Variable focus lens device having temperature fluctuation compensating feature for lens device liquid

A variable focus lens device comprising:

• a lens member including a lens container having a disc-shaped transparent elastic film, a transparent sealing member facing the transparent elastic film and disposed across a predetermined gap to define an internal volume therebetween, and a transparent liquid filling the internal volume;
• an actuator for varying a focus of the lens member by deforming the transparent elastic film through varying a pressure inside the internal volume;
• and
• a temperature compensator, in communication with the internal volume, for absorbing a temperature variation component of the transparent liquid that varies due to thermal expansion and contraction,
• wherein the temperature compensator includes a narrow passage in the lens container that, while in communication with the internal volume, restricts flow of the transparent liquid during sudden actuator-initiated liquid pressure fluctuations;
• a lens container ventilation hole;
• a liquid collector for collecting transparent liquid overflowing through the ventilation hole;
• and a joining member for communicating the liquid collector with the ventilation hole.