Light amount adjustment apparatus and image pickup apparatus

An image pickup apparatus, comprising:

• a lens barrel having a predetermined lens group disposed inside;
• an apparatus body configured to support said lens barrel;
• and
• a light amount adjustment apparatus incorporated in said lens barrel and configured to adjust the amount of light fetched through said lens group;
• said light amount adjustment apparatus including
• a light amount adjustment member configured to be operated in a predetermined direction to adjust the amount of light transmitted through a lens group,
• a rotatable magnet formed in a disk shape,
• a driving arm configured to be pivoted by rotation of said magnet to operate said light amount adjustment member,
• a core having a pair of confronting portions positioned so as to sandwich said magnet from an outer circumference side and a connecting portion configured to connect end portions of said confronting portions to each other,
• a coil through which one of said confronting portions of said core extends, and
• a base member having said core attached to said base member and supporting said magnet for rotation on said base member,
• said base member having a plurality of attaching projections provided at least at two places of said base member for attaching said core to said attaching projections, and
• said attaching projections having a small projection for fitting with said core.