Patent ID: 7065306

Claim:
A toner residual amount detection apparatus comprising: a developing device for developing an electrostatic image formed on an image bearing member by a toner, said developing device being provided on and movable with respect to an apparatus main body; toner residual amount detection means for detecting an amount of residual toner in said developing device, said toner residual amount detection means performing a detection operation at predetermined frequencies in a predetermined period; counting means for determining whether each of detection results obtained from said toner residual amount detection means is less than a predetermined toner residual amount value and counting a number of times which is determined that the detection result is less than the predetermined toner residual amount value; control means for, in a case where the number of times counted by said counting means exceeds a reference number of times, determining and displaying that the toner residual amount is insufficient, and for, in a case where a number of times of image forming operation performed after said displaying is equal to or greater than a predetermined number of times, inhibiting the image forming operation; and change means for changing the reference number of times to a smaller value in a case where the toner residual amount is insufficient.