Patent ID: 8730597
Filing Date: 2014-05-20
Classification: G02B

Abstract:
1. A holding apparatus configured to hold an optical member, the holding apparatus comprising: a holding member configured to hold the optical member and including a contact surface that contacts with a projection portion of the optical member; and a structure supporting the holding member, wherein the contact surface inclines relative to a plane orthogonal to an optical axis of the optical member, wherein an inclination angle of the contact surface relative to the plane is set so that a relative position of an optical surface of the optical member to the structure is kept constant in a direction parallel to the optical axis when the optical member shrinks or expands, wherein the inclination angle is set based on at least one of a thermal expansion coefficient of the optical member, a shape of the optical member, a thermal expansion coefficient of the holding member, or a shape of the holding member, and wherein a following equation is satisfied: where α