SERIAL DOT PRINTER FOR OFFICE MACHINES

摘要

The printer comprises a solid or liquid ink jet head arranged to print one dot at a time on paper running over a platen. The head is carried by a carriage movable transversely with simple harmonic reciprocating motion. In order to reduce the effect of inertial forces when the carriage reverses its movement, the drive is effected by an eccentric peg on a disc, the peg engaging in a guide slot of the carriage perpendicular to the direction of reciprocation. An eccentric cam track in the disc engages a peg on a counterweight for counterbalancing the inertial forces of the carriage. In order to synchronize the printing operation with the carriage movement, an optical strobe disc is rigid with the disc and has slots disposed at a pitch varying according to the harmonic motion. The platen is rotated intermittently by a helical cam carried by the disc and a peg wheel. In order to compensate for discharge of a smoothing or reservoir circuit feeding the printing head, the duration of the pulses applied thereto can be increased in accordance with the rate at which dots are being printed. In a modification the strobe disc is replaced by a linear transducer of capacitive type, with one part carried by the carriage.