Virtual image display device and optical unit

Abstract

To provide a virtual image display device and an optical unit which prevent an uncured region from remaining in an adhesive and which secure the strength against external force not only in a surface direction but also in a rotational direction of peeling from an end part.SOLUTION: A virtual image display device 100A includes: an image element 11a; a projection optical system 12a for projecting an image formed on the image element 11a; a case CA for storing the image element 11a and the projection optical system 12a in a positioned state; and an optical appearance component 123 which image light ML emitted from the projection optical system 12a enters. The optical appearance component 123 includes first and second bonding surfaces SJ1, SJ2 which extend in a direction of intersecting with each other and which are respectively bonded to the case CA. The second bonding surface SJ2 is provided at a position of separating from the first bonding surface SJ1 across the case CA.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a head-mounted virtual image display device and an optical unit that enable viewing of a virtual image. [Background technology]

[0002] A known virtual image display device is one in which an image element case that houses an image display element and a lens barrel that houses a projection lens are bonded together by a plate-like portion and a connecting portion while adjusting the relative positions of the image display element and the projection lens (Patent Document 1). With this virtual image display device, even if variations occur in the optical system due to manufacturing errors in the projection lens, etc., the variations can be corrected when positioning the projection lens and the image display element. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-211674 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the device of the background art described above, when the image element case and the lens barrel are bonded with a photocurable adhesive, uncured areas of the adhesive tend to remain deep inside. Also, in surface bonding, although the strength against external forces in the surface direction is strong, it is difficult to obtain strength against external forces in the rotation direction that peel off the edge. [Means for solving the problem]

[0005] A virtual image display device and optical unit in one aspect of the present invention comprises an image element, a projection optical system that projects an image formed on the image element, a case that stores the image element and the projection optical system in a positioned state, and an optical appearance component into which the image light emitted from the projection optical system is incident, the optical appearance component having a first adhesive surface and a second adhesive surface extending in directions that intersect each other and are each adhered to the case, and the second adhesive surface is provided at a position spaced apart across the case. [Brief description of the drawings]

[0006] [Figure 1] FIG. 2 is an external perspective view illustrating a state in which the head-mounted display device is worn. [Diagram 2] FIG. 2 is a side cross-sectional view illustrating an optical system and the like included in one of the virtual image display devices. [Diagram 3] FIG. 2 is a perspective view illustrating an optical unit and its supporting structure. [Figure 4] FIG. 2 is a side cross-sectional view of a barrel and an optical member held therein. [Diagram 5] The rear view of the remaining part excluding the barrel cover is shown. [Figure 6] FIG. 2 is a perspective view illustrating a structure of a see-through mirror. [Figure 7] 1A and 1B are a front view and a plan view of a virtual image display device or an optical unit. [Figure 8] 13 is a partially enlarged side view illustrating the fixing of the see-through mirror to the case. FIG. [Figure 9] FIG. 11 is a perspective view illustrating a see-through mirror in a second embodiment. [Figure 10] FIG. 2 is a rear perspective view illustrating the structure of the see-through mirror. [Figure 11] 13 is a partially enlarged side view illustrating the fixing of the see-through mirror to the case. FIG. [Figure 12] 11A and 11B are a front view and a plan view illustrating a virtual image display device according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] [First embodiment] Hereinafter, a first embodiment of a virtual image display device according to the present invention will be described with reference to FIGS.

[0008] Fig. 1 is a diagram for explaining the wearing state of a head mounted display device (hereinafter also referred to as a head mounted display or HMD) 200, in which the observer or wearer US wearing the HMD 200 recognizes an image as a virtual image. In Fig. 1 etc., X, Y, and Z are an orthogonal coordinate system, the +X direction corresponds to the lateral direction in which the eyes EY of the observer or wearer US wearing the HMD 200 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 HMD 200 includes a first virtual image display device 100A for the right eye, a second virtual image display device 100B for the left eye, a pair of temple-shaped support devices 100C that support the virtual image display devices 100A and 100B, and a user terminal 90 that is an information terminal. The first virtual image display device 100A functions as an HMD alone, and is composed of a first display drive unit 102a arranged at the top, and a first combiner 103a that is shaped like a pair of glasses and covers the front of the eyes. Similarly, the second virtual image display device 100B functions as an HMD alone, and is composed of a second display drive unit 102b arranged at the top, and a second combiner 103b that is shaped like a pair of glasses and covers the front of the eyes. The support device 100C is a mounting member that is mounted on the head of the wearer US, and supports the upper end sides of the pair of combiners 103a and 103b via the display drive units 102a and 102b that are integrated in appearance. The first virtual image display device 100A and the second virtual image display device 100B are optically identical or are left-right inverted versions of each other, and a detailed description of the second virtual image display device 100B will be omitted.

[0010] FIG. 2 is a side cross-sectional view for explaining the internal structure of the first virtual image display device 100A. The first virtual image display device 100A includes a first image element 11a, a first display unit 20a, and a first circuit member 80a. The first display unit 20a is an imaging optical system that forms a virtual image, and includes a projection lens 21, a prism mirror 22, and a see-through mirror 23. In the first display unit 20a, the projection lens 21 and the prism mirror 22 function as a first projection optical system 12a into which the image light ML from the first image element 11a is incident. The first display unit 20a has the first projection optical system 12a and the see-through mirror 23 in an integrated state. The projection lens 21 constituting the first projection optical system 12a corresponds to the first optical member 2a arranged on the light exit side of the first image element 11a, and the prism mirror 22 corresponds to the second optical member 2b arranged on the light exit side of the first optical member 2a, which is the projection lens 21. Moreover, the first image element 11a, the projection lens 21, and the prism mirror 22 correspond to a part of the first display drive unit 102a shown in Fig. 1, and the see-through mirror 23 corresponds to the first combiner 103a shown in Fig. 1. The projection lens 21 and the prism mirror 22 constituting the first projection optical system 12a are fixed together with the first image element 11a in a state where they are positioned relative to each other within a container-shaped barrel 41. The barrel 41 is a case CA that houses the first projection optical system 12a and the first image element 11a in a positioned state.

[0011] In the first virtual image display device 100A, the first image element 11a is a self-luminous image light generating device. The first image element 11a emits image light ML to the first projection optical system 12a. The first image element 11a is stored and supported in the barrel 41 from the rear. The first image element 11a is, for example, an organic EL (organic electroluminescence) display, and forms a color still image or moving image on a two-dimensional display surface 11d. The first image element 11a is driven by a display control device 88 including a driving circuit member 80a to perform a display operation. The first image element 11a is not limited to an organic EL display, and can be replaced with a display device using an inorganic EL, an organic LED, an LED array, a laser array, a quantum dot light-emitting element, or the like. The first image 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 such as a backlight. As the first image element 11a, instead of the LCD, LCOS (Liquid crystal on silicon, LCoS is a registered trademark), a digital micromirror device, etc. may be used. In the first virtual image display device 100A, an optical device excluding the drive circuit member 80a and the display control device 88 is called an optical unit 100.

[0012] The first display unit 20a includes two reflecting surfaces, and the optical path is bent by the see-through mirror 23 and the prism mirror 22. The first display unit 20a is an off-axis optical system OS. The projection lens 21, the prism mirror 22, and the see-through mirror 23 are arranged asymmetrically about an axis. In the first display unit 20a, the optical axis AX is bent in an off-axis plane parallel to the YZ plane, which is a reference plane, so that the optical elements 21, 22, and 23 are arranged along the off-axis plane (i.e., the reference plane). Specifically, in the off-axis plane parallel to the YZ plane and corresponding to the paper surface, the optical path portion P1 from the projection lens 21 to the reflecting surface 22b, the optical path portion P2 from the reflecting surface 22b to the see-through mirror 23, and the optical path portion P3 from the see-through mirror 23 to the pupil position PP are arranged to be folded in two stages in a Z-shape.

[0013] In the first display unit 20a, the optical path portion P1 from the projection lens 21 to the reflecting surface 22b extends in a slightly upward diagonal direction toward the rear based on the viewpoint or in a direction nearly parallel to the Z direction. The optical path portion P2 from the reflecting surface 22b to the see-through mirror 23 extends in a downward diagonal direction toward the front. When the horizontal plane direction (XZ plane) is used as a reference, the inclination of the optical path portion P2 is greater than the inclination of the optical path portion P1. The optical path portion P3 from the see-through mirror 23 to the pupil position PP extends in a slightly upward diagonal direction toward the rear or in a direction nearly parallel to the Z direction. In the illustrated example, the portion of the optical axis AX corresponding to the optical path portion P3 is approximately -10° toward the +Z direction, with downward being negative. In other words, the see-through mirror 23 reflects the image light ML so that the optical axis AX or the optical path portion P3 is directed upward by a predetermined angle, that is, approximately 10° upward. As a result, the exit optical axis EX, which is an extension of the portion of the optical axis AX corresponding to the optical path portion P3, extends at an angle of approximately 10° downward with respect to the central axis HX that is parallel to the forward +Z direction.

[0014] In the first display unit 20a, the projection lens 21 includes a first lens 21o, a second lens 21p, and a third lens 21q. The projection lens 21 receives the image light ML emitted from the first image element 11a and makes it incident on the prism mirror 22. The projection lens 21 condenses the image light ML emitted from the first image element 11a into a state close to a parallel light beam. The optical surfaces of the first lens 21o, the second lens 21p, and the third lens 21q constituting the projection lens 21, that is, the entrance surface and the exit surface thereof, are free curved surfaces or aspheric surfaces. The entrance surface and the exit surface of the first lens 21o, the second lens 21p, and the third lens 21q are asymmetrical with respect to the optical axis AX in the vertical direction parallel to the YZ plane and intersecting the optical axis AX, and are symmetrical with respect to the optical axis AX in the horizontal direction or the X direction. The first lens 21o, the second lens 21p, and the third lens 21q are formed of, for example, resin, but may also be made of glass. An anti-reflection film may be formed on the optical surfaces of the first lens 21o, the second lens 21p, and the third lens 21q that constitute the projection lens 21.

[0015] The prism mirror 22 is an optical member having a refracting and reflecting function that has a function combining a mirror and a lens, and reflects the image light ML from the projection lens 21 while refracting it. The prism mirror 22 has an entrance surface 22a arranged on the light exit side of the first optical member 2a, a reflecting surface 22b that bends the optical axis AX, and an exit surface 22c that faces the reflecting surface 22b and is arranged in a direction symmetrical to the entrance surface 22a. The prism mirror 22 emits the image light ML that is incident from the front where the projection lens 21 is arranged, so as to bend it in a direction inclined downward 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 entrance surface 22a, the reflecting surface 22b, and the exit surface 22c that are optical surfaces that constitute the prism mirror 22 are asymmetrical with respect to the optical axis AX in the vertical direction that is parallel to the YZ plane and intersects with the optical axis AX, and are symmetrical with respect to the optical axis AX in the horizontal direction or X direction. The optical surfaces of the prism mirror 22, that is, the entrance surface 22a, the reflection surface 22b, and the exit surface 22c, are, for example, free curved surfaces. The entrance surface 22a, the reflection surface 22b, and the exit surface 22c are not limited to free curved surfaces, but may be aspheric surfaces. The prism mirror 22 is formed of, for example, resin, but may also be made of glass. The reflection surface 22b is not limited to one that reflects the image light ML by total reflection, but may also be a reflection surface made of a metal film or a dielectric multilayer film. In this case, a reflection film made of a single layer or multilayer film made of a metal such as Al or Ag is formed on the reflection surface 22b by deposition or the like, or a sheet-like reflection film made of a metal is attached. Although detailed illustration is omitted, an anti-reflection film may be formed on the entrance surface 22a and the exit surface 22c.

[0016] Exit surface 22c of prism mirror 22 is generally concave, and is concave on an off-axis plane parallel to the YZ plane and through which optical axis AX passes, i.e., on the paper, and is also concave in cross section CS perpendicular to the YZ plane and passing through the center of exit surface 22c. Since exit surface 22c of prism mirror 22 is exposed at exit port 41o of barrel 41, making it concave makes it easier to avoid contact with external objects and reduces the occurrence of damage.

[0017] The see-through mirror 23, i.e., the first combiner 103a, is a mirror that has optical transparency in the visible wavelength range. The see-through mirror 23 is a curved plate-like optical appearance part 123 that functions as a concave surface mirror, and partially reflects the image light ML from the prism mirror 22 and partially transmits the outside light OL. The image light ML emitted from the projection optical system 12a is incident on the see-through mirror 23, and the see-through mirror 23 reflects the image light ML from the projection optical system 12a toward the pupil position PP. The see-through mirror 23 has a partially reflecting surface 23c and an outer surface 23o. The see-through mirror 23 covers the pupil position PP where the eye EY or pupil is located and has a concave shape toward the pupil position PP, and as a result, has a convex shape toward the outside world. The pupil position PP or its opening PPa is called the eye point or eye box, and corresponds to the exit pupil EP of the first display unit 20a including the see-through mirror 23. The see-through mirror 23 is a concave mirror having a positive power, and makes it possible to enlarge and view the intermediate image IM formed on the first image element 11a and re-focused by the first projection optical system 12a.

[0018] The see-through mirror 23 has a structure in which a transmissive reflective film 23a is formed as a concave partially reflective surface 23c on the back surface of a substrate 23b, which is a plate-like body having optical transparency. The partially reflective surface 23c or the transmissive reflective film 23a is asymmetric about the optical axis AX in the vertical direction that is parallel to the YZ plane and intersects with the optical axis AX, and is symmetric about the optical axis AX in the horizontal direction or X direction. The partially reflective surface 23c of the see-through mirror 23 is, for example, a free-form surface. The partially reflective surface 23c is not limited to a free-form surface, and can also be an aspheric surface.

[0019] The partially reflecting surface 23c of the see-through mirror 23 transmits a part of the light when reflecting the image light ML. As a result, the outside light OL passes through the see-through mirror 23, making it possible to see through the outside world, and a virtual image can be superimposed on the outside world image. In this case, if the base material 23b is thin, about a few mm or less, the change in magnification of the outside world image can be kept small. The reflectance of the partially reflecting surface 23c to the image light ML and the outside light OL is set to 10% or more and 50% or less in the assumed range of incidence angles of the image light ML, from the viewpoint of ensuring the brightness of the image light ML and facilitating the observation of the outside world image by see-through. The base material 23b of the see-through mirror 23 is formed of, for example, a resin, but can also be made of glass. The base material 23b is formed of the same material as the support plate 61 that supports it from the periphery, and has the same thickness as the support plate 61. The transmissive reflecting film 23a is formed of, for example, a dielectric multilayer film consisting of a plurality of dielectric layers with adjusted film thicknesses. The transmissive reflective film 23a may be a single-layer film or a multi-layer film of a metal such as Al or Ag with an adjusted thickness. The transmissive reflective film 23a can be formed by laminating layers using deposition, for example, but may also be formed by attaching a sheet-like reflective film. An anti-reflection film AR is formed on the outer surface 23o of the base material 23b.

[0020] The anti-reflection film AR does not need to be formed directly on the substrate 23b, and for example, the substrate 23b may be covered with a hard coat film, and the anti-reflection film AR or an antifouling coat may be formed thereon. The transmissive reflective film 23a does not need to be formed directly on the substrate 23b, and for example, the substrate 23b may be covered with a hard coat film, and the transmissive reflective film 23a may be formed thereon. The transmissive reflective film 23a may be covered with a protective film or an antifouling coat.

[0021] Regarding the optical path, the image light ML from the first image element 11a enters the projection lens 21 and is emitted from the projection lens 21 in a substantially collimated state. The image light ML that passes through the projection lens 21 enters the prism mirror 22 and passes through the entrance surface 22a while being refracted, is reflected by the reflection surface 22b with a high reflectance close to 100%, and is refracted again by the exit surface 22c. The image light ML from the prism mirror 22 forms an intermediate image IM once, then enters the see-through mirror 23 and is reflected by the partial reflection surface 23c with a reflectance of about 50% or less. The image light ML reflected by the see-through mirror 23 enters the pupil position PP where the eye EY or pupil of the wearer US is located. External light OL that passes through the see-through mirror 23 and the support plate 61 around it also enters the pupil position PP. That is, the wearer US wearing the first virtual image display device 100A can observe a virtual image generated by the image light ML superimposed on an outside world image.

[0022] FIG. 3 is a perspective view for explaining the optical unit 100 and its support structure in the virtual image display devices 100A and 100B. In the first virtual image display device 100A, the first display unit 20a is housed in the barrel 41, i.e., the case CA, and is fixed to the -X side portion 52a of the elongated frame 52 shown by the dotted line, for example, by adhesive, and is supported so as to be suspended from the frame 52 and is disposed below the frame 52. In the second virtual image display device 100B, the second display unit 20b is housed in the barrel 41, i.e., the case CA, and is fixed to the +X side portion 52b of the elongated frame 52 shown by the dotted line, for example, by adhesive, and is supported so as to be suspended from the frame 52 and is disposed below the frame 52. The frame 52 is formed of a metal material such as a magnesium alloy from the viewpoint of ensuring rigidity and light weight. The frame 52 has a recess RE on the upper side for arranging the drive circuit member 80a, and is covered from above and below by the exterior member 71 together with the barrel 41 (see FIG. 2).

[0023] The first display unit 20a has the first projection optical system 12a and the first combiner 103a in an integrated state, and the second display unit 20b has the second projection optical system 12b and the second combiner 103b in an integrated state. The upper end 61g of the first combiner 103a is fixed by adhesion or the like in a positioned state to the barrel 41 or case CA that houses the first projection optical system 12a. The barrel 41 that supports the first combiner 103a has a space that houses the first image element 11a in addition to the first projection optical system 12a, and supports the first image element 11a in a positioned state relative to the projection lens 21 and the like shown in FIG. 2 and the like. The upper end 61g of the second combiner 103b is fixed by adhesion or the like in a positioned state to the barrel 41 or case CA that houses the second projection optical system 12b. The barrel 41 supporting the second combiner 103b has space for accommodating the second image element 11b in addition to the second projection optical system 12b, and supports the second image element 11b in a state in which it is positioned relative to something similar to the projection lens 21 shown in Figure 2, etc.

[0024] The structure of the barrel 41, i.e., the case CA, will be described with reference to Figs. 4 and 5. The barrel 41, i.e., the case CA, includes a barrel body 41a and a barrel cover 41u, and houses the first optical member 2a and holds the second optical member 2b. The barrel body 41a and the barrel cover 41u are formed of a resin material, for example, polycarbonate resin to which a black pigment has been added to give it light blocking properties. The barrel body 41a is a bathtub-shaped container with an open top, and has an injection port 41o at a part of the bottom. The barrel cover 41u is fixed so as to cover the barrel body 41a from above. The barrel body 41a has two side plate members 41c, a bottom plate member 41d, a front plate member 41e, and two protrusions 41f and 41g. Of these, the two side plate members 41c are called side walls SW. The two side plate members 41c extend substantially parallel to a reference plane HS along which the optical axis AX extends, and are spaced apart from each other. The bottom plate member 41d extends substantially along the XZ plane perpendicular to the reference plane HS along which the optical axis AX extends, and has an outlet 41o at its rear end. A guard member 41q is provided behind and to the side of the outlet 41o in the bottom plate member 41d, and covers the lower portion of the side surface 22s (see FIG. 5) of the second optical member 2b. The front plate member 41e connects the front end of the bottom plate member 41d to the front ends of the two side plate members 41c. The two protrusions 41f, 41g extend laterally so as to protrude outward from the upper portions of the two side plate members 41c. In other words, the barrel 41, i.e., the case CA, has a pair of protrusions 41f, 41g extending from the two side plate members 41c that constitute the side wall SW or the side surface.

[0025] On the inner side of one side plate member 41c (see FIG. 4), stepped guide protrusions 45a, 45b, 45c, and 45d are formed as protrusions that support the first lens 21o, the second lens 21p, and the third lens 21q constituting the first optical member 2a and the prism mirror 22 of the second optical member 2b. Although not shown, guide protrusions similar to the guide protrusions 45a, 45b, 45c, and 45d are also formed on the inner side of the other side plate member 41c (see FIG. 5). The first lens 21o is bonded in a biased and positioned state by the two first guide protrusions 45a provided on the inner sides of the two side plate members 41c and facing each other, and is supported by the barrel body 41a. Similarly, the second lens 21p is adhered in a positioned state by the second guide protrusion 45b and supported by the barrel body 41a, and the third lens 21q is adhered in a positioned state by the third guide protrusion 45c and supported by the barrel body 41a. The prism mirror 22 is adhered in a positioned state via a protrusion 22t provided on a side surface 22s of the prism mirror 22 by the fourth guide protrusion 45d and supported by the barrel body 41a.

[0026] The barrel cover 41u is disposed on the opposite side of the bottom plate member 41d and covers the inside of the barrel body 41a to form a storage space IS. The barrel cover 41u includes a top plate 41x and a rear plate 41y. The top plate 41x extends parallel to the XZ plane, and the rear plate 41y is disposed at an angle so as to cover the outside of the reflecting surface 22b of the prism mirror 22 of the second optical member 2b. In the barrel cover 41u, a holder base 41s for positioning, which is lowered by a predetermined height from the surroundings, is formed on the front +Z side, and an insertion opening 41z is formed in front of the holder base 41s. The holder base 41s provided on the barrel cover 41u faces the base plate 31b of the holder 31 for the first image element 11a. The base plate 31b extends horizontally along the holder base 41s, and is fixed to the barrel 41 by adhesive while covering a part or all of the insertion opening 41z. An inner surface 41m of the rear plate 41y is inclined with respect to the XZ plane and the XY plane, and extends along the reflecting surface 22b of the prism mirror 22 to the vicinity of the reflecting surface 22b.

[0027] The diaphragm plate member 26 is disposed between the first optical member 2a and the second optical member 2b inside the barrel 41. The diaphragm plate member 26 has a central portion 26a and two side portions 26b (see FIG. 5). In other words, the diaphragm plate member 26 has a shape with an open upper end.

[0028] In the barrel 41, the first image element 11a supported by a support frame 31a extending vertically downward from the base plate 31b of the holder 31 is inserted from above through the insertion opening 41z in the space ISa facing the front plate member 41e, and is fixed in a positioned state.

[0029] With reference to FIG. 6, a structure for fixing the first combiner 103a, ie, the see-through mirror 23, to the case CA (see FIG. 4) will be described.

[0030] A pair of mounting parts 62a, 62b are formed on the upper end 61g of the see-through mirror 23 so as to protrude toward the inside of the see-through mirror 23, i.e., the -Z side. The mounting parts 62a, 62b are spaced apart in the horizontal X direction. One mounting part 62a includes a plate-shaped member 62e parallel to the XZ plane extending horizontally, and a convex part 62f protruding upward from the plate-shaped member 62e and extending in the horizontal X direction. The other mounting part 62b includes a plate-shaped member 62e parallel to the XZ plane extending horizontally, and a convex part 62f protruding upward from the plate-shaped member 62e and extending in the horizontal X direction. In other words, the pair of mounting parts 62a, 62b includes a pair of plate-shaped members 62e and a pair of convex parts 62f. Each plate-like member 62e is provided with a first adhesive surface SJ1 extending parallel to the vertical XZ plane as a partial region of the upper surface 62g, and a second adhesive surface SJ2 extending parallel to the vertical XY plane is provided on the front surface 62h of each protrusion 62f. The first adhesive surface SJ1 and the second adhesive surface SJ2 are used to fix the see-through mirror 23 to a pair of protrusions 41f, 41g formed on the case CA. The first adhesive surface SJ1 and the second adhesive surface SJ2 extend in directions intersecting each other. More specifically, the first adhesive surface SJ1 and the second adhesive surface SJ2 are arranged adjacent to each other, perpendicular to each other, without any space between them.

[0031] 7 and the like, the fixing of the first combiner 103a, i.e., the see-through mirror 23, to the case CA will be described. In FIG. 7, an area AR1 is a front view of the case CA and the see-through mirror 23, and an area AR2 is a plan view of the case CA and the see-through mirror 23.

[0032] A pair of opposing inner surfaces 62s of a pair of mounting parts 62a, 62b provided on the see-through mirror 23 are fitted to a pair of lateral side surfaces 51s that are provided at the boundary between the front plate member 41e and the side plate member 41c of the case CA shown in FIG. 4 and narrow in a stepped shape, so as to sandwich them. As a result, the pair of inner surfaces 62s are fitted to the pair of lateral side surfaces 51s with a predetermined play, and the positioning of the see-through mirror 23 in the ±X direction is performed so as to reduce tilt. A pair of stepped back surfaces 62t of the pair of mounting parts 62a, 62b abut against a pair of front surfaces 51r that are provided at the boundary between the front plate member 41e and the side plate member 41c of the case CA and narrow in a stepped shape. As a result, the positioning of the see-through mirror 23 in the ±Z direction is performed so as to reduce tilt. Furthermore, the multiple convex ridges 59p protruding from the bottom surfaces 59j of the pair of protrusions 41f, 41g come into contact with the pair of top surfaces 62g of the pair of mounting parts 62a, 62b, and positioning in the ±Y directions is performed. After the above positioning, that is, after the six-axis positioning, adhesive AD is supplied from the periphery between the protrusions 41f, 41g and the mounting parts 62a, 62b, and the supplied adhesive AD is cured by ultraviolet light or the like, thereby completing the fixation of the see-through mirror 23 or the first combiner 103a to the case CA. In other words, the see-through mirror 23 is integrated with the case CA, and the see-through mirror 23 is integrated with the first projection optical system 12a.

[0033] 8, a gap GA1 between a first adhesive surface SJ1, which is a top surface 62g provided on the mounting portion 62b of the see-through mirror 23, and a bottom surface 59j provided on the protrusion 41g of the case CA, is filled with an adhesive AD and hardened, thereby bonding the mounting portion 62b and the protrusion 41g. That is, the first adhesive surface SJ1 is bonded to the bottom surface 59j of the protrusion 41g. Also, a gap GA2 between a second adhesive surface SJ2, which is a front surface 62h provided on the mounting portion 62b, and a back surface 59k provided on the protrusion 41g of the case CA, is filled with an adhesive AD and hardened, thereby bonding the mounting portion 62b and the protrusion 41g by the hardened adhesive AD. That is, the second adhesive surface SJ2 is bonded to the back surface 59k of the protrusion 41g. At this time, the second adhesive surface SJ2 is separated from the case CA to avoid interference when positioning the see-through mirror 23. As shown in the figure, the adhesive AD is filled not only in the gap GA1 between the first adhesive surface SJ1 extending in the XZ direction and the bottom surface 59j, but also in the gap GA2 between the second adhesive surface SJ2 extending in the XY direction and the back surface 59k. This makes it less likely to break even if various external forces are applied to the see-through mirror 23 relative to the case CA, compared to the case where the case is bonded only to the first adhesive surface SJ1. In other words, even if an external force in a direction along the first adhesive surface SJ1 or an external force in a direction along the second adhesive surface SJ2 (specifically, a rotational force around the X axis) acts on the joint between the case CA and the see-through mirror 23, the structure makes it difficult for the case CA and the see-through mirror 23 to peel off due to these external forces, making it easier to ensure the strength of these joints and less likely to cause damage to these joints.

[0034] The gap GA2 between the second adhesive surface SJ2 provided on the mounting portion 62b of the see-through mirror 23 and the back surface 59k provided on the protrusion 41g of the case CA can be utilized as a play when positioning the see-through mirror 23, which is the optical appearance part 123, with respect to the case CA. This ensures the positioning accuracy of the see-through mirror 23 with respect to the case CA, and allows the adhesive AD filled in the gap GA2 to fix the see-through mirror 23 to the case CA with sufficient strength.

[0035] The first adhesive surface SJ1 and the second adhesive surface SJ2 provided on one mounting portion 62b of the see-through mirror 23 have been described above, but the first adhesive surface SJ1 and the second adhesive surface SJ2 provided on the other mounting portion 62a are also joined to the protrusion 41f of the case CA in the same manner as shown in Fig. 8. As a result, the front plate member 41e and the like, which are part of the case CA, are sandwiched between the first adhesive surface SJ1 and the second adhesive surface SJ2.

[0036] The first adhesive surface SJ1 provided on the mounting portion 62a and the first adhesive surface SJ1 provided on the mounting portion 62b are provided at positions spaced apart with the front plate member 41e of the case CA in between. The second adhesive surface SJ2 provided on the mounting portion 62a and the second adhesive surface SJ2 provided on the mounting portion 62b are provided at positions spaced apart with the front plate member 41e, which is a part of the case CA, in between. By providing the pair of second adhesive surfaces SJ2 at positions spaced apart with the case CA in between, the strength of the joint corresponding to the second adhesive surface SJ2 can be increased around the Z axis and around the Y axis, and the mounting accuracy and mounting strength of the see-through mirror 23 to the case CA can be increased.

[0037] In addition, the base material 23b of the see-through mirror 23 is formed from a light-transmitting material, and it is relatively easy to harden the adhesive AD that is filled in the gaps GA1 and GA2 and has photocuring properties (specifically, UV curing properties).

[0038] The first combiner 103a is fixed to the case CA, for example, before the holder 31 for the image elements 11a and 11b is fixed to the case CA. Conversely, if the holder 31 is fixed prior to the first combiner 103a, the holder 31 is positioned relative to the first projection optical system 12a.

[0039] The virtual image display devices 100A, 100B of the first embodiment described above include image elements 11a, 11b, projection optical systems 12a, 12b that project images formed on the image elements 11a, 11b, a case CA that stores the image elements 11a, 11b and the projection optical systems 12a, 12b in a positioned state, and an optical appearance component 123 into which the image light ML emitted from the projection optical systems 12a, 12b is incident, and the optical appearance component 123 has a first adhesive surface SJ1 and a second adhesive surface SJ2 that extend in directions that intersect with each other and are respectively adhered to the case CA, and the second adhesive surface SJ2 is provided at a position spaced apart across the case CA.

[0040] In the virtual image display devices 100A and 100B, the optical appearance part 123 has the first adhesive surface SJ1 and the second adhesive surface SJ2 that extend in mutually intersecting directions and are respectively attached to the case CA, so that sufficient adhesive strength can be ensured not only against an external force along the first adhesive surface SJ1 but also against an external force in the rotational direction applied to the end of the first adhesive surface SJ1. In addition, since the second adhesive surface SJ2 is provided at a position spaced apart from the case CA, the assembly accuracy and assembly strength of the optical appearance part 123 can be improved.

[0041] Second Embodiment The virtual image display device of the second embodiment will be described below. Note that the virtual image display device of the second embodiment is a partial modification of the virtual image display device of the first embodiment, and the description of the parts common to the virtual image display device of the first embodiment will be omitted.

[0042] 9 and 10, a rectangular protrusion 62j is formed on the upper end 61g of the see-through mirror 23, which is the optical appearance component 123, so as to protrude upward, i.e., to the +Y side of the see-through mirror 23. The protrusion 62j is a plate-like member parallel to the XY plane extending in the vertical direction, and a third adhesive surface SJ3 extending parallel to the vertical XY plane is provided on the back surface 62p of the protrusion 62j. The third adhesive surface SJ3 is added to the first adhesive surface SJ1 and the second adhesive surface SJ2, and is used for reinforcement to fix the see-through mirror 23 to a pair of protrusions 41f, 41g (see FIG. 3) formed on the case CA.

[0043] The see-through mirror 23 is formed by injection molding, and the protrusion 62j is a gate mark where molten resin was injected. The protrusion 62j is formed in the center of the upper end 61g of the see-through mirror 23. In other words, the third adhesive surface SJ3 provided on the protrusion 62j is arranged facing the middle position of the two second adhesive surfaces SJ2. By placing the molding gate that becomes the protrusion 62j in the center, the flow of the resin becomes symmetrical, the formation of flow marks on the base material 23b can be suppressed, and shrinkage during molding can be made uniform. The width of the protrusion 62j is about 1 cm, and the thickness of the protrusion 62j from the front to the rear is 1 mm or more, and preferably about 1.5 mm or more. From the viewpoint of molding, the thickness of the base material 23b and the support plate 61, which are the main body of the see-through mirror 23, is also 1 mm or more, and preferably about 1.5 mm or more. By making the thickness of the base material 23b or the support plate 61 1 mm or more, the base material 23b or the support plate 61 can be molded with high precision, and by making the thickness of the protrusion 62j 1 mm or more, it becomes easy to maintain the strength of the protrusion 62j and to suppress flow marks. The thickness of the mounting parts 62a, 62b or the plate-like member 62e is also 1 mm or more, and is preferably about 1.5 mm or more. The thickness of the mounting parts 62a, 62b or the plate-like member 62e is the same as the thickness of the base material 23b or the support plate 61, or is relatively thicker than the thickness of the base material 23b or the support plate 61. The thickness of the protrusion 62j in the Z direction is the same as the thickness of the base material 23b or the support plate 61, or is relatively thinner than the thickness of the base material 23b or the support plate 61.

[0044] As shown in FIG. 11, adhesive AD is filled into the gap GA3 between the third adhesive surface SJ3, which is the back surface 62p provided on the protrusion 62j, and the front surface 59q provided on the front plate member 41e of the case CA, and the gap GA3 is hardened, and the protrusion 62j and the front plate member 41e are joined by the hardened adhesive AD.

[0045] In the virtual image display devices 100A and 100B of the second embodiment described above, the optical appearance part 123 has a third adhesive surface SJ3 facing in the opposite direction to the second adhesive surface SJ2, and a part of the case CA is sandwiched between the second adhesive surface SJ2 and the third adhesive surface SJ3. In this case, the front plate member 41e and the protrusions 41f and 41g, which are part of the case CA, are sandwiched between the second adhesive surface SJ2 and the third adhesive surface SJ3, and three-point fixing is achieved by the second adhesive surface SJ2 and the third adhesive surface SJ3 extending parallel to the vertical direction Y, so that the fixation of the optical appearance part 123 to the case CA can be more stabilized and the attachment accuracy can be improved. In particular, from the viewpoint of sandwiching the front plate member 41e and the protrusions 41f and 41g, which are part of the case CA, between the second adhesive surface SJ2 and the third adhesive surface SJ3, the strength against external forces such as rotational forces around the X axis can be improved.

[0046] Third Embodiment Hereinafter, the virtual image display device of the third embodiment will be described. Note that the virtual image display device of the third embodiment is a partial modification of the virtual image display device of the first embodiment, and the description of the parts common to the virtual image display device of the first embodiment will be omitted.

[0047] Virtual image display devices 100A and 100B according to the third embodiment will be described with reference to Fig. 12. In Fig. 12, an area BR1 is a front view of the case CA and the see-through mirror 23, and an area BR2 is a plan view of the case CA and the see-through mirror 23.

[0048] A pair of plate-like members 62n extending parallel to the vertical YZ plane are provided on a pair of mounting portions 62a, 62b formed on an upper end 61g of the see-through mirror 23. Fourth adhesive surfaces SJ4 extending parallel to the vertical YZ plane are provided on inner surfaces 62r of both plate-like members 62n. The fourth adhesive surface SJ4 is added to the first adhesive surface SJ1 and the second adhesive surface SJ2, and is used for reinforcement in fixing the see-through mirror 23 to a pair of protrusions 41f, 41g formed on the case CA.

[0049] An adhesive AD is filled and hardened in a gap GA4 between a fourth bonding surface SJ4, which is an inner surface 62r provided on the pair of plate-like members 62n, and an outer surface 59s of a pair of protrusions 41f, 41g of the case CA, and the protrusion 62j and the pair of protrusions 41f, 41g are joined by the hardened adhesive AD. The pair of plate-like members 62n can provide strength against external forces not only in the lateral X direction, but also in the Y and Z directions, and can increase the fixing strength of the see-through mirror 23 against an external force that rotates it around the horizontal Z axis.

[0050] [Variations and Others] The present invention has been described above based on the embodiments, 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 present invention. For example, the following modifications are also possible.

[0051] In the above, it has been described that the HMD 200 comprises a first virtual image display device 100A and a second virtual image display device 100B, but the HMD 200 or the optical unit 100 may also be configured to support a single first virtual image display device 100A or second virtual image display device 100B in front of the eyes by a support device 100C.

[0052] The first adhesive surface SJ1 and the second adhesive surface SJ2 are not limited to flat surfaces and may be curved surfaces, but if they are curved surfaces, it is preferable that the back surface 59k or the bottom surface 59j facing them are also curved surfaces having a corresponding curvature. Similarly, the third adhesive surface SJ3 and the fourth adhesive surface SJ4 may also be curved surfaces.

[0053] In the above embodiment, the adhesive surface SJ1 is made up of two regions and is arranged at positions spaced apart with the case CA in between, but the adhesive surface SJ1 may also be made up of a single region.

[0054] The adhesive surfaces SJ1, SJ2, SJ3, and SJ4 are used as an auxiliary means for temporarily positioning the see-through mirror 23 relative to the case CA, but they may not be used for such temporary positioning, or they may be used for precise positioning.

[0055] In the third embodiment shown in FIG. 12, the see-through mirror 23 may have the protrusion 62j shown in FIG. 9 and a third adhesive surface SJ3 provided thereon.

[0056] The optical members 2a, 2b of the first projection optical system 12a are not limited to those shown in the figure, and for example, the number of optical elements constituting the first optical member 2a and the shape of the optical surface can be changed as appropriate depending on the purpose of use of the HMD 200, etc.

[0057] The optical appearance part 123 is not limited to the see-through mirror 23, and may be something like a light guide plate. Here, the light guide plate guides the image light emitted from the image element to a position facing the pupil while reflecting it on the inner surface, and the image light is incident on the inside from an incident surface provided at the end, or the image light is incident on the inside via a diffraction element provided in a part of the parallel plate constituting the light guide plate. The light guide plate as the optical appearance part 123 is, for example, a half mirror disposed at an incline inside. The light guide plate as the optical appearance part 123 may be one in which a diffraction element is provided on the surface of the light extraction region or the light capture region, or one in which a number of inclined mirrors are built in the light guide plate in the light extraction region or the light capture region.

[0058] When the virtual image display devices 100A and 100B are configured with a birdbath type optical system, a plane half mirror for light branching arranged at an angle and a concave half mirror covering the outside world side of the plane half mirror are arranged in front of the eyes. In this case, the plane half mirror and the concave half mirror are the optical appearance parts 123. Therefore, in order to fix the plane half mirror and the concave half mirror, which are the optical appearance parts 123, to the case CA that houses the projection optical system, if the plane half mirror and the concave half mirror have a first adhesive surface SJ1 and a second adhesive surface SJ2 that extend in intersecting directions and are respectively adhered to the case CA, and if the second adhesive surface SJ2 is provided at a position separated from the case CA, the adhesive surfaces can respond to stress from various directions, and the assembly accuracy and assembly strength of the plane half mirror and the concave half mirror can be improved.

[0059] The optical appearance part 123 is not limited to the optical element arranged on the outermost side of the HMD 200. In other words, even if a light-reducing shade or a protective cover is provided in front of the see-through mirror 23 or the light guide plate, which are the optical appearance part 123, the see-through mirror 23 and the like are optical appearance parts 123 from the viewpoint of being optical parts exposed in front of the eye.

[0060] In the above description, the see-through mirror 23 is integrated with the first projection optical system 12a via the case CA, but the point at which the see-through mirror 23 is fixed to the case CA is not limited to the protrusions 41f, 41g, and can be the main body of the case CA. Furthermore, a receiving portion can be provided on any one of the optical elements that make up the first projection optical system 12a, and the see-through mirror 23 can be directly fixed to this receiving portion.

[0061] In the above description, it is assumed that the HMD 200 is used by being mounted on the head, but the virtual image display devices 100A and 100B can also be used as handheld displays that are not mounted on the head and are peered into like binoculars. In other words, in the present invention, the head mounted display also includes a handheld display.

[0062] A virtual image display device in a specific embodiment includes an image element, a projection optical system that projects an image formed on the image element, a case that stores the image element and the projection optical system in a positioned state, and an optical appearance part into which the image light emitted from the projection optical system is incident, and the optical appearance part has a first adhesive surface and a second adhesive surface that extend in directions intersecting each other and are respectively attached to the case, and the second adhesive surface is provided at a position separated by the case. Here, the optical appearance part is fixed to the case by using the first adhesive surface and the second adhesive surface, and is integrated with the case. As a result, the optical appearance part is also integrated with the projection optical system held in the case.

[0063] In the head mounted display device, the optical appearance part has a first adhesive surface and a second adhesive surface that extend in mutually intersecting directions and are respectively attached to the case, so that sufficient adhesive strength can be ensured not only against an external force along the first adhesive surface but also against an external force in a rotational direction applied to the end of the first adhesive surface. In addition, since the second adhesive surface is provided at a position separated from the case, the assembly accuracy and assembly strength of the optical appearance part can be improved.

[0064] In a specific embodiment of the virtual image display device, the second adhesive surface is spaced apart from the case to avoid interference when positioning the optical appearance part.

[0065] In a specific embodiment of the virtual image display device, the first adhesive surface and the second adhesive surface are arranged in a state where they are orthogonal to each other and adjacent to each other. In this case, the first adhesive surface and the second adhesive surface are arranged in an L-shape. This allows the first adhesive surface and the second adhesive surface to be formed together in one place, making it possible to assemble the optical appearance component in a space-saving manner.

[0066] In a specific embodiment of the virtual image display device, the case has a pair of protrusions extending from both sides, the first adhesive surface is adhered to the bottom surfaces of the pair of protrusions, and the second adhesive surface is adhered to the back surfaces of the pair of protrusions. In this case, the optical appearance component can be stably assembled to the pair of protrusions provided on the case.

[0067] In a specific embodiment of the virtual image display device, the optical appearance part is a mirror having optical transparency.

[0068] In a specific embodiment of the virtual image display device, the optical appearance part is a plate-shaped see-through mirror having a concave partially reflective surface, and the first and second adhesive surfaces are formed on an attachment part formed on the upper end of the see-through mirror. In this case, the see-through mirror is fixed to the case at the attachment part on its upper end and supported by the case so as to be suspended from the case. The thickness of the see-through mirror is 1 mm (millimeter) or more. When the base material of the see-through mirror is formed by injection molding, the thickness of the injection gate or gate mark is less than the thickness of the base material or the attachment part. The thickness of the attachment part is greater than or equal to the thickness of the base material.

[0069] In a specific embodiment of the virtual image display device, the see-through mirror is formed from a light-transmitting base material. When a light-curing adhesive is used as the adhesive, the light-transmitting base material of the see-through mirror allows the curing light to easily reach the joint, and the adhesive can be cured quickly and reliably.

[0070] In a specific embodiment of the virtual image display device, the first adhesive surface is formed on an upper surface of a plate-shaped member of the mounting portion, and the second adhesive surface is formed on a front surface of a pair of protrusions protruding from the plate-shaped member of the mounting portion.

[0071] In a specific embodiment of the virtual image display device, the optical appearance part has a third adhesive surface facing in the opposite direction to the second adhesive surface, and a part of the case is sandwiched between the second adhesive surface and the third adhesive surface. In this case, a part of the case is sandwiched between the second adhesive surface and the third adhesive surface, and three-point fixing is achieved by the second adhesive surface and the third adhesive surface extending in parallel, so that the fixing of the optical appearance part to the case can be more stabilized and the installation accuracy can be improved.

[0072] In a specific embodiment of the virtual image display device, the third adhesive surface is a molding gate that is disposed opposite to the intermediate position of the two second adhesive surfaces. In this case, the third adhesive surface can be provided by reusing the gate.

[0073] In a specific embodiment, the optical unit comprises an image element, a projection optical system that projects an image formed on the image element, a case that stores the image element and the projection optical system in a positioned state, and an optical appearance component into which the image light emitted from the projection optical system is incident, the optical appearance component having a first adhesive surface and a second adhesive surface that extend in directions that intersect with each other and are each adhered to the case, and the second adhesive surface is provided at a position spaced apart across the case. [Explanation of symbols]

[0074] 11a, 11b...image element, 12a...first projection optical system, 12b...second projection optical system, 21...projection lens, 22...prism mirror, 23...see-through mirror, 23a...transmissive reflective film, 23b...substrate, 23c...partially reflective surface, 31...holder, 31a...support frame, 31b...base plate, 41...barrel, 41a...barrel main body, 41c...side plate member, 41d...bottom plate member, 41e...front plate member, 41f, 41g...projection portion, 41u...barrel cover, 41z...insertion port, 52...frame, 59j...bottom surface, 59k...rear surface, 59k...front surface, 59p...protruding portion, 59s...outer surface, 61...support plate, 61g...upper end, 62a, 62b...mounting portion, 62e...plate-shaped member, 62f...protruding portion, 62g...top surface, 62h...front surface, 62j...projection, 62n...plate-shaped member, 62p...rear surface, 62r...inner surface, 71...exterior member, 90...user terminal, 100...optical unit, 100A, 100B...virtual image display device, 100C...support device, 102a, 102b...display drive unit, 103a, 103b...combiner, 123...optical appearance part, AD...adhesive, AR...anti-reflection film, AX...optical axis, CA...case, EP...exit pupil, EY...eye, GA1, GA2, GA3, GA4...gap, IM...intermediate image, IS...storage space, ML...image light, OL...external light, PP...pupil position, SJ1...first adhesive surface, SJ2...second adhesive surface, SJ3...third adhesive surface, SJ4...fourth adhesive surface, US...wearer

Claims

1. An imaging element; a projection optical system that projects an image formed on the image element; a case for housing the image element and the projection optical system in a positioned state; an optical appearance component on which the image light emitted from the projection optical system is incident; Equipped with The optical appearance component has a first adhesive surface and a second adhesive surface that extend in directions intersecting each other and are respectively adhered to the case, The second adhesive surface is provided at a position spaced apart from the case. Virtual image display device.

2. The second adhesive surface is spaced from the case to avoid interference when positioning the optical appearance part. The virtual image display device according to claim 1 .

3. The first adhesive surface and the second adhesive surface are disposed in a perpendicular and adjacent state. The virtual image display device according to claim 1 .

4. The case has a pair of protrusions extending from both sides, the first adhesive surface is adhered to bottom surfaces of the pair of protrusions, The second adhesive surface is adhered to the rear surfaces of the pair of protrusions. The virtual image display device according to claim 3 .

5. The virtual image display device according to claim 1 , wherein the optical appearance part is a mirror having optical transparency.

6. The optical appearance component is a plate-shaped see-through mirror having a concave partially reflective surface, The first adhesive surface and the second adhesive surface are formed on a mounting portion formed on an upper end of the see-through mirror. The virtual image display device according to claim 5 .

7. The see-through mirror is formed from a light-transmitting base material. The virtual image display device according to claim 6 .

8. The first adhesive surface is formed on an upper surface of a plate-like member of the mounting portion, The second adhesive surface is formed on a front surface of a pair of protruding portions of the mounting portion that protrude from the plate-like member. The virtual image display device according to claim 6 .

9. The optical appearance part has a third adhesive surface facing in a direction opposite to the second adhesive surface, a portion of the case is sandwiched between the second adhesive surface and the third adhesive surface; The virtual image display device according to claim 1 .

10. The virtual image display device according to claim 1 , wherein the third adhesive surface is a molding gate that is disposed opposite to an intermediate position between the two second adhesive surfaces.

11. An imaging element; a projection optical system that projects an image formed on the image element; a case for housing the image element and the projection optical system in a positioned state; an optical appearance component on which the image light emitted from the projection optical system is incident; Equipped with The optical appearance component has a first adhesive surface and a second adhesive surface that extend in directions intersecting each other and are respectively adhered to the case, The second adhesive surface is provided at a position spaced apart from the case. Optical unit.

Images