Developing device and image forming apparatus

摘要

An image forming apparatus includes a latent image carrier carrying a latent image, a developing device visualizing the latent image utilizing a two-component developer, a supply device supplying toner according to a change in toner density in the two-component developer inside the developing device, and a control device having an input side connected to a density sensor detecting a value of the toner density and an image information acquisition device acquiring information on an image formed on the latent image carrier, and an output side connected to a driving device driving the supply device. When the detected value is higher than a target value of the toner density stored by the control device, the control device performs control to stop the driving device or drive the driving device to supply toner in an amount less than a combined toner supply amount of first and second toner supply amounts.

主权项

1. An image forming apparatus comprising:
an electrostatic latent image carrier configured to carry an electrostatic latent image; a developing device configured to visualize the electrostatic latent image utilizing a two-component developer; a supply device configured to supply toner according to a change in toner density of toner contained in the two-component developer inside the developing device; and a control device having an input side connected to a density sensor configured to detect a value of the toner density and an image information acquisition device configured to acquire information on an image formed on the electrostatic latent image carrier, and an output side connected to a driving device configured to drive the supply device, wherein the control device is configured to store a target value of the toner density, the control device including
a feedforward control unit configured to determine a first toner supply amount matching the target value based on an input from the image information acquisition device, anda feedback control unit configured to determine a second toner supply amount based on a difference between the detected value of the toner density obtained by the density sensor and the target value and based on an aggregation of the difference over a plurality of times that the difference is determined, and the feedback control unit divides a difference value between the detected value and the target value into an integration block and a proportion block, and determines the second toner supply amount by adding respective computational values of the integration block and the proportion block, and wherein when the control device obtains a comparison result indicating that the detected value is higher than the target value, the control device performs control to stop the driving device, or performs control to drive the driving device to supply toner in an amount less than a combined toner supply amount obtained by adding the first toner supply amount and the second toner supply amount.