Patent ID: 8547038

Claim:
A high-pressure discharge lamp lighting device in operative connection with a color wheel and a discharge lamp, comprising: an electric power detection circuit that detects a supply power supplied to the discharge lamp for each segment that corresponds to a rotation angle of the color wheel; and a control circuit that includes: a sampling circuit for sampling the supply power, a memory that stores results of sampling the supply power, a mean power calculator that calculates the mean power at a designated duration based on the results retained in the memory, and a power control part that controls a feedback supply power to the discharge lamp based on the mean power, wherein sampling the supply power follows a sampling cycle set to Ts>Tc/C and Ts≠N×Tc, wherein N is a whole number, Ts is the sampling cycle, C is a total number of segments of the color wheel, and Tc is a cycle for scanning of all the segments of the color wheel.