Illumination optical system and projection type display apparatus using the same

摘要

In an illumination optical system comprising a light source unit, an integrator unit for homogenizing a luminous flux from the light source unit, and a light valve for modulating light from the integrator unit according to predetermined image information and outputting thus modulated light; effective luminous flux quantity adjusting means adapted to adjust a light quantity caused by an effective luminous flux on the light valve is disposed within or near the integrator unit.