Is it time to upgrade to LCD monitors from your CRT computer monitors?There is no doubt that CRT computer monitors have a very limited mass-market lifespan. Several manufacturers have stopped manufacturing CRTs completely, which means they are not easy to purchase, yet there are attributes of CRTs that LCD screens have not been able to match. The LCD is simply not a good choice in some environments based on their needs. The characteristics your job's requirements will help determine whether you switch to an LCD.
What's inside CRT monitors?Despite the decades of technological advances in computing, the work horse of personal computing has been, until very recently, the large, desk mounted CRT monitors. These computer monitors managed to revolutionize computing, and allowed personal computers to become a fact of daily life by utilizing the technology of the cathode ray tubes; a technology first suggested for transmitting images in 1907. Yet, if opened by professionals for examination, what you would see inside the standard CRT monitor is basically the inner workings of a cathode ray tube television.
CRTs produce images when the moving electron beam inside the large cathode tube moves back and forth, firing electronic beams at phosphor dots on the inside of the glass tube line by line. The phosphors in your CRT are chemicals that emit red, green, or blue light when struck by electrons. The smoothness of the image is determined by the scan rate of the beam (screen flicker increases as the speed decreases).
LCD monitors, liquid crystal displays, are flat panels.This digital technology was first invented in 1971.Initially used in watches and calculators, its functionality was quickly adopted and began redefining computer, medical, and industrial electronics. In computing, LCDs have been used for years in laptops, and are now ever present as flat panel computer screens, as well as being integrated into new technology television screens. It took until 2003 for the volume of these flat screens to escalate and capture half the monitor market. As of 2005, LCD monitors exceed CRTs sales by more than 2-to-1. They are also known as flat panels in both computer monitor and television screen design.
Going Within
Basic CRT internals
Sandwiched layers of an LCD design
How are images created in LCD monitors?There are no cathode ray tubes in the very thin LCD monitors. Instead, thin "sandwiches" of glass contain liquid-crystal filled cells (red, green and blue cells ) that make up a pixel. Arrays of TFTs (thin film transistors) provide the voltage power causing the crystals to untwist and realign so that varying amounts of light can shine through each, creating images. This particular sensitivity to light makes LCD technology very useful in projection (such as LCD front projectors), where light is focused through LCD chips
Specifically, there are five layers to the flat display: a backlight, polarized glass sheet, colored pixel layering, coating of liquid crystal solution that responds to signals off a wired grid of x and y coordinates, followed by a second glass sheet. To create an image, electrical charges, precision coordinated in various degrees and volts effect the orientation of the liquid crystals, opening and closing them and changing the amount of light that passes through specific colors of pixels. Liquid crystal display technology has increased its accuracy, thanks to advances such as thin film transistors (TFTs - also known as active-matrix technologies) that can produce sharp and more accurate color images than earlier passive-matrix technologies.
