Patent ID: 7245440

Claim:
A variable focus lens having an optical axis, comprising: a housing that defines a chamber for containing a conductive liquid and an insulating liquid, the two fluids having different refractive indices and contacting one another to form a surface of contact that comprises a deformable refractive surface having a periphery that is caused to move along the wall of the housing as a function of an applied electric voltage (V), wherein the housing comprises: an upper wall portion inclined at first angle relative to a plane perpendicular to the optical axis (Δ) of the lens; a lower wall portion inclined at a second angle relative to said plane, wherein the second angle is greater than the first angle; a junction zone (B′) between the upper and lower wall portions, wherein the surface of the housing at the junction zone presents a variation in wall inclination relative to the plane perpendicular to the optical axis of the lens sufficient to substantially block movement of the deformable refractive surface at said junction zone upon an incremental increase in applied voltage.