摘要:
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.
摘要:
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.
摘要:
An image forming apparatus includes an image bearer, a toner image forming device, a plurality of image density detectors, and a controller. The plurality of image density detectors are disposed at predetermined intervals opposite the image bearer in a width direction of the image bearer. The controller causes the toner image forming device to form toner image patterns having an identical density at the plurality of positions on the image bearer and the plurality of image density detectors detects a density of the toner image patterns. Based on the detected density of the toner image patterns, the controller identifies multiple cyclic fluctuations of the density of the toner image patterns and adjusts an image forming condition based on the multiple cyclic fluctuations of the density of the toner image patterns to decrease an amplitude caused by the multiple cyclic fluctuations of the density of the toner image patterns.
摘要:
An image forming apparatus includes an endless belt-shaped image bearer that is rotatably supported and entrained around rollers; a transfer member positioned to contact an outer surface of the image bearer; a transfer device to transfer a toner image conveyed while being carried on the outer surface of the image bearer onto a transfer medium conveyed between the image bearer and the transfer member; a toner image sensor to detect the toner image transferred onto the transfer medium; and a conveyance speed controller to fine-tune a conveyance speed of the transfer medium. Based on fine-tuning data of the conveyance speed controller, a detection result of the toner image sensor is corrected and image forming conditions are corrected based on the corrected detection result.
摘要:
An image forming apparatus includes a latent image bearer; a charger; an exposure device; a developing device; a potential detector to detect a surface potential at a detection position between an exposure position and a development position on the latent image bearer in a direction of rotation of the latent image bearer; and a potential controller to determine an image forming condition. The potential controller includes a potential calculator to calculate an exposed area potential based on a detected potential smaller in charging polarity than a potential threshold, out of the detected surface potential, and a threshold determiner to set the potential threshold between the exposed area potential and an unexposed area potential of the latent image bearer based on at least one of a change in the unexposed area potential, a change with time of the latent image bearer, and a change in an ambient condition.
摘要:
An image forming apparatus includes an image bearing belt of a multi-layer structure, a toner image forming device, a nip forming device, a transfer power source, an environment-condition detector, and a controller. The toner image forming device forms a toner image on a surface of the image bearing belt. The transfer power source outputs a transfer bias including a superimposed voltage, in which a direct current voltage is superimposed on an alternating current voltage to transfer the toner image from the image bearing belt onto a recording medium at a transfer nip. The environment-condition detector detects an environment condition. The controller controls the transfer bias output from the transfer power source to perform a bias switching process to switch the transfer bias between a transfer bias including the superimposed voltage and a transfer bias including a direct current voltage based on a detected result of the environment-condition detector.
摘要:
An image forming apparatus includes a latent image bearer; a charger; an exposure device; a developing device; a potential detector to detect a surface potential at a detection position between an exposure position and a development position on the latent image bearer in a direction of rotation of the latent image bearer; and a potential controller to determine an image forming condition. The potential controller includes a potential calculator to calculate an exposed area potential based on a detected potential smaller in charging polarity than a potential threshold, out of the detected surface potential, and a threshold determiner to set the potential threshold between the exposed area potential and an unexposed area potential of the latent image bearer based on at least one of a change in the unexposed area potential, a change with time of the latent image bearer, and a change in an ambient condition.
摘要:
An image forming apparatus includes an endless belt-shaped image bearer that is rotatably supported and entrained around rollers; a transfer member positioned to contact an outer surface of the image bearer; a transfer device to transfer a toner image conveyed while being carried on the outer surface of the image bearer onto a transfer medium conveyed between the image bearer and the transfer member; a toner image sensor to detect the toner image transferred onto the transfer medium; and a conveyance speed controller to fine-tune a conveyance speed of the transfer medium. Based on fine-tuning data of the conveyance speed controller, a detection result of the toner image sensor is corrected and image forming conditions are corrected based on the corrected detection result.
摘要:
In an image forming apparatus, a processor performs: a solid density stabilization of adjusting, in accordance with detected toner adhesion amounts of solid toner images of solid tone patterns, a condition to form solid images with respective target image densities; a misregistration reduction of adjusting, in accordance with detection timing of position detection toner images of misregistration detection patterns, a condition to reduce misregistration of toner images; and a halftone density stabilization of adjusting, in accordance with detected toner adhesion amounts of area coverage modulation toner images, a condition to form halftone images with respective target image densities. The processor continuously performs the solid density stabilization and the misregistration reduction, and starts the halftone density stabilization when the solid density stabilization is completed and the misregistration reduction is not completed, to concurrently perform a step of the misregistration reduction and at least a step of the halftone density stabilization.
摘要:
An image forming apparatus includes a image forming unit; an image bearing member having a surface to bear a toner image and a test pattern; the surface having a first time-surface positioned identical to the test pattern, an integer multiple of revolutions upstream or downstream from the test pattern in a surface movement direction, and a second time-surface positioned different from the test pattern, shorter than one revolution upstream or downstream from the test pattern; a reflection light detector to detect the amount of light reflected from the test pattern and the first and second time-surfaces of the image bearing member; and a controller to control the image forming unit based on the detection result and determine whether to execute a first-surface control to detect at least the first time-surface or a second-surface control to detect only the second time-surface based on use condition of the image forming apparatus.