METHOD FOR MANUFACTURE OF REFLECTING MIRROR, REFLECTING MIRROR, ILLUMINATION DEVICE, AND PROJECTOR

摘要

An auxiliary reflecting mirror is manufactured by heating the central portion of a quartz glass tube and compressing the central portion by pushing two end portions of the quartz glass tube so that the wall thickness of the central portion thickens, accommodating the quartz glass tube after thickening the wall thickness of the central portion in a mold having inner surfaces formed to the reflecting surface shape, which is to be formed in an auxiliary reflecting mirror, and forming an expanded portion by expanding the central portion, of which the wall thickness was thickened, by introducing a gas from the two ends of the quartz glass tube, cutting the quartz glass tube in at least the central portion of the expanded portion, evaporating a reflecting film on the outer surface of the expanded portion and forming a reflecting surface.