Method of inspecting microscopic surface defects
Patent 4449818 Issued on May 22, 1984. Estimated Expiration Date: 
February 9, 2002. 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.
February 9, 2002. 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.InventorsAssigneeApplicationNo. 06/347248 filed on 02/09/1982US Classes:356/237.3, Detection of object or particle on surface250/559.08, With camera250/559.46, With camera or plural detectors348/126, Of electronic circuit chip or board348/128, Of surface (e.g., texture or smoothness, etc.)356/30, CRYSTAL OR GEM EXAMINATION356/600SURFACE ROUGHNESSExaminersPrimary: Sikes, William L.Assistant: Koren, Matthew W. Attorney, Agent or FirmInternational ClassG01N 21/88 (20060101)Foreign Application Priority Data1981-02-10 JPAbstractA method is provided for inspecting defects in the surface of an object to be inspected, wherein oblique lighting and perpendicular lighting are alternately applied to a location where a defect or a foreign substance possibly exists. Brightness detected in the location under the application of oblique lighting is evaluated as a foreign substance so as to be discriminated from a defect. Defects are classified through shape recognition of a defect pattern obtained under the application of perpendicular lighting.Other References
Field of SearchFor flaws or imperfections | |
