Dell 2145cn, Service Manual

Page: 35 / 210

Product spec and feature
2-24
17) Scan Part
1) Pictorial signal input part : output signal of CCD passes through MP Cap change to AFE, and defined
signal between AFE and Image Processor processes the Image signal. When AFE accept each pixel,
CDS(Correlated Double Sampling ) technique which samples arm-level twice is used on each pixel by using
IP signal.
2) Pictorial image processing part : read CCD Pixel data in terms of 600dpi Line and process Error
Diffusion Algorithm on Text mode and Photo mode, and then store Data at Scan Buffer on PC Scan mode
without algorithm.
On every mode Shading Correction and Gamma Correction are executed ahead, then processing is
executed later.
* Scan Image Control Specification
1. Minimum Scan Line Time: 0.36ms for Copy.
2. Scan Resolution : Max. 600DPI
3. Scan Width : 216mm
4. main function
- Internal 12 bit ADC
- White Shading Correction
- Gamma Correction
- CCD Interface
- 256 Gray Scale
3) CCD Operating Part : CCD Image sensor use +5V and Inverter uses +24V
- CCD Maximum Operating Frequency : 12MHz
- CCD Line time : 0.36ms for Copy.
- White Data output Voltage : 0.7V 0.5V ( Copy, 0.36ms/line)
- Maximum Inverter Current : 600 mA Max.( +24V)