Side light white LED will shift from NB to LCD TV

On plant survey of consumers, most of them think that LCD TV 50mm thickness is not attractive, and 30mm's products can get the favor of consumers, in order to produce attractive products, side light type white LED will turn to LCD TV from NB.

Generally side light type LED is mostly applied in the Portable display device or laptop computer (NB) with TFT backlight, due to LCD related industry have been toward the ultra-thin LCD TV/ panel design, and side light type white LED backlight with side light type cold cathode fluorescent lamp (CCFL) and RGB, LED and direct CCFL and LED with this advantage, so the application of gradually attention.

Side light white LED backlight module design in the thinnest thickness

By Hitachi will be listed as the world's first ultra-thin LCD TV manufacturers, which will begin in December 2007 sales of 32 inches, the thickness of only 35mm LCD TV, the aircraft used CCFL backlight, priced at 230 thousand yen (about $2116).

By Hitachi recently for the 60 respondents as the "LCD TV 50mm 30mm for the thickness and preference questionnaire, among them, only 1.6% of respondents believe that the relative thickness of 50mm LCD TV is attractive, as high as 55.6% of the respondents said the 30mm LCD TV has the attraction of ultra-thin display LCD TV is one of the trends of the future design of TV.

CCFL because of its low cost, with high reliability, the ultra-thin LCD TV is preferred by and backlight market, but if the single "thickness", and more than CCFL LED backlight "slim" advantage.

Recently published various manufacturers ultra-thin TV LCD panel, Samsung Electronics (SAMSUNG ELectronics) show in late October the thinnest 40 inch LCD panel, the side light type white LED backlight, expects the production started in the middle of 2008, Samsung Electronics launched time history is Hitachi make the night more than half a year, but the thickness of can match the OLED TV (Sony OLED TV 27 inch 9mm thickness).

Sony OLED TV has recently listed the size is only 11 inches, so the future OLED size will up to 40 inches level. Samsung SDI OLED blueprint for the future size as an example, its production will be 42 inch OLED panel in 2010, so the LCD camp to close to OLED TV in ultrathin TV thickness, should give priority to the side light type LED backlight led to TV with the LCD panel.

Side light white LED saves space

LCD TV to be thin, there are 2 main factors, respectively, the backlight module and the power supply board thickness, because the entire area with LCD backlight module and the power supply board panel is similar, only LCD TV part of the area, in other words, the thickness of the thinnest part of LCD TV, a great the relationship with the backlight module.

The application of side light type backlight module with LED LCD in TV, its thickness is CCFL type direct type and side light type, and LED direct type is thin, with Samsung 40 inches, the thickness of 10mm TV with the LCD panel, the backlight module thickness of only about 5mm.

Why mining direct type backlight module design, its thickness is not easy to reduce? The reason is that Ruo Guangyuan (either CCFL or LED) is too close to the above optical film is easy to produce Mura (uneven), so the back of the light source and the optical membrane between the need to maintain a certain distance; and if the RGB LED is the direct type back light source, light is longer mixing space.

With side light type CCFL backlight module, because CCFL tube diameter is LED encapsulation thickness is high, so the thickness of the LCD panel side light type LED backlight can be thinner than the CCFL side light type.

The thickness of the backlight module although the side light type RGB LED and type LED can be white is very thin, but also to the ultra-thin LCD TV low power consumption design, which can cooperate with the white LED light source with low power consumption requirements, the reason is the luminous efficiency white LED RGB LED is good, so in the same size as the 40 inch TV grade LCD panel, which uses a number and the power consumption is about 1 times higher than the former.

Side light white LED backlight applications in LCD TV disadvantages

Although the above mentioned side light type white LED used in LCD TV backlight advantages, but also can not be ignored in the design has some problems, such as can not make regional control and use the number of teeth and power consumption than direct white LED light guide plate, high development and other issues.

Direct type LED backlight (either RGB or white LED) is one of the biggest advantage, because LED is a point source, it can achieve regional control, this makes LCD TV screen brightness can be adjusted partition shading, dynamic contrast value increased to 100 thousand the number of more than 1, the power consumption can be compared with CCFL backlight, low dynamic image quality is better, this is difficult to achieve the function of CCFL backlight.

And side light type LED is composed by the point source line source, rather than by the point source distribution to the TV LCD panel using the whole area, so it can not make the regional control function, so the dynamic contrast value and increasing dynamic image quality without help; furthermore, in order to make the light side light type LED the uniform distribution of the whole piece to TV with the LCD panel, so the light flux density and high demand, so in the same size, side light type white LED using a number of anti than direct white LED a little more; in addition, because of the side light type LED light source in the bright state, so the consumption of direct type LED backlight electricity is the high area control.

Ultra-thin light guide plate is currently used in LED backlight NB cost is still high, to be more than 40 inches large area will be a challenge, not only to prevent large area light fragmentation guide ultra-thin, how will the side light source evenly distributed to the other side of the light guide plate micro structure