Abstract: A switching power supply includes: a transformer; a switching device, which is connected to a primary coil of the transformer; a switching controller; a voltage generation circuit, which rectifies and smooths an AC voltage induced in an auxiliary coil provided on the primary side of the transformer, and output the rectified and smoothed AC voltage as a first DC voltage; and an overvoltage protection circuit, wherein the auxiliary coil and the switching controller are connected via a capacitor, and the switching controller stops the switching control depending on a change in at least one of a current and a voltage between electrodes of the capacitor, the change being caused by a voltage rise of the AC voltage induced in the auxiliary coil.

Abstract: A switching power supply includes: a transformer; a switching device, which is connected to a primary coil of the transformer; a switching controller; a voltage generation circuit, which rectifies and smooths an AC voltage induced in an auxiliary coil provided on the primary side of the transformer, and output the rectified and smoothed AC voltage as a first DC voltage; and an overvoltage protection circuit, wherein the auxiliary coil and the switching controller are connected via a capacitor, and the switching controller stops the switching control depending on a change in at least one of a current and a voltage between electrodes of the capacitor, the change being caused by a voltage rise of the AC voltage induced in the auxiliary coil.

Abstract: 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.

Abstract: A heating device including: a heat generating unit configured to receive an AC voltage from a power supply; a zero-crossing signal generating unit configured to generate a zero-crossing signal which is a square pulse signal synchronizing with a zero-crossing timing of the AC voltage, the zero-crossing signal being a first level at the zero-crossing timing and being a second level at other timings; and a control device configured to perform a detecting process in which an abnormality in a frequency or an output wave of the power supply or is detected, and an error processing, in a case where the abnormality in the frequency of the power supply or the abnormality in the output waveform of the power supply is detected and the level of a zero-crossing signal at a detection timing of detecting the abnormality is the second level.

Abstract: A heating device including: a heat generating unit configured to receive an AC voltage from a power supply; a zero-crossing signal generating unit configured to generate a zero-crossing signal which is a square pulse signal synchronizing with a zero-crossing timing of the AC voltage, the zero-crossing signal being a first level at the zero-crossing timing and being a second level at other timings; and a control device configured to perform a detecting process in which an abnormality in a frequency or an output wave of the power supply or is detected, and an error processing, in a case where the abnormality in the frequency of the power supply or the abnormality in the output waveform of the power supply is detected and the level of a zero-crossing signal at a detection timing of detecting the abnormality is the second level.

Abstract: 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.

Abstract: An image forming apparatus including a photosensitive body, a charger configured to charge the photosensitive body, an exposure unit configured to expose the photosensitive body charged by the charger, a developer transport section configured to cause relative movement with respect to the photosensitive body for transporting developer therebetween, a current measurement section configured to measure a current flowing between the photosensitive body and the developer transport section, and a determination unit configured to compare a current with a threshold, the current measured by the current measurement section when the photosensitive body and the developer transport section move relatively to each other and a first area of the photosensitive body that needs to be exposed faces the developer transport section, and determine whether an exposure of the photosensitive body is proper based on a result of the comparison.

Abstract: An image forming apparatus, according to the present invention can include, an image carrier, a charger configured to charge the image carrier, an exposure unit configured to form an electrostatic latent image by exposing the image carrier, a developing unit configured to develop the electrostatic latent image, a detection unit configured to detect the density of a developer adherent to the image carrier, and a controller configured to determine a deteriorated state of the image carrier, by charging the image carrier and then conducting a development, in a condition where a potential difference between the charger and the developing unit is set to be smaller than that at the time of image formation, before detecting a density of a developer on an unirradiated portion on the image carrier, so that a detection result to be used for its decision of the deteriorated state of the image carrier is obtained.

Abstract: An image forming apparatus includes: a calculating device configured to, in a testing mode to replace a discharge path between a charging wire and a grid of a charger with a testing resistor having a predetermined resistance, calculate a charge voltage using the resistance of the testing resistor and a detection value by a grid-current detecting circuit; and a controller configured to, in an image forming mode to actually form an image, detect the charge voltage from a feedback voltage using a relation between a value of the feedback voltage which is detected by a charge-voltage detecting circuit in the testing mode and the charge voltage calculated by the calculating device.

Abstract: 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.

Abstract: An image forming apparatus includes an object to be cleaned, a cleaning device, a generation device, a control device, a voltage detection device and a load resistance detection device. The cleaning device cleans the object to be cleaned. The generation device generates a cleaning voltage in the cleaning device. The control device controls the generation device thereby to control the cleaning voltage. The voltage detection device detects the cleaning voltage generated in the cleaning device. The load resistance detection device detects a load resistance between the object to be cleaned and the cleaning device, based on at least one control parameter to be used by the control device to control the generation device and the cleaning voltage detected by the voltage detection device.

Abstract: An image forming apparatus comprising a photosensitive body, a charger configured to charge the photosensitive body, an exposure unit configured to expose the photosensitive body charged by the charger, a developer transport section configured to cause relative movement with respect to the photosensitive body for transporting developer therebetween, a current measurement section configured to measure a current flowing between the photosensitive body and the developer transport section, and a determination unit configured to compare a current with a threshold, the current measured by the current measurement section when the photosensitive body and the developer transport section move relatively to each other and a first area of the photosensitive body that needs to be exposed faces the developer transport section, and determine whether an exposure of the photosensitive body is proper based on a result of the comparison.

Abstract: An image forming apparatus is provided. The image forming apparatus includes a photosensitive member which carries an electrostatic latent image; a charger comprising a charging wire extended in a direction parallel to an axial direction of the photosensitive member, the charger serving to charge the photosensitive member, and a promoting unit which is provided on at least one side of a region of the charger which is opposite to an image forming region in which the electrostatic latent image is formed, the promoting unit promoting a leakage current of the charger; detecting unit which detects a leakage current of the charger; and a correction unit which corrects the charging wire if the leakage current is detected.

Abstract: An image forming apparatus includes: a calculating device configured to, in a testing mode to replace a discharge path between a charging wire and a grid of a charger with a testing resistor having a predetermined resistance, calculate a charge voltage using the resistance of the testing resistor and a detection value by a grid-current detecting circuit; and a controller configured to, in an image forming mode to actually form an image, detect the charge voltage from a feedback voltage using a relation between a value of the feedback voltage which is detected by a charge-voltage detecting circuit in the testing mode and the charge voltage calculated by the calculating device.

Abstract: An image-forming device includes a cleaning unit, a toner detection unit, a control unit, and a cleaning target member in the housing. The cleaning unit applies a predetermined voltage with a predetermined absolute value to the cleaning target member to remove toner from the cleaning target member through an electrostatic force. The toner detection unit detects an amount of toner on the cleaning target member at least twice to detect a first amount of toner and a second amount of toner. The first amount and the second amount of toner are detected when a first voltage having a first absolute value is applied as the predetermined voltage at a first time and when a second voltage having a second absolute value is applied as the predetermined voltage at a second time. The control unit determines the predetermined absolute value based on the first toner amount and the second toner amount.

Abstract: An image forming apparatus is provided. The image forming apparatus includes an image forming unit; a fuser having a heating unit to which an alternating voltage is applied from an alternating power supply so as to perform heating; a zero-cross pulse generating unit that generates a zero-cross pulse; a voltage estimating unit that estimates the alternating voltage on the basis of a width of the zero-cross pulse; a temperature detecting unit that detects the temperature of the fuser; a heating control parameter setting unit that sets a heating control parameter for controlling the heating unit on the basis of the alternating voltage estimated by the voltage estimating unit and the temperature of the fuser; and a heating control unit that controls the heating unit on the basis of the heating control parameter set by the heating control parameter setting unit.

Abstract: A power device includes a transformer, a control signal outputting unit, and a power adjusting unit. The transformer has a primary coil and a secondary coil. The control signal outputting unit variably controls a parameter value and outputs, based on the parameter value, a control signal for controlling output power from the secondary coil. The power adjusting unit receives the control signal from the control signal outputting unit and adjusts power supplied to the primary coil based on the control signal. The power adjusting unit modifies a rate of change within a range in which the parameter value can be variably controlled, the rate of change being a rate of change in the power supplied to the primary coil with respect to the parameter value.

Abstract: 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.

Abstract: An image forming apparatus, according to the present invention can include, an image carrier, a charger configured to charge the image carrier, an exposure unit configured to form an electrostatic latent image by exposing the image carrier, a developing unit configured to develop the electrostatic latent image, a detection unit configured to detect the density of a developer adherent to the image carrier, and a controller configured to determine a deteriorated state of the image carrier, by charging the image carrier and then conducting a development, in a condition where a potential difference between the charger and the developing unit is set to be smaller than that at the time of image formation, before detecting a density of a developer on an unirradiated portion on the image carrier, so that a detection result to be used for its decision of the deteriorated state of the image carrier is obtained.

Abstract: An image forming apparatus is provided. The image forming apparatus includes a photosensitive member which carries an electrostatic latent image; a charger comprising a charging wire extended in a direction parallel to an axial direction of the photosensitive member, the charger serving to charge the photosensitive member, and a promoting unit which is provided on at least one side of a region of the charger which is opposite to an image forming region in which the electrostatic latent image is formed, the promoting unit promoting a leakage current of the charger; detecting unit which detects a leakage current of the charger; and a correction unit which corrects the charging wire if the leakage current is detected.