Lighting optical system for a projection display apparatus

摘要

The structure of the present invention makes dark lines due to a central axis of a cross dichroic prism sufficiently inconspicuous. A stepped reflecting mirror 150 is interposed between a second lens array 130 and a condenser 160. The stepped reflecting mirror 150 has the function of deviating the optical path of part of the partial light fluxes among a plurality of partial light fluxes passing through a plurality of small lenses aligned on the same column in lens arrays 120 and 130 from the optical path of the other partial light fluxes. A planar transparent member may be used in place of the stepped reflecting mirror 150 for the purpose of deviating the optical path. Another technique shifts part of rows in the lens arrays 120 and 130 to deviate the optical path of part of the partial light fluxes.