Video image projector with improve luminous efficiency
First Claim
1. A color image projector comprising a generator of light for producing three color beams each corresponding to a primary color, three imagers for respective spatial modulation of said color beams, means for impinging each color beam on a whole useful surface of a respective imager so as to spatially modulate light in said beam, and means for impinging said color beams on a viewing screen after said color beams have gone each through said respective imager, wherein said generator of light comprises at least one laser source globally illuminating one of said imagers with light emitted by said laser source.
1 Assignment
0 Petitions
Accused Products
Abstract
A three-color image projector, of the type using several colored light beams with primary colors, with improved luminous efficiency. The projector employs spatial rather than temporal beam modulation. The projector includes a generator producing light in the three spectral bands corresponding to the primary colors (red, green, blue). The generator has at least two light sources (S1, S2), one of which produces multi-spectral band light, and the other is a monochromatic source. By comparison with the prior art, where the white light is produced by a single source, this arrangement avoids, in particular, the elimination of a significant quantity of lumens in the excess primary color.
-
Citations
14 Claims
- 1. A color image projector comprising a generator of light for producing three color beams each corresponding to a primary color, three imagers for respective spatial modulation of said color beams, means for impinging each color beam on a whole useful surface of a respective imager so as to spatially modulate light in said beam, and means for impinging said color beams on a viewing screen after said color beams have gone each through said respective imager, wherein said generator of light comprises at least one laser source globally illuminating one of said imagers with light emitted by said laser source.
- 5. A color image projector including a light generator for producing a primary beam, means for separating the primary beam into three colored secondary light beams each corresponding to a respective spectral band, three imagers for spatial modulation or light each imager adapted to receive and spatially modulate light in a respective secondary light beam, and means for projecting the thus modulated secondary beams onto a viewing screen, said light generator comprises a substantially white light source having an emission spectrum, and at least one essentially monochromatic source having a color for which the emission spectrum of the white light source is deficient.
-
13. A color image projector comprising
a generator of light for producing three color beams each corresponding to a primary color and each beam having a predetermined cross-section, three imagers for respectively spatially modulating said three color beams, means for impinging each color beam with a whole cross-section of each beam on a whole surface of a respective imager, whereby said imagers spatially modulate light in said beams, means for impinging said color beams on a viewing screen after said beams have gone through said respective imagers, and said generator comprising at least one laser source which impinges on and globally illuminates said whole surface of the corresponding imager with light emitted by said laser source.
-
14. A color image projector comprising a light generator for producing a primary beam having a predetermined cross-section and means for impinging said primary beam with a whole cross-section of said primary beam on a whole surface of a single modulation screen associated with a color filter device so as to constitute a three-color modulating screen, whereby said modulation screen spatially modulates said primary beam in accordance with the colors of the filter device, and means for impinging said primary beam on a viewing screen after said beam has gone through said modulation screen, and said light generator comprising at least one laser source and means for globally illuminating said whole surface of said modulation screen with light emitted by said laser source.
Specification