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Print Speed Doubler for Matrix Printers

IP.com Disclosure Number: IPCOM000050072D
Original Publication Date: 1982-Sep-01
Included in the Prior Art Database: 2005-Feb-10
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Bealle, FJ: AUTHOR

Abstract

Matrix printers normally print lines of text one at a time. The speed and density of printing is dependent on the energization period of the printhead wires and limited by the allowable power dissipation of the head.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 73% of the total text.

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Print Speed Doubler for Matrix Printers

Matrix printers normally print lines of text one at a time. The speed and density of printing is dependent on the energization period of the printhead wires and limited by the allowable power dissipation of the head.

Speed can be traded-off with density so it is possible to effectively double the effective printing speed of a given matrix printhead by reducing the character size and printing two lines at a time. With a 24-wire head, for instance, half size characters can be printed one above the other at 360 rather than 180 cps and still be legible.

To convert a normal matrix printer system to the double speed system proposed, no modifications to the printhead or other mechanical mechanisms are required. The logic is merely modified to permit completely different and independent characters in the upper and lower parts of any line. For instance, if the printhead is supplied with characters from read-only storage (ROS) character generator memory, then the ROS must be divided into two independent character sets - an upper and a lower set. The upper set typically would have all its half-size printing characters squeezed into the top half (for instance, the upper 12 positions for each full size matrix used in a 24-wire printhead) and only blank in the lower half.

The lower set would be the complement of the upper with half size characters in its lower half and blanks in its top half.

In a typical printing operation, characters w...