How Does a Flat Screen TV Work?

By Jamie Robertson

How Does a Flat Screen TV Work?
i Jamie Robertson

The set-up

Housed between two sheets of glass is the technology that allows flat screen TVs to work. Depending on the type of flat screen TV, the process can differ slightly. In a plasma TVs are cells that contain the gases xenon and neon as well as electrodes. There are two types of electrodes, display and address, that are arranged in a grid-like pattern on either side of the cells. These electrodes are later used to charge the cells and excite the gases.

In a LCD flat screen TV, tiny liquid-crystal-filled cells are between the glass sheets. A bright white light is located behind the cells and illuminates them to create the picture.

Powering the picture

The power supply enters the TV and creates the energy needed to create the picture. In a plasma TV, electric pulses excite the gases, which produce release ultraviolet photons. These photons react with the phosphor material that is contained in the cells. The phosphor then produces light.

In an LCD screen, the energy untwists the crystals to allow them to filter the white light that is generated by the lamp Depending on the amount energy running through the cell, it will untwist to the desired level.

Creating the image

The light is then used to create the colors needed for the picture. The picture is received through a source such as cable or an antenna. These signal tells the TV what picture to create. In both types of TVs, the cells contain three colors: red, green and blue. In a plasma display, the individual pixels receive color information from software located on the electrostatic silicon board at the back of the TV. A balance of the three colors is used to create the entire spectrum of color needed to recreate images.

In an LCD display, the white light is filtered to block out the unneeded colors until the correct hue is obtained. If the crystal is all the way untwisted, then the color produced is white. The colored areas of the pixels work to create the entire spectrum of colors.