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:
Apr. 07, 1987
Filed:
Oct. 15, 1985
David B Holland, Wilmslow, GB;
Glenn P Wood, Hale, GB;
Ciba-Geigy AG, Basel, CH;
Abstract
There is described a method of preparing a silver halide sensitized hologram having interference fringes generally parallel to the substrate which comprises effecting an imagewise photographic exposure using actinic light and effecting a holographic exposure using laser light, wherein the reference beam enters the holographic material from the opposite side to the object beam, of the holographic material, the photographic exposure and the holographic exposure being either sequential or simultaneous, developing the holographic material using a silver halide developing agent and then bleaching out the developed silver. In the processed hologram a part of the holographic image when viewed by reflection exhibits a color relatively close to the laser light used for the holographic exposure when exposed for an appropriate time. However, in those areas where the photographic image would have been present before bleaching these areas exhibit a color of a shorter wavelength. In these areas there has been more overall exposure and thus after processing more shrinkage of the emulsion has occurred. This differential shrinkage causes the holographic image to appear multicolored.