Canon Kabushiki Kaisha

Yukiharu Ono

Yasuhisa Sato

Akira Tajima

An optical system for forming a view-finder image in combination with an image of exposure condition indicia as applied to a cinematographic camera includes a first image plane at which a focusing screen lies with the exposure condition indicia located at a desired large distance from the finder field of view, and a prism positioned ahead of a second image plane at which both the images are erected, and oriented so that the image of the indicia can be seen immediately adjacent the finder field of view by a photographer looking through an ocular of the system.

Photographic camera with an image of exposure condition indicia visible

In the disclosed camera, an SLR viewfinder displays exposure conditions by means of a translucent indicia carrier adjacent the focusing plate which defines the field of view of the finder. A light source illuminates the translucent indicia carrier and its light is passed by suitable lenses to a viewer. Ghost images of the indicia indications, which might be caused by indicia image light beams being internally reflected by the plate and lenses, are effectively eliminated by an optical deflector that orients light from the source along an optical axis parallel to or away from the light passing through the focusing plate's field of view. According to one embodiment of the invention, the light deflector is a prism. According to another, it is a mirror.

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Yokohama, Japan

Yukiharu Ono