US Patent 11397835 Data device including OFN functionality

A data entry device including a housing, data entry circuitry located within the housing, a keypad mounted in the housing and having a plurality of movable key elements which, when depressed, are displaced to at least a predetermined extent from a first location within the housing to a second location within the housing and Optical Finger Navigation (OFN) circuitry mounted inside the housing, being operative for sensing at least some of the plurality of movable key elements when depressed and displaced to at least the predetermined extent from the first location within the housing to the second location within the housing and providing a key displacement output indicating key displacement to the data entry circuitry.