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:
Dec. 26, 1978
Filed:
Dec. 09, 1976
Matsushita Electric Works, Ltd., Osaka, JP;
Abstract
An echo-type switch using ultrasonic wave for detecting any object present in a predetermined area with reliable operation irrespective of environmental variations or foreign waves. After the wave is once radiated, the detection is suspended for a fixed time period T.sub.1 and presence or absence of reflected wave received is confirmed during another period T.sub.2. If reflected wave is received in the period T.sub.2, this period is again set for further confirming if the received wave continues and, until absence of the received wave is confirmed after several times of the waves received during the period T.sub.2, next ultrasonic wave is not radiated. Only in case the reflected wave received continues for more than two of the periods, the presence of the object to be detected in the area is indicated.