Heating device and image processing device

Abstract

The present invention relates to a heating device and an image processing device. In an embodiment, the heating device comprises a cylindrical body, a heater unit, a support member, a first heat conducting portion, and a second heat conducting portion. The cylindrical body has a thin film shape. The heater unit is arranged on the inner side of the cylindrical body. The heater unit sets the axial direction of the cylindrical body as the long side direction. The support member supports the heater unit. The first heat conducting portion is arranged between the inner surface of the cylindrical body and the heater unit. The first heat conducting portion abuts against the first surface of the heater unit. The second heat conducting portion is arranged between the heater unit and the support member. The second heat conducting portion abuts against the second surface of the heater unit on the side opposite to the first surface.

Description

Technical Field

[0001] The present invention relates to a heating device and an image processing device. Background Art

[0002] An image forming device for forming an image on a sheet is used as an image processing device. The image forming device includes a heating device for fixing a toner (recording agent) to the sheet. The heating device includes a cylindrical body and a heater unit. The cylindrical body has a thin film shape. The heater unit is disposed inside the cylindrical body. The heater unit is oriented such that the axial direction of the cylindrical body is the longitudinal direction. When a sheet passing through the heating device is heated, a temperature distribution is generated in the heater unit according to the size of the sheet. The temperature distribution of the heater unit is sought to be uniform in the heating device. Summary of the Invention

[0003] A heating device according to an embodiment includes: a thin film-shaped cylindrical body; a heater unit, which is arranged on the inner side of the cylindrical body and has the axial direction of the cylindrical body as the long side direction; a support component, which supports the heater unit; a first heat conducting portion, which is arranged between the inner surface of the cylindrical body and the heater unit and abuts against the first surface of the heater unit; and a second heat conducting portion, which is arranged between the heater unit and the support component and abuts against the second surface of the heater unit on the side opposite to the first surface.

[0004] The image processing apparatus according to the embodiment includes the above-mentioned heating device. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Figure 1 This is a schematic diagram of the configuration of an image processing device according to an embodiment.

[0006] Figure 2 This is a diagram showing the hardware configuration of the image processing device according to the embodiment.

[0007] Figure 3 It is a front cross-sectional view of the heating device according to the embodiment.

[0008] Figure 4 This is a front sectional view of the heater unit.

[0009] Figure 5 This is a bottom view of the heater unit.

[0010] Figure 6 This is a top view of the heater thermometer and thermostat.

[0011] Figure 7 This is an electrical circuit diagram of the heating device according to the embodiment.

[0012] Figure 8 It is a front cross-sectional view of a heating device according to a first modified example of the embodiment.

[0013] Figure 9 It is a front cross-sectional view of a heating device according to a second modified example of the embodiment. DETAILED DESCRIPTION

[0014] The heating device of the embodiment includes a cylindrical body, a heater unit, a support member, a first heat conducting portion, and a second heat conducting portion. The cylindrical body has a thin film shape. The heater unit is arranged on the inner side of the cylindrical body. The heater unit sets the axial direction of the cylindrical body as the longitudinal direction. The support member supports the heater unit. The first heat conducting portion is arranged between the inner surface of the cylindrical body and the heater unit. The first heat conducting portion abuts against the first surface of the heater unit. The second heat conducting portion is arranged between the heater unit and the support member. The second heat conducting portion abuts against the second surface of the heater unit on the side opposite to the first surface.

[0015] Hereinafter, a heating device and an image processing device according to embodiments will be described with reference to the drawings.

[0016] Figure 1 This is a schematic diagram of the configuration of an image processing device according to an embodiment.

[0017] The image processing apparatus according to the embodiment is an image forming apparatus 1. The image forming apparatus 1 performs a process of forming an image on a sheet (paper).

[0018] The image forming apparatus 1 includes a housing 10 , a scanner section 2 , an image forming unit 3 , a sheet feeding section 4 , a conveying section 5 , a paper discharge tray 7 , a reversing unit 9 , a control panel 8 , and a control section 6 .

[0019] The housing 10 forms the outer appearance of the image forming apparatus 1 .

[0020] The scanner unit 2 reads image information of the copy object as light and dark, generates an image signal, and outputs the generated image signal to the image forming unit 3 .

[0021] The image forming unit 3 forms an output image (hereinafter referred to as a toner image) using a recording agent such as toner based on an image signal received from the scanner unit 2 or an image signal received from the outside. The image forming unit 3 transfers the toner image onto the surface of the sheet S. The image forming unit 3 heats and pressurizes the toner image on the surface of the sheet S to fix the toner image to the sheet S. The image forming unit 3 will be described in detail later.

[0022] The sheet feeding section 4 feeds the sheets S one by one to the conveying section 5 in accordance with the timing of forming a toner image by the image forming unit 3. The sheet feeding section 4 includes a sheet storage section 20 and a pickup roller 21.

[0023] The sheet storage section 20 stores sheets S of predetermined sizes and types.

[0024] The pickup roller 21 takes out the sheets S one by one from the sheet storage unit 20 . The pickup roller 21 supplies the taken-out sheets S to the conveying unit 5 .

[0025] The conveying section 5 conveys the sheet S supplied from the sheet supply section 4 to the image forming unit 3 . The conveying section 5 includes a conveying roller 23 and registration rollers 24 .

[0026] The conveying roller 23 conveys the sheet S supplied from the pickup roller 21 toward the registration roller 24 . The conveying roller 23 causes the leading end of the sheet S in the conveying direction to strike the nip N of the registration roller 24 .

[0027] The registration rollers 24 align the position of the leading end of the sheet S in the conveying direction by bending the sheet S in the nip N. The registration rollers 24 convey the sheet S in accordance with the timing at which the image forming unit 3 transfers the toner image to the sheet S.

[0028] The image forming unit 3 will be described.

[0029] The image forming unit 3 includes a plurality of image forming sections 25 , a laser scanning unit 26 , an intermediate transfer belt 27 , a transfer section 28 , and a fixing device 30 .

[0030] The image forming unit 25 includes a photoreceptor drum 25d. The image forming unit 25 forms a toner image on the photoreceptor drum 25d in response to an image signal from the scanner unit 2 or externally. The multiple image forming units 25Y, 25M, 25C, and 25K form toner images using yellow, magenta, cyan, and black toners, respectively.

[0031] A charger, developer, and other components are located around the photoreceptor drum 25d. The charger charges the surface of the photoreceptor drum 25d. The developer contains developer, which includes yellow, magenta, cyan, and black toners. The developer develops the electrostatic latent image on the photoreceptor drum 25d. As a result, a toner image based on the toner of each color is formed on the photoreceptor drum 25d.

[0032] The laser scanning unit 26 scans the charged photoreceptor drum 25d with laser light L, exposing the photoreceptor drum 25d. The laser scanning unit 26 uses laser light LY, LM, LC, and LK to expose the photoreceptor drums 25d of the image forming units 25Y, 25M, 25C, and 25K, respectively, for each color. This forms an electrostatic latent image on the photoreceptor drum 25d.

[0033] The toner image on the surface of the photoreceptor drum 25 d is primarily transferred to the intermediate transfer belt 27 .

[0034] The transfer section 28 transfers the toner image primarily transferred onto the intermediate transfer belt 27 onto the surface of the sheet S at a secondary transfer position.

[0035] The fixing device 30 heats and pressurizes the toner image transferred to the sheet S, thereby fixing the toner image to the sheet S. The fixing device 30 will be described in detail later.

[0036] The reversing unit 9 reverses the sheet S to form an image on the back side of the sheet S. The reversing unit 9 reverses the sheet S discharged from the fixing device 30 in a zigzag pattern. The reversing unit 9 conveys the reversed sheet S toward the registration rollers 24 .

[0037] The paper discharge tray 7 places the discharged sheet S on which an image is formed.

[0038] The control panel 8 is a part of an input unit for inputting information used by an operator to operate the image forming apparatus 1. The control panel 8 includes a touch panel and various hardware keys.

[0039] The control unit 6 controls each unit of the image forming apparatus 1. The control unit 6 will be described in detail later.

[0040] Figure 2 This is a hardware configuration diagram of an image processing device according to an embodiment. Image forming device 1 includes a CPU (Central Processing Unit) 91, memory 92, auxiliary storage device 93, and other components connected by a bus, and executes programs. Through program execution, image forming device 1 functions as a device comprising a scanner 2, an image forming unit 3, a sheet feeding unit 4, a conveying unit 5, a reversing unit 9, a control panel 8, and a communication unit 90.

[0041] The CPU 91 functions as the control unit 6 by executing programs stored in the memory 92 and the auxiliary storage device 93. The control unit 6 controls the operation of each functional unit of the image forming apparatus 1.

[0042] The auxiliary storage device 93 is configured using a storage device such as a hard disk device or a semiconductor storage device. The auxiliary storage device 93 stores information.

[0043] The communication unit 90 includes a communication interface for connecting the device to an external device. The communication unit 90 communicates with the external device via the communication interface.

[0044] The fixing device 30 will be described in detail.

[0045] Figure 3 2 is a front cross-sectional view of a heating device according to an embodiment. The heating device according to the embodiment is a fixing device 30. The fixing device 30 includes a pressure roller 30p and a film unit 30h.

[0046] The pressure roller 30 p forms a nip N with the film unit 30 h. The pressure roller 30 p presses the toner image on the sheet S entering the nip N. The pressure roller 30 p rotates to convey the sheet S. The pressure roller 30 p includes a metal core 32 , an elastic layer 33 , and a release layer 34 .

[0047] The metal core 32 is formed into a cylindrical shape from a metal material such as stainless steel. Both axial ends of the metal core 32 are supported for rotation. The metal core 32 is driven by a motor (not shown). The metal core 32 abuts against a cam member (not shown). The rotation of the cam member moves the metal core 32 toward and away from the membrane unit 30h.

[0048] The elastic layer 33 is formed of an elastic material such as silicone rubber and is formed on the outer peripheral surface of the metal core 32 with a certain thickness.

[0049] The mold release layer 34 is formed of a resin material such as PFA (a copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether) and is formed on the outer peripheral surface of the elastic layer 33 .

[0050] For example, when the outer diameter of the pressure roller 30 p is 20 mm to 40 mm, the outer diameter of the metal core 32 is preferably set to 10 mm to 20 mm, the thickness of the elastic layer 33 is set to 5 mm to 20 mm, and the thickness of the release layer 34 is set to 20 μm to 40 μm.

[0051] The hardness of the outer peripheral surface of the pressure roller 30 p is preferably 40° to 70° under an ASKER-C hardness load of 9.8 N. This ensures the area of ​​the nip N and the durability of the pressure roller 30 p.

[0052] The pressure roller 30p contacts and separates from the film unit 30h via a linkage mechanism utilizing, for example, a cam. When the pressure roller 30p contacts the film unit 30h and is pressed by the pressure spring, a nip N is formed. If a sheet S becomes clogged in the fixing device 30, the pressure roller 30p can be separated from the film unit 30h to remove the sheet S. Furthermore, when the cylindrical film 35 is stopped, such as during sleep mode, plastic deformation of the cylindrical film 35 is prevented by separating the pressure roller 30p from the film unit 30h.

[0053] The pressure roller 30p is driven by a motor to rotate. When the pressure roller 30p rotates with the nip N formed, the cylindrical film 35 of the film unit 30h rotates accordingly. The pressure roller 30p rotates with the sheet S positioned in the nip N, thereby conveying the sheet S in the conveyance direction W.

[0054] The film unit 30h heats the toner image on the sheet S entering the nip N. The film unit 30h includes a cylindrical film (cylindrical body) 35, a heater unit 40, a first heat-equalizing member 49 (first heat transfer portion), a second heat-equalizing member 50 (second heat transfer portion), a lubricating layer 51, a supporting member 36, a stay 38, a heater thermometer 62, a thermostat 68, and a film thermometer 64.

[0055] The cylindrical film 35 is formed into a cylindrical shape. It comprises, in order from the inner circumference, a base layer, an elastic layer, and a release layer. The base layer is formed into a cylindrical shape from a material such as nickel (Ni). The elastic layer is laminated on the outer circumference of the base layer. The elastic layer is formed from an elastic material such as silicone rubber. The release layer is laminated on the outer circumference of the elastic layer. The release layer is formed from a material such as PFA resin.

[0056] To shorten the preheating time, the thicknesses of the elastic layer and the release layer are preferably set so that their respective thermal capacitances do not become excessively large. For example, if the inner diameter of the tubular film 35 is 20 mm to 40 mm, the base layer can be 30 μm to 50 μm thick, the elastic layer 100 μm to 300 μm thick, and the release layer 20 μm to 40 μm thick. To improve frictional sliding properties with the first heat-balancing member 49, the inner side of the base layer can also be coated (e.g., with a fluorine coating).

[0057] Figure 4 yes Figure 5 Front cross-sectional view of the heater unit along line IV-IV. Figure 5 2 is a bottom view of the heater unit (viewed from the +z direction). The heater unit 40 includes a substrate (heat generating substrate) 41 , a heat generating element module 45 , and a wiring module 55 .

[0058] The substrate 41 is formed of a metal material such as stainless steel or a ceramic material such as aluminum nitride. The substrate 41 is formed in an elongated rectangular plate shape. The substrate 41 is positioned radially inward of the cylindrical film 35. The substrate 41 has its longitudinal direction oriented in the axial direction of the cylindrical film 35.

[0059] In the present application, the x direction, the y direction, and the z direction are defined as follows.

[0060] The y direction is the longitudinal direction of the substrate 41 (heater unit 40). As described below, the +y direction is the direction from the central heating element 45a toward the first end heating element 45b1.

[0061] The x direction is the short-side direction of the substrate 41. The +x direction is the conveyance direction of the sheet S (downstream direction).

[0062] The z direction is the normal direction of the substrate 41. The +z direction is the direction in which the heating element assembly 45 is arranged relative to the substrate 41. An insulating layer 43 is formed of a glass material or the like on the +z direction surface of the substrate 41. The +z direction surface (first surface 40a) of the heater unit 40 is connected to the cylindrical film 35 (see FIG. 1 ) via the first heat-dissipating member 49. Figure 3 ) are opposite to the inner circumference of the .

[0063] The heating element assembly 45 is formed on the +z direction surface of the insulating layer 43. The heating element assembly 45 is formed of a silver-palladium alloy, etc. The outer shape of the heating element assembly 45 is formed into a rectangular shape with the y direction as the longitudinal direction and the x direction as the lateral direction.

[0064] like Figure 5 As shown, the heating element module 45 includes a plurality of heating elements 45b1, 45a, and 45b2 arranged along the y direction. The heating element module 45 includes a first end heating element 45b1, a center heating element 45a, and a second end heating element 45b2 arranged in parallel along the y direction.

[0065] The central heating element 45a is arranged at the central portion in the y direction of the heating element unit 45. The central heating element 45a may be formed by combining a plurality of small heating elements arranged in a row in the y direction.

[0066] The first end portion heating element 45 b 1 is disposed in the +y direction of the central portion heating element 45 a and at the end portion of the heating element unit 45 in the +y direction.

[0067] The second end portion heating element 45 b 2 is disposed at the end portion of the heating element unit 45 in the −y direction relative to the central portion heating element 45 a .

[0068] The boundary between the central heating element 45a and the first end heating element 45b1 is arranged parallel to the x-direction. The boundary between the central heating element 45a and the first end heating element 45b1 may also be arranged to intersect the x-direction. The same applies to the boundary between the central heating element 45a and the second end heating element 45b2.

[0069] The heating element assembly 45 generates heat by being energized. The resistance value of the central heating element 45a is smaller than the resistance values ​​of the first end heating element 45b1 and the second end heating element 45b2. The resistance values ​​of the first end heating element 45b1 and the second end heating element 45b2 are substantially the same. Here, the resistance value of the central heating element 45a is set as "central resistance value A", and the resistance value of the first end heating element 45b1 (second end heating element 45b2) is set as "end resistance value B". For example, the ratio of the central resistance value A to the end resistance value B (A:B) is preferably in the range of 3:1 to 7:1, and more preferably in the range of 4:1 to 6:1.

[0070] The sheet S having a small width in the y direction passes through the center portion of the fixing device 30 in the y direction. In this case, the control unit 6 only generates heat from the center heating element 45a. On the other hand, in the case of a sheet S having a large width in the y direction, the control unit 6 generates heat from the entire heating element assembly 45. Therefore, the center heating element 45a, the first end heating element 45b1, and the second end heating element 45b2 are controlled to generate heat independently of each other. In addition, the first end heating element 45b1 and the second end heating element 45b2 are also controlled to generate heat in the same manner.

[0071] The wiring assembly 55 is formed of a metal material such as silver and includes a central contact 52 a , a central wiring 53 a , an end contact 52 b , a first end wiring 53 b 1 , a second end wiring 53 b 2 , a common contact 58 , and a common wiring 57 .

[0072] The central contact 52 a is arranged in the −y direction of the heat generating element module 45 .

[0073] The central wiring 53a is arranged in the +x direction of the heat generating element module 45. The central wiring 53a connects the end side in the +x direction of the central heat generating element 45a and the central contact 52a.

[0074] The end contact 52b is arranged in the -y direction of the central contact 52a.

[0075] The first end wiring 53b1 is arranged in the +x direction of the heating element module 45 and the +x direction of the central wiring 53a. The first end wiring 53b1 connects the +x direction end side of the first end heating element 45b1 to the +x direction end of the end contact 52b.

[0076] The second end wiring 53b2 is arranged in the +x direction of the heating element module 45 and in the -x direction of the central wiring 53a. The second end wiring 53b2 connects the +x end of the second end heating element 45b2 to the -x end of the end contact 52b.

[0077] The common contact 58 is arranged in the +y direction of the heat generating element assembly 45 .

[0078] The common wiring 57 is arranged in the −x direction of the heat generating element module 45. The common wiring 57 connects the −x direction edges of the central heat generating element 45a, the first end heat generating element 45b1, and the second end heat generating element 45b2 to the common contact 58.

[0079] Thus, the second end wiring 53b2, the central wiring 53a, and the first end wiring 53b1 are arranged in the +x direction of the heat generating element 45. In contrast, only the common wiring 57 is arranged in the -x direction of the heat generating element 45. Therefore, the center 45c of the heat generating element 45 in the x direction is arranged closer to the -x direction than the center 41c of the substrate 41 in the x direction.

[0080] like Figure 3 As shown, a straight line CL is defined connecting the center pc of the pressure roller 30p and the center hc of the film unit 30h. The center 41c of the substrate 41 in the x-direction is positioned closer to the +x direction than the straight line CL. The center 49c of the first heat-leveling member 49 in the x-direction coincides with the center 41c of the substrate 41 in the x-direction. The +x-direction end of the first heat-leveling member 49 (the downstream end in the conveyance direction of the sheet S) coincides with the +x-direction end of the substrate 41. Thus, the first heat-leveling member 49 extends in the +x-direction of the nip N, making it easier for the sheet S to be peeled from the film unit 30h after passing through the nip N.

[0081] The center 45c of the heating element unit 45 in the x direction is located on the straight line CL. The heating element unit 45 is entirely included in the area of ​​the nip N and is located at the center of the nip N. This makes the heat distribution in the nip N uniform, and the sheet S passing through the nip N is evenly heated.

[0082] like Figure 4 As shown, a heating element assembly 45 and a wiring assembly 55 are formed on the +z direction surface of the insulating layer 43. A protective layer 46 is formed of a glass material or the like so as to cover the heating element assembly 45 and the wiring assembly 55. The protective layer 46 protects the heating element assembly 45 and the wiring assembly 55.

[0083] like Figure 3 As shown, the heater unit 40 is arranged inside the cylindrical film 35. The surface of the heater unit 40 in the +z direction (the first surface 40a, see Figure 4 ) is opposite to the roller gap N via the first heat equalizing component 49.

[0084] The first heat-scaling member 49 is oriented longitudinally along the axial direction of the cylindrical film 35. The first heat-scaling member 49 is formed into a rectangular plate shape. The outer shape of the first heat-scaling member 49 is the same as that of the substrate 41 of the heater unit 40. The first heat-scaling member 49 preferably has the same length as that of the substrate 41 of the heater unit 40 in the x- and y-directions.

[0085] The first heat-equalizing member 49 is disposed between the inner surface of the cylindrical film 35 and the heater unit 40. The first heat-equalizing member 49 is disposed on the heating element assembly 45 side of the substrate 41 of the heater unit 40. The first heat-equalizing member 49 is disposed on the +z direction surface (first surface 40a, see Figure 4 )Contact configuration.

[0086] The first heat sink member 49 has a higher thermal conductivity than the substrate 41 of the heater unit 40. The first heat sink member 49 has a higher thermal conductivity than the second heat sink member 50. For example, when the substrate 41 and the second heat sink member 50 are made of stainless steel, the first heat sink member 49 is formed of a metal material such as copper or aluminum or carbon. The thickness of the first heat sink member 49 is preferably not more than the thickness of the second heat sink member 50.

[0087] The second heat sink member 50 sets the axial direction of the cylindrical film 35 as the long side direction. The second heat sink member 50 is formed in a rectangular plate shape similarly to the first heat sink member 49. The second heat sink member 50 is formed of a member different from the first heat sink member 49. The outer shape of the second heat sink member 50 is the same as the outer shape of the substrate 41 of the heater unit 40. The second heat sink member 50 preferably has the same length as the substrate 41 of the heater unit 40 in the x direction and the y direction.

[0088] The second heat sink member 50 is disposed between the heater unit 40 and the support member 36. The second heat sink member 50 is disposed on the side opposite to the heating element assembly 45 side of the substrate 41 of the heater unit 40. The second heat sink member 50 is in contact with the -z direction surface (second surface 40b, refer to Figure 4 )Contact configuration.

[0089] The second heat sink member 50 has a higher thermal conductivity than the substrate 41 of the heater unit 40. The second heat sink member 50 has a lower thermal conductivity than the first heat sink member 49. For example, when the substrate 41 is made of stainless steel and the first heat sink member 49 is made of copper, the second heat sink member 50 is formed of a metal material such as aluminum.

[0090] The contact area A2 of the second heat sink member 50 with the support member 36 is smaller than the contact area A1 of the first heat sink member 49 with the heater unit 40 (A2 < A1). The contact surface (-z direction surface) of the first heat sink member 49 with the heater unit 40 is a flat surface. The contact surface (-z direction surface) of the second heat sink member 50 with the support member 36 is a flat surface.

[0091] The lubricating layer 51 is disposed between the inner surface of the cylindrical film 35 and the first heat sink member 49. For example, the lubricating layer 51 is a fluorine coating formed on the +z direction surface (first surface 49a) of the first heat sink member 49. The lubricating layer 51 is formed over the entire first surface 49a of the first heat sink member 49. Thereby, the slidability between the first heat sink member 49 and the cylindrical film 35 is ensured.

[0092] The thickness of the lubricating layer 51 is preferably set so as not to hinder as much as possible the heat transfer from the heater unit 40 to the tubular film 35. For example, the thickness of the lubricating layer 51 may be set to 1 μm or more and 100 μm or less.

[0093] Grease (not shown) may also be applied to the inner peripheral surface of the cylindrical film 35. In this case, the grease is arranged on the lubricating layer 51 (see Figure 3 ) and the inner circumferential surface of the cylindrical film 35. The first heat-leveling member 49 contacts the inner circumferential surface of the cylindrical film 35 via the lubricating layer 51 and the grease. When the heater unit 40 generates heat, the viscosity of the grease decreases. This ensures the sliding properties between the first heat-leveling member 49 and the cylindrical film 35.

[0094] The support member 36 is formed from an elastic material such as silicone rubber or fluororubber, or a resin material such as polyimide resin, PPS (polyphenylene sulfide), PES (polyethersulfone), or liquid crystal polymer. The support member 36 is arranged to cover both sides of the heater unit 40 in the -z and x directions. The support member 36 supports the heater unit 40 via the second heat-scaling member 50. Rounded chamfers are formed at both ends of the support member 36 in the x direction. The support member 36 supports the inner circumference of the tubular film 35 at both ends of the heater unit 40 in the x direction.

[0095] When the sheet S passing through the fixing device 30 is heated, a temperature distribution occurs in the heater unit 40 depending on the size of the sheet S. If the temperature in the heater unit 40 reaches a localized high temperature, there is a possibility that the temperature may exceed the heat resistance of the support member 36 formed of a resin material. The second heat equalizing member 50 evens out the temperature distribution in the heater unit 40, thereby ensuring the heat resistance of the support member 36.

[0096] The stay 38 is formed of a steel plate material or the like. The cross section perpendicular to the y direction of the stay 38 is formed into a U shape. For example, the stay 38 is formed by bending a steel material having a thickness of 1 mm to 3 mm. The stay 38 is mounted on the -z direction of the support member 36 in such a manner that the support member 36 blocks the opening of the U shape. The stay 38 extends in the y direction. Both ends of the stay 38 in the y direction are fixed to the housing of the image forming device 1. Thus, the film unit 30h is supported on the image forming device 1. The stay 38 increases the bending rigidity of the film unit 30h. Flanges (not shown) for limiting the movement of the tubular film 35 in the y direction are mounted near both ends of the stay 38 in the y direction.

[0097] The heater thermometer 62 is positioned in the -z direction relative to the heater unit 40, across the second uniform heat member 50. For example, the heater thermometer 62 is a thermistor. The heater thermometer 62 is mounted on and supported by the -z surface of the support member 36. The temperature sensing element of the heater thermometer 62 contacts the second uniform heat member 50 via a hole extending through the support member 36 in the z direction. The heater thermometer 62 measures the temperature of the heater unit 40 via the second uniform heat member 50.

[0098] The thermostat 68 is arranged similarly to the heater thermometer 62. The thermostat 68 is incorporated into an electrical circuit described later. The thermostat 68 shuts off power to the heating element assembly 45 when the temperature of the heater unit 40 detected by the second heat equalizing member 50 exceeds a predetermined temperature.

[0099] Figure 6 This is a top view of the heater thermometer and the thermostat (viewed from the -z direction). Figure 6 The description of the support member 36 is omitted. In addition, the following description of the arrangement of the heater thermometer, the thermostat, and the thin film thermometer is for describing the arrangement of the respective temperature sensing elements.

[0100] The plurality of heater thermometers 62 (62a, 62b) are arranged in a row along the y-direction. The plurality of heater thermometers 62 are disposed on the heating element assembly 45. The plurality of heater thermometers 62 are disposed within the y-direction range of the heating element assembly 45. The plurality of heater thermometers 62 are disposed at the center of the heating element assembly 45 in the x-direction. That is, when viewed from the z-direction, the plurality of heater thermometers 62 and the heating element assembly 45 at least partially overlap.

[0101] The plurality of thermostats 68 ( 68 a , 68 b ) are also arranged in the same manner as the plurality of heater thermometers 62 described above.

[0102] The plurality of heater thermometers 62 include a central heater thermometer 62 a and an end heater thermometer 62 b (a thermometer disposed on one side in the longitudinal direction).

[0103] The central heater thermometer 62a measures the temperature of the central heating element 45a. The central heater thermometer 62a is disposed within the central heating element 45a. That is, the central heater thermometer 62a overlaps the central heating element 45a when viewed in the z direction.

[0104] The end heater thermometer 62b measures the temperature of the second end heating element 45b2. As previously described, the first end heating element 45b1 and the second end heating element 45b2 are controlled to generate heat in the same manner. Therefore, the temperature of the first end heating element 45b1 is the same as the temperature of the second end heating element 45b2. The end heater thermometer 62b is positioned within the range of the second end heating element 45b2. That is, when viewed in the z direction, the end heater thermometer 62b overlaps the second end heating element 45b2.

[0105] The plurality of thermostats 68 include a central thermostat 68 a and end thermostats 68 b .

[0106] The central thermostat 68a shuts off power to the heating element assembly 45 when the temperature of the central heating element 45a exceeds a predetermined temperature. The central thermostat 68a is positioned within the central heating element 45a. That is, when viewed in the z-direction, the central thermostat 68a and the central heating element 45a overlap.

[0107] The end thermostat 68b cuts off the power supply to the heating element assembly 45 when the temperature of the first end heating element 45b1 exceeds a predetermined temperature. As previously mentioned, the first end heating element 45b1 and the second end heating element 45b2 control heat generation in the same manner. Therefore, the temperature of the first end heating element 45b1 is the same as the temperature of the second end heating element 45b2. The end thermostat 68b is arranged within the range of the first end heating element 45b1. That is, when viewed from the z direction, the end thermostat 68b overlaps with the first end heating element 45b1.

[0108] As described above, the central heater thermometer 62a and the central thermostat 68a are disposed on the central heating element 45a. Thus, the temperature of the central heating element 45a is measured. Furthermore, if the temperature of the central heating element 45a exceeds a predetermined temperature, power to the heating element assembly 45 is shut off.

[0109] The end heater thermometer 62b is placed on the second end heater 45b2 (end heater). This measures the temperature of the second end heater 45b2. Since the temperature of the first end heater 45b1 and the second end heater 45b2 are the same, the temperatures of the first and second end heaters 45b1, 45b2 are measured.

[0110] The end thermostat 68b is disposed on the first end heating element 45b1 and shuts off power to the heating element assembly 45 when the temperature of the first end heating element 45b1 and the second end heating element 45b2 exceeds a predetermined temperature.

[0111] A plurality of heater thermometers 62 and a plurality of thermostats 68 are arranged alternately along the y direction. As described above, a first end heating element 45b1 is arranged in the +y direction of the central heating element 45a. An end thermostat 68b is arranged within the range of the first end heating element 45b1. The central heater thermometer 62a is arranged closer to the +y direction than the center of the central heating element 45a in the y direction. The central thermostat 68a is arranged closer to the -y direction than the center of the central heating element 45a in the y direction. As described above, a second end heating element 45b2 is arranged in the -y direction of the central heating element 45a. An end heater thermometer 62b is arranged within the range of the second end heating element 45b2. Thus, the end thermostat 68b, the central heater thermometer 62a, the central thermostat 68a, and the end heater thermometer 62b are arranged in sequence from the +y direction toward the -y direction.

[0112] Generally, the thermostat 68 utilizes the bending deformation of the bimetallic device accompanying temperature changes to connect and disconnect the electrical circuit. The thermostat is formed to be slender corresponding to the shape of the bimetallic device. In addition, terminals extend outward from both ends of the long side direction of the thermostat 68. Connectors for external wiring are connected to the terminals by riveting. Therefore, space needs to be ensured on the outside of the long side direction of the thermostat 68. There is no extra space in the x direction in the fixing device 30, so the long side direction of the thermostat 68 is arranged along the y direction. At this time, when multiple thermostats 68 are arranged adjacent to each other in the y direction, it becomes difficult to ensure connection space for external wiring.

[0113] As described above, the plurality of heater thermometers 62 and the plurality of thermostats 68 are arranged alternately along the y direction. Thus, the heater thermometer 62 is arranged next to the thermostat 68 in the y direction. Therefore, it is possible to ensure connection space for external wiring relative to the thermostat 68. Furthermore, the degree of freedom in the layout of the thermostat 68 and the heater thermometer 62 in the y direction is increased. Thus, by arranging the thermostat 68 and the heater thermometer 62 at the most appropriate position, the temperature of the fixing device 30 can be controlled. Furthermore, it is easy to separate the AC wiring connected to the plurality of thermostats 68 and the DC wiring connected to the plurality of heater thermometers 62. Consequently, the generation of noise in the electrical circuit is suppressed.

[0114] like Figure 3 As shown, the film thermometer 64 is arranged inside the cylindrical film 35 and in the +x direction of the heater unit 40. The film thermometer 64 is in contact with the inner peripheral surface of the cylindrical film 35 and measures the temperature of the cylindrical film 35.

[0115] Figure 7 : is an electrical circuit diagram of a heating device according to an embodiment. Figure 7 middle, Figure 5 The bottom view is placed on the top of the paper. Figure 6 The top view is arranged at the bottom of the paper. Figure 7 , a plurality of thin film thermometers 64 are shown above the plan view below together with a cross section of the tubular film 35. The plurality of thin film thermometers 64 include a central thin film thermometer 64a and an end thin film thermometer 64b (a thermometer disposed on one side in the longitudinal direction).

[0116] The central film thermometer 64a is in contact with the central portion of the cylindrical film 35 in the y direction. The central film thermometer 64a is in contact with the cylindrical film 35 within the range of the central heating element 45a in the y direction. The central film thermometer 64a measures the temperature of the central portion of the cylindrical film 35 in the y direction.

[0117] The end film thermometer 64b is in contact with the -y end of the cylindrical film 35. The end film thermometer 64b is in contact with the cylindrical film 35 within the y-direction range of the second end heating element 45b2. The end film thermometer 64b measures the temperature of the -y end of the cylindrical film 35. As previously described, the first end heating element 45b1 and the second end heating element 45b2 control heat generation in the same manner. Therefore, the temperature of the -y end of the cylindrical film 35 is the same as the temperature of the +y end.

[0118] The power supply 95 is connected to the central contact 52a via the central bidirectional thyristor 96a. The power supply 95 is connected to the end contact 52b via the end bidirectional thyristor 96b. The CPU 91 controls the on / off of the central bidirectional thyristor 96a and the end bidirectional thyristor 96b independently of each other. When the CPU 91 turns on the central bidirectional thyristor 96a, power is supplied from the power supply 95 to the central heating element 45a. As a result, the central heating element 45a generates heat. When the CPU 91 turns on the end bidirectional thyristor 96b, power is supplied from the power supply 95 to the first end heating element 45b1 and the second end heating element 45b2. As a result, the first end heating element 45b1 and the second end heating element 45b2 generate heat. As a result, the heating of the central heating element 45a, the first end heating element 45b1 and the second end heating element 45b2 is controlled independently of each other. The center heating element 45 a , the first end heating element 45 b 1 , and the second end heating element 45 b 2 are connected in parallel to the power source 95 .

[0119] The power supply 95 is connected to the common connection point 58 via the central thermostat 68a and the end thermostat 68b. The central thermostat 68a and the end thermostat 68b are connected in series.

[0120] When the temperature of the central heating element 45a rises abnormally, the temperature detected by the central thermostat 68a exceeds a predetermined temperature.

[0121] When the temperature of the first end heating element 45b1 rises abnormally, the detected temperature of the end thermostat 68b exceeds the predetermined temperature. At this time, the end thermostat 68b cuts off the power supply from the power supply 95 to the entire heating element assembly 45. As mentioned above, the first end heating element 45b1 and the second end heating element 45b2 also control heat generation. Therefore, when the temperature of the second end heating element 45b2 rises abnormally, the temperature of the first end heating element 45b1 also rises. Therefore, in the case where the temperature of the second end heating element 45b2 rises abnormally, the end thermostat 68b also cuts off the power supply from the power supply 95 to the entire heating element assembly 45.

[0122] The CPU 91 (control unit 6) measures the temperature of the central heating element 45a through the central heater thermometer 62a. The CPU 91 measures the temperature of the second end heating element 45b2 through the end heater thermometer 62b. The temperature of the second end heating element 45b2 is the same as the temperature of the first end heating element 45b1. When the fixing device 30 is started, the CPU 91 measures the temperature of the heating element assembly 45 through the heater thermometer 62. When the temperature of the heating element assembly 45 is lower than the predetermined temperature, the CPU 91 heats the heating element assembly 45 only for a short time. Thereafter, the CPU 91 starts the rotation of the pressure roller 30p. The viscosity of the grease applied to the inner circumference of the tubular film 35 is reduced by the heat generated by the heating element assembly 45. Thus, the sliding property of the first heat equalizing component 49 and the tubular film 35 is ensured at the start of the rotation of the pressure roller 30p.

[0123] The CPU 91 measures the temperature of the center portion of the cylindrical film 35 in the y direction using the center film thermometer 64a. The CPU 91 measures the temperature of the end portion of the cylindrical film 35 in the -y direction using the end film thermometer 64b. The temperature of the end portion of the cylindrical film 35 in the -y direction is the same as the temperature of the end portion of the cylindrical film 35 in the +y direction. During operation of the fixing device 30, the CPU 91 measures the temperature of the center portion and the end portion of the cylindrical film 35 in the y direction. The CPU 91 performs phase control or frequency control on the power supplied to the heating element assembly 45 using the center bidirectional thyristor 96a and the end bidirectional thyristor 96b. Based on the temperature measurement result of the center portion of the cylindrical film 35 in the y direction, the CPU 91 controls the power supply to the center heating element 45a. Based on the temperature measurement result of the end portion of the cylindrical film 35 in the y direction, the CPU 91 controls the power supply to the first end heating element 45b1 and the second end heating element 45b2.

[0124] As described above, the fixing device 30 of the embodiment includes a cylindrical film 35, a heater unit 40, a support member 36, a first heat equalizing member 49, and a second heat equalizing member 50. The cylindrical film 35 has a film shape. The heater unit 40 is arranged on the inner side of the cylindrical film 35. The heater unit 40 sets the axial direction of the cylindrical film 35 as the long side direction. The support member 36 supports the heater unit 40. The first heat equalizing member 49 is arranged between the inner surface of the cylindrical film 35 and the heater unit 40. The first heat equalizing member 49 abuts against the first surface 40a of the heater unit 40. The second heat equalizing member 50 is arranged between the heater unit 40 and the support member 36. The second heat equalizing member 50 abuts against the second surface 40b of the heater unit 40 on the opposite side of the first surface 40a. The above configuration achieves the following effects.

[0125] The heater unit 40 is sandwiched between the first and second heat-equalizing members 49, 50. Therefore, uneven temperature distribution on both the front and back surfaces (the first surface 40a and the second surface 40b) of the heater unit 40 in the longitudinal direction can be suppressed. Consequently, the temperature distribution of the heater unit 40 can be evened out.

[0126] This can suppress damage to the tubular film 35 due to a temperature rise in the non-sheet-passing region (region where the sheet does not pass), and can also suppress damage to the supporting member 36 .

[0127] Furthermore, compared with a case where the heat equalizing member is disposed on only one of the first surface 40 a and the second surface 40 b of the heater unit 40 , the temperature distribution of the heater unit 40 can be more effectively equalized.

[0128] The first heat-uniform member 49 has a higher thermal conductivity than the second heat-uniform member 50. The above configuration achieves the following effects.

[0129] The heat from the heater unit 40 is easily transferred to the cylindrical film 35, while the heat from the heater unit 40 is less likely to be transferred to the support member 36. In other words, the heat from the heater unit 40 is less likely to escape toward the support member 36. Therefore, the temperature distribution of the heater unit 40 can be made uniform without significantly degrading the temperature-raising performance of the cylindrical film 35.

[0130] The first heat equalizing member 49 and the second heat equalizing member 50 have higher thermal conductivity than the substrate 41 of the heater unit 40. The above configuration achieves the following effects.

[0131] Compared to a case where at least one of the first heat equalizing member 49 and the second heat equalizing member 50 has a thermal conductivity lower than that of the substrate 41 of the heater unit 40 , the temperature distribution of the heater unit 40 can be more effectively equalized.

[0132] The heater unit 40 includes a substrate 41 and heating elements 45b1, 45a, and 45b2 disposed on a surface of the substrate 41 facing the first heat equalizing member 49. The above configuration provides the following effects.

[0133] Compared to a case where the first heat equalizing member 49 is disposed on the side opposite to the heating elements 45b1, 45a, and 45b2 of the substrate 41, the heat from the heating elements 45b1, 45a, and 45b2 is more easily transferred to the tubular film 35. Therefore, the temperature distribution of the heater unit 40 can be equalized without significantly degrading the heating performance of the tubular film 35.

[0134] The cylindrical film 35 forms a nip N with the pressure roller 30 p . The heater unit 40 faces the nip N. The above configuration achieves the following effects.

[0135] The heat distribution in the nip N becomes more uniform compared to a case where the heater unit 40 is arranged offset from the nip N. Therefore, the sheet S passing through the nip N can be heated uniformly.

[0136] The fixing device 30 includes a lubricating layer 51 disposed between the inner surface of the cylindrical film 35 and the first heat equalizing member 49. The above configuration provides the following effects.

[0137] The sliding properties between the first heat equalizing member 49 and the cylindrical film 35 can be ensured.

[0138] The thickness of the lubricating layer 51 is not less than 1 μm and not more than 100 μm. The above configuration achieves the following effects.

[0139] While ensuring the sliding property between the first heat equalizing member 49 and the cylindrical film 35 , it is possible to suppress the obstruction of the heat transfer from the heater unit 40 to the cylindrical film 35 .

[0140] The contact area A2 between the second heat-distributing member 50 and the support member 36 is smaller than the contact area A1 between the first heat-distributing member 49 and the heater unit 40. The above configuration achieves the following effects.

[0141] Compared with the case of A2 ≥ A1, the heat of the heater unit 40 is less likely to escape toward the support member 36. Therefore, the temperature distribution of the heater unit 40 can be made uniform without significantly deteriorating the temperature increase performance of the cylindrical film 35.

[0142] The first heat transfer portion is a plate-shaped first heat equalizing member 49, with the longitudinal direction of the cylindrical film 35 being the axial direction. The second heat transfer portion is a plate-shaped second heat equalizing member 50 formed of a member different from the first heat equalizing member 49. The above configuration achieves the advantage of easily setting the thermal conductivity of the first and second heat transfer portions with a simple configuration.

[0143] The image forming apparatus 1 according to the embodiment includes the fixing device 30 described above.

[0144] The fixing device 30 can equalize the temperature distribution of the heater unit 40. Therefore, the image forming apparatus 1 can improve image quality.

[0145] Next, modifications of the embodiment will be described.

[0146] The first heat equalizing member 49 of the embodiment has a higher thermal conductivity than the second heat equalizing member 50. However, the first heat equalizing member 49 may have a thermal conductivity lower than that of the second heat equalizing member 50.

[0147] In the embodiment, the first heat equalizing member 49 is disposed on the side of the substrate 41 on which the heat generating elements 45b1, 45a, and 45b2 are located. Alternatively, the first heat equalizing member 49 may be disposed on the side of the substrate 41 opposite to the side on which the heat generating elements 45b1, 45a, and 45b2 are located. In this case, the heat generating elements 45b1, 45a, and 45b2 are disposed in the -z direction relative to the substrate 41.

[0148] The heater unit 40 in the embodiment faces the nip N. However, the heater unit 40 may be arranged offset from the nip N. For example, the fixing device may include a nip forming portion (e.g., a pad forming the nip N) and a heating portion (e.g., a heater unit arranged at a position different from the pad).

[0149] The fixing device 30 of the embodiment includes the lubricating layer 51 disposed between the inner surface of the tubular film 35 and the first heat equalizing member 49 . However, the fixing device 30 may not include the lubricating layer 51 .

[0150] The thickness of the lubricating layer 51 in the embodiment is 1 μm to 100 μm. However, the thickness of the lubricating layer 51 may be less than 1 μm or more than 100 μm. For example, the thickness of the lubricating layer 51 may be changed according to the required specifications.

[0151] In the embodiment, the contact area A2 between the second heat-averaging member 50 and the support member 36 is smaller than the contact area A1 between the first heat-averaging member 49 and the heater unit 40. However, the contact area A2 between the second heat-averaging member 50 and the support member 36 may be greater than the contact area A1 between the first heat-averaging member 49 and the heater unit 40.

[0152] In the embodiment, the contact surface (-z direction surface) of the second heat-scaling member 50 with the support member 36 is a flat surface. In contrast, the contact surface of the second heat-scaling member 150 with the support member 36 may also be a surface having concave and convex 150a (see Figure 8For example, the concavo-convex 150a may be formed over the entire surface in the -z direction of the second heat equalizing member 150. For example, the second heat equalizing member 150 may abut against the support member 36 through point contact or line contact.

[0153] The first heat conducting portion of the embodiment is a plate-shaped first heat equalizing member 49 with the axial direction of the cylindrical film 35 as the longitudinal direction. The second heat conducting portion is a plate-shaped second heat equalizing member 50 formed of a member different from the first heat equalizing member 49. Alternatively, the first heat conducting portion and the second heat conducting portion may be formed as a single unitary heat equalizing member 249 (see FIG. Figure 9 For example, the heat-equalizing member 249 may have a U-shape that sandwiches the heater unit 40 when viewed from the axial direction of the cylindrical film 35. For example, the heat-equalizing member 249 may apply force in the direction sandwiching the heater unit 40. With this configuration, the heater unit 40 can be supported with a simple structure.

[0154] The image processing apparatus in the embodiment is an image forming apparatus 1, and the heating device is a fixing device 30. Alternatively, the image processing apparatus may be a decolorizing apparatus, and the heating device may be a decolorizing unit. The decolorizing apparatus uses decolorizing toner to decolorize (erase) an image formed on a sheet. The decolorizing unit heats the decolorizing toner image formed on the sheet passing through the roller nip to thereby decolorize it.

[0155] According to at least one embodiment described above, the fixing device 30 includes a cylindrical film 35, a heater unit 40, a support member 36, a first heat equalizing member 49, and a second heat equalizing member 50. The cylindrical film 35 has a film shape. The heater unit 40 is arranged on the inner side of the cylindrical film 35. The heater unit 40 sets the axial direction of the cylindrical film 35 as the long side direction. The support member 36 supports the heater unit 40. The first heat equalizing member 49 is arranged between the inner surface of the cylindrical film 35 and the heater unit 40. The first heat equalizing member 49 abuts against the first surface 40a of the heater unit 40. The second heat equalizing member 50 is arranged between the heater unit 40 and the support member 36. The second heat equalizing member 50 abuts against the second surface 40b of the heater unit 40 on the opposite side of the first surface 40a. Through the above configuration, the following effects are achieved.

[0156] The heater unit 40 is sandwiched between the first and second heat-equalizing members 49, 50. Therefore, uneven temperature distribution on both the front and back surfaces (the first surface 40a and the second surface 40b) of the heater unit 40 in the longitudinal direction can be suppressed. Consequently, the temperature distribution of the heater unit 40 can be evened out.

[0157] Although several embodiments have been described, these embodiments are provided for illustrative purposes only and are not intended to limit the scope of the invention. These embodiments can be implemented in various other ways and can be omitted, replaced, or modified without departing from the spirit of the invention. These embodiments and their variations are intended to be included within the scope and spirit of the invention and are also intended to be included within the scope of the invention set forth in the claims and their equivalents.

Claims

1. A heating device, characterized in that: have: Film-like cylinder; a heater unit disposed inside the cylindrical body, with the axial direction of the cylindrical body being the longitudinal direction; a supporting member supporting the heater unit; a first heat conducting portion disposed between the inner surface of the cylindrical body and the heater unit and in contact with the first surface of the heater unit; as well as The second heat conducting portion is disposed between the heater unit and the supporting member and abuts against a second surface of the heater unit opposite to the first surface. The heating device is a fixing device, The first heat conducting part and the second heat conducting part constitute a heat equalizing part formed integrally by the same component. The heat equalizing member has a U-shape sandwiching the heater unit when viewed from the axial direction of the cylindrical body.

2. The heating device according to claim 1, characterized in that The first heat conducting portion has a higher thermal conductivity than the second heat conducting portion.

3. The heating device according to claim 1, characterized in that The first heat transfer portion and the second heat transfer portion have a higher thermal conductivity than a substrate of the heater unit.

4. The heating device according to claim 1, characterized in that The heater unit comprises: substrate; and The heating element is disposed on a surface of the substrate facing the first heat conducting portion.

5. The heating device according to claim 1, characterized in that The heating device further includes a lubricating layer disposed between the inner surface of the cylindrical body and the first heat transfer portion.

6. The heating device according to claim 5, characterized in that The lubricating layer has a thickness of 1 μm or more and 100 μm or less.

7. The heating device according to claim 1, characterized in that A contact area between the second heat conducting portion and the supporting member is smaller than a contact area between the first heat conducting portion and the heater unit.

8. An image processing device, characterized in that: A heating device according to any one of claims 1 to 7 is provided.

Images