Submicron diameter particle detection utilizing high density array
US5282151A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 28, 1991 |
| Grant date | Jan 25, 1994 |
| Priority date | — |
| Expiry date | Feb 28, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2021/6467
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Submicron diameter particle detection utilizing a high density array is disclosed. The high density array, such as a charge coupled device, is utilized to detect light scattered at a sensing region by particles illuminated by a light source, such as a laser source. Charge storage is utilized to buffer each data frame transferred from the high density array and the multiple serial outputs are processed by parallel processing that includes threshold detection and analog-to-digital converting. A micro-computer and associated digital storage receives the digital outputs and provides outputs indicative of submicron particle sizing. Further improvement in minimum detectable particle sizing of particles carried by a fluid is realized by use of beam shaping optics to shape the illumination beam passed through the sensing region to form either an astigmatic (highly elliptical) beam cross-section, with the fluid being directed towards the imaging system orthogonal to the object plane, or a circular beam cross-section with the flow directed parallel to object plane, and with the focal point of the beam being substantially centrally positioned within the sensing region in either case.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.