Abstract: A color printer has multiple developing-agent-containing cartridges each having storage units, and a cartridge holding unit for rotatably holding the developing-agent-containing cartridges. With one of the multiple developing-agent-containing cartridges positioned at an image formation position, a latent image on an image carrying member is developed by the developing agent contained in the developing-agent-containing cartridge. An access position where the storage units of the developing-agent-containing cartridges are accessed is a position other than the image formation position. This provides an image formation device and a control method thereof whereby storage units provided to developing-agent-containing cartridges can be accessed in a precise manner.

Abstract: An image forming apparatus includes an image bearing member, a developing device, which includes a developer carrying member and a storage device, a contact/separation mechanism and control device. The control device operates the developer carrying member according to a state of the developing device.

Abstract: An image forming apparatus, including: an image bearing member on a surface of which an electrostatic latent image is formed; a developing device which contains a developer and which has a rotatable developer carrying member, which abuts against the surface of the image bearing member, and a storage device storing information on image formation history, the developing device being adapted to visualize the electrostatic latent image on the surface of the image bearing member as the developer carrying member carries the developer to the electrostatic latent image; a moving mechanism which moves the developing device to one of a first position where development is performed and a second position where development is not performed; and a control device which controls, based upon the information on image formation history stored in the storage device, an operation for giving a charge to the developer according to a lapsed time from a finish time of image formation, in a state in which the developing device is move

Abstract: A color printer has multiple developing-agent-containing cartridges each having storage units, and a cartridge holding unit for rotatably holding the developing-agent-containing cartridges. With one of the multiple developing-agent-containing cartridges positioned at an image formation position, a latent image on an image carrying member is developed by the developing agent contained in the developing-agent-containing cartridge. An access position where the storage units of the developing-agent-containing cartridges are accessed is a position other than the image formation position. This provides an image formation device and a control method thereof whereby storage units provided to developing-agent-containing cartridges can be accessed in a precise manner.

Abstract: A color printer has multiple developing-agent-containing cartridges each having storage units, and a cartridge holding unit for rotatably holding the developing-agent-containing cartridges. With one of the multiple developing-agent-containing cartridges positioned at an image formation position, a latent image on an image carrying member is developed by the developing agent contained in the developing-agent-containing cartridge. An access position where the storage units of the developing-agent-containing cartridges are accessed is a position other than the image formation position. This provides an image formation device and a control method thereof whereby storage units provided to developing-agent-containing cartridges can be accessed in a precise manner.

Abstract: A developing apparatus includes a developer carrying member for carrying a developer to develop an electrostatic image formed on an image bearing member with the developer; a developer regulating member regulates an amount of the developer carried on the developer carrying member; and a controller for controlling a potential difference between the developer carrying member and the developer regulating member such that the potential difference is larger in at least a part of non-developing operation than in a developing operation when the developer carrying member carries the developer.

Abstract: An image forming apparatus, including: an image bearing member on a surface of which an electrostatic latent image is formed; a developing device which contains a developer and which has a rotatable developer carrying member, which abuts against the surface of the image bearing member, and a storage device storing information on image formation history, the developing device being adapted to visualize the electrostatic latent image on the surface of the image bearing member as the developer carrying member carries the developer to the electrostatic latent image; a moving mechanism which moves the developing device to one of a first position where development is performed and a second position where development is not performed; and a control device which controls, based upon the information on image formation history stored in the storage device, an operation for giving a charge to the developer according to a lapsed time from a finish time of image formation, in a state in which the developing device is move

Abstract: 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.

Abstract: An object of the present invention is to provide an image forming apparatus that has an image bearing body, a flexible charging member constituting a nip portion together with the image bearing body, the nip portion being provided with conductive particles, and a developing member for developing an electrostatic image formed on the image bearing body, with use of a developing agent, wherein the developing agent has substantially spherical toner.

Abstract: An image forming apparatus includes a flexible charging member, which forms a nip portion between itself and an image bearing member. The charging member charges the image bearing member and is applied with a voltage when the charging member at least charges the image bearing member for an image formation. The nip portion is provided with an electrically conductive particles developing device for developing an electrostatic image formed on the image bearing member with a developer. The developing device executes a developing operation and, at the same time, executes a collecting operation for collecting a residual developer on the image bearing member.

Abstract: An image forming apparatus includes an image bearing member, a flexible changing member and a developing device. When a first area to be an image forming area of the image bearing member, is present in a nip portion, a superimposed voltage resulting from a direct current voltage and an alternating voltage having a peak to peak voltage smaller than an alternating voltage applied when a charging potential of the image bearing member is converged is applied to the charging member. When a part of a second area to be a non-image area of the image bearing member exists in the nip portion, a direct current voltage without an alternating voltage is applied to the charging member.

Abstract: A color printer has multiple developing-agent-containing cartridges each having storage units, and a cartridge holding unit for rotatably holding the developing-agent-containing cartridges. With one of the multiple developing-agent-containing cartridges positioned at an image formation position, a latent image on an image carrying member is developed by the developing agent contained in the developing-agent-containing cartridge. An access position where the storage units of the developing-agent-containing cartridges are accessed is a position other than the image formation position. This provides an image formation device and a control method thereof whereby storage units provided to developing-agent-containing cartridges can be accessed in a precise manner.

Abstract: A developing apparatus includes a developer carrying member for carrying a developer to develop an electrostatic image formed on an image bearing member with the developer; a developer regulating member for regulating an amount of the developer carried on the developer carrying member; and control means for controlling a potential difference between the developer carrying member and the developer regulating member such that the potential difference is larger in at least a part of non-developing operation than in a developing operation when the developer carrying member carries the developer control means for controlling a potential difference between the developer carrying member and the developer regulating member such that the potential difference is larger in at least a part of non-developing operation than in a developing operation when the developer carrying member carries the developer.

Abstract: An image forming apparatus includes an image bearing member and an electrostatic image forming device, which is adapted to form an electrostatic image on the image bearing member, and which includes an electrifying member contacted with the image bearing member to electrify the image bearing member. The electrifying member includes a first conductive member to which voltage is applied, and a developer carrying member cooperating with the image bearing member to form a nip therebetween and is adapted to carry developer to the nip and to develop the electrostatic image with the developer. The electrifying member also includes a second conductive member to which a voltage is applied. A resistance value between the second conductive member and a developer layer of the developer carried on the developer carrying member is greater than a resistance value between the first conductive member and a surface of the image bearing member.

Abstract: An image forming apparatus includes an image bearing member; an electrostatic image forming unit for forming an electrostatic image on said image bearing member, the electrostatic image forming unit including a flexible charge member for electrically charging the image bearing member, the charge member forming a nip between the image bearing member and itself and is supplied with an oscillating voltage, wherein electroconductive particles are provided in the nip; and a developing unit for developing an electrostatic image formed on the image bearing member with a developer, the developing unit being capable of a residual developer on the image bearing member, wherein a frequency f (cycle/sec) of the oscillating voltage and a peripheral speed v (mm/sec) of the image bearing member satisfy |f/v|≧12 (cycle/mm).

Abstract: 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.

Abstract: 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.

Abstract: An object of the present invention is to provide an image forming apparatus in which when a first area to be an image forming area of the image bearing member exists in said nip portion, a superimposed voltage resulting from a direct current voltage and an alternating voltage having a peak to peak voltage smaller than an alternating voltage applied when a charging potential of the image bearing member is converged is applied to the charging member, and wherein when a part of a second area to be a non-image area of the image bearing member exists in said nip portion, a direct current voltage without an alternating voltage is applied to the charging member.

Abstract: An object of the present invention is to provide an image forming apparatus that has an image bearing body, a flexible charging member constituting a nip portion together with the image bearing body, the nip portion being provided with conductive particles, and a developing member for developing an electrostatic image formed on the image bearing body, with use of a developing agent, wherein the developing agent has substantially spherical toner.

Abstract: 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 discha