Scanner is a device that optically scanning images, printed text, handwriting, or an object, and converts it into a digital image. With the development of technology, we are now able to choose among the various models of scanners based their main characteristics, such as scanning speed, resolution, image quality and overall accuracy, reliability scan tool or even its size.
Modern scanners typically use a charge-coupled device (CCD) or a Contact Image Sensor (CIS) as the image sensor, whereas older drum scanners use a photomultiplier tube as the image sensors. A rotary scanner, used for high-speed document scanning, is another type of drum scanner, using a CCD instead of a photomultiplier. Other types of scanners are planetary scanners, which take photographs of books and documents, and 3D scanners, for producing three-dimensional model of the object.