Abstract: An image forming apparatus forms a latent image on a photoconductor by irradiating light beams from a plurality of light sources onto the photoconductor. A detection unit detects a time difference between timings of start writing on the photoconductor by the light beams in a main scanning direction. A calculation unit calculates a shift of each of the light beams in a sub-scanning direction based on the time difference detected by the detection unit and a rotation speed of the photoconductor. A correction unit corrects irradiated positions on the photoconductor by the light beams in the sub-scanning direction based on the shift calculated by the calculation unit.

Abstract: An image forming apparatus and image forming method capable of achieving both high-speed printing of less-than-full-color images and high quality printing of multicolor images. The apparatus includes a color shift pattern output unit, a correction amount acquisition unit, and a correction unit to correct at least one or more positions of an image in a sub-scanning direction on a recording medium when a first transfer member transfers an unfixed image and a second transfer member transfers an unfixed image.

Abstract: A maintenance pattern forming method includes conveying, generating, and forming. The conveying conveys a transfer member on a surface of a conveying member such that there is a spacing area between two adjacent transfer members on the surface of the conveying member. The generating generates a timing signal for at least one of a plurality of colors formed by a color image forming apparatus. The forming forms at least one of a process control pattern, a position adjustment pattern, and a blade curl suppression pattern onto the spacing area based on the timing signal.

Abstract: An image forming apparatus includes a light source, a deflector, beam detectors, a clock generator, a measurement mechanism, a frequency corrector, and a phase corrector. The light source illuminates in response to image data. The deflector deflects an optical beam into a scanning beam. The beam detectors including first and second beam detectors detect the scanning beam. The clock generator generates writing clock signals. The measurement mechanism measures a count number of the writing clock signals generated during a period between the scanning beam is detected by the first and second beam detectors. The frequency corrector corrects a frequency of the writing clock signals such that the count number measured becomes substantially equivalent to a predetermined number. The phase corrector varies a phase of the writing clock signals such that the count number is substantially constant before and after the phase of the writing clock signals is varied.

Abstract: In an image forming device, a correction unit corrects image formation operation based on a plurality of correction patterns. A pattern creation unit forms an electrostatic latent image of the correction patterns on a photoconductor and transferring the image to an intermediate transfer body to form the correction patterns thereon. A pattern detecting unit detects the correction patterns formed on the intermediate transfer body. A speed detecting unit detects a movement speed of the correction patterns on the intermediate transfer body are moved. A timing holding unit computes a set value of detection start timing for starting detection of each correction pattern to hold the set value. The correction unit is provided to determine, in advance of correcting image formation operation, a detection start timing based on the movement speed and the set value.

Abstract: An image forming apparatus includes a light source which illuminates in response to image data, and a deflector to deflect an optical beam output from the light source into a scanning beam running along a main scanning line across an image forming area in a main scanning direction. There are plurality of beam detectors to detect the scanning beam at a plurality of different positions along the main scanning line, the plurality of beam detectors including first and second beam detectors detecting the scanning beam at positions in front-end and rear-end sides, respectively, in the main scanning direction.

Abstract: An image forming apparatus is disclosed that has an optical device including an optical source that is driven corresponding to image data, a deflection unit that deflects an optical beam output from the optical source in a main scanning direction, and an optical element that reflects the optical beam onto a photosensitive drum; a detection device that is arranged outside the optical device and detects a positional shift of the optical beam in a sub-scanning direction defined as a direction orthogonal to the main scanning direction; and a control unit that corrects the positional shift in the sub-scanning direction using an output from the detection device.

Abstract: A maintenance pattern forming method includes conveying, generating, and forming. The conveying conveys a transfer member on a surface of a conveying member such that there is a spacing area between two adjacent transfer members on the surface of the conveying member. The generating generates a timing signal for at least one of a plurality of colors formed by a color image forming apparatus. The forming forms at least one of a process control pattern, a position adjustment pattern, and a blade curl suppression pattern onto the spacing area based on the timing signal.

Abstract: In an image forming device, a correction unit corrects image formation operation based on a plurality of correction patterns. A pattern creation unit forms an electrostatic latent image of the correction patterns on a photoconductor and transferring the image to an intermediate transfer body to form the correction patterns thereon. A pattern detecting unit detects the correction patterns formed on the intermediate transfer body. A speed detecting unit detects a movement speed of the correction patterns on the intermediate transfer body are moved. A timing holding unit computes a set value of detection start timing for starting detection of each correction pattern to hold the set value. The correction unit is provided to determine, in advance of correcting image formation operation, a detection start timing based on the movement speed and the set value.

Abstract: An image forming apparatus includes a light source, a deflector, beam detectors, a clock generator, a measurement mechanism, a frequency corrector, and a phase corrector. The light source illuminates in response to image data. The deflector deflects an optical beam into a scanning beam. The beam detectors including first and second beam detectors detect the scanning beam. The clock generator generates writing clock signals. The measurement mechanism measures a count number of the writing clock signals generated during a period between the scanning beam is detected by the first and second beam detectors. The frequency corrector corrects a frequency of the writing clock signals such that the count number measured becomes substantially equivalent to a predetermined number. The phase corrector varies a phase of the writing clock signals such that the count number is substantially constant before and after the phase of the writing clock signals is varied.