What is a scanner – Epson GT-6500 EN User Manual
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What Is a Scanner
A scanner is a device that performs the following functions:
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Reflects light off your documents
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Separates the light by color and intensity
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Converts that reflected light to digital data
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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:
1-2
Overview