Automatic accurate alignment system
US4672557A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 15, 1983 |
| Grant date | Jun 9, 1987 |
| Priority date | — |
| Expiry date | Nov 15, 2003 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F9/7088
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An accurate alignment system for positioning at a required position an object to be worked which has on its surface straight-line areas whose image density changes relatively abruptly at their both side edges. The system comprises holding means for holding the object to be worked, moving means for moving the holding means, camera means for taking at least a part of the image of the surface of the object held on the holding means and outputting analog signals showing the densities of x-y matrix arrayed pixels, A/D converter means for converting the analog signals output by the camera means into multi-value digital signals, operation means for performing a mathematical operation on the multi-value digital signals to produce binary digital signals, detecting means for detecting the position of at least one side edge of each straight-line area and thus the position of the straight-line area on the basis of the binary digital signals, and movement control means for actuating the moving means according to the detected position of the straight-line area and thus positioning the object held on the holding means at the required position.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.