Electro-optical keyboard apparatus

A keyboard comprising a plurality of key assemblies (10) having a key lever (12) pivoting at one end (11), having a key button (16) attached, and having a code flag member (20) attached by flexible means to the opposite end of the key levers. The code flag members have bar coded indicia (40) and include an end portion (24) which engages a striker bar (14) when the key lever is depressed to flex the flexible means so that the code flag member is moved into a position adjacent to a sensing means (22) which includes a light beam (28) directed to a single photodetector (30). When fully depressed the end portion (24) slips off the striker bar (14) so that the code flag member "snaps" through the sensing assembly (22) thereby producing a series of pulses by the photodetector corresponding to the coded indicia for the actuated key assembly. When the actuated key assembly is manually released, the code flag member returns on a different path which does not go through the sensing assembly.