Speckle reduction using screen vibration techniques and apparatus

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.

What is claimed is: 
     
         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.   
     
     
         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 approximate 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 , wherein the at least actuating element comprises at least one electromagnetic wave generator, and the waves generated are electromagnetic waves. 
     
     
         12 . A speckle reducing system according to  claim 11 , further comprising a plurality of radiating antennas located on a surface of the display screen, each of the plurality of radiating antennas configure to receive electromagnetic waves thereby imparting the vibration to the display screen. 
     
     
         13 . A speckle reducing system according to  claim 12 , 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. 
     
     
         14 . 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.   
     
     
         15 . A method according to  claim 14 , 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. 
     
     
         16 . A method according to  claim 15 , wherein the velocity of the vibration of the display screen is greater than about 20 Hz. 
     
     
         17 . A method according to  claim 14 , wherein the screen may be excited at an excitation frequency which is bandwidth limited. 
     
     
         18 . A method according to  claim 17 , wherein the excitation frequency is in the approximate range of 10 Hz to 100 Hz. 
     
     
         19 . A method according to  claim 14 , the waves impact the screen at a frequency substantially equal to a resonance frequency of the screen. 
     
     
         20 . A method according to  claim 14 , wherein the at least actuating element comprises at least one audio speaker, and generating waves comprises generating sound waves. 
     
     
         21 . A method according to  claim 20 , 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. 
     
     
         22 . A method according to  claim 20 , further comprising providing audio content for media displayed on the screen while generating the sound waves using the at least one audio speaker. 
     
     
         23 . A method according to  claim 20 , 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. 
     
     
         24 . A method according to  claim 14 , wherein the at least actuating element comprises at least one electromagnetic wave generator, and generating waves comprises generating electromagnetic waves. 
     
     
         25 . A method according to  claim 24 , 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. 
     
     
         26 . A method according to  claim 25 , 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.