Microsoft has been rumored to be working on a foldable notepad-like device, much like the company’s Courier concept. A patent from earlier this year provided an outline for such a device, but a new patent has emerged this week with a lot more detail. The patent references a “hinged device,” and has been filed by Microsoft Surface engineers that are responsible for creating various Surface hinges and devices.

The device appears to have two separate screens and sections that fold together or flat, much like Lenovo’s Yoga Book. The images also show how the mysterious device could flip over and be used as a nightstand. While there’s not much detail about software for such a device, Microsoft’s patent filing includes a lot of intricate details around how the hinge works. Microsoft appears to be using gear-like cogs to create this adjustable hinge, allowing the device to hold in different positions.

Several examples of use are provided in the filing, including a user interface that stretches across both displays with a very small gap. A virtual keyboard and trackpad is also show on one section, while the other has a weather broadcast running. Previous reports have suggested Microsoft’s Courier-like device would include two displays that fold over like a book, and a stylus for taking notes. Windows Central previously reported that Microsoft is also reportedly working on a dedicated notebook app for the device, that is said to mimic writing like a real notebook.

None of the patent filing images show a stylus with the device, but the filing does appear to be largely focused on what looks like a unique hinge for such a product. Microsoft’s engineers obsess over hinge details for its range of Surface devices, and the company has created a unique kickstand for the Surface Pro and Surface Studio devices, and a detachable display for the Surface Book.

It’s not clear if such a device will ever make it to market. Microsoft previously toyed with the idea of a Surface Mini, but CEO Satya Nadella canceled the project just weeks before it was due to be unveiled. Surface chief Panos Panay described the canceled device as “awesome” and “like a Moleskine,” and leaked Surface Mini images gave us a closer look at what Microsoft was experimenting with.

In the lead up to Microsoft’s Surface Studio launch, the software maker filed patents for an all-in-one PC that were identical to the hardware it eventually unveiled. If Microsoft is truly preparing to launch a new mobile device, these patent images could be giving us an early look at what it has planned.