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:
Jun. 26, 2001
Filed:
Aug. 04, 2000
Eiichi Kido, Yamatokoriyama, JP;
Hiroshi Ishii, Osaka, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
When electrostatic capacity C,[F/m,] per unit area of an elastic member when an ac voltage of an arbitrary frequency f [Hz] is applied is given by C,=C,·(f/1000),, using electrostatic capacity C,[F/m,] per unit area when an ac voltage of 1 kHz is applied and using a rate of change a, electrostatic capacity C of a micro-region of an elastic member per unit area is substituted with C,per each frequency component which forms a voltage of a rectangular pulse equivalent to a voltage applied to a charge system. Then, the elastic member is made of such a material that the rate of change a falls within a range of a ≦−0.1544·log(C,/C,) +0.0307, and further, within a range of a ≦−0.146·log(C,/C,) −0.0688. Consequently, it is possible to provide a contact charging device which incorporates conditions for improving charge uniformity, which are obtained by taking frequency characteristics of the electrostatic capacity into consideration.