JP2015045794A - Optical element and manufacturing method of optical element, and image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the contraction of a matrix during curing with a simple method, and prevent a change in interval between interference fringes created by two light flux exposure during the curing of the matrix.SOLUTION: Between a lower substrate 2 and upper substrate 3, glass beads 5 are arranged as a gap material bonded to the lower substrate 2 with an adhesive. Between the lower substrate 2 and upper substrate 3, a volume hologram 4 is attached to be closely adhered to the lower substrate 2 and upper substrate 3. The volume hologram 4 has an interference fringes formed thereon by two light flux exposure, and the volume hologram 4 is cured by UV light or heat.

Description

  The present invention relates to an optical element using a hologram, a manufacturing method thereof, and an image display device.

  In recent head-mounted displays, an image scanned on a spectacle lens by a laser is reflected (diffracted) on the lens and directly written on the retina to achieve miniaturization. If a mirror is used on the spectacle lens, the shape of the spectacle lens is restricted, and the degree of freedom in designing the head mounted display is reduced. In addition, when a mirror is used, keystone correction is required, which causes a reduction in resolution.

  In view of this, a head-mounted display has been developed in which a volume hologram element is pasted on a spectacle lens so that light is diffracted in an arbitrary direction by the hologram and written to the retina. By using the volume hologram element, the shape of the spectacle lens is not restricted, and the degree of freedom in design is improved. Further, since the volume hologram element is used, the keystone correction is unnecessary and the resolution can be increased.

  As a method of manufacturing a volume hologram, a film-like hologram is adhered to a base material, and further, the hologram is protected by a cover layer, and then irradiated with two light beams of laser light, whereby the volume hologram layer is subjected to a refractive index difference. There is a method of generating interference fringes (for example, Patent Document 1). In this method, the UV light is then irradiated and heated, whereby the material of the matrix portion is cured and the interference fringes are fixed, thereby completing the hologram element.

  Since UV curing of the matrix is accompanied by contraction of the matrix, the interference fringe interval created by the two-beam exposure of the laser becomes narrow as the matrix shrinks. Therefore, in Patent Document 1, in consideration of this shrinkage, a method of obtaining a desired interference fringe interval by performing two-beam exposure using a laser having a wavelength slightly longer than the wavelength to be diffracted or changing the angle of the two beams. Is disclosed.

JP 2006-208772 A

  However, since the amount of curing shrinkage of the matrix varies, it is difficult for the method of Patent Document 1 to suppress the variation in the interference fringe spacing. Further, the manner of shrinkage is not uniform, and there is a difference in the amount of shrinkage between the surface that is in contact with the substrate and the surface that is not in contact. Further, the amount of curing shrinkage of the matrix varies depending on process conditions such as the intensity of UV light used for curing, time, and heating temperature, and also varies depending on the elasticity and thickness of the substrate. Therefore, it is necessary to actually investigate the cure shrinkage, diffraction wavelength and diffraction angle by several exposure experiments, predict the interference fringe interval by calculation, and feed back the laser wavelength and angle of two-beam exposure from here. It is very complicated.

  In view of the above-described circumstances, the present invention is an optical element in which shrinkage during matrix curing is prevented by a simple method and a change in an interference fringe interval created by two-beam exposure is prevented, and an optical element manufacturing method An object of the present invention is to provide an image display device.

  One aspect of the optical element according to the present invention is disposed between a first base material having translucency, a second base material having translucency, and the first base material and the second base material. A gap member, and a hologram disposed between the first base material and the second base material, the hologram having a portion in contact with the first base material, and the second base It has the part which touches a material, It is characterized by the above-mentioned.

  According to one aspect of the optical element according to the present invention, since the gap material is disposed between the first base material and the second base material, even if the hologram tends to shrink during the hardening of the hologram matrix, It cannot shrink in the height direction between the base material and the second base material. In addition, since the hologram has a portion in contact with the first base material and a portion in contact with the second base material, the hologram is a surface of the first base material and the second base material at the time of matrix curing. It cannot shrink in any direction. Therefore, since the interference fringe spacing created during the two-beam exposure does not change during matrix curing, it is not necessary to perform complicated adjustment work after the curing process.

  In one aspect of the optical element according to the present invention described above, the gap material may be glass beads. In this case, the glass beads can prevent shrinkage in the height direction between the first base material and the second base material even when the hologram is about to shrink during the matrix hardening of the hologram. Further, due to the translucency of the glass beads, the diffraction due to the interference fringes of the hologram is not affected.

  In one aspect of the optical element according to the present invention described above, the gap material may be a resin bead. In this case, the resin beads can prevent shrinkage in the height direction between the first base material and the second base material even when the hologram is about to shrink during the matrix hardening of the hologram. In addition, the translucency of the resin beads does not affect the diffraction caused by the interference fringes of the hologram.

  In one aspect of the optical element according to the present invention described above, the gap material is disposed between one side of the first base material and the hologram in a plan view as viewed from a direction perpendicular to the first base material. You may do it. In this way, the gap material does not affect the diffraction due to the interference fringes of the hologram.

  In one aspect of the optical element according to the present invention described above, the gap material may be disposed in a region where light does not enter. In this way, the gap material does not affect the diffraction due to the interference fringes of the hologram.

  One aspect of the optical element according to the present invention is disposed between a first base material having translucency, a second base material having translucency, and the first base material and the second base material. The hologram has a portion in contact with the first base material and a portion in contact with the second base material, and the first base material is a surface in contact with the hologram. It has a convex part, and the said convex part has a part which touches the said 2nd base material, It is characterized by the above-mentioned.

  According to one aspect of the optical element of the present invention, the hologram has a portion in contact with the first base material, and has a portion in contact with the second base material, and the first base material is in contact with the hologram. Since the convex portion has a portion in contact with the second base material, even if the hologram tends to shrink when the hologram is hardened, the convex portion is between the first base material and the second base material. It cannot shrink in the height direction. Further, since the hologram is in close contact with the first base material and the second base material, the hologram cannot shrink in the surface direction of the first base material and the second base material at the time of matrix curing. Therefore, since the interference fringe spacing created during the two-beam exposure does not change during matrix curing, it is not necessary to perform complicated adjustment work after the curing process.

  In one aspect of the method for producing an optical element according to the present invention, a step of arranging a gap material on one surface of a first base material having translucency, and on the one surface side of the first base material, Arranging the second base material so as to face each other through the gap material, injecting a hologram material between the first base material and the second base material, and exposing the hologram material A step of forming an interference fringe on the hologram, and a step of curing the hologram on which the interference fringe is formed.

  According to one aspect of the optical element manufacturing method of the present invention, the gap material is disposed between the first base material and the second base material. In the height direction between the first base material and the second base material, it cannot shrink. Further, since the hologram is in close contact with the first base material and the second base material by the injection process, the hologram cannot shrink in the surface direction of the first base material and the second base material at the time of matrix curing. Therefore, since the interference fringe spacing created during the two-beam exposure does not change during matrix curing, it is not necessary to perform complicated adjustment work after the curing process.

  In one aspect of the method for producing an optical element according to the present invention, a step of placing a gap material on one surface of a first substrate having translucency, and the one surface on the first substrate, A step of arranging a hologram material, a step of pressure-bonding a second substrate so as to face the one surface side of the first substrate via the gap material and the hologram material, and exposing the hologram material Thus, the method includes a step of forming interference fringes on the hologram and a step of curing the hologram on which the interference fringes are formed.

  According to one aspect of the optical element manufacturing method of the present invention, the gap material is disposed between the first base material and the second base material. In the height direction between the first base material and the second base material, it cannot shrink. Further, since the hologram is pressure-bonded to the first base material and the second base material by the injection process, the hologram cannot be contracted in the surface direction of the first base material and the second base material at the time of matrix curing. Therefore, since the interference fringe spacing created during the two-beam exposure does not change during matrix curing, it is not necessary to perform complicated adjustment work after the curing process.

  Next, an aspect of the image display device according to the present invention includes the above-described optical element according to the present invention. Such an image display device may include an image forming unit such as a liquid crystal display and a collimating optical system, and can be adapted to a form mounted on the observer's head such as a head-mounted display.

  As described above, according to the present invention, an image display device that is mounted on the observer's head, such as a head-mounted display, can be manufactured by using an optical element that can be preferably manufactured by a simple method. It is possible to obtain an optical device that can improve the fitting property with respect to the face of the observer and can obtain a wide angle of view while reducing the cost.

It is a figure which shows the structure of the optical element which concerns on 1st Embodiment. It is a top view of the optical element concerning a 1st embodiment. It is a figure explaining the manufacturing method of the optical element concerning a 1st embodiment. It is a figure explaining the manufacturing method of the optical element concerning a 1st embodiment. It is a figure explaining the manufacturing method of the optical element concerning a 1st embodiment. It is a figure explaining the manufacturing method of the optical element concerning a 1st embodiment. It is a figure explaining the manufacturing method of the optical element concerning a 1st embodiment. It is a figure explaining the manufacturing method of the optical element concerning a 1st embodiment. It is a figure explaining the manufacturing method of the optical element concerning a 1st embodiment. It is a figure explaining the method of two-beam exposure in the manufacture process of the optical element which concerns on 1st Embodiment. It is a flowchart which shows the manufacturing method of the optical element which concerns on 1st Embodiment. It is a figure which shows the hologram sheet used for the optical element which concerns on 2nd Embodiment. It is a figure explaining the manufacturing method of the optical element which concerns on 2nd Embodiment. It is a figure explaining the manufacturing method of the optical element which concerns on 2nd Embodiment. It is a figure explaining the manufacturing method of the optical element which concerns on 2nd Embodiment. It is a figure explaining the manufacturing method of the optical element which concerns on 2nd Embodiment. It is a flowchart which shows the manufacturing method of the optical element which concerns on 2nd Embodiment. It is a figure which shows the structure of the optical element which concerns on a modification. It is a perspective view which shows the head mounted display which concerns on an application example. It is a figure which shows the internal structure of the head mounted display which concerns on an application example. It is a figure which shows the structure of the optical element which concerns on a comparative example. It is a figure which shows the structure of the optical element which concerns on a comparative example.

  Hereinafter, various embodiments according to the present invention will be described with reference to the accompanying drawings.

<A: First Embodiment>
<Optical element>
FIG. 1 is a diagram illustrating an example of the configuration of the optical element of the present embodiment. As shown in FIG. 1, the optical element 1 includes a lower substrate 2 made of glass or the like, an upper substrate 3 made of the same material as the lower substrate 2, a volume hologram 4, and an adhesive 6. And glass beads 5 as gap members attached to the lower substrate 2.

  As the lower substrate 2 and the upper substrate 3, those having a thickness of 500 to 3000 μm were used. The glass beads 5 have a diameter of 10 to 50 μm. Therefore, the thickness of the volume hologram 4 of the optical element 1 is 10 to 50 μm. Since the glass beads 5 that are generally widely used have a diameter of 15 to 20 μm, when such glass beads 5 are used, the thickness of the volume hologram 4 is 15 to 20 μm.

  The lower substrate 2 and the upper substrate 3 are preferably made of a transparent and highly rigid material such as glass. It is also preferable to use the same material for the lower base material 2 and the upper base material 3 in order to prevent interference fringes from changing during matrix hardening, which will be described later.

  The volume hologram material includes, for example, a binder polymer, a high-refractive index photopolymerizable monomer, a plasticizer, and a photopolymerization initiator. In order to improve the refractive index modulation, the photopolymerizable monomer is chlorine. In addition, a composition including atoms that contribute to a high refractive index such as bromine is used.

  FIG. 2 shows a plan view of the optical element 1 when viewed from the direction of the arrow A shown in FIG. As shown in FIG. 2, the glass beads 5 are distributed and arranged outside the region where the volume hologram 4 is arranged. For example, when the optical element 1 is used as a diffraction element in a head-mounted display, the area where the volume hologram 4 is disposed is used as a light incident area where light is incident. That is, the glass beads 5 are disposed outside the light incident area of the volume hologram 4. However, the present invention is not limited to such a configuration, and the glass beads 5 may be arranged in the light incident region of the volume hologram 4. In FIG. 2, a sealing member 7 is a member that seals the volume hologram injection port.

  Although the interference fringes of the optical element 1 are formed by two-beam exposure described later, the optical element 1 of the present embodiment has a glass bead 5 as a gap material between the lower base material 2 and the upper base material 3. Therefore, the volume hologram 4 cannot contract in the longitudinal direction of FIG. 1 when the matrix is cured by UV light or the like after two-beam exposure. Further, since the volume hologram 4 is in close contact with the lower base material 2 and the upper base material 3, the volume hologram 4 cannot contract in the lateral direction of FIG. Therefore, the interference fringe interval created at the time of two-beam exposure does not change at the time of matrix hardening, and complicated feedback work such as adjustment of the laser beam wavelength and angle at the time of two-beam exposure is not required.

<Optical element manufacturing method>
A method for manufacturing the optical element 1 will be described with reference to FIGS. FIG. 11 is a flowchart for explaining an example of the manufacturing method of the optical element 1. First, as shown in FIG. 3, the glass beads 5 are attached on the lower substrate 2 using the adhesive 6 (FIG. 11: Step S1).

  Next, as shown in FIG. 4, the upper base material 3 is attached onto the glass beads 5, and the lower base material 2 is covered with the upper base material 3 (FIG. 11: Step S2). Then, as shown in FIG. 5, the volume hologram material 4 is injected from the injection port (FIG. 11: Step S3). 8 is a plan view seen from the direction of arrow A shown in FIG. As shown in FIG. 8, there is a portion where the adhesive 6 is not applied on the lower substrate 2, and the portion is formed as the sealing port 8. In the present embodiment, the volume hologram material is injected from the sealing port 8 in the direction of arrow B shown in FIG. Thus, the volume hologram material can be brought into close contact with the lower substrate 2 and the upper substrate 3 by using the method of injecting the volume hologram material.

  As shown in FIG. 6, when the injection of the volume hologram material is completed, the sealing port 8 is sealed with the sealing member 7 (FIG. 11: Step S5). FIG. 9 is a plan view seen from the direction of arrow A shown in FIG. As shown in FIG. 9, the sealing port 8 is sealed by the sealing member 7. As the sealing member 7, an acrylic UV curable adhesive is used.

  Next, as shown in FIG. 7, two-beam exposure is performed by irradiating laser light at a desired angle from the upper base material 3 side and the lower base material 2 side (FIG. 11: step S6). FIG. 10 is a diagram for explaining a two-beam exposure method in the present embodiment. As shown in FIG. 10, laser light of a predetermined wavelength is emitted from a laser light source 50, and this laser light is split by a beam splitter 51. Next, the angles of the divided laser beams are changed by mirrors 52, 53, and 54, and one of them is converted into parallel light (reference light) using an objective lens 55 and a collimator lens 57. The other is also made into parallel light (object light) using the objective lens 56 and the collimator lens 58. Thereafter, these lights are combined again and interfered to form interference fringes on the volume hologram 4.

  By intentionally changing the incident angle of the laser beam when forming interference fringes so that it matches the wavelength of the light source from a specific incident angle, the reflected light peak during reproduction can be adjusted to the target wavelength. It is. This relationship is based on Bragg's condition, 2 dsin θ = λ. Here, d is the interval between the interference fringes, θ is half the angle formed by the reproduction incident light and the reproduction light, and λ is the wavelength. Is possible.

  After the two-beam exposure is completed as described above, a curing process using UV light or heat is performed (FIG. 11: Step S7). When the curing process using UV light or heat is performed, the matrix of the volume hologram 4 is cured, and the volume hologram 4 tends to shrink when the matrix is cured. However, in the present embodiment, since the glass beads 5 as the gap material are disposed between the lower base material 2 and the upper base material 3, the volume hologram 4 is shown when the matrix is cured by UV light or the like. 7 cannot shrink in the longitudinal direction. Further, since the volume hologram 4 is in close contact with the lower base material 2 and the upper base material 3, the volume hologram 4 cannot contract in the lateral direction of FIG. Therefore, since the interference fringe interval created at the time of two-beam exposure does not change at the time of matrix curing, the curing shrinkage amount, the diffraction wavelength, or the diffraction angle is examined after the curing process, and the interference fringe interval is predicted by calculation. Troublesome work such as feedback of the laser beam wavelength and angle during two-beam exposure is not required.

<Comparative example>
A comparative example will be described with reference to FIGS. 21 and 22. FIG. 21 is a diagram illustrating an example of an optical element of a comparative example. As shown in FIG. 21, in the optical element of the comparative example, a volume hologram 61 is arranged on a substrate 60 formed of glass or the like, and a protective layer 62 formed of PET or the like is formed on the volume hologram 61. Has been placed. The substrate 60 has a thickness of 1 mm, the volume hologram 61 has a thickness of 20 μm, and the protective layer 62 has a thickness of 50 to 100 μm.

  When the optical element of the comparative example having such a structure is subjected to the two-beam exposure as described above to form interference fringes on the volume hologram, and then cured by UV light or the like, the matrix of the volume hologram is cured. Then, it contracts in the horizontal and vertical directions shown in FIG. In the optical element of the comparative example, since the base material is glass and the protective layer is PET or the like and the rigidity is different from each other, the shrinkage proceeds on the protective layer side rather than the base material side as shown in FIG. As a result, the interval between the interference fringes of the volume hologram becomes narrower than the interval between the interference fringes created by the two-beam exposure.

  Therefore, even if the optical element of the comparative example is used for a head-mounted display or the like and the interval between interference fringes created by two-beam exposure is determined so as to extract only light of a specific wavelength, Since the interval between the interference fringes has changed, it becomes impossible to extract the light of the specific wavelength.

  In the optical element of the comparative example, in order to eliminate such inconvenience, the amount of shrinkage is anticipated, and a two-beam exposure is performed using a laser having a wavelength slightly longer than the wavelength to be diffracted. A complicated operation such as examining the diffraction wavelength or diffraction angle, predicting the interference fringe interval by calculation, and feeding back the laser light wavelength and angle at the time of two-beam exposure is required. As shown in FIG. 22, since the volume hologram 61 has different shrinkage amounts on the base 60 side and the protective layer 62 side, it is complicated to give complete feedback.

  On the other hand, in the optical element 1 of the present embodiment, glass beads 5 as a gap material are provided between the lower base material 2 and the upper base material 3, and the volume hologram 4 is made to have a highly rigid lower base material 2 and upper base material. Since they are in close contact with the material 3, interference fringes do not change even during matrix curing.

<B: Second Embodiment>
A second embodiment of the present invention will be described with reference to FIGS. In this embodiment, a hologram film as shown in FIG. 12 is used. As shown in FIG. 12, in the hologram film of this embodiment, a cover film 9 such as PET is attached above the film-like volume hologram 4, and a release film such as PET is attached below the volume hologram 4. 10 is affixed.

  The cover film 9 has a thickness of 50 to 200 μm, the film-shaped volume hologram 4 has a thickness of 10 to 50 μm, preferably 15 to 20 μm, and the release film 10 has a thickness of 50 to 200 μm.

  Hereinafter, a method for producing the optical element 1 of the present embodiment using this hologram film will be described. FIG. 17 is a flowchart for explaining a method for manufacturing the optical element 1 of the present embodiment.

First, as shown in FIG. 13, the glass beads 5 are attached onto the lower substrate 2 using the adhesive 6 (FIG. 17: Step S10). Next, the release film 10 is peeled from the hologram film, and the volume hologram 4 is attached to the lower substrate 2 as shown in FIG. 14 (FIG. 17: Step S11). Then, as shown in FIG. 14, the cover film 9 is peeled off (FIG. 17: Step S12). In this state, as shown in FIG. 14, the thickness of the volume hologram 4 is larger than the diameter of the glass beads 5. This is because the upper substrate 3 is brought into close contact with the volume hologram 4.

  Next, as shown in FIG. 15, the upper base material 3 is pressed against the volume hologram 4, and the lower base material 2 is covered with the upper base material 3 (FIG. 17: Step S13). FIG. 16 is a plan view seen from the direction of arrow A shown in FIG. As shown in FIG. 16, the lower base material 2 and the upper base material 3 are in close contact with the volume hologram 4 in a wide range.

  Thereafter, similarly to the first embodiment, laser beams are irradiated at different angles from the upper substrate 3 side and the lower substrate 2 side, respectively, and two-beam exposure is performed to form interference fringes on the volume hologram 4. (FIG. 17: Step S14).

  After the two-beam exposure is completed as described above, a curing process using UV light or heat is performed (FIG. 17: Step S15). When the curing process using UV light or heat is performed, the matrix of the volume hologram 4 is cured, and the volume hologram 4 tends to shrink when the matrix is cured. However, also in this embodiment, since the glass beads 5 as the gap material are disposed between the lower base material 2 and the upper base material 3, the volume hologram 4 is shown when the matrix is cured by UV light or the like. It cannot shrink in 15 vertical directions. Further, since the volume hologram 4 is in close contact with the lower substrate 2 and the upper substrate 3, the volume hologram 4 cannot contract in the lateral direction of FIG. Therefore, since the interference fringe interval created at the time of two-beam exposure does not change at the time of matrix curing, the curing shrinkage amount, the diffraction wavelength, or the diffraction angle is examined after the curing process, and the interference fringe interval is predicted by calculation. Troublesome work such as feedback of the laser beam wavelength and angle during two-beam exposure is not required.

<C: Modification>
The present invention is not limited to the above-described embodiments, and various modifications described below are possible. Of course, each modification and embodiment may be appropriately combined.
<Modification 1>
In each of the above-described embodiments, examples in which glass beads are used as the gap material have been described. However, the present invention is not limited to such a configuration. For example, resin beads may be used instead of glass beads.

<Modification 2>
Further, as the gap material, not only glass beads and resin beads, but also a gap layer 11 that is a columnar or wall-like convex portion formed on the lower substrate 2 or the upper substrate 3 as shown in FIG. Is also possible. For example, a gap layer such as SiN or SiO 2 may be formed by photolithography.

<Modification 3>
In each of the embodiments described above, the example in which the volume hologram 4 and the lower base material 2 and the upper base material 3 are in close contact with each other has been described. However, the adhesiveness between the volume hologram 4 and the lower base material 2 and the upper base material 3 is excellent. When weak, you may make it adhere | attach the volume hologram 4 to the lower base material 2 and the upper base material 3 using an adhesive agent.

<D: Application example>
The optical element according to the present invention can be applied to various image display devices and the like. Hereinafter, typical application examples will be described.
19 and 20 show examples in which the optical element 1 of the present invention is applied to a MEMS scan type head mounted display 100. FIG. FIG. 19 is a perspective view showing an overall image of the MEMS scan type head mounted display 100. As shown in FIG. 19, the MEMS scan type head mounted display 100 according to the application example is a head mounted display having an appearance like glasses, and image light by a virtual image is given to an observer wearing the head mounted display 100. Can be recognized, and the observer can see the external image in a see-through manner.

  Specifically, the MEMS scan type head mounted display 100 includes a light guide 20, a pair of left and right temples 101 and 102 that support the light guide 20, and a pair of image forming apparatuses 111 and 112 attached to the temples 101 and 102. With. Here, in the drawing, the first display device 100A in which the left side of the light guide 20 and the image forming device 111 are combined is a portion that forms a virtual image for the right eye, and functions alone as an image display device. In the drawing, the second display device 100B in which the right side and the image forming device 112 are combined with the light guide 20 is a portion that forms a virtual image for the left eye, and functions alone as an image display device.

  The internal structure and light guide of the MEMS scan type head mounted display 100 will be described. FIG. 20 is a cross-sectional view of an essential part schematically showing the internal structure and light guide of the MEMS scan type head mounted display according to the present embodiment. As shown in FIG. 20, the first display device 100 </ b> B includes an image forming unit 70, a light guide 20, and an optical element 1 including a volume hologram disposed on the light guide 20.

  The image forming unit 70 includes a light source 71, a collimating lens 72, a MEMS mirror 73, and a correction lens 74. Light including three colors of red, green, and blue is generated from the light source 71, and the light from the light source 71 is emitted toward the MEMS mirror 73 by the parallelizing lens 72. Then, the light reflected by the MEMS mirror 73 is corrected by the correction lens 74 and is incident on the optical element 1.

  The light guide 20 is a plate-like member formed of a light transmissive resin material or the like, and external light is incident through the light incident surface and guided to the observer's eyes.

  In this application example, the optical element 1 is an optical element having the reflective volume hologram of the present invention. The optical element 1 reflects the image light emitted from the light source 71 and incident through the collimating lens 72, the MEMS mirror 73, and the correction lens 74 to form an image on the observer's retina. Therefore, the observer can recognize image light such as video light while recognizing an external state.

DESCRIPTION OF SYMBOLS 1 ... Optical element, 2 ... Lower base material, 3 ... Upper base material, 4 ... Volume hologram, 5 ... Glass bead, 6 ... Adhesive, 7 ... Sealing member, 8 ... Enclosing port, 9 ... Cover film, 10 ... Release film, 11 ... gap layer, 100 ... head mounted display.

Claims (9)

A first base material having translucency;
A second substrate having translucency;
A gap material disposed between the first base material and the second base material;
A hologram disposed between the first base material and the second base material,
The hologram includes an optical element having a part in contact with the first base material and a part in contact with the second base material. The optical device according to claim 1.
The optical element, wherein the gap material is a glass bead. The optical device according to claim 1.
The optical element, wherein the gap material is resin beads. The optical device according to any one of claims 1 to 3,
The optical element, wherein the gap material is disposed between one side of the first base material and the hologram in a plan view as viewed from a direction perpendicular to the first base material. The optical device according to any one of claims 1 to 4,
The optical device, wherein the gap material is disposed in a region where light does not enter. A first base material having translucency;
A second substrate having translucency;
A hologram disposed between the first base material and the second base material,
The hologram has a portion in contact with the first base material, and a portion in contact with the second base material,
The first substrate has a convex portion on the surface in contact with the hologram,
The said convex part has a part which contact | connects the said 2nd base material, The optical element characterized by the above-mentioned. A step of arranging a gap material on one surface of the first base material having translucency;
Disposing a second base material on the one surface side of the first base material so as to face each other with the gap material interposed therebetween;
Injecting a hologram material between the first substrate and the second substrate;
Forming interference fringes on the hologram by exposing the hologram material;
And a step of curing the hologram on which the interference fringes are formed. A step of arranging a gap material on one surface of the first base material having translucency;
Disposing a hologram material on the one surface of the first substrate;
A step of pressure-bonding the second base material so as to face the one surface side of the first base material via the gap material and the hologram material;
Forming interference fringes on the hologram by exposing the hologram material;
And a step of curing the hologram on which the interference fringes are formed. An image display device comprising the optical element according to claim 1.

Images