Display device comprising multifunction glass, production method and optical element having a Fresnel structure

Patent metadata

Field	Value
Publication number	US-9465218-B2
Application number	US-201514613046-A
Country	US
Kind code	B2
Filing date	Feb 3, 2015
Priority date	Feb 25, 2009
Publication date	Oct 11, 2016
Grant date	Oct 11, 2016

Abstract

A multifunction optical element including an image generating module that generates an image, and couples the image into a multifunction glass that has a coupling in area and a coupling out area. The image produced is coupled into the multifunction glass via the coupling in area, guided in the multifunction glass to the coupling in area, and coupled out via the coupling out area, in such a way that the user can perceive the coupled out image superimposed on the surroundings when the holding device is placed on the head of the user. The coupling out area has a Fresnel structure which receives light from the coupling-in-area via a folded beam path and couples the image out of the multifunction optical element. The coupling out element has an imaging property.

First claim

The invention claimed is:

1. A method for producing a multifunction optical element for a display device, the display device comprising an image-generating module which generates an image, the method comprising:
forming the multifunction optical element with a coupling-in area and a coupling-out area, the coupling-in area being located separately from the coupling-out area, wherein a structure of the multifunction optical element is such that the image generated by the image-generating module that is coupled into the multifunction optical element via the coupling-in area, is guided in the multifunction optical element along a folded optical path by multiple total internal reflections from the coupling-in area to the coupling-out area and coupled out via the coupling-out area such that a user can perceive a coupled-out image superimposed on surroundings;
wherein the coupling-out area is formed with a Fresnel structure having an imaging property and which receives light via the folded optical path from the coupling-in area and couples the image out of the multifunction optical element by forming the Fresnel structure to have several Fresnel segments and forming optically effective facets of the Fresnel segments such that the optically effective facets optically correspond to an imaginary optically effective surface which is curved.

2. The method according to claim 1 , further comprising forming the Fresnel structure such that the Fresnel structure presents facets defining cavities and applying a filling material to the Fresnel structure such that the cavities are filled by the filling material and the Fresnel structure together with the filling material presents a smooth continuous surface.

3. The method according to claim 2 , further comprising forming a bulk of the multifunction optical element and the filling material from similar material.

4. The method according to claim 1 , further comprising forming the Fresnel structure to be at least partially reflective.

5. The method according to claim 4 , further comprising forming the Fresnel structure to include a coating that is at least partially reflective.

6. The method according to claim 3 , further comprising forming the Fresnel structure as a continuous Fresnel structure.

7. The method according to claim 1 , further comprising forming the Fresnel structure at a material boundary surface of the multifunction optical element.

8. The method according to claim 1 , further comprising forming optically effective facets of the Fresnel segments to optically correspond to an imaginary optical effective surface which is curved and has neither mirror symmetry nor rotational symmetry.

9. The method according to claim 1 , further comprising forming a shape of the facets as an approximation of a shape of the corresponding surface section of an imaginary effective surface.

10. The method according to claim 1 , further comprising forming the Fresnel structure such that the Fresnel structure presents facets having a maximum facet height in the range of 5-500 μm, in the range of 0.01-0.1 mm, in the range of 200-300 μm, or in the range of 0.05-0.3 mm.

11. The method according to claim 1 , further comprising forming the Fresnel structure such that the Fresnel structure presents facets having a maximum height, wherein the maximum height of each facet is the same.

12. The method according to claim 1 , further comprising producing the multifunction optical element on the basis of production data which are generated computationally by dividing an optical model surface into several height regions and computationally arranging the surface sections of the individual height regions or approximations of these surface sections at a base surface such that they optically correspond to an optical effective surface having said imaging property.

13. The method according to claim 12 , further comprising computiatonally arranging the surface sections or the approximation of the surface sections at a curved base section.

14. The method according to claim 12 , further comprising computationally optimizing the optical model surface for providing said imaging property.

15. The method according to claim 1 , wherein the image is guided in the multifunction optical element along a folded optical path.

16. The method according to claim 1 , further comprising forming the Fresnel structure by at least one of diamond milling, moulding and casting.

17. The method according to claim 1 , further comprising forming the Fresnel structure as a refractive Fresnel structure.

18. The method according to claim 1 , further comprising forming the Fresnel structure such that the Fresnel structure presents facets which are spaced apart from each other.

19. The method according to claim 1 , further comprising forming the Fresnel structure such that the Fresnel structure presents facets which are directly neighbouring.

20. The method according to claim 8 , further comprising forming the Fresnel structure such that the imaginary optical effective surface has no translation symmetry.

Assignees

• Zeiss Carl Ag

Inventors

• Dobschal Hans-Juergen
• Rudolph Guenter
• Lindig Karsten

Classifications

• G02B27/0172 Primary

  characterised by optical features · CPC title

• C03C17/001

  General methods for coating; Devices therefor · CPC title

• C03B11/08

  for making solid articles, e.g. lenses · CPC title

• C03B19/02

  by casting {molten glass, e.g. injection moulding} · CPC title

• G02B27/144

  using partially transparent surfaces without spectral selectivity (G02B27/147 takes precedence) · CPC title