Through-the-lens confocal height measurement
US5543918A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 6, 1995 |
| Grant date | Aug 6, 1996 |
| Priority date | — |
| Expiry date | Jan 6, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B11/026
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Apparatus and method for measuring a change in the height of a surface or the distance between two surfaces. The invention involves converging a light beam having a beam axis and a focus onto the said surface; scanning the focus of the light beam across the surface along the beam axis using a scanning means; measuring intensity of light reflected from the surface during the scanning; determining a maximum of the light intensity; assigning to the maximum of the light intensity a position of the scanning means; repeating these steps to monitor a change in the position of the scanning means assigned to the maximum of the light intensity; and correlating such change in the position of the scanning means to a change in the height of the surface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.