International Business Machines Corporation

Cameron H Hafer

Frank Marion Hughes

Walter Crooks

John A Thompson

Clayton V Wilbur

William J Weiche

Vencil D Engle

Donald J Steger

Ramon L Street

Edward G Stewart

A thermal printer (10) has a thermal transfer medium (28) fed past a thermal printhead (21) at a substantially constant velocity by a feed roll (82) engaging the thermal transfer medium just prior to the printhead to maintain a portion of the thermal transfer medium between the printhead and the feed roll relatively stiff. The feed roll is mounted on a cartridge (30) having the thermal transfer medium supplied therefrom. A drag brake (70) is disposed in the feed path of the thermal transfer medium prior to the feed roll to cause a substantially constant premetering tension to be applied to the thermal transfer medium irrespective of the coefficient of friction between the drag brake and the thermal transfer medium. A carrier (14), which supports the printhead and a feed roll driver (90), is driven separately from the feed roll driver so that various ratios between the velocities of the thermal transfer medium and the carrier are obtained to produce various print qualities. One print quality occurs in a draft mode, which is a relatively high speed, in which there is substantial conservation of the thermal transfer medium. The peel angle of the thermal transfer medium from a recording medium (12) on which printing occurs is maintained at a relatively low angle to increase the contact time between the thermal transfer medium and the recording medium.

Thermal printer

A printing apparatus employing a print head comprising a plurality of thin wire print electrodes mounted in a single plane and held in a closely-spaced row by an electrically insulating resilient material so that the wires are individually movable out of the planar alignment to a limited extent with respect to the other wires in the array. A relatively rigid backing member is provided to support the electrode array and the print head is mounted in a relatively fixed position relative to the print ribbon and a predetermined pressure is produced between the print head and the electrothermal print ribbon during printing operations.

Print head for high resolution electrothermal printing apparatus

Electrothermal printing apparatus includes a thin, planar, endless ribbon of electrically resistive material having a thin conductive layer on an outside surface thereof and a row of spaced-apart, conductive styli individually selectively coupleable to the conductive layer through a voltage source and disposed in contact with the ribbon at the inside surface thereof opposite the conductive layer. Momentarily coupling selected ones of the styli to the voltage source produces heating of discrete areas of the resistive ribbon adjacent the momentarily coupled styli. The ribbon which is mounted on one or more rollers moves relative to the styli and in the same direction and at the same speed as an adjacent length of thermally sensitive paper so that discrete areas of the ribbon heated by the styli remain in contact with the thermally sensitive paper long enough to color discrete areas of the paper adjacent the heated discrete areas of the resistive ribbon.

Electrothermal printing apparatus

Growing community of inventors

San Jose, CA, United States of America

Cameron H Hafer