Data processing system and method for a surface inspection apparatus
US5602401A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 10, 1995 |
| Grant date | Feb 11, 1997 |
| Priority date | — |
| Expiry date | Jul 10, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/94
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A system for processing particle size and position data for a surface under inspection, the system including an air spindle for rotating and a translation stage for translating the surface with respect to a beam of radiation used to detect particles on the surface; a rotational encoder for dividing the surface into a number N of angular vectors; a counter of counting the number of revolutions of the surface; a processor for collecting particle size and position data at each angular vector during each revolution; first and second FIFO memories having at least N address spaces, each address space allocated for a specific angular vector; and a routine for writing the collected particle size and position data to the first memory and for reading particle size and position data from the second memory and switching memories every M revolutions. The FIFO memories are programmed to store only the greater of stored size data and incoming size data.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.