User Interface Display on Spine of Foldable Electronic Device

This publication describes systems and techniques to provide a display on a spine of a foldable electronic device, such as a smartphone. While in a folded state, a foldable electronic device has an internal surface and an external surface. The external surface includes an area resembling a spine of a closed hardback book. If a display screen is incorporated at the internal surface, a user cannot see the screen while the device is closed. If a display screen is incorporated at the external surface, a user cannot discreetly view the display to see incoming notifications. To ameliorate these issues by enabling a user to have discreet interaction with an electronic device while in a folded state, the spine of the device is utilized as a display. A spine display can provide text, graphics, and other information to a user of the electronic device as part of a user interface (UI). If a “primary” display screen is disposed on an internal surface of a device in a folded state, a spine display can be implemented as an “auxiliary” display screen. If a display screen is disposed on an external surface of a folded device, a spine display can be implemented as a segment of the display screen. The spine display can discreetly provide notifications to a user without physical interaction with the device. Alternatively, the user can interact with the spine display via touch, such as with a thumb, to scroll through various notifications or deactivate an alert. In some cases, a user can customize the functionality of the spine display—e.g., using an operating system feature