Wavelength plate, polarization conversion device using the same, illumination optical system, and image display apparatus

摘要

A wavelength plate includes: a first quartz plate unit including a plurality of quartz plates which have main surfaces disposed in the same plane and are jointed with each other; and a second quartz plate unit including a plurality of quartz plates which have main surfaces disposed on a main surface of the first quartz plate unit and are jointed with each other in a position different from a joint position of the first quartz plate unit.