Penbook

Penbook

The PDF document linked at the end is also very interesting.

excerpt:
"IMPLEMENTATION
In the following, we first introduce the custom-built hardware setup and its components. Second, we detail the software architecture and integrated components. As there is currently no available slate device which features a built-in projector and paper-like cover, we designed and built such a system consisting of four main components which are described in the following:

1) A tablet computer (Motorola Zoom 2) that serves as the upright touch screen.
2) A smartphone (Samsung Galaxy SII) connected to a laser pico-projector (Microvision ShowWx+ HDMI) in order to control the projected screen and its content. The optical path of the projection passes two mirrors in order to increase its overall length. Despite the low brightness of the projector, the projection can be seen very well in standard indoor lighting due to the short distance to the projection surface and the innate sharp focus of the laser projector.
3) An Anoto pen, which supports hand-written input on paper equipped with a specific pattern. The pen does not dispense ink; instead, strokes made with the pen are projected on the paper. The pen tracks the Anoto pattern on the paper to track its position on the projection screen using a built in infrared camera. The information is sent via Bluetooth to the mobile phone. We reverse-engineered the communication protocol of the pen and wrote a driver to connect the digital pen to Android that allows fine-grained control over its features. Additionally, a capacitive cap was added to enable pen-touch input on the touch screen. The above mentioned components are integrated into an aluminum case with a flexible stand and a foldable cover that contains the projection screen.

The commercial availability of projector phones (e.g. Samsung Galaxy Beam) indicates that that device could be built in a form factor similar to standar slate devices. The Penbook software components are jointly distributed between the devices."




http://www.uni-ulm.de/fileadmin/website_uni_ulm/iui.inst.100/institut/Papers/Prof_Rukzio/2013/its128na-winkler.pdf