US 2009/0213333 A1Published application

Projection display apparatus

AssigneeYoung Optics Inc.

InventorSung-Nan Chen

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Abstract

A projection display apparatus includes a polarization beam splitter, a light source, a polarization changing device, an optical uniformizing element, a light valve module and a projection lens. The light source emits an illumination beam. The polarization beam splitter, the polarization changing device, the optical uniformizing element, and the light valve module are disposed in the optical path of the illumination beam. The polarization beam splitter transmits the illumination beam. The polarization changing device changes the polarization direction of the illumination beam and reflects the illumination beam back to the polarization beam splitter. The optical uniformizing element is between the polarization beam splitter and the polarization changing device for uniformizing the illumination beam. The light valve module converts the illumination beam reflected by the polarization changing device via the polarization beam splitter into an image beam. The projection lens is disposed in the optical path of the image beam.

Claims14

Dependent claims

A projection display apparatus, comprising:

at least a light source, capable of emitting an illumination beam;
a polarization beam splitter, disposed in the optical path of the illumination beam and transmitting the illumination beam emitted from the light source;
a polarization changing device, disposed in the optical path of the illumination beam for changing the polarization direction of the illumination beam transmitted from the polarization beam splitter and reflecting the illumination beam back to the polarization beam splitter;
an optical uniformizing element, disposed in the optical path of the illumination beam and between the polarization beam splitter and the polarization changing device for uniformizing the illumination beam;
a light valve module, disposed in the optical path of the illumination beam, and converting the illumination beam reflected by the polarization changing device via the polarization beam splitter into an image beam transmitting to the polarization beam splitter;
and
a projection lens, disposed in the optical path of the image beam and projecting the image beam from the polarization beam splitter into a frame.

4 more elements

Dependencies are inferred from the claim text.