When Samsung moves in display technology, it usually means that a technology, if not quite mature enough to ship immediately, is getting close to commercial viability. So when this week it confirmed rumors that it was buying Netherlands company Liquavista, a Philips spin out, it was effectively giving its blessing to a technology called electrowetting.
Liquavista and about five other companies around the world, are start-ups pushing this technology and Samsung appears to be the first major to take the leap. Think of eletrowetting as the way fluids (this was first noticed in Mercury) will form droplets where there is a surface electrical charge. Modern versions of this squeeze an immiscible fluid (which won’t mix with anything) in a sandwich between hundreds of tiny electrodes and a glass substrate which acts as a counter electrode. The process these days relies on Indium Tin Oxide, which is going to create a run on the rare element Indium, or rather a search for a replacement (if one of these electrowetting companies hasn’t already found one).
Alongside Liquavista, companies like the US’s Advanced Liquid Logic and France’s Varioptic are also active in this area and if they really have similar technology, they could immediately become the object of acquisition desire at companies like Sony and LG.
The benefit of electrowetting is that it can behave like E-ink in that it can operate on ultra-low power – except that Liquavista claims that it can refresh 70 times faster, with the same electrical power as E-Ink, which is about 10% of a current LCD screen. E-Ink works by having white particles positively charged and black particles negatively charged, and attracting them to a glass substrate with an opposite charge. This takes time for the particles to shift and is usually used in e-Reader applications where page turns are infrequent. The benefit is that once they have moved, these particles take no further power to remain where they are and a book page can be read for hours without any further power being used.
The problem with E-Ink, is that it is tough to show color or to refresh at rates fast enough to show video, and the best known exponent of a hybrid that can attempt this is Pixel Qi, which is working on a technology for exploitation this year or next.
There are a variety of other hybrids, mostly those which change refresh rates with each software application, on conventional LCD screens and turn the backlight off or down, so use far less power when reading books than when watching video. Also there is one from Qualcomm’s MEMS technology in its Mirasol displays and this is due for commercial exploitation this year, and has already been shown offering low power video. This works using micromechanical mirrors and like E-Ink is purely reflective and uses no backlight.
The Holy Grail is to have handsets where the software doesn’t have to turn off their screens all the time when you leave them for ten seconds or so without pressing a button. Right now handset screens can use up to 50% of the power of the device and as the screen surface area goes up, this goes up exponentially. Tablet screens are power monsters. The company that brings to market the cheapest video capable, low power, high resolution screen, will secure the largest global market share in a 1 billion a year screen industry.
Today Samsung may take the screens from Liquavista and put them in eReaders, but Tablets are the natural destination, because fundamentally the difference between an eReader with a battery cycle of a month, and a tablet with a battery cycle of ten hours, is the screen technology.
AMOLED screens are supposed to deliver some of this, but are around 40% of the conventional LCD display with a backlight, and already dynamic LED backlighting, which turns LEDs off on dark areas of the screen, have matched OLEDs in power, though not in resolution. So as screen size goes up the OLED approach (organic light emitting diodes) just gets you back to where you were, or worse.
Samsung says that Liquavista already has displays that work and in future this technology will move into transparent and transflective displays, which sounds like perhaps it’s a 2012, if not 2013 time frame, which would make the Qualcomm MEMS architecture still favorite.