PHOSPHOR WHEEL ILLUMINATION USING LASER LIGHT REFLECTIVE REGION

摘要

Image projection illumination apparatus and methods are provided. A color wheel has a blue laser light reflecting region and other regions respectively coated with different color light emitting phosphors. Blue laser light of a given polarization is directed by reflection or transmission by a blue laser light polarization selective filter through a polarization changing element with changed polarization onto the color wheel. When the color wheel reflecting region is aligned with the incident light, incident light is reflected back through the polarization changing element with further changed polarization by the other of reflection or transmission by the filter for image projection. When the other regions are respectively aligned with the incident light, the different color light is emitted by the phosphors along the light path for image projection. In a described embodiment, the reflecting region has a portion coated with at least one of blue, green and cyan color producing phosphor and an uncoated reflecting portion; and aligning the reflecting region with the incident light directs both reflects incident light and phosphor emitted blue, green and/or cyan color light for image projection.

主权项

1. An illumination apparatus for image projection, comprising:
a source of blue laser light; a movable color wheel having a blue laser light reflecting region and other regions respectively coated with different color light emitting phosphors; a filter having blue laser light polarization selective reflectance and transmittance properties; and a polarization changing element; wherein the source, color wheel, filter and polarization changing element are relatively positioned and configured so that:
blue laser light of a given polarization emitted by the source is directed by one of reflection or transmission by the filter through the polarization changing element and incident with changed polarization onto the color wheel;movement of the color wheel aligning the reflecting region with the incident light reflects incident light back through the polarization changing element and directs the reflected incident light with further changed polarization by the other of reflection or transmission by the filter along a light path for image projection; andmovement of the color wheel respectively aligning the other regions with the incident light emits the different color light by the phosphors along the light path for image projection.