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. 12, 2001
Filed:
Mar. 30, 1999
J. David Zook, Golden Valley, MN (US);
William R. Herb, Minneapolis, MN (US);
David W. Burns, San Jose, CA (US);
Honeywell International Inc., Morristown, NJ (US);
Abstract
A sensor device for detecting vibration, including a light source for providing a laser light, a first optical fiber connected to the source for transmitting the laser light, an oscillator positioned to receive the transmitted laser light and adapted to reflect the light as a frequency modulated light; a second optical fiber positioned to capture the frequency modulated light to transmit the frequency modulated light; and a frequency modulated discriminator for receiving the frequency modulated light from the second optical fiber and producing a signal responsive of vibration of the oscillator. In a preferred embodiment, the frequency modulated discriminator further includes a frequency meter for determining the average number of cycles per unit time to provide a second signal responsive of the temperature of the oscillator. The optical fibers may be a pair of different fibers positioned for transmitting the laser light and the frequency modulated light respectively, or the same fiber positioned for transmitting both the laser light and the frequency modulated light. In this latter embodiment, the device further includes a beam splitter to direct the frequency modulated light to the discriminator. The preferred oscillator includes a microchip having a microbeam mounted on a thin silicon cantilever such that deflection of the beam perpendicular to the plane of the microchip changes the tension in the microbeam to change its resonant frequency. Also preferred is a microbeam including a thin metal deposit to create a bimorph structure.