Samsung Display Backs OLED

By Bob Raikes
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Samsung Display (SD) had lots to show us, but also lots of “no photos” signs and staff were keen to really limit what we snapped. That was a disappointment, so we’ll have to stick to, mainly, words.

The first displays we looked at were a highlight in the middle of the suite. Four 55″ transparent OLEDs with FullHD had been made into a video wall configuration with UltraHD overall resolution. Bezel gaps were 3.5mm, but the really surprising thing was the transparency, which was quoted at 30%, with a target of 50% shortly. Transparent LCDs tend to have de-saturated colours, as they have thinner filters to improve transmissivity. However, the OLEDs are quoted as supporting 97% of AdobeRGB, so have wide colour gamut. Brightness is quoted at 150 cd/m², with peak brightness of 1,000 cd/m². Later, the company wants to boost resolution to support UltraHD and develop a “mirror style” version.

Samsung Display has been promoting curved displays heavily. Samsung’s TV division, as a consequence of its very tight vertical integration, has a real competitive advantage in curved LCD. While in 2014, Samsung Display was offering curved LCD in UltraHD only, the firm is now extending this to its FullHD TV panels. There is a new pixel structure to improve the performance of curved LCDs.

The UltraHD panels have been improved with new colour performance which is getting to 90% of DCI P3, without QDs. The firm told us that with new red LEDs, 100% of P3 could be achieved. UltraHD panels at 65″ and 78″ will be promoted, with 88″ as a plan. The curve radius stays at 4,000 mm. An 88″ panel is in plan and will have QDs to boost gamut.

There were new UltraHD panels with lower frame rate performance at 40″ and 48″. Last year, all the SD panels with UltraHD had 120Hz refresh, but this year because of demand from China, there will be 60 Hz UltraHD panels. To get power requirements down, transmittance has been increased to 6.6%.

Another trend is to narrower bezels for curved displays and will be down to 5.x mm by Q1 2016. Samsung is developing its integrated gate driver technology, which puts the row driver onto the panel itself. This technology has been on small panels in the past, but now it is being promoted on panels up to 55″ and this will help to make slimmer bezels on the sets.

Samsung promoted its RGBW LCD technology for TV under the “green” banner.

Moving to monitors, we saw the “5K” panel that we saw at CES last year, but which made it into products towards the end of 2014. SD has now got some in-house lamination and bonding facilities and was showing a 27″ PLS panel for monitor use which it described as “full frameless” and which has optical bonding to improve the contrast ratio and minimise the effect of ambient light.

Samsung has curved LCDs for monitors and will tighten the radius to around 1,800 mm by Q3 2015 on the 27″. The current 34″ curved panel has a 3,000 mm radius, while a 2,000 mm radius panel is “under development”. Finally, we looked at a new 23.8″ VA panel for monitors. Like other panel makers, SD is keen to move away from TN to VA and PLS for monitors.

Notebook panels remain a good market for SD, and we were shown a “green” 3,200 x 1,800 panel that takes just 4.6W and a 15.6″ UltraHD panel which is already in mass production.

Turning to touch, Samsung was showing its OCTL (On-cell Touch) technology on 13.3″ and 15.6″ FullHD panels which use PLS and have 220 cd/cd/m² brightness and 45% gamut.

The Samsung colour vision tester – if you can see one “18” on the smartphone, you are red/green colour blind – if you can see three, you’re not!

Moving down in size, an 8″ OCTL 1280 x 800 display for tablets features 10 finger touch. There were also 8.4″ and 10.5″ 2560 x 1600 panels which are in mass production now. A 14″ panel with 3840 x 2400 (16:10 aspect) will be available in Q3 of this year.

We moved to look at smartphone displays which, these days, are all OLED now. There are a range of panels from 4.7″ to 6″ and we were allowed to take a photograph of a new system that Samsung has developed to show those with good colour vision a simulation of what someone with colour blindness would see. Staff had fun checking this with your reporter, who has some red/green colour blindness. The tests confirmed that the technology worked! (fyi I can clearly see the 18 on the smarphone, but not on the small smartphone image or the background).

Flexible displays were the second star attraction of the show. I wrote an editorial (Samsung Displays Sets the Future for Tablets) in last week’s issue.

The flexible product idea that really excited us was a “tri-fold” flexible display that, when folded, was about the size of a large smartphone or phablet, although somewhat thicker. The exciting part is when you unclip the device, it becomes a 10″ tablet. Now, we think that a 10″ tablet that fits in your pocket is something that will really transform the out of home tablet user. I remarked to Samsung that the user is not likely to want to open up the clips to see inside for simple messages, and there was frantic scribbling as we talked about the kind of display that needs to be on the outside. (of course, I was talking to the display team. I’m sure that the Samsung Electronics team has been working on this concept for a long time!).

A second design concept showed a phablet-sized flip phone that folded in half. Unlike previous flip phones, this one had almost all the “inner” surface as a single display.

A third demonstration showed the same display being rolled and unrolled continuously on a 10mm spool. We heard last year that full bend testing had been done for 100,000 bends (hmmm…. by a strange coincidence (?), that’s the same number that Cambrios quotes in the testing of its silver nanowire materials!).

The only, slight, downside is that the minimum bend radius is around 10mm, so where there is a bend, the phone tends to be quite thick. The flexible displays are just 0.2 mm thick.

Performance is what you would expect from an OLED, and the basic display was used in the Galaxy Note Edge, so it’s good. We were concerned about durability, but the firm told us that it would be as good as the Note Edge.

Finally, we looked at a display for augmented reality displays that has 40% transparency. We commented that this must be difficult, with 4 or 5 transistors per pixel, but staff told us that the current design uses 7!

As well as these segments, SD had a display of automotive panels that it was showing to auto makers, but we couldn’t take photos and there was no time for notes in this tour!

Analyst Comment

Samsung told us that the transparent video wall was getting a lot of attention, and I’m not surprised. There are a lot of architects and store designers that would love to have a display that more or less disappears when its not having something displayed, rather than being a “black hole on the wall”. At the moment, there is quite a largish border on the top or bottom of the 2 x 2 configuration, but that will, inevitably, shrink.

Given all the negatives about Samsung’s problems with making large OLEDs, it was quite surprising that the firm was showing a big OLED. On the other hand, this application is a low volume one that should command a significant price premium – exactly the kind of application that might be useful if you want to limit demand and develop your production process.

It’s clear that there is going to be a huge revolution in device form factors, especially wearable technology and in automotive, enabled by the new flexible displays. Exciting times to be in the display business!