The present disclosure relates to a display device and a heat release method.
In general, an electronic component, a light-emitting element, or the like installed in a display device produces heat during operation. Therefore, the display device is required to efficiently release the heat produced by the electronic component, the light-emitting element, or the like in the display device. For example, PTL 1 listed below discloses a technology of releasing heat produced by a high-temperature part to an outside via a heat-transfer member partially fixed to the high-temperature part.
However, for example, according to the technology disclosed in PTL 1, the heat-transfer member is bonded to the high-temperature part with adhesive. Therefore, for example, in a case where the high-temperature part deforms over time like a battery, tensile strength is generated between the adhesive and the high-temperature part due to a difference in thermal expansion between the adhesive and the high-temperature part. This may result in separation of the heat-transfer member from the high-temperature part. As a result, there is a possibility that it becomes difficult for the heat-transfer member to release heat produced by the high-temperature part to the outside. As described above, it has been desired to further improve performance of the display device including a mechanism for releasing heat produced by the high-temperature part to the outside.
Accordingly, the present disclosure proposes a display device and heat release method that make it possible to release heat to an outside more stably.
According to the present disclosure, there is provided a display device including a second member that is attachable to a first member including a high-temperature part. The second member includes: a first heat-transfer member that is deformable and partially contactable with the high-temperature part; and an elastic body that allows the first heat-transfer member to abut on the high-temperature part.
In addition, according to the present disclosure, there is provided a heat release method including: installing a second member that is attachable to a first member including a high-temperature part; installing, in the second member, a first heat-transfer member that is deformable and partially contactable with the high-temperature part, and an elastic body that allows the first heat-transfer member to abut on the high-temperature part; and releasing heat of the high-temperature part to an outside.
According to the present disclosure, the deformable first heat-transfer member, which is included in the second member that is attachable to a first member including the high-temperature part, comes into contact with the high-temperature part. The elastic body allows the first heat-transfer member to abut on the high-temperature part by using its elastic force. This allows the first heat-transfer member to follow deformation of the high-temperature part while maintaining contact with the high-temperature part even in a case where the high-temperature part deforms over time.
As described above, according to the present disclosure, it is possible to release heat to an outside more stably.
It is to be noted that the above-described effects are not necessarily limitative. In addition to or in place of the above effects, there may be achieved any of the effects described in the present specification or other effects that may be grasped from the present specification.
Hereinafter, preferred embodiments of the present invention are described in detail with reference to the appended drawings. It is to be noted that, in the present specification and drawings, repeated description is omitted for components substantially having the same functional configuration by assigning the same reference numerals.
It is to be noted that, the description is given in the following order.
With regard to existing heat release structures installed in a variety of display devices, a high-temperature part and a heat-transfer member are coupled to each other in a fixed state. For example, in many case, a structure in which a heat sink (heat spreader) made of aluminum or copper is fixed to the high-temperature part has been adopted. When the heat sink is adopted as the heat release structure, the weight of the display device has been increased and the number of components has been increased due to the heat sink in many cases. In addition, designs of the display devices have been limited because a space for installing the heat sink should have been ensured in the display device. In addition, for example, when the aluminum heat sink, which has often been used in general, is adopted as head-mounted products, the weight of the head-mounted products increases and wearability is deteriorated. Therefore, technologies of releasing heat of the high-temperature part without adopting the heat sink have been under development. For example, the above-exemplified PTL 1 discloses the display device including a deformable heat-transfer member attached to the heat-transfer member and a casing. However, for example, in a case where the high-temperature part such as a battery deforms over time, there is a possibility that the heat-transfer member of such a display device separates from the high-temperature part and it becomes difficult for the heat-transfer member to release heat of the high-temperature part to an outside. Accordingly, the inventors of the present disclosure diligently researched such a possibility, and invented the present technology.
A display device according to the present embodiment includes a second member attachable to a first member including a high-temperature part. The second member includes a first heat-transfer member and an elastic body. The first heat-transfer member is deformable and at least partially contactable with the high-temperature part. The elastic body allows the first heat-transfer member to abut on the high-temperature part. The elastic body allows the first heat-transfer member to abut on the high-temperature part while the second member is attached to the first member, for example. In the present embodiment, the wording “abut” means that at least a portion of an object is in contact with at least a portion of another object. In other words, the elastic body allows at least a portion of the first heat-transfer member to come into contact with at least a portion of the high-temperature part. The display device according to the present embodiment may be implemented as a variety of stationary display devices (such as a stationary liquid crystal display device or a stationary organic EL display device, for example) or a wearable display such as a head-mounted display (HMD), for example. Next, with reference to
The HMD, which serves as an example of the display device 10 according to the present embodiment, includes a front block 100, the rear block 200, and couplers 300. The display device 10 is worn on the head of a user such that the front block 100, the rear block 200, and the couplers 300 surround the head of the user.
It is to be noted that, in the following description, a direction in which the front block 100 and the rear block 200 are disposed in the head-mounted display 10 with the head of the user is interposed therebetween is referred to as an X-axis direction. Here, a direction from the front block 100 to the rear block 200 along the X-axis direction is deemed to be a positive direction of the X axis. In addition, two directions orthogonal to each other in a plane perpendicular to the X-axis direction are respectively referred to as the Y-axis direction and the Z-axis direction. In this case, the Z-axis direction is a direction corresponding to the height of the user.
The front block 100 includes a display unit 110 and has a function of providing the user with a variety of images. The display unit 110 is disposed in front of the eyes of the user when the display device 10 is worn by the user. The display unit 110 of the front block 100 may be a transparent display or a non-transparent display. The transparent display does not block a field of view of the user in a state where no image is displayed. In addition, the display unit 110 may be disposed in front of both of the eyes of the user or one of the eyes of the user. The front block 100 may include a camera (not illustrated) for capturing an image of the field of view of the user corresponding to a direction of the face of the user wearing the HMD.
As illustrated in
The couplers 300 have a function of coupling the front block 100 to the rear block 200. Examples of material for the couplers 300 may include metal material, resin material, and the like. For example, aluminum alloy, titanium alloy, stainless steel, acetylcellulose, a polyamide, or the like may be used.
The couplers 300 extend in a rear direction respectively from the first side end 101 of the front block 100 and the second side end 102 of the front block 100 positioned on the opposite side from the first side end 101 in the Y-axis direction. A coupler 301 extending from the first side end 101 in the rear direction is coupled to a first side end 201 of the rear block 200. A coupler 302 extending from the second side end 102 in the rear direction is coupled to a second side end 202 of the rear block 200. The second side end 202 is positioned on the opposite side from the first side end 201 in the Y-axis direction. It is to be noted that the couplers 300 are not limited to the above-described couplers as long as the front block 100 and the rear block 200 are coupled and the front block 100, the rear block 200, and the couplers 300 are worn on the head of the user.
The rear block 200 includes the first member 210 including the high-temperature part, and the second member 220 attachable to the first member 210. The rear block 200 forms an internal space 280 when the second member 220 is attached to the first member 210. For example, the second member 220 may be attached to the first member 210 so as to seal the internal space 280. Alternatively, the second member 220 may be attached to the first member 210 such that a portion of the internal space 280 communicates with an outside. As illustrated in
As illustrated in
It is possible to produce the first member 210 through a variety of known methods by using a variety of known materials. For example, the first member 210 may be produced through injection molding by using thermoplastic resin as the material. In the case where the display device 10 is the HMD, the first member 210 constitutes a surface that does not abut on the head of the user in the rear block 200, for example.
The shape of the first member 210 is not limited to the shape exemplified in
It is possible to produce the second member 220 through a variety of known methods by using a variety of known materials. For example, the second member 220 may be produced through injection molding by using thermoplastic resin as the material. In the case where the display device 10 is the HMD, a surface of the second member 220 that abuts on the head of the user may be produced by using a variety of foamed plastics as material. For example, urethane foam, polyolefin foam, polyethylene foam, or the like may be used as material for the production.
As schematically illustrated in
The first heat-transfer member 230 is coupled to the high-temperature parts in a state where the second member 220 is attached to the first member 210 (specifically, the first heat-transfer member 230 is in contact with the battery 250, which is an example of the first high-temperature part, without being fixed). The first heat-transfer member 230 has a function of transferring heat of the high-temperature parts in the internal space 280 to a predetermined position of a casing of the rear block 200 and releasing the heat of the high-temperature parts from the predetermined position to the outside of the rear block 200. In other words, the first heat-transfer member 230 is thermally coupled to the high-temperature parts. In addition, in the present embodiment, the first heat-transfer member 230 is deformable, and the position of the first heat-transfer member 230 may relatively change in the internal space 280. This allows the first heat-transfer member 230 to easily follow deformation of the high-temperature parts even in a case where the high-temperature parts deform over time, for example. Examples of the deformable first heat-transfer member 230 include a sheet member.
For example, it is preferable that lightweight material with high thermal conductivity be used as material for the first heat-transfer member 230. Examples of such lightweight material with high thermal conductivity include carbon-based material, metal material, thermally conductive synthetic resin material, and the like. Specifically, for example, a copper sheet, an aluminum sheet, a graphite sheet, a thermally conductive acrylic sheet, a silicone sheet, or the like may be used as the material for the first heat-transfer member 230. When the lightweight material with high thermal conductivity is used as the material for the first heat-transfer member 230, it is possible to release heat of the high-temperature parts to the outside of the rear block 200 more efficiently while suppressing increase in mass of the rear block 200. It is more preferable that the graphite sheet be used as the material for the first heat-transfer member 230. When the graphite sheet is used as the material for the first heat-transfer member 230, it is possible to design a lightweight display device with good thermal conductivity while reducing its space.
As schematically illustrated in
For example, the first heat-transfer member 230 may have a thickness that allows flexibility to be maintained in such a manner that workability is not deteriorated when attaching the first heat-transfer member 230 to the second member 220. The first heat-transfer member 230 may have a thickness of 0.6 mm or less in a case of a structure in which the second member 220 has a partially stepped surface opposed to the internal space 280 of the first member 210 as illustrated in
For example, the first heat-transfer member 230 is installed on at least a portion, facing the battery 250, of the surface of the second member 220 opposed to the internal space 280. As described above, because the second member 220 includes the first heat-transfer member 230, the elastic body 240 allows the first heat-transfer member 230 to be coupled to the battery 250 when the second member 220 is attached to the first member 210. This makes it possible to release heat of the battery 250 from the second member 220 to the outside via the first heat-transfer member 230. At this time, the area of surface in which the first heat-transfer member 230 is coupled to the battery 250 is preferably larger than area of surface in which the elastic body 240 is coupled to the first heat-transfer member 230. When the area of the surface in which the first heat-transfer member 230 is coupled to the battery 250 is larger than the area of the surface in which the elastic body 240 is coupled to the first heat-transfer members 230, it is possible for the first heat-transfer member 230 to efficiently transfer the heat of the battery 250 to the second member 220. The first heat-transfer member 230 is preferably attached to a wide area of the surface of the second member 220 opposed to the internal space 280. As the area of surface in which the first heat-transfer member 230 comes into contact with the second member 220 increases, it becomes possible for the first heat-transfer member 230 to transfer the heat of the battery 250 to the second member 220 more efficiently. This makes it possible to release the heat transferred to the second member 220, from the second member 220 to the outside of the rear block 200 within a shorter time. It is to be noted that, for example, in a case where a surface of the second member 220 adjacent to the internal space 280 includes a part such as a rib or a boss that requires effort to attach the first heat-transfer members 230, the first heat-transfer members 230 may be attached to portions other than such a part.
A plurality of the first heat-transfer members 230 may be attached to the surface of the second member 220 opposed to the internal space 280, for example. For instance, as illustrated in
The elastic body 240 is a member having predetermined elasticity, and is installed so as to be in contact with the first heat-transfer member 230. Specifically, when the second member 220 is attached to the first member 210, the elastic body 240 presses the first heat-transfer member 230 with its elasticity, coupling the first heat-transfer member 230 to the battery 250. For example, as illustrated in
The elastic body 240 may be bonded to the second member 220 with adhesive, adhesive tape, or the like. In addition, the elastic body 240 may be bonded to the first heat-transfer member 230 with adhesive, adhesive tape, or the like.
The area of the surface in which the elastic body 240 is in contact with the first heat-transfer member 230 is not specifically limited as long as the elastic body 240 has restoring force that allows the first heat-transfer member 230 to abut on the battery 250. The area of the surface in which the elastic body 240 is in contact with the first heat-transfer member 230 may be the same as the area of a surface in which the battery 250 is in contact with the first heat-transfer member 230, for example.
In addition, the length of the elastic body 240 (in other words, the thickness of elastic body 240) in a direction perpendicular to the surface in which the elastic body 240 is in contact with the first heat-transfer member 230 (X-axis direction) is preferably longer than the amount of change in dimension of the battery 250 obtained when the dimension of the battery 250 changes over time. If the amount of temporal change in dimension of the battery 250 is 1 mm, the length of the elastic body 240 in the direction perpendicular to the surface in which the elastic body 240 is in contact with the first heat-transfer member 230 may be approximately 3 mm, for example. A margin for swelling of the battery 250 may be set to a value equivalent to the length of the elastic body 240 in the direction perpendicular to the surface in which the elastic body 240 is in contact with the first heat-transfer member 230. As a result, this makes it possible to prevent the rear block 200 from getting damaged. For example, this makes it possible to prevent an attachment between the first member 210 and the second member 220 from being damaged due to swelling of the battery 250.
The battery 250 supplies electric power necessary to operate the display device 10. The battery 250 is disposed in the internal space 280. It is possible to use, as the battery 250, a battery detachable from the display device 10. For example, when detaching the second member 220 from the first member 210, the battery 250 appears from the opening 203, allowing the user to detach the battery 250. Examples of such a battery 250 include an existing primary battery and an existing secondary battery. Specific examples of the battery 250 include an alkaline battery, a silver-oxide battery, a zinc-air battery, a nickel metal hydride battery, a lithium-ion secondary battery, and the like. In addition, the shape of the battery 250 is not specifically limited. For example, the battery 250 may have a polygonal shape, a cylindrical shape, a laminated shape, or the like. Examples of the battery 250 includes a battery that may deform over time. It is to be noted that
The control board 260 has a function of controlling an operation of the display device 10. The control board 260 includes a central processing unit (CPU), a memory, an input/output (I/O) unit, a resistor, a coil, a capacitor, or the like that constitute a circuit. Examples of a board constituting the control board 260 include a rigid board that does not have flexibility, and a flexible base that has flexibility. As the rigid board, for example, a paper phenolic board, a glass composite board, a glass epoxy board, or the like may be used. As material for the flexible board, for example, polyimide or polyester may be used.
The control board 260 may be subjected to an insulating process according to a known method. The control board 260 may be subjected to the insulating process by using a method of applying insulating material, for example. Specifically, polyvinyl resin, acrylate resin, urethane resin, or the like may be applied through handpainting, spraying, dipping, potting, or the like.
The control board 260 is fixed in the internal space 280 by using a fixture member installed in the internal space 280. The control board 260 may be disposed in parallel to a YZ-plane as illustrated in
In addition, in many cases, the amount of heat produced by the control board 260, which is an example of the high-temperature part, is larger than the amount of heat produced by the battery 250. Therefore, the control board 260 is preferably disposed at a position farther away from the opening 203 than the battery 250 in the internal space 280, for example. In the case where the display device 10 is an HMD, the control board 260 is disposed at the above-described position. This makes it possible to dispose the control board 260, which produces higher heat than the battery 250, at a position farther away from the head of the user. Accordingly, it is possible to reduce health damage to the user from the heat produced by the control board 260.
In addition, the high-temperature parts may be disposed depending on possible temperatures of the high-temperature parts. For example, sometimes a high-temperature part with small heat capacity has a higher temperature than a high-temperature part that produces a large amount of heat even in a case where the high-temperature part with small heat capacity produces a small amount of heat. In addition, sometimes a high-temperature part partially has a high temperature depending on a structure or material of the high-temperature part. Therefore, when the high-temperature parts are disposed depending on the possible temperatures reached by the high-temperature parts, it is possible to reduce health damage to the user. For example, a high-temperature part that produces higher heat may be disposed at a position away from the head of the user.
The second heat-transfer member 270 is in contact with a high-temperature part, and has a function of releasing heat of the high-temperature part installed in the internal space 280 to the outside of the rear block 200. In addition, the second heat-transfer member 270 is deformable, and may have a sheet shape. For example, as material for the first heat-transfer member 230, carbon-based material, metal material, thermally conductive synthetic resin material, or the like may be used. Specifically, a graphite sheet, a thermally conductive acrylic sheet, a silicone sheet, or the like may be used.
For example, as illustrated in
For example, as illustrated in
In a case where the second heat-transfer member 270 is electrically conductive, the second heat-transfer member 270 is installed on a non-electrically conductive portion of the control board 260. In addition, in the case where the second heat-transfer member 270 is electrically conductive, an insulated heat-transfer member may be used as the second heat-transfer member 270. If the insulated heat-transfer member is used as the second heat-transfer member 270, it is possible to prevent leakage of current flowing to the control board 260.
In addition, for example, as illustrated in
The second heat-transfer member 270 is preferably attached to a wide area of the inner surface of the first member 210, for example. As the area of the surface in which the second heat-transfer member 270 is in contact with the first member 210 increases, it becomes possible for the second heat-transfer member 270 to transfer the heat of the control board 260 to the first member 210 more efficiently. This makes it possible to release the heat transferred to the first member 210, from the first member 210 to the outside of the rear block 200 within a shorter time. It is to be noted that, for example, in a case where a part such as a rib or a boss that requires effort to attach the second heat-transfer member 270 is installed on the inner surface of the first member 210, the second heat-transfer member 270 may be attached to portions other than such a part.
The second heat-transfer member 270 may have thickness that allows flexibility to be maintained in such a manner that workability is not deteriorated when attaching the second heat-transfer member 270 to the first member 210. For example, the second heat-transfer member 270 may have a thickness of 0.3 mm or less in a case where the first member 210 is curved toward the positive direction of the X-axis and the second heat-transfer member 270 is attached to the inner surface of the first member 120 as illustrated in
The second heat-transfer member 270 may be in contact with a plurality of high-temperature parts. For example, in a case where a plurality of types of high-temperature parts is stored in the internal space 280, the second heat-transfer member 270 may be coupled to a plurality of high-temperature parts including heating elements that produce relatively larger amounts of heat among the plurality of types of high-temperature parts, and another portion of the second heat-transfer member 270 may be coupled to the first member 210. This makes it possible to release heat of the high-temperature parts that produce large amounts of heat, to the outside from the first member 210 disposed at a position away from the head of the user when the display device 10 is used as the HMD. As a result, it is possible to further reduce health damage to the user from the heat produced by the high-temperature parts.
It is to be noted that, in the case where the display device 10 is used as the HMD, the display device 10 may include a known adjustment mechanism for fitting the display device 10 to the size of the head of the user.
The configuration of the display device 10 according to the present embodiment has been described above. Next, a flow of processes to release heat produced in the display device 10 according to the present embodiment is described.
First, the control board 260 is operated by electric power supplied from the battery 250, and the display unit 110 supported by the front block 100 provides the user with a variety of images. At this time, the battery 250 and the control board 260 store heat. The heat of the battery 250 is transferred to the first heat-transfer member 230 that is in contact with the battery 250. Next, the heat transferred to the first heat-transfer member 230 is further transferred to the second member 220, and is released from the second member 220 to the outside of the rear block 200.
In a case where the battery 250 swells over time, stress is applied from the first heat-transfer member 230 to the elastic body 240 due to the swelled battery 250. In this case, the elastic body 240 generates restoring force against the stress applied to the elastic body 240 due to its elasticity. As a result, it is possible for the elastic body 240 to cause the first heat-transfer member 230 to abut on the battery 250. This makes it possible to efficiently release heat to the outside of the rear block 200 via the first heat-transfer member 230 even in a case where a dimension of the battery 250 is changed over time. Accordingly, for example, it is possible to maintain the temperature of the battery 250 at 60□ or less during an operation of the display device 10.
In addition, the heat of the control board 260 is transferred to the second heat-transfer member 270 in contact with the control board 260. Next, the heat transferred to the second heat-transfer member 270 is further transferred to the first member 210, and is released from the first member 210 to the outside of the rear block 200. Accordingly, for example, it is possible to maintain the temperature of the control board 260 at 85□ or less during an operation of the display device 10.
In many cases, the amount of heat produced by the control board 260 is larger than the amount of heat produced by the battery 250. Therefore, it is possible for the display device 10 according to the present embodiment to release heat of the control board 260 from the first member 210 to a direction different from a direction in which the head of the user is positioned. As a result, it is possible to reduce health damage to the user from the heat produced by an operation of the display device 10.
A display device in which the graphite sheet serving as the first heat-transfer member is attached to the second member and the graphite sheet is contact with the battery by using the elastic body in the rear block, and a display device in which the graphite sheet is not attached were respectively designed, and thermal simulations of the display devices were performed by using a known application. The same battery was used for the both display devices, and the both display devices had the same configuration except the presence or absence of the first heat-transfer member. As a result, it was found that a battery surface temperature of the display device including the graphite sheet in contact with the battery was 6□ colder than a battery surface temperature of the display device in which the graphite sheet is not attached.
As described above, according to the display device of the present embodiment, it is possible to release heat of the high-temperature parts to the outside of the display device via the first heat-transfer member that is not fixed to the high-temperature parts. In addition, it is possible to release the heat of the high-temperature parts to the outside more stably.
The details of the preferred embodiments of the present disclosure have been described above with reference to the accompanying drawings, whilst the present technology is not limited to such examples. It is obvious that a person having ordinary skill in the art of the present disclosure may find various alterations or modifications within the scope of the technical idea described in the claims, and it should be understood that these alterations and modifications naturally come under the technical scope of the present disclosure.
Further, the effects described herein are merely illustrative or exemplary, and are not limitative. That is, the technique according to the present disclosure may achieve, in addition to or in place of the above effects, other effects that are obvious to those skilled in the art from the description of the present specification.
It is to be noted that the present technology may also have the following configurations.
(1) A display device including
a second member that is attachable to a first member including a high-temperature part,
the second member including
the first high-temperature part is detachable, and
the second high-temperature part is fixed to the first member.
(4) The display device according to (2) described above, in which the first high-temperature part is deformable over time.
(5) The display device according to any one of (2) to (4) described above, in which area of a surface in which the first heat-transfer member is in contact with the first high-temperature part is larger than area of a surface in which the elastic body is in contact with the first heat-transfer member.
(6) The display device according to any one of (2) to (5) described above, in which
a space is formed by attaching the second member to the first member, and
the space stores a second heat-transfer member including a portion coupled to the second high-temperature part and another portion coupled to a space-side surface of the first member.
(7) The display device according to (6) described above, in which heat of the first high-temperature part is mainly released from the second member to an outside via the first heat-transfer member, and heat of the second high-temperature part is mainly released from the first member to an outside via the second heat-transfer member.
(8) The display device according to any one of (2) to (7) described above, in which
the first high-temperature part and the second high-temperature part produce heat, and
an amount of heat produced by the first high-temperature part is less than an amount of heat produced by the second high-temperature part.
(9) The display device according to any one of (2) to (8) described above, in which the display device is to be worn on a head of a user, and the first high-temperature part is positioned closer to the head of the user than the second high-temperature part is.
(10) The display device according to any one of (2) to (9) described above, in which the first high-temperature part is a battery.
(11) The display device according to any one of (2) to (10) described above, in which the second high-temperature part is a control board that controls an operation of the display device.
(12) The display device according to any one of (1) to (11) described above, in which the first heat-transfer member has a sheet shape.
(13) A heat release method including:
installing a second member that is attachable to a first member including a high-temperature part;
installing, in the second member,
releasing heat of the high-temperature part to an outside.
Number | Date | Country | Kind |
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2018-142835 | Jul 2018 | JP | national |
Filing Document | Filing Date | Country | Kind |
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PCT/JP2019/025784 | 6/28/2019 | WO | 00 |