JP2016018103A - Optical element and display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical element that can suppress distortion of an image of an external object, and a display device using the optical element.SOLUTION: The optical element includes a first light-transmitting member 21 having a first face 21a, a second face 21b, and a first reflective part 24 including a plurality of projections 24a; a second light-transmitting member 22 having a third face 22a, a fourth face 22b, and a second reflective part 25 including a plurality of recesses 25a; and a light-transmitting layer 23 having a refractive index different from the refractive index of the first light-transmitting member 21 and from the refractive index of the second light-transmitting member 22. Each of the plurality of projections 24a has a first inclined face 26a inclined with respect to the second face 21b; and each of the plurality of recesses 25a has a second inclined face 27a inclined with respect to the fourth face 22b. The first light-transmitting member 21 and the second light-transmitting member 22 are disposed in such a manner that the plurality of projections 24a meshes with the plurality of recesses 25a via the light-transmitting layer 23.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an optical element and a display device.

For example, as disclosed in Patent Document 1, a display device such as a head-up display including a half mirror has been proposed.
However, in such a display device, since the half mirror is curved, there is a problem that the installation area of the half mirror becomes large and the entire display device becomes large.

  On the other hand, it is conceivable to use a laminate having a Fresnel lens structure as disclosed in Patent Document 2, for example, as the half mirror of the display device as described above. Since such a laminated body can have a function as a half mirror while flattening the surface, the installation area of the laminated body can be reduced in the display device, and the entire display device can be downsized.

Japanese Patent Laid-Open No. 11-30764 JP 2007-206657 A

  However, in a laminated body having a Fresnel lens structure as described above, that is, an optical element, light transmitted through the laminated body is refracted by the Fresnel lens structure and emitted in a direction different from the incident direction. Therefore, there has been a problem that an image of an external object visually recognized through the laminated body is distorted.

  One aspect of the present invention is made in view of the above problems, and provides an optical element capable of suppressing distortion of an image of an external object, and a display device using such an optical element. One of the purposes.

  According to one aspect of the optical element of the present invention, the first reflection includes a first surface, a second surface facing the first surface, and a plurality of convex portions provided on the second surface. A first light transmissive member provided with a portion, a third surface, a fourth surface opposite to the third surface, and the fourth surface. A second light transmissive member including a second reflecting portion including a plurality of concave portions to be copied, and a refractive index of the first light transmissive member and a refractive index of the second light transmissive member are different from each other. A light transmission layer having a refractive index, and each of the plurality of convex portions includes a first inclined surface inclined with respect to the second surface, and each of the plurality of concave portions includes the first A second inclined surface inclined with respect to the surface of the first light transmitting member and the second light transmitting member so that the plurality of convex portions engage with the plurality of concave portions via the light transmitting layer. Light transmissive member Wherein the but are arranged.

  According to one aspect of the optical element of the present invention, the convex portion of the first reflective portion and the concave portion of the second reflective portion that follows the convex portion are arranged so as to engage with each other via the light transmission layer. Therefore, the transmitted light among the light incident on the optical element is refracted in opposite directions at the boundary between the convex portion and the light transmission layer and at the boundary between the concave portion and the light transmission layer. Thereby, the direction of the light incident on the optical element and the direction of the light emitted from the optical element become substantially parallel. Therefore, according to one aspect of the optical element of the present invention, distortion of an image of an external object can be suppressed.

The plurality of convex portions may constitute a Fresnel lens structure.
According to this configuration, it is possible to collect the reflected light among the light incident from the first light transmissive member side.

The plurality of convex portions may include a convex portion having a triangular cross section.
According to this configuration, it is easy to form the convex portion.

The plurality of convex portions may form a stripe structure, and may reflect light traveling in the first direction from the first light transmissive member toward the second light transmissive member.
According to this configuration, it is possible to deflect the reflected light among the light incident from the first light transmitting member side.

The plurality of convex portions include a first convex portion, a second convex portion adjacent to the first convex portion, and the first inclined surface included in the first convex portion. It is good also as a structure further provided with the 1st connection surface connected to the said 1st inclined surface with which a part is provided, and the 1st light absorption member provided in this 1st connection surface.
According to this configuration, it is possible to suppress degradation in visibility due to light obliquely incident on the back cut portion and stray light.

The plurality of concave portions include a first concave portion, a second concave portion adjacent to the first concave portion, and the second inclined surface provided in the first concave portion. It is good also as a structure further provided with the 2nd connection surface connected to this inclined surface, and the 2nd light absorption member provided in this 2nd connection surface.
According to this configuration, it is possible to suppress degradation in visibility due to light obliquely incident on the back cut portion and stray light.

At least one of the first surface and the third surface has a curved portion, and the first surface with respect to light traveling from the first light transmissive member side toward the second light transmissive member side. The deflecting action of one reflecting part may be different from the deflecting action of the curved surface part with respect to the light.
According to this configuration, light incident from different directions can be reflected in the same direction.

The light transmission layer may be made of a metal.
According to this configuration, the reflectance and transmittance of the light transmission layer can be adjusted by adjusting the thickness.

One aspect of the display device of the present invention includes an image forming apparatus that emits image light, and the optical element that is provided on an optical path of the image light.
According to one aspect of the display device of the present invention, since the optical element is provided, distortion of an image of an external object can be suppressed.

It is a schematic block diagram which shows the display apparatus of 1st Embodiment. It is a partial expanded section which shows the optical element of 1st Embodiment. It is a partial expanded section which shows the optical element of 1st Embodiment. It is a top view which shows the optical element of 1st Embodiment. It is a partial expanded sectional view which shows another example of the optical element of 1st Embodiment. It is a partial expanded sectional view which shows another example of the optical element of 1st Embodiment. It is a schematic block diagram which shows the display apparatus of 2nd Embodiment. It is a schematic block diagram which shows the display apparatus of 3rd Embodiment. It is a perspective view which shows the optical element of 3rd Embodiment. It is a schematic block diagram which shows another example of the display apparatus of 3rd Embodiment. It is a schematic block diagram which shows the display apparatus of 4th Embodiment.

Hereinafter, a display device according to an embodiment of the present invention will be described with reference to the drawings.
The scope of the present invention is not limited to the following embodiment, and can be arbitrarily changed within the scope of the technical idea of the present invention. Moreover, in the following drawings, in order to make each structure easy to understand, the actual structure may be different from the scale, number, or the like in each structure.

  In the drawings, an XYZ coordinate system is appropriately shown as a three-dimensional orthogonal coordinate system, the Z-axis direction is a vertical line direction, and the Y-axis direction and the X-axis direction are horizontal directions. The Y-axis direction is the direction of the line of sight Ma of the observer M shown in FIG. The + Y direction is the direction of the line of sight Ma of the observer M.

(First embodiment)
FIG. 1 is a schematic configuration diagram illustrating a display device 10 according to the present embodiment. 2 to 4 are diagrams showing the optical element 20. 2 and 3 are partially enlarged sectional views. FIG. 4 is a plan view. In FIG. 1 and FIG. 2, the illustration of the light absorbing member is omitted.

  As shown in FIG. 1, the display device 10 of the present embodiment includes an image forming device 30 and an optical element 20. The display device 10 of the present embodiment is a head-up display. The observer M visually recognizes an image of an external object located across the optical element 20, that is, an external scenery, and visually recognizes an image by the image forming apparatus 30. In the following description, the + Y side is the external side, and the -Y side is the viewing side.

  The image forming apparatus 30 is disposed at a position closer to the optical element 20 than the focal point of the Fresnel lens structure formed on the optical element 20 described later. Although not shown, the image forming apparatus 30, for example, combines a plurality of liquid crystal panels that form image light by modulating red, green, and blue light and image light that is emitted from each liquid crystal panel. A photosynthesis system; and a projection optical system that emits the synthesized light. As a result, the image light L obtained by combining the three color image lights is emitted from the image forming apparatus 30 toward the optical element 20.

  The optical element 20 includes a viewing side light transmissive member 21, an external side light transmissive member 22, and a light transmissive layer 23. The viewing side light transmissive member 21 corresponds to a first light transmissive member in the claims, and the external side light transmissive member 22 corresponds to a second light transmissive member in the claims.

  As shown in FIG. 2, the viewing-side light transmissive member 21 includes a viewing surface 21 a, a forming surface 21 b, and a viewing-side reflecting portion 24. Moreover, the viewing side light transmissive member 21 includes a plurality of light absorbing members as shown in FIG. The viewing surface 21a corresponds to the first surface of the claims. The formation surface 21b corresponds to the second surface of the claims. The viewing side reflection part 24 is equivalent to the 1st reflection part of a claim.

  The planar view (ZX plane view) shape of the viewing-side light transmissive member 21 is not particularly limited, and may be rectangular, polygonal, or circular. In this embodiment, the planar view (ZX plane view) shape of the visual recognition side light transmissive member 21 is, for example, a rectangular shape as shown in FIG.

As shown in FIG. 1, the viewing surface 21 a is a surface on the viewer M side of the viewing-side light transmissive member 21. In the present embodiment, the visual recognition surface 21a is a flat surface. FIG. 1 shows a case where the line of sight Ma of the observer M is orthogonal to the viewing surface 21a. The image light L is incident on the viewing surface 21a from the image forming apparatus 30.
The formation surface 21b is a surface facing the visual recognition surface 21a. As shown in FIG. 2, a viewing-side reflecting portion 24 is provided on the formation surface 21 b.

The viewing side reflection part 24 includes a plurality of convex parts. The viewing-side reflecting unit 24 reflects at least a part of the incident light and transmits at least a part of the incident light.
The plurality of convex portions are provided so as to protrude from the formation surface 21b to the light transmission layer 23 side (+ Y side). The plurality of convex portions constitutes a convex Fresnel lens structure in the present embodiment. Each convex part is provided with an inclined surface (first inclined surface). The plurality of convex portions includes a central convex portion 24a and a plurality of annular convex portions. In the following description, the annular convex portion 24b, the annular convex portion 24c, and the annular convex portion 24d will be described on behalf of the plurality of annular convex portions.

  The central convex portion 24a, the annular convex portion 24b, the annular convex portion 24c, and the annular convex portion 24d correspond to the convex portions in the claims. Furthermore, the annular convex part 24b corresponds to a first convex part, and the annular convex part 24c adjacent to the annular convex part 24b corresponds to a second convex part.

  The central convex portion 24a has a convex lens shape. As shown in FIG. 4, the central convex portion 24a has a circular shape in plan view (ZX plane view). As shown in FIG. 2, the central convex portion 24a includes an inclined surface 26a that is inclined with respect to the forming surface 21b. In the present embodiment, the inclined surface 26a is a curved surface.

  As shown in FIG. 4, the annular convex portion 24 b, the annular convex portion 24 c, and the annular convex portion 24 d have an annular shape that is concentric with the central convex portion 24 a in plan view (ZX plane view). The annular convex part 24b, the annular convex part 24c, and the annular convex part 24d are provided so as to surround the central convex part 24a in this order. The width (the length in the radial direction) of the annular convex portion 24b, the width of the annular convex portion 24c, and the width of the annular convex portion 24d become smaller in this order.

  As shown in FIG. 3, the annular convex portion 24 b includes an inclined surface 26 b and a back cut surface 28 a. The annular convex portion 24c includes an inclined surface 26c and a back cut surface 28b. The annular convex portion 24d includes an inclined surface 26d and a back cut surface 28c.

  The inclined surface 26b is inclined with respect to the forming surface 21b. In the present embodiment, the inclined surface 26b is a curved surface. In the present embodiment, the curvature of the inclined surface 26b is the same as the curvature of the inclined surface 26a of the central convex portion 24a. The same applies to the inclined surface 26c and the inclined surface 26d.

  In the present embodiment, the back cut surface 28a, the back cut surface 28b, and the back cut surface 28c are orthogonal to the formation surface 21b, respectively. The back cut surface 28a, the back cut surface 28b, and the back cut surface 28c connect adjacent inclined surfaces. That is, the back cut surface 28a connects the inclined surface 26a of the central convex portion 24a and the inclined surface 26b of the annular convex portion 24b. The back cut surface 28b connects the inclined surface 26b of the annular convex portion 24b and the inclined surface 26c of the annular convex portion 24c. The back cut surface 28c connects the inclined surface 26c of the annular convex portion 24c and the inclined surface 26d of the annular convex portion 24d. The back cut surface 28b corresponds to a first connection surface in the claims.

  In the present embodiment, a light absorbing member is provided on each back cut surface. That is, the light-absorbing member 40a is provided on the back cut surface 28a. A light absorbing member 40b is provided on the back cut surface 28b. A light absorbing member 40c is provided on the back cut surface 28c. The light absorbing member 40a, the light absorbing member 40b, and the light absorbing member 40c have a property of absorbing at least a part of incident light. The light absorbing member 40b corresponds to the first light absorbing member in the claims.

  As shown in FIG. 2, the external light transmissive member 22 includes an external side surface 22 a, a formation surface 22 b, and an external reflection part 25. Moreover, the external light transmissive member 22 includes a plurality of light absorbing members as shown in FIG. The external side surface 22a corresponds to the third surface of the claims. The formation surface 22b corresponds to the fourth surface of the claims. The external side reflection part 25 is corresponded to the 2nd reflection part of a claim.

  As shown in FIG. 2, the external side light transmissive member 22 is disposed such that the formation surface 22 b faces the formation surface 21 b of the viewing side light transmissive member 21. As shown in FIG. 4, the external light transmissive member 22 is provided so as to overlap the visual light transmissive member 21 in plan view (ZX plane view). The shape of the external light transmissive member 22 in plan view is not particularly limited, like the visual light transmissive member 21. In the present embodiment, the planar view shape of the external light transmissive member 22 is, for example, a rectangular shape. In the present embodiment, the refractive index of the external light transmissive member 22 is the same as the refractive index of the viewing side light transmissive member 21.

The external side surface 22 a is a surface of the external side light transmissive member 22 opposite to the viewing side light transmissive member 21. In the present embodiment, the outer side surface 22a is a plane. The external side surface 22a is provided in parallel with the visual recognition surface 21a. Light from the outside is incident on the external side surface 22a.
The formation surface 22b is a surface facing the external side surface 22a. An external reflecting portion 25 is provided on the formation surface 22b.

The external reflection part 25 includes a plurality of recesses. The external reflection unit 25 reflects at least a part of the incident light and transmits at least a part of the incident light.
The plurality of recesses are formed on the formation surface 22b. The plurality of concave portions constitutes a concave Fresnel lens structure in the present embodiment. Each recess includes an inclined surface (second inclined surface). The plurality of recesses include a central recess 25a and a plurality of annular recesses. In the following description, the annular recess 25b, the annular recess 25c, and the annular recess 25d will be described on behalf of the plurality of annular recesses.

  The central recess 25a, the annular recess 25b, the annular recess 25c, and the annular recess 25d correspond to the recesses in the claims. Furthermore, the annular recess 25b corresponds to a first recess, and the annular recess 25c adjacent to the annular recess 25b corresponds to a second recess.

  The central recess 25a has a concave lens shape. As shown in FIG. 4, the central recess 25a has a circular shape in plan view (ZX plane view). As shown in FIG. 2, the central recess 25a includes an inclined surface 27a that is inclined with respect to the formation surface 22b. In the present embodiment, the inclined surface 27a is a curved surface.

  As shown in FIG. 4, the annular recess 25 b, the annular recess 25 c, and the annular recess 25 d are annular concentric with the central recess 25 a in plan view (ZX plane view). The annular recess 25b, the annular recess 25c, and the annular recess 25d are formed surrounding the central recess 25a in this order. The width of the annular recess 25b (the length in the radial direction), the width of the annular recess 25c, and the width of the annular recess 25d decrease in this order.

  The central concave portion 25a, the annular concave portion 25b, the annular concave portion 25c, and the annular concave portion 25d correspond to the central convex portion 24a, the annular convex portion 24b, the annular convex portion 24c, and the annular convex portion 24d, respectively. .

  As shown in FIG. 3, the annular recess 25 b includes an inclined surface 27 b and a back cut surface 29 a. The annular recess 25c includes an inclined surface 27c and a back cut surface 29b. The annular recess 25d includes an inclined surface 27d and a back cut surface 29c.

  The inclined surface 27b is inclined with respect to the forming surface 22b. In the present embodiment, the inclined surface 27b is a curved surface. In the present embodiment, the curvature of the inclined surface 27b is the same as the curvature of the inclined surface 27a of the central recess 25a. The same applies to the inclined surface 27c and the inclined surface 27d.

  In the present embodiment, the back cut surface 29a, the back cut surface 29b, and the back cut surface 29c are orthogonal to the formation surface 22b. The back cut surface 29a, the back cut surface 29b, and the back cut surface 29c connect adjacent inclined surfaces. That is, the back cut surface 29a connects the inclined surface 27a of the central recess 25a and the inclined surface 27b of the annular recess 25b. The back cut surface 29b connects the inclined surface 27b of the annular recess 25b and the inclined surface 27c of the annular recess 25c. The back cut surface 29c connects the inclined surface 27c of the annular recess 25c and the inclined surface 27d of the annular recess 25d. The back cut surface 29b corresponds to a second connection surface in the claims.

  The plurality of concave portions of the external light transmitting member 22 are formed so as to mesh with the plurality of convex portions of the viewing side light transmitting member 21 via the light transmitting layer 23. Each of the plurality of recesses has a shape following the engaging protrusions.

  Here, in the present specification, the engagement between the convex portion and the concave portion includes that the outer shape of each convex portion overlaps the outer shape of the corresponding concave portion in plan view. In the present embodiment, the outer shape of the convex portion in plan view corresponds to the shape of the back cut surface of the convex portion in plan view. Further, the outer shape of the recess in plan view corresponds to the shape of the back cut surface of the recess in plan view.

  Further, the protrusions and the recesses mesh with each other when the viewing-side light transmissive member 21 and the external-side light transmissive member 22 are brought close to each other along the direction of the line of sight Ma of the observer M (Y-axis direction). It includes that the top of the convex portion is accommodated in the corresponding concave portion. Therefore, the configuration in which the convex portion and the concave portion are engaged includes the case where the convex portion and the concave portion corresponding thereto have the same cross-sectional shape and the case where they have different cross-sectional shapes.

  In this specification, the concave portion follows the convex portion means that the distance W1 in the direction of the line of sight Ma (Y-axis direction) between the inclined surface of the concave portion and the inclined surface of the convex portion that meshes with the concave portion is independent of the position. Including being constant. Therefore, when the concave portion follows the convex portion, the inclined surface of the concave portion and the inclined surface of the convex portion are parallel when the inclined surface of the concave portion and the inclined surface of the convex portion are flat. Further, the expression that the concave portion follows the convex portion includes that the concave portion and the convex portion form a relationship between a mold and a product in molding.

  In the present embodiment, as shown in FIG. 2, the recesses are formed to have the same cross-sectional shape as the corresponding protrusions. That is, in this embodiment, the cross-sectional profiles of the plurality of convex portions have substantially the same shape as the cross-sectional profiles of the plurality of concave portions. Thereby, in this embodiment, as shown in FIG. 4, the external shape of each convex part and the external shape of the recessed part corresponding to this convex part mutually overlap in planar view (ZX surface view). In other words, the central convex portion 24a and the central concave portion 25a are concentric, and the radius R11 of the central convex portion 24a and the radius R12 of the central concave portion 25a are the same. The radius of the outer shape of the annular convex portion 24b is the same as the radius of the outer shape of the annular concave portion 25b corresponding to the annular convex portion 24b. The radius of the outer shape of the annular convex portion 24c is the same as the radius of the outer shape of the annular concave portion 25c corresponding to the annular convex portion 24c. The radius of the outer shape of the annular convex portion 24d is the same as the radius of the outer shape of the annular concave portion 25d corresponding to the annular convex portion 24d.

  As shown in FIG. 3, in this embodiment, a light absorbing member is provided on each backcut surface. That is, the light-absorbing member 41a is provided on the back cut surface 29a. A light absorbing member 41b is provided on the back cut surface 29b. A light absorbing member 41c is provided on the back cut surface 29c. The light absorbing member 41a, the light absorbing member 41b, and the light absorbing member 41c have the property of absorbing at least part of the incident light, like the light absorbing member 40a of the viewing side light transmissive member 21. The light absorbing member 41b corresponds to the second light absorbing member in the claims.

  The light transmission layer 23 is a layer sandwiched between the formation surface 21 b of the viewing side light transmission member 21 and the formation surface 22 b of the external side light transmission member 22. The light transmission layer 23 has translucency. The refractive index of the light transmissive layer 23 is different from the refractive index of the viewing side light transmissive member 21 and the refractive index of the external side light transmissive member 22. The light transmission layer 23 is made of, for example, a transparent resin.

  The thickness of the light transmission layer 23 is equal to the distance W <b> 1 between the viewing side reflection part 24 and the external side reflection part 25. The thickness of the light transmission layer 23, that is, the distance W1, is preferably small. This is because the shift between the incident position of the light beam transmitted through the optical element 20 and the emission position from the optical element 20 can be reduced. In the present embodiment, the thickness of the light transmission layer 23, that is, the distance W1 is set to be sufficiently small.

  A part of the light incident on the optical element 20 is reflected by either the viewing-side reflecting part 24 or the external-side reflecting part 25, and the other part of the light incident on the optical element 20 is transmitted. Details will be described below.

In FIG. 2, the light L1 and the light L2 incident on the optical element 20 are shown for explanation. The light L1 is light incident perpendicularly to the external side surface 22a from the external light transmissive member 22 side (+ Y side). That is, the light L1 is an example of light that reflects an external scenery.
The light L2 is light that enters perpendicularly to the viewing surface 21a from the viewing-side light transmissive member 21 side (−Y side). That is, the light L <b> 2 is an example of light that is incident on the optical element 20 by the image forming apparatus 30. However, in practice, the light from the image forming apparatus 30 does not necessarily enter the viewing surface 21a perpendicularly, but the light L2 enters the viewing surface 21a perpendicularly for easy understanding. To do.

  Of the light L1, the light L12a is reflected by the external reflecting portion 25. Of the light L1 that has not been reflected by the external reflection unit 25, the light L12b is reflected by the viewing-side reflection unit 24. In the example shown in FIG. 2, the light L <b> 12 a is light reflected by the inclined surface 27 a of the central recess 25 a in the external reflection part 25. The light L <b> 12 b is light reflected by the inclined surface 26 a of the central convex portion 24 a in the viewing side reflecting portion 24. The light L12a and the light L12b are reflected in a direction diverging with respect to the center line P.

  Of the light L1, the light L11 that has not been reflected by either the external-side reflection unit 25 or the viewing-side reflection unit 24 is transmitted through the optical element 20. However, the reflection by the viewing surface 21a is ignored here. The light L11 is refracted at the boundary between the external reflection part 25 and the light transmission layer 23 and at the boundary between the visual recognition side reflection part 24 and the light transmission layer 23. Here, the concave portion of the external reflection portion 25 has a shape that follows the convex portion of the visual reflection portion 24 that meshes with the concave portion. As a result, the light L11 is refracted in the opposite direction at the boundary between the viewing-side reflection unit 24 and the light transmission layer 23 by the same angle as the angle refracted at the boundary between the external reflection unit 25 and the light transmission layer 23. The Therefore, the light L11 is emitted in a direction parallel to the direction in which the light L1 is incident. That is, in the example of FIG. 2, the light L11 is emitted in a direction perpendicular to the external side surface 22a.

  In the in-plane direction of the optical element 20 (direction perpendicular to the Y axis), the position where the light L11 is emitted is shifted from the position where the light L1 is incident in the direction in which the light L11 is refracted in the light transmission layer 23. If the refraction angle of the light L11 is constant, the magnitude of the deviation is proportional to the distance that the light L11 travels inside the light transmission layer 23. In the present embodiment, since the thickness of the light transmission layer 23, that is, the distance W1 between the viewing-side reflecting portion 24 and the external-side reflecting portion 25 is set to be sufficiently small, the light in the in-plane direction of the optical element 20 The deviation between the position where L1 is incident and the position where the light L11 is emitted is sufficiently small.

  Of the light L2, the light L22a is reflected by the viewing-side reflecting unit 24. Of the light L <b> 2 that has not been reflected by the viewing-side reflection unit 24, the light L <b> 22 b is reflected by the external-side reflection unit 25. In the example shown in FIG. 2, the light L <b> 22 a is reflected by the inclined surface 26 c of the annular convex part 24 c in the viewing side reflection part 24. The light L22b is reflected by the inclined surface 27c of the annular recess 25c in the external reflection part 25. The light L22a and the light L22b are reflected in the direction of focusing with respect to the center line P.

  The light L22a is collected by a convex Fresnel lens structure formed in the viewing-side reflecting unit 24, and the light L22b is collected by a concave Fresnel lens structure formed in the external-side reflecting unit 25. Therefore, the position where the light L22a is collected and the position where the light L22b is collected are shifted by an amount corresponding to the distance W1 between the viewing-side reflection unit 24 and the external-side reflection unit 25. However, in the present embodiment, since the distance W1 is set to be sufficiently small, the deviation of the light collection position of each light is sufficiently small.

  Of the light L2, the light L21 that has not been reflected by either the viewing-side reflecting unit 24 or the external-side reflecting unit 25 is transmitted through the optical element 20. However, the reflection by the external side surface 22a is ignored here. The light L21 is emitted in a direction parallel to the incident direction of the light L2 in the same manner as the light L11. That is, in the example of FIG. 2, the light L21 is emitted in a direction perpendicular to the viewing surface 21a.

  As described above, part of the light incident on the optical element 20 is reflected and the other part of the light incident on the optical element 20 is transmitted. As a result, as shown in FIG. 1, a part of the image light L incident on the optical element 20 from the image forming apparatus 30 is reflected and incident on the eyes of the observer M, and the outside of the optical element 20 (+ Y side) ) Part of the light incident on the optical element 20 passes through the optical element 20 and enters the eye of the observer M. At this time, since the image forming apparatus 30 is provided at a position closer to the optical element 20 than the focal point of the Fresnel lens structure formed on the optical element 20, the image forming apparatus 30 is more external than the optical element 20 on the line of sight Ma of the observer M. A virtual image N is formed on the side (+ Y side). Therefore, both the virtual image N and the external scenery appear in the eyes of the observer M. That is, the observer M can visually recognize both the image by the image light L emitted from the image forming apparatus 30 and the external scenery at the same time.

  According to the present embodiment, the viewing-side reflecting portion 24 and the external-side reflecting portion 25 are provided with the light-transmitting layer 23 having a refractive index different from that of the viewing-side light transmitting member 21 and the external-side light transmitting member 22 interposed therebetween. It has been. The viewing-side reflecting portion 24 is provided with a plurality of convex portions having inclined surfaces, and the outer-side reflecting portion 25 is provided with a plurality of concave portions. The concave portion has an inclined surface following the convex portion corresponding to the concave portion. And the convex part is arrange | positioned so that it may mesh with the concave part corresponding to it. Therefore, the transmitted light among the light incident on the optical element is refracted in opposite directions at the boundary between the convex portion and the light transmission layer 23 and at the boundary between the concave portion and the light transmission layer 23. Thereby, the direction of the light incident on the optical element 20 and the direction of the light emitted from the optical element 20 are parallel to each other. Therefore, according to this embodiment, it can suppress that an external scenery is distorted.

  Further, according to the present embodiment, the direction of the reflected light can be adjusted in a state where the viewing surface 21a and the outer side surface 22a of the optical element 20 are flat. Therefore, the installation area of the optical element 20 can be reduced, and the entire display device 10 can be reduced in size. Moreover, the freedom degree of the layout of the optical element 20 in the display apparatus 10 can be improved.

  Moreover, according to this embodiment, since the Fresnel lens structure is formed in the visual reflection part 24 and the external reflection part 25, the reflected light is condensed while reducing the thickness of the optical element 20. it can.

Further, the light incident on the back cut surfaces provided on the viewing-side reflecting unit 24 and the external-side reflecting unit 25 becomes stray light to generate a double image and reflection of external light, so that the visibility between the image and the scenery is improved. May be reduced.
On the other hand, according to the present embodiment, the light absorbing member is formed on the back cut surfaces of the plurality of annular convex portions in the viewing side reflective portion 24 and the back cut surfaces of the plurality of annular concave portions in the external side reflective portion 25. Is provided. Therefore, for example, as shown in FIG. 3, the light L3 incident on the back cut surface 29b from the outer side surface 22a is absorbed by the light absorbing member 41b. Further, for example, light L4 incident on the back cut surface 28a from the viewing surface 21a is absorbed by the light absorbing member 40a. Therefore, according to the present embodiment, stray light can be prevented from being generated, and the visibility between the image and the scenery can be prevented from being lowered.

  In the present embodiment, the following configuration may be employed.

  In the above description, the light absorbing member is provided on the back cut surface of the convex portion of the reflective side reflection portion 24 and the back cut surface of the concave portion of the external side reflection portion 25. However, the present invention is not limited thereto. In the present embodiment, the light absorbing member may be provided only on the back cut surface of the convex portion, or the light absorbing member may be provided only on the back cut surface of the concave portion. Moreover, the light absorption member may be provided in all the back cut surfaces of a some convex part and a some recessed part, and may be provided in one part.

In the above description, the cross-sectional profile of the plurality of convex portions is substantially the same shape as the cross-sectional profile of the plurality of concave portions, but is not limited to this, and may be appropriately different.
In the configuration described above, the cross-sectional profile of the plurality of convex portions has substantially the same shape as the cross-sectional profile of the plurality of concave portions, and therefore, the back cut surface of the convex portion is provided with the back cut surface of the concave portion corresponding to the convex portion. It is almost the same as the radial position. As a result, the back cut surface of the convex portion and the back cut surface of the corresponding concave portion interfere with each other, and there is a limit to reducing the distance W1 between the visual side reflection portion 24 and the external side reflection portion 25.

  On the other hand, when the cross-sectional profile of the plurality of convex portions is appropriately different from the cross-sectional profile of the plurality of concave portions, the back cut surfaces interfere with each other when the viewing-side reflecting portion 24 and the external-side reflecting portion 25 are brought close to each other. The distance W1 can be further reduced.

Hereinafter, the optical element shown in FIGS. 5 and 6 will be described as a specific example in which the cross-sectional profile of the plurality of convex portions is different from the cross-sectional profile of the plurality of concave portions.
In the following description, the same components as those described above may be denoted by the same reference numerals, and the description thereof may be omitted.

FIG. 5 is a partial enlarged cross-sectional view showing the optical element 120.
As shown in FIG. 5, the optical element 120 includes a viewing-side light transmissive member 21, an external-side light transmissive member 122, and a light transmissive layer 123. The external light transmissive member 122 corresponds to the second light transmissive member in the claims.

  The external light transmissive member 122 includes an external side surface 122a, a forming surface 122b, and an external reflection part 125. The external side surface 122a corresponds to the third surface of the claims. The formation surface 122b corresponds to the fourth surface of the claims. The external side reflection part 125 is equivalent to the 2nd reflection part of a claim.

  The external reflection part 125 includes a plurality of recesses, that is, a center recess 125a, an annular recess 125b, an annular recess 125c, and an annular recess 125d shown in FIG. The plurality of recesses constitutes a concave Fresnel lens structure. The central recess 125a, the annular recess 125b, the annular recess 125c, and the annular recess 125d correspond to the recesses in the claims. Furthermore, the annular recess 125b corresponds to a first recess in the claims, and the annular recess 125c corresponds to a second recess in the claims.

The central concave portion 125a, the annular concave portion 125b, the annular concave portion 125c, and the annular concave portion 125d have shapes that follow the corresponding central convex portion 24a, annular convex portion 24b, annular convex portion 24c, and annular convex portion 24d, respectively. is there.
The annular recess 125b includes a back cut surface 129a. The annular recess 125c includes a back cut surface 129b. The annular recess 125d includes a back cut surface 129c. The back cut surface 129b corresponds to a second connection surface in the claims.

  The position of the back cut surface 129a of the annular recess 125b is located inside the position of the back cut surface 28a of the annular protrusion 24b. In other words, the radius R22 of the central concave portion 125a is smaller than the radius R21 of the central convex portion 24a. The same applies to the annular recess 125c and the annular recess 125d.

  According to this configuration, since the back cut surface of the corresponding convex portion and the back cut surface of the concave portion are displaced in the radial direction, even if the visual side reflection portion 24 and the external side reflection portion 125 are brought close to each other, the convex portion The back cut surface of the part does not interfere with the back cut surface of the recess. Thereby, the distance W2 between the visual side reflection part 24 and the external side reflection part 125 can be made smaller. Therefore, according to this structure, the shift | offset | difference of the condensing position of the Fresnel lens structure of the visual recognition side reflection part 24 and the condensing position of the Fresnel lens structure of the external side reflection part 125 can be reduced more. In addition, since the deviation between the incident position and the emission position of the light transmitted through the optical element 120 can be further reduced, distortion of the external scenery visually recognized by the observer M can be further reduced.

FIG. 6 is a partially enlarged sectional view showing the optical element 220.
As shown in FIG. 6, the optical element 220 includes a viewing-side light transmissive member 21, an external-side light transmissive member 222, and a light transmissive layer 223. The external light transmissive member 222 corresponds to the second light transmissive member in the claims.

  The external light transmissive member 222 includes an external side surface 222a, a forming surface 222b, and an external reflection part 225. The outer side surface 222a corresponds to the third surface of the claims. The formation surface 222b corresponds to the fourth surface of the claims. The external reflection part 225 corresponds to the second reflection part in the claims.

  The external reflection part 225 includes a plurality of recesses, that is, a central recess 225a, an annular recess 225b, an annular recess 225c, and an annular recess 225d shown in FIG. The plurality of recesses constitutes a concave Fresnel lens structure. The central recess 225a, the annular recess 225b, the annular recess 225c, and the annular recess 225d correspond to the recesses in the claims. Furthermore, the annular recess 225b corresponds to a first recess in the claims, and the annular recess 225c corresponds to a second recess in the claims.

The central concave portion 225a, the annular concave portion 225b, the annular concave portion 225c, and the annular concave portion 225d have shapes that follow the corresponding central convex portion 24a, annular convex portion 24b, annular convex portion 24c, and annular convex portion 24d, respectively. is there.
The annular recess 225b includes a back cut surface 229a. The annular recess 225c includes a back cut surface 229b. The annular recess 225d includes a back cut surface 229c. The back cut surface 229b corresponds to a second connection surface in the claims.

The back cut surface 229a, the back cut surface 229b, and the back cut surface 229c are inclined with respect to the normal direction of the formation surface 222b. On the other hand, the back cut surface 28a, the back cut surface 28b, and the back cut surface 28c are orthogonal to the formation surface 21b, respectively.
According to this configuration, for example, the back cut surface 229a of the annular recess 225b is not parallel to the back cut surface 28a of the annular projection 24b corresponding to the annular recess 225b. Can be brought close to each other within a range in which they do not interfere with each other. Thereby, the distance W3 between the visual side reflection part 24 and the external side reflection part 225 can be made smaller. Therefore, according to this configuration, as in the configuration of FIG. 5, it is possible to further reduce the deviation between the condensing position of the Fresnel lens structure of the viewing-side reflecting unit 24 and the condensing position of the Fresnel lens structure of the external-side reflecting unit 225. And distortion of the external scenery visually recognized by the observer M can be further reduced.

In the present embodiment, the Fresnel lens structure may have an elliptical Fresnel lens structure or a linear Fresnel lens structure.
In the present embodiment, the image forming apparatus 30 may be provided outside the focal point of the Fresnel lens structure, that is, at a position farther from the optical element 20 than the focal point of the Fresnel lens structure. In this case, a real image is formed on the viewing surface 21 a side (−Y side) of the optical element 20 by the image light L of the image forming apparatus 30.

  In the present embodiment, the light transmission layer 23 may be made of metal. In this case, the reflectance and transmittance of light can be adjusted by adjusting the film thickness.

Further, in the present embodiment, the configuration of the image forming apparatus 30 is not limited to the configuration exemplified above, and may be any configuration as long as the image light L can be emitted.
In the present embodiment, the line of sight Ma of the observer M may be inclined with respect to the normal line of the viewing surface 21a.

(Second Embodiment)
The second embodiment differs from the first embodiment in that the viewing surface and the outer side surface are curved surfaces.
In the following description, the same components as those in the above embodiment may be denoted by the same reference numerals as appropriate, and the description may be omitted.

FIG. 7 is a schematic configuration diagram showing the display device 310 of the present embodiment.
As shown in FIG. 7, the display device 310 of the present embodiment includes a first image forming device 330 a, a second image forming device 330 b, and an optical element 320. The first image forming apparatus 330a and the second image forming apparatus 330b correspond to the image forming apparatuses recited in the claims.

  For example, the first image forming apparatus 330a and the second image forming apparatus 330b have the same configuration as the image forming apparatus 30 of the first embodiment. The first image forming apparatus 330 a emits image light La toward the optical element 320. The second image forming apparatus 330 b emits image light Lb toward the optical element 320. The first image forming apparatus 330 a and the second image forming apparatus 330 b are disposed at a position closer to the optical element 320 than the focal point of the Fresnel lens structure formed on the optical element 320. The angle of the principal ray of the image light La with respect to the optical element 320 is different from the angle of the principal ray of the image light Lb with respect to the optical element 320.

The optical element 320 includes a viewing side light transmissive member 321, an external side light transmissive member 322, and a light transmissive layer 23. The viewing-side light transmissive member 321 corresponds to the first light transmissive member in the claims. The external light transmissive member 222 corresponds to the second light transmissive member in the claims.
The viewing side light transmissive member 321 is the same as the viewing side light transmissive member 21 of the first embodiment except that the viewing surface 321a is a curved surface. The external light transmissive member 322 is the same as the external light transmissive member 22 of the first embodiment except that the external side surface 322a is a curved surface.

  The viewing surface 321a and the outer side surface 322a have a curved surface portion. Specifically, the viewing surface 321a is a concave curved surface that is concave on the outer side (+ Y side), and the outer side surface 322a is a convex curved surface that is convex on the outer side (+ Y side). The curvature of the viewing surface 321a and the curvature of the outer side surface 322a are the same, and the curvature of the inclined surface formed on the plurality of projections of the viewing-side reflection unit 24 and the plurality of recesses of the outer-side reflection unit 25 are formed. It differs from any of the curvatures of the inclined surfaces. Further, the curvature of the viewing-side reflection unit 24 is equal to the curvature of the external-side reflection unit 25.

Therefore, the deflection action of the viewing-side reflecting unit 24 with respect to the image light La and the image light Lb traveling from the viewing-side light transmissive member 321 side (−Y side) toward the external-side light transmissive member 322 side (+ Y side). The deflection action of the external reflecting section 25 is different from both the deflection action of the viewing surface 321a and the deflection action of the external side surface 322a with respect to the image light La and the image light Lb.
The visual recognition surface 321a corresponds to the first surface and the curved surface portion of the claims. The external side surface 322a corresponds to the third surface and the curved surface portion of the claims.

  The curvature of the viewing surface 321a is designed so that the reflected light of the image light La emitted from the first image forming apparatus 330a enters the eye of the observer M. Further, the curvature of the viewing-side reflection unit 24 is designed so that the reflected light of the image light Lb emitted from the second image forming apparatus 330b is incident on the eyes of the observer M. Thereby, the observer M can visually recognize the virtual image of the image light La, the virtual image of the image light Lb, and the external scenery at the same time.

  In FIG. 7, only the light that enters the eyes of the observer M among the image light La and the image light Lb is illustrated, but in practice, a part of the image light La is reflected by the viewing-side reflection unit 24. Then, a part of the image light Lb is reflected by the viewing surface 321a. However, the curvature of the viewing side reflection unit 24 is designed so that the image light La reflected by the viewing side reflection unit 24 does not enter the eyes of the observer M, and the curvature of the viewing surface 321a is reflected by the viewing surface 321a. The image light Lb is designed not to enter the eyes of the observer M.

  According to the present embodiment, the curvature of the viewing surface 321a and the curvature of the outer side surface 322a are formed in the curvature of the inclined surface formed on the plurality of convex portions of the viewing side reflecting portion 24 and the plurality of concave portions of the outer side reflecting portion 25. It differs from any of the curvatures of the inclined surfaces. Therefore, the angle of the light reflected by the viewing surface 321a and the angle of the light reflected by the external side surface 322a are the angles of the light reflected by the viewing side reflection unit 24 and the light reflected by the external side reflection unit 25, respectively. It is different from any of. Thereby, part of the image light La and part of the image light Lb having different incident angles with respect to the optical element 320 can be reflected toward the observer M. Therefore, according to the present embodiment, the observer M can visually recognize an image obtained by superimposing image lights emitted from two image forming apparatuses arranged at different positions.

  In the present embodiment, only one of the viewing surface 321a and the outer side surface 322a may be a curved surface. Further, the curvature of the viewing surface 321a and the curvature of the outer side surface 322a may be different.

  Moreover, in the said description, although the case where the visual recognition surface 321a was a curved surface, ie, the case where the whole visual recognition surface 321a corresponded to a curved surface part was shown, it is not restricted to this. In this embodiment, it is good also as a structure by which said curved surface part is provided in a part of visual recognition surface 321a. The same applies to the external side surface 322a.

(Third embodiment)
The third embodiment is different from the first embodiment in that a Fresnel lens structure is not formed in the reflection portion of the optical element.
In the following description, the same components as those in the above embodiment may be denoted by the same reference numerals as appropriate, and the description may be omitted.

FIG. 8 is a schematic configuration diagram showing the display device 410 of the present embodiment. FIG. 9 is a perspective view showing the optical element 420 of the present embodiment.
As shown in FIG. 8, the display device 410 of the present embodiment includes an image forming device 430 and an optical element 420.

The image forming apparatus 430 includes an image forming unit 431 and a lens 432.
The configuration of the image forming unit 431 is the same as that of the image forming apparatus 30 of the first embodiment, for example. The image forming unit 431 emits image light Lc. The image light Lc is emitted toward the optical element 420 through the lens 432.

  The lens 432 is disposed so that the focal point is located farther than the optical element 420. In other words, the optical element 420 is disposed closer to the lens 432 than the focal point of the lens 432. The image light Lc is collected by the lens 432 and a virtual image N is formed.

  The optical element 420 includes a viewing side light transmissive member 421, an external side light transmissive member 422, and a light transmissive layer 423. The light transmission layer 423 is the same as the light transmission layer 23 of the first embodiment. The viewing-side light transmissive member 421 corresponds to the first light transmissive member in the claims. The external light transmissive member 422 corresponds to a second light transmissive member in the claims.

  As shown in FIGS. 8 and 9, the viewing-side light transmissive member 421 includes a viewing surface 421 a, a forming surface 421 b, and a viewing-side reflecting portion 424. The viewing surface 421a corresponds to the first surface of the claims. The formation surface 421b corresponds to the second surface of the claims. The visual recognition side reflection part 424 is equivalent to the 1st reflection part of a claim.

The viewing surface 421a is the same as the viewing surface 21a of the first embodiment.
The formation surface 421b is a surface facing the viewing surface 421a. On the forming surface 421b, a viewing-side reflecting portion 424 is provided.

The viewing side reflection part 424 includes a plurality of convex parts 424a.
The convex portion 424a includes an inclined surface 426a (first inclined surface) and an inclined surface 426b (first connection surface). In the present embodiment, the cross section (YZ cross section) of the convex portion 424a has a triangular shape. The plurality of convex portions 424a are formed to extend in one direction (X-axis direction). The plurality of convex portions 424a are arranged in stripes in the vertical direction (Z-axis direction).

  The inclined surface 426a and the inclined surface 426b are planes inclined with respect to the forming surface 421b. The inclination of the inclined surface 426a with respect to the forming surface 421b is smaller than the inclination of the inclined surface 426b with respect to the forming surface 421b. In the present embodiment, the image light Lc emitted from the image forming apparatus 430 is incident on the inclined surface 426a.

  The external light transmissive member 422 includes an external side surface 422a, a formation surface 422b, and an external reflection portion 425. The external side surface 422a corresponds to the third surface of the claims. The formation surface 422b corresponds to a fourth surface in the claims. The external reflection part 425 corresponds to the second reflection part in the claims.

The external side surface 422a is the same as the external side surface 22a of the first embodiment.
The formation surface 422b is a surface facing the outer side surface 422a. An external reflecting portion 425 is provided on the formation surface 422b.

A plurality of recesses 425 a are provided on the formation surface 422 b of the external reflection part 425. The shape of the concave portion 425a follows the shape of the corresponding convex portion 424a.
The recess 425a includes an inclined surface 427a (second inclined surface) and an inclined surface 427b (second connection surface). In the present embodiment, the cross section (YZ cross section) of the recess 425a has a triangular shape. The plurality of recesses 425a are formed extending in one direction (X-axis direction). The plurality of recesses 425a are arranged in stripes in the vertical direction (Z-axis direction).

  The inclined surface 427a and the inclined surface 427b are planes inclined with respect to the formation surface 422b. The inclination of the inclined surface 427a with respect to the forming surface 422b is smaller than the inclination of the inclined surface 427b with respect to the forming surface 422b. In the present embodiment, the image light Lc emitted from the image forming apparatus 430 is incident on the inclined surface 427a.

  The plurality of convex portions 424a and the plurality of concave portions 425a are provided so as to mesh with each other. The inclined surface 426a of the convex portion 424a and the inclined surface 427a of the concave portion 425a are parallel to each other. The inclined surface 426b of the convex portion 424a and the inclined surface 427b of the concave portion 425a are parallel to each other.

  In the present embodiment, a part of the image light Lc emitted from the image forming apparatus 430 is reflected on any one of the inclined surface 426a of the viewing-side reflecting unit 424 and the inclined surface 427a of the external-side reflecting unit 425. And enters the eyes of the observer M. In other words, the convex portion 424a of the viewing-side reflective portion 424 and the concave portion 425a of the external-side reflecting portion 425 are changed from the viewing-side light transmissive member 421 side (−Y side) to the external side light transmissive member 422 side (+ Y side). The image light Lc traveling toward the viewer M is reflected toward the observer M.

  On the other hand, a part of the light incident on the optical element 420 from the outside (+ Y side) is transmitted and is incident on the eye of the observer M. As a result, the observer M can visually recognize the external scenery and the image formed by the image forming apparatus 430 at the same time.

  Note that the direction in which the image light Lc is reflected by the convex portion 424a of the viewing-side reflecting portion 424 or the concave portion 425a of the external-side reflecting portion 425 corresponds to the first direction of the claims.

  According to the present embodiment, since the inclined surface 426a of the convex portion 424a and the inclined surface 427a of the concave portion 425a are parallel to each other, the light transmitted through the optical element 420 is emitted in a direction parallel to the incident direction. Thereby, it can suppress that the external scenery visually recognized by the observer M is distorted.

  In the present embodiment, the plurality of inclined surfaces 426a on which the image light Lc is reflected are connected to each other by the inclined surfaces 426b. Therefore, a step is generated between the adjacent inclined surfaces 426a. Thereby, the image visually recognized by the observer M may become discontinuous at the level difference part. On the other hand, the distance W4 between the observer M and the virtual image N is set to be sufficiently larger than the size of the step, that is, the dimension of the inclined surface 426b in the line of sight Ma direction (Y-axis direction). The effect of the step on the image visually recognized by the person M can be effectively reduced. Examples of the method of adjusting the distance W4 include a method of changing the focal length of the lens 432 and a method of changing the position where the lens 432 is provided with respect to the optical element 420. The same applies to the inclined surface 427a.

  In the present embodiment, the following configuration may be employed.

  A light absorbing member may be provided on at least one of the inclined surface 426b and the inclined surface 427b. Thereby, stray light can be reduced. Alternatively, the inclined surface 426b may be a vertical surface orthogonal to the formation surface 421b. The inclined surface 427b may be a vertical surface orthogonal to the formation surface 422b.

  In the present embodiment, the lens 432 may not be provided. In this case, the virtual image N is not formed, and the mirror image reflected by the optical element 420 is reflected in the eyes of the observer M.

  In the above description, the number of image forming apparatuses 430 is one, but the present invention is not limited to this. In the present embodiment, for example, a configuration in which two image forming apparatuses are provided as in the display apparatus 510 illustrated in FIG. 10 may be employed.

FIG. 10 is a schematic configuration diagram showing the display device 510. In FIG. 10, unlike FIG. 8, the case is seen from the upper side in the vertical direction (+ Z side).
As shown in FIG. 10, the display device 510 includes a right-eye image forming device 530a, a left-eye image forming device 530b, and an optical element 520. The image forming apparatus for right eye 530a and the image forming apparatus for left eye 530b correspond to the image forming apparatus in the claims.

  The right-eye image forming apparatus 530a includes an image forming unit 531a and a lens 532a. The left-eye image forming apparatus 530b includes an image forming unit 531b and a lens 532b. The image forming unit 531a and the image forming unit 531b are the same as the image forming unit 431. The lens 532 a and the lens 532 b are the same as the lens 432.

  The optical element 520 includes a viewing side light transmissive member 521, an external side light transmissive member 522, and a light transmissive layer 523. In FIG. 10, the optical element 520 is arranged in a state of being rotated 90 ° around the line of sight Ma direction (Y-axis direction) with respect to the optical element 420 in FIG. That is, the extending direction of the convex portion 524a is the vertical direction (Z-axis direction). The viewing-side light transmissive member 521 corresponds to the first light transmissive member in the claims. The external light transmissive member 522 corresponds to the second light transmissive member in the claims.

The viewing-side light transmissive member 521 is the same as the viewing-side light transmissive member 421 except for the inclination angle of the inclined surface 526a of the convex portion 524a and the inclination angle of the inclined surface 526b in the viewing-side reflecting portion 524. The external light transmissive member 522 is the same as the external light transmissive member 422 except for the inclination angle of the inclined surface 527a of the recess 525a and the inclination angle of the inclined surface 527b in the external reflection portion 525.
In addition, the visual recognition side reflection part 524 is equivalent to the 1st reflection part in a claim. The external reflection part 525 corresponds to the second reflection part in the claims. The inclined surface 526a corresponds to the first inclined surface in the claims. The inclined surface 527a corresponds to the second inclined surface in the claims.

The cross section (XY cross section) of the convex portion 524a is an isosceles triangle. In the convex portion 524a, the inclination angle of the inclined surface 526a with respect to the forming surface 521b and the inclination angle of the inclined surface 526b with respect to the forming surface 521b are the same.
The cross section (XY cross section) of the recess 525a is an isosceles triangle. In the recess 525a, the inclination angle of the inclined surface 527a with respect to the formation surface 522b and the inclination angle of the inclination surface 527b with respect to the formation surface 522b are the same.
The formation surface 521b corresponds to the second surface of the claims. The formation surface 522b corresponds to the fourth surface of the claims.

  Of the image light Ld emitted from the right-eye image forming apparatus 530a, the light reflected by the inclined surface 526a and the light reflected by the inclined surface 527a enter the right eye RE of the observer M.

  On the other hand, among the image light Le emitted from the image forming apparatus for left eye 530b, the light reflected by the inclined surface 526b and the light reflected by the inclined surface 527b are incident on the left eye LE of the observer M.

As a result, the virtual image NR formed by the image light Ld emitted from the right eye image forming apparatus 530a is visually recognized in the right eye RE of the observer M, and the left eye image forming apparatus 530b is observed in the left eye LE of the observer M. The virtual image NL formed by the image light Le emitted from is visually recognized. At the same time, both eyes of the observer M are incident with light from the outside that is incident from the external side surface 522a and is emitted from the viewing surface 521a.
The viewing surface 521a corresponds to the first surface of the claims. The external side surface 522a corresponds to the third surface of the claims.

  According to this configuration, the image for the right eye and the image for the left eye can be incident on the right eye RE and the left eye LE of the observer M, respectively, so that the observer M can visually recognize the 3D image.

(Fourth embodiment)
The fourth embodiment shows an example in which the display device shown in the first to third embodiments is mounted on a passenger car.
In the following description, the same components as those in the above embodiment may be denoted by the same reference numerals as appropriate, and the description may be omitted.

FIG. 11 is a schematic configuration diagram showing a vehicle 70 on which a display device is mounted.
As shown in FIG. 11, the vehicle 70 according to the present embodiment includes a display device 1100, a front window 72, and a dashboard 73. The vehicle 70 is, for example, a sedan type passenger car.

The display device 1100 has the same configuration as the display device 10 of the first embodiment, for example. The display device 1100 includes an optical element 1000 and the image forming apparatus 30.
The optical element 1000 is provided on the front window 72. The optical element 1000 has the same configuration as the optical element 20 shown in FIG. In FIG. 11, the line of sight of the occupant C is tilted with respect to the normal line of the viewing surface of the optical element 1000.
The image forming apparatus 30 is housed inside a dashboard 73 as shown in FIG.

  The dashboard 73 is provided with an opening 73H for transmitting the image light L. The image light L is emitted toward the optical element 1000 through the opening 73H. A part of the image light L incident on the optical element 1000 is reflected toward the passenger C. As a result, the virtual image N formed by the image light L is visually recognized by the occupant C of the vehicle 70.

  Further, part of the light from the outside passes through the optical element 1000 and is visually recognized by the occupant C. Therefore, the occupant C can visually recognize the image formed by the image forming apparatus 30 and the external scenery at the same time.

  According to the present embodiment, as in the above-described embodiment, the external scenery and the image formed by the image forming apparatus 30 can be simultaneously viewed while suppressing the external scenery from being distorted.

  In the present embodiment, the display device 1100 may have the same configuration as the display devices of the second embodiment and the third embodiment.

  In the first to fourth embodiments, the example in which the display device of the present invention is applied to a head-up display has been described. However, the present invention is not limited to this example. Applicable.

  10, 310, 410, 510, 1100 ... display device, 20, 120, 220, 320, 420, 520, 1000 ... optical element, 21 ... viewing side light transmitting member (first light transmitting member), 21a, 421a, 521a ... viewing surface (first surface), 21b, 421b, 521b ... forming surface (second surface), 22, 122, 222, 322, 422, 522 ... external light transmitting member (second Light transmitting member), 22a, 122a, 222a, 422a, 522a ... external side surface (third surface), 22b, 122b, 222b, 422b, 522b ... formation surface (fourth surface), 23, 123, 223 423, 523 ... Light transmission layer, 24, 424, 524 ... Viewing-side reflecting part (first reflecting part), 24a ... Central convex part (convex part), 24b ... Circular convex part (convex part, first convex part) Part), 24c ... Part (convex part, second convex part), 24d ... annular convex part (convex part), 25, 125, 225, 425, 525 ... external side reflective part (second reflective part), 25a, 125a, 225a ... central recess (recess), 25b, 125b, 225b ... annular recess (recess, first recess), 25c, 125c, 225c ... annular recess (recess, second recess), 25d, 125d, 225d ... circle Annular recesses (recesses), 26a, 26b, 26c, 26d, 426a, 526a, 526b ... inclined surfaces (first inclined surfaces), 27a, 27b, 27c, 27d, 427a, 527a, 527b ... inclined surfaces (second Inclined surface), 28b ... Back cut surface (first connection surface), 29b, 129b, 229b ... Back cut surface (second connection surface), 30, 430 ... Image forming apparatus, 40b ... Light absorbing member (first Light absorption Member), 41b ... light absorbing member (second light absorbing member), 321a ... viewing surface (first surface, curved surface portion), 322a ... external side surface (third surface, curved surface portion), 330a ... first image Forming device (image forming device), 330b ... second image forming device (image forming device), 424a, 524a ... convex portion, 425a, 525a ... concave portion, 426b ... inclined surface (first connecting surface), 427b ... inclined surface (Second connection surface) 530a ... right-eye image forming apparatus (image forming apparatus), 530b ... left-eye image forming apparatus (image forming apparatus), L, La, Lb, Lc, Ld, Le ... image light

Claims (9)

1st light transmission provided with the 1st surface, the 2nd surface facing this 1st surface, and the 1st reflective part containing a plurality of convex parts provided in this 2nd surface Sex members;
A third surface, a fourth surface facing the third surface, and a second reflecting portion provided on the fourth surface and including a plurality of concave portions that follow the plurality of convex portions. A second light transmissive member;
A light transmissive layer having a refractive index different from that of the first light transmissive member and a refractive index of the second light transmissive member;
Have
Each of the plurality of convex portions includes a first inclined surface inclined with respect to the second surface,
Each of the plurality of recesses includes a second inclined surface inclined with respect to the fourth surface,
The first light transmissive member and the second light transmissive member are arranged so that the plurality of convex portions engage with the plurality of concave portions via the light transmissive layer. Optical element.   The optical element according to claim 1, wherein the plurality of convex portions constitute a Fresnel lens structure.   The optical element according to claim 1, wherein the plurality of convex portions include convex portions having a triangular cross section.   The plurality of convex portions form a stripe structure, and reflect light traveling from the first light transmissive member toward the second light transmissive member in a first direction. Optical elements.   The plurality of convex portions include a first convex portion, a second convex portion adjacent to the first convex portion, and the first inclined surface included in the first convex portion. 5. The apparatus according to claim 1, further comprising: a first connection surface connected to the first inclined surface included in the section; and a first light absorbing member provided on the first connection surface. The optical element according to item.   The plurality of concave portions include a first concave portion, a second concave portion adjacent to the first concave portion, and the second inclined surface provided in the first concave portion. 6. The optical element according to claim 1, further comprising: a second connection surface that is connected to the inclined surface; and a second light absorbing member that is provided on the second connection surface. .   At least one of the first surface and the third surface has a curved portion, and the first surface with respect to light traveling from the first light transmissive member side toward the second light transmissive member side. The optical element according to any one of claims 1 to 6, wherein a deflecting action of one reflecting portion is different from a deflecting action of the curved surface portion with respect to the light.   The optical element according to claim 1, wherein the light transmission layer is made of a metal. An image forming apparatus for emitting image light;
The optical element according to any one of claims 1 to 8, provided on an optical path of the image light;
A display device comprising:

Images