Interactions - March/April 2012

built-in flashlight. The challenge is to find applications for the new projectors that will be just as attractive to the hundreds of millions of people currently under-served by computing technology as they are to those accustomed to ubiquitous personal technology.

Social Impacts

It is easy to become breathlessly excited about the possibilities that a new technology brings. Positive scripts for the dramatic worlds we envisage should always be balanced with an appreciation of the less comfortable potential negatives.

Consider, then, sharing. As noted earlier, the always-available large-scale display facilitates collaboration, but it could also be easy to accidently share private information with passers-by. Especially with projector phones, it would be easy to publicly reveal private information, such as messages or calendar entries. In currently available commercial mobile phones with pico projectors, there are no privacy mechanisms to prevent this. As today’s projector phones are just projecting a mirrored image of the device’s display, there is no way of hiding incoming messages or caller IDs from others when using the projection.

The ability to project from a distance also could lead to annoyance or danger for others, either accidently or intentionally. Passers-by can be temporarily blinded when the projection moves and interferes with their field of view. This would be especially dangerous for drivers, dazzled, say, by people in the street playing projector games. Furthermore, it is possible to project symbols or words onto objects and people without their knowledge or agreement. Julius

ENDNOTES:

1. Rukzio, E., Holleis, P., and Gellersen, H. Personal projectors for pervasive computing. IEEE Pervasive Computing. Feb. 2011. 2. See http://www.nttdocomo.com/features/mobil- ity27/ feature.html 3. Rapp, S., Michelitsch, G., Osen, M., Williams, J., Barbish, M., Bohan, R., Valsan, Z., and Emel, M. Spotlight navigation: Interaction with a handheld projection device. Advances in Pervasive Computing: A Collection of Contributions Presented at PERVASIVE 2004. Oesterreichische Computer Gesellschaft, 2004, 397-400. 4. Cao, X., Forlines, C., and Balakrishnan, R. Multiuser interaction using handheld projectors. Proc. UIST’07. ACM Press, 2007, 43-52. 5. Virolainen, A., Åkerman, P., and Häkkilä, J. Burn-to-share—Content sharing with mobile projectors. Proc. Mobile and Ubiquitous Multimedia (MUM). 2010.

6. Mistry, P. and Maes, P. SixthSense—A wearable gestural interface. In Proc. of SIGGRAPH Asia 2009, Emerging Technologies ( Yokohama, Japan). 2009. 7. See http://www.juliusvonbismarck.com/fulgurator/

von Bismarck does this with his “Image Fulgurator” as a form of art [ 7]; what if such practices became widespread? It is uncertain what social norms or even laws to limit public projection will develop. After the introduction of integrated speakers, many people listened publicly to loud music. However, today norms exist that constrain most people from doing so. With projectors, though, making the display private is clearly not an option. There could then be a risk that future mobile devices would be capable of not only spamming our auditory sense but also visually polluting the environment.

ABOUT THE AUTHORS Raimund Dachselt is a professor for user interface and software engineering at the University of Magdeburg, Germany.

Road Map

It is, of course, always dangerous to make predictions about technology. Even so, let’s end this article by plotting the trajectory for picos. Within the next five years, we might expect a large proportion of smartphones to have a built-in projector. Initially, these will be used for the sorts of work and play we already see on touch devices: showing and chatting about pictures, laughing at funny videos, plotting a route on a map, and gaming. It’s likely that by then the devices’ sensors—cameras and motion sensors—will enhance the interaction richness. They will then provide portable surface computing.

The second wave—within 10 years—will see them become an important platform for a range of digital-physical augmentations. By then, projectors will not be simply handheld but attachable, wearable, and embedded. And perhaps by then we will be able to lift our eyes from our handheld mobiles and enjoy a fused physical-digital experience. Now, that would be magical.

Jonna Häkkilä is a docent at the University of Oulu, Finland, and works as a research leader at Nokia Research Center, Finland, where she led user-experience and concepting teams from 2007 to 2011.

Matt Jones is a professor of computer science at Swansea University, U.K.

Markus Löchtefeld is a researcher at the German Research Centre for Artificial Intelligence (DFKI) in Saarbrücken, where he is working in the Innovative Retail Laboratory.

Michael Rohs is an assistant professor at the Institute for Media Informatics of the University of Munich ( Ludwig-Maximilians-Universität München), heading the Mobile and Physical Human-Computer Interaction group.