Circuit and method for maintaining security of video tape using privacy number
US5146495A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 18, 1991 |
| Grant date | Sep 8, 1992 |
| Priority date | — |
| Expiry date | Oct 18, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B33/10
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A circuit for maintaining security of a video tape using a privacy number, including a sensing circuit for sensing lead tape portions of the video tape and producing a desired signal in accordance with the sensed result, a microcomputer for producing a desired control signal in response to the sensed signal from the sensing circuit and producing a switching signal and a display signal when the privacy number is applied, a control circuit for controlling the operation of the sensing circuit in response to the switching signal from the microcomputer, a deck for being driven in accordance with the control signal from the microcomputer, and a display unit for displaying a desired character in accordance with the display signal from the microcomputer. A method of maintaining security of the video tape is provided using the privacy number. According to the disclosed circuit and method, for the video tape to be secured, the lead tape portion of the video tape is exposed to an infrared-ray from an infrared-ray emitting diode preventing unauthorized persons from playing back contents that the user has recorded on the magnetic video tape in the video cassette recorder.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.