Review and analysis of avionic helmet-mounted displays

Abstract

With the development of new concepts and principles over the past century, helmet-mounted displays (HMDs) have been widely applied. This paper presents a review of avionic HMDs and shows some areas of active and intensive research. This review is focused on the optical design aspects and is divided into three sections to explore new optical design methods, which include an off-axis design, design with freeform optical surface, and design with holographic optical waveguide technology. Building on the fundamentals of optical design and engineering, the principles section primarily expounds on the five optical system parameters, which include weight, field of view, modulation transfer function, exit pupil size, and eye relief. We summarized the previous design works using new components to achieve compact and lightweight HMDs. Moreover, the paper presents a partial summary of the more notable experimental, prototype, fielded, and future HMD fixed-wing and rotary-wing programs. © The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

73‐3: High Refractive Index Photopolymer Fabricated Holographic Grating used for RGB Waveguide‐type Display

“…A typical structure of the planar waveguide display system with holographic gratings is illustrated in Fig.1 (Ref. [1][2][3]). The light from the micro display impinges the in-coupled grating after collimating, and diffracted by the grating with angles satisfied the condition of TIR and propagates along the waveguide.…”

41.5: Head‐mounted Display Based on Surface Relief Grating for Augmented Reality

“…Augmented reality (AR) is an attractive technology in several applications, including navigation, education, entertainment, and biomedical applications [1,2]. Many approaches have been studied to realize portable see-through HMD, such as prisms with free-form surfaces [3], projection systems [4], retinal scanning [5], and optical waveguides [6,7]. Among these techniques, optical waveguide with diffractive optical element has the advantage of light-weight, ultra-thin and is appropriate for integration with wearable device.…”

P‐103: Optimization of Field of View and Color Uniformity in a Holographic Waveguide Display

“…Reflective Volume Holographic Grating (VHG) has many advantages when applied as a holographic waveguide display (HWD), such as high see-though transmittance, light weight, small size and cheap cost [1]. However, field of view (FOV) and color uniformity are the two most severe issues to constrain its application scenarios.…”