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:
Oct. 06, 2026
Filed:
Apr. 19, 2022
Dowa Electronics Materials Co., Ltd., Tokyo, JP;
Dowa Ip Creation Co., Ltd., Okayama, JP;
Shinya Sasaki, Okayama, JP;
DOWA ELECTRONICS MATERIALS CO., LTD., Tokyo, JP;
DOWA IP CREATION CO., LTD., Okayama, JP;
Abstract
A carrier core material includes ferrite particles, contains CaSiO3, and has a true density at least equal to 3.5 g/cm3 and at most equal to 4.5 g/cm3. A particle strength index calculated from formula (1) is preferably at most equal to 1.5% by volume. (1): Particle strength index=V2−V1 (In the formula, V1: cumulative value (% by volume) of particle size 22 μm or less in cumulative particle size distribution of carrier core material before crushing test, and V2: cumulative value (% by volume) of particle size 22 μm or less in cumulative particle size distribution of carrier core material after crushing test) Crushing test conditions: 30 g of carrier core material crushed using a sample mill for 60 seconds at a rotational speed of 14000 rpm.