It’s now been a year since Microsoft launched its fourth generation Surface Pen, and even though the latest iteration is now more responsive than ever, it kept the same AAAA battery seen in previous models. If Apple choose to go with a rechargeable battery for its own Apple Pencil, it seems that Microsoft could go in another direction with a solar-powered digital pen.
In a patent published yesterday and spotted by Digital Trends, Microsoft describes a “Stylus with light energy harvesting” that would use the light emitted from the touch screen of a tablet for all of its energy needs. By using a specially optimized light harvesting unit, the patent says that this would be more efficient than harvesting the light from ambient or outdoor lighting:
A light harvesting unit in the stylus includes a light receiving windows that is directed toward the touch screen and is configured to collect light in a wavelength typically emitted by the touch screen. Optionally, the light harvesting unit is also configured to operate with intensity of light that is emitted by the touch screen. Due to the close proximity of the stylus to the touch screen during harvesting, the intensity of light that is collected from the electronic display is significantly higher than intensity from ambient lighting in a room or from outdoor lighting. The higher intensity light may lead to harvesting at a faster rate.
As with all patents, this technology may never see the light of day (pun intended). We've seen a series of interesting Surface Pen-related patents over the past few weeks, including one describing haptic feedback features for the stylus and another one about a new scrolling functionality, but we may get more iterative improvements in the near future before seeing real technological breakthroughs.