Abstract: A developing apparatus includes a developing container for containing a developer comprising toner and a carrier, said developing container is partitioned into a first chamber and a second chamber constituting a circulation path of the developer; a first developing rotatable member, provided in said first chamber, for developing an electrostatic image formed on the image bearing member with the developer in said first chamber; a regulating member for regulating a layer thickness of the developer on said first developing rotatable member; first magnetic pole and second magnetic pole, disposed in said first developing rotatable member in order named in a rotational direction of said first developing rotatable member, said first magnetic pole and second magnetic pole being defective to form a repelling magnetic field; a second developing rotatable member, disposed in said second chamber, for developing the the electrostatic image formed on the image bearing member with the developer magnetically received from sa

Abstract: An image forming apparatus includes an image bearing member having a surface on which an electrostatic latent image is to be formed; a black developing device, containing a black developer including toner and carrier, for developing the electrostatic latent image; at least one color developing device containing a color developer having a color other than black; a supplying device, provided for each of the black developing device and the color developing device, for supplying a supply material containing toner and carrier; a discharging device for discharging the developer. A resistivity of the carrier contained in the black developer is higher than resistivity of the carrier contained in the color developer, and a weight percentage of the carrier contained in the supply material for the black developing device is higher than a weight percentage of the carrier contained in the supply material for the color developing device.

Abstract: A developing apparatus includes a developer container containing a magnetic developer including a toner and a wax contained in the toner. First and second developer carrying members are rotatably provided in the developer container, for carrying the magnetic developer. A regulation member regulates a thickness of a layer of the magnetic developer carried on the first developer carrying member. A first magnet has a first magnetic pole disposed opposite to the second developer carrying member and a second magnetic pole, which is a subsequent magnetic pole, dispose downstream from the first magnetic pole in a rotation direction of the first developer carrying member and having a polarity identical to a polarity of the first magnetic pole. A second magnet has a third magnetic pole, which has a polarity opposite to a polarity of the first magnetic pole, is disposed opposite to the first developer carrying member.

Abstract: A developing apparatus includes a developing container for containing a developer comprising toner and a carrier, said developing container is partitioned into a first chamber and a second chamber constituting a circulation path of the developer; a first developing rotatable member, provided in said first chamber, for developing an electrostatic image formed on the image bearing member with the developer in said first chamber; a regulating member for regulating a layer thickness of the developer on said first developing rotatable member; first magnetic pole and second magnetic pole, disposed in said first developing rotatable member in order named in a rotational direction of said first developing rotatable member, said first magnetic pole and second magnetic pole being defective to form a repelling magnetic field; a second developing rotatable member, disposed in said second chamber, for developing the the electrostatic image formed on the image bearing member with the developer magnetically received from sa

Abstract: A developing apparatus includes a developing container for containing a developer comprising toner and a carrier, said developing container is partitioned into a first chamber and a second chamber constituting a circulation path of the developer; a first developing rotatable member, provided in said first chamber, for developing an electrostatic image formed on the image bearing member with the developer in said first chamber; a regulating member for regulating a layer thickness of the developer on said first developing rotatable member; first magnetic pole and second magnetic pole, disposed in said first developing rotatable member in order named in a rotational direction of said first developing rotatable member, said first magnetic pole and second magnetic pole being defective to form a repelling magnetic field; a second developing rotatable member, disposed in said second chamber, for developing the the electrostatic image formed on the image bearing member with the developer magnetically received from sa

Abstract: An image forming apparatus includes an image bearing member having a surface on which an electrostatic latent image is to be formed; a black developing device, containing a black developer comprising toner and carrier, for developing the electrostatic latent image; at least one color developing device containing a color developer having a color other than black; supplying means, provided for each of the black developing device and the color developing device, for supplying supply material containing toner and carrier; discharging means for discharging the developer, wherein a resistivity of the carrier contained in the black developer in the black developing device is higher than a resistivity of the carrier contained in the color developer in the color developing device, and a weight percentage of the carrier contained in the supply material for the black developing device is higher than a weight percentage of the carrier contained in the supply material for the color developing device.

Abstract: A developing apparatus includes a developer container for containing a developer containing toner and carrier particles having a volume resistivity of 106-1010 ?cm; a developer carrying member for carrying the developer contained in the developer container; a voltage applying means for applying a developing bias voltage having a DC component and an AC component to the developer carrying member when an electrostatic image formed on an image hearing member including a surface layer having a volume resistivity of 109-1014 ?cm is developed by contacting the developer carried on the developer carrying member to the electrostatic image, wherein a volume resistivity of the developer carrying member is 1×10?1-1×102 ?cm.

Abstract: A developing apparatus includes a developer container for containing a developer containing toner and carrier particles having a volume resistivity of 106-1010 &OHgr;cm; a developer carrying member for carrying the developer contained in the developer container; a voltage applying means for applying a developing bias voltage having a DC component and an AC component to the developer carrying member when an electrostatic image formed on an image hearing member including a surface layer having a volume resistivity of 109-1014 &OHgr;cm is developed by contacting the developer carried on the developer carrying member to the electrostatic image, wherein a volume resistivity of the developer carrying member is 1×10−1-1×102 &OHgr;cm.

Abstract: A developing device includes a developing container for containing therein a developer provided with a carrier and a toner, a conveying device for conveying the developer in the developing container, a developer bearing member for bearing thereon the developer conveyed by the conveying device, the developer bearing member conveying the developer to a developing portion for developing a latent image formed on an image bearing member, a magnetic field generating device provided in the developer bearing member for generating a magnetic field, the magnetic field generating device being provided with a first magnetic pole and a second magnetic pole provided so as to be adjacent to the downstream side of the first magnetic pole in the direction of rotation of the developer bearing member and having the same polarity as the first magnetic pole, and a regulating device for regulating the layer thickness of the developer on the developer bearing member at a location substantially opposed to the second magnetic pole.

Abstract: A developing apparatus includes a developer container containing a magnetic developer comprising a toner and a wax contained in the toner, first and second developer carrying member, rotatably provided in the developer container, for carrying the magnetic developer, a regulation member for regulating a thickness of a layer of the magnetic developer carried on the first developer carrying member, and magnetic field generation means for generating a magnetic field for transferring the magnetic developer from the first developer carrying member to the second developer carrying member. A common electrostatic latent image formed on an image bearing member is developed with the developer carried on the first developer carrying member and the developer carried on the developer carrying member in this order.

Abstract: A developing apparatus includes a developing container for containing a developer comprising toner and a carrier, said developing container is partitioned into a first chamber and a second chamber constituting a circulation path of the developer; a first developing rotatable member, provided in said first chamber, for developing an electrostatic image formed on the image bearing member with the developer in said first chamber; a regulating member for regulating a layer thickness of the developer on said first developing rotatable member; first magnetic pole and second magnetic pole, disposed in said first developing rotatable member in order named in a rotational direction of said first developing rotatable member, said first magnetic pole and second magnetic pole being defective to form a repelling magnetic field; a second developing rotatable member, disposed in said second chamber, for developing the the electrostatic image formed on the image bearing member with the developer magnetically received from sa

Abstract: An image forming apparatus has a non-magnetic rotatable cylinder having a diameter of 10 mm to 25 mm, a plurality of magnetic field generating means which is inside the non-magnetic cylinder and fixed, a developing container which houses a two component developer containing a magnetic carrier and a non-magnetic toner and has the non-magnetic cylinder rotatably mounted at an opening portion thereof, agitating conveyer means which is inside the developing container and agitates the two component developer and conveys it to the non-magnetic cylinder, and an image bearing member arranged in opposition to the non-magnetic cylinder at intervals. The image forming apparatus is an image forming apparatus which conveys the two component developer by the rotation of the non-magnetic cylinder, and an electrostatic latent image on the image bearing member is magnetic-brush-developed.

Abstract: A developing device includes a developing container containing a developer having non-magnetic toner and magnetic carriers. A developer carrying member bears and carries the developer contained in the developing container. A magnetic field generating device generates a magnetic field provided in the developer carrying member, wherein an electrostatic latent image formed on an image bearing member is developed with a magnetic brush, which is formed on the developer carrying member by the magnetic field generating device. The image bearing member and the developer carrying member move in opposite directions at a closest portion therebetween. A peak position of a magnetic force Fr generated by the magnetic field generating device in a direction vertical to a surface of the developer carrying member is disposed in the vicinity of the closest portion and downstream in a rotation direction of the developer carrying member from the closest portion.

Abstract: A developing apparatus includes a developer carrying body, opposed to an image bearing body bearing an electrostatic image, for carrying a magnetic developer, a regulating member, provided under the developer carrying body, for regulating an amount of the developer on the developer carrying body, a first magnetic pole provided in the developer carrying body and near a portion regulated by said regulating member, a second magnetic pole, provided at an upstream side of the first magnetic pole in a moving direction of the developer carrying body, for forming a repulsive magnetic field with the first magnetic pole, a first screw for agitating and carrying a developer dropped from the developer carrying body by the repulsive magnetic field, and a second screw for forming a developer circulating path with the first screw and receiving a replenished developer, wherein the first screw has a developer carrying capability lower than a developer carrying ability of the second screw.

Abstract: A developing apparatus includes a developer container for containing a developer comprising magnetic carrier and non-magnetic toner produced through polymerization method; a developer carrying member, provided in an opening of the developer container, for carrying the developer; detecting means for detecting a toner content in the developer, the detecting means including a coil sensor and detecting the toner content using magnetic permeability of the developer.

Abstract: A developing device includes a developer bearing member for bearing and conveying a developer having a toner and a carrier, a first magnetic pole arranged in the developer bearing member, a second magnetic pole arranged in the developer bearing member, a polarity of the second magnetic pole being opposite to a polarity of the first magnetic pole. The second magnetic pole is adjacent to the first magnetic pole and is arranged on a downstream side of the first magnetic pole in a moving direction of the developer bearing member. A regulating member regulates a layer thickness of the developer borne by the developer bearer. The regulating member is arranged in the vicinity of the second magnetic pole and a concentration detector for detecting a concentration of the toner in the developer.

Abstract: A developing device of the present invention includes a developing container containing a developer having non-magnetic toner and magnetic carriers, a developer carrying member for bearing and carrying the developer in the developing container, and a magnetic field generating device for generating a magnetic field provided in the developer carrying member, wherein an electrostatic latent image formed on an image bearing member is developed with a magnetic brush formed on the developer carrying member by the magnetic field generating device, and the image bearing member and the developer carrying member move in opposite directions at a closest portion therebetween, and a peak position of a magnetic force Fr generated by the magnetic field generating device in a direction vertical to a surface of the developer carrying member is disposed in the vicinity of the closest portion and downstream in a rotation direction of the developer carrying member from the closest portion.

Abstract: A developing device includes a developing container for containing therein a developer provided with a carrier and a toner, a conveying device for conveying the developer in the developing container, a developer bearing member for bearing thereon the developer conveyed by the conveying device, the developer bearing member conveying the developer to a developing portion for developing a latent image formed on an image bearing member, a magnetic field generating device provided in the developer bearing member for generating a magnetic field, the magnetic field generating device being provided with a first magnetic pole and a second magnetic pole provided so as to be adjacent to the downstream side of the first magnetic pole in the direction of rotation of the developer bearing member and having the same polarity as the first magnetic pole, and a regulating device for regulating the layer thickness of the developer on the developer bearing member at a location substantially opposed to the second magnetic pole.

Abstract: An image forming apparatus has a non-magnetic rotatable cylinder having a diameter of 10 mm to 25 mm, a plurality of magnetic field generating means which is inside the non-magnetic cylinder and fixed, a developing container which houses a two component developer containing a magnetic carrier and a non-magnetic toner and has the non-magnetic cylinder rotatably mounted at an opening portion thereof, agitating conveyer means which is inside the developing container and agitates the two component developer and conveys it to the non-magnetic cylinder, and an image bearing member arranged in opposition to the non-magnetic cylinder at intervals. The image forming apparatus is an image forming apparatus which conveys the two component developer by the rotation of the non-magnetic cylinder, and an electrostatic latent image on the image bearing member is magnetic-brush-developed.

Abstract: The present invention relates to an image forming apparatus which has an image bearing member for bearing a latent image, charging device for charging the image bearing member by bringing ears of electrically conductive particles into contact with the image bearing member, developing device for visualizing the latent image formed on the image bearing member as a toner image by using a developer containing toner and carrier after the image bearing member has been charged by the charging device, a permeability of the carriers being different from a permeability of the electrically conductive particles, density control device for controlling density of the developer within the developing device, the density control device detecting a permeability of the developer, comparing a detected signal value based on the detected result with a reference value, and controlling the density of the developer on the basis of the comparison result, and reference value correcting device for correcting the reference value, the ref