Ricoh Company, Ltd.

Shinji Minami

Hiroyuki Sugiyama

Yoshinori Nakagawa

Tomoko Takahashi

Masahiko Shakuto

Ryuji Yoshida

Kunihiro Komai

Taichi Urayama

Yasuhide Matsuno

Takahiro Yoshimi

Jyunya Sakuraba

Shigekazu Koguchi

An image forming apparatus includes a rotatable photoconductor, a charging device, a voltage applying device, a current detection device, and control circuitry. The control circuitry is configured to determine a film thickness of the photoconductor based on a charging current detected with the current detection device; determine an estimated film thickness of the film thickness, based on a previous film thickness and travel information of the photoconductor after determination of the previous film thickness; determine a discharging start voltage that the voltage applying device applies to start discharging from the charging device to the photoconductor; determine, from the estimated film thickness and the discharging start voltage, a film thickness determining voltage that the voltage applying device applies to pass a film thickness determining current being a charging current used for determining the film thickness; and apply the film thickness determining voltage to the charging device to determine the film thickness.

Image forming apparatus and image forming method

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.

Image forming apparatus to calculate film thicknesses of a photoconductor film of a photoconductor, image forming method, and non-transitory recording medium storing image forming program

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.

Image forming apparatus and control method for controlling photoconductor film thickness detection

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.

Image forming apparatus, image forming method, and recording medium

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.

Image forming apparatus

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.

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Kanagawa, Japan

Shinji Minami