Beam alignment chamber providing divergence correction

• US 8,066,389 B2
• Filed: 04/30/2009
• Issued: 11/29/2011
• Est. Priority Date: 04/30/2009
• Status: Expired due to Fees

• Current Assignee: IMAX Corporation
• Original Assignee: Eastman Kodak Company
• Inventors: Kircher, James R., Silverstein, Barry D., Harland, Mark A.
• Primary Examiner(s): PYO, KEVIN K
• Application Number:
  US12/432,999
• Publication Number:
  US 20100277699A1
• Time in Patent Office: 943 Days
• Field of Search: 353/30, 353/31, 353/33, 353/37, 353/97, 353/98, 353/119, 359/649, 359/865, 359/850
• US Class Current: 353/119
• CPC Class Codes: G02B 27/1026 for use with reflective spatial light modulators
• CPC Class Codes: G02B 27/1073 characterized by manufacturing or alignment methods
• CPC Class Codes: G02B 27/126 The splitting element being a prism or prismatic array, including systems based on total internal reflection
• CPC Class Codes: G02B 27/143 using macroscopically faceted or segmented reflective surfaces
• CPC Class Codes: G02B 27/149 using crossed beamsplitting surfaces, e.g. cross-dichroic cubes or X-cubes
• CPC Class Codes: G02B 7/1824 Manual alignment

Abstract

A beam alignment chamber comprising: a base, first and second side walls connected to the base, and a front wall located at the front edge of the base having an output opening. The beam alignment chamber further including a plurality of light sources disposed to direct light beams through the first or second side walls, a plurality of reflectors mounted on the base, each having independent yaw and pitch adjustments, each being disposed to direct the light beams from a corresponding light sources along the length of the beam alignment chamber through the output opening forming an aligned array of parallel light beams, and one or more optical elements positioned in the optical path of the aligned array of light beams disposed to correct the beam divergence with respect to at least one axis.

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 side walls connected to the base, and extending along the length of the beam alignment chamber;

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

a plurality of light sources disposed to direct light beams through the first or second side walls, each light beam being uncorrected for divergence with respect to at least one axis;

a plurality of reflectors mounted on the base, each having independent yaw and pitch adjustments, each paired with at least one corresponding light source, the base-mounted reflectors being disposed to direct the light beams from the corresponding light sources along the length of the beam alignment chamber through the output opening forming an aligned array of parallel light beams, the optical distance between each light source and the output opening being substantially equal for each of the light beams; and

one or more optical elements positioned in the optical path of the aligned array of light beams disposed to correct the beam divergence with respect to at least one axis.

2. The beam alignment chamber of claim 1 wherein each base-mounted reflector is paired with a one-dimensional array of light sources, and wherein the aligned array of light beams is a two-dimensional array of light beams.

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

4. 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 on the cover, each having independent yaw and pitch adjustments, each paired with at least one corresponding light source, the cover-mounted reflectors being disposed to direct the light beams from the corresponding light source(s) 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 array of parallel light beams.

5. The beam alignment chamber of claim 4 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.

6. The beam alignment chamber of claim 1 wherein the one or more optical elements comprise a cylinder lens providing correction for the beam divergence with respect to one axis.

7. The beam alignment chamber of claim 1 wherein the one or more optical elements comprise a pair of crossed cylinder lens providing correction for the beam divergence with respect to two axes.

8. The beam alignment chamber of claim 1 wherein the corrected aligned array of light beams is collimated.

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

10. The beam alignment chamber of claim 1 wherein the beam alignment chamber is a component of a laser source system that provides an 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.

11. 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 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;

providing a plurality of arrays of light sources, each array of light sources producing an array of light beams and 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 producing an aligned array of light beams; and

positioning a corrective optical element in the optical path of the aligned array of light beams and having the same optical path distance from each of the arrays of light sources, the corrective optical element being disposed to correct the beam divergence with respect to at least one axis.