JPH10221053A - Method for measuring radius of curvature of spherical face - Google Patents

Method for measuring radius of curvature of spherical face

Info

Publication number
JPH10221053A
JPH10221053A JP9038342A JP3834297A JPH10221053A JP H10221053 A JPH10221053 A JP H10221053A JP 9038342 A JP9038342 A JP 9038342A JP 3834297 A JP3834297 A JP 3834297A JP H10221053 A JPH10221053 A JP H10221053A
Authority
JP
Japan
Prior art keywords
curvature
measuring
radius
spherical
shape
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.)
Pending
Application number
JP9038342A
Other languages
Japanese (ja)
Inventor
Hisashi Shiozawa
久 塩澤
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nikon Corp
Original Assignee
Nikon Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Nikon Corp filed Critical Nikon Corp
Priority to JP9038342A priority Critical patent/JPH10221053A/en
Publication of JPH10221053A publication Critical patent/JPH10221053A/en
Pending legal-status Critical Current

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  • Length Measuring Devices With Unspecified Measuring Means (AREA)
  • A Measuring Device Byusing Mechanical Method (AREA)

Abstract

PROBLEM TO BE SOLVED: To provide a method for highly accurately calibrating a radius of curvature of a measuring stylus with a member which can be highly accurately manufactured relatively easily compared with a sphere as a reference while the member to be the reference may not deform at the time of installation. SOLUTION: The method for measuring a spherical shape of a shape measuring apparatus with a tip of a measuring stylus 4 exhibiting a spherical shape comprises steps of measuring two spherical shapes (a convex face 11a and a concave face 12a) of a convex lens 11 and a concave lens 12 as members one of which has a convex spherical shape and the other has a concave spherical shape wherein their radii of curvature match or difference in their radii of curvature is known by using the measuring stylus 4 whose radius of curvature is unknown and which is of a spherical shape, obtaining the resulted radii of curvature of spherical faces comprising center coordinate arrays of the measuring stylus 4 respectively by calculation and obtaining the radius of curvature of the measuring stylus 4 from the difference between the two radii of curvature.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【0001】[0001]

【発明の属する技術分野】この発明は、三次元座標測定
機や断面形状測定装置の中でも、高い精度が要求される
各種の形状測定装置を校正する際における、当該装置の
測定針の球面形状を測定する方法に関するものである。
BACKGROUND OF THE INVENTION The present invention relates to a method for correcting the spherical shape of a measuring needle of a three-dimensional coordinate measuring machine or a cross-sectional shape measuring device when calibrating various shape measuring devices requiring high accuracy. It relates to a method of measuring.

【0002】[0002]

【従来の技術】近年、機械部品の形状評価のみならず、
光学要素のひとつである非球面光学素子の形状評価用と
しても、三次元座標測定機に代表される形状測定装置は
幅広く用いられている。それは、従来の光学素子が球面
や平面等の幾何形状で構成されていたのに対し、非球面
光学素子は三次元的な自由曲面を有するために、従来の
干渉測定等の光学的な手法による形状測定が困難になっ
たためである。
2. Description of the Related Art In recent years, not only the evaluation of the shape of mechanical parts,
A shape measuring device represented by a three-dimensional coordinate measuring machine is also widely used for evaluating the shape of an aspherical optical element, which is one of the optical elements. That is, while the conventional optical element is configured with a geometrical shape such as a spherical surface or a plane, the aspherical optical element has a three-dimensional free-form surface. This is because the shape measurement became difficult.

【0003】しかしながら、非球面光学素子の形状評価
に三次元座標測定機を使用しようとした場合、従来の機
械部品に要求されていた精度の1桁から2桁以上の高い
精度が要求される。そこで、形状測定装置そのものの高
精度化は言うに及ばず、この測定装置の校正についても
従来の方法を見直す必要が生じてきた。なかでも、通
常、この形状測定装置の測定針には先端部が球形をした
ものを使用するが、この測定針先端が有する曲率半径の
校正は非常に重要な課題となっている。なぜなら、測定
針半径に誤差があった場合、その誤差が測定面の法線方
向の誤差となってしまい、光学素子で重要なパラメータ
のひとつである曲率半径に誤差が生じてしまうからであ
る。
However, when an attempt is made to use a three-dimensional coordinate measuring machine to evaluate the shape of an aspherical optical element, a high precision of one to two or more orders of magnitude required for conventional mechanical parts is required. Therefore, it goes without saying that it is necessary to review the conventional method for calibrating the shape measuring device itself, not to mention improving the accuracy of the shape measuring device itself. Above all, usually, a measuring needle of this shape measuring device has a spherical tip, and calibration of the radius of curvature of the tip of the measuring needle is a very important issue. This is because, if there is an error in the radius of the measurement needle, the error becomes an error in the normal direction of the measurement surface, and an error occurs in the radius of curvature, which is one of the important parameters in the optical element.

【0004】この課題に対して、従来の方法では、図2
に示すように、高精度ミラー1の上に校正用基準球2が
載せられ、この基準球2が押え部材3により転がらない
ように設置されている。そして、この設置状態で、測定
針4の球状部4aを、高精度ミラー1のZ方向の位置Z
1、Z3及び校正用基準球2の頂点の位置Z2に当接さ
せて、それらの位置Z1,Z2,Z3を測定する。得ら
れたZ1、Z3の平均値とZ2との差を求めることによ
り、測定針4の球状部4aの曲率半径Rpが分からなく
ても、校正用基準球2の直径Dが明らかとなる。一方、
同一のセッティングのもとに、測定針4の球状部4aを
校正用基準球2の周面に沿わせて摺動させることによ
り、この校正用基準球2の形状を測定し、得られた測定
針4の中心を通る面の曲率半径R3から先に得られてい
る校正用基準球2の半径(D/2)を引けば、測定針4
の球状部4aの曲率半径Rpを求めることができる。こ
の測定値に基づいて、測定針4の球状部4aを校正し、
適正な形状として、高精度の形状測定装置が提供できる
ようにしている。
[0004] In order to solve this problem, the conventional method employs FIG.
As shown in FIG. 1, a calibration reference sphere 2 is placed on a high-precision mirror 1, and the reference sphere 2 is set so as not to be rolled by a pressing member 3. Then, in this installation state, the spherical portion 4a of the measuring needle 4 is moved to the position Z in the Z direction of the high-precision mirror 1.
1, Z3 and the vertex position Z2 of the calibration reference sphere 2 are brought into contact with each other, and the positions Z1, Z2, Z3 are measured. By calculating the difference between the obtained average value of Z1 and Z3 and Z2, the diameter D of the calibration reference sphere 2 becomes clear even if the radius of curvature Rp of the spherical portion 4a of the measurement needle 4 is unknown. on the other hand,
Under the same setting, the shape of the calibration reference sphere 2 is measured by sliding the spherical portion 4a of the measuring needle 4 along the peripheral surface of the calibration reference sphere 2, and the obtained measurement is performed. By subtracting the radius (D / 2) of the calibration reference sphere 2 obtained earlier from the radius of curvature R3 of the plane passing through the center of the needle 4, the measurement needle 4
Of the spherical portion 4a can be obtained. Based on the measured value, the spherical portion 4a of the measuring needle 4 is calibrated,
As an appropriate shape, a highly accurate shape measuring device can be provided.

【0005】[0005]

【発明が解決しようとする課題】しかしながら、先の従
来の方法では以下の問題があった。
However, the above conventional method has the following problems.

【0006】第一に校正用基準球2の真球度である。こ
の手法で使用する基準球2は、あらゆる方向に対して真
球度が数十nmオーダで保証されている必要があるが、そ
のような真球を入手することは非常に難しい。また、他
の測定手法を用いて真球度を校正して使用することも考
えられるが、実施にあたっては手間が非常にかかってし
まい現実的ではない。
First, the sphericity of the calibration reference sphere 2 is described. The reference sphere 2 used in this method needs to have a sphericity in every direction on the order of several tens of nm, but it is very difficult to obtain such a sphere. It is also conceivable to calibrate and use the sphericity by using another measurement method, but this is not realistic because it takes much time and effort to implement.

【0007】第二に校正用基準球2の固定方法および、
その変形である。この手法では、校正用基準球2を高精
度ミラー1に接触させ、なおかつ校正用基準球2が動か
ないように押さえ部材3で固定する必要がある。しか
し、このように校正用基準球2を固定するのは、校正用
基準球2が押さえ部材3により浮き上がってしまった
り、又、校正用基準球2と押さえ部材3との間でガタ付
きが生じたりして極めて難しいと共に、校正用基準球2
は高精度ミラー1に微小な1点でのみ接触しているた
め、校正用基準球2は固定方法によって簡単に接触点が
変形してしまい、校正用基準球2の直径測定の際に誤差
が生じてしまう。
Second, a method of fixing the calibration reference sphere 2 and
It is a variant. In this method, it is necessary to bring the calibration reference sphere 2 into contact with the high-precision mirror 1 and to fix the calibration reference sphere 2 with the holding member 3 so as not to move. However, fixing the calibration reference sphere 2 in this manner may cause the calibration reference sphere 2 to be lifted up by the pressing member 3 or cause looseness between the calibration reference sphere 2 and the pressing member 3. Is extremely difficult and the reference sphere for calibration 2
Is in contact with only one minute point on the high-precision mirror 1, the contact point of the calibration sphere 2 is easily deformed by the fixing method, and an error occurs when the diameter of the calibration sphere 2 is measured. Will happen.

【0008】そこで、この発明は、球に比べて比較的容
易に高精度なものが製作可能なものを基準とし、また基
準とする部材が設置時に変形することなく、高精度に測
定針の曲率半径が校正できる方法を提供することを課題
としている。
Accordingly, the present invention is based on the object that can be manufactured relatively easily with high precision as compared with a sphere. In addition, the reference member does not deform at the time of installation and the curvature of the measuring needle can be accurately determined. It is an object to provide a method capable of calibrating a radius.

【0009】[0009]

【課題を解決するための手段】かかる課題を達成するた
めに、請求項1に記載の発明は、測定針の先端部が球面
形状を呈する形状測定装置の該球面形状を測定する方法
において、曲率半径が一致または曲率半径の差が既知
で、一方が凸、他方が凹の球面形状を有する部材の、二
つの球面の形状に対し、曲率半径が未知で球面形状の測
定針を用いて前記2つの球面形状を測定し、その結果得
られた測定針の中心座標列が構成する球面の曲率半径を
演算でそれぞれ求め、前記2つの曲率半径の差から測定
針の曲率半径を求める球面曲率半径測定方法としたこと
を特徴としている。
According to a first aspect of the present invention, there is provided a method for measuring a spherical shape of a shape measuring apparatus in which a tip of a measuring needle has a spherical shape. For a member having a spherical shape in which the radii match or the radius of curvature is known and one of which is convex and the other is concave, the two spheres are measured using a spherical measuring needle having an unknown radius of curvature. Spherical radii measured by measuring two spherical shapes, calculating the radii of curvature of the spheres formed by the resulting central coordinate sequence of the measuring needle, and calculating the radius of curvature of the measuring needle from the difference between the two radii of curvature. Method.

【0010】請求項2に記載の発明は、請求項1に記載
の構成に加え、前記測定針の中心座標列から球面の曲率
半径を求める際に、計算上得られる球面と測定値との差
の二乗和が最小となるように最小自乗法を用いて計算す
ることを特徴とする。
According to a second aspect of the present invention, in addition to the configuration of the first aspect, when calculating the radius of curvature of the spherical surface from the center coordinate sequence of the measuring needle, the difference between the spherical surface obtained by calculation and the measured value is obtained. Is calculated using the least squares method so that the sum of squares of

【0011】[0011]

【発明の実施の形態】以下、この発明の実施の形態につ
いて説明する。
Embodiments of the present invention will be described below.

【0012】図1には、この発明の実施の形態を示す。FIG. 1 shows an embodiment of the present invention.

【0013】この実施の形態は、図1の(a)に示す球
面形状の凸面11aを有する凸レンズ11及び図1の
(b)に示す球面形状の凹面12aを有する凹レンズ1
2を使用して測定針4の球状部4aの曲率半径Rpを測
定して校正を行うようにしている。
In this embodiment, a convex lens 11 having a spherical convex surface 11a shown in FIG. 1A and a concave lens 1 having a spherical concave surface 12a shown in FIG.
2, the radius of curvature Rp of the spherical portion 4a of the measuring needle 4 is measured and calibration is performed.

【0014】すなわち、その凸レンズ11と凹レンズ1
2とは、凸面11aの曲率半径Rcvと凹面12aの曲
率半径Rccとが一致しているか、あるいは両曲率半径
Rcv,Rccの差が明らかであるものを使用する。ま
た、その凸レンズ11と凹レンズ12とは、熱変形の影
響の度合いが等しくなるように、同一素材を使用するこ
とが望ましい。この凸レンズ11と凹レンズ12との曲
率半径Rcv,Rccを一致させること、あるいは、曲
率半径Rcv,Rccの差を測定することは、通常のガ
ラスレンズ製作において行われる様に球面の凹、凸を重
ね合わせて生じるニュートン縞を観察して加工、測定す
る行うことにより、サブミクロンオーダを越えて簡便に
実現することができる。このとき、それぞれのレンズ1
1,12の曲率半径Rcv,Rccの値は、リングスフ
ェロメータ等で測定可能であるが、本発明で目的として
いる測定精度とくらべ非常に低いため、レンズ11,1
2の曲率半径Rcv,Rccの値は未知なものとして扱
う。なお、凸レンズ11と凹レンズ12は設置の容易さ
から底が平らな形状が望ましいが、測定面に変形が生じ
ないのであれば、取付けの容易な治工具に接着等で固定
してもかまわない。
That is, the convex lens 11 and the concave lens 1
A value of 2 means that the radius of curvature Rcv of the convex surface 11a matches the radius of curvature Rcc of the concave surface 12a, or that the difference between the two radii of curvature Rcv and Rcc is clear. It is desirable that the convex lens 11 and the concave lens 12 be made of the same material so that the degree of the influence of thermal deformation is equal. Matching the radii of curvature Rcv and Rcc between the convex lens 11 and the concave lens 12 or measuring the difference between the radii of curvature Rcv and Rcc is performed by overlapping concave and convex spherical surfaces as is performed in normal glass lens manufacturing. By observing and processing and measuring the Newtonian fringes generated together, it is possible to easily realize the processing beyond the submicron order. At this time, each lens 1
The values of the radii of curvature Rcv and Rcc of the lenses 1 and 12 can be measured by a ring spherometer or the like, but are very low compared to the measurement accuracy aimed at in the present invention.
The values of the curvature radii Rcv and Rcc of 2 are treated as unknown. The convex lens 11 and the concave lens 12 preferably have flat bottoms for ease of installation. However, if the measurement surface does not deform, the convex lens 11 and the concave lens 12 may be fixed to a jig or tool which can be easily attached by bonding or the like.

【0015】また、図1(a)(b)には図示していな
いが、測定針4と凸レンズ11,凹レンズ12とは駆動
機構によりX、Y、Z方向に相対的に移動可能であると
共に、測定針4が両レンズ11,12の凹凸面11a,
12aに接触したことを検出してその時のX、Y、Z座
標値を演算装置に取り込むことができるようになってい
る。
Although not shown in FIGS. 1A and 1B, the measuring needle 4 and the convex lens 11 and the concave lens 12 can be relatively moved in the X, Y, and Z directions by a driving mechanism. The measuring needle 4 is provided with the uneven surfaces 11a of the two lenses 11 and 12,
The X, Y, and Z coordinate values at that time can be taken into an arithmetic unit by detecting that the contact has come into contact with 12a.

【0016】図1(a)において、測定針4は少なくと
も凸レンズ11の形状が認識できる回数を凸レンズ11
の凸面11aに接触させて形状測定する。演算処理時に
平均化の効果を高めるため、接触回数は多いほどよい。
接触時に得られたX、Y、Z座標値は、凸レンズ11の
凸面11aの曲率半径Rcvに測定針4の球状部4aの
曲率半径Rpを加えた値、すなわち測定針4の中心座標
値を示す。これらの測定点座標で構成されている曲面の
曲率半径R1は(1)式で表現できる。
In FIG. 1A, the measuring needle 4 determines at least how many times the shape of the convex lens 11 can be recognized.
The shape is measured by contacting the convex surface 11a. In order to increase the effect of averaging during arithmetic processing, it is better to increase the number of contacts.
The X, Y, and Z coordinate values obtained at the time of contact indicate the value obtained by adding the radius of curvature Rcv of the convex portion 11a of the convex lens 11 to the radius of curvature Rp of the spherical portion 4a of the measuring needle 4, that is, the central coordinate value of the measuring needle 4. . The radius of curvature R1 of the curved surface constituted by these measurement point coordinates can be expressed by equation (1).

【0017】 R1=Rcv+Rp (1 ) 曲率半径R1は、測定点座標に対して最小自乗法を用い
て球面形状をフィッティングして容易に演算で求めるこ
とができる。
R1 = Rcv + Rp (1) The radius of curvature R1 can be easily calculated by fitting the spherical shape to the measurement point coordinates using the least square method.

【0018】一方、図1(b)においては、凹レンズ1
2を図1(a)と同様な方法で測定する。このとき、凸
レンズ12の測定とできるだけ同じ条件が得られるよ
う、凹レンズ12を凸レンズ11を測定した位置に合わ
せた方が望ましい。得られた測定点座標で構成されてい
る曲面の曲率半径R2は(2)式で表現できる。
On the other hand, in FIG.
2 is measured in the same manner as in FIG. At this time, it is preferable that the concave lens 12 is set at the position where the convex lens 11 is measured so that the same condition as that of the measurement of the convex lens 12 is obtained as much as possible. The radius of curvature R2 of the curved surface constituted by the obtained measurement point coordinates can be expressed by equation (2).

【0019】 R2=Rcc−Rp (2 ) また、RcvとRccとは、あらかじめ等しくなるよう
に製作されているので Rcv=Rcc (3 ) である。そこで、(4)式、(5)式より、未知数Rc
v(=Rcc)および、Rpを求めることができる。
R2 = Rcc−Rp (2) Further, since Rcv and Rcc are previously manufactured to be equal, Rcv = Rcc (3). Therefore, from the equations (4) and (5), the unknown Rc
v (= Rcc) and Rp can be obtained.

【0020】 (R1+R2)/2={( Rcv+Rp)+(Rcc−Rp)}/2 =Rcv (4 ) (R1−R2)/2={( Rcv+Rp)−(Rcc−Rp)}/2 =Rp (5 ) なお、RcvとRccに誤差がある場合も、ニュートン
縞を観測することにより容易にその量eが把握できるの
で、得られた誤差量eでR1またはR2を補正すればR
cv、Rpを求めることは可能である。
(R1 + R2) / 2 = {(Rcv + Rp) + (Rcc-Rp)} / 2 = Rcv (4) (R1-R2) / 2 = {(Rcv + Rp)-(Rcc-Rp)} / 2 = Rp (5) Even when there is an error between Rcv and Rcc, the amount e can be easily grasped by observing Newton's fringes. If R1 or R2 is corrected using the obtained error amount e, R
It is possible to obtain cv and Rp.

【0021】すなわち、上記(3)式は、RcvとRc
cとは、誤差量eがあるので Rcv=Rcc+e (3)´ とする。また、上記(4)式、(5)式は、 (R1+R2)/2={( Rcv+Rp)+(Rcc−Rp)}/2 ={( Rcc+e+Rp)+(Rcc−Rp)}/2 =Rcc+e/2 (4)´ (R1−R2)/2={( Rcv+Rp)−(Rcc−Rp)}/2 ={( Rcc+e+Rp)−(Rcc−Rp)}/2 =Rp+e/2 (5)´ となり、誤差量eは既知であることから、未知数Rc
v,Rccおよび、Rpを求めることができる。
That is, the above equation (3) shows that Rcv and Rc
Since c has an error amount e, Rcv = Rcc + e (3) ′. Equations (4) and (5) are as follows: (R1 + R2) / 2 = {(Rcv + Rp) + (Rcc-Rp)} / 2 = {(Rcc + e + Rp) + (Rcc-Rp)} / 2 = Rcc + e / 2 (4) ′ (R1−R2) / 2 = {(Rcv + Rp) − (Rcc−Rp)} / 2 = {(Rcc + e + Rp) − (Rcc−Rp)} / 2 = Rp + e / 2 (5) ′, Since the error amount e is known, the unknown number Rc
v, Rcc and Rp can be obtained.

【0022】このようなものにあっては、凸レンズ11
や凹レンズ12は、凹、凸を重ね合わせて生じるニュー
トン縞を観察して加工等を行うことができるため、従来
のような校正用基準球2より、比較的容易に高精度のも
のが成形できることから、測定精度も向上することとな
る。また、かかる凸レンズ11及び凹レンズ12を用い
ることにより、従来の校正用基準球2と異なり、単に各
レンズ11,12の平面部をステージに載置するだけで
簡単に固定できると共に、従来の校正用基準球2と異な
り、変形する虞が少ないため、高精度の測定ができる。
In such a case, the convex lens 11
Since the concave lens 12 can be processed by observing Newton's fringes generated by superimposing concave and convex, it can be relatively easily formed with higher precision than the conventional calibration sphere 2. Therefore, the measurement accuracy is also improved. Further, by using the convex lens 11 and the concave lens 12, unlike the conventional calibration sphere 2, the flat portions of the lenses 11 and 12 can be easily fixed simply by being placed on the stage, and the conventional calibration sphere 2 can be used. Unlike the reference sphere 2, since there is little possibility of deformation, high-precision measurement can be performed.

【0023】[0023]

【発明の効果】以上説明してきたように、各請求項に記
載された発明によれば、凸、凹の球面形状を有する部材
は、凸凹を重ね合わせて生じるニュートン縞を観察して
加工等を行うことができるため、従来のような校正用基
準球2より、比較的容易に高精度のものが成形できるこ
とから、測定精度を向上させることができる。また、か
かる凸、凹の球面形状を有する部材を用いることによ
り、従来の校正用基準球2と異なり、単に各部材の平面
部をステージに載置するだけで簡単に固定できると共
に、従来の校正用基準球2と異なり、その凸、凹の球面
形状は変形する虞が少ないため、高精度の測定ができ
る。また、測定針の曲率半径が未知であっても、球面形
状の曲率半径の正確な値を測定することができる。
As described above, according to the invention described in the claims, a member having a convex or concave spherical shape can be processed by observing Newton's fringes generated by superimposing the concave and convex. Since it can be performed, a high-precision one can be formed relatively easily from the calibration reference sphere 2 as in the related art, so that the measurement accuracy can be improved. In addition, unlike the conventional calibration reference sphere 2, the use of the member having such a convex or concave spherical shape makes it possible to simply fix the flat portion of each member on the stage and easily fix the conventional calibration sphere. Unlike the reference sphere 2, the convex and concave spherical shapes are less likely to be deformed, so that highly accurate measurement can be performed. Further, even if the radius of curvature of the measuring needle is unknown, an accurate value of the radius of curvature of the spherical shape can be measured.

【図面の簡単な説明】[Brief description of the drawings]

【図1】この発明の実施の形態に係る測定針の曲率半径
の測定状態を示す説明図である。
FIG. 1 is an explanatory diagram showing a measurement state of a radius of curvature of a measurement needle according to an embodiment of the present invention.

【図2】従来例に係る測定針の曲率半径の測定状態を示
す説明図である。
FIG. 2 is an explanatory diagram showing a measurement state of a radius of curvature of a measuring needle according to a conventional example.

【符号の説明】[Explanation of symbols]

4 測定針 4a 球状部(先端部) 11 凸レンズ(凸の球面形状を有する部材) 11a 凸面(凸の球面形状) 12 凹レンズ(凹の球面形状を有する部材) 12a 凹面(凹の球面形状) 4 Measuring needle 4a Spherical part (tip) 11 Convex lens (member with convex spherical shape) 11a Convex surface (convex spherical shape) 12 Concave lens (member with concave spherical shape) 12a Concave surface (concave spherical shape)

Claims (2)

【特許請求の範囲】[Claims] 【請求項1】 測定針の先端部が球面形状を呈する形状
測定装置の該球面形状を測定する方法において、 曲率半径が一致または曲率半径の差が既知で、一方が
凸、他方が凹の球面形状を有する部材の、二つの球面の
形状に対し、曲率半径が未知で球面形状の測定針を用い
て前記2つの球面形状を測定し、その結果得られた測定
針の中心座標列が構成する球面の曲率半径を演算でそれ
ぞれ求め、前記2つの曲率半径の差から測定針の曲率半
径を求めることを特徴とする球面曲率半径測定方法。
1. A method for measuring a spherical shape of a shape measuring device in which a tip portion of a measuring needle has a spherical shape, wherein a radius of curvature coincides or a difference in radius of curvature is known, one of which is convex and the other is concave is spherical. For the two spherical shapes of the member having the shape, the two spherical shapes are measured using a spherically shaped measuring needle whose radius of curvature is unknown, and the resulting central coordinate sequence of the measuring needles is formed. A method of measuring a radius of curvature of a spherical surface, wherein a radius of curvature of a spherical surface is obtained by calculation, and a radius of curvature of a measuring needle is obtained from a difference between the two radiuses of curvature.
【請求項2】 請求項1に記載の球面曲率半径測定方法
において、 前記測定針の中心座標列から球面の曲率半径を求める際
に、計算上得られる球面と測定値との差の二乗和が最小
となるように最小自乗法を用いて計算することを特徴と
する球面曲率半径測定方法。
2. The spherical radius of curvature measuring method according to claim 1, wherein when calculating the radius of curvature of the spherical surface from the central coordinate sequence of the measuring needle, the sum of squares of the difference between the spherical surface and the measured value obtained by calculation is calculated. A method of measuring a radius of curvature of a spherical surface, wherein calculation is performed using a least square method so as to minimize the radius.
JP9038342A 1997-02-06 1997-02-06 Method for measuring radius of curvature of spherical face Pending JPH10221053A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP9038342A JPH10221053A (en) 1997-02-06 1997-02-06 Method for measuring radius of curvature of spherical face

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP9038342A JPH10221053A (en) 1997-02-06 1997-02-06 Method for measuring radius of curvature of spherical face

Publications (1)

Publication Number Publication Date
JPH10221053A true JPH10221053A (en) 1998-08-21

Family

ID=12522624

Family Applications (1)

Application Number Title Priority Date Filing Date
JP9038342A Pending JPH10221053A (en) 1997-02-06 1997-02-06 Method for measuring radius of curvature of spherical face

Country Status (1)

Country Link
JP (1) JPH10221053A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006349411A (en) * 2005-06-14 2006-12-28 Toshiba Mach Co Ltd Calibration gauge
CN108917689A (en) * 2018-08-01 2018-11-30 京东方科技集团股份有限公司 Radius of curvature measurement equipment and its measurement method
CN112964211A (en) * 2021-01-22 2021-06-15 大连理工大学 Method and device for detecting thickness and surface shape of spherical shell part

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006349411A (en) * 2005-06-14 2006-12-28 Toshiba Mach Co Ltd Calibration gauge
CN108917689A (en) * 2018-08-01 2018-11-30 京东方科技集团股份有限公司 Radius of curvature measurement equipment and its measurement method
WO2020024694A1 (en) * 2018-08-01 2020-02-06 京东方科技集团股份有限公司 Curvature radius measurement device and measurement method thereof
CN108917689B (en) * 2018-08-01 2021-01-22 京东方科技集团股份有限公司 Curvature radius measuring apparatus and measuring method thereof
CN112964211A (en) * 2021-01-22 2021-06-15 大连理工大学 Method and device for detecting thickness and surface shape of spherical shell part

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