COPYRIGHT © 1999 CANON INC. CANON 660/2100 REV.0 FEB. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)Note:1. A color toner cartridge is assumed to have been taken out and put back in whenthe toner cartridge cover is opened. For the control mechanism to start when thecolor toner cartridge cover is closed, the right cover must be closed and, at thesame time, the black toner cartridge and the drum cartridge must be inside (so thatthe color toner cartridge cover may be checked).The black toner cartridge is checked by the black toner cartridge detecting switch.For the control mechanism to start, the right cover and the color toner cartridgecover must be closed and, at the same time, the black toner cartridge and the drumcartridge must be set inside.2. The right cover and the toner cartridge cover must be closed and, at the same time,the black toner cartridge and the drum cartridge must be set inside for the presenceof the drum cartridge to be recognized. (Otherwise, density correction control is notperformed.)C. Image Gradation Correction Control (requires a PS/PCLBoard)The DC controller PCB draws a density detection pattern for each color on the inter-mediate transfer drum using a developing bias and a primary charging bias determinedas a result of image density correction control using image data from the printer board(PS/PCL Board).Then, the DC controller PCB checks the density detection pattern using the densitysensor, and sends data to the printer board, which in response performs gradation cor-rection to ensure ideal halftone images.Image gradation correction control is started in response to a command from theprinter board, and is initiated after image density correction control.CHAPTER 4 IMAGE FORMATION SYSTEM4-22Download free service manual at http://printer1.blogspot.com
