JP4237300B2 - Optical microscope - Google Patents

Description

ここでＮは干渉フィルタの屈折率である。
また使用しているフィルタがファブリペロー干渉フィルタであるとき、エア・スペースにおいてはＮ＝１であるから透過波長λ_Ｆ．Ｐ．は次の数２で表される。
【００１９】
【数２】

なお本実施形態において、フィルタは図４に示すように観察光軸に対して垂直なｘ−ｙ平面に平行な状態からｙ軸と平行な軸を回転軸として回転するようになっている。
【００２０】
この数式のように表されるフィルタの傾斜角と透過波長の関係から波長操作を行い得ることを見出し、実験の結果この式と良く一致する結果が得られることが確かめられた。故にフィルタの角度を操作することによってその角度に対応した透過波長範囲の光を観測することが確かめられたのである。
しかしフィルタを傾けることで透過波長の操作を行うことはできるが、単一波長画像を得ることはできない。このため本発明は試料像の各ポイント別に、測定光の光強度を測定して行き、その位置で観測される光の波長を計算して行くのである。
【００２１】
試料から放射される光は対物レンズ１２６によって集光され、結像レンズ１２８によって試料像が観察面上に結像されている。この試料像をポイント別に測定する機構として本実施形態では、微小領域に分解し、その領域ごとに波長−強度を測定するために、画素単位で測定して行くのである。つまり観察面上の座標（Ｘ，Ｙ）での画素で強度Ｉを測定し、その位置で測定される光の波長λを計算し、記憶部に｛（Ｘ，Ｙ），（λ_Ｘ，Ｙ，Ｉ_Ｘ，Ｙ）｝という４次元データとして記憶していくことで、ある波長における単一波長画像を画素単位で再構成し、観察することができるのである。
【００２２】
また観察光軸と入射光のなす角ｉ、ｊには次のような関係がある。
【数３】

【数４】

ここでｆは試料と対物レンズ１２６の間の焦点距離、Ｆは試料像と結像レンズ１２８の間の焦点距離である。数３、４から、
【００２３】
【数５】

【数６】

が成り立ち、測定されたデータ群｛（Ｘ，Ｙ），（λ_Ｘ，Ｙ，Ｉ_Ｘ，Ｙ）｝を試料の座標（ｘ，ｙ）に関するデータ群に変換することが可能である。
【００２４】
なお、本発明でいう「観察面上に試料像が結像されている」ということは目視可能な状態にあることを必要としない。試料上の各位置（ｘ，ｙ）が試料像上の各位置（Ｘ，Ｙ）と１：１に対応している状態をいう。なぜならば本発明は可視領域でない紫外、赤外などの光を扱う装置においても適用可能であるからである。
また本実施形態においては画素単位で測定を行ったが本発明はこれに限られるものではなく、微小領域ごとに測定するものであればよい。もちろん分解能の向上を考慮すると、微小領域が小さければ小さいほどよい。
【００２５】
【実施例】
第一実施形態
図３に示された測定機構によって、実際に測定を行った。以下、図３を参照して操作手順を追いながら本発明の作用について説明する。
レーザ部１６から出射されたレーザ光は、ビーム拡大機構部３８によりビーム径が拡大され、半透鏡４０、対物レンズ２６を介して試料２４上の広範囲な部位に照射されることは前述の通りである。レーザ光を照射された試料２４からは試料の情報を含んだ光が放射される。その試料の情報を含んだ光は対物レンズ２６で集光される。集光した光には様々な波長の光が含まれており、干渉フィルタ３２を傾斜させることによって透過する光の波長操作を行う。
【００２６】
フィルタ３２を傾斜させる角度、及び何度と何度で測定を行えば測定すべき波長域全域が全視野（すべての位置（Ｘ，Ｙ））で測定できるかは、前述した式によって計算できる。測定に際しては前記数１によってフィルタ３２の傾斜角θ_１、θ_２、θ_３、θ_４、θ_５、…で測定すればよいことをあらかじめ計算してある。
【００２７】
まず観察光軸に対してフィルタが垂直な状態である傾斜角θ_１＝０度で測定を行った。結像レンズ２８によってＣＣＤ検出器３０上の観察面に結像された試料像を各ピクセルごとに波長−強度を測定して行き、測定結果は各ピクセルごとに前述したように｛（Ｘ，Ｙ），（λ_Ｘ，Ｙ，Ｉ_Ｘ，Ｙ）｝の４次元データとして記憶部兼画像処理部３４に記憶される。
【００２８】
このとき観察された画像を図５に示す。同図に示すようにフィルタを透過しているにも関わらず得られた画像は単一波長画像ではないことがわかる。このため各ピクセルごとに測定し、結果を記憶しているのである。
【００２９】
続いてフィルタをθ_２＝３度に傾斜させ、測定を行った。このとき観察された画像を図６に示す。同図に示すように図５と比較して明らかに観測される光の波長や分布状態が異なることがわかる。これはフィルタを傾斜させることで透過波長が操作し得ることを示している。
【００３０】
このようにしてあらかじめ計算されたフィルタの傾斜角θ_３、θ_４、θ_５、…と測定して行き、測定すべき波長域全域が全視野（すべての位置（Ｘ，Ｙ））で測定されるまで測定を行う。
測定すべき波長域全域が全視野（すべての位置（Ｘ，Ｙ））で測定されたら、試料像の観察面上での位置座標（Ｘ，Ｙ）で書かれた測定データを、試料の位置座標（ｘ，ｙ）に変換し、（ｘ，ｙ）に対する各波長ごとの強度値を並べ換える。
【００３１】
試料座標に変換されたデータ群は、画像処理部３４によって解析者が指定した波長の単一波長画像として表示手段３６に表示される。図７は波長５３０ｎｍにおける試料表面での強度変化を示した３次元グラフである。このように得られる画像は単一波長画像であるから正確な解析を行うことができる。
【００３２】
ここで画像処理部のソフト的な改良によってあるｘの値に対するｙ軸方向の波長と強度変化を示す３次元画面やあるポイント（ｘ，ｙ）における波長−強度の変化を示した２次元グラフなどを表示できるようにしても良い。
【００３３】
第二実施形態
図８には本発明の第二の実施形態として図３の測定機構においてフィルタとしてファブリペロー干渉フィルタとバンドパスフィルタとして干渉フィルタを用いた測定機構の概要図が示されている。なお図３と対応するものには符号２００を付して説明を省略する。
【００３４】
ファブリペロー干渉フィルタは、高い分離能を有するが、波長ｍλ（ｍは整数）の光を透過させる性質を持つ。そこでファブリペロー干渉フィルタを使用する際には、透過する光の波長をさらにバンドパスフィルタによって操作するのである。このため測定して行く手順は前述の第一実施形態と同じであるが、透過波長操作において多少異なる。
【００３５】
レーザ部２１６から出射されたレーザ光は、ビーム拡大機構部２３８によりビーム径が拡大され、半透鏡２４０、対物レンズ２２６を介して試料２２４上の広範囲な部位に照射され、レーザ光を照射された試料２２４からは試料の情報を含んだ光が放射される。その試料の情報を含んだ光は対物レンズ２２６で集光される。集光した光には様々な波長の光が含まれており、ファブリペロー干渉フィルタ２５０及びバンドパスフィルタ２５２を傾斜させることによって透過する光の波長操作を行うのである。
【００３６】
ファブリペロー干渉フィルタ２５０及びバンドパスフィルタ２５２を傾斜させる角度、及び何度と何度で測定を行えば測定すべき波長域全域が全視野（すべての位置（Ｘ，Ｙ））で測定できるかは、前述した式数２によってファブリペロー干渉フィルタ２５０の傾斜角ψ_１、ψ_２、ψ_３、ψ_４、ψ_５、…でおよび数１によってバンドパスフィルタ２５２の傾斜角θ_１、θ_２、θ_３、θ_４、θ_５、…で測定すればよいことをあらかじめ計算してある。
【００３７】
第一実施形態との相違はバンドパスフィルタがファブリペロー干渉フィルタを透過する波長ｍλ（ｍ：整数）の光の内、ｍ＝ｎ〜ｎ＋１（ｎ：整数）の光を透過させるバンドパスフィルタを、ｎの値の異なるフィルタが複数枚用意されており、任意のｎ値のフィルタに適宜入れ替え可能となっていることである。
【００３８】
まず観察光軸に対してフィルタが垂直な状態であるファブリペロー干渉フィルタ２５０の傾斜角ψ_１＝０度、バンドパスフィルタの傾斜角θ_１＝０度でｎ＝１のバンドパスフィルタを用いて測定を行った。結像レンズ２８によってＣＣＤ検出器３０上の観察面に結像された試料像を各ピクセルごとに波長−強度を測定して行き、測定結果は各ピクセルごとに前述したように｛（Ｘ，Ｙ），（λ_Ｘ，Ｙ，Ｉ_Ｘ，Ｙ）｝の４次元データとして記憶部兼画像処理部３４に記憶される。
【００３９】
続いてψ_１、θ_１は動かさずにそのままにしておきバンドパスフィルタをｎ＝１のものからｎ＝２のものに入れ換えて測定を行う。そしてｎ＝２で測定を終了したらｎ＝３のバンドパスフィルタに入れ換えて測定を行うというように、備えられたバンドパスフィルタをｎ＝１〜ｋ（ｋは任意の整数）まで入れ換えて順次測定して行く。
【００４０】
一通りバンドパスフィルタを入れ換えて測定を行った後、ファブリペロー干渉フィルタ２５０の傾斜角ψ_１＝０度からψ_２＝３度に傾斜させた。このときバンドパスフィルタ２５２も必要があればθ_１からθ_２に角度を変える。
【００４１】
必要があればというのはファブリペロー干渉フィルタの透過させる光の波長と透過量の関係における半値幅Δλ_Ｆが、バンドパスフィルタが透過させる光の波長と透過量の関係における半値幅Δλ_Ｉに比べて十分小さく、Δλ_Ｉ＞＞Δλ_Ｆとなっているときはバンドパスフィルタの角度は変える必要がないからである。
【００４２】
このような手順で測定を進めて行き、測定すべき波長域全域が全視野（すべての位置（Ｘ，Ｙ））で測定されたら、試料像の観察面上での位置座標（Ｘ，Ｙ）で書かれた測定されたデータを、試料の位置座標（ｘ，ｙ）に変換し、（ｘ，ｙ）に対する各波長ごとの強度値を並べ換える。
試料座標に変換されたデータ群は、画像処理部２３４によって解析者が指定した波長の単一波長画像として表示手段２３６に表示される。
図９に本発明の実施形態にある装置を作動させた際の動作の流れを示したブロック図が示されている。
【００４３】
【発明の効果】
以上説明したように本発明による光学顕微装置によれば、フィルタを傾斜させることにより、透過波長の操作が可能なのでコストを抑えることができるうえ、ポイント別に波長−強度を測定するので正確な単一波長画像を解析することができる。
【図面の簡単な説明】
【図１】図１は、光学顕微装置の測定機構の概要図である。
【図２】図２は本発明の一実施形態にかかる光学顕微装置をラマン分光装置に適用した際の概略構成を示した図である。
【図３】図３は、図２に示すラマン分光装置１４のイメージ測定系である。
【図４】図４は、本発明の測定機構を簡略的に示した模式図である。
【図５】図５は、フィルタの傾斜角θ_１＝０度で測定を行った際に観察された観察画像である。
【図６】図６は、フィルタの傾斜角θ_２＝３度で測定を行った際に観察された観察画像である。
【図７】図７は波長５３０ｎｍにおける試料表面での強度変化を示した３次元グラフである。
【図８】図８はファブリペロー干渉フィルタとバンドパスフィルタとして干渉フィルタを用いた測定機構の概要図である。
【図９】図９は本発明の装置を作動させた際の動作の流れを示したブロック図である。
【符号の説明】
【符号の説明】
２ 測定機構（光学顕微装置）
４ 試料
６ 対物レンズ（集光部）
８ 結像レンズ
１０ フィルタ
１２ 観察像
１４ ラマン分光装置
１６ レーザ部
１８ 顕微試料室
２０ 差分散型トリプル分光器
２２ ＣＣＤ検出器
２４ 試料
２６ 対物レンズ
２８ 結像レンズ
３０ ＣＣＤ検出器
３２ 干渉フィルタ
３３ フィルタ傾斜機構
３４ 記憶部兼画像処理部
３６ 表示手段
３８ ビーム拡大機構部
４０ 半透鏡
４２ ラマン光導入切替部
４４ マスキング
４６ リレーレンズ部
４８ 切替部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical microscope capable of analyzing a sample in detail by measuring light from the sample, and more particularly to improvement of a measurement mechanism for measuring wavelength-light intensity.
[0002]
[Prior art]
An optical microscope such as an optical microscope and a spectrophotometer is a modern general analysis instrument that can obtain information on a measurement object by measuring and analyzing light from the measurement object. When analyzing an object to be measured with such a device, it is important to be able to measure which wavelength of light is emitted from the object to be measured and to what intensity.
[0003]
However, it is very rare that only light of a single wavelength is emitted from the object to be measured, and light of a plurality of wavelengths is usually emitted simultaneously. Therefore, when measuring the wavelength-intensity of light emitted from the object to be measured, a method is employed in which a filter is used to cut off the light having a single wavelength, and the intensity is measured. For this reason, normally, an apparatus provided with a state in which a plurality of filters can be replaced is used.
[0004]
A schematic diagram of the measurement mechanism of the optical microscope as described above is shown in FIG.
The measurement mechanism 2 shown in the figure includes an objective lens 6 that collects light emitted from a sample 4, an imaging lens 8 that forms a sample image, and a filter 10 that transmits only light of a specific wavelength. The observation image 12 of the sample 4 passes through the filter 10 through the objective lens 6 and the imaging lens 8. The observation image 12 of the sample 4 obtained in this way should be a specific wavelength image.
[0005]
[Problems to be solved by the invention]
However, the filter 10 has a drawback that the wavelength that can be transmitted varies depending on the incident angle of incident light. This problem is caused by a change in conditions affecting the incident light, such as a change in the optical path difference of the filter due to a difference in incident angle. In the measurement mechanism 2 having the above-described configuration, a specific wavelength image at a very narrow region of the sample 4, that is, a region on the optical axis (observation optical axis) X ₀ perpendicular to the filter 10 in the sample 4 is appropriately obtained. Although it is possible to obtain a specific wavelength image of a relatively wide area of the sample 4, for example, as shown in FIG. 1, the optical axis of the light emitted from the right end of the sample 4 (shown by a broken line) The optical axis X ₂ of light emitted from the left end of X ₁ and the sample 4 (shown by a two-dot broken line) is θ ₁ and θ _{2 with} respect to the optical axis (observation optical axis) X ₀ perpendicular to the filter 10, respectively. since thus inclined, observation image 12 of the sample 4 were those can not be obtained properly the specific wavelength image gradually shift as little by little wavelength away from the optical axis X _0.
[0006]
For this reason, when an observation image is analyzed as a specific single wavelength image, there is a problem that an error occurs due to a wavelength shift.
In order to solve these problems, the present inventors manipulated the transmission wavelength by changing the angle of the filter taking advantage of the feature, because the transmission wavelength changes due to the difference in the angle of incidence on the filter. It has been conceived to do.
[0007]
The present invention has been made in view of the above problems, and it is an object of the present invention to provide an apparatus capable of observing a single wavelength image even when there is a difference in the angle of incidence on the filter.
[0008]
[Means for Solving the Problems]
In order to solve the above-described problems, an optical microscope according to the present invention combines a light collecting unit that collects light from a sample including sample information and light collected by the light collecting unit as a sample image. In an optical microscope apparatus comprising: an imaging lens for imaging; and a detection unit that measures light intensity at each point of the sample image formed by the imaging lens; A filter that transmits only light, a filter tilt mechanism that changes a specific wavelength range that can be transmitted by tilting the filter with respect to the observation optical axis, and a measurement result detected by the detector at different tilt angles of the filter A storage unit for storing the image, an image processing unit for constructing an analysis image of the sample from the measurement result stored in the storage unit, and a display unit for displaying the output of the image processing unit. 09]
In the present invention, the detection unit decomposes and classifies the sample image formed by the imaging lens into minute polygonal areas, measures the light intensity for each of the divided minute areas, and measures the position and filter. It is preferable to determine the position coordinates and wavelength of the minute region from the inclination and output them to the storage unit.
Further, in the present invention, when the image processing unit constructs an analysis image of a specific wavelength, the measurement result observed for each minute region is read from the storage unit and determined based on the position coordinates of each minute region. It is preferable to synthesize the specific wavelength image of the sample image by displaying the specific wavelength calculation result in each minute region at the display position on the display means.
[0010]
In the present invention, it is preferable to use an interference filter as a filter that transmits only light in a specific wavelength range.
In the present invention, a Fabry-Perot interference filter as a filter that transmits only light in a specific wavelength range, and m = n to n + 1 (n: of light having a wavelength mλ (m: integer) that passes through the Fabry-Perot interference filter. It is preferable to use a band-pass filter that transmits light of an integer).
[0011]
In the present invention, a plurality of filters having different values of n are prepared as the bandpass filter to be used, and it is preferable that the bandpass filter has a configuration that can be appropriately replaced with an arbitrary filter of n values.
In the present invention, it is preferable to use a high-sensitivity CCD detector as the measurement light detection unit for measuring the wavelength and light intensity of the measurement light for each point of the sample image.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
The optical microscope according to the present invention can be used for obtaining a specific wavelength image of an observation image of a relatively wide range of a sample.
For example, stress evaluation of a Si device using micro Raman spectroscopy can be cited as an example. Since the accuracy of stress evaluation of the Si device depends on how accurately a Raman peak specific wavelength image having a very narrow wavelength width is obtained, it is necessary to obtain a specific wavelength image from observation images of a relatively wide range of sites. In such a case, it is preferable to use the optical microscope of the present invention.
[0013]
Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings.
FIG. 2 shows a schematic configuration when an optical microscope according to an embodiment of the present invention is applied to a Raman spectroscopic apparatus. In the present embodiment, a case where a relatively wide area of the Si device is assumed as a sample and a specific wavelength image of the observation image is obtained will be described.
A Raman spectroscopic device 14 which is an optical microscopic device shown in FIG. 1 includes a laser unit 16, a microscopic sample chamber 18, a differential dispersion type triple spectroscope 20, and a CCD detector 22.
FIG. 3 shows an image measurement system of the Raman spectroscopic device 14 shown in FIG.
[0014]
As shown in the figure, an objective lens 26 which is a measurement light condensing unit for condensing light from a sample 24 including sample information and an image formed by using the light collected by the measurement light condensing unit as a sample image An imaging lens 28 to be measured, a CCD detector 30 which is a measurement light detector for measuring the light intensity of the measurement light for each point of the sample image formed by the imaging lens, and a specific wavelength region from the measurement light. An interference filter 32 as a filter that transmits only light, a filter tilt mechanism 33 that changes a specific wavelength range that can be transmitted by tilting the filter with respect to the observation optical axis of the measurement light, and at different tilt angles of the filter The measurement result detected by the measurement light detection unit is stored, and the storage unit / image processing unit 34 that configures the analysis image of the sample from the stored measurement result, and the display unit 3 that displays the output of the image processing unit Comprising a.
[0015]
The laser beam emitted from the laser unit 16 has a beam diameter expanded by the beam expanding mechanism unit 38 and is irradiated to a wide area on the sample 24 via the semi-transparent mirror 40 and the objective lens 26. This observation image is taken by the CCD detector 30 through the objective lens 26, the semi-transparent mirror 40, the Raman light introduction switching unit 42, the interference filter 32, the imaging lens 28, the masking 44, the relay lens unit 46, and the switching unit 48. .
The image photographed by the CCD detector 30 is subjected to image processing to be described later by the image processing device 34, and can be visually observed on the display means 36.
In the present embodiment, the interference filter includes a super notch filter (not shown) for removing Rayleigh light.
[0016]
What is characteristic in the present invention is that the wavelength is manipulated by tilting the filter. The wavelength is calculated for each point of the sample image, the light intensity is measured and stored, and an image of the same wavelength is reconstructed. It can be displayed.
[0017]
FIG. 4 is a schematic diagram schematically showing the measurement mechanism of the present invention in order to show the relationship between the angle of the filter and the transmission wavelength. In addition, the code | symbol 100 is attached | subjected to FIG. 3 and description is abbreviate | omitted.
In the drawing, the light emitted from the sample 124 passes through the objective lens 126, and a sample image is formed on the detection surface by the imaging lens 128. A filter 132 is provided between the objective lens 126 and the imaging lens 128. Is rotatably provided. A coordinate axis xyz indicating the position on the sample is stretched on the sample 124, and a coordinate axis XYZ indicating the position on the sample image is also stretched on the observation surface as shown in the figure.
[0018]
When measuring the light emitted from the point at the position (x, y) on the sample, the straight plane xz connecting the point (x, y) and the center O of the objective lens and the plane yz Are orthogonal to the z axis (observation optical axis), i and j, respectively, and the filter is inclined by θ, the inclination of the filter and the transmission wavelength have the following relationship.
When the filter used is an interference filter, the transmission wavelength λ _I is expressed by the following equation (1).
[Expression 1]

Here, N is the refractive index of the interference filter.
When the filter being used is a Fabry-Perot interference filter, N = 1 in the air space, so that the transmission wavelength λ _{F.F. P.} Is expressed by the following equation (2).
[0019]
[Expression 2]

In this embodiment, as shown in FIG. 4, the filter rotates from a state parallel to the xy plane perpendicular to the observation optical axis as an axis parallel to the y axis.
[0020]
It has been found that wavelength manipulation can be performed from the relationship between the inclination angle of the filter and the transmission wavelength expressed as in this equation, and as a result of experiments, it has been confirmed that a result that closely matches this equation can be obtained. Therefore, it was confirmed that the light in the transmission wavelength range corresponding to the angle was observed by manipulating the angle of the filter.
However, the transmission wavelength can be manipulated by tilting the filter, but a single wavelength image cannot be obtained. For this reason, the present invention measures the light intensity of the measurement light for each point of the sample image and calculates the wavelength of the light observed at that position.
[0021]
The light emitted from the sample is collected by the objective lens 126, and the sample image is formed on the observation surface by the imaging lens 128. In this embodiment, as a mechanism for measuring the sample image for each point, the measurement is performed in units of pixels in order to divide the image into minute regions and measure the wavelength-intensity for each region. That is, the intensity I is measured with the pixel at the coordinate (X, Y) on the observation surface, the wavelength λ of the light measured at that position is calculated, and {(X, Y), (λ _{X, Y is} stored in the storage unit. , I _{X, Y} )}, it is possible to reconstruct and observe a single wavelength image at a certain wavelength in units of pixels.
[0022]
The angles i and j formed by the observation optical axis and the incident light have the following relationship.
[Equation 3]

[Expression 4]

Here, f is a focal length between the sample and the objective lens 126, and F is a focal length between the sample image and the imaging lens 128. From Equations 3 and 4,
[0023]
[Equation 5]

[Formula 6]

Therefore, the measured data group {(X, Y), (λ _{X, Y} , I _{X, Y} )} can be converted into a data group related to the coordinates (x, y) of the sample.
[0024]
In the present invention, “the sample image is formed on the observation surface” does not need to be visible. Each of the positions (x, y) on the sample corresponds to each position (X, Y) on the sample image 1: 1. This is because the present invention can also be applied to an apparatus that handles light such as ultraviolet light and infrared light that is not in the visible region.
In this embodiment, the measurement is performed in units of pixels. However, the present invention is not limited to this, and any measurement may be performed as long as measurement is performed for each minute region. Of course, considering the improvement in resolution, the smaller the smaller region, the better.
[0025]
【Example】
First embodiment Measurement was actually performed by the measurement mechanism shown in Fig. 3. The operation of the present invention will be described below with reference to FIG.
As described above, the laser beam emitted from the laser unit 16 has its beam diameter expanded by the beam expansion mechanism unit 38 and is irradiated to a wide area on the sample 24 through the semi-transparent mirror 40 and the objective lens 26. is there. The sample 24 irradiated with the laser light emits light including sample information. The light containing the sample information is collected by the objective lens 26. The condensed light includes light of various wavelengths, and the wavelength of the transmitted light is controlled by tilting the interference filter 32.
[0026]
The angle at which the filter 32 is tilted and whether the entire wavelength range to be measured can be measured in the entire field of view (all positions (X, Y)) by performing the measurement many times can be calculated by the above-described equation. In the measurement, it is calculated in advance that the measurement may be performed at the inclination angles θ ₁ , θ ₂ , θ ₃ , θ ₄ , θ ₅ ,.
[0027]
First, measurement was performed at an inclination angle θ ₁ = 0 degrees in which the filter was perpendicular to the observation optical axis. The sample image formed on the observation surface on the CCD detector 30 by the imaging lens 28 is measured for wavelength-intensity for each pixel, and the measurement result is {(X, Y ), (Λ _{X, Y} , I _{X, Y} )} is stored in the storage unit / image processing unit 34 as four-dimensional data.
[0028]
The image observed at this time is shown in FIG. As shown in the figure, it can be seen that the image obtained though passing through the filter is not a single wavelength image. For this reason, each pixel is measured and the result is stored.
[0029]
Subsequently, the filter was tilted at θ ₂ = 3 degrees, and measurement was performed. The image observed at this time is shown in FIG. As shown in the figure, it can be seen that the wavelength and distribution state of light clearly observed are different from those in FIG. This indicates that the transmission wavelength can be manipulated by tilting the filter.
[0030]
In this way, the pre-calculated filter tilt angles θ ₃ , θ ₄ , θ ₅ ,... Are measured, and the entire wavelength range to be measured is measured in the entire field of view (all positions (X, Y)). Measure until
When the entire wavelength range to be measured is measured in the entire field of view (all positions (X, Y)), the measurement data written in the position coordinates (X, Y) on the observation surface of the sample image is used as the position of the sample. The coordinates are converted into coordinates (x, y), and the intensity values for each wavelength with respect to (x, y) are rearranged.
[0031]
The data group converted into the sample coordinates is displayed on the display unit 36 as a single wavelength image of the wavelength designated by the analyst by the image processing unit 34. FIG. 7 is a three-dimensional graph showing the intensity change on the sample surface at a wavelength of 530 nm. Since the image obtained in this way is a single wavelength image, accurate analysis can be performed.
[0032]
Here, a three-dimensional screen showing a change in wavelength and intensity in the y-axis direction with respect to a value of x by a software improvement of the image processing unit, a two-dimensional graph showing a change in wavelength-intensity at a point (x, y), etc. May be displayed.
[0033]
Second Embodiment FIG. 8 is a schematic diagram of a measurement mechanism using a Fabry-Perot interference filter as a filter and an interference filter as a bandpass filter in the measurement mechanism of FIG. 3 as a second embodiment of the present invention. Has been. In addition, the code | symbol 200 is attached | subjected to what corresponds to FIG. 3, and description is abbreviate | omitted.
[0034]
A Fabry-Perot interference filter has a high resolution, but has a property of transmitting light having a wavelength mλ (m is an integer). Therefore, when the Fabry-Perot interference filter is used, the wavelength of the transmitted light is further manipulated by the band pass filter. Therefore, the measurement procedure is the same as in the first embodiment described above, but is slightly different in the transmission wavelength operation.
[0035]
The laser beam emitted from the laser unit 216 is expanded in beam diameter by the beam expanding mechanism unit 238 and irradiated to a wide area on the sample 224 via the semi-transparent mirror 240 and the objective lens 226 and irradiated with the laser beam. The sample 224 emits light including sample information. The light containing the sample information is collected by the objective lens 226. The condensed light includes light of various wavelengths, and the wavelength of the transmitted light is controlled by tilting the Fabry-Perot interference filter 250 and the bandpass filter 252.
[0036]
The angle at which the Fabry-Perot interference filter 250 and the bandpass filter 252 are tilted, and whether the entire wavelength region to be measured can be measured in the entire field of view (all positions (X, Y)) by performing measurement repeatedly and repeatedly. , The inclination angles ψ ₁ , ψ ₂ , ψ ₃ , ψ ₄ , ψ ₅ ,... Of the Fabry-Perot interference filter 250 according to the above equation 2 and the inclination angles θ ₁ , θ ₂ , θ of the bandpass filter 252 according to the equation ₁ . ₃ , θ ₄ , θ ₅ ,... Have been calculated in advance.
[0037]
The difference from the first embodiment is that a bandpass filter that transmits light of m = n to n + 1 (n: integer) among light of wavelength mλ (m: integer) that the bandpass filter transmits through the Fabry-Perot interference filter. , A plurality of filters having different values of n are prepared and can be appropriately replaced with arbitrary n-value filters.
[0038]
First, using a bandpass filter with an inclination angle ψ ₁ = 0 degree of the Fabry-Perot interference filter 250 in a state where the filter is perpendicular to the observation optical axis, an inclination angle θ ₁ = 0 degree of the bandpass filter, and n = 1. Measurements were made. The sample image formed on the observation surface on the CCD detector 30 by the imaging lens 28 is measured for wavelength-intensity for each pixel, and the measurement result is {(X, Y ), (Λ _{X, Y} , I _{X, Y} )} is stored in the storage unit / image processing unit 34 as four-dimensional data.
[0039]
Subsequently, ψ ₁ and θ ₁ are left as they are without moving, and the band-pass filter is changed from n = 1 to n = 2, and measurement is performed. When the measurement is completed at n = 2, the measurement is performed by replacing the provided bandpass filter from n = 1 to k (k is an arbitrary integer) so that the measurement is performed by replacing the bandpass filter with n = 3. Go.
[0040]
After the measurement was performed with the bandpass filter replaced, the Fabry-Perot interference filter 250 was tilted from ψ ₁ = 0 degrees to ψ ₂ = 3 degrees. At this time, the bandpass filter 252 also changes the angle from θ ₁ to θ ₂ if necessary.
[0041]
If necessary, the half-value width Δλ _F in the relationship between the wavelength of light transmitted by the Fabry-Perot interference filter and the transmission amount is compared with the half-value width Δλ _I in the relationship between the wavelength of light transmitted by the bandpass filter and the transmission amount. This is because it is not necessary to change the angle of the band-pass filter when Δλ _I >> Δλ _F.
[0042]
When the measurement proceeds in such a procedure and the entire wavelength range to be measured is measured in the entire visual field (all positions (X, Y)), the position coordinates (X, Y) on the observation surface of the sample image The measured data written in (1) is converted into the position coordinates (x, y) of the sample, and the intensity values for each wavelength with respect to (x, y) are rearranged.
The data group converted into the sample coordinates is displayed on the display unit 236 as a single wavelength image of the wavelength designated by the analyst by the image processing unit 234.
FIG. 9 is a block diagram showing a flow of operation when the apparatus according to the embodiment of the present invention is operated.
[0043]
【The invention's effect】
As described above, according to the optical microscope according to the present invention, it is possible to control the transmission wavelength by tilting the filter, so that the cost can be suppressed, and the wavelength-intensity is measured for each point. Wavelength images can be analyzed.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of a measurement mechanism of an optical microscope.
FIG. 2 is a diagram showing a schematic configuration when an optical microscope apparatus according to an embodiment of the present invention is applied to a Raman spectroscopic apparatus.
FIG. 3 is an image measurement system of the Raman spectroscopic device 14 shown in FIG. 2;
FIG. 4 is a schematic diagram schematically showing the measurement mechanism of the present invention.
FIG. 5 is an observation image observed when measurement is performed at an inclination angle θ _{1 of the} filter of 0 °.
FIG. 6 is an observation image observed when measurement is performed at a filter inclination angle θ ₂ = 3 degrees.
FIG. 7 is a three-dimensional graph showing an intensity change on the sample surface at a wavelength of 530 nm.
FIG. 8 is a schematic diagram of a measurement mechanism using an Fabry-Perot interference filter and an interference filter as a bandpass filter.
FIG. 9 is a block diagram showing a flow of operation when the apparatus of the present invention is operated.
[Explanation of symbols]
[Explanation of symbols]
2 Measurement mechanism (optical microscope)
4 Sample 6 Objective lens (Condenser)
8 Imaging Lens 10 Filter 12 Observation Image 14 Raman Spectrometer 16 Laser Unit 18 Microscopic Sample Chamber 20 Differential Dispersion Triple Spectroscope 22 CCD Detector 24 Sample 26 Objective Lens 28 Imaging Lens 30 CCD Detector 32 Interference Filter 33 Filter Tilt Mechanism 34 Storage unit / image processing unit 36 Display means 38 Beam expansion mechanism unit 40 Semi-transparent mirror 42 Raman light introduction switching unit 44 Masking 46 Relay lens unit 48 Switching unit

Claims (8)

A light collecting unit for collecting light from the sample including the sample information;
An imaging lens that forms an image of the light collected by the condenser as a sample image;
A detector for measuring the light intensity for each point of the sample image formed by the imaging lens;
In an optical microscope equipped with
A filter that transmits only light in a specific wavelength region from light including the sample information;
A filter tilting mechanism that changes a specific wavelength range that can be transmitted by tilting the filter with respect to the observation optical axis;
A storage unit that stores measurement results detected by the detection unit at different inclination angles of the filter;
The detection unit decomposes and classifies the sample image formed by the imaging lens into minute polygonal areas, measures the light intensity for each of the divided minute areas, and positions coordinates (X, Y) of the minute areas. ) And the filter inclination θ, the measurement position (x, y) and the wavelength λ are determined and output to the storage unit,
An image processing unit constituting an analysis image of the sample from the measurement result stored in the storage unit;
An optical microscope apparatus comprising display means for displaying the output of the image processing unit. The optical microscope according to claim 1,
  When the filter is an interference filter,
  The angles formed by the orthogonal projection of the measurement position (x, y) and the straight plane yz connecting the objective lens center O on the plane xz and plane yz with the z axis, which is the observation optical axis, are i and j, respectively. Then, i and j are expressed as follows using the focal length f between the sample and the objective lens, the focal length F between the sample image and the imaging lens, and the position coordinates (X, Y) of the minute region. And

  When the thickness of the filter is d and the order of the wavelength is A, i, j, the inclination θ of the filter, and the refractive index of the interference filter are N (n is the same as N). λ _I Is determined,

  An optical microscope apparatus that uses the position coordinates (X, Y) of the minute area, the focal distance f, and the focal distance F to determine the measurement position (x, y) by the following formula.

The optical microscope according to claim 1,
  When the filter is a Fabry-Perot interference filter,
  The angles formed by the orthogonal projection of the measurement position (x, y) and the straight plane yz connecting the objective lens center O on the plane xz and plane yz with the z axis, which is the observation optical axis, are i and j, respectively. Then, i and j are expressed as follows using the focal length f between the sample and the objective lens, the focal length F between the sample image and the imaging lens, and the position coordinates (X, Y) of the minute region. And

  Using i and j and the filter inclination θ, the wavelength λ _{F. P.} Is determined,

  An optical microscope apparatus that uses the position coordinates (X, Y) of the minute region, the focal length f, and the focal length F to determine the measurement position (x, y) according to the following formula.

In the optical microscope apparatus according to claim 1 to 3, wherein said image processing unit when configuring an analysis image of a specific wavelength, reads the observed measurements for each of the minute regions from the storage unit, for each minute region An optical microscope characterized in that a specific wavelength image of a sample image is synthesized by displaying a specific wavelength calculation result in each minute region at a display position on a display means determined based on position coordinates. Apparatus according to any claims 1 to 4, the optical microscope apparatus characterized by using an interference filter as a filter for transmitting only light in a specific wavelength range.   6. The apparatus according to claim 1, wherein a Fabry-Perot interference filter as a filter that transmits only light in a specific wavelength range, and m of light having a wavelength mλ (m: integer) that passes through the Fabry-Perot interference filter. A bandpass filter that transmits light of n to n + 1 (n: integer) is used. 7. The optical microscope according to claim 6 , wherein a plurality of filters having different values of n are prepared as the band-pass filter to be used, and the filter can be appropriately replaced with an arbitrary filter of n values. . Apparatus according to any claims 1 to 7, the optical microscope apparatus characterized by the use of high-sensitivity CCD detector as the measurement light detection unit for measuring the wavelength and light intensity of the measurement light for each point in the sample image .

Images