JP2009251559A - Optical element, preparation method of optical element and projection type display apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical element which dispenses with alignment between a secondary optical source part and a tapered rod array, and can emit homogenized light upon emission from an emission surface at a prescribed angle with respect to incident light and ensures high efficiency of using light, to provide a preparation method of the optical element, and to provide a projection type display apparatus containing the optical element. <P>SOLUTION: In the optical element, a reflection layer having a plurality of opening parts is formed on a transparent substrate. Further, a plurality of tapered structural parts each of which has a shape that spreads in a tapered shape from the substrate side are formed on the opening parts, wherein the reflection layer and the tapered structural parts form an integrated structure. Therefore, the alignment between the secondary optical source part and the tapered rod array are made unnecessary, the emission of homogeneous light into the surface at a prescribed collimator angle with respect to incident light is permitted and the optical element having the high efficiency of using light can be provided. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an optical element, a method for manufacturing the optical element, and a projection display device, and more particularly to an optical element having a tapered rod array structure that controls the light emission angle and uniformizes the intensity distribution.

  In recent years, projectors using spatial light modulators such as LCD (Liquid Crystal Display), DMD (Digital Micro-mirror Device), and LCOS (Liquid Crystal On Silicon) have been actively developed. In particular, the development of a compact, highly portable, and low-priced projector is being promoted rapidly. In order to achieve miniaturization, many configurations have been proposed in which solid-state light sources such as light emitting diodes (LEDs) or semiconductor lasers are used as light sources instead of conventional halogen lamps or high-pressure mercury lamps. I came.

  In addition, as a configuration of an illuminating device that can be miniaturized, a rod integrator that multi-reflects and homogenizes light or a taper rod (light guide element having a larger area on the light exit side than the area on the light incident side) is used. Many things have been proposed. In particular, the tapered rod can make the incident light uniform and collimated at the same time, and the light propagation distance necessary for homogenization and collimation is short, so it is suitable for downsizing and cost reduction. However, in order to sufficiently collimate light with a taper rod, a long taper shape of several tens of mm is generally required, so there is a problem in miniaturization.

  As a means for achieving further miniaturization, a configuration has been proposed in which a plurality of tapered rods are arranged in an array rather than a single tapered rod. For example, in Patent Document 1, a plurality of LEDs capable of emitting light of each color of red, green, and blue (hereinafter, abbreviated as red, green as G, and blue as B) are arranged in a planar shape or a curved shape. LED array, rod lens array in which a plurality of rod lenses for equalizing the illuminance of each color light emitted from each LED of the LED array are arranged in a planar or curved surface, and light emitted from the rod lens array A polarizing beam splitter array (hereinafter abbreviated as PBS array) that performs polarization conversion of the liquid crystal, a liquid crystal light valve that synthesizes an image by modulating each color light emitted from the PBS array, and an image synthesized by the liquid crystal light valve There has been proposed a projection type image display device that is composed of a projection lens that performs enlarged projection.

  In Patent Document 2, an LED group including RGB three colors is used as one light source unit, an array of the LED groups is used as a light source, and a taper rod that couples light emitted from one LED group with one taper rod. This is a projection display device that uses an array to irradiate light beams with uniform illuminance and improved directivity onto a light valve, and enlarge and project an image formed on the light valve onto a screen by a projection lens.

  Further, Patent Document 3 discloses an optical module including a plurality of LEDs, an optical element that receives light from the LEDs and forms a plurality of secondary light sources, and a tapered rod array formed on the secondary light sources. ing. The configuration of a conventional optical module is shown in FIG. In the figure, an LED 102 is arranged on a substrate 101 and necessary wiring is made. The LED 102 is an LED array (planar light source), and the first optical element 103 couples the light emitted from the LED 102 and diffuses the light within the element to form a plurality of secondary light sources 104 having the same amount of emitted light flux. Yes. The second optical element 105 is a tapered rod array that improves the directivity of light emitted from the secondary light source 104 and makes the illuminance uniform. Further, as shown in FIG. 15, for example, the tapered rod has a light source side size of □ 420 μm, an output side size of □ 2 mm, and an overall length of 5.37 mm, and the output surface side has a radius of curvature R = 2. .92 mm spherical surface.

  In addition, an illumination device using such a tapered rod can also be used as an illumination device for a microscope. For example, in Patent Document 4, light from a light source is guided by a plurality of bundle fibers, An illumination optical device for coupling and illuminating light emitted from an emission end face by a rod integrator is shown.

As described above, it has been proposed to use a tapered rod array in order to achieve a small and inexpensive lighting device. Although the method for producing the taper rod array is not described in detail in the above-mentioned patent document, it can be considered that the taper rod array is produced by resin injection molding or glass molding. Further, the mold can be processed by using a recent precision processing machine (for example, Robonano α-0iB manufactured by FANUC).
JP 2003-295315 A JP 2007-288169 A JP 2008-041288 A JP 2007-156291 A

  However, as the number of taper rods increases and miniaturization becomes difficult, there is a limit to the number and size of taper rods. In particular, in Patent Document 3, it is necessary to form the secondary light source unit and the tapered rod array at the same location. Therefore, it is considered that a process of precisely aligning and bonding the secondary light source unit and the taper rod array is necessary, but it is extremely difficult to precisely align the multiple secondary light source units and the multiple taper rod arrays. In order to achieve this, there is a problem that increases the manufacturing cost. In addition, if the alignment accuracy is low, light leaks and the like causes a reduction in efficiency. Furthermore, if there is a gap between the secondary light source part and the tapered rod array part, there is a problem that total reflection increases at the interface between the secondary light source part and air, and the light extraction efficiency decreases.

  The present invention is for solving these problems, and it is not necessary to align the secondary light source unit and the tapered rod array, and the light is uniformized to the exit surface at a predetermined collimation angle with respect to the incident light. It is an object of the present invention to provide an optical element, a method for manufacturing the optical element, and a projection display device that can emit light.

  In order to solve the above problems, in the optical element of the present invention, a reflective layer having a plurality of openings is formed on a transparent substrate. In addition, a plurality of taper structures having a shape extending in a taper shape from the substrate side are formed on the opening, and the reflective layer and the taper structure are integrated. Therefore, it is not necessary to align the secondary light source unit and the tapered rod array, and it is possible to emit uniform light in a plane at a predetermined collimating angle with respect to incident light, and an optical element with high light utilization efficiency. Can be provided.

  Further, since the tapered structure portion has a truncated cone structure or a truncated pyramid structure, an optical element that can be made more isotropic can be obtained.

  Furthermore, it is preferable that the taper structures are two-dimensionally arranged.

  Further, since the tapered structure portion is made of a photocurable material, an optical element that can be easily manufactured can be obtained.

  Furthermore, by using an organic-inorganic hybrid material excellent in mechanical strength, heat resistance, and environmental resistance as a photocurable material, an optical element that can be used for high-intensity light can be provided.

  Further, since the photocurable material is a negative photoresist material, a negative photoresist remaining after the light irradiation portion is cured in the photoresist can be used. Since the negative photoresist is excellent in film thickness controllability and processing resolution, a precise taper rod structure can be more easily produced.

  Furthermore, by having a light incident portion and a scattering reflection portion formed on a surface other than the surface where the light incident portion is provided, it is possible to reuse the light reflected by the reflective layer with respect to the incident light. Therefore, a more efficient optical element can be obtained.

  In addition, since the solid light-emitting element is provided in the opening, an optical element capable of emitting light homogenized at a predetermined collimating angle by one integrated configuration can be provided.

  Furthermore, another method of manufacturing an optical element includes a reflective film forming step of forming a reflective film having a plurality of openings on a transparent substrate, and a photocuring of forming a photocurable material layer on the reflective film. Curable material layer forming step, irradiation step of irradiating the photocurable material layer with light having a predetermined divergence angle from the substrate side, and photocuring to remove the portion of the photocurable material layer that is not irradiated with light And a functional material layer removing step. Therefore, the reflective layer having a plurality of openings and the tapered rod array can be manufactured at the same location without being aligned, and an optical element can be easily manufactured at low cost.

  Another method for producing an optical element includes a reflective film forming step of forming a reflective film having a plurality of openings on a transparent substrate, and photocuring of forming a photocurable material layer on the reflective film. Forming the curable material layer, irradiating light while rotating the substrate at a predetermined angle from the substrate side with respect to the photocurable material layer, and removing the portion of the photocurable material layer that is not irradiated with light And a photocurable material layer removing step. Therefore, the taper angle of the taper rod array can be adjusted easily and precisely by changing the angle of light with which the substrate is exposed.

  Furthermore, when the film thickness of the photocurable resin is larger or the tilt angle of the rotation tilt exposure is larger by irradiating light while changing the relative angle between the substrate and the light to be irradiated in the irradiation process. Even so, a tapered rod array structure can be produced.

  According to another aspect of the present invention, there is provided a projection display device, wherein the optical element, a light modulation element that modulates light emitted from the optical element in accordance with image information, and a light modulated by the light modulation element are enlarged and projected. And a projection lens. Therefore, it is possible to provide a projection display device that is excellent in light reuse efficiency and can be reduced in size, thickness, and weight with a simple configuration.

  In the optical element of the present invention, since the reflective layer and the tapered structure portion are integrated, it is not necessary to align the secondary light source portion and the tapered rod array, and in-plane with a predetermined collimation angle with respect to incident light. It is possible to provide an optical element that can emit uniform light and has high light utilization efficiency.

  FIG. 1 is a cross-sectional view showing the configuration of the optical element according to the first embodiment of the present invention. In the optical element 10 of the present embodiment shown in the figure, a reflective layer 13 having a plurality of openings 12 is formed on a transparent substrate 11, and a taper composed of a plurality of taper rods 14 is formed on the openings 12. A rod array 15 is formed. The tapered rod array 15, the transparent substrate 11 and the reflective layer 13 are in close contact with each other and have an integral structure. That is, the taper rod array 15, the transparent substrate 11, and the reflective layer 13 are integrally formed, and no adhesive or the like exists between them. However, in order to ensure mechanical strength, it is conceivable that the peripheral portion is supplementarily reinforced with an adhesive or the like. Further, the taper rod array 15 is a two-dimensional array and is also arranged in an array in the depth direction of FIG.

  As the specific structure of the tapered rod array 15 in FIG. 1, various shapes such as a truncated pyramid shape as shown in FIG. 2A and a truncated cone shape as shown in FIG. However, in order to make the light angle distribution more isotropic, a truncated cone shape is preferable. Also, in FIG. 2, there is a gap between the arrays on the side that is not in close contact with the substrate on the emission side, but there may be no gap and it may be integrated. Further, as shown in FIG. 2C, a denser array arrangement can be taken as the array arrangement. Further, the surface opposite to the substrate side, which is the emission surface of the tapered rod structure, is not limited to a flat surface. For example, a fine structure may be formed. When light is emitted, reflection may occur at the interface between the emission surface and air, resulting in a loss of light quantity. Therefore, it is preferable to have a fine structure (roughness) that suppresses reflection.

  Moreover, it is preferable that each taper rod 14 of the taper rod array 15 of FIG. 1 is formed of a photocurable material. This is convenient from the viewpoint of production, and it is possible to produce a taper structure with a photocurable material by a production method as described later, and the production is very easy. Note that the photocurable material is a material in which only an irradiated portion is cured by a crosslinking reaction by light irradiation, and an unirradiated portion can be removed by solution treatment or the like. The photocurable material is generally composed mainly of a monomer or oligomer exhibiting a polymerization reaction mixed with a photopolymerization initiator, and undergoes a polymerization crosslinking reaction by light irradiation. As such a material, an acrylic photocurable material, an epoxy photocurable material, a hybrid material of an organic material and an inorganic material synthesized by a sol-gel method, or the like can be used. As a hybrid material of an organic material and an inorganic material, there is a material in which a crosslinkable resin structure is mixed with an inorganic material such as silica. As characteristics, it is excellent in mechanical strength, heat resistance, and environmental resistance with respect to ordinary photocurable materials (such as acrylic photocurable materials). For this reason, when using it in the optical element used with respect to high intensity | strength light, or a severe usage environment, it is good to use the hybrid material of an organic material and an inorganic material as a photocurable material. Moreover, if it is an optical element used with respect to visible light, it is necessary to use a photo-curable material having a high transmittance for visible light. It is better to use materials.

  Further, it is also possible to use a photoresist as the material of each tapered rod 14 of the tapered rod array 15 in FIG. Photoresist is excellent in film thickness controllability and processing resolution, and a precise taper rod array structure can be more easily produced. Further, in order to produce a photoresist by a production method as will be described later, it is necessary to use a negative photoresist, and if it is produced by a production method to be described later, in principle, it is limited to a negative resist. Negative photoresist materials using epoxy-based materials that are relatively inexpensive and have excellent heat resistance, mechanical strength, and transparency to visible light, such as those sold by Kayaku Microchem. SU-8 resist is suitable.

  Furthermore, as a material used for the reflective layer 13 of FIG. 1, a metal film, a dielectric multilayer film, etc. can be used, and a scattering reflective material can also be used. Among them, the metal film has a very thin film thickness and high reflectivity, so that it is easy to form a large number of fine openings and is best. When used as an optical element for visible light, silver or aluminum is the best metal material because of its high reflectivity for visible light. Since silver is particularly corrosive, it is more preferable that a surface protective layer is also formed when used as a reflective layer.

Next, a method for manufacturing the optical element of the present invention will be described with reference to the drawings.
FIG. 3 is a cross-sectional view showing each step of the method for manufacturing an optical element according to the first embodiment of the present invention. In the figure, the same reference numerals as those in FIG. First, as shown to (a) of the figure, the reflective layer 13 which has the opening part 12 on the transparent substrate 11 is formed. Here, silver is used as the reflective layer 13. A generally known method can be used as a method for forming the silver layer having the opening 12. In addition to the lift-off method in which a metal is formed after patterning with a photoresist and then the photoresist is removed, the photoresist is used as a mask. There is a method of etching a metal layer. Next, as shown in FIG. 5B, a photocurable material 21 is applied on the reflective layer 13 including the opening 12. Here, SU-8, which is a negative photoresist, was used as the photocurable material. This SU-8 is cured with light of 400 nm or less and has high transparency to visible light. For the application of the material, a method such as spin coating or spray coating can be used, and there may be a process of evaporating the solvent by a heat treatment process or the like after the application. Alternatively, a thicker film can be applied by repeating the coating and heat treatment processes a plurality of times. And as shown in (c) of the figure, with respect to the SU-8 resist of the applied photocurable material 21, the ultraviolet light 22 is irradiated from the transparent substrate side, and the ultraviolet light 22 that has passed through the opening 12 is used. The SU-8 resist of the photocurable material 21 is exposed. At this time, the irradiated ultraviolet light is divergent light having a predetermined radiation angle by the opening 12, and therefore, the SU-8 resist of the applied photocurable material 21 is exposed radially from the opening 12. It becomes. As a result, exposure is performed in a tapered rod shape from all the openings 12 of the reflective layer 13. Next, as shown in (d) of the figure, the resist part not irradiated with light is washed away with a developer and a rinse with a predetermined solution. As a result, only the cured portion remains in the portion exposed to the taper rod shape, and finally the taper rod array 15 can be collectively formed on the opening 12 of the reflective layer 13.

  Here, in the optical element manufacturing method of the first embodiment, as shown in FIG. 3C, the divergence angle of the light to be exposed is adjusted with respect to the taper angle of the taper rod array to be manufactured. There must be. Adjustment of the light divergence angle is not easy, and as a result, the taper angle of the taper rod array cannot be freely controlled.

  Therefore, a method of manufacturing an optical element according to the second embodiment as shown in FIG. 4 can be considered. In the figure, the same reference numerals as those in FIG. Note that the optical element manufacturing method according to the second embodiment shown in FIGS. 4A to 4D is different from the optical element manufacturing method according to the first embodiment except for FIG. Since it is the same as the process, only the process in FIG. 4C will be described. As shown in FIG. 4C, the ultraviolet light 22 that is substantially parallel light from the transparent substrate side with respect to the applied SU-8 resist is tilted with respect to the reflective layer 13 by a predetermined angle α. Irradiate. Further, during the exposure of the transparent substrate 11, a rotational movement is performed with the dotted line in the figure as the center of rotation. This exposure method is called rotational tilt exposure. For this reason, the applied SU-8 resist is exposed radially from the opening 12. As a result, exposure is performed in a tapered rod shape from all the openings 12 of the reflective layer 13.

  Here, FIG. 5 shows a block diagram of an exposure apparatus for performing rotational tilt exposure. In the figure, light from a mercury lamp light source 31 that irradiates ultraviolet rays is collimated by an optical system 32. The transparent substrate 11 coated with the photocurable material 21 is fixed to the rotary stage 33 so that collimated ultraviolet light is irradiated from the transparent substrate side. The rotary stage 33 rotates around the rotation axis center during exposure. Although omitted in the drawing, it is desirable that the exposure apparatus is equipped with a light intensity homogenizing optical system, a shutter, or the like, which is provided in a normal exposure apparatus, such as a shutter or rotary stage control system. As the exposure light source, it is possible to use an LED or a laser in addition to the mercury lamp shown here.

  FIG. 6 is a schematic perspective view for explaining a portion exposed by rotational tilt exposure. In the figure, an opening 12 exists in the reflective film 13. In the tilt exposure, the light passing through the opening 12 is substantially parallel light and is tilted at a predetermined angle with respect to the substrate. Therefore, the light intensity at a certain moment is as shown by the oblique lines in the figure. Further, since the transparent substrate 11 is rotating, a tapered rod-shaped exposure part 34 is formed as shown in the figure, and finally a tapered rod 35 is formed.

  FIG. 7 is a diagram obtained by photographing an example of the optical element actually produced in the optical element production process of the second embodiment shown in FIG. 4 with a scanning electron microscope. The base is a silver reflective film, and a tapered rod array structure of SU-8 resist is formed from the opening of the reflective film. One tapered rod has a bottom diameter of about 20 μm and a top diameter of about 40 μm, and it can be seen that a very fine tapered rod array can be produced.

  In the manufacturing process of the optical element of the second embodiment shown in FIG. 4, when the film thickness of the photocurable resin is larger or the inclination angle α of the light to be exposed is larger, the taper rod array structure to be produced Some become hollow. FIG. 8 shows an exposed portion when the film thickness of the photocurable resin is thicker than the exposed portion shown in FIG. As shown in the figure, an unexposed portion 36 is formed at the center when the photocurable resin is thick. This eventually becomes a hollow part, which deteriorates the shape of the tapered rod array.

  In such a case, it is preferable to perform exposure while changing the inclination angle α shown in FIG. 5 a plurality of times or changing the inclination angle α. Therefore, the rotary tilt exposure apparatus shown in FIG. 9 is further provided with a rotary stage 37 in addition to the rotary tilt exposure apparatus shown in FIG. At this time, it is desirable that the rotational center of the rotary stage 37 and the center of the surface of the reflective film 13 having the opening 12 are substantially equal.

  FIG. 10 is a cross-sectional view showing a configuration of an optical element according to the second embodiment of the present invention. In the figure, the same reference numerals as those in FIG. 1 denote the same components. The optical element 40 of the present embodiment shown in the figure is provided with a light incident portion 41 for allowing light to enter from a part of the surface different from the surface on which the reflective layer 13 is formed on the transparent substrate 11. The scatterers 42 are formed on all surfaces except the surface on which the reflective layer 13 is formed and the light incident portion 41. There may be a plurality of light incident portions 41, or the light incident portion 41 may be a part of an opening on the surface on which the reflective layer 13 is formed. In addition, the light incident portion 41 is preferably a flat surface that has been optically polished. Various kinds of scatterers 42 can be used, but those having a high reflectance in a wide wavelength range are preferable, and suitable examples thereof include barium sulfate, titanium oxide, polyester, PET, and the like, or a mixture thereof. Etc.

  FIG. 11 is a diagram schematically illustrating the locus of light rays when light is incident from the light incident portion of the optical element according to the second embodiment. As shown in the figure, the light beam incident on the transparent substrate 11 reaches the reflection layer 13 directly or through scattering. The light that has entered the opening 12 of the reflective layer 13 is collimated, homogenized, and emitted while being internally reflected by each tapered rod 14 of the tapered rod array 15. Further, the light incident on the reflective layer 13 other than the opening 12 is reflected, returns to the transparent substrate 11, and enters the reflective layer 13 again through a process such as scattering. Through such a light recycling process, light gradually escapes from the tapered rod array 15. Thus, since the light which did not enter the opening 12 of the reflective layer 13 first is also reused, an optical element with high light utilization efficiency can be obtained.

  FIG. 12 is a cross-sectional view showing a configuration of an optical element according to the third embodiment of the present invention. In the figure, the same reference numerals as those in FIG. 10 denote the same components. In addition to the optical element 40 shown in FIG. 10, the LED element 51 is disposed in the light incident portion 41 in the optical element 50 of the present embodiment shown in the figure. It is preferable that the light emitting part and the light incident part 41 of the LED element 51 are in close contact or bonded with an adhesive. If there is a gap between the light emitting part and the light incident part 41 of the LED element 51, light that is totally reflected is generated at the interface between the LED element 51 and air, so that the light extraction efficiency from the LED element 51 is reduced, and the gap There is a problem in that light leaks from. Therefore, it is preferable that the LED element 51 and the light incident part 41 are adhered to each other or adhered by an adhesive. Furthermore, it is better to use a material having a high refractive index as the adhesive because the light extraction efficiency from the LED element 51 can be increased. The LED element 51 is preferably mounted on an electronic substrate 52, and the electronic substrate 52 and the transparent substrate 11 are preferably fixed by an adhesive layer 53. The LED element 51 may be composed of a plurality of LEDs, or may be a plurality of types of LED elements that mainly emit light of the three primary colors of red, blue, and green. Further, the light source is not limited to the LED element, and a semiconductor laser element, an organic EL element, or the like can be used.

  FIG. 13 is a schematic configuration diagram showing a configuration of a projection type display apparatus according to an embodiment of the present invention. The present embodiment shown in the figure is an example of a color-sequential driving projection type color liquid crystal display device. The projection display device 60 of the present embodiment includes an optical element 50 in FIG. 12, a polarizer 61 for aligning the polarization direction of light emitted from the optical element 50 in one direction, a liquid crystal light valve 62, and a liquid crystal It includes a projection lens 63 that enlarges and projects an image synthesized by the light valve 62 onto the screen. Further, the timing at which the LED element 51 emits light is controlled by the drive circuit on the electronic substrate 52 in the optical element 50, and the color light is sequentially emitted from the LED element 51, for example, R, G, B, R, G, B,. Is configured to emit light. At this time, wiring can be simplified by connecting the same terminals of LEDs of the same color on the electronic substrate 51.

  The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, as a light source, a semiconductor laser, an organic EL element, an inorganic EL element, or the like can be used in addition to an LED. The optical element, the polarizer, the microlens array, and the like may be made of any material such as glass or resin as long as the necessary functions can be obtained. Further, a configuration using a reflective liquid crystal element (LCOS) as the light valve may be used. Also, the color display method is not limited to the color sequential method of the embodiment, and a pixel division filter method can also be used.

It is sectional drawing which shows the structure of the optical element which concerns on the 1st Embodiment of this invention. It is a perspective view which shows the example of the specific structure of the taper rod array 15 of FIG. It is sectional drawing which shows each process by the manufacturing method of the optical element which concerns on the 1st Embodiment of this invention. It is sectional drawing which shows each process by the manufacturing method of the optical element which concerns on the 2nd Embodiment of this invention. It is the schematic which shows the structure of the exposure apparatus for performing rotation inclination exposure. It is a schematic perspective view explaining the part exposed by rotation inclination exposure. It is the figure which image | photographed with the scanning electron microscope from the diagonal the example of the optical element produced at the production process of the optical element of 2nd Embodiment shown in FIG. It is a schematic perspective view explaining the part exposed by rotation inclination exposure when the film thickness of photocurable resin is larger or the inclination | tilt angle (alpha) of the light to expose is larger. It is the schematic which shows another structure of the exposure apparatus for performing rotation inclination exposure. It is sectional drawing which shows the structure of the optical element which concerns on the 2nd Embodiment of this invention. It is a figure which shows typically the locus | trajectory of the light ray when light injects from the light-incidence part of the optical element of 2nd Embodiment. It is sectional drawing which shows the structure of the optical element which concerns on the 3rd Embodiment of this invention. It is a schematic block diagram which shows the structure of the projection type display apparatus which concerns on one embodiment of this invention. It is sectional drawing which shows the structure of the conventional optical module. It is sectional drawing which shows a taper rod.

Explanation of symbols

10, 40, 50; optical element, 11; transparent substrate, 12; opening,
13; reflective layer, 14, 35; taper rod,
15; taper rod array; 21; photocurable material; 22; ultraviolet light;
31; Mercury lamp light source; 32; Optical system; 33 and 37;
34; exposed portion, 36; unexposed portion, 41; light incident portion, 42; scatterer,
51; LED element, 52; electronic substrate, 53; adhesive layer,
60: Projection type display device.

Claims (13)

  A reflective layer having a plurality of openings is formed on a transparent substrate, and a plurality of tapered structures having a shape extending in a tapered shape from the substrate side are formed on the openings, and the reflective layer and the taper are formed. An optical element characterized in that the structure part has an integral structure.   The optical element according to claim 1, wherein the tapered structure portion has a truncated cone structure.   The optical element according to claim 1, wherein the tapered structure portion has a truncated pyramid structure.   The optical element according to claim 1, wherein the tapered structure portions are two-dimensionally arranged.   The optical element according to claim 1, wherein the tapered structure portion is made of a photocurable material.   6. The optical element according to claim 5, wherein the photocurable material is made of a hybrid material of an organic material and an inorganic material.   The optical element according to claim 5, wherein the photocurable material is a negative photoresist material.   The optical element according to claim 1, further comprising a light incident portion and a scattering reflection portion formed on a surface other than the surface on which the light incident portion is provided.   The optical element according to claim 8, wherein a solid light-emitting element is provided in the opening. A reflective film forming step of forming a reflective film having a plurality of openings on a transparent substrate;
A photocurable material layer forming step of forming a photocurable material layer on the reflective film;
An irradiation step of irradiating the photocurable material layer with light having a predetermined divergence angle from the substrate side;
And a photocurable material layer removing step of removing the photocurable material layer in a portion not irradiated with light. A reflective film forming step of forming a reflective film having a plurality of openings on a transparent substrate;
A photocurable material layer forming step of forming a photocurable material layer on the reflective film;
An irradiation step of irradiating the photocurable material layer with light while rotating the substrate at a predetermined angle from the substrate side;
And a photocurable material layer removing step of removing the photocurable material layer in a portion not irradiated with light.   12. The method for manufacturing an optical element according to claim 10, wherein light is irradiated in the irradiation step while changing a relative angle between the substrate and the light to be irradiated. The optical element according to any one of claims 1 to 9,
A light modulation element that modulates light emitted from the optical element according to image information;
And a projection lens for enlarging and projecting the light modulated by the light modulation element.

Images