Should you leave your thin-screen, LCD-TFT desktop monitoron for an extended period of time? The monitor has a limited life, and you will want to extend that life as much as possible.
Electricity consumption is less of an issue, since those monitors use very little electricity.
You can go into the Control Panel and get Power Options for a brief period of time. You can adjust the brightness setting of the monitor.
Let's understand the background of how monitors work.
The older, CRT (Cathode Ray Tube) monitors shoots electrons at a glass plate that has layers of phosphorous compounds called phosphors.
That cathode is a filament like the wire that glows in an incandescent light bulb. It is located in a vacuum sealed glass "tube." A stream of negative electrons flows from the heated cathode into the vacuum, forming a ray.
A positive anode attracts the electrons that come from the cathode. The electrons in the monitors' cathode ray tube, is focused into a tight beam and then accelerated near the flared portion, by the screen. The high-speed beam of electrons hits the phosphor-coated causing it to glow.
There are various ways to cause phosphor to emit visible light. The best way is by radiation such as ultraviolet light or a beam of electrons. Fluorescent colors also absorb invisible ultraviolet light and emit visible light.
The screen glows when an electron beam strikes the phosphor coat inside the CRT. Older black-and-white screens have only one phosphor. It glows white when the light beam strikes it. Color screens have three dot or stripe-shaped phosphors. They emit red, green and blue light, so they are called RGB screens. Three electron beams illuminate the three different colors.
Multisync monitors have more phosphors in a greater variety, and they are struck by electrons more frequently. The result is a higher definition screen image.
The gun that shoots the beam is the weakest part of the CRT. As soon as the monitor is turned on, it heats up, just like our light bulb mentioned previously. True, a CRT lasts longer than a light bulb, but the principle remains the same.
The screen is also covered with a surface that could be damaged over time. Before the advent of Windows, monitors suffered from a constant image from the streams of electrons. That DOS prompt always appeared in the same location on the screen, and the phosphors burned an image or a ghost on the screen. It was visible "behind" any susbequent images. Screensavers, randomized the color and frequency of the electron beams that hit the screen and thereby delayed the effects of burning into the monitor.
Since the power management feature can turn off the monitor, it is better to select "none" in the video card display properties. That will reduce the gun emissions.
However, don't be misled.
Although the screen does "go black" after the specified amount of time, the screen is still on. Want proof? Turn out light. Is the room dark? No it isn't. You can still see radiation from the gun, and a white glow still shines from the monitor. The screen is not burned off. It is merely running at a lower power setting, and the gun is still firing.
Your power management settings in Windows offer the option to turn off the power after a specified amount of time has elapsed. Using a "blank" screensaver together with these power-down options will extend the life of your CRT or LCD monitor.
LCD stands for "Liquid Crystal Display." You are familiar with solid crystals, but there are other kinds as well.
Matter exists in three states: solid, liquid and gas. The molecules in solids stay in the same position relative to the other molecules. The molecules in liquids often move around in the liquid. But some substances exist midway between liquids and solids. In that case, their molecules maintain their position, like molecules in a solid, but sometimes move around, like the molecules in a liquid. Thus, liquid crystals are neither solids nor liquids. That explains their seemingly contradictory name.
Liquid crystals are more like liquids than solids. It takes a great deal of heat to turn a solid into a liquid crystal, but only a little more heat to turn it into a real liquid. For this reason liquid crystals are used to make thermometers. This also explains why LCD screens or laptop computers act differently according to the weather.
LCD screens work because of four factors:
1. Light can be polarized
2. Liquid crystals can make changes in polarized light
3. Liquid crystals can be modified by electric current
4. Some transparent substances can conduct electricity
Your LCD monitor is either passive matrix or active matrix.
Passive-matrix LCDs supply a charge to a particular pixel on the display. The response time or refresh time is often slow. This can be tested by moving the mouse pointer quickly from one side of the screen to the other. A series of "ghosts" will follow the pointer.
Active-matrix LCDs use thin film transistors (TFT), which are tiny switching transistors and capacitors. They are arranged in a grid. To address a particular pixel, the appropriate row is switched on, and a charge is sent down the correct column. Since the other rows that the column intersects are turned off, only the capacitor at the designated pixel receives a charge. The capacitor holds the charge until the next refresh cycle.
There are three subpixels with red, green and blue color filters to create each color pixel. The intensity of each subpixel can range over 256 shades. Combining the subpixels produces a palette of 16.7 million colors (256 shades of red x 256 shades of green x 256 shades of blue). These displays require an enormous number of transistors. For example, a laptop computer with a resolution of 1,024x768 requires 1,024 columns by 768 rows by 3 subpixels, or 2,359,296 transistors etched onto the glass! Some of these transistors may have a problem, thus creating a "bad pixel" on the display over the course of time.
An increase in display size, means the addition of more pixels and transistors. With each increase in the number of pixels and transistors, there is an increase in the chance of including a bad transistor. Manufacturers of large LCDs may reject up to 40 percent of the panels from the assembly line. That affects the LCD price, since the sales of the good LCDs must cover the cost of manufacturing both the good and bad ones.
A blank screen screensaver - none - is more effective with an LCD since current across screen is at its lowest point. However, unlike the CRT, there is no gun to energize, and there is no filament to burn out.
Set your screensaver to Blank (or none) for a period of time, then let power management software auto-power it down to inactive. The light may stay on, but no power is supplied to the LCD layers, so the monitor lifetime will be measurably extended.
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