Image forming apparatus
OwnerTsuneo Todainventor
Life of this patent
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Abstract
The present invention improves the grade of an output image formed by composition of plural images in a simple and low-cost constitution. Cylindrical mirrors corresponding to the respective colors (K, Y, M, C) are respectively provided with a scanning line inclination and bend correcting mechanism. Further, the side registration, the lead registration and the scaling factor are corrected by controlling the modulation timing of a laser beam corresponding to each color. The color aberration caused by the change in the ambient environment is corrected by detecting a variation in the positional relationship between the respective beams by a main scanning position detecting sensor and a sub-scanning position detecting sensor provided by each color to be reflected in the control for the modulation timing.
Claims13
An image forming apparatus, which has a plurality of photoreceptors, and is adapted to form images on the respective photoreceptors by scanning the photoreceptors with plural light beams, respectively, and sequentially transfer the plural images to a transfer body in such a manner that the plural images formed on the respective photoreceptors are superposed one another to form a single image on the transfer body, comprising at least two compensating units from among:
- a first compensating unit that compensates for a relative misregistration of the plural images on the transfer body in the light beam scanning direction;
- a second compensating unit that compensates for a relative misregistration of the plural images on the transfer body in the direction intersecting the scanning direction;
- a third compensating unit that compensates for a difference in relative size between plural images on the transfer body in the scanning direction;
- a fourth compensating unit that compensates for relative inclination of scanning loci of light beams on the transfer body;
- and
- a fifth compensating unit for compensating for a relative bend of scanning loci of light beams on the transfer body.
An image forming apparatus, which has a plurality of photoreceptors, and is adapted to form images on the respective photoreceptors by scanning the photoreceptors with plural light beams, respectively, and sequentially transfer the plural images to a transfer body in such a manner that the plural images formed on the respective photoreceptors are superposed one another to form a single image on the transfer body, comprising:
- a control unit that controls a modulation timing of the light beam or operating image data used in modulating the light beam according to at least one of first correction data set to correct a relative misregistration of the plural images on the transfer body in the light beam scanning direction and second correction data set to correct a relative misregistration of the plural images on the transfer body in the direction intersecting the scanning direction;
- a detecting unit that detects a variation in positional relationship between the light beams;
- and
- a correcting unit that corrects the control for the modulation timing of the light beam by the control unit or the operation of image data used in modulating the light beam according to the variation in the positional relationship between the light beams detected by the detecting unit.
Dependencies are inferred from the claim text.