Rear-projecting device

• US 6,846,082 B2
• Filed: 01/22/2001
• Issued: 01/25/2005
• Est. Priority Date: 01/21/2000
• Status: Expired due to Fees

• Current Assignee: 3D Systems, Inc. (3D Systems Corporation)
• Original Assignee: Dicon A/S
• Inventors: Meyer, Søren Christoph, Raahauge, Kim Niels, Glent-Madsen, Henrik
• Primary Examiner(s): Dowling, William C.
• Application Number:
  US10/181,519
• Publication Number:
  US 20030151727A1
• Time in Patent Office: 1,464 Days
• Field of Search: 353/30, 353/94, 353/122, 345/44, 345/46, 345/82, 362/551, 362/554, 362/555, 362/559, 349/62
• US Class Current: 353/94
• CPC Class Codes: G02F 1/13336 Combining plural substrates to produce large-area displays, e.g. tiled displays
• CPC Class Codes: H04N 9/12 Picture reproducers H04N9/11 takes precedence
• CPC Class Codes: H04N 9/3114 by using a sequential colour filter producing one colour at a time
• CPC Class Codes: H04N 9/3147 Multi-projection systems displays in general H04N9/12; video walls G06F3/1446, G09G2300/026

Abstract

The invention relates to a rear-projecting device including a light guide for distribution of light from a light source to a light projecting area, a spatial light modulating arrangement, the light modulating arrangement is arranged in relation to the light-projecting area such that the arrangement illuminates a sub-area of the light-projecting area, the light projection area is at least partly transparent.

Claims

1. A rear projecting device comprising:

a light guide for distribution of light from a light source to a light-projecting area via a spatial light modulator arrangement,

wherein said light modulating arrangement is arranged in relation to said light-projecting area such that said arrangement illuminates an area of said light-projecting area, said light projection area being at least partly transparent, and wherein the spatial light modulator arrangement comprises a DMD light modulator.

2. The rear-projecting device according to claim 1, wherein said light guide comprises optical fibers.

3. The rear-projecting device according to claim 2, wherein said optical fibers comprise multi-mode fibers.

4. The rear-projecting device according to claim 1, wherein said light-projecting area comprises at least two screens.

5. The rear-projecting device according to claim 1, wherein said light-projecting area is protected by a protective screen.

6. The rear-projecting device according to claim 1, wherein said light guide comprises a plurality of light guides and the light from the light source is distributed to said plurality of light guides via a mixing rod such that each of said plurality of light guides receives a same amount of light.

7. The rear-projecting device according to claim 1, wherein said light guide comprises a plurality of light guides and the light from the light source is distributed to said plurality of light guides via a filter means such that each of said plurality of light guides, receives a same amount of light.

8. The rear projection device according to claim 1, wherein the spatial light modulating arrangement comprises a micro-mechanical transmissive shutter array.

9. The rear-projecting device according to claim 1, wherein the light source comprises a short arc lamp.

10. The rear-projecting device according to claim 9, wherein the light source comprises an arc of less than 3 mm.

11. The rear-projecting device according to claim 9, wherein luminance of light modulated by the spatial light modulator arrangement is controlled by a variation in duty cycle.

12. A traffic sign comprising:

a rear-projecting device including a light guide for distribution of light from a light source to a light-projecting area via a spatial light modulator arrangement, said spatial light modulating arrangement being arranged in relation to said light-projecting area such that said arrangement illuminates an area of said light-projecting area, said light projection area being at least partly transparent, and wherein the spatial light modulator arrangement comprises a DMD light modulator.

13. A rear-projecting device comprising:

a plurality of light emitters arranged for illumination of a light-projecting area comprising a front side and a rear side via at least two spatial light modulating arrangements;

wherein said spatial light modulating arrangements are arranged in relation to the light-projecting area such that each of said arrangements illuminates a sub-area of said light-projecting area, said light projection area being at least partly transparent, and wherein the spatial light modulator arrangement comprises a DMD light modulator.

14. The rear-projecting device according to claim 13, wherein said light emitters comprise light sources.

15. A rear projecting arrangement comprising:

a light input;

a spatial light modulator arrangement; and

a light projecting area;

wherein said spatial light modulator arrangement includes a spatial light modulator having a plurality of electrically controllable shutters controlling the projecting of light to an effective light projecting area, said spatial light modulating arrangement having a modulator dimension (D) in a given direction of the arrangement, said effective light projecting area having a projecting dimension (d) of the projected light in a corresponding direction, said modulator dimension (D) being a maximum distance between two shutters of the modulator arrangement in the direction, where D>

d/20, and wherein the spatial light modulator arrangement comprises a DMD light modulator.

16. The rear projecting arrangement according to claim 15, wherein D>

6 cm and D is a minimum extension of the spatial modulating arrangement.

17. The rear projecting arrangement according to claim 15, wherein D is greater than d/4.