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:
Dec. 23, 1997
Filed:
Jul. 24, 1995
Isao Endo, Hachioji, JP;
Toru Komatsu, Hachioji, JP;
Yotaro Sato, Hachioji, JP;
Hiroyuki Nomori, Hachioji, JP;
Kunio Shigeta, Hachioji, JP;
Masahiro Onodera, Hachioji, JP;
Konica Corporation, Tokyo, JP;
Abstract
A development apparatus for developing a latent image formed on an image forming body with a developer so as to obtain a toner image. A developer conveyance unit conveys the developer, including a toner, to a development zone, between the developer conveyance unit and the image forming body, from an upstream side of the development zone in a conveyance direction to a downstream side thereof. A plate member having an electrode portion is positioned at the upstream side of the development zone, wherein a downstream end portion of the plate member is positioned in contact with the development zone. A power supply unit applies a first voltage, including a DC component and an AC component, to the developer conveyance unit so that an electric field is generated at the development zone. The power supply unit applies a second voltage, including a DC component, to the electrode portion of the plate member, and the plate member controls the electric field with the second voltage. The development apparatus satisfies: V.sub.AC >.vertline.V.sub.DEN .vertline.-.vertline.V.sub.DC .vertline. when an amplitude of the AC component of the first voltage is defined as V.sub.AC (volts), the DC component of the first voltage is defined as V.sub.DC (volts), and the DC component of the second voltage is defined as V.sub.DEN (volts). The development apparatus satisfies: 10.multidot..vertline.Qt.vertline..multidot.d.sub.t .multidot.D.sub.1 >V.sub.AC >5.multidot..vertline.Qt.vertline..multidot.d.sub.t .multidot.D.sub.2 when a closest distance from the developer conveyance unit to the image forming body is defined as D.sub.1 (mm), a closest distance from the developer conveyance unit to the electrode portion is defined as D.sub.2 (mm), an average charge-to-mass of the toner is defined as Qt (.mu.C/g), and an average particle size of the toner is defined as dt (.mu.m).