Measurement of military helmet and head-mounted display (HMD) visor optical properties

摘要

This paper examines the light transmission, absorption, reflection, and scattering characteristics of military helmet visors usedfor see=through helmet-mounted displays (HMDs). HMDs used for the within-visual-rang (WVR) counter-air mission normally use the inner surface of the helmet visor to reflect the HMD image to the pilot's eye. This approach is popular because it minimizes any optical structures that interfere with the pilot's vision, while also maximizing see-through to the ambient scene. In most cases, a reflective coating, which increases the cost of the helmet visor significantly, must be applied to the inner surfaces in order to achieve enough contrast between the HMD image and the external light passing through the visor. Recently, with hte development of high luminance miniature cathode-ray-tubes (CRTs), it has been possible to eliminate the reflective coatings on neutral density helmet visors having a see-through range of 13-35