Pentile OLEDs: introduction and market status - Page 2

The OLED Association reports that Shanghai Tianma demonstrated a new 5.5" Full-HD (400 PPI) AMOLED prototype. This is the highest-resolution display ever shown by the Chinese display maker, and reportedly they have adopted a subpixel scheme not unlike Samsung's Pentile technology. To achieve the high resolution, Tianma developed a dual-FMM technology in-house.

Tianma has been developing LTPS AMOLED technology for quite a while, and according to our information they are getting ready to release the first panels in 2016. Tianma has plans for three separate OLED production lines.

DisplayMate posted yet another interesting display shoot-out, this one testing Samsung's new QHD (2560x1600) Super AMOLED displays used in the upcoming Galaxy Tab S (8.4 and 10.5) tablets. As these displays are very similar to the GS5 display, it's not surprising that DisplayMate found those tablets to offer the best performing displays ever. This is yet another testimony to how great OLED displays are - and the rate of improvement in OLEDs is very rapid.

As DisplayMate found out, the Galaxy Tab S establishes new records for best Tablet display performance in: Highest Color Accuracy, Infinite Contrast Ratio, Lowest Screen Reflectance, and smallest Brightness Variation with Viewing Angle. These are also the highest resolution tablets at QHD.

When Samsung first released the GS5, we thought the 5.1" FHD Super AMOLED display is pretty similar to the 4.99" FHD one used in the GS4. But DisplayMate found out that this is a much superior display in many aspects, one of them being that it is 27% more efficient.

GS5 subpixels

GS4 subpixels

Samsung told DisplayMate that the improvement mostly came from more efficient OLED materials. They also incorporated new display electronics and optics and that helped as well. But now Chipworks posted a teardown of the GS5, and they published a macro image of the display's sub pixels. It turns out that it's a different architecture than the GS4, and this may explains some of the performance boost, too.

Visionox developed a new RGB pixel arrangement for OLED technologies that allowed them to reach 570 PPI. The company refers to this new technology as Z-Type arrangement and it includes 3 sub-pixels (RGB) per pixel (unlike Samsung's Pentile displays). The sub-pixels are densely packed (the aperture ratio seems very high) in a way that does not suffer from jagged edges.

Visionox told me that they cannot yet say when such displays can be commercialized, as there are still manufacturing challenges to overcome. In the meanwhile the company applied for both Chinese and international patents.

The Oculus Rift is a VR HMD being developed by Oculus VR. The high profile company raised $16 million (partly by crowdfunding) and already offer "development kits" HMDs. Their consumer version (Oculus CV) will hopefully be released in 2014 and will feature improved components, for example a Full-HD display. The current versions use LCD displays (7" in size, although early prototypes used 5.6").

Oculus VR development edition

Yesterday, at Oculus' development forums, a new discussion suggested that Oculus aims to adopt an OLED display in the Oculus CV. They quote Oculus CEO Brandon Iribe as saying that the need a much faster display than the current one, and that OLED was the technology that could achieve that.

DisplayMate, the display testing, measurement and calibration experts just got their hands on a pre-release Galaxy Note 3 production unit, with its 5.7" Full-HD Super AMOLED display (386 PPI, PenTile). They put the unit to extensive testing (and also compared it to the Note 2). The conclusion? This is the best performing OLED display ever and it beats LCDs across the board!

The most notable advancement in this new panel is the high brightness. It can achieve 660 cd/m² in high ambient light. It's not just 55% brighter than the Note 2, it's actually the brightest display ever tested at DisplayMate. A very notable achievement for Samsung's OLEDs, which were lagging behind LCDs in brightness.

When Samsung unveiled the Galaxy Note 3 they said it's got a 5.7" Full-HD Super AMOLED display (386 PPI) - but they didn't reveal what is the sub-pixel arrangement. Some sites say it is a Pentile display while other say it not.

Galaxy Note 3 display up close

According to Chinese site RBMen, the Note 3 uses a Diamond Pixel architecture - similarly to the Galaxy S4. Diamond Pixel is indeed a PenTile subpixel scheme, and there are twice as many green subpixels as there are blue and red ones. The green subpixels are oval and small while the red and blue ones are diamond-shaped and larger. So perhaps both reports are right: it is indeed a PenTile display, but not a regular one...

French site Lesnumeriques posted an article on Samsung's KN55S9C curved OLED TV, in which they include a macro-photo showing the TV's sub pixels up close:

As you can see, the blue subpixels are bigger than the red and green ones (about twice as large). This was designed this way because the blue OLED has the lowest lifetime - if it is bigger then you can lower the brightness and so conserve lifetime. We've seen many OLED displays with differently-sized subpixels - including PenTile ones and the rather unique display used in the Note 2.

When Samsung launched the GS4, they said the Super AMOLED display uses PenTile. Back in January, it was reported that Samsung will adopt a new subpixel scheme that uses diamond sub-pixels, but up until now we didn't hear anything official from Samsung. Today the company finally did acknowledge the new design, and published two closeup photos of the GS4 display.

Diamond Pixel, as Samsung's calls their new design, is a PenTile subpixel scheme, in which there are twice as many green subpixels as there are blue and red ones. The green subpixels are oval and small while the red and blue ones are diamond-shaped and larger (the blue subpixel is slightly larger than the red one). DisplayMate says that this is because green is the most efficient (and long lasting) OLED emitter while the blue has the shortest lifetime.

Samsung unveiled their new flagship smartphone, the Galaxy S4. As expected, it sports a 4.99" Full-HD (1920x1080, 441 PPI) Super AMOLED display behind a Corning Gorilla Glass 3. This phone will launch towards the end of April worldwide (on 327 carriers in 155 countries). The S4 seems to be more of an upgrade to the S3 than a revolutionary new handset.

According to previous reports, Samsung Display started producing these 5" Full-HD AMOLED panels in February at a rate of 3 million units per moth (this will grow to almost 10 million monthly units in coming months). The S3 is Samsung's best selling and fastest selling smartphone, and obviously the company hopes that the S4 will sell even better.