Total reflection mirror for SLR camera - enables small shift of totally reflecting surface to be effective for direct electronic switching with min. vibration

摘要

A mirror-reflex system for single lens still or cinematographic cameras, has reduced vibration and noise on the switching over of the mirror and of the shutter action which may be linked with the mirror movement, permitting a direct electronic control of the double function. The reflection is effected through total reflection over an adequate range of angles of incidence in a switched beam splitter, consisting of a pair of prisms (1, 2) with a gap between them of the order of the wavelength of the longest light wave to be covered filled with a non-absorbing medium (3). The closing of the gap is effected by a system (4) actuated from a control unit (5) fed from a power source (6) and having the necessary timing facilities.