LENSLESS USER INPUT DEVICE WITH OPTICAL INTERFERENCE

摘要

PURPOSE: A user input device and a system thereof and a method for operating the user input device are provided to easily reduce physical spaces of an optical element and a sensor. CONSTITUTION: An optical element(104) includes a finger contact surface(105). A light source(102) includes laser which provides light to the finger contact surface. A sensor array(112) detects light reflected from the finger contact surface. A navigation engine generates longitudinal motion information based on longitudinal motion of a finger for the sensor array. A light blocking matter(108) includes an opening linearly aliened with the sensor array.