Heating device and image forming apparatus

Abstract

To solve the problem in which: an urging force can be applied to a power cut-off member by urging both sides of the power cut-off member by urging members, but that requires a space for arranging the plurality of urging members and increases the number of components.SOLUTION: A heating device comprises: a first holding member that holds a heater; a power cut-off member that cuts off supply of power to the heater; a second holding member that holds the power cut-off member; a first urging member to press the power cut-off member against the heater; and a regulation member that regulates the position of the second holding member. In a longitudinal direction of the heater, the second holding member is urged by the first urging member at one end, and the position of the second holding member is regulated by the regulation member at the other end.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a heating device and an image forming apparatus such as a copying machine, a printer, a facsimile machine, or the like that employs an electrophotographic system or an electrostatic recording system. [Background technology]

[0002] Conventionally, a known heating device for an image forming apparatus includes a film, a heater disposed within the film's internal space, a holding member for holding the heater, and a reinforcing member for reinforcing the holding member. The heater may be a planar heater having a planar heating element mounted on a ceramic substrate, and is held by a resin heater holder serving as the holding member. A through-hole is provided along a portion of the holding member's length, and a thermistor is disposed in the space between the holding member and the reinforcing member to detect the heater temperature. The heater is controlled according to the temperature detected by the thermistor. Similarly, a protective element such as a thermostat or a thermal fuse is provided in the space between the holding member and the reinforcing member. The protective element also contacts the heater through another through-hole provided in the holding member. The protective element is a power cut-off element that cuts off power to the heater when the heater exceeds a predetermined temperature.

[0003] Conventionally, a power interruption member is positioned so as to contact the heater. In this case, if the contact pressure with respect to the heater is low or if a clearance occurs between the heaters, the response to temperature becomes slow. Therefore, as in Patent Document 1, the power interruption member is biased toward the heater by a biasing member such as multiple compression springs or a composite spring. This allows the power interruption member to contact the heater with a predetermined pressure. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2013-41096 Summary of the Invention [Problem to be solved by the invention]

[0005] However, although a biasing force can be applied by biasing both sides of the power cut-off member with a biasing member, this requires space to accommodate multiple biasing members and increases the number of parts.

[0006] The invention of the present application was made in consideration of the above situation, and aims to provide a configuration for biasing a power interruption member without biasing both sides of the power interruption member with multiple biasing members. [Means for solving the problem]

[0007] The present invention solves the above problems teeth, A cylindrical first rotor and a rotor element are arranged in the internal space of the first rotor parallel to the longitudinal direction of the first rotor. a thin heater; Across the longitudinal direction of the heater a first holding member for holding the a second rotating body that contacts the outer peripheral surface of the first rotating body, sandwiches the first rotating body together with the heater, and forms a nip between the first rotating body and the second rotating body; and a second rotating body that is disposed in the internal space of the first rotating body and is activated by an abnormal temperature rise of the heater. a power interruption member that interrupts the supply of power to the heater; disposed in the internal space of the first rotor, a second holding member for holding the power interrupting member; and a second holding member for holding the power interrupting member to the heater. Spring biasing towards and a regulating member that regulates the position of the second holding member, a heating device that heats an image formed on a sheet while conveying the sheet through the nip portion, before Chief Secretary In the hand direction, one end side of the second holding member is Spring is energized by The spring is not provided on the other end side of the second holding member, The other end of the second holding member is regulated in position by the regulating member. The power cutoff member is urged toward the heater via the second holding member by the urging force of the spring, with the regulating position of the regulating member as a fulcrum and the urging position of the spring as a force point. It is characterized by: Furthermore, the present invention provides a cylindrical first rotating body, an elongated heater disposed in the internal space of the first rotating body parallel to the longitudinal direction of the first rotating body, a first holding member that holds the heater along the longitudinal direction of the heater, a second rotating body that is in contact with the outer circumferential surface of the first rotating body and that sandwiches the first rotating body together with the heater to form a nip between the first rotating body and the second rotating body, a temperature detection member that is disposed in the internal space of the first rotating body and detects the temperature of the heater, a second holding member that is disposed in the internal space of the first rotating body and holds the temperature detection member, and a temperature detection member that connects the temperature detection member to the heater. a spring that urges the second holding member toward the heater and a regulating member that regulates the position of the second holding member, and heats an image formed on the sheet while transporting the sheet through the nip portion, wherein in the longitudinal direction, one end of the second holding member is urged by the spring, the spring is not provided on the other end of the second holding member, and the position of the other end of the second holding member is regulated by the regulating member, and the temperature detection member is urged toward the heater via the regulating force of the spring, with the regulating position by the regulating member as a fulcrum and the urging position by the spring as a force point. [Effects of the Invention]

[0008] According to the configuration of the present invention, it is possible to provide a configuration for biasing the power interruption member without biasing both sides of the power interruption member with a plurality of biasing members. [Brief explanation of the drawings]

[0009] [Figure 1] Schematic diagram of an image forming apparatus [Figure 2] Cross-sectional view of the fixing device [Figure 3] Schematic diagram of the heating device and pressure roller [Figure 4] Thermostat unit schematic diagram [Figure 5] An exploded view showing the configuration of each component in the heating device [Figure 6] Longitudinal cross-sectional view of the heating device [Figure 7] Longitudinal cross section of the thermostat unit [Figure 8] Diagram showing the relationship of forces acting on the thermostat unit [Figure 9] An exploded view showing the configuration of each component in the heating device [Figure 10] Longitudinal cross-sectional view of the heating device [Figure 11] Longitudinal cross-sectional view of the heating device near the thermostat [Figure 12] An exploded view showing the configuration of each component in the heating device [Figure 13] Longitudinal cross-sectional view of the heating device [Figure 14] Longitudinal cross section of the thermostat unit DETAILED DESCRIPTION OF THE INVENTION

[0010] The following describes embodiments of the present invention with reference to the drawings. Note that the following embodiments do not limit the scope of the invention as claimed, and not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0011] (First embodiment) [Image forming device] FIG. 1 is a schematic diagram of an image forming apparatus 900. When a print signal is generated, a scanner unit 921 emits a laser beam modulated according to image information, and the laser beam scans a photosensitive drum 919, which is a photosensitive member charged to a predetermined polarity by a charging roller 916. This forms an electrostatic latent image on the photosensitive drum 919. Toner is supplied from a developing device 917 to this electrostatic latent image, and a toner image according to the image information is formed on the photosensitive drum 919. Meanwhile, sheets S loaded in a paper feed cassette 911 are fed one by one by a pickup roller 912 and transported by rollers 913 toward registration rollers 914. The sheets S are then transported from the registration rollers 914 to a transfer position in time with the timing at which the toner image on the photosensitive drum 919 reaches a transfer position where the toner image is formed between the photosensitive drum 919 and a transfer roller 920.

[0012] As the sheet S passes through the transfer position, the toner image on the photosensitive drum 919 is transferred to the sheet S. The sheet S is then heated by the fixing device 1, and the toner image is thermally fixed to the sheet S. The sheet S carrying the fixed toner image is discharged by rollers 926 and 927 onto a tray at the top of the image forming apparatus 900.

[0013] Any toner remaining on the photosensitive drum 919 is cleaned by a cleaner 918. A motor 930 is a drive source that drives the fixing device 1 and the like. Power is supplied to the fixing device 1 from a control circuit 940 connected to a commercial AC power supply 9411. The photosensitive drum 919, charging roller 916, scanner unit 921, developing device 917, and transfer roller 920 described above constitute an image forming means that forms an unfixed image on a sheet S. The cartridge 915 is a unit that can be replaced with respect to the image forming apparatus 900. The scanner unit 921 includes a light source 922, a polygon mirror 923, and a reflecting mirror 924.

[0014] [Fixing device] Next, the configuration of the fixing device 1 will be described with reference to Figures 2 and 3. Figure 2 is a cross-sectional view of the fixing device 1 in the conveying direction of the sheet S. The fixing device 1 has a heating device 2 having a cylindrical film 3 as a flexible, rotatable first rotating body, and a pressure roller 4 as a second rotating body that presses the heating device 2 with a pressure means (not shown) to form a nip portion N. By nipping and conveying the sheet S in the nip portion N, the toner image on the sheet S is heated, and the toner image is fixed onto the sheet S.

[0015] 3 is a schematic diagram of the heating device 2 and the pressure roller 4. The heating device 2 and the pressure roller 4 are supported at both ends in the longitudinal direction by a frame of the fixing device 1 (not shown). The pressure roller 4 is driven to rotate by a driving force transmitted from a driving source (not shown) to a driving gear 28. The film 3, which comes into contact with the pressure roller 4, is configured to rotate in response to the pressure roller 4.

[0016] A long and narrow heater 5 is disposed in the internal space of the film 3. The conveying direction of the sheet S in Figure 2 is the short side direction of the heater 5. This is the left-right direction in the figure. The direction perpendicular to the short side direction is the long side direction of the heater 5. This is the front-to-back direction in the figure. The direction perpendicular to the short side direction and the long side direction is the thickness direction of the heater 5. This is the up-and-down direction in the figure. The heater 5 is disposed so as to be able to slide along the inner surface of the film 3. Both ends of the film 3 in the long side direction are supported on the inner surface by flanges 29. Grease is applied between the heater 5 and the film 3 to improve sliding properties.

[0017] The heater 5 is configured to generate heat when it is energized and supplied with power by a power supply (not shown) from a connector 30, which serves as an electrical contact. The heater 5 is held in the internal space of the film 3 by a heater holder 7, which serves as a holding member and is disposed substantially parallel to the film 3. Furthermore, it is preferable that the nip N formed between the film 3 and the pressure roller 4 has a uniform width in the direction of the rotation axis, which is the longitudinal direction of the film 3. Therefore, to reinforce the heater holder 7 against the force of pressure contact, a metal frame member 8 is disposed on the heater holder 7 opposite the pressure roller 4, sandwiching the heater holder 7. The frame member 8 receives a pressing force from a pressure means (not shown) via flanges 29 provided on both ends. As will be described in more detail below, the frame member 8 as a reinforcing member can also be considered a restricting member that restricts the position of the thermostat holder 102. Furthermore, the heater holder 7, which serves as a holding member, can also be considered a restricting member that restricts the position of the thermostat holder 102, instead of the frame member 8.

[0018] 4 is a schematic diagram of the thermostat unit 100. A thermostat 101 serving as a power cutoff member is held by a thermostat holder 102 serving as a holding member. Abutment portion 101a of thermostat 101 forms an electrical contact via a bimetal inside. The surface of abutment portion 101a is positioned to abut against heater 5, and when heater 5 generates heat above a predetermined temperature, the bimetal reverses, releasing the electrical contact and cutting off the power supply (energization) to heater 5.

[0019] To ensure that the thermostat 101 responds quickly to the heat of the heater 5, it is desirable that the contact portion 101a be in stable contact with the heater 5. Therefore, a thermostat spring 103, which is a compression spring serving as a biasing member, presses the thermostat holder 102 against the heater 5. The electric wire 104 of the thermostat 101 is housed in an electric wire guide portion 102a of the thermostat holder 102. The thermostat spring 103 is located closer to the end of the thermostat 101 in the longitudinal direction than the folded-back portion 104a of the electric wire 104.

[0020] FIG. 5 is an exploded view showing the configuration of each component of the heating device 2. FIG. 6 is a longitudinal cross-sectional view of the heating device 2. FIG. 7 is a longitudinal cross-sectional view of the heating device 2 near a thermostat 101. The thermostat 101 is arranged so that a contact portion 101a engages with a hole 7a, which is an opening provided near the center of the heater holder 7 in the longitudinal direction. A thermostat holder 102 holding the thermostat 101 is located between the heater holder 7 and the frame member 8 in the thickness direction of the heater 5, that is, located between the heater holder 7 and the frame member 8. A thermostat spring 103 provided on one end of the thermostat holder 102 in the longitudinal direction of the heater 5 is engaged with the frame member 8 and presses the thermostat holder 102 against the heater 5. A fulcrum 102b provided on the other end of the thermostat holder 102 is also engaged with the frame member 8. That is, the position of the other end side of the thermostat holder 102 is restricted by the frame member 8.

[0021] FIG. 8 is a diagram showing the relationship of forces acting on thermostat holder 102. The distance from fulcrum 102b of thermostat holder 102 to thermostat spring 103 is 2L, and the distance from fulcrum 102b to contact portion 101a of thermostat 101 is L. One end of thermostat holder 102 is biased by thermostat spring 103, generating a biasing force F (indicated by the white arrow in FIG. 8). The biasing force F generates a moment T on the other end of thermostat holder 102. As a result, a force Fa (indicated by the black arrow in FIG. 8) acts on contact portion 101a. From the relationship T=F×2L=Fa×L, F=2F.

[0022] In this embodiment, the load of the thermostat spring 103 is set to 200 gf so that the contact portion 101a of the thermostat 101 contacts the heater 5 with a force of 400 gf. Note that here, the distances from the fulcrum 102b to the contact portion 101a and the thermostat spring 103 are set to a 1:2 relationship, but this is not limitative. If the distance relationship is changed, the spring pressure of the thermostat spring 103 may be changed appropriately based on the relationship of the moment forces described above.

[0023] In this way, one end of the thermostat 101 is biased by the thermostat spring 103, and the position of the fulcrum 102 on the other end is restricted by the frame member 8. This allows the contact portion 101a to be pressed against the heater 5 without the need for springs to bias both sides of the thermostat 101. Because the thermostat spring 103 need only be located on one side, the increase in space required by the spring can be suppressed, leading to a reduction in size. Furthermore, on the other side where the thermostat spring 103 is not located, the space created by not locating the spring can be used as space for wiring the electric wire 104, allowing the heating device 2 to be made more compact.

[0024] (Second embodiment) In this embodiment, the arrangement of the thermistor 201 will be described in addition to the thermostat 101. Note that the same components as those in the first embodiment, such as the image forming apparatus, will be denoted by the same reference numerals, and detailed description thereof will be omitted in this embodiment.

[0025] FIG. 9 is an exploded view showing the configuration of each component in the heating device 2. FIG. 10 is a longitudinal cross-sectional view of the heating device 2. FIG. 11 is a longitudinal cross-sectional view of the heating device 2 near the thermostat 101. In addition to the thermostat 101, the heating device 2 also has a thermistor 201, which is a temperature detection member, disposed in a hole 7b formed near the center of the heater holder 7 in the longitudinal direction. The thermistor 201 continuously detects the temperature of the heater 5, and based on the detection results of the thermistor 201, the CPU, which is control means, controls the power supply to the heater 5 so that the target temperature is reached.

[0026] The thermostat 101 is arranged so that its contact portion 101a engages with a hole 7a formed near the center of the heater holder 7 in the longitudinal direction. A thermostat holder 102 holding the thermostat 101 is arranged at a position sandwiched between the heater holder 7 and the frame member 8 in the thickness direction of the heater 5. A thermostat spring 103 provided on one end of the thermostat holder 102 in the longitudinal direction of the heater 5 is engaged with the frame member 8, pressing the thermostat holder 102 against the heater 5. A fulcrum 102b provided on the other end of the thermostat holder 102 is also engaged with the frame member 8. In other words, the position of the other end of the thermostat holder 102 is restricted by the frame member 8.

[0027] The thermistor 201 is disposed near the center of the heater holder 7 in the longitudinal direction and closer to the connector 30 in the longitudinal direction than the thermostat 101, with the temperature detection part 201a engaging with a hole 7b formed in the heater holder 7. In order for the thermistor 201 to stably detect the temperature of the heater 5, the temperature detection part 201a is pressed against the heater 5 with a desired pressure by a thermistor spring 204, as shown in FIG.

[0028] 11 , the electric wire 104 of the thermostat 101 is arranged so as to pass above the thermistor 201 in the thickness direction of the heater 5. To pass the electric wire 104 above the thermistor 201, a cable guide 202 is fixed to the heater holder 7 as a guide member that guides the electric wire 104 and engages a thermistor spring 204 that biases the thermistor 201 against the heater 5. A guide rib 202a of the cable guide 202 is arranged close to the frame member 8 to prevent the electric wire 104 from contacting the frame member 8 and to prevent the cable guide 202 from being deformed by the reaction force of the thermistor spring 204. The electric wire 104 is arranged so as to pass between the cable guide 202 and the guide rib 202a in the thickness direction of the heater 5 and is connected to the connector 30.

[0029] In this way, one end of thermostat 101 is biased by thermostat spring 103, and the position of fulcrum 102 on the other end is restricted by frame member 8. This allows contact portion 101a to be pressed against heater 5 without biasing both sides of thermostat 101 with springs. Because thermostat spring 103 need only be located on one side, the increase in space required for the spring can be suppressed, and heating device 2 can be made smaller by passing electric wire 104 above the thermistor 201, which is located in the same direction.

[0030] (Third embodiment) In this embodiment, the arrangement of the thermistor 201 will be described in addition to the thermostat 101. Note that the same components as those in the first and second embodiments, such as the image forming apparatus, will be denoted by the same reference numerals, and detailed description thereof will be omitted in this embodiment.

[0031] Fig. 12 is an exploded view showing the configuration of each component in the heating device 2. Fig. 13 is a longitudinal cross-sectional view of the heating device 2. Fig. 14 is a longitudinal cross-sectional view of the heating device 2 near the thermostat 101. In addition to the thermostat 101, the heating device 2 also has a thermistor 201 disposed in a hole 7b provided near the center of the heater holder 7 in the longitudinal direction. The thermistor 201 continuously detects the temperature of the heater 5, and based on the detection results of the thermistor 201, the CPU, which is control means, controls the power supply to the heater 5 so that the target temperature is reached.

[0032] The thermostat 101 is arranged so that its contact portion 101a engages with a hole 7a formed near the center of the heater holder 7 in the longitudinal direction. The thermostat holder 102, which holds the thermostat 101, is arranged at a position sandwiched between the heater holder 7 and the frame member 8 in the thickness direction of the heater 5. The thermistor 201 is arranged near the center of the heater holder 7 in the longitudinal direction and closer to the connector 30 in the longitudinal direction than the thermostat 101, so that its temperature detection portion 201a engages with a hole 7b formed in the heater holder 7. In order for the thermistor 201 to stably detect the temperature of the heater 5, the temperature detection portion 201a is pressed against the heater 5 with a desired pressure by a thermistor spring 204.

[0033] As shown in Fig. 12, the electric wire 104 of the thermostat 101 is arranged so as to pass above the thermistor 201 in the thickness direction of the heater 5. In order to pass the electric wire 104 above the thermistor 201, a wire guide 202 is fixed to the heater holder 7 as shown in Fig. 13. The wire guide 202 guides the electric wire 104 and engages a thermistor spring 204 that biases the thermistor 201 against the heater 5. Specifically, the wire guide 202 is fixed to the shaft 7c of the heater holder 7 with a push nut 301. The push nut 301 is a fastener that is inserted from a certain direction onto a shaft without grooves, with its claws on the inner diameter side gripping the outer diameter of the shaft to fix it in place. 14, the guide rib 202a of the cable guide 202 is disposed close to the frame member 8, preventing the electric wires 104 from contacting the frame member 8 and preventing the cable guide 202 from being deformed by the reaction force of the thermistor spring 204. The electric wires 104 are disposed so as to pass between the cable guide 202 and the guide rib 202a in the thickness direction of the heater 5, and are connected to the connector 30.

[0034] A fulcrum 102b provided on the other end side of the thermostat holder 102 is locked by a locking portion 202b of the cable guide 202. In other words, the position is restricted by the locking portion 202b. The locking portion 202b can be considered a restricting member that restricts the position of the thermostat holder 102 instead of the frame member 8. The thermostat holder 102 is held on the heater holder 7. By attaching the frame member 8 to this, the thermostat spring 103 provided on one end side of the thermostat holder 102 is locked to the frame member 8. The guide rib 202a and the locking portion 202b of the cable guide 202 are disposed adjacent to the frame member 8 and are locked to the frame member 8. This prevents the electric wires 104 from contacting the frame member 8 and prevents the cable guide 202 from being deformed by the reaction force of the thermistor spring 204. The locking portion 202b of the cable guide 202 may be locked by another member such as the heater holder 7 instead of the frame member 8.

[0035] In this way, one end of thermostat 101 is biased by thermostat spring 103, and the position of fulcrum 102 on the other end is restricted by locking portion 202b. This allows contact portion 101a to be pressed against heater 5 without biasing both sides of thermostat 101 with springs. Because thermostat spring 103 need only be located on one side, the increase in space required for the spring can be suppressed, and heating device 2 can be made smaller by passing electric wire 104 above the thermistor 201, which is located in the same direction.

[0036] The configuration for biasing the thermostat unit 100 in the first to third embodiments can also be applied as a configuration for biasing the thermistor 201 instead of the thermostat 101. Like the thermostat 101, the thermistor 201 is held in a holder, which is a holding member. As described above, one end of the holder holding the thermistor 201 can be biased by a biasing member, and the other end can be restricted by a restricting member. Also, in the above description, the thermostat spring 103 that biases one end of the thermostat 101 is configured to be engaged with the frame member 8. However, as long as the pressing force of the thermostat spring 103 can be applied to the thermostat 101, the thermostat spring 103 may be engaged with another member, such as the heater holder 7, instead of the frame member 8. [Explanation of symbols]

[0037] 2 Heating device 8 Frame members 101 Thermostat 103 Thermostat spring

Claims

1. A cylindrical first rotating body, an elongated heater disposed in the internal space of the first rotor and parallel to the longitudinal direction of the first rotor; a first holding member that holds the heater in the longitudinal direction of the heater; a second rotating body that is in contact with an outer circumferential surface of the first rotating body, sandwiching the first rotating body together with the heater to form a nip portion between the second rotating body and the first rotating body; a power cutoff member that is disposed in the internal space of the first rotating body and that is activated when an abnormal temperature rise occurs in the heater to cut off the supply of power to the heater; a second holding member disposed in the internal space of the first rotating body and configured to hold the power interruption member; a spring that biases the power cutoff member toward the heater; a restricting member that restricts the position of the second holding member; a heating device for heating an image formed on a sheet while conveying the sheet through the nip portion, In the longitudinal direction, one end side of the second holding member is biased by the spring, the spring is not provided on the other end side of the second holding member, and the position of the other end side of the second holding member is restricted by the restricting member, A heating device characterized in that the power cut-off member is urged toward the heater via the second retaining member by the urging force of the spring, with the regulating position of the regulating member as a fulcrum and the urging position of the spring as a force point.

2. 2. The heating device according to claim 1, wherein the spring is engaged with the restricting member.

3. A first electric wire and a second electric wire are connected to an end of the power interrupting member close to the one end side of the second holding member and an end of the power interrupting member close to the other end side of the second holding member, respectively; the first electric wire extends from the power interruption member toward the one end side of the second holding member and is folded back midway toward the other end side of the second holding member, 2. The heating device according to claim 1, wherein the spring biases the second holding member at a position closer to the one end than the position where the electric wire is folded back.

4. a temperature detection member that detects a temperature; a third holding member that holds the temperature detection member; a second spring for biasing the temperature sensing member toward the heater; a first guide member that guides the first electric wire and the second electric wire, the first guide member is disposed between the temperature detecting member and the regulating member in a thickness direction perpendicular to the longitudinal and lateral directions of the heater, 4. The heating device according to claim 3, wherein the second spring is engaged with the first guide member.

5. a second guide member that guides the first electric wire and the second electric wire, the second guide member is disposed between the first guide member and the regulating member in the thickness direction, 5. The heating device according to claim 4, wherein the first electric wire and the second electric wire are disposed between the first guide member and the second guide member in the thickness direction.

6. 6. The heating device according to claim 1, wherein the power cutoff member is inserted into an opening in the first holding member and abuts against the heater.

7. The heating device according to any one of claims 1 to 6, wherein the power cut-off member is arranged between the first holding member and the regulating member in a thickness direction perpendicular to the longitudinal and lateral directions of the heater.

8. 8. The heating device according to claim 1, wherein the regulating member is a member that reinforces the first holding member.

9. 2. The heating device according to claim 1, wherein the regulating member is a part of the first holding member.

10. a first electric wire and a second electric wire connected to the power interruption member; 2. The heating device according to claim 1, wherein the restricting member is a member that guides the first electric wire and the second electric wire.

11. the first rotating body is a cylindrical film, the second rotating body is a pressure roller, 11. The heating device according to claim 1, wherein the heater contacts an inner peripheral surface of the cylindrical film.

12. A cylindrical first rotating body, an elongated heater disposed in the internal space of the first rotor and parallel to the longitudinal direction of the first rotor; a first holding member that holds the heater in the longitudinal direction of the heater; a second rotating body that is in contact with an outer circumferential surface of the first rotating body, sandwiching the first rotating body together with the heater to form a nip portion between the second rotating body and the first rotating body; a temperature detection member disposed in the internal space of the first rotating body and configured to detect a temperature of the heater; a second holding member disposed in the internal space of the first rotating body and configured to hold the temperature detecting member; a spring that biases the temperature detection member toward the heater; a restricting member that restricts the position of the second holding member; a heating device for heating an image formed on a sheet while conveying the sheet through the nip portion, In the longitudinal direction, one end side of the second holding member is biased by the spring, the spring is not provided on the other end side of the second holding member, and the position of the other end side of the second holding member is restricted by the restricting member, A heating device characterized in that the temperature detection member is urged toward the heater via the second holding member by the urging force of the spring, with the regulating position of the regulating member as a fulcrum and the urging position of the spring as a force point.

13. an image forming means for forming an image on the sheet; An image forming apparatus comprising: the heating device according to claim 1 , which fixes an image formed on a sheet onto the sheet.

Images