Image representation system

• US 6,428,169 B1
• Filed: 10/02/2000
• Issued: 08/06/2002
• Est. Priority Date: 02/03/1999
• Status: Expired due to Fees

• Current Assignee: JENOPTIK LDT GmbH (Rheinmetall AG)
• Original Assignee: Christhard Deter, Joerg Wunderlich
• Inventors: Wunderlich, Joerg, Deter, Christhard
• Primary Examiner(s): Adams, Russell
• Assistant Examiner(s): Cruz, Magda
• Application Number:
  US09/647,579
• Time in Patent Office: 673 Days
• Field of Search: 353/20, 353/79, 353/84, 359/443, 359/449, 359/460
• US Class Current: 353/20
• CPC Class Codes: G03B 21/56 Projection screens
• CPC Class Codes: G09F 19/18 involving the use of optical projection means, e.g. projection of images on clouds projection apparatus per se G03B

Abstract

An image display system a projector for emitting projection light for generating an image on a light-backscattering projection surface.

The wavelengths of the projection light lie in one or more discrete wavelength regions in the visible spectrum and the projection surface is covered on the projector side by an optical filter which passes only light with wavelengths corresponding to those of the projection light.

Claims

1. An image display system comprising:

a light-backscattering projection surface;

a projector for emitting projection light for generating an image on said light-backscattering projection surface, wavelengths of the projection light lying in one or more discrete wavelength regions in the visible spectrum; and

an optical blocking filter covering the projection surface on the projector side and having a transparent wavelength range or transparent wavelength ranges in the visible spectrum, which correspond to said wavelength region of the projection light which are at the most, up to 50 nm wider than the wavelength region of the projection light, so that essentially only light with wavelengths corresponding to those of the projection light passes said optical filter and reaches said projection surface, while light of all other wavelength ranges in the visible spectrum is prevented from passing through, wherein said light reaching said projection surface is backscattered at the projection surface and passes said optical filter again.

2. The image display system according to claim 1, wherein the wavelengths of the projection light are in a wavelength range with a spectral bandwidth of less than 260 nm.

3. The image display system according to claim 2, wherein the spectral bandwidth is less than 80 nm.

4. The image display system according to claim 1, wherein the projector includes a laser light source for generating the projection light.

5. The image display system according to claim 4, wherein the laser light source emits projection light with wavelengths in the ranges of 610 nm to 630 nm (red), 510 nm to 550 nm (green), and 400 nm to 470 nm (blue).

6. The image display system according to claim 1, wherein the projector is constructed with a light source in the form of a temperature radiator.

7. The image display system according to claim 1, wherein the projector is constructed with a light source in the form of a gas discharge lamp.

8. The image display system according to claim 1, wherein the projector is constructed with a light source in the form of a semiconductor emitter.

9. The image display system according to claim 1, wherein the optical filter absorbs the incident light outside of its transmission range.

10. The image display system according to claim 1, wherein the optical filter reflects the incident light outside of its transmission range.

11. The image display system according to claim 1, wherein the optical filter is applied directly to the projection surface as a layer or layer system.

12. The image display system according to claim 11, wherein the layer system is formed of nonabsorbent dielectric, or absorbent and nonabsorbent thin layers whose thickness is in the order of magnitude of the wavelength of visible light and forms an interference filter.

13. The image display system according to claim 1, wherein the optical filter is arranged as a layer or layer system on a substrate which is transparent to the projection wavelengths.

14. The image display system according to claim 13, in which a plurality of substrates are arranged one behind the other, wherein a layer or a layer system is applied to each of these.

15. The image display system according to claim 13, wherein the substrate is a glass.

16. The image display system according to claim 13, wherein the substrate is a polymer material.

17. The image display system according to claim 13, wherein the substrate is a sheet.

18. The image display system according to claim 13, wherein the optical filter is a combination of a compound filter and interference filter, wherein, in particular, the substrate carrying the thin layers is designed as a compound filter.

19. The image display system according to claim 1, wherein the optical filter is a compound filter.

20. The image display system according to claim 19, wherein the compound filter is gelatin filter or colored glass filter.

21. The image display system according to claim 1, wherein the transparent wavelength range or transparent wavelength ranges of the optical filter is or are up to 50 nm greater than the wavelength range or wavelength ranges of the projection light.