JPH0969352A - electronic microscope - Google Patents

Abstract

(57) [Summary] [Structure] A transmission electron microscope is equipped with a TV camera that can freely change the irradiation position of an electron beam and has a function of scanning, and that can display a transmitted electron image. And the scanning cycle of the TV camera is synchronized. [Effect] Since the irradiation position of the electron beam is constantly changed, damage to the sample can be suppressed to a low level, and since the scanning period of the electron beam and the scanning period of the television camera are synchronized, an ordinary transmission electron microscope image can be obtained. be able to.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron microscope, and more particularly to a transmission electron microscope equipped with a television camera.

[0002]

2. Description of the Related Art Conventionally, when observing a biological sample with a transmission electron microscope, the sample is damaged by an electron beam. When observing a sample that is easily damaged by electron beams,
The amount of electron beams is reduced as much as possible for observation. However, when the electron beam is widely irradiated, a temperature difference between the center and the periphery occurs even if the amount is reduced, and the sample drifts, which causes a problem in observation.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a transmission electron microscope capable of observing a sample easily damaged by an electron beam without drift.

[0004]

According to the present invention, in order to reduce damage and observe a sample without sample drift, an electron beam is finely focused on the sample and the electron beam is two-dimensionally scanned. . On the other hand, on the surface of the image sensor, the electron beam scanning region is made to coincide with the image capturing effective region, and the image reading electron beam scanning is synchronized with the sample electron beam scanning.

[0005]

In the present invention, since the electron beam is converged finely on the sample and the two-dimensional scanning is performed in the observation of the transmission electron beam image, the damage of the sample can be reduced and the observation without drift becomes possible. Further, by synchronizing the scanning of the electron beam on the sample and the scanning of the image reading electron beam of the electrical imaging means, the image acquisition efficiency for the irradiation of the sample with the electron beam can be improved.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The electron microscope of the present invention can scan an electron beam with a deflection coil of the electron microscope in accordance with a scanning beam for reading. Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is an explanatory view of the function when a television camera is attached to the transmission electron microscope. The electron beam 109 generated from the electron gun 101 is bent by the deflection coil 103, is irradiated onto a predetermined position of the sample 104, and forms a transmission electron image on the scintillator 106. The scintillator 1
Reference numeral 06 converts an image of the electron beam 109 into an image of light 110.
Projected on 12. The image pickup tube 107 accumulates the image of the light 110 reflected on the image pickup surface 112 in the form of electric charge on the image pickup surface 112, and reads the electric charge by the scanning electron beam 114 to convert the image into an electric signal. The scanning of the scanning beam is performed by the deflection coil 113.

FIG. 2 is an explanatory view of the movement of the read electron beam 114 for scanning the image pickup surface 112 and the transmitted electron beam image by the electron beam 109. Spot 2 of read scanning beam 114
01 scans the scanning range 200 in the direction 203, and sequentially scans from top to bottom. The feature of this apparatus is that the scanning cycle of the reading scanning beam and the scanning of the electron beam are synchronized as shown in FIG. The spot 202 of the electron beam 109 is made to have the same size as the spot 201 of the read scanning beam 114, the center of the spot 202 is aligned with the center of the spot 201, and the rectangular range 200 is scanned at the same position as the spot 201. Since the deflection coil 103 is located above the sample 104, the irradiation area of the sample is being scanned. Therefore, even if the electron beam 109 is scanned, the image on the imaging surface 112 does not move, but the spot 202 on which the image appears moves. In this way, the electron beam irradiating the sample is always small and partial, but on the monitor of the television camera, a transmission electron microscope image having the same brightness as the normal one can be obtained. Further, since the electron beam is not radiated to the place where the reading scanning beam is not present, the image acquisition efficiency with respect to the electron beam irradiation amount is also good.

FIG. 3 shows changes in the position of the spot. In this way, the spots 201 and 202 continue to scan the same position. If the scanning periods do not match, the brightness may be uneven. If the read scanning beam spot 201 is faster, that is, the scanning cycle is shorter,
Overtake spot 202 on the way. Passing over means scanning the part before the information of the electron beam image is supplied thereto, and the spot 201 suddenly becomes dark from the place overtaking the spot 202. On the contrary, when the spot 201 is slower, the next information is added before the information is read, so that the spot 201 suddenly becomes bright from the spot overtaken by the spot 202. There is no problem if the spots 201 and 202 are out of phase, but the spot movement cycle is the cycle T1.
And the cycle T2, respectively.

[0010]

The transmission electron microscope of the present invention can facilitate observation of a sample that is easily damaged by an electron beam.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of functions of an electron microscope and a television camera.

FIG. 2 is an explanatory diagram of a scanning method on an image pickup surface of a television camera.

FIG. 3 is an explanatory diagram of changes in spot position with time.

[Explanation of Codes] 101 ... Electron Gun of Electron Microscope, 102 ... Converging Lens System,
103 ... Electron microscope deflection coil, 104 ... Sample, 10
5 ... Projection lens system, 106 ... Scintillator, 107 ... Imaging tube, 108 ... Electron gun of imaging tube, 109 ... Electron beam of electron microscope, 110 ... Light generated from scintillator, 111 ...
Optical system, 112 ... Imaging plane, 113 ... Deflection coil of imaging tube, 114 ... Read electron beam.

Claims (1)

[Claims] 1. A means for generating an electron beam, a means for converging the electron beam on a sample, a means for scanning the electron beam on the sample, an electron beam transmitted through the sample being enlarged, and connected. In an electron microscope having a means for imaging and an electrical imaging means for the magnified image, the scanning of the electron beam on the sample is synchronized with the cycle of the image reading electron beam scanning by the electrical imaging means. electronic microscope.