Surface displacement detection and adjustment system

US5672885A · kind A · utility

Assignee

• QC Optics, Inc. · US

Inventors

• Nicholas Allen · Bedford, US
• Abdu Broudour · Newton, US
• Sergey V. Broude · Newton, US
• Eric Chase · Andover, US
• Carl Johnson · Pilot Point, US
• Pascal Miller · North Chelmsford, US
• Jay Ormsby · Salem, US
• Arkady Savikovsky · Burlington, US

Key dates

• Filing date: Jul 10, 1995
• Grant date: Sep 30, 1997
• Expiry date: Jul 10, 2015

Classification

• Technology area (CPC G): Physics
• CPC primary: G01B11/306
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A 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.