Apparatus for reproducing optical card data without position indicators
US4931628A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 17, 1987 |
| Grant date | Jun 5, 1990 |
| Priority date | — |
| Expiry date | Jul 17, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/08547
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In an optical card reproducing apparatus in which an optical card such that data is recorded as a plurality of track trains on an optical recording medium is reproduced and the data is optically detected by detecting the reflected light of the irradiated light from a light source by the optical recording medium, there are provided a memory to record the level of the output signal from the photo detector and a comparator for sequentially comparing the level of the output signal stored in this memory with the level of the output signal from the photo detector obtained by the next scan, and as the result of the comparison, when the output level from the photo detector is higher than the output level read out of the memory, the content of the memory is sequentially rewritten into the higher output level.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.