Patent · US Expired

Displacement sensor

US6311572A · kind A · utility

3Cited by
3References
16Claims
0Family size

Assignee

Inventor

Key dates

Filing dateDec 8, 1998
Grant dateNov 6, 2001
Priority date
Expiry dateDec 8, 2018

Classification

  • Technology area (CPC F)Mechanical Engineering; Lighting; Heating
  • CPC primaryF16F2230/08
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A displacement sensor for acquiring the position of two parts that can be moved relative to one another is described. A sequence of markings are placed on the first part and a plurality of sensors are placed on the second part. The sensors detect each of the sequence of markings as they pass each sensor. To determine the absolute position of the two parts relative to one another without additional, special reference markings, each individual marking has a specific distance from neighboring markings and the absolute position is calculated from the phase shift of the signals of sensors as movement of the sequence of markings is detected. If the speed of movement is not known, this can be determined by means of additional secondary sensors, which are provided at a certain axial distance from the first sensors. The speed of movement of the two parts relative to one another can be calculated using the time delay of the signals from the sensors and secondary sensors. The calculated speed of movement can then be used to calculate the absolute position of the two parts relative to one another.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.