Continuous diffuse illumination method and apparatus
US5461417A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 5, 1993 |
| Grant date | Oct 24, 1995 |
| Priority date | — |
| Expiry date | Oct 5, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N23/74
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The invention pertains to a method and apparatus for providing a continuous, uniform, diffuse lighting environment for use in conjunction with electronic machine vision, or manual microscope inspection systems to inspect specular surfaces such as soldered circuits, ball bearings, reflective packaging, relective packaging, etc. The disclosed invention effectively eliminates apparent variations in surface brightness caused by the reflection of discontinuities in traditional machine vision lighting systems that typically require windows or viewing openings or orifices to allow visual access to the object being observed, thus allowing for a true observation signal from which the effect of surface geometry has been substantially removed. The object being observed is illuminated using a diffuse lighting system that comprises, in combination, an on-observation axis diffuse light source and an off-observation axis light source each controlled under separate brightness control such that a substantially uniform diffuse lighting environment is created over the entire object.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.