Image forming apparatus with a function of detecting an amount of remaining developing agent

摘要

An image forming apparatus is provided that includes an image forming unit including an agitation unit for agitating developing agent contained in a container unit, and a sensor which includes a light emitting unit configured to emit light and a light receiving unit configured to receive the light emitted from the light emitting unit and passing through the container unit. The sensor generates an output in accordance with an amount of light received by the light receiving unit while the agitation unit agitates the developing agent. The image forming apparatus also includes has a medium with instructions stored therein that when executed perform steps including calculating a measurement result based on the output generated by the sensor, and determining, after the agitation is started, whether a current period is an unstable period in which the measurement result is unstable or a stable period in which the measurement result is stable.

主权项

1. An image forming apparatus, comprising:
an image forming unit which includes a container unit for containing a developing agent and an agitation unit for agitating the developing agent contained in the container unit, the image forming unit performing image formation using the developing agent; a sensor which includes a light emitting unit configured to emit light toward the container unit and a light receiving unit configured to receive the light emitted from the light emitting unit and passing through the container unit, the sensor generating an output in accordance with an amount of light received by the light receiving unit while the agitation unit agitates the developing agent; a storage unit; a processing unit; memory having machine readable instructions stored thereon that, when executed by the processing unit, perform the steps of:
calculating a measurement result based on the output generated by the sensor;determining, after the agitation is started, whether a current period is an unstable period in which the measurement result is unstable or a stable period in which the measurement result is stable; andstoring the measurement result in the storage unit during the stable period;during the stable period, detecting an amount of remaining developing agent in accordance with the latest measurement result based on the latest output generated by the sensor; andduring the unstable period, detecting the amount of remaining developing agent in accordance with a previous measurement result stored in the storage unit, wherein the memory further has machine readable instructions stored thereon that, when executed by the processing unit, further perform the step of measuring a length of a suspending period of agitation from when the agitation unit stops performing agitation until when the agitation unit starts performing agitation, wherein the determining step determines whether the current period is the unstable period or the stable period in accordance with the length of the suspending period of agitation, and wherein the determining step includes estimating the length of the unstable period from when the agitation unit starts performing agitation and determining whether the current period is the unstable period or the stable period in accordance with the estimated length of the unstable period, wherein the estimated length of the unstable period increases as the suspending period of agitation is extended.