Optical resizing apparatus

• US 5,860,721 A
• Filed: 06/09/1997
• Issued: 01/19/1999
• Est. Priority Date: 06/09/1997
• Status: Expired due to Term

• Current Assignee: Christie Digital Systems USA Incorporated (Ushio Incorporated)
• Original Assignee: Electrohome Limited
• Inventors: Bowron, John William, Schmidt, Terrence Carl
• Primary Examiner(s): Dowling, William C.
• Application Number:
  US08/871,336
• Time in Patent Office: 589 Days
• Field of Search: 353/122, 353/69, 353/101, 353/38, 353/102, 348/441, 348/445, 348/913, 349/5, 349/7
• US Class Current: 353/101
• CPC Class Codes: H04N 5/74 Projection arrangements for image reproduction, e.g. using eidophor
• CPC Class Codes: H04N 9/3152 for shaping the light beam beam shaping per se G02B27/09

Abstract

A pixellated light valve projector with optical image resizing, comprising: a) a lamp and optical integrator for generating a rectangular beam of light according to a predetermined aspect ratio; b) a pixellated panel for generating a rectangular image of a video signal in any one of a plurality of native pixel formats; c) a relay optical system intermediate the optical integrator and the pixellated panel for automatically concentrating the light onto the image in accordance with the one of the plurality of native pixel formats; d) a projection screen; and e) a projection lens for projecting the image onto the projection screen so that the projected image fills the projection screen in accordance with the one of the plurality of native pixel formats while image brightness level is maintained by concentrating the light onto the image on the pixellated panel.

Claims

1. A pixellated light valve projector with optical image resizing, comprising:

a) an illumination source and optical integrator system for generating a rectangular beam of light according to a predetermined aspect ratio;

b) a pixellated panel for generating a rectangular image in any one of a plurality of native pixel formats;

c) an optical relay system intermediate said optical integrator system and said pixellated panel for automatically concentrating said light onto said image in accordance with said one of said plurality of native pixel formats;

d) a projection screen; and

e) a projection optical system for projecting said image onto said projection screen so that the projected image fills said projection screen in accordance with said one of said plurality of native pixel formats while image brightness level is substantially maintained by concentrating said light onto only an image portion of the panel.

2. The pixellated light valve projector of claim 1, wherein etendu of said lamp is matched to a smallest one of said plurality of native pixel formats, said optical relay system is zoomed to illuminate larger images on said panel provided by larger ones of said plurality of native pixel formats, and said projection optical system is zoomed to fill said projection screen with said image.

3. The pixellated light valve projector of claim 2, wherein magnification of said optical relay system (M) is set according to ##EQU4## where f/lamp is the f/# of the illumination source and optical integrator system, and f/panel is the minimum f/# for illumination of the pixellated panel, and wherein magnification of said projection optical system (M'"'"') is set according to

4. The pixellated light valve projector of claim 3, wherein said smallest one of said plurality of native pixel formats is SVGA having a pixel format of 800×

600 pixels, and wherein said magnification M of said optical relay system is designated as M_SVGA and said magnification M'"'"' of said projection optical system is designated as M'"'"'_SVGA.

5. The pixellated light valve projector of claim 4, wherein a larger one of said plurality of native pixel formats is XGA having a pixel format of 1024×

768 pixels, wherein magnification of said relay optical system is set at M_svga *128%, and wherein magnification of said projection optical system is set at M'"'"'_svga *78.1%.

6. The pixellated light valve projector of claim 4, wherein a larger one of said plurality of native pixel formats is doubled VGA having a pixel format of 1280×

960 pixels, wherein magnification of said relay optical system is set at M_svga *160%, and wherein magnification of said projection optical system is set at M'"'"'_svga *62.5%.

7. The pixellated light valve projector of claim 4, wherein a larger one of said plurality of native pixel formats is NTSC video having a pixel format of 1280×

1024 pixels, wherein magnification of said relay optical system is set at M_svga *165%, and wherein magnification of said projection optical system is set at M'"'"'_svga *62.5%.

8. The pixellated light valve projector of claim 4, wherein a larger one of said plurality of native pixel formats is EWS having a pixel format of 1280×

1024 pixels, wherein magnification of said relay optical system is set at M_svga *165%, and wherein magnification of said projection optical system is set at M'"'"'_svga *62.5%.

9. The pixellated light valve projector according to claim 1, wherein said predetermined aspect ratio of the optical integrator is √

5;

√

3, resulting in a 3% overfill of said panel by said light when said one of said plurality of native pixel formats is characterized by an aspect ratio of either 4;

3 or 5;

4.

10. The pixellated light valve projector according to claim 2, wherein said predetermined aspect ratio of the optical integrator is √

5;

√

3, resulting in a 3% overfill of said panel by said light when said one of said plurality of native pixel formats is characterized by an aspect ratio of either 4;

3 or 5;

4.

11. The pixellated light valve projector according to claim 3, wherein said predetermined aspect ratio of the optical integrator is √

5;

√

3, resulting in a 3% overfill of said panel by said light when said one of said plurality of native pixel formats is characterized by an aspect ratio of either 4;

3 or 5;

4.

12. The pixellated light valve projector according to claim 4, wherein said predetermined aspect ratio of the optical integrator is √

5;

√

3, resulting in a 3% overfill of said panel by said light when said one of said plurality of native pixel formats is characterized by an aspect ratio of either 4;

3 or 5;

4.

13. The pixellated light valve projector according to claim 6, wherein said predetermined aspect ratio of the optical integrator is √

5;

√

3, resulting in a 3% overfill of said panel by said light when said one of said plurality of native pixel formats is characterized by an aspect ratio of either 4;

3 or 5;

4.

14. The pixellated light valve projector according to claim 7, wherein said predetermined aspect ratio of the optical integrator is √

5;

√

3, resulting in a 3% overfill of said panel by said light when said one of said plurality of native pixel formats is characterized by an aspect ratio of either 4;

3 or 5;

4.

15. The pixellated light valve projector according to claim 8, wherein said predetermined aspect ratio of the optical integrator is √

5;

√

3, resulting in a 3% overfill of said panel by said light when said one of said plurality of native pixel formats is characterized by an aspect ratio of either 4;

3 or 5;

4.