Ricoh Company, Ltd.

Yu Yoshioka

Tetsuya Yano

Hideo Nakagawa

Mikio Nakajima

An image forming device includes a photoconductor, a motor, a charging member, a cleaning blade, and an abnormality determining unit. The motor is configured to drive the photoconductor to rotate. The charging member is configured to charge the photoconductor. The cleaning blade is configured to contact the photoconductor and remove residual toner from a surface of the photoconductor. The abnormality determining unit is configured to determine abnormality of the cleaning blade based on a motor current flowing in the motor and a gap between the photoconductor and the charging member.

Image forming device and method for determining abnormality

An image forming device includes a charging power supply used in applying, to a charging unit, a charging voltage for the purpose of electrostatic latent image formation and a charging bias voltage during a cleaning operation; a developing power supply that is capable of outputting a developing bias voltage of positive polarity and negative polarity to a developing unit; a constant-voltage generating-holding unit that is used in generating and holding a constant potential difference between the charging unit and the developing unit; a developing power control unit that performs output control of a developing bias voltage with respect to the developing unit; and a charging power control unit that, when the developing power control unit performs control to output a developing bias voltage of reverse polarity to the charging unit, performs output control of the charging bias voltage of a predetermined level with respect to the charging power supply.

Image forming device, bias voltage control method for image forming device, and computer program product

A power supply unit includes a first power supply configured to supply electric power to a load using electric power supplied from an external power source; a second power supply configured to store the electric power supplied from the external power source and supply the stored electric power to the load; a no-power detecting unit configured to monitor a voltage of the external power source and detect no electric power from the external power source; and an output switching unit configured to switch the electric power to be supplied to the load to the electric power supplied from the second power supply when the no-power detecting unit detects no electric power. A first setting value that is a target output voltage of the first power supply is larger than a second setting value that is a target output voltage of the second power supply.

Power supply unit and image forming apparatus

A power supply device includes: a main power supply configured to feed power to a load with constant-voltage output using an external power supply; an auxiliary power supply configured to feed power to the load using an internal power storage unit; a constant-current/constant-voltage switching power supply configured to feed a part of current flowing through the load by which part the current exceeds an upper limit value of output current of the main power supply instructed by a current upper-limit instruction unit, with the constant-current output from the auxiliary power supply; and an output switching unit switching the constant-current/constant-voltage switching power supply from the constant-current output to the constant-voltage output when a power cut monitoring unit determines stop of power supply from the external power supply.

Growing community of inventors

Tokyo, Japan

Yu Yoshioka