| 摘要 |
A targeting system for a portable image reader, which advantageously combines a number of functions including alignment, aiming, framing and range finding and provides a wide imaging range with an optimal field of view, is described. The targeting system projects a predetermined pattern having two or more components onto the target such that the components maintain a uniform distance between one another to bound the target and further vary in size as a function of their distance between the image reader and the target. The targeting system comprises targeting LED's, apertures positioned over the targeting LED's, and cylindrical lenses positioned over the apertures. With this arrangement, at least two vertical lines are projected onto a target such that the lines maintain a uniform distance apart from one another, but vary in length as a function of the reader distance from the target. This allows the operator to quickly position the imaging device over a target.
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