Drive mechanism for movable mirror of camera

摘要

A movable-mirror drive mechanism of a camera includes a main mirror held by a main-mirror holding frame rotatable between a viewfinder light-guiding position and a retracted position; a sub-mirror held by a sub-mirror holding frame that is rotatably supported by the main-mirror holding frame, wherein the sub-mirror holding frame is positioned in a jutting-out position when the main mirror is in the viewfinder light-guiding position, and the sub-mirror holding frame is retracted with the main mirror when the main mirror is in the retracted position; and a vibration control member which rotates in association with rotation of the main-mirror holding frame and holds the sub-mirror holding frame in the jutting-out position to prevent the sub-mirror holding frame from rotating toward the sub-mirror retracted position when the main mirror rotates to the viewfinder light-guiding position.

主权项

1. A movable-mirror drive mechanism of a camera, comprising:
a main mirror which is supported by a main-mirror holding frame and is driven to rotate between a viewfinder light-guiding position, in which said main mirror is positioned in a photographing optical path to reflect incident light, emanating from an object, toward a viewfinder optical system of said camera, and a retracted position, in which said main mirror is retracted from said photographing optical path to allow said object-emanating light to travel toward a photographic light-receiving medium; a sub-mirror which is supported by a sub-mirror holding frame that is supported by said main-mirror holding frame to be rotatable relative to said main-mirror holding frame, wherein said sub-mirror holding frame is positioned in a projecting position and said sub-mirror reflects part of said incident light emanating from said object in a direction different from a direction toward said viewfinder optical system when said main mirror is in said viewfinder light-guiding position, and wherein said sub-mirror holding frame is positioned in a sub-mirror retracted position and said sub-mirror is retracted with said main mirror from said photographing optical path when said main mirror is in said retracted position; and a vibration control member which rotates in direct response to rotation of said main-mirror holding frame, and holds said sub-mirror holding frame in said projecting position to prevent said sub-mirror holding frame from rotating toward said sub-mirror retracted position at least when said main mirror rotates to said viewfinder light-guiding position, wherein said main-mirror holding frame includes a gear and said vibration control member includes a gear, and said gears are engaged with each other so that a rotational force of said main-mirror holding frame is transmitted to said vibration control member via said gears.