STEMMER Imaging distributes Optotune’s machine vision products

Now available from all STEMMER IMAGING companies through Europe, these innovative lenses consist of an elastic lens material, whose shape can be adjusted in order to focus.This provides an interesting alternative to traditional solid glass or plastic-based optics which are moved backwards and forwards to focus or zoom.

Tunable focus is achieved by changing the shape of these flexible lenses which feature a container filled with an optical liquid and sealed with a thin, elastic polymer membrane. A circular ring pushes onto the centre of the membrane and the shape of the lens, and hence its focus, can be changed by moving the ring or exerting a pressure on the outer part of the membrane or by pumping liquid into or out of the container. A change in lens radius of several microns can have the same optical effect as moving the entire lens several centimetres.

Mark Williamson, Director – Corporate Market Development at STEMMER IMAGING said: “This is a very interesting technology which has many potential applications for machine vision. They are particular useful where objects of different height need to be measured, since the use of tunable lenses removes the need for mechanical actuators. This reduces both complexity in the set-up and the amount of space needed for the optics. In addition, lens response times of the order of just milliseconds can accommodate high throughput inspections.”