Abstract: An electric power supplying device includes a main power supply that supplies electric power to each component of an apparatus, an auxiliary power supply that supplies electric power to an assisted component in the apparatus, the assisted component requiring power supply during start-up time of the apparatus and having a whose start-up time being equal to or longer than a predetermined period of time, a discharging control circuit that controls the auxiliary power supply to cause the auxiliary power supply to output a voltage, the output voltage being lower than a voltage output by the main power supply and being equal to or more than a lower limit voltage of a voltage range that the assisted component is operable, and a power supply prevention circuit that prevents the auxiliary power supply from supplying power to a component other than the assisted component in the apparatus.

Abstract: An image forming apparatus includes a fixing device to fix an image on a recording medium by heating the recording medium, multiple heat storing devices to store heat generated at the fixing device, an electric generating element to generate power by converting the heat into power, and a switch to switch connection and disconnection between the electric generating element and at least one of the multiple heat storing devices.

Abstract: An electric power supplying device includes a main power supply that supplies electric power to each component of an apparatus, an auxiliary power supply that supplies electric power to an assisted component in the apparatus, the assisted component requiring power supply during start-up time of the apparatus and having a whose start-up time being equal to or longer than a predetermined period of time, a discharging control circuit that controls the auxiliary power supply to cause the auxiliary power supply to output a voltage, the output voltage being lower than a voltage output by the main power supply and being equal to or more than a lower limit voltage of a voltage range that the assisted component is operable, and a power supply prevention circuit that prevents the auxiliary power supply from supplying power to a component other than the assisted component in the apparatus.

Abstract: A commercial AC power shutdown detecting apparatus includes a photocoupler including a light-emitting element and a light-receiving element, a lighting circuit that flows a pulsating current through the light-emitting element of the photocoupler to turn on and off light of the light-emitting element, a charging-discharging circuit including a capacitor and a resistor that charges the capacitor via the resistor when the light-emitting element is turned off, and discharges the capacitor via the light-receiving element and the a resistor when the light-emitting element is turned on, and a comparing circuit that compares a voltage value between capacitor terminals with a predetermined voltage value intermediate between a maximum voltage value between the capacitor terminals when the light-emitting element repeats turning light on and off and the consistent DC voltage value, and outputs a shutdown detection signal if the voltage value between the capacitor terminals exceeds the predetermined voltage value.

Abstract: An image forming apparatus includes a heat-generating component, a power generation device including a thermoelectric element, a heat radiation device, a cooling device, a temperature detector that detects a temperature increase of the heat-generating component, and a controller. The heat radiation device includes a first radiator plate interposed between the heat-generating component and a surface of the thermoelectric element and a second radiator plate attached to another surface of the thermoelectric element. The cooling device cools the first radiator plate. The controller controls operations of the cooling device and the power generation device by operating the cooling device if the detected temperature increase reaches at least a predetermined threshold value, and causing the power generation device to generate power without operating the cooling device to cool the first radiator plate passively if the detected temperature increase falls below the predetermined threshold value.

Abstract: An image forming apparatus includes a heat generator configured to generate heat in the image forming apparatus; a converter including a capacitor to convert AC power supplied from an external power supply into DC power for a load unit; a thermoelectric transducer configured to convert the generated heat into DC power for the load unit; a detector configured to detect a voltage of the AC power; and a controller configured to cause the converter to continue supplying the DC power to the load unit when a first elapsed time elapsed since the detected voltage drops below a rated voltage is shorter than a first time period shorter than an upper limit of a period of time over which the capacitor is dischargeable, and cause the thermoelectric transducer to supply the DC power to the load unit when the first elapsed time exceeds the first time period.

Abstract: An image forming apparatus includes a fixing device to fix an image on a recording medium by heating the recording medium, multiple heat storing devices to store heat generated at the fixing device, an electric generating element to generate power by converting the heat into power, and a switch to switch connection and disconnection between the electric generating element and at least one of the multiple heat storing devices.

Abstract: An image forming apparatus includes a heat generator configured to generate heat in the image forming apparatus; a converter including a capacitor to convert AC power supplied from an external power supply into DC power for a load unit; a thermoelectric transducer configured to convert the generated heat into DC power for the load unit; a detector configured to detect a voltage of the AC power; and a controller configured to cause the converter to continue supplying the DC power to the load unit when a first elapsed time elapsed since the detected voltage drops below a rated voltage is shorter than a first time period shorter than an upper limit of a period of time over which the capacitor is dischargeable, and cause the thermoelectric transducer to supply the DC power to the load unit when the first elapsed time exceeds the first time period.

Abstract: An image forming apparatus includes a heat-generating component, a power generation device including a thermoelectric element, a heat radiation device, a cooling device, a temperature detector that detects a temperature increase of the heat-generating component, and a controller. The heat radiation device includes a first radiator plate interposed between the heat-generating component and a surface of the thermoelectric element and a second radiator plate attached to another surface of the thermoelectric element. The cooling device cools the first radiator plate. The controller controls operations of the cooling device and the power generation device by operating the cooling device if the detected temperature increase reaches at least a predetermined threshold value, and causing the power generation device to generate power without operating the cooling device to cool the first radiator plate passively if the detected temperature increase falls below the predetermined threshold value.

Abstract: A heater control device comprising: a storage unit that stores therein a turn-on pattern of a heater specified in units of a predetermined control cycle including a plurality of half-wavelengths of an alternating-current voltage supplied to the heater so as to prevent flickering; a color temperature detecting unit that detects a color temperature of light emitted from a filament of the heater; and a heater control unit that, while operating in a standby mode in which power supplied to the heater is reduced, causes the heater to be fully turned ON at every first period, and then turns ON the heater in the turn-on pattern when the color temperature exceeds a predetermined threshold after the heater is fully turned ON.

Abstract: A heater control device includes a temperature detector that detects a temperature of a heated object heated by a heater; an alternating-current power supply for applying an alternating current voltage to the heater; a turn-on ratio decision unit that determines a turn-on ratio of the heater based on the temperature and a target temperature; a turn-on pattern decision unit that determines a partial turn-on pattern, as the turn-on pattern of the heater, which is a pattern of a turn-on ratio higher than the determined turn-on ratio in terms of a control-period, and to which a partial turn-on instead of a full turn-on is allocated on a half-wavelength basis of the alternating current voltage within the control period based on the turn-on ratio of the heater; and a turn-on controller that controls turn-on of the heater based on the determined turn-on pattern.

Abstract: An image forming apparatus includes a halogen heater in a fixing unit; an AC source applying an alternating voltage to the halogen heater; a half-wave control unit that performs the heater half-wave control to control the halogen heater on the half-wavelength basis, according to a heater-on/off pattern set for each control cycle having a predetermined length; a heater-off-time measuring unit that measures heater-off period of time; a phase-control-execution determining unit that determines, based on the measured heater-off period of time, whether the heater phase control is to be performed on the alternating voltage, the phase control being performed by shifting phase of the alternating voltage; and a phase control unit that performs, when the phase control is determined to be performed, the phase control only for a period of time depending on the measured heater-off period of time after switch-on of the heater and before execution of the half-wave control.

Abstract: A heater control device comprising: a storage unit that stores therein a turn-on pattern of a heater specified in units of a predetermined control cycle including a plurality of half-wavelengths of an alternating-current voltage supplied to the heater so as to prevent flickering; a color temperature detecting unit that detects a color temperature of light emitted from a filament of the heater; and a heater control unit that, while operating in a standby mode in which power supplied to the heater is reduced, causes the heater to be fully turned ON at every first period, and then turns ON the heater in the turn-on pattern when the color temperature exceeds a predetermined threshold after the heater is fully turned ON.

Abstract: A heater control device includes a temperature detector that detects a temperature of a heated object heated by a heater; an alternating-current power supply for applying an alternating current voltage to the heater; a turn-on ratio decision unit that determines a turn-on ratio of the heater based on the temperature and a target temperature; a turn-on pattern decision unit that determines a partial turn-on pattern, as the turn-on pattern of the heater, which is a pattern of a turn-on ratio higher than the determined turn-on ratio in terms of a control-period, and to which a partial turn-on instead of a full turn-on is allocated on a half-wavelength basis of the alternating current voltage within the control period based on the turn-on ratio of the heater; and a turn-on controller that controls turn-on of the heater based on the determined turn-on pattern.

Abstract: An image forming apparatus includes a halogen heater in a fixing unit; an AC source applying an alternating voltage to the halogen heater; a half-wave control unit that performs the heater half-wave control to control the halogen heater on the half-wavelength basis, according to a heater-on/off pattern set for each control cycle having a predetermined length; a heater-off-time measuring unit that measures heater-off period of time; a phase-control-execution determining unit that determines, based on the measured heater-off period of time, whether the heater phase control is to be performed on the alternating voltage, the phase control being performed by shifting phase of the alternating voltage; and a phase control unit that performs, when the phase control is determined to be performed, the phase control only for a period of time depending on the measured heater-off period of time after switch-on of the heater and before execution of the half-wave control.