System and method for improved contrast ratio in a projection system
OwnerGarrett J. Younginventor
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Abstract
A system embodiment comprises an analyzer, a Liquid Crystal Display (LCD), and a compensation plate. The LCD allows, limits or blocks passage of polarized light as a projected image to the analyzer. The LCD includes a plurality of crystals that provide the LCD with a plurality of pixels, and the crystals in the LCD have non-ideal polarization states resulting from receipt and retardance of non-collimated incident angles of light. The non-ideal polarization states introduce unwanted phase shifts of the light in the projected image. The compensation plate is configured to introduce desired phase shifts to compensate for the unwanted phase shifts of the light introduced by non-ideal polarization states introduced by the LCD.
Claims20
A system, comprising:
- an analyzer;
- a Liquid Crystal Display (LCD) to allow, limit or block passage of polarized light as a projected image to the analyzer, wherein the LCD includes a plurality of crystals that provide the LCD with a plurality of pixels, wherein the crystals in the LCD have non-ideal polarization states resulting from receipt and retardance of non-collimated incident angles of light, and wherein the non-ideal polarization states introduce unwanted phase shifts of the light in the projected image;
- and
- a compensation plate configured to introduce desired phase shifts to compensate for the unwanted phase shifts of the light introduced by non-ideal polarization states introduced by the LCD.
A method, comprising:
- setting all pixels in a liquid crystal display (LCD) “on”;
- measuring light transmission when all pixels are set “on”;
- setting all pixels in LCD “off”;
- measuring light transmission when all pixels are set “off”;
- if the measured light transmissions are not acceptable, adjusting a compound angle of a compensation plate with respect to the LCD, and re-measuring light transmission when all pixels are set “on” and when all pixels are set “off”.
A method, comprising:
- turning a liquid crystal display (LCD) “full on” to be transmissive;
- directing light through the full on LCD at a plurality of angles;
- determining retardance for the LCD for the plurality of angles;
- constructing a polar plot to represent the retardance for the plurality of angles;
- and
- using the polar plot to provide an appropriate coating for a compensate plate to compensate for the retardance of the LCD.
Dependencies are inferred from the claim text.