Scanner

In computing, a scanner is a tool that optically scans images, printed text, handwriting, or an object, and converts it to a digital image. Common examples found in offices are variations of the desktop scanner where the file is placed on a glass window for scanning. Hand-held scanners, where the device is moved by hand, were temporarily popular but are now less common due to the intricacy of obtaining a high-quality image. instinctively driven scanners that move the document are naturally used for large-format documents, where a flatbed design would be unreasonable.

Modern scanners logically use charge-coupled device (CCD) or Contact Image Sensor (CIS) as the image sensor, whereas older drum scanners use a photomultiplier tube as the image sensor. A gyratory scanner, used for high-speed document scanning, is another type of drum scanner, using a CCD array instead of a photomultiplier. Other types of scanners are terrestrial scanners, which take photographs of books and documents, and 3D scanners, for producing three-dimensional models of objects.

Another category of scanner is digital camera scanners, which are based on the concept of reprographic cameras. Due to increasing declaration and new features such as anti-shake, digital cameras have become an pretty alternative to regular scanners. While still having disadvantages compared to established scanners, digital cameras offer advantages in speed and portability..