Validity determination using magnetic ink having magnetic powders with different Curie temperatures
US6731111B2 · kind B2 · utility
4Cited by
5References
5Claims
0Family size
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Key dates
| Filing date | Feb 21, 2003 |
| Grant date | May 4, 2004 |
| Priority date | — |
| Expiry date | Feb 21, 2023 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/12465
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
The magnetic powder for validity determining ink is composed of magnetic oxide powder having a Curie temperature between −50° C. and 150° C. and a mean powder particle diameter of 10 &mgr;m or less.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.