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Unformatted text preview: en. Today, most monitors operate at 60 Hz. That is, they
refresh the screen 60 times per second. Better quality monitors operate at 70 to 90 Hz,
refreshing the screen 70 to 90 times per second.
4. Color. Based on this attribute, monitors may be either monochrome or color. A
monochrome monitor can display images only in a single color, usually white, red, green,
blue, or amber. On the other hand, a color monitor can display multi-colored images.
Although a monochrome monitor can display only a single color, it is usually capable of
displaying multiple shades (increased and reduced color intensities) of the same color.
The term gray scales is used to refer to the number of shades of a color that a monitor can
display. Monochrome monitors are rapidly becoming a thing of the past, as most
applications today require color monitors.
A color monitor functions just like a monochrome monitor. To add color, it uses three
electron beams instead of one, and each pixel on the screen is made up of three tiny red,
green, and blue phosphors arranged in the shape of a triangle. When the three electron
beams are combined and focused on a pixel, the phosphors of that pixel light up to form a
tiny spot of white light. Different colors can be displayed by combining various
intensities of the three beams. Color monitors are also called RGB monitors because they
use red, green and blue as the primary additive colors for generating multiple colors.
Color monitors use multiple bits to represent each pixel. For example, if each pixel is
represented by one byte (8 bits), then it can indicate one of 2 s = 256 different colors to
draw the pixels. That is, the monitor is said to support 256 different colors. There are
millions of colors when we consider all the shades and mixtures of color possible, and so
256 seems like far too few colors. Today's high-end monitors usually use 24 bits to
represent each pixel. Such monitors can support 224 or about 16 million different colors.
Based on the resolution and number of colors supported, several standards for color
monitors have evolved. Each one is implemented by installing an add-on board
(commonly known as a graphics adapter bo...
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This document was uploaded on 04/07/2014.
- Spring '14