Lens array-based holographic 3D display with an expanded field of view and eyebox

Abstract

Conventional spatial light modulator (SLM)-based holographic 3D display faces limited field of view (FOV) and eyebox, due to its limited pixel number. In this paper, a lens array is used to expand the FOV and eyebox of an SLM-based holographic display. The hologram is calculated to reconstruct a 3D sub-image array, each sub-image corresponding to a specific perspective of the 3D object. Then, the 3D sub-image array is imaged and magnified by the lens array to integrate to the original 3D image. The FOV is expanded due to the large numerical aperture of the lens, and the eyebox is expanded because the lens array generates multiple viewpoints with a large pitch. The optical experiment realizes a 17.6° FOV and 50 mm eyebox, which contains 4 × 4 viewpoints. Apparent motion parallax is observed through the viewpoint array, which is usually hard to observe in a conventional SLM-based holographic display. The proposed method provides a novel, to the best of our knowledge, way to expand the FOV and eyebox of holographic 3D display without increasing the total pixel number of the SLM.