Extended depth-of-field projection method using a high-speed projector with a synchronized oscillating variable-focus lens

Abstract

For a projector-based virtual reality (VR) or augmented reality (AR) display, a large depth of field and a high-speed image refresh rate are important keys to improve the projector’s performance. Here, we propose a solution that extends the depth of field of the projection using a variable-focus lens and a high-speed projector as well as a control method that synchronizes oscillation of the variable-focus lens with the high-speed projector. The experiment confirms that the proposed system can project the well-focused and dynamically changeable contents on six different planes. Its projection range varies from 0.3 m to 1.5 m, and the refresh rate is 166.7 Hz.

Projection mapping technologies: A review of current trends and future directions

“…Xu et al proposed a multifocal projector comprising an electrically focus-tunable lens (ETL) and a synchronized high-speed projector. 91 ) They modulate the focal length of the ETL at more than 60 Hz, thus making it imperceptible to human observers, and project images precisely when the focusing distance of the projector corresponds to the target surface. The same setup also achieved a varifocal projector in which ETL’s focal length was constantly adjusted to match the target surface.…”

Tunable Liquid Lenses: Emerging Technologies and Future Perspectives

“…The liquid lens control of time and phase needs to be with high precision to meet the needs of many applications. [210][211][212][213] The factors affecting dynamic performance include driving method, aperture, liquid material, and membrane material.…”

Dynamic projection mapping for non-planar objects with a variable focus lens

“…Although such markers are resistant to random occlusion, the technique is only ______________ Further author information: Lihui Wang: wanglihui@gdisit.com employed for dynamic projection of moving objects in 2D space. In addition, to address the problem of the limited depth of field range of projectors, Wang et al utilized the high-speed focus capability of variable focus lens [9][10][11][12][13][14] . It was able to capture changes in the object's distance and attitude through high-speed visual feedback technology, dynamically alter the liquid lens's focal length, and update the projected image in high-speed to correspond with the object's motion in longitudinal space.…”