Image projection system
AssigneeIMAX Corporation
InventorsMichael A. Gibbon, Steven C. Read, Sean M. Adkins
Life of this patent
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Abstract
An electronic projector has a projection system that includes a spatial light modulator (SLM) for importing image information to the projected light beam. The light beam leaving the SLM is prepolarized in a defined orientation and the projected light is polarized in the same orientation so as to effectively block any light that has been scattered within the projector and become depolarized. The SLM may be a digital mirror device (DMD). Reflective surfaces within the projector may be covered or coated with material that alters the polarization of reflected stray light from the defined orientation or depolarizes the reflected stray light.
Claims20
A projection system, comprising:
- a light source for producing a light beam;
- a screen;
- a projection lens for projecting the light beam onto the screen;
- a digital mirror device (DMD) for imparting image information to the light beam upstream of the projection lens;
- a first polarizer means for polarizing, in a defined orientation, light input to the DMD;
- surfaces within the projection system adapted to depolarize scattered light or alter the polarization of scattered light from the defined orientation;
- and
- a second polarizer means for polarizing in the same defined orientation, light passing through said projection lens.
A projection system, comprising:
- a light source for producing a light beam;
- a first polarizer for polarizing the light beam in a defined orientation;
- a digital mirror device (DMD) for imparting image information to the polarized light beam;
- surfaces within the projection system adapted to depolarize scattered light or alter the polarization of scattered light from the defined orientation;
- a screen;
- a projection lens for projecting the light beam onto the screen;
- and
- a second polarizer for polarizing the light beam in the defined orientation after light is reflected off the surfaces and before the light beam reaches the screen.
A projector, comprising:
- a light source for producing a light beam;
- a first polarizer for polarizing the light beam in a defined orientation;
- a plurality of digital mirror devices (DMDs) for imparting image information to the polarized light beam;
- surfaces within the projector adapted to depolarize scattered light or alter the polarization of scattered light from the defined orientation;
- a projection lens for projecting the light beam;
- and
- a second polarizer for polarizing the projected light beam in the defined orientation.
A projector, comprising:
- a light source for producing a light beam;
- a first polarizer for polarizing the light beam in a defined orientation;
- a plurality of digital mirror devices (DMDs) for imparting image information to the polarized light beam;
- surfaces within the projector adapted to depolarize scattered light or alter the polarization of scattered light from the defined orientation;
- a projection lens for projecting the light beam;
- and
- a second polarizer for polarizing the projected light beam in the defined orientation and disallowing the passage of scattered light that has been depolarized or altered in polarization.
A projector, comprising:
- a light source for producing a light beam;
- a first polarizer for polarizing the light beam in a defined orientation;
- a plurality of digital mirror devices (DMDs) for imparting image information to the polarized light beam;
- surfaces within the projector adapted to create diffuse reflective surfaces that depolarize scattered light or alter the polarization of scattered light from the defined orientation;
- a projection lens for projecting the light beam;
- and
- a second polarizer for polarizing the projected light beam in the defined orientation.
Dependencies are inferred from the claim text.