You’ve been able to magnetically stow your Surface Pen to your tablet for ages now, but so far to charge the accessory you still needed an AAAA battery every 6 months.

This does not mean Microsoft has not been working on a rechargeable pen, and we have seen numerous patents over the years for various such solutions.

Today WindowsUnited has uncovered another application, dated October 21, 2019 and published just recently, which addresses the issue of how to fit wireless charging coils onto the edge of ever-thinner tablets.

The patent notes:

Inductive charging with wireless charging coils is a desirable method for charging peripheral devices. However, computer devices such as tablets are getting smaller and thinner. When accessories need to be charged from the main unit, integrating traditional wireless charging coils into the design of a smaller, thinner computing device can be difficult.

Microsoft’s solution is as below:

The disclosed technology provides an electronic device including a metal casing surrounding the electronic device. The metal casing has a first aperture including at least two sub-apertures connected by a channel. The metal casing also has a first surface on a charging target side of the metal casing and a second surface on a charging source side of the metal casing. The electronic device also includes a wireless charging coil located on the charging source side of the metal casing of the electronic device. The wireless charging coil is supplied with current from a power source. The current flowing through the wireless charging coil induces a surface current in the metal casing surrounding the electronic device. The current flowing through the wireless charging coil and the surface current cause a combined magnetic field.

In short, the patent suggests harnessing the metal casing of the tablet itself as part of the wireless charging coil, which would allow for novel and more contact designs, vs a fully independent wireless charging module.

Microsoft, of course, files Surface Pen patents all the time, so there is no clear indication this patent will be implemented in a new device, but given that the Apple Pen now has wireless charging as standard on the iPad Pro, hopefully, Microsoft will be motivated to keep up.

See the full patent here.