Patent ID: 7602557

Claim:
A variable-focus lens comprising: first and second transparent insulating plates ( 21 , 22 ) placed facing each other orthogonally to the axis of the lens; in a space defined between said plates, an insulating liquid ( 31 ) on the first plate ( 22 ), and a conducting liquid ( 32 ) covering the insulating liquid and coming into contact with the second plate ( 21 ), the surface ( 24 ) of the first plate ( 22 ) having high wettability for the insulating liquid and low wettability for the conducting liquid, and the surface ( 23 ) of the second plate ( 21 ) having high wettability for the conducting liquid and low wettability for the insulating liquid; and a conducting plate ( 26 ) deposited on the first plate and provided with a central opening in which the insulating liquid is placed, the conducting plate being, on the inside of the cell, coated with an insulating coating ( 27 ), the wettability characteristics of which are optimized for obtaining the desired miniscus shape at rest between the insulating liquid and the conducting liquid.