How does scanner work? There are many type of scanner. We are going to
talk about the flat beds scanner. Flatbed scanner are the most widely
used and versatile type of scanner. The simple way to describe how a
scanner work is it converts light into digits so your computer
understands. This applies to all types of scanner. A scanner is not much
different from a photocopier. The copier will print a sheet of paper
and a scanner stores the cop of the image in a file.
For a scanner to scan image it use several thousand charge coupled
devices as their eyes. These ting components convert the amount of light
received into electrical impulses. The strength of the impulses depends
on the intensity of light that strikes them. They send that information
to your computer. Computer can only to understand whole numbers. The
impulses are translated from analog to digital. Then the photos are
stored as a group of integers.
For a photo scanner to capture a whole image the scanner divides the
image into a grid and use a row of scan head to record how much light it
reflected in each location. Then when your computer has the data it
creates a file that represents the image in digital form. Each of the
cells that are in the grid is called a pixel each pixel contains a shade
or a color of gray. The photo is completed when the pixels are all
combined. Scanner different in two ways. How many pixels can they
measure? And how the actual scanner process occurs.
The color and the intensity of each pixel are determined in one or more
bits of data. The number of bits is referred to the number of colors
each pixel can contain. The most common are one bit, 8 bit, and 24bit.
The 1 bit scanner is the most basic type of scanner because it only
records black and white. The bits are only able to express two values on
The majority of scanner today have at least 24bit because they collets
8bits of information about each of the three primary scanning colors.
Scanners depend on the quality of light sauce. The lights determine the
quality of the resulting in your scan. Most quality scanners use a cold
cathode bulb. These bulbs produce whiter and more consistent light and
they produce less heat compared the fluorescent bulb.
There is optics inside scanner. Scanner use prisms, lensee and optical
part to direct light from the bulb to the charge coupled devices.
Optical parts can vary in your scanner. The high quality scanner use
high quality glass optics. That is cool corrected and coated for minimum
Some of the lower priced scanner use plastic components to keep the cost
down. Flatbed scanner use several different methods of reading light
values most flatbed scanner use a single pass method with a beam
splitter or a coated charge coupled devices. When a beam is splitter it
uses light to pass through a prism and separates into the three primary
The different charge coupled devices read each color. Some scanner use
the three charge coupled devices to hold down the cost. Color scanner
usually requires .The three separate scanning passes one for each red,
green and blue. The diodes sweep across the source image. They distinct
reading is taken, vertically and horizontally and they determine the
resolution of the scan.