Patent ID: 6445887
Filing Date: 2002-09-03
Classification: G03B

Abstract:
A viewfinder for a camera with an adjustable diopter, said camera having a body frame and a taking lens, said taking lens having an optical axis which defines a longitudinal axis of said camera, said viewfinder comprising:an objective lens mounted on said body frame and having an optical axis extending parallel to said longitudinal axis; an eyepiece lens mounted on said body frame and having an optical axis extending parallel to said longitudinal axis; a focusing screen mounted on said body frame and having a surface on which an object image is formed through said objective lens; a light-rays-directing optical system mounted on said body frame, for causing light rays from said object image to be directed in a first direction parallel to a predefined transverse axis extending transversely with respect to said longitudinal axis; a first reflective optical element for receiving light rays from said object image and reflecting and directing the received light rays in a second direction opposite to said first direction parallel to said transverse axis; a first mechanism for supporting and guiding said first reflective optical element for linear displacement relative to said body frame and along said transverse axis; a second reflective optical element mounted on said body frame for receiving light rays from said first reflective optical element and reflecting and directing the received light rays in a direction parallel to said longitudinal axis and toward said eyepiece lens; a control knob provided for operation by a camera operator; and a second mechanism for responding to operation of said control knob by causing linear displacement of said first reflective optical element along said transverse axis so as to change optical distance between said focusing screen and said eyepiece lens to achieve adjustment in diopter of said viewfinder.