Microsoft patents Samsung's Screen Off Memo feature

Owners of the Samsung Galaxy Note 10 series of handsets would be familiar with Samsung’s Screen Off Memo feature, which allows one to write a note on the screen without unlocking the handset, activated by merely removing the stylus from its slot.

Now Microsoft has won a patent for a very similar feature which it calls “DISPLAY INK RENDERING DURING SYSTEM SLEEP.”

As noted by the patent name, the feature would let users make notes on the screen of a device, such as a phone, tablet, or PC, while the device is in low-power suspend mode.

The patent was applied for in March 2018 and appears to have been granted yesterday, 3rd March 2020.

While there appears to be prior art, Microsoft’s implementation appears to be more sophisticated than Samsung’s.

For one, the device would actually be in sleep mode, with a display controller in communication with a digitizer via a bypass rendering path that bypasses the processor. Pen strokes would be passed to a memory buffer in what Microsoft calls “darkboard rendering”.

Microsoft notes that unlike other implementations, it would not need to be triggered by the removal of a stylus for example, but would always be available. Because it bypasses the operating system it would also be immediately available, with a latency of around 30 milliseconds, versus several seconds for other screen off writing implementations.

In fact, Microsoft suggests this low-latency method of capturing pen strokes may even be used to record writing while the OS is awake, for more natural ink response.

Given that Microsoft will soon be releasing dual-screen devices which are perfect for note-taking, it would not be a surprise to see this feature show up in the Surface Duo or Surface Neo.

The full patent can be seen here.