Thermal printing method

US4887092A · kind A · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventors

• Wolfgang Pekruhn · Berlin, DE
• Ralf Kaiser · Erbenheim, DE
• Hartmut Kirchhoff · Berlin, DE

Key dates

• Filing date: Dec 7, 1988
• Grant date: Dec 12, 1989
• Expiry date: Dec 7, 2008

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B41J2/365
• WIPO field: Textile and paper machines
• WIPO sector: Mechanical engineering

Abstract

In a prior art thermal printing method, the heating elements of a thermal printing head are driven in such fashion that the temperature of each and every individual heating element is first measured individually and successively before this heating element is charged with a current pulse whose intensity of current is dimensioned dependent on the measured temperature. In order to increase the printing speed, the temperatures of all heating elements (R1 . . . Rn) are first successively measured in the novel method fo the present invention in every drive cycle and are extrapolated to isochronic cooling temperature values dependent on the cooling characteristic of the heating elements (R1 . . . Rn). The heating elements (R1 . . . Rn) are then charged with current pulses whose pulse durations are individually dimensioned for every heating element (R1 . . . Rn) dependent on the cooling temperature value calculated for this heating element (R1 . . . Rn).