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Proceedings Paper

Potential see-through performance deficits in U.S. Army developmental helmet-mounted displays
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Paper Abstract

The U.S. Army has several helmet-mounted displays (HMDs) under development, all with unique characteristics and designs. For example, the now cancelled RAH-66 Comanche HIDSS (Helmet Integrated Display Sighting System) uses miniature liquid crystal displays as sources, and Microvision, Inc., of Bothel, Washington, is developing several prototype HMDs for the Army that incorporate a scanning laser or lasers as their source. Gone are new HMD designs that use cathode ray tubes (CRTs) as sources. A potential problem for see-through displays lies in the fact that the MTF (modulation transfer function) of flat panel displays is characterized by a good high-spatial frequency response. Although this seems counterintuitive, this high frequency response may impact the see-through detection and identification of high-spatial frequency targets because of visual masking and/or spatial frequency adaptation. A similar problem exists with the HMDs being developed by Microvision, Inc., where a high-spatial frequency noise pattern is present due to the inclusion of a diffractive exit pupil expander. Simple blurring of the HMD imagery would reduce this potential problem. In an earlier investigation, we found that a little blurring of flat panel displays does not affect small letter acuity even near threshold. Thus, it is possible to reduce the potential for see-through deficits while still maintaining maximum HMD fidelity.

Paper Details

Date Published: 8 September 2004
PDF: 7 pages
Proc. SPIE 5442, Helmet- and Head-Mounted Displays IX: Technologies and Applications, (8 September 2004); doi: 10.1117/12.543308
Show Author Affiliations
Thomas H Harding, UES, Inc. (United States)
Clarence E. Rash, U.S. Army Aeromedical Research Lab. (United States)

Published in SPIE Proceedings Vol. 5442:
Helmet- and Head-Mounted Displays IX: Technologies and Applications
Clarence E. Rash; Colin E. Reese, Editor(s)

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