US Patent No. 9,140,969

ILLUMINATION OPTICAL SYSTEM AND PROJECTOR USING THE SAME


Patent No. 9,140,969
Issue Date September 22, 2015
Title Illumination Optical System And Projector Using The Same
Inventorship Hiroyuki Saitou, Tokyo (JP)
Assignee NEC DISPLAY SOLUTIONS, LTD., Tokyo (JP)

Claim of US Patent No. 9,140,969

1. An illumination optical system comprising:
a light source that generates excitation light;
a fluorescent body that generates fluorescent light by irradiation with the excitation light and that is disposed in a region
wider than an irradiation spot of the excitation light;

a plate in which the fluorescent body is disposed; and
a driving mechanism that moves the plate so that the irradiation spot of the excitation light can intermittently move over
the fluorescent body,

wherein timing of moving the irradiation spot of the excitation light with respect to the fluorescent body is set based on
a service life of the fluorescent body.