Eye-protection device having dual high voltage switching
US7026593B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Aug 11, 2004 |
| Grant date | Apr 11, 2006 |
| Priority date | — |
| Expiry date | Aug 11, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F1/13324
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An auto darkening eye protection device comprising a shutter assembly and a control circuit. The shutter assembly is adjustable between a light state and a dark state. The control circuit comprises a sensing circuit, a weld detect circuit, a positive voltage generator, and a negative voltage generator. The sensing circuit senses incident light and provides an output indicative of the incident light. The weld detect circuit receives the output of the sensing circuit, and enables a dark state drive signal to be delivered to the shutter assembly. The positive and negative voltage generators output the dark state drive signal to the shutter assembly to switch the shutter assembly from the light state to the dark state upon enablement by the weld detect circuit. The dark state drive signal includes a high voltage pulse followed by a stable AC waveform. The high voltage pulse is formed by a positive voltage signal and a negative voltage signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.