Heating device, fixing device, image forming device

Abstract

This invention relates to heating devices, fixing devices, and image forming apparatuses, with the aim of miniaturizing the heating devices. The heating device (9) is characterized by comprising: a fixing belt (20); a conductive member (40) in contact with the inner surface of the fixing belt (20); a heater 22; a support member (24) having a first opposing surface (24d) opposite to the conductive member (40); a plurality of guide ribs (260) having a guide surface (260a) in contact with the inner surface of the fixing belt (20); and screws (42) for fixing the conductive member (40) to the support member (24), the screws (42) being arranged between the guide ribs (260) in the longitudinal direction of the support member (24).

Description

Technical Field

[0001] This invention relates to heating devices, fixing devices, and image forming devices. Background Technology

[0002] In a fixing apparatus that serves as a heating device, a heater is provided as a heating element to heat the fixing belt, which is a rotating component. Furthermore, this heater can be of the type that heats the inner surface of the fixing belt by applying an AC voltage to an impedance heating element formed on a substrate material, and heats the belt through an insulating layer or the like.

[0003] In the configuration where AC voltage is applied to the heater, the insulating layer and the surface layer of the fixing belt in the heater are equivalent to capacitors, and the AC voltage is applied to the fixing clamp via the fixing belt. Then, with the paper in contact with both the transfer clamp and the fixing clamp, this AC voltage propagates through the paper to the transfer clamp. As a result, the AC voltage affects the transfer electric field, causing periodic uneven density patterns, known as striped images, in the transferred image. This problem becomes particularly pronounced in high humidity environments or when using paper with low resistance, such as thin paper.

[0004] In contrast, conventional fixing devices have been configured such that a conductive component contacts the inner surface of the fixing tape, and current is released to the grounding side through the conductive component.

[0005] For example, in Patent Document 1 (Japanese Patent Application Publication No. 2005-166299), one end of the conductive component is mounted on the support member by a mounting component. Furthermore, portions along the inner surface of the metal film are provided on both sides of the heater holder in the paper transport direction, and these portions and the mounting component are positioned in a non-overlapping manner when viewed from the front in a cross-section orthogonal to the length direction of the metal film.

[0006] However, from the perspective of miniaturizing the fixing device, there is still room for further research and exploration regarding the positional relationship between the guiding component that guides the rotating components such as the fixing belt and the fixing component that fixes the conductive components to other components.

[0007] The objective of this invention is to miniaturize the heating device.

[0008] [Patent Document 1] Japanese Patent Application Publication No. 2005-166299 Summary of the Invention

[0009] To address the aforementioned issues, the heating device of the present invention is characterized by comprising: a rotating component; a conductive component in contact with the inner surface of the rotating component; a heating element; a first opposing component having a first opposing surface opposite to the conductive component; a plurality of guide components having guide surfaces in contact with the inner surface of the rotating component; and a fixing component for fixing the conductive component to the first opposing component, the fixing component being disposed between the guide components in the longitudinal direction of the first opposing component.

[0010] According to the present invention, the heating device can be miniaturized. Attached Figure Description

[0011] Figure 1 The diagram shown is a schematic configuration of an image forming apparatus.

[0012] Figure 2 The image shown is a side sectional view of a fixing device with a fixed conductive component.

[0013] Figure 3 The diagram shown illustrates the formation of the stripe image.

[0014] Figure 4 The diagram shows the configuration of the conductive components along their length.

[0015] Figure 5 The image shown is a perspective view of the arrangement of the conductive components along their length.

[0016] Figure 6 The image shown is a side sectional view of the general configuration of the fixing device according to the first embodiment of the present invention.

[0017] Figure 7 Figures (a) and (b) show tilted schematic diagrams of the conductive component.

[0018] Figure 8 The image shown is related to Figure 2 and Figure 6 Side sectional views of different fixing devices.

[0019] Figure 9 What is shown is Figure 8 A three-dimensional view of the conductive components.

[0020] Figure 10 What is shown is Figure 8 The conductivity of the embodiment and the locking hole of the support are shown in a perspective view.

[0021] Figure 11 What is shown is Figure 10 A three-dimensional view of the conductive component being locked in the locking hole.

[0022] Figure 12 The diagram shown is another example of a conductive component.

[0023] Figure 13 The diagram shown is another example of a conductive component.

[0024] Figure 14 The image shown is a three-dimensional view of a conductive component with a bent section and its surrounding area.

[0025] Figure 15 The diagram shown is an example of the arrangement of conductive components along their length.

[0026] Figure 16 The diagram shows different examples of the configuration of conductive components along their length.

[0027] Figure 17 The image shown is a side sectional view of a fixing device in which a conductive component is provided in the insertion hole of the guide rib.

[0028] Figure 18 The image shown is a side cross-sectional view of a fixing device with different extension directions of the conductive components.

[0029] Figure 19 The image shown is a top view of the heater.

[0030] Figure 20 The diagram shows the power supply to the heater.

[0031] Figure 21 The figure shows the shape of the impedance heating element and Figure 19 Top view of different heaters.

[0032] Figure 22 The figure shows the shape of the impedance heating element and Figure 19 , Figure 21 Top view of different heaters.

[0033] Figure 23 The figures shown are temperature distribution diagrams of the fixing belt arrangement direction. (a) is a top view of the heater, and (b) is a temperature distribution diagram of the fixing belt.

[0034] Figure 24 What is shown is Figure 21 A schematic diagram of the divided regions of the heater.

[0035] Figure 25 The image shown is related to Figure 24 Schematic diagrams of segmented regions of different shapes.

[0036] Figure 26 What is shown is Figure 22 A schematic diagram of the divided regions of the heater.

[0037] Figure 27 The diagram shows a perspective view of the heater, the first high thermal conductivity component, and the heater holder.

[0038] Figure 28 The image shown is a top view of the heater with the first high thermal conductivity component configured.

[0039] Figure 29 The image shown is a top view of a heater with different configurations of the first high thermal conductivity component.

[0040] Figure 30 The image shown is a top view of a heater with a different configuration of the first high thermal conductivity component.

[0041] Figure 31 The image shown is related to Figure 2 A side sectional view outlining the different embodiments of the fixing device.

[0042] Figure 32 The diagram shows a perspective view of the heater, the first high thermal conductivity component, the second high thermal conductivity component, and the heater holder.

[0043] Figure 33 The image shown is a top view of a heater with a first high thermal conductivity component and a second high thermal conductivity component configured.

[0044] Figure 34 The image shown is a top view of a heater with different configurations of the first high thermal conductivity component and the second high thermal conductivity component.

[0045] Figure 35 The diagram shown is a schematic of the atomic crystal structure of graphene.

[0046] Figure 36 The diagram shown is a schematic of the atomic crystal structure of graphite.

[0047] Figure 37 The diagram shows the configuration of the second high thermal conductivity component. Figure 33 Top view of different heaters.

[0048] Figure 38 The image shown is related to Figure 2 , Figure 31 A side sectional view outlining the different embodiments of the fixing device.

[0049] Figure 39 The image shown is a side sectional view of a fuser assembly that is different from the one described above.

[0050] Figure 40 The image shown is a side sectional view of a fuser assembly that is different from the one described above.

[0051] Figure 41The image shown is a side sectional view of a fuser assembly that is different from the one described above.

[0052] Figure 42 The image shown is related to Figure 1 A schematic diagram of the different image forming apparatuses.

[0053] Figure 43 The image shown is a side sectional view of the general configuration of the fixing device according to the first embodiment of the present invention.

[0054] Figure 44 What is shown is Figure 43 A top view of the heater in the fixing device.

[0055] Figure 45 The image shown is a perspective view of the heater and the heater holder.

[0056] Figure 46 The image shown is a perspective view of the connector relative to the heater during installation.

[0057] Figure 47 The diagram shown is a schematic of the configuration of the thermistor and the thermostat.

[0058] Figure 48 The diagram shown is a schematic of the groove of the flange. Detailed Implementation

[0059] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Furthermore, in the drawings, the same or equivalent parts are given the same reference numerals, and detailed descriptions thereof are omitted where appropriate. Hereinafter, a fixing device provided in an image forming apparatus will be described as a heating device according to one embodiment of the present invention.

[0060] Figure 1 The diagram shown is a schematic configuration diagram of an image forming apparatus according to one embodiment of the present invention.

[0061] Figure 1 The image forming apparatus 100 shown has four imaging units 1Y, 1M, 1C, and 1Bk that are detachable from the main body of the image forming apparatus. Each imaging unit 1Y, 1M, 1C, and 1Bk is identical in configuration except that it contains different colored developers of yellow, magenta, cyan, and black. These colored developers correspond to the color decomposition components of a color image. Each imaging unit 1Y, 1M, 1C, and 1Bk includes a drum-shaped photoreceptor 2 as an image carrier, a charging device 3, a developing device 4, and a cleaning device 5. The charging device 3 charges the surface of the photoreceptor 2. The developing device 4 supplies toner, which is a developer, to the surface of the photoreceptor 2, forming a toner image. The cleaning device 5 cleans the surface of the photoreceptor 2.

[0062] Furthermore, the image forming apparatus 100 includes an exposure unit 6, a paper feeding unit 7, a transfer unit 8, a fixing unit 9 (which serves as a heating unit), and a paper discharge unit 10. The exposure unit 6 exposes the surface of each photoreceptor 2 and forms an electrostatic latent image on its surface. The paper feeding unit 7 supplies paper P, which serves as a recording medium, to the paper transport path 14. The transfer unit 8 transfers the toner image formed on each photoreceptor 2 onto the paper P. The fixing unit 9 fixes the toner image transferred to the paper P onto the surface of the paper P. The paper discharge unit 10 discharges the paper P out of the apparatus. The imaging unit 1, photoreceptor 2, charging unit 3, exposure unit 6, transfer unit 8, etc., constitute an image forming mechanism for forming an image on paper.

[0063] The transfer apparatus 8 includes an annular intermediate transfer belt 11 serving as an intermediate transfer body, four primary transfer rollers 12 serving as primary transfer components, and a secondary transfer roller 13 serving as a secondary transfer component. The intermediate transfer belt 11 is tensioned and supported by multiple rollers. The primary transfer rollers 12 transfer the toner image on each photoreceptor 2 onto the intermediate transfer belt 11. The secondary transfer roller 13 transfers the toner image transferred onto the intermediate transfer belt 11 onto paper P. The multiple primary transfer rollers 12 contact the photoreceptors 2 via the intermediate transfer belt 11. Thus, the intermediate transfer belt 11 and each photoreceptor 2 are in contact with each other, forming a primary transfer clamping portion between them. On the other hand, the secondary transfer roller 13 contacts one of the rollers that tension and support the intermediate transfer belt 11 via the intermediate transfer belt 11. Thus, a secondary transfer clamping portion is formed between the secondary transfer roller 13 and the intermediate transfer belt 11.

[0064] In addition, a pair of timing rollers 15 are provided along the path from the paper feeding device 7 in the paper transport path 14 to the secondary transfer clamping part (secondary transfer roller 13).

[0065] Next, refer to Figure 1 To illustrate the printing operation of the image forming apparatus described above.

[0066] When the indication signals the start of printing, in each imaging unit 1Y, 1M, 1C, 1Bk, the photoreceptor 2 moves along... Figure 1 The photoreceptor 2 is driven to rotate clockwise, and the charging device 3 charges the surface of the photoreceptor 2 to a uniform high potential. Next, the exposure device 6 exposes the surface of each photoreceptor 2 according to image information from the original document read by the document reading device or printing information from the terminal. As a result, the potential of the exposed portion decreases, forming an electrostatic latent image. Then, toner is supplied to this electrostatic latent image from the developing device 4, and a toner image is formed on each photoreceptor 2.

[0067] The toner image formed on each photoreceptor 2 rotates as each photoreceptor 2 rotates and reaches the primary transfer clamp (position of the primary transfer roller 12). Then, it is transferred to the primary transfer clamp. Figure 1 The intermediate transfer belt 11, driven by a counter-clockwise rotation, sequentially overlaps and transfers the toner image. Then, the toner image transferred onto the intermediate transfer belt 11 is conveyed to the secondary transfer clamping unit (position of the secondary transfer roller 13) as the intermediate transfer belt 11 rotates. The toner image is transferred onto the paper P conveyed in the secondary transfer clamping unit. This paper P is supplied from the paper feeding device 7. After the paper P supplied from the paper feeding device 7 is temporarily stopped by the timing roller 15, it is aligned with the timing of the toner image on the intermediate transfer belt 11 arriving at the secondary transfer clamping unit and then conveyed to the secondary transfer clamping unit. In this way, a full-color toner image is carried onto the paper P. Furthermore, after the toner image is transferred, the toner remaining on each photoreceptor 2 is removed by each cleaning device 5.

[0068] The paper P, with the toner image transferred onto it, is conveyed to the fixing unit 9, where the toner image is fixed onto the paper P. Then, the paper P is discharged from the unit via the paper discharge device 10, completing the series of printing operations.

[0069] Next, the structure of the fixing device will be explained.

[0070] like Figure 2 As shown, the fixing apparatus 9 according to this embodiment includes a fixing belt 20, a pressure roller 21 serving as a counter-rotating or pressurizing component, a heater 22 serving as a heating element, a heater holder 23 serving as a holding component, a support member 24, a thermistor 25 serving as a temperature detection component, a first high thermal conductivity component 28, and a component 40, etc. The fixing belt 20 is composed of an annular belt. The pressure roller 21 contacts the outer peripheral surface of the fixing belt 20, forming a fixing clamping portion N between the roller and the fixing belt 20. The heater 22 heats the fixing belt 20. The heater holder 23 holds the heater 22. The support member 24 supports the heater holder 23. The thermistor 25 detects the temperature of the first high thermal conductivity component 28.

[0071] and Figure 2 The direction orthogonal to the paper surface is the length direction of the fixing belt 20, pressure roller 21, heater 22, heater holder 23, support 24, first high thermal conductivity component 28, etc. Figure 4 The direction of the double arrow X shown is referred to below as the length direction. This length direction includes the width direction of the conveyed paper, the width direction of the fixing belt 20, and the axial direction of the pressure roller 21. Figure 2 Arrow A points in the direction of paper transport. The following will be used as... Figure 2 The upstream side of the paper transport direction below is referred to as the upstream side, and will be used as... Figure 2 The downstream side of the paper transport direction above is simply referred to as the downstream side. Furthermore, the fixing component provided in the fixing device is one type of rotating component provided in the heating device of the present invention. In the fixing device 9 of this embodiment, a fixing belt 20 is provided as a specific example of this fixing component. The support member 24 is one type of component provided in the first opposing member of the heating device of the present invention, and also serves as a support member for the supporting and holding member.

[0072] The fixing belt 20 has a base layer made of a cylindrical substrate of polyimide (PI) with an outer diameter of, for example, 25 mm and a thickness of 40 to 120 μm. To improve durability and ensure release properties, a release layer with a thickness of 5 to 50 μm, made of a fluorinated resin such as PFA or PTFE, is formed on the outermost layer of the fixing belt 20. An elastic layer made of rubber or the like with a thickness of 50 to 500 μm may also be provided between the substrate and the release layer. The fixing belt 20 of this embodiment is a rubberless belt without an elastic layer. In addition, the substrate of the fixing belt 20 is not limited to polyimide, but may also be a heat-resistant resin such as PEEK or a metal substrate such as nickel (Ni) or SUS. Polyimide or PTFE or the like may also be coated on the inner circumferential surface of the fixing belt 20 as a sliding moving layer.

[0073] The pressure roller 21 is composed of, for example, a solid iron core 21a with an outer diameter of 25 mm, an elastic layer 21b formed on the surface of the core 21a, and a release layer 21c formed on the outside of the elastic layer 21b. The elastic layer 21b is formed of silicone rubber and has a thickness of, for example, 3.5 mm. To improve release properties, it is preferable that the surface of the elastic layer 21b is formed with a release layer 21c composed of a fluoropolymer resin layer with a thickness of, for example, about 40 μm.

[0074] The pressure roller 21 applies force to the fixing belt 20 via a force-applying mechanism, causing the pressure roller 21 to press against the heater 22 across the fixing belt 20. This forms a fixing clamping part N, which serves as a clamping part, between the fixing belt 20 and the pressure roller 21. Furthermore, the pressure roller 21 is configured to rotate via a drive mechanism, and the pressure roller 21... Figure 2 When the arrow rotates in the direction of arrow J, the fixing belt 20 rotates accordingly in the direction of arrow J.

[0075] The heater 22 is configured to contact the inner circumferential surface of the fixing belt 20. In this embodiment, the heater 22 contacts the pressure roller 21 via the fixing belt 20, and functions as a clamping part forming member that forms the fixing clamping part N between itself and the pressure roller 21. Furthermore, the fixing belt 20 is the heated component that is heated by the heater 22.

[0076] The heater 22 is a strip-shaped heating element arranged in a planar shape along the width of the fixing belt 20. The heater 22 is composed of a plate-shaped base material 30, an impedance heating element 31 disposed on the base material 30, and an insulating layer 32 covering the impedance heating element 31. It is powered by a power source 200 (see reference 200). Figure 20 An AC voltage is applied to the heater 22, which mainly causes the resistive heating element 31 to heat up and heats the fixing belt 20.

[0077] Furthermore, the heater 22 contacts the inner circumferential surface of the fixing belt 20 on the insulating layer 32 side, and the heat emitted from the impedance heating element 31 is transferred to the fixing belt 20 via the insulating layer 32. In this embodiment, the impedance heating element 31 and the insulating layer 32 are disposed on the fixing belt 20 side (fixing clamping part N side) of the substrate material 30, but conversely, the impedance heating element 31 and the insulating layer 32 can also be disposed on the heater holding member 23 side of the substrate material 30. In this case, since the heat of the impedance heating element 31 is transferred to the fixing belt 20 via the substrate material 30, the substrate material 30 is preferably made of a material with high thermal conductivity, such as aluminum nitride. In addition, by making the substrate material 30 of a material with high thermal conductivity, even if the impedance heating element 31 is disposed on the side of the substrate material 30 opposite to the fixing belt 20 side, the fixing belt 20 can be sufficiently heated.

[0078] The heater holder 23 and the support 24 are arranged on the inner circumference of the fixing belt 20. The support 24 is made of a metal channel material, and its two ends in the longitudinal direction are supported by the two side plates of the fixing device 9. By supporting the heater holder 23 and the heater 22 with the support 24, the heater 22 can reliably receive the pushing force of the pressure roller 21 when the pressure roller 21 is pressurized by the fixing belt 20. Thus, a fixing clamping part N is stably formed between the fixing belt 20 and the pressure roller 21. In this embodiment, the thermal conductivity of the heater holder 23 is set to be smaller than that of the base material 30.

[0079] The support member 24 is formed in a generally U-shape with vertical portions 24a serving as walls on both its upstream and downstream sides in the paper transport direction. The vertical portions 24a abut against the heater holder 23 at their end faces and also support the heater holder 23. The vertical portions 24a are located in the pressure direction of the pressure roller 21. Figure 2 The portion extending in the left and right directions. In addition, the support member 24 is grounded via resistor 41.

[0080] In this embodiment, the support member 24 supports the heater holder 23 by having a portion extending along the pressing direction (left-right direction in the figure) of the pressure roller 21 or a portion having thickness abut against the heater holder 23 from the side opposite to the pressure roller 21 (left side in the figure). This suppresses deflection of the heater holder 23 caused by the pressure applied by the pressure roller 21 (particularly deflection in the length direction in this embodiment). However, the abutment of the support member 24 against the heater holder 23 is not limited to direct contact; it also includes contact via other components. "Contact via other components" means that, in the left-right direction in the figure, other components are sandwiched between the support member 24 and the heater holder 23, and at least at a corresponding position, the support member 24 abuts against other components, while the other components abut against the heater holder 23. Furthermore, the extension in the pressing direction is not limited to the same direction as the pressing direction of the pressure roller 21; it also includes extension from the pressing direction of the pressure roller 21 towards a direction having a certain angle. Even in these cases, the support 24 is able to resist the pressure from the pressure roller 21 and suppress the deflection of the heater holder 23.

[0081] Since the heater support 23 is prone to becoming hot due to the heat from the heater 22, it is preferably made of a heat-resistant material. For example, when the heater support 23 is made of a heat-resistant resin with low thermal conductivity such as LCP or PEEK, heat transfer from the heater 22 to the heater support 23 can be suppressed. As a result, the heater 22 can effectively heat the fixing belt 20.

[0082] The heater retainer 23 has a recess 23b for retaining the first high thermal conductivity component 28 and the heater 22 (see...). Figure 27 ).

[0083] In addition, such as Figure 2 As shown, a guide member 26 for guiding the fixing belt 20 is integrally provided on the heater holder 23. The guide member 26 is respectively provided on the upstream side and the downstream side of the heater holder 23 in the paper transport direction.

[0084] A plurality of guide ribs 260 are provided on the guide member 26. The guide ribs 260 are formed in a generally fan shape. The guide ribs 260 are configured to have an arc-shaped or convex curved guide surface 260a extending along the circumferential direction of the belt along the inner circumferential surface of the fixing belt 20.

[0085] The heater holder 23 has an opening 23a extending through the thickness direction. A thermistor 25 and a thermostat (described later) are disposed in this opening 23a. These thermistors 25 and the thermostat are pressed against the back of the first high thermal conductivity member 28 by spring pressure. However, the openings can also be provided on the first high thermal conductivity member 28 and the second high thermal conductivity member (described later), and the thermistors 25 or the thermostat can be pressed against the back of the base material 30.

[0086] The first high thermal conductivity component 28 is composed of a component with a higher thermal conductivity than the substrate material 30. In this embodiment, the first high thermal conductivity component 28 is made of plate-shaped aluminum. Alternatively, the first high thermal conductivity component 28 may also be made of, for example, copper, silver, graphene, graphite, etc. By forming the first high thermal conductivity component 28 into a plate shape, the positional accuracy of the heater 22 relative to the heater holder 23 or the first high thermal conductivity component 28 can be improved.

[0087] Next, the method for calculating the thermal conductivity described above will be explained. When calculating thermal conductivity, firstly, the thermal diffusivity of the object is measured, and this diffusivity is used to calculate the thermal conductivity.

[0088] Thermal diffusivity was measured using a thermal diffusivity and thermal conductivity measuring device (trade name: ai-PhaseMobile1u, manufactured by Eye-Phase Co., Ltd.).

[0089] To convert the above thermal diffusivity into thermal conductivity, we need the values ​​of density and specific heat capacity.

[0090] Density was measured using a dry automatic density meter (trade name: Accupyc1330, manufactured by Shimadzu Corporation).

[0091] In addition, a differential scanning calorimeter (DSC-60, manufactured by Shimadzu Corporation) was used as the specific heat capacity meter. Sapphire was used to measure the specific heat capacity as a known reference material. In this embodiment, five heat capacity measurements were performed, and the average value at 50°C was used. If density and specific heat capacity are set as ρ and C respectively, the thermal conductivity λ can be obtained from the thermal diffusivity α obtained by the above thermal diffusivity measurement using the following formula (1).

[0092] Equation 1

[0093] λ=ρ×CXα···(1)

[0094] In the fixing apparatus 9 according to this embodiment, when the printing operation begins, the pressure roller 21 is driven to rotate, and the fixing belt 20 begins to rotate passively. At this time, the fixing belt 20 is guided by contact between its inner circumferential surface and the guide surface 260a of the guide rib 260, and thus rotates stably and smoothly. Furthermore, the fixing belt 20 is heated by supplying power to the impedance heating element 31 of the heater 22. Then, when the temperature of the fixing belt 20 reaches the predetermined target temperature, i.e., the fixing temperature, ... Figure 2 As shown, the paper P carrying the unfixed toner image is conveyed to the clamping part N between the fixing belt 20 and the pressure roller 21. The unfixed toner image is heated and pressurized, and then fixed onto the paper P.

[0095] However, in such a fixing device 9, there is a problem with striped images. That is, in the fixing device 9 where AC voltage is applied to the heater 22, the insulating layer provided in the heater 22 and the surface layer of the fixing tape are equivalent to capacitors. At this time, through the contact between the heater 22 and the fixing tape 20, the AC voltage is applied to the fixing clamping part N via the fixing tape 20. And, as Figure 3 As shown, when the paper P is in contact with both the secondary transfer clamping part NA and the fixing clamping part N, the AC voltage is as follows: Figure 3 As shown by the arrow, the voltage propagates through the paper P to the secondary transfer clamping section NA. The effect of this alternating voltage on the transfer electric field causes periodic uneven density, resulting in what is known as a striped pattern, in the transferred image. This problem becomes particularly pronounced in high-humidity environments or when the paper P is low-resistance, such as when thin paper is used. The secondary transfer clamping section NA is a clamping section formed between the secondary transfer roller 13 and the secondary transfer opposing roller 16.

[0096] Furthermore, in such a fixing device 9, image defects sometimes occur due to electrostatic displacement. Specifically, when the paper passes through the fixing clamp N, unfixed toner on the paper P is attracted to the surface of the charged fixing belt 20, and the unfixed toner adheres to the fixing belt 20. Then, by rotating the fixing belt 20, the adhered toner moves again towards the fixing clamp N, and after adhering to the paper, it reaches the paper P in the fixing clamp N. This adhesion of toner causes image defects.

[0097] Therefore, in this embodiment, by providing the conductive member 40 in the fixing device 9, AC voltage can flow from the fixing clamping part N to the fixing belt 20, and then through the conductive member 40 to the ground side. Thus, the formation of the striped image is suppressed. Furthermore, by providing the conductive member 40, the charge on the surface of the fixing belt 20 is removed, suppressing image defects caused by the electrostatic offset.

[0098] The conductive component 40 is formed in the form of a sheet. The conductive component 40 is formed of a conductive material; in this embodiment, it is formed of conductive polyimide with added carbon black. The conductive component 40 is grounded via the support member 24 and the resistor 41. Multiple conductive components 40 may be provided along the length direction, or only one may be provided. The conductive component 40 is disposed between the support member 24 and the guide member 26.

[0099] One end 40a of the conductive member 40, which is a free end, is a contact portion that contacts the inner surface of the fixing tape 20. Through the contact between one end 40a and the inner surface of the fixing tape 20, the charge on the surface of the fixing tape 20 can be released to the ground side via the support member 24 and the resistor 41, thereby removing the charge retained on the surface of the fixing tape 20. In this embodiment, the side opposite to one end 40a of the conductive member 40 is designated as the other end 40b side. Either the one end 40a side or the other end 40b side may be located further from the center position along the length of the conductive member 40 in the direction perpendicular to its width direction, in the direction along the surface of the conductive member 40. In other words, even when the conductive member 40 is not bent and is generally sheet-like, it is also located further from the one end 40a side or the other end 40b side than the position corresponding to the center position in the direction perpendicular to its width direction along the surface of the conductive member 40.

[0100] In this embodiment, the opposing portion 40c of the conductive component 40 faces the first opposing surface 24d of the support member 24, which serves as the first opposing component, and is fixed to the vertical portion 24a by screws 42, which serve as fixing components. A fastening hole 24b for fixing the screws 42 is provided in the vertical portion 24a of the support member 24.

[0101] By fixing the opposing portion 40c to the support member 24 with screws 42, the opposing portion 40c can be arranged along the first opposing surface 24d. That is, in this embodiment, the opposing portion 40c, including the portion fixed by screws 42, is arranged along the first opposing surface 24d. Therefore, the contact position and posture of one end 40a of the conductive member 40 relative to the inner surface of the fixing tape 20 can be stabilized. Furthermore, the contact pressure of the conductive member 40 against the inner surface of the fixing tape 20 can be ensured. Therefore, the contact state of the conductive member 40 relative to the inner surface of the fixing tape 20 can be stabilized.

[0102] In addition, in this embodiment, the conductive component 40 can be made to make solid contact with the support member 24 and grounded via the support member 24.

[0103] The fixing position of screw 42 to conductive component 40, i.e., the position where fastening hole 24b is provided, is set at a position higher than the first opposing surface 24d. Figure 2The central position in the left-right direction is closer to one end 40a of the conductive component 40. In other words, in the paper transport direction... Figure 2 The vertical direction, or a direction orthogonal to that direction, can be considered as a direction different from the length direction. Figure 2 When the fixing tape 20 is divided into two parts in the left-right direction, the fixing position of the screw 42 on the conductive member 40 is set on the same side as one end 40a. Specifically, in this embodiment, regardless of which direction the tape is divided into two parts, the fixing position of the screw 42 on the conductive member 40 is always set on the same side as one end 40a. Thus, in this embodiment, the opposing portion 40c is fixed to the first opposing surface 24d at a position closer to the contact point between the conductive member 40 and the fixing tape 20. This makes the posture of the conductive member 40 and its contact state with the inner surface of the fixing tape 20 more stable.

[0104] In this embodiment, such as Figure 4 and Figure 5 As shown, screw 42 is configured as Figure 4 The guide ribs 260 in the left-right and length directions are positioned between each other. That is, the screw 42 is positioned between the guide ribs 260, in a position where it does not overlap with these guide ribs 260 in the length direction. This prevents interference between the screw 42 and the guide ribs 260. If the screw 42 were positioned where it overlaps with the guide ribs 260 in the length direction, the screw head of the screw 42 would need to be configured to not interfere with the guide ribs 260, and the diameter of the fixing tape 20 would correspondingly increase. In contrast, with the above configuration of this embodiment, as... Figure 2 As shown, even when the guide rib 260 and screw 42 are positioned to overlap when viewed from a cross-section orthogonal to the length direction, screw 42 will not interfere with guide rib 260. Therefore, screw 42 can be compactly arranged within fixing belt 20, and fixing belt 20 can be made smaller in diameter. Thus, fixing device can be miniaturized.

[0105] Especially in this embodiment, such as Figure 2 As shown, the screw 42 is positioned further away from the inner surface of the fixing belt 20 than the guide surface 260a of the guide rib 260. That is, in the radial direction of the fixing belt 20, the screw 42 is positioned further away from the inner surface of the fixing belt 20 than the guide surface 260a. Specifically, this is in the direction from the center of the screw head of the screw 42 to the inner surface of the fixing belt 20, which is the insertion direction of the screw 42. Figure 2 The distance R1 in the upward direction, and the position from the guide surface 260a that is the same as the screw 42, that is, the guide surface 260a and Figure 2When comparing the distance R2 from the center of the screw head in the left and right directions to the inner surface of the fixing belt 20, in the insertion direction of the screw 42, R1 > R2. Alternatively, on a plane orthogonal to the length direction of the fixing belt 20... Figure 2 In the cross-section, the shortest distance between the screw 42 and the inner surface of the fixing belt 20 is greater than the shortest distance between the guide surface 260a and the inner surface of the fixing belt 20. Therefore, the screw 42 does not contact the inner surface of the fixing belt 20, preventing damage to the fixing belt 20 caused by contact of the screw 42.

[0106] Next, refer to Figure 6 This describes an implementation method for configuring conductive components without using fixed components.

[0107] like Figure 6 As shown, the conductive member 40 has a counter portion 40c facing the first counter surface 24d of the support member 24 and the second counter surface 26a of the guide member 26. The first counter surface 24d and the second counter surface 26a restrict the tilting of the conductive member 40. That is, the first counter surface 24d and the second counter surface 26a are arranged on the conductive member 40 facing the support member 24 and the guide member 26. Figure 6 The position where the conductive member 40 is in contact with the conductive member 40 when tilted above or below, and where the tilt of the conductive member 40 is limited. Specifically, in this embodiment, the opposing portion 40c is disposed adjacent to the first opposing surface 24d and the second opposing surface 26a. Furthermore, the first opposing surface 24d is opposite to the first surface 401 (the surface of the conductive member 40 that contacts the fixing tape 20, i.e., the second surface 402). The second opposing surface 26a is opposite to the second surface 402 of the conductive member 40 on the side that contacts the fixing tape 20. In other words, the direction of tape rotation at the end 40a where the conductive member 40 contacts the inner surface of the fixing tape 20 is set as... Figure 6 In this embodiment, when the direction of arrow J' is indicated, the first opposing surface 24d faces the opposing portion 40c from the downstream side of direction J', and the second opposing surface 26a faces the opposing portion 40c from the upstream side of direction J'. In the following description, the side of the conductive member 40 that contacts the fixing tape 20 will be referred to as the "contact side of the conductive member 40", and the side of the conductive member 40 that is opposite to the fixing tape 20 will be referred to as the "opposite side of the contact side of the conductive member 40".

[0108] The opposing portion 40c faces the first opposing surface 24d and the second opposing surface 26a, and extends along the first opposing surface 24d and the second opposing surface 26a. However, the opposing portion 40c does not necessarily have to be provided along both the first opposing surface 24d and the second opposing surface 26a. In this embodiment, the first opposing surface 24d and the second opposing surface 26a are planar portions extending in a direction substantially parallel to the pressing direction of the pressure roller 21.

[0109] The guide member 26 is the second opposing member in this embodiment. This second opposing member can be integrally provided with the heater holder 23 as in this embodiment, or it can be a separate component. In addition, the second opposing member is not limited to a component having a guide surface 260 that guides the inner surface of the fixing belt 20 as in this embodiment.

[0110] The conductive member 40 has a one-end-side bent portion 40d adjacent to the opposing portion 40c and bent toward a first surface 401 opposite to the second surface 402 of the conductive member 40. The one-end-side bent portion 40d is a portion bent by elastic deformation. In this embodiment, the portion of the conductive member 40 from the one-end-side bent portion 40d to one end 40a is bent toward the same side, i.e., downstream in the rotation direction of the fixing belt 20.

[0111] Furthermore, the other end 40b side of the opposing portion 40c of the conductive member 40 is bent. Then, the portion sandwiching the other end 40b side of the opposing portion 40c of the conductive member 40, opposite to one end 40a, is... Figure 6 The conductive component 40 is held in the left-right direction by the vertical portion 24a of the support member 24 and the heater holder 23. Thus, by applying pressure from the pressure roller 21, the conductive component 40 is securely held between the support member 24 and the heater holder 23. Therefore, the other end 40b of the conductive component 40 can be securely positioned relative to the support member 24. Furthermore, the conductive component 40 can be securely contacted with the support member 24 and grounded via the support member 24. Additionally, the conductive component 40 can be held on the support member 24 and the heater holder 23. Moreover, these effects can be achieved without the use of screws or other fixing components, and the fixing device can be miniaturized. Furthermore, the heat capacity of the fixing device can be reduced, thus achieving energy savings.

[0112] Here, when the first opposing surface 24d and the second opposing surface 26a are arranged relative to the opposing portion 40c of the conductive member 40 but not facing each other, unevenness will occur in the extending direction at the free end, i.e., one end 40a, due to the unevenness of the components of the conductive member 40. For example, during the assembly of the components, the conductive member 40 may sometimes... Figure 6 Extending vertically as shown, sometimes as Figure 7 As shown by the dashed line in (a), it tilts towards the support member 24, or as... Figure 7 As shown by the dashed line in (b), it is inclined toward the guide member 26. Then, when the posture of the conductive member 40 or the contact position relative to the inner surface of the fixing tape 20 is uneven, the contact state of the conductive member 40 with respect to the fixing tape 20 becomes unstable.

[0113] However, in this embodiment, as described above, by opposing the first opposing surface 24d with the conductive member 40, it is as follows: Figure 7 As shown in (a), the tilt of the conductive member 40 can be limited, and the opposing portion 40c of the conductive member 40 is provided along the first opposing surface 24d. As a result, unevenness in the contact position and contact posture of the conductive member 40 relative to the fixing tape 20 can be suppressed, and the contact state with the inner surface of the fixing tape 20 can be stabilized.

[0114] Furthermore, by providing the first opposing surface 24d, and maintaining the opposing portion 40c of the conductive member 40 in a vertical shape along the first opposing surface 24d, the contact pressure between the conductive member 40 and the inner surface of the fixing belt 20 can be ensured, and the contact state between the conductive member 40 and the inner surface of the fixing belt 20 can be stabilized. That is, one end 40a of the conductive member 40 contacts the inner surface of the fixing belt 20 and bends in the belt rotation direction, i.e., in the direction of arrow J. In particular, when the fixing belt 20 rotates, one end 40a of the conductive member 40 is subjected to a rotational force from the fixing belt 20 in the direction of arrow J. Therefore, in the conductive member 40, a bent portion 40d bending in the belt rotation direction is formed between the central side portion of the opposing portion 40c, which is maintained in a vertical shape, and one end 40a. The stress generated by the one-sided bend 40d, i.e. the force required for the one-sided bend 40d to elastically recover, ensures the contact pressure of one end 40a of the conductive member 40 against the inner surface of the fixing tape 20. Therefore, the contact state between the conductive member 40 and the inner surface of the fixing tape 20 can be stabilized.

[0115] As described above, by stabilizing the contact state of the conductive member 40 with respect to the inner surface of the fixing belt 20, the AC voltage applied to the fixing clamp N can be stably released to the ground side via the fixing belt 20. Therefore, the aforementioned striped image can be prevented. The charge retained on the fixing belt 20 can be stably released to the ground side via the support member 24. Therefore, image defects caused by electrostatic displacement can be prevented. Furthermore, these effects can be achieved without fixing the conductive member 40 to a predetermined component within the fixing device using screws or other fixing components. Therefore, space is not required for fixing components such as screws, allowing for miniaturization of the fixing device. Additionally, the heat capacity of the fixing device can be reduced, achieving energy savings.

[0116] Furthermore, in this embodiment, one end 40a of the conductive member 40, which is the contact portion, contacts the fixing tape 20 at a position exceeding the first opposing surface 24d of the support member 24. That is, one end 40a of the conductive member 40 is disposed on the opposite side of the opposing portion 40c, sandwiching the first opposing surface 24d. "Sandwiching the opposite side of the first opposing surface" means that the extended surface L (refer to the extended surface L of the first opposing surface 24d) is extended. Figure 6As a boundary, it is configured on one side and the other side. Then, the "first opposing surface" of "the side opposite to the first opposing surface" refers to the surface facing the portion of the conductive member 40 that is opposite to the portion that is sandwiched between one end side bend 40d and one end 40a. In particular, in this embodiment, it refers to the surface facing the opposing portion 40c that includes the portion adjacent to the one end side bend 40d. With this configuration, the contact pressure of the conductive member 40 on the inner surface of the fixing tape 20 can be ensured, and the contact state of the conductive member 40 on the inner surface of the fixing tape 20 can be stabilized.

[0117] In this embodiment, a portion of the conductive member 40 abuts against the support member 24, and the portion further from the abutting portion at one end 40a is bent downstream in the rotation direction of the fixing belt 20. That is, the conductive member 40 is supported by the support member 24 from the opposite side of the rotation direction J of the fixing belt 20 through its abutment against the support member 24. Then, the portion of the conductive member 40 further from the abutting portion at one end 40a, or the portion including the abutting portion at one end 40a, is bent downstream in the rotation direction J. Thus, by bending the side of the conductive member 40 that contacts the inner surface of the fixing belt 20, as described above, the contact pressure of the conductive member 40 on the inner surface of the fixing belt 20 can be ensured, and its contact state can be stabilized.

[0118] Furthermore, in this embodiment, the second opposing surface 26a faces the opposing portion 40c of the conductive member 40 on the contact side of the conductive member 40, just as... Figure 7 As shown in (b), the tilt of the conductive member 40 can be limited by providing the opposing portion 40c of the conductive member 40 along the second opposing surface 26a. This suppresses unevenness in the contact position and posture of the conductive member 40 relative to the fixing belt 20 and stabilizes the contact state of the conductive member 40 with the inner surface of the fixing belt 20. Thus, by providing members opposing each other on both sides of the fixing belt 20 in the rotation direction, the opposing portion 40c of the conductive member 40 can be positioned between the first opposing surface 24d and the second opposing surface 26a. Therefore, the posture of the conductive member 40 is particularly stable, and the contact state of the conductive member 40 with the inner surface of the fixing belt 20 is stable. Furthermore, the tilt of the conductive member 40 mentioned here refers to... Figure 6 The tilt in the vertical direction, in other words, refers to the tilt in the thickness direction of the conductive component 40, or the tilt in the direction in which the conductive component 40 contacts the first opposing surface 24d or the second opposing surface 26a.

[0119] Furthermore, in this embodiment, the phrase "dealt along" the first opposing surface or the second opposing surface means that, in addition to the case where the conductive member is completely parallel to the first opposing surface or the second opposing surface, it also includes cases where there is some degree of inclination. That is, it is sufficient to specify the degree to which the shape of the opposing portion of the conductive member is limited so that the contact position or contact posture of the conductive member relative to the rotating member is stable. In addition, "dealt along" means that the conductive member is disposed close to the first opposing surface or the second opposing surface, and of course does not include cases where the conductive member is disposed at a distance from the first opposing surface or the second opposing surface even if the conductive member is tilted.

[0120] The above description illustrates how unevenness in the components of the conductive part 40 during assembly can cause one end 40a to... Figure 7 (a) or Figure 7 The tilting situation is as shown in (b), but the unevenness in the posture of the conductive component 40 is not limited to this. As an example, after the components of the fixing device 9 are assembled, even if a specified force is applied to the conductive component 40 and applied at one end 40a... Figure 7 (a) or Figure 7 When a force is applied in direction (b), the tilting of the conductive member 40 can be suppressed by the first opposing surface 24d or the second opposing surface 26a of this embodiment, and the contact state of the conductive member 40 with respect to the inner surface of the fixing tape 20 can be stabilized.

[0121] In particular, in this embodiment, the first opposing surface 24d and the second opposing surface 26a are mutually parallel surfaces extending in a direction substantially parallel to the pressing direction of the pressure roller 21. This allows the opposing portion 40c of the conductive member 40 to be maintained in a shape that is vertically erected between the first opposing surface 24d and the second opposing surface 26a, thereby stabilizing the contact state between the conductive member 40 and the inner surface of the fixing tape 20. Furthermore, it is not necessary for the direction to be parallel to the pressing direction. Also, the mutually parallel surfaces mentioned here do not need to be strictly parallel; some degree of error is permissible. Even in these cases, the opposing portion 40c can still be maintained in a shape that is vertically erected in a substantially vertical direction. Alternatively, either the first opposing surface 24d or the second opposing surface 26a can be formed by a flat portion extending in one direction. This allows the opposing portion 40c to be maintained in a shape that is erected along this flat portion. Furthermore, the flat portion extending in this direction does not need to be strictly one direction; it can have some degree of inclination or unevenness.

[0122] In this embodiment, a conductive member 40 is shown disposed between the support member 24 and the downstream guide rib 260, but it can also be disposed between the support member 24 and the upstream guide rib 260. In this case, the opposing portion 40c of the conductive member 40 faces the first opposing surface of the upstream guide rib 260, which is the first opposing member, and the second opposing surface of the support member 24, which is the second opposing member.

[0123] Furthermore, as in this embodiment, the conductive component 40 is preferably applied to a fixing device 9 having a fixing tape 20 without an elastic layer. Such a fixing tape 20 has less flexibility compared to a structure with an elastic layer, making it more difficult to establish a stable contact between the fixing tape 20 and the conductive component 40. By applying the conductive component 40 in such a fixing device 9, stable contact between the conductive component 40 and the fixing tape 20 can be achieved.

[0124] Furthermore, when the fixing belt 20 has a non-conductive elastic layer, this elastic layer also acts as a capacitor, similar to the insulating layer of the heater 22, and is prone to producing the aforementioned striped pattern. Therefore, by eliminating the non-conductive elastic layer from the fixing belt 20, the problem of the striped pattern can be suppressed.

[0125] Additionally, using Figures 8-11 Other embodiments of the method for mounting the conductive component 40 relative to the support member 24 are described.

[0126] like Figure 8 As shown, in this embodiment, a locking hole 24c, serving as an opening, is provided on the support member 24. The locking hole 24c is a hole extending in a direction intersecting the extending direction of the first opposing surface 24d of the support member 24. In this embodiment, it is particularly present in the extending direction intersecting the first opposing surface 24d. Figure 8 It extends horizontally and vertically upwards and downwards.

[0127] The conductive component 40 is mounted onto the support 24 by bending the other end 40b of the conductive component 40 and inserting it into the locking hole 24c. However, the component with the locking hole is not limited to the support.

[0128] like Figure 9 As shown, the conductive component 40 of this embodiment is positioned opposite to the guide rib 260 in the longitudinal direction.

[0129] like Figure 10As shown, the conductive member 40 has a narrow portion 40j, narrower than the rest of the conductive member 40, on one end 40a side but not on the other end 40b. By elastically deforming the conductive member 40, it is inserted into the locking hole 24c of the support member 24 from its other end 40b side. Thus, as... Figure 11 As shown, the narrow portion 40j is disposed within the locking hole 24c, and the other end 40b of the conductive member 40 is locked in the locking hole 24c. Thus, the other end 40b of the conductive member 40 can be reliably positioned relative to the support member 24. Furthermore, these effects are achieved without the need for fixing components such as screws.

[0130] Then, Figure 11 One end 40a of the conductive component 40, such as Figure 8 The bending process, as shown, forms a curved portion 40f on the other side, and the opposing portion 40c is positioned between the first opposing surface 24d and the second opposing surface 260c.

[0131] Even in this embodiment, the opposing portion 40c of the conductive member 40 faces the first opposing surface 24d of the support member 24 and the second opposing surface 260c of the guide rib 260, which is the downstream side of the second opposing member, and is provided along these surfaces. Therefore, as in the aforementioned embodiment, the contact state between the conductive member 40 and the inner surface of the fixing belt 20 can be stabilized. Furthermore, this effect can be achieved without fixing the conductive member 40 to a predetermined component within the fixing device using screws or other fixing components. Therefore, the space required for fixing components such as screws is eliminated, allowing for miniaturization of the fixing device. Additionally, the heat capacity of the fixing device can be reduced, achieving energy savings.

[0132] In this embodiment, in order to insert the other end 40b of the conductive member 40 into the locking hole 24c, a bent portion 40f is formed on the other end side by elastic deformation. The bent portion 40f is a portion of the conductive member 40 that bends towards the side opposite to the side that contacts the fixing belt 20. In other words, the bent portion 40f is a portion that bends downstream of the rotation direction of the fixing belt 20 at one end 40a. The bent portion 40f, sandwiching the opposing portion 40c, is provided on the opposite side of one end 40a of the conductive member 40.

[0133] Assuming that the second opposing surface 260c is not provided on the contact side of the conductive member 40, the conductive member 40 easily extends in the opposite direction to the insertion direction relative to the locking hole 24c. For example, depending on the direction of the conductive member 40 towards... Figure 8As shown by the dotted line, the direction in which the conductive member 40 is inserted into the locking hole 24c results in unevenness in its extension direction. In contrast, by providing the second opposing surface 260c as in this embodiment, the tilting of the opposing portion 40c towards the contact side can be limited, and the opposing portion 40c can be provided along the second opposing surface 260c. This stabilizes the contact state between the conductive member 40 and the inner surface of the fixing tape 20. Furthermore, by aligning the first opposing surface 24d of the support member 24 with the opposing portion 40c, the tilting of the conductive member 40 towards the support member 24 side can be limited, and the contact state between the conductive member 40 and the inner surface of the fixing tape 20 can be stabilized.

[0134] In addition, such as Figure 11 As shown, the end 40a that contacts the inner surface of the fixing tape 20 has a sharp tip. By making the end 40a such a sharp tip, point contact between the end 40a and the fixing tape 20 can be achieved. Alternatively, the contact area can be reduced. This increases the contact pressure of the conductive member 40 on the fixing tape 20 and stabilizes the contact state between the conductive member 40 and the fixing tape 20. Thus, the sharp tip formed at the end 40a defines the portion of the conductive member 40 that contacts the inner surface of the fixing tape 20. However, the configuration of the defining portion of the conductive member 40 is not limited to this. That is, as long as the contact area of ​​the end 40a relative to the inner surface of the fixing tape 20 is smaller than the width of the conductive member 40, especially the root of the end 40a, it is possible to contact the inner surface of the fixing tape 20. Figure 11 Similarly, the contact pressure of one end 40a relative to the inner surface of the fixing belt 20 is increased. For example, as one end 40a having a limiting portion, such as Figure 12 As shown, the conductive member 40 may also have an uneven shape at one end 40a. This uneven shape is formed in the width direction of the conductive member 40. Additionally, as... Figure 13 As shown, the conductive member 40 may also have a slit shape at one end 40a. Furthermore, the conductive member 40 does not necessarily need to have a limiting portion at its front end.

[0135] in addition, Figure 14 The conductive component 40 shown has a bent portion 40g at one end 40a, which bends in the opposite direction to the rotation direction of the fixing belt. The bent portion 40g is provided, for example, before the conductive component 40 is assembled to the fixing device 9, or before the fixing belt 20 is assembled to the fixing device 9. By providing the bent portion 40g, one end 40a of the conductive component 40 can be made to contact the inner surface of the fixing belt 20 more stably.

[0136] In addition, such as Figure 15As shown, the end 40a of the conductive member 40 that contacts the fixing belt 20 is preferably located at or near a position opposite to the central position D in the longitudinal direction of the fixing belt 20. At the position where the conductive member 40 contacts the fixing belt 20, sliding resistance is generated between the fixing belt 20 and the conductive member 40. Therefore, if the conductive member 40 is arranged only on either side of the fixing belt 20 in the longitudinal direction, a deviation in sliding resistance will occur on one side and the other side relative to the central portion in the longitudinal direction, resulting in misalignment of the fixing belt 20. This can lead to breakage of the fixing belt 20. Therefore, by arranging the conductive member 40 as in this embodiment, breakage of the fixing belt 20 caused by misalignment can be prevented. Furthermore, as... Figure 16 As shown, when multiple conductive components 40 are configured, it is preferable that the positions where each conductive component 40 contacts the inner surface of the fixing belt 20 are arranged approximately symmetrically with respect to the central position D in the longitudinal direction, particularly facing the ends of one and the other sides of the fixing belt 20. This prevents damage to the fixing belt 20 caused by misalignment. However, the arrangement of the conductive components 40 in the longitudinal direction is not limited to this.

[0137] In addition, such as Figure 17 As shown, an insertion hole 260b for inserting the conductive member 40 can also be provided in the guide rib 260. In this embodiment, the opposing portion 40c of the conductive member 40 faces the first opposing surface 260b1 and the second opposing surface 260b2 of the sidewall portion forming the insertion hole 260b. That is, the guide rib 260 of this embodiment is both the first opposing member and the second opposing member of the present invention.

[0138] However, in the case of a component with an insertion hole, the component is made of a conductive part and grounded. Alternatively, the inner circumferential surface of the insertion hole can be made of a conductive part and grounded, or this part can be grounded via a support member.

[0139] Similar to the embodiment described above, the conductive component 40 is positioned opposite the first opposing surface 260b1, with the opposing portion 40c disposed along the first opposing surface 260b1. This stabilizes the contact between the conductive component 40 and the inner surface of the fixing belt 20. Similarly, as in the embodiment described above, the conductive component 40 is positioned opposite the second opposing surface 260b2, with the opposing portion 40c disposed along the second opposing surface 260b2. This stabilizes the contact between the conductive component 40 and the inner surface of the fixing belt 20. Furthermore, these effects are achieved without fixing the conductive component 40 to a predetermined component within the fixing device using screws or other fixing components. Therefore, the space required for fixing components such as screws is eliminated, enabling miniaturization of the fixing device. Additionally, the heat capacity of the fixing device can be reduced, resulting in energy savings.

[0140] In this embodiment, for example, by making the insertion hole 260b into a shape that narrows towards the inside, the other end of the conductive member 40 can be inserted into and held in the insertion hole 260b. Furthermore, the member providing the insertion hole 260b is not limited to guide ribs; it can also be a heater holder without guide ribs or a dedicated member for providing the insertion hole.

[0141] Furthermore, the extending direction of the opposing portion 40c of the conductive member 40 is not limited to the above-described embodiment. For example, in Figure 18 In the embodiment shown, the opposing part 40c is in Figure 18 The conductive component 40 extends vertically. It is held by the support member 24 and the heater holder 23. More specifically, the opposing portion 40c of the conductive component 40 faces and is held by the first opposing surface 24e of the support member 24 and the second opposing surface 23e of the heater holder 23. Thus, the opposing portion 40c is positioned along either the first opposing surface 24e or the second opposing surface 23e. With this structure, even in this embodiment, the contact state between the conductive component 40 and the inner surface of the fixing tape 20 can be stabilized.

[0142] Next, use Figure 19 A more detailed description of the configuration of the heater installed in the aforementioned fixing device will be provided. Figure 19 The image shown is a top view of the heater according to this embodiment.

[0143] like Figure 19 As shown, a plurality of (four) impedance heating elements 31, power supply lines 33A and 33B serving as conductors, a first electrode portion 34A, and a second electrode portion 34B are disposed on the surface of the plate-shaped substrate material 30. However, the number of impedance heating elements 31 is not limited to this embodiment. Hereinafter, power supply lines 33A and 33B will be referred to as power supply lines 33, and the first electrode portion 34A or the second electrode portion 34B will be referred to as electrode portion 34.

[0144] In addition, as with Figure 2 In this embodiment, the longitudinal direction of heater 22, etc., is orthogonal to the paper plane, such as... Figure 19 As shown, this is also the arrangement direction X of the multiple impedance heating elements 31. Hereinafter, this direction will also be simply referred to as the arrangement direction. Furthermore, the direction intersecting the arrangement direction, especially the direction perpendicular to it in this embodiment, is different from the thickness direction of the substrate material 30. Figure 19 The vertical direction Y is called the direction that intersects the arrangement direction of the multiple impedance heating elements 31, or simply the arrangement intersection direction. The arrangement intersection direction Y is the direction along the surface of the substrate material 30 where the impedance heating elements 31 are disposed, and it is also the short side direction of the heater 22 or the paper transport direction in the fixing device 9.

[0145] A plurality of heating elements 31 are used to form a heating section 35 divided into multiple sections in the arrangement direction. Each heating element 31 is electrically connected in parallel to a pair of electrode sections 34A and 34B via power supply lines 33A and 33B. The pair of electrode sections 34A and 34B are disposed at one end of the substrate material 30 in the arrangement direction. Figure 19 The power supply lines 33A and 33B are made of conductors with a resistance value smaller than that of the impedance heating element 31. From the viewpoint of ensuring insulation between the impedance heating elements 31, the gap between adjacent impedance heating elements 31 is preferably 0.2 mm or more, more preferably 0.4 mm or more. In addition, if the gap between adjacent impedance heating elements 31 is too large, temperature drop is likely to occur in the gap area. Therefore, from the viewpoint of suppressing temperature unevenness in the arrangement direction, the above-mentioned gap is preferably 5 mm or less, more preferably 1 mm or less.

[0146] The impedance heating element 31 is made of a material with PTC (positive temperature resistivity) characteristics, which has the feature that the resistance value increases and the heater output decreases when the temperature rises.

[0147] By configuring the impedance heating element 31 with PTC characteristics and the heating section 35 divided in the arrangement direction, excessive heating of the fixing belt 20 can be prevented when small-sized paper passes through. Specifically, when paper with a width smaller than the overall width of the heating section 35 passes through, the temperature of the impedance heating element 31 corresponding to the outer region of the paper width rises because the heat of the fixing belt 20 is not absorbed by the paper. Since the voltage applied to the impedance heating element 31 is constant, if the temperature of the impedance heating element 31 on the outer region of the paper width rises, its resistance value increases. Therefore, the output of the heater, i.e., the heat generated, is relatively reduced, and the temperature rise at the end is suppressed. Furthermore, by connecting multiple impedance heating elements 31 in parallel, the temperature rise of the non-paper-passing section can be suppressed while maintaining the printing speed. Additionally, the heating element constituting the heating section 35 can be a heating element other than an impedance heating element with PTC characteristics. Furthermore, the impedance heating elements can be arranged in multiple rows in the cross direction of the heater 22.

[0148] Thus, by dividing the impedance heating element 31 in the arrangement direction, the aforementioned end temperature rise can be suppressed, and temperature unevenness in the arrangement direction of the fixing tape 20 can be suppressed. Since the rigidity of the fixing tape 20 changes according to its temperature, a fixing tape 20 with small temperature unevenness in the arrangement direction is advantageous in ensuring stable contact with the conductive member 40. Therefore, by adopting the configuration of the impedance heating element 31 divided in the arrangement direction in this embodiment, and by adopting the configuration of the first high thermal conductivity member 28 and the second high thermal conductivity member 36 described later, it is preferable that the conductive member 40 can be stably contacted with the fixing tape 20. In addition, it is also advantageous from the viewpoint of ensuring stable contact between the conductive member 40 and the fixing tape 20 when the conductive member 40 is arranged without the installation of fixing members such as screws.

[0149] The impedance heating element 31 can be formed, for example, by coating a paste containing silver-palladium (AgPd) or glass powder onto a substrate material 30 through screen printing, and then sintering the substrate material 30. In this embodiment, the resistance of the impedance heating element 31 is 80 Ω at room temperature. In addition to the aforementioned, the material of the impedance heating element 31 can also be a silver alloy (AgPt) or a ruthenium oxide (RuO2) impedance material. The materials of the power supply line 33 and the electrode portion 34 can be formed with silver (Ag) or silver-palladium (AgPd) through screen printing, etc. The power supply line 33 is composed of a conductor with a lower resistance than the impedance heating element 31.

[0150] The substrate material 30 is preferably a non-metallic material such as alumina, aluminum nitride, ceramics, glass, or mica, which have excellent heat resistance and insulation properties. In this embodiment, an alumina substrate material with a cross-sectional width of 8 mm, a cross-sectional width of 270 mm, and a thickness of 1.0 mm is used. Alternatively, an insulating material can be laminated on a conductive material such as a metal to form the substrate material 30. For low cost, aluminum or stainless steel is preferred as the metallic material for the substrate material 30. By using a stainless steel sheet as the substrate material 30, cracks caused by thermal stress can be suppressed. Furthermore, to improve the heat uniformity of the heater 22 and enhance image quality, the substrate material 30 can also be made of materials with high thermal conductivity such as copper, graphite, or graphene.

[0151] The insulating layer 32 is made of, for example, heat-resistant glass with a thickness of 75 μm. The insulating layer 32 covers the impedance heating element 31 and the power supply line 33, and while insulating and protecting them, it maintains the sliding property with the fixing belt 20.

[0152] Figure 20 The diagram shown is a schematic diagram of the power supply circuit for the heater according to this embodiment.

[0153] like Figure 20 As shown, in this embodiment, the power supply circuit for supplying power to each impedance heating element 31 is configured by electrically connecting the AC power supply 200 to the electrode portions 34A and 34B of the heater 22. Furthermore, a three-terminal bidirectional AC switch 210 is provided in the power supply circuit to control the amount of power supplied. The control unit 220 controls the power supplied to each impedance heating element 31 via the three-terminal bidirectional AC switch 210 based on the temperature detected by the thermistor 25. The control unit 220 is composed of a microcomputer including a CPU, ROM, RAM, I / O interface, etc.

[0154] In this embodiment, thermistors 25 are respectively disposed in the central region of the arrangement direction of the heaters 22 within the minimum paper width and at one end of the arrangement direction of the heaters 22. Furthermore, a thermostat 27 is disposed at one end of the arrangement direction of the heaters 22, serving as a power cut-off mechanism to cut off the power supply to the impedance heating element 31 when the temperature of the impedance heating element 31 reaches or exceeds a predetermined temperature. The thermistors 25 and the thermostat 27 are in contact with the first high thermal conductivity component 28 to detect its temperature.

[0155] In this embodiment, the first electrode portion 34A and the second electrode portion 34B are disposed on the same side in the arrangement direction, but they may also be disposed on different sides. Furthermore, the shape of the impedance heating element 31 is not limited to that of this embodiment. For example, as... Figure 21 As shown, the impedance heating element 31 can be rectangular or, as shown in the figure, ... Figure 22As shown, the impedance heating element 31 is composed of a linear portion, which is then folded back to form a roughly parallelogram shape. Furthermore, as... Figure 21 As shown, the portion extending from the block-shaped impedance heating element 31 toward the power supply line 33 (the portion extending in the direction of intersection) can be either part of the impedance heating element 31 or made of the same material as the power supply line 33.

[0156] Figure 23 The diagram shows the temperature distribution along the arrangement of the fixing belt 20. (a) The diagram shows the configuration of the heater 22. (b) The vertical axis of the diagram represents the temperature T of the fixing belt 20, and the horizontal axis represents the positions of the fixing belt 20 along its arrangement.

[0157] like Figure 23 (a) and Figure 23 As shown in (b), the plurality of impedance heating elements 31 disposed on the heater 22 are divided in the arrangement direction, forming a dividing region B between the impedance heating elements 31. In other words, the plurality of impedance heating elements 31 disposed on the heater 22 are arranged with a spacing B. Hereinafter, the range B that serves as the dividing region will be referred to as spacing B. In spacing B, the area occupied by the impedance heating element 31 is smaller than that of other parts, and the heat generation is smaller. As a result, the temperature of the fixing belt 20 in spacing B becomes smaller than that of other parts, which is the reason for the temperature unevenness of the fixing belt 20 in the arrangement direction. In addition, in the expanded dividing region C (hereinafter simply referred to as region C) including the peripheral region of the dividing region B, the temperature of the heater 22 and the fixing belt 20 also decreases. In addition, the temperature of the heater 22 also decreases at the spacing B. Here, as Figure 23 As shown in the enlarged view of (a), interval B refers to the arrangement direction region that includes the portion of the impedance heating element 31, which is the main heating part of the heater 22, that is divided in the arrangement direction. Furthermore, region C is defined as the area that includes, in addition to interval B, the region corresponding to the connection portion 311 of the impedance heating element 31. This connection portion 311 refers to the portion of the impedance heating element 31 that extends in the arrangement intersection direction and connects to each of the power supply lines 33A and 33B.

[0158] like Figure 24 As shown, even in having Figure 21 In the heater 22 with the rectangular impedance heating element 31 shown, the temperature of the space B is also lower than that of the other parts. Furthermore, even with... Figure 25 In the heater 22 of the impedance heating element 31 with the shape shown, the temperature of the interval B is also lower than that of the other parts. Furthermore, as... Figure 26 As shown, in having Figure 22 In the heater 22 of the impedance heating element 31 with the shape shown, the temperature of the space B is also lower than that of the other parts. However, as Figure 23 or Figure 25 , Figure 26 As shown, by making adjacent impedance heating elements 31 overlap each other in the arrangement direction, it is possible to suppress the temperature drop of the interval B relative to other parts.

[0159] In this embodiment, the first high thermal conductivity component 28 is provided to suppress temperature drop during the aforementioned intervals and to suppress temperature unevenness in the alignment direction of the fixing belt 20. The first high thermal conductivity component 28 will be described in more detail below.

[0160] like Figure 2 As shown, the first high thermal conductivity component 28 is in Figure 2 It is positioned in the left-right direction between the heater 22 and the support member 24, and in particular sandwiched between the heater 22 and the heater holder 23. That is, one side of the first high thermal conductivity member 28 abuts against the back of the heater 22, and the other side abuts against the heater holder 23.

[0161] The support member 24 supports the heater holder 23, the first high thermal conductivity member 28, and the heater 22 by having the abutting surfaces of the two vertical portions 24a extending along the thickness direction of the heater 22, etc., directly abutting against the heater holder 23, or abutting against the heater holder 23 via the conductive member 40. In the arrangement cross direction ( Figure 2 In the vertical direction, the contact surface is located outside the area where the resistive heating element 31 is located. This suppresses heat transfer from the heater 22 to the support member 24, allowing the heater 22 to efficiently heat the fixing belt 20.

[0162] like Figure 27 As shown, the first high thermal conductivity component 28 is made of a plate with a thickness of 0.3 mm, a length of 222 mm in the arrangement direction, and a width of 10 mm in the cross direction. In this embodiment, the first high thermal conductivity component 28 is made of a single plate, but it can also be made of multiple components. Furthermore, in Figure 27 The middle part is omitted Figure 2 The description of the guide component 26 and the guide rib 260.

[0163] The first high thermal conductivity component 28 is embedded in the recess 23b of the heater holder 23 and is held by the heater holder 23 and the heater 22 by mounting the heater 22 above it. In this embodiment, the width of the first high thermal conductivity component 28 in the arrangement direction is set to be approximately the same as the width of the heater 22 in the arrangement direction. The first high thermal conductivity component 28 and the heater 22 are restricted from moving in the arrangement direction by the two side walls (arrangement direction limiting portions) 23b1 forming the recess 23b in the arrangement direction. In this way, by limiting the positional deviation of the first high thermal conductivity component 28 in the arrangement direction within the fixing device 9, the heat transfer efficiency can be improved relative to the target range of the arrangement direction. In addition, the first high thermal conductivity component 28 and the heater 22 are restricted from moving in the arrangement cross direction by the two side walls (arrangement cross direction limiting portions) 23b2 forming the recess 23b in the arrangement cross direction.

[0164] The arrangement direction of the first high thermal conductivity component 28 is not limited to the above. For example, Figure 28 As shown, the first high thermal conductivity component 28 may also be provided only within the range corresponding to the heating element 35 in the arrangement direction (see reference). Figure 28 (The cross-sectional line portion). Additionally, such as... Figure 29 As shown, at the position corresponding to the interval B in the arrangement direction, the first high thermal conductivity component 28 can also be provided only in this entire area. Additionally, in Figure 29 For convenience, the impedance heating element 31 and the first high thermal conductivity component 28 are placed in... Figure 29 The vertical directions are staggered, but both are positioned in approximately the same location along the intersection direction. However, this is not a limitation; the first high thermal conductivity component 28 may also be disposed on a portion of the intersection direction of the impedance heating elements 31, or as described later. Figure 30 That way, it's set up in a way that covers the entirety of the intersecting directions.

[0165] Furthermore, such as Figure 30 As shown, in addition to the position corresponding to the interval B in the arrangement direction, the first high thermal conductivity component 28 can also be provided by sandwiching the interval B in the middle and spanning the impedance heating elements 31 on both sides. This arrangement of the impedance heating elements 31 spanning both sides means that the first high thermal conductivity component 28 and the impedance heating elements 31 on both sides overlap at least partially in the arrangement direction. Alternatively, the first high thermal conductivity component 28 can also be provided corresponding to all intervals B of the heater 22, for example, as shown in... Figure 30 As shown, the first high thermal conductivity component 28 can also be provided only in a position corresponding to a portion of the interval B. Here, providing it in a position corresponding to the interval B in the arrangement direction means that at least a portion of it overlaps with the interval B in the arrangement direction.

[0166] By applying pressure from the pressure roller 21, the first high thermal conductivity component 28 is clamped between the heater 22 and the heater holder 23 and comes into close contact with these components. The contact between the first high thermal conductivity component 28 and the heater 22 improves the heat transfer efficiency in the arrangement direction of the heater 22. Furthermore, by positioning the first high thermal conductivity component 28 in the arrangement direction at a position corresponding to the interval B of the heater 22, the heat transfer efficiency in interval B can be improved. This increases the amount of heat transferred towards the region of interval B in the arrangement direction, causing the temperature in that region to rise. Therefore, temperature unevenness in the arrangement direction of the heater 22 can be suppressed. Consequently, temperature unevenness in the arrangement direction of the fixing belt 20 can be suppressed. Therefore, uneven fixing and gloss unevenness of the image fixed on the paper can be suppressed. Alternatively, unnecessary heating by the heater 22 to ensure sufficient fixing performance in the region of interval B is no longer required, thus achieving energy savings in the fixing device 9. Furthermore, by providing a first high thermal conductivity component 28 throughout the entire area of ​​the heating element 35 in the arrangement direction, the heat transfer efficiency of the heater 22 can be improved in the main heating area of ​​the heater 22, that is, the entire area of ​​the image forming area of ​​the paper through the paper, and the temperature unevenness of the heater 22 and even the fixing belt 20 in the arrangement direction can be suppressed.

[0167] In particular, in this embodiment, the combination of the first high thermal conductivity component 28 and the impedance heating element 31 with the aforementioned PTC characteristics effectively suppresses excessive temperature rise in the non-paper-passing area when small-sized paper passes through. That is, while utilizing the PTC characteristics to suppress the heat generation of the impedance heating element 31 in the non-paper-passing area, the heat from the non-paper-passing portion that has risen in temperature can be effectively transferred to the paper-passing portion, thereby effectively suppressing excessive temperature rise in the non-paper-passing area.

[0168] Furthermore, even around interval B, the temperature is lower because interval B generates less heat, therefore, it is preferable to configure the first high thermal conductivity component 28. For example, in this embodiment, by connecting it with region C (referring to...) Figure 24 The first high thermal conductivity component 28 is provided at the corresponding position, which can significantly improve the heat transfer efficiency in the arrangement direction of the interval B and its surroundings, and further suppress the temperature unevenness in the arrangement direction of the heater 22. In particular, in this embodiment, the first high thermal conductivity component 28 is provided in the entire area of ​​the heating part 35 in the arrangement direction. As a result, the temperature unevenness in the arrangement direction of the heater 22 (fixing belt 20) can be further suppressed.

[0169] Next, different implementations of the fixing device will be described.

[0170] like Figure 31As shown, the fixing apparatus 9 of this embodiment has a second high thermal conductivity member 36 between the heater holder 23 and the first high thermal conductivity member 28. The second high thermal conductivity member 36 is positioned in the stacking direction of the heater holder 23, the support member 24, the first high thermal conductivity member 28, and other components. Figure 31 The second high thermal conductivity component 36 is positioned differently from the first high thermal conductivity component 28 in the left-right direction. More specifically, the second high thermal conductivity component 36 overlaps with the first high thermal conductivity component 28. Furthermore, Figure 31 and Figure 2 The difference refers to the cross-section of the second high thermal conductivity component 36 without its arrangement direction configured. That is, in Figure 31 The section shown is a cross-section with the second high thermal conductivity component 36.

[0171] The second high thermal conductivity component 36 is made of a component with a higher thermal conductivity than the substrate material 30, such as graphene or graphite. In this embodiment, the second high thermal conductivity component 36 is formed from a graphite sheet with a thickness of 1 mm. However, the second high thermal conductivity component 36 may also be formed from a sheet of aluminum, copper, silver, or the like.

[0172] like Figure 32 As shown, multiple second high thermal conductivity components 36 are arranged in the arrangement direction. The depth of the portion of the recess 23b of the heater holder 23 where the second high thermal conductivity components 36 are located is set to be one level deeper than the other portions. A gap is provided between the second high thermal conductivity components 36 and the heater holder 23 on both sides of their arrangement direction. As a result, heat transfer from both ends of the second high thermal conductivity components 36 in the arrangement direction to the heater holder 23 can be suppressed, and the heater 22 can effectively heat the fixing belt 20. In addition, in Figure 32 The middle part is omitted Figure 2 The description of the guide component 26.

[0173] like Figure 33 As shown, the second high thermal conductivity component 36 (refer to the cross-sectional view) is positioned at a location corresponding to interval B in the arrangement direction, overlapping at least a portion of the adjacent impedance heating element 31, and particularly in this embodiment, it is positioned over the entire area of ​​interval B. However, in Figure 33 and the following Figure 37 The image shows a case where the first high thermal conductivity component 28 is only provided in the area corresponding to the heating element 35 in the arrangement direction, but it is not limited to the case described above.

[0174] As shown in this embodiment, in addition to the first high thermal conductivity member 28, by providing a second high thermal conductivity member 36 at a position corresponding to the interval B in the arrangement direction, which overlaps at least a portion of the adjacent impedance heating element 31, the heat transfer efficiency in the arrangement direction in the interval B can be particularly improved, and the temperature unevenness in the arrangement direction of the heater 22 can be further suppressed. Furthermore, the most preferred embodiment is as follows... Figure 34 As shown, at the location corresponding to interval B, the first high thermal conductivity component 28 and the second high thermal conductivity component 36 are provided only over the entire area. Therefore, at the location corresponding to interval B, heat transfer efficiency is particularly improved compared to other areas. Furthermore, in Figure 34 For convenience, the impedance heating element 31, the first high thermal conductivity component 28, and the second high thermal conductivity component 36 are arranged in... Figure 34 The vertical directions are staggered, but they are arranged in approximately the same position in the cross direction of the arrangement. However, it is not limited to this, the first high thermal conductivity component 28 and the second high thermal conductivity component 36 may also be provided on a part of the cross direction of the arrangement of the impedance heating element 31.

[0175] In one embodiment of the present invention, different from the above, the first high thermal conductivity component 28 and the second high thermal conductivity component 36 are made of the aforementioned graphene sheet. This allows the first high thermal conductivity component 28 and the second high thermal conductivity component 36 to be formed along a predetermined direction of the graphene surface, i.e., the alignment direction rather than the thickness direction. Therefore, temperature unevenness in the alignment direction of the heater 22 and the fixing belt 20 can be effectively suppressed.

[0176] Graphene is a sheet-like powder. Graphene is like... Figure 35 The graphene sheet is composed of a planar hexagonal lattice structure of carbon atoms. A graphene sheet refers to sheet-like graphene, usually a single layer. A single layer of carbon can also contain impurities. Additionally, graphene can also possess a fullerene structure. Fullerene structures are generally considered to be compounds formed by cage-like fused polycyclic rings of the same number of carbon atoms, such as C1. 60 C 70 and C 80 Fullerenes or other closed cage-like structures with three coordinated carbon atoms.

[0177] Graphene sheets are man-made, for example, through chemical vapor deposition (CVD).

[0178] Commercially available graphene sheets can be used. The size, thickness, or number of layers of the graphene sheet (described later) can be measured, for example, by transmission electron microscopy (TEM).

[0179] Furthermore, graphite multilayered with graphene exhibits significant anisotropy in thermal conductivity. For example... Figure 36As shown, graphite has layers of carbon atoms arranged in a planar pattern, forming condensed six-membered rings, and has a crystal structure in which these layers are stacked into multiple layers. Covalent bonds are formed between carbon atoms in this crystal structure, between adjacent carbon atoms within a layer, and between carbon atoms between layers. Furthermore, covalent bonds have a stronger binding force than van der Waals bonds, and the bonds within and between layers exhibit significant anisotropy. That is, by using graphite to construct the first high thermal conductivity component 28 or the second high thermal conductivity component 36, the heat transfer efficiency in the alignment direction of the first high thermal conductivity component 28 or the second high thermal conductivity component 36 is greater than that in the thickness direction (i.e., the stacking direction of the component), thus suppressing heat transfer to the heater holder 23. Therefore, while effectively suppressing temperature unevenness in the alignment direction of the heater 22, the heat flowing out towards the heater holder 23 can be minimized. In addition, by making the first high thermal conductivity component 28 or the second high thermal conductivity component 36 from graphite, the first high thermal conductivity component 28 or the second high thermal conductivity component 36 can have excellent heat resistance that does not oxidize up to about 700 degrees Celsius.

[0180] The properties and dimensions of the graphite sheet can be appropriately modified according to the required function of the first high thermal conductivity component 28 or the second high thermal conductivity component 36. For example, by using high-purity graphite or single-crystal graphite, or by increasing the thickness of the graphite sheet, its anisotropy of thermal conductivity can be improved. In addition, in order to increase the speed of the fixing device 9, a thinner graphite sheet can be used to reduce the heat capacity of the fixing device 9. Furthermore, if the width of the fixing imprint section N or the heater 22 is large, the width of the arrangement direction of the first high thermal conductivity component 28 or the second high thermal conductivity component 36 can be increased accordingly.

[0181] From the perspective of improving mechanical strength, the number of layers in a graphite sheet is preferably 11 or more. Alternatively, the graphite sheet may also include single-layer and multi-layer portions.

[0182] The second high thermal conductivity component 36, in the arrangement direction, at the position corresponding to the interval B (and thus region C), only needs to be disposed in a position that overlaps at least partially with the adjacent impedance heating element 31, and is not limited to... Figure 33 The configuration. For example, such as Figure 37 As shown, the second high thermal conductivity component 36A is configured to protrude towards both sides of the substrate material 30 in the cross-arrangement direction. Furthermore, the second high thermal conductivity component 36B is disposed within the area where the impedance heating element 31 is located in the cross-arrangement direction. The second high thermal conductivity component 36C is disposed within a portion of the spacer B.

[0183] In addition, such as Figure 38 As shown, in this embodiment, a thickness-direction space is provided between the first high thermal conductivity component 28 and the heater holder 23. Figure 38The gap in the left and right directions. That is, in the recess 23b of the heater 22, the first high thermal conductivity member 28 and the second high thermal conductivity member 36 used to arrange the heater holder 23 (see reference). Figure 32 In a portion of the area, a relief portion 23c, which serves as an insulating layer, is provided such that the depth of the recess 23b is deeper than that of the portion receiving the first high thermal conductivity member 28. This portion of the area is a portion or all of the portion in the arrangement direction where the second high thermal conductivity member 36 is provided, located in a region where the arrangement directions intersect. This minimizes the contact area between the heater holder 23 and the first high thermal conductivity member 28. Therefore, heat transfer from the first high thermal conductivity member 28 to the heater holder 23 can be suppressed, and the heater 22 can effectively heat the fixing tape 20. Furthermore, in the cross-section where the second high thermal conductivity member 36 is provided in the arrangement direction, as described in the above embodiment... Figure 31 As shown, the second high thermal conductivity component 36 abuts against the heater holder 23.

[0184] Furthermore, particularly in this embodiment, in the direction of the intersection of the arrangement Figure 38 In the vertical direction, a clearance portion 23c is provided throughout the entire area where the resistive heating element 31 is located. This effectively suppresses heat transfer from the first high thermal conductivity member 28 to the heater holder 23, allowing the heater 22 to effectively heat the fixing belt 20. Furthermore, as an insulating layer, in addition to a configuration with a space provided like the clearance portion 23c, it can also be configured to use an insulating member with a lower thermal conductivity than the heater holder 23.

[0185] Furthermore, in the above description, the second high thermal conductivity component 36 is configured as a component different from the first high thermal conductivity component 28, but it is not limited to this. For example, the portion of the first high thermal conductivity component 28 corresponding to the interval B may be made thicker than the other portions.

[0186] In the above Figure 31 or Figure 38 In this embodiment, by aligning the conductive component 40 with the first opposing surface 24d of the support member 24, or with the second opposing surface 26a of the guide member 26, the contact state of the conductive component 40 with the inner surface of the fixing belt 20 can be stabilized, similar to the embodiment described above. Furthermore, these effects can be achieved without fixing the conductive component 40 to a predetermined component within the fixing device using screws or other fixing components. Therefore, the space required for fixing components such as screws is eliminated, enabling miniaturization of the fixing device. Additionally, the heat capacity of the fixing device can be reduced, resulting in energy savings.

[0187] While the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention.

[0188] In addition to the fixing device described above, the present invention can also be applied to, for example, Figures 39-41 The fixing device shown. The following is a description of... Figures 39-41 The structure of each fixing device shown will be briefly explained.

[0189] first, Figure 39 The fixing device 9 shown has a push roller 84 disposed on the side opposite to the fixing belt 20 and the pressure roller 21. The push roller 84 is a counter-rotating component that rotates relative to the fixing belt 20, which is a rotating component. The push roller 84 and the heater 22 are configured to clamp the fixing belt 20 for heating. On the other hand, on the pressure roller 21 side, a clamping part forming member 85 is disposed on the inner circumference of the fixing belt 20. The clamping part forming member 85 is supported by the support member 24. The clamping part forming member 85 and the pressure roller 21 clamp the fixing belt 20 to form a clamping part N.

[0190] Guide ribs 260 are provided on the upstream and downstream sides of the clamping forming member 85. Then, a conductive member 40 is disposed between the upstream guide rib 260 and the support member 24. More specifically, the opposing portion 40c of the conductive member 40 is disposed facing the ground, opposite to the first opposing surface 260d of the upstream guide rib 260 (which is the first opposing member of this embodiment) and the second opposing surface 24f of the support member 24 (which is the second opposing member). Furthermore, the opposing portion 40c is disposed along the first opposing surface 260d and the second opposing surface 24f. One end 40a of the conductive member 40 contacts the inner surface of the fixing belt 20 (which is a rotating member).

[0191] Next, in Figure 40 In the fixing device 9 shown, the aforementioned push roller 84 is omitted. To ensure the circumferential contact length between the fixing belt 20 and the heater 22, the heater 22 is formed in an arc shape along the curvature of the fixing belt 20. Other configurations are the same as... Figure 39 The fixing device 9 shown has the same configuration.

[0192] Finally, for Figure 41The fixing device 9 shown will be described below. The fixing device 9 comprises a heating assembly 92, a fixing roller 93 as a fixing component, and a pressure assembly 94 as a counter-pressure component. The heating assembly 92 includes a heater 22, a first high thermal conductivity component 28, a heater holder 23, a support member 24, and a heating belt 120 as a rotating component, as described in the previous embodiment. The fixing roller 93 is a counter-rotating component that rotates relative to the heating belt 120 as a rotating component. Furthermore, the fixing roller 93 is composed of a solid iron core rod 93a, an elastic layer 93b formed on the surface of the core rod 93a, and a release layer 93c formed outside the elastic layer 93b. Additionally, the pressure assembly 94 is provided on the opposite side of the heating assembly 92 relative to the fixing roller 93. The pressure assembly 94 is equipped with a clamping part forming member 95 and a support member 96, and the pressure belt 97 is configured to be rotatable in such a way that it includes these clamping part forming members 95 and the support member 96. Then, the paper P is heated and pressured by passing it through the fixing clamping part N2 between the pressure belt 97 and the pressure roller 93 to fix the image. Figure 41 Arrow J indicates the direction of rotation of the pressure belt.

[0193] Guide ribs 261 are provided on the upstream and downstream sides of the clamping forming member 95. Multiple guide ribs 261 are arranged in the arrangement direction and are formed in a generally fan shape. The guide ribs 261 have an arc-shaped or convex surface-shaped tire facing surface 261a extending along the circumferential direction of the tire, so as to face the inner circumferential surface of the pressure belt 97.

[0194] A conductive component 40 is disposed between the support member 96 and the downstream guide rib 261. More specifically, the opposing portion 40c of the conductive component 40 is disposed facing the ground, opposite to the first opposing surface 96a of the support member 96 (which is the first opposing component in this embodiment) and the second opposing surface 261b of the downstream guide rib 261 (which is the second opposing component). Furthermore, the opposing portion 40c of the conductive component 40 is disposed along the first opposing surface 96a and the second opposing surface 261b. One end 40a of the conductive component 40 contacts the inner surface of the pressure belt 97, which is a rotating component. Additionally, when the surface layer of the fixing roller 93 and the heating belt 120 are formed of conductive material, [the conductive component]... Figure 6 Similarly, the conductive member 40 can be configured to face the first opposing surface of the support member 24 and the second opposing surface of the guide rib 260 on the upstream side. In this case, one end of the conductive member 40 contacts the inner surface of the heating band 120, which serves as a rotating member.

[0195] Through the above Figures 39-41By arranging the conductive component 40 in a manner similar to that of a fixing device, stable contact can be achieved between the conductive component 40 and the inner surface of the fixing belt 20 (or the inner surface of the pressure belt 97). Therefore, proper static electricity removal can be achieved from the fixing belt 20 or the pressure belt 97. Furthermore, these effects can be obtained without fixing the conductive component 40 to a predetermined component within the fixing device using screws or other fixing components. Therefore, the space required for fixing components such as screws is eliminated, allowing for miniaturization of the fixing device. Additionally, energy savings can be achieved by reducing the heat capacity of the fixing device.

[0196] Furthermore, the present invention is not limited to the fixing apparatus described above, but can also be applied to drying apparatuses for drying ink applied to paper. Moreover, it can be applied to heating apparatuses such as laminators that heat-press film material, serving as a covering member, onto the surface of sheet materials like paper, and heat-sealing machines that heat-press the sealing portions of packaging materials. By applying the present invention to such an apparatus, as described above, stable contact between the conductive component and the rotating component can be achieved. Additionally, as described above, the fixing apparatus can be miniaturized.

[0197] The image forming apparatus involved in this invention is not limited to Figure 1 The color image forming apparatus shown can also be a black and white image forming apparatus, a copier, printer, fax machine, or their multi-functional peripheral devices.

[0198] For example, Figure 42 As shown, the image forming apparatus 100 of this embodiment includes an image forming unit 50 composed of a photosensitive drum or the like, a paper transport unit composed of a pair of timing rollers 15 or the like, a paper feeding device 7, a fixing device 9, a paper discharge device 10, and a reading unit 51. The paper feeding device 7 has multiple paper feed trays, each of which holds paper of different sizes.

[0199] The reading unit 51 reads the image of the original document Q. The reading unit 51 generates image data from the read image. The paper feeding device 7 holds multiple sheets of paper P and feeds the sheets of paper P onto the transport path. The timing roller 15 transports the sheets of paper P on the transport path to the image forming mechanism 50.

[0200] The image forming mechanism 50 forms a toner image on paper P. Specifically, the image forming mechanism 50 includes a photosensitive drum, a charging roller, an exposure unit, a developing unit, a replenishment unit, a transfer roller, a cleaning unit, and a static elimination unit. The toner image is, for example, an image representing the original document Q. The fixing unit 9 heats and pressurizes the toner image to fix it onto the paper P. After the toner image is fixed, the paper P is conveyed to the paper discharge unit 10 via conveying rollers, etc. The paper discharge unit 10 discharges the paper P to the outside of the image forming apparatus 100.

[0201] Next, the fixing device 9 of this embodiment will be described. Details of structures common to the fixing devices of the above embodiments will be omitted as appropriate.

[0202] like Figure 43 As shown, the fixing device 9 includes a fixing belt 20, a pressure roller 21, a heater 22, a heater holder 23, a support 24, a thermistor 25, a first high thermal conductivity component 28, and a conductive component 40.

[0203] A fixing clamping part N is formed between the fixing belt 20 and the pressure roller 21. The clamping width of the fixing clamping part N is 10 mm, and the linear speed of the fixing device 9 is 240 mm / s.

[0204] The fixing belt 20 has a polyimide matrix and a release layer, but no elastic layer. The release layer is made of a heat-resistant film material, for example, a fluoropolymer. The outer diameter of the fixing belt 20 is approximately 24 mm.

[0205] The pressure roller 21 includes a mandrel 21a, an elastic layer 21b, and a release layer 21c. The outer diameter of the pressure roller 21 is 24 to 30 mm, and the thickness of the elastic layer 21b is 3 to 4 mm.

[0206] The heater 22 includes a base material, an insulation layer, a conductor layer including an impedance heating element, and an insulating layer, with an overall thickness of 1 mm. Furthermore, the width Y of the cross direction of the heater 22 is 13 mm.

[0207] A conductive component 40 is disposed between the support member 24 and the downstream guide rib 260. More specifically, the opposing portion 40c of the conductive component 40 is disposed facing the ground, opposite to the first opposing surface 24d of the support member 24 (which is the first opposing component) and the second opposing surface 260c of the downstream guide rib 260 (which is the second opposing component). One end 40a of the conductive component 40 contacts the inner surface of the fixing belt 20, which is a rotating component.

[0208] like Figure 44 As shown, the conductor layer of heater 22 includes multiple resistive heating elements 31, power supply lines 33, and electrode portions 34A to 34C. Even in this embodiment, as... Figure 44 As shown in the enlarged view, the interval B is also formed as a segmentation region divided in the arrangement direction of multiple impedance heating elements 31 (wherein, in Figure 44The interval B is only shown in the enlarged view, but in reality, intervals B are provided between all the impedance heating elements 31. Three heating sections 35A to 35C are formed by the impedance heating elements 31. Heating sections 35A and 35C heat up when the electrode sections 34A and 34B are energized. Heating section 35B heats up when the electrode sections 34A and 34C are energized. For example, heating section 35B can be energized when fixing small-sized paper, and all heating sections can be energized when fixing large-sized paper.

[0209] like Figure 45 As shown, the heater holder 23 holds the heater 22 and the first high thermal conductivity member 28 in its recess 23d. The recess 23d is provided on the heater 22 side of the heater holder 23. The recess 23d includes a surface 23d1 that is recessed on the support member 24 side, which is generally parallel to the base material 30, and is further recessed than the other surfaces of the heater 22; wall portions 23d2 provided on both sides (or one side) of the heater holder 23 in the arrangement direction of the heater holder 23 on the inner side of the heater holder 23; and wall portions 23d3 provided on both sides of the heater holder 23 in the cross-arrangement direction on the inner side of the heater holder 23. The heater holder 23 has a guide member 26. The heater holder 23 is formed of LCP (liquid crystal polymer).

[0210] like Figure 46 As shown, connector 60 has a resin (e.g., LCP) housing and multiple contact terminals disposed within the housing.

[0211] The connector 60 is installed by clamping the heater 22 and the heater retainer 23 together from the front and back sides. In this state, the heating element 35 is electrically connected to the power supply provided in the image forming apparatus by means of the connector 60 through contact (crimping) between each contact terminal and each electrode portion of the heater 22. Thus, power can be supplied to the heating element 35 from the power supply. In addition, to ensure connection with the connector 60, at least a portion of each electrode portion 34 is not covered by the insulating layer and is exposed.

[0212] Flanges 53 are disposed on both sides of the fixing belt 20 in the arrangement direction, holding the two ends of the fixing belt 20 from the inside. Flanges 53 are fixed to the frame of the fixing device 9. Flanges 53 are inserted into both ends of the support member 24 (see reference). Figure 46 (The direction of the arrow starting from flange 53).

[0213] The mounting direction of connector 60 relative to heater 22 and heater retainer 23 is the cross direction of the heater arrangement (see reference). Figure 46(The arrow points in the direction of the connector 60). When the connector 60 is installed onto the heater holder 23, a protrusion on one of the connector 60 and the heater holder 23 engages with a recess on the other, and the protrusion can move relative to the recess. Furthermore, the connector 60 is installed on the heater 22 and the heater holder 23 on either side of the arrangement direction, opposite to the side where the drive motor for the pressure roller 21 is located.

[0214] like Figure 47 As shown, thermistors 25 are provided on the central side and the end side of the fixing belt 20, respectively, facing the inner circumferential surface of the fixing belt 20. The heater 22 is controlled according to the respective temperatures of the central side and the end side of the fixing belt 20 in the arrangement direction detected by the thermistors 25.

[0215] Facing the inner circumferential surface of the fixing belt 20, thermostats 27 are respectively provided on the central side and the end side of the fixing belt 20 in the arrangement direction. When the temperature of the fixing belt 20 detected by the thermostat 27 exceeds a predetermined threshold, the power supply to the heater 22 is stopped.

[0216] Flanges 53 are provided at both ends of the fixing belt 20 along the arrangement direction to hold each end of the fixing belt 20. The flanges 53 are formed of LCP (liquid crystal polymer).

[0217] like Figure 48 As shown, a sliding groove 53a is provided on the flange 53. The sliding groove 53a extends in the contact separation direction of the fixing belt 20 relative to the pressure roller 21. The engaging part of the frame of the fixing device 9 engages with the sliding groove 53a. By the relative movement of this engaging part within the sliding groove 53a, the fixing belt 20 can move relative to the pressure roller 21 in the contact separation direction.

[0218] In the fixing device 9 described above, the arrangement of the fixing member or the conductive member 40 allows the conductive member 40 to maintain stable contact with the inner surface of the fixing belt 20. Furthermore, as described above, the fixing device can be miniaturized.

[0219] In addition to paper (ordinary paper), other recording media include thick paper, postcards, envelopes, thin paper, coated paper (such as coated paper or art paper), tracing paper, and OHP sheets.

Claims

1. A heating device, characterized in that comprises: a rotating member; an electrically conductive member in contact with an inner surface of the rotating member; a heating body; a first opposing member having a first opposing surface opposing a first surface of the electrically conductive member, and a second opposing member having a second opposing surface opposing a second surface of the electrically conductive member, the second surface being a surface on an opposite side from the first surface, the electrically conductive member is disposed between the first opposing member and the second opposing member, and inclination is limited, an opposite side of the electrically conductive member from a side in contact with the rotating member is sandwiched by the first opposing member and the second opposing member, the second opposing member includes a plurality of guide ribs each having a guide surface in contact with the inner surface of the rotating member.

2. The heating device according to claim 1, wherein: an opposite side of the electrically conductive member from a side in contact with the rotating member is inserted into an opening portion provided in the first opposing member.

3. The heating device according to claim 1, wherein: a contact portion of the electrically conductive member in contact with the rotating member is provided at a position in a central portion in a length direction of the rotating member.

4. The heating device according to claim 1, wherein: a plurality of the electrically conductive members are provided, and contact portions of the plurality of the electrically conductive members in contact with the rotating member are provided at positions symmetrical with respect to a central portion in a length direction of the rotating member on one side and the other side.

5. The heating device according to claim 1, wherein: the first opposing member is formed of an electrically conductive material, and the first opposing member is grounded.

6. The heating device according to claim 1, wherein: the rotating member does not have an electrically conductive elastic layer.

7. The heating device according to claim 1, wherein: the heating body has an impedance heating body divided into a plurality of portions.

8. The heating device according to claim 1, wherein: the electrically conductive member has a limiting portion that reduces a contact area with the rotating member at a contact portion in contact with the rotating member.

9. A fixing device, comprising: the heating device according to any one of claims 1 to 8, and heating and fixing a toner image on a recording medium.

10. An image forming apparatus, comprising: the fixing device according to claim 9.

Images