Speckle reduction using screen vibration techniques and apparatus

• US 9,086,578 B2
• Filed: 05/12/2014
• Issued: 07/21/2015
• Est. Priority Date: 07/07/2011
• Status: Active Grant

• Current Assignee: RealD Incorporated
• Original Assignee: RealD Incorporated
• Inventors: Curtis, Kevin, Coleman, David A., Sharp, Gary D.
• Primary Examiner(s): MAHONEY, CHRISTOPHER E
• Application Number:
  US14/275,765
• Publication Number:
  US 20140247484A1
• Time in Patent Office: 435 Days
• Field of Search: 359444-446
• US Class Current: 1/1
• CPC Class Codes: G02B 27/48 Laser speckle optics
• CPC Class Codes: G03B 21/56 Projection screens
• CPC Class Codes: G03B 21/562 Screens moving during projection G03B21/58 - G03B21/62 take precedence
• CPC Class Codes: G03B 31/00 Associated working of cameras or projectors with sound-recording or sound-reproducing means

Abstract

Disclosed herein are systems and related methods for reducing speckle on display screen. More specifically, screen vibration is used to reduce speckle, and in accordance with the disclosed principles, the vibration may be achieved by using wave-based actuation (e.g., acoustic or electromagnetic waves) to vibrate the screen. In an exemplary embodiment, a speckle reducing system may comprise at least one actuating element located proximate to, but not in physical contact with, a display screen. In addition, the at least one actuating element may be configured to generate waves directed towards the display screen. When the waves impact the display screen, the waves impart vibration to the display screen.

Claims

1. A speckle reducing system for reducing speckle on a display screen, the system comprising:

at least one actuating element located proximate to, but not in physical contact with, a display screen;

wherein the at least one actuating element is configured to generate waves directed towards the display screen, the waves impacting the display screen to impart vibration to the display screen, wherein the vibration reduces speckle on the display screen, wherein the at least actuating element comprises at least one electromagnetic wave generator, and the waves generated are electromagnetic waves.

2. A speckle reducing system according to claim 1, wherein the waves impart vibration to the display screen at a velocity larger than one-half of an optical wavelength of light divided by the integration time of the eye of the viewer.

3. A speckle reducing system according to claim 2, wherein the velocity of the vibration of the display screen is greater than about 20 Hz.

4. A speckle reducing system according to claim 1, wherein the screen may be excited at an excitation frequency which is a low frequency.

5. A speckle reducing system according to claim 4, wherein the excitation frequency is in the range of 10 Hz to 100 Hz.

6. A speckle reducing system according to claim 1, the waves impact the screen at a frequency substantially equal to a resonance frequency of the screen.

7. A speckle reducing system according to claim 1, wherein the at least actuating element comprises at least one audio speaker, and the waves generated are sound waves.

8. A speckle reducing system according to claim 7, wherein the at least one audio speaker is located behind the screen, in front of the screen, or a combination thereof.

9. A speckle reducing system according to claim 7, wherein the at least one audio speaker also provides audio content for media displayed on the screen.

10. A speckle reducing system according to claim 7, wherein the sounds waves comprise an audio frequency greater than or lesser than a frequency that can be heard by a viewer.

11. A speckle reducing system according to claim 1, further comprising a plurality of radiating antennas located on a surface of the display screen, each of the plurality of radiating antennas configured to receive electromagnetic waves thereby imparting the vibration to the display screen.

12. A speckle reducing system according to claim 11, wherein the plurality of radiating antennas are located on a back surface of the screen, on a front surface of the screen, or a combination thereof.

13. A method of reducing speckle on a display screen, the method comprising:

positioning at least one actuating element proximate to, but not in physical contact with, a display screen;

generating waves with the at least one actuating element; and

directing the generated waves towards the display screen, the waves impacting the display screen to impart vibration to the display screen, wherein the vibration reduces speckle on the display screen, wherein the at least actuating element comprises at least one electromagnetic wave generator, and generating waves comprises generating electromagnetic waves.

14. A method according to claim 13, wherein the waves impart vibration to the display screen at a velocity larger than one-half of an optical wavelength of light divided by the integration time of the eye of the viewer.

15. A method according to claim 14, wherein the velocity of the vibration of the display screen is greater than about 20 Hz.

16. A method according to claim 13, wherein the screen may be excited at an excitation frequency which is bandwidth limited.

17. A method according to claim 16, wherein the excitation frequency is in the range of 10 Hz to 100 Hz.

18. A method according to claim 13, the waves impact the screen at a frequency substantially equal to a resonance frequency of the screen.

19. A method according to claim 13, wherein the at least actuating element comprises at least one audio speaker, and generating waves comprises generating sound waves.

20. A method according to claim 19, wherein directing waves towards the screen further comprises directing waves towards the back surface of the screen, towards the front surface of the screen, or a combination thereof.

21. A method according to claim 19, further comprising providing audio content for media displayed on the screen while generating the sound waves using the at least one audio speaker.

22. A method according to claim 19, wherein generating sounds waves comprises generating sound waves at an audio frequency greater than or lesser than a frequency that can be heard by a viewer.

23. A method according to claim 13, further comprising positioning a plurality of radiating antennas on a surface of the display screen, each of the plurality of radiating antennas configured to receive electromagnetic waves thereby imparting the vibration to the display screen.

24. A method according to claim 23, further comprising positioning the plurality of radiating antennas on a back surface of the screen, on a front surface of the screen, or a combination thereof.