Theory of Operation 311Transfer Roller Assembly ControlDetecting the Installation of the Transfer Roller AssemblyThe CTD Sensor detects the installation of the Transfer Roller when power to theprinter is turned on, or the front cover is opened and closed.Light emits from the LED of the CTD sensor with the specified intensity and if theoutput of the CTD Sensor is greater than the specified value the controller signalsinstallation of the Transfer Roller.If printing is stopped by a jam, the toner image will be placed on the Transfer Roller.The this case the sensor output result is low, causing the controller to report thetransfer roller as missing. To prevent this, the Transfer Roller is rotated a half turn ifoutput is lower than the specified value. If the output of the CTD sensor is greaterthan the specified value, then the controller senses installation. If the output is lessthan the specified value, the controller senses the transfer roller is not installed.Detecting the Life of the Transfer Roller AssemblyThe Transfer Roller Assembly consists of a bias transfer roller and a waste tonerrecovery system. End of life of the Transfer Roller is detected when the tonerrecovery space becomes full.The full toner recovery space is detected by the Toner Full Sensor.1. Timing check for a full waste toner recovery space is: When the power is turned on. When the front cover is opened and closed. When paper exits the print engine.2. ìTransfer Roller is at End of Lifeî error message is received when the toner fullsensor detects the toner recovery space is full.3. ìReplace Transfer Roller î warning message is received if the print count and thetoner dispense time are counted and the total count exceeds 15,000 prints.
