Process for controlling the operation of a print head

US5219233A · kind A · utility

Assignee

• Siemens Nixdorf Informationssysteme AG · DE

Inventors

• Ralph Bauerle · Berlin, DE
• Dietmar Kottwitz
• Michael Blume · Jena, DE
• Joachim Schwarzkopf · Geesthacht, DE

Key dates

• Filing date: Sep 11, 1991
• Grant date: Jun 15, 1993
• Expiry date: Sep 11, 2011

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B41J19/202
• WIPO field: Textile and paper machines
• WIPO sector: Mechanical engineering

Abstract

A process for controlling the operation of a printing head detects defects in the transport of the printing head along a printed line and if necessary corrects them. A control unit (24) controls a current source (16) which supplies current to a transport motor (12) which moves the printing head (10). The printing elements (14) of the printing head (10) are supplied with pulsed drive current (ID) by a driver component (18). A position indicator (20) records the distance travelled by the printing head (10) along a printed line. According to the invention, the transport time between two printing positions is monitored to detect whether a limit value (G) is exceeded. If the limit value (G) is exceeded, the drive of the printing head (10) is stopped and if necessary the printing head is moved in the opposite direction and/or at least one printing element (14, 15) is operated with less energy that that required for printing. As a result of these measures, a defect due to adhesion of a printing element (14) to a printing ribbon can be detected and eliminated automatically.