US Patent 11573351 Optical sensor having a magnetic optical barrier

An electronic watch includes a frame and a cover. The cover is attached to the frame, and the frame and cover at least partially define an interior volume of the electronic watch. An optical sensor assembly including a light emitter and a light receiver is positioned within the inter volume of the frame. An optical barrier is positioned between the optical sensor assembly and the cover and includes a magnetic material that forms a light blocking-wall between the light emitter and the light receiver. The magnetic material is configured to removably couple the electronic watch with a charging device via a magnetic attraction between the magnetic material and a magnetic component of the charging device.