Reflective member, heating device, fixing device, image forming apparatus

Abstract

The present invention aims to suppress the outflow of heat from the rotating body to the reflective member. [Solution] A reflector 48 provided on a fixing device 40 comprising a fixing belt 42, a pressure roller 41, and a heater 43, comprising a reflective portion 48a that reflects heat from the heater 43, a pressure receiving portion 48b that is thermally connected to the reflective portion 48a and receives the pressure from the pressure roller 41 via the fixing belt 42, and a connecting portion 48c that connects the reflective portion 48a and the pressure receiving portion 48b, wherein a hole 481 is provided in at least one of the pressure receiving portion 48b or the connecting portion 48c.

Description

Technical Field

[0004] ,

[0006] , , , , , , , , , , , ,

[0005]

[0001] The present invention relates to a reflecting member, a heating device, a fixing device, and an image forming apparatus.

Background Art

[0002] In a fixing device (heating device), there is a device in which radiant heat from a heating body is reflected onto the inner surface of a fixing belt by a reflecting member provided inside an endless fixing belt (rotating member) to efficiently heat the fixing belt.

[0003] For example, in Patent Document 1 (Japanese Unexamined Patent Application Publication No. 2023-106335), a reflecting member is provided with a reflecting portion that reflects heat from a heater, and a pressure receiving portion that receives a pressing force from a pressure roller via a fixing belt and a heat equalizing member. The radiant heat from the heater received by the reflecting portion is transmitted to the fixing belt via the pressure receiving portion, thereby enabling efficient heating of the fixing belt.

[0004] However, in the configuration of Patent Document 1, when the inside of the fixing belt is in a cold state, such as at the startup of an image forming apparatus, the heat of the fixing belt flows out to the reflecting member side via the nip forming member, making it difficult for the fixing belt to warm up. As a result, problems such as an increase in the first print time occur.

Summary of the Invention

Problems to be Solved by the Invention

[0005] An object of the present invention is to suppress the outflow of heat from a rotating body to a reflecting member.

Means for Solving the Problems

[0006] To solve the above problems, the present invention provides a reflective member provided in a heating device comprising a rotating body, a pressurizing member, and a heating body, the reflective member comprising a reflective portion that reflects the heat of the heating body, a pressurizing receiving portion that is thermally connected to the reflective portion and receives the pressurizing force of the pressurizing member via the rotating body, and a connecting portion that connects the reflective portion and the pressurizing receiving portion, wherein a recess is provided in at least one of the pressurizing receiving portion or the connecting portion. [Effects of the Invention]

[0007] According to the present invention, the outflow of heat from the rotating body to the reflective member can be suppressed. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic diagram of the image forming apparatus according to this embodiment. [Figure 2] This is a schematic diagram of a fixing device according to one embodiment of the present invention. [Figure 3] This is a perspective view showing the reflector, nip-forming member, and fixing stay. [Figure 4] This is a schematic diagram showing another example configuration of the fixing device. [Figure 5] This diagram shows the heat transfer from the reflector to the fixing belt in a hot state. [Figure 6] This diagram shows the heat transfer from the fixing belt to the reflector in a cold state. [Figure 7] This is a perspective view showing the reflector of this embodiment. [Figure 8] This is a perspective view showing a modified version of the reflector. [Figure 9] This is a perspective view showing a modified version of the reflector. [Figure 10] This is a perspective view showing a modified version of the reflector. [Figure 11] This is a perspective view showing a modified version of the reflector. [Figure 12] This is a perspective view showing a modified version of the reflector. [Figure 13] This is a plan view showing a modified example of a reflector. [Figure 14] This is a schematic diagram showing another example configuration of the fixing device. [Modes for carrying out the invention]

[0009] Embodiments of the present invention will be described below with reference to the drawings. In each figure, the same or corresponding parts are denoted by the same reference numerals, and redundant explanations will be simplified or omitted as appropriate. In the following description, a fixing device provided in an image forming apparatus will be described as an example of a heating device of the present invention.

[0010] The following describes an embodiment of the present invention applied to a laser printer, which is an electrophotographic image forming apparatus. Figure 1 is a schematic diagram of the image forming apparatus 1 of this embodiment. This image forming apparatus 1 includes an image forming unit 100 that forms an image on a paper P, which is a recording medium. The image forming unit 100 is a tandem type image forming apparatus in which image forming units 10Y, 10M, 10C, and 10K for each color (yellow (Y), magenta (M), cyan (C), and black (K)) are arranged along the rotational direction of an intermediate transfer belt 20, which serves as an intermediate transfer body. Each image forming unit 10Y, 10M, 10C, and 10K is equipped with a photoreceptor 11Y, 11M, 11C, and 11K, respectively, which serves as a latent image carrier.

[0011] Furthermore, each image-forming unit 10Y, 10M, 10C, and 10K is equipped with a charging device as a charging means, a light writing device 9 as an electrostatic latent image formation means, and a developing device as a developing means, around the photoreceptor 11Y, 11M, 11C, and 11K. In addition, a primary transfer device as a primary transfer means and a cleaning device as a cleaning means are also equipped around the photoreceptor 11Y, 11M, 11C, and 11K. The charging device uniformly charges the surface of the photoreceptor to a predetermined potential, and the light writing device 9 exposes the photoreceptor surface, which has been uniformly charged by the charging device, according to the image information and writes an electrostatic latent image. The developing device creates a toner image by a developing process that deposits toner of each color (Y, M, C, K) onto the electrostatic latent image on the photoreceptor. The primary transfer device transfers the toner image on the photoreceptor onto the intermediate transfer belt 20, and the cleaning device cleans the photoreceptor by removing any remaining toner.

[0012] The toner images of each color formed on each photoreceptor 11Y, 11M, 11C, and 11K are transferred by the primary transfer device onto the intermediate transfer belt 20 so that they overlap each other, and a color toner image is formed on the intermediate transfer belt 20. The color toner image on the intermediate transfer belt 20 is transported to the region opposite the secondary transfer device 30 (secondary transfer region) as the intermediate transfer belt 20 rotates.

[0013] Meanwhile, a paper feed cassette 60, which serves as a paper feed unit for feeding the paper P to be held, is located below the image forming unit 100. One sheet of paper P is fed from the paper feed cassette 60 by a pickup roller 61. Then, the paper P is transported along the transport path to the secondary transfer area by a pair of registration rollers 62.

[0014] The toner image on the intermediate transfer belt 20 is secondarily transferred by the secondary transfer device 30 onto the paper P conveyed by the resist roller pair 62 at a predetermined timing in the secondary transfer area. The paper P on which the toner image is formed is then conveyed to the fixing device 40 as a heating device, and the toner image is fixed onto the paper P by the action of heat and pressure. The paper P after fixing is conveyed along the conveyance path and discharged to the discharge tray 50 by the discharge roller 63.

[0015] FIG. 2 is a schematic configuration diagram of the fixing device 40 in the present embodiment. The fixing device 40 includes a pressure roller 41 as a pressing member, a fixing belt 42 as a rotating body, a heater 43 (a halogen heater in the example of FIG. 2) as a heating body, a fixing stay 44 as a support member, a nip forming member 45, and a reflector 48 as a reflecting member. Inside the fixing belt 42, the heater 43, the fixing stay 44, the nip forming member 45 held by the fixing stay 44, and the reflector 48 are arranged. In the fixing nip N, which is a nip portion formed between the pressure roller 41 and the fixing belt 42, the image on the paper is fixed by heating and pressing the paper.

[0016] The pressure roller 41, the fixing belt 42, the heater 43, the fixing stay 44, the nip forming member 45, and the reflector 48 extend in a direction perpendicular to the plane of FIG. 2. This direction is the longitudinal direction of these members, and hereinafter, it is simply referred to as the longitudinal direction. This longitudinal direction is also the direction of the rotation axes of the pressure roller 41 and the fixing belt 42. Also, the vertical direction in FIG. 2 is parallel to the conveyance direction B of the paper P, and the horizontal direction in FIG. 2 is parallel to the pressing direction of the pressure roller 41 with respect to the fixing belt 42.

[0017] The nip forming member 45 is composed of a soaking member 45a disposed on the nip surface and a resin pad 45b that supports it. The soaking member 45a is a sliding member or a heat transfer member in the present embodiment. One of the roles of the resin pad 45b is heat insulation, suppressing the heat of the fixing belt 42 from being transmitted to the fixing stay 44 via the nip forming member 45. Thereby, the increase in warm-up time and TEC value is suppressed. The soaking member 45a has, for example, a pad shape extending in the width direction of the fixing belt 42. This soaking member 45a is disposed to average the temperature in the longitudinal direction of the fixing belt. That is, it takes heat from a location with a high temperature of the fixing belt 42 and moves the taken heat to a location with a low temperature of the fixing belt 42 to equalize the temperature in the longitudinal direction of the fixing belt 42.

[0018] In the configuration of FIG. 2, the shape of the nip portion is flat, but it may be a concave shape or other shapes. By forming a concave nip portion, the discharge direction of the leading edge of the paper becomes closer to the pressure roller, and the separation property of the paper with respect to the fixing belt 42 is improved, so the occurrence of jams is suppressed.

[0019] The soaking member 45a is a metal member such as aluminum or copper with high thermal conductivity of 50 [W / m·K] or more, and a coating excellent in sliding performance is applied to the surface of the soaking member 45a. Examples of the coating material include resin-based ones such as polyimide resin, fluororesin, polyphenylene sulfide resin, or saturated polyester resin. Or, glass fiber, carbon, graphite, fluorinated graphite, carbon fiber, molybdenum disulfide, fluororesin, etc. may be mixed with such a resin-based coating material.

[0020] Furthermore, metal-based materials can also be used as coating materials. Examples of metal-based coating materials include molybdenum disulfide, nickel, and composite plating of nickel and fluororesin. Other examples of metal-based coating materials include anodized aluminum or anodized aluminum impregnated with resin or metal. Ceramics can also be used as coating materials. Examples of ceramics used as coating materials include silicon carbide ceramics, silicon ionized aluminum ceramics, alumina ceramics, and mixtures of these with molybdenum disulfide, fluororesin, etc.

[0021] Furthermore, a heat-distributing member 45a made of aluminum or an aluminum alloy is also effective in which an anodized layer is formed on the surface, and molybdenum disulfide produced by secondary electrolysis is filled into the micropores of the anodized layer from the deepest part of the micropores to the outermost layer. In this embodiment, the heat-distributing member 45a having high thermal conductivity is made from a material having a thermal conductivity greater than that of aluminum and is treated as described above. In this way, a heat-distributing member 45a having high thermal conductivity is produced.

[0022] The pressure roller 41 has a silicone rubber layer on the outer circumference of a metal roller, and a release layer (PFA or PTFE layer) is provided on the surface of the silicone rubber layer to obtain release properties. The pressure roller 41 is pressed against the fixing belt side by a spring or the like, and the rubber layer is compressed and deformed to have a predetermined nip width.

[0023] The pressure roller 41 rotates when driving force is transmitted via gears from a drive source such as a motor provided in the image forming apparatus. The fixing belt 42 rotates together with the pressure roller 41 when driving force is transmitted from the pressure roller 41 at the nip section.

[0024] The pressure roller 41 may be a solid roller, but a hollow roller is preferable because it has a lower heat capacity. A heating element such as a halogen heater may also be provided on the pressure roller 41. The silicone rubber layer may be solid rubber, but if there is no heater inside the pressure roller, sponge rubber may be used. Sponge rubber is preferable because it has better heat insulation properties, preventing heat loss from the fixing belt.

[0025] The fixing belt 42 is an endless belt (or film) based on a metal belt such as nickel or SUS, or a resin material such as polyimide. The surface layer of the fixing belt 42 has a release layer such as a PFA or PTFE layer to prevent toner from adhering to it.

[0026] An elastic layer, such as a layer of silicone rubber, may be present between the substrate and the release layer of the fixing belt 42. If the silicone rubber layer is absent, the heat capacity will be reduced and fixing performance will improve, but when the unfixed image is compressed and fixed, subtle irregularities on the belt surface will be transferred to the image, resulting in the problem of orange peel-like marks remaining in the solid areas of the image. To improve this, it is necessary to provide a silicone rubber layer of 100 μm or more. The deformation of the silicone rubber layer will absorb the subtle irregularities, improving the orange peel-like image.

[0027] The fixing stay 44 is a hollow, pipe-shaped metal body made of aluminum, iron, stainless steel, or other metal. In this embodiment, the fixing stay 44 is rectangular, but it may have other cross-sectional shapes. The pressure roller 41 prevents the nip forming member 45 from bending, ensuring a uniform nip width in the longitudinal direction.

[0028] Two heating elements for heating the fixing belt 42 are provided inside the fixing belt 42. In this embodiment, the heater 43 is a halogen heater, and the fixing belt 42 is directly heated from the inner circumference by the radiant heat from the heater 43. Here, the heater 43 only needs to be able to heat the fixing belt 42, and may be an IH coil, a resistance heating element, a carbon heater, etc.

[0029] Furthermore, a reflector 48 is positioned within the fixing belt 42 to reflect heat back to the fixing belt in order to minimize the loss of radiant heat from the heater 43. The reflector 48 is based on high-purity aluminum as a metal component, and high-brightness aluminum is used, which has multiple reflective or protective films formed on its surface to achieve a high reflectivity, for example, a reflectivity of 95% or more. Depending on the configuration, a material in which silver is deposited on an aluminum plate may be used to further improve the reflectivity. In this embodiment, the reflectivity was measured using a spectrophotometer (UH4150 ultraviolet-visible-infrared spectrophotometer manufactured by Hitachi High-Tech Science Corporation) at an incident angle of 5°.

[0030] The reflector 48 of this embodiment has a reflective portion 48a, a pressure receiving portion 48b, and a connecting portion 48c. The reflective portion 48a reflects radiant heat towards the fixing belt side. The pressure receiving portion 48b receives the pressure from the pressure roller 41 via the fixing belt 42 and the heat equalization member 45a. The connecting portion 48c is provided between the reflective portion 48a and the pressure receiving portion 48b. The reflective portion 48a is positioned between the heater 43 and the fixing stay 44. The pressure receiving portion 48b is positioned between the heat equalization member 45a and the resin pad 45b.

[0031] In this embodiment, the reflective portion 48a is the portion of the reflector 48 from one end to the portion facing the heater 43. The pressure receiving portion 48b is the plate portion that is pressed between the heat equalizing member 45a and the resin pad 45b from the other end of the reflector 48, and the portion that extends parallel to this pressed portion. The connecting portion 48c is the portion between the reflective portion 48a and the pressure receiving portion 48b. However, the reflector 48 may consist almost entirely of the reflective portion 48a and the pressure receiving portion 48b, and the connecting portion 48c may be substantially the boundary between the two. The pressure receiving portion 48b is thermally connected to the connecting portion 48c and the reflective portion 48a. Thermal connection means a state in which heat transfer is possible.

[0032] Figure 3 is a perspective view showing the reflector 48, the nip forming member 45, and the fixing stay 44. As shown in Figure 3, the reflector 48 is held in place by the pressure receiving portion 48b being sandwiched between the heat equalizing member 45a and the resin pad 45b, and the part other than the pressure receiving portion 48b is not in contact with other members. The pressure receiving portion 48b is located in the pressurized region that receives the pressure applied by the pressure roller 41. Instead of the configuration shown in Figure 2, the reflector 48 may be in contact with the fixing stay 44 via the heat insulating material 52, as shown in Figure 4. The configuration shown in Figure 4 stabilizes the posture of the reflector 48.

[0033] The pressure receiving portion 48b is positioned between the heat equalization member 45a and the resin pad 45b, in the region that receives pressure from the pressure roller 41. As mentioned above, the reflector 48 is made of aluminum, a metal material with good thermal conductivity, so the heat absorbed by the reflector portion 48a is quickly conducted to the entire component. Then, heat from the reflector 48 is transferred from the pressure receiving portion 48b, which is in contact with the heat equalization member 45a, to the heat equalization member 45a, thereby suppressing the temperature rise of the reflector 48. Furthermore, the heat from the reflector 48 that has been transferred to the heat equalization member 45a is transmitted to the fixing belt 42 through the heat equalization member 45a and used for toner melting. As a result, the heat from the reflector 48 can be used more effectively compared to when the heat from the reflector 48 is dissipated to other components such as the fixing stay 44, the operating time of the heater 43 can be shortened, and power consumption can be reduced.

[0034] Furthermore, as shown in Figures 2 and 3, the reflector 48 is kept in non-contact with the bent portion of the heat-distributing member 45a and the fixing stay 44, with a clearance between them. This prevents heat transfer from the reflector 48 to the bent portion of the heat-distributing member 45a and the fixing stay 44, which is unnecessary from the standpoint of efficient heat utilization.

[0035] Furthermore, as described above, the heat distribution member 45a is coated with a coating that provides excellent sliding performance, and its coefficient of friction with respect to the inner surface of the fixing belt 42 is lower than the coefficient of friction of the surface of the pressure receiving portion 48b with respect to the inner surface of the fixing belt 42. As a result, the sliding resistance of the fixing belt 42 can be reduced compared to when the pressure receiving portion 48b of the reflector 48 is in contact with the inner surface of the fixing belt 42. This suppresses the increase in torque required to rotate the fixing belt 42 and also suppresses wear on the inner surface of the fixing belt 42.

[0036] As in this embodiment, by sliding the heat-distributing member 45a against the inner circumferential surface of the fixing belt 42, it becomes unnecessary for the reflector 48 to have a function that provides good sliding properties against the inner circumferential surface of the fixing belt 42. This eliminates the need to apply a coating with excellent sliding performance to the pressure receiving portion 48b, thereby preventing an increase in manufacturing difficulty and cost.

[0037] As mentioned above, when the inside of the fixing belt 42 is hot, heat from the reflector 48 can be supplied from the reflective part 48a to the fixing nip N via the pressure receiving part 48b, as shown in Figure 5 (see arrow in Figure 5). However, on the other hand, when the inside of the fixing belt 42 is cold, for example, when the image forming apparatus is started up, the heat from the fixing belt 42 flows from the pressure receiving part 48b to the reflective part 48a via the heat equalization member 45a (see arrow in Figure 6). In other words, the heat from the fixing belt 42 is absorbed by the reflector 48. This resulted in problems such as a longer first print time, as it took longer to raise the fixing belt 42 to the fixing temperature required for the fixing operation.

[0038] Figure 7 is a perspective view showing the reflector of this embodiment.

[0039] As shown in Figure 7, the pressure receiving portion 48b of the reflector 48 has a plurality of holes 481. In this embodiment, a plurality of holes 481 are provided in the longitudinal direction of the reflector 48, and each hole 481 extends in the paper transport direction. In other words, each hole 481 is provided with a wide width in the paper transport direction. In this embodiment, the pressure receiving portion 48b is composed of a plurality of plate members arranged in parallel in the longitudinal direction C.

[0040] By providing the holes 481 in the pressure receiving portion 48b, heat transfer in the pressure receiving portion 48b is hindered, and heat transfer within the pressure receiving portion 48b can be restricted. As a result, heat transfer from the pressure receiving portion 48b to the reflecting portion 48a can be suppressed in the cold state inside the fixing belt 42, and consequently, heat outflow from the fixing belt 42 to the reflector 48 can be suppressed. In particular, by providing the holes 481 in the pressure receiving portion 48b, the contact area between the pressure receiving portion 48b and the heat equalization member 45a can be reduced. As a result, heat outflow from the fixing belt 42 to the pressure receiving portion 48b via the heat equalization member 45a can be suppressed in the cold state inside the fixing belt 42.

[0041] Next, we will explain the variations of the reflector 48 in order.

[0042] The reflector 48 shown in Figure 8 has holes 481 extending in the longitudinal direction C. That is, the holes 481 are formed in a longitudinally wide shape, with the length in the longitudinal direction C being longer than the length in the short direction of the pressure receiving portion 48b. This short direction is the direction along the surface of the pressure receiving portion 48b and is perpendicular to the longitudinal direction. Furthermore, this short direction is parallel to the paper transport direction B. Multiple holes 481 are arranged in the longitudinal direction C, and three rows are provided in the paper transport direction B.

[0043] By providing the holes 481 with a wide width in the longitudinal direction, heat can be transferred relatively easily in the longitudinal direction C and relatively less easily in the short direction at the pressure receiving portion 48b. This further suppresses heat transfer from the pressure receiving portion 48b to the connecting portion 48c and the reflecting portion 48a, thereby suppressing heat outflow from the fixing belt to the reflector 48.

[0044] In the reflector 48 shown in Figure 9, the hole 481A extends parallel to the longitudinal direction C in the central part of the longitudinal direction C of the pressure receiving portion 48b (the third of the five plate members in the embodiment), whereas at both ends of the longitudinal direction C (the first, second, fourth, and fifth of the five plate members in the embodiment), the hole 481 is inclined from the upstream side to the downstream side in the paper transport direction B, from the central side to the end side in the longitudinal direction C.

[0045] As the hole 481 is inclined as described above, heat transfer from the pressure receiving portion 48b to the connection portion 48c and then to the reflecting portion 48a is suppressed, as shown in Figure 8 above, and the amount of heat in the pressure receiving portion 48b is made more likely to accumulate towards the center in the longitudinal direction C. This suppresses heat outflow from the end side of the pressure receiving portion 48b in the longitudinal direction C. Therefore, heat outflow from the fixing belt to the reflector 48 can be suppressed.

[0046] The reflector 48 shown in Figure 10 has, in addition to the arrangement of holes 481 in Figure 9, holes 481C at the outermost ends in the longitudinal direction C that extend in the paper transport direction B. This suppresses heat transfer in the longitudinal direction at the ends in the longitudinal direction C and prevents heat from flowing out from the ends of the pressure receiving section 48b in the longitudinal direction C. In this embodiment, holes 481C extending in the paper transport direction B are provided at the outermost ends in the longitudinal direction C, particularly near the edge, within the holes 481b of the pressure receiving section 48b, but they can be provided at the longitudinal ends of the pressure receiving section 48b. The longitudinal ends of the pressure receiving section 48b can be, for example, the regions on both sides when the pressure receiving section 48b is divided into three equal parts in the longitudinal direction C. Note that holes 481C may be added to the arrangement of holes 481 in Figure 8, and the combination of configurations can be selected as appropriate.

[0047] In the reflector 48 shown in Figure 11, the hole 481 is formed in the connection portion 48c rather than the pressure receiving portion 48b. This suppresses heat transfer from the pressure receiving portion 48b to the connection portion 48c and from the connection portion 48c to the reflective portion 48a, making it difficult for heat from the pressure receiving portion 48b to flow out to the reflective portion 48a. Therefore, the outflow of heat from the fixing belt 42 to the reflector 48, especially to the reflective portion 48a, can be suppressed. However, heat transfer suppression portions may be provided in both the pressure receiving portion 48b and the connection portion 48c.

[0048] Furthermore, it is not necessary to provide the heat transfer suppression section over the entire length C. For example, as shown in Figure 12, the holes 481 can be provided only on the central side of the pressure receiving section 48b (the three central holes of the five plate members in this embodiment), and the ends of the pressure receiving section 48b (the plate members at both ends) can be left without holes. This allows heat to flow easily from the fixing belt 42 to the reflector 48 at the longitudinal ends, as in the conventional method. This suppresses the rise in the end temperature of the fixing belt 42 that occurs, for example, when continuously feeding small-sized paper. In this way, the arrangement and size of the holes (or grooves or low-thermal-conductivity sections described later) can be appropriately changed according to the amount of heat mainly required by the fixing belt 42.

[0049] Alternatively, the reflector 48 may be provided with grooves that do not penetrate in the thickness direction instead of holes 481. This restricts heat transfer within the pressure receiving portion 48b or the connecting portion 48c, similar to the case of holes, and suppresses heat transfer from the pressure receiving portion 48b or the connecting portion 48c to the reflecting portion 48a. This suppresses heat outflow from the fixing belt to the reflector 48. In particular, when the grooves are provided in the pressure receiving portion 48b, they can be formed in a concave shape (concave to the left in Figure 2) with respect to the portion that forms the fixing nip N (see Figure 2) between the fixing belt 42 and the pressure roller 41. This reduces the contact area between the pressure receiving portion 48b and the heat equalizing member 45a, and suppresses heat outflow from the fixing belt 42 to the pressure receiving portion 48b side via the heat equalizing member 45a in the cold state inside the fixing belt 42.

[0050] Compared to forming grooves, holes are easier to process, and the aforementioned heat transfer suppression effect can be obtained more significantly. On the other hand, forming grooves can suppress the reduction in strength of the reflector 48 compared to forming holes.

[0051] As shown in Figure 13, a narrowed portion 482 may be formed by making a portion of the pressure receiving portion 48b concave in the short direction, thereby partially reducing its width in the short direction. This reduces the contact area between the pressure receiving portion 48b and the heat equalizing member 45a, thereby suppressing heat outflow from the fixing belt to the reflector 48. However, the narrowed portion 482 may also be provided at the connection portion 48c.

[0052] Furthermore, the pressure receiving portion 48b or the connection portion 48c of the reflector 48 can be made of a material with lower thermal conductivity than the rest of the reflector 48, thereby creating a low-thermal-conductivity section. This allows for suppressing heat transfer, for example, by partially increasing the strength of the pressure receiving portion 48b or the connection portion 48c, and also allows for other functions to be added by changing the material. For the low-thermal-conductivity section, resin materials such as polystyrene or silicone can be used. This allows for both strength and heat transfer suppression effects. Note that "the rest of the reflector 48" does not necessarily mean all of the rest of the reflector 48, but only a part of it.

[0053] In this way, heat transfer suppression parts such as holes, grooves, and low thermal conductivity parts can be provided in the pressure receiving portion 48b or connection portion 48c of the reflector 48. These heat transfer suppression parts are parts that suppress heat transfer from the rotating body to the reflective member, or to the reflective portion within the reflective member.

[0054] Furthermore, the reflector 48 can also be equipped with a combination of the arrangements and configurations of the heat transfer suppression parts shown in Figures 7 to 13.

[0055] Although embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the present invention.

[0056] Figure 14 is a schematic diagram showing another example of the configuration of the fixing device. The fixing device shown in Figure 14 has a concave shape when viewed from the direction of the rotation axis of the fixing stay 44, and the heater 43 is positioned in the recessed part of the fixing stay 44. Similar to the embodiment, the reflective portion 48a of the reflector 48 is positioned between the fixing stay 44 and the heater 43. The reflective portion 48a extends from the lower side in the figure and has a pressure receiving portion 48b sandwiched between the resin pad 45b and the heat equalizing member 45a.

[0057] In the fixing device shown in Figure 14, the heat from the reflector 48 is dissipated to the fixing belt 42 via the heat equalization member 45a, and the heat from the reflector 48 can be used to melt the toner. In addition, in the configuration shown in Figure 14, the reflector 48 is kept non-contact with the bent portion of the heat equalization member 45a and the fixing stay 44 by providing a clearance, thereby preventing heat transfer from the reflector 48 to the bent portion of the heat equalization member 45a and the fixing stay 44.

[0058] Furthermore, although the heat equalization member 45a is placed between the pressure receiving portion 48b of the reflector 48 and the fixing belt 42 as described above, the member placed between the pressure receiving portion 48b and the fixing belt 42 can be any member that has better sliding properties with respect to the inner circumferential surface of the fixing belt 42 than the reflector 48. For example, although its heat dissipation to the fixing belt 42 is inferior to that of the heat equalization member 45a, a sliding sheet made of PTFE or other fibers impregnated with a lubricant such as silicone oil may be placed between the pressure receiving portion 48b and the fixing belt 42 as a sliding member. This sliding sheet may be placed, for example, wrapped around the resin pad 45b and fixed to the back side (fixing stay side) of the resin pad 45b with screws or the like.

[0059] In this embodiment as well, the configuration of the heat transfer suppression unit described above can be applied to the pressurized receiving portion 48b or the connecting portion 48c. This makes it possible to suppress the outflow of heat from the fixing belt 42 to the reflector 48.

[0060] The present invention is not limited to applications to a fixing device, which is an example of a heating device, but can also be applied to heating devices other than fixing devices. For example, the present invention can be applied to heating devices such as drying devices that dry liquids such as ink applied to paper, laminators that heat-press a film as a covering member onto the surface of a sheet such as paper, and heat sealers that heat-press the sealing portion of packaging materials. This makes it possible to suppress the outflow of heat from the rotating body to the reflective member.

[0061] The image forming apparatus according to the present invention is not limited to the color image forming apparatus shown in Figure 1, but may also be a monochrome image forming apparatus, a copier, a printer, a facsimile, or a combination device thereof.

[0062] Recording media include plain paper (P), as well as cardboard, postcards, envelopes, thin paper, coated paper (such as coated paper and art paper), tracing paper, OHP sheets, plastic film, prepreg, copper foil, and the like.

[0063] Examples of the present invention are as follows: <1> A reflective member provided in a heating device comprising a rotating body, a pressurizing member, and a heating element, A reflective portion that reflects the heat of the aforementioned heating element, A pressure receiving portion is thermally connected to the reflective portion and receives the pressurizing force of the pressurizing member via the rotating body, It comprises a connecting portion that connects the reflective portion and the pressure receiving portion, The reflective member is characterized in that a hole is provided in at least one of the pressure receiving portion or the connecting portion. <2> The aforementioned hole is provided in the pressure receiving portion, The aforementioned holes are provided wide in the longitudinal direction of the reflective member. <1> This is the reflective material described. <3> The aforementioned hole is provided in the pressure receiving portion, The aforementioned holes are inclined from the longitudinal center of the pressure receiving portion towards the end, with respect to the direction from the upstream side to the downstream side in the recording medium transport direction. <1> or <2> This is the reflective material described. <4> The hole extending in the recording medium transport direction is provided on the longitudinal end side of the pressure receiving portion. <1> from <3> It is one of the reflective materials described below. <5> A reflective member provided in a heating device comprising a rotating body, a pressurizing member, and a heating element, A reflective portion that reflects the heat of the aforementioned heating element, A pressure receiving portion is thermally connected to the reflective portion and receives the pressurizing force of the pressurizing member via the rotating body, It comprises a connecting portion that connects the reflective portion and the pressure receiving portion, The reflective member is characterized in that a groove is provided in at least one of the pressure receiving portion or the connecting portion. <6> The pressure receiving portion is provided with a concave groove in the portion that forms a nip between the rotating body and the pressure member. <5> This is the reflective material described. <7> A reflective member provided in a heating device comprising a rotating body, a pressurizing member, and a heating element, A reflective portion that reflects the heat of the aforementioned heating element, A pressure receiving portion is thermally connected to the reflective portion and receives the pressurizing force of the pressurizing member via the rotating body, It comprises a connecting portion that connects the reflective portion and the pressure receiving portion, The reflective member is characterized in that at least one of the pressure receiving portion or the connecting portion is provided with a low thermal conductivity portion having a lower thermal conductivity than the rest of the reflective member. <8> <1> from <7> The reflective material described in any of the above, The rotating body and, The aforementioned pressurizing member, This is a heating device comprising the aforementioned heating element. <9> <8> This fixing device is equipped with the heating device described above and fixes an image onto a recording medium by heat. <10> <9> This is an image forming apparatus equipped with the fixing device described above. [Explanation of Symbols]

[0064] 1. Image forming apparatus 40 Fixing device (heating device) 41 Pressure roller (pressure component) 42 Fixing belt (rotating body) 43 Heater (heating element) 45 Nip forming member 45a Heating element 45b Resin pad 48. Reflector (reflective material) 48a Reflector 48b Pressure receiving section 48c Connection 481 Hole B. Paper transport direction (recording medium transport direction) C Longitudinal direction N Fixing nip (nip part) P Paper (recording medium) [Prior art documents] [Patent Documents]

[0065] [Patent Document 1] Japanese Patent Publication No. 2023-106335

Claims

1. A reflective member provided in a heating device comprising a rotating body, a pressurizing member, and a heating element, A reflective portion that reflects the heat of the aforementioned heating element, A pressure receiving portion is thermally connected to the reflective portion and receives the pressurizing force of the pressurizing member via the rotating body, It comprises a connecting portion that connects the reflective portion and the pressure receiving portion, A reflective member characterized in that a hole is provided in at least one of the pressure receiving portion or the connecting portion.

2. The aforementioned hole is provided in the pressure receiving portion, The reflective member according to claim 1, wherein the hole is provided wide in the longitudinal direction of the reflective member.

3. The aforementioned hole is provided in the pressure receiving portion, The reflective member according to claim 1, wherein the hole is inclined from the longitudinal center of the pressure receiving portion toward the end, with respect to the recording medium transport direction from the upstream side toward the downstream side.

4. The reflective member according to claim 1, wherein the hole extending in the recording medium transport direction is provided on the longitudinal end side of the pressure receiving portion.

5. A reflective member provided in a heating device comprising a rotating body, a pressurizing member, and a heating element, A reflective portion that reflects the heat of the aforementioned heating element, A pressure receiving portion is thermally connected to the reflective portion and receives the pressurizing force of the pressurizing member via the rotating body, It comprises a connecting portion that connects the reflective portion and the pressure receiving portion, A reflective member characterized in that a groove is provided in at least one of the pressure receiving portion or the connecting portion.

6. The reflective member according to claim 5, wherein the pressure receiving portion is provided with a concave groove portion in the portion that forms a nip portion between the rotating body and the pressure member.

7. A reflective member provided in a heating device comprising a rotating body, a pressurizing member, and a heating element, A reflective portion that reflects the heat of the aforementioned heating element, A pressure receiving portion is thermally connected to the reflective portion and receives the pressurizing force of the pressurizing member via the rotating body, It comprises a connecting portion that connects the reflective portion and the pressure receiving portion, A reflective member characterized in that at least one of the pressure receiving portion or the connecting portion is provided with a low thermal conductivity portion having a lower thermal conductivity than the rest of the reflective member.

8. A reflective member according to any one of claims 1 to 7, The rotating body and, The aforementioned pressurizing member, A heating device comprising the aforementioned heating element.

9. A fixing apparatus comprising the heating device described in claim 8, for fixing an image onto a recording medium by heat.

10. An image forming apparatus comprising the fixing device described in claim 9.

Images