Occlusion-capable see-through display without the screen-door effect using a photochromic mask.

Conventional occlusion-capable see-through display systems have many practical limitations such as the form factor, narrow field of view, screen-door effect, and diffraction of a real scene. In this Letter, we propose an occlusion-capable see-through display using lens arrays and a photochromic plate. By imaging the occlusion mask on the photochromic plate with near-UV light, the visible light transmittance of the plate changes. Since no black matrix lies on the photochromic plate, our system provides a clear real scene view without the grid structure of the pixels and can prevent diffraction defects of the real scene. We also alleviate the drawback of a narrow field of view using the lens arrays for a reduced form factor.

3D printing-based mirrored image component for seamless modular curved-edge displays.

A facile method for designing and fabricating a concave mirror from a 3D printed mold is proposed for a seamless modular curved-edge display. The concave mirror is placed on the seam of modular curved-edge display, thereby reflecting images at the curved-edge area toward the observer direction. By investigating the concave mirror structures based on parametric modeling, we obtain a continuous image in a modular curved-edge display by optically concealing the seam. We also analyze the luminance distribution and the viewing angle of the seamless modular curved-edge display to show the capability of concealing the seam by the concave mirror.

Eye-box extended retinal projection type near-eye display with multiple independent viewpoints [Invited].

We introduce an approach to expand the eye-box in a retinal-projection-based near-eye display. The retinal projection display has the advantage of providing clear images in a wide depth range; however, it has difficulty in practical use with a narrow eye-box. Here, we propose a method to enhance the eye-box of the retinal projection display by generating multiple independent viewpoints, maintaining a wide depth of field. The method prevents images projected from multiple viewpoints from overlapping one other in the retina. As a result, our proposed system can provide a continuous image over a wide viewing angle without an eye tracker or image update. We discuss the optical design for the proposed method and verify its feasibility through simulation and experiment.

Foveated display system based on a doublet geometric phase lens.

We propose a new concept of a foveated display with a single display module. A multi-resolution and wide field of view (FOV) can be simultaneously achieved using only a single display, based on temporal polarization-multiplexing. The polarization-dependent lens set functions as an optical window or beam expander system depending on the polarization state, which can provide two operating modes: fovea mode for a high-resolution and peripheral mode for a wide viewing angle. By superimposing two-mode images, the proposed system supports a foveated and wide FOV image without an ultra-high-resolution display. We demonstrate the feasibility of the proposed configuration through the proof-of-concept system.

Extended-viewing-angle waveguide near-eye display with a polarization-dependent steering combiner.

A waveguide-based near-eye display (WNED) with an extended viewing angle using a polarization-dependent steering combiner (PDSC) is proposed. The novel eyepiece-combiner is composed of polarization gratings and polarization optics attached to the outcoupler part of the waveguide, which can control the output beam path depending on the polarization state. The viewing angle limited by the grating properties can be extended up to twice. Also, an ultrathinness of about 1.4 mm is suitable for the WNED. The demonstrated prototype system achieves a horizontal field of view of 33.2°, which is 2 times wider than the conventional structure (without the PDSC). The proposed configuration can resolve the viewing angle issue for the WNED.

Retinal projection type lightguide-based near-eye display with switchable viewpoints.

We present a retinal-projection-based near-eye display with switchable multiple viewpoints by polarization-multiplexing. Active switching of viewpoints is provided by the polarization grating, multiplexed holographic optical elements and polarization-dependent eyepiece lens that can generate one of the dual-divided focus groups according to the pupil position. The lightguide-combined optical devices have a potential to enable a wide field of view (FOV) and short eye relief with compact form factor. Our proposed system can support a pupil movement with an extended eyebox and mitigate image problem caused by duplicated viewpoints. We discuss the optical design for guiding system and demonstrate that proof-of-concept system provides all-in-focus images with 37 degrees FOV and 16 mm eyebox in horizontal direction.

Holographically customized optical combiner for eye-box extended near-eye display.

We propose a customizing method of a holographic optical element (HOE) by using a holographic printer, which extends the eye-box with high field of view (FOV) for a holographic augmented reality near-eye display (AR NED). The holographic printer setup to manufacture HOE is presented and a prototype of the AR NED is implemented. To make a simple AR NED system, we propose a total internal reflection holographic printing method using an index-matching optical frame. As a result, the eye-box of the AR NED is extended in both vertical and horizontal directions and FOV of 50° is achieved at the center of the eye-box. Through the simulations and the experimental results, the feasibility of the proposed method is verified.

Dual-focal waveguide see-through near-eye display with polarization-dependent lenses.

A waveguide near-eye display (NED) with a dual-focal plane using a polarization-dependent lens device is proposed. The novel optical device is composed of a geometric phase holographic lens, a wave plate, and a circular polarizer, which is operating as a concave lens or a see-through optical window, depending on the polarization state of the input beam. Such property and ultra-thinness of about 1.5 mm can be applied to a combiner-eyepiece lens for augmented reality. This optical device attached to the waveguide provides two depth planes with polarization multiplexing. We have demonstrated that our proof-of-concept system has image planes at infinity and 20 diopters. The devised system can be expected to offer a better immersive experience, compared to a NED system with a single-focal plane.

Printed cylindrical lens pair for application to the seam concealment in tiled displays.

Seamless tiling of displays is one of the key enabling technologies for the next-generation large-area electronics applications. In this paper, we propose a facile method to demonstrate a seamless display using cylindrical lens pair (CLP) fabricated by dispenser printing method. Optical properties of the printed CLP and corresponding capability of concealing seam in the display are analyzed by a set of luminance simulation and measurement in terms of geometric parameters of the lens. The seamless display with an optimized CLP features a viewing angle of the seam concealment of 40°.