Talking about a couple of years back, the scanners used to be expansive and less appealing on the image quality. Leave alone the text as it used to be almost indescribable with the scanned image. Now the scanners today are based on high image quality and are suitable to every budget. There are now different types of scanners which vary according to the needs of its users and have evolved around them only. Let’s learn more about the different types of scanners.
Different Types of Scanners
Drum Scanners
Drum scanners capture image information using photomultiplier tubes (PMT) technology unlike the charged coupled device (CCD) used in flatbed scanners and film scanners. In the drum scanner the reflective and transmissive originals are mounted to an acrylic cylinder, the scanner drum, which rotates at high speed while it passes the object being scanned in front of precision optics that deliver image information to the PMTs. In most modern color drum scanners 3 matched PMTs are found in use, which read red, blue and green light respectively. In drum scanner light from the original artwork is split into separate red, blue and green beams in the optical bench of the scanner making the digital image
more precise.
Flatbed Scanner
Another type of scanner is the flatbed scanner. A flatbed scanner is usually made of a glass pane, which is illuminated with a bright light found underneath, and a moving optical CCD or CIS array. In the flatbed scanner images to be scanned are placed face down on the glass and the sensor and light source move across the glass pane reading the entire area.
Hand Scanner
A Hand scanner is a manual device that is dragged across the surface of the image to be scanned. Scanning documents in this manner is difficult as this requires a steady hand, to avoid uneven scanning rate that would produce distorted images. They have a "start" button which is held by the user during the scan, some switches to set the optical resolution, and a roller which generates a clock pulse for synchronization with the computer
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