Abstract: An image forming apparatus for forming an image with a fixing member, which fixing member includes a first heating member and a plurality of second heating members is disclosed. The image forming apparatus includes a capacitor, a charging part for charging the capacitor, a first drive part for lighting on/off the first heating member by controlling a first power supply to the first heating member, a second drive part for lighting on/off at least one of the plurality of second heating members by controlling a second power supply to the plurality of second heating members, and a control part for dividing the plurality of second heating members into groups and permitting at least one of the groups to receive the second power supply during a waiting period of the image forming apparatus.

Abstract: An image forming apparatus for forming an image with a fixing member, which fixing member includes a first heating member and a plurality of second heating members is disclosed. The image forming apparatus includes a capacitor, a charging part for charging the capacitor, a first drive part for lighting on/off the first heating member by controlling a first power supply to the first heating member, a second drive part for lighting on/off at least one of the plurality of second heating members by controlling a second power supply to the plurality of second heating members, and a control part for dividing the plurality of second heating members into groups and permitting at least one of the groups to receive the second power supply during a waiting period of the image forming apparatus.

Abstract: An image forming apparatus for forming an image with a fixing member, which fixing member includes a first heating member and a plurality of second heating members is disclosed. The image forming apparatus includes a capacitor, a charging part for charging the capacitor, a first drive part for lighting on/off the first heating member by controlling a first power supply to the first heating member, a second drive part for lighting on/off at least one of the plurality of second heating members by controlling a second power supply to the plurality of second heating members, and a control part for dividing the plurality of second heating members into groups and permitting at least one of the groups to receive the second power supply during a waiting period of the image forming apparatus.

Abstract: A power source control apparatus including a capacitor; a charge control circuit for controlling a charger that charges the capacitor; a discharging circuit for discharging power charged in the capacitor to a heating member for heating. The power source control apparatus is shifted to an energy saving mode in which power supply to a part of power loads is stopped when a first condition is satisfied, and the power source control apparatus terminates the energy saving mode when a second condition is satisfied. In the apparatus, the charge control circuit is supplied with power from a power source circuit that supplies power during the energy saving mode.

Abstract: A main controller controls a capacitor charger to charge a capacitor as necessary. A sub-controller controls a power saving mode and stops a power supply to the main controller when shifting to the power saving mode. A charge control circuit compares a terminal voltage of the capacitor with a predetermined value by a comparator circuit. If the terminal voltage is lower than the reference value, an AND circuit takes a logical product of an output signal of the comparator circuit and a power saving signal indicating the shift to the power saving mode, and outputs a control signal indicating an instruction to charge the capacitor, to the capacitor charger.

Abstract: An induction heating device includes a plurality of induction coils connected to a single high-frequency power source and each being able to be ON/OFF controlled by a switch. A current is selectively fed only to desired part of the induction coils or to all of the induction coils connected in parallel. The coils are driven by a current fed thereto at the same time in the same phase. The device may include inverters for controlling power to be fed coil by coil. The device is free from interference and irregular heating and can readily cope with a change in a heating range while controlling power coil by coil.

Abstract: A power source control apparatus is disclosed. The apparatus comprises a capacitor; a charge control circuit for controlling a charger that charges the capacitor; a discharging circuit for discharging power charged in the capacitor to a heating member for heating. The power source control apparatus is shifted to an energy saving mode in which power supply to a part of power loads is stopped when a first condition is satisfied, and the power source control apparatus terminates the energy saving mode when a second condition is satisfied. In the apparatus, the charge control circuit is supplied with power from a first power source circuit that supplies power during the energy saving mode.

Abstract: An image forming apparatus for forming an image with a fixing member, which fixing member includes a first heating member and a plurality of second heating members is disclosed. The image forming apparatus includes a capacitor, a charging part for charging the capacitor, a first drive part for lighting on/off the first heating member by controlling a first power supply to the first heating member, a second drive part for lighting on/off at least one of the plurality of second heating members by controlling a second power supply to the plurality of second heating members, and a control part for dividing the plurality of second heating members into groups and permitting at least one of the groups to receive the second power supply during a waiting period of the image forming apparatus.

Abstract: An auxiliary power source device includes: a first battery; a first charger receiving power supply from a commercial power source and charging the first battery; a second battery connected with the first battery in series; a second charger receiving power supply from the commercial power source and charging the second battery; a detecting circuit detecting voltages of the first battery and the second battery; and a control part switching charging operation between the first and second chargers for a final target voltage based on a detection result of the detecting circuit.

Abstract: A main controller controls a capacitor charger to charge a capacitor as necessary. A sub-controller controls a power saving mode and stops a power supply to the main controller when shifting to the power saving mode. A charge control circuit compares a terminal voltage of the capacitor with a predetermined value by a comparator circuit. If the terminal voltage is lower than the reference value, an AND circuit takes a logical product of an output signal of the comparator circuit and a power saving signal indicating the shift to the power saving mode, and outputs a control signal indicating an instruction to charge the capacitor, to the capacitor charger.

Abstract: Synchronous rectifier circuits are provided for each secondary windings of a transformer. Field-effect transistors of which ON voltage is lower than the forward voltage of a diode are provided in each of the synchronous rectifier circuits. In an energy saving mode, the field-effect transistors in the synchronous rectifier circuit that outputs a diving voltage are turned OFF. A comparator circuit outputs a signal corresponding to a difference between a control voltage output from one of the synchronous rectifier circuits and a reference voltage. Based on this signal, a pulse-width modulation control circuit ON/OFF controls a field-effect transistor provided corresponding to a primary winding of a transformer in such a manner that the control voltage the reference control voltage attain predetermined levels.

Abstract: An induction heating device includes a plurality of induction coils connected to a single high-frequency power source and each being able to be ON/OFF control led by a switch. A current is selectively fed only to desired part of the induction coils or to all of the induction coils connected in parallel. The coils are driven by a current fed thereto at the same time in the same phase. The device may include inverters for controlling power to be fed coil by coil. The device is free from interference and irregular heating and can readily cope with a change in a heating range while controlling power coil by coil.

Abstract: An induction heating device includes a plurality of induction coils connected to a single high-frequency power source and each being able to be ON/OFF controlled by a switch. A current is selectively fed only to desired part of the induction coils or to all of the induction coils connected in parallel. The coils are driven by a current fed thereto at the same time in the same phase. The device may include inverters for controlling power to be fed coil by coil. The device is free from interference and irregular heating and can readily cope with a change in a heating range while controlling power coil by coil.

Abstract: An induction heating device includes a plurality of induction coils connected to a single high-frequency power source and each being able to be ON/OFF controlled by a switch. A current is selectively fed only to desired part of the induction coils or to all of the induction coils connected in parallel. The coils are driven by a current fed thereto at the same time in the same phase. The device may include inverters for controlling power to be fed coil by coil. The device is free from interference and irregular heating and can readily cope with a change in a heating range while controlling power coil by coil.

Abstract: An induction heating device includes a plurality of induction coils connected to a single high-frequency power source and each being able to be ON/OFF controlled by a switch. A current is selectively fed only to desired part of the induction coils or to all of the induction coils connected in parallel. The coils are driven by a current fed thereto at the same time in the same phase. The device may include inverters for controlling power to be fed coil by coil. The device is free from interference and irregular heating and can readily cope with a change in a heating range while controlling power coil by coil.

Abstract: Synchronous rectifier circuits are provided for each secondary windings of a transformer. Field-effect transistors of which ON voltage is lower than the forward voltage of a diode are provided in each of the synchronous rectifier circuits. In an energy saving mode, the field-effect transistors in the synchronous rectifier circuit that outputs a diving voltage are turned OFF. A comparator circuit outputs a signal corresponding to a difference between a control voltage output from one of the synchronous rectifier circuits and a reference voltage. Based on this signal, a pulse-width modulation control circuit ON/OFF controls a field-effect transistor provided corresponding to a primary winding of a transformer in such a manner that the control voltage the reference control voltage attain predetermined levels.

Abstract: A fixing device for an image forming apparatus includes an inverter circuit for induction heating. In the inverter circuit, a main switch Q1 drives one end of a work coil L1 whose other end is connected to a power source. A serial connection of a capacitor Cs and a subswitch Q2 is connected to opposite ends of the coil L1 in parallel such that one end of the capacitor Cs is connected to the power source E. A second capacitor C1 is connected to the subswitch Q2 in parallel. For a capacitance of 0.1 &mgr;F of the capacitor C1, the factor of the coil L1 and that of the capacitor Cs are selected to be between 70 &mgr;H and 100 &mgr;H and between 1.8 &mgr;F and 5 &mgr;F, respectively. The inverter circuit is operable with optimal efficiency in the event of PWM (Pulse Width Modulation) control using a fixed frequency.

Abstract: A fixing device for an image forming apparatus includes an inverter circuit for induction heating. In the inverter circuit, a main switch Q1 drives one end of a work coil L1 whose other end is connected to a power source. A serial connection of a capacitor Cs and a subswitch Q2 is connected to opposite ends of the coil L1 in parallel such that one end of the capacitor Cs is connected to the power source E. A second capacitor C1 is connected to the subswitch Q2 in parallel. For a capacitance of 0.1 &mgr;F of the capacitor C1, the factor of the coil L1 and that of the capacitor Cs are selected to be between 70 &mgr;H and 100 &mgr;H and between 1.8 &mgr;F and 5 &mgr;F, respectively. The inverter circuit is operable with optimal efficiency in the event of PWM (Pulse Width Modulation) control using a fixed frequency.

Abstract: An induction heating device includes a plurality of induction coils connected to a single high-frequency power source and each being able to be ON/OFF controlled by a switch. A current is selectively fed only to desired part of the induction coils or to all of the induction coils connected in parallel. The coils are driven by a current fed thereto at the same time in the same phase. The device may include inverters for controlling power to be fed coil by coil. The device is free from interference and irregular heating and can readily cope with a change in a heating range while controlling power coil by coil.