Abstract: An image forming apparatus includes an exposure unit, including a plurality of light-emitting units that correspond to a respective plurality of pixels and a lens array optical system, for emitting exposure light. A photosensitive member is exposed by the exposure light from the exposure unit. A correcting unit estimates, from image data, an intensity of ghost light at a position of each pixel on the photosensitive member in a case when the photosensitive member is exposed by the exposure unit, using the image data, and corrects the image data based on the estimated intensity of the ghost light.

Abstract: An image forming apparatus includes: a photosensitive member; and an exposure unit. The exposure unit includes a lens array optical system in which a plurality of lenses are disposed along a predetermined direction, and a light-emitting unit having a plurality of light-emitting elements disposed so as to expose, through the lens array optical system, every Lth pixel in L scanning lines of the photosensitive member. An interval of locations, in a main arrangement direction, that correspond to adjacent lenses in the lens array optical system is configured to be an interval based on the value of L.

Abstract: An image forming apparatus includes: an exposure unit including a plurality of light-emitting units that correspond to a respective plurality of pixels and a lens array optical system; a photosensitive member exposed by the exposure unit; and a correcting unit configured to estimate, from image data, an intensity of ghost light at a position of each pixel on the photosensitive member in the case where the photosensitive member is exposed by the exposure unit using the image data, and correct the image data based on the estimated intensity of the ghost light.

Abstract: An image forming apparatus includes: a photosensitive member; and an exposure unit, including a lens array optical system in which a plurality of lenses are disposed along a predetermined direction, and a light-emitting unit having a plurality of light-emitting elements disposed so as to expose, through the lens array optical system, every Lth pixel in L scanning lines of the photosensitive member. An interval of locations, in a main arrangement direction, that correspond to adjacent lenses in the lens array optical system is configured to be an interval based on the value of L.

Abstract: An image forming apparatus of this invention, when an exposure unit performs exposure, applies, to image data quantized by a first number of bits, compensation data for compensating for unevenness of the exposure intensity occurring on a photosensitive member caused by a lens array used in the exposure unit. This compensation data is obtained by quantizing, by a second number of bits larger than the first number of bits, data corresponding to a change in measurement value obtained by measuring unevenness of exposure occurring on the photosensitive member from a reference value used in the measurement, and requantizing the quantized data by the first number of bits by using sigma-delta modulation.

Abstract: An optical scanning apparatus capable of suppressing a track error is provided. The apparatus includes a swing mirror supported by a torsional vibration system having a first natural frequency and a second natural frequency that is a double of the first natural frequency, and a driving unit applying a swing torque to the vibration system. The apparatus can detect passage of an optical beam at two locations and output track information of the swing mirror, and perform feedback control. When the feedback control is performed, the apparatus sequentially switches target tracks of scanning in a forward and a backward direction, the phases of the second natural frequency of the target tracks being mutually reversed, calculates an amount of offset compensation based on a difference between the predetermined target track and the track for each scanning in the forward and backward direction, and reflects the amount in the feedback control.

Abstract: Disclosed is an oscillator device that includes an oscillating system having a first oscillator, a second oscillator, a first torsion spring for connecting the first and second oscillators each other, and a second torsion spring being connected to the second oscillator and having a common torsional axis with the first torsion spring; a supporting system for supporting the oscillating system; a driving system for driving the oscillating system so that at least one of the first and second oscillators produces oscillation as can be expressed by an equation that contains a sum of a plurality of time functions; a signal producing system for producing an output signal corresponding to displacement of at least one of the first and second oscillators; and a drive control system for controlling the driving system on the basis of the output signal of the signal producing system so that at least one of amplitude and phase of the time function takes a predetermined value.

Abstract: An image forming apparatus of this invention, when an exposure unit performs exposure, applies, to image data quantized by a first number of bits, compensation data for compensating for unevenness of the exposure intensity occurring on a photosensitive member caused by a lens array used in the exposure unit. This compensation data is obtained by quantizing, by a second number of bits larger than the first number of bits, data corresponding to a change in measurement value obtained by measuring unevenness of exposure occurring on the photosensitive member from a reference value used in the measurement, and requantizing the quantized data by the first number of bits by using sigma-delta modulation.

Abstract: An optical scanning apparatus capable of suppressing a track error is provided. The apparatus includes a swing mirror supported by a torsional vibration system having a first natural frequency and a second natural frequency that is a double of the first natural frequency, and a driving unit applying a swing torque to the vibration system. The apparatus can detect passage of an optical beam at two locations and output track information of the swing mirror, and perform feedback control. When the feedback control is performed, the apparatus sequentially switches target tracks of scanning in a forward and a backward direction, the phases of the second natural frequency of the target tracks being mutually reversed, calculates an amount of offset compensation based on a difference between the predetermined target track and the track for each scanning in the forward and backward direction, and reflects the amount in the feedback control.

Abstract: An image forming apparatus comprises a developer carrier (101) for developing an electrostatic latent image by supplying an image carrier with developer inside a developer container (100); an electrode member (104) opposing the developer carrier (101) via a space accommodating the developer; an inverter (301); a transformer (302) for transforming an AC voltage from the inverter (301); a rectifying circuit (303) for rectifying the output of the transformer and generating a DC voltage for image formation; a DC voltage applying unit (306) for applying the AC voltage, which is output from the transformer, to the electrode member (104); and a developer remaining-amount detection unit (305) for detecting amount of developer remaining inside the developer container (100) based upon electrostatic capacitance between the developer carrier (101) and electrode member (104).

Abstract: An image forming apparatus includes an alternating-current high-voltage power supply generating an alternating-current bias for detection of the remaining amount of toner. The alternating-current high-voltage power supply includes a piezoelectric transformer, a piezoelectric-transformer driving unit, a piezoelectric-transformer driving-signal generating unit, a voltage detecting unit, a voltage setting unit, and an controlling unit that feeds back a difference signal between a detection level signal supplied from a detection signal detecting unit and a setting signal supplied from the voltage setting unit to the piezoelectric-transformer driving-signal generating unit to control an output voltage from the piezoelectric-transformer.

Abstract: An image forming apparatus having a thermal fixing unit reduces a current inputted from a commercial power source using electric power charged in the capacitive when warming up the thermal fixing unit. The apparatus comprises a first charging unit to charge the capacitive unit at a first charging rate, and a second charging unit to charge the capacitive unit at a second charging rate lower than the first charging rate and greater than a natural power discharge rate of the capacitive unit. A charge switching control unit switches a power source charging the capacitive unit from the first charging unit to the second charging unit when the image forming apparatus transitions into an energy saving standby mode, and returns the power source charging the capacitive unit from the second charging unit to the first charging unit when the image forming apparatus returns from the energy saving standby mode.

Abstract: An image forming apparatus includes an alternating-current high-voltage power supply generating an alternating-current bias for detection of the remaining amount of toner. The alternating-current high-voltage power supply includes a piezoelectric transformer, a piezoelectric-transformer driving unit, a piezoelectric-transformer driving-signal generating unit, a voltage detecting unit, a voltage setting unit, and an controlling unit that feeds back a difference signal between a detection level signal supplied from a detection signal detecting unit and a setting signal supplied from the voltage setting unit to the piezoelectric-transformer driving-signal generating unit to control an output voltage from the piezoelectric-transformer.

Abstract: An image forming apparatus comprises a developer carrier (101) for developing an electrostatic latent image by supplying an image carrier with developer inside a developer container (100); an electrode member (104) opposing the developer carrier (101) via a space accommodating the developer; an inverter (301); a transformer (302) for transforming an AC voltage from the inverter (301); a rectifying circuit (303) for rectifying the output of the transformer and generating a DC voltage for image formation; a DC voltage applying unit (306) for applying the AC voltage, which is output from the transformer, to the electrode member (104); and a developer remaining-amount detection unit (305) for detecting amount of developer remaining inside the developer container (100) based upon electrostatic capacitance between the developer carrier (101) and electrode member (104).

Abstract: Disclosed is an oscillator device that includes an oscillating system having a first oscillator, a second oscillator, a first torsion spring for connecting the first and second oscillators each other, and a second torsion spring being connected to the second oscillator and having a common torsional axis with the first torsion spring; a supporting system for supporting the oscillating system; a driving system for driving the oscillating system so that at least one of the first and second oscillators produces oscillation as can be expressed by an equation that contains a sum of a plurality of time functions; a signal producing system for producing an output signal corresponding to displacement of at least one of the first and second oscillators; and a drive control system for controlling the driving system on the basis of the output signal of the signal producing system so that at least one of amplitude and phase of the time function takes a predetermined value.

Abstract: An image forming apparatus detects a oscillating state of a oscillation system with a oscillation detector and controls oscillation of the oscillation system such that the oscillation system oscillates a reflective member in a balanced steady state by adjusting a drive force of a drive unit with one or more drive control parameter values on the basis of the detection result obtained by the oscillation detector. When the balanced steady state is detected, the drive control parameter values are stored and are used when an exposure unit is reactivated.

Abstract: An image forming apparatus detects a oscillating state of a oscillation system with a oscillation detector and controls oscillation of the oscillation system such that the oscillation system oscillates a reflective member in a balanced steady state by adjusting a drive force of a drive unit with one or more drive control parameter values on the basis of the detection result obtained by the oscillation detector. When the balanced steady state is detected, the drive control parameter values are stored and are used when an exposure unit is reactivated.

Abstract: An image forming apparatus having a thermal fixing unit reduces a current inputted from a commercial power source using electric power charged in the capacitive when warming up the thermal fixing unit. The apparatus comprises a first charging unit to charge the capacitive unit at a first charging rate, and a second charging unit to charge the capacitive unit at a second charging rate lower than the first charging rate and greater than a natural power discharge rate of the capacitive unit. A charge switching control unit switches a power source charging the capacitive unit from the first charging unit to the second charging unit when the image forming apparatus transitions into an energy saving standby mode, and returns the power source charging the capacitive unit from the second charging unit to the first charging unit when the image forming apparatus returns from the energy saving standby mode.

Abstract: An induction heating apparatus for a fixing device of an image forming apparatus includes a rectifying circuit for rectifying a commercial power supply, an excitation coil, a switching element for switching the supply of the output of the rectifying circuit to the excitation coil, and a switching signal output unit for outputting a switching signal for the switching element thereby supplying the excitation coil with a high frequency current. The invention limits a current supply time to the excitation coil in such a manner that the maximum output for induction heating is set according to the commercial power supply voltage, thereby reducing the first print time without a power consumption in excess of the rating.

Abstract: An induction heating apparatus for a fixing device of an image forming apparatus includes a rectifying circuit for rectifying a commercial power supply, an excitation coil, a switching element for switching the supply of the output of the rectifying circuit to the excitation coil, and a switching signal output unit for outputting a switching signal for the switching element thereby supplying the excitation coil with a high frequency current.