光学的同期検出による3次元形状計測装置

Three-dimensional shape measuring device by optically synchronous detection

Abstract

PROBLEM TO BE SOLVED: To attain a highly sensitive three-dimensional shape measurement even under an environment where a disturbance light is mixed by individually performing the phase modulation of output light from a laser light source that is branched into a plurality of systems by a branch means so that they are related constantly one another. SOLUTION: When a reflection signal light 14 and a reference light 13 enter a optically synchronous detection means 6 with a constant phase difference, interference fringes are formed and a phase grating G with a refractive index distribution corresponding to the interference fringes is formed at the detection means 6 after a constant response time which is determined by the material of the incidence detection means 6. By adjusting the phase modulation using a phase modulation means 3, the position and the grating interval of the grating G formed by the detection means 6 can be adjusted properly. After an effective grating G has been formed in the detection means 6, only the signal light 14 with a constant phase difference to the reference light 13 is diffracted by the formed grating G out of input light 16 where a disturbance light 15 has been mixed in the signal light 14 that enters the detection means 6, and is outputted as a synchronous detection light 17 by the interference with the reference light 13. As the result, only the signal light 14 is converted into an electrical signal 18 by a light receiving means 7. COPYRIGHT: (C)1998,JPO
(57)【要約】 【課題】 外乱光が混入する環境下でも高感度の3次元 形状計測を可能とする。 【解決手段】 レーザ光源1と、レーザ光源1からの出 力光10を2系統に分岐する分岐手段2と、分岐した出 力光10a、10bを各別に位相変調を施し、一方が信 号光11を、他方が参照光13を出力する二つの位相変 調手段3、4と、信号光11に空間的変調を施す空間変 調手段9と、空間的変調された空間変調信号光12を被 計測物体5に照射して得られる反射信号光14に外乱光 15が混入した入力光16と参照光13を入力して、入 力光16の中から参照光13と一定の位相差の反射信号 光14を選択的に同期検出し同期検出光17として出力 するフォトリフラクティブ効果を有する光同期検出手段 6と、同期検出光17を受光して電気信号18に変換す る受光手段7と、電気信号18に基づいて所定の物体計 測処理を実行する計測処理手段8より構成されている。

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    JP-2010038880-AFebruary 18, 2010Toshiba Corp, 株式会社東芝レーザ超音波検査装置およびレーザ超音波検査方法