“Some products marketed as ‘QLED’ use conventional backlight architectures (standard phosphors, optical films, diffuser plates) and rely on picture modes or software tuning to create a more saturated ‘vivid’ look,” a January whitepaper by TÜV Rheinland and QD supplier Nanosys reads. The whitepaper, “Re-defining a ‘true’ Quantum Dot Display,” also points to devices that have QD material at “trace levels, or in packaging and integration designs that limit excitation and light extraction of certain wavelengths.”

“In these cases, the display may still achieve competitive headline gamut coverage, yet the measurable optical signature of an effective QD system is absent or minimal,” the whitepaper says. “The spectrum, color, volume behavior at high luminance, chromaticity stability, and temporal response can remain similar to those of non-QD LCD solutions.”

For now, the German ruling brings needed 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 a backlight-free technology, are also known as QDEL or QD-LED.)

“A quantum dot display should be defined by a combination of measurable material concentration and TV performance outcomes in terms of color purity, color gamut et cetera. Ideally, in a way that is understandable by consumers,” Virey said.

TÜV Rheinland and Nanosys’ whitepaper argues that QD displays should meet certain performance requirements that go beyond color gamut: “The display must deliver the optical advantages associated with quantum dots, including spectral precision, tunability and stability, improved color accuracy behavior across luminance (not just a single 2D gamut number), and, where applicable, temporal performance under backlight modulation.”

With TV marketing remaining murky—and often misleading—digging into detailed performance reviews remains the most reliable way to gauge how a display might perform in the real world.