Laser protection visor with ellipsoidal geometry
US4978182A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 23, 1989 |
| Grant date | Dec 18, 1990 |
| Priority date | — |
| Expiry date | Oct 23, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B5/32
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
The present invention is a laser protection visor. This visor has an ellipsoidal shape. The major axis of the ellipsoid falls on the line connecting the user's eyes. The foci least as far apart as the expected interpupillary distance of the user. The visor has a modulated index of refraction reflection filter disposed thereon having a rejection bandwidth including the wavelength of the expected laser threat. The ellipsoidal shape minimizes the maximum rejection angle needed to prevent laser radiation from reaching either eye. This in turn minimizes the needed rejection bandwidth and thus increases the visual see through at other wavelengths. In the preferred embodiment the modulated index or refraction layer forming the reflection filter is formed of a holographic optical element constructed by capturing an interference pattern in a photosensitive medium. In an alternative embodiment, the visor has an ellipsoidal center segment and peripheral segments which deviate from an ellipsoidal shape in a manner permitting the maximum needed rejection angle at any portion of the peripheral segments to be no greater than the maximum rejection angle needed at the center of the ellipsoidal segm…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.