US Patent No. 9,529,247

PROJECTOR INCLUDING POLARIZATION SEPARATION ELEMENT AND ROTATING PRISM


Patent No. 9,529,247
Issue Date December 27, 2016
Title Projector Including Polarization Separation Element And Rotating Prism
Inventorship Atsushi Katou, Tokyo (JP)
Assignee NEC Display Solutions, Ltd., Tokyo (JP)

Claim of US Patent No. 9,529,247

1. A projector, comprising:
at least one light source;
a polarization separation element that separates light from the light source into two linearly polarized light beams whose
polarization axes are orthogonal to each other to emit the two linearly polarized light beams in the same direction;

a total internal reflection (TIR) prism that transmits the two linearly polarized light beams;
a reflective light modulation element that receives the two linearly polarized light beams that have been emitted from the
TIR prism to modulate and reflect the two linearly polarized light beams toward the TIR prism;

projection lens that enlarges and projects the two linearly polarized light beams that have been modulated by the reflective
light modulation element and that have been transmitted through the TIR prism;

a rotating prism being rotatably arranged in an optical path between the polarization separation element and the TIR prism
to emit the two linearly polarized light beams that have entered from the polarization separation element from different positions
depending on the rotation of the rotating prism;

the at least one light source comprising two solid-state light sources that emit light of a first color;
a rotating wheel including a disk to which a phosphor is affixed and that, due to light from one of the two solid-state light
sources, emits light of a plurality of colors other than the first color;

a reflective element that changes a travel direction of light from the other of the two solid-state light sources; and
a color wheel that receives light from the rotating wheel and light from the reflective element to separate the received light
into a plurality of colors in time division,

wherein the polarization separation element receives light that has been emitted from the color wheel.