Recording head clogging detection method and its device
US6804072B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 25, 2001 |
| Grant date | Oct 12, 2004 |
| Priority date | — |
| Expiry date | May 25, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2220/90
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A clogging detector used for a VTR to check the recording state of a recording head without using the reproducing head. A test signal of a lower frequency than the erasing frequency is recorded before and after an information signal by means of an erasing head. Before and after recording the information signal by means of the recording head, the test signal is reproduced, the reproduction output is detected by a detecting circuit, and the level of the output is compared with a preset level by a comparing circuit. When the level is lower than the preset level, a warming is issued from a warming circuit, thus preventing a recording failure due to the clogging of the head.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.