FOCUS ADJUSTMENT WITH LIQUID CRYSTAL DEVICE IN IMAGING SCANNER

摘要

A method and apparatus for using in an imaging scanner (50). The apparatus includes an illumination source (72), a solid-state imager (62), a liquid crystal device (100), a lens system (64), and a decoding circuitry (90). The liquid crystal device (100) has a liquid crystal material (110) sandwiched between two parallel plate structures (120, 130). The lens system (64) is operative to focus light reflected from the target object onto the array of photosensitive elements in the solid-state imager (62) through the liquid crystal device (100). The decoding circuitry (90) is operative to decode a barcode (40) on the target object from the image captured by the solid-state imager.