Method and system for calibrating a diffractive grating modulator

• US 6,479,811 B1
• Filed: 03/06/2000
• Issued: 11/12/2002
• Est. Priority Date: 03/06/2000
• Status: Expired due to Term

• Current Assignee: Eastman Kodak Company
• Original Assignee: Eastman Kodak Company
• Inventors: Kowarz, Marek W., Brazas, John C., Kruschwitz, Brian E.
• Primary Examiner(s): Allen, Stephone
• Assistant Examiner(s): Spears, Eric J
• Application Number:
  US09/519,227
• Time in Patent Office: 981 Days
• Field of Search: 250/237.R, 250/237.G, 359/573
• US Class Current: 250/237.00G
• CPC Class Codes: G02B 26/0808 by means of one or more diffracting elements
• CPC Class Codes: G02B 27/4255 for alignment or positioning purposes optical displacement encoding scales G01D5/347

Abstract

A diffractive grating modulator system, includes: a diffractive grating modulator active to produce a plurality of output orders of diffraction; an illumination source for directing light onto the diffractive grating modulator; an output system arranged to receive one of the orders of diffraction from the diffractive grating modulator; a detector arranged to receive a different one of the orders of diffraction from the diffractive grating and to produce a signal representing the output of the diffractive grating modulator; an electronic driving system responsive to a data stream for operating the diffractive grating modulator; and a feedback system connected to the detector and the electronic driving system and responsive to the signal for calibrating the diffractive grating modulator.

Claims

1. A diffractive grating modulator system, comprising:

a) a diffractive grating modulator active to produce a plurality of output orders of diffraction;

b) an illumination source for directing light onto the diffractive grating modulator;

c) an output system arranged to receive one of the orders of diffraction from the diffractive grating modulator;

d) a detector arranged to receive a different one of the orders of diffraction from the diffractive grating and to produce a signal representing the output of the diffractive grating modulator;

e) an electronic driving system responsive to a data stream for operating the diffractive grating modulator; and

f) a feedback system connected to the detector and the electronic driving system and responsive to the signal for calibrating the diffractive grating modulator.

2. The system as recited in claim 1 wherein the diffractive grating modulator comprises a plurality of individual pixel elements.

3. The system as recited in claim 2 wherein the detector comprises a plurality of discrete segments and includes imaging optics for forming an image of the diffractive grating modulator onto the detector.

4. The system as recited in claim 1 wherein the diffractive grating modulator is an e electromechanical grating device.

5. The system as recited in claim 1 wherein the output system receives the mth order of diffraction and the detector receives the −

mth order of diffraction.

6. The system as recited in claim 5 wherein the light from the illumination source is normal to the diffractive grating modulator.

7. The system as recited in claim 1 wherein the output system captures the 0th order and the detector captures a higher diffracted order.

8. The system as recited in claim 1 wherein the data stream contains image data.

9. The system as recited in claim 1 wherein the diffractive grating modulator system produces stable power.

10. The system as recited in claim 1 wherein the output system is a display.

11. The system as recited in claim 1 wherein the output system is a printer.

12. A diffractive grating modulator system having a plurality of pixel elements and being active to produce a plurality of output orders of diffraction, comprising:

a) an illumination source for providing light on the diffractive grating modulator;

b) an output system arranged to receive one order of diffraction from the diffractive grating modulator;

c) a detector having a plurality of discrete segments for detecting another order of diffraction from the diffractive grating modulator and producing a signal representing the output of the diffractive grating modulator;

d) an electronic driving system for operating the diffractive grating modulator; and

e) a feedback system connected between the detector and the electronic driving system and responsive to the signal for calibrating the diffractive grating modulator system.

13. The system as recited in claim 12, further comprising an imaging device for producing an image of the diffractive grating modulator onto the detector.

14. The system as recited in claim 12 wherein the diffractive grating modulator is an electromechanical grating device.

15. The system as recited in claim 12, wherein the output system receives the m^th order of diffraction and the detector receives the −

m^th order of diffraction.

16. The system as recited in claim 15, wherein the light from the illumination source is normal to the diffractive grating modulator.

17. The system as recited in claim 12, wherein the output system captures the 0^th order and the detector captures a diffracted order.

18. The system as recited in claim 12, wherein the diffractive grating modulator system produces an image with stable intensity.

19. The system as recited in claim 12, wherein the output system is a display.

20. The system as recited in claim 12, wherein the output system is a printer.