| 摘要 |
An electrophotographic image forming device according to one example embodiment includes an optical emitter positioned to emit a light beam through a window into a reservoir holding toner toward a reflective surface in the reservoir as a paddle positioned within the reservoir rotates. An optical receiver is positioned to sense an amount of the light beam reflected by the reflective surface. At least one processor is configured to receive a signal related to the amount of light sensed by the optical receiver. The at least one processor includes computer executable program instructions including: instructions for calculating an average value for the signal for each of a plurality of sets of paddle revolutions, instructions for calculating a variation value for the signal for each of the plurality of sets of paddle revolutions, instructions for filtering each variation value to determine a plurality of short term variation values, instructions for monitoring whether at least one short term variation value exceeds a first threshold, and instructions for signaling that a toner level in the reservoir is low when the at least one short term variation value exceeds the first threshold. |
