| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a device and a method which read a coded pattern, symbol, or mark such as a bar code. SOLUTION: By this invention, reference points 21a and 21b of, e.g. a bar code 500 are discriminated by prescanning the pattern of the bar code 500. Calculation based upon the positions of those reference points 21a and 21b is used to determine an irreducible visual field 190 for actually picking up the reference points 21a and 21b. Then the magnification of a lens system 160 is adjusted to the irreducible visual field and a final image of the pattern is picked up with high resolution.</p> |
