Samsung Galaxy Note Superbowl Ad
With all of the focus on the Superbowl and the Superbowl ads it was gratifying to see two ads for PenTile equipped products in a single Superbowl. One was for the Galaxy Note with a 5.3-inch diagonal 800 x 1280 format PenTile OLED display http://bit.ly/yW5brS The other ad was for the Motorola RAZR with a 4.3-inch qHD format PenTile OLED display. http://huff.to/wqqHYr
By my count today PenTile has shown up in 118 products to date.
For those who would like more information about PenTile OLED and PenTile RGBW technologies for mobile products, you may wish to attend the up coming talk by Nouvoyance CEO Candice Brown Elliott in Southern California, “AMOLED vs. Hi-Res LCD for Premium Cell Phones”. She will be speaking at the Los Angeles Society for Information Display Chapter’s annual symposium on “Emerging Display Technologies” on February 3rd, 2012. For more information regarding attending the symposium, visit the LA SID Chapter website: http://www.sid.org/ConferencesExhibits/LAChapterEmergingDisplayTechConference.aspx
Ms. Brown Elliott will also be speaking in Northern California, at Stanford University on the 28th of February on the topic of “Reducing Field Sequential Color Break-Up Artifacts using a Hybrid Display with Locally Desaturated Virtual Primaries”. This talk will cover the development of the PenTile Hybrid Multi-Primary Field Sequential Color display that was demonstrated by Samsung in their DisplayWeek 2011 booth last May in Los Angeles. For more information regarding attending the talk, visit the Stanford Center for Image Systems Engineering website: http://scien.stanford.edu/
Perhaps you may have noticed that LG introduced an RGBW OLED TV at CES, using a white OLED process together with traditional RGB+Clear color filters.
http://www.oled-info.com/lg-55em9600
The purpose of this was ostensibly to facilitate the manufacturing of a large diagonal OLED, that is traditionally difficult with shadow mask deposition techniques. My assumption is that they used RGBW to enhance brightness, taking advantage of their white OLED material to attain the longer 30,000 hours or more of lifetime which is now expected for TVs. At CES I was told that the layout was a QUAD layout, which uses 4 subpixels per pixel, unlike PenTile that uses, on average, 2 subpixels per pixel achieved through subpixel rendering.
Similarly, we are also seeing additional announcements of products by Sony using their Sony Whitemagic™ technology.
http://news.in.msn.com/technology/article.aspx?cp-documentid=5762843
The layout of RGBW for Whitemagic also has used 4 subpixels per pixel unlike PenTile’s 2 subpixels per pixel on average. While Sony’s stated purpose for Whitemagic has been to enhance power efficiency, a 4 subpixel per pixel layout only take advantage of the improved light throughput of clear subpixels. It is, no doubt, an improvement to power efficiency, but it forgoes the chance to improve aperture ratio, which a significant part of what is achieved with PenTile technology. As one moves to increasingly higher resolution formats aperture ratio becomes a major limitation, even for low temperature polysilicon (LTPS) backplanes. For PenTile, however, the contribution of improved efficiency in our highest resolution designs is equally attributable to improvements in aperture ratio as well as the improved throughput gained from clear color filters.
Competitive RGBW is a step in the right direction, but there is no substitute for genuine PenTile technology.
I have noticed a question reoccurring recently about some larger SVGA phones being announced at CES. It can be said in general that an WVGA format (800 x 480) OLED phone with more than 4.1-inch diagonal will be an RGB stripe display rather than PenTile OLED. Such a large WVGA format, such as that in the newly announced Nokia Lumina 900 (4.3-inch WVGA) would be too coarse of a pixel density to recommend PenTile due to increased pattern visibility. For sizes of 4.1″ or less for WVGA it is necessary to use PenTile to enable the manufacturing of a phone that meets the required specifications for an OLED display in a phone. This says nothing about any given manufacturers preference for RGB stripe over PenTile or PenTile over RGB stripe, but a simple decision based upon the size and resolution of the display.
As more people are getting experience with the Galaxy Nexus, PenTile OLED 720HD display the reviews are coming back very favorable. That is because we have now entered the “sweet spot” for PenTile resolution performance where pattern visibility is nearly impossible for most people to see. Anyone who is seeing pattern visibility here is also seeing pattern visibility on many popular RGB stripe displays.
Ron Amadeo of Android Police said:
…First off, forget all that technical Pentile stuff. I want to hate Pentile, I really do, but the screen is just gorgeous. I’m normally the type to complain about Pentile’s checkerboard layout, but the pixels are so tiny I just can’t see it. No one else notices it either, everyone that sees the phone marvels at how good it looks…
Hubert Nguyen of Ubergizmo
Ferris2375: I’ve had numerous phones, GS2, iPhone 4…this is the best screen I’ve seen yet.
LaGgY_42o: Its crazy good, by far the best screen on any device I’ve ever seen, blacks are so black u can’t tell where the phone ends and the screen begins without looking really close. Also u can load up pretty much any page in portrait view with far away zoom and STILL read the really really fine text just fine.
Some have noticed some artifacts at brightness settings of less than 40% described as vertical banding. Others have complained about yellowish displays. Such yellowish characteristic apparently is not appearing in every Galaxy Nexus.
B1ck132 http://bit.ly/t2m8fd
I have 2 Gnexes and all i can say is that the screen is great and the screen is bad.
How?
Well basically one of them have a yellowish screen like most reviewers talked about.
The other though has clear whites, nearly as clear as iPhone screen, which is by far has the best whites on a phone screen.
The one with the yellow tint is useable and still is a good screen but its not great or anything.
The other one though is the best screen I’ve ever used.
So keep in mind that your experinces about the screen might vary depending on your device. As far as i can tell this is actually a known issue with AMOLED screens.
While I am not going to speculate on the cause for such banding or yellowish colors, some bloggers have correctly pointed out that these are not PenTile related artifacts. Nothing about PenTile varies between displays. Nor is there any aspect of the algorithms that is configured in bands.
Still one other dot counter, Flanimal felt that an HD 720 PenTile display was a waste of compute power. http://bit.ly/t2m8fd
…The GPU has to do the work for the full 1280×720 resolution, yet not all of this work is converyed on the display…
This commenter still cannot accept the fact that there are as many pixels in this display as there are in an RGB stripe, despite fewer subpixels. Another way of saying this is that there are as many luminance centers here as for the equivalent RGB stripe. While there is reduction in density of red and blue chrominance centers, these are still in excess of the density that can be seen in the human vision system. For PenTile displays the reduction in the computation better matches what we see. If anybody doubts that we have 720 HD worth of data, you should compare the Galaxy Nexus with a screen full of data to the iPhone 4GS with the identical number of subpixels and quickly prove to yourself that the Galaxy Nexus is capable of displaying much more information.
As the Nexus Prime comes to the market it will be interesting to see some A-B comparisons of the iPhone 4 to the Nexus Prime. No doubt there will be some detractors who will zoom in to show fully saturated, orange, single-stroke text on black on both phones, even though that is not how users typically look at their phones.
As it turns out, the Nexus Prime with PenTile Super AMOLED Advanced has exactly the same number of subpixels as the iPhone 4S (1,843,200), but it displays 1280 x 720 pixels rather than the 960 x 640 of the iPhone 4. Because of the larger screen size, the pixel pitch of the Nexus Prime is 316 ppi compared to the slightly higher iPhone 4S pixel pitch of 326 ppi. A key difference will be that the Nexus Prime will show 50% more information. Viewed from the distance where you can just see both displays, corner-to-corner, ask yourself which of these two displays makes better use of 1,843,200 dots.
As we have watched so many bloggers with opinions on PenTile technology it was refreshing to see this blog by Robert at RTT on PenTile OLED technology. http://bit.ly/upovsk
We were impressed at the effort that he put into his image simulations and how clearly he explained his testing. His simulations are reminiscent of some of the simulations that Nouvoyance had done before we had the luxury of building real displays.
Using what he has done will help people get some idea of what a 720 HD PenTile OLED will look like before laying hands on the real thing. While there are 3.1 inch PenTile OLED displays in the market that are more than 300 ppi, they are not 4.65-inch diagonal. The way that users will see such a large diagonal display is far different from how they will look at a 3.1 inch 300 dpi version.
Please read this an judge for yourself.
While I have responded to several blogs that appeared in English it would appear as though there has been misinformation also published in Mandarin. Today’s blog would like to respond to one of the more detailed blogs that appeared a last year (10/26/10) by Shan-Shan as Shan Shan’s Diary – 分类： 科技时代 |字号 订阅 (http://bit.ly/heD5HL)
之前有回應過一些部落格文章, 但他們皆是英文的, 也許在有些中文部落文中會有些許誤導的資訊. 今日文章即將針對過去一年中, 其中一篇較詳盡的部落文作為解說. (10/26/10)
Shan Shan was certainly correct that PenTile technology can have some pattern visibility that can appear grainy when this technology is applied at too low of a resolution. This is only evident when one displays solid fully saturated red color. In general photos, videos and all unsaturated colors are not troubled by such issues with grainy appearance.
在”山山的日志”中, 山山在對某些 PenTile Technology的解說是正確的. 比如說, 在低解析度下, 有些圖像會呈現顆粒感, 但是, 這其實只會發生在全飽和紅色的區域; 在一般的相片, 影片和非飽和的影像是不會有這種顆粒感的狀況存在的.
Most of this blog deals with PenTile OLED that has an RGBG pattern. The most significant error in this blog was the author’s attempt to guess how PenTile OLED would render an image of finely spaced white dots. When he examined such patterns hew saw that we had rendered this with R, G, and B subpixels, but thought that this was some sort of error. He defined what he thought should have been done and highlighted the problem that still existed with doing so. His error was in understanding well enough how subpixel rendering is accomplished.
該文大
多數是針對 PenTile OLED 的RGBG 子像素排列. 該文最明顯的錯誤是, 作者嘗試猜測分析 PenTile OLED 如何渲染一個精細的點陣圖. 很清楚地, 作者並未真正的去做, 否則, 他會了解錯誤發生在哪裡. 作者預測一個黑白點陣圖像如下:
intended to look like:
Desired Image of White Dots
經過PenTile 顯示”應該”會如下, 並且要開啟藍色子像素, 他認為這是失敗的呈現.
Shan-Shan say should look like:
Shan-Shan Suggests this Rendering
但實際上, 原圖經過PenTile 顯示會如下圖:
Whereas, in reality it would appear as below.
Note that the luminance of green is 100%, while the luminance of both the red and the blue would be 50%. The human vision system would see these as a well-balanced white chrominance and would see the luminance center just where you would have expected this to be.
在此請注意, 綠色子像素的亮度是100%, 紅和藍則是50%. 經過人眼系統後, 會巧妙平衡成白色的彩度(Chrominance), 並且亮度中心點會被調整至原本期望的位置.
Correct PenTile OLED Rendering for White Dots
The key to understanding PenTile technology is to understand that we do not confine subpixel addressing to just 2 subpixels, but can use up to 10 subpixels to render any given pixel. PenTile algorithms take great care in placing the luminance center where it is intended to be located, but also uses adaptive filters to sharpen edges. There is a bit more flexibility in where the center of chrominance is located, since the human vision system is far less capable of localizing the position of the center of chrominance.
了解PenTile Technology的主要關鍵是, 我們並不侷限只用兩個子像素來顯現原本的一個像素, 相對的, 我們使用, 甚至高達至10個子像素, 來渲染原本的一個像素. PenTile 演算法絕佳巧妙地將亮度中心放在它原本應該被置放的位置, 並且還使用了自適應濾波器來銳化邊緣. 也正因為人眼系統並無法準確地決定彩度的中心位置, 更為彩度中心位置添加了些靈活性.
Later in this article it speculates that PenTile OLED suffers from chromatic aliasing, where there is color error at edges. This is not the case. Surely if one zooms in to see individual pixels there will be one color at any edge, but this is no different than would be the case for legacy RGB stripe displays.
該文之後又推測PenTile OLED 在邊緣會有色差, 然而並不是這樣的. 當然吾人若將圖像放大去看每個像素, 邊緣會看似錯誤, 但是傳統RGB 顯示器也會有同樣的情形.
The last part of this blog quotes blogs by Ray Soniera of DisplayMate who compared the PenTile OLED in
the Nexus One to an iPhone display. Quantization error seen in the Mars sunset and the color wedges was long ago realized by Mr. Soniera to be caused by the used of 5-6-5 color in this phones SW rather than 24-bit color that is built into all PenTile OLED and PenTile LCD displays. Some users finally realized that this quantization only existed in gallery applications, but not elsewhere, and even disappeared when using the touchscreen, clearly removing the PenTile algorithms from any blame.
最後一個部分是, 作者引用Dr.Soniera 比較Nexus One 的PenTile OLED 和iPhone 顯示器. Dr.Soniera 其實早就明白, “火星日出和色彩漸進圖的量化誤差” 是手機的軟體本身使用5-6-5 color, 而非24-bit color 導致的. PenTile OLED 和PenTile LCD 顯示器本身是使用24 bit color. 有些使用者後來甚至發現, 此量化誤差只發生於”影像應用程式”, 並不是每個地方都會發生. 這並不是PenTile 演算法的錯誤.
Mars Sunset from DisplayMateQuantized Color Bands
Quantized Color Wedges Due to 5-6-5 Color
DisplayMate also criticized the Nexus One display as being too saturated since it has a bigger gamut than sRGB. In fact, this is a property of OLED, not PenTile. OLED displays have a gamut that is close to NTSC gamut, which may well be more appropriate than sRGB for displaying video.
DisplayMate 也批評Nexus One呈現太飽和的顏色, 但這是因為相較於sRGB, 有較大的色域. 事實上, 這是OLED的特色, 並不是PenTile. OLED 顯示器有比較大並接近於NTSC的色域. 因此也比sRGB更適合撥放影片.
DisplayMate also concluded that the Nexus One phone and this display used dynamic color and contrast. This again was an incorrect conclusion. The reason he felt that this was being done was that R+G+B luminance did not equal white luminance. The real reason for this was due to loading of the display power supply and had nothing at all to do with dynamic color and contrast.
DisplayMate 並下結論, Nexus One顯示器是使用動態色彩和對比. 再一次聲明這不是一個正確的結論. 他下此結論的原因是, R+G+B的亮度不等於W. 但主要原因其實是顯示器本身電源的負載, 和動態色彩和對比一點關係也沒有.
Please come to this blog to find the real information about PenTile technology. This is considerable misinformation about PenTile technology being blogged today. We are willing to admit our deficiencies where they may exist, but we strive to correct those inaccuracies, no matter what language in which they are being written.
請參見此部落格, 並找出真正有關PenTile Technology的資訊. 因為誤解導致此文如此陳述PenTile Technology. 如果有不足, 我們非常樂意接受指教批評, 但同時我們也會努力指正解釋被詮釋錯誤和曲解的地方, 無論該文是使用何種語言.
In reading a recent blog http://bit.ly/sIanNL I see that there still seems to be confusion on the value proposition for PenTile between OLED and LCDs. It is very different between PenTile OLED and PenTile LCD. While I have discussed this before in this blog, it is worth reviewing this one more time.
PenTile OLED – reduces current density to improve lifetime while maintaining display brightness
PenTile enables high resolution for OLED. Due to limitations in the luminous efficiency of OLED materials there are tradeoffs between brightness and lifetime. To maintain the brightness of an OLED display without compromising lifetime one has to reduce the current density, i.e the current per unit area of OLED material. OLED lifetime is very dependent upon current density. PenTile eliminates one third of the subpixels and retains the same number of pixels, but when doing this one increases the fill factor of the display. In other words, the ratio of emitting regions to nonemitting region of the OLED display is improved by having fewer subpixels. The net effect is that the current density is reduced, improving the lifetime of OLED displays for comparable brightness. Using subpixel rendering this is all possible without reducing the displays resolution as defined by modulation contrast ratio.
Since OLEDs only consume power where they are lit they are intrinsically lower power for all except images that are predominately white, which is the case even without using PenTile technology. However, it consumes significantly more power to write white images with an OLED than an LCD. On the other hand LCDs have a backlight that remains on all of the time and is only reduced in brightness for darker images based upon global dimming techniques. So, until you define the usage model you cannot say whether an LCD or an OLED panel will be more power efficient.
PenTile LCD – reduces power by about half in high resolution designs
The principal reason for using PenTile for LCDs is to save power. Roughly half of the power can be saved as a result of
1. Improved open area (aperture ratio) which results from using fewer subpixels. Transmissive regions increase in size while the area devoted to opaque transitors and capacitors remain as before, so the opaque regions are a smaller percentage of the total area of display in a PenTile design.
2. Clear (white) subpixels are regions where there is no color filter to absorb light. Since photos, video, and ebook content is heavily weighted to white this becomes an important factor for saving power. ( Note: I will discuss this in more detail in another blog soon.)
3. A type of global dimming which we call Dynamic Backlight Control (DBLC ) looks at peak luminance of images as well as the presence of high luminance fully saturated color and uses this information to reduce backlight power without introducing color or clipping artifacts.
The net effect is that PenTile LCDs can save half of the power for high resolution designs. This can improve both amorphous silicon as well as polysilicon LCD designs.
It was great to see the review from Charlie White from Mashable Tech of the Galaxy Nexus with the 720 HD PenTile OLED display http://on.mash.to/vCBPxF
With that large size comes a gorgeous screen. If the term “1280 x 720-pixel Super AMOLED high-definition display” doesn’t mean much to you, suffice to say that even when a screen measures a huge 4.65 inches diagonally, that high number of pixels is still tightly packed onto the screen, resulting in an exquisitely sharp view. If a screen were any sharper than this, it would be hard to tell the difference unless you had super-human eyesight.
You might have had the opportunity to read some not-so-flattering information about PenTile on the web recently. While we're always excited to hear people discussing our technology, we'd like to correct some misinformation and share a little bit of our own perspective.
That's what we're going to do here. If you have questions, please don't hesitate to ask. We'd love to answer them.
JoelPollack: Almost right, but not quite. What I commented on before was how to sa...
kevin: Incisive! I really appreciate it....
JoelPollack: Most reviews are better than passing. Need I quote more?
"...The d...
kevin: Passing........
JoelPollack: It seems that your LCD is running, but the back light is not on. Chec...
