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:
Nov. 17, 1992
Filed:
Jun. 20, 1991
David J McCartney, Suffolk, GB;
Giles R Chamberlin, Suffolk, GB;
Abstract
A transmission holographic element (30) comprises a holographic material (330) deposited onto a substrate (31) to form a composite substrate structure. The substrate (31) is coated with a mirror coating (32) prior to the deposit of the holographic material (33) which is reflecting at the reading wavelength and non-reflecting at the recording wavelength. This allows the use of substrates that need not be of good optical quality because when the holographic element is exposed to light at the reading wavelength, light is reflected by the mirror coating before passing through the substrate. In addition, the mirror coating is protectred from damage during processing since it is between the substrate (31) and holographic material (33).