Patent ID: 7628497
Filing Date: 2009-12-08
Classification: G02B,G21K,Y10S

Abstract:
1. A mirror unit, comprising: a mirror with a multilayered film formed on a substrate, said multilayered film having two different materials periodically laminated in layers on the substrate; and a substrate deforming unit configured to produce deformation of a shape of the substrate; wherein, in the multilayered film, the number of laminated layers in a predetermined region of the substrate differs from that in another region of the substrate, wherein, with respect to deformations of the mirror, said substrate deforming unit is configured to correct a deformation of a predetermined period, and wherein, among the deformations of the mirror, a deformation of the mirror having a period smaller than the predetermined period is corrected based on making the number of laminated layers of the multilayered film in the predetermined region of the substrate different from that in another region of the substrate by an amount which corresponds to a product of a period of the multilayered film as multiplied by an integral number.