LED backlight applied to the development trend of notebook computers

In terms of the characteristics of LED components, it has a number of technical highlights for introducing product design, but the actual component and manufacturing costs have become a great obstacle to the sales of end products. For example, most manufacturers develop high-end thin and light notebook computers at the same time. , Also actively introduced the side-lit or improved LED backlight panel design with low-cost design solutions, but the product volume compression effect is not as light and thin as the flat Dot structure design. Because the current wedge-shaped light guide plate structure has a thickness of at least 0.5~2.5mm, if the structure of the CCFL light-emitting element assembly is used, the LED circuit and the light guide plate structure are only slightly modified, and the panel thickness will be about 2~2.5mm.

　　The structure of LED components will also affect the final performance of the product

　　 In addition, there are also different components in the LED light-emitting component itself that take cost and benefit considerations. For example, high-end notebook computers emphasize thin and light design, and generally use surface-mounted side-view LEDs. At present, LED components with a height of 3~3.5mm are mostly concentrated in Japan. Even if the components are equipped Product thin design advantages, but the cost will also remain high. Relative to entry-level products, most of the basic traditional LED structure design is continued. At present, the height of such components can be as low as 4~4.5mm. In addition, the non-surface adhesion design causes the components to have a slight height difference after plug-in soldering, and the product is thin The design has certain limitations, but it has an excellent component cost price advantage.

　　Most medium and large laptop panels still continue the CCFL backlight design

　　In the notebook market of medium and large panels, due to the high cost, most of them still adopt CCFL backlight design. Even though the finished product will be slightly heavier, the cost is much lower than the development cost of LED configuration and special light guide plate required for large panels. At present, the thickness of notebook computer panels designed for medium and high-end CCFL backlight sources can reach 1~2mm. The wedge-shaped light guide plate light source configuration directly adopts LEDs. In addition to reaching the bright spots of marketing LED components, under the conditions of thinning and cost , There is no urgent need to fully introduce LED design, which is the main reason why most of the current mid- and low-end notebook computers still have not actively adopted LED backlights.

The difference between the observing flat panel and the wedge-shaped design is mainly due to the difference between the surface structure of Dot and V-Cut. If the same thickness is used for testing and comparison, the brightness performance of the light guide plate of the Dot structure is limited by the physical characteristics of the light, and its brightness performance is significantly lower than V-Cut structure design. At present, for the rapid and precise production of light guide plates, most of them adopt the light guide design of plastic rapid injection molding. The difference in structure design between Dot and V-Cut causes the Dot surface to be flat and the yield performance is good. It is because the structure of V-Cut is slightly complicated, the production yield rate is obviously low, which makes the V-Cut light guide structure more complicated in components and assembly, and causes the related industry to be discouraged.

　　Other auxiliary design solutions

Looking at the overall design of LED backlight design in notebook computers, cost is still the key to considering whether to import or not. Unless it is a thin and light model with a high unit price, the introduction of LED design is not equal to the guarantee of product thin design, some low cost The design method will also cause the terminal design to appear thicker. In terms of cost and benefit, a large number of LED backlight product sizes have been introduced. At present, 13-inch small and medium-sized screens are mostly used, because regardless of the Dot or V-Cut configuration, the amount of LED components for small and medium-sized screens is already the same. It is greatly reduced, and the area of the light guide plate can also be effectively reduced, and the cost is still within the range that the industry can absorb.

　　 If you look at the large screen models of 15-20 inches, the cost of introducing LED backlights will increase significantly. If a thinner design is required at the same time, the cost of the product will be greatly increased, and the yield problem must also be taken into consideration. In addition to the components and light guide plates, the key to the design of LED backlights is that the optical films, brightness enhancement films, and diffusers commonly used in CCFL can also be used in LED backlight design. For example, special optical films are used in both LEDs and CCFLs. The performance of different backlight components is not very different. There are no design restrictions on the use of diffusers or optical films. However, most low-priced products usually do not choose this type of solution, because it can increase the luminous efficiency by 15-20% or It is to improve the uniformity of the light source at the corners, but it is also due to the higher cost, so there are not many manufacturers used