| 摘要 |
An electro-optical scanning unit adapted to sense a bar-code pattern and to generate digital signals corresponding thereto. In the unit, an incandescent light source acts to illuminate a narrow slit, and a reduced image thereof is optically projected to produce a luminous scanning line in a focal plane. An oscillating scanning mechanism interposed in the projection path causes the luminous line to sweep back and forth. The focal plane lies within a window formed in a channel dimensioned to receive an item bearing a bar-code pattern and to locate this pattern so that the bars lie in parallel relation to the luminous line, whereby when the line is swept across the pattern and is reflected thereby, the resultant light pulses are directed toward a photo-detector and converted to corresponding digital signals.
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