Digging Into the New QD-OLED TVs

Formerly rival technologies have come together in Samsung displays

5 min read
Television screen displaying closeup of crystals

Sony's A95K televisions incorporate Samsung's new QD-OLED display technology.

Sony
Blue
Televisions and computer monitors with QD-OLED displays are now on store shelves. The image quality is—as expected—impressive, with amazing black levels, wide viewing angles, a broad color gamut, and high brightness. The products include:

All these products use display panels manufactured by Samsung but have their own unique display assembly, operating system, and electronics.

I took apart a 55-inch Samsung S95B to learn just how these new displays are put together (destroying it in the process). I found an extremely thin OLED backplane that generates blue light with an equally thin QD color-converting structure that completes the optical stack. I used a UV light source, a microscope, and a spectrometer to learn a lot about how these displays work.

rows of green squares alternating with rows of red and blue squares against a black background

Samsung used a unique pixel pattern in its new QD-OLED displays.

Peter Palomaki

A few surprises:

  • The pixel layout is unique. Instead of being evenly arrayed, the green quantum dots form their own line, separate from the blue and red [see photo, above]. (The blue pixels draw their light directly from the OLED panel, the red and green pixels are lit by quantum dots.)
  • The bandwidth of the native QD emission is so narrow (resulting in a very wide color gamut, that is, the range of colors that can be produced, generally a good thing) that some content doesn’t know how to handle it. So the TV “compresses” the gamut in some cases by adding off-primary colors to bring its primary color points in line with more common gamuts. This is especially dramatic with green, where “pure” green actually contains a significant amount of added red and a small amount of added blue.
  • While taking this thing apart was no easy task, and deconstruction cracked the screen, I was surprised at how easily the QD frontplane and the OLED backplane could be separated. It was easier than splitting an Oreo in half. [See video, below.]

As for the name of this technology, Samsung has used the branding OLED, QD Display, and QD-OLED, while Sony is just using OLED. Alienware uses QD-OLED to describe the new tech (as do most in the display industry).

—Peter Palomaki

Story from January 2022 follows:

For more than a decade now, OLED (organic light-emitting diode) displays have set the bar for screen quality, albeit at a price. That’s because they produce deep blacks, offer wide viewing angles, and have a broad color range. Meanwhile, QD (quantum dot) technologies have done a lot to improve the color purity and brightness of the more wallet-friendly LCD TVs.

In 2022, these two rival technologies will merge. The name of the resulting hybrid is still evolving, but QD-OLED seems to make sense, so I’ll use it here, although Samsung has begun to call its version of the technology QD Display.

To understand why this combination is so appealing, you have to know the basic principles behind each of these approaches to displaying a moving image.

In an LCD TV, the LED backlight, or at least a big section of it, is on all at once. The picture is created by filtering this light at the many individual pixels. Unfortunately, that filtering process isn’t perfect, and in areas that should appear black some light gets through.

In OLED displays, the red, green, and blue diodes that comprise each pixel emit light and are turned on only when they are needed. So black pixels appear truly black, while bright pixels can be run at full power, allowing unsurpassed levels of contrast.

But there’s a drawback. The colored diodes in an OLED TV degrade over time, causing what’s called “burn-in.” And with these changes happening at different rates for the red, green, and blue diodes, the degradation affects the overall ability of a display to reproduce colors accurately as it ages and also causes “ghost” images to appear where static content is frequently displayed.

Adding QDs into the mix shifts this equation. Quantum dots—nanoparticles of semiconductor material—absorb photons and then use that energy to emit light of a different wavelength. In a QD-OLED display, all the diodes emit blue light. To get red and green, the appropriate diodes are covered with red or green QDs. The result is a paper-thin display with a broad range of colors that remain accurate over time. These screens also have excellent black levels, wide viewing angles, and improved power efficiency over both OLED and LCD displays.

Samsung is the driving force behind the technology, having sunk billions into retrofitting an LCD fab in Tangjeong, South Korea, for making QD-OLED displays While other companies have published articles and demonstrated similar approaches, only

Samsung has committed to manufacturing these displays, which makes sense because it holds all of the required technology in house. Having both the OLED fab and QD expertise under one roof gives Samsung a big leg up on other QD-display manufacturers.,

Samsung first announced QD-OLED plans in 2019, then pushed out the release date a few times. It now seems likely that we will see public demos in early 2022 followed by commercial products later in the year, once the company has geared up for high-volume production. At this point, Samsung can produce a maximum of 30,000 QD-OLED panels a month; these will be used in its own products. In the grand scheme of things, that’s not that much.

Unfortunately, as with any new display technology, there are challenges associated with development and commercialization.

For one, patterning the quantum-dot layers and protecting them is complicated. Unlike QD-enabled LCD displays (commonly referred to as QLED) where red and green QDs are dispersed uniformly in a polymer film, QD-OLED requires the QD layers to be patterned and aligned with the OLEDs behind them. And that’s tricky to do. Samsung is expected to employ inkjet printing, an approach that reduces the waste of QD material.

Another issue is the leakage of blue light through the red and green QD layers. Leakage of only a few percent would have a significant effect on the viewing experience, resulting in washed-out colors. If the red and green QD layers don’t do a good job absorbing all of the blue light impinging on them, an additional blue-blocking layer would be required on top, adding to the cost and complexity.

Another challenge is that blue OLEDs degrade faster than red or green ones do. With all three colors relying on blue OLEDs in a QD-OLED design, this degradation isn’t expected to cause as severe color shifts as with traditional OLED displays, but it does decrease brightness over the life of the display.

Today, OLED TVs are typically the most expensive option on retail shelves. And while the process for making QD-OLED simplifies the OLED layer somewhat (because you need only blue diodes), it does not make the display any less expensive. In fact, due to the large number of quantum dots used, the patterning steps, and the special filtering required, QD-OLED displays are likely to be more expensive than traditional OLED ones—and way more expensive than LCD TVs with quantum-dot color purification. Early adopters may pay about US $5,000 for the first QD-OLED displays when they begin selling later this year. Those buyers will no doubt complain about the prices—while enjoying a viewing experience far better than anything they’ve had before.

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BMW’s iVision Dee Brings Sci-fi to the Driveway

This concept car’s e-paper skin turns a paint job into an exterior screen

4 min read
Group of four images of cars, each the same car, but colored and patterned differently.

The body of BMW’s latest concept car, the iVision Dee, is like a big e-paper screen, allowing each pixel to assume one of 32 exterior colors.

BMW

Before I met BMW’s iVision Dee at a press preview event in Germany—prior to a public reveal at CES in Las Vegas last week—I’d never seen a car blush, let alone had one make me blush. But then the electric BMW began changing colors and facial expressions, talking at me in intimate detail, splashing a digital avatar of my face on its side window, and filling its windshield with head-up display (HUD) projections worthy of Minority Report.

The “Dee” in this radical concept sedan stands for “Digital Emotional Experience.” That includes its eponymous, sultry-voiced virtual assistant. The body’s 240 laser-cut, Kindle-style “e-ink” panels let the BMW transform instantly to one of 32 exterior colors. Excited by low current—15 volts and less than 100 milliamperes—the panels’ microencapsulated particles create a moveable e-paper display. Feeling hot pink today? Go for it. And don’t worry about dinging the electric driving range: The chameleonic material uses nominal energy, and only while it’s shifting color to another shade.

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Building the Future of Smart Home Security

Engineers must invent new technology to enhance security products’ abilities

4 min read
One engineer peers into a microscope to work on a small circuit while another engineer looks on

In this article, SimpliSafe’s VP of Software Engineering discusses his team’s focus on creating a safer future through enhanced technology.

SimpliSafe

This is a sponsored article brought to you by SimpliSafe.

It’s nearly impossible to find a household today that doesn’t have at least one connected smart home device installed. From video doorbells to robot vacuums, automated lighting, and voice assistants, smart home technology has invaded consumers’ homes and shows no sign of disappearing anytime soon. Indeed, according to a study conducted by consulting firm Parks Associates, smart home device adoption has increased by more than 64 percent in the past two years, with 23 percent of households owning three or more smart home devices. This is particularly true for devices that provide security with 38 percent of Americans owning a home security product. This percentage is likely to increase as 7 in 10 homebuyers claimed that safety and security was the primary reason, after convenience, that they would be seeking out smart homes, according to a report published by Security.org last year.

As the demand for smart home security grows, it’s pertinent that the engineers who build the products and services that keep millions of customers safe continue to experiment with new technologies that could enhance overall security and accessibility. At SimpliSafe, an award-winning home security company based in Boston, Mass., it is the pursuit of industry-leading protection that drives the entire organization to continue innovating.

In this article, Nate Wilfert, VP of Software Engineering at SimpliSafe, discusses the complex puzzles his team is solving on a daily basis—such as applying artificial intelligence (AI) technology into cameras and building load-balancing solutions to handle server traffic—to push forward the company’s mission to make every home secure and advance the home security industry as a whole.

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