QD Display Makes Debut at CES 2022 – Sort of
Perhaps the biggest display-related news to come out of CES 2022 was the official unveiling of the QD Display technology developed by Samsung Display. Fortunately, the 8K Monitor was one of only five media representatives who saw the display at CES. Sony announced they would offer a TV based on the technology, but Samsung Electronics failed to announce a product (although they did win an award for the QD Display technology). Sony pulled all of their TV product from CES, so Samsung Display was the only opportunity to see the display in person.
An initial review of the product is available at: https://youtu.be/MQ7FrgzNRok. Here, we provide more details.
First, QD Display is the new name that Samsung Display Corp. (SDC) will use for this display architecture which most industry watchers had previously called QD OLED. It is fabricated using an oxide backplane upon which blue OLED emitting layers are deposited. There is speculation that dual or even a three-layer blue structure is used to maximize the lifetime of this blue emitting layer, but Samsung Display would not confirm which one they use.
A “clear” subpixel is used for the blue, while red and green quantum dots are patterned for those colors to create subpixels. These quantum dots are inkjet printed on top of the blue OLED layer. In their presentation, SDC says they use color conversion, not filtering as is done in conventional OLED panels. That is not entirely true, as there is a color filter in the display which is needed to clean up any blue light leakage in the red or green subpixels to improve colorimetry and stop ambient light from exciting the R/G quantum dots. However, the color filter does not need to be as aggressive as LCD or OLED displays.
There are several clear advantages compared to a conventional OLED panel. They are summarized in the graphic.
Let’s look at these claims in more detail. First, it must be noted that all comparisons done in the demo were for the 2021 OLED TV (brand not identified). At CES 2022, LG Display announced a new EVO OLED panel with “brightness boost” that will increase luminance about 30% above the 2021 model level, so future comparisons must be clear to which OLED panel it is compared to.
The SDC graphic below shows data to illustrate the spectral profiles of red, green, and blue and then white for the QD Display and the OLED display. This illustration of the relatively stronger output of the RGB and a “peakier” spectrum for white is similar to a quantum dot LCD display. A wider BT2020 color gamut coverage can thus be achieved (90% vs. 76%).
The third column compares the production of white light. Note that there is no difference in the results of the QD Display, but there is in the OLED display. The top chart shows the OLED using the white subpixel to achieve higher white luminance of close to 800 nits, but without the white subpixel, the OLED only creates about 400 nits of white luminance (bottom graphic). OLEDs can struggle to produce bright, saturated colors. This limitation is the main reason the color volume on QLED or QD Displays is much larger than OLEDs (123% vs. 94%). (Note: measurement of color volume is not standardized, so evaluation of the method is needed for better understanding.)
SDC says the display can reach a peak white of 1500 nits, which appears true but only in a very small (<~3%) window. Compared to the OLED in a common 10% window, the QD Display produces about 1000 nits – higher than conventional OLED panels but probably pretty close to the new EVO OLED panels with a brightness boost. This high luminance will improve the picture quality in very bright but tiny objects like stars, sparkle, or specular reflections. This was evident in some of the scenes we saw at CES 2022.
However, also notice that at APL levels 70% to 80%, the luminance of the QD Display is similar to OLED. That means sunlit skiing scenes will not be any brighter.
In the demo, SDC measured the red, green, and white luminance of a 10% patch with the QD Display and an OLED TV set in vivid mode. The results shown below differ somewhat from their published specs.
Next is the viewing angle. The graphic below compares the OLED and QD display at a 60-degree angle vs. on-axis viewing. The data suggests that the QD Display maintains better luminance at this extreme angle (81% vs. 53%), and it has a much lower color shift (0.006 vs. 0.02 Delta u’v’). This improvement was also demonstrated in our tour and was quite noticeable.
Just after CES, Samsung Display issued a press release that highlighted new certification metrics for their QD Display. Three new certifications were revealed: True Color Tones, Pure RGB Luminance, and Ultrawide Viewing Angle. Testing procedure details were not released, however.
Our demo tour looked at varied content that verified many of the claims above. SDC also wanted to illustrate that they thought they had better dark shadow detail rendering than the OLED TV. This rendering is a tone mapping decision for the TV makers, not a fundamental panel technology. Many examples did show this, but there were other examples where the OLED TV revealed better texture detail and did not blow out the highlights. The point is, SDC is a panel maker, and it is the TV makers who will be responsible for fine-tuning the tone mapping to optimize the picture quality.
SDC also notes that the QD display is less reflective than an OLED panel. This improvement appears to be due to the top-emitting architecture vs. the bottom-emitting OLED structure.
Finally, we turned to the backplane technology SDC called “oxide”. We asked if that meant IGZO, and they said they prefer to call it oxide as IGZO is a brand name developed by Sharp. That is the first time we have ever heard of that, so maybe they know something we don’t. Regardless, this backplane allows for swift response times of 0.1 ms for gray-to-gray (much better than LCD) and a 144 Hz TV refresh rate (vs. 120 Hz for OLED) and 175 Hz for monitors.
SDC will offer the QD Display in 55” and 65” 4K resolution and a 34” QHD+ resolution monitor. Dell/Alienware and Samsung Electronics are the first announced customers for this monitor panel. Note: the above specification discussion is for the TV panels, and these specs will be different for the monitor displays.
We also asked about the development of an 8K TV using the QD Display technology. According to SDC, they are now talking to potential customers to understand the requirements for an 8K TV. They acknowledged that some development might be needed to support 8K versions, but other sources suggested that the inkjet printing process is ready to go for 8K resolution panels.
So, the TV and monitor market will see a new display technology introduced, a hybrid between existing OLED and quantum dot-based LCD TVs. The key to better understanding the prospects for QD Displays is how the brands will position and price these sets. For example, will QD Display sit above QLED miniLED displays or below them? How much of a premium will consumers pay for a QD display vs. an OLED one? We will have to wait to get the answers to these critical questions.
