Patent ID: 11860090
Assignee: CORNING INCORPORATED
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 10:
11. An illumination system for providing light intensity control in a light scattering polarimetry (LSP) system for measuring stress in a chemically strengthened glass and in optical communication with an optical compensator and a digital detector with an integration time tI and comprising in order along an axis:
a light source that emits a light beam along the axis at a first intensity;
a rotatable half-wave plate;
a first polarizer having first polarization direction aligned with a second polarization direction of a second polarizer in the optical compensator;
a rotatable light diffuser that has a rotation time of tR; and
wherein the rotatable half-wave plate is set at a rotation angle such that the light beam exiting the first polarizer and incident upon the rotatable light diffuser has a second intensity less than the first intensity that causes the LSP system to have an exposure time tE for the CS glass that falls within an exposure range tR≤tE for measuring the stress in the CS glass.