Patent ID: 7453623
Filing Date: 2008-11-18
Classification: G02B,G03F

Abstract:
1. A mirror apparatus comprising: a mirror including a rear surface and a reflecting surface configured to reflect light; a partition member defining a plurality of gas chambers on a side of the rear surface of the mirror, a part of the rear surface, the part being one of a plurality of parts divided within an effective diameter range of the mirror, forming a part of an inside surface of the plurality of gas chambers; a regulator regulating gas pressure in each gas chamber in order to apply a deformation force to the part of the rear surface; a measuring unit configured to measure the gas pressure in each gas chamber; and a measuring unit configured to measure gas pressure outside of the gas chambers, wherein the gas pressure in each gas chamber is regulated so as to control differential pressure between the gas chambers and the outside of the chambers in order to deform the shape of the mirror.