Monitors

The monitor, or the Video Display Unit (VDU), is the television like screen the computer uses to display information to the user. There are several technologies used to manufacture monitors. Several are as follows;

CRT (Cathode Ray Tube)

CRT monitors host a vacuum tube that houses a flat phosphor covered screen at one end and an electron gun assembly at the other end. The video image on your monitor is created by projecting a narrow beam of electrons onto the phosphor covered screen. The area where the beams hit the phosphor will glow for a brief period of time and then fade out. Because the beam created by the electron beams fade off very quickly, it must retrace its path constantly to keep image on the screen. The electron beams in your monitor must repaint the screen at least 60 times per second or your eye will perceive flicker. This retracing is referred as the monitors referred as monitors “refresh rate”.


                                                     


LCD (Liquid Crystal Display)

LCD displays are created with a collection of liquid pixels called crystal cells. A liquid crystal cell is filled with a liquid that changes the amount of light passes through depending on the eclectic charge provided to the cell. A filter fixed to the cell will glow according to the light passes through. In colour LCD panel/ each pixel is created with three cells; one for reach red, green and blue.

                                                  


LED (Light Emitting Diode)

An LED monitor is basically the new version of the LCD monitor that you connect to your computer. LCD monitors used to be lit mainly with CCFL backlights which include mercury. LED backlighting is usually thought to be better for the environment since it contains no mercury and uses less power than a CCFL system.


There are some advantages to an LED monitor. First one is that the screen gets brighter faster. Before reaches full brightness a CCFL light has to heat up for a few seconds. Another advantage of an LED monitor is that the lighting supply is more even. Since it is lit with many small LEDs rather than one big light source it will usually have less dark or light spots.