Triangular pyramid type cube-corner retroreflective element
US6802616B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jun 13, 2002 |
| Grant date | Oct 12, 2004 |
| Priority date | — |
| Expiry date | Oct 23, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B5/124
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
To provide a retroreflective sheeting not only superior in high-brightness characteristic which is a basic optical characteristic generally requested for a triangular-pyramidal reflective element, that is, reflectivity represented by the reflectivity of the light incoming from the front of the triangular-pyramidal reflective element but also whose entrance angularity and rotation angularity are greatly improved. A pair of triangular-pyramidal cube-corner retroreflective elements characterized in that the optical axis of the triangular-pyramidal reflective element pair tilts so that the angle formed between the optical axis and a vertical line extended from apexes (H1 and H2) of the elements to a bottom plane (Sx-Sx′) ranges between 0.5 and 1.5° in the direction in which the difference (q−p) between the distance (q) from the intersection (Q) of the optical axis and the bottom plane (Sx-Sx′) up to base edges (x,x, . . . ) shared by the element pair and the distance from the intersection (P) of the vertical line and the bottom plane (Sx-Sx′) up to the base edges (x,x, . . . ) shared by the element pair becomes plus (+) or minus (−).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.