Touchscreen Technology

by Brian Dolan

Apple's iPhone has served as a stake in the ground for a number of growing trends that are creeping up in advanced feature phones, but more than any other, the handset may one day be remembered for single-handedly killing off the stylus.

Phones that require a stylus to enable their touch capabilities make use of resistive touchscreen technology, which require pressure. Resistive touchscreens have two layers with a gap in between them-when a user presses down on the top screen with a stylus the lower layer indicates the location.

The iPhone, Prada Phone and nearly all of their touch contemporaries make use of a touch technology called capacitive sensing technology, which makes use of the conductive qualities of human fingers. They require users to touch but not press the screen. The screens have three key parts: a clear capacitive touch screen placed over a high-quality LCD and a final layer of a plastic lens that protects it from wear and tear.

"We are at a cusp of the touchscreen trend," said Sy Choudhury, open operating system product manager, of Qualcomm CDMA Technology. "Two things are happening that are driving the spread of touchscreen phones: The realization that bigger LCD screens are becoming affordable thanks to cost efficiencies and the ability to better integrate user interfaces to capacitive screens than to resistive screens."

Apple's iPhone and Prada's iPhone both make use of Synaptic's capacitive technology. The company's ClearPad solution enables users to perform a number of gestures that the phone can recognize as different commands: single-finger tap, double tap, tap and hold or tap and slide, press, flick and two-finger pinch are among the options.

Choudhury said Neonode, Apple and HTC are credited with pioneering capacitive touchscreen phones with the N1, iPhone and Touch, respectively. The key to these phones success will be how well the capacitive screen is integrated with the phones' UI.

Qualcomm is busy integrating capacitive touchscreen capabilities to Windows Mobile phones, Android-powered handsets as well as BREW-powered phones.

While the industry is on the verge of widespread availability of various touchscreen handsets, Choudhury said the next wave for these advanced handsets is haptics, or tactile feedback and vibrations that contribute greater control of the touch capabilities of a phone.

Immersion's VibeTonz System is arguably the leading one in the budding space thanks to its ability to tie a phone's vibration actuator to tactile cues in response to touchscreen presses. The company claims that haptics can help users to navigate their phones without having to look at the screen as much or hear key sounds, leading to improved execution time and decreased error rates.

The adoption of touchscreen phones has long been hindered because users have had to pick up a stylus, Choudhury said. "Trying to hit that little ‘x' with the stylus was absolutely annoying."

Touchscreen as we knew it is now over. Long live the new paradigm of touch.