Variable focus lens device having temperature fluctuation compensating feature for lens device liquid
US6188526A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 25, 1999 |
| Grant date | Feb 13, 2001 |
| Priority date | — |
| Expiry date | Jun 25, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B7/028
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A variable focus lens device having a temperature compensation function whose construction is simple and which can be inexpensively manufactured. The device has a lens member including a lens container having a transparent elastic film, a transparent sealing member forming an internal volume, and a transparent liquid filling the internal volume, a stack-type piezoelectric actuator for varying the focus of the lens member by deforming the transparent elastic film by fluctuating the pressure inside the internal volume, and a tank connected to the internal volume by narrow passages. The tank and the narrow passages absorb temperature fluctuation components of the transparent liquid, which varies due to thermal expansion and contraction. The tank and the passages thereby form a temperature compensator, that, because the passages are narrow, does not react to sudden oscillating pressure components caused by the stack-type piezoelectric actuator.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.