A scanner that provides a flat, glass surface to hold a sheet of paper, book or other object for scanning. The scan head is moved under the glass.
The type of image scanning device you’ll see most often around the office is a flatbed scanner. This looks just like the work surface of a photocopier, where you put the page to be copied, and that’s pretty much what a flatbed scanner is. You can also use them to scan thick original items, like books or magazines, as well as single pages.
Most printer manufacturers offer multi-function laser or inkjet printers with scanning ability built in, so you don’t need to make space for a separate scanner that might not see a lot of use. Multi-function printers give you the additional perk of acting as a copier or sometimes a fax machine, as well as printing and scanning. That makes them a good option in a small office.
Sheet-fed scanner is smaller in size than flatbed scanner. This type of scanner works like a flatbed scanner except that the document is fed through the scanner and moves along the beam to be read rather than the beam moving along document. This type is not useful for books, but only single sheets.
These scanners are also called Automatic Document Feeders. Sheet-fed scanners use digital imaging system that is specifically designed for scanning loose papers.
Flatbed scanners and sheet-fed scanners are both versatile business machines, but they’re usually pretty limited in the sizes they can scan. Usually, if you routinely need to scan anything larger than a legal sized document, you’re out of luck. If you work with larger pages in your business – such as blueprints, architectural drawings or posters – you’ll need to get a large-format scanner. These rather resemble a musician’s electronic piano, with a flat scanning mechanism mounted atop a stand that brings it up to desk height. To use it, you slide your oversize original into the scanner until the rollers grip it and position it for scanning. From there, it works much like a jumbo sheet-fed scanner, with the document sliding through the scanning mechanism and coming out the other side.
Drum scanner is used for scanning a document and produce at very high resolution rate. There is no any type of scanner that will give you the kind of resolution, detail, sharpness, dynamic range, and color rendition that drum scanning can give you. There are only a few companies that make these scanners, considering the high cost of producing a scanner such as this. It is considered as a tremendous upgrade to a regular flatbed scanner.
A drum scanner uses a photo-multiplier (PM) tube, which is a light sensing device. That’s why it offers a high sensitivity and good signal-to-noise ratio. The image to be scanned is placed on spinning.
Handheld scanner is much like a flatbed scanner. Handheld scanners are small helpful electronic devices that are widely used for digitizing printed documents. Handheld scanner provides lower quality scanners, they are still very popular because they are small and less expensive than their flatbed. They are able to scan items that could not fit in a flatbed scanner due to size or location. Their function includes moving them over the material being captured with the aid of a tray to keep it in a straight line. Experience is required to operate and handle the device since it is very important to keep the scanner straight so that a distortion-free scan is possible.
Low cost and portability is the advantages of handheld scanner but poor quality is its drawback.