JPH04324316A - Fixed-point detection device - Google Patents
Fixed-point detection deviceInfo
- Publication number
- JPH04324316A JPH04324316A JP9436691A JP9436691A JPH04324316A JP H04324316 A JPH04324316 A JP H04324316A JP 9436691 A JP9436691 A JP 9436691A JP 9436691 A JP9436691 A JP 9436691A JP H04324316 A JPH04324316 A JP H04324316A
- Authority
- JP
- Japan
- Prior art keywords
- light
- diffraction
- light source
- diffraction gratings
- fixed point
- 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.)
- Granted
Links
- 238000001514 detection method Methods 0.000 title claims abstract description 39
- 238000005259 measurement Methods 0.000 claims abstract description 10
- 230000003287 optical effect Effects 0.000 claims description 6
- 238000010586 diagram Methods 0.000 description 19
- 230000035945 sensitivity Effects 0.000 description 6
- 230000005540 biological transmission Effects 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 230000001427 coherent effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
Landscapes
- Optical Transform (AREA)
Abstract
Description
【発明の詳細な説明】
【０００１】
【産業上の利用分野】本発明は、光学的に位置が検出さ
れるリニアエンコーダ、ロータリエンコーダ等への装備
に好適な定点検出装置に関する。
【０００２】
【従来の技術】この種の装置としては、リニアエンコー
ダ等に使用される原点位置検出装置が知られている。
【０００３】その装置では、透光部と遮光部とがランダ
ムな格子状に多数形成されたメインスケール（可動）と
、それに対応するパターンが形成されたインデックスス
ケール（固定）とが備えられ、それら格子状のパターン
の重なりが検出されることにより、原点位置が検出され
、あるいは、メインスケールとインデックススケールの
それぞれにスリットを１つ形成し、その重なりを検出す
ることにより、原点位置を検出する。
【０００４】
【発明が解決しようとする課題】しかしながら、従来の
検出方法では、メインスケールとインデックスとの間隔
を広く取れず、又検出感度を高くしようとすると光の回
折が生ずるため、原点検出信号がシャープな特性となら
ず、高感度の検出が困難である。
【０００５】また、メインスケールとインデックススケ
ールとの間隔が変動した場合、光源からの光量が変動し
た場合、原点の検出位置が変化して、高精度の検出が行
なえない。
【０００６】本発明の目的は、スケールと検出ヘッドの
間隔が大きく取れ高感度の定点位置検出が行なえるとと
もに、光源の光量が変動した場合等においても高精度の
定点位置検出が行なえる定点検出装置を提供することに
ある。
【０００７】
【課題を解決するための手段】本発明に係る定点検出装
置は、例えば図１に示すように、入射光の回折効率が測
定方向Ｘに沿って各々変化可能とされ、同一光源３Ａの
光を２つに分割させる一対の回折格子５Ａ，５Ｂと、前
記各々の回折格子５Ａ，５Ｂで回折された光が電気信号
に変換される光／電気変換器７Ａ，７Ｂと、変換された
前記電気信号のレベル値が一致したことを検出する検出
手段９と、を有するものである。
【０００８】
【作用】本発明に係る定点検出装置では、測定方向に沿
って回折効率が変化する一対の回折格子から各々得られ
る回折光が、各々電気信号に変換され、それら電気信号
のレベル値が一致したときに、所望の定点が特定される
。
【０００９】
【実施例】以下、本発明に係る定点検出装置の好適な実
施例を図面に基いて説明する。図１には、本発明が適用
された定点検出装置１が示されており、装置１は光源系
３と、測定方向に沿って回折効率が変化する回折格子５
と、光／電気変換器（Ｏ／Ｉ変換器）７Ａ，７Ｂと、電
気処理回路９（検出手段）とを有している。
【００１０】光源系３では、半導体レーザ等の光源３Ａ
から出射されたレーザ光が、コリメータレンズ３Ｂ、集
光レンズ３Ｃを介して回折格子５に入射される。回折格
子５は、１対の回折格子５Ａ，５Ｂとされており、入射
されたレーザ光はそれら回折格子５Ａ，５Ｂにより分割
され、その回折光は、各々Ｏ／Ｉ変換器７Ａ，７Ｂに入
射される。
【００１１】Ｏ／Ｉ変換器７Ａ，７Ｂでは、入射された
回折光が電気信号（電流Ｉ）に変換され、回路９のアン
プ９Ａ，９Ｂを介して差動増幅器９Ｃ、比較器９Ｄに入
力される。
【００１２】この場合、光源系３でのレーザ光は、回折
格子５Ａ，５Ｂ上で適宜な大きさ、形状になるようにレ
ンズ３Ｂ，３Ｃで絞られ、格子面に対して垂直に入射さ
れる。
【００１３】なお、光源系３等の構成としては、光源系
３のレーザ光が一度ミラー２によって反射されてからＯ
／Ｉ変換器５Ａ，５Ｂに入射されるものが挙げられ（図
２参照）、また、反射型の回折格子では、そのミラー２
が不要となる（図３参照）。
【００１４】一方、回折格子５Ａ，５Ｂは、図４から理
解されるように、その一部が互いに重なり合う（図中、
斜線で示されている）ように配置され、これによりレー
ザ光が両方の回折格子５Ａ，５Ｂに入射される。
【００１５】この場合、レーザ光は回折格子５Ａ，５Ｂ
の格子面に対して垂直に入射される。
【００１６】そして、両方の回折格子５Ａ，５Ｂの回折
効率が等しくなる位置Ｐを中心に、測定方向Ｘに沿って
回折効率が対称となるように設定されている（図５参照
）。
【００１７】従って、それら回折格子５Ａ，５Ｂからの
回折光をＯ／Ｉ変換して得られた電流Ｉがアンプ９Ａ，
９Ｂで電流電圧変換され差動増幅回路９Ｃに入力される
と、図６から理解されるように、極大値、極小値を有す
るＸ−Ｖ（電圧）曲線が得られ、そのＸ−Ｖ曲線のゼロ
クロス点Ｓが求める定点に対応する。なお、回折格子５
Ａ，５Ｂは、全て重ねても良く（図７参照）、また、図
８、図９から理解されるように、隣接させて配置する構
成も好適である。
【００１８】そして、回折格子５Ａ，５Ｂが隣接される
場合、図１０から理解されるように、Ｘ方向以外のＹ方
向（図中、斜線で示された部分）の影響が検出に出ない
ようにする（図１２中、実線で示された曲線）。
【００１９】すなわち、図１２から理解されるように、
レーザ光の照射部分（図中、斜線で示された部分）が小
さいと、図１１中点線で示されたＸ−Ｉ曲線となり、位
置Ｐがずれてしまうので、レーザ光の照射部分をＹ方向
に大きくすることが必要である。
【００２０】以上説明したように、この実施例では、回
折格子５Ａ，５Ｂからの回折光をＯ／Ｉ変換して得られ
る電流Ｉが電気処理回路９で電圧変化に変換され、その
Ｘ−Ｖ曲線のゼロクロス点Ｓが原点位置と対応する点と
して検出される。
【００２１】従って、検出点の検出信号が明確（シャー
プ）であるため、定点検出が高感度で行なえる。
【００２２】また、レーザ光が格子面に対して垂直に入
射されるので、格子面が自身の面方向に沿って移動した
場合にも、検出点Ｓの変化が無く高精度の検出が行なえ
る。
【００２３】この場合、格子面に対して斜め方向からレ
ーザ光が入射されると、図１３から理解されるように、
検出点Ｓが変化する。
【００２４】さらに、回折効率は点Ｐを中心として対称
に変化するので、光源３Ａの光量が変化した場合（図１
４）、光源３Ａの光波長が変化した場合（図１５）、お
よびレーザ光の焦点位置が変動した場合（図１６）にお
いても、検出点Ｓが変化せず、一方向のみの安定、かつ
高精度な検出が可能である。
【００２５】加えて、回折格子５Ａ，５Ｂとして、体積
型ホログラムを使用することにより、体積型ホログラム
が装備されたリニアエンコーダ用のスケールと同一の製
造プロセスで原点（定点）の作成が行なえるので、体積
型ホログラムを用いたリニアエンコーダに容易に原点パ
ターンを形成できるとともに、体積型の位相ホログラム
を用いることにより、より高い感度（Ｓ／Ｎ比）を得る
ことができる。
【００２６】また、リニアエンコーダの原点を特定する
場合、スケールと検出ヘッドとの間隔が大きくとれるの
で、スケール装置の設計自由度が向上される。
【００２７】次に、上記実施例の定点検出装置１で回折
格子５Ａ，５Ｂが製作される原理について説明する。
【００２８】装置１では、可干渉性の光源３Ａと、一対
の回折格子５Ａ，５Ｂ，Ｏ／Ｉ変換器７Ａ，７Ｂ等が設
けられており、回折格子５Ａ，５Ｂは、測定方向Ｘに沿
って回折効率が変化する。
【００２９】そこで、そのような回折格子の一例として
、透過型の体積型ホログラムが使用される場合について
説明する。
【００３０】Ｈ．Ｋｏｇｅｌｎｉｋ，Ｂｅｌｌｓｙｓｔ
．Ｔｅｃｈ．Ｊ．４８，２９０９（１９６９）に記載さ
れたＫｏｇｅｌｉｎｋの論文によると、この種のタイプ
のホログラムでは、回析効率ηが下式数１で与えられる
。
【００３１】
【数１】η＝Ｓｉｎ２ ｛（υ２ ＋ξ２ ）１／２
｝／（１＋ξ２ ／υ２ ）
【００３２】ここで、υ、ξはパラメータとして用いら
れており、各々下式数２で与えられる。
【数２】
υ＝πｎ１ ｄ／λ（ＣＲ ＣＳ ）１／２ ξ＝Δθ
ＫｄＳｉｎ（φ−θＯ ）／２ＣＳ ＝−ΔλＫ２ ｄ
／８πｎＣＳ
【００３３】ただし、
ＣＲ ＝Ｃｏｓθ
ＣＳ ＝Ｃｏｓθ−（Ｋ／β）ＣｏｓφＫ＝２π／Λ
β＝２πｎ／λ
【００３４】ここで、Λ：格子ピッチ、λ：入射光の波
長、Δθ：ブラッグ条件を満足する入射角からのずれ、
Δλ：ブラッグ条件を満足する入射光の波長からのずれ
、θＯ ：ブラッグ条件を満足する入射角、ｎ：回折格
子の屈折率、ｎ１ ：回折格子の屈折率の変化量である
。
【００３５】従って上記数１、数２から、パラメータυ
、またはξが変化されると、回折効率ηが変化されるこ
とがわかる。
【００３６】そして、図１７において、ホログラムを露
光する際の露光パワーの変化、記録媒質αの厚みｄ、格
子面の傾きφ等が変化されると、パラメータυが変化さ
れる。
【００３７】一方、格子ピッチΛ、格子の傾き等が変化
されるとパラメータξが変化される。
【００３８】従って、入射光の波長及び入射角度が一定
であるとすると測定方向に沿って回折効率が変化する回
折格子は、その測定方向に沿って漸次パラメータυ、ξ
が変化するものであることが理解される。
【００３９】そこで、図１８から理解されるように、円
筒波面を有する光ビームＡと、平面波面を有する平行ビ
ームＢとが干渉されて、ホログラムとして記録されると
、Ｘ方向（測定方向）に沿って格子ピッチと格子の傾き
が変化する（格子ベクトルＫの方向が変化する）回折格
子が得られる（図１９参照）。
【００４０】従って、図２０から理解されるように、光
ビームが照射されると、回折効率は、格子ピッチ、格子
の傾きの変化によって変化されるので、図２０に示され
たように、Ｘ方向に沿って変化する電圧Ｖが得られる。
【００４１】なお、透過型のものに代えて、反射型の体
積型ホログラムを使用することも好適であり（図２２参
照）、この場合、平行ビームＢが記録面と反対の面側か
ら入射される。
【００４２】また、干渉させる波面は、２つの円筒波面
であっても良い。
【００４３】
【発明の効果】以上の説明で理解されるように、本発明
に係る定点検出装置では、測定方向に沿って回折効率の
変化する一対の回折格子から各々得られる回折光が、各
々電気信号に変換され、それら電気信号のレベル値が一
致したときに、所望の定点が特定される。従って、定点
位置検出信号がシャープな特性を有するため、定点位置
検出が高感度で行なえる。また、光源からの光量、ある
いは光波長変動や、検出する方向以外の方向への変動に
よる定点位置変動が極めて少なく、高精度な位置検出が
可能である。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixed point detection device suitable for installation in a linear encoder, rotary encoder, etc. whose position is detected optically. 2. Description of the Related Art As a device of this type, an origin position detection device used in a linear encoder or the like is known. [0003] The device is equipped with a main scale (movable) on which a large number of light-transmitting parts and light-shielding parts are formed in a random grid pattern, and an index scale (fixed) on which a pattern corresponding to the main scale is formed. The origin position is detected by detecting the overlap of the grid-like patterns, or the origin position is detected by forming one slit in each of the main scale and index scale and detecting the overlap. [0004] However, in the conventional detection method, it is not possible to maintain a wide interval between the main scale and the index, and when trying to increase the detection sensitivity, light diffraction occurs. does not have sharp characteristics, making it difficult to detect with high sensitivity. Furthermore, if the distance between the main scale and the index scale changes, or if the amount of light from the light source changes, the detection position of the origin changes, making it impossible to perform highly accurate detection. It is an object of the present invention to provide a fixed point detection system that allows a large distance between the scale and the detection head to perform fixed point position detection with high sensitivity, and also enables highly accurate fixed point position detection even when the light intensity of the light source fluctuates. The goal is to provide equipment. Means for Solving the Problems In the fixed point detection device according to the present invention, as shown in FIG. 1, for example, the diffraction efficiency of incident light can be varied along the measurement direction a pair of diffraction gratings 5A, 5B that split the light into two; and optical/electrical converters 7A, 7B that convert the light diffracted by the respective diffraction gratings 5A, 5B into electrical signals; and detection means 9 for detecting that the level values of the electrical signals match. [Operation] In the fixed point detection device according to the present invention, each of the diffracted lights obtained from a pair of diffraction gratings whose diffraction efficiency changes along the measurement direction is converted into an electrical signal, and the level values of these electrical signals are When they match, the desired fixed point is identified. DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the fixed point detection device according to the present invention will be described below with reference to the drawings. FIG. 1 shows a fixed point detection device 1 to which the present invention is applied, and the device 1 includes a light source system 3 and a diffraction grating 5 whose diffraction efficiency changes along the measurement direction.
, optical/electrical converters (O/I converters) 7A, 7B, and an electrical processing circuit 9 (detection means). In the light source system 3, a light source 3A such as a semiconductor laser is used.
Laser light emitted from the diffraction grating 5 is incident on the diffraction grating 5 via the collimator lens 3B and the condenser lens 3C. The diffraction grating 5 is a pair of diffraction gratings 5A and 5B, and the incident laser light is split by these diffraction gratings 5A and 5B, and the diffracted lights are incident on O/I converters 7A and 7B, respectively. be done. [0011] In the O/I converters 7A and 7B, the incident diffracted light is converted into an electric signal (current I), which is input to the differential amplifier 9C and comparator 9D via the amplifiers 9A and 9B of the circuit 9. Ru. In this case, the laser beam in the light source system 3 is focused by lenses 3B and 3C so that it has an appropriate size and shape on the diffraction gratings 5A and 5B, and is incident perpendicularly to the grating plane. . Note that the configuration of the light source system 3 etc. is such that the laser beam of the light source system 3 is once reflected by the mirror 2, and then the laser beam is
/I converters 5A and 5B (see Figure 2), and in the case of a reflection type diffraction grating, the mirror
is no longer necessary (see Figure 3). On the other hand, as understood from FIG. 4, the diffraction gratings 5A and 5B partially overlap each other (in the figure,
(shown with diagonal lines), so that laser light is incident on both diffraction gratings 5A and 5B. In this case, the laser beam is transmitted through the diffraction gratings 5A and 5B.
is incident perpendicularly to the lattice plane. [0016]The diffraction efficiencies are set to be symmetrical along the measurement direction X, centering on a position P where the diffraction efficiencies of both diffraction gratings 5A and 5B are equal (see FIG. 5). Therefore, the current I obtained by O/I conversion of the diffracted lights from the diffraction gratings 5A and 5B is applied to the amplifiers 9A and 5B.
When the current is converted into voltage at 9B and input to the differential amplifier circuit 9C, an X-V (voltage) curve having maximum and minimum values is obtained, as can be seen from FIG. The zero crossing point S corresponds to the desired fixed point. In addition, the diffraction grating 5
A and 5B may be all overlapped (see FIG. 7), or, as can be understood from FIGS. 8 and 9, a configuration in which they are arranged adjacent to each other is also suitable. When the diffraction gratings 5A and 5B are placed adjacent to each other, as can be understood from FIG. (the curve shown as a solid line in FIG. 12). That is, as understood from FIG.
If the area irradiated with the laser beam (the area indicated by diagonal lines in the figure) is small, the X-I curve shown in the dotted line in FIG. 11 will result, and the position P will be shifted. It is necessary to increase the size. As explained above, in this embodiment, the current I obtained by O/I conversion of the diffracted light from the diffraction gratings 5A and 5B is converted into a voltage change in the electrical processing circuit 9, and the A zero-crossing point S of the curve is detected as a point corresponding to the origin position. Therefore, since the detection signal of the detection point is clear (sharp), fixed point detection can be performed with high sensitivity. Furthermore, since the laser beam is incident perpendicularly to the lattice plane, even if the lattice plane moves along its own surface direction, the detection point S does not change and highly accurate detection can be performed. . In this case, when the laser beam is incident on the lattice plane from an oblique direction, as can be understood from FIG.
The detection point S changes. Furthermore, since the diffraction efficiency changes symmetrically around the point P, when the light amount of the light source 3A changes (Fig.
4) Even when the light wavelength of the light source 3A changes (Fig. 15) and the focal position of the laser beam changes (Fig. 16), the detection point S does not change, and the detection point S remains stable in only one direction and the high Accurate detection is possible. In addition, by using volume holograms as the diffraction gratings 5A and 5B, the origin (fixed point) can be created in the same manufacturing process as the scale for linear encoders equipped with volume holograms. An origin pattern can be easily formed in a linear encoder using a volume hologram, and higher sensitivity (S/N ratio) can be obtained by using a volume phase hologram. Furthermore, when specifying the origin of the linear encoder, the distance between the scale and the detection head can be increased, which improves the degree of freedom in designing the scale device. Next, the principle of manufacturing the diffraction gratings 5A and 5B in the fixed point detection device 1 of the above embodiment will be explained. The apparatus 1 is provided with a coherent light source 3A, a pair of diffraction gratings 5A, 5B, O/I converters 7A, 7B, etc., and the diffraction gratings 5A, 5B are arranged along the measurement direction The diffraction efficiency changes. [0029] Therefore, as an example of such a diffraction grating, a case where a transmission type volume hologram is used will be described. [0030]H. Kogelnik, Bellsyst
．． Tech. J. According to the paper by Kogelink described in 48, 2909 (1969), in this type of hologram, the diffraction efficiency η is given by the following equation (1). [Equation 1] η=Sin2 {(υ2 +ξ2)1/2
}/(1+ξ2 /υ2) Here, υ and ξ are used as parameters, and are each given by the following equation (2). [Mathematical 2] υ=πn1 d/λ(CR CS )1/2 ξ=Δθ
KdSin(φ-θO)/2CS =-ΔλK2 d
/8πnCS [0033] However, CR = Cosθ CS = Cosθ - (K/β) CosφK = 2π/Λ β = 2πn/λ [0034] Here, Λ: grating pitch, λ: wavelength of incident light, Δθ: Bragg deviation from the angle of incidence that satisfies the conditions,
Δλ: deviation from the wavelength of incident light that satisfies the Bragg condition, θO: incident angle that satisfies the Bragg condition, n: refractive index of the diffraction grating, n1: amount of change in the refractive index of the diffraction grating. Therefore, from Equations 1 and 2 above, the parameter υ
It can be seen that when , or ξ is changed, the diffraction efficiency η is changed. In FIG. 17, when the exposure power when exposing the hologram is changed, the thickness d of the recording medium α, the inclination φ of the lattice plane, etc. are changed, the parameter υ is changed. On the other hand, when the grating pitch Λ, the grating inclination, etc. are changed, the parameter ξ is changed. Therefore, assuming that the wavelength and angle of incidence of the incident light are constant, a diffraction grating whose diffraction efficiency changes along the measurement direction gradually changes the parameters υ, ξ along the measurement direction.
It is understood that things change. Therefore, as can be understood from FIG. 18, when the light beam A having a cylindrical wavefront and the parallel beam B having a plane wavefront are interfered and recorded as a hologram, the light beam A has a cylindrical wavefront and a parallel beam B has a plane wavefront. A diffraction grating is obtained in which the grating pitch and the grating inclination change along the line (the direction of the grating vector K changes) (see FIG. 19). Therefore, as can be understood from FIG. 20, when a light beam is irradiated, the diffraction efficiency is changed by changes in the grating pitch and the grating inclination, so as shown in FIG. A voltage V that varies along the direction is obtained. Note that it is also suitable to use a reflective volume hologram instead of a transmission type (see FIG. 22), and in this case, the parallel beam B is incident from the side opposite to the recording surface. Ru. Furthermore, the wavefronts to be interfered with may be two cylindrical wavefronts. Effects of the Invention As can be understood from the above explanation, in the fixed point detection device according to the present invention, the diffracted lights obtained from a pair of diffraction gratings whose diffraction efficiencies change along the measurement direction are It is converted into electrical signals, and when the level values of these electrical signals match, a desired fixed point is specified. Therefore, since the fixed point position detection signal has sharp characteristics, fixed point position detection can be performed with high sensitivity. In addition, there is extremely little variation in the fixed point position due to variations in the amount of light from the light source, variations in the wavelength of light, or variations in directions other than the detection direction, and highly accurate position detection is possible.
【図１】本発明が好適とされた定点検出装置の全体概略
構成図である。FIG. 1 is an overall schematic configuration diagram of a fixed point detection device to which the present invention is preferred.
【図２】光源系の他の例を示す構成図である。FIG. 2 is a configuration diagram showing another example of a light source system.
【図３】光源系の他の例を示す構成図である。FIG. 3 is a configuration diagram showing another example of a light source system.
【図４】回折格子の配置例を示す説明図である。FIG. 4 is an explanatory diagram showing an example of arrangement of diffraction gratings.
【図５】Ｘ−Ｉ曲線を示す特性図である。FIG. 5 is a characteristic diagram showing an X-I curve.
【図６】Ｘ−Ｖ曲線を示す特性図である。FIG. 6 is a characteristic diagram showing an X-V curve.
【図７】回折格子の配置例を示す説明図である。FIG. 7 is an explanatory diagram showing an example of arrangement of diffraction gratings.
【図８】回折格子の配置例を示す説明図である。FIG. 8 is an explanatory diagram showing an example of arrangement of diffraction gratings.
【図９】回折格子の配置例を示す説明図である。FIG. 9 is an explanatory diagram showing an example of the arrangement of diffraction gratings.
【図１０】光照射範囲の説明図である。FIG. 10 is an explanatory diagram of a light irradiation range.
【図１１】Ｘ−Ｉ曲線を示す特性図である。FIG. 11 is a characteristic diagram showing an X-I curve.
【図１２】光照射範囲の説明図である。FIG. 12 is an explanatory diagram of a light irradiation range.
【図１３】定点が変動した様子を示す説明図である。FIG. 13 is an explanatory diagram showing how the fixed point fluctuates.
【図１４】光量が変化した場合のＸ−Ｉ曲線である。FIG. 14 is an X-I curve when the amount of light changes.
【図１５】光波長が変化した場合のＸ−Ｉ曲線である。FIG. 15 is an X-I curve when the light wavelength is changed.
【図１６】焦点が変化した場合のＸ−Ｉ曲線である。FIG. 16 is an X-I curve when the focus changes.
【図１７】パラメータの説明図である。FIG. 17 is an explanatory diagram of parameters.
【図１８】透過型の体積型ホログラムで光干渉を示す説
明図である。FIG. 18 is an explanatory diagram showing optical interference in a transmission type volume hologram.
【図１９】回折効率変化の説明図である。FIG. 19 is an explanatory diagram of changes in diffraction efficiency.
【図２０】回折効率変化等の説明図である。FIG. 20 is an explanatory diagram of changes in diffraction efficiency, etc.
【図２１】Ｘ−Ｖ曲線を示す説明図である。FIG. 21 is an explanatory diagram showing an X-V curve.
【図２２】反射型の体積型ホログラムでの光干渉を示す
説明図である。FIG. 22 is an explanatory diagram showing optical interference in a reflective volume hologram.
１ 定点検出装置 ３ 光源系 ３Ａ 光源 ５Ａ，５Ｂ 回折格子 ７Ａ，７Ｂ 光／電気変換器 ９ 電気処理回路 1 Fixed point detection device 3 Light source system 3A light source 5A, 5B Diffraction grating 7A, 7B Optical/electrical converter 9 Electrical processing circuit
Claims (1)
各々変化可能とされ、同一光源の光を２つに分割させる
一対の回折格子と、前記各々の回折格子で回折された光
が電気信号に変換される光／電気変換器と、変換された
前記電気信号のレベル値が一致したことを検出する検出
手段と、を有することを特徴とする定点検出装置。1. A pair of diffraction gratings in which the diffraction efficiency of incident light can be varied along the measurement direction, and the light diffracted by each of the diffraction gratings splits the light from the same light source into two. A fixed point detection device comprising: an optical/electrical converter that converts into a signal; and a detection means that detects that the level values of the converted electrical signals match.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3094366A JP3030905B2 (en) | 1991-04-24 | 1991-04-24 | Fixed point detector |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3094366A JP3030905B2 (en) | 1991-04-24 | 1991-04-24 | Fixed point detector |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH04324316A true JPH04324316A (en) | 1992-11-13 |
| JP3030905B2 JP3030905B2 (en) | 2000-04-10 |
Family
ID=14108317
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3094366A Expired - Fee Related JP3030905B2 (en) | 1991-04-24 | 1991-04-24 | Fixed point detector |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3030905B2 (en) |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0675343A2 (en) * | 1994-03-31 | 1995-10-04 | Sony Magnescale, Inc. | Fixed point detecting device |
| EP1669725A1 (en) * | 2004-12-13 | 2006-06-14 | Sony Corporation | Displacement detection apparatus, displacement gauging apparatus and fixed point detection apparatus |
| EP1707924A2 (en) | 2005-03-28 | 2006-10-04 | Sony Corporation | Displacement detection apparatus, displacement measuring apparatus and fixed point detection apparatus |
| EP1707917A2 (en) * | 2005-04-01 | 2006-10-04 | Sony Corporation | Method of supplying content data and playlist htereof |
| EP2023095A2 (en) | 2007-07-24 | 2009-02-11 | Sony Corporation | Fixed-point detector and displacement-measuring apparatus |
| US7590162B2 (en) | 2003-07-03 | 2009-09-15 | Pd-Ld, Inc. | Chirped bragg grating elements |
| JP2014224746A (en) * | 2013-05-16 | 2014-12-04 | 株式会社ミツトヨ | Origin signal generating device and origin signal generating system |
| JP2014224745A (en) * | 2013-05-16 | 2014-12-04 | 株式会社ミツトヨ | Origin signal generating device and origin signal generating system |
| DE102006023687B4 (en) | 2005-05-23 | 2023-01-19 | Mori Seiki Co., Ltd. | Displacement detector and device for detecting a fixed point |
-
1991
- 1991-04-24 JP JP3094366A patent/JP3030905B2/en not_active Expired - Fee Related
Cited By (20)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0675343A3 (en) * | 1994-03-31 | 1997-06-04 | Sony Magnescale Inc | Fixed point detecting device. |
| US5637868A (en) * | 1994-03-31 | 1997-06-10 | Sony Magnescale Inc. | Fixed point detecting device using detection of light diffracted by holographic diffraction gratings |
| EP0675343A2 (en) * | 1994-03-31 | 1995-10-04 | Sony Magnescale, Inc. | Fixed point detecting device |
| US7590162B2 (en) | 2003-07-03 | 2009-09-15 | Pd-Ld, Inc. | Chirped bragg grating elements |
| US10205295B2 (en) | 2003-07-03 | 2019-02-12 | Necsel Intellectual Property, Inc. | Chirped Bragg grating elements |
| US9793674B2 (en) | 2003-07-03 | 2017-10-17 | Necsel Intellectual Property, Inc. | Chirped Bragg grating elements |
| EP1669725A1 (en) * | 2004-12-13 | 2006-06-14 | Sony Corporation | Displacement detection apparatus, displacement gauging apparatus and fixed point detection apparatus |
| EP3029428A1 (en) | 2004-12-13 | 2016-06-08 | Mori Seiki Co., Ltd. | Displacement detection apparatus, displacement gauging apparatus and fixed point detection apparatus |
| CN100462687C (en) * | 2004-12-13 | 2009-02-18 | 索尼株式会社 | Displacement detection apparatus, displacement gauging apparatus and fixed point detection apparatus |
| EP1707924A2 (en) | 2005-03-28 | 2006-10-04 | Sony Corporation | Displacement detection apparatus, displacement measuring apparatus and fixed point detection apparatus |
| JP2006275654A (en) * | 2005-03-28 | 2006-10-12 | Sony Corp | Displacement detector, displacement measuring apparatus, and fixed-point detector |
| EP1707917A2 (en) * | 2005-04-01 | 2006-10-04 | Sony Corporation | Method of supplying content data and playlist htereof |
| US8214431B2 (en) | 2005-04-01 | 2012-07-03 | Sony Corporation | Content and playlist providing method |
| EP1707917A3 (en) * | 2005-04-01 | 2006-11-29 | Sony Corporation | Method of supplying content data and playlist htereof |
| DE102006023687B4 (en) | 2005-05-23 | 2023-01-19 | Mori Seiki Co., Ltd. | Displacement detector and device for detecting a fixed point |
| US7808649B2 (en) | 2007-07-24 | 2010-10-05 | Mori Seiki Co., Ltd. | Fixed-point detector and displacement-measuring apparatus |
| JP2009031019A (en) * | 2007-07-24 | 2009-02-12 | Sony Corp | Fixed point detecting apparatus and displacement measuring apparatus |
| EP2023095A2 (en) | 2007-07-24 | 2009-02-11 | Sony Corporation | Fixed-point detector and displacement-measuring apparatus |
| JP2014224746A (en) * | 2013-05-16 | 2014-12-04 | 株式会社ミツトヨ | Origin signal generating device and origin signal generating system |
| JP2014224745A (en) * | 2013-05-16 | 2014-12-04 | 株式会社ミツトヨ | Origin signal generating device and origin signal generating system |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3030905B2 (en) | 2000-04-10 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4200395A (en) | Alignment of diffraction gratings | |
| JP3407477B2 (en) | Phase grating, manufacturing method thereof, and optical encoder | |
| JPH0697171B2 (en) | Displacement measuring device | |
| JPH05240613A (en) | Instrument and method for measuring displacement | |
| JP2619566B2 (en) | Optical position detector | |
| JPH03148015A (en) | Position measuring apparatus | |
| US4542989A (en) | Apparatus for position encoding | |
| JPH063167A (en) | Encoder | |
| JPH04324316A (en) | Fixed-point detection device | |
| US20070109556A1 (en) | Methods and Apparatus for Reducing Error in Interferometric Imaging Measurements | |
| US4395124A (en) | Apparatus for position encoding | |
| US5637868A (en) | Fixed point detecting device using detection of light diffracted by holographic diffraction gratings | |
| JPH046884B2 (en) | ||
| JP2718440B2 (en) | Length measuring or angle measuring device | |
| JP2004170153A (en) | Displacement detector | |
| JP2000056135A (en) | Total internal reflection(tir) holography device, its method and used optical assembly | |
| JP2718439B2 (en) | Length measuring or angle measuring device | |
| JPH01176914A (en) | Laser interference type encoder | |
| JP2005055360A (en) | Photoelectric type encoder | |
| JPS6139289Y2 (en) | ||
| JPH0441484B2 (en) | ||
| RU2047086C1 (en) | Transducer of linear movements | |
| Jablonowski | Interference position monitoring system employing Ronchi gratings | |
| JPS59192917A (en) | Position detecting method | |
| JPH0318720A (en) | Displacement measuring instrument |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| S531 | Written request for registration of change of domicile |
Free format text: JAPANESE INTERMEDIATE CODE: R313531 |
|
| S533 | Written request for registration of change of name |
Free format text: JAPANESE INTERMEDIATE CODE: R313533 |
|
| R360 | Written notification for declining of transfer of rights |
Free format text: JAPANESE INTERMEDIATE CODE: R360 |
|
| R370 | Written measure of declining of transfer procedure |
Free format text: JAPANESE INTERMEDIATE CODE: R370 |
|
| S531 | Written request for registration of change of domicile |
Free format text: JAPANESE INTERMEDIATE CODE: R313531 |
|
| S533 | Written request for registration of change of name |
Free format text: JAPANESE INTERMEDIATE CODE: R313533 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20080210 Year of fee payment: 8 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090210 Year of fee payment: 9 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100210 Year of fee payment: 10 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100210 Year of fee payment: 10 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110210 Year of fee payment: 11 |
|
| S111 | Request for change of ownership or part of ownership |
Free format text: JAPANESE INTERMEDIATE CODE: R313111 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110210 Year of fee payment: 11 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| S111 | Request for change of ownership or part of ownership |
Free format text: JAPANESE INTERMEDIATE CODE: R313113 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110210 Year of fee payment: 11 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| LAPS | Cancellation because of no payment of annual fees |