High‐resolution and compact virtual mouse using lens arrays to capture finger images on light sensors

Abstract

To realize a finger positioning device, as called “virtual mouse,” to replace a touchpad, touchscreen, or even real mouse, current positioning technologies cannot achieve a sufficient resolution, a compact volume, and a simple detection algorithm simultaneously. For this problem, using a light‐emitting diode source, two lens arrays, and two light sensors, we design and implement a virtual mouse prototype. The optical architecture is carefully determined for a compact volume, a sufficient resolution, and a high detection accuracy. Corresponding to a compact system volume of 3.1 mm (thickness) × 4.5 mm (length) × 2, a theoretical resolution higher than 25 pixels per inch (ppi) can be obtained over a working area of 10 cm × 10 cm. Experiments are also implemented, in which a mean detection error of 0.24 cm that corresponds to approximately two distinguishable points, and a minimal resolution of 26 ppi over the whole working area are verified. If the system thickness is relaxed to 25 mm, a resolution higher than 200 ppi can be achieved. The proposed virtual mouse, which is simple enough and potential to be extended for three‐dimensional position detection, can be integrated with a flat panel display to achieve a compact display application that can interact with users.