Optical card for data storage for use in a data recording and retrieving apparatus
US4924199A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 18, 1987 |
| Grant date | May 8, 1990 |
| Priority date | — |
| Expiry date | May 18, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/0908
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical card for storing a data signal as optically readable pits including a plurality of track units, each track unit being composed of a single control track having an array of square control blocks extending in first direction, and a plurality of data tracks disposed on respective sides of the control track. The control and data tracks are aligned in a second direction perpendicular to the first direction. Data signals forming a single byte are recorded over a plurality of data tracks at positions which are aligned in the second direction. The control blocks in the control track are arranged such that focusing error, tracking error and clock pulses can be detected by processing signals obtained by optically scanning the control blocks.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.