System for printed circuit board defect detection
US4578810A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 8, 1983 |
| Grant date | Mar 25, 1986 |
| Priority date | — |
| Expiry date | Aug 8, 2003 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2207/30141
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An automatic printed wiring board (PWB) defect detector is described. The detector comprises an array of optical sensors for optically inspecting a printed wire circuit. The array forms a binary image pattern of the PWB which is tested for compliance with logical rules of correctly printed PWB's regarding unterminated conductors; minimum specified lined width; line spacing width; presence of insulators on conductors and vice versa; and maximum line width. The detector comprises a plurality of CCD arrays arranged to form a series of pixels consisting of electronic binary signals corresponding to the instantaneous image viewed by each element in the CCD array. These pixels are formed in an image data stream of sequential pixels line-by-line of the CCD array, i.e., pixel sequential line sequential digital image data. The digital pixel data is formatted in an "N" by "N" bit matrix of points in proper image orientation. All such points are available for sampling. Each pixel progressively occupies each point in the matrix in proper orientation to its neighbors. Each pixel passes through each "N" bit point of the matrix thus forming a moving "window" of "N" by " N" bits in size of a porti…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.