Scanner

Scanner

• The image to be scanned is placed on top of the scanner’s glass plate.
• The computer sends instructions to the logic board about how far the motor is to run and how fast.
• The logic board instructions place the scanning unit into an appropriate position to begin scanning.
• The scanning unit moves across the image to be scanned at a speed designated by the logic board instruction.
• As the scanning unit moves across the image, a light source shines on the image
• The light strikes the image, reflects, and is then reflected by a series of mirrors to the scanner lens.
• The light passes through the scanner lens and reaches the CCD sensors.
• CCD sensors measure the amount of light reflected through the image and converts the light to an analog voltage.
• The analog voltage is changed to digital values by an ADC  – analog to digital converter.
• The digital signals from the CCDs are sent to the logic board and transmitted back to the computer.
• The information is stored in the computer as an electronic file made up of pixels.   
• The group of pixels is changed into a picture by the TWAIN scanning software.