Clear to colored security film
US6045894A · kind A · utility
155Cited by
53References
39Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jan 13, 1998 |
| Grant date | Apr 4, 2000 |
| Priority date | — |
| Expiry date | Jan 13, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31855
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
A multilayer film including multiple polymeric layers designed and made to enable the film to reflect light in the near infrared (IR) portion of the visible spectrum. Depending on the amount and range of red light that is reflected, the film of the present invention appears under certain conditions to exhibit a visible color, commonly cyan. The film appears to be substantially clear when viewed against a diffuse white background from approximately a zero degree observation angle, and appears to be cyan when viewed against that background from an observation angle that is greater than a predetermined shift angle.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.