TYPES OF SCANNERS
A scanner is a device that captures image form photographic prints, posters, magazine pages and similar sources for computer editing and display.
1. Flatbed Scanner:
A flatbed scanner is an optical scanner which helps making use of a flat surface for scanning documents. Flatbed scanner is capable of capturing all elements on the documents and does not requires movement of the document of the document.
These scanner sit on the you desk with a flip-up top that reveals the scanning glass when open. The pane is illuminated with the help of bright light planted underneath it.
The image that is to scanned, is then placed on the glass pane to scan the documents and produce is digital copy.
Depending on its size, a flatbed scanner can fit standard or legal-sized documents, and the flexible cover allows you to scan large documents. Flatbed scanners are also excellent for scanning newspaper articles books and even DVD cases for those who wish to digitize their movie library.
2. Sheetfed Scanner:
In the type of scanner, the document is fed into the horizontal or vertical slot provided in it. The prominent components of a sheetfed scanners scan loose papers placed in a tray by pulling them across a static scanning lens.
They are a bit smaller than standard flatbed scanners making them great if you are working with limited space. Most sheetfed scanner have a lower image resolution than flatbeds, but for document this is not a major concern.
The big advantage of sheetfed scanner is the ability to scan several documents at a time rather than have to manually change page after each scan.
Documents can be loaded into a feeder tray and the machine will pull in one page at a time for scanning, much like a photocopier. Sheetfed document can be a bit more expensive than other types of scanners. However, if time is of concern, the extra investment could be worth the saved hassle.
3. Drum scanner: Drum scanner is used for scanning a document and produce at very high resolution rate. A drum scanner is the one which uses a photomultiplier tube (PMT) (which is a light sensing device) to scan images instead of the charge-coupled device that is typically used in a flatbed scanner.
Photomultiplier tubes are vacuum tubes which are extremely sensitive to light. In drum scanners, the image is mounted on a glass tube.
When the beam of light moves across the image, its reflection is picked up by the photomultiplier tube and processed. Drum scanner is the type of scanner that will give you the kind of resolution, detail, sharpness, dynamic range, and color rendition.
In addition, drum scanners are known for their high resolution, which makes them apt for detailed scans. Drum scanners are not as popular as flatbed scanners, since they have higher cost and large size.
4. Hand-held scanner: A Hand-held scanner is a small manual scanning device which is moved over the object that needs to be scanned. Hand-held scanner function includes moving them over the material being captured with the aid of a tray 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.
In flatbed and sheetfed scanners, you put the documents that is to be scanned inside the device. In contrast, in the case of hand-held scanner, you have to drag it over the document that is to be scanned.
Using a hand-held scanner can be cumbersome task as the hand needs to be steady all the time. Even a slight is a barcode scanner, typically used in shopping stores to valuate goods.
Handheld scanners provide lower quality scans, they are still very popular because they are small and less expensive than flatbed scanners.
5. Photo Scanner: As the name itself suggests, a photo scanner is mostly used to scan photographs. In other words, photo scanner is a type of scanner which helps to digitize a large volume of photographs and negatives.
It boasts of high resolutions and color depth, both of which are necessary for scanning photographs. If you want to buy a scanner to digitize film negatives and slides, then the photo scanner is your best bet.
While flatbed scanners can also scan the photographs, they are not as fast as dedicated photo scanners. Photo scanners usually come with their own specialized photo editing software and also adapters that allows you to work with negatives and slides.
It’s also worth nothing that the in-built software in some photo scanners helps in cleaning and restoring old photograph.
6. Film Scanner: A film scanner is utilized to scan photographic films directly in to a computer. The photographer has direct control over certain aspects, such as cropping, ratio of original image on the film, etc.
Some film scanners available today have specialized software through which it is possible to minimize scratches and improve color quality.
Low-end film scanners most often accept 35mm film strips, while high-end scanners, armed with interchangeable film loaders, can accept 35 mm or 120 mm strips and even individual slides.
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