Design and analysis of a one-moving-group zoom system using a liquid lens

This study presents a three-group inner-focus zoom lens with one-moving group for a mobile camera by use of a liquid lens. When the first and the third groups are fixed, this zoom system has one-moving group, the same total track at all zoom positions and the advantage of mechanical size, which is useful for a compact mobile zoom camera. Especially, the second group of the zoom system is replaced by a liquid lens whose power is varied to maintain the image plane at different magnifications. This variable power can be acquired by changing the curvature between the electrical insulator and the electrolyte in a passive device. In conclusion, the focal length range of this zoom lens is 4.0 mm to 20.0 mm, and the aperture is F/3.5 at a wide position and at F/4.5 at a tele position. This design procedure resulted in a 5× compact zoom lens system useful for a mobile camera.