Patent · US Expired

Method of improving the printing speed of an impact dot printer printing in a near letter quality mode

US4969758A · kind A · utility

18Cited by
1References
3Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 15, 1989
Grant dateNov 13, 1990
Priority date
Expiry dateMar 15, 2009

Classification

  • Technology area (CPC B)Performing Operations; Transporting
  • CPC primaryB41J2/5056
  • WIPO fieldTextile and paper machines
  • WIPO sectorMechanical engineering

Abstract

A method of operating an impact printer having a printhead normally intended to create letter quality characters during one pass across the printing medium at a carriage speed at least three times slower than the carriage speed at which the printer creates draft quality characters wherein the method of operation produces letter quality characters at least 50% faster than the prior art method of operation. To accomplish the throughput increase, the printer is operated in the same faster draft speed for the printing of both draft and letter quality characters. Letter quality characters, however, are created in two passes and the printing medium is not advanced to a next row position until after the two passes. During the first pass, the carriage is moved across the printing medium while printing one of each pair of horizontally close adjacent dots includes in the vertical strokes of the characters comprising a row of characters and a portion of other dots included in the row of characters. During the second pass, the other of each pair of horizontally close adjacent dots included in the vertical strokes of the characters comprising the said row of characters and any remaining unprint…

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.