Patent · US Expired

Method and apparatus for use in measurement of the position of a line or edge of an object

US4781463A · kind A · utility

6Cited by
4References
5Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJul 16, 1986
Grant dateNov 1, 1988
Priority date—
Expiry dateJul 16, 2006

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01B11/024
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

In a digitized picture, the orientation of the line is made nearly, but not exactly, parallel to a coordinate axis. Statistical analysis of the grid points or of the lattice points forming the line, preferably the former, gives the position and orientation of the line with high accuracy. Repeated measurements after small displacements of the line allows further improvement of the accuracy. Rectangular objects can be measured by taking differences between positions of opposite edges. The method can be extended to deal with curved lines, areas or the detection and measurement of edge or line features such as angles or properties of arcs. Measurement apparatus for practicing the method is also disclosed.

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