Abstract: An exposure device includes a reference current generating unit generating a reference current for each image of respective colors, a photoelectric current generating unit generating a photoelectric current in response to a light amount of the light emitting element, a driving unit driving the light emitting element, a first controller, a drive voltage holding unit holding a drive voltage given to the driving unit, a second controller controlling the driving unit based on the drive voltage held, a comparison current generating unit generates a comparison current, a difference current generating unit generating a difference current, of each color, corresponding to a difference between the reference current of each color and the comparison current. The first controller compares a value obtained by adding the difference current of each color to the photoelectric current with the comparison current to control the driving unit so that the photoelectric current becomes the reference current.

Abstract: An exposure device includes plural light-emitting elements, a light amount detection unit, a controller, plural holding units and a connection unit. The controller sequentially determines control values of the light-emitting elements based on comparison between the light amounts detected by the light amount detection unit and a predetermined reference value. The holding units are provided for the light-emitting elements, respectively. Each holding unit holds a control voltage of the controller. When the controller is to sequentially determine control values of a part of the plurality of light-emitting elements, the connection units connects the controller and the holding units corresponding to one or more light-emitting elements for which control values are determined earliest among the part of the plural light-emitting elements, before the controller determines the control values of the one or more light-emitting elements.

Abstract: An exposure device includes a plurality of light emitting elements, a load, a first supplying unit and a second supplying unit. The first supplying unit supplies a driving current to one of (i) light emitting elements used to form an image among the plurality of light emitting elements and (ii) the load, in accordance with a modulation signal. The first supplying unit supplies a bias current to the other. The second supplying unit supplies the bias current to light emitting elements not used to form the image among the plurality of light emitting elements, regardless of the modulation signal.

Abstract: An exposure device includes plural light-emitting elements, a light amount detection unit, a controller, plural holding units and a connection unit. The controller sequentially determines control values of the light-emitting elements based on comparison between the light amounts detected by the light amount detection unit and a predetermined reference value. The holding units are provided for the light-emitting elements, respectively. Each holding unit holds a control voltage of the controller. When the controller is to sequentially determine control values of a part of the plurality of light-emitting elements, the connection units connects the controller and the holding units corresponding to one or more light-emitting elements for which control values are determined earliest among the part of the plural light-emitting elements, before the controller determines the control values of the one or more light-emitting elements.

Abstract: An exposure device includes a plurality of light emitting elements, a load, a first supplying unit and a second supplying unit. The first supplying unit supplies a driving current to one of (i) light emitting elements used to form an image among the plurality of light emitting elements and (ii) the load, in accordance with a modulation signal. The first supplying unit supplies a bias current to the other. The second supplying unit supplies the bias current to light emitting elements not used to form the image among the plurality of light emitting elements, regardless of the modulation signal.

Abstract: An exposure device includes a reference current generating unit generating a reference current for each image of respective colors, a photoelectric current generating unit generating a photoelectric current in response to a light amount of the light emitting element, a driving unit driving the light emitting element, a first controller, a drive voltage holding unit holding a drive voltage given to the driving unit, a second controller controlling the driving unit based on the drive voltage held, a comparison current generating unit generates a comparison current, a difference current generating unit generating a difference current, of each color, corresponding to a difference between the reference current of each color and the comparison current. The first controller compares a value obtained by adding the difference current of each color to the photoelectric current with the comparison current to control the driving unit so that the photoelectric current becomes the reference current.

Abstract: An image formation apparatus includes an imaging light source, a photosensitive body and a correction light source. The imaging light source outputs light modulated in accordance with image data representing an image. An electrostatic latent image is formed at the photosensitive body by the light output from the imaging light source. The correction light source is provided separately from the imaging light source, and outputs light toward the photosensitive body for correcting one of variations in potential on the photosensitive body and irregularities in density distribution of an image, which image is to be formed in accordance with the electrostatic latent image that is formed on the photosensitive body by the imaging light source.

Abstract: An image formation apparatus includes an imaging light source, a photosensitive body and a correction light source. The imaging light source outputs light modulated in accordance with image data representing an image. An electrostatic latent image is formed at the photosensitive body by the light output from the imaging light source. The correction light source is provided separately from the imaging light source, and outputs light toward the photosensitive body for correcting one of variations in potential on the photosensitive body and irregularities in density distribution of an image, which image is to be formed in accordance with the electrostatic latent image that is formed on the photosensitive body by the imaging light source.

Abstract: An image forming device includes a rotating polygon mirror and a correcting component that corrects misregistration of an image region in a predetermined direction. The correcting component carries out the correction by correcting image data used in modulating light beams reflected and deflected by any one reflecting surface among plural reflecting surfaces provided at the rotating polygon mirror, where the light beams scann a body-to-be-illuminated in the predetermined direction, correcting image data by each data unit used in modulating light beams which are reflected and deflected at the same reflecting surface, and correcting image data in accordance with a misregistration amount in the predetermined direction of the image region formed on the body-to-be-illuminated by the light beams which are reflected and deflected, where the misregistration amount is measured in advance for each reflecting surface of the rotating polygon mirror.

Abstract: In a color registration deviation correction method or an image forming apparatus, a pattern image is read out, a color registration deviation amount is detected, and a correction amount of the color registration deviation is calculated. On the basis of the calculated correction amount, it is judged whether correction can be made in an interimage period. In the case where the correction can be made in the interimage period, the color registration deviation correction is made in the interimage period, and in the case where the correction can not be made in the interimage period, the color registration deviation correction is made in the two interimage periods.

Abstract: An image forming apparatus and a method of controlling turn-on of light source used therefor are capable of conducting stable image forming operation and maintaining high effective scanning rate while switching the rotation control of the polygonal motor between the internal control by the internal encoder of the motor and the external control by the horizontal synchronous signal outside of the motor. With the apparatus and method, the period of detecting the timing of start of the fast scanning (referred to as SOS period) is T when the driving motor rotates at a predetermined number of revolutions. T becomes shorter by T2 due to the switching from the internal control to the external control. During the shift from the internal control to the external control, the light source is turned on so that the period T1 from turning-on the light source for detecting the SOS timing to the detection of the SOS signal becomes longer than T2.

Abstract: A motor comprising: a rotor which is supported via a rotating shaft in a radial direction of the rotating shaft, the rotating shaft being disposed around a fixed shaft provided on the side of a stator to form a dynamic-pressure bearing; a stator-side thrust magnet disposed in the stator so as to support the rotor with respect to the stator in a thrust direction of the rotating shaft; a rotor-side thrust magnet disposed in the rotor; and a rotating main body portion mounted to the rotating shaft of the rotor and formed integrally by a resin magnetic material, in which a main magnet portion, an FG magnet portion for generating a speed-of-rotation detecting pulse, and a rotor-side thrust magnet portion serving as said rotor-side thrust magnet are respectively polarized at predetermined positions in the rotating main body portion.