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. 07, 2025
Filed:
Mar. 17, 2021
Powdertech Co.,ltd., Kashiwa, JP;
Makoto Ishikawa, Kashiwa, JP;
Tetsuya Uemura, Kashiwa, JP;
POWDERTECH CO., LTD., Kashiwa, JP;
Abstract
The present invention relates to a ferrite particle containing a crystal phase component containing a perovskite crystal represented by a compositional formula: RZrO(provided that R represents an alkaline earth metal element), having a surface roughness Rz of 0.8 μm or more and 3.5 μm or less, and having a standard deviation Rzσ of the surface roughness Rz falling in a range represented by the following formula 0.15×Rz≤Rzσ≤0.60×Rz. The ferrite particle can be used as an electrophotographic developer carrier core material. In addition, an electrophotographic developer carrier and an electrophotographic developer can be obtained.