Holographic optical element for optical disk pickup head
US5523993A · kind A · utility
14Cited by
7References
20Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | May 17, 1995 |
| Grant date | Jun 4, 1996 |
| Priority date | — |
| Expiry date | May 17, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/0912
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A pickup head for use in optical disk systems such as compact disk players or CD-ROM computer memory includes a holographic optical element that has two decision regions that greatly simplify the design of the pickup head. The two decision regions diffract light that encounters the holographic optical element in two different directions, respectively. The amount of light power incident upon each decision region is utilized to determine a focus error signal and to interpret information stored on the compact or optical disk.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.