Between the real and virtual worlds
Fujitsu Laboratories has developed a next generation of interface, which can accurately detect the users’ finger and what it is touching, creating an interactive touch screen, like a system, using objects in the real word
This new interface is called FMA1127 – a touch sensor controller that converts capacitance generated between the human body and a conductive touch pad to digital data without any analog signal processing. Touch sensor technology compares reference and sensor input impedances to detect touch – all in the digital domain.
In this way, paper and many other objects could be manipulated by touching them, as with a touch screen. So this technology allows users to create simple touch panel sensing electrode interfaces for conventional or flexible printed circuit boards (PCB/FPCB) or ITO film on LCD. Using this technology, information can be imported from a document as data, by selecting the necessary parts with a finger. Sensing electrodes may be used in various shapes (circle, rectangular, slide etc.) and sizes with thick covers and proximity sensing. This innovation gives the possibility to measure the shapes of real-world objects even as curved as books and automatically adjust the coordinate systems for the camera, projector, and real world.
To detect touch with a big precision, the system needs to detect fingertip height accurately. In particular, with the low-resolution camera (320 x 180), if fingertip detection is off by a single pixel, the height changes by 1 cm. This system also includes technology for controlling color and brightness, in line with the ambient light, and correcting for individual differences in hand color.
This FMA1127 has a unique advantage of being strong against water and humidity for cleaning or during usage without malfunctioning. This is due to its differential signal concept. More than this, an AIC (Automatic Impedance Calibration) mode was installed to this system in order to maintain consistent sensitivity against external environmental changes such as temperature, supply voltage and current.
In situations when touch isn’t used, the system can be operated by gesturing; for example the user can manipulate the viewpoint for 3D CAD data. So, there could be applications for this touch system by combining it with current gesture systems.
For the moment Fujitsu Laboratories aim to develop a commercial version of this system by 2014.