| 摘要 |
PROBLEM TO BE SOLVED: To stabilize image density by calculating developing efficiency by measuring a carried toner quantity on a developer carrier and a transferred toner quantity on a latent image carrier, and adjusting the carrying toner quantity and the developing efficiency based on the measured value and the calculated value of the developing efficiency. SOLUTION: Toner carried on the developer carrier 2 is transferred to an electrostatic latent image so as to form the toner image of a reference pattern by a reference pattern forming means 4. Next, the transferred toner quantity T2 of the reference pattern toner image is detected by a latent image carrier toner quantity detecting means 5. The carried toner on the developer carrier 2 is detected by a toner quantity detecting means 3, and the carried toner quantity T1 is detected. Continuously, the developing efficiency is calculated from the transferred toner quantity T2 and the carried toner quantity T1 by an expression η1=T2/T1. Furthermore, a toner transfer quantity control means 7 controls the device so as to control the image density based on the transferred toner quantity T2, the carried toner quantity T1 and the developing efficiency η1. |
