Position controller for removable optical element

摘要

A position controller for a removable optical element in an optical system includes an advancing/retracting ring; a removable optical element holding member supported by the advancing/retracting ring and rotatable about a first rotational axis between an insertion position on the optical axis and a removed position; an insertion holder which holds the removable optical element holding member at the insertion position; a removal drive member supported by the advancing/retracting ring and rotatable about a second rotational axis between an insertion allowance position and a forced removing position; and an insertion/removal controller. A rotational radius from the second rotational axis to a contact point between the removable optical element holding member and the removal drive member is greater than a rotational radius from the first rotational axis to the contact point.

主权项

1. A position controller for a removable optical element provided in a photographing optical system which moves between a ready-to-photograph state and an accommodated state in which no pictures are taken, comprising:
an advancing/retracting ring movable in an optical axis direction of said photographing optical system, wherein said advancing/retracting ring is moved between a first position at which said photographing optical system is in said ready-to-photograph state and a second position at which said photographing optical system is in said lens barrel accommodated state; a removable optical element holding member which holds said removable optical element and is supported by said advancing/retracting ring therein to be rotatable about a first rotational axis, which is parallel to said optical axis, between an insertion position at which said removable optical element is positioned on said optical axis and a removed position at which said removable optical element is removed from a position on said optical axis; an insertion holder which holds said removable optical element holding member at said insertion position when said photographing optical system is in said ready-to-photograph state; a removal drive member which is supported by said advancing/retracting ring to be rotatable about a second rotational axis that is substantially parallel to said optical axis between an insertion allowance position at which said removal drive member is in noncontact with said removable optical element holding member at said insertion position and a forced removing position at which said removal drive member comes in contact with and presses said removable optical element holding member to rotate said removable optical element holding member from said insertion position to said removed position; and an insertion/removal controller which holds said removal drive member in said insertion allowance position when said photographing optical system is in said ready-to-photograph state, and rotates said removal drive member from said insertion allowance position to said forced removing position when said advancing/retracting ring moves in said optical axis direction from said first position to said second position, wherein a first distance from said second rotational axis of said removal drive member to a contact point between said removable optical element holding member and said removal drive member is greater than a second distance from said first rotational axis of said removable optical element holding member to said contact point, and wherein said first rotational axis of said removable optical element holding member and said second rotational axis of said removal drive member are spaced apart from each other.