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:
Nov. 18, 2025
Filed:
Jul. 08, 2024
Oki Electric Industry Co., Ltd., Tokyo, JP;
Hideharu Kuwabara, Tokyo, JP;
Oki Electric Industry Co., Ltd., Tokyo, JP;
Abstract
A drum unit including a photosensitive drum may satisfy an equation of ΔV≤0.489×Q−0.014 (%), where ΔV={1−(V1/V0)}×100 (%). V0 is a surface potential of the photosensitive drum that is measured under a first condition that exposes a surface of the photosensitive drum at an exposure amount Q in a range of 0.13 to 0.34 μJ/cm2 while the photosensitive drum is rotated at a circumferential speed of 151 mm/s with the surface of the photosensitive drum being charged with a voltage having 1000 volts and a first polarity. V1 is a surface potential of the photosensitive drum that is measured under the first condition again after the surface of the photosensitive drum is applied for 406 seconds with a voltage having 2850 volts and a second polarity while the photosensitive drum is rotated at the circumferential speed of 73 mm/s.