Stress measurement device for strengthened glass, stress measuring method for strengthened glass, manufacturing method of strengthened glass, and strengthened glass
US11274981B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Mar 25, 2019 |
| Grant date | Mar 15, 2022 |
| Priority date | — |
| Expiry date | Feb 19, 2040 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/21
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A stress measurement device for strengthened glass includes a polarization phase difference variable member configured to vary a polarization phase difference of a laser light by one wavelength of the laser light or more; an imaging element configured to image a plurality of times at a predetermined time interval a scattered light emitted according to the laser light with the varied polarization phase difference entering the strengthened glass, and obtain a plurality of images; and an arithmetic unit configured to measure a periodic change in luminance of the scattered light using the plurality of images, calculate a change in a phase of the change in luminance, and calculate a stress distribution in a depth direction from a surface of the strengthened glass based on the change in the phase.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.