Liquid crystal shutter with low twisted nematic liquid crystal cells driven with a low frequency or DC voltage
US6097451A · kind A · utility
36Cited by
8References
23Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 25, 1997 |
| Grant date | Aug 1, 2000 |
| Priority date | — |
| Expiry date | Jun 25, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F1/13471
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A liquid crystal shutter construction (18), suitable for a glass shield and a welding glass filter, which shutter construction is able to switch between a high light absorbing dark state and a low light absorbing transparent state, and vice versa, comprising low twisted nematic type liquid crystal cells with a twisting angle between 0.degree. and just below 90.degree., and an electronic circuit output generating a variable cell driving voltage higher than about twice the threshold voltage for at least one of the liquid crystal cells and with a polarity switching frequency of less than 1 Hertz.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.