The latest version of Microsoft's Surface Pen was announced by the company over a year ago, and is said to be the "fastest digital pen on the planet". Even with improvements being made in other departments, it is still powered by a AAAA battery feeding the digitizer, as was the case in previous models. However, it seems that the tech giant had some interesting ideas in mind with regards to the Surface Pen's rechargeable nature months before the latest iteration was announced.
A patent filed by the company back in 2016 was published yesterday, describing a stylus fitted with a light harvesting unit that is "configured to generate energy". In other words, it will be fully powered by the light emitted from a display that is in close proximity to it, thereby terminating its need to be recharged.
Obviously, it looks as though the patent was filed with the thought of a Surface Pen being used upon a Surface device in mind. The energy garnered by the light harvesting unit may be used to either power an operation of the stylus or to recharge its power source. Further explanation of why energy obtained from a touchscreen will be preferred over ambient lighting within a room, for example, has been given in the following way:
"Due to the close proximity of the stylus to the touchscreen 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."
Other patents related to the Surface Pen published in recent months include one that showcased a touch-sensitive retention clip, while another one hinted towards haptic feedback being sported by the stylus in the future. However, as with all patents, it should be noted that there is no guarantee we'll ever see this feature in future iterations of the pen as it is quite possible that the company simply might not be interested in driving this idea forward anymore.