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Variable Ribbon Advance for Matrix Printer

IP.com Disclosure Number: IPCOM000046946D
Original Publication Date: 1983-Sep-01
Included in the Prior Art Database: 2005-Feb-07
Document File: 2 page(s) / 31K

Publishing Venue

IBM

Related People

Feistel, CH: AUTHOR [+2]

Abstract

For the most effective use of a ribbon in a matrix printer, a presettable counter is used which is reset stepwise in proportion to the horizontal print displacement of the head and generates a ribbon advance pulse always after reaching the appropriate count. The figure schematically depicts the output port 1 of the matrix printer control. The output port 1 releases the print wire strobes via bus 2 and feeds a latch 3 via bus 4. The latch 3 is updated whenever new data is present at its input. The output 5 of the latch 3 is connected to a divide-by-N counter 6. Another input 7 to counter 6 feeds a pulse train proportional to horizontal displacement. Counter 6 is reloaded from latch 3 each time it overflows, i.e., each time 1/N of the displacement pulses lead to a zero count.

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Variable Ribbon Advance for Matrix Printer

For the most effective use of a ribbon in a matrix printer, a presettable counter is used which is reset stepwise in proportion to the horizontal print displacement of the head and generates a ribbon advance pulse always after reaching the appropriate count. The figure schematically depicts the output port 1 of the matrix printer control. The output port 1 releases the print wire strobes via bus 2 and feeds a latch 3 via bus 4. The latch 3 is updated whenever new data is present at its input. The output 5 of the latch 3 is connected to a divide-by-N counter 6. Another input 7 to counter 6 feeds a pulse train proportional to horizontal displacement. Counter 6 is reloaded from latch 3 each time it overflows, i.e., each time 1/N of the displacement pulses lead to a zero count. Upon each overflow of counter 6, it generates a ribbon advance strobe on its output line 8 for advancing the ribbon an appropriate amount. Since the ribbon advance rate data is carried with the wire image data, accurate real-time ribbon advance rate adjustments are possible as well as easy to accommodate. When the head is escaping across wide spaces and no printing takes place, the counter is stopped for zero ribbon advance. The described circuitry can also be used to generate velocity profiles of the ribbon stepper motor to get higher ribbon velocities without the need of a sophisticated control.

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