Interactive Multitouch Display

This multitouch display screen design is based on the description in Jeff Han's paper, Han, J. Y. 2005. Low-Cost Multi-Touch Sensing through Frustrated Total Internal Reflection. The figure below comes from his web site. An acrylic panel is edge lit with infrared leds. Since most hobbyists can't afford multiple projectors (i don't even own one, just borrowed it from dr.eel), my design uses a ceiling mount that swivels so that the projector can be used either in standard mode (say for watching movies) or can be aimed downwards, bouncing off a reflector and onto the multitouch display screen. The screen itself can be constructed from hardware store materials and hand tools. touchlib

Comparison of 6 rear-projection films I tried to get my hands on as many of the projection films commonly used by members of the forum to do a side-by-side comparison for my own research. I still haven’t received my HoloLite and HoloGrey samples ($906 USD per sq. meter), but I’m tired of waiting so here are my results with the following films: Polymex 50 micron double matte drafting film ($2 USD sq. m) Rosco Grey ($12 USD sq. m) mind.unity@gmail.com’s film ($90 USD sq. m) IFOHA Digiline White (169 EURO sq. m) IFOHA Digiline Contrast (230 EURO sq. m) 3M Vikuiti ($566 USD sq. m) You may notice how dark the Vikuiti looks in comparison to the other films--this is not an error. The black level and color contrast are much better than the cheaper films, but without a sufficiently bright projector the image is dull (my projector is 1200 lumens). If you had a 3000 lumen projector it would look stunning. Here are my personal opinions of the films: *Drafting film: Nice and bright but looks washed out and has the lowest contrast ratio.

15" TFT panel transformed to something more aesthetic; TransTFT From the side Top view Illuminated by the desklamp Close up from the corner In the dark Posing Conclusion If you feel that you have a good idea for an article or you have already written down one and would like us to post it in MetkuMods, just ask. Questions or comments? Past related articles in MetkuMods: LightPad connects your smartphone to an 11-inch screen, expands up to a 60-inch projection QP Optoelectronics to Launch LightPadTM for Smartphones at CES Suzhou, China – December 19, 2011. QP Optoelectronics Co. Ltd. announced today that it will be showcasing its novel LightPadTM product at the CES 2012 exhibition in Las Vegas, January 10-13, booth #37037 South Hall, Upper Level. The patent pending LightPadTM technology is an ideal companion device to extend the functionality and user interface of smartphones, providing the user with expanded utility via built-in 11" high contrast rear projection screen, up to 60" screen in front projection mode, and a full-size keyboard. Connected with a smartphone, The LightPadTM provides virtually all functions of a notebook computer for an individual. Notebook sized displays are not sufficient for many applications including small group meetings where PowerPoint presentations are common. Specification G1 (2012) G2 (2013) QP Optoelectronics has partnered with Texas Instruments, a leader in DLP- based microdisplays.