CCD and CIS Scanners
 |
CCD (charged coupled device) technology is similar to the function of a digital camera. Photo-sensitive pixels stacked on a semiconductor chip capture and digitize an image that passes through a lens and mirror optical system. A light source is necessary to illuminate the document enough to capture the image. As the system is non-integrated (seperate CCD, lens, light, source, mirrors), the quality of the components is critical to the quality of the image. GTCO Calcomp HD scanners are built with hi-quality full-sized Fuji camera lenses designed for the resolution of the scanner. The CCDs are 4-channel CCDs, capturing and processing true 48-bit RGB data (3 channels) and 16-bit grayscale and monochrome data. The lamp is an extended long-life, color-matched fluorescent tube with a Color Rendering Index (CRI) > 95. These components ensure optimal image quality – especially for color-sensitive graphics, photos, fine arts, detailed maps, and folded or rigid materials that need extra light to capture detail and remove shadows. |
 |
| |
 |
CIS (contact image sensor)—first to be used to make fax machines more compact, CIS has been used primarily for small format devices (scanners, fax, copiers) and is still produced in A4 (Letter-size) widths. CIS combines a row of photo-sensitive pixels placed in contact with small rod lenses to capture an image, and built-in LEDs as the light source. The entire module is about the size of a pencil and this helps to make devices more compact. Placing two or more of these modules together can produce seperate images that software and processing can "stitch" together to make a single wide-format image. Since the components are all integrated, the design and specifications of the CIS are critical to the image quality. In addition, 1200dpi modules were selected to provide even better sharpness for fine lines and details on technical documents. |
