Surface displacement detection and adjustment system
Patent 5672885 Issued on September 30, 1997. Estimated Expiration Date: 
July 10, 2015. 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.
July 10, 2015. 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 ReferencesMethod and apparatus for inspecting specimen surface Surface pit detection system and method Method of and device for recording information, record carrier, and device for reading the recorded information Disk surface inspection method and apparatus therefor Patent #: 4954723 Inventors
AssigneeApplicationNo. 499822 filed on 07/10/1995US Classes:250/559.3, With alignment detection250/559.04, Evaluation by regions, zones, or pixels250/559.39, With comparison to reference or standard250/559.45, With defect discrimination circuitry356/237.2, Surface condition356/622Position of detected arrangement relative to projected beamExaminersPrimary: Allen, Stephone B.Attorney, Agent or FirmInternational ClassG01N 021/89AbstractA surface displacement detection system including a detector for detecting displacement of a surface in a direction normal to the surface as the surface revolves; an encoder which divides the surface into N sectors; a signal processor responsive to the detector for calculating the amount of displacement of the surface in each sector of the surface as it revolves; a displacement value look-up table; and a routine for writing to the table a displacement value for each sector once per M revolutions, and an adjustment system including a focussing actuating element, a routine to read displacement value look-up table, a routine to for updating the position of the focussing actuating element for every sector, according to the displacement values stored in the look-up table. | |
