By Jimmy Kim
DisplaySearch

Ultra-slim has become a main feature for mobile PCs, and TVs are also trying to capitalize on this trend. Recently, Sony officially launched its Bravia X900C and X910C series LCD TVs described as having “ultra-thin floating styles” with only 4.9 mm thickness.

With OLED TV being promoted with under 5.0 mm thickness, a 4.9 mm thickness would be an indispensable specification for ultra-slim LCD TVs to compete in the high-end market. LCD TV thickness has been reduced with the introduction of edge-type LED (E-LED) backlights, which lower LCD module thickness from 30-40 mm to only 10 mm. However, the total thickness of a typical edge-type LCD TV set is still around 30-40 mm. This is mainly due to the modular structure of the LCD TV. The LCD and other components for TV sets are supplied in the form of modules. These require space in the TV set structure for the SMPS, sound board, image processing board, and others electronic components plus the chassis.

However, with the help of the open cell business and BMS (Backlight Module System) business model, TV makers have introduced a single module design to remove the chassis and optimize space configurations in LCD panels and other electronics. With the help of open cell technology, the TV set thickness can be reduced to 10 mm without any additional slimming technology.

Glass LGPs (Light Guide Plate) are being used to further slim TV designs. The current LED thickness for TV is about 3 mm, and the thickness of the LGP should be the same as the LED. However, slimmer LEDs can lead to a decrease in luminance, so the number of LEDs required increases. When glass LGP was introduced, a 1 mm thickness became available. The number of LEDs could be minimized due to the higher transmittance of glass materials.

Sony’s ultra-slim TV (and target thickness for competition with OLED TV) is 4.9 mm. This means that a total of 5 mm must be reduced from the typical 10 mm LCD module. In the below figure, we summarized the component technologies for ultra-slim LCD TVs. 3 mm can be reduced by slimming the optical sheet stack and glass substrate.

Most of the slimming technologies in the above figure have already been adopted in mobile LCDs. The manufacturing cost per unit area is higher for mobile LCDs, but not as much as for large-area LCDs. So the question is how much of a premium will super-slim LCD TV incur? And will this premium be comparable with OLED TV, which is naturally slim because there is no backlight?

In our cost simulation, if we assume a normal 55” 4K LCD module is 1, then the ultra-slim LCD module will be 1.7X. This is still considered to be economical compared with the same specification OLED TV, which would be over 3X that of LCD.

The next question is will consumers pay more for slimness alone? Slim LCD TVs may cost less than OLED TVs, but OLED has several merits beyond just a slim design. Also, consumers see OLED as a totally new technology, while ultra-slim LCD is regarded as just a revised one. Therefore, OLED may be able to justify its premium. Other TV makers should continue to carefully observe the market for now.

This column was reprinted with permission from DisplaySearch and originally appeared here.