Scanning electron microscope
Patent 5874735 Issued on February 23, 1999. Estimated Expiration Date: 
April 14, 2017. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
April 14, 2017. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3909610 Scanning electron device Charged particle beam scanning apparatus Vibration cancellation system for scanning electron microscopes Patent #: 4948971 InventorsAssigneeApplicationNo. 840170 filed on 04/14/1997US Classes:250/310Electron probe typeExaminersPrimary: Nguyen, Hiep T.International ClassH01J 037/28Foreign Application Priority Data1996-09-24 JPAbstractA scanning electron microscope having a unit for reducing image obstacle in an scanning electron microscope which is capable of inexpensively and readily reducing image obstacle caused by any external disturbance such as alternative magnetic field and mechanical vibration in relation to the location of installation of the microscope. In order to reduce the image obstacle, the electron beam deflectors or image shift coils for forming visual image by scanning the surface of sample by using collimated electron beam, is applied superimposing with alternative current for forming alternative magnetic field of the identical frequency, identical intensity, and inverted phase of vibration to the external disturbance to cancel out the fluctuation caused by the external disturbance in the sample surface at the focal plane of the electron beam. | |
