US Patent No. 10,117,312

LIGHT SOURCE DEVICE, PROJECTION DISPLAY DEVICE, AND LIGHT SOURCE CONTROL METHOD


Patent No. 10,117,312
Issue Date October 30, 2018
Title Light Source Device, Projection Display Device, And Light Source Control Method
Inventorship Kenji Suzuki, Tokyo (JP)
Takashi Kaido, Tokyo (JP)
Assignee NEC DISPLAY SOLUTIONS, LTD., Tokyo (JP)

Claim of US Patent No. 10,117,312

1. A light source device comprising:an excitation light source unit that emits excitation light;
a phosphor wheel unit that includes a wheel that produces fluorescence by said excitation light and that, by rotating the wheel, changes a position on the wheel that is irradiated by said excitation light;
a detection unit that detects rotation of said wheel; and
a control unit that, on the basis of the detection result of said detection unit and the fluorescence characteristic of said wheel, changes an intensity of said excitation light such that a change in intensity of the fluorescence emitted by the wheel during one rotation of the wheel is reduced,
wherein said control unit changes the intensity of said excitation light by changing a drive voltage that is supplied to said excitation tight source unit and
wherein said excitation light source unit supplies a feedback voltage that accords with the intensity of said excitation light to said control unit, and
said control unit comprises:
an alternating-current voltage generating unit that generates an alternating-current voltage on the basis of said detection result and said fluorescence characteristic;
a superposing unit that supplies a superposed voltage in which said alternating-current voltage is superposed on said feedback voltage; and
a power supply unit that supplies voltage whose magnitude accords with said superposed voltage as said drive voltage.