CCFL LCD backlight Analysis of strengths and weaknesses

Most LCD monitors on the market are based on CCFL (cold cathode fluorescent lamp ) backlight. CCFL backlight design are mainly two: " side-in " and " straight sets " type , but because of the side- by optical light guide design allows high attrition rates , thereby allowing the backlight brightness of the subject , the brightness of the larger panel size lower , in general, when the liquid crystal panel size over 15 inches , the backlight brightness will be significantly reduced. So we use at home are usually large-size LCD Teluk style .

Teluk type CCFL backlight module does not require a light guide plate , breakage problems are more dull , so I do not need the brightness enhancement film , especially a minority brightness enhancement film industry's patented technology , expensive, Telok style guide can be omitted brightness enhancement film and the optical plate , the cost can be significantly reduced.

But here and there is a problem , the use of Teluk type CCFL backlight LCD, panel size larger the proportion of the cost of its share of the higher backlight module , there was statistical point out that the same is to use straight sets type CCFL backlight module , when 15 inches backlight module cost only 23 % of the total , but it increased to 30 inches by 37% , and the estimate to 57 inches , backlight module cost share will reach 50% . So, Teluk type CCFL backlight only suitable for use in 30 inches or so medium-sized LCD, is not suitable for use in the design of a larger area .OLED Display Meanwhile , CCFL is the use of mercury to produce the gas discharge lighting, although the RoHS EU entered into , as long as "Mercury " dose below standard still acceptable , but no one can guarantee the future is likely to raise the standard to zero content ( do not allow use ) , then CCFL will not be used, or be diverted to non-mercury type CCFL.

Even non-mercury type CCFL technically feasible, but is still confined CCFL light tube of gas-discharge electron illumination , light tubes resistant to external force is limited by the resistance , the larger the collision will cause light pipe rupture, so the lighting failure. And in order to enhance the brightness of the screen , you must increase the number of fluorescent tubes , and then the optical density of the light pipe arrangement is too large will have a huge amount of heat , which will heat the liquid crystal forming a great challenge. Therefore, in order to ensure the heat, the only viable solution is to increase the volume of the liquid crystal.

Incidentally that the use of large -inch CCFL lcd module TV on the number of fluorescent tubes , light pipe length must also be increased due to the number of inches and growth, but longer CCFL light tube with both ends of the middle of the light pipe will prone to brightness and color MURA MURA problems , thereby affecting all of the backlight light , in order to continue to maintain the light are , you must spend to enhance light diffusion film have degrees, but the proliferation of film will bring light transmittance of breakage , reducing the brightness , the results had to reduce the brightness to increase the number of the light pipe to the reinforcing way , but the previously described : the light pipe will increase the heat difficult to design , to increase the thickness of the backlight module , the power consumption increases even under statistics, electricity CCFL backlight LCD TV accounted for 90% of overall electricity consumption high . So, change the backlight technology is one of a change in the direction of the current LCD picture quality .