| Entries |
| Document | Title | Date |
|---|
| 20080199195 | Charger with a probe and controller - This is a charging assembly that is useful in marking processes with an electrostatically charged surface. The assembly includes, besides the charger, a controller and an electric field probe. Charge and current flows can be detected by the probe and corrected immediately after detection of flaws by the probe and conveyed to the controller. If flaws in the charger are determined by the probe, corrections are made to the output by a controller; this is done before a final copy or print is made. The term flaws as used means any non-uniform appearing region in the printed image or any void region within the printed image including any otherwise unacceptable defect such as a jagged line that is visible to an end user. The probe is enabled to detect and indicate flaws and the controller which is in communication with the probe takes corrective action on the flaws. The probe used is a novel probe having two sensing elements surrounded by one or more reference electrodes. | 08-21-2008 |
| 20080205919 | NON-CONTACT CHARGER AND NON-CONTACT CHARGING SYSTEM - A non-contact charger includes: a casing having a recessed portion in which a cordless handset is placeable; a primary coil which is provided in the casing to be opposed to the cordless handset upon placement of the cordless handset in the recessed portion of the casing; an oscillating portion which is oscillatable to generate a magnetic flux energy from the primary coil; a detecting portion which detects at least one of a current value and a voltage value in the oscillating portion; and a controller which stops a generation of the magnetic flux energy based on at least one of the current value and the voltage value detected by the detecting portion. | 08-28-2008 |
| 20080226317 | Image Forming Apparatus and Method - An image forming apparatus, includes: a plurality of image forming stations each of which includes a photosensitive member and a charger that charges a surface of the photosensitive member to a specified surface potential, and is adapted to execute an image forming operation of forming an electrostatic latent image on the photosensitive member charged by the charger and developing the electrostatic latent image with toner to form an image; a plurality of direct-current bias generators that are provided corresponding to the respective plurality of chargers and generate direct-current voltages as direct-current components of charging biases to be given to the chargers; a plurality of series resistors that are provided corresponding to the respective plurality of chargers and electrically connect the plurality of chargers and the direct-current bias generators corresponding to the chargers in a one-to-one relationship; an alternating-current bias generator that generates alternating-current voltages as alternating-current components of the charging biases to be given to the chargers; and a controller that controls the voltage values of the direct-current voltages to be outputted from the respective direct-current bias generators, wherein the direct-current voltage outputted from the direct-current bias generator corresponding to the charger via the series resistor corresponding to the charger and the alternating-current voltage outputted from the alternating-current bias generator are superimposed and applied as the charging bias to each of the plurality of chargers, and the controller sets the voltage value of the direct-current voltage outputted from the direct-current bias generator to the sum of a target voltage preset as a voltage to be applied to the charger corresponding to the direct-current bias generator and a voltage drop caused by the series resistor corresponding to the charger and calculated based on a detection result on a direct current flowing into the charger for each of the direct-current bias generators. | 09-18-2008 |
| 20080240755 | Developing method in imaging-forming device - A developing method in an image-forming device is provided. The developing method includes the steps of charging a photoreceptor; exposing the photoreceptor to form a first latent image on the photoreceptor; developing the first latent image by a first developing unit having a first potential to form a first toner image; and discharging the photoreceptor having the first toner image, such that when the photoreceptor is charged again, the first toner image on the photoreceptor has a second potential, and the second potential is approximately the same as the first potential of the first developing unit. | 10-02-2008 |
| 20080298828 | IMAGE FORMING APPARATUS AND CONTROL METHOD THEREOF - An image forming apparatus capable of varying a transferring force according to an amount of developer, thereby improving transfer quality, and a control method thereof. The image forming apparatus includes a plurality of photoconductive media on which electrostatic latent images are formed, a transfer unit onto which color developer images respectively developed on the plurality of photoconductive media are transferred and superimposed in sequence, and a controller to control in a manner that electric potential differences between image areas and non-image areas of the electrostatic latent images vary in an order in which the color developer images are transferred. | 12-04-2008 |
| 20080304842 | Image forming apparatus - An image forming apparatus includes a high voltage generating circuit | 12-11-2008 |
| 20080304843 | IMAGE FORMING APPARATUS AND PROCESS CARTRIDGE - An image forming apparatus including an image bearing member the moving surface of which travels, a charging device including a charging member located facing the moving surface of the image bearing member, which uniformly charges the moving surface of the image bearing member to form a latent electrostatic image thereon by applying a charging bias in which an AC voltage is overlapped with a DC voltage to the charging member, a developing device to develop the latent electrostatic image with toner to form a toner image on the moving surface of the image bearing member, a transfer device to transfer the toner image on the moving surface of the image bearing member to a recording medium, a fixing device to fix the toner image on the recording medium, an image formation speed switching device to switch from one image formation speed to another image formation speed among multiple image formation speeds by changing a surface traveling speed of the image bearing member according to a particular switching condition, a storage device to store a charging current target of the charging bias applied to the charging member for each of the multiple image formation speeds, an electric current detection device to detect an electric current flown through the charging member and an AC voltage adjustment device to adjust an AC voltage of the charging bias applied to the charging member such that the electric current detected by the electric current detection device approaches the charging current target stored at the storage device which corresponds to the image formation speed when the electric current is detected. With regard to at least two image formation speeds among the multiple image speeds, the charging current target is set for each of the at least two image formation speeds such that each AC voltage adjusted by the AC voltage adjustment device is substantially the same. | 12-11-2008 |
| 20080317488 | Total layer thickness detection apparatus, charging device, image forming apparatus, total layer thickness detection method and computer readable medium storing program for total layer thickness detection - A total layer thickness detection apparatus for a charged body includes: a saturated charge amount detection unit that detects a saturated charge amount of a charged body having plural coating layers with mutually different relative dielectric constants; a storage unit that stores relation information indicating relation of change of the saturated charge amount of the charged body with respect to a change of layer thickness of a surface layer of the charged body; and a calculation part that calculates a total layer thickness of the plural coating layers of the charged body based on the change of the saturated charge amount detected by the saturated charge amount detection unit and the relation information stored in the storage unit. | 12-25-2008 |
| 20090003859 | CHARGING APPARATUS AND IMAGE FORMING APPARATUS - A charging apparatus which is excellent in charging uniformity and thus allows a to-be-charged body to be charged uniformly and in which the generation of discharge products can be reduced, is provided. In the charging apparatus, ions are generated under the difference in electrical potential between the discharge electrode and the induction electrode produced in the ion generating section. The generated ions are caused to flow toward the counter electrode, whereupon the to-be-charged body arranged between the ion generating section and the counter electrode is charged. | 01-01-2009 |
| 20090003860 | Charging device, image forming apparatus, control method of charging device, control program, computer-readable storage medium recording control program - In a charging device of the present invention, with reference to a state (movement speed of a charging receiving material, operating period of charging device) in which the charging device is used which state is obtained by an image formation controlling section, a voltage controlling section sets or changes an applied voltage to be applied between a discharge electrode and an inductive electrode. Accordingly, even in a case where discharge is hard to occur, a necessary amount of ions can be supplied stably. | 01-01-2009 |
| 20090016751 | METHOD AND APPARATUS FOR CLEANING ATTACHMENT ON TRANSFER ROLLER IN AN IMAGE FORMING APPARATUS - An image forming apparatus includes a photoconductor, a transfer roller, and a power supply for providing a voltage signal for the transfer roller to transfer surface attachments on the transfer roller to the photoconductor. Moreover, before providing the voltage signal for the transfer roller, a surface voltage level of the photoconductor can be adjusted according to the voltage signal in order to ensure that the surface voltage level of the photo conductor can be kept in a safe charging range. Therefore, the transferring efficiency of the transfer roller is ensured and damage to the photo conductor is prevented. | 01-15-2009 |
| 20090016752 | IMAGE FORMING APPARATUS AND CONTROL METHOD THEREOF - A storage stores data of charging electric potentials at two or more points on a surface of an image carrier, and coordinates thereof expressed using a main-scanning position and a sub-scanning position thereof. A determination unit determines a correction value of a light power from the data of charging electric potentials at two or more points and coordinates thereof that have been read out from the storage unit. The correction value is applied to the light source so as to reduce the charging electric potential or the charging electric potential unevenness of coordinates on the surface of the image carrier. A correction unit uses the determined charging electric potential or correction value to correct the light power of the light source so as to mitigate an influence of charging unevenness at each set of coordinates. | 01-15-2009 |
| 20090028591 | IMAGE FORMING APPARATUS - An image forming apparatus includes a photosensitive member; a charging device for charging the photosensitive member; an exposure device for exposing the photosensitive member charged by the charging device in accordance with image information; a developing device for developing, with toner, an electrostatic image formed on the photosensitive member by the exposure device into a toner image; a transfer charger for transferring the toner image formed on the photosensitive member by the developing device onto an image receiving member in a transfer portion; a light discharger, provided between the transfer charger and the charging device with respect to a rotational direction of the photosensitive member, for electrically discharging by light the photosensitive member; a current detector for detecting a current flowing through the transfer charger; a corrector for correcting a charging bias voltage applied to the charging device on the basis of an output of the current detector provided when a portion of the photosensitive member charged by the charging device substantially without being subjected to a light discharging operation of the light discharger passes through the transfer portion and on the basis of an output of the current detector provided when a portion of the photosensitive member subjected to a light discharging operation of the light discharger and charged by the charging device passes through the transfer portion. | 01-29-2009 |
| 20090041487 | IMAGE FORMING APPARATUS - In an image forming apparatus, temporary constant voltages are not by using three voltage-current data obtained by applying voltages at three levels to a primary transfer roller to detect currents corresponding to the voltages, respectively. A surface potential of a photosensitive drum is detected by a potential sensor by changing an exposure intensity of an exposure device at three levels in a state in which the temporary constant voltage is applied to the primary transfer roller. A constant voltage during image formation is determined by correcting the temporary constant voltage by using three voltage-current data obtained by detecting currents when surfaces different in potential by light exposure pass through a primary transfer portion. | 02-12-2009 |
| 20090052915 | CONSTANT VOLTAGE LEVELING DEVICE FOR INTEGRATED CHARGING SYSTEM - A charging system for uniformly charging an imaging surface moving in a predefined path including a dicorotron for charging the imaging surface; a discorotron, adjacent to and downstream from said dicortron, for charging the imaging surface; the discorotron including a coronode, a grid and a shield a first power supply for biasing the grid and the shield; a second power supply for energizing each of the coronode; means for determining a voltage level of the imaging surface and generating a feedback signal of the voltage level; and a controller, responsive to the feedback signal and in communication with the first power supply, for controlling the energiziation of the grid and the shield. | 02-26-2009 |
| 20090103936 | Image forming device - An image forming device includes: a high voltage generating circuit for applying an oscillating voltage to a charging member disposed in contact with or proximity to an image carrier, the oscillating voltage having a DC voltage Vdc and an AC voltage Vac superimposed thereon; a current detecting portion for detecting the value of a DC current Idc between the image carrier and the charging member; an AC voltage control portion for controlling the value of the AC voltage Vac so as to secure the detected value of the DC current Idc within a target current range; and an aging control portion for performing rotation driving of the image carrier while securing the AC voltage Vac and the DC voltage Vdc at preset voltage values and setting the frequency of the AC voltage Vac at a frequency different from a frequency during an image forming operation. | 04-23-2009 |
| 20090169227 | IMAGE FORMING APPARATUS - An image forming apparatus includes a standard exposure device ( | 07-02-2009 |
| 20090175640 | Apparatus for forming multi-color image with control of unintended reverse-transfer of developer image onto photoconductor - An apparatus for forming a multi-color is disclosed which includes a controller that performs an anti reverse-transfer control such that a surface potential of a previously-formed separated-developer-image subset of a plurality of single-color separated-developer-images which has been previously transferred onto an image transferred medium is reduced, prior to a subsequent transfer in which a remainder of the plurality of separated-developer-images is transferred onto the image transferred medium after a previous transfer of the previously-formed separated developer-image subset onto the image transferred medium, to thereby prevent a reverse transfer of a part of a developer material on the image transferred medium from the image transferred medium onto a photoconductor at the subsequent transfer. | 07-09-2009 |
| 20090232530 | IMAGE FORMING APPARATUS - An apparatus includes an image bearing member for carrying an image; an intermediary transfer member for receiving the image; a primary transfer member for transfer of the image onto the intermediary transfer member in a primary transfer station; a secondary transfer member for transfer of the image onto a transfer material in a secondary transfer station; a first charging member for charging toner remaining in a region upstream of the primary transfer station and downstream of the secondary transfer station; and a second charging member for charging the toner remaining in a region upstream of the primary transfer station and downstream of the first charging member. The first charging member rubs a surface of, and the second charging member moves in contact with, the intermediary transfer member, to transfer the toner remaining on the intermediary transfer member to the image bearing member simultaneously with the primary transfer. | 09-17-2009 |
| 20090245829 | Image Forming Apparatus - An image forming apparatus comprises an image carrier configured to hold a developing agent image; a transfer unit that transfers the developing agent image to a recording medium; a first application unit that controls a transfer voltage applied to the transfer unit; a recovery unit that recovers the developing agent remaining on the image carrier; a second application unit that controls a recovery voltage applied to the recovery unit; a determination unit that determines whether or not a recovery current flowing between the image carrier and the recovery unit exceeds a first predetermined current value; and a control unit that, when the determination unit makes a positive determination that the recovery current has exceeded the first predetermined current value, performs a protective control for controlling the first application unit such that a transfer current flowing between the image carrier and the transfer unit becomes greater. | 10-01-2009 |
| 20090269092 | IMAGE FORMING APPARATUS - An image forming apparatus including an image carrier that includes a photoconductive layer on which an electrostatic latent image is formed, a charging member that comes in contact with the image carrier and charges the photoconductive layer, and a feeding section that supplies a current to the charging member by applying a vibration voltage with an alternate current component superposed on a direct current component, wherein the alternate current component may contain a first amplitude that eliminates charging non-uniformity when the vibration voltage is applied with a uniform amplitude and a second amplitude that is smaller than the first amplitude. | 10-29-2009 |
| 20090279910 | IMAGE FORMING APPARATUS AND CONTROL METHOD FOR CONTROLLING THE SAME - An image forming apparatus including a latent image bearing member a surface of which is rotated, a charging device, an irradiating device, a developing device, a transfer device, and a control unit. The control unit controls the image forming apparatus to perform subsequent image formation in accordance with a subsequent image forming request when determining that the subsequent image forming request is present at a predetermined determination time after completion of previous image formation, and controls the image forming apparatus to shut down certain predetermined operations including at least rotation of the surface of the latent image bearing member and application of a charging bias from the charging device and a developing bias from the developing device in accordance with a predetermined shutdown sequence when determining that the subsequent image forming request is not present at the predetermined determination time. | 11-12-2009 |
| 20090324268 | IMAGE FORMING APPARATUS - A bias corrector conducts a first bias correction calculation by performing first through third calculations. The first calculation compares a stored target charging current value to a first charging current value detected when a first charging bias was applied by a bias applying device. The second calculation is performed repeatedly to calculate a second charging bias based on the comparison result and then to compare the target charging current value to a second charging current value detected by the current detector when the second charging bias was applied by the bias applying device. The third charging bias is calculated based on the comparison result. A second bias correction calculation then is conducted to correct the charging bias obtained as a result of the first bias correction calculation based on photoconductor information detected by a photoconductor information detector. | 12-31-2009 |
| 20100003042 | IMAGE FORMING APPARATUS - An image forming apparatus includes: a photoconductor; a charging unit configured to charge the photoconductor; an applying unit configured to produce a charging voltage; a current detecting unit configured to detect a charging current; an image forming unit configured to form an image on a recording medium; a conveying unit configured to convey the recording medium; and a control unit. The control unit is operable to: receive a current detecting signal; determine whether an abnormal discharge occurs during an image forming operation based on the current detecting signal; control the applying unit to reduce a value of the charging voltage if it is determined that the abnormal discharge occurs; determine whether the abnormal discharge stops by reducing the value of the charging voltage; and control the conveying unit to eject the recording medium during the image forming operation if it is determined that the abnormal discharge is stopped. | 01-07-2010 |
| 20100008685 | CHARGING APPARATUS - A charging apparatus includes a charging device for electrically charging a photosensitive member; a bias applying device for applying to the charging member a charging bias voltage comprising a DC voltage component and a AC voltage component, wherein the bias applying device effect a constant voltage control with a constant AC component of the charging bias voltage; a AC detector for detecting a AC detected current when the charging member is supplied with a test bias voltage; a DC detector for detecting a DC detected current when the charging member is supplied with the test bias voltage; and a controller for controlling a charging bias voltage to be applied to the charging member; wherein the control means determines a peak-to-peak voltage Vo when a change rate of detected DC current provided by sequentially applying the test bias voltages having different peak-to-peak voltages in order of increasing or decreasing peak-to-peak voltage becomes not more than a predetermined level, and the control means sets a peak-to-peak voltage of the charging bias voltage on the basis of a detected AC current when a peak-to-peak voltage Vp larger than the peak-to-peak voltage Vo and a detected AC current when a peak-to-peak voltage Vq not larger than the peak-to-peak voltage Vo. | 01-14-2010 |
| 20100021190 | Image Forming Apparatus and Image Forming Method - An image forming method includes supplying a protective agent to an image carrier, and charging the image carrier by a plurality of charging units, wherein degrees of discharge deterioration of the surface of the image carrier in the plurality of charging units are different, and wherein, in the amounts of protective agent supplied to charging portions of the plurality of charging units, the amount of protective agent supplied to a charging portion, in which a degree of discharge deterioration of the surface of the image carrier is high, is large. | 01-28-2010 |
| 20100054776 | IMAGE FORMING APPARATUS - An image forming apparatus includes an image bearing member and a charging roller rotatable in contact therewith. Before driving of the image bearing member starts, a bias having the same polarity as that of an image forming bias is applied between the charging roller and the image bearing member. The time of application of the bias varies with the accumulated time of rotation of the image bearing member or the time of making the driving of the image bearing member inactive. | 03-04-2010 |
| 20100061747 | CHARGING VOLTAGE CONTROL METHOD OF IMAGE FORMING APPARATUS USING CONSTANT VOLTAGE CONTROL AND IMAGE FORMING APPARATUS THEREOF - A charging voltage control method of an image forming apparatus and an image forming apparatus thereof. The charging voltage control method of the image forming apparatus includes: applying a charging voltage amount determined by referring to a basic lookup table which determines the charging voltage based on a system load; and correcting the applied charging voltage by using a first correction value which is determined based on a first correction lookup table which determines the first correction value based on a difference between a target current corresponding to the lifespan of the charging roller and a charging current. | 03-11-2010 |
| 20100067930 | IMAGE FORMING APPARATUS - An image forming apparatus includes an image forming unit having image forming elements and a fixing unit. The image forming elements includes an image carrier, a charging unit, a developer carrier, and a developer supplier. The image forming apparatus further includes a post unoperated period image formation preparation processor operable to, when the unoperated period, which is a time period from an end of an image forming operation to a start of a subsequent image forming operation is equal to or greater than a threshold, perform an idling operation to rotate the image carrier while applying a post unoperated period image formation preparation voltage, which is different from a normal image formation voltage, to a given one or more of the image forming elements. | 03-18-2010 |
| 20100080592 | IMAGE FORMING DEVICE - An image forming device includes plural electrostatic latent image holding bodies that hold, on surfaces thereof, electrostatic latent images to be developed with developers of multiple colors, respectively, plural electrification control units that face the electrostatic latent image holding bodies and charge or discharge the surfaces of the electrostatic latent image holding bodies, respectively, a current controller that controls electric currents, each of which is supplied between the electrostatic latent image holding body and the electrification control unit for a corresponding one of the multiple colors, to be a constant target current, a maximum voltage output unit that outputs a maximum voltage among voltages each of which is applied between the electrostatic latent image holding body and the electrification control unit for a corresponding one of the multiple colors, and a detector that detects malfunction of the electrification control units when the maximum voltage exceeds a predetermined value. | 04-01-2010 |
| 20100080593 | IMAGE FORMATION DEVICE AND IMAGE FORMATION METHOD - An image formation device for forming an image on a print medium by an electrophotographic process comprises a photosensitive body on which a developer image to be transferred to the print medium is formed by the electrophotographic process including charging of the photosensitive body, a charging unit which includes a charging wire and a grid and thereby electrically charges the photosensitive body, a charging power unit which applies wire potential to the charging wire, a wire potential measuring unit which measures the wire potential, and a charging control unit which controls the amount of electric charge supplied from the charging unit to the photosensitive body by controlling the wire potential based on the wire potential measured by the wire potential measurement unit. The charging control unit includes a control range restricting unit which restricts a control range of the wire potential within a prescribed electric potential. | 04-01-2010 |
| 20100092192 | IMAGE FORMING APPARATUS - In an image forming apparatus in which a DC bias is applied to charge a photosensitive drum, when a charge eliminating device is in deterioration or failure, there are some cases where a proper charging is not made, and thus poor imaging occurs. A DC bias is applied to a charging member in the charge eliminating operation area of an image bearing member where the charge eliminating device makes charge eliminating operation; and based on the values of an electric current passing through the image bearing member on that occasion, a DC bias application is switched between by constant-current-control and by constant-voltage-control. | 04-15-2010 |
| 20100111550 | IMAGE FORMING APPARATUS - An image forming apparatus includes a rotatable photosensitive member; a charging member for electrically charging the photosensitive member; applying means for applying to the charging member a charging bias in the form of a DC voltage biased with an AC voltage; toner image forming means for forming a toner image on the photosensitive member charged by the charging member; setting means for setting a frequency of a first charging bias at a first frequency in a first mode in which the photosensitive member is rotated at a first speed to effect image formation and for setting a frequency of a second charging bias at a second frequency, different from the first frequency, in a second mode in which the photosensitive member is rotated at a second speed lower than the first speed to effect image formation; detecting means for detecting a current passing between the charging member and the photosensitive member during application of a test bias to the charging member; and adjusting means for adjusting the second charging bias on the basis of an output of the detecting means when the photosensitive member is rotated at the first speed and a test bias having the second frequency is applied to the charging member at the time of switching an image forming mode from the first mode to the second mode. | 05-06-2010 |
| 20100129097 | Image Forming Device and Method of Controlling the Same - In order to prolong life of a charger, there is provided an image forming device including a photosensitive member, a charger, an exposing unit, a developing unit and a control unit. The charger charges the photosensitive member at a charging position, and the exposing unit exposes the photosensitive member to light and forms an electrostatic latent image on the photosensitive member. The developing unit develops the electrostatic latent image formed on the photosensitive member at a developing position, the developing unit having a developing member that carries thereon developer charged to a polarity, the developing member having a surface potential. The control unit controls the charger so that a first voltage having a first absolute value and a second voltage having a second absolute value are selectively applied to the charger, the first absolute value being greater than the second absolute value, the surface potential of the developing member having a third absolute value smaller than the second absolute value, the control unit applying the first voltage to the charger at least during development while applying the second voltage to the charger during operations other than development, the first voltage, the second voltage and the surface potential having a polarity same as the polarity of the developer. | 05-27-2010 |
| 20100135682 | IMAGE FORMING APPARATUS WITH CHARGING DEVICE OF CORONA TYPE - An image forming apparatus includes a rotatable photosensitive member; a corona charger provided with an opening opposed to a surface of the photosensitive member; image forming means for forming a toner image on the photosensitive member; a shutter for opening and closing the opening relative to the photosensitive member; sliding means for sliding in contact with the photosensitive member; measuring means for measuring time elapsed from end of image formation; and control means for controlling the apparatus on the basis of an output of the measuring means such that shutter is closed and the photosensitive member is rotated in contact with the sliding means. | 06-03-2010 |
| 20100215388 | CHARGING DEVICE CONTROLLER FOR CONTROLLING CHARGING DEVICE, ELECTROPHOTOGRAPHIC IMAGE FORMING APPARATUS INCORPORATING THE CHARGING DEVICE AND THE CHARGING DEVICE CONTROLLER, AND CONTROL METHOD FOR CONTROLLING THE CHARGING DEVICE - A charging device controller controls a charging device including a charging roller to charge a surface of an image carrying member carrying a toner image, a cleaning roller to come into contact with the charging roller to remove therefrom foreign substances including toner, and a contact-separation device to make the cleaning roller come into contact with and separate from the charging roller. The charging device controller includes a contact-separation device controller to cause the contact-separation device to make the cleaning roller come into contact with and separate from the charging roller during an image forming operation, which includes a latent image writing operation of writing a latent image on the image carrying member and a development operation of forming a toner image by supplying toner to the latent image, at an operation other than the latent image writing operation performed on the image carrying member. | 08-26-2010 |
| 20100221026 | IMAGE FORMING APPARATUS FEATURING A CHARGING DEVICE FOR CHARGING A PHOTOSENTIVE MEMBER - The present invention provides an image forming apparatus which includes a rotatable photosensitive member, a charging device which charges the photosensitive member, an applying unit which applies an alternating current voltage to the charging device, a processing portion which extracts a discharge current component by removing an alternating current component corresponding to the alternating current voltage from a current flowing between the photosensitive member and the charging device, and a control unit which controls a peak-to-peak value of the alternating current voltage based on the discharge current component extracted by the processing portion. | 09-02-2010 |
| 20100239285 | IMAGE FORMING APPARATUS - An image forming apparatus includes a rotatable photosensitive member; charging device for electrically charging the photosensitive member by being supplied with a charging bias; a current detecting device for detecting a DC current flowing when a test bias in the form of a predetermined DC voltage biased with a predetermined AC voltage is applied to the charging device so as to cause discharging between the photosensitive member and the charging device; and a control device for controlling the charging bias on the basis of an output of the current detecting device. | 09-23-2010 |
| 20100239286 | IMAGE FORMING APPARATUS - An image forming apparatus includes a drum; a charging member; a charging bias applying device; an image forming device; a detecting device for detecting a current passing between the charging member and the drum; an executing device for selectively executing a first mode in which the charging bias of a first frequency is applied to form the image on the drum rotated at a first speed and a second mode in which the charging bias of a second frequency is applied to form the image on the drum rotated at a second speed; a calculating device for calculating information indicating a relationship between an output of the detecting device when the AC voltage of the first frequency is applied and an output of the detecting device when the AC voltage of the second frequency is applied; and an adjusting device for adjusting a peak-to-peak voltage to be applied to the charging member in the first mode based on the output of the detecting device obtained by applying the AC voltage of the first frequency to the charging member and for adjusting a peak-to-peak voltage to be applied to the charging member in the second mode based on the output of the detecting device obtained by applying the AC voltage of the first frequency to the charging member and the information calculated by the calculating device. | 09-23-2010 |
| 20100239287 | IMAGE FORMING APPARATUS - An image forming apparatus includes a rotatable photosensitive member; charging device for electrically charging the photosensitive member by being supplied with a charging bias; a current detecting device for detecting a DC current flowing when a test bias in the form of a predetermined DC voltage biased with a predetermined AC voltage is applied to the charging device so as to cause discharging between the photosensitive member and the charging device; and a control device for controlling the charging bias on the basis of an output of the current detecting device. | 09-23-2010 |
| 20100247126 | Image Forming Apparatus and Charge-Voltage Generating Method - 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. | 09-30-2010 |
| 20100278549 | IMAGE FOMRING APARATUS AND METHOD OF ADJUSTING CHARGE BIAS - An image forming apparatus includes an image carrier configured to carry an image and a charger to which a direct current voltage overlapped with an AC voltage is applied as a charging bias to charge the image carrier. The charger is positioned in contact or contactlessly with the image carrier. The AC voltage applied to the charger in an adjustment of the AC voltage is not less than twice a charging start voltage Vth at which the image carrier starts to be charged. | 11-04-2010 |
| 20100296827 | IMAGE PROCESSING SYSTEM, IMAGE FORMING APPARATUS, CONTROL METHOD OF THE SAME, PROGRAM, AND STORAGE MEDIUM - In an image processing system, a charging process for an executed print process is executed using one of a first charging method and a second charging method. Especially, when executing a print process of an image including a plurality of pages, it is determined before the start of the print process of the image including the plurality of pages on the basis of balance information managed in advance whether execution of the print process of the image including the plurality of pages is possible. When the first charging method is selected, execution of the print process is controlled on the basis of the result of determination. When the second charging method is selected, the print process is executed without determination. | 11-25-2010 |
| 20100322650 | IMAGE FORMING APPARATUS - An image forming apparatus includes an image bearing member; a charging device, including a rotatable magnetic particle carrying member and electroconductive magnetic particles carried on the rotatable magnetic particle carrying member, for charging the image bearing member by contacting the magnetic particles to the image bearing member; the measuring device for measuring magnitudes of a first force in a first direction and a second force in a second direction which are produced in a contact region between the image bearing member and the magnetic particle, wherein the first direction and second direction are independent from each other; and a control device for controlling an image forming operation on the basis of the forces measured by the measuring device. | 12-23-2010 |
| 20100329713 | IMAGE FORMING APPARATUS AND METHOD OF CONTROLLING IMAGE FORMING APPARATUS - An image forming apparatus has a charging unit which charges an image carrier by applying a voltage to a charging member arranged to be in contact with the image carrier. The image forming apparatus includes an alternating voltage applying unit which generates an alternating voltage, a first voltage detection unit which detects a positive peak voltage of the alternating voltage, a second voltage detection unit which detects a negative peak voltage of the alternating voltage, a voltage amplitude determination unit which determines an amplitude value of the alternating voltage based on the positive peak voltage detected, and an alternating voltage control unit which outputs a signal which changes an output from the alternating voltage applying unit. | 12-30-2010 |
| 20110026957 | IMAGE FORMING APPARATUS - An image forming apparatus includes an image carrier, a charging device to be applied with a charging voltage, an exposure device, a developer carrier to be applied with a development voltage, a developer supplying member to be applied with a supply voltage, a developer regulation member to be applied with a regulation voltage, and a voltage controller. The developer carrier has thereon a developer having a charge amount Q/M. The charge amount Q/M satisfies 25 [μC/g]≦|Q/M|≦40 [μC/g]. The image carrier has a surface potential Vopc, the development voltage is expressed as Vdb, and the developer carrier has a developer layer potential Vtnr thereon. The developer layer potential Vtnr relative to a difference between the surface potential Vopc and the development voltage Vdb is expressed by a ratio γ. The ratio γ satisfies 0.1≦γ≦0.2. | 02-03-2011 |
| 20110058833 | IMAGE FORMING APPARATUS - An image forming apparatus includes: a charging unit which charges a surface of an image bearing member by contacting the image bearing member with a charging member to which a charging bias is applied, the charging bias being a voltage obtained by superimposing an AC voltage on a DC voltage; an electrostatic latent image forming unit which forms an electrostatic latent image on the surface of the image bearing member which is charged by the charging unit; a developing unit which develops the electrostatic latent image by using a developing bias formed by the voltage obtained by superimposing the AC voltage on the DC voltage; and a control unit which performs changing control of an AC frequency of the charging bias while maintaining a frequency ratio of an AC frequency of the developing bias to be an integral multiple of the AC frequency of the charging bias. | 03-10-2011 |
| 20110058834 | IMAGE FORMING APPARATUS - An image forming apparatus comprising a rotatable image bearing member for carrying a toner image; a charging member for contacting a surface of the image bearing member to discharge the surface; a cleaning blade for contacting the surface of the image bearing member to remove toner remaining on the surface of the image bearing member after a toner image is transferred from said image bearing member onto a transfer material; and a control device for controlling a voltage applied to said charging member; wherein the control device applies to the charging member a first charged potential which includes a peak-to-peak voltage larger than a discharge starting voltage in image forming operation, and applies to the charging member a second voltage which includes a peak-to-peak voltage is smaller than the discharge starting voltage, for at least one full rotation of said image bearing member, after completion of the image forming operation and before an AC voltage component applied to the charging member is shut off. | 03-10-2011 |
| 20110069982 | CHARGING DEVICE AND IMAGE FORMING APPARATUS USING THE SAME - A charging device includes: a charging member that faces an image carrier and charges a surface of the image carrier; a charging voltage controller that controls a charging voltage to be applied to the charging member when the surface of the image carrier is to be charged, and applies the charging voltage obtained by superposing an AC voltage which is subjected to constant-current control on a DC voltage; a variation range detector that detects a variation range of the AC voltage which changes according to the characteristic change of the charging member; and a response speed controller that reduces a response speed for the variation of the AC voltage in correspondence with the characteristic change when the variation range is larger than a predetermined set value. | 03-24-2011 |
| 20110081155 | IMAGE FORMING APPARATUS - An image forming apparatus includes a rotatable drum; charging means for charging the drum, the charging means including a first carrying member for carrying electroconductive magnetic particles and a second carrying member for carrying the magnetic particles, the second carrying member being disposed at a downstreammost position with respect to a rotational direction of the drum, wherein the magnetic particle is in contact with the drum while charging the drum; latent image forming means, disposed at a position downstream of the charging means, for forming a latent image on the drum; potential detecting means for detecting a surface potential of the drum, the potential detecting means being disposed downstream of the charging means and upstream of the latent image forming means; phase detecting means for detecting information relates to a rotational phase of the second carrying member; control means for controlling voltages applied to the first carrying member and to the second carrying member; and wherein the control means is capable of executing an operation in a control mode for controlling the voltages applied to the first carrying member and to the second carrying member, on the basis of a result of detection by the potential detecting means and a result of detection by the phase detecting means. | 04-07-2011 |
| 20110110677 | IMAGE FORMING APPARATUS - The image forming apparatus includes a charging unit, a latent image forming unit, a transfer unit that develops the latent image, a first application unit that applies a voltage to the charging and transfer units, a second application unit that applies a voltage opposite in polarity to the voltage applied from the first application unit, a detection unit that detects a current flowing through the transfer unit, and a control unit that determines whether or not discharge starts between the charging unit and the image bearing member based on the current detected by the detection unit when the voltage is applied from the first application unit to the charging unit. The variation in potential of the image bearing member may be reduced in an apparatus having a low-cost structure without providing a density detection sensor or a temperature-humidity sensor. | 05-12-2011 |
| 20110299866 | IMAGE FORMING APPARATUS - An image forming apparatus of the present invention has first and second image carriers that are configured by positively-charged single layer type electrophotographic photoreceptors, and a controller that controls an operation for charging or destaticizing the circumferential surfaces of these image carriers. The controller switches between a first mode for causing the first and second image carriers to perform image formation while rotating these image carriers, and a second mode for causing only the first image carrier to perform image formation while rotating the first and second image carriers. In the second mode, the second image carrier is applied with a charging bias and subjected to a destaticizing operation without undergoing a developing operation. The first image carrier is applied with the charging bias and subjected to the developing operation and the destaticizing operation. | 12-08-2011 |
| 20110305471 | Image Forming Device - An image forming device has: an image forming body on which an image is formed in a state in which the image forming body is charged; a charging device having plural discharge portions, and charging the image forming body by discharging of plural discharge portions; and a control section that, when forming the image on the image forming body, operates the plural discharge portions, and when not forming the image on the image forming body, switches between a state of operating some of the plural discharge portions and decreasing output of or stopping the discharge portions other than the some discharge portions, and a state of operating some other of the plural discharge portions and decreasing output of or stopping the discharge portions other than the some other discharge portions. | 12-15-2011 |
| 20110318034 | MAINTENANCE SYSTEM, CLEANING SYSTEM, AND IMAGE FORMING APPARATUS - A maintenance system includes a maintenance device and a control device that controls the operation of the maintenance device. The control device is configured to activate the maintenance device automatically when a numerical value associated with the operation of a maintenance target device reaches a predetermined threshold value and to activate the maintenance device when it receives an instruction from a user. When the control device is instructed to activate the maintenance device by an instruction from the user, the control device changes the preset threshold value such that the operation interval of the maintenance device becomes smaller. | 12-29-2011 |
| 20120033984 | IMAGE FORMING APPARATUS - An image forming apparatus includes an image bearing member; a first charging member for electrically charging the image bearing member by being supplied with an oscillating voltage in the form of a DC voltage biased with a common AC voltage during image formation; a second charging member, provided downstream of the first charging member with respect to a movement direction of the image bearing member, for electrically charging the image bearing member by being supplied with the DC voltage and the common AC voltage during the image formation; detecting portion for detecting an AC current passing through the second charging member; and a setting portion for setting, on the basis of a detection result of the detecting portion when a predetermined AC voltage is applied to the second charging member during non-image formation, the common AC voltage applied to the first charging member and the second charging member during the image formation so that a discharge current between the second charging member and the image bearing member is a predetermined value. | 02-09-2012 |
| 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 |
| 20120106998 | IMAGE FORMING APPARATUS - An image forming apparatus may include a first and second mode. In the first mode, the image forming apparatus uses a second charging member to charge toner that remains on an intermediate transfer member and then transfers the charged, remaining toner to an image carrier in a primary transfer portion. In the second mode, the image forming apparatus transfers the remaining toner adhered to the second charging member in the first mode to the intermediate transfer member. Also in a second mode, the image forming apparatus controls so that a surface potential of the image carrier that reaches the primary transfer portion at a timing at which the remaining toner transferred to the intermediate transfer member passes through the primary transfer portion has a same polarity as that of a surface potential of the image carrier in the first mode and also has an absolute value smaller than that thereof. | 05-03-2012 |
| 20120128382 | IMAGE FORMING APPARATUS - An image forming apparatus includes: a first photosensitive member; a second photosensitive member; a third photosensitive member; a first scorotron-type charger that is configured to charge the first photosensitive member; a second scorotron-type charger that is configured to charge the second photosensitive member; a third scorotron-type charger that is configured to charge the third photosensitive member; a first voltage applying circuit, which is connected to the first scorotron-type charger, and which is configured to apply a voltage to the first scorotron-type charger; and a second voltage applying circuit, which is commonly connected to the second scorotron-type charger and the third scorotron-type charger, and which is configured to apply a voltage to the second scorotron-type charger and the third scorotron-type charger. | 05-24-2012 |
| 20120183316 | INTERDOCUMENT PHOTORECEPTOR SIGNAL SENSING AND FEEDBACK CONTROL OF PAPER EDGE GHOSTING - Apparatus and method for minimizing ghost defect are disclosed. Ghosting results in interdocument bands when paper size is changed and process control instability due to using the interdocument zone (IDZ) for voltage and density control. A controller retrieves feedback measurements of the IDZ and sheet zone (SZ) non-uniformity. In response to the measurements, the transfer current IDZ level is controlled to minimize differences in subsequent charging, photodischarge and development. | 07-19-2012 |
| 20120201553 | IMAGE FORMING APPARATUS - An image forming apparatus includes a rotatable image bearing member; a first charging member for electrically charging the image bearing member; a second charging member, provided downstream of the first charging member with respect to a rotational direction of the image bearing member, for electrically charging the image bearing member; an applying device for applying a voltage to the first charging member and the second charging member; a detecting device for a DC current passing through the second charging member; and a controller for controlling, when an AC voltage and a DC voltage are applied to the second charging member while a DC voltage is applied to the first charging member, the DC voltage applied to the second charging member so that an absolute value of the DC current detected by the detecting device is within a predetermined range. | 08-09-2012 |
| 20120237234 | IMAGE FORMING APPARATUS AND IMAGE FORMING METHOD - An image forming apparatus includes an image carrier to carry a toner image, a transfer member to form a transfer nip by contacting the image carrier surface, and a power supply to output a voltage to the recording material captured in the transfer nip so as to transfer the toner image formed on the image carrier surface. The voltage is switching alternately between a voltage in the transfer direction and a voltage opposite to the voltage in the transfer direction, and a time average value (Vave) of the voltage is set to have a polarity of the transfer direction, and is set to a value in the transfer voltage side, and a change mode to change a cycle of the voltage output from the power supply can be changed based on the toner deterioration information which determines the deterioration status of the toner. | 09-20-2012 |
| 20130064562 | IMAGE FORMING APPARATUS - An image forming apparatus includes photosensitive drums; drum charging members, an AC voltage source for outputting an AC voltage commonly to at least two of the charging members; an AC voltage control devices for the charging members; variable resisters connected between the AC voltage source and the at least two charging members, respectively; use situation detecting means for detecting use situations of the drums, respectively; and adjusting means for adjusting electric resistances of the variable resisters, respectively. The adjusting means adjusts the electric resistances of the resisters in accordance with the detection results of the use situation detecting means such that the discharge currents applied to the at least two charging members are within predetermined ranges, respectively. | 03-14-2013 |
| 20130064563 | IMAGE FORMING APPARATUS - An image forming apparatus includes photosensitive members, charging members supplied with charging voltages each comprising a component of a DC voltage and a component of an AC voltage, AC current measuring devices for measuring AC currents flowing into charging members, and control means for controlling peak-to-peak voltages of the AC voltages, wherein the control means calculates peak-to-peak voltages of the AC voltages required to provide a predetermined discharge current, from results of the measurements of the AC current measuring devices, and determines a maximum value of the required peak-to-peak voltages as a target value of a constant-voltage-control of the AC voltage in an image forming operation. | 03-14-2013 |
| 20130108295 | IMAGE FORMING DEVICE | 05-02-2013 |
| 20130188974 | IMAGE FORMING APPARATUS - An image forming apparatus performs first control, while rotating an image bearing member at a first speed during non-image-formation, to apply a plurality of alternating-current voltages differing in peak-to-peak voltage to a charging device and to detect the value of each alternating current flowing through the image bearing member. When rotating the image bearing member at a second speed during image formation, the image forming apparatus performs second control, while rotating the image bearing member at the second sped before the start of image formation, to apply an alternating-current voltage determined based on the first control to the charging device. In the second control, the image forming apparatus detects the value of the alternating current flowing through the image bearing member, and determines a peak-to-peak voltage of the alternating-current voltage applied to the charging device at the time of image formation based on the detected alternating current value. | 07-25-2013 |
| 20130209117 | IMAGE FORMING APPARATUS - An image-forming apparatus includes: a first image-forming portion; a second image-forming portion; an executing portion for executing an operation in a first mode in which an image is formed on a recording material by the first and second image-forming portions or a second mode in which an image is formed by the second image-forming portion; an AC-voltage source; a first DC-voltage source; a second DC-voltage source; and a controller for controlling the first and second voltage sources and the AC-voltage source so that in the first mode, application of the AC voltage by the AC-voltage source and the DC voltages by the first and second DC-voltage source are performed, and so that in the second mode, application of the DC voltage by the second DC-voltage source is performed, and application of the AC voltage by the AC-voltage source and the DC voltage by the first DC-voltage source are stopped. | 08-15-2013 |
| 20130216249 | APPARATUS AND METHOD FOR SUPPLYING CHARGE VOLTAGE TO ORGANIC PHOTOCONDUCTOR DRUM - Provided is an apparatus and method for supplying a charge voltage to an organic photoconductor (OPC) drum. The apparatus includes a storage unit for storing first service life information of the OPC drum according to a first supplying method, and second service life information of the OPC drum according to a second supplying method, a sensor unit for measuring information about conditions surrounding the apparatus, a control unit for selecting one of the first and second supplying methods according to the measured information and determining a charge voltage corresponding to the service life information according to the selected method, and a voltage supplying unit using the selected method to supply the determined charge voltage to the OPC drum. | 08-22-2013 |
| 20130243460 | IMAGE FORMING APPARATUS, IMAGE FORMING METHOD, AND NON-TRANSITORY COMPUTER READABLE MEDIUM - An image forming apparatus includes an application unit that applies to a holding unit a voltage that generates a potential difference between the holding unit and a photoconductor member such that a toner image is developed on the photoconductor member, the potential difference causing toner included in a two-component developer, held by the holding unit, to transfer from the holding unit to the photoconductor member, and a controller that controls the application unit, subsequent to an expiration of an image quality assurance period throughout which a predetermined image quality is assured, such that the potential of the holding unit is decreased in step with wear of the photoconductor member. | 09-19-2013 |
| 20130259502 | IMAGE FORMATION DEVICE AND IMAGE FORMATION PROGRAM - An image formation device for forming an image by an electrophotographic process includes a charge voltage controller configured to control an application charge voltage to be applied to a charge member, a transfer voltage controller configured to control a transfer voltage to be applied to a transfer member, a charge current detector configured to detect a charge current flowing through the charge member, and a controller configured to determine the application charge voltage according to the application charge voltage and the detected charge current, both detected when the transfer voltage controller applies a predetermined transfer voltage. | 10-03-2013 |
| 20130279927 | IMAGE FORMING APPARATUS - The image forming apparatus is capable of executing a color mode for forming images of a plurality of colors using the plurality of developer bearing members, and a mono-mode for forming images of mono color using one developer bearing member of the plurality of developer bearing members. The control unit, when the color mode is executed, determines the charging bias and, the first laser power and the second laser power for respective image bearing members, based on information about the plurality of image bearing members. The control unit, when the mono-mode is executed, determines the charging bias and, the first laser power and the second laser power to image bearing member for mono-mode, based on information about image bearing member for mono-mode. | 10-24-2013 |
| 20130279928 | IMAGE FORMING APPARATUS - An image forming apparatus includes a photosensitive drum, a charging roller, a transfer roller, a first bias application unit, a second bias application unit, and a control unit. The charging roller contains an ion conductive material. The first bias application unit applies a first bias to the charging roller. The second bias application unit applies a predetermined bias to the transfer roller. The control unit controls the first bias application unit not to apply the first bias to the charging roller in a non-image forming period in which a toner image is not formed on the photosensitive drum. The control unit controls the second bias application unit to apply the second bias, which is a bias that can electrically charge the surface of the photosensitive drum, to the transfer roller in the non-image forming period. | 10-24-2013 |
| 20130294787 | EFFICIENCY OF A CORONA CHARGER - A method of charging a photoreceptor ( | 11-07-2013 |
| 20130294788 | EFFICIENCY OF A CORONA CHARGER - A system for charging a photoreceptor ( | 11-07-2013 |
| 20130294789 | IMAGE FORMING APPARATUS - An image forming apparatus having; an electrostatic latent image support; a charger for charging the electrostatic latent image support; an exposure unit for exposing the electrostatic latent image support with a light beam to form an electrostatic latent image; a development unit for developing the electrostatic latent image into a toner image; a sheet feeding unit for feeding a recording sheet in an image forming operation; a transfer member for transferring the toner image to the recording sheet; a fuser for fusing the toner image onto the recording sheet; and a high-voltage power supply circuit for, in an image forming operation, applying a plurality of bias voltages at least to the charger and to the development unit, wherein the high-voltage power supply circuit supplies a high voltage only to the charger in an operation in an ion generation mode so as to cause the charger to generate ions. | 11-07-2013 |
| 20130308969 | IMAGE FORMING APPARATUS - An image forming apparatus includes photosensitive drums, charging devices, an exposure unit configured to expose surfaces of photosensitive drums to generate a non-image portion potential and expose the surfaces to generate an image portion potential, developing members configured to make a developer adhere to an area where the image portion potential is generated to form a developer image on the photosensitive drums, a control unit configured to control an intensity of the charging voltage, and an acquisition unit configured to acquire thicknesses of photosensitive layers of the respective plurality of photosensitive drums, wherein the control unit is configured to set the intensity of a charging voltage applied to the common charging devices according to a maximum thickness among the thicknesses acquired by the acquisition unit, and individually control the output of the first laser power for the photosensitive drum according to surface potentials of the charged photosensitive drums. | 11-21-2013 |
| 20130308970 | IMAGE FORMING APPARATUS - An image forming apparatus for forming an image on a sheet includes an image bearing drum; a charging member for charging the drum by applying of a voltage while contacting to the drum; an AC voltage generating unit for generating and applying an AC voltage to the charging member; a state detector for detecting a state of the apparatus; a discharge current detector for detecting a discharge current between the charging member and the drum; a discharge current control unit for controlling the AC voltage generating unit on the basis of a result of detection of the discharge current detector; a discriminating unit for discriminating whether to calibrate the discharge current detector before formation of the image, in accordance with a result of detection of the state detector. | 11-21-2013 |
| 20130322902 | Image Forming Apparatus - An image forming apparatus includes: a first image forming unit for a monochrome printing including a first photosensitive member for black, a first charging member and a first collection member; a second image forming unit for a multi-color printing including a second photosensitive member for a color, a second charging member and a second collection member; and a control device configured to, at the color printing mode, apply a first charging bias to the second charging member and apply a first bias having a reverse polarity to a charged polarity of developer to the first and second collection members, and at the monochrome printing mode, apply a second charging bias to the second charging member, apply a second bias having the reverse polarity to the first collection member and apply a third bias to the second collection member. | 12-05-2013 |
| 20130343776 | HIGH-VOLTAGE OUTPUT APPARATUS AND IMAGE FORMING APPARATUS - The high-voltage output apparatus includes a voltage application part that applies a DC voltage to the charge member; a current detection part that detects a value of a current flowing in the image bearing member when the DC voltage is applied to the charge member; and a control part that calculates a plurality of discharge start voltages for the image bearing member, based on a plurality of current values detected by the current detection part as a result of the voltage application part applying a plurality of different DC voltages to the charge member, and controls the DC voltage applied to the charge member, using the plurality of calculated discharge start voltages. Consequently, a high-quality image can be formed by maintaining a potential on a photosensitive drum to be constant irrespective of the states of the circumstances and/or the drum layer thickness. | 12-26-2013 |
| 20140003828 | IMAGE FORMING APPARATUS DETERMINING CHARGED POTENTIAL FLUCTUATION OF PHOTOSENSITIVE MEMBER | 01-02-2014 |
| 20140064758 | IMAGE FORMING APPARATUS - There is provided an image forming apparatus which includes multiple charging rollers and which can suppress accumulation of deposits such as external additives onto a charging roller without reducing productivity of the image forming apparatus. | 03-06-2014 |
| 20140079419 | IMAGE FORMING APPARATUS - An image forming apparatus includes an image forming unit, a charging bias application section, a static eliminating bias application section, and a control section. In the case where the image forming unit causes an image carrier to be rotated without forming an electrostatic latent image on the image carrier, the control section performs a bias control to allow the charging bias application section to apply to a charging section a smaller charging bias than used in forming a toner image and allow the static eliminating bias application section to apply to a static eliminating section a smaller static eliminating bias than used in forming the toner image. The control section performs the bias control to increase respective values of the charging bias and the static eliminating bias every one revolution of the image carrier until the charging bias and the static eliminating bias in forming the toner image are reached. | 03-20-2014 |
| 20140099132 | IMAGE FORMING APPARATUS - In an image forming apparatus, the charging bias supply circuit generates a second charging bias voltage that causes no positive discharge between the charging unit and the photoreceptor drum, during a recovery mode, the charging unit charges the surface of the photoreceptor drum upon application of the second charging bias voltage during the recovery mode, and the cleaning unit rubs the surface of the photoreceptor drum charged by the second charging bias voltage, during the recovery mode. | 04-10-2014 |
| 20140147139 | IMAGE FORMING APPARATUS - An image forming apparatus including: photosensitive members; charging devices to which a common charging power source applies a charging voltage to charge the photosensitive members; an exposure device configured to expose the photosensitive members; developing devices to form developer images on the photosensitive members; a transfer device to transfer the developer images onto a transfer medium; and a control portion configured to set a lower limit value of the charging voltage for each photosensitive member, apply the charging voltage having a magnitude not less than any lower limit value from the charging power source to the charging devices, control the output of the laser power for each photosensitive member individually, and set, based on the image density of the developer image transferred onto the transfer medium earlier, the lower limit value for a photosensitive member on which a developer image to be transferred onto the transfer medium later is formed. | 05-29-2014 |
| 20140147140 | IMAGE FORMING APPARATUS HAVING CHARGING MEMBER FOR CHARGING PHOTOSENSITIVE MEMBER - An image forming apparatus having a photosensitive member, a charging member that charges the photosensitive member to form a charged surface on a surface of the photosensitive member, an applying unit that applies to the charging member a charging bias composed of a direct voltage superimposed with an alternating voltage, and a toner image forming unit that forms a toner image on the charged surface. A current flowing through the charging member when the charging bias is applied to the charging member is detected by a current detection unit, and currents of different predetermined frequency components are respectively extracted from the detected current by extraction units. Based on the extracted currents, the alternating voltage of the charging bias is adjusted by an adjustment unit. | 05-29-2014 |
| 20140169815 | IMAGE FORMING APPARATUS - An image forming apparatus including: a plurality of image forming stations; and a control portion configured to control an image forming operation, each of the image forming stations includes: an image bearing member configured to form a toner image on a surface thereof; and a charging device configured to charge the image bearing member, wherein the toner images formed on the image bearing members of the image forming stations are sequentially transferred to a transfer incurring member to be superimposed, wherein the control portion sets a voltage applied to the charging device in forming an image in an image forming station which performs the transfer later based on image density information of the toner image transferred to the transfer incurring member by an image forming station which performs the transfer earlier in a sequence of the image forming operations. | 06-19-2014 |
| 20140178087 | IMAGE FORMING APPARATUS - An image forming apparatus includes an exposure device configured to expose image bearing members charged by charging devices to form latent images on the image bearing members, and a control unit configured to, in ether one or both of an image forming unit A and an image forming unit B, adjust an amount of exposure by which the image bearing member is exposed and a charging voltage based on information about the image bearing members of the image forming units A and B. The control unit is configured to make the charging voltage and the amount of exposure in the image forming unit A different from the charging voltage and the amount of exposure in the image forming unit B. | 06-26-2014 |
| 20140186064 | IMAGE FORMING APPARATUS - An image forming apparatus includes a plurality of photosensitive drums, and a controller for executing, when an absolute value of a set point of a charged potential is not higher than a predetermined threshold, an operation in a first mode in which charging bias voltages and transfer biases are applied to image regions of the drums, and the charging bias voltages are further applied, and thereafter, image exposures are carried out by exposure members, respectively, and for executing, when the absolute value of the set point of the charged potential is higher than the predetermined threshold, an operation in a second mode in which timings of start of applications of the transfer bias voltages to the transfer members are delayed as compared with those in the first mode, respectively. | 07-03-2014 |
| 20140356006 | Image Forming Apparatus - An image forming apparatus includes an image carrier, a charging member, a transfer member, a cleaning member and a control device configured to switch a first mode and a second mode. When executing the second mode, the control device applies a second charging bias having the same polarity as a first charging bias and having an absolute value smaller than the first charging bias to the charging member, applies a second transfer bias having the same polarity as a first transfer bias and having an absolute value smaller than the first transfer bias to the transfer member, and applies a second cleaning bias having the same polarity as the charged polarity of the toner to the cleaning member and sets a potential difference between a surface potential of the image carrier and the second cleaning bias within a predetermined range. | 12-04-2014 |
| 20140363182 | IMAGE FORMING APPARATUS - An image forming apparatus capable of suppressing deterioration of a charger although an amount of use of the charger is actually small is provided. For that purpose, the image forming apparatus executes simple control of discharge current control in which at least one charging bias smaller in number than number of kinds of test biases in full control of the discharge current control is applied to the charger after a power source is turned on and before an image formation start signal is inputted, and on the basis of a current detected by the detector when the charging bias is applied, selects one from a plurality of modes including a first mode in which a charging bias is set by executing the full control of the discharge current control and including a second member in which the charging bias determined by full control of discharge current control without executing the full control of the discharge current control. | 12-11-2014 |
| 20150023677 | Image Forming Apparatus - An image forming apparatus, comprising: an attachment unit to which a load for image formation is attached; an applying circuit configured to apply an applying voltage to the load; a voltage detection circuit configured to detect the applying voltage; a current detection unit configured to detect a load current; and a control device, wherein the control device is configured to: subject the applying circuit to constant current control in accordance with a detected value of the current detection unit so that the load current becomes a target current; and switch to a constant voltage control by which the applying voltage is controlled to become a target voltage when an absolute value of the load current is smaller than a determination value and an absolute value of the applying voltage is larger than or equal to a threshold during execution of the constant current control. | 01-22-2015 |
| 20150071662 | PROCESSING CARTRIDGE, IMAGE FORMING APPARATUS WITH SAME, AND IMAGE FORMING METHOD - An image forming apparatus includes an electrophotographic photoreceptor that bears a latent image, an electrostatic charging unit that negatively charges the electrophotographic photoreceptor uniformly with electricity, and a latent image writing unit that writes a latent image on the electrophotographic photoreceptor. A one-component developing unit renders the latent image visible by developing thereof. A transfer device transfers the toner image from the electrophotographic photoreceptor onto a transfer medium. The inequality C×V| 03-12-2015 | |
| 20150071663 | IMAGE FORMING DEVICE, BIAS VOLTAGE CONTROL METHOD FOR IMAGE FORMING DEVICE, AND COMPUTER PROGRAM PRODUCT - An image forming device includes a charging power supply used in applying, to a charging unit, a charging voltage for the purpose of electrostatic latent image formation and a charging bias voltage during a cleaning operation; a developing power supply that is capable of outputting a developing bias voltage of positive polarity and negative polarity to a developing unit; a constant-voltage generating-holding unit that is used in generating and holding a constant potential difference between the charging unit and the developing unit; a developing power control unit that performs output control of a developing bias voltage with respect to the developing unit; and a charging power control unit that, when the developing power control unit performs control to output a developing bias voltage of reverse polarity to the charging unit, performs output control of the charging bias voltage of a predetermined level with respect to the charging power supply. | 03-12-2015 |
| 20150098720 | IMAGE FORMING APPARATUS - There is provided an image forming apparatus including: a rotatable photosensitive member; a rotatable charging brush for electrically charging the photosensitive member by injecting electric charges into a surface of the photosensitive member in contact with the surface of the photosensitive member; a power source for applying a voltage to the charging brush; a potential sensor for detecting a surface potential of the photosensitive member; an executing portion for causing the potential sensor to execute detection in such a manner that after a first potential which is the potential of the photosensitive member charged by applying a first voltage to the charging brush is detected by the potential sensor, the electric charges are removed from the photosensitive member by applying a second voltage smaller in absolute value than the first potential to the charging brush, and then a second potential which is the potential of the photosensitive member after removal of the electric charges is detected by the potential sensor; and a notifying portion for providing notification of information on a lifetime of the charging brush or information on exchange of the charging brush on the basis of the first potential and the second potential. | 04-09-2015 |
| 20150104207 | IMAGE FORMING APPARATUS - An image forming apparatus includes a charging member, a charging bias power source, a developing member, a developing bias power source and a controlling device. The charging member electrically charged an image carrier. The charging bias power source applies a DC charging bias to the charging member. The developing member develops a toner image onto the image carrier. The developing bias power source applies an AC and DC developing bias to the developing member. The controlling device carries out, before image forming process, pre-charging control controlling the charging bias power source to electrically charge the image carrier. The controlling device carries out, after the image forming process is started, post-charging control controlling the charging bias power source and developing bias power source to adjust an electrical potential difference between a surface potential of the image carrier and developing bias to a significant electrical potential difference preventing occurrence of image failure. | 04-16-2015 |
| 20150117886 | IMAGE FORMATION APPARATUS AND IMAGE FORMING METHOD - An image formation apparatus includes: a first image formation unit including a first image carrier and a first charging member that charges the first image carrier, the first image formation unit using a first developer and; a second image formation unit including a second image carrier and a second charging member that charges the second image carrier, the second image formation unit using a second developer; and a controller that determines a first charging voltage correction amount for correcting a charging voltage to be applied to the first charging member according to an amount of usage of the first image carrier, and determines a second charging voltage correction amount for correcting a charging voltage to be applied to the second charging member according to an amount of usage of the second image carrier. The second charging voltage correction amount is larger than the first charging voltage correction amount. | 04-30-2015 |
| 20150139674 | IMAGE FORMING APPARATUS - An image forming apparatus includes an electrostatic latent image bearer; a charger to charge a surface of the electrostatic latent image bearer; a power source to output a charging bias supplied to the charger; an electrostatic latent image writing unit to write an electrostatic latent image on the surface of the electrostatic latent image bearer charged by the charger; a developing unit including a developing member to develop the electrostatic latent image to obtain a toner image; a developing power source to output a developing bias supplied to the developing unit; a processor to adjust the charging bias output from the power source to a predetermined target value; and a storage unit to store an adjustment value algorithm. | 05-21-2015 |
| 20160026110 | IMAGE FORMING APPARATUS - An image forming apparatus includes an image bearing member, a transfer device, a first charging device, a static elimination device, a second charging device, a light exposure device, and a development device. The transfer device transfers a developer image of a first polarity onto a recording medium from the image bearing member by receiving a transfer bias of a second polarity. The first charging device charges a region of the image bearing member that has undergone transfer to the first polarity by receiving a first charging bias of the first polarity. An absolute value of the first charging bias is greater during charging of a first region of the image bearing member than during charging of a second region of the image bearing member. The first region includes a trailing end contact section. The second region does not include the trailing end contact section or a leading end contact section. | 01-28-2016 |
| 20160048091 | Image Forming Apparatus, and Method and Computer-Readable Medium for the Same - An image forming apparatus including a controller configured to apply a charging bias to a charger during image formation on a photoconductive body, an absolute value of the charging bias being a first absolute value, apply a development bias to a development roller during the image formation, place the development roller in a development position during the image formation, after the image formation, reduce the absolute value of the charging bias to a second absolute value less than the first absolute value, after reducing the absolute value of the charging bias, separate the development roller away from the photoconductive body and place the development roller in a non-development position, and after placing the development roller in the non-development position, stop applying the development bias to the development roller. | 02-18-2016 |
| 20160062260 | IMAGE FORMING APPARATUS - An image forming apparatus includes a latent image carrier; a charger; a charging power supply; a latent image writer to write; a developing device; a rotary attitude sensor; a controller to perform a data formulating process to formulate a change pattern data and a bias changing process to cause the charging power supply to change the charging bias output based on readings from the rotary attitude sensor and the change pattern data, during a print job; and a surface potential sensor to detect a surface potential of the latent image carrier. In the data formulating process, the controller formulates the change pattern data based on the surface potential of the latent image carrier detected by the surface potential sensor, while the charging power supply outputting a constant charging bias, and based on readings from the rotary attitude sensor while the surface potential is being detected. | 03-03-2016 |
| 20160077456 | IMAGE FORMING APPARATUS - An image forming apparatus includes a photosensitive member, a charging member, a charging voltage source, an exposure device, a developing device, a transfer member, a transfer voltage source, a voltage detecting portion, a current detecting portion, and an executing portion. In a test mode, the executing portion gradually changes a value of a current caused to flow through the transfer member from zero to a predetermined target transfer current and sets the current caused to flow through the transfer member as the predetermined target transfer current, and then gradually changes a current caused to flow through the charging member from zero to an obtained charging current when a region of the photosensitive member subsequently passes through the charging portion and sets the current caused to flow through the charging member when a region of the photosensitive member subsequently passes through the charging portion as the obtained charging current. | 03-17-2016 |
| 20160097987 | IMAGE FORMING APPARATUS - An image forming apparatus, includes an image carrier; a power supply; a charging member, to which the power supply applies a direct current (DC) charging voltage, to charge a surface of the image carrier; and a controller. The controller causes the power supply to apply, to the charging member, the DC charging voltage of a sum of a reference voltage VC and a correction amount α, so that a charged potential VD of the surface of the image carrier assumes a target value that is substantially equal to the reference voltage VC; and to increase an absolute value of the correction amount α to be added to the reference voltage VC in inverse proportion to an absolute value of the reference voltage VC, when the absolute value of the reference voltage VC is smaller compared to a case in which the absolute value of the reference voltage VC is greater. | 04-07-2016 |
| 20160139531 | IMAGE FORMING APPARATUS - An image forming apparatus includes: a plurality of image forming units forming an image in the corresponding color by electrophotographic system; a high-voltage power supply circuit capable of generating a bias voltage; and a control unit that controls a first printing mode and a second printing mode, wherein in the second printing mode, the control unit performs such control that the photosensitive bodies provided on the image forming units not used in the second printing mode continuously rotate at a speed lower than a speed in the first printing mode, and/or such control that a bias voltage whose absolute value is less than an absolute value of a bias voltage in the first printing mode is supplied from the high-voltage power supply circuit to the processing components of the same type provided on the image forming units not used in the second printing mode. | 05-19-2016 |
| 20160161878 | IMAGE FORMING APPARATUS - An image forming apparatus includes a rotatable photosensitive member (drum), a first corona charger, a second corona charger, an image forming portion, a voltage applying portion, a surface potential detecting portion, a controller. The controller determines a condition of voltages applied to the first and second corona chargers during image formation, by setting a first voltage condition for the first corona charger so that the surface potential of the drum is a second potential lower in absolute value than the first potential in a state in which the first corona charger operates, and the second corona charger does not operates, and then by setting a second voltage condition for the second corona charger so that the surface potential of the drum is the first potential in a state in which the first corona charger operates under the first voltage condition, and the second corona charger operates. | 06-09-2016 |
| 20160195830 | PROCESS CARTRIDGE, IMAGE FORMING APPARATUS WITH PROCESS CARTRIDGE, AND METHOD OF FORMING IMAGE BY USING IMAGE FORMING APPARATUS WITH PROCESS CARTRIDGE | 07-07-2016 |
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| 20190146367 | IMAGE FORMING APPARATUS, METHOD FOR FORMING IMAGE, AND NON-TRANSITORY COMPUTER-READABLE STORAGE MEDIUM | 05-16-2019 |
| 20190146368 | APPLYING A CORRECTIVE VOLTAGE | 05-16-2019 |
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