[CES] Sony Prototypes 56-inch 4k OLED TV Using Oxide Semiconductor TFTs

Jan 8, 2013
Fumitada Takahashi, Tech-On!
Many reporters gathered around the 4k OLED TV after the announcement.
Many reporters gathered around the 4k OLED TV after the announcement.
[Click to enlarge image]
The 4k OLED TV exhibited in Sony's booth
The 4k OLED TV exhibited in Sony's booth
[Click to enlarge image]

Sony Corp prototyped a 56-inch OLED TV that can display 4k2k video and will exhibit it at International CES 2013, a trade show of consumer electronics, which runs from Jan 8 to 11, 2013 (local time), in Las Vegas, the US.

The TV was announced by Sony President and CEO Kazuo Hirai at a press conference that took place on the day before the opening of the show. The company has not yet decided when to commercialize the TV or its price. But Hirai said, "Sony's commercial OLED monitors have already been mass-produced and widely employed while other companies' OLED TVs have yet to be released," referring to competing South Korean makers and showing confidence in its technologies.

Sony developed the OLED panel of the TV in cooperation with AU Optronics Corp (AUO). As a driver element, Sony employed an oxide semiconductor TFT instead of low-temperature polysilicon TFT, which is commonly used for OLED panels.

Oxide semiconductor TFTs tend to be in an insulating state, and they have characteristics of semiconductor like Sharp Corp's IGZO (In-Ga-Zn-O). Driver elements using those oxides are drawing much attention in the display industry as a trump card for increasing resolution and lowering power consumption.

This time, Sony did not disclose the details of the composition of the oxide semiconductor. As for reasons why the company employed an oxide semiconductor TFT, it said that low-temperature polysilicon TFTs make it difficult to increase panel size while oxide semiconductor TFTs enable to easily improve the response speed of panel enough for use in TVs.

As for the structure of the OLED device, a method that Sony calls "super top emission" was employed. The method has already been employed for commercial LCD monitors that have been commercialized. Because it uses a structure in which light is extracted from the top side of a panel, the method makes it easy to realize a high-brightness panel with a high aperture ratio.