US Patent No. 9,888,220

LIGHT SOURCE DEVICE, PROJECTION-TYPE DISPLAY DEVICE, AND LIGHT GENERATION METHOD


Patent No. 9,888,220
Issue Date February 06, 2018
Title Light Source Device, Projection-type Display Device, And Light Generation Method
Inventorship Shinichiro Chikahisa, Tokyo (JP)
Assignee NEC DISPLAY SOLUTIONS, LTD., Tokyo (JP)

Claim of US Patent No. 9,888,220

1. A light source device comprising:
a yellow phosphor that emits yellow fluorescence excited by exciting light;
an exciting laser light source that emits blue exciting laser light as the exciting light;
a red laser light source that emits red laser light;
a first light combining unit that generates first composite light by combining the emitted yellow fluorescence with the emitted
red laser light;

a blue laser light source that emits blue laser light;
a second light combining unit that generates second composite light by combining the combined first composite light with the
emitted blue laser light; and

a filter that filters out light having a predetermined wavelength from the combined second composite light,
wherein the first light combining unit emits the emitted exciting laser light to the yellow phosphor and combines yellow fluorescence
emitted in the yellow phosphor by the emitted exciting laser light with the red laser light, and

wherein the first light combining unit comprises:
a first dichromic mirror that reflects the emitted red laser light in a combining direction and lets the yellow fluorescence
emitted from the yellow phosphor in the combining direction pass therethrough; and

a second dichromic mirror that reflects the emitted exciting laser light toward the yellow phosphor and lets the red laser
light and the yellow fluorescence from the first dichromic mirror pass therethrough in the combining direction.