US Patent No. 9,740,088

LIGHT SOURCE APPARATUS AND PROJECTION DISPLAY APPARATUS PROVIDED WITH SAME INCLUDING WAVEPLATE AND DICHROIC PRISM


Patent No. 9,740,088
Issue Date August 22, 2017
Title Light Source Apparatus And Projection Display Apparatus Provided With Same Including Waveplate And Dichroic Prism
Inventorship Takashi Ishikawa, Tokyo (JP)
Assignee NEC Display Solutions, Ltd., Tokyo (JP)

Claim of US Patent No. 9,740,088

1. A light source apparatus comprising:
a phosphor wheel provided with a plurality of ring-shaped light-emitting regions that are arranged concentrically and that
emit illumination light beams of a plurality of colors due to irradiation with excitation light;

a light source unit that emits said excitation light simultaneously to said plurality of ring-shaped light-emitting regions;
and

a plurality of optical elements into which are irradiated said plurality of illumination light beams that are emitted due
to the irradiation of said excitation light; wherein:

said light source unit radiates excitation light of a fourth wavelength and of a first polarization;
said plurality of ring-shaped light-emitting regions include: a first ring-shaped light-emitting region including a phosphor
region that emits illumination light of a second wavelength by being irradiated with said excitation light; and a second ring-shaped
light-emitting region including a phosphor region that emits illumination light of a third wavelength by being irradiated
with said excitation light and a diffusion-reflection region that diffuses and reflects illumination light of the fourth wavelength
by being irradiated with said excitation light;

said plurality of optical elements include: a first optical element into which illumination light of said second wavelength
is irradiated, and a second optical element into which illumination light of said third wavelength and illumination light
of said fourth wavelength are irradiated;

a wave plate that transmits said excitation light and a plurality of illumination light beams from said phosphor wheel is
provided between said light source unit and said phosphor wheel; and

a dichroic prism is provided on a light path between said light source unit and said wave plate that transmits said excitation
light from said light source unit, reflects illumination light of said second wavelength that is transmitted by said wave
plate toward said first optical element, and reflects illumination light of said third wavelength and illumination light of
said fourth wavelength that are transmitted by said wave plate toward said second optical element.