Sysetm for optically sensing the placement of magnetic tape cartridge media in a computer memory backup device
US5365383A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 13, 1990 |
| Grant date | Nov 15, 1994 |
| Priority date | — |
| Expiry date | Nov 13, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B15/17
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A computer memory backup device which utilizes standardized computer tape cartridges is disclosed. The focus of the invention is upon the techniques for ascertaining the appropriate placement of such cartridges to allow operation of the computer memory backup device. The device being connected to a computer allows for the determination of a cartridge presence through the use of an optical sensor mechanism. The sensor mechanism includes a light emitting diode (l.e.d.), light pipe and phototransistor. During any time that the cartridge is not in the computer memory device or improperly or incompletely inserted the electromagnetic radiation emitted by the l.e.d. will be directed by the light pipe to the phototransistor. In this manner a negative determination is correctly made. When the cartridge is correctly and completely inserted, the pathway of the electromagnetic radiation is blocked between the light pipe and the phototransistor. In this manner a positive determination is correctly made. To enhance the accuracy of the disclosed device, time domain filtering is used to screen erroneous electromagnetic radiation from causing an incorrect cartridge in determination.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.