International Business Machines Corporation

Gregory N Baker

Ludwig R Siegl

Delbert C Thomas, Jr

John E Bateson

Charles J Weber

Lee T Zimmerman

Earl T Brown

Hortensia E Delgado

Willard B Greene

A printer is provided with facilities for increasing the printing throughput. This involves a partial line turnaround operation. The printer has means to move a form or document past a print line, a ribbon drive assembly, and a print assembly incorporating a plurality of print wires arranged in print head groups, each group comprising a predetermined number of print wires. If, as an example, the print assembly has two, four, six, or eight print heads, each can accommodate eight wires in the embodiment described. The print wires are arranged in a slanted serrated pattern and provision is made herein to insure that the print heads move at least far enough to print their assigned character locations prior to the performance of any turnaround in individual lines being printed. Routine involves the accessing of tables stored in conjunction with a microprocessor, the tables indicating the optimum turnaround situations for the different print head configurations. In addition, an emitter is provided in the printer unit which has character emitters, margin emitters and other emitters as well as turnaround emitters that are used in conjunction with the turnaround decision making process to reverse direction of the print head assembly in order to start printing of a new line.

Partial line turnaround for printers

A microprocessor controlled printer includes a forms feed assembly, a dot matrix print assembly, a ribbon drive assembly and a number of emitter assemblies associated with the foregoing to provide positional information during operation of the printer which prints on a line-by-line basis. During the printing of characters, such as Kanji characters, extremely accurate control of dot placement is required. In order to achieve a balance between the operating cycle times of the microprocessor and the forms feed assembly, the microprocessor analyzes emitter pulses in two stages. One stage involves use of relatively low frequency emitter pulses for start-up, normal speed, and high speed operations. Another stage involves use of an additional emitter track that produces high frequency pulses utilized by the microprocessor during stopping conditions to achieve greater precision in final positioning of the forms.

Microprocessor controlled positioning system

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Boca Raton, FL, United States of America

Gregory N Baker