JP2017120384A - Virtual image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a see-through type virtual image display device capable of ensuring satisfactory image visibility by reducing generation of ghost light.SOLUTION: The virtual image display device has a connection part SS connecting a first reflection plane R1 and a second reflection plane R2. The first reflection plane R1, which is positioned relatively closer to the image light incident side, protrudes toward a viewer than the second reflection plane R2 which is positioned at the output side of the image light. A connection plane SSa, which is the surface of the connection part SS, has a shape which extends, from the first reflection plane R1 to the second reflection plane R2, from the side closer to the viewer toward the side away from the viewer.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a virtual image display device that presents an image formed by an image display device (video element) to an observer.

  Various optical systems have been proposed as an optical system incorporated in a virtual image display device such as a head-mounted display (hereinafter also referred to as HMD) that is worn on the observer's head (for example, see Patent Document 1).

  As such a virtual image display device, for example, as a see-through optical system for visually recognizing image light (video light) and allowing an observer to visually recognize an external image, light guide that reflects and guides video light by a plurality of reflecting surfaces. A member to which a member is applied is known (see, for example, Patent Document 1). In the above-mentioned Patent Literature 1 and the like, there are adjacent surfaces (for example, the first surface S11 and the fourth surface S14 in FIG. 3 in Patent Literature 1) as a plurality of reflecting surfaces.

  However, in the see-through type HMD as described above, external light entering the light guide member is reflected unintentionally inside the light guide member and guided inside the light guide member, and is visually recognized by an observer. That is, ghost light. In particular, in the connection part of the adjacent reflecting surfaces in the light guide member, depending on the shape, a part of the component of the external light that has entered the light guide member is reflected to guide the light guide direction (downstream of the optical path of the image light) In some cases, the light is guided in the direction toward the head. In particular, in order to reduce the size of the apparatus, it is important to appropriately process extra components related to ghost light.

JP, 2015-72438, A

  An object of the present invention is to provide a virtual image display device that is a see-through type virtual image display device and that can suppress the generation of ghost light as described above and ensure good image visibility.

  A first virtual image display device according to the present invention includes a video element that generates video light, a plurality of reflection surfaces that are reflected by an inner surface to guide video light from the video element, and video light and A light guide member that overlaps and visually recognizes external light, and the light guide member is disposed on the side opposite to the incident side of the external light and is adjacent to the first reflective surface. And a second reflection surface located on the image light exit side from the first reflection surface, and the first reflection surface is equal to or higher than the second reflection surface in a connecting portion connecting the first reflection surface and the second reflection surface. Overhangs.

  In the virtual image display device, the first reflection surface is a connection portion that connects the first reflection surface and the second reflection surface, which are a pair of reflection surfaces adjacent to each other on the viewer side, among the plurality of reflection surfaces that guide video light. Is projected beyond the second reflecting surface located on the image light emitting side from the first reflecting surface. In other words, when the virtual image display device is attached, the surface on the upstream side of the optical path of the image light protrudes to the viewer side more than the surface on the downstream side of the optical path. In this case, the connecting portion that connects the two reflecting surfaces has a shape that extends from the first reflecting surface to the second reflecting surface toward the side away from the viewer. As a result, even if external light that is a component incident on the light guide member from the side opposite to the viewer toward the viewer is incident on the connection portion and part of the light is reflected, the reflected component is Then, the light is reflected as it is and goes to the outside of the light guide member or toward the upstream side of the optical path of the image light, and is not directed to the downstream side of the optical path or is difficult to face. That is, it is possible to prevent the inside of the light guide member from being guided toward the downstream side of the optical path and being viewed by an observer and resulting in ghost light, and good image visibility can be ensured.

  In a specific aspect of the present invention, the first reflecting surface is a free-form surface, and the second reflecting surface is a flat surface. In this case, the first reflecting surface has a function of suppressing aberration correction, and the second reflecting surface can improve the visibility of external light in the see-through.

  In another aspect of the present invention, in the connecting portion, the thickness n in the protruding direction of the first reflecting surface with respect to the second reflecting surface is maintained at 0 ≦ n ≦ 2 mm over the entire connecting portion. In this case, the connection portion keeps the first reflecting surface overhanging the viewer side more than the second reflecting surface, and the connection portion becomes too large so that external light reflects unintentionally at the connection portion. Can be suppressed. Moreover, it can suppress that a connection part is conspicuous.

  In still another aspect of the present invention, the connection portion has a connection surface that continuously connects the first reflection surface and the second reflection surface. In this case, the reflection component of the external light incident on the connection surface can be prevented from becoming ghost light.

  In still another aspect of the present invention, the light guide member includes a first surface including the first reflection surface and the entire extension surface extending the first reflection surface, and an extension obtained by extending the second reflection surface and the second reflection surface. The second surface including the entire surface is connected to the second surface by a connecting portion, and the first surface is projected beyond the second surface in the entire connected range. In this case, generation | occurrence | production of the ghost light inside a light guide member can be suppressed in the whole extended surface which extended the 1st reflective surface and the 2nd reflective surface.

  A second virtual image display device according to the present invention includes a video element that generates video light, a plurality of reflective surfaces that are reflected on the inner surface to guide the video light from the video element, and the video light A light guide member that overlaps and visually recognizes external light, and the light guide member is disposed on the side opposite to the incident side of the external light and is adjacent to the first reflective surface. And a second reflecting surface located on the image light exit side from the first reflecting surface, and a connecting portion that connects the first reflecting surface and the second reflecting surface. The connecting portion is a first reflecting surface. However, at the location where the concave portion is formed to be recessed from the second reflective surface, an inclined connection surface is formed that maintains an inclination angle of a predetermined value or less with respect to the second reflective surface in accordance with the concave portion.

  In the virtual image display device, the connecting portion that connects the first reflecting surface and the second reflecting surface, which are a pair of reflecting surfaces adjacent to each other on the viewer side, among the plurality of reflecting surfaces that guide video light is the first reflecting surface. An inclined connection surface that holds an inclination angle equal to or smaller than a predetermined value with respect to the second reflecting surface is formed according to the concave portion formed to be recessed from the second reflecting surface. As a result, external light that is a component incident on the light guide member from the side opposite to the observer toward the observer side is reflected even if it is incident on the connecting portion inclined connection surface and part of the light is reflected. By adjusting the optical path of each component, it can be suppressed that the component is visually recognized by the observer and becomes ghost light, and good image visibility can be secured.

  In a specific aspect of the present invention, in the connection portion, the inclination angle of the inclined connection surface with respect to the second reflection surface is different from the difference between the concave portion of the first reflection surface with respect to the second reflection surface and the guide of the light guide member of the connection portion. It depends on the width of the light direction. In this case, an inclined connection surface having a desired inclination angle can be formed according to the shape of the concave portion and the width of the concave portion in the light guide direction.

  In another aspect of the present invention, the width of the connection portion in the light guide direction of the light guide member is 1.7 mm or more. In this case, it is sufficient to form an inclined connection surface having a desired inclination angle.

  In yet another aspect of the present invention, in the connection portion, the thickness n in the protruding direction of the first reflection surface with respect to the second reflection surface is maintained at −0.2 ≦ n ≦ 2 mm over the entire connection portion. Yes. In this case, in addition to the location where the first reflecting surface protrudes beyond the second reflecting surface to the viewer side at the connection portion, there are also locations where the first reflecting surface is recessed from the second reflecting surface. The difference in position between the first reflecting surface and the second reflecting surface at such a location becomes too large, that is, the connecting portion becomes too large and external light reflects unintentionally at the connecting portion. Can be suppressed. Moreover, it can suppress that a connection part is conspicuous.

を満たす。この場合、ゴースト光の抑制に際して、導光部材の形状に応じた傾斜角度とすることができる。 In still another aspect of the present invention, the maximum inclination angle θ of the inclined connection surface with respect to the second reflection surface is the light guide member on the third reflection surface facing the first reflection surface and the second reflection surface among the plurality of reflection surfaces. of the center of the connecting portion for the length of the light guiding direction to the length of the exit side of the image light and L _2, the refraction angle of external light incident from the third reflecting surface and alpha _1, perpendicular to the second reflecting surface When the thickness of the light guide member in any direction is D,

Meet. In this case, when suppressing the ghost light, the inclination angle can be set according to the shape of the light guide member.

  In still another aspect of the invention, the maximum inclination angle of the inclined connection surface with respect to the second reflecting surface is 6.9 ° or less. In this case, the inclination angle of the inclined connection surface can be made sufficiently small to suppress ghost light.

  In yet another aspect of the present invention, the connecting portion is sand-printed or black-painted. In this case, external light incident on the connection portion can be absorbed or diffused, and generation of ghost light due to external light can be suppressed.

  In still another aspect of the present invention, the reflecting surfaces facing the first reflecting surface and the second reflecting surface are sand-printed or black-coated on the incident side of the image light with respect to the light guide direction of the light guide member. It has a part. In this case, the generation of ghost light due to the external light can be suppressed by absorbing or diffusing the external light incident from the reflective surface facing the first reflective surface and the second reflective surface.

  In still another aspect of the present invention, the light guide member includes two or more non-axisymmetric curved surfaces, and the first surface and the third surface of the plurality of reflective surfaces constituting the light guide member are opposed to each other. When the external world is visually recognized through the first surface and the third surface, the diopter is substantially 0, and the image light from the image element is totally reflected by the third surface, After being totally reflected by the surface and reflected by the second surface, the light passes through the first surface and reaches the observation side. In this case, it is possible to reduce the size of the apparatus while maintaining a good see-through state in which an external environment is superimposed on the image of the video light.

  In still another aspect of the present invention, the light guide member includes a fourth surface that is adjacent to the first surface and reflects the image light to be incident on the third surface, and the first reflective surface is the fourth surface. And the second reflecting surface is the first surface. In this case, generation of ghost light inside the miniaturized light guide member can be suppressed.

  In still another aspect of the present invention, the optical system further includes a projection optical system that causes the image light from the image element to enter the light guide member.

  In yet another aspect of the present invention, the projection optical system includes at least one non-axisymmetric aspheric surface, and the one non-axisymmetric aspheric surface is formed from two points in different corner regions on the light exit surface of the image element. The components that should reach the observer's eyes in the bundle of emitted image light beams are arranged at positions where they do not cross each other. In this case, the entire optical system including the projection optical system can be further downsized, and thus the entire apparatus can be downsized.

  In still another aspect of the present invention, a direction perpendicular to the normal direction of the light exit surface of the image element and corresponding to the light guide direction of the light guide member is defined as a first direction, and the normal direction and the first When the direction perpendicular to the direction is the second direction, the projection optical system is disposed perpendicular to the optical axis of the projection optical system passing through the center of the image element and parallel to the normal direction, and A quadrangular aperture that extends parallel to one direction and is axisymmetric about a first axis that intersects the optical axis of the projection optical system, and is non-axisymmetric about a second axis that extends parallel to the second direction and intersects the optical axis of the projection optical system Or a diaphragm that forms a rectangular opening that is arranged non-perpendicular to the optical axis of the projection optical system.

  In still another aspect of the present invention, in the light guide member, the light emitting unit disposed on the light emitting side from the intersection of the light incident unit disposed on the light incident side and the projection optical system optical axis of the projection optical system, and observation The distance to the intersection with the visual axis assumed as the reference of the visual line of the person is 48 mm or less. In this case, when applied as an HMD, the apparatus can be sufficiently downsized from the viewpoint of long-time use, design, and the like.

  In yet another aspect of the present invention, the light guide member has a semi-transmissive reflection portion that partially reflects and transmits image light from the image element and external light, and transmits light with the semi-transmissive reflection portion interposed therebetween. Connected to the member. In this case, the light guide member has a structure in which the transflective portion is sandwiched in cooperation with the light transmissive member, so that the image light can be visually recognized and the external image can be visually confirmed or viewed through the observer. Can be observed.

  In still another aspect of the present invention, the light guide member is configured as a pair of left and right, and the pair of left and right light guide members and the light transmission member are integrally connected with the light transmission member interposed between the pair of left and right light guide members. This is an optical member. In this case, it is possible to recognize an image by binocular vision, and it is possible to easily and accurately perform alignment for binocular vision by the light transmitting member.

It is a perspective view explaining simply the appearance of an example of a virtual image display device concerning a 1st embodiment. It is a top view which shows the optical path of the main-body part which comprises a virtual image display apparatus. (A) is the perspective view which shows the shape of a light guide member, (B) is the perspective view which looked at the light guide member of (A) from another angle, (C) is (A) It is a side view of a light guide member. (A) is a figure for demonstrating an example of approach to the connection part of the light guide member of external light, (B) is a part of (A) in order to demonstrate the reflective component of external light It is a figure which shows a mode that it expanded, (C) is a figure of the comparative example about (B). (A) is sectional drawing shown about the structure of a projection optical system, (B) is a front view of the lens-barrel of a projection optical system. (A) is a figure which shows notionally an example about the arrangement | positioning relationship between an imaging | video element and the aperture_diaphragm | restriction of a projection optical system, (B) is a modification about arrangement | positioning relationship between an imaging | video element and the aperture_diaphragm | restriction of a projection optical system FIG. (A) is a conceptual diagram which shows the mode of the peripheral side of an apparatus about one structural example of an image display apparatus, (B) is a conceptual diagram which shows the mode of the center side of an apparatus. It is a figure for demonstrating the light guide member which comprises the virtual image display apparatus which concerns on 2nd Embodiment. It is a figure for demonstrating an example of the approach to the connection part of the light guide member of external light. (A) shows again FIG.3 (C) for the comparison explanation with 1st Embodiment, (B) is the conceptual diagram which extracted a part of (A), (C) These are the figures corresponding to (B), and are the conceptual diagrams which extracted a part of light guide member of the virtual image display apparatus in this embodiment. It is a figure for demonstrating the modification of the light guide member which comprises the virtual image display apparatus which concerns on 2nd Embodiment. (A) is a top view shown notionally for describing one modification of a light guide device, and (B) is a front view. It is a top view which shows the optical path of a main-body part about another example of a virtual image display apparatus. It is a figure which expands and conceptually shows a part of light guide member about an example of the mode of light guide in a light guide device. It is a perspective view explaining simply the appearance of the virtual image display device of one modification.

[First Embodiment]
Hereinafter, the virtual image display device according to the first embodiment of the present invention will be described in detail with reference to FIG. 1 and the like.

  As shown in FIG. 1, the virtual image display device 100 according to the present embodiment is a head-mounted display having an appearance like glasses, and image light based on a virtual image is given to an observer or a user wearing the virtual image display device 100. This is a virtual image display device capable of visually recognizing (image light) and allowing an observer to visually recognize or observe an external image. The virtual image display device 100 includes first and second optical members 101a and 101b that cover the front of an observer so as to be seen through, a frame portion 102 that supports both optical members 101a and 101b, and rear sides from both left and right ends of the frame portion 102. 1st and 2nd image formation main-body parts 105a and 105b added to the part over the vine part (temple) 104 are provided. Here, the first display device 100A in which the first optical member 101a on the left side and the first image forming main body portion 105a in the drawing are combined is a portion that forms a virtual image for the right eye, and can be used alone as a virtual image display device. Function. Further, the second display device 100B in which the second optical member 101b on the right side in the drawing and the second image forming main body portion 105b are combined is a portion that forms a virtual image for the left eye, and functions alone as a virtual image display device. To do. By comparing FIG. 2 with FIG. 1, for example, the first and second image forming main body portions 105 a and 105 b include a projection lens 30 that is a projection optical system and an image display device 80 (video) including an image generation unit 81. It can be seen that each element is configured. FIG. 2 illustrates the display device for the left eye, and the display device for the right eye is omitted, but the display device for the right eye has the same structure. In addition to the above, a nose receiving portion 40 having a role of supporting the frame portion 102 by contacting the observer's nose is provided.

  As shown in FIG. 2, the display device 100 </ b> B can be regarded as including a projection see-through device 70 that is a projection optical system and an image display device 80 that forms video light. The projection see-through device 70 includes the second optical member 101b or the light guide device 20 and a projection lens 30 for image formation, and plays a role of projecting an image formed by the image display device 80 as a virtual image onto the observer's eyes. Have. In other words, the projection see-through device 70 guides light from the image plane OI, which is a surface for emitting image light (video light) formed on the image display device 80, and makes the observer visually recognize a virtual image. It is also an imaging optical system that re-images on the observer's retina. The second optical member 101b or the light guide device 20 is composed of a light guide member 10 for light guide and see-through and a light transmitting member 50 for see-through. Note that the second image forming main body portion 105 b includes the image display device 80 and the projection lens 30. Further, the image plane OI is also a panel plane indicating the panel position of the panel constituting the image display device 80. Furthermore, when the image display device 80 is self-luminous illumination, the image plane OI can be said to be a light emitting surface.

  Here, the optical axis reference of the optical system is determined as follows. First, let the center optical axis about the projection lens 30 be a lens optical axis (projection optical system optical axis) LX. A central axis extending along the light guide direction of the light guide member 10 is defined as a light guide axis DX. The light guide axis DX is an axis extending through the center and along the flat plate shape in the flat light guide member 10. Further, on the light emission side of the light guide member 10, the central axis assumed as the reference of the observer's line of sight is defined as the line of sight axis SX. The line-of-sight axis SX is guided from the center position of the assumed eye position EY that is assumed as the eye position (hereinafter also simply referred to as the eye EY to include the case where the eye is actually placed at the assumed eye position EY). This is an axis extending toward the center of the light emission range of the member 10. Further, in the light guide member 10, an intersection point between a light incident portion (second light guide portion 12 to be described later) arranged on the light incident side and a lens optical axis LX of the projection lens 30 is defined as an intersection point C <b> 1. An intersection point between a light emission part (first light guide portion 11 described later) arranged on the light emission side and the visual axis SX is defined as an intersection point C2. Here, it is assumed that the distance (interval) from the intersection C1 to the intersection C2 indicated by the bidirectional arrow AA in the drawing is 48 mm or less. The line-of-sight axis SX is inclined about 7 ° (more precisely, 6.7 °) with respect to the lens optical axis LX. Further, the visual axis SX is inclined by about 10 ° from a state perpendicular to the light guide axis DX. That is, the line-of-sight axis SX and the light guide axis DX intersect so as to form a reflection angle of about 80 °. In the above case, the lens optical axis LX and the light guide axis DX intersect so as to form a reflection angle of about 106.7 °.

  In the image display device 80, the image plane OI is a plane perpendicular to the lens optical axis LX, and the lens optical axis LX passes through the center of the image plane OI. Here, the x direction (direction corresponding to the X direction) which is the horizontal direction on the plane parallel to the image plane OI is defined as the first direction DD1, and the y direction (direction corresponding to the Y direction) which is the vertical direction is defined as the second direction. Let it be DD2. The z direction is the normal direction of the image plane OI and the direction in which the lens optical axis LX extends. In the present embodiment, the emission angle of the light beam of the image light emitted from the image plane OI is asymmetric about the left and right (x direction) with respect to the center line (lens optical axis LX) of the image plane OI. The vertical direction (y direction) is symmetric with respect to the center of the image plane OI.

  The image display device 80 includes an image generation unit 81 that forms an image plane OI composed of matrix-like pixels by self-luminous illumination that includes an organic EL (organic EL panel) as a light source, and a stage immediately after the image generation unit 81. In addition to the light distribution control unit 82 that controls the light distribution for each component of the video light GL emitted from the image plane OI of the image generation unit 81, a drive control unit that controls the operation of the image generation unit 81 and the like (Not shown). Although details will be described later (see FIG. 7), here, the color filter layer CF disposed immediately after the image generation unit 81 functions as the light distribution control unit 82, whereby the image plane of the video light GL is displayed. The emission angle of the component light emitted from the peripheral side of the OI is adjusted. For example, among the partial light bundles of the image light GL, the partial light bundle GLa emitted from the inner side relatively close to the human body (observer) and the partial light bundle GLb emitted from the outer side relatively far from the human body, The injection angle is different. Here, the partial light bundles GLa and GLb mean components that should reach the observer's eyes among the light bundles constituting the image light GL.

  The projection lens 30 is a projection optical system that projects the video light GL emitted from the image display device 80 toward the light guide device 20. In this embodiment, in particular, a lens having a non-axisymmetric aspherical surface (non-axisymmetric aspherical surface or free-form surface) is arranged on the side close to the image display device 80, so that the entire optical system can be reduced in size. Yes. Here, the projection lens 30 is provided with a stop ST. The aperture stop ST forms a non-axisymmetric quadrangular opening to appropriately shield each component such as the partial beam bundle GLa of the image light GL emitted asymmetrically as described above. The detailed shape and structure of the aperture stop ST will be described later with reference to FIG.

  As described above, the light guide device 20 includes the light guide member 10 for light guide and see-through and the light transmitting member 50 for see-through. The light guide member 10 is a part of the prism-type light guide device 20 and is an integral member, but the first light guide portion 11 (light emitting portion) on the light emission side and the second light guide on the light incident side. It can be divided into the portion 12 (light incident portion). The light transmission member 50 is a member (auxiliary optical block) that assists the see-through function of the light guide member 10, and is fixed integrally with the light guide member 10 to form one light guide device 20.

  Hereinafter, with reference to FIG. 2, the role of the projection see-through device 70 which is a virtual image optical system, that is, the light guide device 20 and the projection lens 30 will be described in detail.

  The projection lens 30 is an optical system that performs projection by allowing the image light GL from the image display device 80 to be incident. As a component, the projection lens 30 includes three optical elements (first optical elements) along the lens optical axis LX that is the optical axis of the projection optical system. 1 to 3rd lens) 31-33. Each of the optical elements 31 to 33 includes an aspheric lens including both an axisymmetric aspheric surface (non-axisymmetric aspheric surface) and an axially symmetric aspheric surface (axisymmetric aspheric surface). An intermediate image corresponding to the display image of the image generation unit 81 is formed inside the light guide member 10 in cooperation with the unit. In the present embodiment, in particular, not only the lens surface 31a on the light exit side among the lens surfaces of the first lens 31 disposed on the light exit side, but also each lens surface of the third lens 33 disposed on the light incident side. Among these, the lens surface 33a on the light exit side is a non-axisymmetric aspheric surface. In addition, the 1st-3rd lenses 31-33 which comprise the projection lens 30 are accommodated and supported in the 2nd image formation main-body part 105b by the lens-barrel (refer FIG. 5), for example. Further, the projection lens 30 has a diaphragm ST between the second lens 32 and the third lens 33 among the first to third lenses 31 to 33. The aperture stop ST is arranged at a position where the image light GL is superimposed most in the projection lens 30 and appropriately stops the light. Here, since the lens surface includes a non-axisymmetric aspheric surface, the components of each partial light bundle are also bent in a complicated manner. The aperture stop ST has a shape and structure corresponding to this.

  The light guide device 20 is composed of the light guide member 10 and the light transmission member 50 as described above. Among these, as for the light guide member 10, the center side (front side) part near a nose is extended linearly in planar view. Of the light guide member 10, the first light guide portion 11 disposed on the center side close to the nose, that is, on the light exit side, includes a first surface S11, a second surface S12, and a side surface having an optical function. The second light guide portion 12 having the third surface S13 and disposed on the peripheral side away from the nose, that is, on the light incident side, includes the fourth surface S14 and the fifth surface as side surfaces having an optical function. S15. Among these, the first surface S11 and the fourth surface S14 are continuously adjacent, and the third surface S13 and the fifth surface S15 are continuously adjacent. In addition, the second surface S12 is disposed between the first surface S11 and the third surface S13, and the fourth surface S14 and the fifth surface S15 are adjacent to each other at a large angle. Furthermore, here, the first surface S11 and the third surface S13 which are arranged to face each other have a planar shape substantially parallel to each other. On the other hand, other surfaces having an optical function, that is, the second surface S12, the fourth surface S14, and the fifth surface S15 are non-axisymmetric curved surfaces (free curved surfaces).

  Here, from the viewpoint of suppressing the ghost light in the see-through, the plurality of reflecting surfaces constituting the light guide member 10 are defined in another way. Specifically, first, among the surfaces S11 to S15 which are a plurality of reflecting surfaces in the light guide member 10, a fourth surface S14 and a first surface S11 which are a pair of adjacent reflecting surfaces arranged on the viewer side. , The fourth surface S14 relatively positioned on the incident side of the image light GL is defined as a first reflecting surface R1, and the first surface S11 relatively positioned on the image light emitting side is defined as a second reflecting surface R2. Further, a portion connecting the first reflecting surface R1 and the second reflecting surface R2 is a connecting portion SS, and in particular, the surface of the connecting portion SS, that is, the first reflecting surface R1 and the second reflecting surface R2 are continuously and smoothly smoothed. A surface to be connected is defined as a connection surface SSa. In this case, the first reflection surface R1 on the incident side is a free-form surface (fourth surface S14), and the second reflection surface R2 on the emission side is a flat surface (first surface S11). In the present embodiment, the first reflecting surface R1 projects beyond the second reflecting surface R2 to the viewer side at the connection portion SS. Here, regarding the wording that one of the two surfaces adjacent to each other in the connection portion protrudes closer to the viewer than the other surface, a typical example in the drawing is a second reflecting surface R2 that is a flat surface. , The normal direction of the plane including this surface (reference surface) is defined as the overhang direction DS, and the first reflection surface R1 projects to the viewer side compared to the second reflection surface R2 with respect to the overhang direction DS. . Further, the fact that one surface projects to the viewer side “more than” the other surface means that the second reflective surface R2 is located on the first reflective surface R1 anywhere in the entire connecting portion SS with respect to the projecting direction DS. This means that there is no projecting portion (see FIG. 3). Here, the overhang direction DS is also referred to as a thickness direction.

  Although details will be described later with reference to FIGS. 3 and 4, the light guide member 10 has a shape / structure that satisfies the above-described conditions with respect to the extending direction (thickness direction) DS. The generation of ghost light due to external light can be suppressed.

  Returning to FIG. 2, the light transmission member 50 is integrally fixed to the light guide member 10 as described above to form one light guide device 20, and a member (assuming the see-through function of the light guide member 10 ( Auxiliary optical block). The light transmission member 50 includes a first transmission surface S51, a second transmission surface S52, and a third transmission surface S53 as side surfaces having an optical function. Here, the second transmission surface S52 is disposed between the first transmission surface S51 and the third transmission surface S53. The first transmission surface S51 is on a surface obtained by extending the first surface S11 of the light guide member 10, and the second transmission surface S52 is joined and integrated with the second surface S12 by the adhesive layer CC. It is a curved surface, and the third transmission surface S53 is on a surface obtained by extending the third surface S13 of the light guide member 10. Among these, since 2nd transmissive surface S52 and 2nd surface S12 of the light guide member 10 are integrated by joining via the thin contact bonding layer CC, they have the shape of the substantially same curvature.

  Among the plurality of surfaces constituting the light guide member 10, the surfaces S14 and S15 other than the surfaces from the first surface S11 to the third surface S13 have different signs of curvature depending on the direction of at least one free-form surface. At least one point is included. As a result, the light guide member 10 can be miniaturized while precisely guiding the image light.

  Of the light guide member 10, the main body 10 s exhibits high light transmittance in the visible range and is an integrally formed product. However, as described above, the light guide member 10 is functionally connected to the first light guide portion 11. This can be divided into the second light guide portion 12. The first light guide portion 11 allows the image light GL to be guided and emitted, and allows the external light HL to be seen through. The second light guide portion 12 allows the image light GL to be incident and guided.

  In the first light guide portion 11, the first surface S11 functions as a refracting surface that emits the image light GL to the outside of the first light guide portion 11, and also functions as a total reflection surface that totally reflects the image light GL on the inner surface side. To do. The first surface S11 is arranged in front of the assumed eye position EY (eye EY), and has a planar shape as described above. The first surface S11 is a surface formed by the hard coat layer 27 applied to the surface of the main body 10s.

  The second surface S12 has a half mirror layer 15 attached to the surface of the main body 10s, and functions as a semi-transmissive reflective surface (semi-transmissive reflective portion) that reflects the image light GL and transmits the external light HL.

  The third surface S13 functions as a total reflection surface that totally reflects the video light GL on the inner surface side. The third surface S13 is arranged substantially in front of the eye EY, and has a planar shape like the first surface S11. The first surface S11 and the third surface S13 are parallel to each other. Due to the smooth surface, when the external light HL is viewed through the first surface S11 and the third surface S13, the diopter is 0, and in particular, no zooming occurs. Yes. The third surface S13 is a surface formed by the hard coat layer 27 applied to the surface of the main body 10s.

  In the second light guide portion 12, the fourth surface S14 functions as a total reflection surface that totally reflects the video light GL on the inner surface side. The fourth surface S14 also functions as a refracting surface that allows the image light GL to enter the second light guide portion 12. That is, the fourth surface S <b> 14 serves both as a light incident surface on which the image light GL is incident on the light guide member 10 from the outside and a reflection surface on which the image light GL is propagated inside the light guide member 10. The fourth surface S14 is a surface formed by the hard coat layer 27 applied to the surface of the main body 10s.

  In the second light guide portion 12, the fifth surface S15 is formed by forming a light reflecting film RM formed of an inorganic material on the surface of the main body 10s, and functions as a reflecting surface.

  The light transmissive member 50 exhibits high light transmittance in the visible range, and the main body portion of the light transmissive member 50 is formed of a material having substantially the same refractive index as the main body 10 s of the light guide member 10. The light transmitting member 50 is formed by bonding a main body portion to the main body 10s of the light guide member 10 and then forming a hard coat together with the main body 10s in the bonded state. That is, the light transmitting member 50 is the same as the light guiding member 10, but the hard coat layer 27 is applied to the surface of the main body portion. The first transmission surface S51 and the third transmission surface S53 are surfaces formed by the hard coat layer 27 applied to the surface of the main body portion.

  The light guide device 20 is formed by coating the base material to be the light guide member 10 and the light transmitting member 50 and then coating the joined base material by dipping. That is, the hard coat layer 27 of the light guide member 10 is provided on the entire light guide device 20 together with the light transmissive member 50.

  As described above, inside the light guide member 10, the image light from the image generation unit 81 is guided by five reflections from the first surface S11 to the fifth surface S15 including at least two total reflections. ing. This makes it possible to achieve both the display of the video light GL and the see-through for visually recognizing the external light HL, and to correct the aberration of the video light GL.

  Hereinafter, an optical path of the image light GL and the like in the virtual image display device 100 will be described. The image light GL emitted from the image display device 80 is provided with the desired astigmatism while being converged by passing through the respective lenses 31 to 33 constituting the projection lens 30 and provided to the light guide member 10. The light enters the fourth surface S14 having a positive refractive power. The astigmatism is canceled while passing through each surface of the light guide member 10, and video light is finally emitted toward the eyes of the observer in an intended state.

  The image light GL incident on the fourth surface S14 of the light guide member 10 and passing through the fourth surface S14 advances while converging, and has a relatively weak positive refractive power when passing through the second light guide portion 12. The light is reflected by the surface S15 and is incident again on the fourth surface S14 from the inside and reflected.

  The image light GL reflected by the fourth surface S14 of the second light guide portion 12 is incident on the third surface S13 having substantially no refractive power in the first light guide portion 11 and is totally reflected, substantially. Is incident on the first surface S11 having no refractive power and is totally reflected.

  Here, the video light GL forms an intermediate image in the light guide member 10 before and after passing through the third surface S13. The image plane of the intermediate image corresponds to the image plane OI of the image generation unit 81.

  The image light GL totally reflected by the first surface S11 is incident on the second surface S12 while diverging. In particular, the image light GL incident on the half mirror layer 15 is partially transmitted through the half mirror layer 15. However, it is partially reflected and reenters the first surface S11 and passes therethrough. The half mirror layer 15 acts as a layer having a relatively strong positive refractive power with respect to the image light GL reflected here. The first surface S11 acts as having no refractive power with respect to the video light GL passing through the first surface S11.

  The video light GL that has passed through the first surface S11 enters the pupil of the observer's eye EY or an equivalent position thereof as a substantially parallel light beam. That is, the observer observes the image formed on the image generation unit 81 with the video light GL as a virtual image.

  On the other hand, among the external light HL, the light incident on the + X side from the second surface S12 of the light guide member 10 passes through the third surface S13 and the first surface S11 of the first light guide portion 11, but this At this time, since the third surface S13 and the first surface S11 are substantially parallel to each other, aberrations and the like hardly occur. That is, the observer observes an external field image without distortion through the light guide member 10. Similarly, of the external light HL, the light incident on the −X side with respect to the second surface S12 of the light guide member 10, that is, the light incident on the light transmission member 50 is the third transmission surface S53 provided thereon. When passing through the first transmission surface S51, the third transmission surface S53 and the first transmission surface S51 are substantially parallel to each other, so that no aberration or the like occurs. That is, the observer observes an external field image without distortion through the light transmission member 50. Further, among the external light HL, the light incident on the light transmissive member 50 corresponding to the second surface S12 of the light guide member 10 is transmitted through the third transmissive surface S53 and the first surface S11. Since the surface S53 and the first surface S11 are substantially parallel to each other, aberrations and the like hardly occur. That is, the observer observes an external image with little distortion through the light transmission member 50. The second surface S12 of the light guide member 10 and the second transmission surface S52 of the light transmission member 50 both have substantially the same curved surface shape, have substantially the same refractive index, and the gap between them is substantially the same. The adhesive layer CC is filled with the same refractive index. That is, the second surface S12 of the light guide member 10 and the second transmission surface S52 of the light transmission member 50 do not act as a refractive surface with respect to the external light HL.

  In the so-called see-through type optical system as described above, in general, leakage light or the like is likely to enter from the outside during light guide, and ghost light may be generated due to this. In particular, in the case of an optical system to which the plate-like light guide member 10 as described above is applied, two adjacent surfaces are connected to the same surface (for example, an observer-side surface) among the plate-like surface portions. In this case, there is a concern that ghost light is generated when light from the outside hits a portion connecting the two surfaces and part of the light is guided in an unintended direction. On the other hand, in the virtual image display device 100 according to the present embodiment, the first reflecting surface R1 (fourth surface S14) and the second of the plurality of reflecting surfaces constituting the light guide member 10 are described as described above. Since the reflection surface R2 (first surface S11) has a specific shape and structure, generation of components that cause ghost light is suppressed in the connection portion SS (connection surface SSa) that connects the reflection surface R2 (first surface S11). Making it possible.

  Hereinafter, with reference to FIG.3 and FIG.4, 1st reflective surface R1 (4th surface S14) which is a pair of adjacent reflective surfaces among several reflective surfaces which comprise the light guide member 10 in this embodiment, and The second reflection surface R2 (first surface S11) and the connection portion SS (connection surface SSa) connecting them will be described in detail.

As described above and as shown in FIGS. 3A, 3B, and 3C, the first reflecting surface R1 is relatively relative to the first reflecting surface R1 and the second reflecting surface R2. The second reflection surface R2 is relatively positioned on the image light exit side. In other words, the first reflecting surface R1 is on the upstream side of the optical path of the video light GL with respect to the second reflecting surface R2. In this case, if a component occurs from the outside to the downstream side of the optical path, that is, from the first reflecting surface R1 side to the second reflecting surface R2 due to leakage light (external light) from the outside, the ghost is generated. It seems to be easy to become light. In the present embodiment, the first reflecting surface R1 and the second reflecting surface R2 have shapes or structures that can cope with this. Specifically, as described above and as shown in more detail in FIGS. 3 (A), 3 (B), and 3 (C), the connection portion SS has a first extension direction (thickness direction) DS. The reflecting surface R1 projects beyond the second reflecting surface R2 to the viewer side. That is, in the connection portion SS and its periphery, the first reflecting surface R1 always protrudes toward the viewer side compared to the second reflecting surface R2, and the second reflecting surface R2 is closer to the viewer side than the first reflecting surface R1. The protruding part does not exist. Thereby, as shown in FIG.3 and FIG.4, in connection part SS, connection surface SSa as a surface which connects 1st reflective surface R1 and 2nd reflective surface R2 continuously smoothly is 1st reflective surface R1. From the side closer to the observer to the side facing away from the viewer from the second reflecting surface R2, the inner surface of the connection surface SSa is the surface facing the upstream side of the optical path, and there is no place facing the downstream side of the optical path It has become. Here, as shown in FIG. 3, in the connection portion SS, the connection surface SSa is assumed to have a maximum thickness n _max of 2 mm or less in the extending direction (thickness direction) DS. Further, it is assumed that the thickness n of the extending direction (thickness direction) DS of the connection surface SSa over the entire connection portion SS is maintained and changed between 0 ≦ n ≦ 2 mm. When the expression about the relationship between the first reflecting surface R1 and the second reflecting surface R2 is revised using the thickness n, the thickness n, that is, the step between the first reflecting surface R1 and the second reflecting surface R2 is partially Specifically, even though there may be a place where the thickness is 0 mm, the thickness n does not become 0 mm over the entire surface of the first reflective surface R1 and the second reflective surface R2, and the first reflective surface R1 is always the second reflective surface R1. There are locations that protrude beyond the reflecting surface R2 (thickness n> 0 mm), and the thickness n ≧ 0 mm is always maintained over the entire surface. That is, the relationship between the first reflecting surface R1 and the second reflecting surface R2 is not reversed and the thickness (step) is not negative. Further, the state of thickness n ≦ 2 mm is always maintained over the entire surface, that is, the step between the first reflecting surface R1 and the second reflecting surface R2 is not excessively increased. In the above case, the connection portion SS maintains the first reflection surface R1 overhanging the observer side more than the second reflection surface R2, and the connection portion SS becomes too large, so that external light is generated in the connection portion SS. Unintentional reflection can be suppressed. Moreover, it can suppress that the connection part SS is conspicuous.

  Hereinafter, with reference to FIG. 4 (A) and 4 (B), the process in the light guide member about the external light OL which goes to the connection surface SSa of the connection part SS from the outside is demonstrated. Here, FIG. 4A is a diagram for explaining an example of the external light OL entering the connection portion SS in the light guide member 10, and in the drawing, the light guide direction of the video light is indicated by an arrow AP. Shall. FIG. 4B is a diagram conceptually showing a part of FIG. 4A enlarged, and shows a state of the reflection component RL on the connection surface SSa (connection portion SS) of the external light OL. Yes. As described above, with regard to the ghost light, there is a problem that the component reflected by the connection surface SSa in the external light OL is directed to the downstream side of the optical path. That is, there is a problem that a component along the arrow AP indicating the light guide direction is generated in the drawing. For this reason, as shown in FIGS. 4A and 4B, the external light OL, which is a problem component of the external light incident on the connection surface SSa from the outside, travels from the upstream side of the optical path to the downstream side of the optical path. It is like approaching. With respect to such a problem, in the present embodiment, as described above, the inner surface of the connection surface SSa is a surface facing the upstream side of the optical path, so that the external light OL hits the connection surface SSa as illustrated. In this case, even if a part is reflected to generate the reflection component RL, the reflection component RL is reflected as it is and goes to the outside of the light guide member 10 or toward the upstream side of the optical path of the image light GL. It is possible not to face the downstream side or to be difficult to face. That is, it is possible to prevent the inside of the light guide member 10 from being guided toward the downstream side of the optical path and being viewed by an observer, resulting in ghost light, and good image visibility can be ensured. On the other hand, for example, when the orientation of the connection surface SSa is reversed as in the comparative example shown in FIG. 4C, that is, when the relationship between the first reflective surface R1 and the second reflective surface R2 is reversed. As shown in the drawing, there is a possibility that the reflection component RL of the external light OL is directed downstream of the optical path of the image light GL, and there is a possibility of generating ghost light. In the present embodiment, since there is no portion as shown in FIG. 4C, generation of ghost light due to external light is suppressed.

  Furthermore, in the present embodiment, the two reflecting surfaces connected at the connecting portion as described above have an overhanging relationship toward the observer even on the entire extended surface (surface that does not function optically) obtained by extending the reflecting surfaces. It is kept. Specifically, as shown in FIG. 3A, first, the first reflecting surface R1 (fourth surface S14) and the first reflecting surface R1 formed in the optically functioning region portion ER1 are formed. A surface constituted by the entirety of the extended surface PF1 that does not function optically in the region outside the extended region portion ER1 is defined as a first surface SF1. Similarly, the second reflecting surface R2 (first surface S11) formed in the optically functioning region portion ER2 and the non-optically extending extension in the region outside the region portion ER2 extending from the second reflecting surface R2. A surface constituted by the entire surface PF1 is defined as a second surface SF2. In this case, the connection surface SSa of the connection portion SS continuously and smoothly connects the first surface SF1 and the second surface SF2, and the first surface SF1 is not less than the second surface SF2 in the entire connected range. Projecting to the observer side. Thereby, generation | occurrence | production of the ghost light resulting from external light is suppressed also in the range beyond 1st reflective surface R1 and 2nd reflective surface R2 which have an optical function.

  Further, as in the configuration shown in the present application, in an optical system configured to form an intermediate image and guide light by using total reflection by the light guide member, the size of the device has been conventionally reduced. In order to maintain high accuracy, the optical path is adjusted while suppressing aberration by using a free curved surface in the light guide member or the like. For example, in Patent Document 1 (Japanese Patent Application Laid-Open No. 2015-72438), in addition to the light guide member, a part of the projection lens (lens surface on the light emission side) is provided with a free curved surface to reduce the aberration while correcting the aberration. Responds to the request. However, there is a design limit for downsizing due to restrictions such as the necessity of maintaining the total reflection condition for light guide in the light guide member. Specifically, for example, when it is desired to reduce the distance from the intersection C1 to the intersection C2 in the light guide device 20 illustrated in FIG. 2, that is, to reduce the length of the light guide device 20 in the light guide direction, Reflection conditions tend to be a problem. In this case, if the lens surface 33a is not configured as a non-axisymmetric aspherical surface as in the present application, the partial light bundle GLa, which is a component emitted from the inside of the image display device 80 near the human body, is formed on each surface S11. , S13, and S14, it may be particularly difficult to control to satisfy the total reflection condition. For example, it is conceivable to adjust the shape on the side close to the surface S13 of the surface S12 through which a component that makes the total reflection condition stricter passes so that the partial light beam GLa satisfies the total reflection condition. However, when performing such adjustment, not only the side close to the surface S13 but also the entire portion of the surface S12 from the side close to the surface S13, which is the entire range through which the partial light bundle GLa passes, to the center side is adjusted. There is a need to. At this time, a part of the adjusted part (a part near the center of the surface S12) is also a range through which the partial light bundle GLb, which is a component emitted from the outside of the human body in the image display device 80, passes. Therefore, various restrictions are imposed on the shape adjustment of the surface S12, and it becomes difficult to correct aberrations as a whole optical system. In addition, as another candidate for the adjustment location, for example, it may be possible to adjust the surface S14 which is a non-axisymmetric aspheric surface and the partial beam bundle GLa and the partial beam bundle GLb are reflected in areas separated from each other. . However, the surface S14 is a place where not only the reflection of the video light GL but also the transmission is performed. For example, the reflection region of the partial light beam GLa and the transmission region of the partial light beam GLb overlap each other. For this reason, various restrictions are imposed also when adjusting surface S14.

  On the other hand, in the present embodiment, not only the lens surface 31a of the first lens 31 disposed on the light exit side, but also the lens surface 33a on the light exit side of the third lens 33 disposed on the light incident side. Is a non-axisymmetric aspheric surface. As described above, the lens surface 33a is a lens surface located on the side of the projection lens 30 that is relatively close to the image display device 80. For this reason, for example, as shown in the figure, out of the peripheral area (referred to as the corner area) of the image plane OI, the light is emitted from two points P1 and P2 of the different corner areas IA and OA on the inside and outside. The partial beam bundles GLa and GLb pass through the lens surface 33a before crossing each other. That is, in the above case, the lens surface 33a that is a non-axisymmetric aspheric surface is a light beam of video light emitted from two points P1 and P2 in different corner regions on the image plane OI that is the light emission surface of the image display device 80. Among the bundles, the partial light bundles GLa and GLb, which are components that should reach the eyes of the observer, are arranged at positions where they do not intersect each other. By making the lens surface 33a in such a position a non-axisymmetric aspheric surface (free curved surface), the lens surface 33a has a partial light bundle GLa emitted from an inner region close to the human body in the image surface OI, and It has an individual effect on the partial light bundle GLb emitted from the outer region far from the human body in the image plane OI. That is, for example, it is possible to individually perform aberration correction for the partial beam bundle GLa and aberration correction for the partial beam bundle GLb. Furthermore, the aperture ST provided on the inner surface of the projection lens 30 is asymmetrically deformed in accordance with the difference in the exiting status of the partial light bundles such as the partial light bundles GLa and GLb. Shading is possible.

  As a comparison, for example, regarding the lens surface 31a, the passage range of the partial beam bundle GLa and the passage range of the partial beam bundle GLb already overlap at this position, and the partial beam bundle GLa and the partial beam bundle GLb are separated. Thus, aberration correction cannot be performed individually, and only aberration correction for the entire light beam can be performed. In the present embodiment, a non-axisymmetric aspheric surface (lens surface 33a) is arranged at a position where components (partial beam bundles GLa, GLb) of the image light beam bundle that should reach the observer's eyes do not intersect each other. For example, the optical system is further miniaturized and extended while maintaining various optical precisions such as resolution and angle of view equivalent to those of the virtual image display device disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 2015-72438). Can downsize the entire apparatus. Specifically, as described above, in the light guide device 20, for example, the distance (interval) from the intersection C1 to the intersection C2 can be set to 48 mm or less. In such a downsized optical system, since the light guide range is short, it may be particularly important to deal with the problem that light enters during light guide and ghost light is generated. In the present embodiment, as described above, it is possible to cope with ghost light generation inside the light guide member 10. The distance (interval) from the intersection C1 to the intersection C2 may be, for example, not more than 48 mm, for example, 51 mm or less, and more specifically, for example, about 50.1 mm. Can be considered. When the distance (interval) from the intersection point C1 to the intersection point C2 is set to 51 mm or less, for example, an HMD that can be worn while wearing glasses can be realized.

  Further, in this case, the entire length of the projection lens 30 can be made shorter than before, and the lens thicknesses of the lenses 31 to 33 can be made thinner. As a result, further downsizing can be realized, and a more stylish appearance can be realized.

  In the present embodiment, as described above, the visual axis SX is inclined by 6.7 ° with respect to the lens optical axis LX and is inclined by approximately 10 ° from a state perpendicular to the light guide axis DX. The exterior shape is also made more stylish.

  In the present embodiment, as described above, the configuration of the projection lens 30 is a complicated off-axis optical system and has a more dense lens arrangement. Corresponding to this, the light emitted from the image display device 80 is further adjusted. That is, for each partial light beam emitted from the image plane OI that is the light emission surface of the image display device 80, the emission angle is asymmetric with respect to the lens optical axis LX indicating the center of the image display device 80.

  Explaining the above in the first and second directions DD1 and DD2, the x-rays in the plane (xy plane) parallel to the plane of the image plane OI of the image display device 80 with respect to each partial beam bundle constituting the video light GL. The emission angles in the second direction DD2 that is the y direction (vertical direction) of the light bundles emitted from the pixels arranged along the first direction DD1 that is the direction (horizontal direction) are different from each other. Become. Further, in the present embodiment, the curvature of the lens surface 33a of the projection lens 30 is changed according to the passage position of the partial light flux emitted from the image display device 80. Furthermore, the curvature of the lens surface 33a is changed corresponding to the incident angle of the partial light bundle (for example, the partial light bundle GLa and the partial light bundle GLb in FIG. 2) on the surface S12 of the light guide member 10.

  In the case of the configuration of the present embodiment, for example, as apparent from the relationship between the partial beam bundle GLa and the partial beam bundle GLb described above, the symmetry of the entire emitted beam bundle is broken, so that the light is narrowed down. At this time, even if a diaphragm having a normal symmetric shape and arrangement is provided, a desired function is not always achieved, and ghost light or the like may not be sufficiently removed. On the other hand, in the present embodiment, the diaphragm ST provided in the projection lens 30 has an asymmetry corresponding to the component of the video light GL, so that it is possible to surely remove excess light and perform high-performance image formation. It is said.

  Hereinafter, the structure of the diaphragm ST provided in the projection lens 30 will be described with reference to FIGS. FIG. 5A is a cross-sectional view illustrating a configuration of an example of the projection lens 30, and FIG. 5B is a front view of a lens barrel 39 that configures the projection lens 30. FIG. 6A is a diagram conceptually showing an arrangement relationship between the image display device 80 and the aperture stop ST of the projection lens 30 in the example shown in FIG. FIG. 6B is a diagram conceptually showing a modified example of the positional relationship between the image display device 80 and the aperture stop ST of the projection lens 30.

  Hereinafter, first, an example shown in FIGS. 5A, 5B, and 6A will be described. Here, as shown in the figure, it is assumed that a diaphragm ST is provided as a part of the inner surface of the lens barrel 39. Further, as shown in FIG. 5A, the aperture stop ST has a structure on a frame arranged perpendicular to the lens optical axis LX between the second lens 32 and the third lens 33. In particular, as shown in FIG. 5B, the aperture stop ST has a trapezoidal shape when viewed from the front. Thus, unnecessary light is appropriately cut corresponding to each partial beam bundle emitted from the image plane OI in the above-described asymmetric state so that unnecessary light (ghost light) is not generated inside or outside the image. It is possible to do.

  Hereinafter, the shape and structure of the aperture stop ST will be described in more detail. First, as shown in FIGS. 5A and 5B, here, similarly to the above, the x direction is the first direction DD1, and the y direction is the second direction DD2. In other words, it is perpendicular to the normal direction of the image plane OI (Z direction in which the lens optical axis LX in FIG. 2 extends) and the light guide direction of the light guide member 10 (of the light guide axis DX in FIG. 2). (Direction extending in the XZ plane as in the light guide direction in FIG. 2) is a first direction DD1, and a direction perpendicular to the normal direction of the image plane OI and the first direction DD1 is a direction corresponding to the direction extending in FIG. That is, the second direction DD2. Further, here, as shown in FIGS. 5B and 6A, in the aperture stop ST, an axis that intersects the lens optical axis LX passing through the center of the image plane OI and is parallel to the first direction DD1 is the first. The axis is XX1, and the axis that intersects the lens optical axis LX and is parallel to the second direction DD2 is the second axis XX2. Further, as shown in FIG. 6A and the like, a point where the first axis XX1, the second axis XX2, and the lens optical axis LX intersect is defined as an intersection CS. The intersection CS indicates the center of the aperture stop ST. In the above case, the rectangular opening OP formed by the stop ST corresponds to the asymmetry in the first direction DD1 and the symmetry in the second direction DD2 of each partial light bundle constituting the video light GL. The first axis XX1 is axisymmetric, and the second axis XX2 is non-axisymmetric.

  Next, a modification example shown in FIG. 6B will be described. As described above, FIG. 6B is a diagram conceptually showing the positional relationship between the image display device 80 and the aperture stop ST of the projection lens 30, and corresponds to FIG. 6A. Note that in FIG. 6B, the first axis XX1 and the like defined in FIG. 6A are similarly described in order to facilitate comparison with FIG. 6A. In the above example, the diaphragm arranged perpendicular to the normal direction of the image plane OI (the Z direction in which the lens optical axis LX in FIG. 2 extends) is shown as an example. As shown in FIG. 6B, the rectangular opening OP is provided obliquely with respect to the optical axis of the projection optical system. That is, as can be seen from comparison with FIG. 6A, the aperture stop ST shown in FIG. 6B is arranged so as to be rotated around the y-axis from the vertical arrangement state illustrated in FIG. 6A. It has become. As described above, the aperture stop ST is arranged so as to be inclined with respect to the lens optical axis LX, that is, arranged in a non-perpendicular manner, so that the opening can be rectangular (rectangular) instead of trapezoidal in front view. It can be a shape that looks like a trapezoid. By making the inclination degree of the aperture stop ST with respect to the lens optical axis LX correspond to the change in the emission angle, it becomes possible to more strictly remove unnecessary light. From another viewpoint, in this case, light is shielded spatially (three-dimensionally) in consideration of the depth direction along the lens optical axis LX. In this case, in addition to the case where the stop ST is formed along a non-vertical plane, the stop ST may be formed along a curved surface (non-plane).

  Hereinafter, as another viewpoint, light emission from the image display device 80 will be described. The light emitted from the image display device 80 has an angular luminance characteristic, and the angular luminance characteristic greatly depends on the pixel aperture shape. In general, the larger the aperture shape, the larger the full value half-angle of the angle luminance characteristic, i.e., it is emitted with high brightness even in a larger angle direction with respect to the panel normal, and the smaller the aperture shape, the total The half-value becomes smaller and becomes peaky. In particular, in an ultra-compact display device used for an HMD such as the virtual image display device 100 of this embodiment, the aperture shape of one pixel may be less than 10 μm. In this case, for example, the normal direction of the image plane OI The luminance in the direction inclined by about 20 ° with respect to the normal direction cuts 50%. As a result, luminance unevenness of the image may occur. In particular, in the case of an optical system in which the state of the light flux varies depending on the panel position as in the present embodiment, luminance unevenness can be a big problem. Therefore, in the present embodiment, the occurrence of uneven brightness is suppressed by adjusting the pixel layout so that the aperture of the pixel becomes larger as the emission angle becomes larger. In the case of the present embodiment, for example, the second direction DD2 is greater than the first direction DD1 so that the emission angle can be adjusted to be different in the second direction DD2 (y direction) depending on the position in the first direction DD1 (x direction). And the size of each aperture pixel may be changed depending on the position in the first direction DD1. It is also possible to maximize the luminance at a certain angle with respect to the normal direction of the panel depending on the substrate structure of the panel. That is, the direction of the light beam having the highest luminance among the light beams emitted from the image display device 80 can be made different depending on the pixel position of the image display device 80.

  Hereinafter, a more specific example of the optical configuration of the image display device 80 in the virtual image display device 100 will be described in detail with reference to FIG.

  First, as described above, the image display device 80 operates the image generation unit 81 in addition to the color filter layer CF disposed immediately after the image generation unit 81 as the image generation unit 81 and the light distribution control unit 82. It is a self-luminous image display device having a drive control unit (not shown) for controlling. An example of the configuration of the image display device 80 will be described more specifically with reference to FIGS. 7A and 7B. In the image display device 80, the image generation unit 81 includes a plurality of transparent electrodes that are pixel electrodes. (Anode) 71a, counter electrode (cathode) 72a, organic EL layer 73a as a light emitting functional layer (light emitting layer) disposed between transparent electrode 71a and counter electrode 72a, and protective layer 74a. The color filter layer CF as the light distribution control unit 82 is formed on the protective layer 74a. The color filter layer CF is composed of red, green, and blue color filter portions CFr, CFg, and CFb, and the color filter portions CFr, CFg, and CFb for each color are respectively connected to a plurality of transparent electrodes (anodes) 71a that are pixel electrodes. Correspondingly, they are arranged in a matrix. With the configuration as described above, the image display device 80 operates the electrodes 71a and 72a as appropriate to cause the organic EL layer 73a to emit light, so that the image generation unit 81 emits the video light GL from the image plane OI. It has become. That is, the image display device 80 includes the organic EL as a light source, and emits the video light GL for each pixel constituting the image plane OI. Further, the light emitted from the image generation unit 81 as the video light GL passes through the color filter layer CF, so that the color video light (image light) GL is emitted from the image display device 80. Here, in the present embodiment, in the color filter layer CF as the light distribution control unit 82, the pitch of the matrix pixels constituting the image plane OI, that is, the plurality of transparent electrodes 71a, 71a, 71a arranged in the matrix shape. The color filter portions CFr, CFg, and CFb for each color are arranged so that the pitch is different from the pitch. As a result, as shown in FIG. 7A, the positions of the color filter portions CFr, CFg, and CFb for each color correspond to each other on the peripheral side away from the lens optical axis LX that is the central optical axis of the image display device 80. The color filter layer CF is shifted with respect to the electrodes 71a, 71a, 71a (in the illustrated case, the position of the color filter portions CFr, CFg, CFb for each color is shifted to the right side or the position of the outer edge is shifted). The light distribution state of the component light emitted through is inclined in an oblique direction (in the illustrated case, right oblique direction), and the component light is emitted so as to approach the lens optical axis LX side. On the other hand, as shown in FIG. 7B, in the vicinity of the lens optical axis LX of the image display device 80, that is, in the center side, the above-described deviation does not occur or is small, so that the emitted component The component light is emitted vertically or substantially vertically without tilting the light distribution state. Thus, by adjusting the inclination of the emitted light for each position or for a certain area unit, a desired emission state (asymmetric state) can be configured.

  In other words, in the image display device 80, the image generation unit 81 is a pixel matrix formed by arranging pixels on the image plane OI in a matrix by a plurality of transparent electrodes 71a that are pixel electrodes. The color filter layer CF as the light control unit 82 has an image plane OI that has a large deviation from the center side toward the peripheral side with respect to the pitch of the matrix-like pixels constituting the image plane OI (the pitch of the transparent electrodes 71a). Each position has a different shape. Thus, the light distribution state is controlled to be suitable for each position of the image plane OI. That is, the light at the angle that should be the principal ray of the light emitted at each position is the strongest, and as a result, the color filter layer CF as the light distribution control unit 82 has each position on the image plane OI. Control is performed so that light is emitted with an intensity distribution that is strongest in the axial direction of the principal ray of the component emitted from. As described above, in the present embodiment, the color filter layer CF functions as the light distribution control unit 82 that controls the light distribution of the image light GL that is the emitted light.

  As described above, in the virtual image display device 100 according to the present embodiment, the first reflection relatively positioned on the incident side of the video light GL in the connection portion SS that connects the first reflection surface R1 and the second reflection surface R2. The surface R1 is projected to the viewer side more than the second reflection surface R2 positioned relatively on the image light emission side, and the connection surface SSa, which is the surface of the connection portion SS, extends from the first reflection surface R1 to the second. The shape is such that it extends toward the side away from the side closer to the observer over the reflecting surface R2. Thereby, even if a part of the external light OL is reflected, the reflection component RL is not directed to the downstream side of the optical path or is difficult to be directed to suppress the generation of ghost light. In addition, in the virtual image display device 100 according to the present embodiment, the projection lens 30 includes two different corner areas IA and OA from two points P1 and P2 on the image plane OI that is the light emission surface of the image display device 80, respectively. By making the lens surface 33a in a position where components that should reach the observer's eye of the bundle of emitted image light beams do not cross each other into a non-axisymmetric aspherical surface, various optical properties such as resolution and angle of view are obtained. While maintaining the accuracy, the optical system can be further downsized, and thus the entire apparatus can be downsized. At this time, in particular, by including the aperture stop ST that forms the square-shaped opening OP having a non-linear symmetry, each light flux from each point of the image display device 80 in the second direction DD2 as described above. Even if the light is emitted at different angles, light can be adjusted appropriately at the aperture stop ST, and a high-quality image can be provided.

[Second Embodiment]
The virtual image display device according to the second embodiment will be described below with reference to FIG. In addition, the virtual image display apparatus which concerns on 2nd Embodiment changes a part of light guide member among the virtual image display apparatuses of 1st Embodiment, and FIG. 8 is a figure corresponding to FIG. 4 (A). It is a figure which shows an example of the light guide member integrated in the virtual image display apparatus which concerns on this embodiment. In addition, since the parts that are not particularly described are the same as those in the first embodiment, the illustration and description of the entire virtual image display device are omitted.

  In the present embodiment, as in the first embodiment, as shown in FIG. 8, in the light guide member 10, a plurality of reflecting surfaces are configured by surfaces S <b> 11 to S <b> 15, and are arranged on the viewer side and adjacent to each other. It has a fourth surface S14 and a first surface S11 which are a pair of reflecting surfaces. In other words, the light guide of the image light in the light guide member 10 is common to the configuration of the first embodiment. Similarly to the case of the first embodiment, the fourth surface S14 relatively positioned on the incident side of the image light GL is defined as the first reflecting surface R1, and the first surface relatively positioned on the image light emitting side. Let S11 be the second reflecting surface R2. Further, a portion connecting the first reflecting surface R1 and the second reflecting surface R2 is a connecting portion SS, and in particular, the surface of the connecting portion SS, that is, the first reflecting surface R1 and the second reflecting surface R2 are continuously and smoothly smoothed. An inclined surface to be connected is defined as a connection surface (inclined connection surface) SSa. In this case, the first reflection surface R1 on the incident side is a free-form surface (fourth surface S14), and the second reflection surface R2 on the emission side is a flat surface (first surface S11). Furthermore, here, among the surfaces S11 to S15 constituting the plurality of reflecting surfaces of the light guide member 10, the first reflecting surface R1 (fourth surface S14) and the second reflecting surface R2 (first surface S11) are opposed to each other. The third surface S13 that is a surface is referred to as a third reflecting surface R3. The third reflecting surface R3 is a flat surface parallel to the second reflecting surface R2.

  On the other hand, in the present embodiment, for example, as shown in FIG. 8, the first reflection surface R1 has a concave portion TR that is recessed from the second reflection surface R2, and the light guide member 10 is connected to the connection portion SS. In the vicinity thereof, a concave portion CP is provided as a portion where the concave portion TR is formed. In the above points, the light guide member 10 in the present embodiment is different from that in the first embodiment. That is, in the first embodiment, the first reflecting surface R1 always protrudes toward the viewer as compared to the second reflecting surface R2 at the connection portion SS of the light guide member 10 and its periphery, and the second reflecting surface R2 is The part which protruded to the observer side rather than 1st reflective surface R1 did not exist. On the other hand, in the present embodiment, there is a portion where the first reflecting surface R1 protrudes closer to the viewer side than the second reflecting surface R2. In other words, the second embodiment is different from the first embodiment in that a state as shown in FIG. 4C exists. In the present embodiment, the connection portion SS has an inclination angle of the connection surface (inclined connection surface) SSa with respect to the second reflective surface R2 in the concave portion CP according to the concave portion TR of the first reflective surface R1, that is, according to the degree of dent. The connection portion SS is formed so as to keep θ below a predetermined value, thereby suppressing ghost light. In addition, in the concave portion CP, as shown in the figure, the surface portion includes a region A1 of the concave portion TR (end portion on the connection portion SS side) of the first reflecting surface R1, a region AS of the connection surface SSa of the connection portion SS, and It is comprised with area | region A2 of the edge part by the side of the connection part SS of 2nd reflective surface R2.

  As described in the first embodiment, in order to suppress the generation of ghost light, in the processing of the external light OL, it is avoided as much as possible that the component reflected by the connection portion SS (connection surface SSa) goes to the downstream side of the optical path. For this purpose, it is assumed that there is no portion where the second reflecting surface R2 protrudes closer to the viewer than the first reflecting surface R1, and there is a connecting surface SSa that smoothly connects these surfaces at the connecting portion SS. It is preferable not to go downstream in the optical path. However, the relationship between the first reflecting surface R1 and the second reflecting surface R2 is shown in the first embodiment in terms of the optical design of each reflecting surface, for example, due to the demand for miniaturization of the apparatus and maintenance of the angle of view and resolution. This state cannot always be maintained, and there may be a case where there is a portion where the first reflecting surface R1 protrudes closer to the viewer than the second reflecting surface R2.

  In this embodiment, even when such a situation is assumed, that is, when the component reflected by the connection portion SS (connection surface SSa) is directed toward the downstream side of the optical path, the ghost resulting from this The structure is such that generation of light is suppressed.

Hereinafter, with reference to FIG. 8 and FIG. 9, among the light guide member 10 constituting the virtual image display device according to the present embodiment, in particular, details regarding the first reflection surface R1, the second reflection surface R2, the connection portion SS, and the like. Explained. First, as shown in FIG. 8, in the present embodiment, the length of the light guide member 10 in the light guide direction (the direction of the arrow AP) in the third reflective surface R3 is larger than the center PP of the connection portion SS. the incident-side length of the light and L _1, the length of the exit side and L _2. That is, as shown in the figure, a perpendicular is drawn from the center PP to the third reflecting surface R3, and the foot (intersection) is defined as a foot (intersection) H. In this case, the foot (intersection) the length of the incident-side length of the image light for H from the light guide direction (the direction of the arrow AP) L _1, the length of the exit side length L _2. From the viewpoint of see-through, the total length of the combined i.e. length and the length L ₁ and length L ₂ of the third reflecting surface R3 is preferably as long as possible. For example, if it has the same length as the light guide member of the example shown in the first embodiment, it is desirable that L ₁ = 14 mm and L ₂ = 19.5 mm. The thickness D of the light guide member 10 (that is, the distance from the second reflecting surface R2 to the third reflecting surface R3) is, for example, about D = 10 mm from the viewpoint of securing the angle of view of the image light. Can be considered.

In the configuration as described above, the problem that is most likely to be a problem as the external light OL is obliquely incident from the portion on the image light incident side of the third reflection surface R3 (third surface S13) (third reflection surface R3). Is a reflection component RL that is reflected by the connection surface SSa of the connection portion SS. If such a reflection component RL propagates at an angle such that it directly faces the second surface S12 after reflection on the connection surface SSa, after reflection on the second surface S12, the eyes of the observer May reach the ghost light. On the other hand, as shown in FIG. 8, the reflection component RL reflected by the connection surface SSa does not directly reach the second surface S12, but goes to the third reflection surface R3 (third surface S13). If it is reflected at an angle, it can be prevented from reaching the observer's eye as a result. Specifically, as shown in FIG. 8, the reflection component RL is directed toward the third surface S13 (third reflection surface R3) positioned in front of the second surface S12. In this way, it is considered that the optical path of the reflection component RL deviates from the optical path of the image light and is not visually recognized as ghost light. Therefore, in this embodiment, the angle and shape of the connection surface SSa are adjusted in view of the above contents with respect to the angle at which the external light OL is incident, thereby suppressing the generation of ghost light. . Here, as shown in FIG. 9, the incident angle of the outside light OL for the third reflecting surface R3 and the incident angle alpha _0, and the refraction angle alpha ₁ after the incident. Furthermore, the angle between the normal of the reflection component RL and the second reflecting surface R2 (or the third reflecting surface R3) after reflecting the connecting surface SSa the angle alpha _2. Here, in order to simplify the description, it is assumed that the connection surface SSa has a constant or substantially constant inclination. That is, the maximum value of the inclination angle θ of the connection surface SSa with respect to the second reflection surface R2 is also the maximum inclination angle θ.

と表される。ここで、外光ＯＬが、第３反射面Ｒ３から入射する（特に導光方向に近い斜めの方向から入射する）条件は、α_０＜９０°（すなわちｓｉｎα_０＜１）であることから、上式（１）は、

となる。 Hereinafter, the relationship between the numerical values described above will be described with reference to relational expressions. First, the relationship between the incident angle α ₀ and the refraction angle α ₁ of the external light OL as incident light on the third reflecting surface R 3 is determined using the refractive index n ₁ (relative refractive index with respect to air) of the light guide member 10. By Snell's law,

It is expressed. Here, the condition that the external light OL is incident from the third reflecting surface R3 (particularly from an oblique direction close to the light guide direction) is α ₀ <90 ° (that is, sin α ₀ <1). The above formula (1) is

It becomes.

すなわち、

となる。 Next, with respect to the refraction angle α ₁ , the inclination angle (maximum inclination angle) θ, and the angle α ₂ , from the reflection condition on the inclined connection surface SSa,

That is,

It becomes.

となっていれば反射成分ＲＬが第２面Ｓ１２よりも手前に位置する第３面Ｓ１３（第３反射面Ｒ３）に到達すると考えられる。上式（４）に、上式（３）を代入し、変形すると、

となる。なお、上式（５）において、屈折角α_１の値は、上式（２）に示すように、導光部材１０の屈折率ｎ_１から算出できる。 Here, since the outer light OL is not visually recognized as ghost light, as described above, the propagation angle of the reflected component RL after reflected on the inclined connecting surfaces SSa angle alpha ₂ is sufficient that sufficiently small values It will be good. Here, from the situation shown in the figure, it is considered that the angle α ₂ only needs to be a sufficiently small value in the relationship between the ratio of the length L ₂ and the thickness D. That is,

If so, it is considered that the reflection component RL reaches the third surface S13 (third reflection surface R3) positioned in front of the second surface S12. Substituting the above equation (3) into the above equation (4) and transforming it,

It becomes. In the above equation (5), the value of the refraction angle α ₁ can be calculated from the refractive index n ₁ of the light guide member 10 as shown in the above equation (2).

  When the inclination angle (maximum inclination angle) θ of the inclined connection surface SSa with respect to the second reflecting surface R2 satisfies the above equation (5), the shape of the light guide member 10 is taken into account and the inclined connection surface is accordingly determined. Even when the component reflected by SSa goes to the downstream side of the optical path, generation of ghost light due to this can be suppressed.

すなわち、上記構成例の場合、最大傾斜角度θが、１０．９°未満となっていれば、上記要件を満たし、十分なゴースト光抑制の効果が期待される構成になる。 About the light guide member 10 which concerns on this embodiment, as an example which shall have a structure and shape (size) equivalent to 1st Embodiment, in the whole structure other than local parts, such as connection part SS, above-mentioned length, an angle, etc. As specific numerical values, it is assumed that n ₁ = 1.52, L1 = 14 mm, L2 = 19.5 mm, and D = 10 mm. In such a case, the inclination angle (maximum inclination angle) θ may satisfy the following expression (6) from the above expression (5).

That is, in the case of the above configuration example, if the maximum inclination angle θ is less than 10.9 °, the above requirement is satisfied and a sufficient ghost light suppression effect is expected.

  Hereinafter, the inclination angle θ, that is, the shape and structure of the connecting portion SS (or the inclined connecting surface SSa) will be further considered.

と近似できる。導光部材１０の光学設計にも依るが、最大差Ｇについては、例えば、０．２ｍｍ程度となることが想定される。一方、幅Ｗについては、１．７ｍｍ以上とすること場合が考えられる。以上の場合、上式（７）により、傾斜接続面ＳＳａの傾斜角度（最大傾斜角度）θは、６．９°程度とすることができる。例えば、傾斜角度（最大傾斜角度）θを６．９°以下とすれば、上式（６）より、傾斜接続面ＳＳａで反射された成分が光路下流側に向かうような場合であっても、これに起因するゴースト光の発生を十分に抑えることができると考えられる。 As shown in a partially enlarged view in FIG. 9, in the connection portion SS, the width of the light guide member 10 in the light guide direction (the direction of the arrow AP) is defined as a width W, and the first reflection surface R1 and the second reflection surface R2. If the step difference from the maximum difference (maximum difference in the overhang direction) is the maximum difference G,

Can be approximated. Although depending on the optical design of the light guide member 10, the maximum difference G is assumed to be about 0.2 mm, for example. On the other hand, the width W may be 1.7 mm or more. In the above case, according to the above equation (7), the inclination angle (maximum inclination angle) θ of the inclined connection surface SSa can be set to about 6.9 °. For example, if the inclination angle (maximum inclination angle) θ is 6.9 ° or less, from the above equation (6), even when the component reflected by the inclined connection surface SSa goes to the downstream side of the optical path, It is considered that the generation of ghost light due to this can be sufficiently suppressed.

  In the above description, it is assumed that the inclination angle θ is also the maximum inclination angle θ, but the same can be considered when the inclination angle on the inclined connection surface SSa differs depending on the position. That is, the above relationship can be maintained because the inclination angle is equal to or smaller than the predetermined value in the entire area of the inclined connection surface SSa.

Hereinafter, with reference to FIG. 10, the shape and configuration of the connection portion SS in the vertical direction (y direction) will be described while comparing the difference from the case of the first embodiment. FIG. 10A shows again FIG. 3C for comparison with the first embodiment. FIG. 10B is a conceptual diagram in which a portion related to the connection portion SS is extracted as a part of FIG. FIG. 10C is a diagram corresponding to FIG. 10B, and is a conceptual diagram in which a portion related to the connection portion SS in the present embodiment is extracted. As is clear from a comparison between FIG. 10B and FIG. 10C, the maximum thickness n in the overhang direction (thickness direction) differs between the first embodiment and the present embodiment. Specifically, in the first embodiment, as shown in FIG. 10B, and as described above, the thickness n of the connecting surface SSa in the protruding direction (thickness direction) DS in the connecting portion SS. Is maintained between 0 ≦ n ≦ 2 mm and changes. That is, the connection surface SSa has a maximum thickness n _max of 2 mm or less in the overhang direction (thickness direction), and the thickness n is a negative value over the entire connection portion SS (the first value). The positional relationship between the reflecting surface R1 and the second reflecting surface R2 is not reversed). On the other hand, in the present embodiment, as shown in FIG. 10C, the thickness n in the protruding direction of the first reflecting surface R1 with respect to the second reflecting surface R2 is −0 over the entire connecting portion SS. 2 ≦ n ≦ 2 mm. That is, there may be a portion where the positional relationship between the first reflecting surface R1 and the second reflecting surface R2 is reversed, and n may be a negative value. In other words, the first reflective surface R1 can be in a state of being recessed with respect to the second reflective surface R2. A portion in such a situation forms the concave portion CP shown in FIGS. Note that the case where n is the minimum negative value corresponds to the case where the above-described maximum difference G is 0.2 mm.

  Hereinafter, with reference to FIG. 11, a modification of the light guide member constituting the virtual image display device according to the present embodiment will be described. In the modification shown in FIG. 11, the connecting portion SS has a processed surface portion PS1 that is sand-printed or black-painted. Further, among the third reflecting surface R3 which is the reflecting surface facing the first reflecting surface R1 and the second reflecting surface R2, the sand printing is performed particularly on the incident side of the image light from the connection portion that is likely to cause the problem of the external light OL. Or it has the processing surface part PS2 painted black. By having the processed surface portions PS1 and PS2 that are sand-printed or black-painted in the above-described places, it is possible to absorb or diffuse the external light OL and suppress the generation of ghost light due to the external light OL. In addition, it is good also as a structure which has only any one among process surface parts PS1 and PS2, and it is good also as a structure which has both like illustration.

  As described above, in the virtual image display device according to this embodiment, in the connection portion SS that connects the first reflection surface R1 and the second reflection surface R2, the inclination angle θ of the connection surface SSa, which is the surface, with respect to the second reflection surface R2. Thus, even when the reflection component RL from which a part of the external light OL is reflected is directed toward the downstream side of the optical path, generation of ghost light due to this is suppressed.

  In addition to this, for example, in order to suppress generation of ghost light due to stray light from the light source side, black coating may be applied to various places as necessary. For example, it may be possible to deal with ghost light or the like caused by image light by blackening the edge of the lens.

  In the above description, the second reflecting surface R2 and the third reflecting surface R3 are parallel planes, but the present invention can also be applied to a case where the second reflecting surface R2 and the third reflecting surface R3 are configured by parallel curved surfaces.

  Further, in the above, in the first reflecting surface R1, the first reflecting surface R1 is recessed from the second reflecting surface R2, and the concave portion TR is partially formed (see FIG. 10C). It is also conceivable that the concave portion TR is formed over the entire surface.

[Others]
Although the present invention has been described with reference to each embodiment, the present invention is not limited to the above-described embodiment, and can be implemented in various modes without departing from the scope of the present invention. For example, in the above, image light beams emitted from two points P1 and P2 of different corner areas IA and OA on the image plane OI that is the light emission surface of the image display device 80 reach the observer's eye. Although the non-axisymmetric aspheric surface (lens surface 33a) is arranged at a position where the power components do not intersect with each other, it may not have such a surface shape.

  In the above description, the image generating unit 81 including an OLED (organic EL) is used as the image display device (video element) 80. However, the image display device 80 is not limited to this, and a transmissive liquid crystal display device is used. Various things, such as what is comprised with a backlight, can be utilized.

  Further, for example, a configuration using a reflective liquid crystal display device is possible, and a digital micromirror device or the like can be used instead of the image generation unit 81 formed of a liquid crystal display device or the like. Moreover, an LED array etc. can also be used as a self-light-emitting element.

  Moreover, in the said embodiment, although the panel type image display apparatus 80 containing OLED (organic EL) is used, it can replace with this and a scanning type image display apparatus can also be used. Specifically, for example, a light diffusing element is arranged on the image plane OI, and light is scanned at the position of the image plane OI by a scanning illumination optical system to form an image. By injecting, a configuration similar to the above can be applied.

  Moreover, in the said embodiment, although the left and right light guide apparatuses 20 are each produced separately, it can also be set as the structure which shares not only this but a light transmissive member, for example. 12A and 12B are conceptual diagrams for explaining a modification of the light guide device. In this example, the pair of left and right light guide members 10 and 10 and the light transmissive member 150 are connected by sandwiching one light transmissive member 150 by the pair of left and right light guide members 10 and 10 to form an integrated optical member. It functions as a light guide device 20 in which the left and right are integrated. In this case, alignment for binocular vision can be performed easily and accurately by the light transmission member 150. For example, as shown in FIG. 12A, the right and left angles can be defined by bending the center portion CE of the light transmitting member 150 appropriately. For example, as shown in FIG. 12B, by providing depressions CVa and CVb at the upper and lower ends in the center part CE, the depressions CVa and CVb can be made to the light transmitting member 150 in the manufacturing process. It can be used for positioning (position fixing) for bonding and fixing the light guide members 10, 10, or used as a location for providing a nose receiving portion.

  In the above description, the light guide device 20 includes the light incident part (second light guide part 12) to the light emission part (first light guide part 11) as a single member. Besides, for example, the image light GL is directly incident on the light guide portion by total reflection without passing through the light reflection surface configured by the light reflection film RM (see FIG. 2), or the light guide of the light guide device 20. The member 10 may be configured to be separated into a light incident part and a light guide part constituted by a prism or the like.

  In the above description, the projection lens 30 composed of a plurality of lenses is employed as the projection optical system. However, the present invention is not limited to this, and for example, as shown in FIG. 13, the projection prism optical system 230 that is a prism-like member. The projection optical system may be configured as described above. Also in this case, for example, among the light beams of the image light emitted from the image display device 80 among the surfaces 231a to 233a contributing to the optical path change in the projection prism optical system 230, the light reaches the observer's eye. By making the light incident surface 233a arranged at a position where the partial light bundles GLa and GLb, which are power components, do not intersect with each other, a non-axisymmetric aspheric surface (free curved surface), appropriate aberration correction can be performed. Note that the reflecting surface 232a and the light exit surface 231a, which are surfaces other than the light incident surface 233a, may also be non-axisymmetric aspheric surfaces (free curved surfaces). Furthermore, in the drawing, the projection prism optical system 230 that is a projection optical system and the light guide device 20 (light guide member 10) are not connected but are separate, but these are connected and integrated. It is also possible to have a configuration. Here, for example, the projection prism optical system 230 has a non-linear shape corresponding to each of the partial beam bundles as described above, and an appropriate stop process is performed by providing the arranged aperture ST. be able to.

  Among the above, in FIG. 6B and the like, the diaphragm ST disposed obliquely is described as a modified example. However, the arrangement and the shape of the opening OP when disposed obliquely are other than those described above. In addition, various modes are possible. For example, the tilting direction may be reversed from the case shown in FIG. The arrangement and shape of the aperture stop ST can be optimized according to various situations such as the shape of the light beam and the difference in light to be captured. For example, the shape of the opening OP can be changed as appropriate, such as which of the left and right in the horizontal direction is increased.

  In the above description, the half mirror layer (semi-transmissive reflective film) 15 is formed in a horizontally long rectangular region. However, the contour of the half mirror layer 15 can be appropriately changed according to the application and other specifications. Further, the transmittance and reflectance of the half mirror layer 15 can be changed according to the application and the like.

  In the above description, the virtual image display device 100 including the pair of display devices 100A and 100B is described. However, a single display device can be used. That is, the projection fluoroscopic device 70 and the image display device 80 are not provided for each of the right eye and the left eye, but only for either the right eye or the left eye. An image display device 80 may be provided so that the image is viewed with one eye.

  In the above description, the half mirror layer 15 is merely a semi-transmissive film (dielectric multilayer film). However, the half mirror layer 15 can be replaced with a planar or curved hologram element. In addition, instead of the half mirror layer 15, a plurality of fine reflecting surfaces can be arranged on the curved surface, a Fresnel mirror, or another diffraction element can be used.

  In the above description, the light guide member 10 and the like extend in the horizontal direction in which the eyes EY are arranged. However, the light guide member 10 can be arranged to extend in the vertical direction. In this case, the light guide member 10 has a structure arranged in parallel, not in series.

  In addition, the connection portion SS can be provided at various locations according to the number of reflections of the reflection surface and the like, and the number of reflection surfaces associated therewith. The connection portion SS having the shape and structure described above is provided at a plurality of locations. It may be provided.

  In each of the above embodiments, for example, conceptually shown in FIG. 14, when the video light GL is guided by the light guide member 10 in the light guide device 20, the video light GL passes through the vicinity of the connection portion SS. The position (imaging position) AR2 of the intermediate image of the component is separated from the reflection position AR1 of the component on the first reflection surface R1 (fourth surface S14) (in the illustrated case, the fourth surface S14 and the first surface). An intermediate image is formed (formed) on the third surface S13 side facing S11.) In other words, the position AR2 of the intermediate image of the image light GL reflected near the connection portion SS is separated from the connection portion SS, and the image light GL when passing through the reflection position AR1 near the connection portion SS and its periphery is blurred. It is in a state. As a result, when the video light GL passes near the connection portion SS, an unintended component is slightly introduced due to reflection or scattering of external light near the connection portion SS and guided by the light guide member 10. Even if there is, it is possible to suppress the influence such as the generation of ghost light. More specifically, by separating the intermediate image position AR2 from the reflection position AR1, for example, even if an unintended component as described above is included, the image light GL is transmitted to the observer's eye with respect to the component. Can be guided and emitted at a position away from the range of the optical path where the light is guided and emitted, so that it is difficult to see the invading outside light. Further, since the video light GL is in a blurred state when passing through the vicinity of the connection portion SS, the connection portion SS having a complicated uneven shape can be prevented from being focused at the position of the eyes of the observer, and the connection portion SS Can be prevented from being visually recognized. Contrary to the above case, if the configuration is such that the position AR2 of the intermediate image is close to the vicinity of the connection portion SS, it is likely to be affected by components caused by outside light unintentionally entering the video light GL. The possibility is considered to increase. On the other hand, as described above, in each embodiment, the reflection position AR1 of the component reflected at least near the connection portion SS in the image light GL reflected by the first reflection surface R1 (fourth surface S14) is set. Such a situation can be avoided by separating the intermediate image from the position AR2.

  Moreover, various aspects are possible also about the external appearance structure of a virtual image display apparatus, for example, it is also possible to apply this invention in the virtual image display apparatus 200 of an external appearance shape as shown in FIG. In addition, about each part which comprises the virtual image display apparatus 200 of illustration, what is shown with the same code | symbol as the virtual image display apparatus 100 shown in FIG. 1 is the same, and description is abbreviate | omitted. That is, regarding the light guide members 10 and 10 in the virtual image display device 200, it is possible to incorporate the structures as in the above-described embodiments.

  Further, for example, as in the case where an optical system is configured by bonding a projection prism (prism-shaped projection optical system) to a parallel flat light guide member, members of two parts (or two or more parts) are joined. The connection part (joint part) may have a structure adapted to external light as in the present application.

AP ... arrow, C1 ... intersection, C2 ... intersection, CC ... adhesive layer, CE ... center part, CF ... color filter layer, CFr, CFg, CFb ... color filter part for color, CS ... intersection, CVa, CVb ... recessed part Part, DD1 ... first direction, DD2 ... second direction, DS ... extension direction (thickness direction), DX ... light guide axis, ER1 ... region portion, ER2 ... region portion, EY ... predicted eye position (eye), GL ... Image light, GLa, GLb ... Partial beam, HL ... External light, IA, OA ... Corner area, LX ... Lens optical axis, OI ... Image plane, OL ... Outside light, OP ... Opening, P1, P2 ... Point, PF1 ... extension surface, R1 ... first reflection surface (S14 ... fourth surface), R2 ... second reflection surface (S11 ... first surface), R3 ... third reflection surface (S13 ... third surface), RL ... reflection Component, RM: Light reflecting film, S11-S15: Surface, S 1-S53 ... transmission surface, SF1 ... first surface, SF2 ... second surface, SS ... connection portion, SSa ... connection surface (inclined connection surface), SX ... line of sight, XX1 ... first axis, XX2 ... second axis 31-33 ... lens (optical element), 10 ... light guide member, 10s ... main body, 11 ... light guide part (light emitting part), 12 ... light guide part (light incident part), 15 ... half mirror layer (half) Transmitting / reflecting part, 20 ... light guide device, 27 ... hard coat layer, 30 ... projection lens (projection optical system), 31a ... lens surface, 33a ... lens surface, 39 ... lens barrel, 40 ... nose receiving part, 50 ... light Transmissive member, 70 ... projection fluoroscopic device, 71a, 71a, 71a ... transparent electrode, 72a ... counter electrode, 73a ... organic EL layer (light emitting layer), 74a ... protective layer, 80 ... image display device (video element), 81 ... Image generation unit 82 ... Light distribution control unit 100 ... Imaginary Image display device, 100A, 100B ... display device, 101a, 101b ... optical member, 102 ... frame portion, 105a, 105b ... image forming body portion, 150 ... light transmitting member, 230 ... projection prism optical system (projection optical system), 231a ... light emitting surface, 232a ... reflecting surface, 233a ... light incident surface A1, A2, AS ... region, CP ... concave, G ... maximum difference, PP ... center, PS1, PS2 ... machined surface portion, TR ... concave portion, W: width, n ₁ ... refractive index, α ₀ ... incidence angle, α ₁ ... refraction angle, α ₂ ... angle, θ ... tilt angle (maximum tilt angle), 200 ... virtual image display device

Claims (20)

An image element for generating image light;
A light guide member that has a plurality of reflection surfaces and guides the image light from the image element by being reflected by the inner surface, and makes the image light and the external light visible in an overlapping manner,
The light guide member is disposed on the opposite side to the outside light incident side of the plurality of reflection surfaces and is adjacent to the first reflection surface, and on the image light emission side from the first reflection surface. A virtual image display having a second reflecting surface positioned and projecting the first reflecting surface beyond the second reflecting surface at a connection portion connecting the first reflecting surface and the second reflecting surface. apparatus. The first reflecting surface is a free-form surface;
The virtual image display device according to claim 1, wherein the second reflecting surface is a flat surface.   The thickness n in the projecting direction of the first reflecting surface with respect to the second reflecting surface in the connecting portion is maintained at 0 ≦ n ≦ 2 mm over the entire connecting portion. The virtual image display device according to any one of the above.   4. The virtual image display device according to claim 1, wherein the connection unit includes a connection surface that continuously connects the first reflection surface and the second reflection surface. 5.   The light guide member includes a first surface including the first reflection surface and the entire extension surface extending the first reflection surface, and the second reflection surface and the entire extension surface extending the second reflection surface. The first surface is extended beyond the second surface in the entire connected range, and is connected to the second surface including the second surface by the connecting portion. The virtual image display device described. An image element for generating image light;
A light guide member that has a plurality of reflection surfaces and guides the image light from the image element by being reflected by the inner surface, and makes the image light and the external light visible in an overlapping manner,
The light guide member is disposed on the opposite side to the outside light incident side of the plurality of reflection surfaces and is adjacent to the first reflection surface, and on the image light emission side from the first reflection surface. Having a second reflection surface located, and having a connecting portion connecting the first reflection surface and the second reflection surface,
The connection portion maintains an inclination angle equal to or less than a predetermined value with respect to the second reflection surface according to the concave portion at a location where the first reflection surface is recessed from the second reflection surface to form a concave portion. A virtual image display device that forms an inclined connection surface.   In the connecting portion, the inclination angle of the inclined connecting surface with respect to the second reflecting surface is the difference between the concave portion of the first reflecting surface with respect to the second reflecting surface, and the light guide of the light guide member of the connecting portion. The virtual image display device according to claim 6, which is determined according to a width with respect to a direction.   The virtual image display device according to any one of claims 6 and 7, wherein a width of the connection portion in the light guide direction of the light guide member is 1.7 mm or more.   The thickness n in the projecting direction of the first reflecting surface with respect to the second reflecting surface in the connecting portion is maintained at −0.2 ≦ n ≦ 2 mm over the entire connecting portion. 9. The virtual image display device according to any one of items 1 to 8. The maximum inclination angle θ of the inclined connection surface with respect to the second reflection surface is the light guide of the light guide member on the third reflection surface facing the first reflection surface and the second reflection surface among the plurality of reflection surfaces. the center of the connecting portion to the direction of the length to the length of the exit side of the image light and L _2, the refraction angle of external light incident from the third reflecting surface and alpha _1, perpendicular to the second reflecting surface When the thickness of the light guide member in any direction is D,

The virtual image display device according to any one of claims 6 to 9, wherein   The virtual image display device according to any one of claims 6 to 10, wherein a maximum inclination angle of the inclined connection surface with respect to the second reflecting surface is 6.9 ° or less.   The virtual image display device according to claim 6, wherein the connection portion is sand-printed or black-painted.   The reflective surface opposite to the first reflective surface and the second reflective surface has a portion that is sanded or blackened on the incident side of image light from the connection portion with respect to the light guide direction of the light guide member. The virtual image display device according to any one of claims 6 to 12. The light guide member includes two or more non-axisymmetric curved surfaces,
The first surface and the third surface of the plurality of reflecting surfaces constituting the light guide member are arranged to face each other, and when the outside is visually recognized through the first surface and the third surface. The diopter is almost 0,
The image light from the image element is totally reflected by the third surface, totally reflected by the first surface, reflected by the second surface, and then passes through the first surface to reach the observation side. The virtual image display device according to any one of claims 1 to 13. The light guide member includes a fourth surface that is adjacent to the first surface and reflects video light to be incident on the third surface;
The first reflective surface is the fourth surface;
The virtual image display device according to claim 14, wherein the second reflection surface is the first surface.   The virtual image display device according to any one of claims 1 to 15, further comprising a projection optical system that causes video light from the video element to enter the light guide member.   The projection optical system includes at least one non-axisymmetric aspheric surface. The one non-axisymmetric aspheric surface is image light emitted from two points in different corner regions on the light exit surface of the image element. The virtual image display device according to claim 16, wherein the components that should reach the eyes of the observer are arranged at positions where they do not cross each other. A direction perpendicular to the normal direction of the light emitting surface of the image element and corresponding to the light guide direction of the light guide member is defined as a first direction, and the normal direction and the first direction are defined as the first direction. When the vertical direction is the second direction,
The projection optical system is disposed perpendicular to the optical axis of the projection optical system that passes through the center of the image element and is parallel to the normal line direction, and extends in parallel with the first direction so that the optical axis of the projection optical system A quadrangular opening that is axisymmetric about a first axis that intersects the optical axis and extends parallel to the second direction and is axisymmetric about a second axis that intersects the optical axis of the projection optical system, or the optical axis of the projection optical system The virtual image display device according to any one of claims 16 and 17, further comprising a diaphragm that forms a square-shaped opening that is arranged non-perpendicular to the vertical direction.   In the light guide member, it is assumed that the light emission part arranged on the light emission side from the intersection of the light incident part arranged on the light incident side and the projection optical system optical axis of the projection optical system and the observer's line of sight The virtual image display device according to any one of claims 16 to 18, wherein a distance to an intersection with the visual axis to be performed is 48 mm or less.   The light guide member includes a transflective portion that partially reflects and transmits image light from the video element and external light, and is connected to the light transmissive member with the transflective portion interposed therebetween. The virtual image display device according to any one of claims 1 to 19.

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