公开(公告)号：CA2018071C

公开(公告)日：1995-06-27

申请号：CA2018071

申请日：1990-06-01

Applicant: IBM

Inventor： BUDD RUSSELL A ,  GIBSON BRUCE D ,  KANTOR SHERWOOD ,  OVERBY WAYNE A ,  STANICH MIKEL J

IPC: G02B26/10 ,  B41J2/44 ,  G02B27/00 ,  G03G15/04 ,  G06K15/12 ,  H04N1/053 ,  H04N1/113 ,  H04N1/12 ,  H04N1/19 ,  H04N1/191 ,  G03G13/04

Abstract: This is an electronic scheme for correcting for mechanical misalignment and chromatic aberrations from laser beam to laser beam in the scan direction of a multiple beam laser scanning system for use in an electrophotographic machine. Each beam is first corrected for mechanical misalignment and thereafter for chromatic aberrations. A reference laser beam produces two pulses near the start of scan (SOS) and two pulses near the end of scan (EOS). A non-reference laser beam then produces SOS and EOS pulses from which the mechanical misalignment is calculated. A gated clock is energized by the reference pulse and a tapped delay line is used for nanosecond resolution. After accomplishing correction for mechanical misalignment, chromatic aberrations are corrected by measuring the amount of total pel displacement of the non-reference scan line relative to the reference scan line and inserting appropriate delays at selected intervals throughout the non-reference scan in order to maintain pel placement accuracy to a desired tolerance.