Patent ID: 9134590
Filing Date: 2015-09-15
Classification: G02B,G03B

Abstract:
1. A camera body having a substantially circular opening formed in a front side thereof, a lens barrel being capable of being attached and detached to and from said opening and includes a plurality of circular-arc-shaped lens-side bayonet lugs which are provided at a rear end of said lens barrel and project toward an outer peripheral side, and wherein said camera body comprises: a plurality of body-side bayonet lugs which project from a peripheral edge of said opening toward an inner peripheral side and are concentric with said lens-side bayonet lugs, wherein said lens-side bayonet lugs are positioned immediately behind said body-side bayonet lugs when said lens barrel is mounted to said camera body; a plurality of circular-arc openings which are provided between said body-side bayonet lugs that are adjacent to one another, wherein said lens-side bayonet lugs pass through said circular-arc openings when said lens barrel is mounted to said camera body; a circular arc protrusion which is provided inside said camera body and projects forward, wherein a central portion of said circular arc protrusion in a lengthwise direction thereof is spaced, toward said inner peripheral side, from one of said circular arc openings, wherein both sides of said circular arc protrusion in said lengthwise direction are positioned at an inner peripheral side of two of said body-side bayonet lugs, respectively, and wherein said circular arc protrusion is concentric with said body-side bayonet lugs; a plurality of body-side contact portions which are provided on a front end surface of said circular arc protrusion and are arranged thereon in said lengthwise direction of said circular arc protrusion, wherein said body-side contact portions come into contact with lens-side contact portions which are provided on said lens barrel when said body-side bayonet lugs are positioned immediately behind said lens-side bayonet lugs; and two rearward biasers which are provided immediately behind two of said body-side bayonet lugs, respectively, to bias and move said lens-side bayonet lugs rearward, wherein two of said body-side contact portions which are located at both ends in said lengthwise direction and said two rearward biasers lie on radial-direction extension lines of said circular arc protrusion, respectively, as viewed in an optical axis direction.