Motionless parallel readout head for an optical disk recorded with arrayed one-dimensional holograms
US5285438A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 31, 1991 |
| Grant date | Feb 8, 1994 |
| Priority date | — |
| Expiry date | Oct 31, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03H2270/22
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A motionless parallel head reads an optical disk having an active surface encoded with an arrayed multiplicity of one-dimensional holograms. Each 1-D hologram is a computer-encoded representation of, typically, one 128 pixel slice of an image. A group, typically 128, 1-D holograms are positionally distributed, and positionally shifted or staggered one to the next, radially along the disk's active surface so as to fit a complete radius. Typically 14,000 groups are circumferentially-displaced around a 51/4" Compact Disk (CD), forming a herringbone pattern. During readout the encoded CD is simultaneously illuminated along the entirety of one of its radius lines within which a group of holographic data blocks are fitted. The illuminated group of holographic data blocks are optically transformed in parallel by one or more lenses, and preferably by a Hybrid refractive/diffractive Optical Lens (HOL), so as to two-dimensionally spatially encode the wavefront of the light beam by which the group of holographic data blocks was illuminated. The 2-D spatially-encoded light beam is detectable by an array of light detectors. When the disk is rotated then sucessive groups of holographic data bloc…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.