METHOD AND SYSTEM FOR REDUCING SPECKLE BY VIBRATING A LINE GENERATING ELEMENT

• US 20090034037A1
• Filed: 12/20/2007
• Published: 02/05/2009
• Est. Priority Date: 08/01/2007
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Krycho, Steven Paul, Khan, Sajjad A.
• Granted Patent: US 8,059,340 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G02B 27/48 Laser speckle optics
• CPC Class Codes: H04N 9/3161 using laser light sources using laser beams scanning the display screen H04N9/3129

Abstract

Provided is a method and system for reducing speckle in an image produced from a light source. The method, in one embodiment, includes providing a line generating element, the line generating element having a collection of optical elements having an axis. The method, in this embodiment, further includes directing an input beam of light at the line generating element while the line generating element is being vibrated back and forth in a direction substantially transverse to the axis.

Claims

1. A method for reducing speckle in an image produced from a light source, the method comprising:

providing a line generating element, the line generating element having a collection of optical elements having an axis; and

directing an input beam of light at the line generating element while the line generating element is being vibrated back and forth in a direction substantially transverse to the axis.

2. The method of claim 1 wherein the collection of optical elements have a maximum pitch, and further wherein the line generating element is being vibrated a distance equal to at least about the maximum pitch.

3. The method of claim 2 wherein an amount of time it takes for the line generating element to travel the distance is equal to or less than about a human retina response time.

4. The method of claim 3 wherein the amount of time is at most about 16.67 milliseconds.

5. The method of claim 1 wherein the line generating element is a lenticular array or cylindrical lenslet array.

6. The method of claim 1 wherein line generating element is a diffractive optical element or a holographic optical element.

7. The method of claim 1 wherein the line generating element comprises a material having intrinsic diffusive properties.

8. The method of claim 1 wherein a layer of material having diffusive properties is located proximate the line generating element.

9. The method of claim 8 wherein the layer of material having diffusive properties is coupled directly to the line generating element.

10. The method of claim 1, further including providing a spatial light modulator configured to receive the input beam of light altered by the line generating element and modulate that altered beam of light onto a display screen.

11. The method of claim 1 wherein the input beam of light includes a red beam of light, a green beam of light and a blue beam of light.

12. The method of claim 1 wherein the line generating element is vibrated using a motor based device or a piezo-electric actuator based device.

13. The method of claim 1 wherein the input beam of light is a laser beam of light and further wherein the vibration is configured to reduce objective speckle.

14. A system for reducing speckle in an image produced from a light source, comprising:

a light source operable to transmit an input beam of light;

a line generating element in optical communication with the input beam of light, the line generating element having a collection of optical elements configured to convert the input beam of light into one or more individual line beams of light;

a vibration source coupled to the line generating element, the vibration source configured to vibrate the line generating element back and forth in a direction substantially transverse to an axis of the collection of optical elements;

a spatial light modulator positioned in optical communication with the line generating element, the spatial light modulator configured to modulate the one or more individual line beams of light; and

a display screen positioned to receive the modulated individual line beams of light.

15. The system of claim 14 wherein the collection of optical elements has a fixed pitch, and wherein the vibration source is configured to vibrate the line generating element a distance equal to at least about the fixed pitch.

16. The system of claim 15 wherein the vibration source is configured to vibrate the line generating element at a speed such that an amount of time it takes for the line generating element to travel the distance is equal to or less than about 16.67 milliseconds.

17. The system of claim 14 wherein a layer of material having diffusive properties is located in contact with the line generating element.

18. The system of claim 14 wherein the vibration source is a first vibration source, and further including a second vibration source configured to vibrate the display screen.

19. The system of claim 14 wherein the spatial light modulator includes an array of digital micromirror devices.

20. The system of claim 14, further including an RGB scrolling mechanism configured to scroll the individual line beams of light across the spatial light modulator in temporal sequence.

21. The system of claim 14 wherein the collection of optical elements are substantially parallel to one another.

22. The system of claim 14 wherein the collection of optical elements are not substantially parallel to one another.