5/30/2023 0 Comments Dot by dot vs fullSome quantum-dot producers are marketing their product as cadmium-free. The European Union restricts the use of cadmium in household appliances. Still, there are health and environmental concerns, especially if a bunch of quantum-dot TVs end up in landfills. Some quantum dots also contain cadmium, which is toxic at high levels-think “factory emission” levels rather than “sealed tube or film in your TV” levels. The red and green quantum dots combine with blue light to produce a "pure" white that can be efficiently channeled by the set's color filters. Here's a sheet of quantum-dot film on top of a blue LED backlight system. The film layer also purportedly works better with full-array backlight systems, which will be used in a lot of UHD and HDR TVs. According to QD Vision, the oxygen-barrier film needed for film-based dots is costly, which explains why Nanoco and Nanosys are partnering with Dow and 3M for that film.įilm-based suppliers say their method has the upper hand due to "light coupling," or the ability to feed all that quantum-dot light directly into a light-guide plate. QD Vision claims its tube-based approach is easier and cheaper to implement, and it can boost the color performance of cheaper edge-lit LCD sets. They get, in some cases, better than OLED-type color at a fraction of the cost.”Īs you'd expect, companies making film-based and tube-based solutions are touting each approach as superior. Nothing in the supply chain gets changed, nothing in the factory gets changed. “They remove a diffuser sheet in front of the light-guide plate and replace it with quantum-dot film. “The attraction to the OEM is that this is a pure drop-in solution,” says Nanoco CEO Michael Edelman, whose company makes quantum-dot film in a licensing deal with Dow Chemical. They’re closer to OLED in color performance, and they also can get brighter. That's a big reason LG is the only company putting big money into building them.Ĭonversely, quantum-dot sets don’t require overhauling the LCD fabrication process, and they produce a much wider color gamut than traditional LCDs. But they're expensive to build and expensive to buy-you're looking at $3,500 to as much as $20,000-and the manufacturing process differs in several key ways. In most peoples' eyes, OLED TVs are the best tech available. The purer the color you start with, the more relaxed the filter function can be. “When you purify the color using a color filter, then you will get practically no transmission through the filter. Nanosys makes film-based quantum-dot systems for several products. “A filter is a very lossy thing,” says Nanosys President and CEO Jason Hartlove. It’s kind of dirty, with a lot of light falling in a color range unusable by the set’s color filters. In a normal LCD, white light produced by the LEDs has a wider spectrum. Translation: Pure red and pure green light, which travels with the blue light through the polarizers, liquid crystals, and color filters.īecause that colored light is the good stuff, quantum dots have an advantage over traditional LCD TVs when it comes to vivid hues and color gamut. If you observed quantum-dot light with a spectrometer, you would see a very sharp and narrow emission peak. It's lit with an ultraviolet flashlight, which is what makes the dots glow red. This is a batch of red quantum dots being prepared in a 70-liter vat.
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