Abstract: An image forming apparatus includes a latent image bearer to bear a latent image, a potential sensor having a vibrator driven by a drive frequency to detect a surface potential of the latent image bearer, a developer bearer to bear developer that develops the latent image on the latent image bearer, and a power supply to apply a superimposed voltage obtained by superimposing an alternating voltage on a direct current voltage on the developer bearer. The frequency of the alternating voltage is not a multiple of the drive frequency and is a value obtained by adding a predetermined value to a multiple of the driving frequency.

Abstract: An electrophotographic image forming apparatus includes a latent image bearer to rotate and bear a latent image, a charging device to charge the a latent image bearer, a developing device to develop the latent image with developer including toner and use a developing voltage including an AC component, and a lubricant applicator to apply lubricant onto a surface of the latent image bearer. An amount of the lubricant applied by the lubricant applicator onto the latent image bearer per centimeter in an axial direction of the latent image bearer is equal to or greater than 0.845 mg for a running distance of 1.0 kilometer of the latent image bearer, and a difference between a largest value and a smallest value of the developing voltage is in a range of 200 V to 400 V.

Abstract: An image forming apparatus includes a latent image bearer to bear a latent image, a potential sensor having a vibrator driven by a drive frequency to detect a surface potential of the latent image bearer, a developer bearer to bear developer that develops the latent image on the latent image bearer, and a power supply to apply a superimposed voltage obtained by superimposing an alternating voltage on a direct current voltage on the developer bearer. The frequency of the alternating voltage is not a multiple of the drive frequency and is a value obtained by adding a predetermined value to a multiple of the driving frequency.

Abstract: An image forming apparatus includes an image forming device to form a toner image onto a recording medium by transferring the toner image directly or indirectly onto the recording medium, the image forming device including a developer to develop a latent image formed on an image carrier into the toner image; and a controller to control the image forming device. The controller determines whether a first estimated time period is greater than a first predetermined time period, the first estimated time period being a time period from a time when image formation of one page of the image completes to an estimated time when image formation of a subsequent page of the image will start; and stops operating the developer based on a determination indicating that the first estimated time period is greater than the first predetermined time period.

Abstract: An electrophotographic image forming apparatus includes a latent image bearer to rotate and bear a latent image, a charging device to charge the a latent image bearer, a developing device to develop the latent image with developer including toner and use a developing voltage including an AC component, and a lubricant applicator to apply lubricant onto a surface of the latent image bearer. An amount of the lubricant applied by the lubricant applicator onto the latent image bearer per centimeter in an axial direction of the latent image bearer is equal to or greater than 0.845 mg for a running distance of 1.0 kilometer of the latent image bearer, and a difference between a largest value and a smallest value of the developing voltage is in a range of 200 V to 400 V.

Abstract: An image forming apparatus includes: an image forming device to form a toner image onto a recording medium by transferring the toner image directly or indirectly onto the recording medium, the image forming device including a developing unit to develop a latent image formed on an image carrier into the toner image; and a controller to control the image forming device.

Abstract: An image forming apparatus includes an image bearer, an image forming device, a toner concentration detector, a toner supply device, an image density detector, and a controller including a memory device. At a predetermined timing before image formation is started, the controller adjusts a developing potential to adjust an image density of a detection toner image on the image bearer and drives the toner supply device or the developing device to adjust a toner concentration in the developing device. After the image formation is started, the controller drives the toner supply device to adjust the toner concentration, and, in a predetermined sheet interval, adjusts the target concentration based on the image density of the detection toner image formed in a non-image area of the image bearer. When the toner concentration is higher than the target concentration plus a threshold, the controller suspends image formation and readjusts the developing potential.

Abstract: An image forming apparatus is provided. The image forming apparatus includes an image forming device to form images of color toners on corresponding image bearers of at least four image bearers; a transferring device to transfer the color toner images on the image bearers to a transfer medium; and a controller to control the image forming apparatus. The controller performs a compulsory toner consumption processing for the color toners to compulsory consume deteriorated toners. When the compulsory toner consumption processing is performed on three or more toners, compulsory consumption toner images of the color toners are formed on the corresponding image bearers and then transferred to the transfer medium to form a compulsory consumption combined toner image including at least two overlaid image portions, wherein the at least two overlaid image portions are arranged side by side with a space therebetween in a width direction of the transfer medium.

Abstract: An image forming apparatus includes a first electric charging unit having an electric discharge wire to uniformly electrify a surface of the electrostatic latent image bearer, a second electric charging unit having a second electric discharge wire to execute a pre-electric charge removal electric charging process by electrifying the surface of the electrostatic latent image bearer subsequent to a transfer process to transfer a toner image, and a first electric charge removing device to diselectrify the surface of the electrostatic latent image bearer by irradiating it with electric charge removing light subsequent to the pre-electric charge removal electric charging process. The first electric charge removing device is disposed within an electric discharge region of the second electric discharge wire on a downstream side of an extreme upstream edge of the electric discharge region of the second electric discharge wire in a rotational direction of the electrostatic latent image bearer.

Abstract: An image forming apparatus includes a latent image bearer; a developing device containing two-component developer and including a developer bearer, a development voltage source, and a toner concentration detector; a toner supply device to supply toner to the developing device; a transfer device; and a controller to keep a toner concentration in the developer in the developing device at a target toner concentration during image formation. The controller executes forced toner consumption in which the developing device supplies the toner to the latent image bearer the toner at a predetermined forced toner consumption timing, while inhibiting the toner supply device from supplying toner. When the toner concentration falls to a prescribed toner density lower than the target toner concentration, the controller completes the forced toner consumption and executes a post-consumption toner supply operation.

Abstract: An image forming apparatus includes an image bearer, an image forming device, a toner concentration detector, a toner supply device, an image density detector, and a controller including a memory device. At a predetermined timing before image formation is started, the controller adjusts a developing potential to adjust an image density of a detection toner image on the image bearer and drives the toner supply device or the developing device to adjust a toner concentration in the developing device. After the image formation is started, the controller drives the toner supply device to adjust the toner concentration, and, in a predetermined sheet interval, adjusts the target concentration based on the image density of the detection toner image formed in a non-image area of the image bearer. When the toner concentration is higher than the target concentration plus a threshold, the controller suspends image formation and readjusts the developing potential.

Abstract: An image forming apparatus is provided. The image forming apparatus includes an image forming device to form images of color toners on corresponding image bearers of at least four image bearers; a transferring device to transfer the color toner images on the image bearers to a transfer medium; and a controller to control the image forming apparatus. The controller performs a compulsory toner consumption processing for the color toners to compulsory consume deteriorated toners. When the compulsory toner consumption processing is performed on three or more toners, compulsory consumption toner images of the color toners are formed on the corresponding image bearers and then transferred to the transfer medium to form a compulsory consumption combined toner image including at least two overlaid image portions, wherein the at least two overlaid image portions are arranged side by side with a space therebetween in a width direction of the transfer medium.

Abstract: An image forming apparatus includes a latent image bearer; a developing device containing two-component developer and including a developer bearer, a development voltage source, and a toner concentration detector; a toner supply device to supply toner to the developing device; a transfer device; and a controller to keep a toner concentration in the developer in the developing device at a target toner concentration during image formation. The controller executes forced toner consumption in which the developing device supplies the toner to the latent image bearer the toner at a predetermined forced toner consumption timing, while inhibiting the toner supply device from supplying toner. When the toner concentration falls to a prescribed toner density lower than the target toner concentration, the controller completes the forced toner consumption and executes a post-consumption toner supply operation.

Abstract: An image forming apparatus includes a first electric charging unit having an electric discharge wire to uniformly electrify a surface of the electrostatic latent image bearer, a second electric charging unit having a second electric discharge wire to execute a pre-electric charge removal electric charging process by electrifying the surface of the electrostatic latent image bearer subsequent to a transfer process to transfer a toner image, and a first electric charge removing device to diselectrify the surface of the electrostatic latent image bearer by irradiating it with electric charge removing light subsequent to the pre-electric charge removal electric charging process. The first electric charge removing device is disposed within an electric discharge region of the second electric discharge wire on a downstream side of an extreme upstream edge of the electric discharge region of the second electric discharge wire in a rotational direction of the electrostatic latent image bearer.

Abstract: An image forming apparatus has a system speed of from 400 to 2,000 mm/sec and includes an endless intermediate transfer belt to transfer a sheet-shaped medium bearing an image formed of a toner. The intermediate transfer belt includes a first layer including at least a substrate; a second layer; and an electric resistance controlling material and has a surface resistivity of from 1×108 to 1×1013 ?/?, a volume resistivity of from 1×106 to 1×1012 ?·cm, and a surface roughness not greater than 50 ?m. The toner includes a mother particle which is surface-treated with a fluidizer, comprising a charge controlling agent and at least two external additives which are inorganic particulate materials and particulate polymers formed of polymeric particulate materials or thermosetting resins adhering to the surface of the mother particle.

Abstract: An image forming apparatus includes multiple image forming units each including a latent image bearer and a developing device, a transfer device to transfer toner images from the latent image bearers onto a surface of endless rotary member, a cleaner to clean the surface of the endless rotary member, and a control unit to execute a forcible toner consumption process to forcibly consume degraded toner stored in applicable one or more developing devices. The forcible toner consumption process includes a step of forming a toner image formed for forced consumption in a non-image region of the latent image bearer with an amount of toner corresponding to a difference between an image area ratio of a developed image and a prescribed threshold when the image area ratio of the developed image is lower than the prescribed threshold.

Abstract: An image forming apparatus includes multiple image forming units each including a latent image bearer and a developing device, a transfer device to transfer toner images from the latent image bearers onto a surface of endless rotary member, a cleaner to clean the surface of the endless rotary member, and a control unit to execute a forcible toner consumption process to forcibly consume degraded toner stored in applicable one or more developing devices. The forcible toner consumption process includes a step of forming a toner image formed for forced consumption in a non-image region of the latent image bearer with an amount of toner corresponding to a difference between an image area ratio of a developed image and a prescribed threshold thereof when the image area ratio of the developed image is lower than the prescribed threshold.

Abstract: An image-forming apparatus, comprising: a rotatable photoreceptor; a charging device configured to charge a surface of the photoreceptor to be a target charge potential; an exposure device configured to expose a charged portion on the surface of the photoreceptor to form an electrostatic latent image; a developing device configured to develop the electrostatic latent image using toner to form a toner image; a transfer device configured to apply a transfer bias between the photoreceptor and a transfer member by applying an electrical potential of opposite polarity to the target charge potential to the transfer member facing the photoreceptor, and which transfers the toner image on the photoreceptor onto a body to be transferred by the transfer bias; a neutralization device configured to neutralize the surface of the photoreceptor by irradiating the surface with neutralization light after the transferring; and a pre-rotation device configured to perform a pre-rotation process.

Abstract: An image forming apparatus has a system velocity of 400 to 1,700 mm/sec and includes a fixing belt including a base layer; a silicon rubber layer; and a fluorine resin layer. A thickness L2 of the fluorine resin layer is in range of 2?L2?20 ?m. A thickness L1 of the silicone rubber layer is in range of 400?L1?750 ?m. The toner includes a release agent and a binder resin including a crystalline polyester resin and an amorphous polyester resin. A ratio W/R of a height W of third falling peak of an infrared absorption spectrum of the crystalline polyester resin to a height R of the maximum rising peak of an infrared absorption spectrum of the amorphous polyester resin is from 0.045 to 0.850. The content of inorganic fine particles is 0.80 to 5.00 parts per 100 parts of toner base particles.

Abstract: A toner pattern for detecting the degree of toner deterioration is created on a photosensitive element and transferred to an intermediate transfer belt by a primary transfer unit under a transfer condition different from that at the time of image formation. A toner adhesion amount detection unit detects the toner adhesion amount of the toner pattern at multiple places. A degree-of-toner-deterioration calculation unit calculates the degree of toner deterioration on the basis of the variation in data of the toner adhesion amount at multiple places detected by the toner adhesion amount detection unit. A background potential determination coefficient in a process control unit is controlled on the basis of the degree of toner deterioration calculated by the degree-of-toner-deterioration calculation unit.