JPH0426685B2 - - Google Patents
Info
- Publication number
- JPH0426685B2 JPH0426685B2 JP61275019A JP27501986A JPH0426685B2 JP H0426685 B2 JPH0426685 B2 JP H0426685B2 JP 61275019 A JP61275019 A JP 61275019A JP 27501986 A JP27501986 A JP 27501986A JP H0426685 B2 JPH0426685 B2 JP H0426685B2
- Authority
- JP
- Japan
- Prior art keywords
- focus
- light
- signal
- axis
- edge
- 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
- 230000003287 optical effect Effects 0.000 claims description 37
- 238000005259 measurement Methods 0.000 claims description 36
- 239000000523 sample Substances 0.000 claims description 23
- 238000001514 detection method Methods 0.000 claims description 15
- 238000005286 illumination Methods 0.000 claims description 15
- 230000001934 delay Effects 0.000 claims description 4
- 238000003708 edge detection Methods 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 238000000034 method Methods 0.000 description 2
- 230000007423 decrease Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
Landscapes
- Length Measuring Devices By Optical Means (AREA)
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、光学測定機に係り、特に、投影機や
測定顕微鏡に用いるのに好適な、拡大光学系とオ
ートフオーカス系を備え、測定対象物のエツジで
規定される形状を座標値として自動的に取込むこ
とにより測定する機能を有する光学測定機に関す
る。[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an optical measuring instrument, and in particular, it is equipped with a magnifying optical system and an autofocus system suitable for use in a projector or a measuring microscope, and is suitable for use in a measuring microscope. The present invention relates to an optical measuring instrument that has a function of measuring a shape defined by the edges of an object by automatically capturing it as coordinate values.
投影機や測定顕微鏡の如く、載物台上に測定対
象物を載置し、拡大光学系で投影し、スクリーン
もしくは接眼レンズに形成されたヘアラインに測
定点の像が合致するように載物台を移動させて、
その移動量を特定することにより、測定対象物の
形状を測定する光学測定機が普及している。
Like a projector or a measuring microscope, the object to be measured is placed on the stage, projected by an enlarging optical system, and the stage is set so that the image of the measurement point matches the hairline formed on the screen or eyepiece. move the
Optical measuring instruments that measure the shape of an object to be measured by specifying the amount of movement have become widespread.
このような光学測定機においては、測定点がヘ
アラインに合致したことを判定するのは肉眼であ
るため、個人誤差、測定能率等の点で問題があ
り、これを解消するため、測定点を自動的に検出
して電気的に座標の取込みを行うエツジ検出装置
が開発されている。 In such optical measuring machines, it is the naked eye that determines whether the measurement point matches the hairline, so there are problems with individual errors and measurement efficiency. An edge detection device has been developed that detects edges visually and captures coordinates electrically.
第５図は、出願人が特開昭61−128105で開示し
たエツジ検出装置を含む投影機を示したものであ
る。 FIG. 5 shows a projector including an edge detection device disclosed by the applicant in Japanese Patent Laid-Open No. 128105/1983.
この投影機においては、光源１からの光をコン
デンサレンズ２を介して載物台３の下方から、該
載物台３上の測定対象物４に照射する。その透過
光は、投影レンズ５を介してスクリーン６上に投
影され、該スクリーン６上に測定対象物４の画像
が結像される。この投影画像により、間接的に測
定対像物４の寸法測定等を行うのであるが、その
エツジを検出するためのエツジ１２が、スクリー
ン６と接するように設けられた透明板２２に固定
されている。このエツジ１２は、その受光面を投
影像の明暗のエツジが通過すると受光量が変化す
ることを利用して、エツジ信号を発生するように
構成されているため、図示しない測長エンコーダ
が組込まれた載物台３を移動させつつ、前記セン
サ１２から得られるエツジ信号で測長エンコーダ
の信号から得られた座標値を取込むことによつ
て、エツジで規定された測定対象物４の形状が、
能率的に個人誤差なく測定できる。 In this projector, light from a light source 1 is irradiated from below a stage 3 through a condenser lens 2 onto an object 4 to be measured on the stage 3. The transmitted light is projected onto a screen 6 via a projection lens 5, and an image of the measurement object 4 is formed on the screen 6. This projected image indirectly measures the dimensions of the object to be measured 4, and the edge 12 for detecting the edge is fixed to a transparent plate 22 provided in contact with the screen 6. There is. This edge 12 is configured to generate an edge signal by utilizing the change in the amount of light received when the bright and dark edges of the projected image pass through its light-receiving surface, so a length measurement encoder (not shown) is incorporated. The shape of the object to be measured 4 defined by the edges is determined by capturing the coordinate values obtained from the length measurement encoder signals using the edge signals obtained from the sensor 12 while moving the table 3. ,
Can be measured efficiently and without individual error.
従つて、このような従来の光学測定機において
は、透過照明による像端面の位置検出等、測定す
べき形状が測定対象物４の輪郭そのもので、その
像がコントラストの高い鮮明な明暗のエツジから
形成されている場合等には良好なエツジ信号が得
られる。 Therefore, in such conventional optical measuring instruments, the shape to be measured is the outline of the object 4 to be measured, such as detecting the position of the image end face using transmitted illumination, and the image is not clearly defined by bright and dark edges with high contrast. If such an edge is formed, a good edge signal can be obtained.
しかしながら、測定すべき形状が、第６図に示
す如く、測定対象物４の凹部８の直径Ｄであるよ
うな場合には、例えば透過照明系の代わりに落射
照明系を切換えて使用しても、その凹部８のエツ
ジ８Ａの像は明暗の差が少ないため、良好なエツ
ジ信号が得られず測定が困難となるという問題点
を有していた。
However, if the shape to be measured is the diameter D of the recess 8 of the object to be measured 4, as shown in FIG. Since the image of the edge 8A of the recessed portion 8 has little difference in brightness, a problem arises in that a good edge signal cannot be obtained and measurement is difficult.
本発明は、前記従来の問題点を解消するべくな
されたもので、測定すべき形状が、その像の明暗
の差が少ないエツジ部から形成されている場合に
も良好なエツジ信号を得ることができ、そのエツ
ジ信号を用いることにより測定対象物の制限を受
けることなく形状測定が可能であり、しかも、測
定対象物に集光するプローブ光の焦点がずれたと
しても、迅速且つ確実に焦点を合わせることがで
き、従つて測定点と拡大光学系との距離を常に一
定とすることができる光学測定機を提供すること
を目的とする。
The present invention was made to solve the above-mentioned conventional problems, and it is possible to obtain a good edge signal even when the shape to be measured is formed from an edge portion where the difference in brightness of the image is small. By using the edge signal, it is possible to measure the shape of the object to be measured without being subject to any restrictions. Moreover, even if the focus of the probe light focused on the object to be measured shifts, it can be quickly and reliably focused. It is an object of the present invention to provide an optical measuring device that can adjust the distance between the measuring point and the magnifying optical system, and therefore can always keep the distance between the measuring point and the magnifying optical system constant.
本発明は、光学測定機において、落射照明系及
び拡大光学系と、前記落射照明系の照明光に重畳
して測定対象物の測定点に集光するようプローブ
光を照射する発光素子、該測定対象物から反射さ
れるプローブ光を２分し、且つ該２分されたプロ
ーブ光のそれぞれの焦点面から光軸上で互いに逆
方向に偏位させたピンホールを含む光学手段、該
光学手段からプローブ光を入射するようそれぞれ
のピンホールの背面に置かれた２つの受光素子を
含む焦点検出系と、該焦点検出系の２つの受光素
子からの出力を差動増幅して焦点信号を形成する
焦点信号回路、該焦点信号回路から出力された焦
点信号を遅延させて帰還信号を生成するＺ軸設定
回路、該Ｚ軸設定回路から出力される帰還信号に
よりＺ軸を駆動させるＺ軸駆動回路からなるオー
トフオーカス系と、前記焦点信号回路から出力さ
れた焦点信号の絶対値を求める絶対値変換器と参
照値の比較器から構成され、該焦点信号の絶対値
が所定の値を越えた時にエツジ信号を出力するエ
ツジ判定回路とを備え、測定対象物と前記拡大光
学系とを光軸に垂直な面内で相対移動させつつ、
前記エツジ信号の出力時に相対移動量を特定する
ことにより、測定対象物のエツジで形成される形
状の測定を行うようにして、前記目的を達成した
ものである。
The present invention provides an optical measuring instrument that includes an epi-illumination system, a magnification optical system, a light-emitting element that irradiates probe light so as to be superimposed on the illumination light of the epi-illumination system and converge on a measurement point of a measurement object, and An optical means that divides the probe light reflected from the object into two, and includes a pinhole that is deviated from the focal plane of each of the two divided probe light in opposite directions on the optical axis, from the optical means. A focus detection system includes two light-receiving elements placed on the back side of each pinhole to receive the probe light, and a focus signal is formed by differentially amplifying the outputs from the two light-receiving elements of the focus detection system. A focus signal circuit, a Z-axis setting circuit that delays the focus signal output from the focus signal circuit to generate a feedback signal, and a Z-axis drive circuit that drives the Z-axis using the feedback signal output from the Z-axis setting circuit. It consists of an autofocus system, an absolute value converter for determining the absolute value of the focus signal output from the focus signal circuit, and a reference value comparator, and when the absolute value of the focus signal exceeds a predetermined value, an edge determination circuit that outputs an edge signal, while relatively moving the measurement target and the magnifying optical system in a plane perpendicular to the optical axis;
The object is achieved by specifying the amount of relative movement when outputting the edge signal to measure the shape formed by the edges of the object to be measured.
本発明においては、落射照明系の照明光に重畳
して測定対象物の測定点に集光するようプローブ
光を照射する発光素子、該測定対象物から反射さ
れるプローブ光を２分し、且つ該２分されたプロ
ーブ光のそれぞれの焦点面から光軸上で互いに逆
方向に偏位させたピンホールを含む光学手段、該
光学手段からプローブ光を入射するようそれぞれ
のピンホールの背面に置かれた２つの受光素子を
含む焦点検出系と、該焦点検出系の２つの受光素
子からの出力を差動増幅して焦点信号を形成する
焦点信号回路、該焦点信号回路から出力された焦
点信号を遅延させて帰還信号を生成するＺ軸設定
回路、該Ｚ軸設定回路から出力される帰還信号に
よりＺ軸を駆動させるＺ軸駆動回路からなるオー
トフオーカス系と、前記焦点信号回路から出力さ
れた焦点信号の絶対値を求める絶対値変換器と参
照値の比較器から構成され、該焦点信号の絶対値
が所定の値を越えた時にエツジ信号を出力するよ
うにしている。従つて、測定すべき形状が、その
像の明暗の差が少ないエツジ部から形成されてい
る場合にも、良好なエツジ信号が得られ、そのエ
ツジ信号を用いることにより測定対象物によらず
形状測定が可能となる。更に、測定対象物に集光
するプローブ光の焦点がずれたとしても、迅速且
つ確実に焦点を合わせることができ、従つて測定
点と拡大光学系との距離を常に一定とすることが
できる。
In the present invention, a light emitting element emits probe light so as to be superimposed on the illumination light of an epi-illumination system and converges on a measurement point of a measurement target, a light emitting element that divides the probe light reflected from the measurement target into two, and optical means including pinholes that are deviated in opposite directions on the optical axis from the respective focal planes of the divided probe light, and placed on the back surface of each pinhole so that the probe light is incident from the optical means; a focus detection system including two light-receiving elements of the focus detection system; a focus signal circuit that differentially amplifies outputs from the two light-receiving elements of the focus detection system to form a focus signal; and a focus signal output from the focus signal circuit. an autofocus system consisting of a Z-axis setting circuit that delays and generates a feedback signal, a Z-axis drive circuit that drives the Z-axis with the feedback signal output from the Z-axis setting circuit, and a Z-axis drive circuit that generates a feedback signal output from the focus signal circuit. It consists of an absolute value converter for determining the absolute value of the focus signal and a reference value comparator, and outputs an edge signal when the absolute value of the focus signal exceeds a predetermined value. Therefore, even when the shape to be measured is formed from edge parts with little difference in brightness and darkness in the image, a good edge signal can be obtained, and by using the edge signal, the shape can be determined regardless of the object to be measured. Measurement becomes possible. Furthermore, even if the focus of the probe light focused on the object to be measured shifts, it can be focused quickly and reliably, and therefore the distance between the measurement point and the magnifying optical system can always be kept constant.
以下、図面を参照して、本発明の実施例を詳細
に説明する。
Embodiments of the present invention will be described in detail below with reference to the drawings.
第１図は、実施例を投影機に適用した実施例の
全体構成を示したものである。 FIG. 1 shows the overall configuration of an embodiment in which the embodiment is applied to a projector.
図において、載物台３上の測定対象物４は、落
射照明系３０の照明光３０Ａで照明され、その拡
大像が、拡大光学系の一例である投影レンズ５に
よつて、その結像画に位置するスクリーン６に投
影される。 In the figure, an object to be measured 4 on a stage 3 is illuminated with illumination light 30A from an epi-illumination system 30, and its enlarged image is formed into an image by a projection lens 5, which is an example of an enlarging optical system. The image is projected onto a screen 6 located at .
前記載物台３は、Ｘ軸モータ３２Ｘ及びＹ軸モ
ータ３２Ｙによつて、投影レンズ５の光軸と垂直
な面内で移動可能であり、Ｘ軸検出器３４Ｘ、Ｙ
軸検出器３４Ｙからの電気信号をＸ軸カウンタ３
６Ｘ、Ｙ軸カウンタ３６Ｙでそれぞれ計数するこ
とにより、載物台３の投影レンズ５に対する座標
値が得られるようにされている。なお、載物台３
は、キーボード３８からの指令等によつて、
CPU４０でＸ−Ｙ軸設定回路４２、Ｘ−Ｙ軸駆
動回路４４を制御することによつて移動される。 The document table 3 is movable in a plane perpendicular to the optical axis of the projection lens 5 by an X-axis motor 32X and a Y-axis motor 32Y, and the X-axis detectors 34X, Y
The electric signal from the axis detector 34Y is sent to the X-axis counter 3.
By counting with the 6X and Y-axis counters 36Y, the coordinate values of the stage 3 relative to the projection lens 5 can be obtained. In addition, the loading table 3
is determined by commands from the keyboard 38, etc.
The CPU 40 controls the X-Y axis setting circuit 42 and the X-Y axis driving circuit 44 to move the image.
前記落射照明系３０の照明系３０Ａに重畳し
て、オートフオーカス系４６の焦点検出系４８か
らプローブ光５０が照射され、ハーフミラー５
２，５４を介して測定対象物４上に集光されてい
る。 The probe light 50 is irradiated from the focus detection system 48 of the autofocus system 46 superimposed on the illumination system 30A of the epi-illumination system 30, and the half mirror 5
The light is focused on the object to be measured 4 via the beams 2 and 54.
この測定対象物４から反射するプローブ光５０
を用いることによつて、焦点検出系４８、焦点信
号回路５６、Ｚ軸設定回路５８、Ｚ軸駆動回路６
０及びＺ軸モータ６２を含むオートフオーカス系
４６が形成されている。即ち、プローブ光５０が
測定対象物４上で集光する状態にあるように、Ｚ
軸モータ６２が作動してボールねじ機構等により
載物台３をＺ方向に上下することによつて、投影
レンズ５と測定点ｑとは常に一定の距離が保たれ
るようになつている。 Probe light 50 reflected from this measurement object 4
By using the focus detection system 48, focus signal circuit 56, Z-axis setting circuit 58, Z-axis drive circuit 6
An autofocus system 46 including 0 and Z axis motors 62 is formed. In other words, the Z
By operating the shaft motor 62 and moving the stage 3 up and down in the Z direction using a ball screw mechanism or the like, a constant distance is always maintained between the projection lens 5 and the measurement point q.
又、前記焦点信号回路５６からは、焦点のずれ
は略比例する焦点信号Ｉが出力され、この焦点信
号ＩはＺ軸駆動回路６０にフイードバツクされる
と共に、エツジ判定回路６４に入力され、ある一
定のレベルを超えるとエツジ信号Ｋが出力される
ように構成されている。 Further, the focus signal circuit 56 outputs a focus signal I in which the focus shift is approximately proportional. The edge signal K is output when the level exceeds .
第１図において、６６はメインバス、６８は表
示器、７０はプリンタである。 In FIG. 1, 66 is a main bus, 68 is a display, and 70 is a printer.
第２図は、前記実施例の焦点検出系４８、焦点
信号回路５６及びエツジ判定回路６４の具体的な
構成を示したものである。 FIG. 2 shows the specific configuration of the focus detection system 48, focus signal circuit 56, and edge determination circuit 64 of the embodiment.
前記焦点検出系４８において、レーザダイオー
ド４８Ａから照射されたプローブ光５０は、集光
レンズ４８Ｂで発散角が抑制され、ハーフミラー
５２，５４で一部反射された後、投影レンズ５に
より測定対象物４上の測定点ｑに集光される。測
定点ｑから反射されたプローブ光５０は、逆の経
路で焦点検出系４８に戻り、プローブ光５０を２
分する手段である回折格子４８Ｃによつて±１次
方向に一部が分離される。分離された一方の光軸
（図の左側）上では、焦点面の手前にピンホール
４８Ｄがあり、背面に受光素子４８Ｅがある。一
方、他方の光軸（図の右側）上では、焦点面の後
部にピンホール４８Ｆが設けられ、その背面に受
光素子４８Ｇがある。これら受光素子の前面には
レーザダイオードの波長に合わせて千渉フイルタ
等を設けてもよい。両受光素子４８Ｅ，４８Ｇの
出力は、それぞれプリアンプ４８Ｈ，４８Ｉで増
幅された後、焦点信号回路５６を構成する差動増
幅器５６Ａで差動増幅されて焦点信号Ｉが形成さ
れる。 In the focus detection system 48, the probe light 50 irradiated from the laser diode 48A has its divergence angle suppressed by the condenser lens 48B, is partially reflected by the half mirrors 52 and 54, and is then directed to the measurement target by the projection lens 5. The light is focused on measurement point q on 4. The probe light 50 reflected from the measurement point q returns to the focus detection system 48 on the opposite path, and the probe light 50 is
A portion is separated in the ±1st order direction by a diffraction grating 48C serving as a separating means. On one of the separated optical axes (on the left side of the figure), there is a pinhole 48D in front of the focal plane, and a light receiving element 48E on the back side. On the other hand, on the other optical axis (on the right side of the figure), a pinhole 48F is provided at the rear of the focal plane, and a light receiving element 48G is located at the rear of the pinhole 48F. A filter or the like may be provided in front of these light receiving elements in accordance with the wavelength of the laser diode. The outputs of both light receiving elements 48E and 48G are amplified by preamplifiers 48H and 48I, respectively, and then differentially amplified by a differential amplifier 56A forming a focus signal circuit 56 to form a focus signal I.
前記エツジ判定回路６４は、焦点信号Ｉの絶対
値を求める絶対値変換器６４Ａと、参照値Vrの
の比較器６４Ｂとから構成されており、焦点信号
Ｉの絶対値が所定値Vrを超えた時にエツジ信号
Ｋを発生してメインバス６６に出力する。 The edge determination circuit 64 includes an absolute value converter 64A that calculates the absolute value of the focus signal I, and a reference value Vr comparator 64B. At the same time, an edge signal K is generated and output to the main bus 66.
前記Ｚ軸設定回路５８は、本実施例では遅延回
路的な作用を有するローバスのフイルタ回路５８
Ａから構成されており、該フイルタ回路５８Ａで
焦点信号Ｉを若千遅延させて帰還信号Ｊを生成し
Ｚ軸駆動回路６０に出力する。 In this embodiment, the Z-axis setting circuit 58 is a low-pass filter circuit 58 that functions like a delay circuit.
The filter circuit 58A delays the focus signal I by a few thousand seconds to generate a feedback signal J, which is output to the Z-axis drive circuit 60.
以下、実施例の作用を説明する。 The effects of the embodiment will be explained below.
今、第３図Ａに示した状態から、載物台３をＸ
方向に移動させて、測定対象物４の凹部８の長さ
Ｌを測定する場合の、焦点信号Ｉ、帰還信号Ｊ及
びエツジ信号Ｋの変化状態は、第４図に示す如く
となる。 Now, from the state shown in Figure 3A, move the stage 3 to
When the length L of the concave portion 8 of the object 4 is measured by moving the object 4 in the direction, the change states of the focus signal I, the feedback signal J, and the edge signal K are as shown in FIG.
即ち、第３図Ａの状態から、測定点ｑが測定対
象物４の凹部８の入側エツジに対応するａ点を横
切ると、第２図において測定点ｑの位置が下がる
ため、焦点検出系４８において、プローブ光５０
は光軸上で焦点面より手面に集光するようにな
る。従つて、受光素子４８Ｅの出力の方が受光素
子４８Ｇの出力よりも大きくなり、第４図Ａに示
す如く、焦点信号Ｉは直ちに増大する。しかしな
がら、Ｚ軸設定回路５８に含まれるフイルタ回路
５８Ａは、急激な立上がり信号には応答しないロ
ーパスフイルタであるため、第４図Ｂに示す如
く、帰還信号Ｊは直ぐには追髄できず、Ｚ軸駆動
回路６０若千遅れて動作する。このため、第４図
Ａに示す如く、ａ点では、焦点信号Ｉの絶対値
が、エツジ判定回路６４の参照レベルVrよりも
大きくなつて、エツジ信号Ｋが立上がる（第４図
Ｃのｆ）。 That is, when the measurement point q crosses the point a corresponding to the entrance edge of the recess 8 of the measurement object 4 from the state shown in FIG. 3A, the position of the measurement point q lowers in FIG. At 48, the probe light 50
The light will be focused on the hand surface rather than the focal plane on the optical axis. Therefore, the output of the light receiving element 48E becomes larger than the output of the light receiving element 48G, and the focus signal I immediately increases as shown in FIG. 4A. However, since the filter circuit 58A included in the Z-axis setting circuit 58 is a low-pass filter that does not respond to a sudden rising signal, the feedback signal J cannot be immediately refined as shown in FIG. 4B, and the Z-axis The drive circuit 60 operates with a slight delay. Therefore, as shown in FIG. 4A, at point a, the absolute value of the focus signal I becomes larger than the reference level Vr of the edge determination circuit 64, and the edge signal K rises (f in FIG. 4C). ).
この後、Ｚ軸駆動回路６０が作動するため、載
物台３は上昇して、第３図Ｂに示す如く、プロー
ブ光５が測定対象物４上で集光する位置で停止す
る。従つて、測定対象物４の凹部８の平面上のｂ
点では、第４図Ａに示す如く、焦点信号Ｉはほぼ
零となつている。 Thereafter, the Z-axis drive circuit 60 is activated, so the stage 3 rises and stops at a position where the probe light 5 is focused on the object to be measured 4, as shown in FIG. 3B. Therefore, b on the plane of the recess 8 of the measurement object 4
At this point, the focus signal I is almost zero, as shown in FIG. 4A.
更に、載物台３がＸ方向に移動して測定対象物
４の凹部の出側エツジに対応するｃ点に到達する
と、焦点検出系４８における戻つてきたプローブ
光５０の集光位置は焦点面より後方になるため、
第４図Ａに示す如く、焦点信号Ｉは急減する。次
いで、ａ点と同様にまずエツジ信号Ｋが出力（第
４図Ｃのｇ）された後で、Ｚ軸駆動回路６０が作
動して、載物台３は焦点信号Ｉがほぼ零になるま
で下降する。 Further, when the stage 3 moves in the X direction and reaches point c corresponding to the exit edge of the recess of the measurement target 4, the focal point of the returned probe light 50 in the focus detection system 48 is at the focal plane. Because it is further backwards,
As shown in FIG. 4A, the focus signal I suddenly decreases. Next, similarly to point a, after the edge signal K is first output (g in FIG. 4C), the Z-axis drive circuit 60 is activated and the stage 3 is moved until the focus signal I becomes almost zero. descend.
従つて、第４図Ｃに示す如く、ａ点及びｃ点に
おいてエツジ信号Ｋの立上がりｆ，ｇでCPU４
０に指令を行い、Ｘ軸カウンタ３６Ｘの値を読込
むことによつて、測定対象物４の凹部８の長さＬ
が測定できる。この測定値は、例えば第１図の表
示器６８やプリンタ７０で出力される。 Therefore, as shown in FIG. 4C, when the edge signal K rises f and g at points a and c, the CPU 4
By issuing a command to 0 and reading the value of the X-axis counter 36X, the length L of the recess 8 of the measurement object 4 can be determined.
can be measured. This measured value is outputted, for example, by the display 68 or printer 70 in FIG.
なお、前記実施例は落射照明系のみを含むもの
を例示していたが、本発明の適用範囲はこれに限
定されず、本発明によるオートフオーカス系を用
いたエツジ検出と、従来の像の明暗の変化を利用
してエツジ信号を発生するセンサとを組合わせる
ことによつて、様々な測定対象物について自動的
に座標値を読込むことが可能となる。 Note that although the above-mentioned embodiments have been exemplified as including only an epi-illumination system, the scope of application of the present invention is not limited to this, and includes edge detection using an autofocus system according to the present invention and conventional image detection. By combining this with a sensor that generates edge signals using changes in brightness and darkness, it becomes possible to automatically read coordinate values for various measurement objects.
又、前記実施例は、投影機的な構成であつた
が、例えば顕微鏡等にも適用できるものである。
この場合は、拡大光学系としては対物レンズが用
いられ、その中間像をオートフオーカス式の撮像
管等で中継することによりテレビモニタに映し出
して、その映像を見ながらキーボードから測定手
順等の指令を行うことができる。 Further, although the above embodiment has a projector-like configuration, it can also be applied to, for example, a microscope.
In this case, an objective lens is used as the magnifying optical system, and the intermediate image is displayed on a TV monitor by relaying it with an autofocus type image pickup tube, etc., and commands such as measurement procedures are given from the keyboard while viewing the image. It can be performed.
以上説明した通り、本発明によれば、測定すべ
き形状が、その像の明暗の差が少ないエツジ部か
ら形成されている場合にも、良好なエツジ信号が
得られる。従つて、そのエツジ信号を用いること
によつて、測定対象物の制限を受けることなく、
形状測定が可能となる。更に、測定対象物に集光
するプローブ光の焦点がずれたとしても、迅速且
つ確実に焦点を合わせることができ、従つて測定
点と拡大光学系との距離を常に一定とすることが
できるという優れた効果を有する。
As explained above, according to the present invention, a good edge signal can be obtained even when the shape to be measured is formed from an edge portion with a small difference in brightness and darkness of its image. Therefore, by using the edge signal, it is possible to measure without being limited by the measurement target.
Shape measurement becomes possible. Furthermore, even if the focus of the probe light focused on the object to be measured shifts, it can be focused quickly and reliably, and therefore the distance between the measurement point and the magnifying optical system can always be kept constant. Has excellent effects.
第１図は、本発明が採用された投影機の実施例
の全体構成を示すブロツク線図、第２図は、前記
実施例のオートフオーカス系の構成を詳細に示す
ブロツク線図、第３図Ａ，Ｂは、前記実施例の作
用を説明するための要部断面図、第４図は、前記
実施例における各部信号波形の例を示す線図、第
５図は、従来のエツジ検出装置が採用された投影
機の一例の構成を示す光学系統図、第６図は、従
来例でエツジ検出が困難な測定対象物の形状の例
を示す斜視図である。
３…載物台、４…測定対象物、５…投影レンズ
（拡大光学系）、６…スクリーン、３０…落射照明
系、ｑ…測定点、３４Ｘ…Ｘ軸検出器、３４Ｙ…
Ｙ軸検出器、３６Ｘ…Ｘ軸カウンタ、３６Ｙ…Ｙ
軸カウンタ、４６…オートフオーカス系、４８…
焦点検出系、４８Ａ…レーザダイオード、４８Ｃ
…回折格子、４８Ｄ，４８Ｆ…ピンホール、４８
Ｅ，４８Ｇ…受光素子、５０…プローブ光、５６
…焦点信号回路、Ｉ…焦点信号、５６Ａ…差動増
幅器、５８…Ｚ軸設定回路、６０…Ｚ軸駆動回
路、６２…Ｚ軸モータ、６４…エツジ判定回路、
Ｋ…エツジ信号。
FIG. 1 is a block diagram showing the overall configuration of an embodiment of a projector to which the present invention is adopted, FIG. 2 is a block diagram showing the detailed configuration of the autofocus system of the embodiment, and FIG. Figures A and B are sectional views of essential parts for explaining the operation of the embodiment, Figure 4 is a diagram showing examples of signal waveforms at various parts in the embodiment, and Figure 5 is a conventional edge detection device. FIG. 6 is an optical system diagram showing the configuration of an example of a projector employing the above method, and is a perspective view showing an example of the shape of a measuring object for which edge detection is difficult in the conventional example. 3... Stage, 4... Measurement object, 5... Projection lens (magnifying optical system), 6... Screen, 30... Epi-illumination system, q... Measurement point, 34X... X-axis detector, 34Y...
Y-axis detector, 36X...X-axis counter, 36Y...Y
Axis counter, 46...Auto focus system, 48...
Focus detection system, 48A...Laser diode, 48C
...Diffraction grating, 48D, 48F...Pinhole, 48
E, 48G... Light receiving element, 50... Probe light, 56
...Focus signal circuit, I...Focus signal, 56A...Differential amplifier, 58...Z-axis setting circuit, 60...Z-axis drive circuit, 62...Z-axis motor, 64...edge determination circuit,
K...Edge signal.
Claims (1)
の測定点に集光するようプローブ光を照射する発
光素子、該測定対象物から反射されるプローブ光
を２分し、且つ該２分されたプローブ光のそれぞ
れの焦点面から光軸上で互いに逆方向に偏位させ
たピンホールを含む光学手段、該光学手段からプ
ローブ光を入射するようそれぞれのピンホールの
背面に置かれた２つの受光素子を含む焦点検出系
と、 該焦点検出系の２つの受光素子からの出力を差
動増幅して焦点信号を形成する焦点信号回路、該
焦点信号回路から出力された焦点信号を遅延させ
て帰還信号を生成するＺ軸設定回路、該Ｚ軸設定
回路から出力される帰還信号によりＺ軸を駆動さ
せるＺ軸駆動回路からなるオートフオーカス系
と、 前記焦点信号回路から出力された焦点信号の絶
対値を求める絶対値変換器と参照値の比較器から
構成され、該焦点信号の絶対値が所定の値を越え
た時にエツジ信号を出力するエツジ判定回路とを
備え、 測定対象物と前記拡大光学系とを光軸に垂直な
面内で相対移動させつつ、前記エツジ信号の出力
時に相対移動量を特定することにより、測定対象
物のエツジで形成される形状の測定を行うことを
特徴とする光学測定機。[Scope of Claims] 1. An epi-illumination system and a magnifying optical system; a light-emitting element that irradiates probe light so as to be superimposed on the illumination light of the epi-illumination system and converge on a measurement point of the measurement target; and the measurement target. an optical means including a pinhole which divides the probe light reflected from the optical means into two and is deviated from the focal plane of each of the two divided probe lights in mutually opposite directions on the optical axis; a focus detection system that includes two light-receiving elements placed on the back of each pinhole so that the light is incident thereon; and a focus signal that differentially amplifies the outputs from the two light-receiving elements of the focus detection system to form a focus signal. A Z-axis setting circuit that delays the focus signal output from the focus signal circuit to generate a feedback signal, and a Z-axis drive circuit that drives the Z-axis using the feedback signal output from the Z-axis setting circuit. It consists of a focus system, an absolute value converter for determining the absolute value of the focus signal output from the focus signal circuit, and a reference value comparator, and when the absolute value of the focus signal exceeds a predetermined value, an edge signal is generated. and an edge determination circuit that outputs an edge signal, while moving the object to be measured and the magnifying optical system relative to each other in a plane perpendicular to the optical axis, and specifying the amount of relative movement when outputting the edge signal. An optical measuring machine characterized by measuring a shape formed by the edges of an object.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP27501986A JPS63128213A (en) | 1986-11-18 | 1986-11-18 | Optical measuring machine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP27501986A JPS63128213A (en) | 1986-11-18 | 1986-11-18 | Optical measuring machine |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63128213A JPS63128213A (en) | 1988-05-31 |
| JPH0426685B2 true JPH0426685B2 (en) | 1992-05-08 |
Family
ID=17549742
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP27501986A Granted JPS63128213A (en) | 1986-11-18 | 1986-11-18 | Optical measuring machine |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63128213A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07119581B2 (en) * | 1988-07-16 | 1995-12-20 | アンリツ株式会社 | Shape measuring device |
| US5864778A (en) * | 1994-04-05 | 1999-01-26 | Vialog Visuelle Automations Anlagen Gmbh | Device and process for measuring and calculating geometrical parameters of an object |
| JP2007231767A (en) * | 2006-02-28 | 2007-09-13 | Honda Motor Co Ltd | Camshaft lubricating device for ohc engine |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58129304A (en) * | 1982-01-29 | 1983-08-02 | Sumitomo Electric Ind Ltd | Optical measuring method and measuring device used in said method |
| JPS6191516A (en) * | 1984-10-12 | 1986-05-09 | Ya Man Ltd | Non-contact optical type displacement measuring apparatus having focusing mechanism |
-
1986
- 1986-11-18 JP JP27501986A patent/JPS63128213A/en active Granted
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58129304A (en) * | 1982-01-29 | 1983-08-02 | Sumitomo Electric Ind Ltd | Optical measuring method and measuring device used in said method |
| JPS6191516A (en) * | 1984-10-12 | 1986-05-09 | Ya Man Ltd | Non-contact optical type displacement measuring apparatus having focusing mechanism |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS63128213A (en) | 1988-05-31 |
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