Wearable device

Abstract

Provided is a wearable device that effectively suppresses the conduction, to the human body, of heat emitted from a heat source, and therefore does not cause a user discomfort. A smart watch (wearable device) 1 has a configuration in which at least a heat source 10 is housed in a housing 2 that can be worn on the human body. In the housing 2, between the heat source 10 and a wall 2a of the housing 2, the wall being in contact with the human body, an insulation material 11 is disposed to suppress the conduction of heat generated by the heat source 10 to the human body, or, a heat storage member (heat storage foam 14 or heat storage sheet) is disposed to store the heat generated by the heat source 10.

Description

Technical Field

[0001] The present invention relates to a wearable device, which is a small and lightweight electronic device wearable on the human body.

Background Art

[0002] In the future, wearable devices that are expected to be globally popular include those with the same functions as smartphones, such as reading received emails and checking messages posted on SNS, those with functions of recording exercises such as jogging and swimming, capturing heart rate, pulse, sleep time, etc. for maintaining health, and those with functions of superimposing and displaying information in the virtual space on real-world objects. And as forms of such wearable devices, various types such as watch type, bracelet type, glass type, earphone type, wear type, ring type, etc. have been put into practical use.

[0003] Since the wearable device as described above is worn by the user for a long time, further miniaturization and weight reduction are required compared to information terminals such as smartphones. However, heat sources such as a processor, an IC chip, and a battery are accommodated inside its housing. For this reason, part of the heat generated by the heat source is transmitted to the human body through the housing. In this case, when the temperature of the heat transmitted to the human body exceeds the body temperature, for example, exceeds 44°C, a problem occurs that the user feels very uncomfortable.

[0004] For example, in Patent Document 1, in a head-mounted display used by a user by wearing it on the head, a heat conductive material is used for frames (a display unit right extension part and a display unit left extension part) extending left and right from a display unit (image display unit) which is a heat generating source, and a configuration is proposed in which heat generated in the display unit (image display unit) is absorbed by this heat conductive material.

[0005] In addition, Patent Document 2 proposes a configuration in which a heat storage material is provided between a control circuit and a battery in an electronic device that houses the control circuit and the battery in a housing, and a gap (air insulation layer) is provided between the control circuit and the battery.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, in the head-mounted display proposed in Patent Document 1, heat generated by the display unit, which is a heat source, is conducted to a frame portion (display unit right extension portion and display unit left extension portion) having a high thermal conductivity to suppress the temperature rise of the display unit. However, since the user directly receives the heat transmitted to the frame portion, it may cause discomfort to the user.

[0008] In addition, since the electronic device proposed in Patent Document 2 is not a wearable device that the user wears on the body, no consideration is given to heat conduction to the user's body.

[0009] The present invention has been made in view of the above problems, and an object thereof is to provide a wearable device that effectively suppresses the conduction of heat emitted from a heat source to the human body and does not cause discomfort to the user.

Means for Solving the Problems

[0010] In order to achieve the above object, a first invention is a wearable device configured by accommodating at least a heat source inside a housing wearable on a human body, wherein inside the housing, a heat insulating material that suppresses conduction of heat generated by the heat source to the human body is disposed between a wall of the housing that contacts the human body and the heat source.

[0011] Here, an air layer may be formed between the heat insulating material and the heat source. Also, a heat diffusion sheet may be disposed on a surface of the heat insulating material on the heat source side. Further, an air layer may be formed between the heat diffusion sheet and the heat source.

[0012] A second invention is a wearable device configured by accommodating at least a heat source inside a housing wearable on a human body, wherein inside the housing, a heat storage member that stores heat generated by the heat source is disposed between a wall of the housing that contacts the human body and the heat source.

[0013] Here, the heat storage member may be a heat storage foam or a heat storage sheet including a latent heat storage material that liquefies and stores heat at a temperature equal to or higher than the melting point. In this case, as the latent heat storage material, it is desirable to use one having a melting point of 37°C to 44°C, a freezing point of 32°C to 40°C, more preferably a melting point of 40°C to 44°C, and a freezing point of 37°C to 40°C.

[0014] And, an air layer may be formed between the heat storage member and the heat source. Also, a heat diffusion sheet may be disposed on a surface of the heat storage member on the heat source side. Further, an air layer may be formed between the heat diffusion sheet and the heat source.

Advantages of the Invention

[0015] According to the first invention, in a state where a user wears and uses the wearable device on the body, conduction of a part of the heat generated from the heat source to the body is suppressed by the heat insulation effect of the heat insulating material, so that even if the user wears the wearable device for a long time, the user does not feel discomfort.

[0016] Here, if an air layer is formed between the heat insulating material and the heat source, the air layer functions as a heat insulating layer. Therefore, the heat insulating effect of this air layer and the heat insulating effect of the heat insulating material work together to more effectively suppress the heat conduction from the heat source to the user's body, and the user will not feel discomfort. Also, if a heat diffusion sheet is arranged on the surface of the heat insulating material on the heat source side, part of the heat generated by the heat source is radiated into the housing from the heat diffusion sheet, and the amount of heat conducted to the heat insulating material is significantly reduced due to this heat radiation, so the user will not feel discomfort. In this case, if an air layer is formed between the heat diffusion sheet and the heat source, the heat radiation effect of the heat diffusion sheet and the heat insulating effects of the air layer and the heat insulating material work together to more effectively suppress the heat conduction to the user's body.

[0017] According to the second invention, in a state where the user is wearing and using the wearable device on the body, part of the heat generated from the heat source is stored in the heat storage member (heat storage foam or heat storage sheet), so the heat conduction to the user's body is suppressed, and even if the user wears the wearable device for a long time, the user will not feel discomfort.

[0018] Also, part of the heat generated by the heat source is stored (absorbed heat) by the heat storage member, and since the heat storage member functions as a cooling means, the temperature rise inside the housing is prevented, and various electronic devices constituting the heat source are thermally protected, and the durability of these electronic devices is enhanced.

[0019] Here, if a latent heat storage material contained in a heat storage foam or a heat storage sheet as the heat storage member has a melting point of 37°C to 44°C and a freezing point of 32°C to 40°C, the latent heat storage material melts and stores heat at a temperature of 37°C to 44°C, which is higher than the body surface temperature of the user (for example, 32°C to 33°C). Therefore, it is possible to suppress the temperature of the heat received by the user from the wearable device from exceeding the limit temperature (the lowest temperature at which the user feels discomfort), which is 44°C. When the user removes the wearable device from the body when the wearable device is not in use, if the temperature of the wearable device drops below the freezing point of 32°C to 40°C, the latent heat storage material solidifies (phase change from liquid to solid) and releases the stored heat. Therefore, the latent heat storage material returns to the initial state (the state without heat storage).

[0020] Also, in the second invention, similar to the first invention, if an air layer is formed between the heat storage member and the heat source, the air layer functions as a heat insulation layer. Therefore, the heat insulation effect of this air layer and the heat storage effect of the heat storage member work together to more effectively suppress the heat conduction from the heat source to the user's body, and the user will not feel discomfort. Further, if a heat diffusion sheet is arranged on the surface of the heat storage member on the heat source side, part of the heat generated by the heat source is radiated from the heat diffusion sheet into the housing, and the amount of heat conducted to the heat storage member is greatly reduced due to the heat radiation. Therefore, the user will not feel discomfort. In this case, if an air layer is formed between the heat diffusion sheet and the heat source, the heat radiation effect of the heat diffusion sheet, the heat insulation effect of the air layer, and the heat storage effect of the heat storage member work together to more effectively suppress the heat conduction to the user's body.

Brief Description of the Drawings

[0021]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Embodiments for Carrying Out the Invention

[0022] The embodiments of the First Invention will be described below with reference to the accompanying drawings.

[0023] [First Invention] First, the schematic configuration of a smartwatch as one form of the wearable device according to the present invention will be described with reference to FIG. 1.

[0024] That is, FIG. 1 is a perspective view of the main part of the smartwatch. The illustrated smartwatch 1 has functions similar to those of a smartphone, such as reading received emails and checking messages posted on SNS, functions for recording exercises such as jogging and swimming, and functions for capturing heart rate, pulse, sleep time, etc. to help maintain health. It includes a housing 2 and bands 3 extending from both sides of the housing 2.

[0025] The above-mentioned housing 2 is composed of a rectangular container-shaped case 2A with an open upper surface and a transparent cover 2B that covers the upper surface opening of the case 2A, and a sealed space is formed inside. Here, the case 2A is made of a metal such as stainless steel (SUS), aluminum, or titanium, and the cover 2B is made of transparent glass or transparent resin.

[0026] The case 2A that constitutes a part of the housing 2 includes a bottom wall 2a that contacts a part of the body (specifically, the wrist) of the user wearing the smartwatch 1, and side walls 2b that vertically rise from the four peripheries of the bottom wall 2a. Push buttons 4 and 5 for performing operations such as mode switching are provided on a part of the side wall 2b.

[0027] By the way, since heat sources 10 (see Figure 2), such as a processor, an IC chip, and a battery, are housed inside the housing 2 of the smartwatch 1 as described later, a part of the heat generated by the heat source 10 is transmitted to the body (wrist) through a part of the housing 2 (specifically, the bottom wall 2a of the case 2A). In this case, as described above, when the temperature of the heat transmitted to the body (wrist) is equal to or higher than the body temperature, for example, 44°C or higher, the problem that the user feels extremely uncomfortable occurs.

[0028] Therefore, in the present invention, a heat insulation structure for blocking or suppressing heat conduction from the heat source 10 to the body (wrist) of the user is provided inside the housing 2. Hereinafter, embodiments of the heat insulation structure will be described.

[0029] <Embodiment 1> FIG. 2 is a longitudinal sectional view schematically showing the internal configuration of the housing of the smart watch according to Embodiment 1 of the first invention. As shown in the figure, a heat source 10 such as a processor, an IC chip, and a battery is housed in the center of the housing 2. In this embodiment, inside the housing 2, a flat heat insulating material 11 for suppressing the conduction of heat generated by the heat source 10 to the user's wrist is disposed between the bottom wall 2a of the housing 2 (case 2A) that contacts the user's wrist and the heat source 10. In this case, the heat insulating material 11 is disposed over the entire inner surface of the bottom wall 2a of the housing 2 (case 2A). Note that, as the heat insulating material 11, for example, foamed plastic materials such as rigid urethane foam, rigid polystyrene foam, phenolic foam, and acrylic foam are preferably used.

[0030] In a state where the user wears and uses the smart watch 1 having the above heat insulating structure on the wrist, since a part of the heat generated from the heat source 10 to the user's wrist is suppressed by the heat insulating effect of the heat insulating material 11, even if the user wears the smart watch 1 for a long time, the user does not feel discomfort on the wrist.

[0031] Here, FIG. 10 shows the results of a thermal cycle test for the heat insulating material (thickness: 3 mm) and the SUS plate (thickness: 1 mm). In FIG. 10, the horizontal axis represents the elapsed time (min), and the vertical axis represents the temperature (° C.). The test was performed by using a Peltier device to repeatedly raise and lower the temperature in the range of 30° to 50° C. at a predetermined time interval and measuring the surface temperatures of the heat insulating material and the SUS plate.

[0032] As is clear from the test results shown in FIG. 10, while the SUS plate repeats heating and cooling in the temperature range of 30° C. to 50° C. as indicated by the broken line C in FIG. 10, the temperature change of the heat insulating material is suppressed in the range of 32.5° C. to 44° C. as indicated by the two-dot chain line B in FIG. 10.

[0033] Therefore, for example, when the case 2A of the housing 2 is made of stainless steel (SUS), if there is no heat insulation structure like the present embodiment, the user will feel heat at a temperature of 50°C exceeding the limit temperature of 44°C on the wrist and will experience a great deal of discomfort.

[0034] On the other hand, in the smartwatch 1 according to the present embodiment having a heat insulation structure in which a heat insulating material 11 is disposed between the heat source 10 and the bottom wall 2a of the case 2A inside the housing 2, as is clear from the results shown in FIG. 10, since the amount of heat conducted from the heat source 10 through the heat insulating material 11 and the bottom wall 2a of the case 2A can be significantly suppressed, the user will feel heat below the limit temperature of 44°C on the wrist, and the user will not experience a great deal of discomfort.

[0035] In addition, the heat insulation structure according to the present embodiment is simply configured by merely incorporating the heat insulating material 11 between the heat source 11 in the housing 2 and the bottom wall 2a, so that high assemblability is ensured for the smartwatch 1.

[0036] <Embodiment 2> Next, Embodiment 2 of the first invention will be described below with reference to FIG. 3.

[0037] FIG. 3 is a longitudinal sectional view schematically showing the internal configuration of the housing of the smartwatch according to Embodiment 2 of the first invention. In this figure, the same reference numerals are given to the same elements as those shown in FIG. 2, and the repeated description thereof will be omitted hereinafter.

[0038] This embodiment is characterized in that, in the heat insulation structure in Embodiment 1, a gap δ is formed between the heat insulating material 11 and the heat source 10, and an air layer 12 is formed in this gap δ portion, and the other configurations are the same as those in Embodiment 1.

[0039] In this embodiment, an air layer 12 is formed between the heat insulating material 11 and the heat source 10, and thus the air layer 12 functions as a heat insulating layer. For this reason, the heat insulating effect of the air layer 12 and the heat insulating effect of the heat insulating material 11 work together to more effectively suppress the heat conduction from the heat source 10 to the user's wrist, and an effect that the user is not uncomfortable is obtained.

[0040] <Embodiment 3> Next, Embodiment 3 of the first invention will be described below with reference to FIG. 4.

[0041] FIG. 4 is a longitudinal sectional view schematically showing the configuration inside the housing of the smart watch according to Embodiment 2 of the first invention. Also in this figure, the same reference numerals are given to the same elements as those shown in FIG. 2, and the repeated description thereof will be omitted below.

[0042] This embodiment is characterized in that in the heat insulating structure according to Embodiment 1, a heat diffusion sheet 13 is disposed on the surface (upper surface) on the heat source 10 side of the heat insulating material 11, and other configurations are the same as those in Embodiment 1. Here, as the heat diffusion sheet 13, a graphite film, an aluminum foil, or a composite of both is preferably used.

[0043] In this embodiment, since the heat diffusion sheet 13 is disposed on the surface on the heat source 10 side of the heat insulating material 11, part of the heat generated by the heat source 10 is radiated inside the housing 2, and the amount of heat conducted to the heat insulating material 11 is significantly reduced by that amount of heat radiation. For this reason, the temperature felt by the user on the wrist is kept low, and the user does not feel uncomfortable on the wrist.

[0044] <Embodiment 4> Next, Embodiment 4 of the first invention will be described below with reference to FIG. 5.

[0045] FIG. 5 is a longitudinal sectional view schematically showing the configuration inside the housing of the smart watch according to Embodiment 4 of the first invention. Also in this figure, the same reference numerals are given to the same elements as those shown in FIGS. 2 to 4, and the repeated description thereof will be omitted below.

[0046] This embodiment is characterized in that an air layer 12 is formed between the heat diffusion sheet 13 and the heat source 10 in the heat insulation structure according to Embodiment 3, and other configurations are the same as those shown in Embodiment 3.

[0047] According to this embodiment, since the air layer 12 is formed between the heat diffusion sheet 13 and the heat source 10, the heat dissipation effect of the heat diffusion sheet 13 and the heat insulation effects of the air layer 12 and the heat insulation material 11 are combined to obtain the effect that the heat conduction to the user's body is more effectively suppressed.

[0048] [Second Invention] Next, the second invention will be described. Hereinafter, the smart watch 1 shown in FIG. 1 will be described as an example of the wearable device according to the second invention in the same manner as the first invention. Therefore, the description of the configuration of the smart watch 1 will be omitted here, and only the embodiment of the heat storage structure of the smart watch 1 will be described.

[0049] [Embodiment 1] Embodiment 1 of the second invention will be described below with reference to FIG. 6.

[0050] FIG. 6 is a longitudinal sectional view schematically showing the internal configuration of the housing of the smart watch according to Embodiment 1 of the second invention. Also in this figure, the same reference numerals are given to the same elements as those shown in FIG. 2, and the description thereof will be omitted here.

[0051] This embodiment is characterized in that a heat storage foam 14 as a heat storage member for storing the heat generated by the heat source 10 is disposed between the bottom wall 2a in contact with the human body (user's wrist) of the housing 2 and the heat source 10 inside the housing 2, and other configurations are the same as those of the smart watch 1 (see FIG. 2) according to Embodiment 1 of the first invention.

[0052] Here, the heat storage form 14 is a member containing a latent heat storage material that liquefies and stores heat at a temperature above the melting point. For example, heat storage particles are stirred and mixed into an aqueous dispersion acrylic emulsion resin to prepare a binder for mechanical foaming. After applying this binder for mechanical foaming to a PET film, it is heat-treated with a dryer to cure and form. Note that as the base material form, polyurethane foam, polyethylene foam, melamine foam, acrylic foam, etc. are used, and as the binder resin, polyurethane-based resin, polyolefin-based resin, vinyl chloride-based resin, polyamide-based resin, acrylic-based resin, etc. are used. In addition, as the latent heat storage material, fatty acid esters such as methyl decanoate and ethyl decanoate, alkanes (paraffins) such as decane, undecane, and dodecane are used. Note that the latent heat storage material has the property of absorbing the heat of fusion (latent heat) when undergoing a phase change from solid to liquid, and releasing the heat of solidification (latent heat) when undergoing a phase change from liquid to solid. In this embodiment, the latent heat storage material used has a melting point of 37°C to 39°C and a freezing point of 33°C to 35°C.

[0053] Note that in this embodiment, the heat storage form 14 is used as the heat storage member, but a heat storage sheet may also be used as the heat storage member. Here, the heat storage sheet is obtained by uniformly blending particulate latent heat storage material into a resin such as vinyl chloride and coating and forming it into a thick film.

[0054] In a state where the user wears and uses the smartwatch 1 having the heat storage structure as described above on the wrist, when the internal temperature of the housing 2 exceeds 37°C to 39°C, which is the melting point of the latent heat storage material contained in the heat storage form 14, due to the heat generated from the heat source 10, the latent heat storage material melts and liquefies, and the heat storage form 14 absorbs the heat of fusion (latent heat) from the surroundings to store heat. For this reason, the heat storage form 14 functions as a cooling means, and the temperature rise in the housing 2 is suppressed by the heat storage by the heat storage form 14, and the amount of heat conducted to the user's wrist through the bottom wall 2a of the housing 2 (case 2A) is greatly suppressed. As a result, even if the user wears the smartwatch 1 for a long time, the user does not feel discomfort.

[0055] Here, FIG. 10 shows the results of a thermal cycle test on a heat storage form (thickness 3 mm, melting point 38°C) and a SUS plate (thickness 1 mm). This thermal cycle test was conducted by using a Peltier device to repeatedly increase and decrease the temperature in the range of 30° to 50°C at predetermined time intervals and measuring the surface temperatures of the heat storage form and the SUS plate.

[0056] As is clear from the test results shown in FIG. 10, the SUS plate repeats heating and cooling in the temperature range of 30°C to 50°C as shown by the dashed line C in FIG. 10, while the temperature change of the heat storage form fluctuates with a small amplitude around the melting point of 38°C of the latent heat storage material as shown by the solid line A in FIG. 10, and the maximum temperature of the heat storage form is kept lower than the maximum temperature of the heat insulating material shown by the two-dot chain line B in FIG. 10.

[0057] Therefore, for example, when the case 2a of the housing 2 is made of stainless steel (SUS), if there is no heat storage structure as in this embodiment, the user will feel heat at a temperature of 50°C exceeding the limit temperature of 44°C on the wrist and will feel very uncomfortable.

[0058] On the contrary, in the smartwatch 1 according to this embodiment having a heat storage structure in which a heat storage form 14 is arranged between the heat source 10 and the bottom wall 2a of the case 2A inside the housing 2, as is clear from the results shown in FIG. 10, the amount of heat conducted from the heat source 10 through the heat storage form 14 and the bottom wall 2a of the case 2A can be greatly suppressed, so that the user will feel heat below the limit temperature of 44°C on the wrist and the user will not feel very uncomfortable.

[0059] When the user removes the smartwatch 1 from the wrist and the temperature of the smartwatch 1 drops below the freezing point of 33°C to 35°C when the smartwatch 1 is not in use, the latent heat storage material contained in the heat storage foam 14 solidifies (phase change from liquid to solid) and releases the stored heat. Therefore, the heat storage foam 14 returns to its initial state (state without heat storage). Or when the heat generation of the smartwatch 1 decreases while the user is wearing the smartwatch 1 on the wrist, when the temperature of the latent heat storage material drops below the freezing point due to the body surface temperature of the user (32°C to 33°C), similarly, the latent heat storage material solidifies (phase change from liquid to solid) and releases the stored heat. Therefore, the heat storage foam 14 returns to its initial state (state without heat storage). Note that since the heat of fusion and the heat of solidification are latent heats, the temperature of the heat storage foam 14 hardly changes due to heat storage or heat release.

[0060] Also, in the present embodiment, the heat storage foam 14 functions as a cooling means. As described above, since the rise in the internal temperature of the housing 2 is suppressed by the heat storage in the heat storage foam 14, the heat deterioration of the processor, IC chip, battery, etc. constituting the heat source 10 is prevented, and the effect that their durability is enhanced can be obtained.

[0061] Furthermore, the heat storage structure according to the present embodiment is simply configured by simply incorporating the heat storage foam 14 between the heat source 10 in the housing 2 and the bottom wall 2a of the case 2A. Therefore, high assemblability is ensured for the smartwatch 1.

[0062] <Embodiment 2> Next, Embodiment 2 of the second invention will be described below with reference to FIG. 7.

[0063] FIG. 7 is a longitudinal sectional view schematically showing the internal configuration of the housing of the smartwatch according to Embodiment 2 of the second invention. In this figure, the same reference numerals are given to the same elements as those shown in FIG. 6, and the repeated description thereof will be omitted below.

[0064] In this embodiment, in the heat storage structure in Embodiment 1, a gap δ is formed between the heat storage foam 14 and the heat source 10, and an air layer 12 is formed in the portion of this gap δ. Other configurations are the same as those in Embodiment 1.

[0065] In this embodiment, since an air layer 12 is formed between the heat storage foam 14 and the heat source 10, the air layer 12 functions as a heat insulation layer. Therefore, the heat insulation effect of this air layer 12 and the heat storage effect of the heat storage foam 14 work together to more effectively prevent heat conduction from the heat source 10 to the user's wrist, and the effect that it does not cause discomfort to the user is obtained.

[0066] <Embodiment 3> Next, Embodiment 3 of the second invention will be described below with reference to FIG. 8.

[0067] FIG. 8 is a longitudinal sectional view schematically showing the configuration inside the housing of the smartwatch according to Embodiment 3 of the second invention. Also in this figure, the same elements as those shown in FIG. 6 are given the same reference numerals, and the repeated description thereof will be omitted below.

[0068] This embodiment is characterized in that, in the heat storage structure (see FIG. 6) according to Embodiment 1, a heat diffusion sheet 13 is arranged on the surface (upper surface) on the heat source 10 side of the heat storage foam 14. Other configurations are the same as those in Embodiment 1. Here, as the heat diffusion sheet 13, a graphite film, an aluminum foil, or a composite of both is preferably used.

[0069] In this embodiment, since the heat diffusion sheet 13 is arranged on the surface (upper surface) on the heat source 10 side of the heat storage foam 14, a part of the heat generated by the heat source 10 is dissipated inside the housing 2, and the amount of heat conducted to the heat storage foam 14 is suppressed to be small by that amount of heat dissipation. Also, the heat of the heat source 10 is dispersed by the heat diffusion sheet 13, and a part of the heat is absorbed by the heat storage foam 14, so that the smartwatch 1 does not become locally hot. Therefore, the temperature felt by the user on the wrist is kept low, and the user does not feel discomfort on the wrist.

[0070] <Embodiment 4> Next, Embodiment 4 of the second invention will be described below with reference to FIG. 9.

[0071] FIG. 9 is a longitudinal sectional view schematically showing the internal configuration of the housing of the smart watch according to Embodiment 4 of the second invention. In this figure, the same reference numerals are given to the same elements as those shown in FIG. 8, and the repeated description thereof will be omitted below.

[0072] This embodiment is characterized in that an air layer 12 is formed between the heat diffusion sheet 13 and the heat source 10 in the heat storage structure according to the above-described Embodiment 3, and other configurations are the same as those shown in Embodiment 3.

[0073] According to this embodiment, since the air layer 12 is formed between the heat diffusion sheet 13 and the heat source 10, the heat dissipation effect of the heat diffusion sheet 13, the heat insulation effect of the air layer 12, and the heat storage effect of the heat storage foam 14 are combined to obtain an effect that heat conduction to the user's body is more effectively suppressed.

[0074] In Embodiments 1 to 4 of the second invention, the case where the heat storage foam 14 is used as the heat storage member has been described. However, the same effect can be obtained by configuring in the same manner even when a heat storage sheet is used as the heat storage member.

[0075] By the way, with the miniaturization, thinning, and internal narrowing of the wearable device including the smart watch exemplified in the above embodiments, the mounting components including the heat insulation material and the heat storage foam (heat storage sheet) are also required to be thinned. Therefore, it is desirable to use a heat insulation material having a small thickness in the present invention. The upper limit of the thickness of the heat insulation material is preferably 5 mm or less, 4 mm or less, or 3.5 mm or less, and the lower limit is preferably 0.01 mm or more, 0.1 mm or more, or 0.5 mm or more.

[0076] On the one hand, generally, as the thickness of the heat insulating material decreases, its heat insulating effect tends to decline.

[0077] However, when having the same thickness, a heat storage foam or a heat storage sheet having both a heat insulating function and a heat storage function is more likely to exhibit the level of heat insulating effect required for wearable devices than a heat insulating material (foamed plastic-based foam or air layer) having only a heat insulating function, and as a result, it is less likely to cause discomfort to the human body. This can also be understood from the heat cycle test shown in FIG. 10.

[0078] Therefore, in a wearable device where the use of a thin heat insulating material is required, among the above heat insulating materials, using a heat storage member such as a heat storage foam or a heat storage sheet is more suitable than using a heat insulating material such as a foamed plastic-based foam or an air layer in that it is less likely to cause discomfort to the human body even if it is thin.

[0079] In addition, in the above embodiment, the heat cycle test showing the results in FIG. 10 was performed on a heat storage foam and a heat insulating material both having a thickness of 3 mm. In view of this test result, even when the thickness of the heat storage foam or the heat storage sheet is made thinner than 3 mm, it is considered that the optimal heat insulating performance for the wearable device can be ensured.

[0080] From the above viewpoints, when using a heat storage member such as a heat storage foam or a heat storage sheet as the heat insulating material, its thickness is more preferably such that the upper limit value is 3 mm or less, 2 mm or less, or 1.5 mm or less, and the lower limit value is 0.01 mm or more, 0.05 mm or more, or 0.1 mm or more.

[0081] By the way, the above has described the form in which the present invention is applied to a smart watch as one form of a wearable device. However, the present invention can be similarly applied to any other wearable device, for example, smart glasses, smart earphones, smart caps, smart rings, smart wear, and the like.

[0082] In addition, the present invention is not limited to the embodiments described above, and it goes without saying that various modifications are possible within the scope of the technical idea described in the claims, the specification, and the drawings.

Explanation of Reference Numerals

[0083] 1 Smartwatch (wearable device) 2 Housing 2A Case 2a Bottom wall of the case 2b Side wall of the case 2B Cover 3 Band 4, 5 Push buttons 10 Heat source 11 Heat insulating material 12 Air layer 13 Heat diffusion sheet 24 Heat storage foam (heat storage member) δ Gap

Claims

1. A wearable device configured to accommodate at least a heat source inside a housing wearable on a human body, inside the housing, between the wall of the housing that contacts the human body and the heat source, there is disposed in contact with the wall that contacts the human body a heat insulating material composed of at least one foamed plastic material selected from the group consisting of rigid urethane foam, rigid polystyrene foam, phenolic foam, and acrylic foam, which suppresses conduction of heat generated by the heat source to the human body. A wearable device, characterized in that a heat diffusion sheet is disposed on the surface of the heat insulating material on the heat source side.

2. The wearable device according to claim 1, characterized in that an air layer is formed between the heat insulating material and the heat source.

3. The wearable device according to claim 1, characterized in that an air layer is formed between the heat diffusion sheet and the heat source.

Images