Apple: pixels as touch sensors for brighter, thinner screens

How can you make a touchscreen thinner and brighter at the same time? Use the pixels as touch sensors, says Apple.

Touchscreens and multitouch technology make up a significant majority of Apple's

research into future user interface improvements, and the iPhone introduced some of

those UI paradigm shifts into our increasingly mobile computing. Since almost all

interaction with the iPhone—and presumably the hopefully imminent Apple tablet—

involves a touchscreen, Apple hopes to improve on touchscreen technology by using

each individual LCD pixel as a touch sensor.

Apple has filed a patent application, published today, for a "display with dual-function

capacitive elements." By mixing display and sensing functions into each individual pixel, it

would make touchscreens thinner, lighter, and brighter than they currently are today.

The way current touchscreens found on most smartphones work is by overlaying a touch-

sensitive panel on top of a traditional LCD panel. The touch-sensitive panel is essentially

a grid array of capacitors, most commonly made from the transparent conductor indium tin

oxide (ITO). When your fingertip comes in contact with the small magnetic fields present in

the capacitors, it causes the voltage along those capacitors to fluctuate. A processor

translates these fluctuations into touch positions.

The need for additional layers covering the LCD screen means it is thicker, and despite

the fact that ITO is transparent, it does absorb some light coming from the LCD display

underneath. Apple's solution involves using each individual pixel as a capacitive sensor,

eliminating the need for an additional layer for a separate touch sensor.

Part of the magic of Apple's patent relies on forming an IPS LCD display using a low

temperature polycrystalline silicon instead of the more common amorphous silicon.

Materials engineering nerds may want to look at the patent for a more detailed

explanation, but suffice it to say that the poly-Si allows for a much faster switching

frequency for driving the individual pixels. (For those unaware, the individual pixels in an

LCD panel switch on and off at a rate much faster than we can perceive—it's this same

switching that can cause eye fatigue from staring at your screen all day.)

Apple's idea takes advantage of the faster switching of poly-Si to drive the pixels one

instant, and use the capacitive properties of the individual pixels as touch sensors the

next. The switching happens fast enough to give a clear, bright display, as well as

responsive touch sensing. The elimination of the separate touch-sensing layer also makes

for a thinner, lighter, brighter, and simpler touchscreen unit.

Apple proposes its solution for mobile devices, making references to iPhones, iPods, and

even MacBooks, but don't be surprised if such an innovation also makes its way into an

Apple tablet.

Apple's latest patent probably isn't tablet related, but feel free to speculate anyway

Yeah, we're pretty sick of the iSlate talk too, so we'll completely refrain from predicting any possible future applications for Apple's latest patent, a new type of LCD circuitry that better integrates capacitive touch by somehow integrating touch sensitivity into the display pixels themselves. It's pretty obscure, techy stuff, but the result should be less circuitry within the display in theory boosting efficiency and, notably, reducing thickness. You know what that means: even thinner tablets. (Sorry, we couldn't resist.)

CES – Robotics: Evolution Robotics Mint bot is the Swiffer of Roombas, keeps track of its positioning

If you haven't figured out how to clean your floor robotically by now, you might be a lost cause, but Evolution Robotics is willing to give it a try with its new Mint machine. The bot uses regular Swiffer pads, and is designed for cleaning hard floors with a shove of the wet-nap. Outside of its lack of vacuum, the Mint also differentiates itself with its "NorthStar" positioning tech, which lets the bot keep track of its exact location with GPS-style tech, relative to a base station, ensuring that it hits every spot and doesn't waste time with random meandering. Mint should hit retail in Q4 of this year for under $250. Check out a video of it in action after the break.