CCD, an acronym
for "Charged Coupled Device", is the key component inside your scanner
for light-sensing. It contains an array of photosensitive cells
that react to incoming light based on its properties, such as intensity
and color. During the scanning process, CCD will first capture the
incoming light (via an optical lens) and then generate various analog
signals to "reflect" the incoming light properties. For further
information regarding analog signal, please click Here.
Most scanners sold on the market today utilize CCD as their light-sensing
device. This type of scanner provides better color saturation.
CIS, an acronym for "Contact Image Sensor", has the same function
as a CCD accept it does not require the use of an optical lens to
concentrate the light source and is smaller in size.
Scanners sold on the market today that appear to be "slimmer" than
usual, such as Mustek Plug-N-Scan 1200 CP, utilize CIS as their
light-sensing device. This type of scanner provides a sharper image
A/D Converter, short for Analog / Digital Converter, is a component
inside your scanner that converts the analog signals generated by
the CCD or CIS into digital signals. The conversion from analog
signals to digital signals is crucial for your computer.