JPWO2016132984A1 - Optical element, reflective aerial imaging element using the same, and manufacturing method thereof - Google Patents

Abstract

An object of the present invention is to provide an optical element capable of reducing the size of a useless area that is not used for forming a real image of a projection object and increasing the size. An optical element 1 which is formed in a flat plate shape having a rectangular shape in plan view and is arranged in parallel with a reflective surface 2 parallel to the thickness direction at a predetermined period, and the optical element 1 is a first formed in a polygonal planar shape. A small piece portion 3 and a plurality of second small piece portions 4 formed in a planar shape of a right isosceles triangle and arranged at four corners of the first small piece portion 3, the first small piece portion 3 being parallel to one side thereof The second small piece portion 4 has a reflective surface 2 that is inclined with respect to the two orthogonal sides, the reflective surface 2 of the first small piece portion 3 and the reflective surface 2 of the second small piece portion 4. The hypotenuse 41 of the second small piece 4 is joined to the side 31 perpendicular to the reflective surface 4 of the first small piece 3 and the side 31 parallel to the reflective surface 2 of the first small piece 3 so that they are parallel to each other. Yes.

Description

  The present invention relates to a reflective aerial imaging element that forms a real image of a projection object in the air, an optical element used for the reflective aerial imaging element, and a method of manufacturing the same.

  A conventional reflective aerial imaging element is disclosed in Patent Document 1. FIG. 15 shows a plan view of a conventional reflective aerial imaging element. The reflection-type aerial imaging element 10 is formed by stacking two flat optical elements 1 having a square planar shape in the vertical direction, and inside each optical element 1 is parallel to one side and the thickness direction of the optical element 1. The reflecting surfaces 2 are arranged in parallel at a predetermined period. The reflection type aerial imaging element 10 is formed by joining the two optical elements 1 so that the reflection surfaces 2 are orthogonal to each other.

  In the reflective aerial imaging element 10 having the above configuration, when a projection object is arranged below the lower optical element 1 and light is irradiated toward the projection object, a part of the light reflected by the projection object is obtained. The light enters the lower optical element 1 from the lower incident surface 18, is reflected by the reflecting surface 2, and then enters the upper optical element 1. The light reflected by the reflection surface 2 of the upper optical element 1 is emitted from the emission surface 19 on the upper surface of the reflective aerial imaging element 10, and the position of the object to be projected and the surface object is relative to the reflective aerial imaging element 10. A real image of the projection object is formed in the air. Thereby, the image of the projection object is displayed in a state of floating in the air. That is, an aerial image of the projection object is displayed.

  At this time, as shown in FIG. 15, when the reflecting surfaces 2 of both optical elements 1 are projected on a plane parallel to the incident surface 18 and inclined by 45 ° with respect to the user's line-of-sight direction EL, the visibility of the aerial image is improved. You can do it best.

  Patent Document 2 describes that a plurality of flat plate-like reflective aerial imaging elements are joined at their end faces to form a large flat-plate reflective aerial imaging element. That is, it describes that tiling is performed using a plurality of reflective aerial imaging elements. As a result, a large image can be displayed in a state of floating in the air.

JP2011-81300A (6th page, FIGS. 4 to 6) JP2013-101230A (6th page, 7th page, FIG. 6, FIG. 7)

  However, according to the reflective aerial imaging element 10 in which the reflecting surface 2 is arranged in parallel to one side of the optical element 1 as in the above-mentioned Patent Document 1, the viewing direction EL is set in order to optimize the visibility of the aerial image. On the other hand, it is necessary to incline the reflecting surface 2 and the formation area of the aerial image becomes narrow. This is because the projection object is often formed in a rectangle with one side facing the user. That is, when the reflecting surface 2 is inclined with respect to the line-of-sight direction EL, a rectangular region 30 (shown by a one-dot chain line in the figure) facing one side of the user in the reflective aerial imaging element 10 is an actual image of the projection object. Used for imaging. Therefore, a useless invalid area 40 that is not used for forming a real image of the projection object is formed outside the rectangular area 30. Therefore, if an effective area for imaging a real image of the projection object is to be enlarged, the entire reflective aerial imaging element 10 including the invalid area 40 needs to be further enlarged.

  In addition, when the reflective aerial imaging element is enlarged by tiling as in Patent Document 2, a useless invalid area 40 that is not used for imaging a real image of the projection object is further increased.

  An object of the present invention is to provide an optical element that can be easily enlarged by reducing a useless area that is not used for imaging, and a reflective aerial imaging element using the optical element. It is another object of the present invention to provide an optical element that can reduce a useless area that is not used for imaging and can be easily enlarged, and a method for manufacturing a reflective aerial imaging element.

In order to achieve the above object, the present invention is an optical element which is formed in a flat plate shape having a rectangular shape in plan view, and has a reflecting surface parallel to the thickness direction arranged in parallel at a predetermined cycle,
The optical element is
A first small piece formed in a polygonal planar shape;
A plurality of second small pieces formed in a planar shape of a right-angled isosceles triangle and arranged at four corners of the first small pieces;
With
The first small piece portion has the reflective surface parallel to one side thereof,
The second small piece portion has the reflective surface inclined with respect to the two orthogonal sides,
The side of the first small piece portion perpendicular to the reflective surface and the reflection of the first small piece portion so that the reflective surface of the first small piece portion and the reflective surface of the second small piece portion are parallel to each other. The oblique side of the second small piece portion is joined to a side parallel to the surface.

The present invention also relates to a method for manufacturing a flat optical element in which reflective surfaces parallel to the thickness direction are arranged in parallel at a predetermined period.
A first laminated block forming step of laminating a plurality of transparent plates provided with the reflecting surface on at least one surface to form a first laminated block having a square surface perpendicular to the reflecting surface;
A second laminated block forming step of cutting one of the first laminated blocks along both diagonal lines of a square surface perpendicular to the reflecting surface to form a plurality of triangular laminated second laminated blocks whose bottom faces are right-angled isosceles triangles; ,
On the two opposing surfaces perpendicular to the reflective surface of the first laminated block and the reflective so that the reflective surface of the first laminated block and the reflective surfaces of the plurality of second laminated blocks are parallel to each other A joining block forming step of joining the slope of the second laminated block on two opposing faces parallel to the face to form a joining block;
A joining block cutting step for cutting the joining block at a predetermined cycle along a direction perpendicular to the reflecting surface;
It is characterized by having.

The present invention also provides a reflective aerial in which two planar optical elements having reflective surfaces parallel to the thickness direction arranged in parallel at a predetermined period are arranged in parallel in the thickness direction, and the reflective surfaces of the two optical elements are orthogonal to each other. In the manufacturing method of the imaging element,
A first laminated block forming step of laminating a plurality of transparent plates provided with the reflecting surface on at least one surface to form a first laminated block having a square surface perpendicular to the reflecting surface;
A second laminated block forming step of cutting one of the first laminated blocks along both diagonal lines of a square surface perpendicular to the reflecting surface to form a plurality of triangular laminated second laminated blocks whose bottom faces are right-angled isosceles triangles; ,
On the two opposing surfaces perpendicular to the reflective surface of the first laminated block and the reflective so that the reflective surface of the first laminated block and the reflective surfaces of the plurality of second laminated blocks are parallel to each other A joining block forming step of joining the slope of the second laminated block on two opposing faces parallel to the face to form a joining block;
A joining block cutting step of cutting the joining block at a predetermined period along a direction perpendicular to the reflecting surface to form a plurality of the optical elements;
An optical element bonding step of bonding a plurality of the optical elements in the thickness direction;
It is characterized by having.

  According to the present invention, the reflection surface is inclined with respect to the first small piece portion that is formed in a polygonal planar shape and the reflection surface is parallel to one side, and the two sides that are orthogonal to each other and are formed in a planar shape of a right isosceles triangle. And a plurality of second small pieces arranged at the four corners. And the hypotenuse of the second small piece on the side perpendicular to the reflective surface of the first small piece and the side parallel to the reflective surface so that the reflective surface of the first small piece and the reflective surface of the second small piece are parallel to each other Are joined. As a result, it is possible to increase the size of the optical element and the reflective aerial imaging element by reducing a useless area that is not used for imaging a real image of the projection object.

  Moreover, according to this invention, a 1st lamination | stacking block formation process, a 2nd lamination | stacking block formation process, a joining block formation process, and a joining block cutting process are provided. Thereby, it is possible to improve the manufacturing efficiency of the optical element and the reflective aerial imaging element that have a small useless area that is not used for imaging the real image of the projection object.

The perspective view which shows the aerial image display apparatus provided with the reflection type aerial imaging element of 1st Embodiment of this invention. The perspective view which expanded the principal part of FIG. The top view which shows the reflection type aerial imaging element of 1st Embodiment of this invention The perspective view which shows the optical element used for the reflection type aerial image formation element of 1st Embodiment of this invention. The figure which shows the manufacturing process of the reflection type air imaging element of 1st Embodiment of this invention. The perspective view which shows the transparent plate of the reflection type aerial imaging element of 1st Embodiment of this invention. The perspective view which shows the original block material formed at the manufacturing process of the reflection type aerial imaging element of 1st Embodiment of this invention. The perspective view which shows the 1st lamination | stacking block formed at the manufacturing process of the reflection type aerial imaging element of 1st Embodiment of this invention. The perspective view which shows the 2nd lamination | stacking block formed at the manufacturing process of the reflection type aerial imaging element of 1st Embodiment of this invention. The figure for demonstrating joining of the 1st lamination block and the 2nd lamination block in the manufacturing process of the reflective type aerial imaging element of a 1st embodiment of the present invention. The perspective view which shows the joining block formed at the manufacturing process of the reflection type aerial imaging element of 1st Embodiment of this invention. It is a front view which shows the joining block formed at the manufacturing process of the reflection type aerial imaging element of 1st Embodiment of this invention, and is a figure for demonstrating formation of the optical element of the other modification of 1st Embodiment. The top view which shows the original block material formed at the manufacturing process of the reflection type aerial imaging element of 3rd Embodiment of this invention The top view which shows the original block material formed at the manufacturing process of the reflection type aerial imaging element of 4th Embodiment of this invention Plan view showing a conventional reflective aerial imaging element

<First Embodiment>
Embodiments of the present invention will be described below with reference to the drawings. For convenience of explanation, the same reference numerals are assigned to the same parts as those in the conventional example shown in FIG. FIG. 1 is a perspective view of an aerial image display apparatus provided with the reflective aerial imaging element of the first embodiment. FIG. 2 shows an enlarged perspective view of the main part of FIG. The X direction, the Y direction, and the Z direction indicate the depth direction, the width direction, and the thickness direction of the optical element 1, respectively. In FIG. 2, an arrow P indicates an optical path.

  The aerial image display device 100 includes a reflective aerial imaging element 10 and a light source 20. The reflective aerial imaging element 10 is formed by arranging a plurality (two in this embodiment) of optical elements 1 each having a square planar shape in the thickness direction (Z direction). The optical element 1 is made of, for example, glass. The optical element 1 may be formed of a transparent resin such as an acrylic resin.

  Inside the optical element 1, reflective surfaces 2 (see FIG. 2) parallel to the thickness direction are arranged in parallel at a predetermined cycle (for example, a cycle of about 0.4 mm). That is, the plurality of reflecting surfaces 2 are arranged in parallel at a predetermined period in a direction perpendicular to the thickness direction. Further, the reflecting surfaces 2 of the pair of adjacent optical elements 1 are orthogonal to each other.

  A transparent reinforcing plate 5 that covers the optical element 1 is provided on one end face (the lower end face in FIG. 1) of the optical element 1 in the juxtaposed direction (Z direction). The reinforcing plate 5 is formed of the same material as the optical element 1. The strength of the reflective aerial imaging element 10 can be improved by the reinforcing plate 5. In addition, you may provide the reinforcement board 5 in the both end surfaces (upper end surface and lower end surface in FIG. 1) of the parallel arrangement direction of the optical element 1. FIG. The material of the reinforcing plate 5 may be different from the material of the optical element 1.

  The light source 20 is disposed on one optical element 1 side (below the reinforcing plate 5 in FIG. 1). The light source 20 is made of an LED, for example, and emits white illumination light L. The light source 20 may be formed by a CCFL (Cold Cathode Fluorescent Lamp).

  FIG. 3 is a plan view of the reflective aerial imaging element 10, and FIG. 4 is a perspective view of the optical element 1. The planar shapes of the optical element 1 and the reflective aerial imaging element 10 are formed in a square having a side length of about 283 mm. The optical element 1 has a first small piece portion 3 and a plurality of second small piece portions 4. The first small piece 3 is formed in a square planar shape, and the reflecting surface 2 is parallel to one side 31. The second small piece portion 4 is formed in a planar shape of a right-angled isosceles triangle, and the reflective surface 2 is inclined with respect to the orthogonal two sides 42 and 43 and is arranged at the four corners of the optical element 1. At this time, the reflective surface 2 of the first small piece portion 3 and the reflective surface 2 of the second small piece portion 4 are parallel to each other on the side 31 and the reflective surface 2 perpendicular to the reflective surface 2 of the first small piece portion 3. The oblique side 41 of the second small piece portion 4 is joined to the parallel side 31. The hypotenuse 41 of the second small piece 4 is formed to have the same length as the one side 31 of the first small piece 3.

  Further, the reflecting surface 2 is inclined by 45 ° with respect to the two orthogonal sides 42 and 43 of the second small piece portion 4. A pair of optical elements 1 are joined together so that the reflective surface 2 of one optical element 1 and the reflective surface 2 of the other optical element 1 are orthogonal to each other, thereby forming a reflective aerial imaging element 10.

  In the aerial image display device 100 configured as described above, a projection object OB (see FIGS. 1 and 2) of a two-dimensional image is disposed on one optical element 1 side (below the reinforcing plate 5 in FIG. 1), and a light source 20 is turned on. Illumination light L emitted from the light source 20 is reflected by the projection object OB, and as shown by an arrow P (see FIG. 2), a part of the reflected light is incident on the lower optical element 1 from the lower incident surface 18. Then, after being reflected by the reflecting surface 2 of the lower optical element 1, it enters the upper optical element 1.

  The light reflected by the reflecting surface 2 of the upper optical element 1 is emitted upward from the emission surface 19 on the upper surface of the reflective aerial imaging element 10, and the object to be projected and the surface object are reflected on the reflective aerial imaging element 10. A real image (aerial image FI) of the projection object is formed in the air at the position. Thereby, the aerial image FI of the projection object OB is displayed in a state of floating in the air.

  At this time, the reflecting surface 2 is inclined by 45 ° with respect to the two orthogonal sides 42 and 43 of the second small piece portion 4. For this reason, all the reflecting surfaces 2 of the optical element 1 are inclined by 45 ° with respect to one side of the optical element 1. Therefore, when the projection object is formed in a rectangular shape with one side facing the user, the entire area of the reflective aerial imaging element 10 can be used for imaging a real image of the projection object OB. Therefore, in the reflective aerial imaging element 10, a useless area (unused area) that is not used for imaging a real image of the projection object OB can be reduced, and an area of an effective area (used area) for imaging. Can be obtained easily.

  Using the reflective aerial imaging element 10 as described above, for example, if the projection object OB is information related to a product or the like, it is possible to advertise the product or the like using the aerial image FI. In addition, a touch panel of a device used at a medical site or a construction site may be displayed as an aerial image FI. Thereby, contamination of an apparatus etc. can be prevented. The reflective aerial imaging element 10 may be mounted on a game machine or the like.

  The projection object OB is not limited to a two-dimensional image, and may be a three-dimensional object. The projection object OB may be an image displayed on a display device such as a liquid crystal panel. At this time, the light source incorporated in the display device can be used without the light source 20.

  FIG. 5 is a diagram showing a manufacturing process of the reflective aerial imaging element 10. The manufacturing process of the reflective aerial imaging element 10 includes a first laminated block forming process, a second laminated block forming process, a joining block forming process, a joining block cutting process, a polishing process, an optical element joining process, and a reinforcing plate joining process. Yes. Moreover, the first laminated block forming step includes a reflecting surface forming step, a laminating step, and an original block material cutting step.

  In the reflecting surface forming step, as shown in FIG. 6, the reflecting surface 2 is formed on both surfaces of the transparent plate 11 made of glass having a rectangular shape by sputtering or vapor deposition of aluminum or silver. In the present embodiment, the reflecting surface 2 is formed by arranging aluminum having a thickness of 100 nm on the transparent plate 11. The reflective surface 2 may be formed only on one side of the transparent plate 11.

  Although the manufacturing method of the transparent plate 11 is not particularly limited, for example, a fusion method can be used. The fusion method is a method in which melted glass is put into a heart-shaped bottle whose upper surface is opened and the cross-sectional shape is squeezed at the lower end, and the glass overflowing from the upper surface of the bottle flows downward and is integrated under the bottle. Thereby, since a glass surface is formed only by surface tension without contact other than air, a smooth surface can be obtained.

  In the present embodiment, the length in the short direction, the length in the longitudinal direction, and the thickness of the transparent plate 11 are 200 mm, 400 mm, and 0.4 mm, respectively. Note that the transparent plate 11 may be formed of a transparent resin such as an acrylic resin instead of the glass.

  In the laminating step, as shown in FIG. 7, a plurality of transparent plates 11 are bonded using an epoxy-based adhesive and stacked in a direction perpendicular to the reflecting surface 2. At this time, a spacer having a predetermined particle diameter may be sandwiched between the transparent plates 11. In the present embodiment, silica particles having an average particle diameter of about 10 μm are used as spacers, and 480 transparent plates 11 are laminated. As a result, an adhesive layer having a thickness of about 16.5 μm is formed between adjacent transparent plates 11. With the spacer, the thickness of the adhesive layer can be made uniform while maintaining the parallelism between the reflecting surfaces 2. The adhesive is not limited to an epoxy adhesive, and may be an acrylic adhesive, for example.

  Then, a predetermined pressure is applied downward from the reflecting surface 2 of the uppermost transparent plate 11 in FIG. 7 until the adhesive is cured.

  Thereby, the rectangular parallelepiped original block material 13 is formed. At this time, the length of the original block material 13 in the direction perpendicular to the reflecting surface 2 (the length in the stacking direction LM) is formed to be about 200 mm. The ratio of the length D1 of the original block material 13 in the stacking direction LM and the length D2 of the long side of the transparent plate 11 is 1: 2.

  In the original block material cutting step, the original block material 13 is cut along the cutting line C1 (see FIG. 7) using, for example, a wire saw (not shown). Instead of a wire saw, the original block material 13 may be cut using a slicer or the like. The cutting line C <b> 1 is formed so as to pass through the center of the long side of the transparent plate 11. Thereby, the original block material 13 is cut along the stacking direction LM at the center of the long side of the transparent plate 11, and two cubic first stacked blocks 14 are formed as shown in FIG.

  At this time, the peripheral surface 14a of the 1st lamination | stacking block 14 which consists of a cut surface of the original block material 13 is square, and the peripheral surface 14b perpendicular | vertical to the reflective surface 2 and the peripheral surface 14a is also square. As will be described later, the entrance surface 18 and the exit surface 19 of the optical element 1 are formed in parallel to the peripheral surface 14a or the peripheral surface 14b. When the entrance surface 18 and the exit surface 19 are formed in parallel with the peripheral surface 14a, the peripheral surface 14b may be rectangular, and when formed in parallel with the peripheral surface 14b, the peripheral surface 14a may be rectangular.

  Further, since the ratio of the lengths D1 and D2 (see FIG. 7) of the original block material 13 is formed to be 1: 2, a plurality of first laminated blocks 14 having a square peripheral surface 14b are simultaneously formed by the original block material cutting step. it can.

  In the second laminated block forming step, one first laminated block 14 is cut along cutting lines C2 along both diagonal lines of the peripheral surface 14b perpendicular to the reflecting surface 2. A wire saw, a slicer, or the like is used for cutting the first laminated block 14. As a result, as shown in FIG. 9, a plurality of second laminated blocks 15a and 15b having a bottom surface 15c having a right isosceles triangle and a triangular prism shape are formed. Here, the cutting line C2 is composed of a diagonal line of the peripheral surface 14b of the first laminated block 14, but may be a diagonal line of the peripheral surface 14a.

  In the pair of second laminated blocks 15a, the inclined surface 151c and the reflecting surface 2 are perpendicular to each other, and in the pair of second laminated blocks 15b, the inclined surface 151c and the reflecting surface 2 are parallel to each other. In the following description, the second laminated blocks 15a and 15b may be collectively referred to as “second laminated block 15”.

  In the joining block forming step, as shown in FIGS. 10 and 11, the slope 151 c of the second laminated block 15 b is joined on two opposing faces parallel to the reflecting surface 2 of the first laminated block 14. Further, the inclined surface 151c of the second laminated block 15a is joined to two opposing surfaces (peripheral surfaces 14a) perpendicular to the reflecting surface 2 of the first laminated block 14. Thereby, the reflecting surface 2 of the 1st laminated block 14 and the reflective surface 2 of the 2nd laminated block 15 are mutually parallel, and the bottom face is a square prism-shaped joining block 16 formed.

  At this time, the first laminated block 14 and the second laminated block 15a are joined so that the reflective surface 2 of the first laminated block 14 and the reflective surface 2 of the second laminated block 15a are continuous. At this time, it joins so that one edge part of each lamination direction LM of each of the 1st lamination block 14 and the 2nd lamination block 15a may become the same edge part of lamination direction LM in original block material 13 (refer to Drawing 7). .

  Thereby, the same transparent plate 11 is joined to the first laminated block 14 and the second laminated block 15a. For this reason, even if the thickness variation of the transparent plate 11 occurs, the reflective surface 2 of the first laminated block 14 and the reflective surface 2 of the second laminated block 15a can be made continuous with high accuracy.

  An adhesive such as an epoxy resin or an acrylic resin is used for joining the first laminated block 14 and the second laminated block 15. When the second laminated block 15 is pressed and joined to the first laminated block 14 using a separately provided holding member, an adhesive may not be used.

  In this embodiment, in order to form the first laminated block 14 and the second laminated block 15 from one original block material 13, the arrangement period of the reflective surface 2 of the first laminated block 14 and the reflective surface 2 of the second laminated block 15 are used. Is substantially the same. For this reason, at the time of formation of the joining block 16, in the joining location of the 2nd lamination block 15a and the 1st lamination block 14, the lamination direction of the reflective surface 2 of the 2nd lamination block 15a and the reflective surface 2 of the 1st lamination block 14 Deviation in LM can be reduced. Therefore, a step or the like is hardly generated at the joining portion of the reflecting surface 2, and distortion and streaks of the aerial image FI can be prevented when the optical element 1 cut out from the joining block 16 is used as described later.

  In the joining block cutting step, the joining block 16 is cut along a plurality of cutting lines C3 (see FIG. 11) using, for example, a wire saw or a slicer. The cutting line C3 is formed in a direction perpendicular to the reflecting surface 2. Thereby, the joining block 16 is cut | disconnected with a predetermined period (for example, 1.8 mm period) along the direction perpendicular | vertical to the reflective surface 2, and the optical element 1 (refer FIG. 4) is formed in multiple numbers.

  In the polishing step, in order to finish the optical element 1 to a predetermined thickness (for example, 1.2 mm), both end faces in the thickness direction of the optical element 1 are roughly polished (wrapped) using a lapping apparatus. After that, polishing (polishing) is performed on both end surfaces in the thickness direction of the optical element 1 by using a polishing apparatus to finish a mirror finish.

  In the optical element bonding step, the two optical elements 1 are bonded using an adhesive so that the reflecting surfaces 2 are orthogonal to each other. Thereby, the two optical elements 1 are arranged in parallel in the thickness direction. As the adhesive, the same adhesive as that used in the first laminated block forming step is used. In addition, you may join the two optical elements 1 using the adhesive agent different from the adhesive agent used at a 1st lamination | stacking block formation process.

  In the reinforcing plate joining step, the reinforcing plate 5 is bonded to one end surface of the optical elements 1 in the juxtaposed direction with an adhesive. At this time, the adhesive used in the first laminated block forming step is used. In addition, you may use the adhesive agent different from the adhesive agent used at a 1st lamination | stacking block formation process. Thus, the reflective aerial imaging element 10 is manufactured.

  FIG. 12 is a diagram for explaining the formation of the optical element 1 according to another modification of the present embodiment. As indicated by a two-dot chain line 200, the unevenness of the joining block 16 caused by the tolerance at the time of joining the first laminated block 14 and the second laminated block 15 may be removed by cutting or grinding. At this time, the planar shape of the first small piece portion 3 is an octagon. For example, when the joining block 16 is cut or ground by the two-dot chain line 200 on the left side, the right side, and the lower side, the planar shape of the first small piece portion 3 is a heptagon. Further, for example, when the joining block 16 is cut or ground by the upper and lower two-dot chain lines 200, the planar shape of the first small piece portion 3 is a hexagon. Further, for example, when the joining block 16 is cut or ground by the upper two-dot chain line 200, the planar shape of the first small piece portion 3 is a pentagon. In addition, what part of the outer peripheral part of the joining block 16 is removed may be determined according to the joining state of the first joining block 14 and the second joining block 15 in the outer peripheral part.

  In addition, when two joining blocks 16 are prepared and one joining block 16 is cut by a one-dot chain line 300 in FIG. 12, the planar shape of the first small piece portion 3 of the optical element 1 having a rectangular shape in plan view becomes a pentagon. Further, the other joining block 16 is cut along a perpendicular line to the one-dot chain line 300 so that the optical element 1 obtained from the other joining block 16 has the same size as the optical element 1 obtained from the one joining block 16. Cut with (not shown). Then, by joining both optical elements 1, the planar shape of the reflective aerial imaging element 10 is formed in a rectangular shape. Thereby, the optical element 1 and the reflective aerial imaging element 10 having a desired aspect ratio can be obtained. That is, by optimizing the aspect ratio of the optical element 1 and the reflective aerial imaging element 10 according to the shape of the desired aerial image FI, it does not contribute to the imaging of the optical element 1 and the reflective aerial imaging element 10. The area can be reduced and the usage efficiency can be improved.

  As described above, according to the present embodiment, the rectangular plane shape and the reflecting surface 2 are formed in a planar shape of a right isosceles triangle with the first small piece portion 3 parallel to the side 31 and the two orthogonal to each other. The reflective surface 2 is inclined with respect to the sides 42 and 43 and has a plurality of second small piece portions 4 arranged at four corners. The reflective surface 2 of the first small piece portion 3 and the reflective surface 2 of the second small piece portion 4 are provided. And the oblique side 41 of the second small piece portion are joined to the side 31 perpendicular to the reflective surface 2 of the first small piece portion 3 and the side 31 parallel to the reflective surface 2 so as to be parallel to each other. Thereby, the useless area | region which is not used for the imaging of the real image of the to-be-projected object OB can be made small, and the optical element 1 and the reflection type aerial imaging element 10 can be enlarged. Also, two first laminated blocks 14 having the same area and a square planar shape can be created, the first small piece portion 3 can be formed from one, and the second small piece portion 4 can be formed from the other. Therefore, the optical element 1 and the reflective aerial imaging element 10 having a square planar shape can be easily manufactured.

  In addition, since the angle of inclination of the reflecting surface 2 is 45 ° with respect to the two orthogonal sides 42 and 43 of the second small piece portion 4, a useless area that is not used for forming a real image of the projection object OB can be easily reduced. Thus, the optical element 1 and the reflective aerial imaging element 10 can be easily enlarged.

  Moreover, two said optical elements 1 are arranged in parallel in the thickness direction, and the reflective surfaces 2 of the two optical elements 1 are orthogonal. Thereby, the useless area | region which is not used for the imaging of the real image of the to-be-projected object OB can be made small, and the reflective aerial imaging element 10 can be enlarged.

  In addition, since the transparent reinforcing plate 5 that covers the optical element 1 is provided on one end face of the optical element 1 in the parallel direction, the strength of the reflective aerial imaging element 10 can be improved.

  Moreover, the manufacturing process of the optical element 1 includes a first laminated block forming process, a second laminated block forming process, a joining block forming process, and a joining block cutting process. As a result, it is possible to improve the manufacturing efficiency of the optical element 1 and the reflective aerial imaging element 10 that can be easily enlarged by reducing a useless area that is not used for forming a real image of the projection object OB.

  Moreover, in the 1st lamination | stacking block formation process, since the transparent plate 11 is adhere | attached via the spacer, the thickness of a contact bonding layer can be equalize | maintaining, maintaining the parallel of reflective surfaces 2. FIG.

  In addition, one original block material 13 on which the transparent plate 11 is laminated is cut in a direction perpendicular to the reflecting surface 2 to form a plurality of first laminated blocks 14. Thereby, the arrangement cycle of the reflective surface 2 of the first laminated block 14 and the arrangement cycle of the reflective surface 2 of the second laminated block 15 are substantially the same. For this reason, at the time of formation of the joining block 16, in the joining location of the 2nd lamination block 15a and the 1st lamination block 14, the lamination direction of the reflective surface 2 of the 2nd lamination block 15a and the reflective surface 2 of the 1st lamination block 14 Deviation in LM can be reduced. Therefore, a step or the like is hardly generated at the joining portion of the reflecting surface 2, and the aerial image FI can be prevented from being distorted or streaked in the reflective aerial imaging element 10 using the optical element 1 cut out from the joining block 16. .

  Further, in the joining block forming step, the first laminated block 14 and the second laminated block 15a formed from the same original block material 13 are joined on a plane perpendicular to the reflecting surface 2, and one end portion of both of the lamination directions LM is formed. On the original block material 13, it arrange | positions at the same edge part of the lamination direction LM. Thereby, the same transparent plate 11 is joined to the first laminated block 14 and the second laminated block 15a. For this reason, even if the thickness variation of the transparent plate 11 occurs, the reflective surface 2 of the first laminated block 14 and the reflective surface 2 of the second laminated block 15a can be made continuous with high accuracy.

  Further, one of the adjacent first laminated blocks 14 of the same original block material 13 is joined to the second laminated block 15 formed from the other. Thereby, the shift | offset | difference in the lamination direction LM of the reflective surface 2 of the 2nd laminated block 15 and the reflective surface 2 of the 1st laminated block 14 can be reduced further.

  The ratio of the length D1 of the original block material 13 in the stacking direction LM to the length D2 of one side (long side) of the transparent plate 11 is 1: 2, and the center of one side of the transparent plate 11 is in the stacking direction LM. The original block material 13 is cut along. Thereby, two 1st laminated blocks 14 can be formed only by cutting the original block material 13 once. Therefore, the manufacturing efficiency of the optical element 1 and the reflective aerial imaging element 10 can be further improved.

  In the reinforcing plate joining step, the reinforcing plates 5 may be joined to both end faces of the optical elements 1 in the juxtaposed direction. Thereby, the strength of the reflective aerial imaging element 10 can be further improved. Further, the reinforcing plate 5 may be omitted from the reflective aerial imaging element 10.

  In the present embodiment, both surfaces of the transparent plate 11 are made of the reflective surface 2, but only one surface of the transparent plate 11 may be made of the reflective surface 2. In this case, since the illumination light L emitted from the light source 20 is incident on the adhesive layer in the aerial image display device 100, it is desirable that the refractive index of the adhesive or the spacer is substantially the same as the refractive index of the transparent plate 11. .

Second Embodiment
Next, a second embodiment of the present invention will be described. This embodiment is different from the first embodiment in that the formation of the original block material 13 is omitted. Other parts are the same as those in the first embodiment.

  In the reflecting surface forming step of FIG. 5, the transparent plates 11 (see FIG. 8) having a square planar shape are bonded to each other with an adhesive, and 480 transparent plates 11 are stacked in a direction perpendicular to the reflecting surface 2. Thereby, the cube-shaped 1st laminated block 14 (refer FIG. 8) is formed. At this time, a plurality of first laminated blocks 14 are formed. The steps after the second laminated block forming step are the same as those in the first embodiment.

  According to this embodiment, the same effect as that of the first embodiment can be obtained. Moreover, since the formation of the original block material 13 is omitted, the manufacturing efficiency of the optical element 1 and the reflective aerial imaging element 10 can be further improved.

<Third Embodiment>
Next, a third embodiment of the present invention will be described. FIG. 13 shows a plan view of the original block material formed in the manufacturing process of the reflective aerial imaging element 10 of the third embodiment. For convenience of explanation, the same reference numerals are assigned to the same parts as those in the first embodiment shown in FIGS. In the present embodiment, the configuration of the original block material 13 is different from that of the first embodiment. Other parts are the same as those in the first embodiment.

  In the laminating process of FIG. 5, the original block member 13 is formed by laminating the rectangular transparent plate 11 having a ratio of the length in the short direction to the length in the long direction of 1: 4. Further, the length D1 of the original block material 13 in the stacking direction LM is formed to be the same as the length of the transparent plate 11 in the short direction. In the original block material cutting step of FIG. 5, the original block material 13 is cut along a plurality of cutting lines C1. The cutting line C1 is formed in parallel to the short direction of the original block material 13, and is formed so as to divide the original block material 13 into four equal parts in the longitudinal direction. As a result, four first laminated blocks 14 having substantially the same cubic shape are formed from the same original block material 13.

  And one of the adjacent 1st laminated blocks 14 of the same original block material 13 and the 2nd laminated block 15 formed from the other are joined in a joining block formation process. Thereby, the joining block 16 is formed.

  According to this embodiment, the same effect as that of the first embodiment can be obtained. In addition, more four first laminated blocks 14 can be obtained from the same original block material 13 than in the case of the first embodiment. Further, in the joining block forming step, one of the adjacent first laminated blocks 14 of the same original block material 13 is joined to the second laminated block 15 formed from the other. Thereby, when the joining block 16 is formed, the lamination direction of the reflective surface 2 of the second laminated block 15a and the reflective surface 2 of the first laminated block 14 at the joint location between the second laminated block 15a and the first laminated block 14 is determined. The shift in LM can be further reduced.

  In the present embodiment, one of the non-adjacent first laminated blocks 14 of the same original block material 13 and the second laminated block 15 formed from the other may be joined in a joining block forming step.

<Fourth embodiment>
Next, a fourth embodiment of the present invention will be described. FIG. 14 is a plan view of the original block material 13 formed in the manufacturing process of the reflective aerial imaging element 10 of the fourth embodiment. For convenience of explanation, the same reference numerals are assigned to the same parts as those in the first embodiment shown in FIGS. In the present embodiment, the configuration of the original block material 13 is different from that of the first embodiment. Other parts are the same as those in the first embodiment.

  In the laminating process of FIG. 5, the original block member 13 is formed by laminating the rectangular transparent plate 11 having a ratio of the length in the short direction to the length in the longitudinal direction of, for example, 1: 2.2. Further, the length D1 of the original block material 13 in the stacking direction LM is formed to be the same as the length of the transparent plate 11 in the short direction. In the original block material cutting step of FIG. 5, first, the original block material 13 is cut along a cutting line C <b> 1 at the center in the longitudinal direction of the original block material 13. Thereafter, the original block material 13 is cut along the cutting lines C1 at both ends of the original block material 13 in the longitudinal direction. The cutting line C1 is formed in parallel to the short direction of the original block material 13, and the distance between the adjacent cutting lines C1 is formed to be the same as the length of the original block material 13 in the short direction. Thus, two first laminated blocks 14 having substantially the same cubic shape are formed from the same original block material 13.

  In the present embodiment, extra regions 17 in which the length in the direction perpendicular to the cutting line C1 is less than the length in the short direction of the original block material 13 are formed at both ends in the longitudinal direction of the original block material 13. . Thereby, even when the original block material 13 is cut at a portion slightly shifted in the left-right direction with respect to the cutting line C1 at the center in the longitudinal direction of the original block material 13, the cutting line C1 at the end in the longitudinal direction of the original block material 13 is Can be shifted in the direction. Therefore, the planar shape of the peripheral surfaces 14a and 14b of the first laminated block 14 can be surely made square.

  Then, in the joining block forming step, one of the adjacent first laminated blocks 14 of the same original block material 13 is joined to the second laminated block 15 formed from the other. Thereby, the joining block 16 is formed.

  According to this embodiment, the same effect as that of the first embodiment can be obtained. In addition, an extra region 17 whose length in the direction perpendicular to the cutting line C <b> 1 is less than the length in the short direction of the original block material 13 is formed at both ends in the longitudinal direction of the original block material 13. Thereby, even when the original block material 13 is cut at a portion slightly shifted in the left-right direction with respect to the cutting line C1 at the center in the longitudinal direction of the original block material 13, the cutting line C1 at the end in the longitudinal direction of the original block material 13 is Can be shifted in the direction. Therefore, the peripheral surfaces 14a and 14b of the first laminated block 14 can be surely made square.

  INDUSTRIAL APPLICABILITY The present invention can be used for a reflective aerial imaging element that forms a real image of a projection object in the air, an optical element used for the reflective aerial imaging element, and a method for manufacturing the same.

DESCRIPTION OF SYMBOLS 1 Optical element 2 Reflecting surface 3 1st small piece part 4 2nd small piece part 5 Reinforcement board 10 Reflection type aerial imaging element 11 Transparent board 13 Original block material 14 1st laminated block 14a, 14b Peripheral surface 15, 15a, 15b 2nd Laminated block 15c Bottom surface 16 Bonding block 18 Incident surface 19 Outgoing surface 20 Light source 31, 42, 43 Side 41 Oblique side 100 Aerial video display device 151c Slope OB Projected object FI Aerial video C1, C2, C3 Cutting line L Illumination light LM Laminating direction

Claims (15)

An optical element which is formed in a flat plate shape having a rectangular shape in plan view and has a reflecting surface parallel to the thickness direction arranged in parallel at a predetermined cycle,
The optical element is
A first small piece formed in a polygonal planar shape;
A plurality of second small pieces formed in a planar shape of a right-angled isosceles triangle and arranged at four corners of the first small pieces;
With
The first small piece portion has the reflective surface parallel to one side thereof,
The second small piece portion has the reflective surface inclined with respect to the two orthogonal sides,
The side of the first small piece portion perpendicular to the reflective surface and the reflection of the first small piece portion so that the reflective surface of the first small piece portion and the reflective surface of the second small piece portion are parallel to each other. An optical element, wherein a hypotenuse of the second small piece is bonded to a side parallel to the surface.   The optical element according to claim 1, wherein a planar shape of the first small piece portion is formed in a square shape.   2. The optical element according to claim 1, wherein a planar shape of the first small piece portion is formed in any one of a pentagon, a hexagon, a heptagon, and an octagon.   The optical element according to any one of claims 1 to 3, wherein an inclination angle of the reflection surface is 45 ° with respect to two orthogonal sides of the second small piece portion.   5. A reflective aerial imaging element, wherein two optical elements according to claim 1 are arranged side by side in the thickness direction, and the reflecting surfaces of the two optical elements are orthogonal to each other.   The reflective aerial imaging element according to claim 5, wherein a transparent reinforcing plate that covers the optical element is provided on one end surface or both end surfaces of the optical element in the side-by-side direction. In the method of manufacturing a flat optical element in which reflective surfaces parallel to the thickness direction are arranged in parallel at a predetermined period,
A first laminated block forming step of laminating a plurality of transparent plates provided with the reflecting surface on at least one surface to form a first laminated block having a square surface perpendicular to the reflecting surface;
A second laminated block forming step of cutting one of the first laminated blocks along both diagonal lines of a square surface perpendicular to the reflecting surface to form a plurality of triangular laminated second laminated blocks whose bottom faces are right-angled isosceles triangles; ,
On the two opposing surfaces perpendicular to the reflective surface of the first laminated block and the reflective so that the reflective surface of the first laminated block and the reflective surfaces of the plurality of second laminated blocks are parallel to each other A joining block forming step of joining the slope of the second laminated block on two opposing faces parallel to the face to form a joining block;
A joining block cutting step for cutting the joining block at a predetermined cycle along a direction perpendicular to the reflecting surface;
An optical element manufacturing method comprising:   The method for manufacturing an optical element according to claim 7, wherein in the first laminated block forming step, the plurality of transparent plates are bonded via a spacer.   The said 1st lamination block formation process WHEREIN: The original block material which laminated | stacked the said some transparent plate is cut | disconnected in the direction perpendicular | vertical to the said reflective surface, The said some 1st lamination | stacking block is formed. Or the manufacturing method of the optical element of Claim 8.   In the joining block forming step, the first laminated block and the second laminated block formed from the same original block material are joined on a plane perpendicular to the reflecting surface, and one end portion of both of the laminated directions is The method for manufacturing an optical element according to claim 9, wherein the same end portion in the stacking direction of the original block material is used.   The said joining block formation process WHEREIN: One of the said 1st laminated blocks which the same said original block material adjoins, and the said 2nd laminated block formed from the other are joined. A method for manufacturing an optical element.   The ratio of the length of the original block material in the stacking direction to the length of one side of the transparent plate is 1: 2, and in the first stacking block forming step, the ratio is one along the stacking direction at the center of one side of the transparent plate. The method for manufacturing an optical element according to claim 9, wherein the plurality of first laminated blocks are formed by cutting the original block material. Production of a reflective aerial imaging element in which two planar optical elements having reflective surfaces parallel to the thickness direction arranged in parallel at a predetermined period are arranged in parallel in the thickness direction, and the reflective surfaces of the two optical elements are orthogonal to each other. In the method
A first laminated block forming step of laminating a plurality of transparent plates provided with the reflecting surface on at least one surface to form a first laminated block having a square surface perpendicular to the reflecting surface;
A second laminated block forming step of cutting one of the first laminated blocks along both diagonal lines of a square surface perpendicular to the reflecting surface to form a plurality of triangular laminated second laminated blocks whose bottom faces are right-angled isosceles triangles; ,
On the two opposing surfaces perpendicular to the reflective surface of the first laminated block and the reflective so that the reflective surface of the first laminated block and the reflective surfaces of the plurality of second laminated blocks are parallel to each other A joining block forming step of joining the slope of the second laminated block on two opposing faces parallel to the face to form a joining block;
A joining block cutting step of cutting the joining block at a predetermined period along a direction perpendicular to the reflecting surface to form a plurality of the optical elements;
An optical element bonding step of bonding a plurality of the optical elements in the thickness direction;
A method for manufacturing a reflective aerial imaging element, comprising:   The said 1st lamination block formation process WHEREIN: The original block material which laminated | stacked the said transparent plate is cut | disconnected in the direction perpendicular | vertical to the said reflective surface, The said some 1st lamination | stacking block is formed, The said 1st lamination | stacking block is formed. Manufacturing method for reflective aerial imaging elements.   In the joining block forming step, the first laminated block and the second laminated block formed from the same original block material are joined on a plane perpendicular to the reflecting surface, and one end portion of both of the laminated directions is The method of manufacturing a reflective aerial imaging element according to claim 14, wherein the same end portions in the stacking direction of the original block material are used.

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