Lock out tab for magnetic disc envelope
US4003088A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 8, 1975 |
| Grant date | Jan 11, 1977 |
| Priority date | — |
| Expiry date | Oct 8, 1995 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K7/015
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In a system of the type wherein a floppy magnetic disc enclosed in an envelope stores data on both sides, unless great care is taken in inserting the floppy disc into the using apparatus, which reads from or writes thereon, one can accidentally or erroneously erase or write over data. This invention provides a floppy disc with a hole which can align with one or the other of a pair of two holes through an envelope in which said disc rotates. An opaque moveable means can be positioned to block one or the other of these pair of holes. A photocell will produce enabling signals by sensing light passing through only one of the pair of holes when the floppy disc is positioned one way in the using apparatus and through the other of the pair of holes when the floppy disc is positioned another way in the using apparatus. Accordingly, only when the floppy disc is correctly positioned in the using apparatus can the transducer head be enabled to write or read.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.