Atmel brings handset makers multitouch option
Atmel has launched a set of controllers that will let handset makers go head-to-head with the Apple iPhone with devices carrying multitouch. Atmel has built support for multi-fingered gestures into the software that ships with the controllers.
Atmel’s foray into multitouch capacitive touchscreen technology comes as the result of its purchase of UK-based Quantum Research Group earlier in the year. A longstanding developer of capacitive sensors, QRG filed a lawsuit against Apple over the sensor used in the iPod’s ‘click wheel’ several years ago and later threatened action over the iPhone’s multitouch screen.
Chris Ard, director of marketing at Atmel, said the arrival of the iPhone has made handset makers look seriously at capacitive touchscreens in place of the cheaper resistive technologies they have used up to now. Ard claimed Atmel’s approach is more advanced than other multitouch technologies being used today.
“We believe that we have unique IP on this. I think we are alone in individually addressing the touchscreen elements,” Ard said, claiming that the matrix addressing used by other systems cannot always detect multiple fingers when they align along one of the addressing lines. “We are the only ones with true multitouch right now. You can look at it as an array of mini-touchscreens.”
Ard said Atmel will supply software that recognises gestures such as pinches and drags with multiple fingers. Although Apple has filed for patents on the use of gestures with multitouch displays, Ard pointed out that they are only at the stage of applications – they have not been awarded.
On a typical handset display, the controller treats the surface as 48 mini-touchscreens, Ard said. There are two types of screen that the controller will work with. One is aimed at high-end handsets. The other works with a single-layer sensing array which is cheaper but less accurate, largely due to the need to have transparent contact wires snake around the touch elements to make contact. A multilayer sensing array allows more direct connections but is slightly thicker and more expensive.
“We think the single-layer version will be the most important part of the market because it will reduce the cost, taking it down to that of the resistive screen products,” said Ard. “It offers better light transmission than resistive and, because the sensor sits behind the display panel, you can’t damage it.”
Ard claimed the capacitive design will help with the design of thinner phones as the sensor is about 150µm thick versus the 500µm of a resistive touchscreen sensor array.