TCL’s German QLED ban puts pressure on TV brands to be more honest about QDs
“Some products marketed as ‘QLED’ use conventional backlight architectures (standard phosphors, optical films, diffusion plates) and rely on image modes or software adjustments to create a more saturated ‘vivid’ look,” reads a January white paper from TÜV Rheinland and vendor QD Nanosys. The white paper, “Redefining a ‘True’ Quantum Dot Display,” also highlights devices that contain QD material at “trace levels, or in packaging and integration designs that limit the excitation and extraction of light of certain wavelengths.”
“In these cases, the display can still achieve competitive gamut coverage, but the measurable optical signature of an effective QD system is absent or minimal,” the white paper states. “Spectrum, color, high luminance volume behavior, chromaticity stability and temporal response can remain similar to non-QD LCD solutions. »
For now, the German ruling brings increased scrutiny to “QLED” and other potentially misleading display terms.
A clear understanding of what constitutes QD displays is also essential for QD-OLED displays and will only become more important if true quantum dot electroluminescent displays ever take off. (These displays, using backlight-less technology, are also known as QDELs or QD-LEDs.)
“A quantum dot display should be defined by a combination of measurable material concentrations and TV performance in terms of color purity, color gamut, etc. Ideally, in a way that consumers can understand,” Virey said.
The white paper from TÜV Rheinland and Nanosys claims that QD displays should meet certain performance requirements that go beyond color gamut: “The display must provide the optical benefits associated with quantum dots, including spectral precision, tunability and stability, improved color accuracy behavior across the entire luminance (not just a single 2D gamut number), and, where applicable, temporal performance under backlight modulation.”
As TV marketing remains obscure – and often misleading – detailed performance analysis remains the most reliable way to gauge a screen’s performance in the real world.
