Switchable retardation device with reduced residual retardation
US11435641B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 30, 2020 |
| Grant date | Sep 6, 2022 |
| Priority date | — |
| Expiry date | Dec 30, 2040 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F1/13306
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A switchable optical retardation device includes a switchable retardation element including liquid crystals and an electrical driver circuit. While in a first state, the switchable retardation element modifies light transmitted through the switchable retardation element by causing a phase shift of a first retardation angle. While in a second state, the switchable retardation element modifies the light transmitted through the switchable retardation element by causing a phase shift of a second retardation angle distinct from the first retardation angle. The electrical driver circuit provides a first voltage for placing the switchable retardation element in the first state and a second voltage for placing the switchable retardation element in the second state. The first voltage is greater than the second voltage, the second voltage is a non-zero voltage, and the electrical driver circuit alternatingly provides the first voltage and the second voltage with a predefined frequency.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.