CHAPTER 4 LASER EXPOSURE SYSTEMCOPYRIGHT © 2002 CANON INC. 2000 CANON iR1600/iR2000 REV.1 JAN. 20024-42 Generating the Horizontal Signal2.1 OutlineThe laser emission start signal (horizontal sync) is used to direct laser light to the photo-sensitive drum. The sync signal is generated by the BD PCB based on the laser beam re-flected by the BD mirror mounted in the laser beam path.2.2 Signals Used[1] laser emission signal (LONO*). It is generated based on the BD input signal; laser isemitted when it goes ‘0’.[2] BD input signal (BDIN*). It goes ‘0’ upon detection of laser light.[3] horizontal sync signal. It is generated based on the BD input signal.[4] horizontal synch signal (BDO*). It is used to synchronize the video signals in laserscanning direction in laser scanning direction.[5] image data. It is read from image memory with reference to the horizontal sync signal.[6] video signal (VDO, VDO*). It is used to form an image on the photosensitive drum.
