| 摘要 |
PURPOSE:To improve readout precision by scanning a light beam curvedly and allowing one scanning line to cross a bar code completely. CONSTITUTION:When a bar code 20 moves at some angle to a window 4 as shown in a figure, a scan need to be made as shown by an arrow C so as to read the bar code 20 completely. For the purpose, the scanning line 21 is curved arcuately as shown by an arrow C, and then the possibility that one scanning line crossed the bar code increases substantially even when scanning line intervals W3 are increased above the bar code height Hd, thereby reading the bar code completely over a wide range of readout with W1. Further, scanning lines are curved not only in the direction C, but also various directions to reduce the scanning lines, thereby reducing the number of scanning lines greatly on the whole.
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