JP2983318B2 - Shape measuring device and measuring method - Google Patents
Shape measuring device and measuring methodInfo
- Publication number
- JP2983318B2 JP2983318B2 JP3066478A JP6647891A JP2983318B2 JP 2983318 B2 JP2983318 B2 JP 2983318B2 JP 3066478 A JP3066478 A JP 3066478A JP 6647891 A JP6647891 A JP 6647891A JP 2983318 B2 JP2983318 B2 JP 2983318B2
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- Japan
- Prior art keywords
- optical system
- light
- measured
- reflected
- light component
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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- Measurement Of Optical Distance (AREA)
- Length Measuring Devices By Optical Means (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、三角測量法の原理を利
用して、プラスチックや軟質金属などから成る被測定物
の表面形状を高精度に測定できるようにした形状測定装
置と形状測定法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shape measuring apparatus and a shape measuring method capable of measuring the surface shape of an object to be measured made of plastic, soft metal or the like with high accuracy by utilizing the principle of triangulation. About.
【０００２】[0002]
【従来の技術】物体の形状を測定する方法として、接触
式と非接触式とが知られるが、接触式は測定子の接触圧
による被測定物の変形によって正確な測定ができないこ
とがあるばかりでなく、被測定物を傷つけるなどの欠点
がある。このため、光学原理に基づく非接触式の測定方
式が重要性を増しつつある。その種の測定法は格子投影
法と光触針法とに大別され、このうち光触針法として三
角測量法、焦点位置合わせ法、同軸線形変位法などが知
られる。2. Description of the Related Art As a method for measuring the shape of an object, a contact type and a non-contact type are known. However, the contact type is often unable to perform accurate measurement due to deformation of an object to be measured due to a contact pressure of a probe. In addition, there are drawbacks such as damaging the object to be measured. For this reason, a non-contact measurement method based on the optical principle is becoming increasingly important. Such measurement methods are broadly classified into a grid projection method and an optical stylus method. Among them, a triangulation method, a focus alignment method, a coaxial linear displacement method and the like are known as the optical stylus method.
【０００３】ここで、三角測量法による測定例を図９〜
図１２により説明する。図中、３０は同測定に用いる形
状測定装置であり、その装置本体３１の一方には半導体
レーザ等で成るレーザ光源１３と、このレーザ光源１３
から放射された出射光１２を集光するレンズ１６とが配
置されて照射光学系１０を形成している。又、装置本体
３１の他方には、電荷結合素子等で成る検出部２６と、
この検出部２６への入射光２２を集束するためのレンズ
２３とが配置され、そのレンズ２３の光軸２１が照射光
学系１０の光軸１１と角度θを有して偏角するような収
束光学系２０を形成している。[0003] Here, examples of measurement by the triangulation method are shown in FIGS.
This will be described with reference to FIG. In the figure, reference numeral 30 denotes a shape measuring device used for the measurement, and a laser light source 13 made of a semiconductor laser or the like and a laser light source 13
An illumination optical system 10 is formed by arranging a lens 16 for condensing outgoing light 12 radiated from the lens. Further, on the other side of the device main body 31, a detection unit 26 formed of a charge-coupled device or the like,
A lens 23 for converging the light 22 incident on the detection unit 26 is arranged, and the convergence is such that the optical axis 21 of the lens 23 is deflected at an angle θ with the optical axis 11 of the irradiation optical system 10. An optical system 20 is formed.
【０００４】なお、照射光学系１０の延長上には被測定
物３５が置かれ、その被測定物３５が図示せぬ移動機構
によって紙面の直角方向と左右方向とに移動可能とされ
ている。そして、照射光学系の光軸１１と被測定物３５
の表面との交点を測定点Ｐとして、その測定点Ｐにレン
ズ１６で集光された出射光１２が照射光４０として焦点
が合うよう照射されるようになっている。特に、照射光
４０は被測定物３５の表面で反射されるが、その反射光
４５には入射角と同角度で反射する正反射光４７と任意
方向に散乱する散乱光４６とが含まれる。An object 35 to be measured is placed on an extension of the irradiation optical system 10, and the object 35 can be moved in a direction perpendicular to the plane of the paper and in a horizontal direction by a moving mechanism (not shown). Then, the optical axis 11 of the irradiation optical system and the DUT 35 are measured.
The point of intersection with the surface is set as a measurement point P, and the emitted light 12 condensed by the lens 16 at the measurement point P is radiated so as to be focused as irradiation light 40. In particular, the irradiation light 40 is reflected on the surface of the object 35, and the reflected light 45 includes specularly reflected light 47 reflected at the same angle as the incident angle and scattered light 46 scattered in an arbitrary direction.
【０００５】ここで、照射光学系１０の光軸１１と測定
点Ｐにおける接線Ｈとが成す角α１が、図９のようにα
１＝π／２（π＝９０゜）であるとき、正反射光４７は
入射方向へ帰還されるが、散乱光４６の一部はレンズ２
３を介して検出部２６における検出点Ｑに集束される。
このとき、検出部２６における検出点Ｑを基準位置と成
し、被測定物３５の測定点Ｐと形状測定装置３０との間
隔が初期規定されることになる。Here, the angle α1 formed by the optical axis 11 of the irradiation optical system 10 and the tangent H at the measurement point P is αα as shown in FIG.
When 1 = π / 2 (π = 90 °), the specularly reflected light 47 is returned in the incident direction, but a part of the scattered light 46 is
The light is converged on the detection point Q in the detection unit 26 via 3.
At this time, the detection point Q in the detection unit 26 is a reference position, and the distance between the measurement point P of the DUT 35 and the shape measuring device 30 is initially defined.
【０００６】そして、被測定物３５が図９の矢印の如く
変位量Ｚだけ移動されると、その変位量Ｚに相応した位
置に被測定物３５の測定点Ｐ´が変位されることによ
り、その測定点Ｐ´にて反射される反射光のうち、照射
光学系１０の照射光軸１１に対して角度θ´だけ偏角さ
れた収束光学系２０の光軸２１´に沿う散乱光成分がレ
ンズ２３を介して検出部２６の検出点Ｑ´に集束され
る。When the object 35 is moved by a displacement Z as shown by an arrow in FIG. 9, the measuring point P 'of the object 35 is displaced to a position corresponding to the displacement Z. Of the reflected light reflected at the measurement point P ′, a scattered light component along the optical axis 21 ′ of the converging optical system 20 deflected by an angle θ ′ with respect to the irradiation optical axis 11 of the irradiation optical system 10 is The light is focused on the detection point Q ′ of the detection unit 26 via the lens 23.
【０００７】なお、その検出点Ｑ´は、検出部２６にお
ける検出点Ｑよりも検出量Ｓだけ変位した部位に集束さ
れるため、その検出量Ｓに対する三角比から検出点Ｑを
基準とする被測定点Ｐと、検出点Ｑ´による被測定点Ｐ
´とを勘案して変位量Ｚを検知することができる。Since the detection point Q 'is focused on a portion displaced by the detection amount S from the detection point Q in the detection section 26, the detection point Q' based on the detection point Q is determined from the triangular ratio with respect to the detection amount S. Measurement point P and measured point P by detection point Q '
', The displacement Z can be detected.
【０００８】一方、図１０に示すように、被測定物３５
の測定点Ｐａにおける接線Ｈａが照射光学系１０から収
束光学系２０にかけて正の傾斜を有するようなとき、す
なわちα２＞π／２なる関係の場合、正反射光４７ａは
照射光学系１０よりも外方に反射されることになるが、
図１１に示すように、被測定物３５の測定点Ｐｂにおけ
る接線Ｈｂが照射光学系１０から収束光学系２０にかけ
て負の傾斜を有するようなとき、すなわちα３＜π／２
なる関係の場合、測定点Ｐｂにおける正反射光４７ｂ
が、収束光学系２０の光軸２１に沿う散乱光４６ｂと略
同一方向に反射され、これがレンズ２３を介して検出部
２６の正反射結像点Ｒに結像されることがある。On the other hand, as shown in FIG.
When the tangent line Ha at the measurement point Pa has a positive slope from the irradiation optical system 10 to the converging optical system 20, that is, in a relationship of α2> π / 2, the specularly reflected light 47a is out of the irradiation optical system 10. Will be reflected towards
As shown in FIG. 11, when the tangent line Hb at the measurement point Pb of the DUT 35 has a negative slope from the irradiation optical system 10 to the converging optical system 20, that is, α3 <π / 2.
In the case of the following relationship, the regular reflection light 47b at the measurement point Pb
Is reflected in substantially the same direction as the scattered light 46 b along the optical axis 21 of the converging optical system 20, and this may be imaged at the regular reflection image point R of the detection unit 26 via the lens 23.
【０００９】又、図１２に示すように、形状測定装置３
０において、４５゜以上の急斜面であるシャドウ部３６
をもつ被測定物３５´の測定点Ｐｃに、照射光学系１０
による照射光４０を照射した場合には、照射光学系１０
の光軸１１と収束光学系２０の光軸２１とが角度θを有
して偏角されることによって、シャドウ部３６で反射光
が遮断されるシャドウ効果を発生することになる。Further, as shown in FIG.
At 0, the shadow portion 36 is a steep slope of 45 ° or more.
The irradiation optical system 10 is placed at the measurement point Pc of the DUT 35 ′ having
When the irradiation light 40 is irradiated by the irradiation optical system 10
And the optical axis 21 of the converging optical system 20 are deflected with an angle θ, thereby generating a shadow effect in which reflected light is blocked by the shadow section 36.
【００１０】[0010]
【発明が解決しようとする課題】このように、三角測量
法の原理を利用した従来の形状測定装置によれば、図１
１のように照射光学系の光軸と被測定物の測定点におけ
る接線Ｈとの成す角度α３がα３＜π／２なる関係の場
合、正反射光成分が検出部に散乱光成分とともに集束さ
れて正反射結像点Ｒを形成し、その結像点Ｒが散乱光成
分の検出点Ｑに対して誤差量Ｍを発生するため、被測定
物の形状を正確に測定することができないという欠点が
あった。As described above, according to the conventional shape measuring apparatus utilizing the principle of the triangulation method, FIG.
When the angle α3 between the optical axis of the irradiation optical system and the tangent line H at the measurement point of the object to be measured has a relationship of α3 <π / 2, as in 1, the specular reflected light component is focused on the detection unit together with the scattered light component. The point that the shape of the object to be measured cannot be measured accurately because the image forming point R generates an error amount M with respect to the detection point Q of the scattered light component. was there.
【００１１】又、図１２のように、収束光学系の光軸に
対して被測定物の測定部が急傾斜を有してシャドウ部に
位置する場合には、シャドウ効果が発現して測定不能に
なるという欠点があった。Further, as shown in FIG. 12, when the measuring part of the object to be measured is located in the shadow part with a steep inclination with respect to the optical axis of the converging optical system, the shadow effect appears and measurement becomes impossible. Had the disadvantage of becoming
【００１２】一方、変調格子縞位相法やモアレトポグラ
ッフィ法等の格子投影法により被測定物の表面形状を測
定する場合には、被測定物の表面に格子縞等を投影して
その画像処理をしなければならないため、その処理機構
が煩雑になるという欠点がある。On the other hand, when measuring the surface shape of an object to be measured by a grating projection method such as a modulation grating fringe phase method or a moire topography method, the image processing is performed by projecting a lattice fringe or the like onto the surface of the object to be measured. Therefore, there is a disadvantage that the processing mechanism becomes complicated.
【００１３】そこで、本発明は三角測量法の原理を利用
して、被測定物の表面形状を広範に亙って精度良く高速
で測定することのできる形状測定装置と形状測定法を提
供することを目的とする。Accordingly, the present invention provides a shape measuring device and a shape measuring method capable of measuring the surface shape of an object to be measured over a wide range with high accuracy at high speed by utilizing the principle of triangulation. With the goal.
【００１４】[0014]
【課題を解決するための手段】本発明は上記目的を達成
するため、被測定物に対して直線偏光を照射する照射光
学系と、被測定物から入射方向と異なる方向へ反射した
反射光のうち散乱光成分を検出する検出部と、この検出
部に散乱光成分を導くための収束光学系とを含み、その
収束光学系が被測定物からの反射光を正反射光成分と散
乱光成分とに分光して該散乱光成分のみ前記検出部へ入
射させる偏光素子を有して成ることを特徴とする形状測
定装置を提供するものである。In order to achieve the above object, the present invention provides an irradiation optical system for irradiating a linearly polarized light to an object to be measured, and an optical system for reflecting reflected light from the object to be measured in a direction different from the incident direction. And a converging optical system for guiding the scattered light component to the detecting unit. The converging optical system converts the reflected light from the object to be measured into a specular reflected light component and a scattered light component. And a polarizing element that separates the light into the scattered light component and makes the scattered light component incident on the detection unit.
【００１５】特に、本発明は照射光学系の光軸の周囲
に、複数の収束光学系を設けた形状測定装置を提供す
る。In particular, the present invention provides a shape measuring apparatus provided with a plurality of converging optical systems around the optical axis of an irradiation optical system.
【００１６】又、本発明は光源より放射されるレーザ光
を集束しながら所定方向に振動する直線偏光として被測
定物に照射し、その被測定物から入射方向と異なる方向
へ反射する反射光をレンズで集束するとともに、その反
射光を偏光素子に通して正反射光成分と散乱光成分とに
分光し、このうち散乱光成分のみ検出部に入射させて被
測定物の表面形状を測定するようにしたことを特徴とす
る形状測定法を提供するものである。Further, the present invention irradiates an object to be measured as linearly polarized light oscillating in a predetermined direction while converging laser light emitted from a light source, and reflects reflected light reflected from the object in a direction different from the incident direction. While converging with a lens, the reflected light is passed through a polarizing element to be separated into a specularly reflected light component and a scattered light component, and only the scattered light component is incident on the detection unit to measure the surface shape of the object to be measured. The present invention provides a shape measuring method characterized by the following.
【００１７】[0017]
【作用】本発明によれば、被測定物からの反射光を偏光
素子を介して正反射光成分と散乱光成分とに分け、散乱
光成分を被測定物の形状測定に供するようにしているこ
とから、三角測量法の欠点とされる正反射光の影響によ
る検出誤差を解消することができる。According to the present invention, reflected light from an object to be measured is divided into a specular reflection component and a scattered light component via a polarizing element, and the scattered light component is used for measuring the shape of the object to be measured. Therefore, it is possible to eliminate a detection error due to the effect of specular reflection light, which is a disadvantage of the triangulation method.
【００１８】又、照射光学系の光軸の周囲に、複数の収
束光学系を配設したことにより、測定部が急傾斜を有し
て一つの収束光学系が反射光の死角（シャドウ位置）に
あっても、他の収束光学系により被測定物の形状測定を
行うことが可能となることから、三角測量法において発
現するシャドウ効果を解消することができる。Further, since a plurality of converging optical systems are provided around the optical axis of the irradiation optical system, the measuring section has a steep inclination, and one converging optical system is used as a blind spot (shadow position) of reflected light. However, since the shape of the object to be measured can be measured by another converging optical system, the shadow effect that appears in the triangulation method can be eliminated.
【００１９】[0019]
【実施例】以下、本発明の実施例を図面に基づいて詳細
に説明する。先ず、図１及び図２において、本発明に係
る形状測定装置の一例を説明する。Embodiments of the present invention will be described below in detail with reference to the drawings. First, an example of a shape measuring apparatus according to the present invention will be described with reference to FIGS.
【００２０】図示するように、本例の形状測定装置７０
は、装置本体７１の一方に設けられる照射光学系５０
と、装置本体７１の他方に設けられる収束光学系６０と
を備える。このうち、照射光学系５０は半導体レーザな
どで成るレーザ光源５３をもち、その前方には該レーザ
光源５３より放射された出射光５２を集光するレンズ５
４と、その出射光５２を振動方向が互いに直交する直線
偏光としてのＰ波８２とＳ波８１とに分けるための偏光
面５５ａをもった偏光素子（偏光ビームスプリッタ５
５）が設置される。又、照射光学系５０には、偏光面５
５ａを透過するＰ波８２を除き、Ｓ波８１を被測定物７
５に集光しつつ照射するレンズ５６が設けられる。As shown, the shape measuring device 70 of the present embodiment is
Is the irradiation optical system 50 provided on one side of the apparatus main body 71.
And a converging optical system 60 provided on the other side of the apparatus main body 71. Among them, the irradiation optical system 50 has a laser light source 53 composed of a semiconductor laser or the like, and a lens 5 for condensing outgoing light 52 emitted from the laser light source 53 in front of it.
4 and a polarization element (a polarization beam splitter 5) having a polarization surface 55a for dividing the emitted light 52 into a P wave 82 and an S wave 81 as linearly polarized light whose vibration directions are orthogonal to each other.
5) is installed. The irradiation optical system 50 has a polarization plane 5.
Except for the P-wave 82 that passes through 5a, the S-wave 81 is
5 is provided with a lens 56 for irradiating light while condensing the light.
【００２１】一方、収束光学系６０は、被測定物７５で
反射された反射光８５を入射させるためのレンズ６３を
備える。特に、そのレンズ６３は照射光学系５０のレン
ズ５６が成す光軸５１に対して所定の偏角θを成す光軸
６１を形成する。又、収束光学系６０には、その光軸６
１に沿って反射光８５を散乱光成分８６ａと正反射光成
分８７ａとに分ける偏光面６５ａをもった偏光素子（偏
光ビームスプリッタ６５）が設けられる。特に、その偏
光ビームスプリッタ６５は、反射光８５に含まれる散乱
光８６と正反射光８７のうち、散乱光８６を散乱光成分
８６ａとして透過する一方、正反射光８７をその進行方
向に対して直角方向に向きを変えることができる。つま
り、正反射光８７はＳ波の性質を維持していることから
偏光面６５ａで屈折され、正反射光成分８７ａとして除
去されることになる。更に、収束光学系６０には、偏光
ビームスプリッタ６５を透過した散乱光成分８６ａを検
出する電荷結合素子等で成る検出部６６が設けられる。
そして、その検出部６６は散乱光成分８６ａを入射光６
２として受光し、その受光部を検出点Ｑとして検知でき
るようになっている。なお、収束光学系６０におけるレ
ンズ６３と偏光ビームスプリッタ６５とは、光軸６１に
対して配置順位が逆さであっても一向に構わない。On the other hand, the converging optical system 60 is provided with a lens 63 for allowing the reflected light 85 reflected by the object 75 to enter. In particular, the lens 63 forms an optical axis 61 having a predetermined declination θ with respect to the optical axis 51 formed by the lens 56 of the irradiation optical system 50. The converging optical system 60 has its optical axis 6
A polarization element (polarization beam splitter 65) having a polarization plane 65a that divides the reflected light 85 into a scattered light component 86a and a regular reflected light component 87a along 1 is provided. In particular, the polarizing beam splitter 65 transmits the scattered light 86 as a scattered light component 86a among the scattered light 86 and the specularly reflected light 87 included in the reflected light 85, and transmits the specularly reflected light 87 in the traveling direction. Can be turned at right angles. That is, since the specular reflection light 87 maintains the property of the S wave, it is refracted by the polarization surface 65a and is removed as the specular reflection light component 87a. Further, the converging optical system 60 is provided with a detection unit 66 including a charge-coupled device for detecting the scattered light component 86a transmitted through the polarization beam splitter 65.
Then, the detection unit 66 converts the scattered light component 86a into the incident light 6
2, and the light receiving portion can be detected as a detection point Q. The lens 63 and the polarization beam splitter 65 in the converging optical system 60 may be arranged in one direction even if the arrangement order is reversed with respect to the optical axis 61.
【００２２】ここで、上記のように構成される形状測定
装置７０による被測定物７５の形状測定法を説明する。
なお、被測定物７５、又は形状測定装置７０は、図１、
２において図示せぬ移動機構により紙面の直角方向と左
右方向とに移動可能とされている。Here, a method of measuring the shape of the workpiece 75 by the shape measuring device 70 configured as described above will be described.
In addition, the measured object 75 or the shape measuring device 70 is the same as that shown in FIG.
2, a moving mechanism (not shown) is capable of moving in a direction perpendicular to the plane of the paper and in a left-right direction.
【００２３】先ず、レーザ光源５３より放射された出射
光５２は、レンズ５４により集光された後、偏光ビーム
スプリッタ５５に入射される。出射光５２はその進行方
向に直角なあらゆる方向に振動する成分を有するも、偏
光ビームスプリッタ５５により完全に偏光している光
（直線偏光）とされる。特に、その出射光５２は偏光面
５５ａにより屈折されるＳ波８１と、偏光面５５ａを透
過するＰ波８２に分光される。このうち、直線偏光とし
てのＳ波８１はレンズ５６により集光され、そして照射
光８０として被測定物７５の測定点Ｐに焦点を合わせて
照射される。First, the outgoing light 52 emitted from the laser light source 53 is condensed by a lens 54 and then enters a polarizing beam splitter 55. The outgoing light 52 has a component that oscillates in any direction perpendicular to the traveling direction, but is converted into a completely polarized light (linearly polarized light) by the polarization beam splitter 55. In particular, the emitted light 52 is split into an S wave 81 refracted by the polarization plane 55a and a P wave 82 transmitted through the polarization plane 55a. Among them, the S-wave 81 as linearly polarized light is condensed by the lens 56, and is irradiated as the irradiation light 80 while focusing on the measurement point P of the object 75.
【００２４】ここで、図２のように、照射光学系５０の
光軸５１と被測定物７５の測定点Ｐにおける接線Ｈとの
成す角α１が、α１＝π／２なる関係にあるとき、測定
点Ｐにおける反射光８５のうち、正反射光８７は光軸５
１に沿う方向に反射され、偏光ビームスプリッタ５５へ
と帰還される。なお、正反射光８７が偏光ビームスプリ
ッタ５５へ帰還されても、光の波動性より出射光５２と
の間に可干渉性が発現するに留まり、各々の進行方向及
び各成分等に影響することはない。Here, as shown in FIG. 2, when the angle α1 formed between the optical axis 51 of the irradiation optical system 50 and the tangent H at the measurement point P of the object 75 has a relationship of α1 = π / 2, Of the reflected light 85 at the measurement point P, the regular reflected light 87 is the optical axis 5
The light is reflected in the direction along 1 and is returned to the polarization beam splitter 55. Even if the specularly reflected light 87 is returned to the polarization beam splitter 55, coherence between the reflected light 87 and the outgoing light 52 is only manifested due to the wave nature of the light, which affects each traveling direction and each component. There is no.
【００２５】又、測定点Ｐにおける反射光８５のうち、
収束光学系６０の光軸６１に沿う方向へ反射された散乱
光８６は、レンズ６３を介して集束されつつ偏光ビーム
スプリッタ６５に入射され、その偏光面６５ａを透過し
た散乱光成分８６ａが入射光６２として検出部６６にお
ける検出点Ｑに集束される。そして、このとき検出部６
６による検出点Ｑを基準位置と成し、被測定物７５の測
定点Ｐと形状測定装置７０との間隔を初期規定するので
ある。In the reflected light 85 at the measuring point P,
The scattered light 86 reflected in the direction along the optical axis 61 of the converging optical system 60 is incident on the polarization beam splitter 65 while being focused through the lens 63, and the scattered light component 86a transmitted through the polarization plane 65a is converted into the incident light. As 62, the light is focused on the detection point Q in the detection unit 66. At this time, the detecting unit 6
The detection point Q by 6 is used as a reference position, and the distance between the measurement point P of the measured object 75 and the shape measuring device 70 is initially defined.
【００２６】その後、被測定物７５が図示せぬ移動機構
により、図２の矢印の如く変位量Ｚだけ移動されると、
測定点Ｐが変位量Ｚに相応した位置である測定点Ｐ´に
変位される。この結果、照射光８０が測定点Ｐ´にて反
射され、その光軸５１に対して角度θ´だけ偏角された
光軸６１´方向に散乱する散乱光成分がレンズ６３と偏
光ビームスプリッタ６５を介して検出部６６の検出点Ｑ
´に集束されることになる。そして、その検出点Ｑ´
は、検出部６６における検出点Ｑよりも検出量Ｓだけ変
位した部位に集束されるため、その検出量Ｓに対する三
角比から検出点Ｑを基準とする測定点Ｐと検出点Ｑ´に
よる測定点Ｐ´とを勘案して変位量Ｚを検知することが
できる。Thereafter, when the object 75 is moved by a displacement Z as shown by an arrow in FIG.
The measurement point P is displaced to a measurement point P 'which is a position corresponding to the displacement Z. As a result, the illuminating light 80 is reflected at the measurement point P ′, and the scattered light component scattered in the direction of the optical axis 61 ′ deviated by an angle θ ′ with respect to the optical axis 51 becomes the lens 63 and the polarizing beam splitter 65. Through the detection point Q of the detection unit 66
′. Then, the detection point Q '
Is focused on a part displaced by the detection amount S from the detection point Q in the detection unit 66, and therefore, a measurement point P based on the detection point Q and a measurement point The displacement amount Z can be detected in consideration of P ′.
【００２７】一方、図１のように、照射光学系５０の光
軸５１と被測定物７５の測定点Ｐにおける接線Ｈとの成
す角α１が、α１＜π／２なる関係にあって、正反射光
８７が収束光学系６０の光軸６１に沿う散乱光８６と略
同一方向に反射されるとき、その正反射光８７はＳ波の
性質を維持しているので偏光ビームスプリッタ６５の偏
光面６５ａにより屈折され、光軸６１の直角方向へ正反
射光成分８７ａとして反射されることになる。On the other hand, as shown in FIG. 1, the angle α1 between the optical axis 51 of the irradiation optical system 50 and the tangent H at the measurement point P of the object 75 has a relationship of α1 <π / 2. When the reflected light 87 is reflected in substantially the same direction as the scattered light 86 along the optical axis 61 of the converging optical system 60, the specular reflected light 87 maintains the property of the S-wave, so that the polarization plane of the polarizing beam splitter 65 The light is refracted by 65a and is reflected as a regular reflection light component 87a in a direction perpendicular to the optical axis 61.
【００２８】なお、被測定物７５の測定点Ｐにおける接
線Ｈが照射光学系５０から収束光学系６０にかけて正の
傾斜を有するとき、すなわち照射光学系５０の光軸５１
と被測定物７５の測定点Ｐにおける接線Ｈとの成す角α
１が、α１＞π／２なる関係にあるとき、正反射光８７
は照射光学系５０より外方に反射されることになる。When the tangent H at the measurement point P of the object 75 has a positive slope from the irradiation optical system 50 to the converging optical system 60, that is, the optical axis 51 of the irradiation optical system 50
Α between the tangent H at the measurement point P of the object 75 and the measurement point P
1 has a relationship of α1> π / 2, the regular reflection light 87
Is reflected outward from the irradiation optical system 50.
【００２９】このように、本例の形状測定装置７０によ
れば、照射光学系５０において、レーザ光源５３より放
射された出射光５２を偏光ビームスプリッタ５５を介し
てＳ波８１とＰ波８２に分け、このうちＳ波８１を照射
光８０として被測定物７５に照射する一方、収束光学系
６０において、被測定物７５からの反射光８５を偏光ビ
ームスプリッタ６５を介して正反射光成分８７ａ（Ｓ
波）と散乱光成分８６ａとに分け、このうち検出部６６
の検出点Ｑに散乱光成分８６ａを集束するようにしたた
め、三角測量法の欠点とされる正反射光８７の影響によ
る検出部６６での誤差量を解消することができる。As described above, according to the shape measuring apparatus 70 of the present embodiment, in the irradiation optical system 50, the outgoing light 52 emitted from the laser light source 53 is converted into the S-wave 81 and the P-wave 82 via the polarization beam splitter 55. While the S-wave 81 is irradiated on the object 75 as the irradiation light 80, the reflected light 85 from the object 75 is reflected by the converging optical system 60 via the polarizing beam splitter 65 into a regular reflection light component 87 a ( S
Wave) and a scattered light component 86a.
Since the scattered light component 86a is focused on the detection point Q, the error amount in the detection unit 66 due to the influence of the specularly reflected light 87, which is a drawback of the triangulation method, can be eliminated.
【００３０】ここで、形状測定装置７０を使用し、被測
定物７５として直径４ｍｍの略真球なる鋼球を測定した
結果を図３及び図４に示す。なお、図３は横軸を鋼球の
直径とし、縦軸に鋼球の高さをとって図示したものであ
る。又、図４は測定値が鋼球の真理形状から偏差した度
合いを２倍にして±５０μｍの偏差範囲と併せて図示し
たものである。そして、この測定結果から本実施例の形
状測定装置７０を使用して以上のような鋼球の表面形状
を測定した場合、偏差が±５０μｍ以内の精度を有する
ことが判る。FIGS. 3 and 4 show the results of using a shape measuring device 70 to measure a steel ball having a diameter of about 4 mm, which is a true sphere, as the object 75 to be measured. In FIG. 3, the horizontal axis represents the diameter of the steel ball, and the vertical axis represents the height of the steel ball. FIG. 4 is a graph showing the degree of deviation of the measured value from the true shape of the steel ball by a factor of two, together with a deviation range of ± 50 μm. From the measurement results, it can be seen that when the surface shape of the steel ball as described above is measured using the shape measuring device 70 of the present embodiment, the deviation has an accuracy within ± 50 μm.
【００３１】次に、本発明に係る形状測定装置の他の実
施例を説明する。なお、以下の説明において、上記例と
同一の箇所、及び同一の機能を有する部位には同一符号
を付して詳細な説明を省略する。先ず、図５に示す形状
測定装置９０は、先の実施例と同一構成とした照射光学
系９５の左右に、２つの収束光学系９１，９２を設けた
例である。Next, another embodiment of the shape measuring apparatus according to the present invention will be described. In the following description, the same portions as those in the above example and portions having the same functions are denoted by the same reference numerals, and detailed description thereof will be omitted. First, a shape measuring apparatus 90 shown in FIG. 5 is an example in which two converging optical systems 91 and 92 are provided on the left and right of an irradiation optical system 95 having the same configuration as the previous embodiment.
【００３２】そして、本例の形状測定装置９０によれ
ば、照射光学系９５からの照射光が照射される被測定物
７５´の測定点Ｐの傾斜が略４５゜以上の急斜面である
場合、収束光学系９２では被測定点Ｐがシャドウ部７６
となって形状測定を行うことができないが、他方側に配
置された収束光学系９１により測定点Ｐの形状を計測す
ることが可能となり、シャドウ部７６によるシャドウ効
果を解消することができる。According to the shape measuring apparatus 90 of the present embodiment, when the inclination of the measuring point P of the object 75 ′ to be irradiated with the irradiation light from the irradiation optical system 95 is a steep slope of about 45 ° or more, In the converging optical system 92, the measured point P is
Therefore, the shape measurement cannot be performed, but the shape of the measurement point P can be measured by the converging optical system 91 arranged on the other side, and the shadow effect by the shadow unit 76 can be eliminated.
【００３３】なお、図５には収束光学系９１，９２が二
次元的に配設された状態が示されるが、それらを照射光
軸の周囲に任意の偏角を有して三次元的に配設するよう
にしてもよい。又、本例の形状測定装置９０によれば２
つの収束光学系を配設しているが、これを３つ以上にし
ても構わない。FIG. 5 shows a state in which the converging optical systems 91 and 92 are two-dimensionally arranged. The converging optical systems 91 and 92 are three-dimensionally arranged at an arbitrary angle around the irradiation optical axis. It may be arranged. Further, according to the shape measuring apparatus 90 of this example, 2
Although two converging optical systems are provided, three or more converging optical systems may be provided.
【００３４】次に、図６に示す形状測定装置１００は、
照射光学系１０１の偏光ビームスプリッタ５５により、
レーザ光源５３から放射された出射光５２のＰ波８２を
透過させるとともにＳ波８１を反射させ、このうちＰ波
８２を被測定物７５の形状測定に適用する構成とした例
である。そして、本例に係る形状測定装置１００によれ
ば、収束光学系１０２の光軸６１上に、反射光８５のう
ちの正反射光８７を正反射光成分８７ｂとして透過する
一方、散乱光８６を散乱光成分８６ｂとして屈折する偏
光面１０６ａをもった偏光ビームスプリッタ１０６が設
置される。Next, the shape measuring apparatus 100 shown in FIG.
The polarization beam splitter 55 of the irradiation optical system 101
This is an example in which the P-wave 82 of the emitted light 52 emitted from the laser light source 53 is transmitted and the S-wave 81 is reflected, and the P-wave 82 is applied to shape measurement of the DUT 75. Then, according to the shape measuring apparatus 100 according to the present example, the specularly reflected light 87 of the reflected light 85 is transmitted as the specularly reflected light component 87b on the optical axis 61 of the converging optical system 102, while the scattered light 86 is transmitted. A polarization beam splitter 106 having a polarization plane 106a that refracts as the scattered light component 86b is provided.
【００３５】又、図７に示す形状測定装置１１０は、照
射光学系１１１の光源１１３に予め直線偏光を発生する
ものを使用した例であり、これによれば照射光学系１１
１の光軸５１上から偏光ビームスプリッタ５５を排除す
ることができる。The shape measuring apparatus 110 shown in FIG. 7 is an example in which a light source 113 of the irradiation optical system 111 which generates linearly polarized light is used in advance.
The polarization beam splitter 55 can be eliminated from the one optical axis 51.
【００３６】更に、図８に示す形状測定装置１２０は、
収束光学系１２２における光軸６１の被測定物７５側に
Ｐ波成分とＳ波成分との変換を行う１／２波長板１２４
を設置した例である。そして、本例によれば、被測定物
７５において反射される波成分と光軸６１上における偏
光ビームスプリッタ６５の以降で検出される波成分とを
相違させている。Further, the shape measuring device 120 shown in FIG.
A half-wave plate 124 that converts between a P-wave component and an S-wave component on the object to be measured 75 side of the optical axis 61 in the converging optical system 122.
This is an example in which is installed. Then, according to this example, the wave component reflected by the device under test 75 is different from the wave component detected on the optical axis 61 after the polarization beam splitter 65.
【００３７】[0037]
【発明の効果】以上の説明から明らかなように、本発明
によれば照射光学系より被測定物に対して所定方向に振
動する直線偏光を照射し、被測定物から収束光学系に反
射する反射光を偏光素子に通して正反射光成分と散乱光
成分とに分け、正反射光成分を除外する一方、散乱光成
分を検出部に入射させて被測定物の形状測定に用いるよ
うにしたことから、三角測量法の欠点とされる正反射光
の影響による検出部での誤差量を解消し、被測定物の測
定部におけるキズ、ゴミ、粗さ等の影響を減少させるこ
とができる。このため、三角測量法を適用した形状測定
装置と形状測定法でありながら、被測定物の形状を精度
よく高速で測定することができる。As is apparent from the above description, according to the present invention, the object to be measured is irradiated with linearly polarized light oscillating in a predetermined direction from the irradiation optical system, and reflected from the object to the converging optical system. The reflected light is passed through a polarizing element to be divided into a specular reflected light component and a scattered light component, and the specular reflected light component is excluded. On the other hand, the scattered light component is incident on the detection unit and used for shape measurement of the object to be measured. Therefore, it is possible to eliminate the amount of error in the detection unit due to the effect of specular reflection light, which is a drawback of the triangulation method, and to reduce the influence of scratches, dust, roughness, and the like on the measurement unit of the measured object. For this reason, the shape of the object to be measured can be accurately measured at high speed while using the shape measuring device and the shape measuring method to which the triangulation method is applied.
【００３８】又、照射光学系の周囲に、所定の偏角を有
して複数の収束光学系を配設していることから、三角測
量法において発現するシャドウ効果を解消し、被測定物
の表面形状が広範に亙って測定可能になる。Further, since a plurality of converging optical systems are arranged around the irradiation optical system with a predetermined declination, the shadow effect that appears in the triangulation method is eliminated, and Surface morphology can be measured over a wide range.
【００３９】しかも、格子投影法のように、被測定物の
表面に格子縞を投影したり、その画像処理を行うなどの
繁雑さがなく、簡易構造にして被測定物の表面形状を高
精度且つ高速にて測定することができる。Furthermore, unlike the grid projection method, there is no need to project lattice fringes on the surface of the object to be measured or to perform image processing thereof. It can be measured at high speed.
【図１】本発明に係わる形状測定装置の実施例を示す側
面図FIG. 1 is a side view showing an embodiment of a shape measuring apparatus according to the present invention.
【図２】同形状測定装置による被測定物の形状測定を説
明する説明図FIG. 2 is an explanatory view illustrating shape measurement of an object to be measured by the shape measurement device.
【図３】同形状測定装置により被測定物の表面を実測し
た測定値を示す実測図FIG. 3 is an actual measurement diagram showing measured values obtained by actually measuring the surface of the object to be measured by the same shape measuring apparatus.
【図４】同形状測定装置により被測定物の表面を実測し
た測定値の偏差を示す偏差図FIG. 4 is a deviation diagram showing deviations of measured values obtained by actually measuring the surface of an object to be measured by the same shape measuring apparatus.
【図５】本発明に係る形状測定装置の第２実施例を示す
側面図FIG. 5 is a side view showing a second embodiment of the shape measuring apparatus according to the present invention.
【図６】本発明に係る形状測定装置の第３実施例を示す
側面図FIG. 6 is a side view showing a third embodiment of the shape measuring apparatus according to the present invention.
【図７】本発明に係る形状測定装置の第４実施例を示す
側面図FIG. 7 is a side view showing a fourth embodiment of the shape measuring apparatus according to the present invention.
【図８】本発明に係る形状測定装置の第５実施例を示す
側面図FIG. 8 is a side view showing a fifth embodiment of the shape measuring apparatus according to the present invention.
【図９】従来の形状測定装置により傾斜した被測定物の
形状測定を説明する説明図FIG. 9 is an explanatory view for explaining the shape measurement of an object to be measured inclined by a conventional shape measuring apparatus
【図１０】従来の形状測定装置により傾斜した被測定物
の形状測定を説明する説明図FIG. 10 is an explanatory view for explaining the shape measurement of an object to be measured inclined by a conventional shape measuring apparatus.
【図１１】従来の形状測定装置により傾斜した被測定物
の形状測定を説明する説明図FIG. 11 is an explanatory view illustrating shape measurement of an object to be measured inclined by a conventional shape measurement device.
【図１２】三角測量法を使用した形状測定装置に発現す
るシャドウ効果を説明する説明図FIG. 12 is an explanatory diagram illustrating a shadow effect that appears in a shape measuring device using a triangulation method.
５０ 照射光学系 ５２ 出射光 ５３ レーザ光源 ５４ レンズ ５５ 偏光ビームスプリッタ ５５ａ 偏光面 ５６ レンズ ６０ 収束光学系 ６２ 入射光 ６３ レンズ ６５ 偏光ビームスプリッタ ６５ａ 偏光面 ６６ 検出部 ７０ 形状測定装置 ７１ 装置本体 ７５ 被測定物 ８０ 照射光 ８１ Ｓ波 ８２ Ｐ波 ８５ 反射光 ８６ 散乱光 ８６ａ 散乱光成分 ８７ 正反射光 ８７ａ 正反射光成分 Reference Signs List 50 irradiation optical system 52 outgoing light 53 laser light source 54 lens 55 polarizing beam splitter 55a polarizing surface 56 lens 60 converging optical system 62 incident light 63 lens 65 polarizing beam splitter 65a polarizing surface 66 detecting unit 70 shape measuring device 71 device main body 75 measured Object 80 Irradiation light 81 S wave 82 P wave 85 Reflected light 86 Scattered light 86a Scattered light component 87 Regular reflected light 87a Regular reflected light component
───────────────────────────────────────────────────── フロントページの続き (58)調査した分野(Int.Cl.6，ＤＢ名) G01B 11/00 - 11/30 ──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. 6 , DB name) G01B 11/00-11/30
Claims (3)
射光学系と、被測定物から入射方向と異なる方向へ反射
した反射光のうち散乱光成分を検出する検出部と、この
検出部に散乱光成分を導くための収束光学系とを含み、
その収束光学系が被測定物からの反射光を正反射光成分
と散乱光成分とに分光して該散乱光成分のみ前記検出部
へ入射させる偏光素子を有して成ることを特徴とする形
状測定装置。An irradiation optical system for irradiating the object with linearly polarized light; a detection unit for detecting a scattered light component of reflected light reflected from the object in a direction different from the incident direction; A converging optical system for guiding the scattered light component to
A shape characterized in that the converging optical system has a polarizing element that separates reflected light from the object into a specular reflected light component and a scattered light component and makes only the scattered light component incident on the detection unit. measuring device.
光学系を設けた請求項１記載の形状測定装置。2. The shape measuring apparatus according to claim 1, wherein a plurality of converging optical systems are provided around the optical axis of the irradiation optical system.
がら所定方向に振動する直線偏光として被測定物に照射
し、その被測定物から入射方向と異なる方向へ反射する
反射光をレンズで集束するとともに、その反射光を偏光
素子に通して正反射光成分と散乱光成分とに分光し、こ
のうち散乱光成分のみ検出部に入射させて被測定物の表
面形状を測定するようにしたことを特徴とする形状測定
法。3. A laser beam emitted from a light source is focused on the object to be measured as linearly polarized light that oscillates in a predetermined direction while being focused, and reflected light reflected from the object in a direction different from the incident direction is focused by a lens. In addition, the reflected light is passed through a polarizing element to be separated into a specular reflected light component and a scattered light component, and only the scattered light component is incident on the detection unit to measure the surface shape of the object to be measured. A shape measuring method characterized by the following.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3066478A JP2983318B2 (en) | 1991-03-29 | 1991-03-29 | Shape measuring device and measuring method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3066478A JP2983318B2 (en) | 1991-03-29 | 1991-03-29 | Shape measuring device and measuring method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH04301509A JPH04301509A (en) | 1992-10-26 |
| JP2983318B2 true JP2983318B2 (en) | 1999-11-29 |
Family
ID=13316930
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3066478A Expired - Fee Related JP2983318B2 (en) | 1991-03-29 | 1991-03-29 | Shape measuring device and measuring method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2983318B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7078720B2 (en) | 2003-08-12 | 2006-07-18 | Fuji Xerox Co., Ltd. | Range finder for measuring three-dimensional geometry of object and method thereof |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5266952B2 (en) * | 2008-08-19 | 2013-08-21 | オムロン株式会社 | Optical measuring apparatus and measuring method |
-
1991
- 1991-03-29 JP JP3066478A patent/JP2983318B2/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7078720B2 (en) | 2003-08-12 | 2006-07-18 | Fuji Xerox Co., Ltd. | Range finder for measuring three-dimensional geometry of object and method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH04301509A (en) | 1992-10-26 |
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