HP Color 9850mfp Service Manual - Page 88

II UNIT EXPLANATION WRITE 2.2 Operation hp Color 9850mfp 2.2.1 Image writing The RGB image data from the CCD sensor is converted into digital data, individually, in the A/D converter board (ADB) and then, it is sent to the overall control board (OACB). The OACB converts RGB signals to YMCK signals with the image processing board (IPB). The converted YMCK signals are divided to the laser drive board Y, M, C, K (LDB Y, M, C, K) by the IPB. They are written on the drums for each color with laser light from the each laser drive board. [1] [2] [3] [1] Laser light [2] Polygon mirror [3] Drum 2.2.2 Color registration correction control In a black-and-white MFP, a transfer image formed on its drum is transferred onto paper directly; however, in this engine, a color image is split into 4 colors, yellow (Y), magenta (M), cyan (C), and black (K), the images for each color are formed on each dedicated drum, they are combined on the transfer belt (1st transfer), and then the combined image is transferred onto paper (2nd transfer). At the 1st transfer, the transfer locations for each color must be matched to prevent the color drift. This control is called the color registration correction control. 2-14