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Print Hammer Firing Technique

IP.com Disclosure Number: IPCOM000061724D
Original Publication Date: 1986-Sep-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 2 page(s) / 48K

Publishing Venue

IBM

Related People

Carrington, JE: AUTHOR [+4]

Abstract

Hammer energization in a printer having a band of characters of constant pitch can be adapted for subscan operation with a plurality of optional hammers by incorporating individual hammer firing pulse delays to compensate for the serial comparing sequence necessary between a band image buffer and print line buffer. Referring to the figure, in a printer having a moving print band 1 with embossed characters 2 at constant pitch, a plurality of hammers 3 are optioned or concurrently aligned with respective characters for printing. Because the band 1 is constantly moving and the hammers 3 require flight time to reach the band, the hammers must be selected and energized with respect to a timing mark 4 a predetermined time before the desired character 2 arrives at the point of impact.

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Print Hammer Firing Technique

Hammer energization in a printer having a band of characters of constant pitch can be adapted for subscan operation with a plurality of optional hammers by incorporating individual hammer firing pulse delays to compensate for the serial comparing sequence necessary between a band image buffer and print line buffer. Referring to the figure, in a printer having a moving print band 1 with embossed characters 2 at constant pitch, a plurality of hammers 3 are optioned or concurrently aligned with respective characters for printing. Because the band 1 is constantly moving and the hammers 3 require flight time to reach the band, the hammers must be selected and energized with respect to a timing mark 4 a predetermined time before the desired character 2 arrives at the point of impact. The selection of the print hammers to be fired is made by comparing an image of the band characters serially with the characters desired for the print position. For each subscan, in which all aligned hammers of a group will be checked, this electronic comparison is done serially, thus necessitating a slightly different selection time for each hammer. Hammer firing is done accurately, however, by inserting delay circuit 5 in the energization circuit of each hammer and providing an amount of additional firing signal delay corresponding to the hammer position in the series of comparisons with a subscan. Thus, in addition to the hammer flight time required of all...