Abstract: A fuel cell system includes: a fuel cell; a voltage regulator that regulates an output voltage of the fuel cell; and a controller configured to perform a refresh process of decreasing the output voltage of the fuel cell to a reduction voltage at which an oxide film formed on the cathode is reduced, by controlling the voltage regulator. The controller, before the refresh process, calculates a first amount, the first amount being an amount by which the oxide film is to be removed from the cathode. The controller determines, as the output voltage of the fuel cell, a refresh voltage that enables the first amount of the oxide film to be removed within a preset reference time. The controller operates the voltage regulator so as to cause the output voltage of the fuel cell to become the refresh voltage when the refresh process is performed.

Abstract: An image forming apparatus includes a rotatable photoconductor, a charging device, a voltage applying device, a current detection device, and control circuitry.

Abstract: An image forming apparatus includes a photoconductor, a charging roller to charge the photoconductor, a power source to apply a charging bias to the charging roller, a current sensor to generate a feedback signal representing an output current flowing from the charging roller to the photoconductor, a memory, and circuitry. The circuitry calculates film thicknesses of a photoconductor film of the photoconductor at a plurality of points of time based on a voltage of the charging bias and the output current, calculates travel distances of the photoconductor charged at the plurality of points of time, associates the film thicknesses with the travel distances, stores the film thicknesses and the travel distances in the memory, calculates a present estimated film thickness based on the film thicknesses and the travel distances, and calculates an estimated film thickness range corresponding to a present travel distance based on the present estimated film thickness.

Abstract: An image forming apparatus includes a rotatable photoconductor, a charging device, a voltage applying device, a current detection device, and control circuitry.

Abstract: An image forming apparatus includes a photoconductor, a power supply, and circuitry. The power supply is configured to apply a charging voltage to the photoconductor. The circuitry is configured to control film thickness detection of detecting a charging current corresponding to the charging voltage to detect a film thickness of a surface of the photoconductor. The circuitry is further configured to determine a sampling period taken to detect the charging current; calculate a variation in the charging current detected; and determine whether the variation is greater than a threshold. The circuitry is configured to: determine the sampling period according to a determination result as to whether the variation is greater than the threshold; and sample the charging current for the sampling period determined, on a subsequent film thickness detection control.

Abstract: An image forming apparatus includes a photoconductor, a power supply, and circuitry. The power supply is configured to apply a charging voltage to the photoconductor. The circuitry is configured to control film thickness detection of detecting a charging current corresponding to the charging voltage to detect a film thickness of a surface of the photoconductor. The circuitry is further configured to determine a sampling period taken to detect the charging current; calculate a variation in the charging current detected; and determine whether the variation is greater than a threshold. The circuitry is configured to: determine the sampling period according to a determination result as to whether the variation is greater than the threshold; and sample the charging current for the sampling period determined, on a subsequent film thickness detection control.

Abstract: A fuel cell system includes: a fuel cell; a voltage regulator that regulates an output voltage of the fuel cell; and a controller configured to perform a refresh process of decreasing the output voltage of the fuel cell to a reduction voltage at which an oxide film formed on the cathode is reduced, by controlling the voltage regulator. The controller, before the refresh process, calculates a first amount, the first amount being an amount by which the oxide film is to be removed from the cathode. The controller determines, as the output voltage of the fuel cell, a refresh voltage that enables the first amount of the oxide film to be removed within a preset reference time. The controller operates the voltage regulator so as to cause the output voltage of the fuel cell to become the refresh voltage when the refresh process is performed.

Abstract: An image forming apparatus includes a photoconductor, a charging roller to charge the photoconductor, a power source to apply a charging bias to the charging roller, a current sensor to generate a feedback signal representing an output current flowing from the charging roller to the photoconductor, a memory, and circuitry. The circuitry calculates film thicknesses of a photoconductor film of the photoconductor at a plurality of points of time based on a voltage of the charging bias and the output current, calculates travel distances of the photoconductor charged at the plurality of points of time, associates the film thicknesses with the travel distances, stores the film thicknesses and the travel distances in the memory, calculates a present estimated film thickness based on the film thicknesses and the travel distances, and calculates an estimated film thickness range corresponding to a present travel distance based on the present estimated film thickness.

Abstract: An image forming apparatus includes a photoconductor, a charger that charges the photoconductor, a transfer unit that transfers a toner image formed on the photoconductor to a transfer device, a charging power supply that outputs AC voltage for applying a charging bias to the charger, a transfer power supply that outputs DC voltage or DC current for applying a transfer bias to the transfer unit, an output detector that detects an output value of the DC voltage or the DC current, and a controller that calculates load impedance of the photoconductor based on the detected output value of the DC voltage or DC current detected by the output detector while modifying the output of the AC voltage by the charging power supply and sets the output of the AC voltage that the load impedance starts converging into a predetermined value as an adjusted AC output to the charging power supply.

Abstract: An image forming apparatus includes a photoconductor, a charger that charges the photoconductor, a transfer unit that transfers a toner image formed on the photoconductor to a transfer device, a charging power supply that outputs AC voltage for applying a charging bias to the charger, a transfer power supply that outputs DC voltage or DC current for applying a transfer bias to the transfer unit, an output detector that detects an output value of the DC voltage or the DC current, and a controller that calculates load impedance of the photoconductor based on the detected output value of the DC voltage or DC current detected by the output detector while modifying the output of the AC voltage by the charging power supply and sets the output of the AC voltage that the load impedance starts converging into a predetermined value as an adjusted AC output to the charging power supply.

Abstract: An image forming apparatus includes an electrostatic latent image bearer; a charger to charge a surface of the electrostatic latent image bearer; a power source to output a charging bias supplied to the charger; an electrostatic latent image writing unit to write an electrostatic latent image on the surface of the electrostatic latent image bearer charged by the charger; a developing unit including a developing member to develop the electrostatic latent image to obtain a toner image; a developing power source to output a developing bias supplied to the developing unit; a processor to adjust the charging bias output from the power source to a predetermined target value; and a storage unit to store an adjustment value algorithm.

Abstract: A high-voltage power source includes a high-voltage power source unit configured to apply high voltage obtained by superposing a high alternating-current voltage on a high direct-current voltage to a charging member, an output unit configured to output a first direct-current voltage having a first voltage value according to an externally input pulse-width modulation signal, a direct-current voltage conversion unit configured to convert the first direct-current voltage into a second direct-current voltage, a generation unit configured to boost the second direct-current voltage to generate a high direct-current voltage, a peak value detection unit configured to detect a positive peak value and a negative peak value from an alternating-current component of the high direct-current voltage, and a voltage difference output unit configured to output a third direct-current voltage having a third voltage value to the direct-current voltage conversion unit.

Abstract: An image forming apparatus includes an electrostatic latent image bearer; a charger to charge a surface of the electrostatic latent image bearer; a power source to output a charging bias supplied to the charger; an electrostatic latent image writing unit to write an electrostatic latent image on the surface of the electrostatic latent image bearer charged by the charger; a developing unit including a developing member to develop the electrostatic latent image to obtain a toner image; a developing power source to output a developing bias supplied to the developing unit; a processor to adjust the charging bias output from the power source to a predetermined target value; and a storage unit to store an adjustment value algorithm.

Abstract: A high-voltage power source includes a high-voltage power source unit configured to apply high voltage obtained by superposing a high alternating-current voltage on a high direct-current voltage to a charging member, an output unit configured to output a first direct-current voltage having a first voltage value according to an externally input pulse-width modulation signal, a direct-current voltage conversion unit configured to convert the first direct-current voltage into a second direct-current voltage, a generation unit configured to boost the second direct-current voltage to generate a high direct-current voltage, a peak value detection unit configured to detect a positive peak value and a negative peak value from an alternating-current component of the high direct-current voltage, and a voltage difference output unit configured to output a third direct-current voltage having a third voltage value to the direct-current voltage conversion unit.

Abstract: A radio network controller in a mobile communication network detects characteristics of mobile devices that are wireless connected to a radio base station managed by the radio network controller. The radio network controller decides whether the mobile devices can be classified into at least one group according to the detected characteristics. When it is decided that the mobile devices can be classified into at least one group, radio base stations to which the mobile devices can be wireless connected are changed according to the classified group so that radio resources in the radio base stations can be uniformly used. By sharing the radio resources owned by a radio base station, the radio resources under the control of the radio network controller can be effectively utilized.

Abstract: A data management system that allows client terminals on a network to register records with search keywords to distributed data management servers and to retrieve them by entering a specific search keyword. The entire coverage area of the network is divided into a plurality of primary areas, and each primary area is further subdivided into a plurality of secondary areas. Primary and secondary servers are deployed over the network, one for each individual primary area and secondary area, respectively. The primary servers employ a primary hash function that processes a given search keyword to derive a primary server identifier indicating one of the primary servers that governs a particular primary area where the secondary server having a record relevant to the given search keyword is located.