Abstract: An ink has viscosity of 7.5 mPa·s or less at 25° C. The ink includes: a pigment a, a polyethylene glycol b, a water-soluble solid additive c that is solid at 25° C., a penetrating agent d, a surfactant e, and water. The polyethylene glycol b includes a first polyethylene glycol b1 having a number average molecular weight of 150 or more and less than 450 and a second polyethylene glycol b2 having a number average molecular weight of 450 or more and less than 1050. In the ink, a content of the first polyethylene glycol b1 is 5 mass % or more and 10 mass % or less. In the ink, a content of the second polyethylene glycol b2 is 1 mass % or more and 5 mass % or less. A content of the water-soluble solid additive c being 3 mass % or more and 10 mass % or less.

Abstract: An ink has viscosity of 7.5 mPa·s or less at 25° C. The ink includes: a pigment a, a polyethylene glycol b, a penetrating agent c, a surfactant d, and water. The polyethylene glycol b includes a first polyethylene glycol b1 having a number average molecular weight of 150 or more and less than 450 and a second polyethylene glycol b2 having a number average molecular weight of 450 or more and less than 1050. In the ink, the content of the first polyethylene glycol b1 is 5 mass % or more and 10 mass % or less. In the ink, the content of the second polyethylene glycol b2 is 5 mass % or more and 10 mass % or less.

Abstract: An ink includes: a self-dispersing pigment; 0.40 mass % or more and 5.0 mass % or less of a resin having a glass transition temperature of ?40° C. or more and 30° C. or less; a first water-soluble organic solvent including a polyethylene glycol having a number average molecular weight of 200 or more and 600 or less; a second water-soluble organic solvent including triethanolamine; a third water-soluble organic solvent different from the first water-soluble organic solvent and the second water-soluble organic solvent; and water. A content of the first water-soluble organic solvent is 7.0 mass % or more and 20 mass % or less. A content of the second water-soluble organic solvent is 0.10 mass % or more and 2.0 mass % or less.

Abstract: An ink includes: a pigment, a pigment dispersion resin, 7 mass % or more and 20 mass % or less of polyethylene glycol having a molecular weight of 200 or more and 600 or less, 1 mass % or more and 15 mass % or less of 3-methyl-1,5-pentanediol, 1 mass % or more and 10 mass % or less of triethylene glycol monobutyl ether, and water.

Abstract: An inkjet ink includes: a pigment, a preservative, a zwitterionic compound, and water. The zwitterionic compound is a zwitterionic compound that has a zwitterionic structure in an environment with a pH of 7.5 or more and 9 or less. The preservative includes at least one of 2-(2-hydroxy-5-methylphenyl)benzotriazole, orthophenylphenol, sodium dihydroxydimethoxybenzophenonedisulfonate, para-aminobenzoic acid, ferulic acid, benzalkonium chloride, or the like. In the inkjet ink, the content of orthophenylphenol is 4 mass % or less and the content of ferulic acid is 7 mass % or less.

Abstract: An anomaly detecting unit detects an anomaly object in a target image. A characteristic amount watching unit watches at least two basic characteristic amounts of the anomaly object, determines whether values of the basic characteristic amounts satisfy a predetermined watching determination condition of any one of predetermined plural anomaly types or not, if it is determined that the values of the basic characteristic amounts satisfy the watching determination condition, determines as an auxiliary characteristic amount for the anomaly object a characteristic amount corresponding to the anomaly type of which the values of the basic characteristic amounts satisfy the watching determination condition, and starts watching a value of the auxiliary characteristic amount. An anomaly type determining unit determines an anomaly type of the anomaly object on the basis of the basic characteristic amounts and the auxiliary characteristic amount currently watched by the characteristic amount watching unit.

Abstract: An abnormality detection unit detects an abnormal object in target images repeatedly acquired. An abnormality type selection unit selects, for each of the target images, an abnormality type of the abnormal object from a plurality of specific abnormality types based on values of at least two basic feature amounts. A feature amount monitoring unit monitors the values of the basic feature amounts and a value of an auxiliary feature amount corresponding to the abnormality type currently selected by the abnormality type selection unit. An adjustment processing unit executes an adjustment process corresponding to the auxiliary feature amount being monitored by the feature amount monitoring unit. The abnormality type selection unit changes the abnormality type to be selected, in accordance with the change in the values of the basic feature amounts mentioned above.

Abstract: An image forming apparatus includes an image carrier, a developing device, a voltage applier, a current detector, a cleaning blade, and a control device. The control device acts as a measurer and an estimator. The measurer changes the DC bias to a first value and a second value, and acquires a first magnitude of the developing current corresponding to the first value, and a second magnitude of the developing current corresponding to the second value, from the current detector. The estimator calculates a current ratio between the first magnitude and the second magnitude, and estimates deterioration status of the cleaning blade, according to the value of the current ratio.

Abstract: An anomaly detecting unit detects an anomaly object in a target image. A characteristic amount watching unit watches at least two basic characteristic amounts of the anomaly object, determines whether values of the basic characteristic amounts satisfy a predetermined watching determination condition of any one of predetermined plural anomaly types or not, if it is determined that the values of the basic characteristic amounts satisfy the watching determination condition, determines as an auxiliary characteristic amount for the anomaly object a characteristic amount corresponding to the anomaly type of which the values of the basic characteristic amounts satisfy the watching determination condition, and starts watching a value of the auxiliary characteristic amount. An anomaly type determining unit determines an anomaly type of the anomaly object on the basis of the basic characteristic amounts and the auxiliary characteristic amount currently watched by the characteristic amount watching unit.

Abstract: An image forming apparatus includes an image carrier, a developing device, a voltage applier, a current detector, a weight detector, and a control device. The control device acts as a first measurer, a second measurer, and an estimator. The first measurer acquires a toner use amount indicating weight per unit area, of the toner that has migrated from the developing agent carrier to the image carrier, according to a detection result provided by the weight detector. The second measurer acquires the developing current from the current detector. The estimator calculates a value of decision coefficient, obtained by dividing variance of an estimated value in a regression model between the toner use amount and the developing current, by variance of a sample value, and estimates deterioration status of the toner, according to the value of the decision coefficient.

Abstract: An image forming apparatus includes an image carrier, a developing device, a voltage applier, a current detector, a weight detector, and a control device. The control device acts as a first measurer, a second measurer, and an estimator. The first measurer acquires a toner use amount indicating weight per unit area, of the toner that has migrated from the developing agent carrier to the image carrier, according to a detection result provided by the weight detector. The second measurer acquires the developing current from the current detector. The estimator calculates a value of decision coefficient, obtained by dividing variance of an estimated value in a regression model between the toner use amount and the developing current, by variance of a sample value, and estimates deterioration status of the toner, according to the value of the decision coefficient.

Abstract: An image forming apparatus includes an image carrier, a developing device, a voltage applier, a current detector, a cleaning blade, and a control device. The control device acts as a measurer and an estimator. The measurer changes the DC bias to a first value and a second value, and acquires a first magnitude of the developing current corresponding to the first value, and a second magnitude of the developing current corresponding to the second value, from the current detector. The estimator calculates a current ratio between the first magnitude and the second magnitude, and estimates deterioration status of the cleaning blade, according to the value of the current ratio.

Abstract: According to one embodiment, an image forming apparatus includes an image forming portion, and a control portion. The image forming portion includes an image carrier, a charging device, and a cleaning device. The charging device includes a charging roller which contacts a surface of the image carrier. The cleaning device includes a cleaning blade, and an adjustment portion. The cleaning blade slidably contacts the surface of the image carrier. The adjustment portion adjusts a linear pressure of the cleaning blade exerted on the surface of the image carrier. The control portion executes, when a rate of increase of an outer layer resistance value of the charging roller caused by a decrease in the function of the cleaning blade is greater than or equal to a first rate, linear pressure adjustment control of controlling the adjustment portion to increase the linear pressure of the cleaning blade.

Abstract: According to one embodiment, an image forming apparatus includes an image forming portion, and a control portion. The image forming portion includes an image carrier, a charging device, and a cleaning device. The charging device includes a charging roller which contacts a surface of the image carrier. The cleaning device includes a cleaning blade, and an adjustment portion. The cleaning blade slidably contacts the surface of the image carrier. The adjustment portion adjusts a linear pressure of the cleaning blade exerted on the surface of the image carrier. The control portion executes, when a rate of increase of an outer layer resistance value of the charging roller caused by a decrease in the function of the cleaning blade is greater than or equal to a first rate, linear pressure adjustment control of controlling the adjustment portion to increase the linear pressure of the cleaning blade.

Abstract: An image forming apparatus has a plurality of image forming portions, an intermediate transfer belt having an elastic layer, a plurality of primary transfer members, a contact-separation mechanism, a secondary transfer member, a driving device, a voltage applying device, and a control portion. The contact-separation mechanism is switchable between an all-color pressure state where the primary transfer members are all in pressed contact with the image carrying members via the intermediate transfer belt and an all-color apart state where the primary transfer members are all away from the intermediate transfer belt. At first power-on, the control portion starts driving the image carrying members and the intermediate transfer belt in the all-color apart state, then transits to the all-color pressure state, and then ejects toner from the developing device to the image carrying members to reduce the surface friction coefficient on the image carrying members and the intermediate transfer belt.

Abstract: An image forming apparatus has an image carrier, an electrifying member, and a charge eliminating device, and eliminates remaining charge on the surface of the image carrier by the charge eliminating device. The charge eliminating device includes a discharge member. The discharge member includes an electro conductive knit fabric knitted in a cylindrical shape using twisted yarn made of twisted metal fibers and a support member having a cylindrical shape and inserted in the electro conductive knit fabric, and is disposed to face the image carrier in a noncontact manner. A magnet member is disposed inside the image carrier within a charge elimination nip width between two tangential lines of an outer circumference surface of the discharge member, the two tangential lines being parallel to a straight line passing through a rotation center of the image carrier and a center axis of the discharge member.

Abstract: An image forming apparatus has a plurality of image forming portions, an intermediate transfer belt having an elastic layer, a plurality of primary transfer members, a contact-separation mechanism, a secondary transfer member, a driving device, a voltage applying device, and a control portion. The contact-separation mechanism is switchable between an all-color pressure state where the primary transfer members are all in pressed contact with the image carrying members via the intermediate transfer belt and an all-color apart state where the primary transfer members are all away from the intermediate transfer belt. At first power-on, the control portion starts driving the image carrying members and the intermediate transfer belt in the all-color apart state, then transits to the all-color pressure state, and then ejects toner from the developing device to the image carrying members to reduce the surface friction coefficient on the image carrying members and the intermediate transfer belt.

Abstract: An image forming apparatus includes a photoreceptor and an exposure device. The exposure device is configured to expose a surface of the photoreceptor and to form an electrostatic latent image. The exposure device includes a light source, a polygon mirror and a polygon motor. The light source is configured to emit a beam. The polygon mirror is configured to deflect the beam emitted from the light source. The polygon motor is configured to rotate the polygon mirror. The polygon motor is rotated at least temporarily when an aging mode to remove moisture from the surface of the photoreceptor is executed.

Abstract: In an image forming apparatus, a resistance component of an inner impedance of an electricity removing member is equal to or lower than a value that is obtained by multiplying a calculated resistance value by a first specific value, the calculated resistance value being calculated based on a predetermined formula as a DC resistance value of the electricity removing member that is required to reduce a pre-electricity-removal potential of a photoconductor to a predetermined post-electricity-removal potential during an electricity removal time, the first specific value being calculated based on a ratio of a linear speed of the electricity removing member to a linear speed of the photoconductor, and a resistance component of the contact impedance of the electricity removing member is equal to or lower than a value that is obtained by multiplying the calculated resistance value by a second specific value that is calculated based on the ratio.

Abstract: An image forming apparatus includes a photoreceptor and an exposure device. The exposure device is configured to expose a surface of the photoreceptor and to form an electrostatic latent image. The exposure device includes a light source, a polygon mirror and a polygon motor. The light source is configured to emit a beam. The polygon mirror is configured to deflect the beam emitted from the light source. The polygon motor is configured to rotate the polygon mirror. The polygon motor is rotated at least temporarily when an aging mode to remove moisture from the surface of the photoreceptor is executed.