Blue color News

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.

At CES 2013 Panasonic unveiled a 56" 4K (3840x2160) OLED TV panel prototype that was produced using an all-printing method. Back in January we assumed Panasonic were using SMOLED materials, but now Sumitomo Chemical revealed (as part of their 2013-2015 plan presentation) that this TV prototype used the company's PLED materials.

Panasonic has been working on OLED printing technologies for quite some time and back in 2009, they teamed up with Sumitomo to jointly-develop OLED TVs, based on Sumitomo's P-OLED materials and technology. I thought this partnership is not active anymore, but evidently I was wrong on that one. 

A few months ago Samsung said that the new Galaxy S3 has a Pentile displays (a 4.8" 1280x720 HD Super AMOLED one to be exact) because PenTile increased the lifetime of OLED panels. I have discussed this with Joel Pollack, an Executive VP at Nouvoyance (Samsung's company that developed the PenTile matrix scheme), and he explains this claim further.

An OLED display is made from colored (RGB) sub pixels. A blue OLED has the lowest luminous efficiency (lower then red and green) and so needs to be driven at higher current - which means a lower lifetime.

Dupont published some new OLED material specification, you can see them in the photo below. The lifetime (LT50) of their Blue fluorescent material is now over 33,000 hours (the the 0.14c0.13 blue, anyway) - which they say is good enough for OLED TVs. Their solution-processed materials are now more efficient than their evaporated-materials, but lifetime is probably lower (it's a bit hard to know since they only publish LT95 for those materials).

I had an interesting discussion with a Dupont employee involved in their OLED program. In January 2012 it was reported that the company is building a $30 million pilot production line for OLED TV displays using their new nozzle printing technology. It turns out that the report wasn't accurate - the facility that DuPont is building is a material production facility. They have no intention to start producing displays...

My first meeting at SID was with Universal Display's Janice Mahon. UDC had some pretty interesting updates for us at SID, and some nice exhibits in the booth as well - only OLED lighting panels, but quite interesting ones. This post will be rather long...

Update: We discussed this with Nuovoyance's VP, he explains better why PenTile displyas lasts longer...

Some people really dislike Pentile displays, but Samsung keep producing AMOLED with PenTile - even in their flagship devices such as the new Galaxy S3 (which sports a 4.8" 1280x720 HD Super AMOLED). Today we hear that Samsung says that one of the major advantages of PenTile AMOLED displays is increased lifetime.

In PenTile displays, there are twice as many green subpixels as there are blue suxpixels. Blue OLEDs feature the lowest lifetime, and so Pentile displays "tend" to last longer, according to Samsung. In any case, as the resolution gets higher, it's getting harder to actually notice the "fuzziness" caused by the Pentile Matrix...

Universal Display's CFO (Sidney Rosenblatt) attended Goldman Sachs Technology and Internet Conference 2012 yesterday, and he gave some very interesting updates. First of all, he commented on the recent AUO and Idemitsu Kosan (IK) agreement. According to Sid, IK are not selling emitter materials - they are offering organic materials that go into other layers of the OLED stack. They do not believe the AUO-IK agreement will have any effect of PHOLED sales to AUO, and in fact he tells us that UDC and Idemitsu Kosan are developing OLED materials together for Sony.

Host materials

In their latest earning report of 3Q 2011, UDC announced that they started to offer OLED host materials - and had almost $8 million in revenue from those materials. Today Sidney explained this business a bit further. Host materials are the materials that you put the emitting materials into (Sidney used a metaphor - if the OLED is chocolate milk, then the milk is the host material and the chocolate is the emitter). These materials are considered a commodity, and UDC didn't think to sell those as it's not an interesting market for them.