PC-D320/PC-D340/FAX-L400 Chapter 2: Technical Reference2-154.1 Laser/Scanner SectionThis section comprises a Laser unit, cylindrical lens, 4-faced polygon mirror, scanner motor,imaging lens, reflection mirror and BD sensor. The Laser is driven in accordance with the Laserdrive signals that are sent from the SCNT board. This Laser light passes through the cylindricallens to fall on the 4-faced polygon mirror that is rotating at a fixed speed. The Laser light isreflected from the 4-faced polygon mirror and passes through the imaging lens, and reflectsfrom the reflection mirror to scan the photosensitive drum in the toner cartridge.BD MalfunctionThe CPU on the ECNT board determines a BD malfunction if the /BDI signalis not detected within 0.1 second after the scanner motor is forcibly driven.Or, if the detected cycle of the /BDI signal has not reached the specified valuewithin 2 seconds after the scanner motor reached its specified rotationnumber.Laser/scanner unit MalfunctionIf the /BDI signal is not detected within 1.5 seconds after the scanner motor isforcibly driven, the CPU on the ECNT board extends the time to 120 seconds,the CPU determines a scanner malfunction.The Laser/scanner unit contains parts that require adjustment that cannotadjust in the field. Never disassemble the Laser/scanner unit.NOTE
