Scan head of a flatbed scanner. Flatbed or desktop scanners capture images from printed media using the scan head. The scan head contains a lamp (white tube) that illuminates the image. Light is reflected by a series of two or three mirrors to a lens (centre), which focuses the image through filters. Most scanners have three filters (red, green and blue) through which separate images are passed onto the charge-coupled device (CCD) array (upper right). The CCD array converts light into electrons, producing an electronic version of the image.