What Is a Scanner
A scanner is a device that performs the following functions:
❏Reflects light off your documents
❏Separates the light by color and intensity
❏Converts that reflected light to digital data
❏Sends the digital data to your computer for further processing
Basic scanning principles
A scanner normally includes two components: a light source that illuminates the document and a sensor that detects the light reflected off the document. The sensor is composed of CCD element arrays that detect the brightness of the reflected light and produce corresponding digital signals.
The document is read by a horizontal row of sensors that move vertically down the page. Data from the sensors is read at regular intervals (such as 300 times per inch), achieving very high resolutions.
Data is organized horizontally and vertically; the scanning direction is referred to by the following terms: