Diffraction sheet and method for manufacturing the same, three-dimensional display device, light beam reproduction device, three-dimensional spatial display system, light beam reproduction method, and program
A three-dimensional display device including a diffraction sheet including a transparent substrate, and a diffraction layer having a first diffraction pattern formed in a first array pattern and a second diffraction pattern formed in a second array pattern on the transparent substrate, the diffraction sheet measuring 10 inches or more in diagonal; one of a liquid crystal device having a plurality of pixels and a color filter having a plurality of types of color filters; and a light source. The first diffraction pattern and the second diffraction pattern are overlapped with the pixels or the color filters in a direction normal to the diffraction sheet with an amount of displacement being 1/10 or less of a pitch of the pixels or the color filters.
1. A method for manufacturing a diffraction sheet, comprising:
forming a first uncured resin layer on a transparent substrate measuring 10 inches or more in diagonal;
bringing a first diffraction pattern formed on a first surface of a first plate into contact with the first uncured resin layer, the first diffraction pattern being formed in a rectangular area measuring 10 inches or more in diagonal;
placing a first mask having a plurality of first apertures formed based on a first array pattern on the first plate;
irradiating the first mask with light to cure a portion of the first uncured resin layer that overlaps the first apertures;
forming a second uncured resin layer on a surface of the transparent substrate on which the first uncured resin layer is formed;
bringing a second diffraction pattern, which is different from the first diffraction pattern, formed on a first surface of a second plate into contact with the second uncured resin layer, the second diffraction pattern being formed in a rectangular area measuring 10 inches or more in diagonal;
placing a second mask having a plurality of second apertures formed based on a second array pattern different from the first array pattern on the second plate; and
irradiating the second mask with light to cure a portion of the second uncured resin layer that overlaps the second apertures, wherein
the first uncured resin layer has a cured hardness of 0.5 MPa to 100 GPa at room temperature.
2. The method according to claim 1 , wherein the forming of the second uncured resin layer produces the second uncured resin layer thicker than the first uncured resin layer.
3. The method according to claim 2 , wherein the second uncured resin layer and the first uncured resin layer have a difference in thickness which is larger than or equal to a height of the second diffraction pattern.
4. The method according to claim 1 , wherein at least one of the first plate and the second plate has a release layer on the first surface.
5. The method according to claim 4 , wherein the release layer includes, as a main component, at least one of a thermosetting resin, silicone, a fluorine-based resin, and a polymer having an alkyl group.
6. A diffraction sheet, comprising:
a transparent substrate; and
a diffraction layer having a first diffraction pattern formed in a first array pattern on a first resin layer of the transparent substrate and a second diffraction pattern formed in a second array pattern on a second resin layer different from the first array pattern on a same side of the transparent substrate as the first diffraction pattern,
wherein the second diffraction pattern is thicker than the first diffraction pattern,
the diffraction sheet has a rectangular shape in a plan view measuring 10 inches or more in diagonal, and
the first resin layer has a cured hardness of 0.5 MPa to 100 GPa at room temperature.
7. The diffraction sheet according to claim 6 , wherein the second diffraction pattern and the first diffraction pattern have a difference in thickness which is larger than or equal to a height difference between surface concavities and convexities of the second diffraction pattern.
8. The diffraction sheet according to claim 6 , wherein the second diffraction pattern and the first diffraction pattern have a difference in thickness of 100 nm-10 μm.
9. The diffraction sheet according to claim 6 , further comprising:
a color filter including a plurality of color filters and positioned between the first and second diffraction patterns and the transparent substrate,
wherein the first and second diffraction patterns have displacement relative to the plurality of color filters in a plan view in an amount of 1/10 or less of a pitch of the plurality of color filters.
10. The diffraction sheet according to claim 6 , wherein the first diffraction pattern and the second diffraction pattern include a color material, and
the diffraction layer is a color filter.
11. The diffraction sheet according to claim 6 , wherein the first diffraction pattern and the second diffraction pattern have a gap of 1 μm-100 μm.