LIGHT WAVE RANGE FINDER

PROBLEM TO BE SOLVED: To enable a range measurement to be correctly conducted even if a position adjustment of a diaphragm member is not made when manufactured or used over a long period.SOLUTION: The present invention relates to a light wave range finder 100 that compares reflection light with internal reference light to measure a distance to a measured object, and includes: a light source 230 that emits a prescribed broadening beam of light along an optical axis; a diaphragm member 224 that is equipped with a slit opening 224a arrangeable on the optical axis, orthogonal to the optical axis and extending in a horizontal direction, and narrows a width of the broadening beam of light from the light source; and a collimate lens 221 that is arranged between the light source and the diaphragm member, and emits the beam of light to the slit opening and, across the slit opening up and down, an area Lf with a height dimension 20 times a height dimension h of the slit opening. An amount of light of the light source is set so that reflection light from a measured object in a measurement distance set by the light wave range finder is equal to or greater than a reference value enabling a distance measurement.SELECTED DRAWING: Figure 4 【課題】製造時や経年使用時において絞り部材の位置調整を行わなくとも距離測定を正確に行えるものとする。【解決手段】反射光と内部参照光とを比較して被測定物までの距離を測定する光波距離計１００である。所定の広がりの光束を光軸に沿って射出する光源２３０と、光軸上に配置可能であり光軸と直行し水平方向に伸びるスリット開口２２４ａを備え、光源からの光束の広がり幅を絞る絞り部材２２４と、光源と絞り部材との間に配置され、光束がスリット開口と、このスリット開口を上下に挟み、スリット開口の高さ寸法ｈの２０倍の高さ寸法の領域Ｌｆに射出するコリメートレンズ２２１とを含み、光源の光量を光波距離計で設定された測定距離における被測定物からの反射光が距離測定可能な基準値以上になるように設定した。【選択図】図４