JP3850279B2 - 3D shape measuring device - Google Patents

Description

よって，２ｉ(偶数)枚目のミラーで反射した像の角度α_2i+1は以下の式（４）に示すようになる。

ここで、Ｂｅはミラー群の角度β_jで決まる固定値である。
【００５４】
また、２ｉ−１(奇数)枚目のミラーで反射した像の角度α_2iは以下の式（５）に示すようになる。

ここで、Ｂｏはミラー群の角度β_jで決まる固定値である。
【００５５】
それぞれの場合の複数枚ミラー全体への入射角をα_in、射出角度α_outとすると、全体の曲り角δαは、ミラー枚数が２ｉ（偶数）枚のときは以下の式（６）で示され、ミラー群の角度β_jで決まる固定値Ｂｅとなる。
δα＝α_out−α_in＝Βe ・・・（６）
また、ミラー枚数が２ｉ−１(奇数)枚のときは、以下の式（７）で示される。
δα＝α_out−α_in＝Ｂo−２α_in ・・・（７）
図４は、本実施の形態１にかかる立体形状測定装置の受光光学系を説明するための図である。
上記のモデルを計測する反射光８の進行角度で適用すると、図１に示した受光光学系９０ａの構成として図４（ａ）に示すように、２枚ミラー１７ａ，１７ｂで構成した場合のように、ｘ軸が副走査方向１２、ｙ軸が走査光光軸方向４０の反対方向、α_inはスポット光６からの直接反射光８が走査面６となす角を主走査方向１１に垂直な平面に投影した角θで、α_outは受光光学系９０ａから射出する反射光８が走査面６となす角を主走査方向１１に垂直な平面に投影した角となる。
【００５６】
ここで、α_outについては走査集光レンズ３の光軸に対して入射する反射光は平行に近いほうが受光光学系９ｂの配置の自由度が増すので、α_outの範囲は９０°−φ〜９０°＋φとなる。なお、角度φは、あまり大きくない角度が望ましい。よって、ミラー枚数が偶数と奇数では、それぞれ上述した式（４），式（５）より、以下に示すように、式（８），式（９）となる。
偶数枚：９０°−θ−φ＜Ｂｅ＜９０°−θ＋φ ・・・（８）
奇数枚：９０°＋θ−φ＜Ｂｏ＜９０°＋θ＋φ ・・・（９）
一方、図４（ｂ）に示すように、走査光学手段の変化により、スポット光６が点Ａから点Ａ’と副走査方向１２に距離ｄｓ動いた場合、スポット光６の移動について、このモデルを適用すると、ｘ軸が副走査方向１２、ｙ軸が走査光光軸方向４０の反対方向、α_inはＡＡ’がｘ軸上となす角で常に０、α_outが受光光学系９０ａから射出する見かけ上の発光点１３の移動前後の点Ｂ、点Ｂ’の直線ＢＢ’がｘ軸となす角に相当する。この場合、点Ｂと点Ｂ’の副走査方向１２成分の移動距離をｄｒとすると、α_in＝０より次式となる。
ｄｒ／ｄｓ＝cos(α_out)＝cos(δα)
よって、走査光学系の変形による測定高さ誤差を低減するには、上記式（２）より、受光光学系９０ａの反射光曲げ角δαの範囲は−９０°〜９０°となる。
【００５７】
従って、ミラー枚数が偶数と奇数では、それぞれ上記式（６），式（７）より、以下の式（１０），式（１１）となる。
偶数枚：−９０°＜δα＝Ｂｅ＜９０° ・・・（１０）
奇数枚：−９０°＜δα＝Ｂｏ＜９０° ・・・（１１）
受光光学系９０ａを偶数枚のミラーで構成した場合、上記式（８）と式（１０）を同時に満たすには、式の両辺を比較して以下の式（１２）となる。
−９０°＜９０°−θ−φかつ ９０°−θ＋φ＜９０°
φ＜１８０°−θかつ φ＜θ ・・・（１２）
θの範囲は０〜９０°に対して、上記式（１２）を満たすφは容易に選択できるのは明らかである。
【００５８】
一方、受光光学系９０ａを奇数枚のミラーで構成した場合、上記式（９）と式（１１）とを同時に満たすには、式の両辺を比較して、以下の式（１３）となる。
−９０°＜９０°＋θ−φかつ ９０°＋θ＋φ＜９０°
φ＜１８０°＋θ かつ φ＜−θ ・・・（１３）
θの範囲は０〜９０°に対して、上記式（１３）の条件、φ＜−θを満たすφをとると、θが大きい場合、走査集光レンズに入射する角度が大きくなり、受光性能（収差，開口など）に問題が生じるため、特殊な走査集光手段の必要性や、θの範囲制限が発生し、実現が困難となる。
【００５９】
上記受光光学系９０ａを偶数枚のミラーで構成すると、反射光の曲り角は上記式（４）で示すように、固定値Ｂｅとなる。ここで、Ｂｅの式は隣り合った２ｊ枚目と２ｊ−１枚目の角度βの差(β_2j−β_2j-1)の合計となっている。つまり、ミラー間の相対角度が一定の場合、全体の角度が変化したとしても、固定値Ｂｅ、つまり、反射光の曲り角は変化しないことになる。
【００６０】
一方、受光光学系９０ａを奇数枚のミラーで構成すると、反射光の曲り角は上記式（５）で示したように、固定値Ｂｏとなる。この場合は、隣り合ったミラーの角度差(β_2j−β_2j-1)の合計とは別に、最終の２ｉ−１番目のミラー角度β_2i-1と入射角α_inがあるので、ミラー間の相対角度が一定であっても、全体の角度が変化すると反射光の曲り角が変化することになる。
【００６１】
このように、受光光学系９０ａを走査線７と平行な２枚以上の偶数枚のミラーで構成すると、スポット光６の走査光学系の変形による移動で発生する測定高さ誤差を低減でき、さらに、ミラー間の相対位置が保たれていると、受光光学系が主走査方向１１回りに回転しても、高さ誤差を抑えることができる。
【００６２】
（実施の形態２）
次に本発明の実施の形態２にかかる立体形状測定装置について説明する。
図５は、本発明の実施の形態２にかかる立体形状測定装置の受光光学系の構成を説明するための図であり、図５（ａ）は、図１に示した受光光学系９０ａを、入射面と射出面が主走査方向１１と平行なプリズム１７ｃで構成したものを示している。
【００６３】
図５（ａ）において、該プリズム１７ｃは、スポット光６の点Ａからの反射光８を、主走査方向１１と垂直な面内で曲げる作用があり、これにより反射光８を走査集光レンズ３に導いている。プリズム１７ｃを射出する反射光８の見かけ上の発光点１３を点Ｂとし、スポット光６の位置が副走査方向１２向きに点Ａから点Ａ’に距離ｄｓ移動した場合、見かけ上の発光点Ｂは点Ｂ’となり、副走査方向１２への移動距離をｄｒとする。その場合、プリズムの特性上、発光点Ｂの移動の副走査方向１２成分の向きは、点Ａの移動の向きと同じになりプリズムの入射面・射出面の角度や屈折率の組合せを選択することにより、スポット光６の、副走査方向１２の移動距離ｄｓと、見かけ上の発光点１３の副走査方向１２の移動距離ｄｒとの関係が上記式（２）を満たすことが可能となる。
【００６４】
このように、受光光学系９０ａを、主走査方向１１と垂直な平面内で光を曲げる作用のあるプリズム１７ｃで構成することにより、スポット光６の走査光学系の変形による移動で発生する測定高さ誤差を低減することができる。
さらに、プリズムの特性上、プリズム１７ｃが主走査方向１１周りに回転した場合でも、見かけ上の発光点１３の位置ずれを抑えられるので測定する高さ誤差を押えることができる。
【００６５】
図５（ｂ）は、請求項５に記載した構成の立体形状測定装置の基本的な構造を示しており、受光光学系９０ａを、図５（ａ）におけるプリズム１７ｃに代えて、円筒レンズ１７ｄを用いて構成している。
図５（ｂ）において、上記プリズム１７ｃを用いたときの説明と同じく、発光点Ｂの副走査方向１２の移動の向きはＡの向きと同じで、スポット光６の副走査方向１２の移動距離ｄｓと見かけ上の発光点１３の副走査方向１２の移動距離ｄｒとの関係が、上記式（２）を満たすことが可能となる。
【００６６】
また、図５（ｃ）は、請求項６に記載した立体形状測定装置の基本的な構成を示しており、受光光学系９０ａをプリズムシート１７ｅを用いて構成している点が特徴である。
【００６７】
図５（ｃ）において、上記プリズム１７ｃを用いたときの説明と同じく、発光点Ｂの副走査方向１２の移動の向きはＡの向きと同じで、スポット光６の副走査方向１２の移動距離ｄｓと見かけ上の発光点１３の副走査方向１２の移動距離ｄｒとの関係が上記式（２）を満たすことが可能となる。さらに、プリズムシート１７ｅは、図５（ｃ）に示すように、シート状に制作することが可能なため、空間的な体積が少なく、ほかの光学部品の配置に対して与える影響が少なくなるので、光学設計上の自由度が増し、付加的な機能や性能向上が容易となる。
なお、図５（ｃ）では、断面形状が鋸状のプリズムシート１７ｅを用いる場合を示したが、多段の凹凸形状となっている回折格子でも同様に実施することができる。
【００６８】
（実施の形態３）
次に本発明の実施の形態３にかかる立体形状測定装置について説明する。
図６は、本発明の実施の形態３にかかる立体形状測定装置の基本的な構成を説明するための図であり、図６（ａ）は、本発明の請求項７に記載された立体形状測定装置の主要な構成を示している。
【００６９】
図６（ａ）において、一体型受光光学系（プリズム）１８は、請求項３に記載した構成（図３（ｂ）に相当）を有する受光光学系の２つのミラーを内面に設けたものとなっており、スポット光６からの反射光８はプリズム１８の内面にある２つのミラー１７ａ，１７ｂを経由して走査集光レンズ３へ導かれるように構成されている。
【００７０】
また、図６（ｂ）に示すように、位置検出素子１０と受光光学系９ｂとの間に補正プリズム１９を設けた構成を有している。この場合、図６（ｃ）に示すように、反射光８の片側の光を８ａとし、反対側の光を８ｂとすると、プリズム１８で曲ることにより、反射光８ａと反射光８ｂとの間に光路長差が発生する。そのため単に走査光学系・受光光学系９ｂを通して位置検出素子１０上に集光しても一点に集光しない。そこで補正プリズム１９により、反射光８ａと反射光８ｂとの間に、プリズム１８で生じた光路長差とは反対方向の光路長差を発生させ、プリズム１８で発生する光路長差を相殺するように構成すると、位置検出素子１０上で反射光８は１点に集光するようになる。
【００７１】
すなわち、プリズム１８の入射面１８ａへの入射角をα₁とし、プリズム１８の射出面１８ｂからの射出角をα₂とし、補正プリズム１９の入射面１９ａへの入射角をβ₁とし、さらに、補正プリズム１９の射出面１９ｂからの射出角をβ₂とすると、プリズム１８と補正プリズム１９の屈折率が同じで、スポット光６と位置検出素子１０上の像との間の光学倍率が１の場合、α₁＝β₂、かつα₂＝β₁だと、プリズム１８で発生する光路長差は補正プリズム１９で発生する光路長差で相殺され、反射光８の両端の光８ａと光８ｂの光路長とが同じになり、位置検出素子１０上の像サイズが小さくなり、測定高さ精度が改善されることになる。
【００７２】
一般に、プリズム１８の形状はコストやサイズの制限から、角度α₁，α₂を収差が最小になる最適な組合せにとれないことが多いので、その場合、上記の条件を満たす補正プリズム１９を配することにより、プリズム１８で発生する収差を改善することができる。また、補正プリズム１９の位置だと走査位置に関係なく反射光８の位置は、ほぼ一定のため、補正プリズム１９のサイズを小さくでき、コスト上も有利となる。
【００７３】
なお、プリズム１８と補正プリズム１９の屈折率が異なったり、光学倍率が１でなかったりする場合でも、プリズム１８での入射角α₁，射出角α₂に対して、光路長差を補正（相殺）するのに適合する補正プリズム１９の入射角β₁と射出角β₂とを選ぶことで収差を改善し、位置検出素子１０上の像サイズを最適にすることができる。
【００７４】
また、反射光８がプリズム１８を通過すると、反射光の放射角が変化するために非点収差が発生する。つまり、図６（ｃ）に示すように、主走査方向１１と垂直な面に投影した反射光８の入射前の放射角γ₁と、射出後の放射角γ₂とが、プリズム１８の作用により異なる。一方、副走査方向１２と垂直な面に投影した反射光８の放射角は、プリズム１８が平行ガラスとしての作用しかないので入射前と射出後で同じである。そのため、非点収差が発生し、集光しても直線の像となり点像とならない。直線像の直線方向が位置検出素子１０の位置を検出する方向と直交していると、測定高さ精度に影響がないが、一般には部品精度や組立て精度の問題で直角にならないので、測定高さ精度の低下要因となる。こうした問題に対しても先述の補正プリズム１９を配置することにより、非点収差が補正され、結像状態を改善することができる。
【００７５】
また、受光光学系９０ａをプリズムシートで構成した場合、上記図６（ａ）の構成で説明したのと同様の受光光学系９０ａで発生する収差を改善する補正プリズム１９を、位置検出素子１０と受光光学系９ｂとの間に設けることにより、位置検出素子上の反射光８の像サイズを小さくし、測定高さ誤差を改善する効果が得られる。
【００７６】
また、請求項９に記載した立体形状測定装置の構成においては、受光光学系９０ａを円筒レンズで構成した場合、反射光８は主走査方向１１と垂直な面内で曲り走査光学系へ導かれるが、同時にレンズとしての効果により、主走査方向１１に垂直な平面に投影した反射光８の放射角が変化するので、反射光８に非点収差が発生する。そこで、円筒レンズを位置検出素子１０と受光光学系９ｂとの間に、受光光学系９０ａを構成する円筒レンズと直角の方向にパワーをもつ方向に設けることにより、位置検出素子１０上の反射光８の像サイズを小さくし、測定高さ誤差を改善する効果を得ることができる。
【００７７】
（実施の形態４）
次に本発明の実施の形態４にかかる立体形状測定装置について説明する。
請求項１０から請求項１７に記載された立体形状測定装置について、図７〜図１０を用いて説明する。
図７は、請求項１０に記載した立体形状測定装置の基本的な構成を示す図である。
【００７８】
図７において、走査集光レンズ３に入射する反射光８の見かけ上の発光点１３が、走査集光レンズ３を通過した走査光４の見かけ上の集光点４１を通り、走査光４に垂直な面（見かけ上の走査面３０）上にある場合、走査光学系を射出した、反射光８の見かけ上の集光点１４までの距離Ｌｄｒと、走査集光レンズ３に入射する、光源１から出た光の見かけ上の発光点１５までの距離Ｌｄｓとが走査位置にかかわらず常に一致するように構成されている。
【００７９】
ここで光源１は固定しているので距離Ｌｄｓは一定となり、反射光８の距離Ｌｄｒも走査位置に関わらず常に一定になる。位置検出素子１０と走査集光レンズ３との間に配置している受光光学系９ｂも固定されているので、受光光学系９ｂにより集光された反射光８の像は常に位置検出素子１０上で結像し、像サイズも一定となる。
【００８０】
よって、位置検出素子１０上の像サイズが大きいと高さの測定精度が低下するので、この場合、走査位置に関係なく常に測定高さ精度は一定となる。つまり、走査集光レンズ３に入射する反射光８の見かけ上の発光点１３の位置を、走査位置に関係なく、見かけ上の走査面３０上に配することにより、走査位置に関係なく、常に安定した高さの測定が可能になり、また、全走査範囲全体の総合的な測定高さ精度も向上することになる。
なお、走査集光レンズ３と実際の走査面１６との間に、走査光４の集光距離を変える光学系がない場合、見かけ上の走査面３０は実際の走査面１６と一致することになる。
【００８１】
図８は、請求項１１に記載した立体形状測定装置の基本的な構成を示し、該立体形状測定装置の走査光伸縮手段の構成を説明するための図である。
図８において、走査集光レンズ３と走査面１６との間に、収束光の集光点までの距離を変える作用をもつ手段３１を挿入して、走査面１６に対して走査集光レンズ３からみた、見かけ上の走査面３０の位置を、見かけ上の発光点１３の位置と一致するまで移動することにより、上記請求項１０に記載した立体形状測定装置を実現している。
【００８２】
図８（ａ）では、見かけ上の発光点１３の位置が、走査面１６より走査光進行方向４０側にある場合、収束光の集光点までの距離を短くする作用をもつ手段（集光距離変更手段）３１を挿入して、見かけ上の走査面３０を走査面１６に対して走査光進行方向４０に動かして、請求項１１の構成を実現している。
【００８３】
また、図８（ｂ）では、見かけ上の発光点１３の位置が走査面１６より走査光進行方向４０の逆側にある場合、収束光の集光点までの距離を長くする作用をもつ手段３１を挿入して、見かけ上の走査面３０を走査面１６に対して走査光進行方向４０と逆方向に動かして請求項１１の構成を実現している。
【００８４】
図９は、請求項１２と請求項１３に記載した立体形状測定装置の基本的な構成を示しており、該立体形状測定装置の走査光伸縮手段の構成を説明するための図である。
図９（ａ）は、収束光の集光点までの距離を短くする作用をもつ手段３１を、主走査方向１１の軸と平行な４枚のミラー群３２で構成した例である。
図９（ａ）において、走査光４が４枚のミラーの間を折れ曲って進むことにより、光学的な距離（光路長）が経過して走査集光レンズ３からみたときの走査光４の見かけ上の集光点４１に対して、実際の集光点の位置が光進行方向４０と逆側に移動する。つまり、実際の走査面１６に対して見かけ上の走査面３０は光進行方向に移動することになる。
【００８５】
ミラーの間隔や角度を選んで見かけ上の走査面３０上に、見かけ上の発光点１３が位置するようにする。実際には、ミラー枚数は３枚以上であれば同様の作用が得られるのは明らかである。
【００８６】
さらに、ミラー群３２が偶数枚のミラーで構成されており、かつ、ミラー間の相対関係が固定されている場合、ミラー群３２全体に主走査方向１１周りの回転が発生しても、請求項３に記載した立体形状測定装置において述べたように、射出する走査光４の角度変化は発生せず、信頼性の高い測定が可能となる。
【００８７】
また、図９（ｂ）は、収束光の集光点までの距離を長くする作用をもつ手段３１を、主走査方向１１の軸と平行な平行ガラス３３で構成した例である。
図９（ｂ）において、走査光が屈折率ｎで厚みｔのガラス中を進むことにより、次の式（３０）で示される距離Ｌ，走査光４の集光点が光進行方向４０側に移動する。
Ｌ＝ｔ（１−１／ｎ） ・・・（３０）
つまり、実際の走査面１６に対して、見かけ上の走査面３０は光進行方向４０と逆方向に移動する。そこで、屈折率ｎと厚みｔを選んで、見かけ上の走査面３０上に見かけ上の発光点１３が位置するようにする。
【００８８】
図１０は、請求項１４に記載した立体形状測定装置の基本的な構成を示しており、該立体形状測定装置の反射光伸縮手段の構成を説明するための図である。
図１０において、受光光学系９０ａと走査集光レンズ３との間に、収束光の集光点までの距離を変える作用をもつ手段（反射光発光点距離変更手段）３４を挿入して、走査光学系に入射する反射光８の見かけ上の発光点１３を走査面１６上の位置まで移動する構成となっている。
【００８９】
図１０（ａ）は、見かけ上の発光点１３の位置が、走査面１６より走査光進行方向４０と逆方向にある場合、収束光の見かけ上の集光点までの距離を長くする作用をもつ手段３４を挿入して、見かけ上の発光点１３を走査光進行方向４０に動かして、請求項１３に示す構成を実現している。収束光の見かけ上の集光点までの距離を長くする作用を持つ手段３４として、図９（ａ）でスポット光の集光距離を変える手段３１として使用した、主走査方向４０と平行な複数のミラー群で同様に構成すると、請求項１５に記載した立体形状測定装置を実現するものとなる。
【００９０】
図１０（ｂ）は、見かけ上の発光点１３の位置が、走査面１６より走査光進行方向４０側にある場合、収束光の見かけ上の集光点までの距離を短くする作用をもつ手段３４を挿入して、見かけ上の発光点１３を走査光進行方向４０と逆方向に動かして請求項１３の構成を実現している。
【００９１】
収束光の見かけ上の集光点までの距離を短くする作用を持つ手段３４として、図９（ｂ）でスポット光の集光距離を変える手段３１として使用した主走査方向４０と平行な平行ガラスを用いて構成すると、請求項１６に記載した立体形状測定装置を実現することができる。
【００９２】
また、図１０（ａ）,（ｂ）において、見かけ上の発光点の距離を変える手段３４を、主走査方向１１の方向に伸びた円筒レンズで構成すると、上記請求項１７に記載した立体形状測定装置を実現することができる。その場合、走査光学手段に入射する反射光８に非点収差が発生するので、位置検出素子１０上の反射光の像は直線状となる。像の線方向が位置検出素子１０の位置を検出する方向と垂直であれば、測定高さ精度に対して影響はないが、少しでも垂直から外れると測定高さ精度が低下する要因となる。このような場合には、請求項９記載の立体形状測定装置と同様の補正用円筒レンズを受光光学系９ｂの前後に追加することにより、非点収差を改善することができ、測定高さの精度低下を防止することができる。
【００９３】
（実施の形態５）
次に本発明の実施の形態５にかかる立体形状測定装置について説明する。請求項１８から請求項２３に記載された立体形状測定装置について、図１１〜図１３を用いて説明する。
【００９４】
図１１は、本発明の実施の形態５にかかる立体形状測定装置の基本的な構成を説明するための図であり、図１１（ａ）は、請求項１８に記載した立体形状測定装置の基本的な構成を示す図である。
図１１（ａ）において、図１に示した受光光学系９０ａが、その内面に２枚のミラー１７０ａ，１７０ｂをもつプリズム１８０で構成されており、スポット光６からの反射光８は、プリズムの透過面１８０ａ上の点Ａを通過してプリズム内に入射し、ミラー１７０ａ上の点Ｂとミラー１７０ｂ上の点Ｃで２回反射して透過面１８０ｂ上の点Ｄより射出され、走査集光レンズ３へ導かれるように構成されている。
【００９５】
反射光８は、２つのミラー１７０ａ，１７０ｂ間を折れ曲って進むので走査集光レンズ３から見たときの、ミラー１７０ｂからの射出光の見かけ上の発光点は、走査光進行方向４０に移動する。同時に、反射光は屈折率ｎのプリズム内を通過するので、反射光のプリズム内の通過距離をｔ（＝距離ＡＢ＋距離ＢＣ＋距離ＣＤ）とし、屈折率をｎとすると、先述の式（３０）に示されるように、見かけ上の発光点は走査光進行方向４０とは反対方向に移動する。
【００９６】
こうした２つの見かけ上の発光点の移動は、それぞれ逆方向になるのでミラーの間隔やプリズムのサイズを選ぶことにより、移動方向をお互いに相殺することができ、見かけ上の発光点を走査面１６上に位置する効果と、スポット光６の、副走査方向位置変化による発光点１３の位置変化をほぼ同じにすることができるという２つの作用を同時に得ることができる光学系を、一体のプリズム１８を用いて実現することができる。
【００９７】
さらに、図１１（ｂ）は、請求項１９に記載した立体形状測定装置の基本的な構成を示している。
図１１（ｂ）において、走査光４がプリズム１８１の平行な２つの透過面１８１ｃと透過面１８１ｄとを、それぞれ通過点Ｅと点Ｆで通過するように構成されている。その距離ＥＦをｔとし、プリズム屈折率ｎとすると、同様に先述の式（３０）により、２枚の平行ガラスによる効果である、見かけ上の走査面３０の移動が起こり、走査光による見かけの走査面３０も変更することができるので、スポット光６の、副走査方向位置変化による発光点１３の位置変化をほぼ同じにすることができるのとあわせて、自由度の高い設計が可能となる。
【００９８】
以上に示した請求項１８と請求項１９記載の立体形状測定装置は、請求項７記載の立体形状測定装置でも述べたように、プリズム１８０,１８１の入射面や射出面が反射光８と垂直でない場合に、発生する収差を改善する補正プリズムを設けることも可能である。
【００９９】
図１２は、本実施の形態５における立体形状測定装置の構成を説明するための図であり、図１２（ａ）は、請求項２０記載の立体形状測定装置の基本的な構成を示している。
図１２（ａ）において、図１に示した受光光学系９０ａが、主走査方向１１と平行な入射面と射出面をもつプリズム１８２で構成されており、スポット光６からの反射光８は、入射面１８２ａ上の点Ａを通過してプリズム内に入射し、入射面１８２ｂ上の点Ｂよりプリズムから射出され走査集光レンズ３へ導かれるように構成されている。
【０１００】
この場合、反射光８が折れ曲って進むのと、射出する反射光８の放射角が変わるのとで、見かけ上の発光点１３の位置が移動する。同時に、反射光８は屈折率ｎのプリズム内を通過するので、反射光８のプリズム内の通過距離をｔ（＝距離ＡＢ）とし、その屈折率をｎとすると、先述の式（３０）に示されるように、見かけ上の発光点が走査光進行方向４０とは反対方向に移動する。プリズム１８２の入射／射出面の角度、屈折率、及びプリズムのサイズを選ぶことにより、２つの見かけ上の発光点の移動は、その移動方向がお互いに相殺することにより、見かけ上の発光点が走査面１６上に位置する効果と、スポット光６の、副走査方向位置変化による発光点の位置変化をほぼ同じにすることができるという２つの効果を同時に実現することができる光学系を、一体のプリズム１８を用いて実現することができる。
【０１０１】
さらに、図１２（ｂ）は、請求項２１記載の立体形状測定装置の基本構成を示す。
図１２（ｂ）において、走査光４が、主走査方向１１に平行で、お互いに平行な２つの透過面１８３ｃと１８３ｄとをそれぞれ通過点Ｃと点Ｄで通過する。その距離ＣＤをｔとして、プリズム１８３の屈折率をｎとすると、同様に先述の式（３０）により、２枚の平行ガラスによる効果である、見かけ上の走査面の移動が起こり、走査光による見かけの走査面が変更され、スポット光６の、副走査方向位置変化による発光点の位置変化をほぼ同じにすることができることとあわせて、より自由度の高い設計が可能となる。
【０１０２】
なお、以上に示した、請求項２０と請求項２１記載の立体形状測定装置は、上記請求項８に記載した立体形状測定装置の説明で述べたように、プリズム１８２,１８３で発生する収差を改善する補正プリズムを設けた場合でも、同様に効果を得ることができる。
【０１０３】
図１３は、本実施の形態５における立体形状測定装置の構成を説明するための図である。
なお、図１３（ａ）は、上記図１２（ｂ）において、受光光学系９０ａを構成するプリズムを、プリズムシート１８４に置き換えたものであり、図１２（ｂ）で示した立体形状測定装置と同様、２枚の平行ガラスによる効果である、見かけ上の走査面の移動が起こり、走査光による見かけの走査面が変更され、スポット光６の、副走査方向位置変化による発光点の位置変化をほぼ同じにすることができることとあわせて、より自由度の高い設計が可能となる。
また、図１２（ａ）においても、プリズム１８２をプリズムシートへ置き換えることにより、同等の効果が実現することができる。
【０１０４】
また、図１３（ｂ）は、請求項２３に記載した立体形状測定装置の基本構造を示しており、受光光学系９０ａを、主走査方向１１に伸びている円筒レンズ１８５を用いて構成している点が特徴である。
図１３（ｂ）において、スポット光６からの反射光８は、入射面１８５ａ上の点Ａを通過して円筒レンズ内に入射し、折れ曲って入射面１８５ｂ上の点Ｂより円筒レンズから射出され、走査集光レンズ３へと導かれるように構成されている。また、レンズのパワーにより射出した反射光８の放射角が変わり、見かけ上の発光点の位置が、見かけ上の走査面上に配され、請求項５記載の立体形状測定装置において説明したように、スポット光６の走査光学系の変形による移動で発生する測定高さ誤差を低減することができ、また、上記請求項１７記載の立体形状測定装置において説明したように、反射光の見かけ上の発光点が走査面上にない場合に、走査面に対して見かけ上の発光点の位置を移動して、走査面と反射光の見かけ上の発光点の位置を一致させることができる効果が実現されている。
【０１０５】
さらに、走査光４が通過する平行ガラスと一体化することにより、請求項１３記載の立体形状測定装置において説明したように、実際の走査面に対して、見かけ上の走査面が光進行方向と逆方向に移動するので、見かけ上の走査面上に見かけ上の発光点を位置させることができるので、より自由度の高い設計が可能となる。
【０１０６】
なお、以上の説明では、反射光の方向は主に、主走査方向と垂直な面内の１方向の反射光を代表例として説明したが、上記いずれの実施の形態においても走査光束が描く面内以外のどの方向の反射光についても、主走査方向と垂直な面に反射光を投影した光に対して実施可能である。さらに、複数方向の受光光学系が同時にある場合でも実施可能である。
また、受光光学系を構成するプリズムや円筒レンズ，シートプリズムについて、いずれも個数が１個の場合を例として説明したが、複数個で構成されている場合でも実施可能であることは言うまでもない。
【０１０７】
【発明の効果】
以上のように、本発明の請求項１にかかる立体形状測定装置によれば、走査光束を測定対象の物体に照射して得られた反射光を光位置検出器によって検出し、各走査位置における検出結果から上記物体の立体形状を測定する立体形状測定装置において、光束を発生する手段と、該光束を偏向して走査させる偏向走査手段と、該偏向走査手段を通過した光束を集光する走査集光手段と、上記走査集光手段を通過した光束（以下、走査光束）の集光点が描く軌跡（以下、走査線）上の測定対象となる物体からの反射光を上記走査集光手段、及び上記偏向走査手段に導き、上記光位置検出器に入射させるとともに、上記走査光束と上記走査線の両者に垂直な方向（以下、副走査方向）に上記物体が移動した場合、上記光位置検出器にて得られる像の、上記副走査方向の移動の向きが、上記物体の移動の向きと同じで、かつ、上記像の移動距離が上記物体の移動距離の２倍未満となる反射光光路変換手段とを備えたものとしたので、走査光学系から射出する反射光の見かけ上の集光点の光源に対する相対的な位置が、走査光学系の変形にかかわらずほぼ一定になるので、位置検出素子上の像の位置変化が抑えられ、発生する測定高さ誤差を低減することができるという効果が得られる。
【０１０８】
また、本発明の請求項２にかかる立体形状測定装置によれば、請求項１記載の立体形状測定装置において、上記反射光光路変換手段は、上記走査線と平行に配置された２枚以上の偶数枚の鏡としたので、単純なミラーの組合せにより、容易に走査光学系の変形で発生する測定高さ誤差を低減することができるという効果が得られる。
【０１０９】
また、本発明の請求項３にかかる立体形状測定装置によれば、請求項２記載の立体形状測定装置において、上記鏡と鏡の間の相対位置関係が常に一定に保たれているものとしたので、反射光光路変換手段全体が主走査方向の軸周りに回転しても、反射光光路変換手段を射出する反射光の見かけ上の発光点の位置がほぼ同じになり、発生する測定高さ誤差を低減することができるという効果が得られる。
【０１１０】
また、本発明の請求項４にかかる立体形状測定装置によれば、請求項１記載の立体形状測定装置において、上記反射光光路変換手段は、上記走査線と平行な入射面と射出面とを持つ、くさび型のプリズムとしたもので、単純な部品で容易に走査光学系の変形で発生する測定高さ誤差を低減でき、さらに、反射光光路変換手段全体が走査光の走査する方向の軸周りに回転しても、反射光光路変換手段を射出する反射光の見かけ上の発光点の位置がほぼ同じになり、高さデータの変化も低減することができるという効果が得られる。
【０１１１】
また、本発明の請求項５にかかる立体形状測定装置によれば、請求項１記載の立体形状測定装置において、上記反射光光路変換手段は、上記走査線の方向に伸びた円筒レンズとしたので、単純な部品で容易に走査光学系の変形で発生する測定高さ誤差を低減でき、反射光光路変換手段全体が走査光の走査する方向の軸周りに回転しても、反射光光路変換手段を射出する反射光の見かけ上の発光点の位置がほぼ同じになり、高さデータの変化も低減することができるという効果が得られる。
【０１１２】
また、本発明の請求項６にかかる立体形状測定装置によれば、請求項１記載の立体形状測定装置において、上記反射光光路変換手段は、シート状の形状を有し、光を屈折させる光学素子としたので、１つの部品で容易に走査光学系の変形で発生する測定高さ誤差を低減でき、さらに、反射光光路変換手段全体が走査光の走査する方向の軸周りに回転しても、反射光光路変換手段を射出する反射光の見かけ上の発光点の位置がほぼ同じになり、高さデータの変化も低減でき、また、さらに、反射光光路変換手段の配置上の制限を低減でき、設計上の自由度が増すので、より最適な設計が可能になるという効果が得られる。
【０１１３】
また、本発明の請求項７にかかる立体形状測定装置によれば、請求項３記載の立体形状測定装置において、上記反射光光路変換手段を構成する偶数枚の鏡が、ひとつのプリズム本体の内面に形成されており、上記反射光を上記光位置検出器上に集光した像の収差を改善する補正プリズムを、上記走査集光手段と上記光位置検出器との間に設けたので、反射光がプリズムで構成された反射光光路変換手段の入射面や射出面に対して斜めに入射すると、発生する収差が修正され、位置検出素子上の像サイズが小さくなり、高さ測定精度が向上するという効果が得られる。
【０１１４】
また、本発明の請求項８にかかる立体形状測定装置によれば、請求項４または請求項６記載の立体形状測定装置において、上記反射光を上記光位置検出器上に集光した像の収差を改善する補正プリズムを、上記集光手段と上記光位置検出器との間に設けたので、反射光がプリズムで構成された反射光光路変換手段の入射面や射出面に対して斜めに入射すると、発生する収差が修正され、位置検出素子上の像サイズが小さくなり、高さ測定精度が向上するという効果が得られる。
【０１１５】
また、本発明の請求項９にかかる立体形状測定装置によれば、請求項５記載の立体形状測定装置において、上記反射光を上記光位置検出器上に集光した像の収差を改善する円筒レンズを、上記集光手段と上記光位置検出器との間に設けたので、反射光が円筒レンズで構成された反射光光路変換手段に入射すると、発生する非点収差が修正され、位置検出素子上の像が点状に小さくなり、高さ測定精度を向上することができるという効果が得られる。
【０１１６】
また、本発明の請求項１０にかかる立体形状測定装置によれば、走査光束を測定対象の物体に照射して得られた反射光を光位置検出器によって検出し、各走査位置における検出結果から上記物体の立体形状を測定する立体形状測定装置において、光束を発生する手段と、該光束を偏向して走査させる偏向走査手段と、該偏向走査手段を通過した光束を集光する走査集光手段と、上記走査集光手段を通過した光束（以下、走査光束）の集光点が描く軌跡（以下、走査線）上の測定対象となる物体からの反射光を上記走査集光手段、及び上記偏向走査手段に導き、上記光位置検出器に入射させるとともに、上記走査集光手段を射出した上記走査光束の見かけ上の集光点が描く軌跡を通り、かつ、上記走査光束に垂直な面（以下、仮想走査面）に対して、上記集光点の上記走査集光手段に入射する反射光の見かけ上の発光点が、常に上記仮想走査面上に位置するようになる反射光光路変換手段とを備えたものとしたので、走査光学系から射出する反射光の見かけ上の集光点と光源から射出される光束の見かけ上の発光点との間の相対的な位置が、走査位置にかかわらずほぼ一定になり、走査位置による位置検出素子上の像サイズの変化が低減され、高さ測定精度を向上させることができるという効果が得られる。
【０１１７】
また、本発明の請求項１１にかかる立体形状測定装置によれば、請求項１０記載の立体形状測定装置において、上記走査集光手段を通過した上記走査光束が上記走査面に到達する間の光路に設けられ、上記走査光束の集光距離を変化させる集光距離変更手段を備えたものとしたので、走査集光手段からみた見かけ上の走査面の位置が、走査集光手段からみた反射光の見かけ上の発光点まで移動し、走査位置に関係なく、常に安定した高さ測定が可能になるという効果が得られる。
【０１１８】
また、本発明の請求項１２にかかる立体形状測定装置によれば、請求項１１記載の立体形状測定装置において、上記集光距離変更手段は、上記走査線と平行な３枚以上の鏡から構成されているものとしたので、反射光の見かけ上の発光点が走査面に対して走査光進行方向に移動している場合に、走査集光手段からみた見かけ上の走査面の位置を走査光の進行方向に移動して、見かけ上の走査面と反射光の見かけ上の発光点の位置とを一致させることができ、走査位置に関係なく、常に安定した高さ測定が可能になるという効果が得られる。
【０１１９】
また、本発明の請求項１３にかかる立体形状測定装置によれば、請求項１１記載の立体形状測定装置において、上記集光距離変更手段は、上記走査線と平行な入射面と射出面とを有する平行ガラスで構成するようにしたので、反射光の見かけ上の発光点が走査面に対して走査光進行と逆方向に移動してる場合に、走査面に対して走査集光手段からみた見かけ上の走査面の位置を走査光進行と逆方向に移動して、見かけ上の走査面と、反射光の見かけ上の発光点の位置とを一致させることができ、走査位置に関係なく、常に安定した高さ測定が可能になるという効果が得られる。
【０１２０】
また、本発明の請求項１４にかかる立体形状測定装置によれば、請求項１０記載の立体形状測定装置において、上記測定対象からの上記反射光が上記走査集光手段に到達する間の光路に設けられ、上記反射光の見かけ上の発光点までの距離を変化させる反射光発光点距離変更手段を備えたものとしたので、走査集光手段からみた反射光の見かけ上の発光点の位置を、走査面まで移動して、走査位置に関係なく、常に安定した高さ測定が可能になるという効果が得られる。
【０１２１】
また、本発明の請求項１５にかかる立体形状測定装置によれば、請求項１４記載の立体形状測定装置において、上記反射光発光点距離変更手段は、上記走査線と平行な３枚以上の鏡から構成したので、反射光の見かけ上の発光点の位置が走査面に対して走査光進行方向と逆方向に移動している場合に、走査面に対して見かけ上の発光点の位置を走査光進行方向に移動して、見かけ上の走査面と反射光の見かけ上の発光点の位置を一致させることができ、走査位置に関係なく、常に安定した高さ測定が可能になるという効果が得られる。
【０１２２】
また、本発明の請求項１６にかかる立体形状測定装置によれば、請求項１４記載の立体形状測定装置において、上記反射光発光点距離変更手段は、上記走査線と平行な入射面と射出面を有する平行ガラスで構成したものとしたので、反射光の見かけ上の発光点が走査面に対して走査光進行に移動している場合に、走査面に対して見かけ上の発光の位置を走査光進行と逆方向に移動して、走査面と反射光の見かけ上の発光点の位置を一致させることができ、走査位置に関係なく、常に安定した高さ測定が可能になるという効果が得られる。
【０１２３】
また、本発明の請求項１７にかかる立体形状測定装置によれば、請求項１４記載の立体形状測定装置において、上記反射光発光点距離変更手段は、上記走査線方向に伸びた円筒レンズから構成したので、反射光の見かけ上の発光点が走査面上にない場合に、走査面に対して見かけ上の発光の位置を移動して、走査面と反射光の見かけ上の発光点の位置が一致するようになるので、走査位置に関係なく、常に安定した高さ測定が可能になるという効果が得られる。
【０１２４】
また、本発明の請求項１８にかかる立体形状測定装置によれば、請求項１６記載の立体形状測定装置において、上記反射光光路変換手段を構成する平行ガラスは、上記走査線と平行に配置された２枚以上の偶数枚の鏡をその内面に形成されて一体化されたものとしたものとしたので、複数の機能をもった手段を一体化することにより、部品点数を抑えられ、部品コストや組立て調整工数が削減可能となり、総合的なコストを低減することができるという効果が得られる。
【０１２５】
また、本発明の請求項１９にかかる立体形状測定装置によれば、請求項１８記載の立体形状測定装置において、上記反射光光路変換手段を構成する一体化された平行ガラスは、上記走査光束の集光距離を変化させる、上記走査線と平行な入射面と射出面とを備えたものとしたので、複数の機能をもった手段を一体化することにより、部品点数を抑えられ、部品コストや組立て調整工数が削減可能となり、総合的なコストを低減できるという効果が得られる。
【０１２６】
また、本発明の請求項２０にかかる立体形状測定装置によれば、請求項４、請求項６または請求項８のいずれかに記載の立体形状測定装置において、上記反射光の見かけ上の発光点までの距離を変化させる反射光発光点距離変更手段を、上記反射光光路変換手段を構成するプリズムと一体的に形成したので、複数の機能をもった手段を一体化することにより、部品点数を抑えられ、部品コストや組立て調整工数が削減可能となり、総合的なコストを低減することができるという効果が得られる。
【０１２７】
また、本発明の請求項２１にかかる立体形状測定装置によれば、請求項２０記載の立体形状測定装置において、上記走査線と平行な入射面と射出面とを有する平行ガラスからなる、上記走査光束の集光距離を変化させる集光距離変更手段を、上記反射光光路変換手段を構成するプリズムと一体的に形成したので、複数の機能をもった手段を一体化することにより、部品点数を抑えられ、部品コストや組立て調整工数が削減可能となり、総合的なコストを低減することができるという効果が得られる。
【０１２８】
また、本発明の請求項２２にかかる立体形状測定装置によれば、請求項５記載の立体形状測定装置において、上記反射光光路変換手段を構成する円筒レンズが、上記測定対象からの上記反射光が上記走査集光手段に到達する間の光路に設けられ、上記反射光の見かけ上の発光点までの距離を変化させる反射光発光点距離変更手段を一体化することにより、部品点数を抑えられ、部品コストや組立て調整工数が削減可能となり、総合的なコストを低減することができるという効果が得られる。
【０１２９】
また、本発明の請求項２３にかかる立体形状測定装置によれば、請求項２２記載の立体形状測定装置において、上記反射光光路変換手段を構成する円筒レンズは、上記走査光束の集光距離を変化させる、上記走査線と平行な入射面と射出面とを有する平行ガラスからなる集光距離変更手段とを一体化することにより、部品点数を抑えられ、部品コストや組立て調整工数が削減可能となり、総合的なコストを低減することができるという効果が得られる。
【図面の簡単な説明】
【図１】本発明にかかる立体形状測定装置の全体的な構成を示す斜視図である。
【図２】本発明の実施の形態１にかかる立体形状測定装置の原理を説明するための図であり、スポット光が移動した場合（図（ａ））及びスポット光の移動が走査光学系の変形により発生している場合（図（ｂ））を示す。
【図３】上記実施の形態１にかかる立体形状測定装置において、ミラー群の反射による物体と像移動の関係を説明するための図であり、ミラーがそれぞれ、１枚（図（ａ））及び複数枚（図（ｂ））の場合を示す。
【図４】上記実施の形態１における立体形状測定装置の受光光学系の構成を説明するための図であり、２枚ミラーによる受光光学系の構成（図（ａ））及びスポット光の移動（図（ｂ）を示す。
【図５】実施の形態２における立体形状測定装置の受光光学系の構成を説明するための図であり、受光光学系をそれぞれ、プリズム（図（ａ））、円筒レンズ（図（ｂ））、及びフレネルプリズム（図（ｃ））で構成した場合を示す。
【図６】本発明の実施の形態３にかかる立体形状測定装置の基本的な構成を説明するための図であり、一体型受光光学系の構成（図（ａ））、補正プリズムの設置（図（ｂ））、光路長差の発生（図（ｃ））を示す。
【図７】本発明の実施の形態４にかかる立体形状測定装置の基本的な構成を説明するための図である。
【図８】上記実施の形態４における立体形状測定装置の走査光伸縮手段の構成を説明するための図であり、見かけ上の発光点の位置が走査面よりぞれぞれ、走査光進行方向側（図（ａ））及び走査光進行方向の逆側（図（ｂ））にある場合を示す。
【図９】上記実施の形態４における立体形状測定装置の走査光伸縮手段の構成を説明するためのほかの図であり、走査光伸縮手段をそれぞれ、ミラー群（図（ａ））及び平行ガラス（図（ｂ））で構成した場合を示す。
【図１０】上記実施の形態４における立体形状測定装置の反射光伸縮手段の構成を説明するための図であり、見かけ上の発光点の位置が走査面よりそれぞれ、走査光進行方向と逆方向（図（ａ））及び走査光進行方向（図（ｂ））にある場合を示す。
【図１１】本発明の実施の形態５にかかる立体形状測定装置の基本的な構成を説明するための図であり、受光光学系がその内面に２枚のミラーを持つプリズムで構成されている場合（図（ａ））及び走査光がプリズムの平行な２つの透過面を通過するように構成されている場合（図（ｂ））を示す。
【図１２】上記実施の形態５における立体形状測定装置の構成を説明するための他の図であり、受光光学系が主走査方向と平行な入射面と射出面を持つプリズムで構成されている場合（図（ａ））及び走査光が主走査方向に平行で、お互いに平行な２つの透過面を通過する場合（図（ｂ））を示す。
【図１３】上記実施の形態５における立体形状測定装置の構成を説明するための他の図であり、受光光学系にプリズムシート（図（ａ））及び円筒レンズ（図（ｂ））を用いた場合を示す。
【図１４】従来の立体形状測定装置の全体的な構成を示す斜視図である。
【図１５】従来の立体形状測定装置における、三角測量による高さ計測の問題点を説明するための図であり、死角が発生（図（ａ））、多重反射による高さ測定誤差（図（ｂ））、及び複数の方向から反射光を測定（図（ｃ））する場合を示す。
【図１６】従来の立体形状測定装置における、走査位置と受光像位置との関係を示す断面図である。
【図１７】従来の立体形状測定装置における、受光光学系に走査光学系が含まれる場合の構成を示す斜視図である。
【図１８】従来の立体形状測定装置における、スポット光位置ずれと高さ誤差とを説明するための図であり、一方向（図（ａ））及び複数方向（図（ｂ））の反射光を測定する場合を示す。
【図１９】従来の立体形状測定装置における、走査位置による高さ測定精度の変化を示す図である。
【符号の説明】
１ 光源
２ 回転鏡
３ 集光・走査レンズ
４ 走査光
５ 測定対象
６ 測定対象上のスポット光
６ａ 走査直線の端に位置するスポット光
６ｂ 走査直線のもう一方の端に位置するスポット光
７ 走査直線
８ａ 測定対象からの反射光
８ｂ 測定対象からの反射光
９ 受光光学系
９ａ,９０ａ 受光光学系（測定対象と走査光学系の間に位置）
９ｂ 受光光学系（走査光学系と位置検出素子の間に位置）
１０ 位置検出素子
１１ 主走査方向
１２ 副走査方向
１３ 走査光学系に入射する反射光の見かけの発光点
１４ 受光光学系に入射する反射光の見かけの集光点
１５ 光源から射出する光束の見かけの発光点
１６ スポット光６が集光する走査面
１７ａ,１７０ａ,１７１ａ 受光光学系を構成するミラー
１７ｂ,１７０ｂ,１７１ｂ 受光光学系を構成するミラー
１７ｃ 受光光学系を構成するプリズム
１７ｄ 受光光学系を構成する円筒レンズ
１７ｅ 受光光学系を構成するフレネルプリズム
１８,１８０,１８１,１８２,１８３,１８４,１８５ 受光光学系を構成する一体型受光光学系
１８ａ,１８０ａ,１８１ａ,１８２ａ,１８３ａ,１８４ａ,１８５ａ 一体型受光光学系（１８１,１８２,１８３,１８４,１８５）を構成する反射光の入射面
１８ｂ,１８０ｂ,１８１ｂ,１８２ｂ,１８３ｂ,１８４ｂ,１８５ｂ 一体型受光光学系（１８１,１８２,１８３,１８４,１８５）を構成する反射光８の射出面
１８１ｃ,１８３ｃ,１８４ｃ,１８５ｃ 一体型受光光学系を構成する走査光の入射面
１８１ｄ,１８３ｄ,１８４ｄ,１８５ｄ 一体型受光光学系を構成する走査光の射出面
１９ 受光光学系と位置検出素子の間に位置する補正プリズム
１９ａ プリズムを構成する反射光の入射面
１９ｂ プリズムを構成する反射光の射出面
３０ 走査集光レンズ３からみた見かけ上の走査面
３１ スポット光の集光距離を変える手段（集光距離変更手段）
３２ スポット光の集光距離を変えるミラー群
３３ スポット光の集光距離を変える平行ガラス
３４ 見かけ上の発光点の距離を変える手段（反射光発光点距離変更手段）
４０ 走査光の進行方向
４１ 走査集光レンズからみた見かけ上の集光点[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a three-dimensional shape measuring apparatus, and in particular, scans an object to be measured linearly using irradiation light such as a laser using a polygon mirror and a deflection scanning condensing unit such as an fθ lens, and reflects reflected light of the scanning light by triangulation. When measuring the three-dimensional shape of the measurement object based on the principle, it relates to a three-dimensional shape measuring device that suppresses the decrease in measurement accuracy due to the deformation of the scanning optical system and the change in the height accuracy due to the scanning position. is there.
[0002]
[Prior art]
Conventionally, three-dimensional shapes are geometrically optically measured by projecting various kinds of light onto an object and measuring the reflected light with a photodetector, or by using multiple objects under natural light or general illumination. There are roughly two methods for obtaining the three-dimensional shape of an object by measuring with a camera from the direction and correlating a plurality of images.
The former is further classified into various types according to the light projection method, the type of photodetector, and the positional relationship therebetween.
[0003]
FIG. 14 shows an example of a conventional three-dimensional shape measuring apparatus often used for industrial equipment and the like.
In FIG. 14, the light emitted from the light source 1 is deflected by a rotating mirror 2 such as a polygon mirror, and the scanning light 4 is condensed by a condensing / scanning lens 3 such as an fθ lens. By forming the light 6 a and rotating the rotary mirror 2, the spot light 6 a scans a straight line on the surface of the measuring object 5 (hereinafter referred to as a scanning straight line 7) up to the spot light 6 b.
[0004]
Of the light irregularly reflected on the surface of the measuring object 5, the reflected light 8 having a direction different from the direction of the scanning light 4 is imaged on the position detection element 10 such as a PSD or a CCD camera via the light receiving optical system 9. The height information of the spot irradiated with the spot light 6 is obtained by the triangulation method from the position information of the image obtained by converting this into an electrical signal.
[0005]
The spot light 6 scans the measurement target on the scanning line 7, and the measurement target 5 is a direction perpendicular to the plane formed by the main scanning direction 11 that is the direction of the scanning line 7 and the traveling direction 40 of the scanning light 4 ( The spot light 6 scans the measurement object 5 two-dimensionally in the sub-scanning direction 12) in synchronization with the rotation of the rotary mirror 2, and the height information of each scanning position is stored in the memory. By storing and arranging, the three-dimensional shape of the measurement object 5 can be measured.
[0006]
FIG. 15 shows a problem of height measurement by triangulation in a conventional three-dimensional shape measuring apparatus.
In the height measurement by triangulation, the reflected light 8 is measured from a direction different from the direction of the scanning light 4, so that it is affected by the shape of the measurement object 5 and the reflectance distribution. Therefore, as shown in FIG. 15A, a blind spot is generated, and a height measurement error due to multiple reflection occurs as shown in FIG. 15B.
[0007]
FIG. 15C shows an example in which reflected light is measured from a plurality of directions.
In FIG. 15 (c), when the shape of the reflected light measurement object 5 is complicated or when the luminance change is severe, the reflected light 8a (dead angle generation), 8b (double reflection generation), 8c (measurement) from a plurality of directions. No influence of subject 5). . . It is necessary to select the height output value by the reflected light 8c measured from the direction not affected by the blind spot or the multiple reflection.
[0008]
FIG. 16 is a cross-sectional view showing the relationship between the scanning position and the received light image position in the conventional three-dimensional shape measuring apparatus, and shows the problem of triangulation when the spot light 6 scans the scanning straight line 7.
In FIG. 16, in the conventional three-dimensional shape measuring apparatus shown in FIG. 14, the reflected light 8 from the measuring object 5 is separated from the scanning optical system composed of the rotary mirror 2 and the condensing / scanning lens 3 and is an independent light receiving optical system. When guided to the position detection element 10 via 9, the image position on the position detection element 10 is moved by the scanning position, and a height change H is generated. Therefore, a position detection element wider than the height measurement range is required, and performance degradation such as a decrease in measurement accuracy and a decrease in processing speed occurs.
[0009]
FIG. 17 is a perspective view showing the configuration of an apparatus when a light receiving optical system includes a scanning optical system in a conventional three-dimensional shape measuring apparatus.
In FIG. 17, the light receiving optical system 9 is divided into a light receiving optical system 9a and a light receiving optical system 9b, and a scanning optical system is included between the light receiving optical system 9a and the light receiving optical system 9b.
[0010]
The reflected light 8 reaches the position detection element 10 via the scanning optical system, and the movement of the reflected light 8 due to the scanning position is canceled by the scanning optical system. Then, the image movement on the position detection element 10 is mainly caused by the change in the height of the measurement object 5, and the height measurement accuracy is improved, so that the performance can be improved.
[0011]
Further, a plurality of light receiving optical systems 9a, 9b, and position detecting elements 10 in FIG. 17 are provided, and the reflected light 8 from the measuring object 5 is measured from multiple directions, and the triangle shown in FIG. There are also generally three-dimensional shape measuring devices that attempt to solve the problems of surveying.
The conventional three-dimensional shape measuring apparatus is configured as described above.
[0012]
[Problems to be solved by the invention]
FIG. 18 is a diagram for explaining a spot light position shift and a height error in a conventional three-dimensional shape measuring apparatus.
When the reflected light is measured from multiple directions by the linear scanning using the scanning optical system in the conventional three-dimensional shape measuring apparatus and the three-dimensional shape measurement is performed by triangulation, the reflected light 8 is shown in FIG. When the light receiving optical system 9 for measuring the light does not change and only the position of the spot light 6 on the measurement object 5 changes from the point A to the point B, the image position on the position detection element 10 changes from A ′ to B ′. Therefore, there was a problem that the height could not be measured accurately.
[0013]
In particular, when the spot light 6 is guided to the measuring object 5 through a scanning optical system including a deflecting unit such as a polygon mirror or a galvano mirror and a condensing / scanning lens such as an fθ lens, Due to deterioration of the rotating part, deformation of the fθ lens holding part, etc., the optical axis of the scanning light 4 causes an angular shift or a positional shift with the environmental change such as temperature or the passage of time, and the position of the spot light 6 changes. There was a problem that accurate height measurement was difficult.
[0014]
Further, when measuring the reflected light 8 in a plurality of directions in order to measure the height of the measurement object 5 having a complicated shape as shown in FIG. As shown, when the position of the spot light 6 changes from the point A to the point B, when the reflected light is received by the light receiving optical system 9R / position detection element 10R, the image position on the position detection element 10R changes from A ′ to B ′. Since the object to be measured is apparently positioned at the height of the point C ′, a measurement height error of h ′ occurs.
[0015]
On the other hand, when the reflected light is received by the light receiving optical system 9L and the position detecting element 10L, the image changes from A ″ to B ″, the object to be measured looks like a point C ″, and the height error h ′ is positive or negative. On the other hand, a measurement height error of h ″ having a different size occurs.
[0016]
As described above, since the direction and degree of the height error due to the positional deviation of the spot light 6 differ depending on the direction of the reflected light, the error may be enlarged when a correct height is selected from a plurality of height data. On the other hand, there is a problem that the measurement accuracy of the height may be deteriorated.
[0017]
Thus, when performing height measurement by triangulation, it is necessary to suppress changes in the position and angle of the spot light 6 in order to measure with high accuracy. Therefore, when the spot light 6 is scanned by the scanning optical system as described in the conventional example, it is necessary to construct a special scanning optical system for suppressing the influence of the angle change of the rotary mirror, or the usage environment is limited. As a result, there are problems such as the need to suppress the deformation of the scanning optical system and the need for periodic maintenance work to calibrate the height error.
[0018]
Further, in order to suppress the image movement due to the scanning position as shown in FIG. 17, the light receiving optical system 9 is divided into the light receiving optical system 9a and the light receiving optical system 9b, and the light receiving optical system 9a and the light receiving optical system are divided. In the case of the conventional example in which the scanning optical system is arranged between 9b and the reflected light 8 is guided to the position detecting element 10 through the scanning optical system, there are the following problems.
[0019]
FIG. 19 is a diagram showing a change in height measurement accuracy depending on a scanning position in a conventional three-dimensional shape measuring apparatus.
In FIG. 19, when the reflected light 8 of the spot light 6 is guided to the scanning optical system including the rotary mirror 2 and the condensing / scanning lens 3 through the light receiving optical system 9a, the path of the reflected light 8 is bent halfway. The apparent light emission point 13 of the reflected light 8 incident on the scanning condensing lens 3 is caused by the scanning light collection because the spread angle of the reflected light 8 is changed by the light receiving optical system 9a. The spot light 6 that has passed through the optical lens 3 is no longer positioned on the scanning surface 16 where the light is condensed.
[0020]
In the case of a general scanning optical system, the distance Ldr to the apparent condensing point 14 of the reflected light 8 after the reflected light 8 passes through the scanning optical system composed of the condenser lens 3 and the rotary mirror 2 is the scanning position. Regardless, there is no guarantee that it will always be constant. At this time, the distance Lds to the apparent light emitting point 15 of the light emitted from the light source 1 incident on the scanning condensing lens 3 is always constant regardless of the scanning position. The position changes with respect to the light emitting point 15 whose position does not change.
[0021]
That is, since the condensing point of the reflected light 8 by the light receiving optical system 9b and the distance to the light receiving surface of the position detecting element 10 change depending on the scanning position, the image size on the position detecting element 10 also changes. As the image size increases, the measurement height accuracy deteriorates, so the height measurement accuracy also changes depending on the scanning position.
As a result, even if the image size on the position detection element 10 is minimized and the height measurement accuracy is maximized at a certain scanning position, the image height is large at other scanning positions and the accuracy is lowered. There was a problem that the accuracy decreased. Therefore, in order to maintain the height accuracy, it is necessary to devise a scanning optical system that also considers special light receiving performance, which causes a problem in design.
[0022]
The present invention was made to solve the conventional problems as described above, and even if the position of the spot light is shifted due to deformation of the scanning optical system composed of a rotating mirror or scanning condensing lens, measurement is performed. It is an object of the present invention to provide a three-dimensional shape measuring device that can suppress a change in height accuracy without requiring a three-dimensional shape measuring device that does not deteriorate accuracy and a scanning optical system that takes into account special light-receiving performance.
[0023]
[Means for Solving the Problems]
The solid shape measuring apparatus according to claim 1 of the present invention detects reflected light obtained by irradiating an object to be measured with a scanning light beam by an optical position detector, and detects the three-dimensional shape of the object from the detection result at each scanning position. In a three-dimensional shape measuring apparatus for measuring a shape, a means for generating a light beam, a deflection scanning means for deflecting and scanning the light beam, Deflection scan Scanning condensing means for condensing the light beam that has passed through the means, and an object to be measured on a locus (hereinafter referred to as a scanning line) drawn by a condensing point of the light beam that has passed through the scanning condensing means (hereinafter referred to as a scanning light beam) The reflected light from the light is guided to the scanning condensing unit and the deflection scanning unit, and is incident on the optical position detector, and in a direction perpendicular to both the scanning light beam and the scanning line (hereinafter referred to as a sub scanning direction). When the object moves, the moving direction of the image obtained by the optical position detector in the sub-scanning direction is the same as the moving direction of the object, and the moving distance of the image is the same as that of the object. And a reflected light path changing means that is less than twice the moving distance.
[0024]
A solid shape measuring apparatus according to claim 2 of the present invention is the solid shape measuring apparatus according to claim 1, wherein the reflected light path changing means is an even number of two or more sheets arranged in parallel with the scanning line. This is a mirror.
[0025]
A solid shape measuring apparatus according to claim 3 of the present invention is the solid shape measuring apparatus according to claim 2, wherein the relative positional relationship between the mirrors is always kept constant. is there.
[0026]
The solid shape measuring apparatus according to claim 4 of the present invention is the solid shape measuring apparatus according to claim 1, wherein the reflected light path changing means has an entrance surface and an exit surface parallel to the scanning line. It is a wedge-shaped prism.
[0027]
According to a fifth aspect of the present invention, there is provided the three-dimensional shape measuring apparatus according to the first aspect, wherein the reflected light path changing means is a cylindrical lens extending in the direction of the scanning line. .
[0028]
According to a sixth aspect of the present invention, there is provided a three-dimensional shape measuring apparatus according to the first aspect, wherein the reflected light path changing means has a sheet-like shape and refracts light. It is a thing.
[0029]
The solid shape measuring apparatus according to claim 7 of the present invention is the solid shape measuring apparatus according to claim 3, wherein an even number of mirrors constituting the reflected light path conversion means are formed on the inner surface of one prism body. A correction prism for improving the aberration of an image obtained by condensing the reflected light on the optical position detector is provided between the scanning condensing means and the optical position detector.
[0030]
According to an eighth aspect of the present invention, in the three-dimensional shape measuring apparatus according to the fourth or sixth aspect, the aberration of an image obtained by condensing the reflected light on the optical position detector is improved. A correction prism is provided between the light condensing means and the optical position detector.
[0031]
A three-dimensional shape measuring apparatus according to claim 9 of the present invention is the three-dimensional shape measuring apparatus according to claim 5, wherein a cylindrical lens for improving aberration of an image obtained by condensing the reflected light on the optical position detector is provided. These are provided between the light condensing means and the optical position detector.
[0032]
According to a tenth aspect of the present invention, there is provided a three-dimensional shape measuring apparatus that detects reflected light obtained by irradiating an object to be measured with a scanning light beam by an optical position detector, and detects the object from a detection result at each scanning position. In the three-dimensional shape measuring apparatus for measuring the three-dimensional shape of, a means for generating a light beam, a deflection scanning means for deflecting and scanning the light beam, Deflection scan Scanning condensing means for condensing the light beam that has passed through the means, and an object to be measured on a locus (hereinafter referred to as a scanning line) drawn by a condensing point of the light beam that has passed through the scanning condensing means (hereinafter referred to as a scanning light beam) The reflected light from the beam is guided to the scanning condensing unit and the deflecting scanning unit, is incident on the optical position detector, and is a locus drawn by an apparent condensing point of the scanning light beam emitted from the scanning condensing unit. The apparent light emitting point of the reflected light incident on the scanning condensing means at the condensing point is always on the virtual scanning with respect to a plane (hereinafter referred to as a virtual scanning surface) that passes through and is perpendicular to the scanning light beam. And a reflected light optical path conversion means that comes to be positioned on the surface.
[0033]
A solid shape measuring apparatus according to an eleventh aspect of the present invention is the solid shape measuring apparatus according to the tenth aspect, wherein the three-dimensional shape measuring apparatus is provided in an optical path while the scanning light beam that has passed through the scanning condensing means reaches the scanning surface. And a focusing distance changing means for changing the focusing distance of the scanning light beam.
[0034]
A solid shape measuring apparatus according to a twelfth aspect of the present invention is the solid shape measuring apparatus according to the eleventh aspect, wherein the focusing distance changing means is composed of three or more mirrors parallel to the scanning line. It is supposed to be.
[0035]
The solid shape measuring apparatus according to a thirteenth aspect of the present invention is the solid shape measuring apparatus according to the eleventh aspect, wherein the focusing distance changing means has a parallel surface having an incident surface and an emission surface parallel to the scanning line. It is assumed to be composed of glass.
[0036]
A three-dimensional shape measuring apparatus according to a fourteenth aspect of the present invention is the three-dimensional shape measuring apparatus according to the tenth aspect, wherein the three-dimensional shape measuring apparatus is provided in an optical path while the reflected light from the measurement object reaches the scanning condensing means. The reflected light emitting point distance changing means for changing the distance to the apparent light emitting point of the reflected light is provided.
[0037]
The solid shape measuring apparatus according to claim 15 of the present invention is the solid shape measuring apparatus according to claim 14, wherein the reflected light emission point distance changing means is composed of three or more mirrors parallel to the scanning line. It is a thing.
[0038]
The solid shape measuring apparatus according to claim 16 of the present invention is the solid shape measuring apparatus according to claim 14, wherein the reflected light emission point distance changing means has an entrance surface and an exit surface parallel to the scanning line. It consists of parallel glass.
[0039]
The three-dimensional shape measuring apparatus according to claim 17 of the present invention is the three-dimensional shape measuring apparatus according to claim 14, wherein the reflected light emission point distance changing means comprises a cylindrical lens extending in the scanning line direction. It is.
[0040]
The solid shape measuring apparatus according to claim 18 of the present invention is the solid shape measuring apparatus according to claim 16, wherein the parallel glass constituting the reflected light path changing means is arranged in parallel with the scanning line. An even number of mirrors equal to or greater than one are formed on the inner surface and integrated.
[0041]
A three-dimensional shape measuring apparatus according to a nineteenth aspect of the present invention is the three-dimensional shape measuring apparatus according to the eighteenth aspect, wherein the integrated parallel glass constituting the reflected light optical path changing means condenses the scanning light beam. An incident surface parallel to the scanning line and an exit surface that change the distance are provided.
[0042]
A solid shape measuring apparatus according to claim 20 of the present invention is the solid shape measuring apparatus according to any one of claim 4, claim 6, or claim 8, up to an apparent light emitting point of the reflected light. The reflected light emitting point distance changing means for changing the distance is formed integrally with the prism constituting the reflected light optical path changing means.
[0043]
A three-dimensional shape measuring apparatus according to a twenty-first aspect of the present invention is the three-dimensional shape measuring apparatus according to the twentieth aspect, wherein the scanning light flux is made of parallel glass having an entrance surface and an exit surface parallel to the scan line. The condensing distance changing means for changing the condensing distance is formed integrally with the prism constituting the reflected light path conversion means.
[0044]
A three-dimensional shape measuring apparatus according to a twenty-second aspect of the present invention is the three-dimensional shape measuring apparatus according to the fifth aspect, wherein the cylindrical lens constituting the reflected light path changing means is configured such that the reflected light from the measurement object is The reflected light emission point distance changing means is provided integrally in the optical path while reaching the scanning condensing means, and changes the distance to the apparent light emission point of the reflected light.
[0045]
A three-dimensional shape measuring apparatus according to a twenty-third aspect of the present invention is the three-dimensional shape measuring apparatus according to the twenty-second aspect, wherein the cylindrical lens constituting the reflected light path changing means changes a condensing distance of the scanning light beam. , And a converging distance changing means made of parallel glass having an entrance surface and an exit surface parallel to the scanning line are integrated.
[0046]
DETAILED DESCRIPTION OF THE INVENTION
(Embodiment 1)
The invention described in claims 1 to 5 of the present invention will be described below as a first embodiment with reference to FIGS.
FIG. 1 is a perspective view showing the overall configuration of a three-dimensional shape measuring apparatus according to the present invention, and shows the configuration of a typical optical system.
In FIG. 1, light emitted from a light source 1 is deflected by a rotary mirror 2 such as a polygon mirror, and scanning light 4 is condensed by a condensing / scanning lens 3 such as an fθ lens to spot light 6a on a measurement object 5. The spot light 6a is scanned on the straight line 7 up to the spot light 6b by the rotation of the rotary mirror 2. The reflected light 8 in a direction different from the light traveling direction of the scanning light 4 passes through the scanning optical system of the condensing / scanning optical lens 3 and the rotary mirror 2 via the light receiving optical system 90a, and is received by the light receiving optical system 9b. The height information of the point irradiated with the spot light 6 is obtained by the triangulation method from the position information of the image formed on the position detecting element 10 such as a CCD camera and converted into an electric signal.
[0047]
The spot light 6 scans the measurement object 5 on the straight line 7, and the measurement object 5 is in the direction perpendicular to the plane including the main scanning direction 11 that is the direction of the scanning straight line 7 and the light traveling direction 40 of the scanning light 4 By moving in synchronization with the rotation of the rotary mirror 2 in the scanning direction 12), the spot light 6 scans the measurement object 5 two-dimensionally and stores the height information of each scanning position on the memory and arranges them. Thus, the three-dimensional shape of the measuring object 5 can be measured.
As described above, in the configuration of the general optical system shown in FIG. 1, the light receiving optical system 90a performs the function of guiding the reflected light 8 from the measurement object 5 to the scanning optical means.
[0048]
FIG. 2 is a diagram for explaining the principle of the three-dimensional shape measuring apparatus according to the first embodiment.
As shown in FIG. 2A, when the spot light 6 moves a distance ds in the sub-scanning direction 12, out of the moving components of the position of the apparent light emitting point 13 of the reflected light 8 incident on the scanning optical means, The movement in the scanning direction 12 has an effect of moving in the same direction as the movement ds of the spot light 6 and further by substantially the same distance (dr).
[0049]
When the movement of the spot light 6 in the sub-scanning direction 12 is caused by the deformation of the scanning optical system, when ds = dr, the relative distance projected between the spot light 6 and the apparent light emission point 13 in the sub-scanning direction 12 is Since it is constant, the relative light projection point 15 of the light source 1 shown in FIG. 2 (b) and the projected relative light spot 14 after passing through the scanning optical means of reflected light are projected in the sub-scanning direction 12. The position is also constant. Therefore, unless the apparent light emission point 15 of the light source moves, the apparent condensing point 14, that is, the image position on the position detection element 10, that is, the height data to be measured, is influenced by the position variation of the spot light 6. It becomes constant without receiving. Even if the distance ds and dr do not match, assuming that the measurement height error inherently generated by the movement of the spot light (distance ds) is hs, the following equation (1) is obtained depending on the apparent movement distance dr of the light emitting point 13. As shown in FIG. 4, the actual measurement error hr can be improved.
[0050]
hr / hs = dr / ds-1 (1)
Here, when the condition that hr is improved from hs, that is, the condition that the absolute value of hr / hs is smaller than 1, the above equation (1) is transformed,
-1 <hr / hs = dr / ds-1 <1
0 <dr / ds <2 (2)
This relationship can be derived.
[0051]
When the distance dr = ds, hr = 0 as described above, and no measurement height error occurs. If dr ≠ ds satisfies the above formula (2), an error in measurement height can be reduced even if the spot light 6 moves due to deformation of the scanning optical system.
[0052]
Next, a specific configuration corresponding to the three-dimensional shape measuring apparatus described in claims 2 and 3 for realizing the above configuration will be described.
FIG. 3 is a diagram for explaining the relationship between the object and the image position due to the mirror group reflection in the first embodiment, and FIG. 3A shows the positional relationship between the object and the image in the reflection of one mirror. Indicates.
[0053]
In FIG. 3A, when the object moves from point A to point B and the image moves from point A ′ to point B ′, the angle formed by vector AB and the x axis is α ₁ , The angle between the mirror surface and the x axis is β ₁ (In either case, the direction of rotation from the x axis to the y axis is positive), and the angle between A′B ′ and the x axis is α ₂ Then, the following formula (3) is established from geometrical conditions.
α ₂ = 2β ₁ ―Α ₁ ... (3)
As shown in FIG. 3B, when reflection occurs at a plurality of mirrors, the following equation is obtained by combining the above equation (3).

Therefore, the angle α of the image reflected by the 2i (even) -th mirror _{2i + 1} Is as shown in the following equation (4).

Where Be is the angle β of the mirror group _j It is a fixed value determined by.
[0054]
The angle α of the image reflected by the 2i-1 (odd) number of mirrors _2i Is as shown in the following equation (5).

Where Bo is the angle β of the mirror group _j It is a fixed value determined by.
[0055]
In each case, the incident angle to the entire mirror is α _in , Injection angle α _out Then, when the number of mirrors is 2i (even number), the total bending angle δα is expressed by the following formula (6), and the angle β of the mirror group _j The fixed value Be determined by
δα = α _out -Α _in = Βe (6)
Further, when the number of mirrors is 2i-1 (odd number), it is expressed by the following formula (7).
δα = α _out -Α _in = Bo-2α _in ... (7)
FIG. 4 is a diagram for explaining a light receiving optical system of the three-dimensional shape measuring apparatus according to the first embodiment.
When the above model is applied at the traveling angle of the reflected light 8 to be measured, as shown in FIG. 4A, the configuration of the light receiving optical system 90a shown in FIG. X-axis is the sub-scanning direction 12, y-axis is the direction opposite to the scanning light optical axis direction 40, α _in Is an angle θ obtained by projecting an angle formed by the direct reflected light 8 from the spot light 6 with the scanning surface 6 onto a plane perpendicular to the main scanning direction 11, and α _out Is an angle obtained by projecting the angle formed by the reflected light 8 emitted from the light receiving optical system 90 a with the scanning surface 6 onto a plane perpendicular to the main scanning direction 11.
[0056]
Where α _out As for the reflected light incident on the optical axis of the scanning condenser lens 3, the degree of freedom of arrangement of the light receiving optical system 9b increases as the parallel light is closer to parallel. _out The range is 90 ° −φ to 90 ° + φ. Note that the angle φ is preferably not so large. Therefore, when the number of mirrors is an even number and an odd number, Expressions (8) and (9) are obtained as shown below from Expressions (4) and (5), respectively.
Even number of sheets: 90 ° −θ−φ <Be <90 ° −θ + φ (8)
Odd number sheet: 90 ° + θ−φ <Bo <90 ° + θ + φ (9)
On the other hand, as shown in FIG. 4B, when the spot light 6 moves a distance ds from the point A to the point A ′ and the sub-scanning direction 12 due to the change of the scanning optical means, this model is used for the movement of the spot light 6. Is applied, the x-axis is the sub-scanning direction 12, the y-axis is the opposite direction of the scanning light optical axis direction 40, and α _in Is the angle between AA 'and the x axis, always 0, α _out Corresponds to the angle formed by the straight line BB ′ between the point B and the point B ′ before and after the movement of the apparent light emitting point 13 emitted from the light receiving optical system 90a. In this case, if the moving distance of the 12 components in the sub-scanning direction between point B and point B ′ is dr, α _in From = 0, the following equation is obtained.
dr / ds = cos (α _out ) ＝ cos (δα)
Therefore, in order to reduce the measurement height error due to the deformation of the scanning optical system, the range of the reflected light bending angle δα of the light receiving optical system 90a is −90 ° to 90 ° from the above equation (2).
[0057]
Therefore, when the number of mirrors is an even number and an odd number, the following expressions (10) and (11) are obtained from the expressions (6) and (7), respectively.
Even number of sheets: -90 ° <δα = Be <90 ° (10)
Odd number sheets: −90 ° <δα = Bo <90 ° (11)
When the light receiving optical system 90a is composed of an even number of mirrors, in order to satisfy the above equations (8) and (10) at the same time, the following equations (12) are obtained by comparing both sides of the equations.
-90 ° <90 ° -θ-φ and 90 ° -θ + φ <90 °
φ <180 ° −θ and φ <θ (12)
It is clear that φ satisfying the above equation (12) can be easily selected for the range of θ from 0 to 90 °.
[0058]
On the other hand, when the light receiving optical system 90a is composed of an odd number of mirrors, the following formula (13) is obtained by comparing both sides of the formula in order to satisfy the above formula (9) and formula (11) simultaneously.
-90 ° <90 ° + θ-φ and 90 ° + θ + φ <90 °
φ <180 ° + θ and φ <−θ (13)
If θ satisfies the condition of the above equation (13) and φ <−θ with respect to the range of 0 to 90 °, when θ is large, the incident angle to the scanning condensing lens increases, and the light receiving performance Problems (aberration, aperture, etc.) arise, necessitating the need for special scanning condensing means and the limitation of the range of θ, making it difficult to realize.
[0059]
When the light receiving optical system 90a is composed of an even number of mirrors, the bending angle of the reflected light becomes a fixed value Be as shown in the above equation (4). Here, the expression of Be is the difference between the adjacent β angles of 2j and 2j−1 (β _2j -Β _2j-1 ). That is, when the relative angle between the mirrors is constant, even if the entire angle changes, the fixed value Be, that is, the bending angle of the reflected light does not change.
[0060]
On the other hand, when the light receiving optical system 90a is composed of an odd number of mirrors, the bending angle of the reflected light becomes a fixed value Bo as shown in the above equation (5). In this case, the angle difference between adjacent mirrors (β _2j -Β _2j-1 ), The final 2i-1th mirror angle β _2i-1 And incident angle α _in Therefore, even if the relative angle between the mirrors is constant, the bending angle of the reflected light changes when the overall angle changes.
[0061]
Thus, if the light receiving optical system 90a is composed of two or more even number of mirrors parallel to the scanning line 7, it is possible to reduce the measurement height error caused by the movement of the spot light 6 due to the deformation of the scanning optical system. If the relative position between the mirrors is maintained, the height error can be suppressed even if the light receiving optical system rotates about the main scanning direction 11.
[0062]
(Embodiment 2)
Next, the three-dimensional shape measuring apparatus according to the second embodiment of the present invention will be described.
FIG. 5 is a diagram for explaining the configuration of the light receiving optical system of the three-dimensional shape measuring apparatus according to the second embodiment of the present invention. FIG. 5 (a) shows the light receiving optical system 90a shown in FIG. In the figure, an incident surface and an exit surface are configured by a prism 17 c parallel to the main scanning direction 11.
[0063]
In FIG. 5A, the prism 17c has an action of bending the reflected light 8 from the point A of the spot light 6 in a plane perpendicular to the main scanning direction 11, thereby causing the reflected light 8 to be scanned and condensed. Leading to 3. When the apparent light emission point 13 of the reflected light 8 exiting the prism 17c is set to the point B, and the position of the spot light 6 moves from the point A to the point A ′ by the distance ds in the sub-scanning direction 12, the apparent light emission point. B is a point B ′, and the moving distance in the sub-scanning direction 12 is dr. In that case, due to the characteristics of the prism, the direction of the sub-scanning direction 12 component of the movement of the light emitting point B is the same as the direction of movement of the point A, and the combination of the angle of incidence and exit surface and the refractive index of the prism is selected Thus, the relationship between the movement distance ds of the spot light 6 in the sub-scanning direction 12 and the apparent movement distance dr of the light emitting point 13 in the sub-scanning direction 12 can satisfy the above formula (2).
[0064]
In this way, by configuring the light receiving optical system 90a with the prism 17c having an action of bending light in a plane perpendicular to the main scanning direction 11, the measurement height generated by the movement of the spot light 6 due to the deformation of the scanning optical system. Error can be reduced.
Further, due to the characteristics of the prism, even when the prism 17c is rotated around the main scanning direction 11, the apparent positional deviation of the light emitting point 13 can be suppressed, so that the height error to be measured can be suppressed.
[0065]
FIG. 5B shows a basic structure of the three-dimensional shape measuring apparatus having the configuration described in claim 5, and the light receiving optical system 90 a is replaced with the prism 17 c in FIG. It is configured using.
In FIG. 5B, the direction of movement of the light emitting point B in the sub-scanning direction 12 is the same as the direction of A as in the case of using the prism 17c, and the movement distance of the spot light 6 in the sub-scanning direction 12 is the same. The relationship between ds and the apparent movement distance dr of the light emitting point 13 in the sub-scanning direction 12 can satisfy the above formula (2).
[0066]
FIG. 5C shows a basic configuration of the three-dimensional shape measuring apparatus according to the sixth aspect, which is characterized in that the light receiving optical system 90a is configured using the prism sheet 17e.
[0067]
In FIG. 5C, the direction of movement of the light emission point B in the sub-scanning direction 12 is the same as the direction of A as in the description when the prism 17c is used, and the movement distance of the spot light 6 in the sub-scanning direction 12 is the same. The relationship between ds and the apparent movement distance dr of the light emitting point 13 in the sub-scanning direction 12 can satisfy the above formula (2). Furthermore, as shown in FIG. 5C, the prism sheet 17e can be produced in a sheet shape, so that the spatial volume is small and the influence on the arrangement of other optical components is reduced. The degree of freedom in optical design is increased, and additional functions and performance can be easily improved.
FIG. 5C shows the case where the prism sheet 17e having a saw-like cross section is used, but the same can be applied to a diffraction grating having a multi-stage uneven shape.
[0068]
(Embodiment 3)
Next, a three-dimensional shape measurement apparatus according to Embodiment 3 of the present invention will be described.
FIG. 6 is a diagram for explaining a basic configuration of a three-dimensional shape measuring apparatus according to the third embodiment of the present invention, and FIG. 6A is a three-dimensional shape described in claim 7 of the present invention. The main structure of a measuring device is shown.
[0069]
In FIG. 6A, an integrated light receiving optical system (prism) 18 includes two mirrors of the light receiving optical system having the configuration described in claim 3 (corresponding to FIG. 3B) on the inner surface. Thus, the reflected light 8 from the spot light 6 is configured to be guided to the scanning condenser lens 3 via the two mirrors 17a and 17b on the inner surface of the prism 18.
[0070]
Further, as shown in FIG. 6B, a correction prism 19 is provided between the position detection element 10 and the light receiving optical system 9b. In this case, as shown in FIG. 6C, when the light on one side of the reflected light 8 is 8a and the light on the opposite side is 8b, the light is bent by the prism 18 so that the reflected light 8a and the reflected light 8b An optical path length difference occurs between them. For this reason, even if light is condensed on the position detecting element 10 through the scanning optical system / light receiving optical system 9b, the light is not condensed at one point. Therefore, the correction prism 19 generates an optical path length difference in the opposite direction to the optical path length difference generated by the prism 18 between the reflected light 8a and the reflected light 8b, and cancels the optical path length difference generated by the prism 18. If it comprises, the reflected light 8 will condense on one point on the position detection element 10. FIG.
[0071]
That is, the incident angle of the prism 18 with respect to the incident surface 18a is expressed as α. ₁ And the exit angle from the exit surface 18b of the prism 18 is α ₂ And the incident angle of the correcting prism 19 on the incident surface 19a is β ₁ Furthermore, the exit angle from the exit surface 19b of the correction prism 19 is β ₂ If the refractive indexes of the prism 18 and the correction prism 19 are the same and the optical magnification between the spot light 6 and the image on the position detection element 10 is 1, α ₁ = Β ₂ And α ₂ = Β ₁ Then, the optical path length difference generated in the prism 18 is canceled out by the optical path length difference generated in the correction prism 19, and the optical path lengths of the light 8a and the light 8b at both ends of the reflected light 8 become the same. Therefore, the measurement height accuracy is improved.
[0072]
In general, the shape of the prism 18 has an angle α due to cost and size limitations. ₁ , Α ₂ Therefore, in this case, the aberration generated in the prism 18 can be improved by providing the correction prism 19 that satisfies the above conditions. In addition, since the position of the reflected light 8 is substantially constant regardless of the scanning position at the position of the correction prism 19, the size of the correction prism 19 can be reduced, which is advantageous in terms of cost.
[0073]
Even when the refractive index of the prism 18 and the correction prism 19 are different or the optical magnification is not 1, the incident angle α at the prism 18 ₁ , Injection angle α ₂ In contrast, the incident angle β of the correction prism 19 adapted to correct (cancel) the optical path length difference. ₁ And the exit angle β ₂ Is selected, the aberration can be improved and the image size on the position detection element 10 can be optimized.
[0074]
Further, when the reflected light 8 passes through the prism 18, astigmatism occurs because the radiation angle of the reflected light changes. That is, as shown in FIG. 6C, the radiation angle γ before incidence of the reflected light 8 projected onto the surface perpendicular to the main scanning direction 11 is obtained. ₁ And the radiation angle after injection γ ₂ Is different depending on the action of the prism 18. On the other hand, the radiation angle of the reflected light 8 projected onto the surface perpendicular to the sub-scanning direction 12 is the same before and after the incident because the prism 18 only acts as a parallel glass. Therefore, astigmatism occurs, and even if it is condensed, it becomes a linear image and does not become a point image. If the linear direction of the straight line image is orthogonal to the direction in which the position of the position detection element 10 is detected, the measurement height accuracy is not affected. However, in general, the measurement height does not become a right angle due to problems in parts accuracy and assembly accuracy. It becomes a factor of decreasing accuracy. By arranging the above-described correction prism 19 for such a problem, astigmatism can be corrected and the imaging state can be improved.
[0075]
Further, when the light receiving optical system 90a is configured by a prism sheet, the correction prism 19 for improving the aberration generated in the light receiving optical system 90a similar to that described in the configuration of FIG. By providing it between the light receiving optical system 9b, an effect of reducing the image size of the reflected light 8 on the position detection element and improving the measurement height error can be obtained.
[0076]
In the configuration of the three-dimensional shape measuring apparatus according to the ninth aspect, when the light receiving optical system 90a is formed of a cylindrical lens, the reflected light 8 is guided to the curved scanning optical system in a plane perpendicular to the main scanning direction 11. However, since the radiation angle of the reflected light 8 projected onto the plane perpendicular to the main scanning direction 11 changes due to the effect as a lens, astigmatism occurs in the reflected light 8. Therefore, by providing a cylindrical lens between the position detection element 10 and the light receiving optical system 9b in a direction having power in a direction perpendicular to the cylindrical lens constituting the light receiving optical system 90a, reflected light on the position detection element 10 is obtained. The effect of reducing the image size of 8 and improving the measurement height error can be obtained.
[0077]
(Embodiment 4)
Next, a three-dimensional shape measurement apparatus according to Embodiment 4 of the present invention will be described.
The three-dimensional shape measuring apparatus according to claims 10 to 17 will be described with reference to FIGS.
FIG. 7 is a diagram showing a basic configuration of the three-dimensional shape measuring apparatus according to claim 10.
[0078]
In FIG. 7, the apparent light emission point 13 of the reflected light 8 incident on the scanning condensing lens 3 passes through the apparent condensing point 41 of the scanning light 4 that has passed through the scanning condensing lens 3, and becomes the scanning light 4. When it is on a vertical surface (apparent scanning surface 30), the distance Ldr from the scanning optical system to the apparent condensing point 14 of the reflected light 8 and the light source incident on the scanning condensing lens 3 The distance Lds to the apparent light emission point 15 of the light emitted from 1 is always matched regardless of the scanning position.
[0079]
Here, since the light source 1 is fixed, the distance Lds is constant, and the distance Ldr of the reflected light 8 is always constant regardless of the scanning position. Since the light receiving optical system 9b disposed between the position detecting element 10 and the scanning condensing lens 3 is also fixed, the image of the reflected light 8 collected by the light receiving optical system 9b is always on the position detecting element 10. And the image size is also constant.
[0080]
Therefore, if the image size on the position detection element 10 is large, the measurement accuracy of the height is lowered. In this case, the measurement height accuracy is always constant regardless of the scanning position. That is, by arranging the apparent light emitting point 13 position of the reflected light 8 incident on the scanning condenser lens 3 on the apparent scanning surface 30 regardless of the scanning position, it is always possible regardless of the scanning position. A stable height can be measured, and the overall measurement height accuracy of the entire scanning range can be improved.
If there is no optical system for changing the condensing distance of the scanning light 4 between the scanning condensing lens 3 and the actual scanning surface 16, the apparent scanning surface 30 coincides with the actual scanning surface 16. Become.
[0081]
FIG. 8 shows a basic configuration of the three-dimensional shape measuring apparatus according to the eleventh aspect and is a diagram for explaining the configuration of the scanning light expansion / contraction means of the three-dimensional shape measuring apparatus.
In FIG. 8, means 31 having an action of changing the distance to the condensing point of the convergent light is inserted between the scanning condensing lens 3 and the scanning surface 16, so that the scanning condensing lens 3 is connected to the scanning surface 16. The three-dimensional shape measuring apparatus according to claim 10 is realized by moving the apparent position of the scanning plane 30 until it coincides with the apparent position of the light emitting point 13.
[0082]
In FIG. 8A, when the apparent light emission point 13 is located on the side of the scanning light traveling direction 40 from the scanning surface 16, a means (condensing light) that shortens the distance of the convergent light to the condensing point. The distance changing means) 31 is inserted, and the apparent scanning surface 30 is moved in the scanning light traveling direction 40 with respect to the scanning surface 16 to realize the configuration of claim 11.
[0083]
Further, in FIG. 8B, when the apparent light emission point 13 is positioned on the opposite side of the scanning light traveling direction 40 from the scanning surface 16, the means for increasing the distance of the convergent light to the condensing point. 31 is inserted, and the apparent scanning surface 30 is moved in the direction opposite to the scanning light traveling direction 40 with respect to the scanning surface 16 to realize the configuration of claim 11.
[0084]
FIG. 9 shows the basic configuration of the three-dimensional shape measuring apparatus according to the twelfth and thirteenth aspects, and is a diagram for explaining the configuration of the scanning light expansion / contraction means of the three-dimensional shape measuring apparatus.
FIG. 9A shows an example in which the means 31 for reducing the distance of the convergent light to the condensing point is composed of four mirror groups 32 parallel to the axis in the main scanning direction 11.
In FIG. 9A, the scanning light 4 is bent between the four mirrors so that the optical distance (optical path length) passes and the scanning light 4 is viewed from the scanning condenser lens 3. The position of the actual condensing point moves to the side opposite to the light traveling direction 40 with respect to the apparent condensing point 41. That is, the apparent scanning surface 30 moves in the light traveling direction with respect to the actual scanning surface 16.
[0085]
The apparent light emitting point 13 is positioned on the apparent scanning plane 30 by selecting the mirror interval and angle. In practice, it is clear that the same effect can be obtained if the number of mirrors is three or more.
[0086]
Further, when the mirror group 32 is composed of an even number of mirrors and the relative relationship between the mirrors is fixed, even if rotation about the main scanning direction 11 occurs in the entire mirror group 32, the claims are made. As described in the three-dimensional shape measuring apparatus described in 3, the angle change of the emitted scanning light 4 does not occur, and highly reliable measurement is possible.
[0087]
FIG. 9B shows an example in which the means 31 having the function of increasing the distance to the converging point of the convergent light is constituted by the parallel glass 33 parallel to the axis in the main scanning direction 11.
In FIG. 9B, the scanning light travels through the glass having the refractive index n and the thickness t, whereby the distance L indicated by the following equation (30) and the condensing point of the scanning light 4 are on the light traveling direction 40 side. Moving.
L = t (1-1 / n) (30)
That is, the apparent scanning surface 30 moves in the direction opposite to the light traveling direction 40 with respect to the actual scanning surface 16. Therefore, the refractive index n and the thickness t are selected so that the apparent light emitting point 13 is positioned on the apparent scanning surface 30.
[0088]
FIG. 10 shows a basic configuration of the three-dimensional shape measuring apparatus according to the fourteenth aspect, and is a diagram for explaining the configuration of the reflected light expansion / contraction means of the three-dimensional shape measuring apparatus.
In FIG. 10, a means (reflected light emission point distance changing means) 34 having an action of changing the distance of the convergent light to the condensing point is inserted between the light receiving optical system 90a and the scanning condensing lens 3 for scanning. The apparent light emission point 13 of the reflected light 8 incident on the optical system is moved to a position on the scanning surface 16.
[0089]
FIG. 10A shows an effect of increasing the distance of the convergent light to the apparent condensing point when the apparent light emitting point 13 is in the direction opposite to the scanning light traveling direction 40 from the scanning surface 16. The apparent light emitting point 13 is moved in the scanning light traveling direction 40 to realize the configuration shown in claim 13. A plurality of means parallel to the main scanning direction 40 used as the means 31 for changing the light collection distance of the spot light in FIG. 9A as the means 34 for increasing the distance to the apparent light collection point of the convergent light. If the same mirror group is used, the three-dimensional shape measuring apparatus described in claim 15 is realized.
[0090]
FIG. 10B shows a means for shortening the distance of the convergent light to the apparent condensing point when the apparent light emitting point 13 is located on the scanning light traveling direction 40 side from the scanning surface 16. 34 is inserted, and the apparent light emitting point 13 is moved in the direction opposite to the scanning light traveling direction 40 to realize the structure of claim 13.
[0091]
As means 34 for shortening the distance of the convergent light to the apparent condensing point, parallel glass parallel to the main scanning direction 40 used as means 31 for changing the condensing distance of the spot light in FIG. 9B. If the configuration is used, the three-dimensional shape measuring apparatus described in claim 16 can be realized.
[0092]
10 (a) and 10 (b), when the means 34 for changing the apparent light emitting point distance is constituted by a cylindrical lens extending in the main scanning direction 11, the three-dimensional shape described in the above-mentioned claim 17 is used. A measuring device can be realized. In that case, since astigmatism occurs in the reflected light 8 incident on the scanning optical means, the image of the reflected light on the position detection element 10 is linear. If the line direction of the image is perpendicular to the direction in which the position detecting element 10 is detected, there is no effect on the measurement height accuracy, but if it is slightly out of the vertical, the measurement height accuracy will be reduced. In such a case, astigmatism can be improved by adding a correction cylindrical lens similar to the three-dimensional shape measuring apparatus according to claim 9 before and after the light receiving optical system 9b. A reduction in accuracy can be prevented.
[0093]
(Embodiment 5)
Next, a three-dimensional shape measurement apparatus according to Embodiment 5 of the present invention will be described. A three-dimensional shape measuring apparatus according to claims 18 to 23 will be described with reference to FIGS.
[0094]
FIG. 11 is a diagram for explaining a basic configuration of a three-dimensional shape measuring apparatus according to a fifth embodiment of the present invention, and FIG. 11 (a) is a basic diagram of the three-dimensional shape measuring apparatus according to claim 18. It is a figure which shows a typical structure.
In FIG. 11A, the light receiving optical system 90a shown in FIG. 1 includes a prism 180 having two mirrors 170a and 170b on its inner surface, and the reflected light 8 from the spot light 6 The light passes through the point A on the transmission surface 180a and enters the prism, is reflected twice by the point B on the mirror 170a and the point C on the mirror 170b, is emitted from the point D on the transmission surface 180b, and is scanned and condensed. It is configured to be guided to the lens 3.
[0095]
Since the reflected light 8 is bent between the two mirrors 170a and 170b, the apparent light emission point of the light emitted from the mirror 170b when viewed from the scanning condenser lens 3 moves in the scanning light traveling direction 40. To do. At the same time, since the reflected light passes through the prism having the refractive index n, when the passing distance of the reflected light in the prism is t (= distance AB + distance BC + distance CD) and the refractive index is n, the above-described equation (30) As shown, the apparent light emission point moves in the direction opposite to the scanning light traveling direction 40.
[0096]
Since the two apparent light emission points move in opposite directions, the movement directions can be canceled out by selecting the mirror interval and the prism size. An optical system that can simultaneously obtain the two effects that the effect of positioning on the top and the position change of the light emission point 13 due to the position change of the spot light 6 in the sub-scanning direction can be made substantially the same. It can be realized using.
[0097]
Furthermore, FIG.11 (b) has shown the basic composition of the three-dimensional shape measuring apparatus as described in Claim 19. FIG.
In FIG. 11B, the scanning light 4 is configured to pass through two parallel transmission surfaces 181c and 181d of the prism 181 at a passing point E and a point F, respectively. When the distance EF is t and the prism refractive index is n, the apparent movement of the scanning surface 30, which is the effect of the two parallel glasses, is caused by the above-described equation (30). Since the scanning surface 30 can also be changed, the position change of the light emission point 13 due to the position change of the spot light 6 in the sub-scanning direction can be made substantially the same, and a design with a high degree of freedom is possible. .
[0098]
In the three-dimensional shape measuring apparatus according to the eighteenth and nineteenth aspects described above, the incident surfaces and the exit surfaces of the prisms 180 and 181 are perpendicular to the reflected light 8 as described in the three-dimensional shape measuring apparatus according to the seventh aspect. If this is not the case, it is possible to provide a correction prism that improves the generated aberration.
[0099]
FIG. 12 is a diagram for explaining the configuration of the three-dimensional shape measuring apparatus according to the fifth embodiment, and FIG. 12A shows the basic configuration of the three-dimensional shape measuring apparatus according to claim 20. .
In FIG. 12A, the light receiving optical system 90a shown in FIG. 1 includes a prism 182 having an entrance surface and an exit surface parallel to the main scanning direction 11, and the reflected light 8 from the spot light 6 is The light passes through the point A on the incident surface 182a and enters the prism, and is emitted from the prism from the point B on the incident surface 182b and guided to the scanning condenser lens 3.
[0100]
In this case, the apparent position of the light emitting point 13 moves depending on whether the reflected light 8 bends and advances and the radiation angle of the emitted reflected light 8 changes. At the same time, since the reflected light 8 passes through the prism having the refractive index n, if the passing distance of the reflected light 8 in the prism is t (= distance AB) and the refractive index is n, the above equation (30) is obtained. As shown, the apparent light emission point moves in the direction opposite to the scanning light traveling direction 40. By selecting the angle of incidence / exit surface of the prism 182, the refractive index, and the size of the prism, the movement of the two apparent light emission points is offset by the movement direction of each other, so that the apparent light emission point is changed. An optical system that can simultaneously realize the effect of being located on the scanning surface 16 and the effect of allowing the spot light 6 to have substantially the same change in the position of the light emitting point due to the change in position in the sub-scanning direction is integrated. This prism 18 can be used.
[0101]
Furthermore, FIG.12 (b) shows the basic composition of the three-dimensional shape measuring apparatus of Claim 21. FIG.
In FIG. 12B, the scanning light 4 passes through two transmission surfaces 183c and 183d that are parallel to the main scanning direction 11 and parallel to each other at a passing point C and a point D, respectively. When the distance CD is t and the refractive index of the prism 183 is n, the apparent scanning plane movement, which is the effect of the two parallel glasses, similarly occurs according to the above equation (30). In addition to the fact that the apparent scanning plane is changed and the position change of the light emission point due to the position change of the spot light 6 in the sub-scanning direction can be made substantially the same, the design with a higher degree of freedom becomes possible.
[0102]
The three-dimensional shape measuring apparatus according to claim 20 and claim 21 described above has the aberration generated by the prisms 182 and 183 as described in the explanation of the three-dimensional shape measuring apparatus according to claim 8. Even when a correction prism to be improved is provided, the same effect can be obtained.
[0103]
FIG. 13 is a diagram for explaining the configuration of the three-dimensional shape measuring apparatus according to the fifth embodiment.
FIG. 13A shows a configuration in which the prism constituting the light receiving optical system 90a in FIG. 12B is replaced with a prism sheet 184, and the three-dimensional shape measuring apparatus shown in FIG. Similarly, the apparent scanning plane movement, which is the effect of the two parallel glasses, occurs, the apparent scanning plane is changed by the scanning light, and the position of the light emission point due to the position change of the spot light 6 in the sub-scanning direction is changed. Along with being able to be almost the same, it is possible to design with a higher degree of freedom.
Also in FIG. 12A, an equivalent effect can be realized by replacing the prism 182 with a prism sheet.
[0104]
FIG. 13B shows the basic structure of the three-dimensional shape measuring apparatus according to claim 23, and the light receiving optical system 90 a is configured using a cylindrical lens 185 extending in the main scanning direction 11. This is a feature.
In FIG. 13B, the reflected light 8 from the spot light 6 passes through the point A on the incident surface 185a and enters the cylindrical lens, and is bent and emitted from the cylindrical lens from the point B on the incident surface 185b. And is configured to be guided to the scanning condenser lens 3. Further, the radiation angle of the reflected light 8 emitted by the power of the lens changes, and the position of the apparent light emitting point is arranged on the apparent scanning surface, as described in the three-dimensional shape measuring apparatus according to claim 5. The measurement height error caused by the movement of the spot light 6 due to the deformation of the scanning optical system can be reduced, and the apparent shape of the reflected light can be reduced as described in the three-dimensional shape measuring apparatus according to claim 17. When the light emitting point is not on the scanning surface, the apparent light emitting point position can be moved relative to the scanning surface, and the scanning surface and the apparent light emitting point position of the reflected light can be matched. Has been.
[0105]
Furthermore, by integrating with the parallel glass through which the scanning light 4 passes, as described in the three-dimensional shape measuring apparatus according to claim 13, the apparent scanning surface is the light traveling direction with respect to the actual scanning surface. Since it moves in the reverse direction, the apparent light emitting point can be positioned on the apparent scanning plane, so that a design with a higher degree of freedom is possible.
[0106]
In the above description, the direction of the reflected light has been described mainly with the reflected light in one direction in the plane perpendicular to the main scanning direction as a representative example. However, in any of the above embodiments, the surface drawn by the scanning light beam The reflected light in any direction other than the inside can be applied to the light projected on the surface perpendicular to the main scanning direction. Further, the present invention can be implemented even when there are simultaneous light receiving optical systems in a plurality of directions.
Further, although the case where the number of prisms, cylindrical lenses, and sheet prisms constituting the light receiving optical system is one has been described as an example, it goes without saying that the present invention can be implemented even when the number of prisms is plural.
[0107]
【The invention's effect】
As described above, according to the three-dimensional shape measuring apparatus according to the first aspect of the present invention, the reflected light obtained by irradiating the object to be measured with the scanning light beam is detected by the optical position detector, and at each scanning position. In the three-dimensional shape measuring apparatus for measuring the three-dimensional shape of the object from the detection result, means for generating a light beam, deflection scanning means for deflecting and scanning the light beam, Deflection scan Scanning condensing means for condensing the light beam that has passed through the means, and an object to be measured on a locus (hereinafter referred to as a scanning line) drawn by a condensing point of the light beam that has passed through the scanning condensing means (hereinafter referred to as a scanning light beam) The reflected light from the light is guided to the scanning condensing unit and the deflection scanning unit, and is incident on the optical position detector, and in a direction perpendicular to both the scanning light beam and the scanning line (hereinafter referred to as sub-scanning direction). When the object moves, the moving direction of the image obtained by the optical position detector in the sub-scanning direction is the same as the moving direction of the object, and the moving distance of the image is the same as that of the object. Since the reflected light path changing means that is less than twice the moving distance is provided, the relative position of the reflected condensing point of the reflected light emitted from the scanning optical system with respect to the light source is The position detection element is almost constant regardless of deformation. Change in position of the image is suppressed, the effect is obtained that it is possible to reduce the measuring height error occurring.
[0108]
Moreover, according to the solid shape measuring apparatus according to claim 2 of the present invention, in the solid shape measuring apparatus according to claim 1, the reflected light optical path changing means includes two or more sheets arranged in parallel with the scanning line. Since the number of mirrors is an even number, it is possible to easily reduce the measurement height error caused by the deformation of the scanning optical system by a simple combination of mirrors.
[0109]
According to the three-dimensional shape measuring apparatus according to claim 3 of the present invention, in the three-dimensional shape measuring apparatus according to claim 2, the relative positional relationship between the mirrors is always kept constant. Therefore, even if the entire reflected light path conversion unit rotates about the axis in the main scanning direction, the apparent light emission point position of the reflected light exiting the reflected light path conversion unit is substantially the same, and the generated measurement height The effect that the error can be reduced is obtained.
[0110]
Further, according to the three-dimensional shape measuring apparatus according to the fourth aspect of the present invention, in the three-dimensional shape measuring apparatus according to the first aspect, the reflected light optical path changing means includes an incident surface and an emission surface parallel to the scanning line. It is a wedge-shaped prism with a simple component that can easily reduce the measurement height error caused by deformation of the scanning optical system, and the reflected light path conversion means as a whole is an axis in the scanning direction of the scanning light. Even if it rotates around, the position of the apparent light emission point of the reflected light emitted from the reflected light path changing means becomes almost the same, and the effect that the change of the height data can be reduced is obtained.
[0111]
Further, according to the three-dimensional shape measuring apparatus according to the fifth aspect of the present invention, in the three-dimensional shape measuring apparatus according to the first aspect, the reflected light optical path changing means is a cylindrical lens extending in the direction of the scanning line. The measurement light error caused by the deformation of the scanning optical system can be easily reduced with a simple component, and the reflected light optical path changing means can be rotated even if the entire reflected light optical path changing means is rotated around the scanning direction of the scanning light. As a result, the positions of the apparent light emission points of the reflected light emitted from the light source are almost the same, and the change in the height data can be reduced.
[0112]
According to a three-dimensional shape measuring apparatus according to a sixth aspect of the present invention, in the three-dimensional shape measuring apparatus according to the first aspect, the reflected light optical path changing means has a sheet-like shape and is an optical device that refracts light. Since the element is used, it is possible to easily reduce the measurement height error caused by the deformation of the scanning optical system with a single component. Further, even if the entire reflected light path changing means rotates about the scanning light scanning axis. The position of the apparent light emission point of the reflected light exiting the reflected light optical path changing means is almost the same, the change in height data can be reduced, and further, the restriction on the arrangement of the reflected light optical path changing means is reduced. In addition, since the degree of freedom in design increases, an effect that a more optimal design is possible can be obtained.
[0113]
Further, according to the three-dimensional shape measuring apparatus according to claim 7 of the present invention, in the three-dimensional shape measuring apparatus according to claim 3, the even number of mirrors constituting the reflected light optical path converting means are the inner surfaces of one prism body. The correction prism for improving the aberration of the image obtained by condensing the reflected light on the optical position detector is provided between the scanning condensing means and the optical position detector. When light is incident obliquely on the incident surface or exit surface of the reflected light path changer composed of prisms, the generated aberrations are corrected, the image size on the position detection element is reduced, and height measurement accuracy is improved. The effect of doing is obtained.
[0114]
According to the three-dimensional shape measuring apparatus according to claim 8 of the present invention, in the three-dimensional shape measuring apparatus according to claim 4 or 6, aberration of an image obtained by condensing the reflected light on the optical position detector. Since the correction prism for improving the light is provided between the light condensing means and the optical position detector, the reflected light is incident obliquely on the incident surface and the exit surface of the reflected light path changing means constituted by the prism. As a result, the generated aberration is corrected, the image size on the position detection element is reduced, and the height measurement accuracy is improved.
[0115]
According to a three-dimensional shape measuring apparatus according to claim 9 of the present invention, in the three-dimensional shape measuring apparatus according to claim 5, a cylinder for improving aberration of an image obtained by condensing the reflected light on the optical position detector. Since the lens is provided between the condensing means and the optical position detector, astigmatism that occurs when reflected light enters the reflected light path changing means constituted by a cylindrical lens is corrected, and position detection is performed. The image on the element is reduced to a dot shape, and the effect that the height measurement accuracy can be improved is obtained.
[0116]
Further, according to the three-dimensional shape measuring apparatus according to claim 10 of the present invention, the reflected light obtained by irradiating the object to be measured with the scanning light beam is detected by the optical position detector, and the detection result at each scanning position is detected. In the three-dimensional shape measuring apparatus for measuring the three-dimensional shape of the object, means for generating a light beam, deflection scanning means for deflecting and scanning the light beam, Deflection scan Scanning condensing means for condensing the light beam that has passed through the means, and an object to be measured on a locus (hereinafter referred to as a scanning line) drawn by a condensing point of the light beam that has passed through the scanning condensing means (hereinafter referred to as a scanning light beam) The reflected light from the beam is guided to the scanning condensing unit and the deflecting scanning unit, is incident on the optical position detector, and is a locus drawn by an apparent condensing point of the scanning light beam emitted from the scanning condensing unit. The apparent light emitting point of the reflected light incident on the scanning condensing means at the condensing point is always on the virtual scanning with respect to a plane (hereinafter referred to as a virtual scanning surface) that passes through and is perpendicular to the scanning light beam. Since it is provided with reflected light path changing means that comes to be located on the surface, the apparent condensing point of the reflected light emitted from the scanning optical system and the apparent light emitting point of the light beam emitted from the light source The relative position between Becomes, the change of the image size on the position detecting device according to the scanning position is reduced, there is an advantage that it is possible to improve the high measurement accuracy.
[0117]
According to the three-dimensional shape measuring apparatus of the eleventh aspect of the present invention, in the three-dimensional shape measuring apparatus according to the tenth aspect, an optical path during which the scanning light beam that has passed through the scanning condensing means reaches the scanning surface. Provided with a condensing distance changing means for changing the condensing distance of the scanning light beam, the apparent scanning surface position viewed from the scanning condensing means is reflected light viewed from the scanning condensing means. Thus, it is possible to obtain an effect that it is possible to move to an apparent light emission point and to always perform stable height measurement regardless of the scanning position.
[0118]
According to a three-dimensional shape measuring apparatus according to a twelfth aspect of the present invention, in the three-dimensional shape measuring apparatus according to the eleventh aspect, the condensing distance changing means is composed of three or more mirrors parallel to the scanning line. Therefore, when the apparent light emission point of the reflected light moves in the scanning light traveling direction with respect to the scanning surface, the position of the apparent scanning surface viewed from the scanning condensing means is changed to the scanning light. By moving in the direction of travel, the apparent scanning surface and the position of the apparent light emission point of the reflected light can be made coincident, and stable height measurement is always possible regardless of the scanning position. Is obtained.
[0119]
According to a three-dimensional shape measuring apparatus of the thirteenth aspect of the present invention, in the three-dimensional shape measuring apparatus according to the eleventh aspect, the condensing distance changing means includes an incident surface and an emission surface parallel to the scanning line. When the apparent light emission point of the reflected light moves in the direction opposite to the scanning light travel, the apparent surface seen from the scanning condensing means with respect to the scanning surface. The position of the upper scanning surface can be moved in the direction opposite to the direction of the scanning light, and the apparent scanning surface can be matched with the apparent light emitting point position of the reflected light. The effect that stable height measurement becomes possible is acquired.
[0120]
According to the three-dimensional shape measuring apparatus of the fourteenth aspect of the present invention, in the three-dimensional shape measuring apparatus according to the tenth aspect, the reflected light from the measuring object is in an optical path while reaching the scanning light collecting means. Since the reflected light emitting point distance changing means is provided and changes the distance to the apparent light emitting point of the reflected light, the position of the apparent light emitting point of the reflected light viewed from the scanning light collecting means is determined. Thus, it is possible to obtain an effect that it is possible to move to the scanning surface and always perform stable height measurement regardless of the scanning position.
[0121]
According to a three-dimensional shape measuring apparatus according to a fifteenth aspect of the present invention, in the three-dimensional shape measuring apparatus according to the fourteenth aspect, the reflected light emission point distance changing means includes three or more mirrors parallel to the scanning line. Since the position of the apparent light emission point of the reflected light moves in the direction opposite to the scanning light traveling direction with respect to the scanning surface, the apparent light emission point position is scanned with respect to the scanning surface. Moving in the light traveling direction, the apparent scanning surface and the position of the apparent light emission point of the reflected light can be matched, and the effect is that stable height measurement is always possible regardless of the scanning position. can get.
[0122]
According to a three-dimensional shape measuring apparatus of the sixteenth aspect of the present invention, in the three-dimensional shape measuring apparatus according to the fourteenth aspect, the reflected light emission point distance changing means includes an incident surface and an emission surface parallel to the scanning line. Since the apparent light emission point of the reflected light has moved to the scanning light progression relative to the scanning surface, the apparent light emission position is scanned with respect to the scanning surface. By moving in the opposite direction to the light travel, the position of the apparent light emission point on the scanning surface and reflected light can be matched, and the effect is that stable height measurement is always possible regardless of the scanning position. It is done.
[0123]
According to the three-dimensional shape measuring apparatus of the seventeenth aspect of the present invention, in the three-dimensional shape measuring apparatus according to the fourteenth aspect, the reflected light emission point distance changing means is composed of a cylindrical lens extending in the scanning line direction. Therefore, when the apparent light emission point of the reflected light is not on the scanning surface, the position of the apparent light emission point of the scanning surface and the reflected light is moved by moving the apparent light emission position with respect to the scanning surface. Since they coincide with each other, it is possible to obtain an effect that a stable height measurement is always possible regardless of the scanning position.
[0124]
According to the three-dimensional shape measuring apparatus of the eighteenth aspect of the present invention, in the three-dimensional shape measuring apparatus according to the sixteenth aspect, the parallel glass constituting the reflected light path changing means is arranged in parallel with the scanning line. In addition, two or more even mirrors are formed on the inner surface and integrated, so by integrating multiple means with multiple functions, the number of parts can be reduced and the parts cost can be reduced. As a result, it is possible to reduce the number of man-hours for assembly and adjustment, and the overall cost can be reduced.
[0125]
According to a three-dimensional shape measuring apparatus of the nineteenth aspect of the present invention, in the three-dimensional shape measuring apparatus according to the eighteenth aspect, the integrated parallel glass that constitutes the reflected light optical path changing means is configured so that the scanning light flux Since it has an entrance surface and an exit surface that change the condensing distance and is parallel to the scanning line, integrating the means with multiple functions can reduce the number of parts, Assembling adjustment man-hours can be reduced, and the effect of reducing the overall cost can be obtained.
[0126]
According to a three-dimensional shape measuring apparatus according to claim 20 of the present invention, in the three-dimensional shape measuring apparatus according to any one of claim 4, claim 6 or claim 8, an apparent light emission point of the reflected light. Since the reflected light emission point distance changing means for changing the distance to the prism is integrally formed with the prism constituting the reflected light optical path conversion means, the number of parts can be reduced by integrating the means having a plurality of functions. It is possible to reduce the parts cost and the assembly adjustment man-hours, and the overall cost can be reduced.
[0127]
Further, according to the three-dimensional shape measuring apparatus according to claim 21 of the present invention, in the three-dimensional shape measuring apparatus according to claim 20, the scanning made of parallel glass having an incident surface and an exit surface parallel to the scanning line. Since the condensing distance changing means for changing the condensing distance of the light beam is integrally formed with the prism constituting the reflected light optical path converting means, the number of parts can be reduced by integrating the means having a plurality of functions. It is possible to reduce the parts cost and the assembly adjustment man-hours, and the overall cost can be reduced.
[0128]
According to the three-dimensional shape measuring apparatus according to claim 22 of the present invention, in the three-dimensional shape measuring apparatus according to claim 5, the cylindrical lens constituting the reflected light optical path changing means is the reflected light from the measurement object. Is provided in the optical path while reaching the scanning condensing means, and by integrating the reflected light emitting point distance changing means for changing the distance to the apparent light emitting point of the reflected light, the number of parts can be reduced. In addition, it is possible to reduce the part cost and the assembly adjustment man-hour, and the effect that the total cost can be reduced is obtained.
[0129]
According to a three-dimensional shape measuring apparatus according to a twenty-third aspect of the present invention, in the three-dimensional shape measuring apparatus according to the twenty-second aspect, the cylindrical lens that constitutes the reflected light optical path changing means has a condensing distance of the scanning light beam. By integrating the condensing distance changing means made of parallel glass with the incident surface and exit surface parallel to the scanning line, the number of parts can be reduced, and the parts cost and assembly adjustment man-hours can be reduced. As a result, the overall cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an overall configuration of a three-dimensional shape measuring apparatus according to the present invention.
FIG. 2 is a diagram for explaining the principle of the three-dimensional shape measuring apparatus according to the first embodiment of the present invention, in which the spot light moves (FIG. (A)) and the movement of the spot light is that of the scanning optical system; The case (Figure (b)) which has generate | occur | produced by deformation | transformation is shown.
FIG. 3 is a diagram for explaining the relationship between an object and image movement due to reflection of a mirror group in the three-dimensional shape measurement apparatus according to the first embodiment, and includes one mirror (FIG. (A)) and The case of a plurality of sheets (FIG. (B)) is shown.
FIG. 4 is a diagram for explaining the configuration of the light receiving optical system of the three-dimensional shape measuring apparatus according to the first embodiment, and shows the configuration of the light receiving optical system using two mirrors (FIG. (A)) and the movement of spot light ( The figure (b) is shown.
5 is a diagram for explaining a configuration of a light receiving optical system of the three-dimensional shape measuring apparatus according to Embodiment 2, and the light receiving optical system is a prism (FIG. (A)) and a cylindrical lens (FIG. (B)), respectively. , And a Fresnel prism (FIG. (C)).
FIG. 6 is a diagram for explaining a basic configuration of a three-dimensional shape measuring apparatus according to a third embodiment of the present invention; a configuration of an integrated light receiving optical system (FIG. (A)); and installation of a correction prism ( Fig. (B)) shows the occurrence of the optical path length difference (Fig. (C)).
FIG. 7 is a diagram for explaining a basic configuration of a three-dimensional shape measuring apparatus according to a fourth embodiment of the present invention.
FIG. 8 is a diagram for explaining the configuration of the scanning light expansion / contraction means of the three-dimensional shape measuring apparatus according to the fourth embodiment, and the positions of the apparent light emission points are different from the scanning surface, respectively, and the scanning light traveling direction; The case is shown on the side (Fig. (A)) and on the opposite side of the scanning light traveling direction (Fig. (B)).
FIG. 9 is another view for explaining the configuration of the scanning light expansion / contraction means of the three-dimensional shape measuring apparatus according to the fourth embodiment, wherein the scanning light expansion / contraction means are respectively a mirror group (FIG. (A)) and a parallel glass; The case of (Fig. (B)) is shown.
FIG. 10 is a diagram for explaining the configuration of reflected light expansion / contraction means of the three-dimensional shape measuring apparatus according to the fourth embodiment, where the apparent light emission point positions are opposite to the scanning light traveling direction from the scanning plane, respectively. (Fig. (A)) and the scanning light traveling direction (Fig. (B)).
FIG. 11 is a diagram for explaining a basic configuration of a three-dimensional shape measuring apparatus according to a fifth embodiment of the present invention, in which a light receiving optical system is configured by a prism having two mirrors on the inner surface thereof. A case (FIG. (A)) and a case where the scanning light is configured to pass through two parallel transmission surfaces of the prism (FIG. (B)) are shown.
FIG. 12 is another diagram for explaining the configuration of the three-dimensional shape measuring apparatus according to the fifth embodiment, in which the light receiving optical system includes a prism having an entrance surface and an exit surface parallel to the main scanning direction. The case (FIG. (A)) and the case where the scanning light is parallel to the main scanning direction and pass through two transmission surfaces parallel to each other (FIG. (B)) are shown.
FIG. 13 is another view for explaining the configuration of the three-dimensional shape measuring apparatus according to the fifth embodiment, in which a prism sheet (FIG. (A)) and a cylindrical lens (FIG. (B)) are used for the light receiving optical system. Indicates the case where
FIG. 14 is a perspective view showing an overall configuration of a conventional three-dimensional shape measuring apparatus.
FIG. 15 is a diagram for explaining a problem of height measurement by triangulation in a conventional three-dimensional shape measuring apparatus, where a blind spot occurs (FIG. (A)), and a height measurement error due to multiple reflection (FIG. ( b)) and the case of measuring reflected light from a plurality of directions (FIG. (c)).
FIG. 16 is a cross-sectional view showing a relationship between a scanning position and a received light image position in a conventional three-dimensional shape measuring apparatus.
FIG. 17 is a perspective view showing a configuration when a light receiving optical system includes a scanning optical system in a conventional three-dimensional shape measuring apparatus.
FIG. 18 is a diagram for explaining a spot light position shift and a height error in a conventional three-dimensional shape measuring apparatus, and reflected light in one direction (FIG. (A)) and plural directions (FIG. (B)). The case where is measured.
FIG. 19 is a diagram showing a change in height measurement accuracy depending on a scanning position in a conventional three-dimensional shape measuring apparatus.
[Explanation of symbols]
1 Light source
2 Rotating mirror
3. Condensing / scanning lens
4 Scanning light
5 Measurement object
6 Spot light on the measuring object
6a Spot light located at the end of the scanning line
6b Spot light located at the other end of the scanning line
7 Scanning straight line
8a Reflected light from measurement object
8b Reflected light from measurement object
9 Receiving optical system
9a, 90a Receiving optical system (positioned between measuring object and scanning optical system)
9b Light receiving optical system (position between scanning optical system and position detection element)
10 Position detection element
11 Main scanning direction
12 Sub-scanning direction
13 Apparent emission point of reflected light incident on scanning optical system
14 Apparent condensing point of reflected light incident on light receiving optical system
15 Apparent emission point of luminous flux emitted from light source
16 Scanning surface where spot light 6 is focused
17a, 170a, 171a Mirrors constituting the light receiving optical system
17b, 170b, 171b Mirrors constituting the light receiving optical system
17c Prism constituting light receiving optical system
17d Cylindrical lens constituting light receiving optical system
17e Fresnel prism constituting light receiving optical system
18, 180, 181, 182, 183, 184, 185 Integrated light receiving optical system constituting light receiving optical system
18a, 180a, 181a, 182a, 183a, 184a, 185a The incident surface of the reflected light constituting the integrated light receiving optical system (181, 182, 183, 184, 185)
18b, 180b, 181b, 182b, 183b, 184b, 185b The exit surface of the reflected light 8 constituting the integrated light receiving optical system (181, 182, 183, 184, 185)
181c, 183c, 184c, 185c Scanning light incident surface constituting an integrated light receiving optical system
181d, 183d, 184d, 185d Scanning light exit surface constituting an integrated light receiving optical system
19 Correction prism positioned between light receiving optical system and position detection element
19a Incident surface of reflected light constituting the prism
19b The exit surface of the reflected light constituting the prism
30 Apparent scanning plane viewed from the scanning condensing lens 3
31 Means for Changing the Condensing Distance of Spot Light (Condensing Distance Changing Means)
32 Mirrors that change the focusing distance of spot light
33 Parallel glass to change the focusing distance of spot light
34 Means for changing the apparent light emitting point distance (reflected light emitting point distance changing means)
40 Direction of travel of scanning light
41 Apparent condensing point seen from scanning condensing lens

Claims (23)

In a three-dimensional shape measuring apparatus for detecting reflected light obtained by irradiating an object to be measured with a scanning light beam by an optical position detector and measuring the three-dimensional shape of the object from the detection result at each scanning position,
Means for generating luminous flux;
Deflection scanning means for deflecting and scanning the luminous flux;
And scanning condensing means for condensing a light beam having passed through said deflection scanning means,
Reflected light from an object to be measured on a trajectory (hereinafter referred to as a scanning line) drawn by a condensing point of a light beam (hereinafter referred to as a scanning light beam) that has passed through the scanning light condensing means is converted into the scanning light focusing means and the deflection scanning. When the object moves in a direction perpendicular to both the scanning light beam and the scanning line (hereinafter referred to as a sub-scanning direction), the light position detector obtains the light position detector. A reflected light path changing means in which the moving direction of the image to be moved is the same as the moving direction of the object, and the moving distance of the image is less than twice the moving distance of the object. A three-dimensional shape measuring apparatus comprising: The three-dimensional shape measuring apparatus according to claim 1,
The three-dimensional shape measuring apparatus, wherein the reflected light optical path changing means is an even number of two or more mirrors arranged in parallel with the scanning line. The three-dimensional shape measuring apparatus according to claim 2,
A three-dimensional shape measuring apparatus characterized in that the relative positional relationship between the mirrors is always kept constant. The three-dimensional shape measuring apparatus according to claim 1,
The three-dimensional shape measuring apparatus, wherein the reflected light path conversion means is a wedge-shaped prism having an entrance surface and an exit surface parallel to the scanning line. The three-dimensional shape measuring apparatus according to claim 1,
The three-dimensional shape measuring apparatus, wherein the reflected light path changing means is a cylindrical lens extending in the direction of the scanning line. The three-dimensional shape measuring apparatus according to claim 1,
The three-dimensional shape measuring apparatus, wherein the reflected light path changing means is an optical element having a sheet shape and refracting light. In the three-dimensional shape measuring apparatus according to claim 3,
An even number of mirrors constituting the reflected light path conversion means are formed on the inner surface of one prism body,
A three-dimensional shape measuring apparatus characterized in that a correction prism for improving the aberration of an image obtained by condensing the reflected light on the optical position detector is provided between the scanning condensing means and the optical position detector. . In the three-dimensional shape measuring apparatus according to claim 4 or 6,
A three-dimensional shape measuring apparatus characterized in that a correction prism for improving the aberration of an image obtained by condensing the reflected light on the optical position detector is provided between the scanning condensing means and the optical position detector. . The three-dimensional shape measuring apparatus according to claim 5,
A three-dimensional shape measuring apparatus characterized in that a cylindrical lens for improving the aberration of an image obtained by condensing the reflected light on the optical position detector is provided between the condensing means and the optical position detector. In a three-dimensional shape measuring apparatus for detecting reflected light obtained by irradiating an object to be measured with a scanning light beam by an optical position detector and measuring the three-dimensional shape of the object from the detection result at each scanning position,
Means for generating luminous flux;
Deflection scanning means for deflecting and scanning the luminous flux;
And scanning condensing means for condensing a light beam having passed through said deflection scanning means,
Reflected light from an object to be measured on a trajectory (hereinafter referred to as a scanning line) drawn by a condensing point of a light beam (hereinafter referred to as a scanning light beam) that has passed through the scanning light condensing means is converted into the scanning light focusing means and the deflection scanning. And a plane perpendicular to the scanning light beam (hereinafter, referred to as a path that is drawn by an apparent condensing point of the scanning light beam emitted from the scanning light condensing unit, and is incident on the optical position detector). A reflected light path changing means that an apparent light emitting point of reflected light incident on the scanning light collecting means at the light collecting point is always located on the virtual scanning surface with respect to the virtual scanning surface). A three-dimensional shape measuring apparatus comprising: The three-dimensional shape measuring apparatus according to claim 10, wherein
A three-dimensional shape provided with a condensing distance changing means for changing a condensing distance of the scanning light beam provided in an optical path while the scanning light beam passing through the scanning light condensing means reaches the scanning surface. measuring device. The three-dimensional shape measuring apparatus according to claim 11, wherein
The three-dimensional shape measuring apparatus, wherein the condensing distance changing means is composed of three or more mirrors parallel to the scanning line. The three-dimensional shape measuring apparatus according to claim 11, wherein
The three-dimensional shape measuring apparatus, wherein the condensing distance changing means is made of parallel glass having an entrance surface and an exit surface parallel to the scanning line. The three-dimensional shape measuring apparatus according to claim 10, wherein
Reflected light emission point distance changing means for changing the distance to the apparent light emission point of the reflected light is provided in the optical path while the reflected light from the measurement object reaches the scanning condensing means. A three-dimensional shape measuring apparatus. The three-dimensional shape measuring apparatus according to claim 14,
The reflected light emission point distance changing means is composed of three or more mirrors parallel to the scanning line. The three-dimensional shape measuring apparatus according to claim 14,
The three-dimensional shape measuring apparatus, wherein the reflected light emitting point distance changing means is made of parallel glass having an entrance surface and an exit surface parallel to the scanning line. The three-dimensional shape measuring apparatus according to claim 14,
The three-dimensional shape measuring apparatus, wherein the reflected light emitting point distance changing means is composed of a cylindrical lens extending in the scanning line direction. The three-dimensional shape measuring apparatus according to claim 16, wherein
The parallel glass constituting the reflected light path conversion means is formed by integrating two or more even-numbered mirrors arranged in parallel with the scanning line on the inner surface thereof, and measuring the three-dimensional shape apparatus. The three-dimensional shape measuring apparatus according to claim 18,
The integrated parallel glass constituting the reflected light path changing means has a three-dimensional shape having an entrance surface and an exit surface parallel to the scan line, which change the focusing distance of the scan light beam. measuring device. In the three-dimensional shape measuring apparatus according to any one of claims 4, 6, and 8,
The three-dimensional shape measurement characterized in that the reflected light emission point distance changing means for changing the distance to the apparent light emission point of the reflected light is formed integrally with the prism constituting the reflected light optical path conversion means. apparatus. The three-dimensional shape measuring apparatus according to claim 20,
A condensing distance changing means for changing a condensing distance of the scanning light beam, which is made of parallel glass having an incident surface and an exit surface parallel to the scanning line, is integrated with a prism constituting the reflected light path conversion means. A three-dimensional shape measuring apparatus characterized by being formed. The three-dimensional shape measuring apparatus according to claim 5,
A cylindrical lens constituting the reflected light path conversion means is provided in an optical path while the reflected light from the measurement object reaches the scanning light collecting means, and the distance to the apparent light emission point of the reflected light is set. A three-dimensional shape measuring apparatus, wherein the reflected light emission point distance changing means to be changed is integrated. The three-dimensional shape measuring apparatus according to claim 22,
The cylindrical lens constituting the reflected light path conversion means is integrated with a focusing distance changing means made of parallel glass having an incident surface and an exit surface parallel to the scanning line, which changes the focusing distance of the scanning light beam. A three-dimensional shape measuring apparatus characterized by being configured.

Images