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:
Jul. 09, 2019
Filed:
Jun. 26, 2018
Ngk Spark Plug Co., Ltd., Nagoya-shi, Aichi, JP;
Hideto Yamada, Komaki, JP;
Haruki Yoshida, Tajimi, JP;
Kuniharu Tanaka, Komaki, JP;
Michitaka Yamada, Tajimi, JP;
Yusuke Nomura, Aichi, JP;
NGK SPARK PLUG CO., LTD., Nagoya-shi, JP;
Abstract
The spark plug includes an insulator formed of an alumina-based sintered body, and the insulator contains Si, Ba, and a rare earth element. In an analysis of the insulator by using a scanning transmission electron microscope having an electron-probe diameter of 1 nm, Si and a rare earth element are detected at a crystal grain boundary having a thickness of 15 nm or less, a content of an alkaline earth metal is less than a detection limit at the crystal grain boundary, and a diffraction spot is present in an electron diffraction pattern of a portion where Ba is detected.