Machine-vision ring-reflector illumination system and method
US6238060A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 7, 2000 |
| Grant date | May 29, 2001 |
| Priority date | — |
| Expiry date | Feb 7, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R31/308
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An illumination method and apparatus for machine-vision systems, including a ring-light source (e.g., LEDs arranged in one or more circular rows), and a reflective-ring focusing element. The illumination source exhibits multidirectional ring-illumination properties which are useful for illumination of small components (which are being inspected or measured) without unwanted shadows. One embodiment provides a dark field illumination system. One embodiment of the present invention uses a strobed (or pulsed) power supply to drive the LEDs. Yet another embodiment of the present invention uses a xenon strobe ring-light source and a backplane slit in place of the row of LEDs. In one such xenon strobe embodiment, a color filter is also placed in series with the light path in order to obtain a monochromatic light. While xenon flashtube light sources tend to exhibit a five per cent (5%) flash-to-flash variation in intensity which makes accurate measurements of certain characteristics difficult, they are useful in certain cases where intense white, or especially ultraviolet, light is desired. Strobed LEDs provide very little flash-to-flash variation in intensity. The compact ring-light gener…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.