Abstract: An electrophotographic photosensitive member includes an electroconductive support member and a photosensitive layer. The uppermost layer of the electrophotographic photosensitive member defines a surface layer, and the surface layer contains polytetrafluoroethylene particles, a charge transporting material, and polyvinyl acetal. The proportion of the polyvinyl acetal content to the polytetrafluoroethylene particles content in the surface layer is in the range of 0.1% by mass to 15.0% by mass, and the charge transporting material content in the surface layer is 35% by mass or more relative to the total mass of the surface layer.

Abstract: An electrophotographic photosensitive member includes an electroconductive support member and a photosensitive layer. The uppermost layer of the electrophotographic photosensitive member defines a surface layer, and the surface layer contains polytetrafluoroethylene particles, a charge transporting material, and polyvinyl acetal. The proportion of the polyvinyl acetal content to the polytetrafluoroethylene particles content in the surface layer is in the range of 0.1% by mass to 15.0% by mass, and the charge transporting material content in the surface layer is 35% by mass or more relative to the total mass of the surface layer.

Abstract: A developing apparatus of the present disclosure includes a developing sleeve including a plurality of magnetic substance portions bearing, on a surface thereof, developer containing toner and carrier and conveying the developer to a developing area facing a photosensitive drum, and a magnet roller disposed within the developing sleeve and generating magnetic fluxes passing through the magnetic substance portion. The magnetic substance portion includes, on an end surface thereof, a high flux density portion disposed at least one of upstream and downstream parts in a conveyance direction of the developing sleeve and through which the magnetic fluxes pass and a low flux density portion through which the magnetic fluxes whose density is lower than the magnetic fluxes passing through the high flux density portion pass.

Abstract: An image forming apparatus that can reduce a toner bearing amount stably regardless of a density of an image. The image forming apparatus comprises a first generating unit which generates a reference pattern, and a second generating unit which generates, based on image data, a correction pattern for thinning out dots at a region from halftone density to high density. The image data is converted based on the reference pattern generated by the first generating unit and the correction pattern generated by the second generating unit. The image forming apparatus further comprises a photoreceptor. The photoreceptor is charged, the charged photoreceptor is exposed based on the converted image data to form an electrostatic latent image, and the electrostatic latent image is developed.

Abstract: An exposure unit forms an electrostatic latent image on the surface of the photoconductor by exposing a photoconductor charged by a charging unit. The electrostatic latent image includes a patterned latent image having a periodic pattern and a printing latent image according to image information to be printed. The patterned latent image includes exposed sections exposed by the exposure unit and unexposed sections less exposed than the exposed sections. Each of the exposed sections occupies 30% or more and 70% or less of an area of one period of the patterned latent image. The period of the patterned latent image in a width direction intersecting the periodic pattern is 100% or more and less than 400% of an average particle diameter of the toner.

Abstract: A developing device includes a developing member and a carrier collecting member. An outer surface of the developing member includes a plurality of protrusion portions aligned at regular intervals that are equal to or larger than an average particle diameter of toner particles and smaller than an average particle diameter of magnetic carrier particles. Each protrusion portion has a first face formed at one side of an apex of each protrusion portion and a second face formed at the other side of the apex, and an inclination angle of the first face is less than an inclination angle of the second face. In the circumferential direction of the developing member, when a downward direction of the first face is set to be positive, a relative velocity of a surface velocity of an image bearing member to a surface velocity of the developing member is set to be positive.

Abstract: An image forming apparatus that can reduce a toner bearing amount stably regardless of a density of an image. The image forming apparatus comprises a first generating unit which generates a reference pattern, and a second generating unit which generates, based on image data, a correction pattern for thinning out dots at a region from halftone density to high density. The image data is converted based on the reference pattern generated by the first generating unit and the correction pattern generated by the second generating unit. The image forming apparatus further comprises a photoreceptor. The photoreceptor is charged, the charged photoreceptor is exposed based on the converted image data to form an electrostatic latent image, and the electrostatic latent image is developed.

Abstract: An image forming apparatus includes: an image bearing member; an electric potential sensor which detects electric potential of a toner image; a density sensor which acquires information of a density of the toner image; and a controller which controls contrast electric potential and the AC bias based on a result of the detection of the density sensor and a predetermined target value, wherein the controller decreases the development contrast, and increases the AC bias, when a charging electric potential difference, which is a potential difference between a potential of a predetermined toner image developed by the development device on the image bearing member and the DC bias applied to the development device when the predetermined toner image is developed, increases from a first predetermined value to a second predetermined value;

Abstract: An image forming apparatus includes: a developing container; a concave-convex member which has a plurality of grooves formed in a rotation direction; a collecting portion; and a receiving member, wherein each groove has side surfaces including a first side surface formed in one direction and a second side surface formed in the other direction in a circumferential direction of the concave-convex member, wherein the first side surface has a smaller inclination angle than the second side surface, and when a direction which moves down the first side surface in the circumferential direction of the concave-convex member is set to be positive, a relative velocity of a surface velocity of the concave-convex member to a surface velocity of the receiving member is set to be positive, at a position in which the concave-convex member and the receiving member come into contact with each other.

Abstract: An image forming apparatus includes a photosensitive member, a first developer carrying member for carrying a developer comprising toner and a carrier for developing an electrostatic image formed on the photosensitive member, and a second developer carrying member for carrying the developer received from the first developer carrying. The second developer carrying member is disposed downstream of the first developer carrying member with respect to a rotational direction of the photosensitive member. In addition, a voltage source applies a developing bias voltage to the first developer carrying member and second developer carrying member, and a driving device rotates the first developer carrying member at a peripheral speed higher than that of the photosensitive member and rotates the second developer carrying member at a peripheral speed which is higher than that of the photosensitive member and which is lower than that of the first developer carrying member.

Abstract: The image forming apparatus includes an image carrier, a developer carrier, a magnetic field generation unit that is fixedly disposed in a hollow part of the developer carrier and includes a plurality of magnetic poles disposed in a circumferential direction of the developer carrier, a conductive member disposed so as to oppose a predetermined magnetic pole, of the plurality of magnetic poles, which is located odd-number pole upstream of a magnetic pole corresponding to a developing area D in a rotational direction of the developer carrier, a power source that can apply a voltage to the conductive member, a potential detection unit configured to detect pre-development and post-development potentials of a predetermined image formed on the image carrier, and a changing unit configured to change the voltage to be applied from the power source to the conductive member based on a detection result obtained by the potential detection unit.

Abstract: An image heating apparatus for allowing a surface of a heated toner image borne on a recording material to be glossed without generating a batter in the heated toner image is provided. In an image heating apparatus (9) including heating means (11 and 12) for heating an unfixed toner image (ta) borne on a recording material (P) and pressure means (21 and 22) for pressurizing an unfixed toner image (tb) heated by the heating means to gloss a surface of the unfixed toner image, the pressure means includes: pressure force changing means (54L and 54R) for changing a pressure force when the pressure means pressurizes the unfixed toner image; temperature detecting means (51 and 52) for detecting a temperature of the pressure means; and pressurization control means (53).

Abstract: An image forming apparatus is provided in which on-surface potential unevenness of an image carrier can be suppressed, and with which an output image having excellent on-surface uniformity of color or the like can be obtained. The image forming apparatus includes: a photoconductive image carrier; charger which charges the image carrier; image exposing unit which exposes an image on a surface of the image carrier after the charging to form a latent electrostatic image; developing unit which develops the latent electrostatic image by adhering toner to the latent electrostatic image to form a toner image; and transfer charger which transfers the obtained toner image to a final supporting member such as plain paper.

Abstract: The present invention further improves gradation characteristics from a highlight region to a high-density region. First, the correction processing receives image data, and an image attribute discrimination discriminates whether the data are related to a character/thin line or others on the basis of attribute information on a pixel of interest. If it is discriminated that the data are related to a character/thin line, a pattern matching to data stored in a line buffer is performed to obtain a pixel distance, and in accordance with the pixel distance, a correction amount is determined on the basis of an LUT set in a correction amount determination. Subsequently, on the basis of the determined correction amount, corrected image data are generated and output to the following step.

Abstract: The electrophotographic image recording apparatus includes a photoconductive image bearing member, a charging unit, an exposure unit, developing means, a transferring unit suited to superimpose and transfer the plural kinds of toner images obtained by the developing means, and a processing unit adapted to execute halftone processing image data to be sent to the exposure unit, wherein the plural kinds of toners include two kinds of toners of the same hue and differing in density from each other, and the processing unit tone-processes by the use of a screen pattern having different screen angles for the respective toners. In an electrophotographic image recording apparatus for forming an image by the use of a plurality of colorants including two kinds of colorants of substantially the same hue and differing in density from each other, and an image processing apparatus, a higher quality of image is achieved.

Abstract: An image forming apparatus includes an electrophotographic photoconductive body for forming an electrostatic latent image thereon; an exposure device for exposing the electrophotographic photoconductive body to form an electrostatic latent image; a storage device for storing information related to potential characteristics at a plurality of areas divided on a surface of the electrophotographic photoconductive body in advance; an information obtaining device for obtaining the information related to potential characteristics, wherein light quantities exposed by the exposure device are determined according to the information related to potential characteristics stored by the storage device and the information related to potential characteristics obtained by the information obtaining device.

Abstract: An image heating apparatus for allowing a surface of a heated toner image borne on a recording material to be glossed without generating a batter in the heated toner image is provided. In an image heating apparatus (9) including heating means (11 and 12) for heating an unfixed toner image (ta) borne on a recording material (P) and pressure means (21 and 22) for pressurizing an unfixed toner image (tb) heated by the heating means to gloss a surface of the unfixed toner image, the pressure means includes: pressure force changing means (54L and 54R) for changing a pressure force when the pressure means pressurizes the unfixed toner image; temperature detecting means (51 and 52) for detecting a temperature of the pressure means; and pressurization control means (53).

Abstract: The present invention provides: a toner kit having a deep toner and a pale toner which are separated from each other, wherein: the deep toner and the pale toner satisfy prescribed conditions for an L*a*b* color coordinate system where a* represents a hue in the red-green direction, b* represents a hue in the yellow-blue direction, and L* represents a lightness; the pale toner and the deep toner to be used in the toner kit; and a method for forming an image using the toner kit. Thus, the present invention can form a high quality image, while suppressing graininess and roughness over the areas covering from the low density area to the high density area.

Abstract: The image forming apparatus has an image forming portion capable of forming an image on a transferring medium by the use of a hypochromatic toner and a hyperchromatic toner of substantially the same color. The image forming portion is provided with a developing device for developing with the hypochromatic toner and the hyperchromatic toner, wherein, in an image area in which the hyperchromatic toner and the hypochromatic toner are mixedly present, the recording rate of the hyperchromatic toner is 1/16, the minimum size Wmini of a toner image of the hyperchromatic toner is 50 ?m or less on the transferring medium. Thereby, it is achieved to reduce graininess.

Abstract: The present invention provides: a toner kit having a deep toner and a pale toner which are separated from each other, wherein: the deep toner and the pale toner satisfy prescribed conditions for an L*a*b* color coordinate system where a* represents a hue in the red-green direction, b* represents a hue in the yellow-blue direction, and L* represents a lightness; the pale toner and the deep toner to be used in the toner kit; and a method for forming an image using the toner kit. Thus, the present invention can form a high quality image, while suppressing graininess and roughness over the areas covering from the low density area to the high density area.