Patent ID: 8305691

Claim:
A lens element comprising: a deformable membrane having a region adapted for transmission of image forming light rays; a light transmissive member opposing the deformable membrane, the light transmissive member partially delimiting a cavity, the cavity being further partially delimited by the deformable membrane; and an optical fluid disposed in the cavity, wherein a linear temperature expansion coefficient of the optical fluid is different than a linear temperature expansion coefficient of the deformable membrane, the deformable membrane, the light transmissive member and the optical fluid defining an imaging axis about which the image forming light rays are transmitted; wherein the deformable membrane includes a formation formed thereon, the formation being formed at a location of the deformable membrane other than at the region adapted for transmission of image forming light rays, the lens element being adapted so that when the deformable membrane exhibits thermal expansion, the deformable membrane deforms preferentially at the formation.