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:
Mar. 21, 2000
Filed:
Jan. 23, 1998
James R Cherry, Windham, NH (US);
Abel Raynus, Malden, MA (US);
Armatron International, Inc., Melrose, MA (US);
Abstract
An obstacle detection system includes an acoustic piezoelectric transducer capable of radiating and receiving ultrasonic energy. During a BIT transmission period, a controller briefly enables a transmit circuit which provides an AC transmit signal that induces oscillatory motion in a piezoelectric element within the transducer. At the end of BIT transmission period the controller disables the transmit circuit and begins BIT receive period operation. Once the transmit circuit is disabled, the oscillatory motion of the piezoelectric element begins to dampen out causing the transducer to generate and provide a vibration generated signal which is input to a receive circuit which detects the presence of the vibration generated signal and provides received status signal indicative thereof. If the vibration generated signal is not present during this period, a system fault exists and the controller notifies the system user.