PURPOSE: To improve the durability of an optical element by constituting the optical element of plural holding bodies and a deforming member held between the plural holding bodies and reducing the rigidity of the deforming member in the direction turned to the inside.
CONSTITUTION: The rigidity of the center part of the deforming member 5 is lower than that of a part close to the surface. When the deforming member 5 is constituted of two parts, a liquid substance or an elastic body with low rigidity can be used as a core part 5b. It is preferable to set up the rigidity of the outside elastic body 5a to 5×105dyne/cm2 or more and less than 1×108dyne/cm2. The rigidity of the inside core part 5b is preferably ≤5×105dyne/cm2 and ≥1×105dyne/cm2. Consequently, the durability of the optical element can be improved.
NOSE TETSUSHI
NAKAJIMA TOSHIYUKI
BABA TAKESHI
MATSUGI MASAKAZU
NIWA YUKICHI
