1. © Yitzhak Weissman StereoBright ™ Innovative technology from Advanced Visual Solutions (Patent Pending) Ver. 1.02

2. January 2003 © Yitzhak Weissman 2 Advantages Create large stereoscopic images by using two commercial mini-projectors Obtain twice the amount of light compared to conventional systems Reduce cost, size, weight, noise and heat generation by half

3. January 2003 © Yitzhak Weissman 3 Principle Exploit the native polarization properties of LCD projectors to achieve near 100% optical efficiency

4. January 2003 © Yitzhak Weissman 4 Polarization structure of LCD projector Liquid-crystal image generators create linearly-polarized images In modern commercial LCD projectors, the green component is polarized perpendicularly to the blue and the red components

5. January 2003 © Yitzhak Weissman 5 Polarization structure of LCD projector (ctd.)

6. January 2003 © Yitzhak Weissman 6 Prior-art generation of orthogonal images Mount polarizers on both projection lenses Polarizers are aligned at 45° to the polarization directions of the beam and at 90° to each other Result: two orthogonal images with light intensity reduced by 50%

7. January 2003 © Yitzhak Weissman 7 Prior-art generation of orthogonal images (ctd.) Projector beams incident on polarizers Orthogonally polarized beams with intensity reduced by 50%

8. January 2003 © Yitzhak Weissman 8 Polarization-rotated beams Original polarizations Polarization states rotated by 45° Left eye view Right eye view

9. January 2003 © Yitzhak Weissman 9 Viewing polarization-rotated beams If the green content of the stereo pair is switched, each eye sees the correct image Switching can be done either by hardware, or by a simple preprocessing of the content

10. January 2003 © Yitzhak Weissman 10 Switching the green component by hardware

11. January 2003 © Yitzhak Weissman 11 Switching the green component by preprocessing R left G left B left R right G right B right R left G right B left R right G left B right Original Processed

12. January 2003 © Yitzhak Weissman 12 Manipulation of polarization Polarization states can be manipulated with retardation films Half-wavelength retardation films are used to rotate the state of polarization Quarter-wavelength retardation films are used to convert linear polarization to circular polarization and vice-versa

13. January 2003 © Yitzhak Weissman 13 StereoBright versus polarizing filters Polarizing filterStereoBright filter

14. January 2003 © Yitzhak Weissman 14 Comments Same method can be used to create circularly-polarized images StereoBright does not offer any advantage when using DLP projectors, since their light is unpolarized

15. January 2003 © Yitzhak Weissman 15 Summary Smart utilization of native polarization properties of LCD projectors to achieve a stereoscopic image with nearly 100% optical efficiency Allows the use of mini presentation projectors to create bright stereoscopic display No extra cost and complexity