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:
Aug. 02, 1994
Filed:
Mar. 11, 1993
Hiroshi Yamaguchi, Fujisawa, JP;
Minori Noguchi, Yokohama, JP;
Makiko Kohno, Kawasaki, JP;
Toshihiko Nakata, Hiratsuka, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A method for detecting a photoacoustic signal includes the steps of modulating the intensity of light obtained from a light source at a predetermined modulation frequency, exciting a specimen by directing the intensity-modulated light onto the specimen, thereby generating a photoacoustic effect in the specimen, detecting the photoacoustic effect generated in the specimen and producing a detection signal indicative of the detected photoacoustic effect, and extracting information about the surface and interior of the specimen from the detection signal, wherein the intensity-modulated light is emitted from an aperture of a near-field optical scanning microscope used in directing the intensity-modulated light onto the specimen while a distance between the aperture of the near-field optical scanning microscope and the surface of the specimen is maintained constant irrespective of the photoacoustic effect generated in the specimen.