Image display device

Abstract

To provide an image display device which can suppress conduction of noise generated in a display element while securing sufficient heat radiation for the display element including a light emitting part.SOLUTION: An image display device comprises: display elements 11a, 11b which include light emitting parts of image light; optical systems 12a, 12b which emit the image light from the display elements 11a, 11b; resin-made cover members 71a, 71b which cover the optical systems 12a, 12b; and sheet type heat radiation members SDa, SDb which are attached across the cover members 71a, 71b and the display elements 11a, 11b and conduct the heat of the display elements 11a, 11b to the cover members 71a, 71b.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to an image display device that enables viewing of a virtual image formed by a display element or the like having a light-emitting portion. [Background technology]

[0002] A virtual image display device having a structure in which a metal frame member that supports an optical system and a display element are connected with a heat dissipation sheet to dissipate heat is known (Patent Document 1). Furthermore, Patent Document 1 also describes, as one embodiment, the provision of a noise reduction sheet that reduces noise generated by the display element (see FIG. 21 of Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-54979 A Summary of the Invention [Problem to be solved by the invention]

[0004] The device of Patent Document 1 above discloses that a noise reduction sheet is placed between the display element and the heat dissipation sheet to reduce the spread of noise generated by the display element through the heat dissipation sheet. However, in this case, the noise reduction sheet suppresses the thermal conduction from the display element to the heat dissipation sheet, which may result in insufficient heat dissipation depending on the configuration of the device. [Means for solving the problem]

[0005] An image display device according to one aspect of the present invention includes a display element including a light-emitting portion that generates image light, an optical system that emits the image light from the display element, a resin cover member that covers the optical system, and a sheet-type heat dissipation member that is attached from the cover member to the display element and that conducts heat from the display element to the cover member. and a metal frame that supports the optical system, and the sheet-type heat dissipation member is spaced apart from the frame. . [Brief description of the drawings]

[0006] [Figure 1] FIG. 1 is an external perspective view illustrating a mounting state of an image display device according to a first embodiment. [Diagram 2] 1A to 1C are a plan view, a front view, a side view, and a bottom view of an image display device. [Diagram 3] 1A to 1C are a front view, a side view, a perspective view, and the like showing the inside of an image display device with an exterior member removed. [Figure 4] FIG. 2 is an exploded perspective view of the remaining portion of the image display device with the exterior member removed. [Diagram 5] FIG. 2 is a perspective view showing an image display device in a state in which a sheet-type heat dissipation member is attached. [Figure 6] 3A and 3B are a plan view and a bottom view of an optical unit combining the left and right display units. [Figure 7] 1A is a perspective view illustrating the connection between a first frame and a fixed member, a perspective view illustrating the positional relationship between the fixed member and a first cover member, and a perspective view illustrating the positional relationship between the first frame, the fixed member, and the first cover member. [Figure 8] 1 shows a bottom view of an upper exterior member and a plan view of a lower exterior member. [Figure 9] 1 is a conceptual side cross-sectional view illustrating an internal optical system of an image display device. [Figure 10] 11A and 11B are diagrams illustrating correction of distortion of a display image. [Figure 11] FIG. 11 is a conceptual side cross-sectional view illustrating an image display device according to a second embodiment. [Figure 12] FIG. 13 is a conceptual diagram for explaining a heat insulation structure in the image display device. [Figure 13] FIG. 13 is a conceptual side cross-sectional view illustrating an image display device according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] [First embodiment] Hereinafter, the structure, operation, etc. of the image display device according to the present invention will be described with reference to FIGS.

[0008] FIG. 1 is a diagram for explaining a wearing state of the image display device 200. The image display device 200 is a head mounted display (hereinafter also referred to as HMD) 201, and allows an observer or wearer US wearing the image display device to recognize an image as a virtual image. In FIG. 1 and the like, X, Y, and Z are an orthogonal coordinate system, and the +X direction corresponds to the lateral direction in which the eyes EY of the observer or wearer US wearing the image display device 200 or HMD 201 are aligned, the +Y direction corresponds to the upward direction perpendicular to the lateral direction in which the eyes EY are aligned for the wearer US, and the +Z direction corresponds to the forward direction or front direction for the wearer US. The ±Y directions are parallel to the vertical axis or vertical direction.

[0009] The image display device 200 includes a main body 200a arranged to cover the front of the eyes of the wearer US, and a pair of temple-shaped support devices 200b that support the main body 200a. From a functional perspective, the main body 200a includes a first display device 100A for the right eye and a second display device 100B for the left eye. The first display device 100A is composed of a display driver 102 arranged at the top and a combiner 103a shaped like a pair of glasses that covers the front of the eyes. The second display device 100B is similarly composed of a display driver 102 arranged at the top and a combiner 103b shaped like a pair of glasses that covers the front of the eyes.

[0010] The appearance of the main body 200a of the image display device 200 will be described with reference to FIG. 2. In FIG. 2, an area AR1 is a plan view of the main body 200a, an area AR2 is a front view of the main body 200a, an area AR3 is a side view of the main body 200a, and an area AR4 is a bottom view of the main body 200a. A pair of display drive units 102 arranged on the +Y side, i.e., the upper side, of the main body 200a are connected and integrated, and are covered by a dome-shaped upper exterior member 107a elongated in the horizontal direction and a flat plate-shaped lower exterior member 107b. The first combiner 103a and the second combiner 103b have a shape like a hemisphere with the upper part cut off protruding forward, i.e., in the +Z direction, and are arranged to protrude downward from the lower exterior member 107b.

[0011] With reference to FIG. 3, an outline of the internal structure of the main body 200a shown in FIG. 2 with the upper exterior member 107a and the lower exterior member 107b removed will be described. In FIG. 3, region BR1 is a front view exposing the upper part of the main body 200a, region BR2 is a side view exposing the upper part of the main body 200a, region BR3 is a perspective view exposing the upper part of the main body 200a, and region BR4 is a perspective view exposing the internal optical system of the main body 200a. The first display device 100A for the right eye includes a first display element 11a, a first optical system 12a, and a first combiner 103a as the first display unit 100a. The first optical system 12a is covered by a first cover member 71a made of resin, which is an inner cover, and the first display element 11a is arranged so as to cover the opening 71o of the first cover member 71a, and is fixed to the outer frame of the first optical system 12a via a rectangular frame-shaped first holder 72a. The first display element 11a is, for example, a self-luminous display device, and includes a light-emitting unit to generate first image light as image light. The first optical system 12a emits the image light (first image light) from the first display element 11a. In other words, the first display unit 100a includes the first display element 11a, and displays an image using the first image light.

[0012] 4, the first optical system 12a is fixed to the upper surface of a plate-shaped first frame 61a by adhesive or the like, and the first combiner 103a is fixed at its upper end to the front half of the periphery of the first frame 61a by adhesive or the like. That is, the first optical system 12a and the first combiner 103a are supported by the first frame 61a. The first frame 61a is a semicircular metal member and is made of, for example, a magnesium alloy.

[0013] Returning to FIG. 3, the second display device 100B includes a second display element 11b, a second optical system 12b, and a second combiner 103b as the second display unit 100b. The second optical system 12b is covered by a resin second cover member 71b that is an inner cover, and the second display element 11b is arranged so as to cover the opening 71o of the second cover member 71b, and is fixed to the outer frame of the second optical system 12b via a rectangular frame-shaped second holder 72b. The second display device 100B for the left eye has the same structure and function as the first display device 100A for the right eye. That is, the second display element 11b is similar to the first display element 11a, the second optical system 12b is similar to the first optical system 12a, and the second combiner 103b is similar to the first combiner 103a. Therefore, for example, the second display element 11b includes a light emitting unit to generate second image light as image light, and the second optical system 12b emits the second image light from the second display element 11b. The second display unit 100b includes the second display element 11b and displays an image using the second image light. However, if the first optical system 12a, the first combiner 103a, etc. are asymmetric in the left and right X direction, the second optical system 12b, the second combiner 103b, etc. will be the left and right inverted version of the first optical system 12a, the first combiner 103a, etc.

[0014] 4, the second optical system 12b is fixed to the upper surface of a plate-shaped second frame 61b by adhesive or the like, and the second combiner 103b is fixed at its upper end to the front half of the periphery of the second frame 61b by adhesive or the like. That is, the second optical system 12b and the second combiner 103b are supported by the second frame 61b. The second frame 61b is a semicircular metal member, and is made of, for example, a magnesium alloy.

[0015] Returning to FIG. 3, the first display device 100A and the second display device 100B are connected internally via a fixing member 78. The fixing member 78 is a rod-shaped metal member, and is made of, for example, a magnesium alloy. By making the fixing member 78 of a magnesium alloy, it is possible to provide an effect of cooling the first frame 61a and the second frame 61b by dissipating heat. The fixing member 78 fixes the first display unit 100a and the second display unit 100b relatively at both ends. The fixing member 78 is a member equivalent to the arms of a balance, and supports the pair of display units 100a, 100b equivalent to a pair of plates at the center. The fixing member 78 has a shape that allows the first optical system 12a and the second optical system 12b to rotate in two or more rotational directions when aligning the first display unit 100a and the second display unit 100b before fixing them.

[0016] 5, the image display device 200 according to this embodiment has a first sheet-type heat dissipation member SDa and a second sheet-type heat dissipation member SDb attached to the first display element 11a and the second display element 11b. For example, the first sheet-type heat dissipation member SDa is a heat conductive member that is attached from the first resin cover member 71a to the first display element 11a and conducts heat from the first display element 11a to the first cover member 71a. Similarly, the second sheet-type heat dissipation member SDb is a heat conductive member that conducts heat from the second display element 11b to the second resin cover member 71b.

[0017] Each of the sheet-type heat dissipation members SDa, SDb is a thermally conductive tape made of a graphite sheet having an adhesive surface, and is directly attached to the first display element 11a, etc. That is, in the above embodiment, the sheet-type heat dissipation members SDa, SDb conduct the heat generated in the display elements 11a, 11b to the cover members 71a, 71b, thereby ensuring sufficient heat dissipation.

[0018] Here, the noise generated in the first display element 11a and the second display element 11b is a problem. Specifically, there is a possibility that a situation will occur in which an electromagnetic wave is generated by a weak electric power or the like in a circuit board of an organic EL panel constituting the first display element 11a, etc., and this becomes noise and is transmitted to other members, causing an influence. In order to avoid or suppress such a situation, in the above example, a low-conductivity resin is used as the cover members 71a and 71b, which are the heat dissipation destination. That is, in the above case, a low-conductivity material is interposed during heat conduction by the sheet-type heat dissipation members SDa and SDb, thereby avoiding or suppressing the conduction of noise generated in the first display element 11a and the second display element 11b.

[0019] Furthermore, the first sheet-type heat dissipation member SDa and the second sheet-type heat dissipation member SDb are separated from the first frame 61a and the second frame 61b, which are metal frames supporting the first optical system 12a and the second optical system 12b, thereby preventing noise generated in the first display element 11a and the like from being conducted to the first frame 61a and the like via the first sheet-type heat dissipation member SDa and the like.

[0020] The first sheet-type heat dissipation member SDa and the second sheet-type heat dissipation member SDb are arranged so as not to overlap each other, i.e., so that the graphite sheets do not overlap each other, thereby preventing noise from one from being transmitted to the other.

[0021] Further, in the illustrated example, the first cover member heat dissipation member CDa and the second cover member heat dissipation member CDb are attached to the first cover member 71a and the second cover member 71b. Each cover member heat dissipation member CDa, CDb is a thermally conductive tape made of a graphite sheet having an adhesive surface, and is a thermally conductive member that conducts heat by being directly attached to the first cover member 71a, etc. In the illustrated example, the cover member heat dissipation members CDa, CDb are attached to the outer surfaces of the cover members 71a, 71b, and are provided along the first optical system 12a and the second optical system 12b housed inside the cover members 71a, 71b. By dissipating heat through thermal conduction in the cover member heat dissipation members CDa, CDb, it is possible to reduce the temperature rise inside the cover members 71a, 71b. That is, it is possible to avoid or suppress deterioration such as image distortion caused by temperature changes in the first optical system 12a and the second optical system 12b.

[0022] Here too, the graphite sheets are arranged so as not to overlap each other. That is, the first cover member heat dissipation member CDa and the second cover member heat dissipation member CDb are arranged so as not to overlap each other, and further, they are arranged so as not to overlap the first sheet-type heat dissipation member SDa and the second sheet-type heat dissipation member SDb.

[0023] Support of the first display unit 100a and the second display unit 100b by the fixing member 78 will be described with reference to Figs. 4, 6, and 7. In Fig. 6, region CR1 is a plan view of the optical unit OU in which the left and right display units 100a and 100b are connected, and region CR2 is a bottom view of the optical unit OU. In Fig. 7, region DR1 is a perspective view explaining the connection between the first display unit 100a and the fixing member 78, region DR2 is a perspective view explaining the positional relationship between the fixing member 78 and the first cover member 71a, and region DR3 is a perspective view explaining the positional relationship between the first display unit 100a, the fixing member 78, and the first cover member 71a. Fixed portions 81a and 82a, which are spherical members similar to components of a ball joint, are formed on both ends of the fixing member 78, as will be described in detail later. After the first display unit 100a and the second display unit 100b are aligned, the fixing parts 81a and 82a are adhered to the recesses 81b and 82b, which are hemispherical recessed members provided at the inner ends of the display units 100a and 100b or the frames 61a and 61b, with an adhesive or the like, and are placed in a state of being stopped from rotating. The connecting member 81, which combines the fixing part 81a and the recess 81b, is covered by the extension part 71c of the first bar member 71a. The connecting member 82, which combines the fixing part 82a and the recess 82b, is also covered by the extension part 71c of the second cover member 71b.

[0024] As described above, the first frame 61a is a semicircular metal member, and is made of, for example, a magnesium alloy. By forming the first frame 61a from a magnesium alloy, it is possible to improve the efficiency of dissipating heat generated by the display element 11a and the like. Recesses 81b are formed at both left and right ends of the first frame 61a, but only one of the recesses 81b is used for connection to the fixing member 78. An optical aperture OA is formed in the first frame 61a, and a plate-shaped optical element 28 that seals the optical aperture OA is disposed therein. The plate-shaped optical element 28 is a part of the first optical system 12a. As described above, the second frame 61b is a semicircular metal member, and is made of, for example, a magnesium alloy. By forming the second frame 61b from a magnesium alloy, it is possible to improve the efficiency of dissipating heat generated by the display element 11b and the like. Recesses 82b are formed at both left and right ends of the second frame 61b, but only one of the recesses 82b is used for connection to the fixing member 78. The second frame 61b also has an optical aperture OA formed therein, and a plate-shaped optical element 28 that seals the optical aperture OA is disposed therein.

[0025] The upper exterior member 107a and the lower exterior member 107b will be described with reference to FIG. 8. In FIG. 8, an area ER1 is a bottom view showing the inside of the upper exterior member 107a, and an area ER2 is a plan view showing the inside of the lower exterior member 107b. The upper exterior member 107a and the lower exterior member 107b are formed of a resin material. The outer edge 7a of the upper exterior member 107a and the outer edge 7b of the lower exterior member 107b have the same shape, and by butting them together, a space for storing the first optical system 12a and the second optical system 12b shown in FIG. 3 can be formed. The upper exterior member 107a and the lower exterior member 107b are fixed using fastening parts 7f, 7g such as screw holes. The lower exterior member 107b has a pair of openings OP1, and the first frame 61a and the second frame 61b can be arranged in the openings OP1 as shown by dotted lines. A gap GP is provided between the opening OP1 and the frames 61a, 61b, allowing the frames 61a, 61b to be misaligned in the XZ plane and in the Y direction within the opening OP1. That is, the first display unit 100a and the second display unit 100b shown in FIG. 3 and the like are fixed to the lower exterior member 107b while remaining aligned with each other, and even when stored in the upper exterior member 107a and the lower exterior member 107b, the positional relationship between the two display units 100a, 100b at the time of completing positioning is maintained. A screw hole 7j is formed in the lower exterior member 107b, and the display units 100a, 100b can be fixed by screws to a pair of fastening portions 78z (see FIGS. 6 and 7) provided on the bridge 78a of the fixing member 78.

[0026] 3 and 4, an elastic sheet 75 is disposed above the first frame 61a and the second frame 61b. An outer peripheral portion 75a of the elastic sheet 75 is sandwiched between an outer edge 7a of the upper exterior member 107a and an outer edge 7b of the lower exterior member 107b shown in FIG. 8, thereby enabling airtight or liquid-tight sealing between the exterior members 107a and 107b. A pair of openings OP21 and OP22 are formed in the elastic sheet 75. An inner peripheral portion 75b around one opening OP21 is sandwiched between an upper surface of the first frame 61a and a lower end of the first cover member 71a, thereby enabling airtight or liquid-tight sealing between the first frame 61a and the first cover member 71a. An inner peripheral portion 75c around the other opening OP22 is sandwiched between an upper surface of the second frame 61b and a lower end of the second cover member 71b, thereby enabling airtight or liquid-tight sealing between the second frame 61b and the second cover member 71b.

[0027] Referring to FIG. 3, a rectangular circuit board 91 is disposed above the fixing member 78 and between the left and right display units 100a and 100b. The circuit board 91 includes a control device 92 that controls the display operation of the first display element 11a and the second display element 11b. The control device 92 outputs drive signals corresponding to display images to the left and right display elements 11a and 11b to control the display operation of the left and right display elements 11a and 11b. The control device 92 includes, for example, an IF circuit, a signal processing circuit, etc., and causes the left and right display elements 11a and 11b to perform two-dimensional image display in response to image data or image signals received from the outside. The control device 92 includes a main board (not shown) that controls the operation of the first display device 100A and the operation of the second display device 100B. The main board may have, for example, an interface function for communicating with an external device (not shown) and converting signals received from the external device, and an integration function for linking the display operation of the first display device 100A with the display operation of the second display device 100B.

[0028] The circuit board 91 is supported on the fixing member 78 by the board support portion 74. The circuit board 91 is fixed on the board support portion 74. The board support portion 74 is a resin member that covers the fixing member 78 from above, the front, and the rear, and is detachable from the fixing member 78 together with the circuit board 91 by snap-fitting using the fitting portion 51.

[0029] FIG. 9 is a side cross-sectional view explaining the optical structure of the first display unit 100a. The first display unit 100a includes a first display element 11a and an imaging optical system 20. The imaging optical system 20 is also called a light guide optical device. The imaging optical system 20 includes a projection lens 21, a prism mirror 22, a plate-shaped optical element 28, and a see-through mirror 23. In the imaging optical system 20, the projection lens 21, the prism mirror 22, and the plate-shaped optical element 28 correspond to the first optical system 12a shown in FIG. 3 and the like, and the see-through mirror 23 corresponds to the first combiner 103a. The first display element 11a, the projection lens 21, and the prism mirror 22 are fixed to the first frame 61a in a state of being mutually aligned by a frame body (not shown), and are housed in a space SP1 sandwiched between the first cover member 71a and the first frame 61a. The plate-shaped optical element 28 is disposed so as to fit into a step formed in the optical aperture OA of the first frame 61a, and the periphery of the optical aperture OA is kept airtight.

[0030] As described above, the first display element 11a is a self-luminous display device having a light-emitting portion. The first display element 11a is, for example, an organic EL (organic electro-luminescence) display, and forms a color still image or moving image on a two-dimensional display surface 11d. The first display element 11a is arranged along an xy plane that is rotated and tilted around the X axis with respect to the XY plane. The first display element 11a is driven by a control device 92 provided on a circuit board 91 to perform a display operation. The first display element 11a is not limited to an organic EL display, and can be replaced with a display device using a micro LED display, inorganic EL, organic LED, laser array, quantum dot light-emitting element, or the like. The first display element 11a is not limited to a self-luminous image light generating device, and may be composed of an LCD or other light modulation element, and may form an image by illuminating the light modulation element with a light source (light-emitting portion) such as a backlight. As the first display element 11a, instead of an LCD, LCOS (Liquid crystal on silicon, LCoS is a registered trademark), a digital micromirror device, or the like can also be used.

[0031] The projection lens 21 passes the image light (first image light) ML emitted from the first display element 11a and makes it incident on the prism mirror 22. The projection lens 21 collects the image light ML emitted from the first display element 11a into a state close to a parallel light beam. The projection lens 21 includes a first lens 21p and a second lens 21q. The prism mirror 22 has an inner reflection surface 22b, and makes the image light ML emitted from the projection lens 21 enter the inside from the entrance surface 22a, totally reflects it at the inner reflection surface 22b, and emits it to the outside from the exit surface 22c. At this time, the prism mirror 22 emits the image light ML incident from the front so as to be folded back in a direction inclined with respect to a direction in which the incident direction is reversed (the direction of the light source as seen from the prism mirror 22). The plate-shaped optical element 28 refracts the image light ML from the prism mirror 22 while passing it, and the see-through mirror 23 reflects the image light ML emitted from the prism mirror 22 toward the pupil position PP. The pupil position PP is a position where the image light ML from each point on the display surface 11d is incident in a predetermined divergent or parallel state so as to be superimposed on the image light ML from an angular direction corresponding to the position of each point on the display surface 11d.

[0032] The see-through mirror 23 is a curved plate-like optical member that functions as a concave surface mirror, and reflects the image light ML incident from the prism mirror 22 through the plate-like optical element 28 toward the pupil position PP. The see-through mirror 23 covers the pupil position PP where the eye EY or pupil is located, has a concave shape toward the pupil position PP, and has a convex shape toward the outside world. The see-through mirror 23 is a mirror plate having a structure in which a mirror film 23c is formed on the front or back surface of the plate-like body 23b. The reflecting surface 23a of the see-through mirror 23 has transparency. The outside light OL that passes through the see-through mirror 23 and the support plate 41 around it is also incident on the pupil position PP. In other words, the wearer US wearing the image display device 200 can observe a virtual image by the image light ML superimposed on the outside world image.

[0033] In the above, the optical surfaces constituting the projection lens 21, the prism mirror 22, the plate-like optical element 28, and the see-through mirror 23 include free-form surfaces, and at least some of the optical surfaces can be replaced with aspherical or spherical surfaces.

[0034] The imaging optical system 20 is an off-axis optical system OS due to the see-through mirror 23 being a concave mirror, etc. In the present embodiment, the projection lens 21, the prism mirror 22, the plate-shaped optical element 28, and the see-through mirror 23 are arranged non-axisymmetrically and have a non-axisymmetric optical surface. In this imaging optical system 20, that is, the off-axis optical system OS, the optical axis AX is bent so that the optical axis AX extends along an off-axis plane (a plane parallel to the YZ plane) corresponding to the paper surface. In this imaging optical system 20, the optical axis AX is bent within the off-axis plane parallel to the YZ plane, so that the optical elements 21, 22, and 23 are arranged along the off-axis plane. The imaging optical system 20 includes optical axis portions AX1, AX2, and AX3 that are arranged along an off-axis plane (a plane parallel to the YZ plane) that is a reference plane extending in the vertical direction and are inclined to each other before and after the reflecting surface. The optical axis AX as a whole extends along the optical path of the chief ray emitted from the center of the display element 11a and passes through the eye ring ER corresponding to the eye point or the center of the pupil. When viewed in a cross section parallel to the YZ plane, the optical axis AX is arranged in a Z-shape with multiple optical axis portions AX1, AX2, and AX3. In other words, on an off-axis plane parallel to the YZ plane, the optical path P1 from the projection lens 21 to the internal reflection surface 22b, the optical path P2 from the internal reflection surface 22b to the see-through mirror 23, and the optical path P3 from the see-through mirror 23 to the pupil position PP are folded back in two stages in a Z-shape.

[0035] As shown in FIG. 10, the display image formed on the display surface 11d of the first display element 11a is a corrected image DA1 that has a distortion such as trapezoidal distortion in advance. In other words, since the imaging optical system 20 is an off-axis optical system OS, it is not easy to completely remove distortion such as trapezoidal distortion by the optical system itself. Therefore, by making the image displayed on the first display element 11a have an inverse distortion that cancels out the distortion formed by the projection lens 21, the prism mirror 22, the plate-shaped optical element 28, and the see-through mirror 23, the pixel arrangement of the projected image IG1 of the virtual image observed at the pupil position PP through the imaging optical system 20 can be a lattice pattern corresponding to the original display image DA0, and the outline can be made rectangular. In other words, the first display element 11a corrects the distortion formed by the projection lens 21, the prism mirror 22, the plate-shaped optical element 28, and the see-through mirror 23. As a result, it is possible to suppress aberration as a whole including the first display element 11a while allowing distortion generated by the see-through mirror 23 and the like. This increases the degree of freedom in the arrangement and size of optical elements such as the prism mirror 22, making it possible to easily ensure the optical performance of the first display unit 100a while achieving a compact size of the first display unit 100a.

[0036] The above describes the first display unit 100a, but the second display unit 100b has a similar structure to the first display unit 100a and similarly guides image light (second image light) to form a virtual image, so a description of its specific structure will be omitted.

[0037] As described above, the image display device 200 according to the present embodiment includes the display elements 11a and 11b including the light emitting portion of the image light ML, the optical systems 12a and 12b that emit the image light ML from the display elements 11a and 11b, the resin cover members 71a and 71b that cover the optical systems 12a and 12b, and the sheet-type heat dissipation members SDa and SDb that are attached from the cover members 71a and 71b to the display elements 11a and 11b and conduct the heat of the display elements 11a and 11b to the cover members 71a and 71b. In this case, the image display device 200 ensures sufficient heat dissipation by conducting the heat generated by the display elements 11a and 11b to the cover members 71a and 71b by the sheet-type heat dissipation members SDa and SDb. In addition, the cover members 71a and 71b that are the heat dissipation destinations are made of resin, thereby suppressing the conduction of noise generated by the display elements 11a and 11b. In other words, in the image display device 200, by interposing a material with low conductivity during heat conduction, the conduction of noise generated in the display elements 11a and 11b is suppressed.

[0038] Second Embodiment Hereinafter, an image display device according to the second embodiment will be described with reference to Fig. 11 etc. Note that the image display device according to this embodiment is a partial modification of the image display device according to the first embodiment, and other configurations are similar except for the structure related to heat dissipation, so that detailed illustrations and explanations will be omitted for components with the same reference numerals as in other drawings in the overall configuration, and matters explained with reference to other drawings as appropriate will be used as necessary.

[0039] Fig. 11 is a conceptual cross-sectional side view illustrating an image display device 200 of this embodiment, and corresponds to Fig. 9. Here, of the first display unit 100a and the second display unit 100b that are symmetrical on the left and right sides and that constitute the image display device 200, the first display unit 100a will be described as a representative.

[0040] In this embodiment, as shown in an enlarged view in the figure, a recess RE is provided in the first frame 61a, which is a metal frame supporting the first optical system 12a, near the first display element 11a. As shown in the figure, the recess RE is a recessed portion formed in the flat first frame 61a, into which a part of the first display element 11a is inserted. In other words, the recess RE forms a space that functions as an adjustment allowance when, for example, assembling and adjusting the first display element 11a.

[0041] In this embodiment, after the first display element 11a is assembled and adjusted, the grease-like heat dissipation member GDa is provided by filling the recessed portion RE of the first frame 61a with grease. The grease-like heat dissipation member GDa is formed from the first display element 11a to the first frame 61a, and conducts heat generated in the first display element 11a to the first frame 61a. In other words, the image display device 200 is provided with the grease-like heat dissipation member GDa, which is filled in the recessed portion RE of the first frame 61a and serves as a heat conducting member that conducts heat from the first display element 11a to the first frame 61a.

[0042] As a result, the first frame 61a functions as a heat sink that dissipates heat from the first display element 11a. In other words, the first frame 61a is made of a magnesium alloy and is close to the first display element 11a. In addition, in the above embodiment, the grease-like heat dissipation member GDa is filled between the first frame 61a and the first display element 11a to connect the two together, thereby further increasing the efficiency of dissipating heat generated by the display element 11a and the like.

[0043] Here, the grease-like heat dissipation member GDa is made of a low-conductivity material (insulator), and suppresses the conduction of noise generated in the first display element 11a to the first frame 61a during the above-mentioned heat conduction.

[0044] Furthermore, in the case of the above configuration, as conceptually shown in Fig. 12, the elastic sheet 75 functions as a heat insulating member provided between the first frame 61a as a heat dissipation member and the first optical system 12a. That is, in the case of the above configuration, the elastic sheet 75 is interposed between the first frame 61a and the first optical system 12a, and the heat transferred to the first frame 61a via the grease-like heat dissipation member GDa can be blocked or suppressed from being directed toward the first optical system 12a and further toward an electronic circuit (not shown) for image formation by the elastic sheet 75. Note that it is also possible to deform the shape of the elastic sheet 75 in various ways in order to further exert the above-mentioned effects.

[0045] Although the first display unit 100a has been described above, the second display unit 100b has a similar structure to the first display unit 100a, and therefore a detailed description of the structure will be omitted. In other words, the second display unit 100b can also be provided with a similar grease-like heat dissipation member GDb.

[0046] In the above embodiment, a grease-like heat dissipation member GDa or the like is adopted instead of the sheet-type heat dissipation member SDa or the like in the first embodiment described with reference to Figure 5. However, it is also possible to provide a sheet-type heat dissipation member SDa or a heat dissipation member CDa for the cover member in addition to the grease-like heat dissipation member GDa, as exemplified in Figure 13, which corresponds to Figure 11.

[0047] As described above, the image display device 200 according to the present embodiment includes the display elements 11a and 11b including the light emitting portion of the image light ML, the optical systems 12a and 12b that emit the image light ML from the display elements 11a and 11b, the metal frames 61a and 61b that support the optical systems 12a and 12b and have recesses RE into which parts of the display elements 11a and 11b are inserted, and the grease-like heat dissipation members GDa and GDb that are filled in the recesses RE of the frames 61a and 61b and conduct the heat of the display elements 11a and 11b to the frames 61a and 61b. In this case, the image display device 200 ensures sufficient heat dissipation by conducting the heat of the display elements 11a and 11b to the frames 61a and 61b through the grease-like heat dissipation members GDa and GDb. In addition, the use of a grease-like member as a heat conducting medium suppresses the conduction of noise generated in the display elements 11a and 11b. In other words, in the image display device 200, by interposing a material with low conductivity during heat conduction, the conduction of noise generated in the display elements 11a and 11b is suppressed.

[0048] [Variations and Others] The present invention has been described above with reference to each embodiment, but the present invention is not limited to the above embodiments and can be embodied in various forms without departing from the spirit of the invention. For example, the following modifications are also possible.

[0049] The imaging optical system 20 incorporated in the first display unit 100a is not limited to the one shown in the figure, and may have various configurations. Specifically, the imaging optical system 20 is an off-axis optical system OS having asymmetry in the Y direction or vertical direction, but it may also be an off-axis optical system having asymmetry in the X direction or horizontal direction. The optical elements constituting the imaging optical system 20 shown in FIG. 9 are also merely exemplary, and modifications such as increasing or decreasing the number of lenses, adding mirrors, or adding light-guiding members are possible.

[0050] A dimming device that adjusts light by limiting the light transmitted through the combiners 103a and 103b can be attached to the outside world side of the combiners 103a and 103b. The dimming device adjusts the transmittance electrically, for example. As the dimming device, a mirror liquid crystal, an electronic shade, etc. can be used. The dimming device may adjust the transmittance according to the illuminance of outside light.

[0051] The combiners 103a and 103b can be replaced with light-shielding mirrors, in which case the optical system becomes a non-see-through type that does not assume direct observation of the outside world image.

[0052] The first frame 61a, the second frame 61b, and the fixing member 78 are not limited to those made of a metal material, and may be made of fiber reinforced plastic (FRP).

[0053] The structure of the connecting members 81, 82 is not limited to a ball joint type, but can be replaced with various mechanisms that increase the degree of rotational freedom to two or more axes.

[0054] In the above description, it is assumed that the image display device 200 is used by being mounted on the head, but the image display device 200 can also be used as a handheld display that is not mounted on the head and is peered at like binoculars. In other words, in the present invention, the head mounted display also includes a handheld display.

[0055] In the above embodiment, the heat dissipation member SDa or the like may be disposed between the left and right display units 100a, 100b and configured to suppress the conduction of noise generated in the display elements 11a, 11b to the circuit board 91 that controls the display operation.

[0056] In the above, the light is guided in the vertical direction or the Y direction, but a configuration in which the light is guided in the horizontal direction or the X direction is also possible.

[0057] Although the above describes the image display device 200 as being for both eyes, it is possible to omit one of the parts for the right eye or the left eye of the image display device 200, in which case it becomes a monocular head-mounted display.

[0058] In addition, in the above embodiment, it is also possible to extend the first sheet-type heat dissipation member SDa attached to the display element 11a or the first cover member heat dissipation member CDa attached to the first cover member 71a, etc., to the upper exterior member 107a and the lower exterior member 107b made of a resin material, thereby conducting heat to the upper exterior member 107a and the lower exterior member 107b.

[0059] 5, the first sheet-type heat dissipation member SDa and the second sheet-type heat dissipation member SDb are attached to extend in both left and right directions (+X direction and -X direction) from the first display element 11a and the second display element 11b, but it is also possible to extend them in only one direction. By extending them in the left and right directions and leaving them open in the upward direction (+Y direction), the FPCs (flexible printed circuits) of the first display element 11a and the second display element 11b (not shown) can be extended in this direction while avoiding interference from the first sheet-type heat dissipation member SDa, etc.

[0060] In addition, in the above, it is stated that the heat dissipation members CDa, CDb for the cover members do not overlap the sheet-type heat dissipation members SDa, SDb. However, if it is possible to suppress the generation of noise, for example, the first sheet-type heat dissipation member SDa and the first cover member heat dissipation member CDa may be connected to each other to speed up the heat transfer time (to improve the thermal conduction performance).

[0061] In a specific embodiment, the first image display device comprises a display element including an image light emitting portion, an optical system that emits the image light from the display element, a resin cover member that covers the optical system, and a sheet-type heat dissipation member that is attached from the cover member to the display element and conducts heat from the display element to the cover member.

[0062] In the above image display device, sufficient heat dissipation is ensured by conducting heat from the display element to the cover member using a sheet-type heat dissipation member. In addition, a resin is used as the cover member to which the heat is dissipated, i.e., by using a material with low conductivity for heat conduction, the conduction of noise generated by the display element is suppressed.

[0063] In a specific aspect, the display element includes a first display element that generates a first image light as the image light and a second display element that generates a second image light as the image light, and the sheet-type heat dissipation member includes a first sheet-type heat dissipation member that conducts heat of the first display element and a second sheet-type heat dissipation member that conducts heat of the second display element. In this case, a binocular image can be formed by the first image light and the second image light.

[0064] In a specific aspect, the display device includes a first display unit including a first display element and displaying an image using a first image light, a second display unit including a second display element and displaying an image using a second image light, and a fixing member that fixes the first display unit and the second display unit relatively, the fixing member having a shape that allows the first optical system and the second optical system to rotate in two or more rotational directions when aligning the first display unit and the second display unit before fixing them. In this case, since the fixing member has a shape that allows the first optical system and the second optical system to rotate in two or more rotational directions, the first display unit and the second display unit can be positioned and aligned with a high degree of freedom relative to the fixing member before being fixed. Note that after alignment, the first display unit and the second display unit can be fixed to the fixing member using an adhesive or a fastener, thereby stably maintaining their relative positional relationship.

[0065] In a specific aspect, the display device includes a metal frame that supports the optical system, and the sheet-type heat dissipation member is spaced from the frame, thereby making it possible to prevent noise generated in the display element from being transmitted to the frame via the sheet-type heat dissipation member.

[0066] In a specific aspect, the frame has a recess into which a part of the display element is inserted, making it possible to adjust the position of the display element.

[0067] In a specific aspect, the display device includes a grease-like heat dissipation material that is filled in the recess of the frame and that conducts heat from the display element to the frame. In this case, heat conduction is possible through the grease-like heat dissipation material.

[0068] In a specific aspect, the cover member houses the optical system therein, and includes a cover member heat dissipation member provided on the outer surface of the cover member along the optical system and conducting heat of the cover member. In this case, the cover member heat dissipation member prevents or suppresses a temperature rise of the optical system housed inside the cover member, thereby suppressing image distortion and the like.

[0069] In a specific aspect, the sheet-type heat dissipation member is a graphite sheet, which enables highly efficient heat conduction.

[0070] In a specific embodiment, the second image display device comprises a display element including an image light emitting portion, an optical system that emits the image light from the display element, a metal frame that supports the optical system and has a recess into which a part of the display element is inserted, and a grease-like heat dissipation member that is filled in the recess of the frame and conducts heat from the display element to the frame.

[0071] In the above image display device, sufficient heat dissipation is ensured by conducting heat from the display element to the frame using a grease-like heat dissipation material. In addition, a grease-like material is used as a heat conducting medium, i.e., by using a material with low electrical conductivity during heat conduction, the conduction of noise generated by the display element is suppressed.

[0072] In a specific aspect, a heat insulating member is provided between the frame and the optical system. In this case, the heat insulating member can block or suppress the heat conducted to the frame from being directed toward the optical system. [Explanation of symbols]

[0073] 7a, 7b...outer edge, 7f, 7g...fastening portion, 7j...hole, 11a...first display element (display element), 11b...second display element (display element), 11d...display surface, 12a...first optical system (optical system), 12b...second optical system (optical system), 20...imaging optical system, 21...projection lens, 22...prism mirror, 22a...entrance surface, 22b...internal reflection surface, 22c...exit surface, 23...see-through mirror, 23a...reflection surface, 23b...plate-shaped body, 23c...mirror film, 28...plate-shaped optical element, 41...support plate, 51...fitting portion, 61a ...first frame (frame), 61b...second frame (frame), 71a...first cover member (cover member), 71b...second cover member (cover member), 71c...extension portion, 71o...opening, 74...substrate support portion, 75...elastic sheet (insulating member), 75a...outer periphery, 75b, 75c...inner periphery, 78...fixing member, 78a...bridge, 78z...fastening portion, 81, 82...connecting member, 81a, 82a...fixing portion, 81b, 82b...recess, 91...circuit board, 92...control device, 100a...first display unit, 100b...second display unit, 102...display drive unit, 103a, 103b...combiner, 107a...upper exterior member, 107b...lower exterior member, 200...image display device, 200a...main body, 200b...support device, AR1-AR4...area, AX...optical axis, AX1, AX2, AX3...optical axis portion, BR1-BR4...area, CDa...heat dissipation member for first cover member (heat dissipation member for cover member), CDb...heat dissipation member for second cover member (heat dissipation member for cover member), CR1, CR2...area, DA0...display image, DA1 ...corrected image, DR1-DR3...area, ER...eye ring, ER1, ER2...area, EY...eye, GDa, GDb...grease-like heat dissipation material, GP...gap, IG1...projected image, ML...image light, OA...optical aperture, OL...external light, OP1, OP21, OP22...aperture, OS...optical system, OU...optical unit, P1-P3...optical path, PP...pupil position, RE...recess, SDa...first sheet-type heat dissipation material (sheet-type heat dissipation material), SDb...second sheet-type heat dissipation material (sheet-type heat dissipation material), SP1...space, US...wearer

Claims

1. A display element including an image light emitting portion; an optical system that emits image light from the display element; a resin cover member for covering the optical system; a sheet-type heat dissipation member attached to the cover member and the display element, the sheet-type heat dissipation member conducting heat from the display element to the cover member; A metal frame for supporting the optical system; an exterior member that covers the display element, the optical system, the cover member, and the frame; The sheet-type heat dissipating member is spaced from the frame, The display device, wherein the display element is disposed so as to cover the opening of the cover member.

2. the display element includes a first display element that generates a first image light as the image light, and a second display element that generates a second image light as the image light, the sheet-type heat dissipation member includes a first sheet-type heat dissipation member that conducts heat from the first display element; The image display device according to claim 1 , further comprising a second sheet-type heat dissipation member for conducting heat from the second display element.

3. a first display unit including the first display element and configured to display an image using the first image light; a second display unit including the second display element and configured to display an image using the second image light; a fixing member that fixes the first display unit and the second display unit relatively to each other, 3. The image display device according to claim 2, wherein the fixing member has a shape that enables a first optical system for the first display unit and a second optical system for the second display unit to be rotated in a rotational direction about two or more axes when aligning the first display unit and the second display unit before fixing them.

4. The image display device according to claim 1 , wherein the frame has a recess into which a part of the display element is inserted.

5. The image display device according to claim 4 , further comprising a grease-like heat dissipation member filled in the recess of the frame and conducting heat from the display element to the frame.

6. The cover member accommodates the optical system therein, 6. The image display device according to claim 1, further comprising a cover member heat dissipation member provided along the optical system on an outer surface of the cover member to conduct heat of the cover member.

7. 7. The image display device according to claim 1, wherein the sheet-type heat dissipation member is a graphite sheet.

8. A display element including an image light emitting portion; an optical system that emits image light from the display element; a resin cover member for covering the optical system; a metal frame that supports the optical system and has a recess into which a part of the display element is inserted; a grease-like heat dissipation material filled in the recess of the frame and configured to conduct heat from the display element to the frame; a heat insulating member between the frame and the optical system; an exterior member that covers the display element, the optical system, the cover member, and the frame; The display device, wherein the display element is disposed so as to cover the opening of the cover member.

Images