US Patent 12124224 Sensors for characterizing movement of a watch crown

A watch body includes a housing at least partially defining an interior of the watch body. A retaining feature is formed in or extends from the housing. A watch crown is retained by the retaining feature and is operable to be rotated by a user. The watch crown has a surface facing the housing. The watch crown is entirely external to the interior of the watch body. An electromagnetic radiation source is disposed within the housing and is operable to emit a beam of electromagnetic radiation toward the surface. A sensor is disposed within the housing and is operable to characterize a movement of the watch crown based at least in part on a portion of the beam of electromagnetic radiation that impinges on the surface and is redirected by the surface.