Optical design of a head-mounted display (HMD) using an off-axis three-mirror system (OTS) and freeform surfaces

In recent years, with technological advances, head-mounted display systems (HMDs) for virtual reality (VR) and augmented reality (AR) have been adopted for their applications in the military, government, education, training, medical visualization, aerospace, entertainment industries, and tourism. For this reason, a compact and light HMD but without sacrificing their performance is necessary. In this paper, the optical design of a lightweight and compact head-mounted display (HMD) system is proposed. We use an off-axis three-mirror system (OTS) with freeform surfaces for the correction of the aberrations and obtain a wide field of view (FOV), a compact structure with an exit pupil size over 7 mm and eye relief of 25 mm.