High speed defect detection apparatus having defect detection circuits mounted in the camera housing
US5440648A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Nov 19, 1991 |
| Grant date | Aug 8, 1995 |
| Priority date | — |
| Expiry date | Nov 19, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2207/30124
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A defect detection system includes a video camera with defect detection circuits for detecting defects in video signals being outputted by corresponding sections of an array sensor such as a TDI CCD two-dimensional array sensor. Each defect detection circuit includes a subtraction circuit for subtracting a prior stored pixel from an incoming pixel to generate a difference. Comparators compare the difference with positive and negative limits defining an acceptable range of difference values. The prior stored pixel is updated to the succeeding pixel only when the difference value is acceptable. Memories store the defect pixels from the respective detection circuits along with X-coordinates and end of line bits. The memories are sequentially read up to their end of line bits, and the defect pixel values along with coordinates expanded to include section indicating bits are transferred from the camera to further processing facilities.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.