Optically detecting a click event

摘要

An imaging system captures a sequence of images representing finger lift-up and finger put-down motions over a sensing area and produces an image signal for use in detecting a click event. At least one light source illuminates a finger interface upon which a user places a finger (or thumb). Light reflected from the finger is captured by an image sensor as image data corresponding to the sequence of images. At least one image signal is produced in connection with or based on the image data. The image signal is used to detect a finger lift-up or finger put-down motion. A click, such as a single click, double click or triple click, is detected based on a combination of finger lift-up and finger put-down motions within a configurable time range.