Apparatus for stopping down diaphragm to an intermediate setting, upon

Abstract

A diaphragm apparatus of lens includes diaphragm opening and closing ring and a diaphragm supporting ring for supporting a plurality of diaphragm blades and for opening and closing a diaphragm aperture in accordance with the relative rotation of the diaphragm blades. A diaphragm value setting ring sets a diaphragm value. A releasing member is actuated upon a release of a shutter to rotate the diaphragm opening and closing ring to thereby stop-down the latter. A cam mechanism operates in association with the rotation of the diaphragm value setting ring to restrict the angular displacement of the diaphragm opening and closing ring into the stopping-down direction, and a stopping-down mechanism rotates the diaphragm supporting ring into the stopping-down direction in association with the rotation of the diaphragm value setting ring in a first angular range from a full open position of the diaphragm value setting ring to a predetermined intermediate diaphragm value thereof. A diaphragm data transmitting member, that is separate from the diaphragm value setting ring, transmits diaphragm value data to a camera body side. An associated mechanism that is provided between the diaphragm value setting ring and the diaphragm data transmitting member maintains the diaphragm data transmitting member to a predetermined position in the diaphragm range in which the diaphragm aperture changes, regardless of an angular position of the diaphragm value setting ring.