REMOTE CONTROLLED REFRACTING CHART PROJECTOR

摘要

An ophthalmic refracting chart projector having rotary slide discs, the images on which are projected on a screen, having remote operating controls permitting selective showing of the slides in selectable sequence. The discs each define a plurality of slide apertures disposed peripherally around the disc and positionable one at a time in the optical axis of the projector. The discs are each interconnected to a driving motor for rotation and the control means of the motor is effective to cause continuous or incremental rotation in response to slide selection at a master keyboard. There is included multiplexing means dedicated to each of the switches of the keyboard for slide apertures, a free running counter to sample the state of the switches and latching means connected to the multiplexers for recording the state of the switches. Comparators responsive to the indication of the latches compare it to the relative position of the discs as indicated through an up/down counter, and supply the control circuit for the disc driving motors.