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:
Aug. 03, 2021
Filed:
Mar. 06, 2020
Keiji Makabe, Shizuoka, JP;
Tsuneyasu Nagatomo, Shizuoka, JP;
Kohsuke Satoh, Shizuoka, JP;
Daichi Hisakuni, Shizuoka, JP;
Kousuke Suzuki, Shizuoka, JP;
Shintaro Akiyama, Shizuoka, JP;
Keiji Makabe, Shizuoka, JP;
Tsuneyasu Nagatomo, Shizuoka, JP;
Kohsuke Satoh, Shizuoka, JP;
Daichi Hisakuni, Shizuoka, JP;
Kousuke Suzuki, Shizuoka, JP;
Shintaro Akiyama, Shizuoka, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
An image forming apparatus is provided that includes: an image bearer; a charger; an irradiator; a developing device containing a toner; and a transfer device. The image bearer has a Martens hardness of from 185 to 250 N/m. The toner satisfies a relation 0.13≤X/Dn≤0.16, where X [μm] represents an average value of an amount of deformation of the toner by micro-indentation at when a load reaches 3.00×10N at a loading rate of 3.0×10N/sec under an environment of 32 degrees C. and 40% RH, and Dn [μm] represents a number average particle diameter of the toner. The toner contains an external additive comprising silica particles and particles composed mainly of strontium titanate. The particles composed mainly of strontium titanate further contain a third element M selected from the group consisting of La, Mg, Ca, Sn, and Si.