Type disc typewriter with electronic positioning control

摘要

Keyboard generated signals are digitally encoded and converted to varying voltages for application to a coil for generating magnetic forces. The magnetic forces act on a spring mass system including a type disc to rotate the type disc to a selected angular position. The rest position of the disc at any selected angular position is established when the applied magnetic force and the force of an oppositely acting spring reach equilibrium condition. The spring stores or releases energy according to whether the applied magnetic force is greater or less than the existing spring force. The parameters of the system are so chosen that movement from one angular position of rest to another is smoothly accomplished in a given time.