JPH08298090A - Automatic sample searching device for electron microscope - Google Patents

Abstract

PURPOSE: To make visual field searching of a sample, measuring and storing of the structure of a sample image easy by arranging a means for continuously displaying the sample image during moving on a sample image display device, a driving control means of a sample stage, and a memory function. CONSTITUTION: Visual field searching of a sample 5 is conducted in such way that a sample stage 12 is moved with a sample stage driving control part 3, the moving state of the sample 5 is picked up as an image with a TV camera set in a main body 1, and displayed on a screen of a monitor 10. The state of visual field searching of the sample 5 is easily confirmed. During searching of the sample 5, move of the sample image is immediately stopped if necessary to measure the structure of the sample image. When the measured data is automatically recorded and stored with an image measuring device 14 serving as a memory function, since move of the sample image is automatically resumed within the range previously set, visual field searching of the sample, and measuring and storing of the structure of the sample image are easily conducted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron microscope apparatus,
In particular, the present invention relates to an automatic sample retrieval device for an electron microscope, which is suitable for finding a specific structure in a sample from a wide field of view, measuring it, and collecting statistics.

[0002]

2. Description of the Related Art In an electron microscope, a sample is observed and a desired visual field is searched for by observing an image projected on a fluorescent screen by moving a sample stage of an electron microscope main body. If the sample is very small, such as a virus or asbestos fiber, the fluorescent plate must be observed through a stereomicroscope installed in the electron microscope body. This work is very complicated and involves considerable fatigue, and as a result, the accuracy of the sample search is reduced due to human error such as missing the sample. Recently, a means for displaying and observing a transmission electron microscope image on a CRT monitor screen using a TV camera is also used. The method is a method of automatically controlling the sample field of view by controlling the sample stage with a CPU, but means such as displaying the sample image during sample movement, measuring the sample image, and storing the measurement data is available. Not taken.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to display a sample image on a display device provided outside the device for a visual field search of a sample, which has conventionally been performed manually for a long time while observing on a fluorescent screen. By doing so, the moving sample image can be easily and continuously observed. At the same time, it is an object of the present invention to provide an automatic sample retrieval device for an electron microscope which can easily measure a sample by automatically measuring the target structure displayed on the display device and recording the measured data.

[0004]

In order to achieve the above object, the present invention provides means for continuously displaying a moving sample image by driving a sample stage on a sample image display device, and means for displaying the sample image on the display device. A means for controlling the CPU of the drive of the sample stage so that the display of the moving sample image does not overlap or drop, and the sample image is measured by the image measuring device, and the measurement data is automatically saved by the memory function. It consists of means to do.

[0005]

The field of view of the sample is searched by using the X-axis and Y-axis sample stage drive mechanism of the electron microscope apparatus main body, and the sample image at that time is captured by the TV camera installed in the main body.
Since it can be displayed on the CRT monitor screen, it is possible to easily confirm how the sample visual field is searched. During the search of the sample, if necessary, for example, when the target structure is displayed, the movement of the sample image is immediately stopped and the structure is measured. When the measurement data is automatically saved by the memory function, the movement of the sample image is automatically restarted within the preset range, so the field of view of the sample and the measurement and storage of the structure of the sample image are saved. Can be done easily.

[0006]

FIG. 1 shows an embodiment of the present invention. The electron beam 3 emitted from the electron gun 2 of the electron microscope body 1 is converged by the irradiation lens 4 and irradiated on the sample 5. The electron beam 3 that has passed through the sample 5 is magnified by the objective lens 6 and the magnifying lens 7. The irradiation lens 4, the objective lens 6 and the magnifying lens 7 are controlled by the lens controller 11.
The electron beam 3 magnified by the magnifying lens 7 is projected on the TV camera 8. Electron beam 3 projected on TV camera 8
Becomes an image signal and is input to the TV camera amplifier 9. The image signal amplified by the TV camera amplifier 9 is displayed on the monitor 10. The magnification of the sample image displayed on the monitor 10 is controlled by the lens controller 11.
An image measuring device 14 for measuring, analyzing, and recording the displayed image is connected to the monitor 10. Sample 5
Is on the sample stage 12, and the movement of the sample 5 is restricted by the sample stage drive controller 13. Reference numeral 15 denotes an input device, which is connected to the image measuring device 14 to input information of image measurement, analysis, and recording to measure a specific structure existing in a certain visual field. The procedure will be described below with reference to the flowchart of FIG. First, the magnification of the observation visual field is set by the lens controller 11 (step A1). The magnification information is transmitted to the sample stage drive controller 13. At this time, the moving speed of the sample stage 12 is automatically set by the sample stage drive controller 13 in accordance with the magnification information so that the moving state of the sample 5 can be recognized on the monitor 10 (step A).
2). Next, the moving range of the sample stage 12 is set by the sample stage drive controller 13 (step A3). The search start point is selected by the sample stage drive controller 13 of the sample stage 12 (step A4). At the same time, all the information related to the driving of the sample stage for searching such as the observation magnification, the moving range of the sample stage, the moving speed, etc.
Recorded in 4. The image measurement device 14 can also start and temporarily stop the sample search. When the search is started, the sample stage 12 is moved by the control of the sample stage drive control unit 13 within the set movement range, and the moving images are continuously displayed on the monitor 10 (step A5). When the structure of is found, the sample stage drive control unit 1
The stop information is input via 3 to temporarily stop the movement of the sample stage 12 (step A6). At the same time, the image measuring device 14 performs automatic analysis of the structure such as measurement, analysis, and recording (step A7). When this automatic analysis is completed, the control of the sample stage 12 by the sample stage drive control unit 13 is restarted in step 4, and the temporarily stopped movement of the sample stage 12 is restarted. As described above, step A4 is performed until the movement of the entire setting range is completed.
From step A7, the search is ended (step A8).

By continuing the above operation, a specific structure in a specific area can be measured efficiently and accurately.

Next, the setting of the movement range of the sample stage and the state of movement will be described by taking asbestos analysis as an example. FIG. 3 schematically shows the moving range and moving state of the sample stage. When searching for asbestos fibers, it is usually 100 vertical.
One mesh hole of μm × 100 μm in width must be observed from end to end, and a total of 30 to 50 holes must be uniformly searched. In this case, the moving range and moving state of the sample stage are set as follows. First of all, Fig. 3
As shown in (a), in the case of one mesh hole of 100 μm in length × 100 μm in width, the size of the length and width is already determined, so that there is no gap within that range, and there is no overlapping or missing part. Further, the sample stage drive controller controls the sample stage so that the field of view continuously moves. At this time, the moving speed of the sample stage is controlled in accordance with the observation magnification so that the moving sample image can be observed on the monitor. There are many kinds of meshes other than 100 μm, but the size standard is internationally determined. Therefore, for sizes other than 100 μm, the size of the mesh is stored in the image analysis device in advance, and the sample stage drive control unit controls the sample stage based on the information, so that the optimum size can be obtained for all types of meshes. It is possible to automatically search by moving speed. When the search for one mesh hole is completed, subsequently, as shown in FIG. 3B, the mesh is moved to the next mesh hole and the same search is performed. FIG. 3 (c) shows a case where the designated visual field range is automatically searched regardless of the mesh holes.

FIG. 4 schematically shows a series of operations for measuring, analyzing and recording the structure displayed on the monitor. If asbestos fibers are found during sample search, the movement of the sample stage is stopped first, and the magnification of the sample is enlarged to a size where the fibers can be confirmed on the monitor. By setting measurement software such as a checkerboard-shaped calibration mesh in the image analysis device in advance on the monitor screen according to the magnification, fibers can be easily measured on the monitor. Moreover, since the elemental analysis of the fiber can also be performed by controlling the operation of the X-ray analysis apparatus from the image analysis apparatus, the identification and structural analysis of asbestos fibers can be perfectly performed.

[0010]

According to the present invention, it is possible to continuously and easily search for a sample by observing a moving sample image on a sample image display device, which was conventionally performed on the fluorescent plate. It will be possible. Further, by measuring and storing the sample with the image measuring device, the sample can be measured with good reproducibility, and the functionality of the electron microscope is improved.

[Brief description of drawings]

FIG. 1 is a block diagram of an electron microscope showing an embodiment of the present invention.

FIG. 2 is a flowchart for performing an automatic search.

FIG. 3 is an explanatory view showing a search range and a moving state of a sample stage.

FIG. 4 is an explanatory diagram showing a specific example of measurement of a sample.

[Explanation of symbols]

1 ... Electron microscope body, 2 ... Electron gun, 3 ... Electron beam, 4 ... Irradiation lens, 5 ... Sample, 6 ... Objective lens, 7 ... Magnifying lens, 8 ... TV camera, 9 ... TV camera amplifier, 10 ... Monitor , 11 ... Lens control device, 12 ... Sample stage, 1
3 ... Sample stage drive control unit, 14 ... Image measuring device, 1
5 ... Input device.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Takeo Ueno 832 Nagakubo, Horiguchi, Hitachinaka City, Ibaraki Prefecture 2 Hitachi Measurement Engineering Co., Ltd. (72) Inventor Hiroyuki Kobayashi 882, Ichige, Hitachinaka City, Ibaraki Hitachi, Ltd. Factory Measuring Instruments Division

Claims (3)

[Claims] 1. A driving mechanism for a sample stage of an electron microscope, comprising means for displaying a magnified image of the moving sample so that an overlapped portion or a missing portion does not occur in the magnified image of the sample displayed on the display means. As described above, the driving mechanism for the sample stage has a means for controlling the CPU so as to move a predetermined area of the sample according to the magnification, and measures an enlarged image of the sample displayed on the display means. Therefore, an image measuring device is provided, and when the stage movement is temporarily stopped at any position during the movement of the stage, the sample image is measured by the measuring device,
The automatic sample retrieval device for electron microscopes is characterized in that the results are recorded and stored, and when the storage is completed, the movement of the sample stage is automatically restarted. 2. The electron microscope according to claim 1, wherein, when a specific pattern is present in the sample, the image measuring device recognizes the pattern of the sample to be measured and the pattern and size can be arbitrarily set. Automatic sample retrieval device. 3. The method according to claim 1, wherein after the measurement of the specific pattern in the sample is completed, an electron beam is converged on a target structure and the generated characteristic X-ray is automatically analyzed, and the result is analyzed. Automatic sample retrieval device for electron microscopes that automatically records and saves.