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1.
How does an interlaced monitor differ from a non-interlaced monitor?
Older
monitors sometimes employed a scanning technique where odd lines were
first refreshed followed by the even lines. While this was an inexpensive
way of increasing screen resolution it caused flicker. For this reason,
most monitors are now non-interlaced. Non-interlaced monitors refresh
each line of the display in turn from top to bottom.top of screen
2. Why is the viewable area less than the stated monitor size?
Typical computer monitors range in size from 14
to 21 inches. The size of the monitor is determined by measuring the diagonal
distance across the surface of the cathode ray tube (CRT). Since the CRT
is encased in a plastic housing, the viewable area of a monitor is always
less than the stated monitor size. The viewable area is then the diagonal
measurement of the portion of the CRT that is visible. Typically, the
viewable area of a monitor will be about one inch smaller than the
stated CRT size.top of screen
3. What is a Pixel?
Pixels or picture elements are the number of dots
on the screen and are composed of one red, green and blue glowing phosphor
dot. The more dots, the sharper the image. top of screen
4. What is dot pitch (DPI)?
Dot pitch refers to the distance between two same-colored
red, green or blue phosphor screen dots. Typical dot pitches range in
distance from .25 to .39 millimeters. A smaller DPI indicates that more
pixels are present in a measure of screen space and this yields a sharper
screen image.top of screen
5. Why is the entire display suddenly displaying incorrect colors?
Monitors use a DAC (digital to analog) circuit to
convert the digital information maintained in the random access memory
of the video card into the analog signals used to control the monitor's
electron gun. If the entire screen suddenly starts displaying colors
incorrectly, it can indicate a failure of the DAC circuit in the monitor.
Try using the monitor on another computer to ascertain if the problem
resides with the video card or the monitor. top of screen
6. What is degaussing?
Degaussing is a process by which monitors reverse
internal magnetization by introducing a magnetic field that is stronger
than the offending internal magnetization. Most modern monitors
are manufactured with a degaussing coil and degauss at startup.
Most modern monitors also have a manual degaussing control. If your
monitor develops a color problem on part of the screen, it may be caused
by either internal or external magnetic interference. To correct
the problem, degauss the monitor and remove the offending external magnetic
generator. top of screen
7. How is the resolution set in Windows 95?
Resolution or desktop area as it is referred to
in Windows is the measure of dots on the screen. Higher resolutions result
in more viewable information, but the information will be smaller and
more difficult to view. Windows resolutions are stated in horizontal by
vertical dimensions and maintain an aspect ratio of 4 by 3. Typical Window
resolutions are: 640 by 480, 800 by 600, 1024 by 768, 1152 by 864 and
1280 by 1040. In Windows, resolution is set by double-clicking Control
Panel, Display and then the Settings tab. top of screen
8. How is the refresh rate set in Windows 95?
Slow refresh rates will cause a monitor to flicker.
A refresh rate of 70Hz is said to be flicker-free. The refresh rate is
typically set by a utility program furnished by the video card manufacturer.top of screen
9. What is the difference between 256, high and true colors?
The number of colors that can be displayed on a
monitor is actually limited by video memory rather than the monitor.
The terms 256 colors, high colors and true colors are used to indicate
the number of bits used to store color information. The more bits,
the more colors and the more video memory required. 256 colors uses
8-bits and hence only 256 different colors are available for display if
you select 256 colors. High color uses 16-bits and hence 65,536
(64k) colors are available for display by selecting high color.
True colors uses 24-bits and hence 16 million colors are available for
display by selecting true colors.
Note,
it is difficult for the human eye to distinguish a difference between
16 and 24-bit color. The difference between 8 and 16-bit color is
extremely noticeable. top of screen
10. Why do I see two horizontal lines displayed across my brand new
monitor?
Aperture-grille monitors such as Sony Trinitron,
Mitsubishi Diamondtron and ViewSonic SonicTron use a technology called
aperture-grille that uses alternating red, green and blue vertical phosphor
stripes instead of dot triangles to yield sharper images and brighter
colors. Aperture-grille technology uses 1, 2 or 3 (depending on
monitor size) horizontal stabilizing wires which can be seen as fine lines
across the screen on bright images. The visible horizontal stabilizing
wires are a normal characteristic of all aperture-grille monitors.top of screen
11. Why is my monitor flickering?
Flickering results when the "excited" phosphor begins
to decay before being refreshed. Typically, a vertical refresh rate
above 70 Hz will eliminate flicker. Remember, the vertical
refresh rate, measured in Hertz, represents the number of times per second
the monitor/video card refreshes the entire screen. Since our peripheral
vision is more sensitive to flicker, scan the edges of the display with
your peripheral vision to check for flicker.
The
Video Electronics Standards Association (VESA) has set 85 Hz as the standard
for flicker-free viewing, but it's generally best to set the refresh rate
at the lowest point at which flicker is not noticeable. Excessive
refresh rates degrade image quality and can actually harm a monitor if
the refresh rate is outside of the monitor's supported range. top of screen
12. Why are my screen colors and portions of my display suddenly distorted?
External electro-magnetic influences can easily
cause display distortion. If your monitor suddenly displays distorted
images or incorrect colors on portions of the display, check for any magnetized
objects around the monitor. Monitors located next to each other,
surge protectors, overhead lights and speakers can negatively effect a
monitor's display.top of screen
13. Why does my monitor make a snapping noise followed by a clicking noise
during startup?
Monitors typically degauss at startup often resulting
in a snapping noise which can be followed by a clicking noise that results
from the monitor switching into video mode after degaussing. top of screen
14. Why are display images shrinking and expanding as the displayed
images change?
A failing monitor power supply will often cause
images to shrink or expand as the displayed image changes. top of screen
15. Why is the color on portions of the display not changing as the
displayed images change?
Unchanging colors on a portion of the display typically
indicate a problem with the random access memory of the video card.
Try using the monitor on another computer to ascertain if the problem
resides with the video card or the monitor. top of screen
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