Patent ID: 8581866
Filing Date: 2013-11-12
Classification: G06F

Abstract:
1. A user input device of an electronic apparatus, the user input device comprising: a first substrate on which a plurality of first electrodes are formed; a second substrate that is spaced apart from the first substrate, and on which a plurality of second electrodes are formed, wherein an array of driving electrode pairs is defined by the first electrodes and the second electrodes; an electro-rheological fluid contained in a gap between the first substrate and the second substrate; a plurality of lighting keypad units disposed on the second substrate, each lighting keypad unit of the plurality of lighting keypad units comprising at least one key symbol, wherein the at least one key symbol of one of the plurality of lighting keypad units is different than the at least one key symbol of another one of the plurality of lighting keypad units, and a control unit which cuts off a driving voltage which is applied to at least a first portion of the driving electrode pairs to drive the electro-rheological fluid from at least a second portion of the driving electrode pairs when the second substrate has a predetermined magnitude of displacement in response to a pressure applied thereto.