Digital projector using arrayed light sources

• US 8,132,919 B2
• Filed: 04/30/2009
• Issued: 03/13/2012
• Est. Priority Date: 04/30/2009
• Status: Active Grant

• Current Assignee: IMAX Theatres International Limited (IMAX Corporation)
• Original Assignee: Eastman Kodak Company
• Inventors: Harland, Mark A., Silverstein, Barry D., Kircher, James R.
• Primary Examiner(s): Epps, Georgia Y
• Assistant Examiner(s): CHOWDHURY, SULTAN U.
• Application Number:
  US12/432,856
• Publication Number:
  US 20100277698A1
• Time in Patent Office: 1,048 Days
• Field of Search: 353/30, 353/31, 353/33, 353/37, 353/73, 353/81, 353/94, 353/97, 353/98, 353/99, 353/119, 372/50.12, 372/108, 372/34, 372/35, 372/36, 372/50.23, 372/101, 372/107, 359/485.06, 359/489.02, 359/489.07, 359/489.09, 359/489.15, 359/811, 359/819, 359/822, 385/53.94, 385/88, 385/89, 385/92, 385 76- 77, 385/78
• US Class Current: 353/31
• CPC Class Codes: G02B 19/0028 refractive and reflective surfaces, e.g. non-imaging catadioptric systems
• CPC Class Codes: G02B 19/0057 in the form of a laser diode array, e.g. laser diode bar semiconductor laser arrays with beam combining arrangement H01S5/4012
• CPC Class Codes: G02B 27/0977 Reflective elements
• CPC Class Codes: G02B 27/102 for generating a colour image from monochromatic image signal sources
• CPC Class Codes: G02B 27/1073 characterized by manufacturing or alignment methods
• CPC Class Codes: G02B 27/145 having sequential partially reflecting surfaces
• CPC Class Codes: G02B 7/1825 made by screws, e.g. for laser mirrors
• CPC Class Codes: G03B 21/28 Reflectors in projection beam in illumination beam G03B21/2066
• CPC Class Codes: H04N 9/3164 using multiple light sources

Abstract

A beam alignment chamber extending in a length direction comprising a base having a front edge, and two side edges, first and second opposed side walls connected to the base, and extending along the length of the base, a front wall located at the front edge of the base having an output opening. The beam alignment chamber further comprises a plurality of arrays of light sources disposed to direct light beams through the first or second side walls, and a plurality of reflectors mounted on the base, each having independent yaw and pitch adjustments, each reflector being paired with a corresponding array of light sources, the base-mounted reflectors being disposed to direct the light beams along the length of the beam alignment chamber through the output opening forming an aligned two-dimensional array of parallel light beams.

Claims

1. A beam alignment chamber extending in a length direction comprising:

a base having a front edge, and two side edges;

first and second opposed side walls connected to the base, and extending along the length of the base;

a front wall located at the front edge of the base having an output opening;

a plurality of arrays of light sources located outside the beam alignment chamber disposed to direct light beams into the beam alignment chamber through the first or second side walls; and

a plurality of reflectors mounted on the base within the beam alignment chamber, each having independent yaw and pitch adjustments, each reflector being paired with a corresponding array of light sources, the reflectors being disposed to direct the light beams along the length of the beam alignment chamber through the output opening forming an aligned two-dimensional array of parallel light beams.

2. The beam alignment chamber of claim 1 wherein the arrays of light sources are disposed to direct light through both the first and second side walls.

3. The beam alignment chamber of claim 1 further including a cover spaced apart from the base and connected to the first and second side walls, together with a plurality of reflectors mounted to the cover within the beam alignment chamber, each having independent yaw and pitch adjustments, each paired with a corresponding one-dimensional array of light sources, the cover-mounted reflectors being disposed to direct the light beams along the length of the beam alignment chamber through the output opening, and, together with the light beams associated with the base-mounted reflectors, forming the aligned two-dimensional array of parallel light beams.

4. The beam alignment chamber of claim 3 wherein adjustment holes are provided in the cover to access the independent yaw and pitch adjustments for both the cover-mounted and base-mounted reflectors.

5. The beam alignment chamber of claim 1 wherein the optical distance between each light source and the output opening is substantially equal for each of the light beams.

6. The beam alignment chamber of claim 5 wherein each light beam entering the beam combining chamber is uncorrected for divergence with respect to at least one axis, and further including one or more optical elements positioned in the optical path of the aligned two-dimensional array of light beams disposed to correct the beam divergence with respect to at least one axis.

7. The beam alignment chamber of claim 6 wherein the corrected aligned two-dimensional array of light beams is collimated.

8. The beam alignment chamber of claim 6 wherein the one or more optical elements comprise a cylinder lens providing correction for the beam divergence with respect to one axis.

9. The beam alignment chamber of claim 6 wherein the one or more optical elements comprise a pair of crossed cylinder lenses providing correction for the beam divergence with respect to two axes.

10. The beam alignment chamber of claim 1 wherein each light beam entering the beam combining chamber is uncorrected for divergence with respect to at least one axis, and wherein the reflectors are cylindrical reflectors that correct the beam divergence with respect to one axis.

11. The beam alignment chamber of claim 1 wherein the light sources are laser light sources.

12. The beam alignment chamber of claim 1 wherein the beam alignment chamber is a component of a laser source system that provides a two-dimensional array of parallel laser beams for use in a laser projection system, and wherein the laser projection system further comprises:

an illumination system configured to uniformize laser light it receives;

an image forming system configured to interact with laser light that has been both uniformized by the illumination system; and

a projection system configured to project the laser light image onto a viewing screen.

13. A method for aligning a plurality of light beams comprising:

forming a chamber between at least opposing first and second side walls that extend from a base and having an output;

mounting a plurality of reflectors inside the chamber along the base, spaced apart between the first and second side walls, wherein each reflector has independent yaw and pitch adjustments and is disposed at an oblique angle relative to the side walls; and

providing a plurality of arrays of light sources positioned outside the chamber, each array of light sources producing an array of light beams that are directed into the chamber through one of the first or second side walls, each array of light sources being paired with a corresponding reflector, the reflectors being disposed to reflect the array of light beams from the paired array of light sources toward the output of the chamber.

14. The method of claim 13 further comprising providing a cover for the chamber and mounting one or more additional reflectors inside the chamber along the cover, spaced apart between the first and second side walls, and providing a plurality of additional arrays of light sources, each additional array of light sources producing an array of light beams and being paired with a corresponding additional reflector, the additional reflectors being disposed to reflect the array of light beams from the paired additional array of light sources toward the output of the chamber.