Image forming apparatus, and method and computer-readable medium therefor

A method implementable on a processor coupled with an image forming apparatus, the image forming apparatus comprising:

• an image carrying body configured to carry an electrostatic latent image thereon;
• a developing device comprising:
• a development roller configured to carry developer thereon;
• and
• a developing chamber configured to store developer therein;
• a developer box comprising:
• a developer container configured to store developer therein;
• and
• a transporter configured to transport the developer stored in the developer container to the developing chamber of the developing device;
• a developer sensor configured to output a signal varying depending on an amount of the developer stored in the developing chamber;
• and
• a storage configured to store a counter value, the method comprising:
• controlling the developing device to supply the developer stored in the developing chamber to the electrostatic latent image carried on the image carrying body, thereby developing the electrostatic latent image;
• each time the development roller rotates by a particular rotational amount, incrementing the counter value stored in the storage;
• calculating a remaining amount of developer in the developing chamber, based on the signal received from the developer sensor;
• when the counter value is less than a first value, setting a remaining amount threshold to a first threshold, whereas, when the counter value is equal to or more than a second value, setting the remaining amount threshold to a second threshold, the second value being equal to or more than the first value, the second threshold being less than the first threshold;
• and
• when the calculated remaining amount is less than the set remaining amount threshold, controlling the transporter to transport the developer stored in the developer container to the developing chamber.

A non-transitory computer-readable medium storing computer-readable instructions that are executable by a processor coupled with an image forming apparatus, the image forming apparatus comprising:

• an image carrying body configured to carry an electrostatic latent image thereon;
• a developing device comprising:
• a development roller configured to carry developer thereon;
• and
• a developing chamber configured to store developer therein;
• a developer box comprising:
• a developer container configured to store developer therein;
• and
• a transporter configured to transport the developer stored in the developer container to the developing chamber of the developing device;
• a developer sensor configured to output a signal varying depending on an amount of the developer stored in the developing chamber;
• and
• a storage configured to store a counter value, the instructions being configured to, when executed by the processor, cause the processor to perform:
• a developing process to control the developing device to supply the developer stored in the developing chamber to the electrostatic latent image carried on the image carrying body, thereby developing the electrostatic latent image;
• a counting process to, each time the development roller rotates by a particular rotational amount, increment the counter value stored in the storage;
• a developer remaining amount calculating process to calculate a remaining amount of developer in the developing chamber, based on the signal received from the developer sensor;
• a threshold setting process comprising:
• when the counter value is less than a first value, setting a remaining amount threshold to a first threshold;
• and
• when the counter value is equal to or more than a second value, setting the remaining amount threshold to a second threshold, the second value being equal to or more than the first value, the second threshold being less than the first threshold;
• and
• a developer supply process to, when the calculated remaining amount is less than the set remaining amount threshold, control the transporter to transport the developer stored in the developer container to the developing chamber.