Camera with pin registration for film and end-of-film indication means

摘要

A standard 35mm single lens reflex camera is modified to include a pair of film frame registration pins located in the hinged rear cover plate, these pins being movable toward film covering the film aperture, with the ends of the pins being tapered to readily enter a pair of sprocket holes on opposite sides of each frame of film, for precisely registering the position of each frame with the film aperture. The registration pins engage the film before and during each exposure, and are retracted before each advancement or rewinding of the film. Also located on the camera's rear cover plate is a spring-biased indicator pin extending toward the film, and aimed directly at an electrical ground contact on the film guide. This indicator pin is blocked from contacting the ground by the top edge of any film present, but when the top edge of the film is not present, as during the last phase of re-winding or when there is no film in the camera, the indicator pin will automatically reach the electrical contact, thereby closing a circuit and turning on an indicator light.