摘要 |
A method for detecting low toner in an electro-photographic toner cartridge having an optical sensor using a light beam to detect the presence or absence of toner in the cartridge includes transmitting to a processor a signal related to the strength of the light beam sensed as a paddle disposed within the cartridge rotates. The processor calculates an average value for the signal for each of a plurality of sets of paddle revolutions. The processor then calculates a variation value for the signal for each of the plurality of sets of paddle revolutions. The processor filters each variation value to determine a plurality of short term variation values. The processor monitors whether at least one short term variation value exceeds a first threshold. When the at least one short term variation value exceeds the first threshold, the processor signals that the toner level is low.
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