Highly efficient and compact frontlighting for polarization-based reflection light valves
First Claim
1. An optical device comprising an array of polarizing plates, each one of said polarizing plates having opposing surfaces that are tilted relative to entrance and exit surfaces of said one polarizing plate, and including:
- a polarizing layer formed on one of said opposing tilted surfaces; and
a half-wave optical retardation layer formed on said polarizing layer;
said array of polarizing plates converting unpolarized light, which is incident on said entrance surface at an oblique angle from a normal to said entrance surface, to a polarized light having a first polarization and exiting approximately perpendicular to said exit surface.
1 Assignment
0 Petitions
Accused Products
Abstract
An optical device and a display are disclosed that include an illumination source which provides unpolarized light. An array of polarizing plates have an entrance surface, which receives the unpolarized light at an oblique angle, and an exit surface which provides a polarized light having a first polarization and exiting the array at a substantially perpendicular direction to the exit surface. A light valve selectively rotates the polarized light to form an image forming light, and an imaging lens receives the image forming light and forms an image. Each of the polarizing plates in the array has opposing surfaces that are tilted relative to its entrance and exit surfaces. Each polarizing plate includes a polarizing layer formed on one of the opposing tilted surfaces, and a half-wave optical retardation layer formed on the polarizing layer.
-
Citations
27 Claims
-
1. An optical device comprising an array of polarizing plates, each one of said polarizing plates having opposing surfaces that are tilted relative to entrance and exit surfaces of said one polarizing plate, and including:
-
a polarizing layer formed on one of said opposing tilted surfaces; and a half-wave optical retardation layer formed on said polarizing layer; said array of polarizing plates converting unpolarized light, which is incident on said entrance surface at an oblique angle from a normal to said entrance surface, to a polarized light having a first polarization and exiting approximately perpendicular to said exit surface. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25)
-
-
26. A display comprising:
-
an illumination source which provides unpolarized light; an array of polarizing plates having an entrance surface, which receives said unpolarized light at an oblique angle, and an exit surface which provides a polarized light having a first polarization and exiting said array at a substantially perpendicular direction to said exit surface; a light valve for selectively rotating said polarized light to form an image forming light; and an imaging lens for receiving said image forming light to form an image.
-
-
27. A frontlighting device for a reflective light valve comprising an array of polarizing plates, each one of said polarizing plates having opposing surfaces that are tilted relative to entrance and exit surfaces of said one polarizing plate, and including:
-
a polarizing layer formed on one of said opposing tilted surfaces; and a half-wave optical retardation layer formed on said polarizing layer; said array of polarizing plates converting unpolarized light, which is incident on said entrance surface at an oblique angle from a normal to said entrance surface, to a polarized light having a first polarization and exiting approximately perpendicular to said exit surface for illuminating said reflective light valve.
-
Specification