JP3799674B2

JP3799674B2 - Optical measuring machine

Info

Publication number: JP3799674B2
Application number: JP22200696A
Authority: JP
Inventors: 房生清水
Original assignee: Nikon Corp
Current assignee: Nikon Corp
Priority date: 1996-08-23
Filing date: 1996-08-23
Publication date: 2006-07-19
Anticipated expiration: 2016-08-23
Also published as: JPH1062141A

Description

【０００１】
【発明の属する技術分野】
本発明は、光電的手段を用いて被検物の端面位置を検出する光学測定機に関する。
【０００２】
【従来の技術】
光電的手段を用いて検出した被検物の端面位置に基づいて所望の寸法や形状を測定する装置に、画像処理測定機がある。測定範囲の広い画像処理測定機では、その構造としてブリッジ・ブリッジ固定形が採用される。ブリッジ・ブリッジ固定形の画像処理測定機は、テレビカメラを備える光学観察部がＸ軸方向に移動自在に設けられ、前記光学観察部の光軸に垂直な面内で前記Ｘ軸に直交するＹ軸方向に移動自在なステージ上に載置された被検物の拡大画像をテレビカメラで捉える。前記テレビカメラで捉えた画像を画像処理装置で処理して被検物の端面位置を検出し、前記検出した位置の情報に基づいて、被検物の所望の寸法や形状を求めている。
【０００３】
また、前記画像処理測定機は、ステージが設置されたベース部に光学観察部の光軸に交差してＸ軸方向に延在する線状光源、例えば蛍光灯を有する透過照明装置を備え、被検物を透過照明する。更に、前記画像処理測定機は、前記光学観察部に、例えばＬＥＤやハロゲンランプなどの反射照明装置を備え被検物を上方から反射照明する。
【０００４】
【発明が解決しようとする課題】
この様な画像処理測定機によって、繰り返し性良く・再現性良く被検物の端面を検出して高精度で測定するためには、照明装置による照明光量が時間や場所などによって変化しないことが必要である。しかし、照明装置の光源からの光量は、経時変化する。更に、線状光源からの光量は長手方向の位置によっても変化する。この為、従来は作業開始前毎に作業者が照度計などを用いて照明装置から観察光学部に入射する光量を計測し、照明装置の制御装置を調整して光量の経時変化の影響を除去していた。
【０００５】
しかしながら、この方法では線状光源の場所による光量の違いは除去されず、被検物がステージ上に載置される場所によって測定値が異なるという問題点があった。
本発明は、照明光源の場所による照明光量の違いの測定値への影響を除去し、安定した測定結果を得る光学測定機を提供することにある。
【０００６】
【課題を解決するための手段】
請求項１に記載の発明は、被検物を載置するステージ（１）の載物面に垂直な光軸を有し、前記光軸に垂直な面内で前記ステージに対して、互いに直角な２方向の少なくとも一方向に相対移動自在な測定ヘッド（７）と、前記測定ヘッドに備えられ、前記測定ヘッドが捉えた光を光電変換する光電変換手段（６）と、前記載物面に対して前記測定ヘッドと反対側に前記測定ヘッドの相対移動方向に延在して設置された透過照明装置（８）と、前記測定ヘッドの相対移動を制御すると共に、前記測定ヘッドの相対位置を表す座標値を求める装置コントローラ（１４）と、前記光電変換手段からの信号に基づいて前記被検物の端面を検出する端面検出手段（１２）と、前記透過照明装置からの光量を制御する照明装置コントローラ（１５）と、前記装置コントローラ、端面検出手段及び照明装置コントローラを制御する主制御装置（１３）を有する光学測定機において、前記透過照明装置は、線状光源または面状光源（８）であり、前記主制御装置は、前記光電変換手段が検出した受光量に基づく情報を前記座標値に関連付けて記憶すると共に、前記記憶した情報に基づいて前記照明装置コントローラを制御して測定を行うことを特徴とする。
【０００７】
請求項２に記載の発明は、被検物を載置するステージ（１）の載物面に垂直な光軸を有し、前記光軸に垂直な面内で前記ステージに対して、互いに直角な２方向の少なくとも一方向に相対移動自在な測定ヘッド（７）と、前記測定ヘッドに備えられ、前記測定ヘッドが捉えた光を光電変換する光電変換手段（６）と、前記載物面に対して前記測定ヘッドと反対側に前記測定ヘッドの相対移動方向に延在して設置された透過照明装置（８）と、前記測定ヘッドの相対移動を制御すると共に、前記測定ヘッドの相対位置を表す座標値を求める装置コントローラ（１４）と、前記光電変換手段からの信号に基づいて前記被検物の端面を検出する端面検出手段（１２）と、前記装置コントローラ、及び端面検出手段を制御する主制御装置（１３）を有する光学測定機において、前記透過照明装置は、線状光源または面状光源（８）であり、前記主制御装置は、前記光電変換手段が検出した受光量に基づく情報を前記座標値に関連付けて記憶すると共に、前記記憶した情報に基づいて前記光電変換手段の感度を制御して測定を行うことを特徴とする。
【０００８】
請求項３に記載の発明は、被検物を載置するステージ（１）の載物面に垂直な光軸を有し、前記前記光軸に垂直な面内で前記ステージに対して、互いに直角な２方向の少なくとも一方向に相対移動自在な測定ヘッド（７）と、前記測定ヘッドに備えられ、前記測定ヘッドが捉えた光を光電変換する光電変換手段（６）と、前記載物面に対して前記測定ヘッドと反対側に前記測定ヘッドの相対移動方向に延在して設置された透過照明装置（２８）と、前記測定ヘッドの相対移動を制御すると共に、前記測定ヘッドの相対位置を表す座標値を求める装置コントローラ（１４）と、前記光電変換手段からの信号に基づいて前記被検物の端面を検出する端面検出手段（１２）と、前記透過照明装置からの光量を制御する照明装置コントローラ（２５）と、前記装置コントローラ、端面検出手段及び照明装置コントローラを制御する主制御装置（１３）を有する光学測定機において、前記透過照明装置は、線状光源または面状光源（８）であり、前記測定ヘッドに斜設され、前記測定ヘッドが受けた光の一部を反射する半透過鏡（３１）と、前記反射された光の光量を検出する光電センサ（３０）とを更に設けて、前記主制御装置は、前記光電センサが検出した受光量に基づく情報を前記座標値に関連付けて記憶すると共に、前記記憶した情報に基づいて前記照明装置コントローラを制御して測定を行うことを特徴とする。
【０００９】
請求項４に記載の発明は、被検物を載置するステージ（１）の載物面に垂直な光軸を有し、前記光軸に垂直な面内で前記ステージに対して、互いに直角な２方向の少なくとも一方向に相対移動自在な測定ヘッド（７）と、前記測定ヘッドに備えられ、前記測定ヘッドが捉えた光を光電変換する光電変換手段（６）と、前記載物面に対して前記測定ヘッドと反対側に前記測定ヘッドの相対移動方向に延在して設置された透過照明装置（２８）と、前記測定ヘッドの相対移動を制御すると共に、前記測定ヘッドの相対位置を表す座標値を求める装置コントローラ（１４）と、前記光電変換手段からの信号に基づいて前記被検物の端面を検出する端面検出手段（１２）と、前記装置コントローラ、及び端面検出手段を制御する主制御装置（１３）を有する光学測定機において、前記透過照明装置は、線状光源または面状光源（８）であり、前記測定ヘッドに斜設され、前記測定ヘッドが受けた光の一部を反射する半透過鏡（３１）と、前記反射された光の光量を検出する光電センサ（３０）とを更に設けて、前記主制御装置は、前記光電センサが検出した受光量に基づく情報を前記座標値に関連付けて記憶すると共に、前記記憶した情報に基づいて前記光電変換手段の感度を制御して測定を行うことを特徴とする。
【００１０】
【発明の実施の形態】
図１は、本発明装置の第１の実施形態を説明する斜視図である。図１において、不図示の被検物を載せたステージ１がベース２にＹ軸方向に延在して固設されたガイド部材３、３’に案内されてＹ軸方向に移動自在に設けられている。ベース２のＹ軸方向の中央部には、図１に示したＸ軸方向に延在しステージ１を跨いで固設されて、キャリッジ４をＸ軸方向に移動自在に案内するブリッジ５が設けられている。キャリッジ４には、ステージ１の上面に垂直な光軸を有する結像レンズ群とテレビカメラ６とからなる測定ヘッド７と、測定ヘッド７をその光軸方向、即ち図１に示すＺ軸方向に移動させてテレビカメラ６の撮像面に被検物の像を結像させる上下動部及びその駆動部９とが設けられている。
【００１１】
また、ステージ１を支持するベース２には、測定ヘッド７の光軸の軌跡と一致してＸ軸方向に延在する線状光源、例えば蛍光灯を光源とする透過照明装置８が設けられ、該透過照明装置８からの光は、ステージ１のステージガラス１Ａを通して被検物を下方から透過照明する。一方、測定ヘッド７には、被検物を上方から照明する、例えばハロゲンランプを光源とする反射照明装置（不図示）が設けられている。ステージ１及びキャリッジ４には、夫々ステージ１及びキャリッジ４を移動させる駆動部１０、１１と夫々の移動量を検出する測長部（不図示）とが設けられている。
【００１２】
テレビカメラ６で捉えた画像の信号は画像処理装置１２に送られ、所定の画像処理を行って所定の被検物の端面位置の座標値を求める。それらの求めた座標値に基づいてホストコンピュータ１３で演算処理することにより、被検物の所望の寸法や形状を算出する。
１４は、ステージ１、キャリッジ４及び測定ヘッド７を駆動する駆動部１０、１１、９を制御すると共に、前記各部の測長部からの信号を受けて測定ヘッド７のＸ、Ｙ座標値を求める装置コントローラである。１５は、透過照明装置８及び反射照明装置の点滅及び光量を制御する照明装置コントローラである。装置コントローラ１４及び照明装置コントローラ１５は、何れもホストコンピュータ１３の指令によって制御される。
【００１３】
かような構成の画像処理測定機による測定は、測定に先立って以下の光量校正を行う。画像処理装置１２はテレビカメラ６の受光面全面で受光した総受光量、または所定の一部の受光面で受光したスポット受光量を検出し、その値をホストコンピュータ１３に送出する。ホストコンピュータ１３は、画像処理装置１２から受けた前記受光量をその時の測定ヘッド７の座標値と共に記憶する。ホストコンピュータ１３は、測定ヘッド７の各座標位置における前記受光量の平均値と前記平均値からの偏差を算出し、前記座標値と共に記憶する。
【００１４】
測定に当たって、ホストコンピュータ１３は、更に前記記憶した座標値と、平均受光量及び偏差とを参照して、照明装置８の光源が所定の場所で所定の光量を発光するように照明装置コントローラ１５を制御する。前記受光量の平均値及び偏差は、測定作業開始時又は装置の保守整備時など所定の時に求める。
この様にして、テレビカメラ６が受光する光量が一定になるように照明装置コントローラ１５を制御することによって、常に一定の照明条件が得られるので安定した測定が可能となる。線状光源には第３の実施形態で詳述する光ファイバを用いたものもあるが、最も簡便な線状光源である蛍光灯は場所による光量変化が大きいのでその効果が大きい。
【００１５】
前記説明を、光量校正の手順を示す図２、及び測定の手順を示す図３のフローチャートによって説明する。全ての動作はホストコンピュータ１３の指令によって行われる。
ステージ１上に何も載置しない状態でホストコンピュータ１３が光量校正を指令すると、図２のフローに従う光量校正が開始され、まず各部が初期設定される（ステップ１）。次いで、測定ヘッド７をＸ軸の一端に移動する（ステップ２）。そして、テレビカメラ６が受光した光量を検出してその光量値をホストコンピュータ１３に送出する（ステップ３）。ホストコンピュータ１３は受けた光量値と予め設定した所定値とを比較し（ステップ４）、前記受光量が前記所定値以下であれば、照明装置の光源の寿命と判断して作業を中断してホストコンピュータ１３に警告表示すると共に、警告音を発して（ステップ５）、光量校正を終了する。
【００１６】
ステップ４で前記受光量が前記所定値以上であれば、ホストコンピュータ１３は受けた光量値をその時の測定ヘッド７の座標値と共に内部の記憶装置に記憶する（ステップ６）。次いで、測定ヘッド７は所定量だけＸ軸上を移動し（ステップ７）、測定ヘッド７の位置が測定範囲内にあるか否かを判断する（ステップ８）。測定範囲内にあればステップ３に戻りステップ３〜ステップ８を繰り返す。その結果、測定ヘッド７のＸ軸座標値と受光量との関係を表すマップが前記憶装置に記憶される。ステップ８で測定範囲外と判断されれば、ステップ９に進み、前記マップに基づいて受光量の平均値と前記平均値からの偏差を求め、前記平均値と、測定ヘッド７のＸ軸座標値と前記偏差との関係を表す光量校正表を前記記憶装置に記憶して（ステップ９）、光量校正を終了する。
【００１７】
ステージ１上に被検物を載置してホストコンピュータ１３から測定を指令すると、図３のフローに従う測定がスタートする。そして、測定装置各部を測定が行える状態に初期設定する。この時、照明装置コントローラ１５への指令値として前記受光量の平均値が設定される（ステップ１１）。次いで、測定ヘッド７及びステージ１を所定の位置に移動し被検物の測定箇所をテレビカメラ６で捉える（ステップ１２）。そして、測定ヘッド７のＸ軸座標値を装置コントローラ１４から読み込み（ステップ１３）、前記光量校正表を参照して、測定ヘッド７の現在のＸ軸座標値に対応する偏差を補正した指令値を与えて照明装置コントローラ１５を制御する（ステップ１４）。そして、ホストコンピュータ１３からの指示に従って測定動作を行い（ステップ１５）、次いで全ての測定が終了したか否かを判断する（ステップ１６）。全ての測定が終了していなければ、ステップ１２に戻り測定ヘッド７及びステージ１を次の所定の位置に移動する。ステップ１６で、全ての測定が終了していれば測定を終了する。
【００１８】
なお、ステップ１４とステップ１５との間に、図４に示したようなテレビカメラ６が受けた光量を検出して前記平均受光量と比較し、一致又は所定の範囲内でなければ一致又は所定の範囲内なるように更に照明装置コントローラへの指令値を変更するステップ１４Ａ及びステップ１４Ｂを加えても良い。これにより、受光量の経時変化の影響も除くことができる。この場合、平均受光量に代えて、経時変化、位置によるばらつきを考慮して定めた所定の値としても良い。
【００１９】
次に、前記第１の実施形態の一部を変更した第２の実施形態を説明する。第２の実施形態の装置においては、画像処理装置１２にホストコンピュータ１３の指令によってテレビカメラ６の感度を変化させる感度調整部を更に設け、第１の実施形態における照明装置コントローラ１５の制御に代えて前記感度調整部を制御する。測定ヘッド７の位置による照明装置８から光量の変化に基づくテレビカメラ６の受光量の変化をテレビカメラ６の感度を変化させることによって、前記受光量の変化によるテレビカメラ６の出力信号の変化を除くことができる。
【００２０】
図３は、第３の実施形態の画像処理測定機の要部断面図である。以下に説明する構成以外の部分は第１の実施形態の装置と同様である。図３において、透過照明装置２８の、端面を測定ヘッド７に向けてライン状に並べられた光ファイバ２９の他方の端面は、例えばハロゲンランプ等の光源を有する照明装置コントローラ２５に結合され、線状光源を構成している。前記照明装置コントローラ２５はホストコンピュータ１３からの指令によってハロゲンランプが発する光量を変化させる。
【００２１】
測定ヘッド７の結像光学系３２の一部には半透過鏡３１が斜設され、透過照明装置２８からの光の一部を受光量を検出する光電センサ３０に導く。光電センサ３０で検出された受光量はホストコンピュータ１３に入力され、第１の実施形態におけるテレビカメラ７で検出された受光量と同様に測定ヘッド６のＸ軸座標値と共にホストコンピュータ１３の記憶装置に記憶される。
【００２２】
本第３の実施形態の装置では、第１の実施形態の装置におけるテレビカメラ６が検出した受光量に代えて光電センサ３０が検出した受光量が用いられる他は、第１の実施形態の装置と同様に動作する。
更に、第３の実施形態の装置において、画像処理装置１２にホストコンピュータ１３の指令によってテレビカメラ６の感度を変化させる感度調整部を更に設け、第３の実施形態における照明装置コントローラ２５の制御に代えて前記感度調整部を制御する第４の実施形態とすることもできる。
【００２３】
以上の説明では被検物の端面位置を検出する装置として画像処理装置を用いているが、これに限定されるものではなく、ラインセンサや、光電変換素子を被検物像の端部がよぎるときの前記光電変換素子の出力信号の変化に基づいて被検物の端面を検出する装置などを用いても良い。
また、照明装置としてＸ軸方向に延在する一つの線状光源を用いる例を説明したが、Ｘ、Ｙの２軸方向に延在する面光源を用いて、Ｘ、Ｙ座標値と受光量とを関連づけて記憶し、これに基づいて照明装置コントローラ、又はテレビカメラ、ラインセンサ、光電変換素子などの感度を制御しても良い。
【００２４】
【発明の効果】
請求項１〜４の何れに記載の発明も、線状光源の場所による照明光量の違いの測定値への影響を除去し、安定した測定結果が得られる光学測定機を実現する。
【図面の簡単な説明】
【図１】本発明の第１の実施形態を説明する斜視図である。
【図２】図１の装置による光量校正の手順を示すのフローチャートである。
【図３】図１の装置による測定の手順を示すのフローチャートである。
【図４】図３のフローチャートに追加するフローをしめすフローチャートである。
【図５】本発明の第２の実施形態の要部の断面図である。
【符号の説明】
１……ステージ
６……テレビカメラ（光電変換手段）
７……測定ヘッド
８……透過照明装置
１２……画像処理装置（端面検出手段）
１３……ホストコンピュータ（主制御装置）
１４……装置コントローラ
１５……照明装置コントローラ
２５……照明装置コントローラ
２８……透過照明装置
２９……光ファイバ
３０……光電センサ
３１……半透過鏡[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical measuring machine that detects an end face position of a test object using photoelectric means.
[0002]
[Prior art]
There is an image processing measuring instrument as an apparatus for measuring a desired dimension and shape based on the end face position of a test object detected using a photoelectric means. An image processing measuring instrument having a wide measuring range employs a bridge / bridge fixed type as its structure. In the bridge / bridge fixed image processing measuring machine, an optical observation unit including a television camera is provided movably in the X-axis direction, and Y is orthogonal to the X-axis in a plane perpendicular to the optical axis of the optical observation unit. A TV camera captures an enlarged image of the test object placed on a stage that is movable in the axial direction. An image captured by the television camera is processed by an image processing device to detect the end face position of the test object, and a desired size and shape of the test object are obtained based on the detected position information.
[0003]
In addition, the image processing measuring machine includes a transmission illumination device having a linear light source, for example, a fluorescent lamp, extending in the X-axis direction so as to intersect the optical axis of the optical observation unit at the base portion where the stage is installed. The specimen is transmitted through. Furthermore, the image processing measuring machine includes a reflection illumination device such as an LED or a halogen lamp in the optical observation unit, and reflects and illuminates the object to be examined from above.
[0004]
[Problems to be solved by the invention]
In order to detect the end face of the test object with high repeatability and reproducibility with such an image processing measuring instrument, it is necessary that the amount of light emitted by the illumination device does not change depending on the time or place. It is. However, the amount of light from the light source of the lighting device changes with time. Furthermore, the amount of light from the linear light source also varies depending on the position in the longitudinal direction. For this reason, conventionally, before starting work, the operator measures the amount of light incident on the observation optical unit from the illumination device using an illuminometer, etc., and adjusts the control device of the illumination device to eliminate the effects of changes in the amount of light over time. Was.
[0005]
However, this method has a problem that the difference in the amount of light depending on the location of the linear light source is not removed, and the measurement value varies depending on the location where the test object is placed on the stage.
An object of the present invention is to provide an optical measuring machine that eliminates the influence of the difference in the amount of illumination light on the measurement value depending on the location of the illumination light source and obtains a stable measurement result.
[0006]
[Means for Solving the Problems]
The invention according to claim 1 has an optical axis perpendicular to the surface of the stage (1) on which the test object is placed, and is perpendicular to the stage within the plane perpendicular to the optical axis. A measurement head (7) that is relatively movable in at least one of two directions, a photoelectric conversion means (6) that is provided in the measurement head and photoelectrically converts light captured by the measurement head, On the other hand, the transmitted illumination device (8) installed on the opposite side of the measurement head in the direction of relative movement of the measurement head, and the relative movement of the measurement head are controlled, and the relative position of the measurement head is set. An apparatus controller (14) for obtaining a coordinate value to be expressed; an end face detection means (12) for detecting an end face of the test object based on a signal from the photoelectric conversion means; and an illumination for controlling the amount of light from the transmission illumination device. Device controller (15) and front Device controller, in the optical measuring machine having a main controller (13) for controlling the end face detection device and a lighting device controller, the transmitted illumination device is a linear light source or a planar light source (8), the main control unit The information based on the amount of received light detected by the photoelectric conversion means is stored in association with the coordinate value, and the illumination device controller is controlled based on the stored information to perform measurement.
[0007]
The invention according to claim 2 has an optical axis perpendicular to the surface of the stage (1) on which the test object is placed, and is perpendicular to the stage within the plane perpendicular to the optical axis. A measurement head (7) that is relatively movable in at least one of two directions, a photoelectric conversion means (6) that is provided in the measurement head and photoelectrically converts light captured by the measurement head, On the other hand, the transmitted illumination device (8) installed on the opposite side of the measurement head in the direction of relative movement of the measurement head, and the relative movement of the measurement head are controlled, and the relative position of the measurement head is set. An apparatus controller (14) for obtaining a coordinate value to be expressed, an end face detection means (12) for detecting an end face of the test object based on a signal from the photoelectric conversion means, the apparatus controller, and the end face detection means are controlled. Has main controller (13) In that optical measuring machine, the transmitted illumination device is a linear light source or a planar light source (8), the main control unit associates the information based on the received light amount of the photoelectric conversion means detects the coordinate values The measurement is performed while the sensitivity of the photoelectric conversion means is controlled based on the stored information.
[0008]
The invention described in claim 3 has an optical axis perpendicular to the surface of the stage (1) on which the object to be tested is placed, and is mutually relative to the stage within the plane perpendicular to the optical axis. A measuring head (7) that is relatively movable in at least one of two directions perpendicular to each other; a photoelectric conversion means (6) that is provided in the measuring head and photoelectrically converts light captured by the measuring head; A transmission illumination device (28) installed on the opposite side of the measurement head in the relative movement direction of the measurement head, and controls the relative movement of the measurement head and the relative position of the measurement head A device controller (14) for obtaining a coordinate value representing the angle, an end face detection means (12) for detecting an end face of the test object based on a signal from the photoelectric conversion means, and a light amount from the transmission illumination device. Lighting device controller (25) The device controller, in the optical measuring machine having a main controller (13) for controlling the end face detection device and a lighting device controller, the transmitted illumination device is a linear light source or a planar light source (8), the measuring head The main control is further provided with a semi-transparent mirror (31) that is obliquely mounted to reflect a part of the light received by the measuring head and a photoelectric sensor (30) that detects the amount of the reflected light. The apparatus stores information based on the amount of received light detected by the photoelectric sensor in association with the coordinate value, and performs measurement by controlling the illumination device controller based on the stored information.
[0009]
The invention according to claim 4 has an optical axis perpendicular to the surface of the stage (1) on which the test object is placed, and is perpendicular to the stage within the plane perpendicular to the optical axis. A measurement head (7) that is relatively movable in at least one of two directions, a photoelectric conversion means (6) that is provided in the measurement head and photoelectrically converts light captured by the measurement head, In contrast, a transmission illumination device (28) installed on the opposite side of the measurement head in the direction of relative movement of the measurement head, controls the relative movement of the measurement head, and sets the relative position of the measurement head. An apparatus controller (14) for obtaining a coordinate value to be expressed, an end face detection means (12) for detecting an end face of the test object based on a signal from the photoelectric conversion means, the apparatus controller, and the end face detection means are controlled. Main controller (13) In the optical measuring instrument for the transmitted illumination device is a linear light source or a planar light source (8), said obliquely provided in the measuring head, semitransparent mirror for reflecting part of the light which the measuring head is received ( 31) and a photoelectric sensor (30) for detecting the amount of the reflected light, and the main controller stores information based on the amount of received light detected by the photoelectric sensor in association with the coordinate value. In addition, the measurement is performed by controlling the sensitivity of the photoelectric conversion means based on the stored information.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a perspective view for explaining a first embodiment of the apparatus of the present invention. In FIG. 1, a stage 1 on which a test object (not shown) is placed is guided by guide members 3 and 3 'fixed to the base 2 so as to extend in the Y-axis direction, and is movably provided in the Y-axis direction. ing. At the center of the base 2 in the Y-axis direction, there is provided a bridge 5 that extends in the X-axis direction shown in FIG. 1 and is fixed over the stage 1 to guide the carriage 4 so as to be movable in the X-axis direction. It has been. The carriage 4 has a measuring head 7 composed of an imaging lens group having an optical axis perpendicular to the upper surface of the stage 1 and a television camera 6, and the measuring head 7 in the optical axis direction, that is, the Z-axis direction shown in FIG. An up-and-down moving unit that moves and forms an image of the test object on the imaging surface of the television camera 6 and its driving unit 9 are provided.
[0011]
The base 2 that supports the stage 1 is provided with a transmission illumination device 8 that uses a linear light source, for example, a fluorescent lamp, as a light source that extends in the X-axis direction in line with the trajectory of the optical axis of the measuring head 7. The light from the transmission illumination device 8 transmits and illuminates the test object from below through the stage glass 1A of the stage 1. On the other hand, the measuring head 7 is provided with a reflection illumination device (not shown) that illuminates the test object from above, for example, using a halogen lamp as a light source. The stage 1 and the carriage 4 are provided with drive units 10 and 11 for moving the stage 1 and the carriage 4, respectively, and a length measuring unit (not shown) for detecting the amount of movement of each.
[0012]
An image signal captured by the television camera 6 is sent to the image processing device 12, and predetermined image processing is performed to obtain a coordinate value of the end face position of a predetermined test object. Based on the obtained coordinate values, the host computer 13 performs arithmetic processing to calculate desired dimensions and shapes of the test object.
14 controls the drive units 10, 11, and 9 that drive the stage 1, the carriage 4, and the measurement head 7, and obtains X and Y coordinate values of the measurement head 7 by receiving signals from the length measuring units of the respective units. It is a device controller. Reference numeral 15 denotes an illuminating device controller that controls blinking and light quantity of the transmission illuminating device 8 and the reflective illuminating device. Both the device controller 14 and the lighting device controller 15 are controlled by commands from the host computer 13.
[0013]
In the measurement by the image processing measuring machine having such a configuration, the following light quantity calibration is performed prior to the measurement. The image processing device 12 detects the total amount of received light received on the entire light receiving surface of the television camera 6 or the spot received light received on a predetermined part of the light receiving surface, and sends the value to the host computer 13. The host computer 13 stores the received light amount received from the image processing device 12 together with the coordinate value of the measuring head 7 at that time. The host computer 13 calculates an average value of the received light amount at each coordinate position of the measuring head 7 and a deviation from the average value, and stores them together with the coordinate value.
[0014]
In the measurement, the host computer 13 further refers to the stored coordinate value, the average received light amount, and the deviation so that the light source of the illumination device 8 emits a predetermined amount of light at a predetermined location. Control. The average value and deviation of the amount of received light are obtained at a predetermined time such as at the start of measurement work or during maintenance of the apparatus.
In this way, by controlling the illumination device controller 15 so that the amount of light received by the television camera 6 is constant, a constant illumination condition is always obtained, so that stable measurement is possible. Some linear light sources use an optical fiber that will be described in detail in the third embodiment, but fluorescent lamps, which are the simplest linear light sources, have a great effect because the amount of light varies greatly depending on the location.
[0015]
The above explanation will be described with reference to the flowchart of FIG. 2 showing the procedure of light quantity calibration and FIG. 3 showing the procedure of measurement. All operations are performed by commands from the host computer 13.
When the host computer 13 commands light quantity calibration in a state where nothing is placed on the stage 1, light quantity calibration according to the flow of FIG. 2 is started, and each unit is initially set (step 1). Next, the measuring head 7 is moved to one end of the X axis (step 2). Then, the amount of light received by the television camera 6 is detected and the amount of light is sent to the host computer 13 (step 3). The host computer 13 compares the received light quantity value with a predetermined value set in advance (step 4), and if the received light amount is equal to or less than the predetermined value, the host computer 13 determines that the life of the light source of the lighting device is interrupted and stops the operation. A warning is displayed on the host computer 13 and a warning sound is emitted (step 5), and the light quantity calibration is terminated.
[0016]
If the amount of received light is greater than or equal to the predetermined value in step 4, the host computer 13 stores the received light quantity value in the internal storage device together with the coordinate value of the measurement head 7 at that time (step 6). Next, the measurement head 7 moves on the X axis by a predetermined amount (step 7), and determines whether or not the position of the measurement head 7 is within the measurement range (step 8). If it is within the measurement range, return to Step 3 and repeat Step 3 to Step 8. As a result, a map representing the relationship between the X-axis coordinate value of the measuring head 7 and the amount of received light is stored in the previous storage device. If it is determined in step 8 that it is outside the measurement range, the process proceeds to step 9 where the average value of received light amount and the deviation from the average value are obtained based on the map, and the average value and the X-axis coordinate value of the measuring head 7 are obtained. Is stored in the storage device (step 9), and the light amount calibration is terminated.
[0017]
When a test object is placed on the stage 1 and measurement is instructed from the host computer 13, measurement according to the flow of FIG. 3 starts. And each part of a measuring apparatus is initialized to the state which can be measured. At this time, the average value of the amount of received light is set as a command value to the illumination device controller 15 (step 11). Next, the measurement head 7 and the stage 1 are moved to predetermined positions, and the measurement location of the test object is captured by the television camera 6 (step 12). Then, the X-axis coordinate value of the measuring head 7 is read from the apparatus controller 14 (step 13), and the command value obtained by correcting the deviation corresponding to the current X-axis coordinate value of the measuring head 7 is referred to the light quantity calibration table. Then, the lighting device controller 15 is controlled (step 14). Then, a measurement operation is performed in accordance with an instruction from the host computer 13 (step 15), and then it is determined whether or not all the measurements are completed (step 16). If all measurements have not been completed, the process returns to step 12 to move the measurement head 7 and the stage 1 to the next predetermined position. If all the measurements are completed in step 16, the measurement is terminated.
[0018]
Note that the amount of light received by the television camera 6 as shown in FIG. 4 is detected between step 14 and step 15 and compared with the average amount of received light. Further, step 14A and step 14B for changing the command value to the lighting device controller may be added so as to be within the range of. Thereby, the influence of the temporal change in the amount of received light can also be eliminated. In this case, instead of the average amount of received light, a predetermined value determined in consideration of a change with time and variation due to position may be used.
[0019]
Next, a second embodiment in which a part of the first embodiment is changed will be described. In the apparatus of the second embodiment, the image processing apparatus 12 is further provided with a sensitivity adjustment unit that changes the sensitivity of the television camera 6 in accordance with a command from the host computer 13, and is replaced with the control of the illumination device controller 15 in the first embodiment. To control the sensitivity adjustment unit. By changing the sensitivity of the television camera 6 based on the change in the amount of light received from the illumination device 8 according to the position of the measurement head 7, the change in the output signal of the television camera 6 due to the change in the amount of received light. Can be excluded.
[0020]
FIG. 3 is a cross-sectional view of a main part of the image processing measuring machine according to the third embodiment. Portions other than the configuration described below are the same as those of the apparatus of the first embodiment. In FIG. 3, the other end face of the optical fiber 29 arranged in a line with the end face facing the measuring head 7 of the transmissive illuminating apparatus 28 is coupled to an illuminating apparatus controller 25 having a light source such as a halogen lamp. The light source is configured. The lighting device controller 25 changes the amount of light emitted by the halogen lamp in response to a command from the host computer 13.
[0021]
A semi-transmissive mirror 31 is obliquely provided in a part of the imaging optical system 32 of the measuring head 7 and guides a part of the light from the transmission illumination device 28 to the photoelectric sensor 30 that detects the amount of received light. The amount of received light detected by the photoelectric sensor 30 is input to the host computer 13 and the storage device of the host computer 13 together with the X-axis coordinate value of the measuring head 6 in the same manner as the amount of received light detected by the television camera 7 in the first embodiment. Is remembered.
[0022]
In the apparatus of the third embodiment, the apparatus of the first embodiment is used except that the amount of received light detected by the photoelectric sensor 30 is used instead of the amount of received light detected by the television camera 6 in the apparatus of the first embodiment. Works as well.
Further, in the apparatus according to the third embodiment, the image processing apparatus 12 is further provided with a sensitivity adjustment unit that changes the sensitivity of the television camera 6 according to a command from the host computer 13, and is used for controlling the illumination device controller 25 according to the third embodiment. Instead, a fourth embodiment in which the sensitivity adjustment unit is controlled may be employed.
[0023]
In the above description, the image processing apparatus is used as an apparatus for detecting the end face position of the test object. However, the present invention is not limited to this, and the end of the test object image crosses the line sensor or the photoelectric conversion element. A device that detects the end face of the test object based on a change in the output signal of the photoelectric conversion element may be used.
Moreover, although the example which uses the one linear light source extended to the X-axis direction as an illuminating device was demonstrated, using the surface light source extended to the two-axis direction of X, Y, X, Y coordinate value and received light amount May be stored in association with each other, and the sensitivity of the lighting device controller, television camera, line sensor, photoelectric conversion element, or the like may be controlled based on this.
[0024]
【The invention's effect】
The invention according to any one of claims 1 to 4 also realizes an optical measuring machine that eliminates the influence of the difference in the amount of illumination light on the measurement value depending on the location of the linear light source and obtains a stable measurement result.
[Brief description of the drawings]
FIG. 1 is a perspective view illustrating a first embodiment of the present invention.
FIG. 2 is a flowchart showing a procedure of light amount calibration by the apparatus of FIG. 1;
FIG. 3 is a flowchart showing a measurement procedure by the apparatus of FIG. 1;
4 is a flowchart showing a flow to be added to the flowchart of FIG. 3. FIG.
FIG. 5 is a cross-sectional view of a main part of a second embodiment of the present invention.
[Explanation of symbols]
1 …… Stage 6 …… TV camera (photoelectric conversion means)
7: Measuring head 8: Transmitting illumination device 12: Image processing device (end face detection means)
13 …… Host computer (main control unit)
14 …… Device controller 15 …… Lighting device controller 25 …… Lighting device controller 28 …… Transmission lighting device 29 …… Optical fiber 30 …… Photoelectric sensor 31 …… Semi-transmissive mirror

Claims

It has an optical axis perpendicular to the surface of the stage on which the test object is placed, and is relatively movable in at least one of two directions perpendicular to the stage within the plane perpendicular to the optical axis. A measuring head;
A photoelectric conversion means provided in the measurement head for photoelectrically converting light captured by the measurement head;
A transmitted illumination device installed extending in the relative movement direction of the measurement head on the opposite side to the measurement head with respect to the object surface;
An apparatus controller that controls the relative movement of the measuring head and obtains a coordinate value representing the relative position of the measuring head;
End face detection means for detecting an end face of the test object based on a signal from the photoelectric conversion means;
An illumination device controller that controls the amount of light from the transmission illumination device;
In the optical measuring machine having the apparatus controller, the end surface detecting means and the main controller for controlling the illumination apparatus controller,
The transmitted illumination device is a linear light source or a planar light source,
The main control device stores information based on the amount of received light detected by the photoelectric conversion means in association with the coordinate value, and controls the illumination device controller based on the stored information to perform measurement. Optical measuring machine.

It has an optical axis perpendicular to the surface of the stage on which the test object is placed, and is relatively movable in at least one of two directions perpendicular to the stage within the plane perpendicular to the optical axis. A measuring head;
A photoelectric conversion means provided in the measurement head for photoelectrically converting light captured by the measurement head;
A transmitted illumination device installed extending in the relative movement direction of the measurement head on the opposite side to the measurement head with respect to the object surface;
An apparatus controller that controls the relative movement of the measuring head and obtains a coordinate value representing the relative position of the measuring head;
End face detection means for detecting an end face of the test object based on a signal from the photoelectric conversion means;
In an optical measuring machine having the apparatus controller and a main controller for controlling the end face detection means,
The transmitted illumination device is a linear light source or a planar light source,
The main control device stores information based on the received light amount detected by the photoelectric conversion means in association with the coordinate value, and controls sensitivity of the photoelectric conversion means based on the stored information to perform measurement. An optical measuring machine.

It has an optical axis perpendicular to the surface of the stage on which the test object is placed, and is relatively movable in at least one of two directions perpendicular to the stage within the plane perpendicular to the optical axis. A measuring head;
A photoelectric conversion means provided in the measurement head for photoelectrically converting light captured by the measurement head;
A transmitted illumination device installed extending in the relative movement direction of the measurement head on the opposite side to the measurement head with respect to the object surface;
An apparatus controller that controls the relative movement of the measuring head and obtains a coordinate value representing the relative position of the measuring head;
End face detection means for detecting an end face of the test object based on a signal from the photoelectric conversion means;
An illumination device controller that controls the amount of light from the transmission illumination device;
In the optical measuring machine having the apparatus controller, the end surface detecting means and the main controller for controlling the illumination apparatus controller,
The transmitted illumination device is a linear light source or a planar light source,
A semi-transparent mirror that is obliquely mounted on the measurement head and reflects a part of the light received by the measurement head;
A photoelectric sensor that detects the amount of the reflected light is further provided, and the main control device stores information based on the received light amount detected by the photoelectric sensor in association with the coordinate value, and the stored information. And measuring the illumination device controller based on the optical measuring instrument.

Measurement having an optical axis perpendicular to the surface of the stage on which the specimen is placed, and being relatively movable in at least one of two directions perpendicular to the stage within the plane perpendicular to the optical axis. Head,
A photoelectric conversion means provided in the measurement head for photoelectrically converting light captured by the measurement head;
A transmitted illumination device installed extending in the relative movement direction of the measurement head on the opposite side to the measurement head with respect to the object surface;
An apparatus controller that controls the relative movement of the measuring head and obtains a coordinate value representing the relative position of the measuring head;
End face detection means for detecting an end face of the test object based on a signal from the photoelectric conversion means;
In an optical measuring machine having the apparatus controller and a main controller for controlling the end face detection means,
The transmitted illumination device is a linear light source or a planar light source,
A semi-transparent mirror that is obliquely mounted on the measurement head and reflects a part of the light received by the measurement head;
A photoelectric sensor that detects the amount of the reflected light is further provided, and the main control device stores information based on the received light amount detected by the photoelectric sensor in association with the coordinate value, and the stored information. And measuring the sensitivity by controlling the sensitivity of the photoelectric conversion means.