Depth-Enhanced Holographic Super Multi-View Maxwellian Display Based on Variable Filter Aperture

• Published in: Micromachines (Basel) Vol. 14; no. 6; p. 1167
• Main Authors: Tu, Kefeng, Chen, Qiyang, Wang, Zi, Lv, Guoqiang, Feng, Qibin
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 31-05-2023; MDPI
• Subjects: Aperture; Apertures; Back propagation; Depth of field; Holograms; holographic display; Holography; Image acquisition; Image enhancement; Image filters; Image processing; Image reconstruction; Information display systems; Innovations; Light emitting diodes; Mathematical analysis; near-eye display; Parallax; Pupils; Recording; Retina; Spherical waves; super multiview; three-dimensional display; Three-dimensional display systems; Wave fronts; Wave propagation; China; near-eye display; three-dimensional display; super multiview; holographic display; depth of field
• ISSN: 2072-666X; 2072-666X
• DOI: 10.3390/mi14061167

The super multi-view (SMV) near-eye display (NED) effectively provides depth cues for three-dimensional (3D) displays by projecting multiple viewpoint images or parallax images onto the retina simultaneously. Previous SMV NED suffers from a limited depth of field (DOF) due to the fixed image plane. Aperture filtering is widely used to enhance the DOF; however, an invariably sized aperture may have opposite effects on objects with different reconstruction depths. In this paper, a holographic SMV display based on the variable filter aperture is proposed to enhance the DOF. In parallax image acquisition, multiple groups of parallax images, each group recording a part of the 3D scene on a fixed depth range, are captured first. In the hologram calculation, each group of wavefronts at the image recording plane (IRP) is calculated by multiplying the parallax images with the corresponding spherical wave phase. Then, they are propagated to the pupil plane and multiplied by the corresponding aperture filter function. The size of the filter aperture is variable which is determined by the depth of the object. Finally, the complex amplitudes at the pupil plane are back-propagated to the holographic plane and added together to form the DOF-enhanced hologram. Simulation and experimental results verify the proposed method could improve the DOF of holographic SMV display, which will contribute to the application of 3D NED.