发明名称 Light amount control device and optical apparatus with guard portion to protect ND filter from lever member
摘要 Provided is a light amount control device eliminating a deviation in image forming position over the entire area of the variable range of an aperture due to an ND filter and assuring smooth stopping operation. The light amount control device of the present invention includes: a first shading member and a second shading member which are adapted to move within a plane perpendicular to an optical axis to vary an area of a light passage opening; a lever member which is connected with the first shading member and the second shading member and which is rotatable; an actuator for driving the lever member; and an ND filter mounted to the first shading member. The ND filter is configured to cover an entirety of the light passage opening in an open state, and the second shading member has a guard portion which, with the light passage opening being in a closed state, is arranged between the lever member and the ND filter, preventing the ND filter from coming into contact with the lever member.
申请公布号 US7172349(B2) 申请公布日期 2007.02.06
申请号 US20050042310 申请日期 2005.01.24
申请人 CANON KABUSHIKI KAISHA 发明人 MIYAKAWA MASAE
分类号 G03B9/04;G03B9/08;G03B9/02;G03B9/36;G03B9/40;G03B17/04 主分类号 G03B9/04
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