Patent ID: 7264162

Claim:
An arrangement for electro-optically reading indicia having parts of different light reflectivity, comprising: a) a plurality of variable focus optical lenses spaced apart along an optical path each lens having a pair of light-transmissive liquids arranged along the optical path, the liquids of each lens being immiscible, of different optical indicies of refraction, and of substantially same density, one of the liquids of each lens having a drop shape accommodated in a well in a rest state for optically modifying the light beam passing through said one liquid along the optical path toward the indicia to have a first optical characteristic; b) a light source for generating a light beam with a cross-section, and for directing the light beam along the optical path through the lenses toward the indicia located within a range of working distances away from the light source; and c) a controller for controlling one of lenses to focus the light beam at one of the working distances at which the indicia is located, and for controlling the other of the lenses to optically modify the light beam to have a selected cross-section at said one working distance, the controller being operative for applying a voltage across said one liquid of each lens to change the shape thereof, and for optically modifying the light beam to have a second different optical characteristic.