US Patent 11928262 Passive haptics as reference for active haptics

The combination of active and reference haptics on an electronic device, such as a wearable display device, can convey information to a user without requiring the user to look at the device. An electronic device may include a housing, a display disposed in the housing and including an interface surface arranged for user contact and a reference haptic. The interface surface includes an active haptic output that provides a time-dependent haptic output and a reference haptic disposed on the housing or the interface surface to provide a time-independent haptic output related to the time-dependent haptic output.