LCD means liquid crystal display. You may see others calling it liquid crystal diode. This is not correct. One single word makes the whole meaning wrong. It must be confused with LED, otherwise known as light emitting diode. This is the red light that we commonly see in the clock radios. However today, LED lights are already produced in many colors. What is a diode? It is an electronic valve which prevents the current from going in another direction that will interfere with the functioning of the light projection of the TV.

There has been much advancement in LED technology in the last few years, allowing new applications. The manufacturing cost of LEDs has been relatively expensive because the process used a sapphire substrate. Researchers at Purdue University have developed a process for replacing the sapphire with inexpensive silicon. Currently, a 30-watt LED bulb can cost about $30, but this number should come down dramatically with the application of the new research.

The ac supply was plugged in to the power adapter and I could see the power LED was lighted up. Checking the output voltage of the power adapter I got about 19 volts which is good. Even though the LED has lit and correct output voltage, this doesn't mean that the power adapter can maintain when there is a load (the LCD Monitor) connected to it.

I once came across a Compaq 17" LCD Monitor that have a precise output voltage from the power adapter but when connected to the Monitor, the display appeared for a fraction of a second before shutting down. Usually in this case, your experienced would tell you that it could be the inverter circuit are faulty or the lamps have problem. You would be surprised that the actual cause of the shutdown was due to the power adapter. It can't sustain the output voltage when there is a load on it.

There are also lamps that contain two light-emitting diodes, so that a reversal in biasing will change the color, mostly from green to red and vice versa. Light emitting diodes are currently available in various colors like green, red, yellow, orange, white and blue. In general, light emitting diodes operate at 1.7 to 3.3 volts. This characteristic makes them completely compatible with solid state circuits. They have a response time of nanoseconds. They also offer good contrast ratio for the visibility. The power requirement is typically from 10- 150 mW. They have a lifetime of 10,000 working hours. Their semiconductor properties make them durable by adding a significant ruggedness factor.

The first LCD TV was made public back in 1971. It was rather a disappointment because it failed in the phantom images part that can be seen during action sequences. After some alterations and corrections, as well as addition of the reverse pull-down correction in the LCD, we can now see today that these televisions have excellent images and have no distortion in picture transmission. Because of the success of his work, Fergason started building his company and manufacturing LCD TVs.