplating is performed on the components to be bonded, the components can have a surface with a low degree of oxidation. The electroplating material used in the electroplating process can be an antioxidant material, such as tin, nickel, and gold.

[0084] Second Embodiment

[0085] Next, a second embodiment of the invention will be described. According to the first embodiment, stress generated at each joint region should be prevented from affecting another joint region, so as to reduce the stress generated by the deformation of each component due to thermal expansion at each joint region. (Refer to...) Figure 9 The power supply configuration according to the second embodiment is described. It should be noted that in the following description, components identical to those in the first embodiment are indicated by the same reference numerals, and detailed explanations thereof will not be provided.

[0086] Figure 9 A longitudinal section of the heater 70 in the power supply configuration according to this embodiment is shown, and it corresponds to... Figure 7A , Figure 7B and Figure 7C The power supply configuration according to this embodiment includes a junction region 408 connecting the electrode 76e and the intermediate member 100, and a junction region 409 connecting the terminal 200 and the intermediate member 100. Unlike the junction regions 401 and 402 according to the first embodiment, a junction region 408 is disposed between the electrode 76e and the intermediate member 100. The junction regions 408 and 409 connecting the electrode 76e and the intermediate member 100 are arranged such that when these regions are viewed in a direction perpendicular to the flat surface portion of the intermediate member 100, they do not overlap each other. In this way, the degrees of freedom for the junction regions 408 and 409 to deform due to thermal expansion are greater than the degrees of freedom when the junction regions 408 and 409 are arranged to overlap each other. As a result, stress generated in one junction region of the junction regions 408 and 409 can be prevented from affecting stress generated in the other region; in other words, stress enhancement can be reduced.

[0087] The difference in deformation caused by thermal expansion between heater holder 17 and heater 70 can cause intermediate member 100 to bend. This is because the effect of the relative difference in deformation caused by thermal expansion between heater holder 17 and heater 70 extends to intermediate member 100 before being absorbed by the deformed portion 204 of terminal 200 as described above. Therefore, according to this embodiment, intermediate member 100 is bonded to electrode 76e and terminal 200 in two engagement regions 408 and 409, which do not overlap when viewed in a direction orthogonal to the flat surface portion of intermediate member 100. As a result, intermediate member 100 is unlikely to bend. In the power supply configuration according to this embodiment, materials with relatively small coefficients of linear expansion that are approximately similar to each other are preferably selected for use in heater holder 17 and heater 70.

[0088] It should be noted that the power supply configuration according to this embodiment is not limited to... Figure 9The power supply structure shown is designed to reduce the impact of stress caused by thermal expansion in one joint area on stress in other joint areas. Furthermore, according to this embodiment, the joint areas are arranged at different locations along the longitudinal direction of the heater 70 in the intermediate member 100, allowing for efficient utilization of the space along the longitudinal direction of the heater 70.

[0089] Third Embodiment

[0090] Next, a third embodiment of the present invention will be described. In the following description, components identical to those in the first embodiment are indicated by the same reference numerals and will not be described in detail therewith. The heater 70 according to the third embodiment has the same structure as that shown in the first embodiment of FIG. 5.

[0091] Figure 10 A longitudinal section of the heater 70 in the power supply configuration according to this embodiment is shown. Figure 10 A cross-section of the power supply configuration for electrode 76e in Figure 6 is shown. It should be noted that the power supply configurations for electrodes 76a to 76d are the same as those for electrode 76e. Figure 10 As shown, according to this embodiment, a titanium intermediate member 101 is disposed on the electrode 76e of the heater 70, and the electrode 76e and the intermediate member 101 are bonded to each other in a bonding region 410. The intermediate members 101 are arranged and bonded such that a nickel intermediate member 102, a copper intermediate member 100, and a phosphor bronze terminal 200 are stacked on top of each other from below in the order mentioned. The bonding region connecting the intermediate members 101 and 102 is bonding region 411. The bonding region connecting the intermediate members 102 and 100 is bonding region 412. The bonding region connecting the intermediate member 100 and the terminal 200 is bonding region 413.

[0092] The heater 70 is made of ceramic, with a linear expansion coefficient of approximately 0.1 to 10 × 10⁻⁶. -6 / ℃. As for the material of the intermediate components, titanium has a linear expansion coefficient of approximately 8.4 × 10⁻⁶. -6 At ℃, the linear expansion coefficient of nickel is approximately 13.4 × 10⁻⁶. -6 At ℃, the linear expansion coefficient of pure copper is approximately 17.7 × 10⁻⁶. -6 At ℃, the linear expansion coefficient of phosphor bronze is approximately 18.2 × 10⁻⁶. -6 / ℃.

[0093] It should be noted that the method for joining the members in the joint area is the same as that according to the first embodiment, and therefore will not be described in detail. According to this embodiment, the two joint areas, in which an intermediate member is disposed, are arranged so that they do not overlap when viewed in a direction perpendicular to the flat surface portion of the intermediate member 100. More specifically, joint areas 410 and 411, joint areas 411 and 412, and joint areas 412 and 413 are positioned so that they do not overlap when viewed in a direction orthogonal to the flat surface portion of the intermediate member 100.

[0094] The materials used for the intermediate components are further selected such that the linear expansion coefficients of intermediate components 100 and 101, disposed between intermediate component 101 and terminal 200 bonded to electrode 76e, are both within a range determined by the linear expansion coefficients of intermediate component 100 and terminal 200. The materials used for intermediate components 100 and 102 are selected such that the linear expansion coefficients gradually change from intermediate component 101 to terminal 200. More specifically, the material used for intermediate component 100 is selected such that the linear expansion coefficient of intermediate component 100 is between the linear expansion coefficients of intermediate component 101 and terminal 200, and is closer to the linear expansion coefficient of intermediate component 101 than the linear expansion coefficient of terminal 200. The material used for intermediate component 102 is selected such that the linear expansion coefficient of intermediate component 102 is between the linear expansion coefficients of intermediate component 101 and terminal 200, and is closer to the linear expansion coefficient of terminal 200 than the linear expansion coefficient of intermediate component 101. As a result, it can be expected that the relative difference in deformation caused by thermal expansion between adjacent members in each joint region can be smaller, and the stress can be further reduced.

[0095] Furthermore, the linear expansion coefficient of the intermediate member 101 can be set based on the linear expansion coefficient of the electrode 76e of the heater 70. The intermediate member 101 is disposed between the heater 70 and the terminal 200; however, when the heater 70 is made of ceramic, for example, the linear expansion coefficient of the intermediate member 101 can be a linear expansion coefficient outside the range determined by the linear expansion coefficients of the heater 70 and the terminal 200. Ceramics are a so-called brittle material and are particularly susceptible to tensile stress. Therefore, the material used for the intermediate member 101 can be selected such that the linear expansion coefficient of the intermediate member 101 is less than that of the ceramic. Thus, it is expected that the stress caused by the thermal expansion of each of the members in the joint region 410 can act in a direction that reduces the expansion of the heater 70, making damage to the heater 70 less likely.

[0096] Because multiple intermediate components are stacked between the electrode 76e and the terminal 200 in the power supply configuration, the material for each intermediate component can be selected from a variety of materials with different coefficients of linear expansion. This also increases the selection of materials for the terminal 200 and can reduce the overall manufacturing cost of the heater 70. According to this embodiment, the number of layers or multiple layers of materials to be stacked is not limited, and the coefficient of linear expansion of an intermediate component only needs to be within a range between the coefficient of linear expansion of the intermediate component opposite the electrode and the coefficient of linear expansion of the terminal 200 in a stepwise manner.

[0097] As a modification to the power supply structure according to this embodiment, the following can be used: Figure 11 The structure shown is different. Figure 10 In the illustrated configuration, two mating regions 510 and 514 are disposed between the electrode 76e and the intermediate member 101. There is a mating region 511 that connects intermediate members 101 and 102, a mating region 512 that connects intermediate members 102 and 100, and a mating region 513 that connects intermediate member 100 and terminal 200. In this example, mating regions 511, 512, and 513 correspond to mating regions 411, 412, and 413, respectively. Similarly, according to this modification, the two mating regions with the intermediate member disposed therebetween are arranged so that they do not overlap when viewed in a direction orthogonal to the flat surface portion of the intermediate member 100. Therefore, the advantageous effects described in connection with the embodiment can also be provided according to the modification.

[0098] Fourth embodiment

[0099] Next, a fourth embodiment of the present invention will be described. In the following description, components identical to those in the first embodiment are indicated by the same reference numerals and will not be described in detail therewith. The heater 70 according to the fourth embodiment has the same structure as that in the first embodiment and is shown in FIG. 5.

[0100] Figure 12A and Figure 12B The power supply configurations for electrodes 76f and 76g according to this embodiment are shown. Since the power supply configurations for electrodes 76h and 76i are the same as those for electrodes 76f and 76g, the power supply configurations for electrodes 76f and 76g will be described below, and the power supply configurations for electrodes 76h and 76i will not be described. Figure 12A As shown, terminal 200 is secured to heater holder 17. More specifically, positioning portion 202 (see...) Figure 1BThe heater retainer 17 has a hole through which a positioning boss 21 is inserted. A rotation stop 203 has a recess that engages with a rotation stop boss 22 in the heater retainer 17. When the positioning part 202 is placed via the positioning boss 21 and the rotation stop 203 engages with the rotation stop boss 22, a push nut 303 is fitted onto the positioning boss 21, thus securing the terminal 200 to the heater retainer 17.

[0101] A cable (not shown) is plugged at the clamping portion 201 of the terminal 200, and the cable extends in the transport direction F for transporting the recording material P. (Refer to...) Figure 12B The electrical configuration according to this embodiment is described. An intermediate member 100 is placed on electrodes 76f and 76g, and electrodes 76f and 76g are electrically bonded to the intermediate member 100 via ultrasonic bonding. Electrode 76f and intermediate member 100 are bonded in bonding regions 415 and 416, and electrode 76g and intermediate member 100 are bonded in bonding regions 417 and 418.

[0102] Unlike the first embodiment, the joining regions 415 and 416, and the joining regions 417 and 418, are aligned in the transport direction F for transporting the recording material P. The regions where the power supply structures for electrodes 76f and 76g are provided correspond to the regions on the heater 70 where heating elements 74a and 74b are not present. Therefore, when the longitudinal direction of electrodes 76f and 76g is aligned with the transport direction F for transporting the recording material P, sufficient space can be ensured for providing electrodes 76f and 76g. Simultaneously, similar to the first embodiment, when the longitudinal direction of electrodes 76f and 76g is aligned with the longitudinal direction of the heater 70, the arrangement of electrodes 76f and 76g is the same as the arrangement of electrodes 76a to 76e. More specifically, with... Figure 12A and Figure 12B Compared to the example shown, more space must be ensured in the longitudinal direction of the heater 70 to place the electrodes 76f and 76g therein, which may result in an increase in the size of the image forming apparatus.

[0103] In the power supply configuration according to this embodiment, connector 300 can be omitted. At connector 300, terminal 302 generates pressure on connector 300. Therefore, in order to ensure conductivity between connector 300 and electrodes 76f to 76i through the pressure of terminal 302 in a high-temperature environment, a portion of gold-plated titanium copper is sometimes used for terminal 302. Therefore, using such a component for terminal 302 increases the manufacturing cost of heater 70. According to this embodiment, the manufacturing cost of heater 70 can be reduced without connector 300. Furthermore, according to this embodiment, by arranging electrodes 76f to 76i in the manner described above, the size of heater 70 can be reduced compared to conventional heaters.

[0104] Although the areas used to provide electrodes 76f to 76i correspond to the non-heating portions of heater 70, reducing the size of the heater would make these areas more susceptible to the heat generated by heater 70. However, according to this embodiment, the presence of a joint area arranged as described above minimizes the stress caused by the thermal expansion of each component. In this way, the reliability of the power supply structure is not compromised even if the size of heater 70 is smaller than that of a conventional heater.

[0105] While the invention has been described with reference to exemplary embodiments, it should be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the appended claims should be given the broadest interpretation to include all such modifications and equivalent structures and functions.

Claims

1. An image heating apparatus comprising: a tubular film that rotates while being in contact with a recording material; a heater including: (i) a substrate disposed in an inner space of the tubular film and having a longitudinal direction that is a direction orthogonal to a direction in which the recording material is transported; (ii) first, second, third, fourth, and fifth heat generating elements disposed in the substrate; and (iii) first, second, third, fourth, and fifth electrodes configured to supply power to the first to fifth heat generating elements, respectively; and first, second, third, fourth, and fifth terminals disposed in the inner space of the tubular film, the first, second, third, fourth, and fifth terminals being electrically connected to the first to fifth electrodes, respectively, wherein the image heating apparatus heats an image formed on the recording material by heat of the heater, the first heat generating element is disposed at a center position of the heater in the longitudinal direction, the second heat generating element is disposed on one end side of the heater in the longitudinal direction compared to the first heat generating element, the third heat generating element is disposed on the other end side of the heater in the longitudinal direction compared to the first heat generating element, the fourth heat generating element is disposed on the one end side of the heater in the longitudinal direction compared to the second heat generating element, the fifth heat generating element is disposed on the other end side of the heater in the longitudinal direction compared to the third heat generating element, a width of the second heat generating element, a width of the third heat generating element, a width of the fourth heat generating element, and a width of the fifth heat generating element are smaller than a width of the first heat generating element with respect to the longitudinal direction, the first terminal has a first clamping portion for clamping a first wire electrically connected to the first terminal to the first terminal, the second terminal has a second clamping portion for clamping a second wire electrically connected to the second terminal to the second terminal, the third terminal has a third clamping portion for clamping a third wire electrically connected to the third terminal to the third terminal, the fourth terminal has a fourth clamping portion for clamping a fourth wire electrically connected to the fourth terminal to the fourth terminal, the fifth terminal has a fifth clamping portion for clamping a fifth wire electrically connected to the fifth terminal to the fifth terminal, the first clamping portion faces the one end side of the heater in the longitudinal direction with respect to a position of the first terminal electrically connected to the first electrode, the second clamping portion faces the one end side of the heater in the longitudinal direction with respect to a position of the second terminal electrically connected to the second electrode, a position at which the third clamping portion is electrically connected to the third terminal with respect to the third electrode faces the other end side of the heater in the longitudinal direction, a position at which the fourth clamping portion is electrically connected to the fourth terminal with respect to the fourth electrode faces the other end side of the heater in the longitudinal direction, a position at which the fifth clamping portion is electrically connected to the fifth terminal with respect to the fifth electrode faces the one end side of the heater in the longitudinal direction.

2. The image heating apparatus according to claim 1, further comprising a press member that abuts against the tubular film and forms a nip portion for conveying a recording material between the tubular film and the press member itself.

3. The image heating apparatus according to claim 2, wherein the press member forms the nip portion with the heater via the tubular film.

4. An image forming apparatus, comprising: an image forming unit that forms an image on a recording material; and a fixing unit that fixes the image formed on the recording material on the recording material, wherein the fixing unit is the image heating apparatus according to any one of claims 1 to 3.

Images