Canon LBP 2460 Service Manual - Page 71

CHAPTER 2 2. Operation When the power is switched ON, the printer enters WAIT mode. At the end of the WAIT mode, the DC controller sends the READY signal (/RDY) to the video controller to inform it that printer is ready to print. When the /RDY signal is "L" and data for a page is prepared, the video controller sends the PRINT signal (/PRNT) to the DC controller. When the DC controller receives the /PRNT signal, it starts the operation of the INITIAL ROTATIONS (INTR) period. At the end of the INTR period, the DC controller sends the VERTICAL SYNC REQUEST signal (/VSREQ) to the video controller. The video controller receives the /VSREQ signal, and sends the VERTICAL SYNC signal (/VSYNC) to the DC controller. When the /VSYNC signal is received, the print sequence is started. The video controller sends the VIDEO signal (VDO) synchronized with the HORIZONTAL SYNC signal (/BD) and VERTICAL SYNC signal (/VSYNC) from the DC controller to the laser driver through the DC controller. In response to the VDO signal, the laser driver switches the laser diode ON and OFF. The laser beam is scanned repeatedly across the photosensitive drum with the scanning mirror to form the latent electrostatic image of the original image. The latent electrostatic image on the photosensitive drum is transferred onto the paper in the electronic photographic process, and the paper is sent out through the face-down or face-up trays. When a page is being printed, the DC controller checks for other /PRNT or /VSYNC signals from the video controller. If none have arrived, the DC controller begins operation of the last rotations period (LSTR). At the end of this period, the printer enters standby (STBY) mode. If other /PRNT or /VSYNC signals arrive-during printing, the print sequence continues. The last rotations operation is performed and the printer enters standby mode. 2 - 25