Method of determining surface relief without making contact therewith
US4762419A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 28, 1987 |
| Grant date | Aug 9, 1988 |
| Priority date | — |
| Expiry date | Jan 28, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B11/24
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method of rapidly determining surface relief of an object or a structure without making contact therewith based on quantifying the degree to which the image of an illuminated point or small spot on the surface is defocussed. Said point or spot is illuminated by a source of electromagnetic radiation such as a laser, and the relief is determined in the form of a profile where the height of any point on the profile is represented by the ratio of the energy values of two beams derived by splitting a single beam reflected from the surface under investigation: one of the beams acting as a reference and the other of the beams being limited by the action of a diaphragm and constituting a measurement beam.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.