drum scanner
Drum scanners are special film scanners for professional applications. Drum scanners are 2D scanners and consist of a rotating glass cylinder on which the flexible reflective and transparent originals, images, photos, slides, films, etc., are clamped and scanned.
While the drum rotates at high speed, the originals are scanned in a spiral and pixel by pixel, while the original is illuminated by a strongly focused halogen beam.
Horizontal scanning is achieved by the light and scanning device undergoing a line-by- line feed. The light reflected from the original is detected by a sensor, separated by filters into the primary colorsred (R), green (G) and blue (B), photo-sensorically amplified and digitized. The reflected light can be amplified via photomultipliers.
The drum scanner is characterized by its high accuracy, resolution and light sensitivity and is therefore used in the professional environment of photo and image processing, layout and printing technology.