| 摘要 |
A portable hand-held reader unit for reading two-dimensional information and generating an image therefrom wherein an optical axis of the reader is oriented obliquely to the surface containing the coded information. The reader includes a sensing system designed such that the rectilinear dimension of the generated image corresponding to an axis of the coded information undergoing the most distortion from oblique reading is magnified, by the lens system or the resolution configuration of the image sensor, to a greater extent than that of the rectilinear dimension undergoing the least distortion from oblique reading. Alternatively, the sensor is oriented relative to the optical axis such that the received image does not exhibit the distortion which may result from oblique reading. The coded information may contain height-to-width ratio of the coded information such that the generated image can be automatically corrected for distortion from oblique reading. Ranging marker beams may be used in conjunction with the obliqueness correcting embodiments to align the reader with the coded information.
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