Apparatus for filtering a laser beam in an analytical instrument
US5719667A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 30, 1996 |
| Grant date | Feb 17, 1998 |
| Priority date | — |
| Expiry date | Jul 30, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2201/0633
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An optical illuminator assembly for an analytical instrument, such as a clinical hematology or a flow cytometer instrument, including a laser diode having a diverging laser beam output, a collimating lens to collimate the diverging laser beam, a spatial filter operating on the collimated laser beam to spatially filter the beam, and a focussing lens to focus the spatially filtered beam into a flow cell containing particles suspended in a moving stream. A beam shaping aperture is preferably inserted between the spatial filter and the focussing lens to shape the laser beam. The spatial filter preferably includes an objective lens, a collimating lens, and a filter aperture interposed between the objective and imaging lenses. The filter aperture is preferably rectangular, having a height to width ratio in the range of 1:2 to 1:3 such that each dimension is on the order of tens of micrometers. The beam shaping aperture is preferably a rectangular aperture having a height to width ratio in a range of from 3:1 to 5:1 such that each dimension is on the order of hundreds of micrometers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.