Circuit for detecting calcification in a coffee maker
US5369398A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 5, 1992 |
| Grant date | Nov 29, 1994 |
| Priority date | — |
| Expiry date | Nov 5, 2012 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA47J31/58
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The system described in the specification detects and visually indicates the presence of significant calcification in a conduit made of clear (i.e., light-transmitting) material. The present invention directly determines calcification and indicates cleaning of the clear water conduit. An infrared transmitting circuit emits an infrared pulse through the clear conduit. As long as calcification has not formed on the conduit to block the infrared pulse, a phototransistor or infrared receiving circuit receives the infrared pulse. When calcification has formed to a degree sufficient to block the emitted infrared pulse, the receiving circuit determines that calcification has occurred and provides a visual indication to a user that the conduit needs cleaning.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.