Overlapping facets

Abstract

This invention provides an optical device that reduces heterogeneity in images externally connected to nominal observation points. [Solution] By specifically controlling the configuration of facet overlap, a waveguide including at least two parallel planes, i.e., the first, middle, and last partial reflection facets, is configured such that when the facets are geometrically projected onto one of the surfaces, the facets overlap, preferably adjacent facets, and the start and end of non-adjacent facets coincide along at least a portion of the waveguide.

Claims

1. An optical device, Optical devices are (a) Includes a waveguide, the waveguide is (i) A first surface of at least one pair of surfaces parallel to each other, (ii) A first region to which light is connected to the waveguide, (iii) Having a first arrangement of facets, The facet is, (A) (I) a first facet located proximal to the first region and (II) having a first width in the direction between the first pair of surfaces, (B) (I) The last facet is located at the distal end of the first arrangement of facets from the first region, and (II) has a third width in the direction between the first pair of surfaces, (C) (I) comprising one or more intermediate facets located between the first facet and the last facet, and (II) having a second width in the direction between the first pair of surfaces, (b) Each of the facets is (i) The width is within the plane of the facet, (ii) A surface that is at least partially reflective, (iii) An oblique angle with respect to the first pair of surfaces, (iv) The facet has a facet initiation portion on the proximal side of the width of the facet, (v) The facet has a facet termination portion on the distal side of the width of the facet, (c) The geometric projection is on one of the first pair of surfaces in the direction of a nominal ray connected outward from the waveguide, the nominal ray being the central ray of light connected outward from the waveguide, (d) Each geometric projection of the last facet and the one or more intermediate facets overlaps with each geometric projection adjacent to the one or more intermediate facets and the first facet, (e) The geometric projection of the facet start portion of each of the last facet and the one or more intermediate facets coincides with the geometric projection of the non-adjacent facet end portions of each of the one or more intermediate facets and the first facet, (f) An optical device in which the coincidence is along at least a portion of the waveguide.

2. The optical device according to claim 1, wherein the first width of the first facet is less than the second width of one or more intermediate facets.

3. The optical device according to claim 1, wherein many of the facets intersect with the nominal rays externally connected from the waveguide, and the number of facets is constant for all of the first array.

4. The optical device according to claim 1, wherein light corresponds to an image, and the central ray is a central ray from the center of the image.

5. The optical device according to claim 1, wherein light corresponds to an image, and the central ray corresponds to the central pixel of the image.

6. The optical device according to claim 1, wherein the last facet has a reflectance that is substantially 100% of the nominal reflectance, and the nominal reflectance is the total reflection required at a specific location in the waveguide.

7. The optical device according to claim 1, wherein the third width is less than the second width.

8. The optical device according to claim 7, wherein the third width is substantially half the second width.

9. One or more intermediate facets, (a) 1, (b) 2, (c) 3, (d) 4, (e) 5, and, (f) Multiple, An optical device according to claim 1, selected from the group consisting of the following.

10. The optical device according to claim 1, wherein a certain number of facets overlap in the line of sight toward the nominal observation point of the optical coupling from the waveguide by one of the first pair of surfaces.

11. The optical device according to claim 1, wherein the width of one facet of the plurality of facets in the first array of facets is monotonically constant with respect to the width of one adjacent facet of the plurality of facets in the first array of facets.

12. The optical device according to claim 1, wherein the spacing between adjacent facets in a pair of the first array of facets changes monotonically with respect to the spacing between adjacent facets in another pair of the first array of facets.

13. The optical device according to claim 12, wherein the interval changes monotonically.

14. The optical device according to claim 1, wherein the light from the first region is such that at least a portion of the light strikes the first facet before it strikes one of the one or more intermediate facets.

15. The optical device according to claim 1, wherein the spacing between adjacent facets is greater than the coherence length of the light connected to the waveguide.

16. (a) The first width is substantially equal to the second width, (b) The optical device according to claim 1, wherein the first facet has a first portion corresponding to the geometric projection of the first facet that does not overlap with the geometric projection of an adjacent intermediate facet.

17. The optical device according to claim 15, wherein the first portion is transparent to light.

18. The optical device according to claim 15, wherein the first portion has a reflectance substantially twice that of the adjacent facets.

19. The optical device according to claim 1, wherein each of the facets has a uniform partial reflectance across the entire facet.

20. The optical device according to claim 1, wherein the reflectance of one or more of the facets is different from the reflectance of another one or more of the other facets.

21. The waveguide further, (a) Having a second pair of surfaces that are parallel to each other and not parallel to the first pair of surfaces, (b) The optical device according to claim 1, wherein the facets are configured such that when the image is connected to the waveguide in the first region with the initial direction of propagation at a connection angle inclined to both the surfaces of the first pair and the second pair, the image travels along the waveguide by the amount of four folding reflections.

22. The optical device according to claim 19, wherein the second pair of surfaces is perpendicular to the first pair of surfaces.

23. The optical device according to claim 19, wherein each of the facets is oblique to the second pair of surfaces.

Images