PREFACE:
The monitor is the visual interface between you and your computer. A wise choice in a computer monitor can save much frustration and even eyesight. The choice of a good monitor is a trade-off between cost and resolution. The components of resolution are the number of pixels that can be displayed which are counted in both the horizontal and vertical screen directions. The size of the pixels and the technology used to display these pixels determine the clarity and ease of view.
Damaged monitors can be repaired. Whether it's economically feasible depends on the damage and the cost of the monitor. I recently received an email about this, but unfortunately, lost it. Check your local area for these services, try the phone book yellow pages. Also check with the manufacturer.
PIXELS:
A pixel is generally referred to as a singular dot on the screen. However on Cathode Ray Tube (CRT) monitors, three patches of phosphor arranged in a pattern are needed to represent a single pixel. The three patches are red, green, and blue. There are two primary methods of arrangement for these patches as shown below, one uses circles the other uses stripes:
The distance between the centers of the phosphor arrangements determines the quantity known as dot pitch (dp). This spacing can vary from .25mm dp to .51mm dp. A dp below .28mm is acceptable, a dp above .28mm results in the display looking grainy and text becomes unreadable.
Todays LCD monitors offer high brightness and contrast, longer life and of course they are lighter and take up less deskspace.
RESOLUTION:
The entire monitor screen is represented by a number of horizontal and vertical pixels. More pixels translates into finer detail. But since objects on the screen like text letters and icons only have so many pixels to start with, a higher resolution results in smaller text letters and icons on the screen. Therefore, the size of the screen in inches determines how readable the image, text, or icons are at a given resolution.
IMAGE SIZE:
The physical screen size is a measure in inches of a diagonal of the entire tube. Since the entire tube is larger than the area dotted with phosphor (the display area or viewable area), a 15" tube may only have a 12" diagonal of actual viewable area.
MAGIC:
There is a complex interaction between human eye-sight, physical screen size, pixel dp, and resolution. The following are general rules: A 14" monitor can comfortably display 640X480 pixel resolution, a 15" monitor can comfortably display 800X600 pixel resolution, a 17" monitor can comfortably display 1024X768 pixel resolution and a 20" or larger monitor can comfortably display 2048X1024 pixels.
HORIZONTAL SCAN FREQUENCY AND VESA:
The Horizontal Scan Frequency determines how many times each second the entire screen is redrawn or refreshed. The Video Electronics Standard of America calls for no less than a 70Hz Horizontal Scan Frequency Non-Interlaced. Interlacing is a trick that effectively halves the Horizontal Scan Frequency by redrawing only odd number rows on one Horizontal pass and then only even numbered rows on the next Horizontal pass. So the monitor must support at least VESA standard 70Hz refresh rate at the desired pixel resolution which depends on the monitor size.
BANDWIDTH:
The monitor receives analog video signals from the video card through the video cable. This data transfer requires bandwidth. The bandwidth is determined by both horizontal and vertical scan frequency and picture resolution and color depth. A 1024X768 true color image at VESA refresh rate can require 200MHz or more of bandwidth. Sometimes monitor manufacturers specify this quantity as well. As usual, the higher the better.
CONTROLS:
There are several controls on the monitor that adjust the picture display as outlined in the following paragraphs. It is important to have these controls on the front of the monitor where they are easily accessible. These controls can be implemented in either digital (buttons) or analog (dials). Analog dials can wear out over time. Digital controls often times use an on-screen menu to reduce the necessity for each control to have it's own button. Keep in mind that the on-screen menu is generated by the monitor and not the video card nor the CPU. After the monitor has been adjusted to your likes and needs, the adjustments have to be remembered by the monitor. In the case of analog dials, this is the current position of the the controls. In the case of digital controls, these settings have to be maintained by the monitor. A multi-synching monitor allows the monitor to save adjustment settings for each screen resolution setting. For instance, at 1024X768, you may need to shift the image to the left, but at 640X480 you may need to shift the image to the right instead. So instead of having to turn dials or punch a lot of buttons every time you switch screen resolution, the multi-synching monitor saves control positions for each screen resolution. Also, keep in mind that some video cards duplicate some of these controls and can be set up using software provided by the manufacturer.
DEGAUSS:
The degauss button is necessary when a static charge or a temporary magnetic field accumulates on the monitor. If you have ever seen a TV or monitor that had one corner of the picture distorted with a blue or red or green cast to it, you needed to "degauss" the tube. Some monitors degauss every time the monitor is powered on. I like a separate button.
TO EXPLAIN THE FOLLOWING TOPICS, REFER TO THIS SCREEN IMAGE:
TILT:
Tilt controls the image plane of view, tilted forward at the top or bottom.
PIN CUSHION:
The pin cushion effect is like dropping a pebble in a pond or sticking a pin in the center of a pin cushion and pulling it out slightly or pushing it in slightly.
TRAPEZOID:
The trapezoid control shifts the top or bottom to the right or the left.
ROTATION:
Self explanatory.
BRIGHTNESS:
A monitor that requires the brightness control to be set at or near the maximum setting should be avoided, this requires more power which translates into shorter life span for the monitor.
CONTRAST:
Contrast improves the clarity of the image and is preferential to brightness.
HORIZONTAL SIZE:
HORIZONTAL DISPLACEMENT:
VERTICAL SIZE:
VERTICAL DISPLACEMENT:
COLOR REPLICATION:
The ability of the monitor to accurately reproduce colors is of large importance to some users. Computer magazines compare monitors from time to time and evaluate this aspect with special test equipment. The basic concept is: How red is the red? How blue is the blue? How green is the green? Some monitors have controls that allow these settings to be changed independently. A "Gamma" setting allows these to be set in unison.
PHYSICAL ABERRATIONS AND DISTORTIONS:
From time to time, parts of the screen may develop problems. If you have tried the degauss, then it may be time to replace the monitor.
