Uniform speckle reduced laser projection using spatial and temporal mixing
First Claim
1. A digital image projector comprising:
- a) a light assembly for a particular color channel configured to project light along a light path from at least one laser array light source including multiple lasers, the projected light from the multiple lasers overlapping in a far field illumination portion of the light path to form a combined light beam, the far field illumination portion of the light path being a portion beyond a far field distance wherein a laser intensity pattern from an individual laser satisfies a far field criterion such that only the size of the laser intensity pattern varies and the structure of the laser intensity pattern does not vary;
b) a temporally varying optical phase shifting device configured to be in the light path downstream from the far field distance;
c) an optical integrator downstream of the temporally varying optical phase shifting device;
d) a spatial light modulator located downstream of the optical integrator in the light path, the spatial light modulator; and
e) projection optics located downstream of the spatial light modulator in the light path, the projection optics configured to direct speckle reduced light from the spatial light modulator toward a display surface.
18 Assignments
0 Petitions
Accused Products
Abstract
A digital image projector includes a light assembly configured to project light along a light path from at least one laser array light source, the projected light having an overlapping far field illumination in a far field illumination portion of the light path; a temporally varying optical phase shifting device configured to be in the light path; an optical integrator configured to be in the light path; a spatial light modulator located downstream of the temporally varying optical phase shifting device and the optical integrator in the light path, the spatial light modulator configured to be located in the far field illumination portion of the light path; and projection optics located downstream of the spatial light modulator in the light path, the projection optics configured to direct substantially speckle free light from the spatial light modulator toward a display surface.
-
Citations
20 Claims
-
1. A digital image projector comprising:
-
a) a light assembly for a particular color channel configured to project light along a light path from at least one laser array light source including multiple lasers, the projected light from the multiple lasers overlapping in a far field illumination portion of the light path to form a combined light beam, the far field illumination portion of the light path being a portion beyond a far field distance wherein a laser intensity pattern from an individual laser satisfies a far field criterion such that only the size of the laser intensity pattern varies and the structure of the laser intensity pattern does not vary; b) a temporally varying optical phase shifting device configured to be in the light path downstream from the far field distance; c) an optical integrator downstream of the temporally varying optical phase shifting device; d) a spatial light modulator located downstream of the optical integrator in the light path, the spatial light modulator; and e) projection optics located downstream of the spatial light modulator in the light path, the projection optics configured to direct speckle reduced light from the spatial light modulator toward a display surface. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A stereoscopic digital image projector comprising:
-
a) a light assembly configured to project polarized light having a common first polarization state along a light path from at least one laser array light source, the projected polarized light having an overlapping far field illumination in a far field illumination portion of the light path; b) a polarization rotator configured to be in the light path of the projected polarized light and actuable to controllably rotate the polarization state of the projected polarized light from the first polarization state to a second polarization state; c) a temporally varying optical phase shifting device configured to be in the light path; d) a polarization maintaining optical integrator configured to be in the far field portion of the light path; e) a micro-electromechanical spatial light modulator located in the light path downstream of the polarization rotator, temporally varying optical phase shifting device, and the optical integrator, the spatial light modulator configured to form a first modulated light from light of the first polarization state and to form a second modulated light from light of the second polarization state; f) a synchronizing device configured to synchronize the polarization rotator with image data; and g) projection optics located downstream of the spatial light modulator in the light path, the projection optics configured to direct substantially speckle free light from the spatial light modulator toward a display surface. - View Dependent Claims (12, 13, 14, 15)
-
-
16. A digital image projector comprising:
-
a) a light assembly for a particular color channel configured to project light along a light path from at least one laser array light source including multiple lasers, the projected light from the multiple lasers overlapping in a far field illumination portion of the light path, the far field illumination portion of the light path being a portion beyond a far field distance wherein a laser intensity pattern from an individual laser satisfies a far field criterion such that only the size of the laser intensity pattern varies and the structure of the laser intensity pattern does not vary; b) a temporally varying optical etendue shifting device configured to be in the light path downstream from the far field distance; c) an optical integrator downstream of the temporally varying optical phase shifting device; d) a spatial light modulator located downstream of the the optical integrator in the light path, the spatial light modulator; and e) projection optics located downstream of the spatial light modulator in the light path, the projection optics configured to direct speckle reduced light from the spatial light modulator toward a display surface. - View Dependent Claims (17, 18, 19)
-
-
20. A method of reducing laser speckle in a laser displayed image, the method comprising:
-
a) projecting light from a laser array light source including multiple lasers in a particular color channel along a light path, the projected light from the multiple lasers overlapping in a far field illumination portion of the light path, the far field illumination portion of the light path being a portion beyond a far field distance wherein a laser intensity pattern from an individual laser satisfies a far field criterion such that only the size of the laser intensity pattern varies and the structure of the laser intensity pattern does not vary; b) temporally varying the projected light using a temporally varying optical phase shifting device or a temporally varying optical etendue shifting device configured to be in the light path downstream from the far field distance; c) optically integrating the projected light subsequently to temporally varying the projected light; d) spatially modulating the projected light subsequently to optically integrating the projected light; and e) optically projecting speckle reduced light toward a display surface subsequently to spatially modulating the projected light.
-
Specification