公开(公告)号：BR9003727A

公开(公告)日：1991-09-03

申请号：BR9003727

申请日：1990-07-31

Applicant: IBM

Inventor： BUDD RUSSELL ALAN ,  GIBSON BRUCE DAVID ,  KANTOR SHERWOOD ,  OVERBY WAYNE ARLAN ,  STAINICH MIKEL JOHN

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

Abstract: This is an electronic scheme for correcting for mechanical misalignment (41) and chromatic aberrations (42) 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 correctected 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.