The filing, originally reported on by Patently Apple, includes a description about how the keyboard's keys could have 'an associated key display' connected to 'control circuitry in the keyboard' via a 'coherent fiber bundle.' Each key would operate as an adjustable digital display, and could be made from materials such as glass, ceramic, metal, polymer, or even crystalline materials like sapphire. --- Send in a voice message: https://anchor.fm/talktech/message