WHAT IS SCANNER AND DIFFERENT TYPES OF SCANNER?

WHAT IS SCANNER AND DIFFERENT TYPES OF SCANNER?

Scanner is device use to scan document and images and convert it into digital format.

Types of scanners:
1.Flatbed scanner
2.Sheet-fed scanner
3.Handheld scanner
4.Drum scanner

Flatbed scanners are desktop scanners.
Parts of flatbed scanner:
1.Charge coupled device (CCD) array
2.Mirrors
3.Scan head
4.Lens
5.Filters
6.Interface ports
7.Control circuitry
The core component of scanner is CCD array.CCD is technology for image capture in scanners.
CCD is collection of tiny light sensitive diodes,which converts light into electric charge.
The image of document that we scan reaches the CCD array through a series of mirrors,filters and lenses.

Sheet-fed scanners are similar to flatbed scanners except that the document is moved and the scan head is immobile.

Handheld scanners use same basic technology as a flatbed scanner,but depends on the user to move them.
This type of scanner does not provide good image quality.

Drum scanners are very powerful.They use technology called a photomultiplier tube(PMT).
In PMT,the document to be scanned is mounted on a glass cylinder.
At the center of the cylinder is a sensor that splits light bounced from the document into three beams.
Each beam is sent through a colour filter into PMT where the light is changed into an electric signal.   

           

               FOR MORE INFORMATION WATCH THE BELOW VIDEO