Startup beats QDs and OLEDs to colour rendering

May 24, 2017 // By Julien Happich
Two-year old Californian startup PixelDisplay aims to revolutionize the colour rendering of LCD displays with a new technology which it claims exceeds Quantum Dot and OLED colour gamut.

Demonstrating the trade-marked Vivid Color technology at DisplayWeek, PixelDisplay's CTO David Wyatt accepted to share more details with eeNews Europe.

In a presentation "Ultra-Wide Gamut LCD using Vivid Color Technology," nominated for Distinguished Paper during the tradeshow's technical symposium, the CTO detailed the optimization steps the PixelDisplay has taken to design a white LED backlight that would generate more saturated and non-overlapping red, green and blue (RGB) primary colours, each with a FWHM (full width at half maximum) emission narrowed down to 10nm.

In a live demonstration at DisplayWeek, the company is putting different light sources (LED, Laser, iPhone, Vivid Color) into an integrating sphere with a live spectroradiometer showing the spectral characteristics, showing visitors real working hardware rather than simulations.

The proprietary InGaN LED developed by the company, together with a custom blend of nitride, silicate and aluminate based-phosphors and newly developed colour filters to efficiently suppress colour crosstalk, achieves a high colour gamut (97.8% Rec. 2020 in CIE 1976), comparable to laser-lit displays.

Measured emission spectra for a conventional
white LED versus the Vivid Color LED.

Emitting at three peak wavelengths of 467nm, 532nm, and 630nm for the primary blue, green and red colours respectively, consistent with the three primary colours of Rec. 2020 standard, the new white LED design not only outshines state-of-the-art QDs and OLEDs while being cheaper, it could also enable the use of more transmissive colour-filters, further improving power-efficiency and battery-life.

Discussing why most LCD displays use commercial white LEDs for their backlight (optimized for the broadest spectrum rather than three narrow RGB peaks), Wyatt explains that today's "White" LED is essentially a "hack". "It's really Blue + yellow, which psychovisually appears white to humans because it triggers complementary colour optic nerves".