Osram Opto Semiconductors GmbH of Regensburg, Germany has unveiled new Quantum Colors conversion technology – developed in part in the SSL4EU and Hi-Q-LED projects funded by the European Union (EU) and the German Ministry of Education and Research (BMBF) – that it claims will set new standards in LED backlighting for TV displays, in offering much better coverage of the color space, significant cost savings compared with conventional quantum dot sheets, and zero cadmium usage.
For many years leading manufacturers of TVs have been demanding an ever broader color space, notes the firm. With the advent of Ultra HD, the TV standard is once again moving to a larger color triangle. Quantum Colors was developed for precisely this standard. Initial customer projects are in progress, and the technology is scheduled for backlighting LEDs for the mass market by the end of 2016.
Picture: Quantum Colors technology combines a blue chip, red phosphor layer and green quantum converter layer.
Quantum Colors technology is based on a green quantum converter layer that is combined with red phosphor layer on a blue-light-emitting chip, and does not require any cadmium. Advantages over quantum dot sheets (which have been used up to now for high-quality color rendering in TV backlighting) include what is claimed to be superior coverage of the color space due to a narrow green peak with a full width at half maximum (FWHM) of only 30nm. Color space standards such as DCI can be covered 100% and REC2020 more than 80%. Also, the technology does not require the system or any other components to be adapted, simplifying production processes and the entire system.
Compared with solutions based on quantum dot sheets, costs can be halved, it is reckoned. "For a 55-inch Ultra HD TV with 100% DCI coverage, the complete cost of the light source can be as low as 55 euros, based on our Quantum Colors technology," says Peter Lenz, product marketing LED at Osram Opto. "The cost of just the quantum dot sheets in existing solutions is twice as high [according to report 'The Price of QD Material is Falling, But Not Enough from DisplaySearch', issued on 6 February]."
Another advantage is the constant color throughout the life of the LED, says the firm. Quantum dot sheets take on a bluish tinge over time. As far as lifetime is concerned, Quantum Colors LEDs should last at least 30,000 hours; initial tests have produced positive results, concludes Osram Opto.
