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.

Date of Patent:
Sep. 10, 1996

Filed:

Sep. 02, 1994
Applicant:
Inventors:

Nahoko Hisata, Hachiouji, JP;

Tomio Endo, Hachiouji, JP;

Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01N / ;
U.S. Cl.
CPC ...
73606 ; 73611 ; 73613 ; 73620 ; 73631 ; 73634 ;
Abstract

Ultrasonic wave converged by an acoustic lens is made incident onto a sample and wave reflected from the sample is received and converted into received electric signal by a transducer. A part of this electric signal is picked up by a gate section and the signal thus picked up is applied to an attenuator where it is converted into a variable ratio of input to output. The strength of the signal thus gain-adjusted is compared with a threshold value by a comparator. Responsive to the comparison result thus obtained, the gain of the attenuator is adjusted to make the input/output ratio of the attenuator a desired value. A computer calculates the focus position of the acoustic lens from a gain curve of the attenuator changing when the acoustic lens is moved from a position, remote enough from its focus position, to the sample. Drivel signal responsive to the result thus calculated is applied to a Z-drive control section. As the result, the distance of the acoustic lens relative to the sample is adjusted to bring the acoustic lens to the focus position.


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