JPH0756445B2 - Optical measurement device for minute clearance - Google Patents
Optical measurement device for minute clearanceInfo
- Publication number
- JPH0756445B2 JPH0756445B2 JP59252621A JP25262184A JPH0756445B2 JP H0756445 B2 JPH0756445 B2 JP H0756445B2 JP 59252621 A JP59252621 A JP 59252621A JP 25262184 A JP25262184 A JP 25262184A JP H0756445 B2 JPH0756445 B2 JP H0756445B2
- Authority
- JP
- Japan
- Prior art keywords
- interference
- minute clearance
- distribution
- light intensity
- minute
- 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.)
- Expired - Lifetime
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B11/00—Measuring arrangements characterised by the use of optical techniques
- G01B11/14—Measuring arrangements characterised by the use of optical techniques for measuring distance or clearance between spaced objects or spaced apertures
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Length Measuring Devices By Optical Means (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 この発明は、二つの部材間におけるサブミクロンオーダ
ーの微小すきまを光学的に高精度で測定する微小すきま
の光学的測定装置に関し、磁気デイスク装置やVTRの記
録媒体とヘツド間の微小すきまの測定などに利用できる
ものである。Description: TECHNICAL FIELD The present invention relates to an optical measuring device for minute clearance, which optically measures a minute clearance on the order of submicron between two members with high accuracy, and a magnetic disk device. It can also be used for measuring the minute clearance between the VTR recording medium and the head.
従来、この種の測定法として、白色光を用い微小すきま
によつて生ずる干渉色を肉眼によりとらえて、干渉色と
間隙の関係を示すカラースケールによつてすきまを換算
する方法が主として用いられていた。Conventionally, as a measurement method of this kind, a method has been mainly used in which white light is used to capture an interference color caused by a minute gap with the naked eye, and the gap is converted by a color scale showing a relationship between the interference color and a gap. It was
しかし、この方法では色の読取りを肉眼により行なうた
め、色の識別限界のため0.15μｍ以下のすきまを測定す
ることができない。また精度も悪く、個人差によるが、
±0.5μｍ程度の誤差は生ずる。However, in this method, since the color is read with the naked eye, it is not possible to measure a clearance of 0.15 μm or less due to the color discrimination limit. The accuracy is also poor, depending on individual differences,
An error of about ± 0.5 μm occurs.
この発明は、かかる問題点を解決するためになされたも
ので、高精度かつ高分解に微小すきまを自動的に測定す
ることができる微小すきまの光学的測定装置を得ること
を目的とする。The present invention has been made in order to solve such a problem, and an object thereof is to obtain an optical measuring device for a minute clearance capable of automatically measuring the minute clearance with high accuracy and high resolution.
この発明に係る微小すきまの光学的測定装置は、少なく
とも二つの異なる波長によって生じる光干渉を干渉光強
度としてそれぞれ独立に検出する光電変換素子と、光電
変換素子で検出された二つの検出信号をディジタル値に
変換し記憶する波形記憶装置と、この波形記憶装置で記
憶した干渉光強度の極小値及び極大値がそれぞれ−１と
１になるようにする規格化演算部と、少なくとも二つの
波長λ１，λ２に対して規格化された干渉光強度分布よ
り二つ部材間に形成された微小すきまの最小値の干渉次
数を求める干渉次数演算部、上記規格化された干渉光強
度分布と上記干渉次数から二つの部材間に形成された微
小すきま値の分布を求める微小すきま分布演算部、上記
微小すきま値分布の演算結果を記録・表示する微小すき
ま分布記録表示制御部からなる演算制御手段とを設けた
ものである。An optical measuring device for a minute clearance according to the present invention includes a photoelectric conversion element that independently detects optical interference caused by at least two different wavelengths as interference light intensity, and two detection signals detected by the photoelectric conversion element. A waveform storage device for converting and storing the converted value into a value, a standardization calculation unit for making the minimum value and the maximum value of the interference light intensity stored in the waveform storage device respectively −1 and 1, and at least two wavelengths λ 1 , Λ 2 , the interference order calculator for obtaining the interference order of the minimum value of the minute clearance formed between the two members from the interference light intensity distribution standardized for λ 2 , the normalized interference light intensity distribution and the interference Minute clearance distribution calculator that calculates the distribution of minute clearance values formed between two members from the order, minute clearance distribution record display system that records and displays the calculation result of the above minute clearance value distribution And an arithmetic control unit composed of a control unit.
この発明においては、少なくとも二つの異なる波長によ
って生じる光干渉を干渉光強度としてそれぞれ独立に光
電変換素子で検出した後、この干渉光強度の極小値及び
極大値がそれぞれ−１と１になるよう規格化された干渉
光強度分布より二つ部材間に形成された微小すきまの最
小値の干渉次数を求めると共に、上記規格化された干渉
光強度分布と上記干渉次数から二つの部材間に形成され
た微小すきま値の分布を求める。In the present invention, the optical interference caused by at least two different wavelengths is independently detected as the interference light intensity by the photoelectric conversion element, and then the minimum value and the maximum value of the interference light intensity are set to -1 and 1, respectively. The minimum interference order of the minute gap formed between the two members is obtained from the standardized interference light intensity distribution, and the standardized interference light intensity distribution and the interference order formed between the two members are formed. Obtain the distribution of minute clearance values.
以下、この発明の微小すきまの光学的測定装置の実施例
について図面に基づき説明する。第１図はその一実施例
の構成を示すブロツク図である。この第１図において、
１は光源であり、一般的に白色光源を用いている。An embodiment of an optical measuring device for a minute clearance according to the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the embodiment. In FIG. 1,
Reference numeral 1 is a light source, which generally uses a white light source.
この光源１から発生した光線は集光レンズ２で集光され
てダイクロイツクミラー3,フイルタ４を通つてミラー５
で反射されるようになつている。The light beam generated from the light source 1 is condensed by a condenser lens 2, passes through a dichroic mirror 3 and a filter 4, and then a mirror 5
It is supposed to be reflected by.
ダイクロイツクミラー３は、集光レンズ２で集光された
光を一定の波長λ０以上のものは反射させ、一定の波長
λ０以下のものは透過させるものであり、また、フイル
タ４は、ダイクロイツクミラー３より透過した光を中心
波長λ１に限定するフイルタである。The dichroic mirror 3 reflects the light condensed by the condensing lens 2 if it has a constant wavelength λ 0 or more and transmits it if it has a constant wavelength λ 0 or less. This is a filter that limits the light transmitted through the dichroic mirror 3 to the central wavelength λ 1 .
一方、６はダイクロイツクミラー３より反射した一定波
長λ０以上の光を反射させるミラーであり、このミラー
６で反射した波長λ０以上の光はフイルタ７を通り、ダ
イクロイツクミラー８で反射されるようになつている。Meanwhile, 6 is a mirror for reflecting a predetermined wavelength lambda 0 or more of the light reflected from the dichroic mirror 3, the wavelength lambda 0 or more light reflected by the mirror 6 passes through the filter 7, is reflected by the dichroic mirror 8 It is becoming like this.
また、フイルタ７は中心波長λ２に限定するフイルタで
あり、ダイクロイツクミラー８は、ミラー５より反射さ
れた波長λ１の光を反射させ、フイルタ７より透過され
た波長λ２の光を透過させ、波長λ１と波長λ２の光を
ほぼ同一の光軸上に合成するものである。ここで波長λ
０，λ１，λ２の関係は、当然次のような関係でなくて
はならない。Further, the filter 7 is a filter limited to the central wavelength λ 2 , and the dichroic mirror 8 reflects the light of the wavelength λ 1 reflected by the mirror 5 and transmits the light of the wavelength λ 2 transmitted by the filter 7. Then, the light having the wavelength λ 1 and the light having the wavelength λ 2 are combined on substantially the same optical axis. Where wavelength λ
The relationship of 0 , λ 1 , and λ 2 must be the following relationship.
λ１＜λ０＜λ２ ………（１） ダイクロイツクミラー８で反射した光は波長λ１，λ２
による光を集光レンズ９で集光して、ハーフミラー10に
入射されるようになつている。ハーフミラー10はこの集
光レンズ９で集光した光を対物レンズ11の方向に反射さ
せ、この対物レンズ11を通過した光は模擬ヘツド12に入
射するようになつている。λ 1 <λ 0 <λ 2 (1) The light reflected by the dichroic mirror 8 has wavelengths λ 1 and λ 2.
The light is condensed by the condenser lens 9 and is incident on the half mirror 10. The half mirror 10 reflects the light condensed by the condenser lens 9 toward the objective lens 11, and the light passing through the objective lens 11 enters the simulated head 12.
模擬ヘツド12を通過した光は記録媒体13で反射され、再
び模擬ヘツド12,対物レンズ11,ハーフミラー10,集光レ
ンズ14を通り、光電変換素子15に入射するようになつて
いる。The light that has passed through the simulated head 12 is reflected by the recording medium 13, passes through the simulated head 12, the objective lens 11, the half mirror 10, and the condenser lens 14 again, and enters the photoelectric conversion element 15.
この光電変換素子15は、模擬ヘツド12,記録媒体13から
の反射光をそれぞれ独立に検出し、電気信号に変換する
もので、この実施例ではR.G.B独立に検出するTV（テレ
ビ）カメラを用いている。The photoelectric conversion element 15 independently detects reflected light from the simulated head 12 and the recording medium 13 and converts it into an electric signal. In this embodiment, a TV (television) camera that detects RGB independently is used. There is.
この光電変換素子15の出力はTVモニター16および波形記
憶装置17に送出するようになつている。波形記憶装置17
は、光電変換素子15によつて独立に検出した波長λ１，
λ２の光を光電変換した信号を独立にA/D変換して記憶
するものであり、この波形記憶装置17の出力は演算制御
装置18に送出するようになつている。The output of the photoelectric conversion element 15 is sent to the TV monitor 16 and the waveform storage device 17. Waveform storage device 17
Is a wavelength λ 1 , independently detected by the photoelectric conversion element 15,
A signal obtained by photoelectrically converting light of λ 2 is independently A / D converted and stored. The output of the waveform storage device 17 is sent to the arithmetic and control unit 18.
演算制御装置18は波形記憶装置17の制御と波形記憶装置
17のデータを比較して微小すきま値を演算するものであ
る。The arithmetic and control unit 18 controls the waveform storage unit 17 and the waveform storage unit.
It compares 17 data and calculates a minute clearance value.
一方、上記模擬ヘツド12の変位は変位計プローブ19aで
検出してその検出出力を変位計アンプ19cに送るように
なつており、また記録媒体13の変位は変位計19bで検出
して変位計アンプ19cに送るようになつている。On the other hand, the displacement of the simulated head 12 is detected by the displacement gauge probe 19a and the detection output is sent to the displacement gauge amplifier 19c, and the displacement of the recording medium 13 is detected by the displacement gauge 19b. It is supposed to be sent to 19c.
変位計アンプ19cは図中h0で示す模擬ヘツド12と記録媒
体13との間の最小すきまを演算測定する変位計アンプで
あり、主としてこの発明の本装置の精度確認用に用いた
もので、通常は使用しない。The displacement gauge amplifier 19c is a displacement gauge amplifier that calculates and measures the minimum clearance between the simulated head 12 and the recording medium 13 shown by h 0 in the figure, and is mainly used for confirming the accuracy of the present device of the present invention. Not normally used.
次に動作について説明する。光源１より発する広帯域の
波長部分を持つ光は集光レンズ２を通つてダイクロイツ
クミラー３に結像し、λ０以下の波長成分をもつ光は透
過し、フイルタ４を透過することにより中心波長λ１を
有する光がミラー５によつて反射されダイクロイツクミ
ラー８に入射される。Next, the operation will be described. Light having a broadband wavelength portion emitted from the light source 1 passes through the condenser lens 2 to form an image on the dichroic mirror 3, light having a wavelength component of λ 0 or less is transmitted, and light passing through the filter 4 causes the central wavelength The light having λ 1 is reflected by the mirror 5 and enters the dichroic mirror 8.
一方、ダイクロイツクミラー３に結像した光のうちλ０
以上の波長成分をもつ光は反射してミラー６によつてフ
イルタ７に入射される。フイルタ７を透過することによ
り中心波長λ２を有する光がダイクロイツクミラー８に
入射される。On the other hand, of the light imaged on the dichroic mirror 3, λ 0
The light having the above wavelength components is reflected and is incident on the filter 7 by the mirror 6. Light having a central wavelength λ 2 is incident on the dichroic mirror 8 by passing through the filter 7.
ダイクロイツクミラー８に入射された前述の光のうち波
長λ１を有する光は反射し、波長λ２を有する光は透過
することにより波長λ１，λ２の光は合成され同一の光
軸を有して集光レンズ９へ入射される。この光はハーフ
ミラー10によつて反射して対物レンズ11へ入射し模擬ヘ
ツド12へ照射される。Of the above-mentioned lights incident on the dichroic mirror 8, the light having the wavelength λ 1 is reflected, and the light having the wavelength λ 2 is transmitted, whereby the lights having the wavelengths λ 1 and λ 2 are combined to form the same optical axis. It is then incident on the condenser lens 9. This light is reflected by the half mirror 10, enters the objective lens 11, and is irradiated to the simulated head 12.
以上のように照射された二つの波長成分λ１，λ２を有
する光は模擬ヘツド12の面12aと記録媒体13の面13aとで
反射し、その光路差によつてそれぞれ干渉光となつて、
対物レンズ11,ハーフミラー10を通つて集光レンズ14に
より光電変換素子15上で結像する。The light having the two wavelength components λ 1 and λ 2 irradiated as described above is reflected by the surface 12a of the simulated head 12 and the surface 13a of the recording medium 13, and is converted into interference light by the optical path difference. ,
An image is formed on the photoelectric conversion element 15 by the condenser lens 14 through the objective lens 11 and the half mirror 10.
光電変換素子15で結像した波長λ１，λ２それぞれの成
分による干渉光を独立に光電変換して波形記憶装置17に
入力され、波形記憶装置17にてA/D変換した後に記憶さ
れる。The interference light due to the respective components of the wavelengths λ 1 and λ 2 imaged by the photoelectric conversion element 15 is independently photoelectrically converted and input to the waveform storage device 17, which is stored after being A / D converted by the waveform storage device 17. .
波形記憶装置17は演算制御装置18によつて波形記憶のタ
イミング制御や記憶の制御が行なわれ、記憶されたデー
タは、演算制御装置18に転送される。The waveform storage device 17 is subjected to waveform storage timing control and storage control by the arithmetic control device 18, and the stored data is transferred to the arithmetic control device 18.
第２図は、二つの波長λ１，λ２によつて得た干渉光の
強度分布の一例で横軸は第１図中矢印で示したｘ軸を示
すもので、模擬ヘツド12と記録媒体13とで形成される微
小すきまh0の位置を示すものである。縦軸は、干渉によ
つて生じた明暗の光強度を示す。FIG. 2 shows an example of the intensity distribution of the interference light obtained by the two wavelengths λ 1 and λ 2. The horizontal axis shows the x-axis indicated by the arrow in FIG. 1, and the simulated head 12 and the recording medium are used. The position of the minute clearance h 0 formed by 13 and 13 is shown. The vertical axis represents the light intensity of light and dark produced by the interference.
この第２図のように、干渉光強度は入射光の照度むら、
記録媒体13および模擬ヘツド12からの反射強度むら、す
きまの大きさによるコントラスト変化などにより、極大
値、極小値が一定の値を示さず干渉強度にむらが生じて
いる。この状態は一般に次の（２）式のように表わされ
る。As shown in FIG. 2, the intensity of the interference light is uneven in the illuminance of the incident light,
Due to the unevenness of the reflection intensity from the recording medium 13 and the simulated head 12, the contrast change due to the size of the clearance, etc., the maximum and minimum values do not show constant values, and the interference intensity becomes uneven. This state is generally expressed by the following equation (2).
Ｉ（ｘ）：干渉光強度 I1（ｘ）：記録媒体からの反射光強度 I2（ｘ）：模擬ヘツドからの反射光強度 λ ：光の波長 ｈ（ｘ）：すきま分布 ｘ ：すきま位置 （２）式により、干渉強度むらを除去すると となる。この実施例では、Inormal（ｘ）を求めるため
に次のような手順で演算処理を行なつた。 I (x): Interference light intensity I 1 (x): Reflected light intensity from recording medium I 2 (x): Reflected light intensity from simulated head λ: Light wavelength h (x): Clearance distribution x: Clearance position If the interference intensity unevenness is removed by the equation (2), Becomes In this embodiment, in order to obtain Inormal (x), arithmetic processing is performed in the following procedure.
（ｉ）第２図における干渉強度分布の極大値（図中Ｐで
示す）を求める。(I) The maximum value (indicated by P in the figure) of the interference intensity distribution in FIG. 2 is obtained.
（ii）極大値および極小値を結ぶ包絡線Ipeak（ｘ）,Ib
ottom（ｘ）を推定する（図中破線で示す）。この推定
には、３次のスプライン関数を用いた。(Ii) Envelope Ipeak (x), Ib connecting the maximum and minimum values
Estimate ottom (x) (shown by the broken line in the figure). A cubic spline function was used for this estimation.
（iii）Ｉ（ｘ）からInormal（ｘ）への変換には推定し
たIpeak（ｘ）,Ibottom（ｘ）より （iv）以上の演算をそれぞれλ１，λ２の波長より得た
干渉光強度分布に対して行なう。（第３図） このようにして求めた規格化干渉光強度分布Inormal
1（ｘ），Inormal2（ｘ）は、（３）式より次のような
関係にある。(Iii) From the estimated Ipeak (x), Ibottom (x) for the conversion from I (x) to Inormal (x) (Iv) The above calculation is performed on the interference light intensity distribution obtained from the wavelengths of λ 1 and λ 2 , respectively. (Fig. 3) Normalized interference light intensity distribution Inormal obtained in this way
1 (x) and Inormal 2 (x) have the following relationship from the equation (3).
この式より、すきま分布ｈ（ｘ）は となる。ここでm1およびm2は干渉次数と呼ばれる整数で
（５），（６）式におけるcos関数の周期性によつて生
ずるものである。m1,m2を求めるために（７），（８）
より m1λ１−m2λ２＝β ………（９） となる。 From this equation, the clearance distribution h (x) is Becomes Here, m 1 and m 2 are integers called interference orders, which are generated by the periodicity of the cos function in equations (5) and (6). (7), (8) to find m 1 and m 2
Therefore, m 1 λ 1 −m 2 λ 2 = β (9)
ただし となる。適当なλ１，λ２を選ぶことにより、すきまの
最小値が数ミクロン以上の値でもm1とm2の差が０か１で
あるようにすることができる。この条件を設ければ
（９）式より β０のとき β＞０のとき となることが理論上明らかである。よつて演算制御装置
18により（10）式を用いてβを求め、βの値によつて
（11）式または（12）式を用いてm1,m2の値を求まり、
（７）式または（８）式を用いてすきま分布ｈ（ｘ）を
得ることができ、微小すきまの測定が行なえる。However Becomes By selecting appropriate λ 1 and λ 2 , the difference between m 1 and m 2 can be 0 or 1 even if the minimum clearance is a value of several microns or more. If this condition is set, when β0 from Eq. (9), When β> 0 It is theoretically clear that Yotsetsu control unit
18 is used to find β using equation (10), and the value of β is used to find the values of m 1 and m 2 using equation (11) or equation (12),
The clearance distribution h (x) can be obtained by using the expression (7) or the expression (8), and the minute clearance can be measured.
第４図は模擬ヘツド12に曲率半径20mmの平凸レンズを用
い、記録媒体13と模擬ヘツド12のすきま最小値h0を０〜
１μｍごとに変化させたときの測定例である。また第５
図は変位計19によつて求めたすきま最小値h0と本測定装
置より得たh0との比較であり±0.03μｍ以下の測定精度
を有していることがわかる。In FIG. 4, a plano-convex lens having a radius of curvature of 20 mm is used as the simulated head 12, and the minimum clearance h 0 between the recording medium 13 and the simulated head 12 is 0 to 0.
It is an example of measurement when changing every 1 μm. The fifth
Figure it can be seen that a comparator is is ± 0.03 .mu.m or less in the measurement accuracy of the h 0 obtained from the measuring device and the gap minimum value h 0 determined connexion by the displacement gauge 19.
なお、上記実施例では二つの異なる波長による干渉光を
得るのにダイクロイツクミラー3,8を用いた光学系によ
つて二つの異なる波長の光を合成し、模擬ヘツド12,記
録媒体13に照射した例を示したが、光源に２種類の波長
を発振させるレーザを用いてもよく、また白色光源を直
接模擬ヘツド12,記録媒体13に照射し、干渉光を光電変
換素子で検出する直前で２種の波長による干渉光をフイ
ルタによつて選別してもよい。In the above embodiment, light of two different wavelengths is combined by an optical system using dichroic mirrors 3 and 8 to obtain interference light of two different wavelengths, and the simulated head 12 and the recording medium 13 are irradiated with the light. However, a laser that oscillates two kinds of wavelengths may be used as a light source, and a white light source may be directly irradiated onto the simulation head 12 and the recording medium 13 and immediately before the interference light is detected by the photoelectric conversion element. The interference light of two kinds of wavelengths may be sorted by a filter.
さらに上記実施例では模擬ヘツド12と記録媒体13間のす
きまを測定する例を示したが物体の表面形状を測定する
のにも利用でき、模擬ヘツドの代わりに平面度のよいオ
プテイカルフラツトなどの参照面を使い記録媒体の代わ
りに被測定物を配置すれば被測定物の表面粗さ、平面度
などの測定が可能となり同様の効果が得られる。Further, in the above embodiment, an example of measuring the clearance between the simulated head 12 and the recording medium 13 is shown, but it can also be used to measure the surface shape of an object, such as an optical flat with good flatness instead of the simulated head. If the object to be measured is arranged in place of the recording medium using the reference surface of, the surface roughness and flatness of the object to be measured can be measured, and the same effect can be obtained.
この発明は以上説明したとおり、少なくとも二つの波長
によつて生ずる光干渉をそれぞれ独立に検出する光電変
換素子によつて電気信号に変換し、波形記憶装置によつ
てA/D変換を行つて、そのデータを用いて演算制御装置
によつて干渉光強度を規格し、干渉次数を求め、微小す
きま分布を求める処理を行うように構成したので、容易
な構成で精度の高い微小すきま測定が行えると共に、同
一光軸の光よりに２波長を同時に検出し、この検出結果
に基づいて微小すきま値を演算するため短時間に微小す
きま値が測定できるという効果がある。As described above, the present invention converts an electric signal generated by at least two optical interferences caused by at least two wavelengths into an electric signal by the photoelectric conversion element, and performs A / D conversion by a waveform storage device. The data is configured to standardize the interference light intensity by the arithmetic and control unit, obtain the interference order, and perform the process for obtaining the minute clearance distribution, so that it is possible to perform highly accurate minute clearance measurement with an easy configuration. Since two wavelengths are simultaneously detected from the light of the same optical axis and the minute clearance value is calculated based on the detection result, there is an effect that the minute clearance value can be measured in a short time.
第１図は、この発明の微小すきまの光学的測定装置の一
実施例の構成を示すブロツク図、第２図は同上微小すき
まの光学的測定装置より得た干渉光強度分布の一例を示
す図、第３図は同上微小すきまの光学的測定装置におけ
る演算制御装置により、規格化した干渉光強度分布、第
４図は同上微小すきまの光学的測定装置により求めた微
小すきまの例を示す図、第５図は同上微小すきまの光学
的測定装置の測定精度を示す図である。 １……光源、２……集光レンズ、3,8……ダイクロイツ
クミラー、４……フイルタ、5,6……ミラー、12……模
擬ヘツド、13……記録媒体、15……光電変換素子、17…
…波形記憶装置、18……演算制御装置、19a,19b……変
位計プローブ、19c……変位計アンプ。FIG. 1 is a block diagram showing the construction of an embodiment of an optical measuring device for a minute clearance of the present invention, and FIG. 2 is a diagram showing an example of an interference light intensity distribution obtained from the optical measuring device for a minute clearance. , FIG. 3 is the same as the above, the interference light intensity distribution standardized by the arithmetic and control unit in the optical measurement apparatus for the minute clearance, and FIG. 4 is a diagram showing an example of the minute clearance obtained by the optical measurement apparatus for the minute clearance. FIG. 5 is a diagram showing the measurement accuracy of the optical measurement device for minute clearances. 1 ... Light source, 2 ... Focusing lens, 3,8 ... Dichroic mirror, 4 ... Filter, 5,6 ... Mirror, 12 ... Simulated head, 13 ... Recording medium, 15 ... Photoelectric conversion Element, 17 ...
… Waveform memory device, 18 …… Computer control device, 19a, 19b …… Displacement probe, 19c …… Displacement amplifier.
Claims (4)
る光干渉を干渉光強度としてそれぞれ独立に検出する光
電変換素子と、光電変換素子で検出された二つの検出信
号をディジタル値に変換し記憶する波形記憶装置と、こ
の波形記憶装置で記憶した干渉光強度の極小値及び極大
値がそれぞれ−１と１になるようにする規格化演算部
と、少なくとも二つの波長λ１，λ２に対して規格化さ
れた干渉光強度分布より二つ部材間に形成された微小す
きまの最小値の干渉次数を求める干渉次数演算部、上記
規格化された干渉光強度分布と上記干渉次数から二つの
部材間に形成された微小すきま値の分布を求める微小す
きま分布演算部、上記微小すきま値分布の演算結果を記
録・表示する微小すきま分布記録表示制御部からなる演
算制御手段とを備えたことを特徴とする微小すきまの光
学的測定装置。1. A photoelectric conversion element for independently detecting optical interference caused by at least two different wavelengths as interference light intensity, and a waveform storage for converting two detection signals detected by the photoelectric conversion element into digital values and storing them. A device, a normalization operation unit for making the minimum value and the maximum value of the interference light intensity stored in the waveform storage device respectively -1 and 1, and normalizing at least two wavelengths λ 1 , λ 2 . The interference order calculator for obtaining the minimum interference order of the minute clearance formed between the two members from the generated interference light intensity distribution, formed between the two members based on the standardized interference light intensity distribution and the interference order. A minute clearance distribution calculating unit for obtaining the distribution of the minute clearance values that have been recorded, and an arithmetic control unit including a minute clearance distribution record display control section for recording and displaying the calculation result of the minute clearance value distribution. An optical measuring device for minute clearances characterized by the above.
値および極小値を極大包絡線、極小包絡線を三次のスプ
ライン関数によって推定することにより、干渉強度むら
を除去する処理を行なうことを特徴とする特許請求の範
囲第１項記載の微小すきまの光学的測定装置。2. A normalizing operation unit estimates a maximum value and a minimum value of the interference light intensity by using a maximum envelope curve and a minimum envelope curve by a cubic spline function to remove the interference intensity unevenness. An optical measuring device for a minute clearance according to claim 1.
の規格化された干渉強度をInormal1（Ｘ），Inoromal2
（Ｘ）とすると、 の値を求め、 を用いて干渉次数m1,m2を計算することを特徴とする特
許請求の範囲第１項記載の微小すきまの光学的測定装
置。3. An interference order calculator is provided with two wavelengths λ 1 and λ 2.
The normalized interference intensity of Inormal 1 (X), Inoromal 2
(X) Find the value of An optical measuring device for a minute clearance according to claim 1 , wherein the interference orders m 1 and m 2 are calculated by using.
をｈ（Ｘ）とすると、 または によって求める処理を行なうことを特徴とする特許請求
の範囲第１項記載の微小すきまの光学的測定装置。4. The minute clearance distribution calculating unit, when the minute clearance distribution is h (X), Or The optical measuring device for microscopic clearance according to claim 1, characterized in that the processing is performed by
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59252621A JPH0756445B2 (en) | 1984-11-29 | 1984-11-29 | Optical measurement device for minute clearance |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59252621A JPH0756445B2 (en) | 1984-11-29 | 1984-11-29 | Optical measurement device for minute clearance |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS61130807A JPS61130807A (en) | 1986-06-18 |
| JPH0756445B2 true JPH0756445B2 (en) | 1995-06-14 |
Family
ID=17239904
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP59252621A Expired - Lifetime JPH0756445B2 (en) | 1984-11-29 | 1984-11-29 | Optical measurement device for minute clearance |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0756445B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63205503A (en) * | 1987-02-20 | 1988-08-25 | Mitsubishi Electric Corp | Optical measuring instrument for fine gap |
| US5311287A (en) * | 1992-02-25 | 1994-05-10 | International Business Machines Corporation | Direct access storage device with head-disc dynamics monitor |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5817305A (en) * | 1981-07-24 | 1983-02-01 | Hitachi Ltd | Device for measuring magnetic head spacing |
-
1984
- 1984-11-29 JP JP59252621A patent/JPH0756445B2/en not_active Expired - Lifetime
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5817305A (en) * | 1981-07-24 | 1983-02-01 | Hitachi Ltd | Device for measuring magnetic head spacing |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS61130807A (en) | 1986-06-18 |
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