TV Type – LCD
There are actually several types of LCD TVs. For flat panel televisions there are two very common types, LED backlight and cold cathode fluorescent light (CCFL) backlight. We also have another called LCD rear projection. Below are the descriptions of each technology and the pros/cons for each one. Currently the most common on show room floors are the flat panel types.
LCD - LED Backlight
LCD - Conventional Backlight
LCD - Rear Projection
This TV type works similar to a DLP. An arc lamp is used as a light source. The light produce by an arc lamp is uneven, the center of it is brighter then the edges. For that reason the light is passed through a diffuser to create a beam of light that is evenly distributed. The beam of light goes through prisms and filters to separate the light into red, green and blue. The three individual colors of light pass through a polarizing filter then pass a LCD panel that is approx. 1.5” by 2”. The three colors of light are combined to display the picture. This setup is used in rear project TVs and projectors.
These displays are often 50”-65”, bright picture, this technology is used in high-end televisions.
The lamp needs to be replaced every 6,000 - 8,000 hours of use. It is bulky, most LCD rear projection TVs are about 1.5' deep. The lamp uses a cooling fan which can collect dust and it generates a small amount of noise. The lamp will slowly reduce in brightness.