The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 06, 1984
Filed:
Apr. 06, 1979
Applicant:
Inventors:
Jean-Luc Leveque, Montfermeil, FR;
Gilbert Gras, Aulnay sous Bois, FR;
Assignee:
L'Oreal, Paris, FR;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01J / ;
U.S. Cl.
CPC ...
356434 ;
Abstract
Method and apparatus to measure the quantity of sebum secreted by the skin, by passing light through the specimen. The light passed through the specimen is modulated at a predetermined frequency, and only light of the same modulated frequency is measured by a receiver. The apparatus includes automatic zero calibration, and several embodiments of stabilized phototransistor circuits.