Quantitative dispenser for a liquid
US4944922A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 14, 1989 |
| Grant date | Jul 31, 1990 |
| Priority date | — |
| Expiry date | Apr 14, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T436/118339
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A quantitative dispenser for a liquid includes a pipette having a downwardly directed nozzle which serves to pick up and deliver a predetermined quantity of a liquid and a mechanism for moving the pipette downwardly to dip the lower end of the pipette into the liquid supply. A detector is provided for detecting reflection of light which is projected downwardly to the surface of the liquid while the pipette is moved downwardly to approach the surface. A control circuit is connected to the detector to determine the stop point for the downwardly moving pipette with the aid of information received from the detector. The detector is provided with a spot type reflection sensor having a light convergent optical element having a focal point at a certain distance below the detector whereby the stop point of the downwardly moving pipette is determined so as to correspond to a point of maximum intensity of the incoming reflected light.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.