Canon Kabushiki Kaisha

Masahiro Uehara

Hideyuki Matsubara

Tadashi Okanishi

Eijiro Ohashi

An image forming apparatus includes a feeding unit, a regulation member, a detection unit, and a control unit. The feeding unit feeds a recording material from a storage unit to a conveying path. In the storage unit, the regulation member controls a trailing edge of the recording material in a feeding direction. The detection unit detects time until the recording material reaches a predetermined position along the conveying path after the feeding unit begins to feed the recording material. The control unit determines a state of the regulation member based on the detected time. Where the time detected by the detection unit is a value between a first threshold and a second threshold, which is larger than the first threshold, the control unit determines that the regulation member is shifting from a position corresponding to a size of the recording material in the feeding direction.

Image forming apparatus and image forming system

An image forming apparatus includes a latent image forming unit that forms a latent image on an image bearing member, a developing unit that develops the latent image to obtain a developer image, and a transfer unit that transfers the developer image to a recording medium. A first supply unit supplies a voltage to a charging unit and the transfer unit, with the first supply unit including a transformer, and a second supply unit supplies a voltage to the transfer unit, with the second supply unit including a transformer and supplying a voltage supplied opposite in polarity to the voltage supplied from the first supply unit. In addition, a detection unit detects current flowing through the transfer unit, and a control unit is configured to control power supply. When a power is supplied from the first supply unit to the charging unit, the control unit sets a discharge start voltage in which discharging starts between the image bearing member and the charging unit is based on a current detected by the detection unit, and when power is supplied from the second supply unit to the transfer unit, the control unit sets one or more adjusted voltages by calculating one or more voltages to be supplied from the transfer unit so that a current detected by the detection unit is to be a predetermined value. The first supply unit supplies a voltage to the charging unit based on the discharge start voltage and the adjusted voltage set by the control unit.

Image forming apparatus with power supply control

A power supply device includes a plurality of DC voltage generating circuits that share a voltage control circuit controlling a voltage to be supplied to a voltage stabilizing capacitor. The voltage control circuit and the DC voltage generating circuits are controlled so that supplying voltage to the capacitor is stopped to stop output, that a first DC voltage generating circuit among the plurality of DC voltage generating circuits is driven for a predetermined time period and is then stopped, and that supplying voltage to the capacitor is started and also a second DC voltage generating circuit among the plurality of DC voltage generating circuits starts to be driven to output a positive bias, in order to sequentially perform a stop of output from the first DC voltage generating circuit and a start of output from the second DC voltage generating circuit. Accordingly, overshoot of an output voltage is prevented.

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Susono, Japan

Masahiro Uehara