Sony Unveils 0.23-inch High-performance OLED Panel
Sony Corp announced a 0.23-inch OLED panel for wearable devices in a lecture delivered at SID 2014 (lecture number: 18.1).
It is smaller than the 0.5-inch OLED panel that Sony announced at SID 2012, but its performance is much higher, the company said. Sony expects to start to ship the new panel in 2015.
The pixel count and pitch of the 0.23-inch panel are 640 x 480 and 7.8μm, respectively. It has a 110% color gamut on NTSC standards.
The performance of the new panel is much higher than the 0.5-inch OLED panel that Sony announced in 2012 and employed for its cameras and head-mounted displays (HMDs) in 2013. Specifically, the company improved contrast ratio from 10,000:1 to 100,000:1, brightness from 200 to 800cd/m2 and power consumption from 440 to 140mW. It also improved viewing angle so that the new display can be viewed with a high visibility from an angle of 70° with respect to the screen (20° from an axis vertical to the screen).
To drastically improve the performance, Sony greatly changed the shapes and positions of subpixels using red (R), green (G) and blue (B) color filters. The R and G subpixels have the shape of a square while the B subpixels have the shape of a vertically-long rectangle. And they are placed in pixels with almost no extra space. As a result, the aperture ratio of pixels, etc improved, increasing the ratio of brightness to current (cd/A) by 70%.
The OLED device used for the panel has a structure that emits white light. This time, Sony changed its cavity design to improve emission intensity of colors from blue to yellow. Luminance half-life was quadrupled, and power consumption was reduced by 80% when the brightness is the same.