Signal reflector and optical system
US5046818A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 29, 1989 |
| Grant date | Sep 10, 1991 |
| Priority date | — |
| Expiry date | Jun 29, 2009 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF21W2111/02
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An optical system is provided for traffic signal devices. The optical system includes an illuminating source for emitting light; a prismatic reflector for receiving and reflecting the emitted light; and a lens for receiving and for redirecting the reflected emitted light. The illuminating source and the reflector are aligned along a first axis that is vertically inclined relative to a central horizontal axis of the traffic signal device in a range between approximately 2 degrees and 4 degrees. The reflector has a substantially parabolic contour and has a plurality of substantially vertical critical angle prisms formed on an outside surface of the reflector. The prism have included angles of greater than 90 degrees but less than or equal to 95 degrees, or included angles of greater than or equal to 85 degrees but less than 90 degrees. The prisms are arranged to have included angles sequentially increasing from a first predetermined included angle proximate to the illumination source to a second predetermined included angle proximate to the lens. The traffic signal device includes a housing and the lens has an outer face spaced exterior from the housing allowing a portion of the refl…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.