Apparatus intended for classifying the quantity of a fatty product found on the skin surface
US4392498A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 8, 1981 |
| Grant date | Jul 12, 1983 |
| Priority date | — |
| Expiry date | Apr 8, 2001 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02A90/10
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Measurements of the greasiness of skin are made by applying a plate against a region of skin to be studied and then inserting the plate in a recess of the casing, in register with a photodiode and a phototransistor. A series of n (in this case 5) indicator lamps is connected to a set of n-1 (in this case 4) comparators each comparing a respective voltage threshold level with the voltage delivered by the photoresistor, so that the voltage of the transistor, and hence the greasiness of the deposit on the plate through which luminous flux from the photodiode to the phototransistor passes by reflection from the upper side of the plate, can be determined by observing which lamps are illuminated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.