Abstract: An image forming apparatus is provided with a rotary image bearing member; a charging roller for charging the outer circumferential surface of the image bearing member by rotating in contact with the image bearing member; a brush roller for cleaning adhered matters on the outer circumferential surface of the charging roller by being held in contact with the charging roller due to its own weight and rotating; a driving mechanism for drivingly rotating the brush roller to have a linear velocity difference to the charging roller; and a moving mechanism for reciprocating the brush roller along the longitudinal direction thereof.

Abstract: In an image forming apparatus 1, disposed are: a photoreceptor drum 2; a charging roller which rotates following the photoreceptor drum 2; and a cleaning member 21 which is rotatable with being in contact with surfaces of the photoreceptor drum 2 and the charging roller 3 in an upstream side with respect to the charging roller 3 in a rotation direction of the photoreceptor drum 2. The cleaning member 21 includes a rotational shaft 21a and a brush portion 21b, rotates in a driven direction with respect to the charging roller 3 and a linear-velocity ratio of the cleaning member 21 to the charging roller 3 is smaller than 1.

Abstract: An image forming apparatus charges the surface of a photosensitive member to a predetermined potential. A current detector detects a charging current when the charging bias is applied. A storage stores a target charging current value when the photosensitive member is charged to a required potential. A usage acquiring portion acquires information relating to usage of the charging roller. A bias corrector performs first and second corrections. The first correction compares a charging current value with a stored target charging current value and determines a new charging bias based on the comparison. The second correction determines whether usage of the charging roller is a predetermined first amount or a greater amount based on acquired usage information, and when the usage is the greater amount, changes the target charging current value in accordance with the usage amount and obtains a new charging bias based on the changed target charging current value.

Abstract: 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.

Abstract: The present invention provides an image forming apparatus and an image forming method capable of effectively suppressing the occurrence of image deletion etc. and thus stably obtaining a high-quality image and stably reducing the influence of titanium oxide particles on image quality. The image forming apparatus includes an amorphous silicon photoconductor drum having a heater provided therein; a charging device; and a rotating member that cleans the surfaces of the amorphous silicon photoconductor drum using titanium oxide particles included in toner particles. In the image forming apparatus and the image forming method using the same, the heater controls a difference between the surface temperature of the amorphous silicon photoconductor drum and the outdoor temperature within a predetermined range, and slide friction between the amorphous silicon photoconductor drum and the rotating member and the average primary particle diameter of the titanium oxide particles are set in predetermined ranges.

Abstract: An image forming apparatus includes a plurality of image forming units arranged in parallel, each image forming unit having an image carrying member and a charging roller disposed face to face with the image carrying member for electrically charging the image carrying member, and a shifting mechanism for selectively shifting at least one charging roller between a first position where the charging roller is brought into contact with the corresponding image carrying member to electrically charge the image carrying member in contact manner and a second position where the charging roller is moved away from the corresponding image carrying member to electrically charge the image carrying member in non-contact manner.

Abstract: An image forming apparatus uses a charging roller to charge the surface of a photosensitive member to a predetermined potential. A current detector detects charging current when the charging bias is applied. A bias corrector corrects the charging bias and a storage stores a target charging current value when the photosensitive member is charged to a required potential. The bias corrector performs two corrections. The first correction compares a charging current value with a stored target charging current value, and determines a new bias based on the comparison. The second correction determines whether the bias obtained by the first correction is at a predetermined level or a higher level, and when the corrected charging bias is at the higher level, changes the target charging current value in accordance with the corrected charging bias and obtains a new charging bias on the basis of the changed target charging current value.

Abstract: 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.

Abstract: A tandem 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 and an AC voltage superimposed thereon; a voltage control portion for controlling the peak-to-peak voltage of the AC voltage at a target voltage, the image forming device changing by switching a process speed depending on monochrome image formation and color image formation; a current detecting portion for detecting the value of a DC current between the image carrier and the charging member; and a frequency switching portion for switching the frequency of the AC voltage between frequencies according to the process speed. The voltage control portion includes an initial voltage adjusting portion for adjusting the target voltage on the basis of the value of the DC current detected by the current detecting portion.

Abstract: A cleaning device cleans a charging roller for charging the outer circumferential surface of a photoconductive drum while being rotated in contact with the photoconductive drum, and is provided with a cleaning brush for cleaning the outer circumferential surface of the charging roller by brushing while being rotated in contact with the outer circumferential surface of the charging roller, a rotational driving mechanism for rotating the cleaning brush while making the circumferential speed thereof differ from that of the charging roller, and a thrust driving mechanism for reciprocating the cleaning brush along a direction of a rotary axis of the charging roller while holding the cleaning brush in sliding contact with the outer circumferential surface of the charging roller.

Abstract: The present invention provides an image forming apparatus and an image forming method capable of effectively suppressing the occurrence of image deletion etc. and thus stably obtaining a high-quality image and stably reducing the influence of titanium oxide particles on image quality. The image forming apparatus includes an amorphous silicon photoconductor drum having a heater provided therein; a charging device; and a rotating member that cleans the surfaces of the amorphous silicon photoconductor drum using titanium oxide particles included in toner particles. In the image forming apparatus and the image forming method using the same, the heater controls a difference between the surface temperature of the amorphous silicon photoconductor drum and the outdoor temperature within a predetermined range, and slide friction between the amorphous silicon photoconductor drum and the rotating member and the average primary particle diameter of the titanium oxide particles are set in predetermined ranges.

Abstract: An aspect of the invention provides a charging control device of a color image forming apparatus, and the charging control device can properly control a charging potential of an image bearing body such that fog and uneven density are not generated even in a low-temperature environment. The image forming apparatus includes a high-voltage generation circuit 91 which applies an oscillating voltage to the charging member 42 disposed in contact with an image bearing body 41, a direct-current voltage and an alternating-current voltage being superimposed to form the oscillating voltage; a current detection unit 92 which detects a direct current value passed from the charging member 42 to the image bearing body 41; and a voltage control unit 96 which controls the alternating-current voltage such that the detected direct-current value is maintained in a target current range. The image forming apparatus also includes an aging control unit 95 to perform running-in.

Abstract: An image forming apparatus has a charge removing unit (31) between a transfer roller (11) for transferring a toner image from a surface of a photosensitive drum (4) to a transfer member and a charging unit (3) for electrostatically charging the surface of the photosensitive drum (4) approximately uniformly, with respect to a rotation direction of the photosensitive drum (4). The charge removing unit (31) includes LEDs (311) to irradiate the surface of the photosensitive drum (4) with charge-removing light. A support (312) supports the LEDs (311) approximately in a line along an axial direction of the photosensitive drum (4). A position setting mechanism (313) allows a position of the support (312) to be changed selectively in a direction orthogonal to the axis of the photosensitive drum (4). Thus, the image forming apparatus can suppress uneven charge-distribution in the axial direction of the photosensitive drum (4).

Abstract: An image forming apparatus uses a charging roller to charge the surface of a photosensitive member to a predetermined potential. A current detector detects charging current when the charging bias is applied. A bias corrector corrects the charging bias and a storage stores a target charging current value when the photosensitive member is charged to a required potential. The bias corrector performs two corrections. The first correction compares a charging current value with a stored target charging current value, and determines a new bias based on the comparison. The second correction determines whether the bias obtained by the first correction is at a predetermined level or a higher level, and when the corrected charging bias is at the higher level, changes the target charging current value in accordance with the corrected charging bias and obtains a new charging bias on the basis of the changed target charging current value.

Abstract: An image forming apparatus charges the surface of a photosensitive member to a predetermined potential. A current detector detects a charging current when the charging bias is applied. A storage stores a target charging current value when the photosensitive member is charged to a required potential. A usage acquiring portion acquires information relating to usage of the charging roller. A bias corrector performs first and second corrections. The first correction compares a charging current value with a stored target charging current value and determines a new charging bias based on the comparison. The second correction determines whether usage of the charging roller is a predetermined first amount or a greater amount based on acquired usage information, and when the usage is the greater amount, changes the target charging current value in accordance with the usage amount and obtains a new charging bias based on the changed target charging current value.

Abstract: An image forming apparatus is provided with a rotary image bearing member; a charging roller for charging the outer circumferential surface of the image bearing member by rotating in contact with the image bearing member; a brush roller for cleaning adhered matters on the outer circumferential surface of the charging roller by being held in contact with the charging roller due to its own weight and rotating; a driving mechanism for drivingly rotating the brush roller to have a linear velocity difference to the charging roller; and a moving mechanism for reciprocating the brush roller along the longitudinal direction thereof.

Abstract: A cleaning device cleans a charging roller for charging the outer circumferential surface of a photoconductive drum while being rotated in contact with the photoconductive drum, and is provided with a cleaning brush for cleaning the outer circumferential surface of the charging roller by brushing while being rotated in contact with the outer circumferential surface of the charging roller, a rotational driving mechanism for rotating the cleaning brush while making the circumferential speed thereof differ from that of the charging roller, and a thrust driving mechanism for reciprocating the cleaning brush along a direction of a rotary axis of the charging roller while holding the cleaning brush in sliding contact with the outer circumferential surface of the charging roller.

Abstract: An image forming apparatus has a charge removing unit (31) between a transfer roller (11) for transferring a toner image from a surface of a photosensitive drum (4) to a transfer member and a charging unit (3) for electrostatically charging the surface of the photosensitive drum (4) approximately uniformly, with respect to a rotation direction of the photosensitive drum (4). The charge removing unit (31) includes LEDs (311) to irradiate the surface of the photosensitive drum (4) with charge-removing light. A support (312) supports the LEDs (311) approximately in a line along an axial direction of the photosensitive drum (4). A position setting mechanism (313) allows a position of the support (312) to be changed selectively in a direction orthogonal to the axis of the drum (4). Thus, the image forming apparatus can suppress uneven charge-distribution in the axial direction of the photosensitive drum (4).