Patent application number | Description | Published |
20100149840 | POWER SUPPLY APPARATUS AND IMAGE FORMING APPARATUS - The power supply apparatus for obtaining a direct current from an alternating voltage source includes a first DC/DC converter for outputting a first direct current and a second DC/DC converter for a second direct current lower than the first direct current from the first DC/DC converter, and the output voltage of the first DC/DC converter is changed to a lower direct current and the second DC/DC converter is driven in a continuously-conducting state. | 06-17-2010 |
20100176907 | TRANSFORMER, SWITCHING POWER SUPPLY DEVICE, AND DC-DC CONVERTER DEVICE - The transformer includes: first and second cores each including a magnetic center leg and a magnetic outer leg positioned outside of the magnetic center leg; a first adhesion part that adheres the magnetic center leg of the first core and the magnetic center leg of the second core to each other; a second adhesion part that adheres the magnetic outer leg of the first core and the magnetic outer leg of the second core to each other; a bobbin inserted through the magnetic center leg of the first core and the magnetic center leg of the second core, a primary coil and a secondary coil being wound on the bobbin; and an elastic member that applies pressure to the magnetic outer leg of the first core and the magnetic outer leg of the second core in a neighborhood of the second adhesion part, in an inward direction of the transformer. | 07-15-2010 |
20100232188 | POWER SUPPLY APPARATUS - In a power supply apparatus, a current limitation unit configured to detect a current flowing through a primary winding of a transformer to limit a current to a switching unit has a self-holding unit configured to self-hold a state where the current to the switching unit is limited. | 09-16-2010 |
20110150521 | POWER SUPPLY AND IMAGE FORMING APPARATUS - A synchronous rectification power supply controls driving of a switching unit in such a manner as to start the driving in response to rising of an output voltage at a secondary side of a transformer and to stop the driving after a predetermined time passed. | 06-23-2011 |
20110150522 | POWER SUPPLY DEVICE AND IMAGE FORMING APPARATUS - A power supply device controls drive of a synchronous rectification switch unit by converting a voltage into a current, and comparing a voltage obtained by current-to-voltage conversion with a predetermined value. | 06-23-2011 |
20110311259 | SWITCHING POWER SOURCE AND IMAGE FORMING APPARATUS INCLUDING THE SAME - In a switching power source, an OFF-period of switching is set according to a resonance cycle when a transformer is driven. | 12-22-2011 |
20120207505 | DISCHARGING CIRCUIT AND POWER SUPPLY - A discharging circuit includes a filter unit connected between the input lines of a commercial AC power supply, a switch whose operations are controlled by the filter unit; and a discharging unit which discharges voltage of the capacitance element when the switch unit is turned on. | 08-16-2012 |
20130057875 | SWITCHING POWER SOURCE AND IMAGE FORMING APPARATUS - In a switching power source, in a state where a second voltage smaller than a first voltage is output from an output unit by intermittently driving a switching unit, the switching unit changes a number of driving times of the switching unit for each driving cycle when the switching unit is intermittently driven. | 03-07-2013 |
20130100712 | POWER SOURCE DEVICE AND IMAGE FORMING APPARATUS - A power source device that outputs a DC voltage includes a rectification unit configured to rectify an input pulse voltage, a voltage-current conversion unit disposed on a side where the pulse voltage is input into the rectification unit, a current-voltage conversion unit configured to convert a current from the voltage-current conversion unit into a voltage, and a comparison unit configured to compare the voltage from the current-voltage conversion unit with a reference voltage. An operation of the rectification unit is controlled based on an output from the comparison unit. | 04-25-2013 |
20130108304 | POWER SUPPLY AND IMAGE FORMING APPARATUS | 05-02-2013 |
20130236203 | POWER SUPPLY DEVICE AND IMAGE FORMING APPARATUS - The power supply device includes a transformer, a switching unit for driving a primary side of the transformer, a control unit for outputting a pulse signal to the switching unit to control a switching operation including a period during which the switching unit is active and a period during which the switching unit is inactive, in order to output predetermined electric power from a secondary side of the transformer, and an output control unit for continuously outputting a pulse signal to the control unit in the period during which the switching unit is active, at a predetermined cycle shorter than the period during which the switching unit is inactive. | 09-12-2013 |
20130236206 | POWER SUPPLY DEVICE AND IMAGE FORMING APPARATUS - The power supply device includes a transformer, a switching unit for driving a primary side of the transformer, a detection unit for detecting an output corresponding to a current flowing on the primary side, a transmission unit for transmitting an output voltage from a secondary side to the primary side, and a control unit for controlling an operation of the switching unit in accordance with an output from the transmission unit, in which, when a switching frequency for driving the switching unit falls within a predetermined frequency range including a resonant frequency of the transformer, the control unit controls the switching unit so as to shorten a turn-ON time of the switching unit in accordance with an output from the detection unit. | 09-12-2013 |
20130307917 | POWER SUPPLY APPARATUS AND IMAGE FORMING APPARATUS - The power supply apparatus for obtaining a direct current from an alternating voltage source includes a first DC/DC converter for outputting a first direct current and a second DC/DC converter for a second direct current lower than the first direct current from the first DC/DC converter, and the output voltage of the first DC/DC converter is changed to a lower direct current and the second DC/DC converter is driven in a continuously-conducting state. | 11-21-2013 |
20140254210 | POWER SUPPLY APPARATUS AND IMAGE FORMING APPARATUS - The power supply apparatus includes a transformer having a primary and secondary sides, a first line and a second line to which an AC voltage is input from an AC power supply, a rectifying and smoothing unit that rectifies and smoothes the AC voltage, a shut-off unit provided between the first line and the rectifying and smoothing unit, a switching element that switches a current from the rectifying and smoothing unit to the primary side of the transformer, a first overvoltage detection unit that outputs a voltage corresponding to the AC voltage, a second overvoltage detection unit that outputs an overvoltage detection signal; and a control unit that controls the shut-off unit to shut off the input of the AC voltage. | 09-11-2014 |
20140369086 | POWER SUPPLY APPARATUS AND IMAGE FORMING APPARATUS - The power supply apparatus includes a transformer, a switch element that drives a primary side of the transformer, and a control unit that controls a drive frequency of the switch element, wherein when a state of driving the switch element at a first drive frequency is shifted to a state of driving the switch element at a second drive frequency lower than the first drive frequency, the control unit turns on the switch element at a first timing in which a displacement amount of the transformer caused by the drive of the transformer becomes a first displacement amount and at a second timing in which the displacement of the transformer becomes a second displacement amount smaller than the first displacement amount. | 12-18-2014 |