Canon Kabushiki Kaisha

Renesas Design (uk) Limited

Hiroki Asano

Yasuhiro Shimura

Hiroki Hanayama

Yusuke Saito

Taisuke Minagawa

Kenji Tomiyoshi

An image forming apparatus includes a photosensitive member, a charging member, a developing member, a contacting member contacting the developing member, and first to third power sources. The first power source generates a first voltage and applies it to the charging member. The second power source generates a second voltage, lower than the first voltage, from the first voltage and applies it to the contacting member. The third power source generates a third voltage, lower than the second voltage, from the second voltage and applies it to the developing member.

Image forming apparatus

A voltage generating apparatus includes: a first circuit configured to output a first voltage; a controller configured to control a value of the first voltage output by the first circuit with a control signal; and a storage unit configured to store control information of the first circuit. The controller uses the control signal for communication with the storage unit.

Voltage generating apparatus and image forming apparatus

A resistance switching circuit includes a resistor forming an output resistance of a first power supply. The resistance switching circuit switches between a state in which the resistor forms part of an output resistance and a state in which the resistor does not form part of the output resistance. A control circuit is configured to in a case where a DC voltage with a first polarity is applied to a load from a first power supply, control the resistance switching circuit such that the resistor does not form part of the output resistance, and in a case where a DC voltage with a second polarity is applied to the load from a second power supply, control the resistance switching circuit such that the resistor forms part of the output resistance.

Power supply apparatus capable of switching output resistance

A comparator is presented. The comparator includes an input port for receiving an input voltage; an output port for providing an output voltage; a resistive divider, first and second transistors, and a differential amplifier. The resistive divider has a first node for providing a first voltage and a second node for providing a second voltage. The first transistor has a control terminal coupled to the first node, a first terminal coupled to the input port, and a second terminal coupled to a common node. The second transistor has a control terminal coupled to the second node, a first terminal coupled to the input port, and a second terminal coupled to the common node. The differential amplifier has a first input coupled to the first terminal of the first transistor, a second input coupled to the first terminal of the second transistor and an output coupled to the output port.

Low power comparator

An image forming apparatus includes a rotatable photosensitive member, a charging member, an exposure unit, a developing member, a developing voltage applying portion, a transfer member, a first transfer voltage applying portion, a second transfer voltage applying portion, a common power source, and a controller. The controller carries out control so as to execute an image forming operation, and a non-image forming operation and so as to execute, as the non-image forming operation, a cleaning operation. The controller controls a change in output of the common power source so that a value of a voltage applied from the developing voltage applying portion to the developing member during the cleaning operation is made different from a value of a voltage applied from the developing voltage applying portion to the developing member during formation of the toner image.

Image forming apparatus applying different voltages in image forming operation and cleaning operation

A power supply apparatus includes a transformer including a primary coil and a secondary coil, a switching element connected in series to the primary coil, a first generation unit configured to generate a first voltage to be output to a first load from a voltage generated in the primary coil by turning on and off the switching element, and a second generation unit configured to generate a second voltage to be output to a second load from a voltage generated in the secondary coil by turning on and off the switching element. The first voltage has an absolute value smaller than an absolute value of the second voltage. The first voltage has a polarity different from a polarity of the second voltage.

Power supply apparatus and image forming apparatus

The power supply apparatus includes a control unit configured to perform control of gradually changing a turn-on duty of a first switching element when a first voltage mode is switched to a second voltage mode or when the second voltage mode is switched to the first voltage mode.

Power supply apparatus and image forming apparatus controlling switching elements to output a voltage

The power supply apparatus includes a notification unit configured to notify, according to an input first signal, a control unit that a target voltage is switched from a first voltage to a second voltage higher than the first voltage; and a switching unit configured to switch the target voltage to the first voltage or the second voltage. The switching unit switches the target voltage from the first voltage to the second voltage after the notification unit notifies the control unit that the target voltage is switched from the first voltage to the second voltage.

The power supply apparatus includes a current detection unit configured to detect a current that flows through a first switching element of a transformer, and a control unit controls a turn-on time of the first switching element based on a feedback voltage from a secondary side of the transformer, controls a turn-on time of a second switching element based on a detection result of the current detection unit, and performs switching between a continuous control and an intermittent control based on the feedback voltage, the continuous control being a control to perform an operation of continuing a first period, the intermittent control being a control to perform an operation of alternately repeating the first period and a second period.

The power supply apparatus includes a transformer, a switching unit provided on a primary side of the transformer and configured to perform switching operation for converting an input voltage resulting from rectification and smoothing of an AC voltage and outputting an output voltage from a secondary side of the transformer; a first detection unit configured to detect the output voltage, a feedback unit configured to generate a feedback voltage based on the voltage detected by the first detection unit; a control unit configured to control the switching operation of the switching unit based on the feedback voltage generated by the feedback unit; and a second detection unit configured to detect the AC voltage.

The power supply apparatus includes a transformer, at least one switching element provided on a primary side of the transformer and configured to perform a switching operation to output an output voltage from a secondary side of the transformer, and a control unit configured to determine a turn-on time of a pulse signal for controlling the switching element for each of first cycles, and perform a predetermined control in which a change value of the turn-on time of the pulse signal for each of second cycles each including the first cycles becomes smaller than a change value of the turn-on time of the pulse signal for each of the first cycles, to change the second cycle depending on operation states.

The switching power supply apparatus including a transformer includes a detection unit configured to detect that the power supply apparatus malfunctions and a first holding unit configured to turn off a first switching element and holds the first switching element at turn-off condition, and when the detection unit detects that malfunction occurs, the first holding unit releases the first switching element from the turn-off condition at a timing when the control unit turns on the second switching element by a second control signal.

Power supply apparatus and image forming apparatus controlling switching elements based on detection of a malfunction

The power supply apparatus switches the capacitance of a resonance capacitor to a first value at the time of a continuous operation, and switches the capacitance of the resonance capacitor to a second value smaller than the first value at the time of an intermittent operation.

Power supply apparatus and image forming apparatus switching a capacitance value of a resonance capacitor at a time of a continuous operation and an intermittent operation

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Kawasaki, Japan

Hiroki Asano