Method and system for inspecting surfaces with improved light efficiency
US7564544B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 23, 2007 |
| Grant date | Jul 21, 2009 |
| Priority date | — |
| Expiry date | Jan 5, 2028 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2201/0627
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The radiation beam of discrete light source such as LEDs is shaped by a cylindrical lens and a spherical lens to form two perpendicular narrow lines to illuminate a surface. The first line is projected onto a sample surface to improve illumination efficiency, and the second line is projected onto a pupil plane of an imaging lens to improve illumination uniformity. The layout of the LED chip is optimized to match the aspect ratio of the imaging detector. Multiple LEDs at different wavelengths are combined to improve sensitivity. The full surface of the sample is inspected through the relative motion between the sample and the optics.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.