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:
Jun. 27, 1989
Filed:
Jan. 19, 1988
Yokogawa Electric Corporation, Tokyo, JP;
Abstract
A vibratory transducer comprising a vibratory beam composed of an n-type layer and having at least one end fixed. The vibratory beam is formed by selectively etching an n-type layer formed by adding impurities locally to a single silicon crystal. The vibratory transducer also comprises means for vibrating the vibratory beam and means for detecting vibration of the vibratory beam. The vibratory transducer measures pressure, temperature, density, etc, by detecting change in the resonant frequency of the vibratory beam. The vibratory beam can be finely etched irrespective of the density of the impurities therein by forming the vibratory beam in an alkaline aqueous solution while applying a negative DC or pulsed voltage to a p-type layer and a positive DC or pulsed voltage to an n-type layer. The vibrating and detecting means for the vibratory beam can be easily provided by making a diode and a transistor including the vibratory beam in the transducer.