Patent ID: 7627260

Claim:
A development apparatus for developing and visualizing a latent image formed on a latent image supporting body, by using a two-component developer composed of toner and carrier, comprising: a phase control mechanism, which forms a dividing point at a predetermined point in a flow of a developer within the development apparatus in which a toner density fluctuates spatially due to toner replenishment or toner consumption caused by development, causes the developer divided at the dividing point to pass through different paths, thereby shifts a phase of the fluctuation of the toner density within the developer, and thereafter causes thus obtained developers having shifted phases to merge with each other, to perform phase control; two developer conveying members configured to convey the developer in different directions from each other; and a partition plate disposed between the two developer conveying members, wherein developer passing sections on both ends in axial directions of the pair of developer conveying members, and a single opening section is provided as the phase control mechanism on the partition plate, wherein a center position x of the opening section on the partition plate is located within a distance of (⅛+½·n)λ≦x≦(⅜+½·n)λ (λ: a wavelength that indicates a toner density fluctuation on each of the developer conveying members, n=0, 1, 2, . . . ) from a center position of an opening section of an end section of the development apparatus.