COPYRIGHT © 1999 CANON INC. CANON 660/2100 REV.0 FEB. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)Note:1. Sampling ModeIn APC control, when the LENB* signal is ‘0’ and the SAMPLE* signal is ‘0’ (i.e., theunblanking signal UBLON used to generate the SAMPLE* signal is generated bythe GA), the DATA* signal is forced to go ‘0’.2. Hold/Print ModeIn this mode, the laser intensity resulting from APC control is retained. When theSAMPLE* signal is ‘1’ and the LENB* signal is ‘0’, C1004 retains the laser intensityin the form of a voltage without regard to DATA* signals.When video signals are received, the laser diode is turned on and off according tothe DATA* signals.3. Clear ModeWhen the LENB8 signal is ‘1’, the C1004 is discharged without regard to DATA sig-nals* and SAMPLE* signals.D. Horizontal Sync ControlThe optical path for the laser beam is equipped with a small fixing mirror (BD mirror).The laser beam reaching the scan start position during the unblanking period is reflect-ed by the BD mirror and directed to the BD PCB inside the laser/scanner assembly.When the laser beam arrives, the BD PCB generates BD signals (BD*) for transmis-sion to the GA (IC204) on the DC controller PCB. The GA uses the BD* signals to gen-erate horizontal sync signals (LSYNC*), and sends them to the printer board.*1*1 Reader controller PBC (when making prints with the reader unit installed).CHAPTER 3 LASER EXPOSURE SYSTEM3-7Download free service manual at http://printer1.blogspot.com
