JPH028357Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention temporarily stores an extremely low magnification image projected on a fluorescent screen, and while reading and displaying this, projects a high magnification image on the fluorescent screen. This invention relates to an extremely low magnification display device for an electron microscope that searches a field of view.

[Conventional technology]

In an electron microscope, when viewing an extremely low magnification image of x50, for example, the objective aperture is close to the sample, so
It is not possible to see a wide field of view without removing the movable objective aperture. Therefore, it is often the case that the movable objective aperture is removed to obtain a wide-field image before searching for a sample on the mesh. On the other hand, when observing an image at a magnification of x5000 or more, for example, it is necessary to insert an objective aperture in order to add contrast to the image. × like this
If you try to search over a wide area with a narrow field of view of 5000 times or more, you will have to search around blindly because you will not be able to grasp the relationship between the position of the sample on the mesh and the entire sample.

[Problem that the invention attempts to solve]

Therefore, when trying to search a wide field of view, remove the movable objective diaphragm to create an extremely low magnification image, decide on the desired field of view, and bring that part to the center.
I had to go through the troublesome operation of inserting the movable objective diaphragm again and observing at high magnification.

The present invention is based on the above-mentioned invention, and
The object of the present invention is to provide an extremely low-magnification image display device for an electron microscope that can project a high-magnification image on a fluorescent screen and easily recognize the relationship between the position and the entire sample when searching the field of view. .

[Means for solving problems]

For this purpose, the extremely low magnification display device for an electron microscope of the present invention stores an extremely low magnification image projected on the fluorescent screen of the electron microscope, and reads out and displays the data of the stored image. A magnification display device, comprising an image data readout means for moving a readout address of stored image data in accordance with the amount of movement of the sample, the image data readout means projecting and displaying a high magnification image on a fluorescent screen. When displaying an extremely low-magnification image on the screen, the readout address is moved so that the high-magnification image portion is displayed at the center of the display device.

[Effect]

In the extremely low magnification display device of the electron microscope of this invention,
When searching for a field of view by projecting a high-magnification image onto a fluorescent screen, an extremely low-magnification image is displayed on the display screen, and at the same time, the high-magnification image portion projected on the fluorescent screen is displayed in the center of the displayed image. Always displayed. Therefore, when the field of view is searched and the sample is moved, the extremely low magnification image on the display screen will move corresponding to the movement.

〔Example〕

Examples will be described below with reference to the drawings.

The figure is a diagram for explaining one embodiment of the present invention, in which 1 is a filament, 2 is an anode, 3 is a condenser lens, 4 is a sample stage, 5 is a sample stage drive device, 6 is an objective movable aperture device, 7 is an objective lens, 8 is an intermediate lens, 9 is a projection lens, 1
0 is a fluorescent screen, 11 is an optical lens, 12 is an imaging device, 13 is a storage device, 14 is a readout device, 15
1 indicates a display device, and 16 indicates a control device.

In the figure, when an electron beam emitted from a filament 1 is irradiated onto a sample placed on a sample stage 4 under the control of an anode 2 and a condenser lens 3, the transmitted electrons cause an objective movable aperture device 6 , an observation image of the sample is formed and projected onto a fluorescent screen 10 through an objective lens 7, an intermediate lens 8, and a projection lens 9. This projected image is taken into the imaging device 12 through the optical lens 11 under the control of the control device 16, and the image data is stored in the storage device 13. The control device 16 controls writing/reading of the storage device 13, the sample stage driving device 5, and the reading device 14 based on input instructions from the operator.
The reading device 14
determines the readout area of the storage device 13 where the center of the image projected onto the fluorescent screen 10 is the center of the display image of the display device 15 based on the position signal of the sample stage of the sample stage drive device 5, and selects that area. The read image data is sent to the display device 15 as display data.

In the present invention, in such a transmission electron microscope, the movable objective aperture in the movable objective aperture device 6 is removed and the movable objective aperture is set to an extremely low magnification, for example, ×50, and the control circuit 16 allows the portion of the sample mesh to be viewed based on input instructions from the operator. The sample stage drive device 5 is controlled so that the vicinity is located approximately at the center of the fluorescent screen 10, and the extremely low magnification image is stored in the storage device 13. Storage device 1
The image data stored in 3 is read out by the reading device 14
The image is displayed on the display device 15 through the image, and is displayed, for example, as a crosshair in the center of the image. Therefore, if the magnification is increased as it is, an enlarged image of the vicinity where the crosshairs are displayed will be displayed on the fluorescent screen 10. In order to clearly see this high-magnification image, a movable objective aperture is installed.

Therefore, a control signal is sent from the control circuit 16 to the sample stage drive device 5 based on an input instruction from the operator, and as the image on the fluorescent screen 10 moves, the readout device 14 receives the signal from the sample stage drive device 5. The read address is shifted by the position signal. That is, the amount of movement of the sample is made to correspond to the amount of movement of the image on the display device 15. Due to this, the readout address also moves by the amount that the image on the fluorescent screen 10 moves, so that the high magnification image viewed on the fluorescent screen 10 at that time corresponds to the extremely low magnification image near the crosshair at the center of the displayed image. become. Note that the extremely low magnification image may be fixed and the crosshairs of the image on the display device 15 may be moved in accordance with the amount of movement of the sample. However, from the standpoint of immediately corresponding to the actual movement of the sample, it is easier to understand if the image on the display device 15 is moved in accordance with the amount of movement of the sample.

[Effect of idea]

As is clear from the above explanation, according to the present invention, as the high-magnification image on the fluorescent screen moves, the extremely low-magnification image on the display device also moves at the same time, and the high-magnification image near the center of the display device always moves on the fluorescent screen. This makes it easier to grasp the positional relationship of the sample over a wide range using extremely low-magnification images, which was previously difficult, and it has become extremely easy to find the field of view using high-magnification images.

[Brief explanation of the drawing]

The figure is a diagram for explaining one embodiment of the present invention. 1... filament, 2... anode, 3...
Condenser lens, 4...Sample stage, 5...
...Sample stage drive device, 6...Objective movable aperture device, 7...Objective lens, 8...Intermediate lens, 9...
...Projection lens, 10... Fluorescent screen, 11... Optical lens, 12... Imaging device, 13... Storage device, 1
4... Reading device, 15... Display device, 16...
…Control device.

Claims (1)

[Scope of utility model registration request] An extremely low magnification display device for an electron microscope that stores an extremely low magnification image projected on a fluorescent screen of an electron microscope, reads out and displays the data of the stored image, and reads out the data of the stored image. The image data reading means moves a high-magnification image on a fluorescent screen and displays an extremely low-magnification image on a display screen. An extremely low magnification display device for an electron microscope, characterized in that a readout address is moved so that a portion of the image is displayed at the center of the display device.