| 摘要 |
<p>PURPOSE: To obtain a low cost barcode scanner with a large depth of field by using a rotary deflector so that scan laser beam passes through a different path within the scanner. CONSTITUTION: A laser 42 outputs a narrowed down laser beam, and this laser beam is aimed at a rotary deflector assembly 52 via deflection mirrors 46, 48, and 50, As a result, the double mirror surface of the deflector deflects the laser beam at the primary and secondary deflecting points 51 and 52, and the reflected beam is refracted by a mirror assembly 54, and goes out from the scanner. The reflected beam is converged on external focus planes 41 and 43, the depths of field of these focus planes overlap, and a combination of these depths of field makes the depth of the scanner large. Thereby, a low cost barcode scanner with a large depth of field can be obtained.</p> |
