| 摘要 |
An optical image sensor, particularly a bar code reader, comprises a laser diode emitting a light beam of small area and elliptical cross-section. The light beam is directed onto an optical device for greatly expanding the beam along one axis for expanding the beam cross-section to that of a greatly elongated rectangle having a line-like shape. The line beam is projected from the reader for encompassing and illuminating the entire width of a bar code. Light reflected from the bar code is focused as a complete image of the bar code onto a light detector for simultaneous storage of all the bar code data. The beam expander can comprise a cylindrical lens, a cylindrical mirror, or a conical mirror including means for varying the intercept of the laser beam with the conical surface for selectively varying the width of the expanded beam.
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