Lens design for outdoor sign
US5934795A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 19, 1996 |
| Grant date | Aug 10, 1999 |
| Priority date | — |
| Expiry date | Jun 19, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B3/08
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The present invention comprises a lighting unit having a light source emitting light, a reflector placed behind the light source for reflecting the emitted light, and a lens held in front of the light source. The lens is substantially flat and circular. The lens has a predetermined structure that comprises a light-emitting surface and a light-incident surface opposing the light-emitting surface. The light-incident surface of the lens is formed into a vertically oriented high-frequency waveform. In the first embodiment of the lens, the light-emitting surface is substantially flat and the high-frequency waveform is obtained from a combination of a first primary waveform and the third harmonic of the first primary waveform; that is, the high-frequency waveform is derived from the equation ##EQU1## The first embodiment of the lens spreads the emitted light with a graduated distribution horizontally about 20 degrees as measured from the edge of the lens. In the second embodiment of the lens, the light-emitting surface is formed into a vertically oriented low-frequency waveform derived from the equation ##EQU2## The light-incident surface is formed into a vertically oriented high-frequen…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.