JPH0610610Y2 - electronic microscope - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to improvement of an exhaust system of an electron microscope.

[Prior Art] In an exhaust system such as an electron microscope, when returning an exhausted chamber such as a lens barrel to atmospheric pressure, silica gel (Si
li-cage) and a mesh filter are placed to prevent the introduction of moisture and dust in the atmosphere.

[Problems to be solved by the invention] By the way, since the above-mentioned silica gel is porous and has a large surface area even with a small amount and is highly adsorbable, if it breaks when introduced into the atmosphere due to its powdery or granular form, it may absorb moisture and water. Dust-containing powder, etc. will flow in and pollute the exhaust chamber. In order to prevent this, it is possible to use a fine mesh filter together, but such a filter causes clogging immediately and must be frequently cleaned, and the work is complicated.

The present invention has been made in view of the above points, and an object thereof is to provide a device that prevents the inflow of powdery silica gel containing water and dust when returning the inside of an exhaust chamber such as an electron microscope to atmospheric pressure. There is.

[Means for Solving the Problems] The present invention for achieving the above-mentioned object provides an exhausted chamber, an exhaust pump for exhausting the exhausted chamber to a vacuum, and an atmosphere introduction path of the exhausted chamber. In an electron microscope provided with a silica gel container provided, a high-voltage dust suction means is provided in the atmosphere introduction path on the exhausted chamber side of the silica gel container, and the high-voltage dust suction means forms a zigzag air introduction path. As described above, the plurality of dust absorption electrodes are alternately arranged at different positions.

[Embodiment] Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic configuration diagram of an embodiment of the present invention, and FIG. 2 is a diagram for explaining a high voltage adsorption cylinder described later. In the figure, 1
Is an exhausted chamber such as a lens barrel, the exhausted chamber 1 is connected to an exhaust pump 3 via an exhaust pipe 2, and an exhaust valve 4 is disposed in the exhaust pipe 2. Reference numeral 5 is a leak pipe connected to the exhaust pipe 2, and the leak pipe 5 is provided with a leak valve 6. 7 is a dust collecting electrode 7a, 7b ... 7 as shown in FIG.
e is a high-voltage dust collecting cylinder. Reference numeral 8 is a silica gel container provided on the atmosphere side of the high-voltage dust suction cylinder 7. Reference numeral 9 is an insulating member for electrically insulating and connecting the leak pipe 5 and the high-voltage dust suction cylinder 7, 10 is a protective container, 11 is a leak switch, 12 is a high-voltage power supply, and 13 is a high-voltage introduction terminal. .

With such a configuration, when introducing air into the exhaust chamber 1, the exhaust valve 4 is closed and the leak valve 6 is closed.
To open. When the leak valve 6 is opened, the leak switch 11 is turned on in conjunction with this operation, and the high-voltage dust collecting cylinder 7 receives, for example, 20
KV is applied. Here, the atmosphere is introduced into the exhausted chamber 1 through the leak pipe 5, but most of the moisture and dust in the atmosphere are first adsorbed by the silica gel container 8 and then only a very small amount of water and dust passing therethrough. Of water and dust are adsorbed when passing between the dust-collecting electrodes of the high-voltage dust-collecting cylinder 7. Further, in such an apparatus, even if the silica gel in the silica gel container 8 is broken when introduced into the atmosphere, the powdery silica gel containing water and dust passes between the dust collecting electrodes of the high voltage dust collecting cylinder 7 described above. Since it is adsorbed at that time, it does not pollute the interior of the exhaust chamber 1, and therefore does not adhere to the structure inside the exhaust chamber 1.
Further, in the apparatus configured as described above, since a fine mesh filter is not used as in the prior art, it is not necessary to perform work such as cleaning the filter.

[Advantage of the Invention] According to the present invention, since the high-voltage dust collecting means is provided with the plurality of dust collecting electrodes which are alternately arranged at different positions so as to form the zigzag-shaped air introduction path, Even if the relatively large powdery silica gel containing water and dust is not adsorbed by the first-stage dust collection electrode on the air introduction side, it is adsorbed by the second-stage dust collection electrode, and the silica gel is evacuated. It is possible to reliably prevent inflow to the room,
It is possible to prevent pollution in the exhaust chamber.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of the present invention, and FIG. 2 is a diagram for explaining a high voltage dust collecting cylinder. 1: Exhaust chamber, 2: Exhaust pipe, 3: Exhaust pump, 4: Exhaust valve, 5: Leak pipe, 6: Leak valve, 7: High-voltage dust suction tube, 8: Silica gel container, 9: Insulation member, 10: Protective container, 11: Leak switch, 12: High voltage power supply, 1
3: High voltage introduction terminal.

Claims (1)

[Scope of utility model registration request] 1. An electron microscope comprising: an evacuated chamber; an exhaust pump for evacuating the evacuated chamber to a vacuum; and a silica gel container provided in an air introduction path of the evacuated chamber. The atmosphere introduction path closer to the exhausted chamber is provided with a high-voltage dust suction means, and the high-voltage dust suction means are alternately arranged at different positions so that a zigzag atmosphere introduction path is formed. An electron microscope equipped with a dust collection electrode.