| 摘要 |
PROBLEM TO BE SOLVED: To provide a non-magnetic one-component developing device where a toner layer is stably formed on a developing roller for a long period by reducing a load applied on the toner and suppressing the deterioration of the toner to the minimum, and where the life of the toner is drastically improved and the life of the developing device itself is prolonged, and which is suitable for a developer replenishing type developing device. SOLUTION: A developer supply roller 5 is always energized by a spring 50 which is arranged in the oblong hole 16 of the bearing supporting part 15 of the rotary shaft 5a of the developer supply roller 5 so that it may be separated from a developing roller 3. Besides, by rotating an eccentric cam 51 in contact with the rotary shaft 5a, the developer supply roller 5 bites the developing roller 3 by a prescribed amount. By controlling the device so that the developer supply roller 5 may be brought into strongly press contact with the developing roller 3 at every prescribed amount in the case the total number of image forming sheets is increased, the toner is stuck on the developing roller 3 by the developer supply roller 5, then, the toner layer with the optimum layer thickness is formed on the surface of the developing roller 3. |
