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AssigneeDurst AG Fabrik Fototechnischer Apparate
InventorFranz Obertegger
Estimating the term…
A light measuring apparatus for measuring the light transmitted through filters to a light sensor is equipped with a filter wheel having non light transmissive segments alternating with the light transmissive filters, which filter wheel is manually rotatable by a lever. By repositioning the lever through a certain angle, its motion is translated via a spring and various gears and additional transmission elements to rotate the filter wheel and periodically shield the light sensor. The shielding of the light sensor for short periods permits a determination of an error signal in the light measuring apparatus. To obtain a shielding time period above a required minimum independent of the speed with which the lever is moved, the motion of the filter wheel is automatically delayed by mechanical means.
A light shielding apparatus useable with a light measuring device having a light sensor for sensing the light to be measured, a circuit for generating an error signal upon shielding of the light sensor and for generating an output signal resulting from the light sensed by the light sensor and corrected by the error signal, said apparatus comprising in combination:
Dependencies are inferred from the claim text.