Position feedback enhancement over a limited repositioning area for a moveable member
US4812666A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 17, 1987 |
| Grant date | Mar 14, 1989 |
| Priority date | — |
| Expiry date | Sep 17, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05B2219/37572
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
The invention is directed to a method and apparatus for providing an auxiliary feedback of the position of a pick and place spindle during multi-image repositioning of the spindle at the inspection station, wherein the auxiliary feedback is sufficiently precise to meet lead inspection requirements which are not met by the existing encoder. The auxiliary feedback is achieved by attaching a mapping plate with very accurately spaced reference marks onto the pick and place head and by mounting a second sufficiently precise camera adjacent the inspection station so that at least one reference mark or fiducial of the mapping plate is always in the field of view of the second camera while the component is at the inspection station.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.