Heat insulation structure and electronic device

Abstract

A heat insulation structure according to an embodiment of the present disclosure comprises a foam body and a thermosetting resin covering the foam body.

Description

Thermal insulation structures and electronic devices

[0001] The present disclosure relates to a thermal insulation structure and an electronic device equipped with the thermal insulation structure.

[0002] In electronic devices such as projection display devices, a heat source such as a light source is used, and therefore, methods have been proposed for reducing the rise in ambient temperature caused by this heat source (see, for example, Patent Document 1).

[0003] International Publication No. 2020 / 255838

[0004] In such electronic devices, it is desirable to suppress the influence of the heat source on the surrounding area.

[0005] Therefore, a thermal insulation structure that effectively insulates a heat source from its surroundings is desired.

[0006] A thermal insulation structure according to one embodiment of the present disclosure includes a foam and a thermosetting resin covering the foam.

[0007] In the heat insulating structure according to one embodiment of the present disclosure, the foam is covered with a thermosetting resin, so that the shape of the foam is stably maintained.

[0008] FIG. 1 is a schematic diagram illustrating an example of the configuration of a light-emitting device according to a first embodiment of the present disclosure. FIG. 2 is a perspective view schematically illustrating the configuration of a light source unit and a thermal insulation structure. FIG. 3 is a schematic diagram illustrating a vertical cross-sectional configuration of the light source unit and the thermal insulation structure shown in FIG. 2, as viewed in the direction of the arrows along line II. FIG. 4 is a schematic diagram illustrating a horizontal cross-sectional configuration of the light source unit and the thermal insulation structure shown in FIG. 2. FIG. 5A is a schematic cross-sectional view illustrating an example of a manufacturing process for the thermal insulation structure shown in FIG. 2. FIG. 5B is a schematic cross-sectional view illustrating a process subsequent to FIG. 5A. FIG. 5C is a schematic cross-sectional view illustrating a process subsequent to FIG. 5B. FIG. 5D is a schematic cross-sectional view illustrating an enlarged portion of the cross-sectional configuration of the wound body shown in FIG. 5C. FIG. 5E is a schematic cross-sectional view illustrating a process subsequent to FIG. 5C. FIG. 6A is an enlarged schematic cross-sectional view illustrating a portion of a thermal insulation structure according to a first modification of the first embodiment. FIG. 6B is a schematic diagram illustrating a planar configuration of a portion of a thermosetting resin according to the first modification of the first embodiment. FIG. 7A is an enlarged schematic cross-sectional view illustrating a portion of a thermal insulation structure according to a second modified example of the first embodiment. FIG. 7B is a schematic view illustrating a planar configuration of a portion of a thermosetting resin according to a second modified example of the first embodiment. FIG. 8 is a vertical schematic cross-sectional view illustrating an example of a thermal insulation structure according to a third modified example of the first embodiment. FIG. 9 is a diagram illustrating an example of the configuration of a projection display device to which the light-emitting device shown in FIG. 1 is applied. FIG. 10 is a schematic view illustrating an example of the configuration of a heating device according to a second embodiment of the present disclosure. FIG. 11 is a plan schematic view illustrating the configuration of the heater shown in FIG. 10. FIG. 12 is a schematic view illustrating the cross-sectional configuration of the heater and thermal insulation structure shown in FIG. 10, taken along line II-II. FIG. 13 is a schematic view illustrating the horizontal cross-sectional configuration of the heater and thermal insulation structure shown in FIG. 11. FIG. 14A is a schematic view illustrating the cross-sectional configuration of the heater shown in FIG. 11, taken along line III-III. Fig. 14B is a schematic diagram showing the cross-sectional configuration of the heater shown in Fig. 11 taken along line IV-IV and viewed from the direction of the arrows. Fig. 14C is a schematic diagram showing the cross-sectional configuration of the heater shown in Fig. 11 taken along line V-V and viewed from the direction of the arrows. Fig. 15A is a diagram explaining the manufacturing process of the heater shown in Fig. 11. Fig. 15B is a diagram showing a process following Fig. 15A. Fig. 15C is a diagram showing a process following Fig. 15B. Fig. 16A is a diagram showing a process following Fig. 15C.Fig. 16B is a diagram showing a process subsequent to Fig. 16A. Fig. 17 is a diagram showing a process subsequent to Fig. 16B.

[0009] An embodiment of the present disclosure will be described in detail below with reference to the drawings. The following description is a specific example of the present disclosure, and the present disclosure is not limited to the following aspect. Furthermore, the present disclosure is not limited to the arrangement, dimensions, dimensional ratios, etc. of the components shown in the drawings. The description will be given in the following order. 1. First embodiment (example in which a thermosetting resin is provided around a foam) 1-1. Overall configuration of a light-emitting device 1-2. Specific configuration of a heat-insulating structure 1-3. Method for manufacturing a heat-insulating structure 1-4. Actions and effects 2. Modifications 2-1. Modification 1-1 (first modified example of a heat-insulating structure) 2-2. Modification 1-2 (second modified example of a heat-insulating structure) 2-3. Modification 1-3 (third modified example of a heat-insulating structure) 3. Application example (example of a projection display device) 4. Second embodiment (example of a heating device in which a heat-insulating member is provided around a heat source) 4-1. Overall configuration of a heating device 4-2. Configuration of a heater 4-3. Heater manufacturing method 4-4. Actions and effects 5. Other modifications

[0010] 1 is a schematic diagram illustrating an example of the configuration of a light-emitting device 10 according to a first embodiment of the present disclosure. The light-emitting device 1 is applicable to, for example, electrical equipment such as a projection display device (for example, a projection display device 200 shown in FIG. 8 , which will be described later).

[0011] The light-emitting device 10 includes, for example, an exterior member 11, a transparent plate 12, a control unit 13, a battery 14, a light source unit 15, and a heat insulating structure 16. Here, the light source unit 15 corresponds to a specific example of a "heat source" according to one aspect of the present disclosure.

[0012] The exterior member 11 is, for example, a substantially cylindrical container with its central axis along the Z axis and has a cavity 11V therein. A first end of the cavity 11V in the Z axis direction is open. A second end of the cavity 11V opposite the first end in the Z axis direction is closed. A transparent plate 12 is provided to close the open end of the exterior member 11. The exterior member 11 houses a control unit 13, a battery 14, a light source unit 15, and a heat insulating structure 16 in the cavity 11V. The exterior member 11 is made of, for example, plastic. Examples of plastics that can be used to make the exterior member 11 include ABS (Acrylonitrile Butadiene Styrene) resin, PC (Polycarbonate) / ABS resin, and nylon. The exterior member 11 may also be made of metals such as aluminum alloys (e.g., A1050 and A5052), magnesium (Mg), and stainless steel.

[0013] The transparent plate 12 has high transparency to light in the wavelength band generated by the light source unit 15. Therefore, the light from the light source unit 15 that is extracted through an opening 16M (shown in FIG. 2 to be described later) of the heat insulating structure 16 passes through the transparent plate 12 and is extracted to the outside of the exterior member 11.

[0014] The control unit 13 is electrically connected to both the battery 14 and the light source unit 15. The control unit 13 includes, for example, a wiring board and an IC (Integrated Circuit) mounted on the wiring board. The control unit 13 inputs a drive signal to the light source unit 15 in response to, for example, an externally input signal. The lighting state of the light source unit 15 is controlled in response to the drive signal from the control unit 13.

[0015] The battery 14 supplies power to the control unit 13 .

[0016] The light source unit 15 has a connection unit 15C (shown in FIG. 2, which will be described later). The light source unit 15 is connected to the control unit 13 via the connection unit 15C and is turned on by a drive signal input from the control unit 13. The light source unit 15 includes, for example, a laser or an LED (Light Emitting Diode). The light source unit 15 may include, for example, a discharge lamp such as a metal halide lamp, a high-pressure mercury lamp, a halogen lamp, or a xenon lamp. The light source unit 15 generates heat along with light. The temperature near the light source unit 15 can reach, for example, approximately 70°C to 300°C.

[0017] [1-2. Specific Configuration of Heat Insulation Structure] Fig. 2 is an exploded perspective view that mainly schematically shows the light source unit 15 and the heat insulation structure 16. Fig. 3 is a cross-sectional view that schematically shows a cross section of the light source unit 15 and the heat insulation structure 16 shown in Fig. 2, taken along line II. Fig. 4 is a cross-sectional view that schematically shows an example of a horizontal cross-sectional configuration of the light source unit 15 and the heat insulation structure 16, perpendicular to the Z axis.

[0018] The thermal insulation structure 16 has a generally cylindrical appearance that surrounds the light source unit 15 along a plane perpendicular to the Z axis. The thermal insulation structure 16 has, for example, a through-hole 16H that penetrates in the Z axis direction from the first bottom surface 16S1 to the second bottom surface 16S2. The thermal insulation structure 16 includes a foam 161 having the through-hole 16H and a thermosetting resin 162 that covers the outer surface of the foam 161. The light source unit 15, which is supported by a locking member 17, is inserted into the through-hole 16H. The thermal insulation structure 16 is supported by the locking member 17, for example, by bonding the second bottom surface 16S2 to the locking member 17. Therefore, the light source unit 15 and the thermal insulation structure 16 are fixed in position relative to each other by the locking member 17. The thermal insulation structure 16 may be spaced apart from the outer surface of the light source unit 15 or may be in contact with the outer surface of the light source unit 15.

[0019] The foam 161 has a generally cylindrical appearance, with a sheet-like member containing a plurality of bubbles arranged along a plane perpendicular to the Z axis to surround the periphery of the light source unit 15. The foam 161 has a pair of openings (openings 16M of the heat insulating structure 16) facing each other in the Z axis direction with the light source unit 15 in between. Light generated by the light source unit 15 is extracted through one of the pair of openings. Providing such an opening in the foam 161 makes it possible to utilize the light generated by the light source unit 15, thereby increasing the degree of freedom in component placement.

[0020] Foam 161 is made of a material with heat insulating properties and expands at temperatures higher than room temperature. Specifically, foam 161 is made of an aerogel such as silica aerogel, polymer aerogel, or carbon aerogel. Foam 161 containing aerogel can be easily made thin, making it suitable for use in small electronic devices.

[0021] The thickness of the foam 161 is, for example, 5.0 mm or less. For example, when the light emitting device 10 is applied to a small electronic device, the gaps between components are also small, so the thickness of the foam 161 is preferably 5.0 mm or less. When the temperature of the light source unit 15 is 300°C or less, a foam 161 having a thickness of 2.0 mm or less may be used. For example, the foam 161 may be formed by stacking multiple sheets each having a thickness of about 0.1 mm. By forming the foam 161 by stacking multiple sheets, it becomes easier to adjust the thickness of the foam 161.

[0022] As shown in Figure 3, the foam 161 has a first end face 161E1 and a second end face 161E2 (Figure 3) at both ends in the Z-axis direction. The first end face 161E1 is exposed and in contact with air. As will be described in detail later, in the heat insulating structure 16, the foam 161 is not sealed, which makes it easy to reduce the size of the heat insulating structure 16. The first end face 161E1 may be covered with, for example, another member. Alternatively, the first end face 161E1 may be coated with a resin material or the like.

[0023] The thermosetting resin 162 exhibits a viscosity lower than the viscosity at room temperature in a first temperature range higher than room temperature, and is fluid in the first temperature range. The thermosetting resin 162 hardens in a second temperature range higher than the first temperature range. The foam 161 has heat resistance in the first temperature range and the second temperature range, and expands in the first temperature range. The thermosetting resin 162 is made of, for example, an epoxy resin. The first temperature range for epoxy resin is a temperature range of 50 to 80°C, and the second temperature range is a temperature range of 120°C or higher.

[0024] The heat insulating structure 16 may further include a support 163 that supports the thermosetting resin 162. Here, the support 163 corresponds to a specific example of a "substrate" according to one aspect of the present disclosure.

[0025] The support 163 covers the surface of the thermosetting resin 162 opposite to the foam 161. The support 163 may be embedded in the thermosetting resin 162. The support 163 may be made of, for example, a film. Specifically, the support 163 may be made of, for example, a polyimide film. The support 163 has heat resistance in the first temperature range and the second temperature range.

[0026] [1-3. Manufacturing Method of Thermal Insulation Structure] The thermal insulation structure 16 according to the first embodiment of the present disclosure can be manufactured, for example, as follows. Figures 5A to 5E each show an example of a manufacturing process for the thermal insulation structure 16.

[0027] First, as shown in Fig. 5A, a substantially cylindrical winding core 31 is prepared. Next, a sheet-like foam 161 is placed on thermosetting resin 162 applied to a support 163, and the foam 161 is wound around the winding core 31 so that the foam 161 is in contact with the winding core 31. In this way, the wound body 30 shown in Fig. 5B is produced.

[0028] 5C , wound body 30 is inserted into a cylindrical mold 32 having a predetermined inner diameter, and then wound body 30 is heated from room temperature to a temperature in a first temperature range. By being heated to a temperature in the first temperature range, thermosetting resin 162 becomes fluid, and foam 161 expands in this state.

[0029] FIG. 5D is a schematic diagram showing an enlarged cross-sectional configuration of region VD, indicated by a dashed line in FIG. 5C , of the wound body 30. Region VD represents the vicinity of the overlapping portion between the winding start end and the winding end of the support 163 and the thermosetting resin 162. Arrow P1 in FIG. 5D represents the position of edge E of the winding end of the support 163 and the thermosetting resin 162 at room temperature before heating to a temperature in the first temperature range. In contrast, arrow P2 in FIG. 5D represents the position of edge E of the winding end of the support 163 and the thermosetting resin 162 after heating to a temperature in the first temperature range and maintaining it for 1 to 10 minutes. As shown in FIG. 5D , as the thermosetting resin 162 is heated to the temperature in the first temperature range, the position of edge E moves from position P1 to position P2. That is, the width of the overlapping portion between the winding start end and the winding end of the support 163 and the thermosetting resin 162 narrows. This increases the outer circumferential length of the wound body 30, and ultimately the outer diameter of the wound body 30. As a result, as shown in Fig. 5E, the outer surface of the support body 163 comes into contact with the inner surface of the mold 32. Thereafter, the wound body 30 is heated to a temperature in the second temperature range and maintained there for 5 to 10 minutes, thereby hardening the thermosetting resin 162. After hardening the thermosetting resin 162, the winding core 31 is removed, thereby obtaining the thermal insulation structure 16.

[0030] [1-4. Actions and Effects] The heat insulating structure 16 included in the light emitting device 10 according to the first embodiment of the present disclosure is provided with a foam 161 and a thermosetting resin 162 that covers the foam 161. This allows the shape of the foam 161 to be maintained even when the temperature of the heat insulating structure 16 rises.

[0031] In conventional thermal insulation structures, for example, shrink tubing is used to maintain the shape of the thermal insulation structure when it expands. However, it is difficult to adjust the thickness of the thermal insulation structure by the shrink force of the shrink tubing, and if the shrink force of the shrink tubing is too strong, the shape of the thermal insulation structure may be distorted.

[0032] In contrast, in the heat insulating structure 16 provided in the light emitting device 10 according to the first embodiment of the present disclosure, the thermosetting resin 162 is disposed around the foam 161, which is a heat insulating material. Therefore, the shape of the foam 161 can be stably maintained without using a shrink tube or the like. Therefore, the thickness of the foam 161 can be made larger relative to the thickness of the heat insulating structure 16. As a result, the heat insulating effect can be improved.

[0033] The viscosity of the thermosetting resin 162 decreases in a first temperature range higher than room temperature and hardens in a second temperature range that is even higher. The foam 161 also expands in the first temperature range. Because the thermosetting resin 162 and the foam 161 have the above properties, when the wound body 30 is heated from room temperature to a temperature in the first temperature range during the manufacturing process of the thermal insulation structure 16, the foam 161 expands while the thermosetting resin 162 softens and becomes fluid. Therefore, the reaction force of the foam 161 due to expansion becomes greater than the external force received from the thermosetting resin 162, and the thickness of the foam 161 as a thermal insulation layer increases to a predetermined thickness. When the wound body 30 is further heated and reaches a temperature in the second temperature range where the thermosetting resin 162 hardens, the expansion of the foam 161 can be suppressed by the hardening of the thermosetting resin 162 surrounding the foam 161. In the thermal insulation structure 16 according to the first embodiment of the present disclosure, by employing the thermosetting resin 162 that exhibits such changes in behavior with temperature, it is possible to realize the foam 161 having the desired shape and thickness with high precision. As a result, the light emitting device 10 can effectively shield the heat generated by the light source unit 15, which is a heat-generating body, while achieving a thinner and more compact thermal insulation structure 16. Furthermore, the manufacturing method for the thermal insulation structure 16 according to the first embodiment of the present disclosure allows the manufacturing of a thermal insulation structure 16 having high dimensional precision and high thermal insulation performance.

[0034] Other possible methods include creating a vacuum inside a sealed container or filling the sealed container with aerogel. This sealed container has, for example, an inner wall facing the heat source, an outer wall facing the inner wall, and a connecting portion connecting the inner and outer walls. Such sealed containers have a problem in that when heat is transferred from the heat source to the inner wall, the heat is transferred to the outer wall via the connecting portion, i.e., a heat bridge structure. In a heat bridge structure, sufficient insulation requires a long heat transfer path for heat dissipation. This results in a large sealed container. Therefore, even insulation structures including such sealed containers are difficult to apply to small devices. In particular, sealed containers for maintaining a vacuum state are made of materials with high thermal conductivity, which tends to increase the size of the sealed container. To prevent gas permeation, metal or glass materials are often used for sealed containers for maintaining a vacuum state.

[0035] When a foamed resin such as urethane foam or melamine foam is used as a thermal insulator, such a sealed container is not necessary. However, such a thermal insulator is primarily intended to prevent heat transfer by convection, and therefore tends to be thick. Therefore, such a thermal insulator containing a foamed resin is also difficult to apply to small devices.

[0036] In contrast, the heat insulating structure 16 of the light emitting device 10 contains the thermosetting resin 162, and therefore can maintain the shape of the foam 161 so as to surround the periphery of the light source unit 15. Therefore, the vicinity of the light source unit 15 is more effectively insulated than when the foam 161 is provided only on one side of the light source unit 15. This more effectively reduces the influence of the light source unit 15 on the surroundings, and even components with low heat resistance can be positioned closer to the light source unit 15. In other words, the heat insulating structure 16 can be suitably used in small devices. Furthermore, since the heat insulating structure 16 contains the thermosetting resin 162, the dimensions of the foam 161 can be easily maintained stably.

[0037] Furthermore, in the thermal insulation structure 16, one end surface 161E of the foam 161 is exposed. That is, this thermal insulation structure 16 does not have the above-mentioned heat bridge structure, and there is no need to lengthen the heat transfer path. Therefore, the thermal insulation structure 16 can be made small and easily applied to small devices. Moreover, since such a thermal insulation structure 16 is manufactured under normal temperature and pressure, it can be manufactured more easily than a thermal insulation structure in which the inside of a sealed container is kept in a vacuum state.

[0038] Furthermore, since the foam 161 of the thermal insulation structure 16 contains aerogel, it is easier to reduce its thickness compared to a thermal insulation member containing a foamed resin. Therefore, by using aerogel as the thermal insulation material, the thermal insulation structure 16 can be made smaller, making it easier to apply to small devices.

[0039] As described above, in the first embodiment of the present disclosure, the foam 161 is provided so as to surround the periphery of the light source unit 15, so that the vicinity of the light source unit 15 is more effectively insulated than when a heat insulating member is provided only on one side of the heat source. Therefore, it is possible to more effectively suppress the influence of the light source unit 15 on the surroundings. Such a heat insulating structure 16 makes it easier to arrange components near the light source unit 15, and is therefore suitable for use in small devices.

[0040] Furthermore, the light emitting device 10 having such a heat insulating structure 16 has a high degree of freedom in designing components. For example, it is possible to use components containing a resin with low heat resistance near the light source unit 15, which can reduce the cost required for components.

[0041] 2. Modifications [2-1. Modification 1-1] FIG. 6A is a schematic diagram illustrating an example of a cross-sectional configuration of a portion of a thermal insulation structure 16A according to Modification 1 of the first embodiment of the present disclosure (hereinafter referred to as Modification 1-1). The thermal insulation structure 16A of Modification 1-1 includes a support 163A having the planar configuration shown in FIG. 6B , for example, instead of the support 163 described in the first embodiment. FIG. 6B is a schematic diagram illustrating an example of the planar configuration of the support 163A. The support 163A has a first end T1 and a second end T2. The support 163A has one or more recesses 163U formed in a portion of the first end T1. Except for the above points, the configuration of the thermal insulation structure 16A is substantially the same as the configuration of the thermal insulation structure 16 of the first embodiment.

[0042] The support 163A is arranged around the foam 161, which has a substantially cylindrical shape. As shown in FIG. 6A , a thermosetting resin 162A is provided between the support 163A and the foam 161. The second end T2 overlaps the first end T1 on the opposite side of the foam 161 from the first end T1. The thermosetting resin 162A is also sandwiched between the first end T1 and the second end T2. In the thermal insulation structure 16A, a portion of the thermosetting resin 162A sandwiched between the first end T1 and the second end T2 spreads inside the recess 163U. The thermosetting resin 162A may occupy only a portion of the recess 163U, or may fill the entire recess 163U. Here, the first end T1 corresponds to a specific example of a “first portion” as one aspect of the present disclosure, and the second end T2 corresponds to a “second portion” as one aspect of the present disclosure.

[0043] In the manufacturing process of the thermal insulation structure 16A, a portion of the thermosetting resin 162A flows into the recess 163U of the support 163A when heated to a temperature in the first temperature range. Subsequently, when the thermosetting resin 162A is heated to a temperature in the second temperature range, the thermosetting resin 162A hardens, and the thermosetting resin 162A supported on the second end T2 of the support 163A is bonded to the first end T1 of the support 163A. In the thermal insulation structure 16A, a portion of the thermosetting resin 162A extends into the recess 163U, thereby more firmly bonding the first end T1 and the second end T2. Therefore, the thermal insulation structure 16A according to Modification 1-1 has higher mechanical strength than the thermal insulation structure 16 of the first embodiment.

[0044] [2-2. Modification 1-2] FIG. 7A is a schematic diagram illustrating an example of a cross-sectional configuration of a portion of a thermal insulation structure 16B according to Modification 2 of the first embodiment of the present disclosure (hereinafter referred to as Modification 1-2), corresponding to FIG. 6A illustrating Modification 1-1. While the thermal insulation structure 16A of Modification 1-1 includes a support 163A having one or more recesses 163U, the thermal insulation structure 16B of Modification 1-2 includes a support 163B having one or more through-holes 163H, as shown in FIG. 7B . Except for this, the configuration of the thermal insulation structure 16B is substantially the same as the configuration of the thermal insulation structure 16A of Modification 1-1. FIG. 7B is a schematic diagram illustrating an example of a planar configuration of the support 163B. Like the support 163A, the support 163B also surrounds a substantially cylindrical foam 161 and has a first end T1 and a second end T2. The second end T2 overlaps the first end T1 on the side opposite the foam 161 as viewed from the first end T1. A thermosetting resin 162B is provided between the support 163B and the foam 161. A thermosetting resin 162B is also sandwiched between the first end T1 and the second end T2.

[0045] As shown in FIG. 7A , in the thermal insulation structure 16B, at least one of a portion of the thermosetting resin 162B supported at the first end T1 of the support 163B and a portion of the thermosetting resin 162B supported at the second end T2 of the support 163B spreads inside the through-hole 163H. The thermosetting resin 162B supported at the second end T2 may be connected to the thermosetting resin 162B supported at the first end T1. Furthermore, the thermosetting resin 162B may occupy only a portion of the through-hole 163H, or may fill the entire through-hole 163H. The thermosetting resin 162B supported at the first end T1 of the support 163B is the thermosetting resin 162B sandwiched between the first end T1 and the foam 161. The thermosetting resin 162B supported at the second end T2 of the support 163B is the thermosetting resin 162B sandwiched between the first end T1 and the second end T2.

[0046] In the manufacturing process of the thermal insulation structure 16B, the thermosetting resin 162B flows into the through-hole 163H of the support 163B when heated to a temperature in the first temperature range. Subsequently, the thermosetting resin 162B hardens when heated to a temperature in the second temperature range, and the thermosetting resin 162B supported on the second end T2 of the support 163B is bonded to the first end T1 of the support 163B. In the thermal insulation structure 16B, a portion of the thermosetting resin 162B spreads to the inside of the through-hole 163H, thereby more firmly bonding the first end T1 and the second end T2. Therefore, the thermal insulation structure 16B according to Modification 1-2 has higher mechanical strength than the thermal insulation structure 16 of the first embodiment.

[0047] 8 is a schematic diagram illustrating an example cross-sectional configuration of a thermal insulation structure 16C according to a third modification of the first embodiment of the present disclosure (hereinafter referred to as modification 1-3). In the thermal insulation structure 16C, a support 163C is embedded in a thermosetting resin 162C. Except for the above points, the configuration of the thermal insulation structure 16C is substantially the same as the configuration of the thermal insulation structure 16 of the first embodiment.

[0048] The support 163C may be, for example, a film such as a polyimide film, or a nonwoven fabric such as polyester or polypropylene. Alternatively, it may be a mesh-like sheet member made of polypropylene, etc. The support 163C may be exposed on at least one of the first bottom surface 16S1 and the second bottom surface 16S2.

[0049] 3. Application Examples The light emitting device 10 described in the first embodiment can be applied to electronic devices such as projection display devices.

[0050] FIG. 9 is a diagram showing an example configuration of a projection display device (projection display device 200) to which the light-emitting device 10 is applied. The projection display device 200 is a display device that projects an image onto, for example, a screen. The projection display device 200 is connected to an external image supply device, such as a computer such as a PC or various image players, via an I / F (interface), and projects an image onto a screen or the like based on an image signal input to this I / F. Note that the configuration of the projection display device 200 described below is an example, and the projection display device according to the present technology is not limited to this configuration.

[0051] The projection display device 200 includes a light-emitting device 10 , a multi-lens array 212 , a PbS array 213 , a focus lens 214 , a mirror 215 , dichroic mirrors 216 and 217 , light modulation elements 218 a to 218 c , a dichroic prism 219 , and a projection lens 220 .

[0052] In the light-emitting device 10, light emitted from the light-emitting elements 121 passes through the array lens and is extracted as collimated light. This light is incident on the multi-lens array 212. The multi-lens array 212 has a structure in which a plurality of lens elements are arranged in an array, and focuses the light emitted from the light-emitting devices 1 and 2. The PbS array 213 polarizes the light focused by the multi-lens array 212 into light with a predetermined polarization direction, for example, P-polarized light. The focus lens 214 focuses the light converted by the PbS array 213 into light with a predetermined polarization direction.

[0053] The dichroic mirror 216 transmits red light R and reflects green light G and blue light B out of the light incident via the focus lens 214 and the mirror 215. The red light R transmitted by the dichroic mirror 216 is guided via the mirror 215 to the light modulation element 218a.

[0054] Dichroic mirror 217 transmits blue light B from the light reflected by dichroic mirror 216 and reflects green light G. Green light G reflected by dichroic mirror 217 is guided to light modulation element 218b. Meanwhile, blue light B transmitted by dichroic mirror 217 is guided to light modulation element 218c via mirror 215.

[0055] Each of the light modulation elements 218a to 218c modulates the incident color light and causes the modulated color light to enter the dichroic prism 219. The dichroic prism 219 combines the modulated color light into one optical axis. The combined color light is projected onto a screen or the like via a projection lens 220.

[0056] The projection display device 200 combines three light modulation elements 218a to 218c corresponding to the three primary colors of red, green, and blue to display any color. In other words, the projection display device 200 is a so-called three-plate projection display device.

[0057] Next, a second embodiment of the present disclosure will be described. In the following description, the same components as those in the first embodiment will be denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

[0058] 4. Second Embodiment [4-1. Overall Configuration of Heating Device] Fig. 10 is a schematic diagram illustrating an example of the configuration of a light-emitting device (heating device 20) according to a second embodiment of the present technology. The heating device 20 is applied to, for example, an aroma diffuser, an electronic incense burner, and the like. The heating device 20 has, for example, a heater 25, and also has an exterior member 11, a control unit 13, a battery 14, and a heat insulating structure 16, similar to the first embodiment. In addition, the opening of the exterior member 11 is closed by a lid 18. Here, the heater 25 corresponds to a specific example of a "heat source" according to one aspect of the present disclosure.

[0059] The lid portion 18 has, for example, a circular planar shape. The lid portion 18 is, for example, approximately the same size as the circle that forms the bottom surface of the cylindrical exterior member 11. The lid portion 18 closes the opening of the exterior member 11. The lid portion 18 is made of, for example, plastic. Examples of plastics that form the exterior member 11 include ABS (Acrylonitrile Butadiene Styrene) resin, PC (Polycarbonate) / ABS resin, and nylon. The lid portion 18 may also be made of metals such as aluminum alloys (e.g., A1050 and A5052), magnesium (Mg), and stainless steel.

[0060] Fig. 11 is a schematic plan view illustrating the configuration of the heater shown in Fig. 10. The heater 25 generates heat by, for example, applying a current from the battery 14 in response to a control signal input from the control unit 13. The detailed configuration of the heater 25 will be described later; for example, the heater 25 has a sheet shape and includes a heat generating portion 250X and a connecting portion 250Y. For example, wiring 261 electrically connected to a pair of electrodes of the battery 14 is connected to the connecting portion 250Y via solder 270.

[0061] In this embodiment, the heater 25 is formed, for example, in a cylindrical shape and has a through-hole 25H extending from one bottom surface to the other bottom surface, that is, the heater 25 has openings 25M in the one bottom surface and the other bottom surface, which open to the through-hole 25H.

[0062] Next, the specific configuration of the heater 25 and the thermal insulation structure 16 will be described. Fig. 12 shows a cross section of the heater 25 and the thermal insulation structure 16 shown in Fig. 10 taken along line II-II as viewed in the direction of the arrows. Fig. 13 is a schematic diagram showing an example of the planar configuration of the heater 25 and the thermal insulation structure 16. In the heating device 20, the heater 25 is inserted into the through-hole 16H of the thermal insulation structure 16. At this time, the thermal insulation structure 16 is provided with a foam 161 and a thermosetting resin 162 in this order in contact with the heater 25.

[0063] A lid or the like that covers the opening 25M may be provided on one bottom surface of the heat insulating structure 16. This lid may be integrated with the heat insulating structure 16 or may be formed as a separate body.

[0064] [4-2. Heater Configuration] Fig. 14A is a schematic cross-sectional view of the heater 25 taken along line III-III in Fig. 11. Fig. 14B is a schematic cross-sectional view of the heater 25 taken along line IV-IV in Fig. 11. Fig. 14C is a schematic cross-sectional view of the wiring 261 taken along line V-V in Fig. 11.

[0065] As described above, the heater 25 is a sheet-like heating element having a heat generating portion 250X and a connection portion 250Y. The heater 25 has a configuration in which a conductive film 252 is patterned on a flexible substrate 251. Specifically, the conductive film 252 includes, for example, a plurality of mutually independent conductive films 252A, 252B, and 252C, and extension portions 252D1 and 252D2 in which the conductive films 252A, 252B, and 252C are integrated at one end and the other end, respectively. The mutually independent conductive films 252A, 252B, and 252C are patterned, for example, parallel to one another. The mutually independent conductive films 252A, 252B, and 252C constitute the heat generating portion 250X, and the extension portions 252D1 and 252D2 constitute the connection portion 250Y. A pair of wirings 261 (261A, 261B) is joined to the connection portion 250Y via solder 260.

[0066] The flexible substrate 251 is a flexible supporting base material, and is made of an insulating material such as polyimide (PI) resin.

[0067] The conductive film 252 is preferably formed using a conductive material with relatively high electrical resistance, such as a metal material such as stainless steel or carbon. In the heat generating portion 250X, the conductive film 252 is patterned as multiple independent conductive films 252A, 252B, and 252C, which become hot when current is applied. Meanwhile, in the connection portion 250Y, the conductive film 252 is integrated with the conductive films 252A, 252B, and 252C to form extension portions 252D1 and 252D2 that are wider than the conductive films 252A, 252B, and 252C. This results in a lower electrical resistance than the conductive films 252A, 252B, and 252C. In other words, the temperature of the connection portion 250Y when current is applied is maintained lower than that of the heat generating portion 250X.

[0068] In this embodiment, the conductive film 252 is partially patterned into slits to separate the conductive films 252A, 252B, and 252C, thereby narrowing the individual patterns. However, this does not necessarily require multiple patterns, and the conductive film may be formed using a single narrow conductive film. In other words, if the conductive film in the heat generating portion 250X that continues from the conductive film in the connection portion 250Y is narrow, it may be formed as a single conductive film. Furthermore, the width of the conductive film in the heat generating portion 250X and the width of the conductive film in the connection portion 250Y do not need to be the same at the connection portion. For example, narrow conductive films may extend in different directions from the ends of the connection portion 250Y.

[0069] The pair of wirings 261 (261A, 261B) are, for example, copper (Cu) wirings having a flat plate shape. One end of each of the wirings 261A, 261B is electrically connected to the extension portions 252D1, 252D2, respectively, and the other end is electrically connected to, for example, a pair of electrodes of the battery 14. As shown in FIG. 15C , the wirings 261A, 261B are covered with an insulating film 262 containing, for example, epoxy resin, silicone resin, or fluororesin, except for the connection portions with the extension portions 252D1, 252D2. Note that while FIGS. 14 and 15C show an example in which the wirings 261A, 261B are collectively covered with the insulating film 262, they may also be covered separately.

[0070] 14B, in the connection portion 250Y, the extension portion 252D1, solder 270, and wiring 261A are stacked on the flexible substrate 251, and the extension portion 252D2, solder 270, and wiring 261B are stacked in this order. That is, the extension portion 252D1 and wiring 261A, and the extension portion 252D2 and wiring 261B are joined via the solder 270. For example, the solder 270 may be a solder such as a SnCuNiGe (tin-copper-nickel-germanium) alloy. Other solders that may be used include, for example, SnAgCu (tin-silver-copper), AuSn (gold-tin), Sn (tin), and In (indium) solders.

[0071] [4-3. Heater Manufacturing Method] The heater 25 can be manufactured, for example, as follows. First, as shown in FIG. 15A, a conductive film 252 is formed on a flexible substrate 251. Next, as shown in FIG. 15B, for example, a photoresist is applied onto the conductive film 252, followed by pre-baking, exposure, development, and post-baking. After a resist film having a predetermined pattern is formed, for example, the conductive film 252 having the predetermined pattern is formed by etching. Next, as shown in FIG. 15C, the conductive film 252, excluding a portion (for example, extension portions 252D1 and 252D2), is covered with an insulating film 253 containing, for example, epoxy resin, silicone resin, or fluororesin.

[0072] In parallel with this, wiring 261 to be bonded to conductive film 252 is prepared. First, as shown in FIG. 16A , wiring 261A and 261B covered with insulating film 262 are prepared. Next, as shown in FIG. 16B , a portion of insulating film 262 is removed to expose the ends of wiring 261A and 261B. Next, as shown in FIG. 17 , for example, metal foil or paste-like solder 270 is applied to conductive film 252, and heated to a temperature several tens of degrees higher than the melting temperature of solder 270, thereby bonding conductive film 252 and wiring 261A and 261B. Thereafter, the periphery of the bonded portion is covered with an insulating film, thereby completing heater 25 shown in FIG. 12 .

[0073] 12, it is preferable to bond the extension portions 252D1 and 252D2 to the wiring 261A and 261B at a position as far away as possible from the heat generating portion 250X. Specifically, for example, it is preferable to bond them at a position about 2 mm to 3 mm away from the periphery of the heat generating portion 250X. This makes it possible to prevent a decrease in the bonding strength between the extension portions 252D1 and 252D2 and the wiring 261A and 261B due to heat transfer from the heat generating portion 250X.

[0074] [4-4. Actions and Effects] In the manufacturing process of a typical heater, after patterning the conductive film that will become the heating element, copper plating is applied to predetermined locations to reduce the electrical resistance of the conductive part, but this plating process is one of the factors that increases manufacturing costs.

[0075] In contrast, in the heater 25 according to the second embodiment of the present disclosure, extension portions 252D1 and 252D2 are provided at one end and the other end of the plurality of conductive films 252A, 252B, and 252C that constitute the heat-generating portion 250X, respectively, integrating the plurality of conductive films 252A, 252B, and 252C. The extension portions 252D1 and 252D2 are used as a connection portion 250Y with a pair of wirings 261A and 261B that apply current to the plurality of conductive films 252A, 252B, and 252C. This allows the temperature of the connection portion 250Y to be maintained below the melting point of the solder when current is applied, for example, enabling solder bonding between the conductive films 252 (extension portions 252D1 and 252D2) and the wirings 261 (261A and 261B). This reduces the manufacturing costs of the heater 25 and the heating device 20 including the heater 25.

[0076] Furthermore, since flat wirings are used as the pair of wirings 261A and 261B, the bonding area between the conductive film 252 (extensions 252D1 and 252D2) and the wirings 261A and 261B at the connection portion 250Y is increased, which makes it possible to improve the bonding strength and thus reliability.

[0077] 5. Other Modifications Although the present technology has been described above using the first and second embodiments and application examples, the present technology is not limited to the above-described embodiments, etc., and various modifications are possible. For example, the components and arrangements of the light-emitting device 10 and the heating device 20 exemplified in the above-described embodiments, etc. are merely examples, and it is not necessary to include all of the components, and other components may also be included.

[0078] Furthermore, in the above-described embodiment and the like, the light emitting device 10 and the heating device 20 have been described as having the heat insulating structure 16, but the heat insulating structure 16 may also be provided in other electronic devices.

[0079] In the first embodiment, the heat insulating structure 16 does not have to be cylindrical. For example, the heat insulating structure 16 may have a cylindrical shape with a semicircular or rectangular bottom surface, or may have a cutout portion.

[0080] Furthermore, in the above-described first and second embodiments, examples have been described in which the foam 161 continuously surrounds the periphery of the light source unit 15, but the foam 161 may be separated into a plurality of pieces to surround the light source unit 15. Alternatively, the opening of the foam 161 may be provided on the side surface of the cylinder.

[0081] In the first embodiment, the positioning of the heat insulating structure 16 is described using the locking member 17, but the heat insulating structure 16 may be positioned by other methods. For example, the heat insulating structure 16 may be fixed to the exterior member 11 or the chassis, etc.

[0082] Furthermore, in the above-described embodiments, each component constituting the light emitting device 1 etc. has been specifically listed and described, but it is not necessary to include all components, and other components may also be included.

[0083] Furthermore, the above-mentioned modified examples 1 and 2 can be combined with each other in any way.

[0084] Furthermore, in the first embodiment and some of its modified examples, the thermal insulation structure has a support, but the thermal insulation structure of the present disclosure may not have a support.

[0085] The effects described in this specification are merely examples and are not limited to those described, and other effects may also be obtained.

[0086] The present disclosure may also be configured as follows. According to the thermal insulation structure and electronic device of the present disclosure having the following configuration, a thermosetting resin is provided to cover a foam, so that the foam can be increased in thickness while maintaining its shape, thereby improving the thermal insulation effect. (1) A thermal insulation structure comprising a foam and a thermosetting resin covering the foam. (2) The thermosetting resin exhibits a viscosity lower than that at room temperature in a first temperature range higher than room temperature and hardens in a second temperature range higher than the first temperature range, and the foam has heat resistance in the first temperature range and the second temperature range and expands in the first temperature range. (3) The thermal insulation structure according to (2), wherein the thermosetting resin is an epoxy resin. (4) The thermal insulation structure according to (2) or (3), further comprising a substrate supporting the thermosetting resin. (5) The thermal insulation structure according to (4), wherein the substrate is a film covering the surface of the thermosetting resin opposite to the foam. (6) The thermal insulation structure according to (4) or (5), wherein the base material is embedded in the thermosetting resin. (7) The thermal insulation structure according to any one of (4) to (6), wherein the base material is circumferentially arranged to surround the foam and has a first portion and a second portion overlapping the first portion on the opposite side of the foam from the first portion, the first portion including a through hole or a recess, and a portion of the thermosetting resin supported on the second portion extending into the through hole or the recess. (8) The thermal insulation structure according to any one of (4) to (7), wherein the base material has heat resistance in the first temperature range and the second temperature range. (9) The thermal insulation structure according to any one of (1) to (8), wherein the foam includes an aerogel. (10) The thermal insulation structure according to (9), wherein the aerogel is silica aerogel. (11) The thermal insulation structure according to any one of (1) to (10), wherein the foam is in a sheet form. (12) The heat insulating structure according to any one of (1) to (11), wherein the foam and the thermosetting resin have openings.(13) The heat insulating structure according to any one of (1) to (12), wherein the foam has a cylindrical shape. (14) An electronic device comprising: a heat source; and a heat insulating structure including a foam surrounding the heat source and a thermosetting resin covering the foam.

[0087] This application claims priority based on Japanese Patent Application No. 2023-223730, filed on December 28, 2023, in the Japan Patent Office, the entire contents of which are incorporated herein by reference.

[0088] Those skilled in the art will recognize that various modifications, combinations, subcombinations, and variations may occur depending on design requirements and other factors, and are intended to be within the scope of the appended claims and their equivalents.

Claims

1. A heat insulation structure comprising a foam and a thermosetting resin covering the foam.

2. The thermosetting resin exhibits a viscosity lower than its viscosity at room temperature in a first temperature range higher than room temperature and cures in a second temperature range higher than the first temperature range. The foam has heat resistance in the first temperature range and the second temperature range and expands in the first temperature range. The heat insulation structure according to claim 1.

3. The heat insulation structure according to claim 2, wherein the thermosetting resin is an epoxy resin.

4. The heat insulation structure according to claim 2, further comprising a substrate that supports the thermosetting resin.

5. The heat insulation structure according to claim 4, wherein the substrate is a film that covers the surface of the thermosetting resin opposite to the foam.

6. The heat insulation structure according to claim 4, wherein the substrate is embedded in the thermosetting resin.

7. The substrate surrounds the foam in a loop and has a first portion and a second portion that overlaps the first portion on the side opposite to the foam as seen from the first portion. The first portion includes a through hole or a recess, and a part of the thermosetting resin supported by the second portion extends into the interior of the through hole or the recess. The heat insulation structure according to claim 4.

8. The heat insulation structure according to claim 4, wherein the substrate has heat resistance in the first temperature range and the second temperature range.

9. The heat insulation structure according to claim 1, wherein the foam contains an aerogel.

10. The heat insulation structure according to claim 9, wherein the aerogel is a silica aerogel.

11. The heat insulation structure according to claim 1, wherein the foam is in a sheet shape.

12. The heat insulation structure according to claim 1, wherein the foam and the thermosetting resin have openings.

13. The heat insulation structure according to claim 1, wherein the foam has a cylindrical shape.

14. An electronic device comprising a heat source and a heat insulation structure including a foam surrounding the heat source and a thermosetting resin covering the foam.

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