Method of preparing a multicolored holographic image
US4656106A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 15, 1985 |
| Grant date | Apr 7, 1987 |
| Priority date | — |
| Expiry date | Oct 15, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K1/126
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.