Sharp Kabushiki Kaisha Corporation

Keiji Yasuda

Atsushi Inoue

Tadashi Iwamatsu

Kazuhiro Matsuyama

Takayuki Yamanaka

Nobuyuki Azuma

Hiroshi Tatsumi

Masanori Yamada

Toshihiko Takaya

Katsumi Adachi

Taisuke Kamimura

Tetsunori Mitsuoka

Yukihito Nishio

Kazuhiko Furukawa

A blade is pressed against a developing roller for regulating the amount of toner which is deposited on a surface of the developing roller. The blade is formed with a slant face at its tip end, to which the toner is transported along a direction of rotation of the developing roller. An angle of aperture .theta. at a toner inlet portion defined by the developing roller and the slant face is set at 12.5.degree. or more, the angle of aperture counting in an angle .psi. of the slant face, elastic deformation and radius (R) of the developing roller, and an angle .alpha. related to a nip width w on which the blade contacts with the developing roller. Such an angle of aperture .theta. provides a great allowance for a free length l of the blade, thereby permitting the blade to maintain a constant toner mass for forming a uniform toner layer.

Developing apparatus using one-component toner

The object of the invention is to certainly remove and certainly recover the charged toner remaining on a developing roller after development. A single component toner which is delivered to the developing roller via a toner-supplying roller is made into a relatively thin layer of a predetermined thickness with a charging plate and is frictionally charged with a given quantity of electric charge. Subsequently, the toner is adhered on a photoreceptor drum along by the electrostatic latent image to develop an image at the developing region at which the developing roller comes into contact with the photoreceptor drum. After development, the electric charge of the toner layer on the developing roller is removed with an electric-charge-removing sheet. The toner after development is recovered into a toner hopper via the toner-supplying roller. In rotation direction of the developing roller, the relation of the width Wt of the toner layer to the width Wc of the electric-charge-removing sheet is established so as to be Wc.gtoreq.Wt. Thus, the electric charge of the toner layer on the developing roller is certainly removed.

Developing apparatus having means for removing electric charge of toner

Toner attracted onto an electronic latent image formed on the surface of a photosensitive drum is transferred onto a transfer sheet, using a transfer bias from a transfer bias roller. A transfer belt for transporting the transfer sheet includes an anisotropic conductive layer composed of conductive members and an insulating member. The anisotropic conductive layer is conductive only in the thickness direction thereof and insulating in the other directions. This makes it possible to offer a transfer device that can prevent a transfer electric field from spreading and toner from being projected, and that boasts excellent sheet transportability.

Transfer device with an anisotropin conductive layer

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Nishinomiya, Japan

Keiji Yasuda