Method and apparatus for the automatic inspection of optically transmissive planar objects
US6011620A · kind A · utility
43Cited by
11References
9Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 6, 1998 |
| Grant date | Jan 4, 2000 |
| Priority date | — |
| Expiry date | Apr 6, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/896
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Inspection apparatus for determining defects in a planar light transmissive object. A diffuse light is projected through a mask toward an object under test at an inspection location. A digital video camera observes the inspection location and obtains images of the object. These images are examined and processed by a signal processor to obtain indications of various defects. The mask utilized is of a selected design having either multiple alternating narrow clear and opaque stripes, or a single narrow clear stripe straddled by opaque regions or a single narrow opaque stripe straddled by clear regions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.