Viewing angle lens
US5982550A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 17, 1998 |
| Grant date | Nov 9, 1999 |
| Priority date | — |
| Expiry date | Jun 17, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B2027/0169
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The present invention provides a secondary lens between the display lens and the vacuum florescent display. Both the lenses have an index of refraction greater than 1 which results in a momentary change in the viewing angle while the light passes through each lens. Since two lenses are used, the overall effective lens thickness for effective light shifting is increased while the cross sectional thickness of each lens remains uniform. Preferably, each lens is made of a polycarbonate material and has an index of refraction of 1.59. In another aspect of the present invention, the display lens is constructed of a smoke material and the secondary lens is clear.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.