Abstract: A developing apparatus includes a toner carrying member, disposed opposite an image bearing member for bearing an electrostatic image, for carrying toner to the image bearing member; an electric field forming device for forming an alternating electric field between the image bearing member and the toner carrying member, wherein the alternating electric field includes a first phase in which a constant electric field for urging the toner from said image bearing member toward said toner carrying member continues for a predetermined period, a second phase in which a constant electric field for urging the toner from said toner carrying member toward said image bearing member continues for a predetermined period, and a third phase in which the electric field gradually changes from that in the first phase to that in the second phase within a predetermined period .DELTA.T, and a controller for changing a ratio (.DELTA.T/T), where T is one period of the alternating electric field.

Abstract: An image forming apparatus includes an image bearing member for bearing an image of toner and a charging member contactable to the image bearing member to charge the image bearing member. The charging member is adapted to receive a voltage and the toner has a melt index of not less than 0.5 g/10 min. In the apparatus,P/(V.times.L).ltoreq.50J/m.sup.2where v is a movement speed of the image bearing member when the image bearing member is charged by the charging member (m/sec), L is an effective charging length of the charging member, measured in a direction perpendicular to the movement direction of the image bearing member (m), and P is an amount of electric power consumed by the charging member (W).

Abstract: The present invention provides an image forming apparatus with an image bearing member for bearing an image, and a transfer material bearing member rotatable for bearing a transfer material. The image on the image bearing member is transferred onto the transfer material born by the transfer material bearing member at a transfer position, and a voltage is applied to the transfer material bearing member during the transferring of the transfer material. When a distance between the transfer position and a separation position where the transfer material is separated from the transfer material bearing member along a peripheral surface of the transfer material bearing member in a rotational direction of the transfer material bearing member is L, a whole circumferential length of the transfer material bearing member is L1 and a maximum length of the transfer material usable in the image forming apparatus in the rotational direction of the transfer material bearing member is Hmax, a relation L.ltoreq.

Abstract: The present invention provides an image forming apparatus with an image bearing member capable of rotating while bearing a toner image thereon, a transfer device for transferring the toner image from the image bearing member to a recording material at a transfer position, recording material bearing member capable of rotating while bearing the recording material thereon and adapted to convey the recording material to the transfer position, a pair of rotary members arranged at an upstream side of the recording material bearing member in a recording material conveying direction and adapted to pinch and convey the recording material, and a separation device for separating the recording material from the recording material bearing member at a separation position.

Abstract: A multivalued input recording signal is subjected to pulse-width modulation at a time unit shorter than the period of a clock signal within the period of the recording signal. Alternatively, the multivalued input recording signal is converted into a plurality of different signals each of whose length of time is shorter than a clock signal within the period of the recording signal, thereby performing pulse-width modulation in accordance with a predetermined weighting. This makes it possible to obtain a highly toned recording signal without raising the frequency of the clock signal. Further, density tone data is generated in dependence upon inputted multivalued pixel data, and control is performed using both the irradiation time and emission intensity of a light beam based on the generated density tone data. An image is formed by irradiating a photosensitive body with the controlled light beam.

Abstract: A charging apparatus for electrically charging a member to be charged includes a charging member contactable to the member to be charged to electrically charge the member to be charged. The member to be charged includes a core. A voltage source for applying an oscillating voltage between the member to be charged and the charging member such that a frequency f (Hz) of the oscillating voltage, a Young's modulus E.sub.1 (N/m.sup.2) of the member to be charged, a Young's modulus E.sub.2 of the cure an outer circumferential length 1 (m) of the member to be charged, a thickness t.sub.1 (m) of the member to be charged, and a thickness t.sub.2 of the core satisfy:f1.sup.2 /E.sub.1 t.sub.1.sup.3 +E.sub.2 t.sub.2.sup.3<1.5.times.10.sup.-2 Hz.m (200<f>1500 Hz)15001.sup.1 /E.sub.3 t.sub.1.sup.3 +E.sub.2 t.sub.2.sup.3 <1.5.times.10.sup.-2 Hz.m (1500 Hz<f).

Abstract: An image forming apparatus suitable for use in a laser beam printer includes an image forming unit for forming an image on a photoconductor, and a reproduction unit for reproducing a high density image and a halftone image on the photoconductor. A detector then detects the density of the high density image and the halftone image formed on the photoconductor. A controller controls an image forming condition of the image forming unit based on a detection result by the detector.

Abstract: A developing apparatus includes a rotatable developer carrying member for carrying one component developer to a developing zone for developing an electrostatic latent image for an image bearing member; a regulating member for regulating a thickness of a layer of the developer to be carried by the developer carrying member to the developing zone; a rotatable developer, in contact with the developer carrying member, for supplying the developer; a developer guiding portion for guiding reverse movement of the developer blocked by the regulating member; wherein 0.02.ltoreq.d/Vs.ltoreq.0.1 is satisfied, where d is a minimum distance between the developer guiding portion and the developer feeding member (mm), and Vs is a peripheral speed of the developer feeding member (mm)/sec.

Abstract: An image forming system for forming an image on a recording sheet, including a rotatable image bearing member, a cleaning member contacting the image bearing member to remove toner remaining on the image bearing member, and charger means contacting the image bearing member and disposed at a downstream side of the cleaning member in a direction of movement of the image bearing member. Lubricant having a low resistance is painted on a contacting portion of the cleaning member between the image bearing member and the cleaning member.

Abstract: An image forming apparatus includes an image bearing member; a charging member contactable to the image bearing member to electrically charge the image bearing member, wherein an oscillating voltage is applied between the charging member and the image bearing member; wherein a specific weight .sigma. of the image bearing member defined by weight of an effective charging zone of the image bearing member (g) divided by (cross-sectional area thereof (cm.sup.2) .times.length of effective charging zone (cm)) and a frequency f (Hz) of the oscillating voltage satisfy:.sigma..gtoreq.1.4.times.10.sup.-3 .times.f(200.ltoreq.f.ltoreq.350 Hz).sigma..gtoreq.4.0.times.10.sup.-4 .times.f+0.35, (350 Hz<f.ltoreq.1500 Hz).sigma..gtoreq.0.95, (f>1500 Hz).

Abstract: A charging device including a movable member to be charged, and a charging member which is contactable to the member to be charged so as to charge the member to be charged, wherein the coefficient of dynamic friction between the member to be charged and a surface of the charging member contactable to the member to be charged is not lower than 0.4.

Abstract: An image fixing rotatable member includes an elastic layer into which filler material is mixed, the elastic layer having a surface provided with pores with a porosity of 3-50%, and a resin layer applied and sintered on the elastic layer.

Abstract: A process of producing a cleaning blade including a silicon rubber base and a resin layer which acts as a lubricant on the surface of the rubber is produced by molding a rubber material having resin powder dispersed therein at a temperature less than the softening or melting point of the resin, cutting an end of the rubber, and vulcanizing the molded rubber at a temperature higher than the softening or melting point of the resin. The resin layer is selected from polypropylene, polyvinylidene fluoride, polyethylene, or polyester.

Abstract: A developing apparatus having a container for containing a one component developer, and a rotatable developing roller disposed facing an image bearing member to carry developer from the container to a development zone where it is supplied to an electrostatic latent image carried on an image bearing member. The developing roller includes a metal base member and a resin coating layer thereon in which fine conductive particles are dispersed. The developing roller has a surface including an end region adjacent an end of the roller, and an intermediate region. In the end region, the base member is not roughened and the resin layer is not provided. In the intermediate region, inside the end region, the base member is roughened and is coated with the resin layer. A sealing member is provided for preventing leakage of the developer from the container at the end of the developing roller, the sealing member being faced to the end region of the developing roller.

Abstract: An image fixing apparatus for fixing a toner image on a recording material includes a pair of rotatable members for forming a nip through which the recording material is passed; and bias voltage applying source for applying a bias voltage to at least one of the rotatable members, wherein the bias voltage is automatically changed in accordance with change of an ambient condition.

Abstract: The present invention provides a cleaning blade of a cleaning device for eliminating remaining toner powder from a surface of an image-holding member. The cleaning blade is constituted of silicone rubber. The silicone rubber contains not more than 5% by weight of a low-viscosity organosiloxane component, has rubber hardness within the range of from 40.degree. to 90.degree., and cause permanent compression set of not more than 20% according to JIS A.

Abstract: An image forming apparatus includes a movable image bearing member; an image forming device for forming an image on the image bearing member; and a transfer device for transferring the image from the image bearing member onto a transfer material, the transfer device including a movable transfer member contacted to the image bearing member and for conveying the transfer material by the contact portion. The transfer member is disposed in such a direction that a surface friction in the direction of the movement of the transfer member relative to the image bearing member is large.

Abstract: A recording apparatus includes an input circuit for inputting recording data, a process circuit for performing a recording operation on a photosensitive body on the basis of the recording data input from the input circuit, a designating circuit for designating a recording density, and a control circuit for controlling an operating condition of at least a high-voltage circuit on the basis of designation by the designating circuit. The process circuit includes the high-voltage circuit used for the recording operation.

Abstract: An image forming apparatus includes an area modulation means for forming a halftone image signal by area modulation according to input image data, and a recording unit for performing recording using a particle-type recording material according to the halftone image signal, wherein the length of a short side of a minimum modulation area of the area modulation means formed by the recording unit is set to 0.7-4 times an average particle size of the particle-type recording material.

Abstract: There is disclosed an apparatus for obtaining image signal by tonal processing of an input signal. Pulse-width modulation of the input signal is achieved thorugh comparison with a second signal of a predetermined shaped, for example a triangular signal. In order to avoid the influence of fluctuating factors in pulse-width modulation, the apparatus also has a third signal generator, and the pulse-width modulated signal or a pattern signal generated by the third signal generator is selectively used for image formation.