Valve head, parallel error automatic compensating device and electron microscope

Abstract

The invention provides a valve head, a parallel error automatic compensating device and an electron microscope. The valve head comprises a movable member bearer, a movable member which is accommodated in the mounting hole of the movable member bearer, and movable member supporting device which supports the movable member for floating relative to a fixed member in a direction which is opposite to the fixed member. The movable member has a second sealing plane which matches a first sealing plane of the fixed member, and a circumferential surface which is connected with the second sealing plane and is opposite to the fixed member. The circumferential surface is partially a spherical surface at least in the axial direction of the movable member. The mounting hole has a cylindrical surface which matches the spherical surface. When the movable member floats in a certain floating angle, the spherical surface is always in circumferential linear contact with the cylindrical surface of the mounting hole. According to the valve head provided by the invention, a parallelism error between two planes in each direction can be eliminated, thereby realizing sufficient fitting of the two sealing planes. The parallel error automatic compensating device with the valve head, and the electron microscope with the compensating device can ensure sealing repetition.

Description

technical field [0001] The invention relates to the technical field of automatic error compensation, in particular to a valve head, a parallel error automatic compensation device with the valve head and an electron microscope. Background technique [0002] The scanning electron microscope is an electron optical instrument that uses a focused electron beam to scan the sample surface line by line to obtain a secondary electron image or a backscattered electron image. The path of the electron beam emitted from the electron gun to the sample surface is called the optical path. The middle is called the optical axis. The electron beam is emitted by the electron gun, passes through the lens barrel and finally reaches the sample in the sample chamber. In the actual use process, the replacement frequency of the sample is relatively high, and the field emission electron gun belongs to the electron gun of the long-term working system. The current of the electron gun Once loaded, it is ...

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Problems solved by technology

[0003] Therefore, the technical problem to be solved by the present invention is to overcome the defect that the sealing plane of the valve head in the prior art cannot float, and it is difficult to keep parallel with the sealing plane of the fixed part that cooperates with it, so as to provide a sealing plane that can automatically float. valve head

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