Abstract: An image forming apparatus of the present invention includes a bias power supply for applying a bias VB to a developer carrier on which a developer is deposited. A charge potential deposited on an image carrier, which faces the developer carrier for forming a latent image thereon, is 400 V or below in absolute value. Assume that the potential of the image carrier is lowered to VL after exposure, that a development potential is |VB?VL|, that the maximum set value of the development potential for development is |VB?VL|max, and that the development potential varies in a range satisfying relations: |VB?VL|?|VB?VL|max+|VB?VL|max×0.2 |VB?VL|?|VB?VL|max?|VB?VL|max×0.2 |VB?VL|max?300 V Then image density varies by a width of 10% of image density corresponding to the maximum set value of the development potential or less.

Abstract: In a state deciding apparatus, an information acquiring unit acquires pieces of information of different types related to a state of an image forming apparatus. An index value calculating unit calculates an index value based on the pieces of information acquired. A state change deciding unit decides a change in a subsequent state of the image forming apparatus, based on a temporal change in the index value calculated.

Abstract: An image forming apparatus develops a latent image formed on an image carrier with a developer that forms a magnet brush on a developer carrier. The developer carrier is made up of a sleeve and a stationary magnet roller accommodated in the sleeve. The magnet roller includes a main pole for causing the developer to form the magnet brush and auxiliary poles for helping the main pole exert a magnetic force. An electric field including an oscillation component is formed between the image carrier and the developer carrier. A particular ratio is set up between a distance between the image carrier and the developer carrier, as measured at the boundary of a nip, and the shortest distance between them, between the above shortest distance and the shortest distance between the developer carrier and a metering member, or between the shortest distance between the image carrier and the developer carrier and the amount of developer scooped up to the image carrier.

Abstract: An image forming method including providing a developer including a toner and a magnetic carrier, a developer carrier configured to convey the developer deposited thereon, and magnetic field generating means fixed within the developer carrier, and forming a magnetic field which forms a magnet brush between the image carrier and the developer carrier such that the magnet brush rises, contacts the image carrier and collapses within a range in which the magnetic field is more intense than an electric field capable of separating the toner and the magnetic carrier from each other by using the magnetic field generating means. The magnetic brush rubs the image carrier to thereby develop a latent image formed on the image carrier.

Abstract: An electrophotographic image forming apparatus of the present invention frees images from various defects including the thinning of horizontal lines, the omission of the trailing edge of an image, background contamination, granularity particular to a halftone image, carrier scattering, and image noise. Further, the apparatus of the present invention solves problems ascribable to patches used to sense image density. Moreover, the apparatus of the present invention faithfully reproduces tonality and has a high developing ability.

Abstract: In a developing device including a plurality of developing sections each including a developer carrier that causes a developer deposited thereon to form a magnet brush and contact an image carrier, the developer carrier including: a rotatable nonmagnetic sleeve; and a stationary magnet roller accommodated in the sleeve and including a magnetic pole for scooping up the developer to the sleeve, a magnetic pole for conveying the developer deposited on the sleeve, and a main magnetic pole for causing the developer to rise on the sleeve in a form of the magnet brush. The plurality of developing sections include at least one developing section in which a flux density of the main magnetic pole in a normal direction has an attenuation ratio of 40% or above and at least one developing section in which said flux density has an attenuation ratio of 30% or below.

Abstract: An image forming apparatus of the present invention includes a lubricator for applying a lubricant to an image carrier or a process unit around the image carrier to thereby reduce friction. The apparatus of the present invention insures a uniform halftone image, prevents the trailing edge of an image from being lost, and faithfully reproduces even a horizontal line.

Abstract: An electrophotographic image forming apparatus of the present invention frees images from various defects including the thinning of horizontal lines, the omission of the trailing edge an image, background contamination, granularity particular to a halftone image, carrier scattering, and image noise. Further, the apparatus of the present invention solves problems ascribable to patches used to sense image density. Moreover, the apparatus of the present invention faithfully reproduces tonality and has a high developing ability.

Abstract: An image forming apparatus of the present invention includes a bias power supply for applying a bias VB to a developer carrier on which a developer is deposited. A charge potential deposited on an image carrier, which faces the developer carrier for forming a latent image thereon, is 400 V or below in absolute value.

Abstract: An image forming apparatus of the present invention includes a developing device of the type causing a developer to form a magnet brush on the surface of a developer carrier in a developing region or nip for development. The magnet brush contacts and thereby develops a latent image formed on an image carrier. The apparatus of the present invention increases image density and faithfully reproduces even low-contrast images with a low-cost configuration. Further, the apparatus reduces image defects, including granularity and the omission of the trailing edge of an image, even if the range over which the magnet brush and image carrier contact is reduced.

Abstract: An image forming apparatus of the present invention includes a bias power supply for applying a bias VB to a developer carrier on which a developer is deposited. A charge potential deposited on an image carrier, which faces the developer carrier for forming a latent image thereon, is 400 V or below in absolute value. Assume that the potential of the image carrier is lowered to VL after exposure, that a development potential is |VB−VL|, that the maximum set value of the development potential for development is |VB−VL|max, and that the development potential varies in a range satisfying relations: |VB−VL|≦|VB−VL|max+|VB−VL|max×0.2 |VB−VL|≧|VB−VL|max−|VB−VL|max×0.

Abstract: An image forming apparatus of the present invention includes a lubricator for applying a lubricant to an image carrier or a process unit around the image carrier to thereby reduce friction. The apparatus of the present invention insures a uniform halftone image, prevents the trailing edge of an image from being lost, and faithfully reproduces even a horizontal line.

Abstract: An image forming apparatus including a developing device and an image carrier facing the developing device. The developing device includes a main magnetic pole for causing a developer to magnetically deposit on an outer periphery of a developer carrier in a form of a magnet brush. The image carrier has a coefficient of friction of 0.5 or below, and a flux density in a normal direction has an attenuation ratio of 40% or above.

Abstract: An image forming apparatus of the present invention includes an image carrier made up of a conductive base and photoconductive layer and a toner carrier to which a bias for development is applied. The toner carrier conveys toner deposited thereon to a developing position where the toner carrier faces the image carrier, thereby developing a latent image formed on the image carrier. The apparatus effects low-voltage development that protects the image carrier from electrostatic fatigue, obviates background contamination, and realizes image density as high as 0.5 ×10−3 g/cm2 or above in terms of the amount of toner deposition. Further, the apparatus implements faithful development of the latent image by reducing the edge effect. An image forming process unit removable from the apparatus is also disclosed.

Abstract: An image forming apparatus of the present invention includes a bias power supply for applying a bias VB to a developer carrier on which a developer is deposited. A charge potential deposited on an image carrier, which faces the developer carrier for forming a latent image thereon, is 400 V or below in absolute value.

Abstract: A developing device for an image forming apparatus capable of collecting a developer left on an image carrier with a so-called cleanerless process is disclosed. A ratio of a distance between the image carrier and a developer carrier at the boundary of a nip to a development gap at the center of the nip is selected to be 1.5 or less. This obviates the omission of the trailing edge of an image and granularity and enhances faithful reproduction of horizontal lines and dots despite the use of the cleanerless process.

Abstract: An electrophotographic image forming apparatus of the present invention frees images from various defects including the thinning of horizontal lines, the omission of the trailing edge an image, background contamination, granularity particular to a halftone image, carrier scattering, and image noise. Further, the apparatus of the present invention solves problems ascribable to patches used to sense image density. Moreover, the apparatus of the present invention faithfully reproduces tonality and has a high developing ability.

Abstract: An image forming apparatus of the present invention includes an image carrier made up of a conductive base and a photoconductive layer and a toner carrier to which a bias for development is applied. The toner carrier conveys toner deposited thereon to a developing position where the toner carrier faces the image carrier, thereby developing a latent image formed on the image carrier. The apparatus effects low-voltage development that protects the image carrier from electrostatic fatigue, obviates background contamination, and realizes image density as high as 0.5×10−3 g/cm2 or above in terms of the amount of toner deposition. Further, the apparatus implements faithful development of the latent image by reducing the edge effect. An image forming process unit removable from the apparatus is also disclosed.

Abstract: An image forming apparatus of the present invention includes a lubricator for applying a lubricant to an image carrier or a process unit around the image carrier to thereby reduce friction. The apparatus of the present invention insures a uniform halftone image, prevents the trailing edge of an image from being lost, and faithfully reproduces even a horizontal line.

Abstract: An image forming apparatus of the present invention includes a developing device of the type causing a developer to form a magnet brush on the surface of a developer carrier in a developing region or nip for development. The magnet brush contacts and thereby develops a latent image formed on an image carrier. The apparatus of the present invention increases image density and faithfully reproduces even low-contrast images with a low-cost configuration. Further, the apparatus reduces image defects, including granularity and the omission of the trailing edge of an image, even if the range over which the magnet brush and image carrier contact is reduced.