Patent ID: 8243378
Filing Date: 2012-08-14
Classification: G02B

Abstract:
1. A holding apparatus for holding an optical element, the apparatus comprising: a barrel having a hole on a side thereof and housing the optical element; a first member having one end connected to the barrel, and an opposite end located apart from the one end in a direction perpendicular to an axis of the barrel and outside the barrel; a second member passing through the hole and having one end connected to the opposite end of the first member, and an opposite end located apart from the opposite end of the first member in the direction and inside the barrel, wherein a linear expansion coefficient of the barrel, a linear expansion coefficient of the first member, a linear expansion coefficient of the second member, a dimension of the barrel in the direction, a dimension of the first member in the direction, and a dimension of the second member in the direction are configured so that the opposite end of the second member is in contact with a side of the optical element, and an amount of displacement of the side of the optical element and an amount of displacement of the opposite end of the second member due to a change in temperature correspond to each other, and wherein the linear expansion coefficient of the barrel is smaller than the linear expansion coefficient of the optical element; the linear expansion coefficient of the first member is larger than the linear expansion coefficient of the optical element; and the linear expansion coefficient of the second member is smaller than the linear expansion coefficient of the optical element.