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.

Date of Patent:
May. 21, 2019

Filed:

Dec. 19, 2017
Applicants:

Keiji Makabe, Shizuoka, JP;

Tsuneyasu Nagatomo, Shizuoka, JP;

Kohsuke Satoh, Shizuoka, JP;

Kenji Yoneda, Osaka, JP;

Inventors:

Keiji Makabe, Shizuoka, JP;

Tsuneyasu Nagatomo, Shizuoka, JP;

Kohsuke Satoh, Shizuoka, JP;

Kenji Yoneda, Osaka, JP;

Assignee:

Ricoh Company, Ltd., Tokyo, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G03G 9/08 (2006.01); G03G 9/097 (2006.01); G03G 9/09 (2006.01); G03G 9/087 (2006.01); G03G 15/08 (2006.01);
U.S. Cl.
CPC ...
G03G 9/0825 (2013.01); G03G 9/0819 (2013.01); G03G 9/0827 (2013.01); G03G 9/08711 (2013.01); G03G 9/08755 (2013.01); G03G 9/0904 (2013.01); G03G 9/097 (2013.01); G03G 9/09716 (2013.01); G03G 9/09725 (2013.01); G03G 15/0865 (2013.01);
Abstract

A toner is provided. The toner includes toner particles each including a mother particle and external additive particles covering the mother particle. In a SEM image of the toner, toner particles having a ratio Sd/St of from 5% to 50% are present at a frequency of 15% or more, where Sd representing an area of a largest recessed portion D of each toner particle and St representing whole area of the toner particle, Sd and St determined from the SEM image magnified and binarized to discriminate recessed portions and projected portions of the toner particle from each other. An external additive coverage rate Ca at the largest recessed portion D is from 30% to 100%.


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