Spatial light modulator based optical calibration system

• US 5,323,002 A
• Filed: 06/08/1993
• Issued: 06/21/1994
• Est. Priority Date: 03/25/1992
• Status: Expired due to Term

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Sampsell, Jeffrey B., Florence, James M.
• Primary Examiner(s): FIELDS, CAROLYN
• Application Number:
  US08/073,637
• Time in Patent Office: 378 Days
• Field of Search: 250/252.1 A, 250/504 R, 250/493.1, 250/332, 356/243
• US Class Current: 250/252.1
• CPC Class Codes: G01J 5/53 Reference sources, e.g. standard lamps; Black bodies
• CPC Class Codes: H04N 25/00 Circuitry of solid-state image sensors [SSIS]; Control thereof
• CPC Class Codes: H04N 5/33 Transforming infrared radiation cameras or camera modules for generating image signals from infrared radiation H04N23/20; circuitry of SSIS for transforming infrared radiation into image signals H04N25/20

Abstract

A method and system for calibration of optical systems is disclosed. The system consists of a reference source (12), a spatial light modulator (26) for transmitting the reference source signal through non-imaging optics (30) and into the input of an optical system (36). The output of the optical system is then compared to the input signal and a correction is derived. The correction is stored and used real-time to adjust the output of the system to more accurately reflect the actual input signal.

Claims

1. An optical system comprising:

a. a reference source with at least one reference output signal wherein the value of the reference output signal is known;

b. a spatial light modulator for selectively directing said reference output signal from said reference source to non-imaging optics wherein said non-imaging optics uniformly transmit said reference output signal to the input of said optical system;

c. an output signal from said optical system; and

d. a means for comparing the input of said optical system and the output of said optical system, deriving a correction based upon that comparison and storing it.

2. The system of claim 1 wherein said system is an infrared system.

3. The system of claim 1 wherein said system is a visual display system.

4. The system of claim 1 wherein said system is a photocopier system.

5. The system of claim 1 wherein said system is a printer.

6. The system of claim 1 wherein said reference source is a temperature source.

7. The system of claim 1 wherein said reference source is a color source.

8. The system of claim 1 wherein said reference source is monochrome.

9. The system of claim 1 wherein said spatial light modulator is a deformable mirror device.

10. A method of calibrating an optical system comprising:

a. providing a reference source with at least one reference output, wherein the value of said reference output is known;

b. transmitting an image of the reference output to non-imaging optics with a spatial light modulator;

c. uniformly transmitting an image of the reference output through said non-imaging optics to the input of an optical system;

d. creating an output signal with said optical system;

e. comparing the reference output signal with the optical system output signal; and

f. deriving and storing a correction for said optical system.

11. The method of claim 10 wherein said comparing step further comprises using a comparator to compare between at least two photodetectors.

12. The method of claim 10 wherein said deriving and storing step further comprises the use of a memory table for storing said correction.

13. A method of operating a display system comprising:

a. providing a calibration system, wherein said calibration system further comprises;

i. establishing a reference source;

ii. operating a spatial light modulator for transmitting an image of said reference source; and

iii. transmitting said image of said reference source from said spatial light modulator to non-imaging optics wherein said non-imaging optics transmit said image uniformly to the input of said display system;

b. comparing said input of said display system with the output of said display system;

c. deriving a correction for each pixel at said output of said display system; and

d. storing said correction.

14. The method of claim 13 wherein said spatial light modulator is a deformable mirror device.

15. The method of claim 13 wherein said spatial light modulator is a liquid crystal array.

16. The method of claim 13 wherein said calibration system can be turned off and on.

17. The method of claim 13 wherein said calibration system is in continuous operation.