Abstract: Color shifting correction is performed first based on shifting amount information indicating a shifting amount with respect to the scanning direction on an image carrier of each image forming unit, and halftone processing is then performed, thus suppressing caused by color shifting correction, and forming a high-quality image. An image forming engine has color shifting amount storage units storing actual shifting amounts with respect to ideal scan directions on image carriers in image forming units. Color shifting correction amount arithmetic units calculate color shifting correction amounts for respective color components using stored color shifting amounts. Color shifting correction units perform color shifting correction by converting coordinates upon reading image data from bitmap memories using calculated color shifting correction amounts, and perform tone correction. Data after tone correction undergo halftone processing.

Abstract: With this invention, color shifting correction is performed first based on shifting amount information indicating a shifting amount with respect to the scanning direction on an image carrier of each image forming unit, and halftone processing is then performed, thus suppressing generation of moiré due to the color shifting correction, and forming a high-quality image. To this end, an image forming engine has color shifting amount storage units C, M, Y, and K (black) which store actual shifting amounts with respect to ideal scan directions on image carriers C, M, Y, and K in image forming units C, M, Y, and K. Color shifting correction amount arithmetic units C, M, Y, and K calculate color shifting correction amounts for respective color components on the basis of the stored color shifting amounts.

Abstract: A color image forming apparatus of a so-called tandem type which has image forming units in correspondence with colors is provided. In the color image forming apparatus, a color discrepancy amount storage unit stores information of a color discrepancy amount of each of the image forming units, which is measured in advance. A first color discrepancy correcting unit performs color discrepancy correction in a pixel unit by performing coordinate conversion of bitmap data to be printed based on the information of the color discrepancy amount stored in the color discrepancy amount storage unit. A second color discrepancy correcting unit performs color discrepancy correction in less than a pixel unit by performing tone correction of the bitmap data corrected by the first color discrepancy correcting unit based on the information of the color discrepancy amount stored in the color discrepancy amount storage unit.

Abstract: With this invention, color shifting correction is performed first based on shifting amount information indicating a shifting amount with respect to the scanning direction on an image carrier of each image forming unit, and halftone processing is then performed, thus suppressing generation of moiré due to the color shifting correction, and forming a high-quality image. To this end, an image forming engine has color shifting amount storage units C, M, Y, and K (black) which store actual shifting amounts with respect to ideal scan directions on image carriers C, M, Y, and K in image forming units C, M, Y, and K. Color shifting correction amount arithmetic units C, M, Y, and K calculate color shifting correction amounts for respective color components on the basis of the stored color shifting amounts.

Abstract: A color image forming apparatus of a so-called tandem type which has image forming units in correspondence with colors is provided. In the color image forming apparatus, a color discrepancy amount storage unit stores information of a color discrepancy amount of each of the image forming units, which is measured in advance. A first color discrepancy correcting unit performs color discrepancy correction in a pixel unit by performing coordinate conversion of bitmap data to be printed based on the information of the color discrepancy amount stored in the color discrepancy amount storage unit. A second color discrepancy correcting unit performs color discrepancy correction in less than a pixel unit by performing tone correction of the bitmap data corrected by the first color discrepancy correcting unit based on the information of the color discrepancy amount stored in the color discrepancy amount storage unit.

Abstract: An image forming engine has color shifting amount storage units C, M, Y, and K (black) which store actual shifting amounts relative to ideal scan directions on image carriers C, M, Y, and K in image forming units C, M, Y, and K. Color shifting correction amount arithmetic units calculate color shifting correction amounts for respective color components to base on the stored color shifting amounts. Color shifting correction units C, M, Y, and K perform color shifting correction by converting coordinates upon reading out image data from bitmap memories C, M, Y, and K on the basis of the calculated color shifting correction amounts, and then perform tone correction. Data after tone correction undergo halftone processing by halftone processors. C, M, Y, and K to suppress moire. PWM processors C, M, Y, and K generate PWM signals for scanning, and output them to exposure units C, M, Y, and K of the respective image forming units.

Abstract: A color image forming apparatus of a so-called tandem type which has image forming units in correspondence with colors is provided. In the color image forming apparatus, a color discrepancy amount storage unit stores information of a color discrepancy amount of each of the image forming units, which is measured in advance. A first color discrepancy correcting unit performs color discrepancy correction in a pixel unit by performing coordinate conversion of bitmap data to be printed based on the information of the color discrepancy amount stored in the color discrepancy amount storage unit. A second color discrepancy correcting unit performs color discrepancy correction in less than a pixel unit by performing tone correction of the bitmap data corrected by the first color discrepancy correcting unit based on the information of the color discrepancy amount stored in the color discrepancy amount storage unit.

Abstract: An image forming system includes an information processing apparatus and an image forming apparatus. The information processing apparatus performs image generation, color conversion, and extraction of image characteristics to generate compressed data. The image forming apparatus decompresses the compressed data and determines a writing address into an image data storing unit on the basis of an amount of shift to convert the density of the image data in fractional pixel units.

Abstract: An image forming system includes an information processing apparatus and an image forming apparatus. The information processing apparatus performs image generation, color conversion, and extraction of image characteristics to generate compressed data. The image forming apparatus decompresses the compressed data and determines a writing address into an image data storing unit on the basis of an amount of shift to convert the density of the image data in fractional pixel units.

Abstract: A color image forming apparatus of a so-called tandem type which has image forming units in correspondence with colors is provided. In the color image forming apparatus, a color discrepancy amount storage unit stores information of a color discrepancy amount of each of the image forming units, which is measured in advance. A first color discrepancy correcting unit performs color discrepancy correction in a pixel unit by performing coordinate conversion of bitmap data to be printed based on the information of the color discrepancy amount stored in the color discrepancy amount storage unit. A second color discrepancy correcting unit performs color discrepancy correction in less than a pixel unit by performing tone correction of the bitmap data corrected by the first color discrepancy correcting unit based on the information of the color discrepancy amount stored in the color discrepancy amount storage unit.

Abstract: With this invention, color shifting correction is performed first based on shifting amount information indicating a shifting amount with respect to the scanning direction on an image carrier of each image forming unit, and halftone processing is then performed, thus suppressing generation of moiré due to the color shifting correction, and forming a high-quality image. To this end, an image forming engine has color shifting amount storage units C, M, Y, and K (black) which store actual shifting amounts with respect to ideal scan directions on image carriers C, M, Y, and K in image forming units C, M, Y, and K. Color shifting correction amount arithmetic units C, M, Y, and K calculate color shifting correction amounts for respective color components on the basis of the stored color shifting amounts.

Abstract: An oxide superconductor comprising a crystal of LnBa.sub.2 Cu.sub.3 O.sub.y (wherein Ln is at least one of rare earth elements including Y) and, finely dispersed therein, Ln.sub.2 BaCuO.sub.5 and a composite oxide of PtBaCuO having an average particle diameter of 0.1 to 10 .mu.m is disclosed. The oxide superconductor is produced by melting a raw material powder comprising a composite oxide of Ln, Ba and Cu, rapidly solidifying the melt, pulverizing the resultant solid, mixing a Pt powder with the pulverized mixture, forming a resultant mixture, heating a resultant formed body to bring the formed body to a partially-molten state and cooling the partially-molten material.