The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 16, 1989
Filed:
Mar. 25, 1987
B Jin Chang, Ann Arbor, MI (US);
Kaiser Optical Systems, Ann Arbor, MI (US);
Abstract
The present invention is a manner of constructing holographic optical elements for use in laser eye protection. A photosensitive layer, preferably formed of dichromated gelatin, is disposed on a transparent supporting substrate with a reflecting surface conformal to the outer surface of the photosensitive layer. The photosensitive layer is exposed with light from a laser point source. The photosensitive layer records the interference patterns between light incident directly from the laser point source and light reflected from the reflecting surface. The photosensitive layer is developed to form a holographic optical element. When this holographic optical element is disposed before the eye, with the center of the eye located at a point equivalent to the location of the laser point source, laser light directed toward the center of the eye is diffracted by the holographic optical element and effectively reflected away from the eye. Construction of the holographic optical element in this manner enables the use of a flatter spectacle lens while minimizing flare. The blocking angles at any particular portion of the holographic optical element can be reduced, thus increasing the transmissibility of the eyewear, without sacrificing protection. This technique also prevents the holographic optical element from being retroflective at all angles, thereby presenting a noncooperative target cross section to illuminating lasers. 1