Anoto technology, developed by Ericsson spin-off company Anoto, achieves this using a combination of a proprietary pattern, advanced image processing and Bluetooth wireless technology.
The Anoto technology – apparently a working prototype exists – consists of a piece of paper, a pen and a web server. On the paper, a proprietary pattern has been printed, in which any position can be expressed as X-Y co-ordinates. The pen contains a digital camera, an image processing unit and a Bluetooth radio transceiver. When writing on paper covered with the pattern, digital snapshots of the grid are taken, each containing enough information to make an accurate calculation of the position. This information can then be transmitted to a mobile phone or PC via Bluetooth technology.
The pattern consists of small dots slightly dislocated from a strict grid arrangement. A very small part of the pattern, 2x2mm, gives the exact location in the full pattern.
The pen contains a rechargeable battery and enough memory to store several pages of writing. It holds an ordinary ink cartridge, and a force-sensing resistor measures the stylus tip force.
The pattern is illuminated by infrared light and a CMOS sensor acquires images of the pattern at 100 frames per second.
Meanwhile, design consultancy PDD has developed its own solution. The E-Pen is based on an innovation from BT’s Adastra Park research labs. The SmartQuill pen can commit hand-written notes straight to computer via a mobile telephone link or by docking into a PC. Handwriting recognition is achieved through accelerometers that monitor hand movements in the x and y planes as well as the speed at which the pen is moved.
PDD’s idea is to take this design, remove the back-end, and replace it with an RF transmitter – using Bluetooth to transmit the signal