Microsoft's current focus on touch-display interaction - as evidenced by its pushing of Metro UI in Windows 8 and its Surface interactive tables and Windows-based tablet product lines - is clear, but it looks like the company has another trick up its sleeve: the reintroduction of the light pen.
A popular accessory in the eight-bit microcomputing era, the light pen as a product dates back to 1950s and the Whirlwind real-time computer system developed by the Massachusetts Institute of Technology for the US Navy. Its operation was simple: long before the idea of a mouse, it allowed the user to interact with a computer simply by pointing and clicking on the screen.
A light pen typically takes the form of a stylus which contains a small photoreceptor in its tip. This stylus tracks the light emitted by activated phosphor on a cathode-ray tube display - although later models work with liquid-crystal displays too - in order to figure out where on the screen the user is pointing. Using the light pen, an operator could quickly highlight large areas of text for modification and even - in later implementations - draw freehand.
light pens have largely disappeared thanks to the advent of various touch-sensitive overlay technologies which quickly add capacitive or resistive touch-detection capabilities to devices like tablets and mobile phones. Unlike a light pen, a touch-sensitive screen is typically operated using your fingertip or a cheap plastic stylus.
The downside of the current state of the art in touch-sensitivity should be obvious: it's near-impossible to add touch sensitivity to an existing desktop or laptop computer without replacing the display. Although add-on overlays do exist, these typically require dismantling the surround of the display - not something your average user feels particularly comfortable doing.
Faced with an operating system clearly designed to be prodded but an embarrassment of non-proddable computers on the market, Microsoft has apparently decided to bring back the light pen - a simple add-on device which can bring pen control to any computer or laptop on the market today.
According to Technology Review
, which claims that Microsoft has not yet decided whether or not it will actually release the gadget, the system works by using a side-looking camera to peer at the display and read positioning information encoded in the blue pixels - blue being chosen to minimise the image disruption perceived by the human eye.
While clever, the design - created by Microsoft's Andreas Nowatzyk and Anoop Gupta - does have one drawback: it requires high-resolution image sensors which are currently hard to come by. As a result, the company has yet to decide whether it's worth developing the hardware required to make the reborn light pen a commercial reality.
One thing seems clear, however: Microsoft is doing all it can to ensure that Metro UI on the desktop is a success.