Patent Number: 8,511,919

Title: Light quantity adjustment device and image pickup apparatus including same

Abstract: A light quantity adjustment device includes: an aperture mechanism that varies an aperture opening through drive of aperture blades to restrict a quantity of light that passes through the aperture opening; and an ND filter inserted in and removed from an optical path on a light incident side or a light exit side of the aperture opening. The ND filter has a distribution of transmittance in which the transmittance differs in a direction of interposition of the ND filter in the optical path of the aperture opening, and includes a recessed portion formed by recessing a center portion of a distal-end region of the ND filter on a side of interposition in the optical path of the aperture opening in a direction opposite the direction of interposition.

Inventors: Abe; Hirofumi (Utsunomiya, JP)

Assignee: Canon Kabushiki Kaisha

International Classification: G03B 9/02 (20060101)

Expiration Date: 2021-08-20 0:00:00