Holographic efficiency adjustment
US5210625A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 29, 1991 |
| Grant date | May 11, 1993 |
| Priority date | — |
| Expiry date | Mar 29, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S359/90
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A hologram efficiency adjusting process that includes scanning the brightness effect of a hologram, which is either the hologram to be adjusted or a hologram representative of the hologram to be adjusted, to provide brightness vs. position information. The brightness information is utilized to produce a variable duty cycle half-tone mask that contains a pattern defining the areas of the hologram which are to be removed, with the pattern being unresolvable by the viewer of the hologram from which holograms have been removed pursuant to the mask pattern. The hologram to be adjusted is then photoresist coated and etched in accordance with the mask. Alternatively, the brightness information can be utilized to directly expose, for example by a laser scanner, photoresist disposed on the hologram to be adjusted.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.