Compact liquid lens having an adjustable focal length

Abstract

The invention relates to a lens () having an adjustable focal length, comprising: a container () enclosing an internal space () of the container (), wherein the internal space () is filled with a transparent liquid (L), and wherein the container () comprises a circumferential lateral wall () surrounding said internal space (), wherein the lateral wall () is connected to a transparent cover element () and to a transparent and elastically deformable membrane () such that the liquid (L) is arranged between the membrane () and the cover element (), an annular lens shaper () connected to the membrane () so that an inner circumferential edge () of the lens shaper () defines a central area () of the membrane () and light passing said area () is refracted depending on a curvature of said area (), and an actuator configured to move the lens shaper () towards or away from the cover element () to adjust said curvature of said area () of the lens () and therewith the focal length of the lens (), wherein for moving the lens shaper (), the actuator comprises a coil () integrated into the lateral wall (), wherein the actuator is configured to generate an electrical current in the coil () so that the coil () generates a magnetic field to move the lens shaper ().