Patent application number | Description | Published |
20080298091 | Image Forming Apparatus - The present invention can include an image forming apparatus having an electrical load, a supplying circuit configured to supply an electrical power to the electrical load, and an output circuit configured to output a voltage according to a current value of the electrical power being supplied to the electrical load. The present invention may also provide for a controller configured to control an electrical current flowing in the electrical load based on an output voltage value of the output circuit as a feedback value, and an inhibiting circuit configured to inhibit a reverse current to flow in the output circuit when the supplying circuit is turned off. | 12-04-2008 |
20090027924 | Feedback Control Device - A feedback control device is provided. The feedback control device includes a controlled-system which outputs and output in correspondence with a control signal; a feedback signal generating member which generates a feedback signal as the output of the controlled-system; a reference signal unit which outputs a reference control signal to the controlled-system; and a determination unit which determines a version of the controlled-system on the basis of the feedback signal generated by the feedback signal generating member when the reference signal unit outputs the reference control signal to the controlled-system. | 01-29-2009 |
20090035008 | Image Forming Apparatus - An image forming apparatus capable of shortening a time needed for the assembly work is provided. The image forming apparatus of the invention comprises a low-voltage power supply and a housing, wherein the low-voltage power supply includes a substrate provided with a low-voltage power supply circuit, a pair of connection cords each connected to the substrate and an external power supply, a casing made of metal and provided with an accommodation portion inside which the substrate is fixed and a notch located on an opening edge of the accommodation portion, a lid body made of metal and configured to cover the accommodation portion and to define a cord insertion port by closing the notch, and a ring body made of resin and inserted into the notch in a state where both the connection cords are inserted in the ring body and to be attached to the cord insertion port. | 02-05-2009 |
20090052923 | Image Forming Apparatus - An image forming apparatus is configured to reduce follow-up delay in impedance fluctuation and to reduce an accuracy fall in power supply control. The image forming apparatus includes a transfer element, a supply element, a detection element, a modification element, and a switch element. The supply element supplies electricity that depends on a set value to the transfer element. The detection element detects the control object value supplied to the transfer element. Depending on a difference between the control object value detected by the detection element and a target value, the modification element operates modification of the set value. The switch element switches between a short interval mode and a long interval mode. In a short interval mode, an execution time interval for modification of the set value is shorter, while, in a long interval mode, the execution time interval for modification of the set value is longer. | 02-26-2009 |
20090202265 | Image Forming Apparatus - An image forming apparatus includes an image carrier for carrying developer image, a transfer device configured to transfer the developer image to a recording media, a forward bias applying circuit configured to apply a forward bias voltage to the transfer device, and a reverse bias applying circuit configured to apply a reverse bias voltage to the transfer device. The apparatus includes a detecting circuit configured to detect inflow current flowing from the image carrier into the forward bias applying circuit, and a decision circuit configured to determine a lower limit of the reverse bias voltage based on a detected value of the inflow current when the detected value of the inflow current exceeds a first predetermined value. The reverse bias applying circuit applies the reverse bias voltage of the determined lower limit to the transfer device at least before the forward bias voltage is applied to the transfer device. | 08-13-2009 |
20090237001 | Light Output Device and Image Forming Apparatus Including the Same - A light output device includes a feedback-signal generating unit configured to generate a feedback control signal for maintaining output power of the light at a predetermined value. The feedback-signal generating unit generates the feedback control signal in a gradually rising manner and supplies the generated feedback control signal to the output unit so that output power of the light is gradually increased at a time of power-on. The light output device also includes a discharge circuit configured to discharge a charge stored in the feedback-signal generating unit and thereby accelerate decrease of the feedback control signal and a power-voltage monitoring circuit configured to monitor a voltage of the power supplied to the output unit. The power-voltage monitoring circuit, upon detecting shutdown of the power, controls the discharge circuit and thereby causes discharge of the charge stored in the feedback-signal generating unit. | 09-24-2009 |
20090296763 | LIGHT OUTPUT DEVICE AND IMAGE FORMING APPARATUS INCLUDING THE LIGHT OUTPUT DEVICE - A light output device includes: an output unit including a light source; a control voltage generation unit that detects output power of the light source, and generates a control voltage for controlling a drive current of the light source; a control unit that sets a target value of the output power; a voltage-current conversion unit that converts the control voltage into the drive current; a setting unit that sets an inclination of a characteristic line of control voltage-drive current conversion in the voltage-current conversion unit; and an adjustment unit that adjusts the voltage-current conversion unit such that the drive current becomes a target current value for setting the output power to the target value in a predetermined control voltage value on the characteristic line, wherein the setting unit sets the inclination of the characteristic line to a first inclination where the drive current does not reach a maximum current value. | 12-03-2009 |
20100189457 | IMAGE FORMING APPARATUS - An image forming apparatus includes: an image carrying unit; a charging unit; a transfer unit transferring an developed image to a recording medium in accordance with application of a transfer voltage; an application unit generating the transfer voltage and applying the transfer voltage to the transfer unit; a voltage detection unit detecting the transfer voltage; an inflow current detection unit detecting an inflow current flowing from the image carrying unit charged by the charging unit into the application unit; a transfer current detection unit detecting a transfer current flowing when the transfer voltage is applied to the transfer unit; a determination unit determining an initiating voltage which induces the inflow current; a calculation unit calculating load resistance of the application unit based on the transfer voltage, the transfer current, and the initiating voltage; and an adjustment unit that adjusts the transfer current in accordance with the load resistance. | 07-29-2010 |
20100195150 | Image Forming Apparatus - An image forming apparatus includes: an applying device configured to generate an output signal and apply the output signal to an image forming device; and a controller configured to generate a control signal to supply to the applying device so as to control a value of the output signal so that the value of the output signal is within a predetermined target range and control the applying device using the control signal in a start-up mode and in a normal mode, the normal mode being subsequent to the start-up mode. In the start-up mode, the controller sets a start control signal value larger than a value of the control signal immediately after a first predetermined time, the start control signal value being the value of the control signal during the first predetermined time, the first predetermined time being from a start timing of the start-up mode. | 08-05-2010 |
20100221027 | Light Output Device and Image Forming Apparatus Including the Same - A light output device comprises a controller configured to generate a set signal that sets a reference voltage for determining a predetermined value of an output power of the light in a case of power adjustment wherein the output power is changed to a power different from in a case of power accuracy requirement, and a reference voltage generating section configured to generate the reference voltage according to the set signal. The controller in the case of power accuracy requirement puts a set-signal output port in a high-impedance state, while in the case of power adjustment generates the set signal using a predetermined voltage, the set signal alternating between a high level and a low level. The reference voltage generating section in the case of power accuracy requirement generates the reference voltage on a basis of a level shift voltage generated by level shifting the predetermined voltage. | 09-02-2010 |
20100239291 | HIGH-VOLTAGE POWER SUPPLY - A high-voltage power supply for applying a developing bias to a developing roller of an image forming apparatus is provided. The high-voltage power supply includes: a developing bias application unit that applies a developing bias to the developing roller in accordance with a control voltage that is input therein; a developing bias detection unit that detects the developing bias applied to the developing roller; a control voltage adjustment unit that adjusts the control voltage input to the developing bias application unit such that the developing bias detected by the developing bias detection unit approaches a predetermined target value; and a condensation determination unit that determines condensation of the developing bias application unit based on the control voltage. | 09-23-2010 |
20100254107 | Electronic Apparatus - An electronic apparatus is provided that can include a circuit board; a switch attached to the circuit board; an electronic part mounted on the circuit board; a wiring pattern extending between the switch and the electronic part; and a protrusion protruding from a surface of the wiring pattern. The protrusion may be disposed adjacent to the switch on the circuit board and overlapping the wiring pattern. | 10-07-2010 |
20100272463 | IMAGE FORMING APPARATUS AND HIGH VOLTAGE GENERATING POWER SUPPLY - An image forming apparatus includes, an image forming unit, an irradiating unit, a first low voltage power supply which generates a first low voltage, a first low voltage power supply line, a first switching element, a first high voltage generating unit including a first transformer, a second low voltage power supply, and a control unit. The image forming apparatus further includes an cover which can be opened and closed, wherein the image forming unit detects the opening and closing of the cover; and an interlock switch which interlocks with the opening/closing of the cover and includes a first contact point connected to the first low voltage power supply and a second contact point connected to the first low voltage power supply line, wherein the interlock switch is opened to disconnect the first contact point from the second contact point when the cover is opened. | 10-28-2010 |
20100278547 | Image Forming Apparatus and Voltage Applying Device - An image forming apparatus includes a voltage applying unit for applying a voltage to an electric load; a sub control unit for controlling the voltage applying unit; a restarting unit for restarting the sub control unit in response to receipt of a restart signal; a determining unit for determining whether or not restart of the sub control unit is abnormal restart; and a main control unit. The main control unit generates a control start signal for allowing the voltage applying unit to start generation of the voltage, and the restart signal. When the determining unit determines that restart of the sub control unit is abnormal restart, the main control unit sends again the control start signal to the sub control unit. | 11-04-2010 |
20110123208 | Heating Device and Image Forming Apparatus - A heating device includes: a heat generating unit generating heat in response to energization of an alternating-current power supply; a zero-crossing signal generating circuit generating a zero-crossing signal in synchronization with a zero-crossing time of the alternating-current power supply; an energization regulating unit regulating an energization period of the heat generating unit by the alternating-current power supply; a voltage change rate detecting unit detecting whether a rate of voltage change of the alternating-current power supply at the zero-crossing time is equal to or larger than an predetermined value; a switching unit switching on and off a connection between the alternating-current power supply and the heat generating unit; and an energization disabling unit disabling energization of the heat generating unit by controlling the switching unit when the rate of voltage change is equal to or larger than the predetermined value. | 05-26-2011 |
20110158674 | Multiple-Output Power Supply Unit and Image Forming Apparatus Having the Power Supply Unit - A multiple-output power supply unit includes: a transformer including: a primary winding; and a secondary winding which has a first node and a second node and which generates a secondary-side voltage at the secondary winding; first output terminal to output a first voltage corresponding to the secondary-side voltage; a first constant voltage element; a current limiting resistor; a second constant voltage element; a second output terminal to output a second voltage different from the first voltage; a current generation circuit provided between the first node and the ground so as to cause a predetermined current to flow between the first node and the ground; a transformer driver circuit connected to the primary winding so as to drive the transformer; and a secondary-side voltage control circuit that controls the transformer driver circuit so as to generate the secondary-side voltage having a predetermined value at the first node. | 06-30-2011 |
20110158675 | Multiple-Output Power Supply Unit and Image Forming Apparatus Having the Power Supply Unit - A multiple-output power supply unit includes: a first voltage generation circuit that generates a first voltage applied to a first load; a first output terminal that outputs a second voltage corresponding to the first voltage to a second load; a first constant voltage element that is connected to the first output terminal; a second constant voltage element that is provided between the first constant voltage element and a ground; and a second output terminal that is connected between the first constant voltage element and the second constant voltage element so as to output a third voltage having a predetermined potential difference from the second voltage to a third load that is provided in a state of being electrically connected to the second load. | 06-30-2011 |
20120027436 | Image Forming Apparatus - An image forming apparatus including: a plurality of photosensitive drums; a plurality of scorotron chargers provided for the plurality of photosensitive drums, respectively, a voltage application circuit commonly connected to the plurality of scorotron chargers, a plurality of wires provided for the plurality of scorotron chargers, respectively; a plurality of grid electrodes provided for the plurality of scorotron chargers, respectively; at least one of current detecting units provided for at least one of the plurality of grid electrodes, respectively, and at least one of the current detecting units detecting grid current which flows into at least one of the grid electrodes, respectively; and a control device configured to control the voltage application circuit such that at least one of the grid currents detected by at least one of the current detecting units become equal to or higher than a reference value. | 02-02-2012 |
20120027437 | Image Forming Apparatus - An image forming apparatus, includes: at lease one photosensitive element; a plurality of chargers configured to charge the at lease one photosensitive element; a voltage applying circuit commonly connected to the plurality of chargers and configured to apply a voltage to the plurality of chargers; a current detecting unit configured to detect a current sum of current that flows to the plurality of chargers from the voltage applying circuit; and a control device configured to control the voltage applying circuit so that the current sum detected by the current detecting unit becomes equal to or larger than a reference value. | 02-02-2012 |
20120057888 | Image Forming Apparatus - An image forming apparatus includes: a photosensitive member; a scorotron charger; a developing device; a voltage application circuit; a constant-voltage circuit; a first control device; a deboost circuit; and a second control device, wherein the deboost circuit has a circuit configuration in which a resistor and a control transistor are connected in series with each other, and deboosts the grid voltage by a voltage drop of the resistor to generate the developing voltage, and the second control device provides a control signal to the control transistor to control a current flowing in the resistor, thereby controlling the level of the developing voltage. | 03-08-2012 |
20120082470 | IMAGE FORMING APPARATUS - An image forming apparatus includes: a photoconductor; a charger configured to charge the photoconductor, the charger having a discharge wire and a grid; a charge-voltage applying device configured to generate charge voltage and apply the charge voltage to the discharge wire; and an abnormal-discharge detector provided between an output end portion of the charge-voltage applying device and the ground. The abnormal-discharge detector is configured to detect an abnormal discharge occurring in the charger by detecting an abnormal current passing via the grid and the ground upon occurrence of the abnormal discharge. | 04-05-2012 |
20120113685 | POWER SUPPLY SYSTEM AND IMAGE FORMING APPARATUS - A power supply system includes: a switching power supply; and a control device, wherein the switching power supply includes: a transformer; a semiconductor switching element; a switch control unit; and a rectifying/smoothing circuit, the switch control unit is supplied with power from the main power supply, starts to control the switching of the semiconductor switching element, and oscillates a primary side of the transformer to induce a voltage on the secondary side of the transformer, the control device outputs a control pulse signal to the switch control unit to stop the oscillation of the transformer, thereby changing the mode of the switching power supply to an output stop mode, in an output mode in which the switching power supply smoothes the voltage induced on the secondary side and outputs the smoothed voltage. | 05-10-2012 |
20120114363 | POWER SUPPLY SYSTEM AND IMAGE FORMING APPARATUS - A power supply system includes: a switching power supply and a rectifying/smoothing circuit, the switching power supply configured to output a first output voltage in a normal output mode; a step-down circuit; a control device that controls the switching of the switching power supply between the normal output mode, a low output mode, and an off mode; and an electric storage unit charged by the output of the step-down circuit in the normal output mode and supplies power to the control device in the off mode, wherein, when charging is needed in the mode other than the normal output mode and the low output mode, the control device controls the switching power supply to output the third output voltage, thereby charging the electric storage unit. | 05-10-2012 |
20120134707 | POWER SUPPLY SYSTEM AND IMAGE FORMING APPARATUS INCLUDING THE SAME - A power supply system includes a switching power supply. The switching power supply includes an overcurrent detection circuit. The overcurrent detection circuit includes a current detecting resistor, a reference voltage generation circuit, and a comparison circuit. The current detecting resistor is provided on a secondary side of a transformer. The reference voltage generation circuit generates a first reference voltage when an output voltage of the switching power supply is a first output voltage and a second reference voltage lower than the first reference voltage when the output voltage is a second output voltage. The comparison circuit detects an overcurrent by comparing a voltage across the current detecting resistor with the first reference voltage or the second reference voltage. | 05-31-2012 |
20120230744 | HEATING APPARATUS AND IMAGE FORMING APPARATUS HAVING THE SAME - A heating apparatus includes a switching circuit configured to switch on/off current-feeding from an AC power source to the heater, a temperature detector configured to detect a temperature of the heater, and a current-feed controller configured to execute a first current-feed mode of changing a current-feed ratio of current-feeding time to unit time by controlling switching of the switching circuit so that the temperature detected by the temperature detector falls within a target range. The current-feed controller executes a second current-feed mode of fixing the current-feed ratio to almost 100% or almost 0% during execution of the first current-feed mode in place of the first current-feed mode. | 09-13-2012 |
20130028623 | ZERO-CROSSING DETECTOR CIRCUIT AND IMAGE FORMING APPARATUS HAVING THE SAME - A zero-crossing detector circuit includes: a first capacitor including a first electrode configured to connect to one end of an AC power supply and a second electrode; a second capacitor including a first electrode configured to connect to the other end of the AC power supply and a second electrode; a current path, which is connected in series between the second electrode of the first capacitor and the second electrode of the second capacitor, and which is connected to a reference potential, and which generates a second-electrode-side voltage when the AC current passes through the current path; a signal converting circuit, which is connected to the AC power supply to receive the second-electrode-side voltage and then converts the second-electrode-side voltage into a pulse signal; and a detecting unit, which detects a pulse period of the pulse signal, which and detects zero-crossing points by using the pulse period. | 01-31-2013 |
20130031396 | POWER SUPPLY SYSTEM, IMAGE FORMING APPARATUS HAVING THE SAME, AND LOW-CAPACITY POWER SUPPLY CIRCUIT - A power supply system includes: a switching power supply, which rectifies and smoothes an AC voltage of an AC power supply to generate a first DC voltage in a normal mode; a control unit, which controls the switching power supply to switch between the normal mode and a power saving mode; and a low-capacity power supply circuit, which supplies power to the control unit in the power saving mode, and which includes: a first capacitor, which includes a first electrode connected to one end of the AC power supply, and a second electrode; a second capacitor, which includes a first electrode connected to the other end of the AC power supply, and a second electrode; a rectifying circuit, which rectify an AC voltage applied to both capacitors; and a smoothing circuit, which smoothes the rectified AC voltage to generate a smooth voltage. | 01-31-2013 |
20130038318 | AC VOLTAGE DETECTING CIRCUIT AND IMAGE FORMING APPARATUS HAVING THE SAME - An AC voltage detecting circuit comprises: a first capacitor including a first electrode configured to connect to one end of an AC power supply, and a second electrode; a second capacitor including a first electrode configured to connect to the other end of the AC power supply, and a second electrode; a current-to-voltage converting circuit, which is connected in series between the second electrode of the first capacitor and the second electrode of the second capacitor, and which is connected to a reference potential, wherein the current-to-voltage converting circuit causes the AC current to pass through the current-to-voltage converting circuit when the AC current returns to the AC power supply, and converts an AC current output from the AC power supply into an detection AC voltage; and a voltage detecting unit, which detects an AC input voltage of the AC power supply, based on the detection AC voltage. | 02-14-2013 |
20130111237 | POWER SUPPLY SYSTEM, IMAGE FORMING APPARATUS HAVING THE SAME, AND LOW-CAPACITY POWER SUPPLY CIRCUIT | 05-02-2013 |
20130113292 | POWER SUPPLY SYSTEM, IMAGE FORMING APPARATUS HAVING THE SAME, AND CONTROL METHOD OF THE SAME - A power supply system includes: a switching power supply configured to convert an AC voltage from an AC power supply into predetermined DC voltages, and outputs the DC voltages; a switch circuit provided on an AC input line, the switch circuit being configured to be switched on and off and supply AC power to the power supply when the switch circuit is turned on; a low-capacity power supply circuit connected. to the AC input line at a front stage of the switch circuit, the low-capacity power supply circuit being configured to supply electric power to the switch circuit if the power supply is active and supply predetermined electric power if the power supply is not used; and a control device configured to receive the predetermined electric power from the low-capacity power supply circuit. When the power supply is not used, the control device turns off the switch circuit. | 05-09-2013 |
20130129373 | POWER SUPPLY SYSTEM, IMAGE FORMING APPARATUS HAVING THE SAME, AND LOW-CAPACITY AC PROCESSING CIRCUIT - A power supply system includes: a switching power supply to be connected to an AC power supply, the switching power supply rectifying and smoothing an AC voltage to generate predetermined DC voltage; a first capacitor including a first electrode connected to one end of the AC power supply, and a second electrode; a second capacitor including a first electrode connected to the other end of the AC power supply, and a second electrode; a surge-voltage suppressing circuit connected between the second electrode of the first capacitor and the second electrode of the second capacitor; a rectifier circuit connected to a first contact node between the first capacitor and the surge-voltage suppressing circuit and a second contact node between the second capacitor and the surge-voltage suppressing circuit; and an output-signal generating circuit connected to the rectifier circuit, and uses the rectified current to generate a predetermined output signal. | 05-23-2013 |
20130164016 | POWER SUPPLY SYSTEM AND IMAGE FORMING APPARATUS - A power supply system for AC-DC conversion, includes: a first rectifying/smoothing circuit configured to rectify and smooth an AC voltage applied from an AC power supply; a switching power supply configured to perform voltage conversion on an output voltage of the first rectifying/smoothing circuit, and output the converted voltages; an accumulating unit configured to receive a charging current from the switching power supply; a detecting unit configured to detect input/cutoff of the AC power supply; and a control device configured to receive supply of electric power from the accumulating unit and stop the switching power supply if the detecting unit detects the cutoff of the AC power supply. | 06-27-2013 |
20130170850 | POWER SUPPLY DEVICE PERFORMING VOLTAGE CONVERSION - In a power supply device, the controller outputs a control signal specifying a voltage value. The voltage conversion unit converts a first voltage to a second voltage in response to a control signal specifying a voltage value output from the controller. The voltage conversion unit converts the first voltage to a start voltage, as the second voltage, in response to a first control signal specifying a start voltage value output from the controller and further converts the first voltage to a target voltage, as the second voltage, in response to a second control signal specifying a target voltage value output from the controller. A transition period of time is intervened between generation of the start voltage and generation of the target voltage during which the controller outputs a third control signal specifying the intermediate voltage value between the start voltage value and the target voltage value. | 07-04-2013 |
20130195479 | HEATING DEVICE AND IMAGE FORMING APPARATUS - A heating device includes: an alternating current (AC) power supply line configured to supply AC current from an AC power supply; a heat generation unit configured to generate heat in accordance with the AC current; an energization regulation unit configured to regulate energization time of the AC current to the heat generation unit; a switching unit configured to switch a connection state between the AC power supply and the heat generation unit; and a high-voltage protection unit, which is connected between the AC power supply line at a rear stage of the switching unit, and which is configured to protect the energization regulation unit against an abnormal input high voltage. | 08-01-2013 |
20140186066 | POWER SUPPLY SYSTEM AND IMAGE FORMING APPARATUS HAVING THE SAME - A power supply system includes: a switching power supply configured to rectify and smooth an AC voltage of an AC power supply to generate a predetermined DC voltage; a low-capacity power supply circuit that generates a zero-cross detection signal corresponding to zero-cross points of the AC power supply based on a rectified current flowing in a smoothing capacitor; and a controller configured to receive the zero-cross detection signal from the signal generating circuit and perform a determining process of determining whether it is possible to perform detection process of the zero-cross points based on a voltage value of the zero-cross detection signal. If the control unit determines that it is possible to perform the detection process of the zero-cross points, the control unit performs a zero-cross point detecting process of detecting the zero-cross points based on the zero-cross detection signal. | 07-03-2014 |
20140186067 | SWITCHING POWER SOURCE, POWER-SUPPLY SYSTEM AND IMAGE FORMING APPARATUS - A switching power source includes: a transformer; a semiconductor switching element that is provided at a primary side of the transformer; a rectifying-and-smoothing circuit that is provided at a secondary side of the transformer; a switching controller configured to perform a switching control to turn on-and-off the semiconductor switching element, wherein the switching controller comprises: a stoppage circuit configured to perform a stoppage process to stop the switching control when a first-level control signal is input, a restart circuit configured to restart the switching control when a second-level control signal different in its level from the first-level control signal, and a limiting circuit configured to limit, at the time of a start-up of the switching power source, a performance of the stoppage process performed by the stoppage circuit until an output voltage of the switching power source increases to a target voltage. | 07-03-2014 |
20140210264 | POWER SUPPLY SYSTEM, IMAGE FORMING APPARATUS HAVING THE POWER SUPPLY SYSTEM, AND CONTROL METHOD OF THE POWER SUPPLY SYSTEM - A power supply system includes a switching power supply for outputting a predetermined DC voltage by converting an AC voltage from an AC power supply, a latching relay provided on an AC input line for switching a connection state of the switching power supply and the AC power supply in response to a relay drive signal, a storage circuit storing electricity from the switching power supply, a control device for receiving electric power from the storage circuit in a disconnection state, and a relay drive circuit for generating the relay drive signal and outputting it to the latching relay. The control device determines whether an amount of charge of the storage circuit has decreased to a predetermined amount of charge in the disconnection state, and generates and outputs the relay control signal to the relay drive circuit. | 07-31-2014 |
20140218827 | POWER SUPPLY SYSTEM - A power supply system includes: a switching power supply; a switching unit for switching a connection state between an AC power supply and the switching power supply; an electricity storage unit; an auxiliary power supply circuit for feeding charging current to the electricity storage unit; a driving circuit for driving the switching unit; a voltage detection circuit for detecting a voltage of the AC power supply; and a control device configured to perform: an overvoltage detection process of determining whether the AC power supply is an overvoltage based on a detection value of the voltage detection circuit; and a process of, in a case where an overvoltage is detected, keeping the switching unit at a cutoff state where the alternating current power supply and the switching power supply are disconnected. | 08-07-2014 |
20140233266 | POWER SUPPLY SYSTEM, IMAGE FORMING APPARATUS HAVING THE POWER SUPPLY SYSTEM, AND CONTROL METHOD OF THE POWER SUPPLY SYSTEM - A power supply system includes: a switching power supply for converting an AC voltage from an AC power supply into a DC voltage; a latching relay provided on an AC input line for switching a connection state of the switching power supply with the AC power supply in response to a relay drive signal; a control device for generating a relay control signal; a relay drive circuit for generating the relay drive signal in response to an input of the relay control signal and driving the latching relay by the relay drive signal; a battery for supplying electric power to the control device and the relay drive circuit when they are connected; and a switch for switching the connection state of the battery with respect to the control device and the relay drive circuit. | 08-21-2014 |
20140293358 | POWER SUPPLY SYSTEM AND IMAGE FORMING APPARATUS HAVING POWER SUPPLY SYSTEM - A power supply system includes: a switching power supply generating a voltage from an alternating current power supply; capacitors connected to the alternating current power supply; a rectification circuit configured to rectify an alternating current voltage applied to the capacitors; a backflow regulation regulating backflow of current from the switching power supply; a signal generation circuit generating a detection signal corresponding to a zero cross point of the alternating current power supply; a power supply line connected to the switching power supply and the rectification circuit; an electricity storage unit connected to the power supply line; a voltage limit element configured to limit a voltage of the output line of the rectification circuit, and a control unit, power being fed to the control unit through the power supply line. The control unit is configured to detect a zero cross point based on the detection signal. | 10-02-2014 |
20140293360 | POWER SUPPLY SYSTEM AND IMAGE FORMING APPARATUS HAVING THE POWER SUPPLY SYSTEM - A power supply system includes: capacitors connected to an alternating current power supply; a rectification circuit connected to the capacitors and rectifying an alternating current voltage applied to the capacitors; a signal generation circuit connected to an output line of the rectification circuit and configured to generate a detection signal corresponding to a zero cross point of an alternating current output; an electricity storage unit connected to the output line of the rectification circuit; a backflow regulation element provided on the output line of the rectification circuit and configured to regulate backflow of current; a current limit element configured to limit current flowing from the output line of the rectification circuit towards the electricity storage unit, and a control unit that is connected to the output line of the rectification circuit, and is configured to detect a zero cross point of the alternating current output. | 10-02-2014 |