| 摘要 |
PROBLEM TO BE SOLVED: To shorten a distance measuring time by a modulated light phase difference system. SOLUTION: When modulated light L1 having light intensity modulated with a fixed period T is emitted, and when a subject is irradiated with the emitted modulated light L1, a half period portion of the modulated light of reflected modulated light L2 from the subject is received, to thereby acquire the first detection signalα, the second detection signalβwhose phase is advanced byπ/2 in comparison with the first detection signalα, and the third detection signalγwhose phase is advanced byπ/2 in comparison with the second detection signalβ. A phase differenceΔϕbetween the modulated light L1 and the reflected modulated light L2 is detected by using the first detection signalα, the second detection signalβand the third detection signalγ, and a subject distance d is calculated from the phase differenceΔϕ. COPYRIGHT: (C)2009,JPO&INPIT
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