Pattern inspection method
US4776023A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 11, 1986 |
| Grant date | Oct 4, 1988 |
| Priority date | — |
| Expiry date | Apr 11, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2207/30148
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Two kinds of image corresponding to a reference pattern and a pattern to be inspected are converted into binary images and local images cut out from the binary images are compared with each other to detect differences between the cut out images and recognize these differences as a defect. One of the main subjects of the inspecting method is to moderate excess sensitivity to the different portions to the extent of allowing non-serious actual defects. By setting don't care areas each of which consists of one pixel row neighboring on a binary boundary line in the image, and comparing the remaining portions of the images other than the don't care areas by logical processing it is possible to detect various defects without regarding the quantization error as a defect.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.