Image display device

Abstract

To dissipate generated heat in a more suitable mode regardless of the position of an observation optical system even in a situation where the position of the observation optical system can be adjusted.SOLUTION: An image display device 100 comprises: lenses 20L, 20R that guide light to the eyes of an observer; and a housing that supports the lenses 20L, 20R movably along a predetermined route. The image display device 100 further comprises: surfaces 50A', 50B', and 50C' that are provided in the housing 101, are located in directions different from each other along the route with respect to the lenses 20L, 20R, and dissipate heat generated in the housing 101; and a graphite sheet 50 that connects the surfaces 50A', 50B', and 50C' to each other in a heat transferable manner.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to an image display device. [Background technology]

[0002] In recent years, there has been an increase in the use of HMDs (head-mounted displays), which are worn on the observer's head and display images in front of the observer's eyes. HMDs are used as devices that allow users to experience artificial reality (virtual reality = VR) and mixed reality (mixed reality = MR) because they allow users to easily view images on a large screen and provide stereoscopic vision. An HMD for realizing MR has an imaging unit for capturing images of a subject corresponding to the left and right eyes of the observer, a display unit for displaying the image captured by the imaging unit superimposed on a 3DCG image, and an observation optical system for projecting an image to the observer. The image to be projected to the observer is displayed on a display element such as a small LCD panel corresponding to the observer's left and right eyes, and this image is then enlarged via the observation optical system corresponding to the observer's left and right eyes and projected by being irradiated onto the observer's left and right eyeballs. Furthermore, the captured image of the subject is an image with parallax corresponding to both the left and right eyes. On top of that, a 3DCG image is generated as a parallax image corresponding to both the left and right eyes of the observer, and is displayed superimposed on the image captured by the imaging system, making it possible to present a virtual 3DCG image as if it actually exists. Furthermore, some HMDs are provided with a function for adjusting the position of the observation optical system according to the distance between the observer's eyes. Patent Document 1 discloses a head-mounted display that is equipped with an interpupillary distance adjustment mechanism for adjusting the distance between the observation optical system for the left eye and the observation optical system for the right eye, and that maintains optical accuracy even when an external force such as twisting of the main body is applied. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-015293 Summary of the Invention [Problem to be solved by the invention]

[0004] Generally, when the imaging unit and display elements of an HMD are designed to have a wider angle of view and higher image quality, the power consumption and heat generation tend to increase as the number of pixels and the load of image processing increase. Possible measures to reduce heat generation include the use of cooling means such as fans and the provision of ventilation holes to release heat. However, cooling means such as fans generate noise and vibration, which can be uncomfortable for observers wearing the HMD. Furthermore, ventilation holes can allow dust and other particles to get inside the device, so they are not necessarily an appropriate solution for HMDs, which are optical devices. In the head-mounted display disclosed in Patent Document 1, heat from a heat source located inside the main body exterior, which does not move when adjusting the interpupillary distance, is dissipated to the outside via the surface of the main body exterior parts. However, adjusting the interpupillary distance changes the position of the main body exterior surface that is exposed to the outside, and the area that functions as a heat dissipation surface is hidden by the display exterior parts, making it difficult to dissipate heat sufficiently, and it is possible that a situation will occur in which the temperature of the heat source rises. SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an image display device that realizes a stable heat dissipation configuration regardless of the position of the observation optical system that is arranged by adjusting the interpupillary distance.

[0005] The present invention has been made in consideration of the above-mentioned points, and aims to make it possible to dissipate generated heat in a more suitable manner, regardless of the position of the observation optical system, even in situations where the position of the observation optical system can be adjusted. [Means for solving the problem]

[0006] The image display device according to the present invention includes an observation optical system that guides light to an observer's eye, a housing that supports the observation optical system so as to be movable along a predetermined path, and a The relevantThe device includes a first heat dissipation section and a second heat dissipation section that dissipate heat generated in the housing, and a heat transfer section that connects the first heat dissipation section and the second heat dissipation section to each other so that heat can be transferred therebetween. The first heat dissipation unit is provided at a position where it is exposed when the observation optical system is disposed so as to cover the second heat dissipation unit by moving along the path, and the second heat dissipation unit is provided at a position where it is exposed when the observation optical system is disposed so as to cover the first heat dissipation unit by moving along the path. It is characterized by: [Effects of the Invention]

[0007] According to the present invention, even in a situation where the position of the observation optical system is adjustable, it is possible to dissipate generated heat in a more suitable manner regardless of the position of the observation optical system. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is a front perspective view of the image display device. [Figure 2] FIG. 2 is a rear perspective view of the image display device. [Figure 3] 10A and 10B are diagrams illustrating a case where the distance between lenses of the image display device is adjusted. [Figure 4] FIG. 2 is a partial cross-sectional view of the image display device. [Figure 5] FIG. 2 is a diagram illustrating a configuration related to heat dissipation of the image display device. [Figure 6] 10A and 10B are diagrams illustrating the position of a heat dissipation member when adjusting the lens spacing of the image display device. DETAILED DESCRIPTION OF THE INVENTION

[0009] Preferred embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. In this specification and drawings, components having substantially the same functional configurations are designated by the same reference numerals, and redundant description will be omitted. Furthermore, the following embodiments do not limit the invention according to the claims. Although the embodiments describe multiple features, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined in any desired manner.

[0010] The image display device to which the present invention is applied is an image display device equipped with an observation optical system that guides light to the observer's eyes, and is suitable for use in an HMD (head-mounted display) or an HHD (handheld display). In this embodiment, an image display device 100 used in an HMD will be described. In this disclosure, directions are defined as the forward direction, which the observer faces when wearing the device on the observer's head, and as up, down, left, right, and up, and down, and left, and right, which are seen from the observer. In this disclosure, for convenience, the left-right axis is also referred to as the x-axis, the up-down axis as the y-axis, and the front-back axis as the z-axis.

[0011] Fig. 1 is a perspective view of the image display device 100 as seen from the front (opposite side from the viewer), and Fig. 2 is a perspective view of the image display device 100 as seen from the rear (viewer side). The image display device 100 includes a housing 101 that is thin and long from front to back and that forms the exterior of the device.

[0012] As shown in FIG. 1, left and right imaging cameras 10L and 10R and left and right alignment cameras 11L and 11R are provided on the front surface of a housing 101. The imaging cameras 10L and 10R are stereo cameras that acquire real images to be displayed to an observer via lenses 20L and 20R. The alignment cameras 11L and 11R are stereo cameras that acquire the position and orientation of the image display device 100 by utilizing feature points such as markers and object edges from the acquired images. The alignment cameras 11L and 11R are monochrome cameras, but by utilizing a wide angle of view, a high shutter speed, a long baseline length, and the like, they are capable of performing alignment with high precision and high tolerance to faults. In this embodiment, the imaging cameras 10L, 10R and the alignment cameras 11L, 11R are provided separately, but the imaging cameras 10L, 10R may be configured to acquire display images and alignment information only using the imaging cameras 10L, 10R. Also, the alignment cameras 11L, 11R may be replaced with distance sensors that use ultrasonic waves, infrared rays, or the like.

[0013] The image display device 100 transmits and receives position information and image data to and from an external personal computer or controller via a cable (not shown), and generates a display image in which a 3DCG image is superimposed on a real image. The image display device 100 then displays the generated display image on a display unit such as an LCD (Liquid Crystal Display) or an OLED (Organic Light Emitting Diode). An observer can observe the image on the display unit through an observation optical system (for example, lenses 20L and 20R, which will be described later).

[0014] As shown in Fig. 2, left and right lenses 20L and 20R that constitute the observation optical system are provided on the rear surface of the housing 101. The lenses 20L and 20R are prisms, lenses, etc. that magnify and guide an image displayed on a display unit such as an LCD or OLED provided inside the housing 101, and an observer looks through the lenses 20L and 20R to observe the image on the display unit. Lens hoods 30L and 30R are provided around the lenses 20L and 20R. The lens hoods 30L and 30R correspond to an example of a display exterior.

[0015] Operation buttons 90A-90C are arranged on the top surface of the housing 101 to receive instructions from the viewer, power operations, and the like. The operation buttons 90A-90C are arranged so that the viewer can operate them by grasping the top and bottom of the housing 101. When the operation buttons are arranged in this manner, for example, it is conceivable that the user will press the operation buttons 90A-90C with their second or third finger and support the underside of the image display device 100 facing the operation buttons 90A-90C with their thumb or the like. Therefore, it is desirable that the distance to the underside of the image display device 100 facing the operation buttons 90A-90C be kept within a distance that allows the user (viewer) to hold it with one hand. In light of this, it is desirable that internal components (e.g., an electric circuit board, etc., described below) that may increase the height of the image display device 100 be arranged in a central area inward from the positions where the operation buttons 90A-90C are arranged.

[0016] 3 is a diagram showing the rear of the image display device 100, illustrating an example of a configuration for adjusting the distance between the lenses 20L and 20R in accordance with the interpupillary distance of the viewer. The lenses 20L and 20R are engaged with the lens hoods 30L and 30R so that they can move in unison. As shown in FIGS. 3(a) and 3(b), the viewer can operate the lens hoods 30L and 30R to adjust the positions of the lenses 20L and 20R left and right to match the interpupillary distance of the viewer.

[0017] In this embodiment, an example in which the lens hoods 30L, 30R and a rear cover 41 (described later) are provided as separate bodies is described, but this does not necessarily limit the configuration of the image display device 100 according to this embodiment. For example, to reduce the number of parts, the rear cover 41 may be integrated with each of the lens hoods 30L, 30R, leaving a portion of the lenses 20L, 20R exposed and allowing the distance between the lens hood 30L and the lens hood 30R to be adjusted. Note that this configuration tends to increase the overall size of the image display device 100 because the rear cover 41 covers the range of movement of the lenses 20L, 20R in the interpupillary direction (left and right). In contrast, by providing the lens hoods 30L, 30R and the rear cover 41 as separate bodies and linking the lenses 20L, 20R and the lens hoods 30L, 30R as in this embodiment, the overall size of the image display device 100 can be reduced.

[0018] Next, an example of the internal configuration of the image display device 100 will be described with reference to Fig. 4. Fig. 4 is a partial cross-sectional view of a part of the image display device 100 cut along a plane approximately perpendicular to the x-axis.

[0019] The rear cover 41 and the front cover 42 are engaged with each other to form a housing 101, which houses a circuit board 60 therein. However, the rear cover 41 and the front cover 42 do not cover the lenses 20L, 20R, and the lenses 20L, 20R engaged with the lens hoods 30L, 30R are supported so as to be positioned behind a portion of the rear cover 41. The rear cover 41 also has rail members 31T, 31B above and below the space in which the lens hoods 30L, 30R are disposed. The rail members 31T, 31B are an example of a guide member. The rail members 31T, 31B are provided to extend along the left-right direction (x-axis) and guide the lens hoods 30L, 30R relative to the rear cover 41 so that they can move along a substantially linear path extending in the left-right direction. This allows the lenses 20L, 20R engaged with the lens hoods 30L, 30R to be supported relative to the rear cover 41 (in other words, the housing 101) so as to be movable in the left-right direction (in other words, movable along a path extending in the x-axis direction).

[0020] As in this embodiment, by forming the rail members 31T, 31B and the lens hoods 30L, 30R as separate bodies rather than integrally, it becomes possible to use different materials for each. For example, by using polyacetal resin (POM), which has high slidability and a high specific gravity, for the rail members 31T, 31B and using modified polyphenylene ether (modified PPE), which has a low specific gravity, for the lens hoods 30L, 30R, it becomes possible to achieve weight reduction.

[0021] In this embodiment, the guide members are arranged to movably guide the lens hoods 30L, 30R relative to the rear cover 41, but they may also be arranged to movably guide the lenses 20L, 20R relative to the rear cover 41. As another example, the guide members may be arranged to movably guide each of the lens hoods 30L, 30R and the lenses 20L, 20R relative to the rear cover 41.

[0022] Next, an example of a heat dissipation configuration for dissipating heat generated inside the housing 101 of the image display device 100 to the outside will be described. Fig. 5 is a view of the inside of the image display device 100 as seen from the front. In Fig. 5, the front cover 42, imaging cameras 10L and 10R, and alignment cameras 11L and 11R are not shown in order to show the internal configuration of the image display device 100. Fig. 6 is a view showing the position of the heat dissipation surface as seen from the rear of the image display device 100.

[0023] Devices such as an FPGA (Field-Programmable Gate Array) 61 are mounted on the substrate 60. These devices correspond to an example of a heat source. Due to the arrangement of the buttons 90A to 90C described above with reference to FIGS. 1 and 2, the substrate 60 is disposed near the center in the left-right direction (x-axis direction) of the image display device 100. The substrate 60 is also disposed at the top of the image display device 100 in order to reduce the depth of the image display device 100. Heat generated from the FPGA 61 is transferred to the rear cover 41 by radiation or through intervening components, and is then dissipated to the outside via a surface 50A' of the rear cover 41 located behind a heat dissipation portion 50A of a graphite sheet 50 (described later). A surface 50A' of the rear cover 41 is disposed so as to be located between the lens 20L and the lens 20R. Furthermore, surfaces 50B' and 50C' of the rear cover 41 are disposed so as to be located outside the direction in which the lenses 20L and 20R can move (in other words, the direction in which the lens hoods 30L and 30R can move). That is, the surface 50B' and the surface 50A' are located in different directions relative to the lens 20L along the path along which the lens 20L moves. Similarly, the surface 50C' and the surface 50A' are located in different directions relative to the lens 20R along the path along which the lens 20R moves. With this configuration, when the distance between lenses 20L and 20R is adjusted to be narrower, surface 50A' is covered by lens hoods 30L and 30R. In this case, surfaces 50B' and 50C' are covered by lens hoods 30L and 30R and are exposed to the outside. On the other hand, when the distance between lenses 20L and 20R is adjusted to increase, surface 50A' is covered by lens hoods 30L and 30R and is exposed to the outside. In this case, surfaces 50B' and 50C' are also covered by lens hoods 30L and 30R.

[0024] Graphite sheet 50 is disposed so as to extend in the left-right direction (x-axis) along rear cover 41, and is formed to include heat dissipation sections 50A, 50B, and 50C, and heat transfer section 50D that connects heat dissipation section 50A to heat dissipation sections 50B and 50C so as to enable heat transfer. Each of heat dissipation sections 50A, 50B, and 50C is formed as a planar member that extends in the left-right direction (x-axis) and the up-down direction (y-axis). The heat dissipation unit 50A is connected to the rear cover 41 on the back side (inside the housing 101) of a partial surface 50A' of the rear cover 41 so as to be able to transfer heat therethrough. Similarly, the heat dissipation units 50B and 50C are connected to the rear cover 41 on the back sides (inside the housing 101) of the partial surfaces 50B' and 50C' of the rear cover 41 so as to be able to transfer heat therethrough. As a specific example, the heat dissipation units 50A, 50B, and 50C may be arranged so that their rear surfaces abut against the back sides of the surfaces 50A', 50B', and 50C', respectively.

[0025] As illustrated in FIG. 5 , surface 50A' and surfaces 50B' and 50C' are connected via graphite sheet 50 in a heat-transferable manner, so that even if the spacing between the lenses is adjusted, there will be heat dissipation surfaces that are not covered by lens hoods 30L and 30R and are exposed to the outside. That is, even if the spacing between lenses 20L and 20R is adjusted to increase the spacing between them, surface 50A' of rear cover 41, with which heat dissipation portion 50A of graphite sheet 50 abuts on the back side, will be exposed to the outside. Also, even if the spacing between lenses 20L and 20R is adjusted to decrease the spacing between them, surfaces 50B' and 50C' of rear cover 41, with which heat dissipation portions 50B and 50C of graphite sheet 50 abut on the back side, will be exposed to the outside. This makes it possible to realize a heat dissipation configuration that provides a stable heat dissipation effect regardless of the position of lenses 20L and 20R, thereby suppressing the rise in temperature of the entire image display device 100 and providing the viewer with a more comfortable visual experience.

[0026] Note that surfaces 50A' and 50B' of rear cover 41 correspond to examples of a "first heat dissipation portion" and a "second heat dissipation portion" that are located in different directions relative to lens 20L along the path along which lens 20L moves. Similarly, surfaces 50A' and 50C' of rear cover 41 correspond to examples of a "first heat dissipation portion" and a "second heat dissipation portion" that are located in different directions relative to lens 20R along the path along which lens 20R moves. 5 and 6, of the first and second heat dissipation portions corresponding to the lenses 20L and 20R, respectively, the two heat dissipation portions located between the lenses 20L and 20R may be formed as a single heat dissipation member. In other words, the heat dissipation portion located between the lenses 20L and 20R may be provided as a shared heat dissipation portion between the lenses 20L and 20R.

[0027] In this embodiment, heat transfer section 50D of graphite sheet 50, which connects heat dissipation section 50A to heat dissipation sections 50B and 50C, is provided in a position that does not hinder the movement of lenses 20L and 20R (e.g., outside the area where lenses 20L and 20R can move). As a specific example, in the example shown in FIG. 5, graphite sheet 50 has a portion extending in the left-right direction above lenses 20L and 20R that serves as heat transfer section 50D, and heat transfer section 50D connects heat dissipation section 50A to heat dissipation sections 50B and 50C in a heat-transferable manner. Furthermore, heat transfer section 50D of graphite sheet 50, which is provided above lenses 20L and 20R, and connects heat dissipation section 50A to heat dissipation sections 50A and 50C, is bent so as to be perpendicular to the heat dissipation surfaces. This makes it possible to suppress an increase in the height of image display device 100 (in other words, the height of housing 101). Due to these characteristics, the heat transfer member exemplified as graphite sheet 50 is preferably made of a flexible material.

[0028] Note that the configuration of the heat transfer member illustrated as graphite sheet 50 in FIG. 5 is merely an example and does not necessarily limit the configuration for providing the heat transfer member (e.g., the position where the heat transfer member is provided, etc.). As a specific example, heat transfer member 50D may be provided below lenses 20L and 20R, extending in the left-right direction, to connect heat dissipation member 50A to heat dissipation members 50B and 50C in a heat-transferable manner. However, the area below lenses 20L and 20R is close to the convex parts of the face (e.g., nose, cheekbones, etc.) of the viewer using image display device 100, and a temperature rise in the heat transfer member may cause discomfort to the viewer. In consideration of this situation, it is more desirable to provide heat transfer member 50D at a position farther away from the body parts (e.g., part of the face) of the viewer using image display device 100, as in the configuration shown in FIG. 5.

[0029] In this embodiment, graphite sheet 50 is attached to rear cover 41 using double-sided tape or the like, and is thereby supported by rear cover 41 (in other words, housing 101). The material that can be used as the heat transfer member is not limited to a graphite sheet, but may be, for example, a material made of another material that is flexible and has high thermal conductivity, such as copper foil tape. It is also possible to use a plurality of sheet-like heat transfer members such as graphite sheets, which are laminated together. This configuration is expected to further increase the amount of heat conduction. Copper foil and graphite sheets are also commercially available with adhesive, such as so-called tape, so using such materials makes it easy to create the heat transfer member described above and attach the heat transfer member to rear cover 41. Furthermore, graphite sheet 50 described above may be partially divided to improve the assembly of image display device 100. As a specific example, heat dissipation sections 50A, 50B, and 50C may be divided into heat transfer section 50D, which connects them to enable heat transfer. In this case, it is desirable to provide a joint having a certain area or more to ensure a heat transfer effect between the members joined together. However, providing such a joint may cause thermal resistance in the thickness direction at the joint. Therefore, it is more ideal that a configuration equivalent to graphite sheet 50 described above be formed as a single sheet-like member.

[0030] Although the present invention has been described above with reference to the embodiments, the above embodiments are merely illustrative of specific examples of how the present invention can be implemented, and the technical scope of the present invention should not be construed as being limited by these embodiments. In other words, the present invention can be implemented in various forms without departing from its technical concept or main features. For example, the present invention can be applied to any configuration other than that described with reference to Figures 1 to 6, as long as the observation optical system used to present an image to an observer (user) is configured to be supported so that it can be moved along a predetermined path. As a specific example, the number of observation optical systems is not particularly limited, and may be one, or may be three or more.

[0031] Furthermore, the movable direction of lenses 20L, 20R (in other words, lens hoods 30L, 30R) is not necessarily limited to a direction along a substantially linear path extending in the left-right direction. As a more specific example, lenses 20L, 20R may be supported so as to be movable along a curved path relative to housing 101. Even in such a case, it is sufficient that a heat dissipation portion corresponding to surface 50A' and heat dissipation portions corresponding to surfaces 50B' and 50C' described above are provided for each lens so as to be positioned in different directions along the path along which the lens moves.

[0032] Furthermore, as long as the portions exposed as the lenses 20L, 20R (in other words, the lens hoods 30L, 30R) move function as heat dissipation portions, the configuration of the heat dissipation portions is not necessarily limited to the examples described with reference to Figures 5 and 6. For example, at least a portion of the portions of graphite sheet 50 corresponding to heat dissipation portions 50A, 50B, and 50C may be exposed to the outside of housing 101 from portions of rear cover 41 corresponding to surfaces 50A', 50B', and 50C', and used as heat dissipation portions. In this case, for example, openings may be formed in the portions of rear cover 41 corresponding to surfaces 50A', 50B', and 50C', and the rear surfaces of heat dissipation portions 50A, 50B, and 50C may be exposed from the openings. In this case, the rear surface of heat dissipation portion 50A corresponds to an example of a first heat dissipation portion, and the rear surfaces of heat dissipation portions 50B and 50C correspond to an example of a second heat dissipation portion.

[0033] 5 and 6, rear cover 41 and graphite sheet 50 are provided as separate members, but the configuration is not limited thereto as long as surface 50A' and surfaces 50B' and 50C' are connected to enable heat transfer. As a specific example, rear cover 41 and a configuration (heat transfer member) equivalent to graphite sheet 50 may be integrally formed. [Explanation of symbols]

[0034] 100 Image display device 101 Case 20L, 20R lenses 30L, 30R lens hood 31B, 30T rail components 41 Rear cover 42 Front cover 50 graphite sheets 50A, 50B, 50C heat dissipation section

Claims

1. an observation optical system that guides light to the observer's eye; a housing that supports the observation optical system so as to be movable along a predetermined path; a first heat dissipation section and a second heat dissipation section provided in the housing to dissipate heat generated within the housing; a heat transfer section that connects the first heat dissipation section and the second heat dissipation section to each other so that heat can be transferred therebetween; Equipped with the first heat dissipation unit is provided at a position where it is exposed when the observation optical system is disposed so as to cover the second heat dissipation unit by moving along the path, The second heat dissipation unit is provided at a position where it is exposed when the observation optical system is moved along the path to cover the first heat dissipation unit. An image display device comprising:

2. The image display device according to claim 1 , wherein the heat transfer section is supported so as to extend along the path outside a region in which the observation optical system is movable.

3. 3. The image display device according to claim 2, wherein the heat transfer section is supported by the housing so as to be spaced apart from a position where the image display device abuts against the viewer's head when the image display device is worn on the viewer's head.

4. 4. The image display device according to claim 2, wherein the heat transfer section is supported by the housing so as to be located above the observation optical system when the image display device is worn on the head of the observer.

5. 5. The image display device according to claim 1, wherein the heat transfer portion is made of a flexible material.

6. 6. The image display device according to claim 5, wherein the heat transfer portion is formed of a graphite sheet.

7. An observation optical system that guides light to an observer's eye; a housing that supports the observation optical system so as to be movable along a predetermined path; a first heat dissipation section, a second heat dissipation section, and a third heat dissipation section provided in the housing and configured to dissipate heat generated within the housing; a heat transfer section that connects the first heat dissipation section, the second heat dissipation section, and the third heat dissipation section to each other so that heat can be transferred therebetween; Equipped with the observation optical system includes a first observation optical system that guides light to the left eye of the observer and a second observation optical system that guides light to the right eye of the observer, the first heat dissipation unit and the second heat dissipation unit are provided on the housing so as to be positioned in different directions along the path with respect to the first observation optical system, the second heat dissipation unit and the third heat dissipation unit are provided on the housing so as to be positioned in different directions along the path with respect to the second observation optical system, The second heat dissipation unit is disposed between the first observation optical system and the second observation optical system. An image display device comprising:

8. a guide member formed to extend along the path and supporting the observation optical system so that the observation optical system is movable along the path; The housing supports the observation optical system via the guide member.

10. The image display device according to claim 1 or 7, wherein:

9. a heat source housed within the housing, Each of the first heat dissipation portion and the second heat dissipation portion dissipates heat from at least the heat source.

10. The image display device according to claim 1 or 7, wherein:

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