Laser-based glass thickness measurement system and method
US6496268B1 · kind B1 · utility
Assignees
Inventors
Key dates
| Filing date | Jul 18, 2000 |
| Grant date | Dec 17, 2002 |
| Priority date | — |
| Expiry date | Feb 10, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B17/02
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A laser-based technique to determine glass thickness employs a pulsed laser to induce an ultrasonic wave between the surfaces of a region of glass, causing the surfaces to move in and out at a characteristic frequency. The surface motion is monitored to determine the characteristic frequency, which is proportional to the thickness of the glass in the region of the ultrasonic wave. The pulsed laser produces a short duration pulse that illuminates a surface of the glass, which is absorbed within the glass to cause a rapid thermal expansion that generates the ultrasonic wave. The surface motion induced by the ultrasonic wave is preferably detected with a laser interferometer system, the output of which is analyzed to determine the surface motion's characteristic frequency.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.