JPH0363723B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a scanning microscope that applies radiation absorption spectrum analysis.

In conventional microscopes, a subject (sample) is mainly irradiated with visible light, and the transmitted or reflected light is imaged by a lens system to observe a two-dimensional form. Although it is possible to qualitatively observe a sample to some extent using conventional microscopes using staining, phase contrast methods, and other methods, this is only based on morphological observation.

By the way, the vibrational energy state of a molecule in a substance has a unique value depending on the interatomic distance, valence angle, mass, and bonding force between atoms in the molecule. It is absorbed and discretely transitions to other unique energy states with an energy difference of hν (h...Planck's constant). Infrared absorption spectrometry, for example, is a method that utilizes this phenomenon to perform qualitative analysis of molecules and atoms, and is currently most widely and actively applied. However, in the conventional infrared analysis method, the sample is irradiated with a relatively wide infrared beam and the absorption of the spectrum is observed. When components are mixed together, the effects of the absorption spectra of each component are superimposed, and it is possible to determine to some extent what kind of components are mixed, but in what state? It is impossible to determine the distribution or arrangement.

The purpose of the present invention is to converge radiation, such as an infrared beam, to be irradiated onto a sample using a concave reflector, and to
By detecting the absorption spectrum effect while scanning dimensionally and displaying it as an image with colors corresponding to the wavelength, this scanning method solves the above drawbacks and enables qualitative and quantitative analysis of constituent substances and morphological observation at the same time. The purpose is to provide a type spectroscopic analysis microscope.

The scanning spectroscopic analysis microscope of the present invention includes a radiation generating means, a means for relatively two-dimensionally scanning a sample with the radiation generated from the generating means, and a radiation absorption obtained from the sample at each scanning raw point. photoelectric conversion means for detecting a spectrum and converting it into an electrical signal; means for adding color information corresponding to the radiation absorption spectrum to the signal output from the photoelectric conversion means to form a color display signal; and the color display signal. and display means for displaying a color image based on.

Hereinafter, the present invention will be explained in detail based on the drawings.

FIG. 1 is a diagram showing the basic configuration of the present invention. Reference numeral 1 denotes a radiation generating section, for example, an infrared ray, which includes a radiation source and includes a reflective objective lens for converging the radiation, as shown in the embodiments described later. The radiation absorbed through the sample 2 is separated into spectra by a spectroscope 3, then detected by a detector 4, and converted into a time-series electrical signal in units of scanning raw points. Then, the above detection is repeatedly performed while scanning the sample 2 two-dimensionally by the scanning section 5.

By the way, the time series signal for each scanning element detected by the above-mentioned detector 4 is based on the scanning element position, that is, the detection position x, y, the amplitude of the absorption spectrum, and the wavelength.
Since it consists of dimensional information, when displaying an image on a television monitor, the dimension for the wavelength of the absorption spectrum is displayed in a color with a different tone depending on the wavelength. For this purpose, the signal detected by the detector 4 is amplified by the amplifier 6, and then the color display converter 7
Convert to a signal suitable for color display. and,
Next, the scan converter section 8 converts the signal into a color television signal using the television scanning method, and displays the signal on a color television monitor 9. Details of the display method will be described later using FIGS. 5 and 6.

FIG. 2 shows a block diagram of an example of the configuration of an embodiment of the present invention. In the figure, 10 is an infrared light source. The infrared rays from the infrared light source 10 are transmitted to the plane mirrors 11 and 12 and the collimator mirrors 13 and 1.
4, it is divided into a reference beam 15 and a sample beam 16 to become parallel light, and the sample beam 16 is converged onto a sample 18 by a reflective objective lens 17, and when it passes through the sample 18, it absorbs the spectra unique to the sample. The light is then condensed by a reflective objective lens 19 facing downward, converted into a parallel beam 20, and reflected by a plane mirror 21.
will lead you to Chiyotsupa 22. On the other hand, contrast luminous flux 1
5 passes through a correction shell 24 for correcting the amount of absorption of the sample light beam 16 by the sample holding shell 23, and then is guided to the chopper 22 via a plane mirror 25. The chopping ratio is set to a ratio that sufficiently follows fluctuations in the emission spectrum of the light source. The tapped light beam passes through a convex mirror 26 and then passes through a diffraction grating 2.
7 and spectroscopy. The separated spectrum is photoelectrically converted by the array type detector 28.
If this array type detector 28 is driven by a clock signal from the gate oscillation circuit 29 at a high speed that can sufficiently ignore the scanning speed of the sample and the photoelectric conversion output is read out, each scanned point ( It is possible to sequentially obtain time-series signals corresponding to the waveform of the absorption spectrum at the scanning position). That is, in FIG. 3, the signal during the period _T1 is the time-series signal corresponding to the absorption spectrum of the sample read out by the array type detector 28, and the signal during the period _T2 is:
Infrared light source 1 inserted by tipping
This is a signal corresponding to the emission spectrum of 0. Also
The period T ₃ corresponds to the rest time between readings by the array type detector 28. In this example, a concave diffraction grating is used as the spectroscopic means in order to easily illustrate the configuration, but it is of course possible to use a flat diffraction grating by combining optical systems. .

On the other hand, the position for detecting the 18 absorption spectra of the sample is moved two-dimensionally by moving the sample holding shell 23 two-dimensionally by the vibrator forming the X-scanning section 30 and the pulse motor forming the Y-scanning section 31. This is done by causing the sample 18 to be two-dimensionally scanned by the convergent light of the sample light beam 16. Further, the x-scanning section 30 supplies a scanning reference signal to the position detection section 32, which generates a digitally coded position signal representing the position of each predetermined scanning element point in the x-direction. A control signal for the pulse motor 34 for driving the chopper 22 by supplying a signal with the timing determined to the control gate generator 33, a control signal for the gate oscillation circuit 29,
A control signal for extracting a signal corresponding to the emission spectrum of the light source 10 inserted into the period _T3 in FIG. Each is generated. Note that 35 is a gear box for transmitting the drive of the pulse motor 34 to the chopper 22.

On the other hand, the time-series signal corresponding to the absorption spectrum waveform of each scan point detected by the array type detector is
It is amplified by a logarithmic video amplifier 36 with an excellent noise figure. The reason why the logarithmic video amplifier 36 is used here is that the amplitude of the absorption spectrum varies greatly depending on the type, thickness, and composition of the sample. In order to cope with this problem and maintain the amplification within the dynamic range of the amplifier, it would be time-consuming to adjust the thickness of the sample 18 each time by removing it from the holding shell 23 and polishing or slicing it. Therefore, after amplifying using a logarithmic amplifier with a wide dynamic range, the range in which the necessary signal exists is extracted by the gain adjustment circuit 37 and the dynamic range adjustment circuit 38. (If you take out a narrow range of a logarithmically amplified signal, it will be the same as a linearly amplified signal.) The signal that has undergone these processes is converted into a digital signal by an AD conversion circuit 39, and then a selection circuit 40 converts the signal to the above-mentioned position. Based on the position signal derived from the detection unit 32, the chopper 22 selects and extracts the signal portion of the waveform corresponding to the emission spectrum of the light source 10, which is inserted at an appropriate period during the period _T2 in FIG. 3, and stores it in the line memory. (serial dynamic memory) 41. Using this signal, each time series signal (T ₁ in Figure 3) corresponding to the absorption spectrum signal of sample 18
The flatness of the output with respect to the wavelength of the infrared light source 10 is corrected by dividing the signal of the period (signal of the period ) by the division circuit 42. The output of this division circuit 42 is passed to the next addition circuit 43, which converts the digitally coded position signal detected by the position detection unit 31 into a time series signal of the detected spectrum signal at the sample position corresponding to the position signal. The immediately preceding rest time portion, for example, the position signal of the time-series signal shown in FIG.

The signal read out from the magnetic disk recording section 44 is separated into a position signal by a position signal separation circuit 45, and then the RGB filter function generation circuit 46 outputs R, G, B as shown in FIG. 4b based on this position signal. R (red), G (green), and B generated synchronously as shown in
A multiplier 47 for each filter function signal for (blue),
48, 49, and their respective multipliers 47, 48,
49 is multiplied by a time series signal S corresponding to the absorption spectrum waveform shown in FIG. 4a.
As a result, color signal components of three colors are formed by adding color information of R, G, and B to the time-series signal S. Furthermore, the timing _tO of generation and the time width of generation of the RGB filter function signal shown in Fig. 4b
By varying T _O , it is possible to variably set which wavelength range of the absorption spectrum is displayed in correspondence with the color.

Note that the absorption spectrum waveform signal S shown in FIG. 4a is shown as an analog waveform to aid understanding. Furthermore, the waveforms (cutoff characteristics, etc.) of the R, G, and B filter function signals shown in FIG. 2B can be changed depending on the display method.

Thus, each color signal component obtained by forming the time-series signal corresponding to the absorption spectrum at each scanning raw point into three color signal components corresponding to the wavelengths of the absorption spectrum is processed by the integrator 5.
0, 51, 52 and sample hold circuit 5
3, 54, 55, and the changeover switch 56,
By switching 57 and 58 at the same time, either the signal that has passed through the integrators 50, 51, or 52, or the signal that has been sampled and held at the same timing is extracted as an output signal, and this is output (red).
Each color signal of R, (green) G, and (blue) B is input to the scan converter section 59, and the scan converter section 59 forms a color display signal.Based on this signal, the color television monitor 60
Display a color image on top. That is, when displaying the entire wavelength range of the absorption spectrum corresponding to a color as a mixed color, the changeover switches 56, 57, and 58 are moved to the integrators 50, 51, and 52, and the multipliers 47, 48, and 49 are The average value of the output of
As an RGB signal, the scan converter section 59
The position signal separation circuit 45 is stored in the frame memory within the frame memory.
The separated position signals are stored in correspondence with each other. Then, the frame memory is read out using the scanning method and scanning speed that correspond to the scanning of the television, and the selected reproduction image, which will be described later, is added to the read video signal using the television synchronization signal, character signal, and FIGS. 5 and 6. After adding the video signals corresponding to the spectral waveforms at the positions, the video signals are displayed on the color television monitor 60.

Next, when you want to display a single spectrum among the absorption spectra, that is, a specific color corresponding to the wavelength of that spectrum, selector switches 56, 57, and 58 are switched to the sample and hold circuit 53,
Switch to 54, 55 side, position signal separation circuit 45
Based on the position signal from the multipliers 50, 5
A sampling pulse is obtained at a timing corresponding to a specific wavelength position to be displayed in the outputs of the multipliers 50, 52, and 52, and the outputs of the multipliers 50, 51, and 52 are simultaneously sampled and held to obtain R, G, and B signals. The R, G, and B signals are led to a scan converter section 59, where they are converted into color television signals and displayed on a color television monitor 60. The image displayed in this way is a one-color display of a specific color corresponding to the spectrum at the specific wavelength position, and becomes a two-dimensional image of the sample displayed with brightness and darkness depending on the spectrum and size at the specific wavelength position.

In the configuration of the above embodiment, the digital circuits after the AD conversion circuit 39 are configured as a hardware system, but there is no problem in using a minicomputer to perform signal processing, and when performing more advanced image processing. The use of minicomputers is considered essential for this purpose.

Next, FIG. 5 shows an embodiment of a display method on a color television monitor. Signal processing for these displays is performed by a video processing section within the scan converter section 59. First, FIG. 5 shows a case where the entire range of the absorption spectrum to be displayed is displayed as a mixed color on a color television monitor 60, and 61 is a two-dimensional image of the sample displayed in color. On the right side of the screen, as shown at 62 and 63, for example, infrared absorption spectrum waveforms at positions 64 and 65 selected in the display image by joysticks on the panel are displayed, respectively. Of course, the selected positions 64 and 65 can be freely moved on the screen using joy sticks.

That is, a display mark appears at the position on the screen specified by the joystick, and at the same time, a time-series signal having an absorption spectrum waveform corresponding to that position is transmitted from the magnetic disk recording section 44 into the scan converter section 59. The signal is taken into the video processing unit of the camera and superimposed on the color television signal.

In the waveform diagrams 62 and 63 corresponding to the absorption spectra displayed on the right side of the screen, the range drawn by thick solid lines 66 and 67 indicates the spectral range in which the color image that has been converted into a color signal is displayed. The color changes continuously according to the spectrum, and the display blinks. The color display spectral ranges 66 and 67 can be arbitrarily set in their positions and ranges as described above. Lower range part 68 of the display screen
is the part that displays the date, sample name, and other characters. FIG. 6 is a diagram illustrating an example of a display method in which a single spectrum among absorption spectra is displayed in a specific color corresponding to that spectrum. 69 and 70 are absorption spectrum waveforms at positions 71 and 72 selected by the joystick as in the example of FIG. And the bright spot 73 on the waveform,
The four points 74, 75, and 76 can also be independently set using knobs on the panel, and each of the four points can be set individually by a different specific color that corresponds to the absorption spectrum at each position. The same screen is divided into four separate images 77, 78, 79, and 80 and displayed simultaneously. In order to make these four bright spots easy to distinguish, they are configured to blink in a color that corresponds to their set position.

In this way, according to this embodiment, in addition to displaying each part of the sample two-dimensionally in colors corresponding to the absorption spectrum, the absorption spectrum at the selected position on the screen is displayed at the same time, so that the selection can be made easily. There are effects such as being able to display the absorption spectrum of a position in an intuitive and easy-to-understand manner.

In the above embodiments, the case where infrared rays were used as the radiation was explained, but the present invention is not limited thereto, and visible rays, ultraviolet rays,
It can also be easily carried out using a spectroscopic analysis microscope using X-rays or the like.

As explained above based on the examples, according to the present invention, it is not only possible to observe the morphology of a sample using various types of radiation, but also to two-dimensionally observe the radiation absorption spectrum of each part on a two-dimensional surface of the sample. Since the image is displayed in a color corresponding to the absorption spectrum wavelength, qualitative and quantitative analysis of the sample can be easily performed on the image screen by determining the color of the image and its area.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the basic configuration of the present invention, FIG. 2 is a block diagram showing the configuration of an example of the embodiment of the present invention, and FIG. 3 is a block diagram showing the configuration of an example of the embodiment of the present invention. An example diagram of time-series signal waveform, 4th
The figure is a waveform diagram for explaining the relationship between the absorption spectrum and the color signal, and FIGS. 5 and 6 are explanatory diagrams of different display examples on a color television monitor. 1... Radiation generating part, 2, 18... Sample, 3...
...Spectroscope, 4...Detector, 5...Scanning section, 6...
Amplifying section, 7... Color display conversion section, 8, 59...
Scan converter section, 9, 60...Color television monitor, 10...Infrared light source, 11,
12, 21, 25... Plane mirror, 13, 14... Collimator mirror, 15... Control light flux, 16... Sample light flux, 17, 19... Reflective objective lens, 20...
Parallel light beam, 22...Chopper, 23...Sample holding shell, 24...Correction shell, 26...Convex mirror, 27...Diffraction grating, 28...Array type detector, 29...Gate oscillation circuit, 30... x scanning section, 31... y scanning section, 32... position detection section, 3
3... Control gate generator, 34... Pulse motor, 35... Gear box, 36... Logarithmic video amplifier, 37... Gain adjustment circuit, 38...
... Dynamic range adjustment circuit, 39 ... AD converter, 40 ... Selection circuit, 41 ... Line memory, 42 ... Division circuit, 43 ... Position signal addition circuit, 44 ... Magnetic disk recording section, 45 ... ...position signal separation circuit, 46...RGB filter function generation circuit, 47, 48, 49...multiplier, 50,5
1, 52... Integrator, 53, 54, 55... Sample hold circuit, 56, 57, 58... Changeover switch, 61... Color display image of sample, 6
2, 63, 85, 86...absorption spectrum waveform,
64, 65, 80, 79...selected position, 66, 6
7...Color display range, 68...Display area for characters, etc., 72, 73, 74, 75...Bright spots on the waveform, 76, 77, 78, 79...Spectral spectra of four specific points in the absorption spectrum, etc. Each image is divided into four.

Claims (1)

[Claims] 1. A radiation generating means, a means for relatively two-dimensionally scanning a sample with the radiation generated from this generating means, and detecting a radiation absorption spectrum obtained from the sample at each scan point and converting it into an electrical signal. a photoelectric conversion means; a means for adding color information corresponding to the radiation absorption spectrum to a signal output from the photoelectric conversion means to form a color display signal; and a display for displaying a color image based on the color display signal. A scanning spectroscopic analysis microscope characterized in that it consists of means.