Larger touch-screen displays lead revenue growth in the smartphone display market, according to the "Quarterly Mobile Phone Display Shipment and Forecast Report," by NPD DisplaySearch. Mobile phone display revenues are expected to reach $33.3 billion by the end of 2012, a 55 percent increase over last year.
Larger smartphone displays that maintain high mobility will command revenue. According to NPD, the AMOLED (active-matrix organic light-emitting diode) is expected to take the lead over low-temperature PolySilicon, thin-film transistor liquid-crystal displays or LTPS TFT LCDs.
Samsung's Galaxy S4 uses a five-inch, 1920 x 1080-pixel AMOLED and Apple outfits the iPhone 5 with a four-inch, 1164 x 640-pixel LTPS TFT LCD. The Galaxy uses an on-cell touch panel applied to the surface of the glass panel; the iPhone uses in-cell touch functionality, where the touch sensors are built in the glass panel.
The on- and in-cell technologies will result in thinner phones. Touch-screen manufacturers such as Wintek produce the on-cell touch layer. Display manufacturers such as LG and Samsung incorporate touch-screen functionality into their displays.
So, which is better, an AMOLED on-cell touch screen or an LTPS TFT LCD in-cell touch screen? It will depend on whether you like the Samsung Galaxy or the Apple iPhone, actually.