DEVELOPING DEVICE, PROCESS CARTRIDGE, IMAGE FORMING APPARATUS, AND DEVELOPING METHOD

PROBLEM TO BE SOLVED: To provide a developing device of a two-component development system that ensures high quality developing by focusing on dynamic developer density, and to provide a process cartridge, an image forming apparatus, and a developing method. SOLUTION: The developing device carries two-component developer on the surface of a developing sleeve and develops a latent image on a photoreceptor in a developing area. In the developing device, predetermined image processing is performed for an image obtained by continuously photographing two-component developer that is in contact with a predetermine area extending from the contact of the predetermined area of the surface of the photoreceptor with the two-component developer to the separation of it therefrom. The PS value, in which the space frequency of a power spectrum obtained by subjecting the image by the image processing to two dimensional fast Fourier transformation analysis is an integral value in the range of 5 to 12 [cycle/mm], is calculated under a plurality of conditions different in scooping quantity. The developing device is set so that a difference between the maximum and the minimum values is 0.08 in the PS value within the range of ±10 [mg/cm2], having a standard scooping quantity of the developing sleeve as a middle. COPYRIGHT: (C)2010,JPO&INPIT