| 摘要 |
An optical scan module having a base; a light source mounted on the base for emitting a light beam; a scanning assembly for receiving the light beam and for generating therefrom a scanning beam directed to an indicia to be read for reflection therefrom; first and second spaced apart detectors receiving the reflected light represented by the indicia, with each detector having a different field of view; and means for selectively acquiring the signal from either the first or the second detector and applying such signal to a decoder. In another embodiment, the invention further provides an arrangement for uniformly collecting light over a scan line swept over a symbol to be electro-optically read, with a pair of photodetectors spaced apart of each other and having fields of view that overlap each other at a working distance in which the symbol is located; and means for analyzing the signal from each photodetector and selecting one of the photodetectors for providing a signal to the decoder depending upon an analysis of the signal.
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