updated 01:35 pm EDT, Wed March 11, 2009
Mitsubishi 3D touch panel
Last week at the Interaction 2009 show in Tokyo, Mitsubishi Electric showed off a prototype capacitive touch panel that can detect the distance between it and a user's finger. The prototype features a 5.7-inch touchscreen with 640x480-pixel resolution and is meant for use in mobile devices, and specifically in interfaces that have a mouse-over function, where the cursor can change depending on what icon or shortcut it is placed over without an actual click or touch. The panel is also capable of judging the speed of the finger's approach by calculating the time variation of capacity on the z-axis and so could trigger different actions based on velocity, not just position.
The finger can be detected from a distance thanks to the use of ITO transparent electrodes, which have a lower sensitivity than copper electrodes but are not transparent and therefore cannot be laid over a display. To overcome this challenge, Mitsubishi switches detection methods. When the finger is away from the screen, the proximity state is enabled; when the finger is very close or in contact with the screen, it is switched to contact state which prioritizes resolution. Power consumption is the same in either state, Mitsubishi says. The screen's response speed is also affected depending on the state, jumping to 50ms in the proximity state but sitting at 10ms in the contact state.
The capacitive method used for this display is of a projection type, making it more suitable to smaller mobile devices, although the company is working on making it usable for screens that are 10 inches in size or larger. The 3D detection method can't currently be applied to capacitive touch panels, the company said.
While production plans are not yet set, Mitsubishi says the panel will first be used in its own products. As it is largely based on an existing product, the company doesn't foresee a significant increase in cost over a traditional 2D display. [via Tech-On]