Apparatus the reflecting shutter principle and mechanical tachistoscopes

The principle employed in the two tachistoscopes described below is that of using a shutter which reflects light down one channel at the same time as it cuts it off from another. The principle has been applied to produce a high speed projection tachistoscope at a fraction of the cost of a comparable electronic model and a simple direct view classroom tachistoscope. The principle can be further adapted to a variety of uses.