Recording/playback system for VCR
US5172241A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 30, 1990 |
| Grant date | Dec 15, 1992 |
| Priority date | — |
| Expiry date | Mar 30, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2211/007
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A recording and playback system for code recording of VCR which comprises a synchronous separator, an 1/2 frequency demultiplier, a microcomputer, a comparator, a control pulse amplifier, a key matrix, a control circuit, a control head, a pulse generating head, and particularly at least demultiplier, transistor, switch, and resistor, whereby it is made to record a code in initial stage of recording, whereby it can be reproduced only when decoding the code in the initial stage of reproducing, while in a state of not selecting a code mode, it operates as similar as the conventional VCR, and even if one knows the code, the code cannot be decoded in other VCR having not the decoding function whereby it cannot be reproduced normally, whereby complete secret preservation can be kept, while in the normal mode being of not code mode, it operates similarly as the conventional system so that it can be easily applied to conventional system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.