Hidden message indicator
US5974003A · kind A · utility
Inventors
Key dates
| Filing date | Nov 26, 1991 |
| Grant date | Oct 26, 1999 |
| Priority date | — |
| Expiry date | Nov 26, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG04F1/00
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A time color indicator and method are provided. The time color indicator includes a base layer segment having a transparent impermeable layer, a substantially non-curing opaque coating, and a release sheet. A portion of the uncoated surface of the transparent layer bears a printed area including a camouflage pattern printed with non-migrating ink and a message segment printed with migrating ink. An indicator layer segment includes a transparent impermeable layer, a substantially non-curing opaque coating, and a release sheet partially folded back to form a finger gripping tab and expose an indicator layer coating portion which contacts and adheres to the base layer adjacent the printed area. The time color indicator is activated by pulling the finger tab to remove the release sheet, causing the indicator layer coating to cover and contact the printed area, with the message segment migrating through the indicator layer coating. In the method of the invention both the base layer segment and indicator layer segment may be formed in the same process steps from a single web of transparent polyester film, the base layer being printed with the message and the indicator layer segment being…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.