scanner has a few basic parts. First there is a cover to keep the light from escaping. Below the cover
is a glass plate where a document placed. There is a scan head which moves across the
document by way of an electric motor. The scan head has a fluorescent lamp or LCD lamp. The CCD
is a charge couple device that converts light energy to electrical energy.
There many mirrors scan head and the reflected light and they light rays are sent to a lens and then
transferred to digital or electrical energy.
A scanner is a hardware with allows a PC to turn a picture or object into digital codes. It allows the
computer to manipulate an image. A scanner has the ability to translate an unlimited number of analog
voltage levels into digital values. Scanners use special software called optical character recognition
(OCR) which gives the ability to read text and print it. The information can then be manipulated in the
computer which now in digital form instead of analog. Most scans are measure in dpi or dots per inch.
The more dots per inch the better the resolution.
A light source underneath the picture or document illuminates the image. White or blank spaces reflect
more light than inked and colored areas. A motor moves the scan head underneath the page. When the
scan head is moving, it captures light that was reflected from individual areas.
A lens focuses the beams of light into light sensitive diodes that modify the amount of light into an
electric current. The amount of the current depends on the amount of light reflected.
The analog to digital (AD) converter stores each analog reading of voltage as a digital pixel representing
either a black or white area. Scanners that are more sophisticated can translate the voltage into shades