Apple has applied for a patent for a low-power OLED display - unsurprising, given the iPhone 4S battery troubles that have been reported over recent weeks, that Apple is looking at ways to lower the power consumption of future mobile devices.
Traditionally, OLEDs - or organic light-emitting diodes - have proved much more energy efficient than other screen technologies such as LCD. This is because when they're not being used, OLEDs can simply shut down. LCD cells, on the other hand, require a modicum of power constantly. However, OLED's aren't 100% efficient, especially when displaying a large blocks of white as this requires all cells in that area to fire up and maintain their full power draw.
Apple's patent application seeks to overcome this issue by utilising a hybrid layer design, incorporating a solid white background transflective sheet. This will be covered by a layer that is opacity-switchable, allowing it to be turned translucent if a small current is passed through it. This means that in general usage and for the majority of colours, the OLED display will be utilised. However, if there is need for a solid section of white, the opacity switchable layer is rendered see-through, allowing the transflective sheet of white to be made visible.
Some reports suggest that a display setup like this could reduce power draw by as much as 30 per cent compared to traditional OLED displays.
Another benefit of this new system would that the Apple logo could be placed on the transflective sheet also. This would mean that it could be possible to have the logo showing on-screen even while the device is powered off - though there's no indication as to whether this would mean Apple removed the traditional Apple logo from the rear of the device.