MULTICOLOR IMAGE FORMING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a multicolor image forming device capable of correctly and accurately detecting the stationary parallel position deviation of each correction image without causing any unstationary position deviation detection error and forming a multicolor image clear and high in image quality. SOLUTION: The peripheral lengthπDd of each photoreceptive drum 11D forming a part of each image forming means and the peripheral lengthπDr of a driving roller 21 driving a carrying belt 23 are formed the same; and a correction image forming means is constituted so that (n) sets of color correction images taken as a set can be formed at intervals obtained by adding the interval obtained by multiplaying the peripheral lengthπDd by an integer (m) including zero (0) to the interval obtained by dividing the peripheral lengthπDd by the integer (n); and also a correction image detecting means 40 is formed so that it can detect position deviation value per each color by averaging each individual position deviation value detected for the same color correction images IMb, IMc, IMb and IMy in each set; then, the unstationary position deviation detection error due to the eccentricity▵Cr of the driving roller 21 and the eccentricity▵Cr of the each photoreceptive drum 11D is excluded.