LED and LCD TV

LED-backlit LCD TV is the use of light-emitting diodes (LED) as a liquid crystal display backlight TV. this does not mean that television use light-emitting diodes for image display With the light-emitting diode TVs increasingly competitive market, coupled with the light emitting diode applications matures, various TV manufacturers have actively into the light-emitting diode-backlit LCD TV, an attempt at a home television on the occasion of regime change can come out on top.

Types of light-emitting diode backlight technology;

LED back-light technology can be divided into direct type (direct back-lit or full LED array back-lit) and side-illuminated (edge LED back-lit) are two, and light-emitting diodes which are used in direct-divided into white light diode and red, green and blue light-emitting diode two kinds.

1-Direct type light-emitting diode backlight technology;

Direct type LED back-light technology is the more pieces of light-emitting diodes arranged in an array, placed behind the LCD diffuser and directly illuminated LCD. Thus, the direct type can comply with different parts of the screen brightness changes quickly fine-tune the brightness of the light-emitting diode, greatly improve the level of dynamic contrast ratio to the plasma display. The disadvantage is the need to use a large number of light-emitting diodes, and higher prices.
Had a direct type LED back-light use white LED, also used red, green and blue color LEDs (RGB LED) using RGB LED can have a wider spectrum of light, that have a wider color field.

2-Side-light emitting diode backlight technology;

Side-light emitting diode backlight technology is to white light emitting diodes on four sides of the LCD, LCD size with the LCD after a close reflective film, light emitting diodes LCD with photos from the gap between the reflective film inside, reflective film on a specially designed micro LED lighting pattern can come back after the LCD according to the light for 90 ° reflection. These reflective sheet was fine in the case without astigmatism sheet also enables the average light-emitting diode light distribution to shine LCD back.

Conventional side-illuminated light-emitting diode backlight brightness compliance can not quickly adjust brightness change different parts of the screen, but recent changes in vendor compliance screen success with the side illuminated LED technology limited quickly adjust brightness.

Liquid crystal display LCD

Liquid Crystal Display, abbreviations: LCD flat thin display device, by a number of color or monochrome pixel composition, placed in front of the light source or reflector side. Low-power liquid crystal display, so much favored by engineers, for battery of electronic equipment.

Each pixel of the liquid crystal display consists of the following parts: two layers of liquid crystal molecules suspended in a transparent electrode (indium tin oxide) between a columns outside on both sides with two mutually perpendicular polarization directions of the polarizing filters. If there is no liquid crystal between the electrodes, wherein the light through a polarizing filter whose polarization direction of the sheet, and the second polarizer perfectly vertical, and therefore is completely blocked. However, if the polarization direction of light through a polarizing filter sheet is rotating LCD, then it can be filtered through another polarizing sheet. Liquid crystal rotates the polarization direction of the light can be controlled by an electrostatic field, in order to achieve light control.

Liquid crystal molecules are easily affected by the induced charge arising from the applied electric field. A small amount of electric charge is applied to the transparent electrode of each pixel or sub-pixel to produce an electrostatic field, the liquid crystal molecules are induced by the electrostatic field induced charge and static torque, leaving the liquid crystal molecules are originally aligned to produce a rotating change, so also changed by rotating the amplitude of light. Changing the certain angle, it is possible through the polarization filters.

Before the charge applied to the transparent electrodes, the liquid crystal molecules are arranged to determine the alignment of the electrode surface, chemical surface electrode may be used as seed crystals. In the most common TN liquid crystal, the liquid crystal vertically aligned upper and lower electrodes. Liquid crystal molecules are spirally arranged, through a polarization filters rotated polarization direction of the light after passing through the LC panel, thereby through another polarizer. In this process, a small portion of the light blocked by the polarizer from the outside appears to be gray. After the charge is applied to the transparent electrodes, the liquid crystal molecules almost completely along the field direction are arranged in parallel, and therefore the direction of polarization of light through a polarizing filter sheet is not rotating, and therefore the light is completely blocked.