Depth enhancement of integral imaging AR display with an electrowetting microlens array

Abstract

Augmented reality (AR) display having vergence-accommodation conflict (VAC) problem which causes dizziness and motion sickness to viewers. It occurs because of the way of displaying a stereoscopic image. This is a severe disadvantage and must be managed for the popularization of AR. Implementing an integral imaging into the AR system can solve this VAC problem, but this system still has a limited depth problem originated from integral imaging. By using focus tunable lens array instead of an ordinary fixed one, the depth limitation of the integral imaging system can be overcome. Electrowetting lens can be implemented into focus tunable microlens array for AR integral imaging with the advantage of small form factor, fast response time and precise focal length control. By using a hexagonal arrangement and solid lens attach, the lens array with high fill-factor for AR display is fabricated. Its specification is well optimized for AR display and focus tunable integral imaging display is constructed with this lens array. Microdisplay with small-sized pixel is loaded with elemental images, and the tunable lens array makes an image of object inside the panel which has a depth of few centimeters. And magnifying lens and beam splitter makes meter scale object into the air. By adjusting the applied voltage for the liquid lens array, the position of central depth plan can vary from tens of centimeters to meter scale, which satisfies enough range for typical AR usage. With the system, objects with various distant can be displayed clearly with some technical implementation.