| 摘要 |
A code scanner, which illuminates a scanned code from a distance, includes a liquid lens which focuses the reflected image of the code on an image sensor. The scanner includes a range detector, preferably laser-based, which determines the distance to the scanned code, and the liquid lens is controlled to focus at the detected distance. A source of illumination is uncontrolled to maintain its intensity substantially constant, regardless of the distance of the scanned code. This can be achieved by controlling the intensity of illumination (directly), or the dispersal angle of illumination in relationship to the distance.
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