OPTICAL DEVICE

摘要

The invention relates to an optical device provided with transparent members such as glass and plastic, in which fogging is prevented effectively without degradation of the optical characteristic (transmissivity) of the transparent members. The optical device includes moisture-absorbing film (16) on the inner wall of a case (13) housing the transparent members (14, 15), rather than direct on the transparent members (14, 15). The film (16) absorbs moisture in the air within the case (13).