DEVELOPING DEVICE AND IMAGE FORMING APPARATUS

PROBLEM TO BE SOLVED: To provide a high-image quality developing device that employs a hybrid developing system in which a plurality of toner carriers are provided so that a decrease in density does not occur during high-speed developing, presents a method of promoting recovery of developing residual toner, can be used at a high speed, and does not generate developing history (memory); and an image forming apparatus.SOLUTION: A developing device 2 uses a first toner carrier 24 and a second toner carrier 25; and the surface roughness of the surface of the first toner carrier 24 located on the upstream side is configured to be smaller than the surface roughness of the second toner carrier 25 located on the downstream side. Accordingly, the problem of developing history (memory) does not occur, and a high-image quality developing device capable of supporting high-speed operation and an image forming apparatus are achieved.