Abstract: A developer-carrying member to be installed in an electrophotographic developing device for carrying and conveying a developer along a surface thereof, is formed of a substrate, and an intermediate electroless plating layer and an electroplating layer disposed in this order on the substrate. As a result of the electroless and electro double plating layer structure, the developer-carrying member is provided with a wear-resistant surface which has an appropriate degree of roughness suitable for conveying the developer thereon and is yet free from minute projections and cracks undesirable from the viewpoint of continuous image forming performances.

Abstract: In a developing method, a layer of electrically charged toner particles is formed on a surface of a developer carrying member, and magnetic particles which retain on their surfaces electrically charged toner particles are dispersed on the surface of the developing carrying member. The toner particles and magnetic particles are carried on the developing carrying member to a developing position where a surface of an electrostatic latent image bearing member for bearing an electrostatic latent image is opposed with a clearance to the surface of the developer carrying member. An alternating electric field is formed at the developing position against the electrostatic image and chains of magnetic particles are formed by stationary magnetic field generating apparatus disposed behind the developer carrying member.

Abstract: An image forming apparatus includes an electrophotographic photosensitive member, a first optical device for forming a first electrostatic latent image on the photosensitive member, and a second optical device for forming a second electrostatic latent image on the photosensitive member. The first optical device includes a light source for illuminating an original to be recorded and a focusing optical system for projecting light reflected from the illuminated original onto the photosensitive member. The second optical device includes a modulated light emitting device for emitting modulated light in response to a record image signal and an optical device for exposing the modulated light onto the photosensitive member.

Abstract: A developing apparatus includes a developer layer thickness regulating zone downstream of one of magnetic poles of a stationary magnet disposed inside a developing sleeve, with respect to the rotational direction of the sleeve. In the regulating zone, there are provided a magnetic member and a non-magnetic member to regulate the layer thickness of the developer containing magnetic carrier particles and toner particles on the sleeve. The magnetic member has a width of not less than 1 mm and not more than 10 mm and a thickness of not less than 0.2 mm and not more than 3 mm.

Abstract: An image forming apparatus includes a first developing device having a first developer carrying member for supplying a first color toner in the first developing zone; a first voltage applying device for applying to the first developer carrying member a first oscillating bias voltage which has a first phase of time period t11 for forming a first electric field applying to the first color toner a force away from the first developer carrying member toward the image bearing member and a second phase of time period t21 for forming a second electric field applying to the first color toner a force away from the image bearing member toward the first developer carrying member; a second developing device having a second developer carrying member for supplying a second color toner in the second developing zone; and second voltage applying device intermittently applying to the second developer carrying member a second oscillating bias voltage having a third phase of time period t12 for forming a third electric field appl

Abstract: A developing apparatus includes a container having a first chamber and a second chamber, the second chamber containing a developer; a rotatable developer carrying member in the first chamber to carry the developer through a developing zone where an electrostatic latent image on an image bearing member is developed; a rotatable supply member disposed in the first chamber and cooperative with the developer carrying member to form a nip therebetween to supply the developer supplied from the second chamber to the developer carrying member; and a partition wall between the first chamber and a second chamber having an opening for permitting supply of the developer from the second chamber to the supply member, wherein the opening has a length smaller than a length of the supply member.

Abstract: A color image forming method, comprising the steps of: providing a particulate developer comprising at least two species of sensitive particles which are capable of respectively absorbing lights having different wavelengths to be decolorized or faded; developing an electrostatic latent image with the particulate developer to form an image comprising the developer; and exposing the developer image to light having a wavelength capable of selectively decolorizing at least one species of the sensitive particles.

Abstract: An image forming apparatus includes an image bearing member movable through first and second developing positions in the order named and a bias voltage applying device applies a first developing bias voltage to a first developer carrying member and a second developing bias voltage to a second developer carrying member. The first bias voltage has a phase of a first electric field for applying to the toner a force from the developer carrying member to the image bearing member for a period t11 in the first developing position and a phase of a second electric field in the opposite direction to the first for a period t21 in the first developing position. The second bias voltage has a phase of a third electric field for applying to the toner a force from the developer carrying member to the image bearing member for a period t12 in the second developing position and a phase of a fourth electric field in the opposite direction to the third for a period t22 in the second developing zone.

Abstract: A method of reverse development for depositing the toner particles to the light potential area of a photosensitive member. The developer used contains magnetic carrier particles and toner particles. An alternating electric field is formed in the developing position or zone. A relative volumetric ratio Q (%) of the magnetic carrier particles in the developing position satisfies 15.0.ltoreq.Q.ltoreq.28.0. The relative volumetric ratio is defined asQ=(M/h).times.(1/.rho.).times.C.sigma./(T+C)where M (g/cm.sup.2) is an amount of applied developer on a developing sleeve surface per unit area, h (cm) is a height of space in the developing position, .rho. (g/cm.sup.3) is a true density of the magnetic carrier particles, C/(T+C) (%) is a weight ratio of the carrier particles in the developer on the surface of the sleeve, and .sigma. is a ratio of a peripheral speed of the sleeve relative to the peripheral speed of the photosensitive member.

Abstract: A developing apparatus including a cylindrical member having an outer diameter of 5-25 mm to carry a developer. In the cylindrical member, there is disposed a stationary magnet having only two magnetic poles adjacent an outer periphery thereof. An elastic member is contacted to said cylindrical member to regulate the thickness of the developer layer.

Abstract: A developing method including forming a layer of electrically charged toner particles on a surface of the developer carrying member and dispersing magnetic particles retaining on their surfaces electrically charged toner particles on the surface of the developer carrying member, carrying the particles on the developer carrying member to a developing position where a surface of an electrostatic latent image bearing member for bearing an electrostatic latent image is opposed with a clearance to the surface of the developer carrying member, applying an alternating electric field across the clearance and forming the magnetic particles into chains of the magnetic particles by magnetic field generating means disposed behind the developer carrying member, and developing the electrostatic latent image by the charged toner particles on the surface of the developer carrying member and on the surfaces of the magnetic particles.

Abstract: A developing apparatus wherein a magnet is stationarily disposed within a sleeve for carrying a developer. Adjacent an outer periphery of the magnet, only two magnetic poles having different polarities. They are diametrically opposed with respect to a center of the sleeve. One of the magnetic poles form a magnetic field in the developing zone, whereas the other magnetic pole forms a magnetic field in the zone for regulating the thickness of the layer of the developer on the sleeve.

Abstract: A developing method utilizing a developer including a mixture of magnetic carrier particles and toner particles wherein a stationary layer containing magnetic particles is formed on a developer carrying member in a developer container. The stationary layer is allowed to expand and contract in order to control an area of the developer supplying opening upstream of the stationary layer with respect to movement of the developer carrying member thus stabilizing the toner content in the developer supplied to the developing station.

Abstract: A magnet is disposed in a sleeve for carrying a developer. At a position between two adjacent magnetic poles along the periphery of the magnet, an elastic plate is contacted to the sleeve. The elastic plate is effective to regulate a thickness of a layer of the developer applied on the carrying member. Of the magnetic poles, the magnetic pole disposed upstream of a contact position between the elastic plate and the sleeve with respect to the rotational direction of the sleeve provides a magnetic force F (Gauss). The elastic plate is contacted to the sleeve with the pressure P (g/cm). In this structure, 0.71P+385.ltoreq.F.ltoreq.-1.43P+1630 is satisfied.

Abstract: A developing apparatus for developing an electrostatic latent image on an electrostatic latent image bearing member includes a container for containing a developer which contains toner particles and magnetic particles, a developer carrying member, opposed to the electrostatic latent image bearing member, for forming a developing position for supplying the toner particles to the latent image bearing member and for carrying the developer from the container to the developing position, magnetic field generating magnet disposed across the developer carrying member from the latent image bearing member for generating a magentic field, developer regulating member for regulating the developer which contains the toner particles and carrier particles and which is carried to the developing position, wherein the magnetic field generating magnet includes one magnetic pole adjacent an upstream side of the regulating member with respect to a movement direction of the developer carrying member, and wherein a magnetic flux den

Abstract: A developing apparatus in which toner and magnetic particles are supplied to a rotatable developing sleeve to which an elastic blade is contacted. Substantially only the toner is passed through the contact portion. At the free end portion of the elastic blade, the magnetic field is concentrated. The concentrated magnetic field confines the magnetic particles.

Abstract: The present invention relates to a developing apparatus using magnetic carrier particles and toner particles under the influence of an alternating current. One embodiment of the present invention includes a developer which is a mixture of toner particles and resin coated magnetic particles. An alternating electric field is formed between a latent image bearing member and developer carrying member to form a toner image corresponding to an electrostatic latent image. An electric resistivity curve of the magnetic particles on a coordinate graph, where the abscissa represents an electric field E (V/cm) applied to the magnetic particles and the ordinate represents an electric resistivity R (ohm-cm) of the magnetic particles, crosses a zone defined by lines, AB, BD, DC and CA, whereA is a point with coordinates (0.2.times.10.sup.3, 10.sup.11);B is a point with coordinates (2.times.10.sup.3, 3.times.10.sup.9);C is a point with coordinates (0.2.times.103, 10.sup.8); andD is a point with coordinates (2.times.10.sup.

Abstract: A developing apparatus for developing a latent image using a developer containing carrier particles and toner particles in a developing position, includes a developer, container, a developer carrying member magnetic field generating pole, disposed across the developer carrying member from its developer carrying surface a regulator for regulating an amount of the toner particles and carrier particles to be applied on the surface of the developer carrying member; a magnetic member disposed upstream of the regulator and the downstream of the developing position and having a surface spaced from the surface of the developer carrying member to form a clearance which decreases toward a downstream side and being from an upstream side effective to enhance the magnetic field formed between the magnetic field generating pole and the magnetic member such that the enhanced magnetic field allows the developer to return to the container after passing through the developing position to enter the developer container while pre

Abstract: A developing apparatus for developing a latent image on a latent image bearing member, including a magnetic device for forming a magnetic brush of a developer mixture containing developer particles and magnetic particles; a movable developer carrying member for developing the latent image on the latent image bearing member, the developer carrying member being contactable with the magnetic brush to receive the developer mixture; a magnetic particle blocking member, disposed opposed to the developer carrying member at a position downstream of the position where the developer carrying member is contacted with the magnetic brush, for blocking the magnetic particles to form a coating of the developer particles on a surface of the developer carrying member, wherein the coating of the developer particles is conveyed by the movement of the developer carrying member to a developing station where the latent image is developed with the conveyed developer particles.

Abstract: A developing apparatus includes a developer supply container, having an opening, for containing a non-magnetic developer and magnetic particles, an endlessly movable developer carrying member of a non-magnetic material for carrying a developer, which is movable between an inside of the developer supply container and an outside of the developer supply container through the opening, a magnetic particle confining member, provided to an outer surface of the developer carrying member with a gap, a magnet for generating a fixed magnetic field, having a magnetic pole disposed inside of the carrying member and upstream of the confining member with respect to movement of the carrying member, and a magnet, disposed outside of the carrying member and downstream of the confining member with respect to movement of the carrying member, for forming a line of magnetic force extending therefrom to the confining member.