Jordan and Hamburg LLP
Projection system using a high-pressure discharge lamp adapted to d.c. lighting, and method of operating the same
This invention provides a method of operating a projection system wherein light emitted from a high-pressure discharge lamp being lit with d.c. lamp current is passed through color segments of a color filter sequentially and then reflected by an optical element to project an image on a screen, the color segments of the color filter including red, green and blue color segments and a color segment comprising a green ND filter having a relatively low lightness. The method includes making lower a crest value of the d.c. lamp current fed to the high-pressure discharge lamp for a first illumination period during which the color segment comprising the green ND filter is illuminated than a crest value of the d.c. lamp current fed to the high-pressure discharge lamp for a second illumination period during which any one of the other color segments is illuminated, in synchronism with the first illumination period.
Phoenix Electric Co., Ltd.
G G H
G03B G03B H04N
inventional inventional inventional
Atsuji Toshitaka
Nakagawa Fujii