JPH03152506A - Visual field limiting stop of infrared microscope device - Google Patents

Abstract

PURPOSE:To improve the operation efficiency of the visual field limiting stop by constituting variable stop plates of the visual field limiting stop by using a wavelength selective material which cuts infrared light and transmits only visible light. CONSTITUTION:The four variable stop plates 25 - 28 incorporated in the visual field limiting stop 11 are constituted by employing heat-ray absorbing filters. Therefore, even when a analytic sample piece 2 is observed through an ocular while the visual field limiting stop 1 is put in a stop-down state, a sample piece area part behind it can be observed. phosphate glass which is about 1mm thick is usable for the heat-ray absorbing filters used for the stop plates 25 - 28. The glass of the heat-ray absorbing filters is bluish, so while the sample piece is illuminated with light in visible observation mode, the border of the visual field range of the visual field limiting stop 11 can be discriminated clearly, which is convenient for the setting of an aperture. Consequently, setting operation for the aperture setting of the visual field limiting stop for an extremely small spectral measurement position specified on the sample piece is easily performed with efficiency.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention is a field-limiting diaphragm for an infrared microscope device that is combined with a Fourier transform infrared spectrophotometer and sets an aperture for a minute spectroscopic measurement site on an analysis sample piece. Regarding.

[Conventional technology]

As is well known, a Fourier transform infrared spectrophotometer is used in combination with an infrared microscope equipped with a field-limiting aperture, and when performing spectroscopic measurements on an analytical sample, the infrared microscope must first be While visually observing the magnified real image of the sample piece through the eyepiece, search for a spectroscopic measurement site (for example, a foreign object), adjust the field-limiting diaphragm to align with this site, and set the aperture in infrared measurement mode. I try to do that.

Next, in Figure 4, which shows the configuration of an infrared microscope device used in combination with an infrared spectrophotometer, 1 indicates the analytical sample piece 2.
3 is a reflection objective, 4 is a reflection condenser, 5 is an epi-illumination light source, 6 is a transmitted-illumination light source, 7 is an eyepiece, and 8 is a Half mirrors 9 and 10 are infrared light reflecting mirrors 11 to be described later.
is a field-limiting diaphragm provided before the reflecting objective mirror 3. Note that an objective lens made of a material that transmits infrared light (for example, a lens made of silicon or germanium) may be used instead of the reflective objective mirror 3 described above.

In addition, the conventional configuration of the field-limiting diaphragm 11 is as shown in FIGS. In total, there are four variable apertures 14 to 17 made of metal on the front and rear, left and right sides, and these four apertures Fi,
The viewing area aperture 18 is set in the central opening area surrounded by 14 to 17. Then, the main body case 12 is moved in correspondence with each aperture plate 14 to 17 so as to variably adjust the position and size of the aperture 18! It is equipped with micrometers 19 to 22 for knots. In addition, 2
3 is a spring that biases the aperture plate in the backward direction.

With this configuration, the analysis sample piece 2 is placed on the stage l, and the epi-illumination light source 5. Alternatively, when illumination light is irradiated onto the sample piece 2 in the visible observation mode in which one of the transmitted illumination light sources 6 is selected, a real image of the sample piece 2 is formed at the position of the field-limiting aperture 11, and this real image is further enlarged with the eyepiece lens 7. observed.

Here, the real image seen through the eyepiece 7 with the diaphragm plates 14 to 17 of the field-limiting diaphragm 11 fully open is shown in Figure 3 (a).
), 2a and 2b in the figure are sample piece 2.
It shows a foreign object in the.

Next, in order to perform infrared spectroscopy on the local part of the foreign object 2a on the sample piece 2, first, while observing the sample piece 2 through the eyepiece 7, each micrometer 19 to 22 of the field-limiting diaphragm 11 is adjusted. The movable aperture plates 14 to 17 are shown in Figure 3 (
b) Move to the 1st position and place the spectroscopic measurement part of the sample piece on the foreign object 2a.
The aperture of the field limiting diaphragm 11 is set in accordance with the minute portion of the image. In this setting state, the transmission range of visible light and infrared light in the next infrared measurement mode is
It is limited to the aperture in the minute range surrounded by 7.

In this state, next the infrared charging reflector 9 shown in FIG. l
O to the position shown in Fig. 5, the infrared microscope device is switched to infrared measurement mode, and the infrared light 24 modulated by the interferometer is passed from the spectrometer side (not shown) into the optical path inside the infrared microscope device. By guiding the infrared light 24 to the sample piece 2. After passing through the field-limiting diaphragm 11, the condensed light 1 is detected by a detector (not shown).

Furthermore, by Fourier transforming the interferogram detected by the detector using a computer, etc., a sample spectrum of the spectroscopic measurement area can be obtained.

By the way, in order to obtain an absorption spectrum specific to the measurement site in the sample piece 2, as a measurement procedure using a spectrometer system, the aperture of the field-limiting diaphragm 11 is aligned with the foreign object 2a on the sample piece 2 as shown in Fig. 3, etc. After setting, the stage l of the infrared microscope device is moved and the sample piece 2 is completely retreated from the field of view of the field-limiting aperture 11, resulting in the state shown in Fig. 3 (C), and the background spectrum is measured here. 0 Next, the stage 1 is moved again to return the sample piece 2 to the position shown in Fig. 3, et al.), and in this state, the sample spectrum for the foreign object 2a is measured, and from the ratio of the sample spectrum to the background spectrum described above, The absorption spectrum of the foreign matter 28 portion is determined.

[Problem to be solved by the invention]

By the way, in the infrared microscope device incorporating the field-limiting diaphragm of the conventional configuration described above, when performing spectroscopic measurements of analysis sample pieces,
There are some difficulties in setting the aperture with a field-limiting diaphragm, as described below.

That is, the field-limiting diaphragm 11 is adjusted from the observation state in the visible observation mode shown in FIG. 3(a), and the diaphragm plate 1 of the field-limiting diaphragm is adjusted as shown in FIG.
When moving from 4 to 17, in this state the minute measurement site (
Except for the foreign object 2a), the other parts are hidden behind the diaphragm plates 14 to 17 and cannot be seen completely (for this reason, the sample piece 2 is temporarily retreated from the field of view (the state shown in Fig. 3 (C)). After measuring the background spectrum in infrared measurement mode,
When switching the infrared 1IJi@ device again to visible observation mode and returning the sample piece 2 to the position shown in Figure 3 (c) in order to measure the sample spectrum for the measurement site (foreign object 2a), if the sample piece 2 It becomes extremely difficult to reproduce the positioning. Therefore, conventionally, the diaphragm plates 14 to 17 of the field-limiting diaphragm 11 are opened, the diaphragm plates 14 to 17 of the field-limiting diaphragm 11 are opened, and the diaphragm plates 14 to 17 of the field-limiting diaphragm 11 are opened to the state shown in FIG. The sample vector is then measured.

However, in this case the aperture settings.

In particular, accuracy on the order of micrometers is required for the accuracy of the field of view size, and if the field of view size differs even slightly from the aperture at the time of background spectrum measurement, it will not be possible to obtain the correct absorption spectrum of the measurement site.

Therefore, careful operation is required to determine the position of the measurement site on the sample piece, and setting it takes a long time. Moreover, when performing spectroscopic measurements at multiple locations on the same sample piece in succession, it is necessary to redo the settings each time, and a large amount of time is spent on setting the aperture. Using the conventional field-of-view-limiting aperture reduces work efficiency. low.

The present invention has been made in consideration of the above points, and is a field-limiting diaphragm for an infrared microscope device that can significantly improve work efficiency compared to the conventional one by improving the diaphragm plate of the field-limiting diaphragm. The purpose is to provide

[Means to solve the problem]

In order to solve the above problems, in the field-limiting diaphragm of the present invention, the variable diaphragm plate of the field-limiting diaphragm is made of a wavelength-selective material that cuts infrared light and transmits only visible light.

[Effect]

With the above configuration, in the visible observation mode, even when the aperture of the field-limiting diaphragm is closed, the area of the analysis sample piece covered by the aperture can be observed through the eyepiece. Therefore, the aperture of the field-limiting diaphragm is set to align with the minute measurement site specified on the sample piece, and in this state, the sample piece is moved back from the field of view to measure the background spectrum, and then the sample piece is removed again. To measure the sample spectrum after returning the specimen to its original position, leave the field-limiting aperture setting unchanged and move the specimen while observing a wide area of the specimen in visible observation mode. It is possible to accurately reproduce the setting position with a simple operation, and thereby an accurate absorption spectrum can be obtained.

In addition, when performing spectroscopic measurements at multiple locations on the same sample piece, it is recommended to leave the field-limiting aperture set at -degrees as is.
By observing the entire sample piece in visible observation mode while searching for another measurement site and aligning the sample piece, it is possible to proceed with spectroscopic measurement operations efficiently without having to measure the background spectrum again. .

The aperture plate may be made of, for example, a filter that absorbs infrared rays (heat ray absorption filter), a material that reflects infrared rays and transmits only visible light, or a suitable thin film interference filter formed on a glass substrate. Things can be adopted.

[Embodiment] FIGS. 1 and 2 show the structure of a field-limiting diaphragm according to an embodiment of the present invention, and the same members corresponding to FIGS. 6 and 7 are given the same reference numerals.

In FIGS. 1 and 2, the four variable diaphragm plates 25 to 28 incorporated in the field-limiting diaphragm 11 are metal diaphragms incorporated in the conventional field-limiting diaphragm (see FIGS. 6 and 7). Instead of the plates 14 to 17, for example, a heat ray absorption filter is used. Therefore, in the visible observation mode of the infrared microscope shown in FIG. 4, even when the analysis sample piece 2 is observed through the eyepiece with the field-limiting aperture 11 closed, the aperture is stopped as shown in FIG. 3 (6). By looking through the plates 25 to 28, the sample piece region behind the aperture plate can also be visually observed.

In addition, as the heat ray absorption filter used for the aperture plates 25 to 28, for example, ■Hoya Glass product HA-30 (thickness II
III phosphate glass) can be used.

The characteristics of this heat ray absorption filter are that visible light is transmitted as is without attenuation, but the transmittance for infrared light in a wavelength range longer than 950 nm is 0.3% or less.

Therefore, it is practically sufficient for spectroscopic measurements in the mid-infrared light and far-infrared light regions. In addition, since the glass color of this heat ray absorption filter is bluish, when illumination light is applied to the sample piece in visible observation mode, the boundary of the field of view at the field-limiting aperture 11 can be clearly distinguished and the aperture It is convenient for setting operations.

Furthermore, when fused silica glass is used as the material for the aperture plates 25 to 28, infrared light with a wavelength of 40 μm or more is transmitted, so spectroscopic measurements in the range of 5 to 40 μm are practically possible. . Note that if a suitable thin film interference filter is formed on this glass material, the infrared light blocking performance can be improved while expanding the spectral infrared region. Furthermore, in addition to the heat ray 1-pass filter, materials that transmit visible light but reflect and cut infrared light may be used as the material for the diaphragm plates 25 to 28.

Moreover, when the material of the aperture plates 25 to 28 is transparent,
In order to make the boundaries of the viewing range easier to see, it is recommended to take measures such as applying a metal film coating to the edges of the aperture plate.
Furthermore, in order to completely cut off infrared light transmission from temporary apertures 25 to 28 in the infrared measurement mode, it is necessary to
In addition to 8, metal variable diaphragm plates 1 & 11 are incorporated into the field-limiting diaphragm 11, and after the aperture is set in visible observation mode, the metal diaphragm plates are configured to narrow down to the positions of diaphragm plates 25 to 28. You can also do it.

〔Effect of the invention〕

Since the field-limiting diaphragm of the infrared microscope apparatus according to the present invention is configured as described above, it achieves the following effects.

In other words, by making the diaphragm plate of the field-limiting diaphragm from a wavelength-selective material that cuts out infrared light and transmits only visible light, analysis can be performed in visible observation mode even when the field-limiting diaphragm is sufficiently closed. A wide area of the sample piece can be visually observed through the eyepiece, making it easy to set the aperture of the field-limiting diaphragm for the minute spectroscopic measurement site specified on the sample piece.

And it can be done efficiently.

[Brief explanation of the drawing]

1 and 2 are a plan view and a side sectional view showing the structure of a field-limiting diaphragm according to an embodiment of the present invention, and FIGS. 3(a) to 3(b) show field-of-view limits corresponding to each operation state of the aperture setting. A schematic diagram showing the field of view range at the aperture, Figures 4 and 5 are configuration diagrams of the infrared microscope device showing the visible observation mode and infrared measurement mode, respectively, and Figures 6 and 7 are the conventional In Figure 0, which is a plan view and a side sectional view showing the structure of the field-limiting diaphragm, 1: stage, 2: analysis sample piece, 7: eyepiece, 11
: Field-limiting aperture, 25-28: Aperture plate. ￥-1 Figure 112 Fertilizer (C) (d”) Figure 3 Figure 4 Figure 6f?J 5th gall

Claims (1)

[Claims] 1) This is a field-limiting diaphragm for an infrared microscope device used in combination with an infrared spectrophotometer, and is located on the optical path common to visible light and infrared light between the stage on which the analysis sample piece is placed and the eyepiece. A field-limiting diaphragm equipped with a variable diaphragm plate is installed, and the field-limiting diaphragm is adjusted while visually observing an enlarged real image of the sample through the eyepiece to set the aperture of the spectroscopic measurement site for the analysis sample piece, A field-limiting diaphragm for an infrared microscope apparatus, characterized in that the variable diaphragm plate of the field-limiting diaphragm is made of a wavelength-selective material that cuts infrared light and transmits only visible light.