| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical scanner capable of obtaining accurate and clear image information independently of a position for scanning an object to be read out. SOLUTION: Plural light receiving parts 71 to 73 are respectively constituted of photodiodes 7a to 7c for detecting the image information of reflected light and defection lenses 7A to 7C constituted so that the beam diameter of reflected light on each of the photodiodes 7a to 7c is set up larger than a beam diameter wD expressed by an equation wD=1.22×2l2 /W×λ(provided thatλis wavelength, W is the diameter of an exit pupil of an image forming means and l2 is the position of an image point). Since the image forming means is an optical element of which main plane almost coincides with its face vertex, a signal change in a state that reflected light is deviated from each of the photodiodes 7a to 7c is eased.
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