Bits & P.C.s: Flat panel monitors
By Richard Heller
One of the hottest computer products today is the LCD Flat Panel Display. Besides being sexy and having a futuristic look, why would you want to own one?
First off, what are they and how do they work? By using a photolithography process, transistors are grown on a sheet of glass. There are three Thin Film Transistors (TFTs) for each pixel on the screen. Each transistor controls a different primary colorred, green and blue. The numerous TFTs are arranged in a grid on the glass. Between the transistor grid and another sheet of glass lies a molecules thick pool of liquid crystal solution.
Sitting behind this assembly is a fluorescent light. When a voltage is applied to the transistor, the liquid crystals in front of it react by straightening out, thereby blocking the backlight from shining through, turning the pixel off. When the voltage is removed, the crystals twist to allow the light to pass through, turning the pixel on. By having different transistors turned either on or off, the numerous colors can be displayed.
Because the pixels are arranged in a grid, circles are round and squares are, well, square. Color saturation is often superior to CRT monitors, which means that images are bright and lush. Besides this, they take up little desk space and use half the power and produce far less heat.
When you are buying a flat panel monitor, there are a number of things to consider. As a rule of thumb, a 15 inch LCD has the same image area as a 17 inch CRT, while a 17 inch LCD is as large a display as a 19 inch CRT. This means that where you may not have been able to place a 19 inch-monitor on your desk, you may now get the same image size with a 17 inch LCD monitor.
One problem that LCD monitors have is that they only have one real natural resolution. Most 15 inch LCDs are 1024×768 displays while 17 inch LCDs are 1280X1024. Depending on the quality of the display, resolutions of
640×480, 800×600, and other standards may be supported. If the resolution is not supported, you may not be able to run certain programs, or you may be forced to run the program in an area the size of a postcard in the center of the screen.
Because of the manufacturing process, not all of the transistors may function properly. Some may be stuck on while others may be stuck off. Most manufacturers include a notice with the product stating the number of dead pixels that they allow without calling the product defective.
Some LCD monitors have problems displaying grayscale or 16-bit color images. Before you make your purchase, be sure to view text and both color and black and white images to see how well they are displayed. You can find 15 inch displays for $200 or so, while a 17 inch monitor will be $400 or more.
Richard Heller is an independent computer specialist who specializes in repairs, installation, upgrades, technical support, Internet sharing, data recovery and diagnostics. If you have any computer or service-related questions, please send them to The Rock River Times or e-mail firstname.lastname@example.org.