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:
Feb. 10, 1998
Filed:
Jan. 31, 1997
Applicant:
Inventors:
Eiji Ozeki, Nagoya, JP;
Kenji Kawakami, Nagoya, JP;
Assignee:
NGK Spark Plug Co., Ltd., Aichi-Ken, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03H / ;
U.S. Cl.
CPC ...
333189 ; 333188 ; 310348 ;
Abstract
A ladder-type electric filter device having rubber plates each provided on one or both sides of each of the piezoelectric resonators so as to be brought into resilient contact with the surface of the associated piezoelectric resonator. The rubber plates are shaped so as to not be brought into contact with the respective corner edges of the respective piezoelectric resonators which generate extensive contour vibrations. Thus, the contour vibrations are not suppressed, the insertion loss can be reduced, and a mechanical quality factor Q can be substantially decreased, thereby improving group delay frequency characteristics.