Light source module for stereoscopic display, imaging device for stereoscopic display and stereoscopic display system

Abstract

A light source module for stereoscopic display includes multi-primary color lasers which output the light with the same polarization direction. Respective lasers are divided into two groups according to the wavelengths of the output light. A light combiner is provided in the output light path of each laser group and is used for combining the output light of all lasers in the group into one output light path. The light source module further includes a polarization conversion rotary member, and the polarization direction of the two output light is periodically and alternately rotated by 90 degree by self-rotation of the polarization conversion rotary member. An imaging device for stereoscopic display includes the light source module for stereoscopic display, the light combiner and a first optical imaging modulator and a second optical imaging modulator. A stereoscopic display system includes the imaging device for stereoscopic display and a projection lens sub-system.

1 . A device with a stereoscopic light source, comprising:
 a first laser generator configured to generate a first laser beam having a first polarization and a first wavelength;   a second laser generator configured to generate a second laser beam having a second polarization and a second wavelength different from the first wavelength; and   a polarization conversion element configured to
 receive the first laser beam and the second laser beam, and 
 periodically rotate the first polarization of the first laser beam and the second polarization of the second laser beam with a predetermined degree so that the first laser beam and second laser beam form a pair of laser beams with periodically rotated orthogonal polarizations. 
   
     
     
         2 . The device of  claim 1 , further comprising a first light combining element when the first laser generator comprises a first plurality of laser generators, wherein
 each of the first plurality of laser generators is configured to generate a laser beam with the first polarization, and   the first light combining element is configured to combine the laser beams generated by the first plurality of laser generators into the first laser beam; and   a second light combining element when the second laser generator comprises a second plurality of laser generators, wherein
 each of the second plurality of laser generators is configured to generate a laser beam with the second polarization, and 
 the second light combining element is configured to combine the laser beams generated by the second plurality of laser generators into the second laser beam 
   
     
     
         3 . The device of  claim 2 , wherein the second laser beam comprises one of a red laser beam, a blue laser beam, and a green laser beam, whichever is brighter;
 the second laser beam comprises a remainder of the red laser, the blue laser, and the green laser.   
     
     
         4 . The device of  claim 1 , wherein the polarization conversion element is rotatable the first polarization and the second polarization at a frequency higher than a visual persistence time of human being. 
     
     
         5 . The device of  claim 1 , wherein the first polarization parallels to the second polarization; and
 the polarization conversion element is further configured to alternatively rotate the first polarization and the second polarization during a period of polarization rotation   
     
     
         6 . The device of  claim 5 , wherein the polarization conversion element comprises a sheet-shaped structure rotatable about an axis, the polarization conversion elements comprising:
 a first region being a polarization changing region to the first laser beam and the second laser beam; and   a second region being a polarization non-changing region to the first laser beam and the second laser beam,   wherein the first region and second region are so arranged that when the polarization conversion element rotates about the axis,
 the first laser beam is incident to the first region when the second laser beam is incident to the second region, and 
 the first laser beam is incident to the second region when the second laser beam is incident to the first region. 
   
     
     
         7 . The device of  claim 6 , wherein the first region is occupied by a half-wave plate, and
 the predetermined degree is 90 degree.   
     
     
         8 . The device of  claim 7 , wherein the axis is perpendicular to the sheet-shaped structure. 
     
     
         9 . The device of  claim 7 , wherein the axis passes through the sheet-shaped structure. 
     
     
         10 . The device of  claim 6 , wherein the polarization conversion element is a sheet-shaped half-wave plate rotatable about an axis passing through the sheet-shape structure, and
 when the polarization conversion element rotates about the axis, the polarization conversion element alternatively passes through a light path of the first laser beam and a light path of the second laser beam.   
     
     
         11 . The device of  claim 1 , further comprising:
 a beam combining element configured to receive the first laser beam and the second laser beam output from the polarization conversion element and combine the first laser beam and the second laser beam into a combined laser beam.   
     
     
         12 . The device of  claim 11 , further comprising:
 a polarization beam splitter configured to split the combined laser beam into a p-polarized component and an s-polarized component;   a first optical image modulator configured to receive the p-polarized component; and   a second optical image modulator configured to receive the s-polarized component.   
     
     
         13 . The device of  claim 1 , wherein the first polarization and the second polarization are p-polarization or s-polarization;
 the p-polarized component comprises a first image signal;   the first optical image modulator is configured to modulate the p-polarized component according to the first image signal;   the s-polarized component comprises a second image signal; and   the second optical image modulator is configured to modulate the s-polarized component according to the second image signal.   
     
     
         14 . A method for generating a stereoscopic image, comprising:
 generating a first laser beam having a first polarization and a first wavelength;   generating a second laser beam having a second polarization a second wavelength different from the first wavelength; and   periodically rotating the first polarization of the first laser beam and the second polarization of the second laser beam with 90 degree so that the first laser beam and second laser beam form a laser beam pair with periodically rotated orthogonal polarizations,   wherein a p-polarization component of the laser beam pair comprises a first image signal, and   an s-polarization component of the laser beam pair comprises a second image signal.   
     
     
         15 . The method of  claim 14 , wherein the second laser beam comprises one of a red laser, a blue laser, and a green laser, whichever is brighter;
 the second laser beam comprises a remainder of the red laser, the blue laser, and the green laser.   
     
     
         16 . The method of  claim 14 , wherein the first polarization and the second polarization are rotated at a frequency higher than a visual persistence time of human being. 
     
     
         17 . The method of  claim 14 , wherein the first polarization parallels the second polarization; and
 the first polarization and the second polarization are alternatively rotated during a period of polarization rotation.   
     
     
         18 . The method of  claim 17 , wherein the periodically and alternatively rotating of the first polarization and the second polarization comprises:
 rotating a sheet-shaped structure, wherein the sheet-shaped structure comprises
 a first region occupied by a half-wave plate; and 
 a second region being a polarization non-changing region to the first laser beam and the second laser beam, 
   respectively transmitting the first laser beam and the second laser beam through the sheet-shaped structure so that
 the first laser beam is incident to the first region when the second laser beam is incident to the second region, and 
 the first laser beam is incident to the second region when the second laser beam is incident to the first region. 
   
     
     
         19 . The method of  claim 14 , further comprising:
 combining the first laser beam and the second laser beam into a combined laser beam after the periodical rotating of the first polarization and the second polarization.   
     
     
         20 . The method of  claim 19 , further comprising:
 splitting the combined laser beam into a p-polarized component and an s-polarized component;   modulating the p-polarized component according to the first image signal; and   modulating the s-polarized component according to the second image signal.