Flatbed scanners
A flatbed scanner is usually composed of a glass pane (or platen), under which there is a bright light which illuminates the pane, and a moving optical array. Images to be scanned are placed face down on the glass, an opaque cover is lowered over it to exclude ambient light, and the sensor array and light source move across the pane, reading the entire area. An image is therefore visible to the detector only because of the light it reflects. Transparent images do not work in this way, and require special accessories that illuminate them from the upper side. Many scanners offer this as an option.
Drum scanners
Drum scanners capture image information with photomultiplier tubes (PMT), rather than the arrays found in flatbed scanners and inexpensive film scanners. One of the unique features of drum scanners is the ability to control sample area and aperture size independently. This is particularly useful for smoothing film grain when scanning black-and white and color negative originals.
While drum scanners are capable of scanning both reflective and transmissive artwork, a good-quality flatbed scanner can produce excellent scans from reflective artwork. As a result, drum scanners are rarely used to scan prints now that high quality inexpensive flatbed scanners are readily available. Film, however, is where drum scanners continue to be the tool of choice for high-end applications. Because film can be wet-mounted to the scanner drum and because of the exceptional sensitivity of the PMTs, drum scanners are capable of capturing very subtle details in film originals.
Hand scanners
Hand scanners come in two forms: document and 3D scanners. Hand held document scanners are manual devices that are dragged across the surface of the image to be scanned. Scanning documents in this manner requires a steady hand, as an uneven scanning rate would produce distorted images - a little light on the scanner would indicate if the motion was too fast. Most hand scanners were monochrome, and produced light from an array of green LEDs to illuminate the image. A typical hand scanner also had a small window through which the document being scanned could be viewed. They were popular during the early 1990s and usually had a proprietary interface module specific to a particular type of computer, usually an Atari ST or Commodore Amiga.
While popularity for document scanning has waned, use of hand held 3D scanners remains popular for many applications, including industrial design, reverse engineering, inspection & analysis, digital manufacturing and medical applications. To compensate for the uneven motion of the human hand, most 3D scanning systems rely on the placement of reference markers – typically adhesive reflective tabs that the scanner uses to align elements and mark positions in space.
Flatbed and other scanner software
If your device can scan then it can work with OmniPage. Mobile scanners, desktop scanners, All-in-one and Multi-function printers all work more productively and with better accuracy using OmniPage.
OmniPage Professional 17 is Nuance’s flagship document conversion and scanning application. It’s designed to handle high volumes of documents from multiple devices and document archiving to popular Electronic Document Management systems. OmniPage Professional allows you to turn paper, forms, digital camera images and PDF files into electronic files you can easily edit, search and share.
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