Abstract: In an image forming apparatus, a bias controller varies one, while keeping the other fixed, of a charging alternating-current frequency, which is the frequency of the charging alternating-current voltage, and a developing alternating-current frequency, which is the frequency of the developing alternating-current voltage. Specifically, in a case where interference fringes appear in a developed image due to interference between the charging and developing alternating-current frequencies, when the recognizable minimum pitch of the interference fringes is A1 (mm), the width of the variation region of the other frequency is B1 (Hz), the rotation speed of an image carrying member is C1 (mm/sec), and the variation speed of the other frequency in the variation region is D1 (Hz/sec), the bias controller varies the other frequency at a variation speed D1 that fulfills |D1|>B1/(A1/C1).

Abstract: An image processing apparatus includes a storage device, an image reading device, a complementary image storage device, and a control device. The complementary image storage device stores a complementary image for complementing an incomplete two-dimensional code. The control device includes a processor and functions, through the processor executing a control program, as a detector, a synthesizer, and an analyzer. The detector detects, from the image obtained through the reading of the image reading device, the incomplete two-dimensional code. The synthesizer synthesizes the incomplete two-dimensional code detected by the detector and the complementary image stored in the complementary image storage device to generate a complete two-dimensional code. The analyzer analyzes the complete two-dimensional code generated by the synthesizer and activates an extension function.

Abstract: An image forming apparatus has a bias controller. The bias controller varies both a charging alternating-current frequency, which is the frequency of a charging alternating-current voltage, and a developing alternating-current frequency, which is the frequency of the developing alternating-current voltage. When the region of the charging and developing alternating-current frequencies in which interference fringes appear in a developed image due to interference between the charging and developing alternating-current frequencies is taken as a variation region and the variation speeds of the charging and developing alternating-current frequencies in the variation region are taken as a first and a second variation speed respectively, the bias controller varies the charging and developing alternating-current frequencies such that one of the first and second variation speeds is a positive-number multiple of the other.

Abstract: An image processing apparatus includes a storage device, an image reading device, a complementary image storage device, and a control device. The complementary image storage device stores a complementary image for complementing an incomplete two-dimensional code. The control device includes a processor and functions, through the processor executing a control program, as a detector, a synthesizer, and an analyzer. The detector detects, from the image obtained through the reading of the image reading device, the incomplete two-dimensional code. The synthesizer synthesizes the incomplete two-dimensional code detected by the detector and the complementary image stored in the complementary image storage device to generate a complete two-dimensional code. The analyzer analyzes the complete two-dimensional code generated by the synthesizer and activates an extension function.

Abstract: An image forming apparatus has a bias controller. The bias controller varies both a charging alternating-current frequency, which is the frequency of a charging alternating-current voltage, and a developing alternating-current frequency, which is the frequency of the developing alternating-current voltage. When the region of the charging and developing alternating-current frequencies in which interference fringes appear in a developed image due to interference between the charging and developing alternating-current frequencies is taken as a variation region and the variation speeds of the charging and developing alternating-current frequencies in the variation region are taken as a first and a second variation speed respectively, the bias controller varies the charging and developing alternating-current frequencies such that one of the first and second variation speeds is a positive-number multiple of the other.

Abstract: In an image forming apparatus, a bias controller varies one, while keeping the other fixed, of a charging alternating-current frequency, which is the frequency of the charging alternating-current voltage, and a developing alternating-current frequency, which is the frequency of the developing alternating-current voltage. Specifically, in a case where interference fringes appear in a developed image due to interference between the charging and developing alternating-current frequencies, when the recognizable minimum pitch of the interference fringes is A1 (mm), the width of the variation region of the other frequency is B1 (Hz), the rotation speed of an image carrying member is C1 (mm/sec), and the variation speed of the other frequency in the variation region is D1 (Hz/sec), the bias controller varies the other frequency at a variation speed D1 that fulfills |D1|>B1/(A1/C1).

Abstract: An image forming apparatus has an image carrying member, a charging member, an exposing device, a destaticizer, a high-voltage generation circuit, a current detector, and a controller. The controller is configured to execute a contamination state check mode having a potential saturation step where the surface potential of the image carrying member is saturated by applying a DC voltage alone to the charging member, an exposure step where the image carrying member of which the surface potential is saturated is exposed to light in an exposure pattern extending continuously over its entire area in the main scanning direction while being displaced at a constant rate in the sub-scanning direction by the exposing device, and a current detection step where the charging current that passes while the exposure pattern formed on the surface of the image carrying member passes through the charging member is detected by the current detector.

Abstract: In an image forming apparatus, a seal member is a non-conductive, flexible member supported by a developing device. The seal member is formed to project from an edge part of the developing device that faces an image carrying member, along a longitudinal direction of the image carrying member. The seal member fills a part of a gap between the developing device and an outer circumferential surface of the image carrying member. An electrode film is adhered to a surface of the seal member. The electrode film is a conductive film. A potential detecting device detects a potential of the electrode film. A charging controller controls a charging voltage based on a result of comparison between a predetermined reference potential and the potential detected by the potential detecting device.

Abstract: In an image forming apparatus (10), a seal member (436) is a non-conductive, flexible member supported by a developing device (43). The seal member (436) is formed to project from an edge part (43b) of the developing device (43) that faces an image carrying member (41), along a longitudinal direction (D1) of the image carrying member (41). The seal member (436) fills a part of a gap between the developing device (43) and an outer circumferential surface of the image carrying member (41). An electrode film (437) is adhered to a surface of the seal member (436). The electrode film (437) is a conductive film. A potential detecting device (642) detects a potential of the electrode film (437). A charging controller (8b) controls a charging voltage based on a result of comparison between a predetermined reference potential and the potential detected by the potential detecting device (642).

Abstract: An image forming apparatus has an image carrying member, a charging member, an exposing device, a destaticizer, a high-voltage generation circuit, a current detector, and a controller. The controller is configured to execute a contamination state check mode having a potential saturation step where the surface potential of the image carrying member is saturated by applying a DC voltage alone to the charging member, an exposure step where the image carrying member of which the surface potential is saturated is exposed to light in an exposure pattern extending continuously over its entire area in the main scanning direction while being displaced at a constant rate in the sub-scanning direction by the exposing device, and a current detection step where the charging current that passes while the exposure pattern formed on the surface of the image carrying member passes through the charging member is detected by the current detector.

Abstract: An image forming apparatus includes a high-voltage generating circuit which applies to a charging member an oscillation voltage in which a DC voltage and an AC voltage are superimposed, a voltage controller which controls the DC voltage and a peak-to-peak voltage value Vpp of the AC voltage, and a current detector which detects a DC current value Idc between the charging member and an image carrier. The voltage controller detects an Idc(O?) when an oscillation voltage having a Vpp(O?) at an intersection point of a straight line L1 passing through coordinates A(Vpp(A), Idc(A)) and coordinates B(Vpp(B), Idc(B)) and a straight line passing through coordinates C(Vpp(C), Idc(C)) and parallel to a coordinate axis representing Vpp. Vpp(O) at an intersection point O of a straight line L2 passing through coordinates C and coordinates O?(Vpp(O?), Idc(O?)) and the straight line L1 is determined as an appropriate peak-to-peak voltage value.

Abstract: An image forming apparatus includes a high-voltage generating circuit which applies to a charging member an oscillation voltage in which a DC voltage and an AC voltage are superimposed, a voltage controller which controls the DC voltage and a peak-to-peak voltage value Vpp of the AC voltage, and a current detector which detects a DC current value Idc between the charging member and an image carrier. The voltage controller detects an Idc(O?) when an oscillation voltage having a Vpp(O?) at an intersection point of a straight line L1 passing through coordinates A(Vpp(A), Idc(A)) and coordinates B(Vpp(B), Idc(B)) and a straight line passing through coordinates C(Vpp(C), Idc(C)) and parallel to a coordinate axis representing Vpp. Vpp(O) at an intersection point O of a straight line L2 passing through coordinates C and coordinates O?(Vpp(O?), Idc(O?)) and the straight line L1 is determined as an appropriate peak-to-peak voltage value.

Abstract: An image forming apparatus includes an image carrying member, a driving device, a charging member, a cleaning member, a voltage applying device, a braking distance detector, a storage for storing a predetermined braking distance value Lc, and a control portion. The control portion obtains as Lon a braking distance when a charging voltage is applied to the charging member and obtains as Loff a braking distance when no charging voltage is applied to the charging member. Let the braking distance observed when no charging voltage is applied at an early stage of use of the image carrying member be represented by Loff(0), then, when the relations Loff<Loff(0) and Lc<Loff/Lon hold, the control portion determines that the degree of smoothness of the surface of the image carrying member is equal to or higher than a predetermined degree of smoothness.

Abstract: An image forming apparatus includes an image carrying member, a driving device, a charging member, a cleaning member, a voltage applying device, a braking distance detector, a storage for storing a predetermined braking distance value Lc, and a control portion. The control portion obtains as Lon the braking distance when the charging voltage is applied to the charging member and obtains as Loff the braking distance when no charging voltage is applied to the charging member. Let the braking distance observed when no charging voltage is applied at an early stage of use of the image carrying member be represented by Loff(0), then, when the relations Loff<Loff(0) and Lc<Loff/Lon hold, the control portion determines that the degree of smoothness of the surface of the image carrying member is equal to or higher than a predetermined degree of smoothness.

Abstract: An image forming apparatus includes a high voltage generating circuit 91 that applies an oscillating voltage in which a DC voltage and an AC voltage are superimposed on each other, to a charging member 42 disposed in contact with an image carrier 41; a voltage control portion 96 that controls a peak-to-peak voltage of the AC voltage to a target voltage value; and an initial voltage adjusting portion 95 that sets a target voltage value based on a DC current value between the image carrier 41 and the charging member 42 which is detected by a current detecting portion 92. When an environmental condition which is used when the target voltage value is set changes, the initial voltage adjusting portion 95 performs an interrupt operation during an image forming process.

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: 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: The present invention provides an image forming apparatus and an image forming method capable of preventing excessive charging in the toner within the cleaning device for effectively preventing generation of the black spots derived from the leak current. In the image forming apparatus comprising a cleaning device having a cleaning blade for scraping out the toner on a latent image carrier body surface and the image forming method using the same, the toner contains a titanium oxide as an additive agent, and with the premise that the fluorescence X ray intensity of the titanium oxide added to the toner before use is X1, and the fluorescence X ray intensity of the titanium oxide added to the toner within the cleaning device is X2, X1 and X2 satisfy the following relationship formula (1): X2/X1?1.2??(1).

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.