【０００１】
【発明の属する技術分野】
本発明は基板上に電子部品を装着する際に、画像処理によって電子部品の中心位置および傾きを検出してその姿勢を矯正する電子部品の装着姿勢矯正方法に関するものである。
【０００２】
【従来の技術】
以下、従来の電子部品の装着姿勢矯正方法について図面を用いて説明する。
【０００３】
図１１は電子部品装着装置における電子部品の吸着から装着までの処理手順を示すフローチャートである。
【０００４】
チップ形電子部品等の微小な電子部品を基板に装着する際には、図１１のフローチャートに示すように、電子部品吸着工程＃１８で電子部品装着装置の電子部品吸着部（図示せず）にて電子部品を吸着して取り出し、次に、画像取り込み工程＃１９で前記同装置の画像取り込み部（図示せず）にて撮像された画像を画像メモリに取り込み、次に、吸着された電子部品の装着姿勢検出工程＃２０で画像処理によって電子部品の姿勢を検出し、次に電子部品の装着姿勢矯正工程＃２１で電子部品の装着姿勢の矯正を行い、次に、電子部品装着工程＃２２で前記同装置の電子部品装着部（図示せず）にて電子部品の基板への装着が行われ、工程＃２３で一連の処理が終了する。
【０００５】
また、従来、上記吸着された電子部品の装着姿勢検出工程＃２０での装着姿勢検出方法としては、特開平４−３５４０７２号公報に記載されたものが知られており、以下にこの従来の電子部品の装着姿勢検出方法について、図面を用いて説明する。
【０００６】
図１２は上記従来の電子部品の装着姿勢検出方法の手順を示すフローチャートであり、図１３、図１４、図１５は同従来の電子部品の装着姿勢検出方法を説明するための処理画面を示す平面図である。
【０００７】
まず、図１２に示すフローチャートの輪郭検出工程＃２４で、図１３に示すように二値輪郭追跡処理によって処理画面上の部品画像の輪郭線を検出し、図１２に示す重心検出工程＃２５で、図１３に示すように前記輪郭線の重心Ｇ（ｘｇ，ｙｇ）を検出し、図１２に示す交点検出工程＃２６で、図１３に示すように重心Ｇ（ｘｇ，ｙｇ）を通るＸ軸およびＹ軸に平行な直線ｍおよびｎと部品の輪郭線との交差点Ｐ１（ｘ１，ｙ１），Ｐ２（ｘ２，ｙ２），Ｐ３（ｘ３，ｙ３），Ｐ４（ｘ４，ｙ４）を求める。
【０００８】
次に、図１３に示すように交点Ｐ３−Ｐ４間の長さをｈｌｎ、交点Ｐ１−Ｐ２間の長さをｖｌｎとしたとき、図１２に示す処理範囲１工程＃２７および処理範囲２工程＃２９で、ｈｌｎ≧ｖｌｎの場合、交点Ｐ１を中心とする二つの処理範囲を決定する。
【０００９】
また、図１２に示す、処理範囲１工程＃２７および処理範囲２工程＃２９で、ｈｌｎ＜ｖｌｎの場合、交点Ｐ３を中心とする二つの処理範囲を決定する。
【００１０】
以下、ｈｌｎ≧ｖｌｎと仮定して説明を行う。このとき、前記二つの処理範囲は、図１４に示すΔｘｒ，Δｘｌで表される範囲となる。
【００１１】
上述のように二つの処理範囲が求められると、図１２に示す最小二乗法による直線検出工程＃２８および＃３０で、これらの処理範囲に含まれる電子部品の輪郭線上の点群データに対してそれぞれ最小二乗法を適用し、図１４に示す直線の傾きθ１，θ２を求める。
【００１２】
図１４に示すように一方の処理範囲に隣の辺が含まれている場合には、傾きθ２は直線の真の傾きに対してその絶対値が小さくなるため、傾きθ１，θ２の内で絶対値の大きい方の傾きをθ３とし、図１２に示す概略傾き決定工程＃３１で電子部品の傾きの概略値を決定する。
【００１３】
上述のように、電子部品の概略の傾きθ３が求められると、図１２に示す四辺の処理範囲決定工程＃３２で、電子部品の辺の長さｈｌ，ｖｌと概略の傾きθ３によって、図１５に示すように交点Ｐ１を中心とする処理範囲Δｘａ０を求める。
【００１４】
ここで、図１５に示すように交点Ｐ１は辺の中心に対して図示のｘｄだけずれているために前記処理範囲Δｘａ０をｘｄだけシフトし、最終的な処理範囲Δｘ０を求める。同様にして、電子部品の他の三辺上の処理範囲をそれぞれ求め、図１２に示す四辺の最小二乗法による直線検出工程＃３３で、四つの処理範囲での電子部品の輪郭線上のそれぞれの点群データについて最小二乗法による直線近似を行い、電子部品の四辺の傾きをそれぞれ求める。
【００１５】
そして、図１２に示す電子部品の傾き／中心演算工程＃３４で求めた四辺の傾きを平均することによって電子部品の傾きを求め、電子部品の中心の演算を行い、図１２に示す工程＃３５で、一連の電子部品の装着姿勢検出の処理を終了するようにしたものであった。
【００１６】
【発明が解決しようとする課題】
しかしながら上記従来の電子部品の装着姿勢検出方法では、図２に示すようなセラミックコンデンサ１等のチップ形電子部品においては、半田等がメッキされている電極部分２が丸みを帯びているため、電極部分２における最小二乗法による近似直線の算出結果が不正確になり、前記電子部品の中心位置および傾きを正確に求めることができなかった。また、対象物の四辺全てについて最小二乗直線を求める方法では処理時間が長くなるという欠点があった。
【００１７】
本発明はこのような従来の課題を解決し、セラミックコンデンサ等、電子部品の一部が丸みを帯びているような電子部品においても、その中心位置および傾きを精度よく検出し、電子部品の姿勢検出を迅速に行って矯正することが可能な電子部品の装着姿勢矯正方法を提供することを目的とするものである。
【００１８】
【課題を解決するための手段】
この課題を解決するために本発明は、二値化処理によって電子部品の輪郭抽出を行い、輪郭追跡処理によって処理画像上の電子部品の外接四角形を求め、この外接四角形の向かい合う一対の辺のそれぞれの中点を中心とした所定の二つの処理範囲内の電子部品の輪郭線上の点群データについて最小二乗法による直線近似を行ってそれらの直線の傾きの平均値を上記電子部品の概略傾きとし、この概略傾きに基づいて電子部品の向かい合う一対の辺における処理範囲を決定し、この決定された各処理範囲内での電子部品の輪郭線上の点群データについて最小二乗法による直線近似を行い、電子部品の向かい合う一対の辺を直線近似し、それらの直線の傾きの平均値を電子部品の傾きとして求め、さらに、他の向かい合う一対の辺について電子部品の傾きに基づいて処理範囲を決定し、この決定された各処理範囲内の電子部品の輪郭線上の点群データについてそれぞれの重心を検出し、それらの重心を通って電子部品の傾きに垂直な傾きを持つ直線をそれぞれ求めて電子部品の他のもう一つの一対の辺の近似直線とし、既に求めた電子部品の向かい合う一対の辺の近似直線との四つの交点をそれぞれ求め、その水平方向および垂直方向の最大値と最小値を求め、それぞれの方向における最大値と最小値の中間値を電子部品の中心位置として求める方法としたものである。これにより、電子部品の姿勢を高速かつ精度よく検出することができる。
【００１９】
【発明の実施の形態】
本発明の請求項１に記載の発明は、二値化処理によって電子部品の輪郭抽出を行い、輪郭追跡処理によって処理画像上の電子部品の外接四角形を求め、この外接四角形の向かい合う一対の辺のそれぞれの中点を中心とした所定の二つの処理範囲内の電子部品の輪郭線上の点群データについて最小二乗法による直線近似を行って、それらの直線の傾きの平均値を電子部品の概略傾きとし、この概略傾きに基づいて電子部品の向かい合う一対の辺における処理範囲を決定し、この決定された各処理範囲内での電子部品の輪郭線上の点線群データについて最小二乗法による直線近似を行い、電子部品の向かい合う一対の辺を直線近似し、それらの直線の傾きの平均値を電子部品の傾きとして求め、さらに、他の向かい合う一対の辺について電子部品の傾きに基づいて処理範囲を決定し、この決定された各処理範囲内の電子部品の輪郭線上の点群データについてそれぞれの重心を検出し、それらの重心を通って電子部品の傾きに垂直な傾きを持つ直線をそれぞれ求めて電子部品の他のもう一つの一対の辺の近似直線とし、既に求めた電子部品の向かい合う一対の辺の近似直線との四つの交点をそれぞれ求め、その水平方向および垂直方向の最大値と最小値を求め、それぞれの方向における最大値と最小値の中間値を電子部品の中心位置として求める方法としたものであり、電子部品の姿勢を高速かつ精度よく検出することができる。
【００２０】
以下、本発明の一実施の形態について図面を用いて説明する。
図１は、同実施の形態による電子部品の装着姿勢矯正方法の処理手順を示すフローチャート、図２はセラミックコンデンサの斜視図、図３〜図１０は同実施の形態による電子部品の装着姿勢矯正方法の各工程を説明するための処理画面を示す平面図である。なお、電子部品装着の全工程については従来と同様であるので、その詳細な説明は省略し、異なる部分についてのみ詳細な説明を行う。
【００２１】
まず、図１に示す電子部品の輪郭抽出工程＃１で、二値輪郭追跡処理により図３に示すように処理画面上の部品画像の輪郭（以下、電子部品という）３を求め、続いて図１に示す輪郭外接四角形算出工程＃２で、図３に示すように処理画面上の電子部品３の外接四角形４を求め、続いて図１に示す輪郭外接四角形中心算出工程＃３で、図３に示すように上記外接四角形４の中心をＭ（ｘｍ，ｙｍ）として求め、続いて図１に示す電子部品３の向かい合う一対の辺における処理範囲算出工程＃４で、あらかじめ設定されている電子部品３の向かい合う一対の辺の長さをｐｌとして、図３に示すようにｘｍを中心とした（数１）で表される処理範囲５（Δｘｔ），６（Δｘｂ）を決定する。
【００２２】
【数１】
【００２３】
上記のように処理範囲５（Δｘｔ），６（Δｘｂ）が求められると、図１に示す各処理範囲における電子部品３の輪郭線上の点群データの検出１工程＃５で、これら処理範囲５，６に含まれる電子部品３の輪郭線上の点群データを検出し、続いて図１に示す点群データの直線近似による電子部品の概略傾き算出工程＃６で、これら二組の点群データに対してそれぞれ最小二乗法を適用して電子部品３の輪郭線の直線近似を行い、図４に示すように電子部品３の向かい合う一対の辺の概略の近似直線７および８を求め、それぞれの直線の傾きの平均値θａｂを電子部品３の概略の傾きとする。
【００２４】
部品の概略の傾きθａｂが求められると、図１に示す概略傾きに基づく電子部品の一対の辺における処理範囲の算出工程＃７で、図５に示すように電子部品３の向かい合う一対の辺における処理範囲をθａｂに基づいて、外接四角形４の中心点Ｍから近似直線７および８に下ろした垂線との交点ＭＴおよびＭＢが中心となるようにｗｄ（＝ｗｌ／２・ｓｉｎθａｂ）だけ移動し、（数２）で表される処理範囲９（Δｘｄｔ），１０（Δｘｄｂ）を決定する。
【００２５】
【数２】
【００２６】
上記のように処理範囲９（Δｘｄｔ），１０（Δｘｄｂ）が求められると図１に示す各処理範囲における電子部品の輪郭線上の点群データの検出工程＃８で、これら処理範囲９，１０に含まれる電子部品３の輪郭線上の点群データを検出し、続いて図１に示す点群データの直線近似による電子部品の向かい合う一対の辺の近似直線算出工程＃９で、これら二組の点群データに対してそれぞれ最小二乗法を適用して電子部品３の輪郭線の直線近似を行い、図６に示すように（数３）で表される電子部品３の向かい合う一対の辺の近似直線１１および１２を求め、それぞれの直線の傾きの平均値Ｓを求める。
【００２７】
このときの電子部品３の傾きをθとすると、電子部品３の傾きθは（数３）で表され、図１に示す電子部品傾きの算出工程＃１０で電子部品３の傾きθを求める。
【００２８】
【数３】
【００２９】
電子部品３の傾きθが求められると、図１に示す電子部品傾きに基づく他の向かい合う一対の辺における処理範囲の算出工程＃１１で、図７に示すように電子部品３の他の向かい合う一対の辺における処理範囲を電子部品３の傾きθに基づいて、外接四角形４の中心点Ｍを通り、傾きＳ（＝ｔａｎ-1θ）を持つ直線１３と電子部品３の端点との交点ＭＬおよびＭＲが中点となるように、１ｄ（＝ｐｌ／２・ｓｉｎθ）だけ移動し、あらかじめ設定されている電子部品の他の向かい合う一対の辺の長さをｗｌとして、図７に示すように（数４）で表される処理範囲１４（Δｙｌ），１５（Δｙｒ）を決定する。
【００３０】
【数４】
【００３１】
上記のように処理範囲１４（Δｙｌ），１５（Δｙｒ）が求められると、図１に示す各処理範囲における電子部品の輪郭線上の点群データの検出工程＃１２で、これら処理範囲１４，１５に含まれる電子部品の輪郭線上の点群データを検出し、図１に示す各処理範囲における電子部品の輪郭線上の点群データの重心の算出工程＃１３で、各処理範囲における重心ＧＬおよびＧＲをそれぞれ求める。
【００３２】
図８は、処理範囲１４および、その付近の処理上の電子部品３の画像の拡大図であり、図中の正方形のマスは、点データすなわち、画素を表し、処理範囲１４に含まれる電子部品３の輪郭線上の点群データ１８について、その重心ＧＬを検出する。これは、処理範囲１５における処理範囲重心ＧＲを求める際も同様である。
【００３３】
次に、図１に示す他の向かい合う一対の辺の近似直線の算出工程＃１４で、図９に示すように、（数５）で表される重心ＧＬおよびＧＲを通り電子部品３の傾きθに垂直な傾きを持つ直線１６および１７を求める。
【００３４】
【数５】
【００３５】
次に、図１に示す算出された電子部品の四辺の近似直線算出工程＃１５で、図１０に示すように既に求めた四本の直線についてそれぞれの交点を求め、それぞれＣａ（ｘａ，ｙａ），Ｃｂ（ｘｂ，ｙｂ），Ｃｃ（ｘｃ，ｙｃ），Ｃｄ（ｘｄ，ｙｄ）とし、そのＸ座標の最大値をＸｍａｘ、最小値をＸｍｉｎ、Ｙ座標の最大値をＹｍａｘ、最小値をＹｍｉｎとして、図１に示す電子部品中心算出工程＃１６で、図１０に示すように（数６）で表される座標Ｐ（ｘｐ，ｙｐ）を電子部品中心として求める。
【００３６】
【数６】
【００３７】
このようにして装着姿勢が検出された電子部品３は、検出結果に基づいて装着姿勢が矯正された後に基板に装着され、図１の＃１７の工程で一連の処理が終了する。
【００３８】
以上のように本発明の電子部品の装着姿勢矯正方法では、まず、吸着した電子部品３の概略の傾きθａｂを求め、この概略の傾きθａｂに基づいて図５に示すような電子部品３の一対の辺における処理範囲９（Δｘｄｔ），１０（Δｘｄｂ）を決定し、この処理範囲９（Δｘｄｔ），１０（Δｘｄｂ）内の電子部品３の輪郭線上の点群データについて最小二乗法による直線近似を行い、それぞれの直線を電子部品３の向かい合う一対の辺の近似直線として求め、それら二本の直線の傾きの平均値を電子部品３の傾きθとして検出し、この傾きθに基づいて図７に示すような電子部品３の他の一対の辺における処理範囲１４（Δｙｌ），１５（Δｙｒ）を決定し、この処理範囲１４（Δｙｌ），１５（Δｙｒ）内の電子部品の輪郭線上の点群データについて各処理範囲における重心をそれぞれ求め、これらの重心を通って電子部品傾きθに垂直な傾きを持つ直線を算出し、求めた四本の直線の交点の中点を電子部品中心として求めるようにしたため、図２に示すようなセラミックコンデンサ１のように電子部品の半田等でメッキされた電極部分２等の電子部品の一部分が丸みを帯びている電子部品においても、その姿勢を精度よく検出することができる。
【００３９】
また、計算量の多くなる最小二乗法による直線検出を、電子部品３の向かい合う一対の辺における二本の直線のみにしたことにより、計算量を減らし、処理時間を短縮することができるため、電子部品３の姿勢を高速かつ精度よく検出することができる。
【００４０】
【発明の効果】
以上のように本発明によれば、セラミックコンデンサのような一部分が丸みを帯びている電子部品であっても、その姿勢を高速かつ精度よく検出し、装着姿勢を正しく矯正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】本発明の一実施の形態による吸着された電子部品の装着姿勢矯正方法の処理手順を示すフローチャート
【図２】セラミックコンデンサの形状を示す斜視図
【図３】図１の＃２，＃３，＃４の工程を説明するための処理画面を示す平面図
【図４】図１の＃５，＃６の工程を説明するための処理画面を示す平面図
【図５】図１の＃７の工程を説明するための処理画面を示す平面図
【図６】図１の＃８，＃９，＃１０の工程を説明するための処理画面を示す平面図
【図７】図１の＃１１の工程を説明するための処理画面を示す平面図
【図８】図１の＃１２，＃１３の工程を説明するための処理画面を示す平面図
【図９】図１の＃１４の工程を説明するための処理画面を示す平面図
【図１０】図１の＃１５，＃１６の工程を説明するための処理画面を示す平面図
【図１１】電子部品装着装置における電子部品の吸着から装着までの全工程を示すフローチャート
【図１２】従来の電子部品の姿勢検出方法の処理手順を示すフローチャート
【図１３】図１２の＃２４，＃２５，＃２６の工程を説明するための処理画面を示す平面図
【図１４】図１２の＃２７，＃２８，＃２９，＃３０，＃３１の工程を説明するための処理画面を示す平面図
【図１５】図１２の＃３２，＃３３，＃３４の工程を説明するための処理画面を示す平面図
【符号の説明】
１ セラミックコンデンサ
２ 電極部分
３ セラミックコンデンサの処理画面上の電子部品画像の輪郭線（電子部品）
４ 同電子部品画像の輪郭の外接四角形
５（Δｘｔ） 電子部品の概略傾き検出処理範囲
６（Δｘｂ） 電子部品の概略傾き検出処理範囲
７ 電子部品の向かい合う一対の辺における一つの辺の概略の近似直線
８ 電子部品の向かい合う一対の辺における他のもう一つの辺の概略の近似直線
９（Δｘｄｔ） 電子部品の傾き検出処理範囲
１０（Δｘｄｂ） 電子部品の傾き検出処理範囲
１１ 電子部品の向かい合う一対の辺における一つの辺の近似直線
１２ 電子部品の向かい合う一対の辺における他のもう一つの辺の近似直線
１３ 電子部品画像の輪郭の外接四角形の中心を通り、電子部品の傾きに等しい傾きを持つ直線
１４（Δｙｌ） 電子部品の他の一対の辺における一つの辺の電子部品の輪郭線上の点群データの重心検出処理範囲
１５（Δｙｒ） 電子部品の他の一対の辺における他のもう一つの辺の電子部品の輪郭線上の点群データの重心検出処理範囲
１６ 電子部品の他の一対の辺における一つの辺の電子部品の輪郭線上の点群データの重心を通り、電子部品の傾きに垂直な傾きを持つ直線
１７ 電子部品の他の一対の辺における他のもう一つの辺の電子部品の輪郭線上の点群データの重心を通り、電子部品の傾きに垂直な傾きを持つ直線
１８ 処理画像上の電子部品の輪郭線上の点群データ
Ｍ 電子部品画像の輪郭の外接四角形の中心
ｐｌ あらかじめ設定されている電子部品の向かい合う一対の辺の長さ
ｗｌ あらかじめ設定されている電子部品の他のもう一つの向かい合う一対の辺の長さ
θａｂ 電子部品の概略傾き
θ 電子部品の傾き
ＭＴ Ｍから近似直線７に下ろした垂線と近似直線７との交点
ＭＢ Ｍから近似直線８に下ろした垂線と近似直線８との交点
ｗｄ 電子部品の向かい合う一対の辺における処理範囲の移動距離
ＭＬ 直線１２と電子部品の一つの端点との交点
ＭＲ 直線１２と電子部品の他のもう一つの端点との交点
１ｄ 電子部品の他の向かい合う一対の辺における処理範囲の移動距離
ＧＬ 電子部品の他の向かい合う一対の辺での一つの処理範囲における電子部品の輪郭線上の点群データの重心
ＧＲ 電子部品の他の向かい合う一対の辺での他のもう一つの処理範囲における電子部品の輪郭線上の点群データの重心
Ｃａ（ｘａ，ｙａ） 算出された近似直線１１と１６との交点
Ｃｂ（ｘｂ，ｙｂ） 算出された近似直線１１と１７との交点
Ｃｃ（ｘｃ，ｙｃ） 算出された近似直線１２と１７との交点
Ｃｄ（ｘｄ，ｙｄ） 算出された近似直線１２と１６との交点
Ｐ（ｘｐ，ｙｐ） 算出された電子部品の中心[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electronic component mounting posture correction method for detecting the center position and inclination of an electronic component by image processing and correcting the posture when mounting the electronic component on a substrate.
[0002]
[Prior art]
Hereinafter, a conventional electronic component mounting posture correction method will be described with reference to the drawings.
[0003]
FIG. 11 is a flowchart showing a processing procedure from the suction of electronic components to the mounting in the electronic component mounting apparatus.
[0004]
When a minute electronic component such as a chip-type electronic component is mounted on a substrate, as shown in the flowchart of FIG. 11, an electronic component suction unit (not shown) of the electronic component mounting device is not mounted in electronic component suction step # 18. Then, the electronic component is picked up and taken out, and then the image picked up by the image pick-up unit (not shown) of the apparatus in the image pick-up step # 19 is picked up in the image memory. In step # 20, the posture of the electronic component is detected by image processing. Next, in step # 21 of correcting the mounting posture of the electronic component, the mounting posture of the electronic component is corrected, and then in step # 22 of mounting the electronic component. Thus, the electronic component is mounted on the substrate in the electronic component mounting portion (not shown) of the apparatus, and a series of processing is completed in step # 23.
[0005]
Conventionally, as a mounting posture detection method in the mounting posture detection step # 20 of the sucked electronic component, a method described in JP-A-4-354072 is known, and this conventional electronic component is described below. A component mounting posture detection method will be described with reference to the drawings.
[0006]
FIG. 12 is a flowchart showing the procedure of the conventional electronic component mounting posture detection method. FIGS. 13, 14, and 15 are plan views showing processing screens for explaining the conventional electronic component mounting posture detection method. FIG.
[0007]
First, in the contour detection step # 24 of the flowchart shown in FIG. 12, the contour line of the component image on the processing screen is detected by the binary contour tracking process as shown in FIG. 13, and in the center of gravity detection step # 25 shown in FIG. , The center of gravity G (xg, yg) of the contour line is detected as shown in FIG. 13, and in the intersection detection step # 26 shown in FIG. 12, the X axis passing through the center of gravity G (xg, yg) as shown in FIG. Then, intersections P1 (x1, y1), P2 (x2, y2), P3 (x3, y3), and P4 (x4, y4) between the straight lines m and n parallel to the Y axis and the contour of the part are obtained.
[0008]
Next, as shown in FIG. 13, when the length between the intersection points P3-P4 is hln and the length between the intersection points P1-P2 is vln, the processing range 1 step # 27 and the processing range 2 step # shown in FIG. In 29, if hln ≧ vln, two processing ranges centering on the intersection P1 are determined.
[0009]
In the processing range 1 step # 27 and the processing range 2 step # 29 shown in FIG. 12, if hln <vln, two processing ranges centering on the intersection P3 are determined.
[0010]
Hereinafter, the description will be made assuming that hln ≧ vln. At this time, the two processing ranges are ranges represented by Δxr and Δxl shown in FIG.
[0011]
When the two processing ranges are obtained as described above, in the line detection steps # 28 and # 30 by the least square method shown in FIG. 12, the point group data on the contour line of the electronic component included in these processing ranges is obtained. The least square method is applied, respectively, to determine the slopes θ1 and θ2 of the straight lines shown in FIG.
[0012]
As shown in FIG. 14, when one processing range includes an adjacent side, the absolute value of the inclination θ2 is smaller than the true inclination of the straight line. The inclination having the larger value is θ3, and the approximate value of the inclination of the electronic component is determined in the approximate inclination determination step # 31 shown in FIG.
[0013]
As described above, when the approximate inclination θ3 of the electronic component is obtained, in the processing range determination step # 32 of the four sides shown in FIG. 12, the side lengths hl and vl of the electronic component and the approximate inclination θ3 are used. As shown, a processing range Δxa0 centered on the intersection P1 is obtained.
[0014]
Here, as shown in FIG. 15, since the intersection P1 is shifted by xd as shown in the figure with respect to the center of the side, the processing range Δxa0 is shifted by xd to obtain the final processing range Δx0. Similarly, the processing ranges on the other three sides of the electronic component are obtained, respectively, and in the straight line detection step # 33 by the least square method of four sides shown in FIG. The point cloud data is linearly approximated by the least square method to obtain the inclinations of the four sides of the electronic component.
[0015]
Then, the inclination of the electronic component is obtained by averaging the inclinations of the four sides obtained in the electronic component inclination / center calculation step # 34 shown in FIG. 12, the center of the electronic component is calculated, and step # 35 shown in FIG. Thus, a series of electronic component mounting posture detection processing is completed.
[0016]
[Problems to be solved by the invention]
However, in the conventional electronic component mounting posture detection method, in the chip-type electronic component such as the ceramic capacitor 1 as shown in FIG. 2, the electrode portion 2 plated with solder or the like is rounded. The calculation result of the approximate straight line by the least square method in the portion 2 becomes inaccurate, and the center position and inclination of the electronic component cannot be obtained accurately. In addition, the method of obtaining the least square line for all four sides of the object has a drawback that the processing time becomes long.
[0017]
The present invention solves such a conventional problem, and even in an electronic component such as a ceramic capacitor in which a part of the electronic component is rounded, its center position and inclination are accurately detected, and the posture of the electronic component is determined. An object of the present invention is to provide a method for correcting the mounting posture of an electronic component that can be quickly detected and corrected.
[0018]
[Means for Solving the Problems]
In order to solve this problem, the present invention performs contour extraction of an electronic component by binarization processing, obtains a circumscribed rectangle of the electronic component on the processed image by contour tracking processing, and each of a pair of sides facing the circumscribed rectangle For the point cloud data on the contour line of the electronic component within the predetermined two processing ranges centered at the center point, a straight line approximation is performed by the least square method, and the average value of the inclinations of the straight lines is set as the approximate inclination of the electronic component. , Based on this approximate inclination, determine the processing range in a pair of sides facing the electronic component, perform a linear approximation by the least square method for the point cloud data on the contour line of the electronic component within each determined processing range, Approximate a pair of opposite sides of an electronic component with a straight line, obtain the average value of the inclinations of those straight lines as the inclination of the electronic component, The processing range is determined based on the inclination of the electronic component, and the center of gravity is detected for the point cloud data on the contour line of the electronic component within each determined processing range. Each straight line having an inclination is obtained as an approximate straight line of another pair of sides of the electronic component, and four intersection points with the approximate straight line of the pair of opposite sides of the electronic component which have already been obtained are obtained respectively, and the horizontal direction and In this method, a maximum value and a minimum value in the vertical direction are obtained, and an intermediate value between the maximum value and the minimum value in each direction is obtained as the center position of the electronic component. Thereby, the attitude of the electronic component can be detected at high speed and with high accuracy.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
According to the first aspect of the present invention, the contour of the electronic component is extracted by the binarization process, the circumscribed rectangle of the electronic component on the processed image is obtained by the contour tracking process, and the pair of sides of the circumscribed rectangle are opposed to each other. The point cloud data on the contour line of the electronic component within the predetermined two processing ranges centered on each midpoint is subjected to straight line approximation by the least square method, and the average value of the straight line inclination is calculated as the approximate inclination of the electronic component. Based on this approximate inclination, a processing range is determined for a pair of opposite sides of the electronic component, and a straight line approximation is performed on the dotted line data on the outline of the electronic component within each determined processing range by the least square method. Approximate a pair of opposite sides of an electronic component with a straight line, obtain the average value of the inclinations of those straight lines as the inclination of the electronic component, and then add an electronic component for the other pair of opposite sides The processing range is determined based on the inclination, the center of gravity is detected for the point cloud data on the contour line of the electronic component within each determined processing range, and the inclination perpendicular to the inclination of the electronic component is passed through the center of gravity. Each of the straight lines having the above is obtained as an approximate straight line of the other pair of sides of the electronic component, and four intersection points with the approximate straight line of the pair of opposite sides of the electronic component that have already been obtained are obtained, respectively. It is a method of obtaining the maximum and minimum values of the direction, and obtaining the intermediate value between the maximum and minimum values in each direction as the center position of the electronic component, and can detect the posture of the electronic component quickly and accurately it can.
[0020]
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a flowchart showing a processing procedure of an electronic component mounting posture correction method according to the embodiment, FIG. 2 is a perspective view of a ceramic capacitor, and FIGS. 3 to 10 are electronic component mounting posture correction methods according to the embodiment. It is a top view which shows the process screen for demonstrating each process of these. Since all steps for mounting the electronic component are the same as in the prior art, detailed description thereof is omitted, and only different portions are described in detail.
[0021]
First, in the contour extraction step # 1 of the electronic component shown in FIG. 1, the contour (hereinafter referred to as an electronic component) 3 of the component image on the processing screen is obtained by the binary contour tracking process as shown in FIG. In the contour circumscribed rectangle calculation step # 2 shown in FIG. 1, the circumscribed rectangle 4 of the electronic component 3 on the processing screen is obtained as shown in FIG. 3, and then in the contour circumscribed rectangle center calculation step # 3 shown in FIG. As shown in FIG. 1, the center of the circumscribed quadrangle 4 is obtained as M (xm, ym), and then, in the processing range calculation step # 4 at a pair of opposite sides of the electronic component 3 shown in FIG. 3, the processing ranges 5 (Δxt) and 6 (Δxb) represented by (Equation 1) with xm as the center are determined as shown in FIG.
[0022]
[Expression 1]
[0023]
When the processing ranges 5 (Δxt) and 6 (Δxb) are obtained as described above, detection of point cloud data on the contour line of the electronic component 3 in each processing range shown in FIG. , 6 to detect point cloud data on the contour line of the electronic component 3, and then, in step # 6 for calculating the approximate inclination of the electronic component by linear approximation of the point cloud data shown in FIG. Is applied to the contour of the electronic component 3 to obtain approximate approximation lines 7 and 8 of a pair of sides facing each other as shown in FIG. The average value θab of the straight line inclination is defined as the approximate inclination of the electronic component 3.
[0024]
When the approximate inclination θab of the component is obtained, the processing range calculation step # 7 for the pair of sides of the electronic component based on the approximate inclination shown in FIG. 1 is performed in the processing step # 7 of the pair of sides of the electronic component 3 as shown in FIG. Based on θab, the processing range is moved by wd (= wl / 2 · sin θab) so that the intersections MT and MB with the perpendicular line drawn from the center point M of the circumscribed square 4 to the approximate straight lines 7 and 8 are centered. The processing ranges 9 (Δxdt) and 10 (Δxdb) represented by (Equation 2) are determined.
[0025]
[Expression 2]
[0026]
When the processing ranges 9 (Δxdt) and 10 (Δxdb) are obtained as described above, in the detection process # 8 of the point cloud data on the contour line of the electronic component in each processing range shown in FIG. The point group data on the outline of the electronic component 3 included is detected, and then, in the approximate straight line calculation step # 9 of the pair of sides facing the electronic component by the linear approximation of the point cloud data shown in FIG. The least square method is applied to each of the group data to perform a linear approximation of the contour line of the electronic component 3, and as shown in FIG. 11 and 12 are obtained, and the average value S of the slopes of the respective straight lines is obtained.
[0027]
If the inclination of the electronic component 3 at this time is θ, the inclination θ of the electronic component 3 is expressed by (Equation 3), and the inclination θ of the electronic component 3 is obtained in the electronic component inclination calculation step # 10 shown in FIG.
[0028]
[Equation 3]
[0029]
When the inclination θ of the electronic component 3 is obtained, in the processing range calculation step # 11 of the other pair of sides based on the electronic component inclination shown in FIG. 1, another pair of the electronic component 3 facing each other as shown in FIG. And the intersection ML of the straight line 13 passing through the center point M of the circumscribed rectangle 4 and having the slope S (= tan −1 θ) and the end point of the electronic component 3 based on the inclination θ of the electronic component 3. As shown in FIG. 7, the length of the other pair of opposite sides of the electronic component that is set in advance is set to wl so that MR moves to the middle point by 1d (= pl / 2 · sin θ) ( The processing ranges 14 (Δyl) and 15 (Δyr) represented by Equation 4) are determined.
[0030]
[Expression 4]
[0031]
When the processing ranges 14 (Δyl) and 15 (Δyr) are obtained as described above, these processing ranges 14 and 15 are detected in step # 12 of detecting point cloud data on the contour line of the electronic component in each processing range shown in FIG. Point group data on the contour line of the electronic component included in FIG. 1, and the center of gravity GL and GR in each processing range are calculated in step # 13 of the center of gravity of the point group data on the contour line of the electronic component in each processing range shown in FIG. For each.
[0032]
FIG. 8 is an enlarged view of an image of the processing range 14 and the electronic component 3 on the processing in the vicinity thereof. The square cells in the drawing represent point data, that is, pixels, and are included in the processing range 14. The center of gravity GL of the point cloud data 18 on the contour line 3 is detected. The same applies to the determination of the processing range center of gravity GR in the processing range 15.
[0033]
Next, in the calculation step # 14 of the approximate straight line of another pair of opposite sides shown in FIG. 1, as shown in FIG. 9, the inclination θ of the electronic component 3 passes through the centroids GL and GR expressed by (Equation 5). The straight lines 16 and 17 having a slope perpendicular to are obtained.
[0034]
[Equation 5]
[0035]
Next, in the approximate straight line calculation step # 15 of the calculated four sides of the electronic component shown in FIG. 1, respective intersections are obtained for the four straight lines already obtained as shown in FIG. 10, and Ca (xa, ya) is obtained. , Cb (xb, yb), Cc (xc, yc), Cd (xd, yd), the maximum value of the X coordinate is Xmax, the minimum value is Xmin, the maximum value of the Y coordinate is Ymax, and the minimum value is Ymin. In the electronic component center calculation step # 16 shown in FIG. 1, the coordinates P (xp, yp) expressed by (Equation 6) are obtained as the electronic component center as shown in FIG.
[0036]
[Formula 6]
[0037]
The electronic component 3 whose mounting posture has been detected in this way is mounted on the substrate after the mounting posture is corrected based on the detection result, and a series of processing ends in the process of # 17 in FIG.
[0038]
As described above, in the electronic component mounting posture correction method of the present invention, first, the approximate inclination θab of the attracted electronic component 3 is obtained, and a pair of electronic components 3 as shown in FIG. 5 is obtained based on the approximate inclination θab. The processing ranges 9 (Δxdt) and 10 (Δxdb) in the sides of the electronic component 3 are determined, and the point group data on the contour line of the electronic component 3 in the processing ranges 9 (Δxdt) and 10 (Δxdb) is linearly approximated by the least square method. Then, each straight line is obtained as an approximate straight line of a pair of opposite sides of the electronic component 3, and an average value of inclinations of the two straight lines is detected as the inclination θ of the electronic component 3, and FIG. The processing ranges 14 (Δyl) and 15 (Δyr) in the other pair of sides of the electronic component 3 as shown are determined, and the point group on the contour line of the electronic components in the processing ranges 14 (Δyl) and 15 (Δyr) is determined. Data The center of gravity in each processing range is obtained, and a straight line having an inclination perpendicular to the electronic component inclination θ is calculated through these centroids, and the midpoint of the intersection of the obtained four straight lines is obtained as the electronic component center. Therefore, even in an electronic component in which a part of the electronic component such as the electrode portion 2 plated with solder or the like of the electronic component is round like the ceramic capacitor 1 shown in FIG. be able to.
[0039]
In addition, since the straight line detection by the least square method, which increases the amount of calculation, is made only to two straight lines on a pair of opposite sides of the electronic component 3, the amount of calculation can be reduced and the processing time can be shortened. The posture of the component 3 can be detected at high speed and with high accuracy.
[0040]
【The invention's effect】
As described above, according to the present invention, even when the electronic component is partially rounded, such as a ceramic capacitor, the posture can be detected at high speed and with high accuracy, and the mounting posture can be corrected correctly. Is obtained.
[Brief description of the drawings]
FIG. 1 is a flowchart showing a processing procedure of a method for correcting an attached electronic component mounting posture according to an embodiment of the present invention. FIG. 2 is a perspective view showing a shape of a ceramic capacitor. FIG. 4 is a plan view showing a processing screen for explaining steps # 3 and # 4. FIG. 4 is a plan view showing a processing screen for explaining steps # 5 and # 6 in FIG. FIG. 6 is a plan view showing a processing screen for explaining the step # 7. FIG. 6 is a plan view showing processing screens for explaining the steps # 8, # 9, and # 10 in FIG. FIG. 8 is a plan view showing a processing screen for explaining the steps # 11 and FIG. 8. FIG. 8 is a plan view showing a processing screen for explaining the steps # 12 and # 13 in FIG. 1. FIG. FIG. 10 is a plan view showing a processing screen for explaining the steps. FIG. 10 is a diagram for explaining the steps # 15 and # 16 in FIG. Fig. 11 is a plan view showing a screen. Fig. 11 is a flowchart showing all steps from electronic component suction to mounting in an electronic component mounting apparatus. Fig. 12 is a flowchart showing a processing procedure of a conventional electronic component attitude detection method. FIG. 14 is a plan view showing a processing screen for explaining steps # 24, # 25, and # 26 in FIG. 12. FIG. 14 is a diagram for explaining steps # 27, # 28, # 29, # 30, and # 31 in FIG. FIG. 15 is a plan view showing a processing screen for explaining the steps # 32, # 33, and # 34 in FIG.
DESCRIPTION OF SYMBOLS 1 Ceramic capacitor 2 Electrode part 3 The outline of the electronic component image on the processing screen of a ceramic capacitor (electronic component)
4 Outline circumscribed rectangle 5 of the same electronic component image (Δxt) Electronic component approximate tilt detection processing range 6 (Δxb) Electronic component approximate tilt detection processing range 7 Approximate approximation of one side of a pair of opposing sides of the electronic component Straight line 8 Approximate approximate line 9 (Δxdt) of the other side of the pair of sides facing the electronic component Electronic component tilt detection processing range 10 (Δxdb) Electronic component tilt detection processing range 11 A pair of facing electronic components Approximate line 12 of one side in the side 12 Approximate line 13 of the other side of the pair of sides facing the electronic component 13 A straight line passing through the center of the circumscribed rectangle of the contour of the electronic component image and having an inclination equal to the inclination of the electronic component 14 (Δyl) The center-of-gravity detection processing range 15 (Δyr) of the point cloud data on the contour of the electronic component on one side of the other pair of electronic components. Center-of-gravity detection processing range 16 of point cloud data on the contour line of the electronic component on the other side of the other pair of sides. Point group on the contour line of the electronic component on the side of the other pair of electronic components. A straight line 17 that passes through the center of gravity of the data and has an inclination perpendicular to the inclination of the electronic component. The electronic component passes through the center of gravity of the point cloud data on the outline of the electronic component on the other side of the other pair of electronic components. A straight line 18 having an inclination perpendicular to the inclination of the point 18 is point cloud data M on the contour of the electronic component on the processed image. Pl is the center of the circumscribed rectangle of the contour of the electronic component image. wl The length of another pair of opposite sides of the electronic component that is set in advance θab The approximate inclination of the electronic component θ The inclination of the electronic component MMT The perpendicular line drawn from the MMT to the approximate straight line 7 and the approximate straight line 7 BM Intersection of perpendicular line drawn from M to approximate straight line 8 and approximate straight line wd Movement distance ML of processing range on a pair of sides facing the electronic component MR Intersection MR of straight line 12 and one end point of electronic component Straight line 12 and electronic component Intersection point 1d with another other end point of the electronic component The movement distance GL of the processing range at another pair of opposite sides of the electronic component A point on the contour line of the electronic component at one processing range at the other pair of opposite sides of the electronic component The center of gravity GR of the group data The center of gravity Ca (xa, ya) of the point group data on the contour of the electronic component in another processing range at another pair of opposite sides of the electronic component. Intersection Cb (xb, yb) calculated intersection Cc (xc, yc) of the approximate lines 11 and 17 calculated intersection Cd (xd, yd) of the approximate lines 12 and 17 calculated Intersection point P (xp, yp) of approximate lines 12 and 16 Calculated center of electronic component
