JP2010276371A - Infrared microscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To identify the target substance existing in the noticeable region on a sample, with high reliability. <P>SOLUTION: A measuring person confirms the surface observation image of the sample by visible light on a screen and selectively indicates the noticeiable region on the sample (S4). Hereupon, the absorption peaks appearing in the infrared absorption spectra measured at the measuring points contained in the noticeiable region are extracted (S5) and the two-dimensional distribution of the measuring points, where the absorption peaks are observed, is acquired at every absorption peak (S6). Thereafter, the coefficient of correlation of the distribution with the noticeable region is calculated at every two-dimensional distribution of the respective peaks (S7). The weighting corresponding to the coefficient of correlation is performed with respect to the respective absorption peaks in the infrared absorption spectra at the respective measuring points in the noticeable region, and then the matching of the spectra with the spectrum of a known substance is executed, so that the substance existing at each of the measuring points is identified (S8). <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an infrared microscope that analyzes a sample by irradiating the sample with infrared light and measuring an absorption spectrum of the transmitted or reflected infrared light.

  In sample analysis using an infrared microscope, the position of a minute region to be measured is usually determined by observing a sample placed on a movable sample stage with visible light, and then Fourier transform infrared spectroscopy is performed. The minute region is irradiated with infrared light (interferogram) generated by an interferometer of a photometer (FTIR) and changing with time. Then, the reflected light or transmitted light is detected by a detector, and the detection signal is subjected to Fourier transform to obtain an infrared absorption spectrum reflecting the absorption of infrared light in the minute region. For example, in the infrared microscope described in Non-Patent Document 1, it is possible to measure a very small area of □ 50 μm or less.

  In the mapping measurement (surface analysis) in the infrared microscope as described above, the sample stage is moved by a predetermined distance in the X-axis direction and the Y-axis direction orthogonal to each other, and within a two-dimensional measurement region set on the sample. The part (micro area | region) which an infrared light hits is scanned, and the infrared absorption spectrum of each part is acquired. Then, the qualitative and quantitative distribution of the substance existing in the measurement region is examined based on the infrared absorption spectrum of each minute region, and the result is displayed on the monitor screen as a two-dimensional or three-dimensional graph. .

  As a method for setting a two-dimensional region on a sample to be measured, a method described in Patent Document 1 is conventionally known. In the qualitative analysis of the substance to be measured, if you prepare a kind of database that stores the standard infrared absorption spectrum of various substances in association with the substance name in advance, and obtain the infrared absorption spectrum of the sample, A known substance having a standard spectrum whose pattern is similar to the spectrum is searched in the database, and the measurement target substance is specified using the search result.

JP 2007-85978 A

"Infrared microscope system AIM-8800", [online], [Search April 30, 2009], Shimadzu Corporation, Internet <URL: http://www.an.shimadzu.co.jp/products/ ir / aim8800.htm>

  When performing a qualitative analysis of small foreign substances adhering to a sample consisting of multiple substances, the overlap is such that the substance of interest partially adheres to the base component constituting the sample. Can be considered a state. In general, the infrared absorption spectrum of the region where the target substance exists is the sum (absorption spectrum) of the absorption peak of the target substance and the absorption peaks of a plurality of base components. In such a case, in order to identify the target substance, an infrared absorption spectrum (hereinafter referred to as “base component spectrum”) in a region where only the base component exists is obtained, and the sum spectrum is obtained by subtracting the base component spectrum. The target substance spectrum in which an absorption peak due to the target substance appears is obtained. And the method of identifying a target substance is performed by performing the matching of the peak of this target substance spectrum and the infrared absorption spectrum of each known various substance one by one.

  However, if the measured infrared absorption spectrum contains absorption peaks such as water vapor or carbon dioxide, or the influence of noise in the measurement system is significant, the target substance spectrum and the infrared absorption spectra of various known substances And the matching accuracy decreases. As a result, there is a problem that it is easy to derive an erroneous result in identification of a target substance.

  The present invention has been made in order to solve these problems, and the object of the present invention is that, for example, the target substance is attached on the base component, and an interfering component such as water vapor or carbon dioxide is present. An object of the present invention is to provide an infrared microscope capable of identifying a target substance with high accuracy even when the influence of noise is so large that it cannot be ignored.

In order to solve the above problems, the present invention provides a red light that irradiates a sample with infrared interference light, detects transmitted light or reflected light from the sample, and measures an infrared absorption spectrum in a measurement region on the sample. In the outer microscope,
a) Irradiating a sample with visible light, creating a sample observation image based on transmitted light or reflected light from the sample, and determining an attention region where a target substance is assumed to be present based on the sample observation image An area determination means;
b) a two-dimensional region spectrum measuring means for irradiating each of a plurality of minute regions set in a two-dimensional region on the sample with infrared interference light and measuring an infrared absorption spectrum in each minute region;
c) a specific peak distribution extracting means for extracting a two-dimensional distribution by extracting a minute region having a peak intensity equal to or greater than a predetermined threshold for each absorption peak in an infrared absorption spectrum in each minute region;
d) For each absorption peak of the infrared absorption spectrum of the minute region included in the attention region determined by the attention region determining means, the two-dimensional distribution of the minute region at the absorption peak obtained by the specific peak distribution extracting means A correlation correlation acquisition means for calculating an index indicating a correlation between the two-dimensional distribution of the micro area of the attention area and the target area, and storing the index in association with an absorption peak;
e) standard spectrum storage means for storing in advance infrared absorption spectra of various known substances;
f) Infrared absorption spectra of known substances stored in the standard spectrum storage means and minute areas included in the attention area while weighting each absorption peak using the index obtained by the distribution correlation acquisition means A substance identification means in the region of interest for identifying a substance present in each minute region in the region of interest by comparing with an infrared absorption spectrum in
It is characterized by having.

As a first aspect of the infrared microscope according to the present invention, the region of interest determination means includes:
An observation image providing means for irradiating the sample with visible light, creating a sample observation image based on transmitted light or reflected light by the sample, and displaying the image on the screen of the display means;
On the sample observation image displayed by the observation image providing means, attention area instruction means for the measurer to select and indicate the attention area on which the target substance is presumed to exist,
It can be set as the structure containing.

  In this first aspect, the measurer visually confirms the sample observation image displayed on the screen of the display means, and the measurer himself / herself is based on the prior knowledge of the color, shape, pattern, etc. A region of interest that is presumed to exist is determined, and the range is selected and instructed.

  As a second aspect of the infrared microscope according to the present invention, the attention area determination unit performs image processing based on a predetermined condition on the created sample observation image, and sets an area that satisfies the condition as the attention area. It can also be configured to be determined.

  The image processing can include processing such as edge extraction and binarization, for example. If it is known that the color, shape, pattern or the like of the attention area is specific, the attention area is automatically extracted by setting these to the predetermined condition. This eliminates the need for the operator to view the sample observation image displayed on the screen of the display means and to select and designate the region of interest one by one, thereby saving labor and increasing throughput.

As a third aspect of the infrared microscope according to the present invention, the region of interest determination means includes:
For a plurality of absorption peaks appearing in the infrared absorption spectrum of each minute region, an intensity distribution in which the two-dimensional intensity distribution of each peak is superimposed on the sample observation image as semi-transmissive image information and displayed on the screen of the display means Display superimposing means;
Based on the sample observation image in which the two-dimensional intensity distribution is superimposed and displayed by the intensity distribution display superimposing means, the two-dimensional intensity distribution at the absorption peak and the region of interest assumed by the measurer match as much as possible from among the plurality of absorption peaks. A region-of-interest matching peak selection means for the measurer to select and indicate an absorption peak to be
Peak-corresponding attention area setting means for determining, as the attention area, the two-dimensional intensity distribution at the absorption peak selected by the measurer by the attention area matching peak selection means;
It is good also as a structure containing.

  The intensity distribution display superimposing means may, for example, define a different display color for each absorption peak and display the two-dimensional intensity distribution of the absorption peak with a translucent gradation display according to the absorption intensity.

  In this third aspect, for a plurality of infrared absorption peaks obtained by measurement, the measurer visually confirms the two-dimensional intensity distribution of each absorption peak, and it can be assumed that the target substance exists from these distributions. The measurer can select the distribution with a simple operation.

  In the first to third aspects, although the method of determining the region of interest is different, the distribution correlation acquisition means is a two-dimensional (spatial) of the region of interest and the absorption peak included in the measured infrared absorption spectrum. An index, for example, a correlation coefficient, that reflects the similarity of the shape with a simple distribution is obtained. Then, when the substance identifying means in the attention area identifies the substance existing in each minute area in the attention area, the weight corresponding to the above index is given to the absorption peak, and the infrared absorption spectrum and measurement of the known substance are performed. Matching with the obtained infrared absorption spectrum is performed.

  The attention area is an area where there is a high possibility that the target substance to be identified exists. In addition, there is a possibility that substances other than the target substance are generally present in the attention area with a small area, especially under the circumstances where the influence of unnecessary components such as water vapor and carbon dioxide and disturbance factors such as measurement system noise cannot be ignored. Can be considered relatively small. That is, there is a high possibility that an absorption peak given a high weight is an absorption peak derived from the target substance. Conversely, absorption peaks derived from substances that are biased in parts other than the region of interest and substances that are present not only in the region of interest but also throughout the region have a low weight. Therefore, such an absorption peak derived from a substance other than the target substance is not easily reflected in the identification of the substance, and as a result, the target substance existing in the region of interest can be identified with high reliability.

As still another fourth aspect of the infrared microscope according to the present invention,
The region-of-interest determination unit selects an absorption peak that minimizes the area of the two-dimensional distribution region obtained by the specific peak distribution extraction unit from the given absorption peak. Determine the distribution area as the attention area,
Further, after a substance existing in the attention area is identified by the substance identification means in the attention area, it is determined whether or not the reliability of the identification result is a certain level or more, and is determined to be a certain level or more. The infrared absorption intensity of the identified substance is subtracted from the infrared absorption spectrum in the minute region included in the two-dimensional distribution, and the selected region of interest is selected for the infrared absorption spectrum after the subtraction. The identification of the region-of-interest material may be repeatedly performed, and the material identification may be repeatedly performed until the region of interest cannot be extracted.

  In the fourth aspect, attention is paid to the area of the region where the absorption peak obtained by measurement is observed. In general, the smaller this distribution area, the fewer types of substances that exist in that area, and the easier it is to identify the substance. Therefore, in order from the smallest area of the distribution region, the substance in the region is identified, and the intensity of the absorption peak of the substance is subtracted from the infrared absorption spectrum to remove the influence of absorption by the substance. As a result, even when a large number of substances are mixed in a sample, each substance can be automatically and accurately identified if there is a micro area consisting only of that substance. Is possible.

  As described above, the sample does not consist of a single substance but contains a plurality of substances, and the target substance noted by the measurer is partially attached to the base substances. When the measured infrared absorption spectrum is mixed with unwanted absorption peaks such as water vapor or carbon dioxide, or when the influence of noise in the measurement system is large, the target substance can be identified. There was a problem that the result was likely to be wrong. On the other hand, according to the infrared microscope according to the present invention, while considering the influence of undesired absorption peaks that can be treated as background noise and the influence of measurement noise relatively low, in other words, in the attention area. While focusing on the wave number (or wavelength) of the absorption peak derived from a substance that is presumed to exist, the infrared absorption spectrum of each minute region in the region of interest and the infrared absorption spectra of various known substances Can be compared. Therefore, the target substance can be identified with higher accuracy than before.

  According to the first aspect of the infrared microscope of the present invention, the measurer observes a visible image on the surface of the sample, and has a clue about visual information such as the shape, shading, pattern, and color of the sample in the image. In addition, by manually selecting a region of interest in which it can be estimated that the target substance exists, the target substance existing in the region can be identified with high accuracy.

  Further, according to the second aspect of the infrared microscope of the present invention, the measurement area is automatically determined from the visible image on the surface of the sample without performing image observation or determination, and exists in the area. The target substance can be identified with high accuracy. Thereby, the detection of a foreign substance and the identification of the foreign substance can be satisfactorily performed in a patterned inspection such as a quality inspection of a production line of a factory, selection of agricultural and marine products, and the like.

  Further, according to the third aspect of the infrared microscope according to the present invention, the area where the measurer can estimate that the target substance exists while visually comparing the visible image of the sample surface and the distribution area of the infrared absorption peak. Selection can be made with a simple operation. Further, according to this aspect, even if the sample surface observation image is unclear due to defocusing or the like, the measurer can easily and accurately estimate the region where the target substance exists.

  Further, according to the fourth aspect of the infrared microscope according to the present invention, even when a large number of substances are mixed in the sample, even in each sample, there is even a minute region consisting only of the substance. If so, highly accurate identification results can be automatically obtained for each substance.

The block diagram of the principal part of the infrared microscope which is one Example (1st Example) of this invention. The flowchart of the identification process in the infrared microscope of 1st Example. Explanatory drawing of the identification process in the infrared microscope of 1st Example. Explanatory drawing of the identification process in the infrared microscope of 1st Example. Explanatory drawing of the identification process in the infrared microscope of 1st Example. Explanatory drawing of the identification process in the infrared microscope of 1st Example. Explanatory drawing of the identification process in the infrared microscope of 1st Example. The flowchart of the identification process in the infrared microscope of another Example (2nd Example) of this invention. The flowchart of the identification process in the infrared microscope of another Example (3rd Example) of this invention. Explanatory drawing of the identification process in the infrared microscope of 3rd Example. The flowchart of the identification process in the infrared microscope of another Example (4th Example) of this invention.

[First embodiment]
Hereinafter, an infrared microscope which is one embodiment (first embodiment) of the present invention will be described with reference to FIGS. FIG. 1 is a configuration diagram of a main part of the infrared microscope of this embodiment, and FIG. 2 is a flowchart of identification processing in the infrared microscope of this embodiment.

  In FIG. 1, an infrared interferometer 1 includes an infrared light source, a fixed mirror, a moving mirror, a beam splitter, and the like, and emits infrared interference light whose amplitude varies with time, that is, an interferogram. This infrared interference light is reflected by the half mirror 4, is narrowed down to a small diameter by a condensing mirror (not shown), and is irradiated onto the sample 3 placed on the sample stage 2. The infrared light reflected from the sample 3 passes through the half mirror 4, enters the infrared detector 6 through the reflecting mirror 5, and is detected by the infrared detector 6. When the infrared interference light is reflected on the surface of the sample 3, the infrared interference light is absorbed at a wavelength (generally a plurality of wavelengths) specific to the substance present at that location. Therefore, the infrared light reaching the infrared detector 6 reflects infrared absorption by the substance in the sample 3.

  A detection signal from the infrared detector 6 is input to the data processing unit 11, and in the data processing unit 11, the Fourier transform operation unit 110 performs a Fourier transform process on the detection signal, thereby indicating red light that indicates absorbance in a predetermined wavelength range. An external absorption spectrum is obtained. On the other hand, visible light emitted from the visible light source 7 hits a wide range on the sample 3, and visible reflected light from the sample 3 is introduced into the CCD camera 8. The CCD camera 8 creates a surface visible image of the sample 3 and inputs the image data to the data processing unit 11.

  The sample stage 2 on which the sample 3 is placed can be moved with high positional accuracy in two axial directions of the X axis and the Y axis orthogonal to each other by a stage driving unit 9 controlled by the measurement control unit 10. By moving the sample stage 2, the irradiation position of the infrared interference light moves on the sample 3. Thereby, it is possible to sequentially perform measurement on a large number of measurement points (micro regions) set in the one-dimensional region or the two-dimensional region on the sample 3. The operations of the infrared interferometer 1 and the stage drive unit 9 are controlled by the measurement control unit 10. An input unit 14 and a display unit 15 are connected to the central control unit 13 and mainly serve as a user interface.

  A spectrum database 12 used for substance identification is connected to the data processing unit 11. In this spectrum database, standard infrared absorption spectrum (hereinafter referred to as “standard spectrum”) data representing the infrared absorbance of each known substance for each wave number (or wavelength) of infrared light is stored in advance. Yes. The data processing unit 11 executes predetermined data processing on the infrared absorption spectrum data at each measurement point obtained when the sample stage 2 is driven two-dimensionally by the measurement control unit 10, and further the spectrum database 12. The substance contained in the sample 3 is identified using the standard spectrum data stored in

  At least a part of the central control unit 13, the data processing unit 11, and the measurement control unit 10 will be described later by executing dedicated control / data processing software installed in the personal computer in advance on the computer. Various functions can be achieved.

  The configuration in FIG. 1 performs reflected infrared measurement and reflected visible observation, but can be changed to a configuration that performs transmitted infrared measurement or a configuration that performs transmitted visible observation. Moreover, you may incorporate the mechanism in which a measurement person can observe the surface visible image of a sample directly visually using an eyepiece.

Next, an analysis procedure for identifying an unknown target substance in a sample in the infrared microscope of the first embodiment will be described with reference to FIG.
When the sample 3 to be measured is placed on the sample stage 2, first, a visible image of the sample 3 is taken by the CCD camera 8, and the acquired image data is input to the data processing unit 11. The data processing unit 11 creates a surface observation image on the sample 3 and displays the image on the screen of the display unit 15 through the central control unit 13 (step S1). The measurer observes this image and designates the measurement range so as to include the region of interest of the measurement object by the input unit 14 (step S2).

  FIG. 3A is an example showing a state where a measurement region is set on an observation image displayed on the screen of the display unit 15. In this figure, a set rectangular measurement region 51 is schematically shown inside the field of view 50 of the microscope. In the measurement area 51, the measurement points are shown for convenience as the respective intersections of the grid. Actually, such measurement points may or may not be displayed. Since the field of view of the infrared microscope is displayed on the screen of the display unit 15, in general, the entire field of view is a part of the sample 3 placed on the sample stage 2. A certain wide range including the region of interest is set as the measurement region 51.

  When the measurement person designates the measurement area 51 and gives an instruction to start measurement, the sample stage is moved sequentially in the measurement area 51 as P11, P12, P13,... 2 is driven, and measurement of an infrared absorption spectrum for each measurement point, that is, mapping measurement is performed. The infrared absorption spectrum obtained at each measurement point in the measurement region 51 is stored as measurement spectrum mapping data in a storage unit (not shown) of the data processing unit 11 (step S3).

  Next, the measurer observes the sample surface image displayed on the screen of the display unit 15, and designates the range of the region of interest in which the target substance is presumed to exist by the input unit 14 (step S3). For example, as shown in FIG. 3B, the attention area 52 can be selected and instructed by tracing the outline (boundary) of a desired area by a cursor operation using a pointing device such as a mouse. In general, a region having a characteristic color, shape, pattern, or the like is a region of interest. Since the measurement point included in the attention area 52 is determined when the attention area 52 is designated, the data processing unit 11 specifies the measurement point included in the attention area 52 and stores the position information thereof. For example, with respect to the attention area 52 designated as shown in FIG. 3B, measurement points such as indicated by ▪ in FIG. 3C are specified, and the position information is stored.

  Next, the data processing unit 11 reads the measurement spectrum of each measurement point belonging to the attention area 52, and extracts the absorption peak whose peak intensity is greater than or equal to a predetermined threshold for the absorption peak appearing in each spectrum (step S5). ). For example, when the measurement spectrum at the measurement point S44 in FIG. 3C is as shown in FIG. 3D, if the threshold th is set, four absorption peaks Pa, Pb, Pc, and Pd are present. Extracted. Since the same processing is performed on the measurement spectrum of each measurement point belonging to the attention area 52, information on the absorption peaks extracted in the measurement spectrum of at least one measurement point belonging to the attention area 52 is collected.

  Thereafter, for each absorption peak extracted as described above, whether or not the absorption peak exists in the measurement spectrum at each measurement point in the measurement region 51 (whether or not the peak intensity is equal to or greater than a predetermined threshold value). ) And mapping the measurement point where the absorption peak exists to extract a two-dimensional distribution region of the peak. Then, for each absorption peak, the two-dimensional distribution region is stored as peak intensity mapping region data (step S6). FIG. 4 is a diagram showing an example of a two-dimensional distribution of absorption peaks (peak intensity mapping region data).

  Next, for each absorption peak described above, the data processing unit 11 calculates a correlation coefficient as an index representing the correlation between the two-dimensional distribution of the absorption peak and the two-dimensional distribution of the region of interest 52. The correlation coefficient takes a value in the range of 0 to 1, and is 1 when both distributions are completely matched. That is, the same absorption peak appears in the measurement spectrum obtained at all measurement points in the attention area, and the above absorption is present in the measurement spectrum obtained at all measurement points in the measurement area and outside the attention area. If no peak appears, the correlation coefficient of the absorption peak is 1. If the correlation coefficient of each absorption peak is obtained, it is stored as attention area peak correlation coefficient data (step S7). As shown in FIG. 5B, a correlation coefficient is obtained for each absorption peak appearing in the infrared absorption spectrum at one measurement point in the region of interest 52.

  After that, the data processing unit 11 has a pattern of the measurement spectrum at the measurement point and the standard infrared absorption spectrum of various known substances stored in advance in the spectrum database 12 for the substance present at each measurement point in the region of interest. Identification is performed based on matching. In this case, instead of performing simple pattern matching, pattern comparison is performed after weighting based on the attention area peak correlation coefficient data obtained as described above for each absorption peak (step S8).

  Specifically, for example, pattern matching between a measured spectrum and a standard spectrum of a certain known substance is executed by the following procedure. First, as shown in FIG. 6B, only the absorption peaks having a correlation coefficient equal to or greater than a certain threshold are selected from the absorption peaks appearing in the measurement spectrum. That is, an absorption peak having a low distribution correlation coefficient is excluded from matching targets. Then, the peak intensity is corrected by multiplying the peak intensity of the selected absorption peak by the correlation coefficient itself or a weighting coefficient obtained from the correlation coefficient. The peak information (wave number or wavelength and relative intensity) obtained by selecting the absorption peak appearing in the measurement spectrum and correcting the peak intensity is compared with the peak information of the standard spectrum of the known substance to calculate the similarity. When the similarities of various kinds of known substances stored in the spectrum database 12 with respect to the standard spectrum are calculated, it can be said that there is a high possibility that the known substances giving a high degree of similarity are substances existing at the measurement point. For example, in the example of FIG. 6B, the absorption peaks Pa and Pc are highly weighted, the absorption peak Pb is excluded from the target, and the absorption peak Pd is weighted low. In contrast, the known substance A shown in FIG. 6C is determined to have a high degree of similarity, and the known substance B shown in FIG. 6D is determined to have a low degree of similarity.

  When the substance identification process is executed as described above for all the measurement points belonging to the attention area 52 and the kind of the known substance and the similarity are obtained, the probability that the similarity is equal to or higher than a certain level. The distribution is obtained by extracting measurement points for known substances having a high value. Then, a semi-transmission image expressing the two-dimensional distribution of the identified substance with a different color for each substance and with a gradation proportional to the absorption intensity of the absorption peak is created. It is superimposed on the observation image and displayed on the screen of the display unit 15 (step S9). FIG. 7 is a view showing an example in which a semi-transmission image 53 of a distribution of a certain substance is displayed superimposed on a surface observation image of a sample. By such display, the measurer can easily confirm the identification result visually.

[Second Embodiment]
An infrared microscope according to another embodiment (second embodiment) of the present invention will be described. Since the overall configuration of the infrared microscope of the second embodiment is the same as that of the first embodiment, description thereof is omitted. FIG. 8 is a flowchart of the identification process in the infrared microscope of the second embodiment. The same steps as those in the first embodiment are denoted by the same step numbers.

  In the first embodiment, the surface area observation image of the sample is viewed by the measurer to indicate the region of interest. However, in the infrared microscope of the second embodiment, regardless of the observation and judgment of the measurer. The attention area is automatically set. That is, in the flowchart shown in FIG. 8, instead of step S4 in the flowchart shown in FIG. 2, step S14 for automatically determining a region of interest by image processing such as edge extraction or binarization is provided. In order to automatically determine the attention area, conditions for extracting as the attention area can be set in advance. For example, a region of interest can be determined by setting a characteristic shape, size, color, pattern, or the like as an extraction condition and searching for an area that satisfies this condition by image processing. All other processes are the same as in the first embodiment.

  The infrared microscope of the second embodiment is used for automating the detection of foreign matter and identification of the foreign matter in a patterned inspection such as quality inspection of a factory production line and sorting of agricultural and marine products. It is suitable for.

[Third embodiment]
An infrared microscope according to still another embodiment (third embodiment) of the present invention will be described. Since the overall configuration of the infrared microscope of the third embodiment is the same as that of the first embodiment, description thereof is omitted. FIG. 9 is a flowchart of the identification process in the infrared microscope of the third embodiment. The same steps as those in the first embodiment are denoted by the same step numbers.

  In the third embodiment, the process of step S4 in the first embodiment is replaced with the processes of steps S241 to S243. Since the processing of each other step is the same as that of the first embodiment, description thereof is omitted.

  In step S241, the data processing unit 11 pays attention to the absorption peak appearing in the measurement spectrum at each measurement point in the measurement region 51, and for each peak, a semi-transparent image colored with a semi-transparent gradation proportional to the absorption intensity. It is created and displayed on the screen of the display unit 15 so as to overlap the surface observation image of the sample. FIGS. 10 (a2) and (b2) show the state where the absorption intensity distributions 54 of the absorption peaks Pa and Pc appearing in the measurement spectra shown in FIGS. 10 (a1) and (b1) are superimposed on the sample surface observation image, respectively. FIG.

  The measurer performs an operation of sequentially switching the absorption peak to be noted as Pa, Pb,..., And confirms the absorption intensity distribution 54 of each absorption peak on the screen, and displays an absorption peak showing a distribution as close as possible to the desired attention area. The selection is made by the input unit 14 (step S242). In the example of FIG. 10, for example, the measurer determines that the peak Pa absorption intensity distribution 54 illustrated in FIG. 10A2 is closest to the region of interest, and performs a predetermined operation with the input unit 14. Then, a region 55 indicated by a dotted line in FIG. 10A3 corresponding to the absorption peak distribution selected by the operation is determined as a region of interest (step S243). In this case, the measurement points included in the attention area are indicated by ■ in FIG. 10 (a3), and do not necessarily coincide with the measurement points set for the attention area designated by the measurer in the first embodiment. Not exclusively.

[Fourth embodiment]
An infrared microscope according to still another embodiment (fourth embodiment) of the present invention will be described. Since the overall configuration of the infrared microscope of the fourth embodiment is the same as that of the first embodiment, description thereof is omitted. FIG. 11 is a flowchart of the identification process in the infrared microscope of the third embodiment. The same steps as those in the first embodiment are denoted by the same step numbers. That is, in the fourth embodiment, the processes of steps S1 to S3 and steps S5 to S9 are the same as those of the first embodiment, step S4 is replaced with steps S341 to S343, and steps S344 and S345 are added. Yes.

  In step S341, the data processing unit 11 examines a two-dimensional distribution region for each of a plurality of absorption peaks included in the measurement spectrum at each measurement point in the measurement region, and calculates the area of the region. Then, an absorption peak that minimizes the area of the distribution region is selected, and the two-dimensional distribution region of the peak is set as a region of interest (step S342). Next, it is determined whether or not the attention area can be extracted (step S343). If the attention area can be set, the process proceeds to step S5, and the above-described processing is executed.

  After performing the subsequent steps S5 to S9 for the attention area set in this manner, it is determined whether or not the reliability (similarity) of the identification result in step S9 has a certain level of accuracy or higher. (Step S344). If the reliability of the identification result is equal to or higher than a certain level, it can be considered that the substance is present, so the infrared absorption intensity of the identified substance is subtracted from the measured spectrum for each minute region (step S345). Thereby, the influence of infrared absorption by the substance is removed from the measurement spectrum, and the process returns to step S341. By the processing in step S345, the absorption peak having the smallest area of the distribution area is removed from the measurement spectrum, so that the distribution area of the absorption peak having the next smallest area of the distribution area is set as the attention area. Become.

  The processes in steps S3 to S8 are repeatedly executed until the attention area cannot be extracted in step S3, that is, until it is determined No in step S343. As a result, even if a large number of substances are mixed in the sample 3, as long as each substance has a minute region containing only the substance, the large number of substances are automatically and sequentially identified. be able to.

  As described above, according to the infrared microscopes of the first to fourth embodiments, the attention area that can be estimated to contain the specific substance is automatically determined by the selection operation of the measurer or image recognition, and is adapted to the attention area. By preferentially handling the infrared absorption peak having the distribution as described above when the substance is identified by matching with known spectral data, the substance distributed in the region of interest can be identified with high accuracy.

  It should be noted that each of the above-described embodiments is an example of the present invention, and it is obvious that any modifications, changes, and additions as appropriate within the scope of the present invention are included in the scope of the claims of the present application.

DESCRIPTION OF SYMBOLS 1 ... Infrared interferometer 2 ... Sample stage 3 ... Sample 4 ... Half mirror 5 ... Reflection mirror 6 ... Infrared detector 7 ... Visible light source 8 ... CCD camera 9 ... Stage drive part 10 ... Measurement control part 11 ... Data processing part DESCRIPTION OF SYMBOLS 110 ... Fourier-transform calculation part 12 ... Spectral database 13 ... Central control part 14 ... Input part 15 ... Display part 50 ... Field of view 51 ... Measurement area 52 ... Attention area 53 ... Semi-transmissive image 54 ... Absorption intensity distribution

Claims (5)

In an infrared microscope that irradiates a sample with infrared interference light, detects transmitted light or reflected light from the sample, and measures an infrared absorption spectrum in a measurement region on the sample.
a) Irradiating a sample with visible light, creating a sample observation image based on transmitted light or reflected light from the sample, and determining an attention region where a target substance is assumed to be present based on the sample observation image An area determination means;
b) a two-dimensional region spectrum measuring means for irradiating each of a plurality of minute regions set in a two-dimensional region on the sample with infrared interference light and measuring an infrared absorption spectrum in each minute region;
c) a specific peak distribution extracting means for extracting a two-dimensional distribution by extracting a minute region having a peak intensity equal to or greater than a predetermined threshold for each absorption peak in an infrared absorption spectrum in each minute region;
d) For each absorption peak of the infrared absorption spectrum of the minute region included in the attention region determined by the attention region determining means, the two-dimensional distribution of the minute region at the absorption peak obtained by the specific peak distribution extracting means A correlation correlation acquisition means for calculating an index indicating a correlation between the two-dimensional distribution of the micro area of the attention area and the target area, and storing the index in association with an absorption peak;
e) standard spectrum storage means for storing in advance infrared absorption spectra of various known substances;
f) Infrared absorption spectra of known substances stored in the standard spectrum storage means and minute areas included in the attention area while weighting each absorption peak using the index obtained by the distribution correlation acquisition means A substance identification means in the region of interest for identifying a substance present in each minute region in the region of interest by comparing with an infrared absorption spectrum in
An infrared microscope comprising: The infrared microscope according to claim 1,
The attention area determination means includes
An observation image providing means for irradiating the sample with visible light, creating a sample observation image based on transmitted light or reflected light by the sample, and displaying the image on the screen of the display means;
On the sample observation image displayed by the observation image providing means, attention area instruction means for the measurer to select and indicate the attention area on which the target substance is presumed to exist,
Infrared microscope characterized by including. The infrared microscope according to claim 1,
The infrared microscope characterized in that the attention area determination means performs image processing based on a predetermined condition on the created sample observation image and determines an area that meets the condition as an attention area. The infrared microscope according to claim 1,
The attention area determination means includes
For a plurality of absorption peaks appearing in the infrared absorption spectrum of each minute region, the intensity distribution is displayed on the screen of the display means by superimposing the two-dimensional intensity distribution of each peak as semi-transparent image information on the sample observation image Display superimposing means;
Based on the sample observation image in which the two-dimensional intensity distribution is superimposed and displayed by the intensity distribution display superimposing means, the two-dimensional intensity distribution at the absorption peak and the region of interest assumed by the measurer are matched as much as possible from the plurality of absorption peaks. A region-of-interest matching peak selection means for the measurer to select and indicate an absorption peak to be
Peak-corresponding attention area setting means for determining, as the attention area, the two-dimensional intensity distribution at the absorption peak selected by the measurer by the attention area matching peak selection means;
Infrared microscope characterized by including. The infrared microscope according to claim 1,
The region-of-interest determination unit selects an absorption peak that minimizes the area of the two-dimensional distribution region obtained by the specific peak distribution extraction unit from the given absorption peak. Determine the distribution area as the attention area,
Further, after a substance existing in the attention area is identified by the substance identification means in the attention area, it is determined whether or not the reliability of the identification result is a certain level or more, and is determined to be a certain level or more. If the infrared absorption intensity of the identified substance is subtracted from the infrared absorption spectrum in the minute region included in the two-dimensional distribution, the selection of the region of interest and the infrared absorption spectrum after the subtraction An infrared microscope characterized by repeatedly performing identification of a material of interest region and repeatedly performing material identification until the region of interest cannot be extracted.

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