Defect inspecting apparatus using multiple color light to detect defects
US5072128A · kind A · utility
60Cited by
9References
14Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jul 20, 1990 |
| Grant date | Dec 10, 1991 |
| Priority date | — |
| Expiry date | Jul 20, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2021/8967
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A defect inspecting apparatus for discriminating one of two surfaces of a flat transparent object such as a pericle. The flat object is irradiated with a beam of light which is supplied from a light source and which is multiple-color light having predetermined wavelength ranges or white light of a broad band, scattered light from the defect is received by an optical element having wavelength selectivity, and scattered lights thereby separated with respect to the particular wavelength ranges are photoelectrically detected. The intensities of photoelectric signals thereby obtained are compared with each other.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.