Light quantity adjustment device and image pickup apparatus including same
US8511919B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Feb 6, 2012 |
| Grant date | Aug 20, 2013 |
| Priority date | — |
| Expiry date | Feb 6, 2032 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B11/00
- WIPO fieldOptics
- WIPO sectorInstruments
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.