Aperture control mechanism
AssigneeAsahi Kogaku Kogyo Kabushiki Kaisha
InventorsTetsuji Shono, Hiroshi Kurei
Life of this patent
Estimating the term…
Abstract
An abutment pin is provided for defining the fully open position of the aperture release member on an interchangeable lens. The aperture drive member on the camera is biased toward the abutment pin so that the rest position of the drive member will always correspond to a fully open aperture regardless of lens misalignment. The aperture stop down is then controlled by measuring the movement of the drive member from its rest, or start, position.
Claims7
In an interchangeable lens type single lens reflex camera of the type having a lens with aperture blades therein for defining a lens aperture, an aperture opening and closing ring for operating said aperture blades, and an aperture release member on said interchangeable lens, said release member being movable in first and second directions to drive said opening and closing ring to open and close said aperture blades, respectively, and an aperture drive member on said camera for controlling the position of said aperture release member, an aperture control mechanism comprising:
- stopper means for limiting the movement of said aperture release member in said first direction to thereby define a fully open aperture position of said aperture release member and a start position of said aperture drive member;
- means for moving said aperture drive member away from said start position;
- and
- control means for detecting the amount of movement of said aperture drive member from said start position and for stopping the movement of said aperture drive member to thereby stop said aperture release member at a position corresponding to a desired aperture.
Dependencies are inferred from the claim text.