Years ago, resistive touch screens dominated the landscape. They were the only game in town for tablet PCs and PDAs, and the stylus was king. More recently, smartphones and tablets have called upon capacitive touch screens capable of tracking one's fingertips. These screens lack the precision that can be achieved with stylus-based input, but they support multitouch gestures that are arguably more important for modern devices.
A traditional capacitive touch screen can only track contact with conductive objects that disturb the display's electrostatic field. That works great for a fingertip, but not so much for the average stylus. Hitachi thinks you should be able to use both, and it's developed a new capacitive screen tech that does just that. The new touch panel is said to work with fingers, plastic styluses (or is that stylii?), gloved hands, and other non-conductive implements. It's apparently quite accurate, too; when tracking a stylus with an 8-mm tip, the screen's margin of error for coordinate detection is claimed to be +/- 0.5 mm.
What's even more intriguing about this display is that it's capable of tracking finger- and stylus-based input simultaneously. Unlike resistive touch screens, which generally require a little bit of pressure, Hitachi says this new capacitive design remains responsive to light touches.
Such a display has all kinds of potential for smartphones and tablets. The former could use an alternative to hardware keyboards with tiny keys and on-screen implementations that lack tactile feedback. The Graffiti shorthand Palm used with its stylus-equipped PDAs remains one of the most intuitive systems I've encountered, and I suspect today's mobile devices have enough horsepower to handle real handwriting recognition, too. Tablets offer a much larger canvas and have even more to gain, especially for students who need to take notes that include diagrams, mathematical formulas, and the occasional doodle.
Hitachi showed off the display at the FPD International exhibition in Japan last week. There's no word yet on how the new screen's cost compares with that of traditional capacitive displays, but production is planned for the second half of next year. DigInfo has posted a short video demo on YouTube if you want to see the prototype in action. Thanks to Slashdot for the tip.