ELECTRONIC TYPEWRITER

摘要

An electronic typewriter has a reduced number of electrically-powered actuators and comprises a motor powering a differential motion transmission unit having first and second output members. Transmission control means powered by a solenoid moves a slider to engage stop members selectively with the first and second output members to permit the second and first output members respectvely to rotate. The first output member drives the carriage transport mechanism. The second output member drives the character carrying element and also powers function devices, namely a correction device, through a motion switching mechanism controlled by a switch control mechanism including another solenoid. The typing ribbon feed is driven by reciprocation of the slider between its two states. The motor is mounted on the frame and drives the motion transmission unit on a carriage through a belt; it also drives a line spacing mechanism through a clutch operated by a further solenoid. The motor and solenoids as well as the print hammer are controlled by an electronic controlling arrangement. In alternative arrangements the motor is mounted on the carriage. A change mechanism controls the output of the motion switching mechanism so that it is applied to the correction device or to the line spacing device depending upon the direction of rotation of the motor. Instead of using a solenoid, the motion switching mechanism is engaged by a friction device driven from the first output member by driving the first output member backwards by one step. The motion switching mechanism is coupled to the line spacing device by a splined bar.