Method of orienting objects using optically smeared images
US4097750A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 18, 1977 |
| Grant date | Jun 27, 1978 |
| Priority date | — |
| Expiry date | Mar 18, 1997 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/682
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
The orientation of an industrial part such as a microcircuit chip having a pattern of dominant parallel lines is determined by an optical method. An image of the parallel line pattern is smeared or defocused in a known direction such that the resultant smeared image of the part reveals the lines in sharp detail when they are parallel to the known direction of smearing and are blurred if the lines are angularly displaced from the known direction. By rotating the image of the pattern relative to the smear direction and determining the angle at which maximum sharpness occurs, the angular orientation is determined. By correlating the pattern of sharp lines of the smeared image with a similar reference pattern of known position, the positional orientation of the part is also determined. When two angularly displaced families of parallel lines are present on the object, positional coordinates relative to two axes are determined.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.