초록 ▼

The image forming apparatus of the invention controls the toner density by any one of the following configurations: by correcting the toner density of the developer in association with the agitation total; by controlling a process parameter so that the density of a toner patch formed on the photorec

The image forming apparatus of the invention controls the toner density by any one of the following configurations: by correcting the toner density of the developer in association with the agitation total; by controlling a process parameter so that the density of a toner patch formed on the photoreceptor corresponds to a prescribed density value and determining that developing performance of the developer is improved and canceling the toner density correction when the process parameter reaches the prescribed value; by changing the toner density reference value when the variation as to the charger output is equal to or greater than a first predetermined value and maintaining the changed toner density reference value until the variation of the charger output again becomes equal to or greater than thefirst predetermined value; or by prohibiting toner supply for a constant duration to prevent excessive toner supply if time from the end of the last operation of the developing unit to the start of a next operation, inclusive of the power-activation is equal to or longer the a predetermined period when the developing unit is activated to commence agitation of the developer.

대표청구항 ▼

[ What is claimed is:] [1.] An image forming apparatus comprising:a toner density sensor for detecting a toner density of a two-component developer stored in a developing vessel;toner density control means for comparing an output from said toner density sensor with a reference toner density and main

[ What is claimed is:] [1.] An image forming apparatus comprising:a toner density sensor for detecting a toner density of a two-component developer stored in a developing vessel;toner density control means for comparing an output from said toner density sensor with a reference toner density and maintaining the toner density of the developer at the reference toner density by controlling the amount of supplying toner to the developing vessel;agitation total detecting means for detecting as an agitation total one of a number of agitations of the developer inside the developing vessel, an approximate operation time of the image forming apparatus and a number of images formed, any of which is proportional to the number of agitations;toner density correcting means for correcting the output from one of said toner density sensor and the reference toner density in association with an augment of the agitation total;toner patch density detecting means for creating a toner patch on a photoreceptor and detecting a density of the toner patch;process parameter controlling means for controlling process parameters including an applied voltage to a main charger in order to adjust the toner patch density detected by said toner patch density detecting means to a predetermined density value; andtoner density correction canceling means for canceling a correction by said toner density correcting means when the process parameter has reached a predetermined value with improvement of developing performances of the developer.