Diaphragm control apparatus of interchangeable lens camera

An SLR camera comprising:

• a diaphragm control apparatus incorporated in a camera body of said SLR camera, to which an interchangeable lens equipped with a diaphragm apparatus is detachably attached, said diaphragm apparatus including a diaphragm operatively-associated rod for driving an adjustable diaphragm to open and shut said adjustable diaphragm, and said diaphragm control apparatus including a slide member that is driven to move said diaphragm operatively-associated rod,
• wherein said diaphragm control apparatus includes a diaphragm drive mechanism including a stepping motor and a lead screw which is driven to rotate by said stepping motor, wherein said slide member is moved by rotation of said lead screw;
• a position detector configured to detect an initial position of said slide member within a predetermined detection range;
• and a controller for adjusting an excitation phase of said stepping motor based on a stop position of said slide member detected by said position detector;
• and
• an elastic biasing member which biases said slide member in a direction toward an open-aperture movable limit position.