| 摘要 |
An optical switch structure of a barcode scanner having a casing includes a wheel center fixedly mounted on an axle and partially protruding out of the scanner casing as a rotated switch, a light shield provided on the wheel or mounted on the axle linked to the wheel, the light shield having a plurality of radial slots, and a U-shaped photo interrupter having two upwardly extending arms with a photodiode light emitter and a phototransistor light receiver inside disposed on either arm, the U-shaped photo interrupter being installed under the light shield so that the photodiode light emitter is disposed at one side of the light shield and the phototransistor light receiver is disposed at the opposite side of the light shield, whereby when the wheel is rotated, the light shield will be rotated simultaneously thereby intermittently blocking light transmitting from the photodiode light emitter to the phototransistor light receiver and therefore converting light signals into pulse signals to turn on the barcode scanner.
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