Abstract: A powder conveying device and an image forming apparatus having the same are disclosed. The powder conveying device to convey powder such as toner, includes a conveying plate to carry powder thereon, a vibration generating device to vibrate the conveying plate, and a plurality of conveying protrusions provided on a surface of the conveying plate to convey the powder loaded on the conveying plate. Each of the conveying protrusions has an incline of an upstream side and an incline of a downstream side on a powder conveying path. The incline of the upstream side is smaller than the incline of the downstream side. The powder conveying device can realized with smaller size and/or with lower cost.

Abstract: An electrophotographic image forming device is provided which includes an image holder on which an electrostatic latent image is formed. A magnetic roller has a magnetic brush including nonmagnetic toner and a magnetic carrier using a magnetic force. Donor rollers are provided which have toner layers that are received from the magnetic roller on an outer circumference of each of the donor rollers. The donor rollers are located opposite to the image holder to develop the toner onto the electrostatic latent image.

Abstract: A powder conveying device and an image forming apparatus having the same are disclosed. The powder conveying device to convey powder such as toner, includes a conveying plate to carry powder thereon, a vibration generating device to vibrate the conveying plate, and a plurality of conveying protrusions provided on a surface of the conveying plate to convey the powder loaded on the conveying plate. Each of the conveying protrusions has an incline of an upstream side and an incline of a downstream side on a powder conveying path. The incline of the upstream side is smaller than the incline of the downstream side. The powder conveying device can realized with smaller size and/or with lower cost.

Abstract: A hybrid type developing apparatus and method forms a magnetic brush of non-magnetic toner and a magnetic carrier on a circumference of a magnetic roller forms a uniform toner layer on the circumference of a donor roller using only toner from the magnetic roller, and develops an electrostatic latent image on an image receptor. The hybrid type developing apparatus includes: a plurality of electrodes on the circumference of the donor roller; first and second brush electrodes in an upstream area and a downstream area, respectively, of the donor roller facing the magnetic roller with respect to a direction of rotation; and a bias applying device for applying a recovery bias to the first brush electrode to remove toner from the donor roller and a supply bias to the second brush electrode to supply toner from the magnetic roller to the donor roller.

Abstract: A developing apparatus usable with an image forming apparatus may include a magnetic roller having disposed therein at least one magnet, and a developing roller rotatably disposed to face the magnetic roller and having a magnetic portion to contain a magnetic material that can be magnetized by a magnet of the at least one magnet disposed nearest to the developing roller.

Abstract: There are provided a hybrid type developing apparatus and method.

Abstract: An electrophotographic image forming apparatus includes: an image receptor on which an electrostatic latent image is formed; a magnetic roller for forming a magnetic brush having a non-magnetic toner and a magnetic carrier by magnetic force; a donor roller facing the image receptor and receiving a toner from the magnetic roller to form a toner layer on an outer circumference thereof; bias applying device for applying a bias voltage to the donor roller to develop the electrostatic latent image by supplying the toner from the toner layer; and toner removing device which contacts the donor roller and removes at least a portion of the toner layer from a surface of the donor roller after developing. A method of developing the latent image on the image receptor is provided by the apparatus.

Abstract: A hybrid type developing apparatus of an electrophotographic image forming apparatus includes: an image receptor on which an electrostatic latent image is formed; a magnetic roller for forming a magnetic brush of non-magnetic toner and magnetic carrier by using magnetic force; a donor roller which faces the image receptor and has a circumference for supporting a toner layer formed by receiving toner from the magnetic roller; a bias voltage applying device for applying a development bias voltage to the donor roller to develop toner of the toner layer to the electrostatic latent image; an electrode positioned at an upstream side at a point closest and most adjacent position between the donor roller and the image receptor and at a downstream side at a point closest and most adjacent position between the donor roller and the magnetic roller and an applied bias voltage of weakening adhesive force of the toner layer to the donor roller and cohesive force of toner to each other.

Abstract: An electrophotographic image forming apparatus is provided which includes a first developing unit which forms a monochrome image in a two-component development method and includes a photosensitive medium on which an electrostatic latent image is formed by a first exposure unit. Additionally, a plurality of second developing units are provided which form a color image in a one-component development method and include a photosensitive medium on which an electrostatic latent image is formed by a second exposure unit. A control unit generates control signals to independently control the operations of the first and second exposure units and the first and second developing units.

Abstract: Provided is an image forming device performing hybrid development that uses magnetic carriers and nonmagnetic carriers. An electrical potential of a non-image portion on an image holder and an electrical potential of a direct current component of a developing bias voltage applied to a developing roller are determined so that a difference between the electrical potentials are less than or equal to a value at which a developing rate of the non-image portion is saturated.

Abstract: An electrophotographic image forming device is provided which includes an image holder on which an electrostatic latent image is formed. A magnetic roller has a magnetic brush including nonmagnetic toner and a magnetic carrier using a magnetic force. Donor rollers are provided which have toner layers that are received from the magnetic roller on an outer circumference of each of the donor rollers. The donor rollers are located opposite to the image holder to develop the toner onto the electrostatic latent image.