DEVELOPING DEVICE AND IMAGE FORMING APPARATUS

摘要

PROBLEM TO BE SOLVED: To prevent printing defects such as image density unevenness due to a deficiency in conveyance quantity of a developer even when a developing device wherein a doctor blade as a developer restricting member is arranged opposite a magnetic pole is used for a full-color printer which is requested to have high print density or a printer whose printing speed is slow.

SOLUTION: The developing device is characterized in that: the restricting member is opposed to he magnetic pole; a peak point of a magnetic force distribution curve of the magnetic pole and a half-value width area of the magnetic force distribution are set upstream from the restricting member in the rotating direction of a developing roll; the restricting member is installed outside the area of the half-value width of the magnetic force distribution; and magnetization is performed so that an area corresponding to ≥80% of the peak value of the magnetic force is distributed having a spread of ≤20° in center angle at the outer periphery of the developing roll.

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