JPH04206334A - Display device of electron microscope - Google Patents

Abstract

PURPOSE:To allow the clear image display of a diffraction pattern by providing a first image pick-up means for picking the image of an electron microscopic image and a second image pick-up means for picking the image of the diffraction pattern, and switching the relative positions of a visual light image formed on a fluorescent plate or its virtual image to the first and second image pick-up means. CONSTITUTION:Separately from a television camera 8a for picking an electron microscopic image, a second television camera 8b having a sensitivity lower than that of the television camera 8a for picking the image of a diffraction pattern is provided. When a diffraction pattern mode is set in a lens control circuit 6, the information of electron beam deflection required for projecting the diffraction pattern on the visual field of the television camera 8b on a fluorescent plate is supplied to a deflector control circuit 13. A signal for switching the television camera from the television camera 8a for electron microscopic image to the television camera 8b for picking the diffraction pattern is supplied from the lens control circuit 6 to a television camera change-over switch 11, and the diffraction pattern is projected on the visual field of the television camera 8b on the fluorescent plate. Thus, the diffraction pattern can be clearly image-displayed.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a display device for an electron microscope, and in particular, an image display device that captures an electron microscope image or a diffraction pattern projected on a fluorescent screen by an imaging means. The present invention relates to a display device for an electron microscope that displays images.

[Prior Art] Conventionally, in order to display an electron microscope image or a diffraction pattern in an electron microscope, an image or pattern projected on a fluorescent screen is imaged by an imaging means such as a television camera.
As a display device for an electron microscope that displays images on an image display device, a device having a configuration as shown in FIG. 4 is known. In FIG. 4, 1 is an objective lens, 2 is an intermediate lens, and 3 is a projection lens, and these lenses constitute an imaging lens system 4. 5 is a lens power supply, and 6 is a lens control circuit. Further, 7 is a fluorescent screen, 8 is a television camera, ] 0 is a cathode ray tube, and 9 is a driver circuit for controlling the operation of the television camera 8 and cathode ray tube 10.

The fluorescent screen 7 is a light transmitting member such as glass coated with a fluorescent substance, and is configured so that the fluorescence emitted from the fluorescent screen by electron beam irradiation can be detected from the bottom surface of the fluorescent screen.

[Problems to be Solved by the Invention] In the device configured as described above, the lens control circuit 6
The imaging lens system 4 is controlled under the conditions set to project an electron microscope image or a diffraction pattern onto the fluorescent screen 7.

A television camera 8 is placed below the fluorescent screen 7.
The image or diffraction pattern projected by the is imaged. Here, in order to capture the electron microscope image projected onto the fluorescent screen 7, the television camera 8 is required to have high sensitivity and high resolution. On the other hand, since the diffraction pattern projected on the fluorescent screen 7 has a locally high brightness at the center of the pattern, the sensitivity of the television camera 8 must be set to low sensitivity in order to image the pattern.

Therefore, as the television camera, one having an automatic gain control function (AGC) for sensitivity is used. However, as shown in FIG. 5, the diffraction pattern is scattered with locally high brightness areas and extremely low brightness areas, so the sensitivity setting using the automatic gain control function of the television camera does not allow for clear diffraction. Unable to image pattern. Therefore, in the case of a diffraction pattern, a problem arises in that an image that is less clear than an electron microscope image is displayed on the cathode ray tube 10.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above-mentioned problems, and an object of the present invention is to provide a display device for an electron microscope that can clearly display an electron microscope image or a diffraction pattern.

[Means for Solving the Problems] The first invention provides an imaging lens system for projecting an electron microscope image or an electron beam carrying a diffraction pattern onto a fluorescent screen;
A display device for an electron microscope comprising an imaging means for imaging an image or a diffraction pattern projected on a fluorescent screen, and a display device for displaying an image or a diffraction pattern taken by the imaging means, wherein the imaging means includes: a first imaging means for imaging an electron microscope image; and a second imaging means lower in sensitivity than the first imaging means for imaging a diffraction pattern.
an imaging means is provided, and when the imaging lens system is set to an electron microscope image display mode, an electron microscope image is taken by the first imaging means, and the imaging lens system is set to a diffraction pattern mode. In such a case, the first image of the visible light image or its virtual image generated on the fluorescent screen is captured by the second image capturing means. It is characterized by comprising means for switching the relative position with respect to the second imaging means.

A second aspect of the present invention provides a first fluorescent screen on which an electron microscope image is projected and a second fluorescent screen lower in sensitivity than the first fluorescent screen on which a diffraction pattern is projected, and the imaging lens system is configured to provide an electron microscope image. When set to display mode, an electron microscope image is projected onto the first fluorescent screen, and when the imaging lens system is set to diffraction pattern mode, a diffraction pattern is projected onto the second fluorescent screen. As in the above 1. Means for switching the relative projection position of the electron beam with respect to the second fluorescent screen is provided, and the image or diffraction pattern projected on the first or second fluorescent screen is imaged by the imaging means. shall be.

[Example] Hereinafter, an example of the present invention will be described based on the drawings. 1st
The figure is a configuration diagram of an apparatus for explaining one embodiment according to the first invention, FIG. 2 is a configuration diagram of an apparatus for explaining another embodiment according to the first invention, and FIG. FIG. 1 is an apparatus configuration diagram for explaining an embodiment according to the present invention.

First, an embodiment according to the first invention will be described based on FIG.

In FIG. 1, the same components as in FIG. 4 are given the same numbers and their explanations are omitted. The apparatus shown in FIG. 1 is different from the conventional example in that, in addition to the television camera 8a for taking electron microscope images, a second television camera having lower sensitivity than the television camera 8a is used to take images of the diffraction pattern. 8b is provided, and when the imaging lens system 4 is set to the electron microscope image display mode, the visible light image generated by the fluorescent screen is captured by the television camera 8a for electron microscope images, and the imaging lens A camera changeover switch 11 is provided to switch the television camera according to the setting of the mode so that a visible light image is captured by the second television camera 8b when the system is set to the diffraction pattern mode. , an electron beam deflector 12 and deflector control for deflecting the electron beam so that an image or a diffraction pattern is projected in the field of view of each television camera (field of view facing the fluorescent screen) depending on the television camera used; This is because the circuit 13 is provided.

- In FIG. 1, when the diffraction pattern mode is set in the lens control circuit 6, a signal for changing the excitation of each lens of the lens system 4 is supplied from the lens control circuit 6 to the lens power supply 5, and The deflector control circuit 13 is supplied with electron beam deflection information necessary for projecting the diffraction pattern onto the field of view of the television camera 8b on the fluorescent screen. Further, a signal for switching the television camera from the television camera 8a for electron microscope images to the television camera 8b for diffraction pattern imaging is supplied from the lens control circuit 6 to the changeover switch 11 of the television camera. As a result, the electron beam carrying the diffraction pattern is deflected, and the diffraction pattern is projected onto the field of view of the television camera 8b on the fluorescent screen.

The diffraction pattern is then imaged by a low-sensitivity television camera 8b placed below the fluorescent screen. The video signal from the television camera 8b is supplied to the cathode ray tube 10 via the driver circuit 9 and displayed as an image. Thereby, the diffraction pattern can be clearly displayed as an image.

Next, another embodiment according to the first invention will be described based on FIG. The embodiment shown in FIG. 2 differs from the first embodiment described above in that in order to project the electron microscope image or diffraction pattern projected onto the fluorescent screen into the field of view of the television camera 8a or television camera 8b, the A mirror 14 and a chain drive motor 15 are provided on the side for switching the direction of light reflection from the fluorescent screen to the direction in which each camera is arranged.

When the electron microscope #J image mode or the diffraction pattern mode is set in the lens control circuit 6, a signal for changing the excitation of each lens of the lens system 4 and a signal for changing the excitation of each lens of the lens system 4 and the mirror 14 are sent from the lens control circuit 6 to the lens power supply 5. A signal for switching the reflection direction to the camera direction corresponding to the set mode is supplied to the chain drive motor 15, and a signal for switching the television camera is supplied to the television camera changeover switch 11. Therefore, a mirror-generated virtual image of an electron microscope image or a visible light image of a diffraction pattern projected onto the central portion of the fluorescent screen is moved by operating the mirror 14 and captured by the television camera 8a or 8b. The video signal from the television camera 8b is then supplied to the cathode ray tube 10 via the driver circuit 9 and displayed as an image. As a result, it is possible to project an image with less aberration than when changing the projection position on the fluorescent screen using an electron beam deflector, so that a clearer image can be displayed.

Next, a second embodiment of the present invention will be described based on FIG. In FIG. 3, the same components as in FIG. 4 are given the same numbers and their explanations are omitted.

The apparatus shown in FIG. 3 is different from the conventional example in that the fluorescent screen includes a first fluorescent screen on which the electron microscope image is projected and a second fluorescent screen with lower sensitivity than the first fluorescent screen on which the diffraction pattern is projected. an electron microscope image is projected onto the first fluorescent screen when the imaging lens system is set to the electron microscope image display mode, and when the imaging lens system is set to the diffraction pattern mode, A fluorescent screen switching mechanism 16 is provided for moving the first or second fluorescent screen placed at the electron beam projection position so that the diffraction pattern is projected onto the second fluorescent screen.

When the electron microscope image mode or the diffraction pattern mode is set in the lens control circuit 6, a signal for changing the excitation of each lens of the lens system 4 is supplied from the lens control circuit 6 to the lens power supply 5, and the fluorescent screen A signal for switching the fluorescent screen to the fluorescent screen 7a or 7b corresponding to the set mode is supplied to the switching mechanism 16. The electron microscope image or diffraction pattern projected onto the fluorescent screen is then captured by a television camera 8. The video signal from the television camera 8 is supplied to a cathode ray tube 10 via a driver circuit 9 and displayed as an image. Thereby, even when a highly sensitive television camera is used, the diffraction pattern can be clearly displayed as an image. Here, if the fluorescent material applied to the fluorescent screen for projecting the diffraction pattern is made to have a lower sensitivity as it approaches the center of the fluorescent screen, a better quality image can be obtained.

Note that the above-described embodiment is only one embodiment of the present invention, and the present invention can be implemented with various modifications. For example, in the first embodiment of the first invention, the projection position of the image or diffraction pattern projected onto the fluorescent screen is changed by the electron beam deflector, but the image or diffraction pattern is projected at the same position on the fluorescent screen. Alternatively, the television camera may be moved according to the projected image. Also, the second
In the embodiment of the present invention, the first fluorescent screen and the second fluorescent screen with different sensitivities are moved to the electron beam projection position, but fluorescent screens with different sensitivities are provided on the same fluorescent screen to move the first fluorescent screen and the second fluorescent screen with different sensitivities.
．． A second fluorescent screen may be used, and the projection position of the image or diffraction pattern projected onto each fluorescent screen may be changed by an electron beam deflector.

[Effects of the Invention] As is clear from the above description, according to the first invention, there is provided an imaging lens system for projecting an electron microscope image or an electron beam carrying a diffraction pattern onto a fluorescent screen; In a display device for an electron microscope, the display device includes an imaging device for capturing an image or a diffraction pattern captured by the imaging device, and a display device for displaying the image or diffraction pattern captured by the imaging device. providing a first imaging means for imaging and a second imaging means lower in sensitivity than the first imaging means for imaging the diffraction pattern;
When the imaging lens system is set to the electron microscope image display mode, an electron microscope image is taken by the first imaging means, and when the imaging lens system is set to the diffraction pattern mode, the first imaging means takes an electron microscope image. The first image of the visible light image generated on the fluorescent screen is captured by the second image capturing means.
．． By providing a means for switching the relative position with respect to the second imaging means, the diffraction pattern can be clearly displayed as an image.

Further, according to the second aspect of the present invention, there is provided an imaging lens system for projecting an electron beam carrying an electron microscope image or a diffraction pattern onto a fluorescent screen, and an imaging lens system for imaging the image or diffraction pattern projected on the fluorescent screen. and a display device for displaying an image or a diffraction pattern captured by the imaging device, a first fluorescent screen on which the electron microscope image is projected as a fluorescent screen, and a first fluorescent screen on which the diffraction pattern is projected. A second fluorescent screen having lower sensitivity than the first fluorescent screen is provided, and when the imaging lens system is set to an electron microscope image display mode, an electron microscope image is projected onto the first fluorescent screen, and the When the image lens system is set to the diffraction pattern mode, the first... By providing means for switching the relative projection position of the electron beam with respect to the second fluorescent screen, and imaging the image or diffraction pattern projected on the first or second fluorescent screen by the imaging means. , even when using a highly sensitive television camera, the diffraction pattern can be displayed clearly.

[Brief explanation of the drawing]

FIG. 1 is an apparatus configuration diagram for explaining an embodiment of the present invention of Ml, FIG. 2 is an apparatus configuration diagram for explaining another embodiment according to the first invention, and FIG. FIG. 4 is an apparatus configuration diagram for explaining an embodiment of the present invention, and FIG. 4 is a diagram for explaining a conventional example. 1: Objective lens 2: Intermediate lens 3: Projection lens 4: Imaging lens system 5: Lens power supply 6 Lens control circuit 7, fluorescent screen 8a: Television camera for electron microscope image 8b = Television camera for diffraction pattern 9, driver circuit 10: Cathode ray tube 11: camera changeover switch 12, electron beam deflector 13: deflector control circuit 14: mirror 15: chain drive motor 16, fluorescent screen drive mechanism

Claims (2)

[Claims] (1) An imaging lens system for projecting an electron microscope image or an electron beam carrying a diffraction pattern onto a fluorescent screen, an imaging means for imaging the image or diffraction pattern projected on the fluorescent screen, and an image taken by the imaging means. In the display device for an electron microscope, the display device includes a display device for displaying an image or a diffraction pattern, the first imaging device serving as the imaging device for capturing the electron microscope image, and the first imaging device for capturing the diffraction pattern. A second imaging means having lower sensitivity than the first imaging means is provided, and when the imaging lens system is set to an electron microscope image display mode, an electron microscope image is taken by the first imaging means, and the When the image lens system is set to the diffraction pattern mode, the visible light image or its virtual image generated on the fluorescent screen is set relative to the first and second imaging means so that the second imaging means takes an image. 1. A display device for an electron microscope, comprising means for switching the target position. (2) An imaging lens system for projecting an electron microscope image or an electron beam carrying a diffraction pattern onto a fluorescent screen, an imaging means for imaging the image or diffraction pattern projected on the fluorescent screen, and imaging by the imaging means. In the display device for an electron microscope, the display device includes a display device for displaying an image or a diffraction pattern, wherein the fluorescent screen is a first fluorescent screen on which the electron microscope image is projected, and a first fluorescent screen on which the diffraction pattern is projected. A second fluorescent screen with low sensitivity is provided, and when the imaging lens system is set to an electron microscope image display mode, an electron microscope image is projected onto the first fluorescent screen, and the imaging lens system is set to a diffraction pattern mode. means for switching the relative projection position of the electron beam with respect to the first and second fluorescent screens so that a diffraction pattern is projected on the second fluorescent screen when the electron beam is set to Alternatively, a display device for an electron microscope, characterized in that the image or the diffraction pattern projected on the second fluorescent screen is imaged by the imaging means.