Canon Kabushiki Kaisha

Manami Sekiguchi

Katsuhiro Sakaizawa

Makoto Nonomura

Yukihiro Ozeki

Yukihiro Ohzeki

A developing roller for electrophotography is disclosed which is composed of a conductive mandrel, a charge-providing layer having a charge-providing performance to a non-magnetic one-component toner, formed at the surface of the roller, a base layer having an elasticity, formed at a position nearer to the mandrel of the roller than the charge-providing layer and an elastic intermediate layer formed at a position between the base layer and the charge-providing layer. The elastic intermediate layer is formed of a composition having a contact angle to water which is smaller than that of a composition for forming the base layer. Also, disclosed are a developing apparatus, an apparatus unit and an image forming apparatus using the developing roller.

Developing roller for electrophotography, developing apparatus, apparatus unit and image forming apparatus

Image forming apparatus featuring a conductive developing roller including a mandrel, an elastic layer, an intermediate layer, and a charge-providing layer formed thereon

The present invention provides an image forming apparatus, which has an image bearing body for bearing a toner image, transferring device for transferring a toner image on the image bearing body to a transferring material, a charging member for charging the image bearing body, having a residual toner after the transfer on a surface thereof by being brought into contact therewith, electrostatic image forming device for forming an electrostatic image on the image bearing body charged by the charging member, developing device for collecting the residual toner on the image bearing body while developing the electrostatic image on the image bearing body by using a toner charged in the same polarity as a charging polarity generated by the charging member, control device for controlling a voltage to be applied to the charging member, and a cleaning sequence for performing a cleaning of the charging member by applying a voltage not higher than a discharge threshold and equal to the polarity of the toner after a discharge voltage reverse to the polarity of the toner is applied onto the charging member, when an image formation is not effected.

Image forming apparatus with cleaning sequence of contact charging members

In accordance with the present invention, an image forming apparatus includes an image bearing member for bearing an electrostatic latent image, a charging device for charging the surface of the image bearing member, an electrostatic latent image forming device for forming the electrostatic latent image on the surface of the image bearing member charged by the charging device, a developing device, which includes a developer bearing member for bearing a single component developer, for performing development by bringing the single component developer into contact with the electrostatic latent image to form a visible image, a transfer device for electrostatically transferring the visible image to a transfer member, and a fixing device for fixing the electrostatically transferred visible image on the transfer member. The developer bearing member includes at least a conductive core bar, an electron-conductive layer composed of an elastic body, and an ion-conductive layer.

Image forming apparatus including a developer bearing member having multiple layers

An image forming apparatus includes an image bearing member for bearing an electrostatic latent image, and a developing device for developing the electrostatic latent image with a developer and collecting the developer remaining on the image bearing member including a developer carrying member for carrying the developer. The developer carried by the developer carrying member comes into contact with the image bearing member as the developer carrying member moves and a regulating member for regulating a layer thickness of the developer carried by the developer carrying member. The regulating member regulates the layer thickness of the developer carried by the developer carrying member so that there will be three to eight layers, wherein V2/V1>1.54 holds where V1 is a peripheral velocity of said image bearing member and V2 is a peripheral velocity of said developer carrying member.

Image forming apparatus featuring a regulating member for regulating a number of layers of a developer carried by a developer carrying member

A developer scraping member for scraping developer from a developer carrying member has a surface layer having a foamed member, a base layer provided inside of the surface layer, and an intrusion preventing layer provided between the surface layer and the base layer. The intrusion preventing layer prevents the developer, which has intruded into the surface layer, from intruding into the base layer.

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Mishima, Japan

Manami Sekiguchi