Patent Publication Number: US-2019187452-A1

Title: Microscope

Description:
The entire content of JP Patent Publication No. 2017-009718, published Jan. 12, 2017, and having the same inventors, is hereby incorporated by reference. 
     TECHNICAL FIELD 
     The present invention relates to a microscope for irradiating a microscopic measurement point on a surface of a macroscopic sample with measurement light such as infrared light, ultraviolet light, or visible light. 
     BACKGROUND ART 
     An infrared microscope is used, for example, for the purpose of studying the molecular structure or the like of an organic substance adhering to the surface of a solid (sample) based on the functional groups of the substance. Specifically, a specific minute site (for example, a measurement point of 15 μm×15 μm) on the surface of the sample is irradiated with infrared light focused to a small diameter. Since a spectrum unique to the molecular structure or the like based on the functional groups of the organic substance or the like is generated from the specific measurement point on the sample surface, this spectrum is detected and analyzed so as to identify and assay the organic substance or the like (for example, see Patent Document 1.) 
     Such an infrared microscope includes an image acquisition device such as a CCD camera or a CMOS camera to allow an analyst to observe the sample surface, and the measurement point on the sample surface is determined while an optical image of the sample surface is being observed. For example, by irradiating a region (for example, a region of 500 μm×400 μm) including the measurement point on the sample surface with visible light from a light source such as a halogen lamp and detecting the visible light reflected by the region including the measurement point on the sample surface with a CCD camera, an optical image is created on the basis of the detected visible light. As a result, the analyst designates the infrared light irradiation position on the sample (for example, a measurement point of 15 μm×15 μm) or designates a measurement range on the sample (for example, a range of 300 μm×200 μm) while observing the optical image. 
       FIG. 4  illustrates the relevant configuration of a conventional infrared microscope. Note that one direction horizontal to the ground is defined as the X-direction, the direction horizontal to the ground and perpendicular to the X-direction is defined as the Y-direction, and the direction perpendicular to the X-direction and the Y-direction is defined as the Z-direction. 
     An infrared microscope  101  includes: an XY stage mechanism  10  which a sample S is placed; an infrared light source  20  for emitting infrared light; a visible light source  30  for emitting visible light; a detection part  240  for detecting infrared light; an image acquisition device  50  having a detection surface for detecting visible light; Cassegrain mirrors  260  and  261 ; a plate-shaped switching mirror  270 ; and a computer  190  for controlling the entire infrared microscope  101 . 
     Although not illustrated in the drawing, the XY stage mechanism  10  includes a stage (sample stage,) an X-direction driving mechanism, and a Y-direction driving mechanism. 
     A sample S can be placed on and removed from the upper surface of the stage. Such a stage can move in the desired X-direction and Y-direction when a driving signal required for the driving mechanism is outputted by a spectrum acquisition part  191   c  of the computer  190 . 
     The infrared light source  20  is a Fourier transform infrared spectrophotometer for emitting infrared light (interferogram) which changes in intensity over time. The infrared light source  20  is disposed so that after the emitted infrared light is reflected by a mirror  21 , a switching mirror  22 , a transmission/reflection switching mirror  23 , concave mirrors  24  and  25 , or semi-transparent mirrors  26  and  27 , the light is focused by the Cassegrain mirrors  260  and  261  irradiated onto a measurement point (for example, 15 μm×15 μm) on the sample S placed on the XY stage mechanism  10 . 
     The detection part  240  includes a detector  241  and a converging mirror  242  or a mirror  243  disposed in front of the detector  241 . 
     The visible light source  30  emits visible light. The visible light source  30  is disposed so that after the emitted visible light is transmitted or reflected by a lens  31 , the switching mirror  22 , the transmission/reflection switching mirror  23 , the concave mirrors  24  and  25 , or the semi-transparent mirrors  26  and  27 , the light is focused by the Cassegrain mirrors  260  and  261  and irradiated onto a region (for example, a region of 500 μm×400 μm) including the measurement point on the surface of the sample S placed on the XY stage mechanism  10 . 
     The image acquisition device  50  includes a CCD camera  51  having a detection surface for detecting visible light and a relay lens  52  disposed in front of the CCD camera  51 . 
     In order for the image acquisition device  50  to acquire an optical image of the region including the measurement point on the surface of the sample S with the same optical axis (light path) as the optical system which guides infrared light to the detection part  240 , a switching mirror  270  capable of moving on the light path and to positions not on light path is disposed on the light path for guiding infrared light to the detection part  240  above (−Z-direction) the XY stage mechanism  10 . 
     As a result, infrared light from the measurement point on the sample S is focused by the Cassegrain mirror  260  to form infrared light advancing in a prescribed direction (−Z-direction,) and after the infrared light is reflected in the −X-direction by the switching mirror  270  disposed on the light path, the light is detected by the detection part  240 . In addition, after visible light from the region including the measurement point on the surface of the sample S is focused by the Cassegrain mirror  260  to form visible light advancing in a prescribed direction (−Z-direction,) the light is detected by the detection surface of the CCD camera  51 . 
     The computer  190  includes a CPU (control part)  191  and a storage part  194 , and a monitor (display device)  93  and an operation part (input device)  92  are further connected thereto. In addition, to explain the functions processed by the CPU  191  in terms of blocks, the CPU  191  has: an optical image acquisition part  91   a  for acquiring an optical image from the image acquisition device  50  and displaying the optical image on the monitor  93 ; an input information acquisition part  91   b  into which input information (measurement range on the sample S) is inputted by the operation part  92 ; a spectrum acquisition part  191   c  for acquiring infrared light information for the measurement points on the sample S from the detection part  240  while moving the stage in the X-direction and the Y-direction on the basis of the input information and storing the information in the storage part  194 ; and a spectrum display control part  191   d  for calculating the infrared spectrum by performing a Fourier transform on the infrared light information and displaying an infrared spectrum distribution image on the monitor  93 . 
     The input information acquisition part  91   b  administers control to make the storage part  194  store the input information (measurement range on the sample S) from the operation part  92 . 
     For example, the analyst uses the operation part (mouse dragging operation or the like)  92  while observing the optical image displayed on the monitor  93  to designate the execution of a “line mapping,” wherein the irradiation positions of infrared light (for example, measurement point of 15 μm×15 μm) are arranged linearly at equal intervals (for example, 30 μm intervals,) a “two-dimensional mapping,” wherein the irradiation positions of infrared light (for example, measurement point of 15 μm×15 μm) are arranged at equal intervals (for example, 50 μm intervals) in the X-direction and the Y-direction, or a “random mapping” resulting in any plurality of irradiation positions of infrared light (for example, measurement point of 15 μm×15 μm.) 
     Here,  FIG. 5  illustrates an example of a monitor screen displayed by the infrared microscope  101 . An optical image (for example, 300 μm×400 μm) acquired from the image acquisition device  50  is displayed on the monitor  93 . Note that if the magnification factor of the optical image displayed on the monitor  93  is changed, the optical image is displayed in accordance with the magnification factor. 
     In addition, “two dimensional mapping” is selected by the operation part  92  so that a measurement image with the rectangular shape of the boldface line illustrating the measurement range (for example, 200 μm×320 μm) of the “two-dimensional mapping” is displayed on the optical image. 
     After setting the coordinates of measurement points to the measurement range on the basis of the input information, the spectrum acquisition part  191   c  acquires infrared light information for measurement points on the sample S from the detection part  240  while moving the stage in the X-direction and the Y-direction and controls the storage part  194  to store the information. 
     For example, defining the upper left end of the rectangular measurement range image as the origin (x 0 , y 0 ,) the spectrum acquisition part  191   c  sets the X-coordinates of the measurement points x 0 , x 1 , . . . , x 4  so that the upper left end of the rectangular measurement range image and the upper right end of the rectangular measurement range image are divided into four equal parts, sets the Y-coordinates of the measurement points y 0 , y 1 , . . . , y 8  so that the upper left end of the rectangular measurement range image and the lower left end of the rectangular measurement range image are divided into eight equal parts, and thereby sets the coordinates (black circles) of a total of 45 measurement points. 
     The spectrum acquisition part  191   c  then moves the stage so that a first measurement point (x 0 , y 0 ) arrives at a prescribed position, acquires infrared light information from the first measurement point (x 0 , y 0 ) and stores the information in the storage part  194 , moves the stage so that a second measurement point (x 1 , y 0 ) arrives at a prescribed position, acquires infrared light information from the second measurement point (x 1 , y 0 ,) and stores the information in the storage part  194 . The spectrum acquisition part  191   c  continues to move the stage in this manner so that the 45 measurement points sequentially arrive at prescribed positions, and then acquires infrared light information from the 45 measurement points and stores the information in the storage part  194 . 
     The spectrum display control part  191   d  administers control to display the infrared spectrum distribution image of the measurement range on the monitor  93  on the basis of the infrared light information from the 45 measurement points (x 0 , y 0 ) to (x 4 , y 8 ) stored in the storage part  194 . 
     PRIOR ART DOCUMENTS 
     Patent Document 
     [PATENT DOCUMENT 1] Japanese Unexamined Patent Application Publication 2000-121554 
     SUMMARY OF INVENTION 
     Problems to be Solved by the Invention 
     Incidentally, with the infrared microscope  101  described above, when the analyst determines that a peak of interest extends outside the measurement range as a result of observing the infrared spectrum distribution image displayed on the monitor  93 , the analyst once again re-designates the measurement range on the sample S to acquire a new infrared spectrum distribution image. At this time, in a “two-dimensional mapping,” the number of measurement points is as large as 45 points, as illustrated in  FIG. 5 , so the mapping takes an immense amount of time. 
     Means for Solving the Problems 
     The present applicant investigated methods for acquiring a spectrum distribution image for a desired measurement range on a sample S in a short amount of time. In a mapping measurement (two-dimensional mapping,) when all of the measurement points (45 measurement points) are handled as one group and input information (measurement range on the sample S) is inputted, a spectrum measurement is performed for all of the measurement points without omitting spectrum measurements for some of the measurement points. Therefore, when the measurement range is re-designated at the point when it is determined that a peak of interest extends outside the measurement range, even if there are overlapping portions in the measurement range before and after modification and there are common measurement points before and after modification, the results of the spectrum measurement executed prior to modification are first abandoned, and a spectrum measurement is newly executed for all of the measurement points included in the measurement range after modification. 
     Therefore, the present applicant discovered that when the measurement range is modified and a mapping measurement is once again executed after a mapping measurement is first executed, if there is overlap in the measurement points before and after the modification of the measurement range, the results of the spectrum measurement already obtained for those measurement points may be kept, and a spectrum measurement may be newly executed for only the non-overlapping measurement points. 
     The microscope of the present invention, which was conceived in order to solve the problems described above, comprises: a measurement light source for emitting measurement light to a measurement point on a sample; a detector for detecting measurement light from the measurement point on the sample; an XY stage mechanism capable of moving a sample stage on which the sample is placed; an input device for inputting input information serving as a measurement range on the sample comprising a plurality of measurement points; and a controller for controlling the XY stage mechanism and obtaining measurement light information in the measurement range on the sample on the basis of the input information; the controller executing an (n-1)th information acquisition step of controlling the XY stage mechanism on the basis of (n-1) th  information serving as an (n-1) th  measurement range inputted by the input device, obtaining measurement light information in the (n-1) th  measurement range, and storing the information in a storage, and then executing an n th  acquisition step of controlling the XY stage mechanism on the basis of nth input information serving as an n th  measurement range inputted by the input range and acquiring measurement light information of the n th  measurement range; and in the n th  acquisition step, the controller using measurement light information in an overlapping part stored in the storage in the (n-1) th  acquisition step to create measurement light information of the nth measurement range without acquiring measurement light information in an overlapping portion of the n th  measurement range overlapping the (n-1) th  measurement range. 
     Here, examples of “measurement light” include infrared light, ultraviolet light, and visible light. In addition, changes in intensity over time may also be induced with an interferometer or another modulation means. 
     Further, “n” is a natural number not less than 1. 
     Effect the Invention 
     As described above, with the microscope of the present invention, measurement points that newly require spectrum measurement (acquisition of measurement light information) are only those present in portions not included in the measurement range prior to modification among the measurement points in the measurement range after modification. As a result, the number of measurement points for which a spectrum measurement is executed becomes small, which makes it possible to reduce the measurement time. 
     Other Means for Solving the Problem, and Effects Thereof 
     In addition, in the microscope of the present invention, measurement points arranged at equal intervals in an X-direction and a Y-direction may be set in the n th  measurement range and the (n-1) th  measurement range. 
     With the microscope of the present invention, it is possible to prevent the ratios of changes for each acquired position of a spectrum (measurement light information) from becoming non-uniform as a result of measurement points in the overlapping portion within the measurement range prior to modification and the measurement points not in the overlapping portion not being evenly spaced and changes in the positions of the measurement points being non-uniform. 
     Further, the microscope of the present invention may comprise: a visible light source for emitting visible light in a region including the measurement point on the sample; and an image acquisition device for acquiring an optical image and displaying the optical image on a display device when visible light from the region including the measurement point on the sample is incident on a detection surface; wherein the input information is inputted using the optical image. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates the relevant configuration of a microscope according to an embodiment of the present invention. 
         FIG. 2  illustrates an example of a monitor screen displayed by an infrared microscope. 
         FIG. 3  illustrates another example of a monitor screen displayed by an infrared microscope. 
         FIG. 4  illustrates the relevant configuration of a conventional infrared microscope. 
         FIG. 5  illustrates an example of a monitor screen displayed by the infrared microscope illustrated in  FIG. 4 . 
     
    
    
     MODES FOR CARRYING OUT THE INVENTION 
     Embodiments of the present invention will be described hereinafter with reference to the drawings. Note that the present invention is not limited to embodiments such as those described below, and the present invention includes various modes within a scope that does not depart from the gist of the present invention. 
       FIG. 1  illustrates the relevant configuration of a microscope according to an embodiment of the present invention. Note that components that are the same as those of the infrared microscope  101  described above are labeled with the same symbols. 
     An infrared microscope  1  includes: an XY stage mechanism  10  on which a sample S is placed; an infrared light source  20  for emitting infrared light; a visible light source  30  for emitting visible light; a detection part  240  for detecting infrared light; an image acquisition device  50  having a detection surface for detecting visible light; Cassegrain mirrors  260  and  261 ; a plate-shaped switching mirror  270 ; and a computer  90  for controlling the entire infrared microscope  1 . 
     The Cassegrain mirror (Schwarzschild reflective/objective mirror)  260  includes a main Cassegrain mirror  260   a  and a secondary Cassegrain mirror  260   b.    
     The secondary Cassegrain mirror  260   b  has a circular shape when viewed from the Z-direction, wherein the upper surface is a convex surface having a hemispherical shape and the lower surface is a flat surface when viewed from the Y-direction or the X-direction. The secondary Cassegrain mirror  260   b  is disposed above the XY stage mechanism  10  and is disposed so that the upper surface faces upward (−Z-direction.) In addition, the main Cassegrain mirror  260   a  has a ring shape having an opening with the same shape as that of the secondary Cassegrain mirror  260   b  when viewed from the Z-direction, wherein the lower surface is a concave surface having a hemispherical shape and the upper surface is a flat surface when viewed from the Y-direction or the X-direction. The main Cassegrain mirror  260   a  is disposed above the XY stage mechanism  10  and above the secondary Cassegrain mirror  260   b  and is disposed so that the upper surface faces upward (−Z-direction.) 
     As a result, after infrared light from the infrared light source  20  is reflected by the secondary Cassegrain mirror  260   b,  the light is focused by the main Cassegrain mirror  260   a  so that measurement points on the sample S are irradiated. In addition, after light from a region including the measurement points on the sample S is focused by the main Cassegrain mirror  260   a,  the light is reflected by the secondary Cassegrain mirror  260   b  so as to advance in the −Z-direction. 
     Note that the Cassegrain mirror (Schwarzschild reflective/objective mirror)  261  also has the same structure as the Cassegrain mirror  260  and is disposed with vertical symmetry while sandwiching the XY stage mechanism  10 . 
     The computer  90  includes a CPU (controller)  91  and a storage  94 , and a monitor (display device)  93  and an operation part (input device)  92  are further connected thereto. In addition, to explain the functions processed by the CPU  91  in terms of blocks, the CPU  91  has: an optical image acquisition part  91   a  for acquiring an optical image from the image acquisition device  50  and displaying the optical image on the monitor  93 ; an input information acquisition part  91   b  into which input information (measurement range on the sample S) is inputted by the operation part  92 ; a spectrum acquisition part  91   c  for acquiring infrared light information for the measurement points on the sample S from the detection part  240  while moving the stage in the X-direction and the Y-direction on the basis of the input information and storing the information in the storage part  94 ; and a spectrum display control part  91   d  for calculating the infrared spectrum by performing a Fourier transform on the infrared light information and displaying an infrared spectrum distribution image on the monitor  93 . 
     The input information acquisition part  91   b  administers control to make the storage part  94  store the input information (n th  measurement range on the sample S) from the operation part  92 . 
     After the spectrum acquisition part  91   c  sets the coordinates of measurement points in the nth measurement range on the basis of the n th  input information and the infrared light information stored in the storage part  94 , the spectrum acquisition part  91   c  acquires infrared light information for the measurement points on the sample S from the detection part  240  while moving the stage in the X-direction and the Y-direction and controls the storage  94  to store the information. 
     (1) When there is no infrared light information in the storage  94   
     (That is, when Acquiring Infrared Light Information for the First Measurement Range) 
     For example, defining the upper left end of the first measurement range image as the origin (x 0 , y 0 ,) the spectrum acquisition part  91   c  sets the X-coordinates of the measurement points x 0 , x 1 , . . . , x 4  so that the upper left end of the first measurement range image and the upper right end of the first measurement range image are divided into four equal parts, sets the Y-coordinates of the measurement points y 0 , y 1 , . . . , y 8  so that the upper left end of the first measurement range image and the lower left end of the first measurement range image are divided into eight equal parts, and thereby sets the coordinates of a total of 45 measurement points (see  FIG. 5 .) 
     The spectrum acquisition part  91   c  then moves the stage so that a first measurement point (x 0 , y 0 ) arrives at a prescribed position, acquires infrared light information from the first measurement point (x 0 , y 0 ) and stores the information in the storage part  94 , moves the stage so that a second measurement point (x 1 , y 0 ) arrives at a prescribed position, acquires infrared light information from the second measurement point (x 1 , y 0 ,) and stores the information in the storage part  94 . The spectrum acquisition part  91   c  continues to move the stage in this manner so that the 45 measurement points sequentially arrive at prescribed positions, and then acquires infrared light information from the 45 measurement points and stores the information in the storage part  94 . Note that in the infrared microscope  1 , even if the acquisition of infrared light information from 45 measurement points is interrupted at an intermediate stage without being completed, or even if there are only spectrum measurement results for some of the measurement points, the information is stored in the storage part  94 . 
     (2) When there is infrared light information for the first measurement range in the storage part  94  when measuring the same sample S under the same measurement conditions (aperture settings, background spectrum, and the like) 
     (That is, when Acquiring Infrared Light Information for the Second Measurement Range) 
     The spectrum acquisition part  91   c  compares the first measurement range and the second measurement range and sets measurement points in a non-overlapping portion of the second measurement range that does not overlap with the first measurement range using a grid of the first measurement range (origin (x 0 , y 0 ,) X-direction intervals, and Y-direction intervals.) That is, the measurement points in the measurement range after modification are also set based on the same origin (x 0 , y 0 ) as the measurement points in the measurement range prior to modification. As a result, the upper left end of the second measurement range is not on the grid points, so when measurement points are set using this as the origin, a discrepancy arises relative to the measurement points of the first measurement range, but the disruption of continuity is prevented. 
       FIG. 2  illustrates an example of a monitor screen displayed by the infrared microscope  1 . An optical image (for example, 500 μm×400 μm) acquired from the image acquisition device  50  is displayed on the monitor  93 . In addition, a first measurement range image of a dotted line indicating the first measurement range (for example, 200 μm×300 μm) is also displayed. The upper left end of the first measurement image then becomes the origin (x 0 , y 0 ,) and the X-coordinates of the measurement points x 0 , x 1 , . . . , x 4  are set so that that the upper left end of the first measurement range image and the upper right end of the first measurement range image are divided into four equal parts, while the Y-coordinates of the measurement points y 0 , y 1 , . . . , y 8  are set so that the upper left end of the first measurement range image and the lower left end of the first measurement range image are divided into eight equal parts. the coordinates (black circles and white circles) of a total of 45 measurement points are thereby set. 
     In addition, a second measurement range image of a boldface line indicating the second measurement range (for example, 250 μm×240 μm) is also displayed. Coordinates (black squares) of 14 measurement points are then set around the origin (x 0 , y 0 ) in the non-overlapping portion of the second measurement range that does not overlap with the first measurement range. 
     The spectrum acquisition part  91   c  then moves the stage so that a 46th measurement point (x 5 , y 0 ) arrives at a prescribed position, acquires infrared light information from the 46th measurement point (x 5 , y 0 ) and stores the information in the storage part  94 , moves the stage so that a 47th measurement point (x 6 , y 0 ) arrives at a prescribed position, acquires infrared light information from the second measurement point (x 6 , y 0 ,) and stores the information in the storage part  94 . The spectrum acquisition part  91   c  continues to move the stage in this manner so that the 14 measurement points sequentially arrive at prescribed positions, and then acquires infrared light information from the 14 measurement points and stores the information in the storage part  94 . 
     (3) When there is infrared light information for the (n-2) th  measurement range and infrared light information for the (n-1) th  measurement range when measuring the same sample S under the same measurement 
     (That is, when Acquiring Infrared Light Information for the n th  Measurement Range) 
     The spectrum acquisition part  91   c  compares the (n-2) th  measurement range, the (n-1) th  measurement range, and the n th  measurement range and sets measurement points in a non-overlapping portion of the n th  measurement range that does not overlap with either the (n-2) th  measurement range or the (n-1) th  measurement range using a grid of the first measurement range. In addition, the spectrum acquisition part  91   c  sets measurement points in an overlapping portion of the (n-3) th  measurement range, the (n-1) th  measurement range, and the n th  measurement range using the origin (x 0 , y 0 ) and intervals of the first measurement range. That is, although there is infrared light information in measurement ranges prior to the (n-3) th  measurement range, with the infrared microscope  1  of the present invention, the concentration of ambient water vapor or carbon dioxide changes as time passes after the acquisition of the infrared light information, and the difference relative to the results of newly performed spectrum measurements becomes large, so they are set so as to not be used. 
       FIG. 3  illustrates another example of a monitor screen displayed by the infrared microscope  1 . An optical image (for example, 500 μm×400 μm) acquired from the image acquisition device  50  is displayed on the monitor  93 . In addition, an (n-2) th  measurement range image of a dotted line indicating the (n-2) th  measurement range (for example, 250 μm×240 μm) is also displayed. Coordinates (black squares and white squares) of fourteen measurement points are then set around the origin (x 0 , y 0 ) in the non-overlapping portion of the (n-2) th  measurement range that does not overlap with either the (n-4) th  measurement range or the (n-3) th  measurement range. 
     In addition, an (n-1) th  measurement range image of a dotted line indicating the (n-1) th  measurement range (for example, 250 μm×240 μm) is also displayed. Coordinates (black triangles) of nine measurement points are set around the origin (x 0 , y 0 ) in the non-overlapping portion of the (n-1) th  measurement range that does not overlap with either the (n-3) th  measurement range or the (n-2) th  measurement range. 
     Further, an nth measurement range image of a boldface line indicating the n th  measurement range (for example, 250 μm×240 μm) is also displayed. Coordinates (black star shapes) of 13 measurement points are set around the origin (x 0 , y 0 ) in the non-overlapping portion of the n th  measurement range that does not overlap with either the (n-2) th  measurement range or the (n-1) th  measurement range. In addition, coordinates (black star shapes) of 14 measurement points are set around the origin (x 0 , y 0 ) in the overlapping portion of the (n-3) th  measurement range, the (n-1) th  measurement range, and the n th  measurement range. 
     The spectrum acquisition part  91   c  then moves the stage so that the 13 new measurement points arrive at prescribed positions, acquires infrared light information from the 13 measurement points, stores the information in the storage  94 , moves the stage so that the 14 measurement points arrive at prescribed positions after a prescribed amount of time has passed, acquires infrared light information from the 14 measurement points, and then stores the information in the storage  94 . 
     The spectrum display control part  91   d  administers control to display the infrared spectrum display image of the n th  measurement range on the monitor  93  on the basis of the infrared light information from the measurement points of the n th  measurement range stored in the storage  94 . 
     As described above, with the infrared microscope  1  of the present invention, measurement points that must be newly subjected to spectrum measurements (acquisition of measurement light information) are only those in the measurement range after modification that are present in portions not included in the measurement range prior to modification. As a result, the number of measurement points for which a spectrum measurement is executed becomes small, which makes it possible to reduce the measurement time. 
     In addition, even if the mapping measurement in the (n-1) th  measurement range is interrupted during the spectrum measurement as a result of mistakenly setting the (n-1) th  measurement range, the results of the completed spectrum measurements are not wasted, and the mapping measurement in the corrected n th  measurement range can be completed in a short period of time. 
     Further, in order to prevent the ratios of changes for each acquired position of a spectrum (measurement light information) from becoming non-uniform as a result of measurement points in the overlapping portion within the measurement range prior to modification and the measurement points not in the overlapping portion not being evenly spaced and changes in the positions of the measurement points being non-uniform, the grid-shaped arrangement of measurement points set in the measurement range prior to modification may be extended over the entire stage, and the measurement points in the measurement range after modification may be set on the grid points so as to keep all of the measurement points in the measurement range after modification at equal intervals. 
     &lt;Other Embodiments&gt; 
     In the infrared microscope  1  described above, a configuration was employed in which the infrared light information of measurement regions prior to the (n-3) th  measurement range are not used, but the configuration may also be such that infrared light information of measurement regions prior to the (n-4) th  measurement range are not used, or such that infrared light information of measurement regions prior to a measurement range earlier than a prescribed time are not used. 
     FIELD OF INDUSTRIAL APPLICATION 
     The present invention can be suitably applied to a microscope or the like which irradiates a sample with measurement light and detects the spectrum discharged from the sample as a result. 
     EXPLANATION OF SYMBOLS 
     
         
           1  infrared microscope 
           10  XY stage mechanism 
           20  infrared light source (measurement light source part) 
           30  visible light source 
           91  CPU (controller) 
           92  operation part (input device) 
           94  storage 
           240  detection part