Image stabilizing control method offering a short waiting time for operation recovery and image forming apparatus incorporating said control method

An image forming apparatus having a charger which charges a photoreceptor and a developing device which forms a visible image on the photoreceptor, comprising:

• an environmental value detector which detects an environmental value;
• a potential detector which detects a surface potential of the photoreceptor charged by said charger;
• first image stabilizing control means for controlling an output of the charger depending on the detected surface potential by said potential detector such that the photoreceptor surface potential is made a desired level;
• a comparator which compares a difference between a first environmental value and a second environmental value, said first environmental value being detected by said environmental value detector when the operation of the image forming apparatus becomes suspended and said second environmental value being detected when it is restored, with a prescribed threshold;
• and
• control means for permitting, where the difference in the environmental value exceeds the threshold, the control by the first image stabilizing control means when operation is restored, and prohibiting the control where the difference is under the threshold.

An image forming apparatus having a charger which charges a photoreceptor and a developing device which forms a visible image on the photoreceptor, comprising:

• an environmental value detector which detects an environmental value;
• a density sensor which detects a density of a test toner patch formed on the photoreceptor;
• image stabilizing control means for controlling at least one of an output of the charger and a developing bias voltage the developing device depending on the detected density by said density sensor;
• a comparator which compares a difference between a first environmental value and a second environmental value, said first environmental value being detected by said environmental value detector when the operation of the image forming apparatus becomes suspended and said second environmental value being detected when it is restored, with a prescribed threshold;
• and
• control means for permitting, where the difference in the environmental value exceeds the threshold, the control by the first image stabilizing control means when operation is restored, and prohibiting the control where the difference is under the threshold.

An image stabilizing control method for an image forming apparatus having an environmental value detection sensor that detects an environmental value, said apparatus operating multiple image forming elements to perform an image forming operation, comprising the steps of:

• detecting a first environmental values by the environmental value detection sensor when the operation of the apparatus becomes suspended;
• detecting a second environmental values by the environmental value detection sensor when the operation of the apparatus is restored;
• determining whether a difference between the first and second environmental values are larger than a prescribed threshold;
• and
• executing an image stabilizing control to set operation parameters of the various image forming elements to the optimal values where the difference exceeds the threshold, and prohibiting the execution of the image stabilizing control where the difference do not exceed the threshold.