CIS

CIS stands for "Contact Image Sensor" and is a low cost sensor technology, mostly used in smaller desktop scanners. The CIS element uses or contains a LSI/SMD (large scale integration/surface mount device) of red, green and blue LEDs to produce white light and only one or two rows (rectangle) of sensor pixels. The pixels and LEDs are placed very close to the document to be scanned.

The advantages over CCD (charge coupled device) or CMOS (complementary metal oxide semiconductor) devices or cameras are that the CIS is more energy efficient, easier to manufacture with good image capture. Using CIS arrays eliminates the need for mirrors and lenses that a CCD or CMOS scanner camera uses. No lens alignment is necessary.

Overall comparison:

• CCD: costs more, best image quality
• CMOS:  costs less than CCD, image quality not as good as CCD
• CIS: lower cost, lower resolution, good image capture