Optical sensor arrangement for an imaging apparatus

An imaging apparatus comprising:

• a housing;
• a toner cartridge having a toner reservoir therein, the toner reservoir having an upper sump area for containing toner and a lower sump area for containing toner;
• a metering bar rotatably positioned between the upper sump area and the lower sump area, the metering bar having a shaft and at least one depression therein for holding toner, wherein rotation of the metering bar transfers toner from the upper sump area to the lower sump area;
• a paddle for moving toner toward the metering bar rotatably disposed in the upper sump area, the paddle having a shaft;
• a cam mounted outside the toner cartridge on one of the shaft of the paddle and the shaft of the metering bar;
• an optical sensor mounted on the housing having an emitter and a receiver, the emitter and the receiver forming an optical path therebetween, the optical sensor having an output that changes when the optical path changes from blocked to unblocked and from unblocked to blocked;
• a flag mounted on the housing having a first arm and a second arm, the flag having a home position where the first arm is disposed in the rotational path of the cam and the second arm is disposed in one of:
• blocking the optical path and unblocking the optical path;
• and
• a blocking member transversely mounted on the second arm for blocking at least a portion of the light emitted by the emitter;
• wherein rotation of one of the shaft of the paddle and the shaft of the metering bar causes the cam to engage and disengage the first arm causing the second arm to change from one of blocking the optical path and unblocking the optical path.

An imaging apparatus comprising:

• a housing;
• a toner cartridge having a toner reservoir therein, the toner reservoir having an upper sump area for containing toner and a lower sump area for containing toner;
• a photoconductive drum disposed in the cartridge;
• a metering bar rotatably positioned between the upper sump area and the lower sump area, the metering bar having a shaft and at least one depression for holding toner, wherein rotation of the metering bar transfers toner from the upper sump area to the lower sump area;
• a paddle for moving toner toward the metering bar rotatably disposed in the upper sump area, the paddle having a shaft;
• a cam mounted outside the toner cartridge on one of the shaft of the paddle and the shaft of the metering bar;
• an optical sensor mounted on the housing having an emitter, a receiver and a pair of opposed arms for housing the emitter and receiver, each of the pair of opposed arms having a distal portion adjacent to the toner cartridge, the emitter and the receiver forming an optical path between the pair of opposed arms, the optical sensor having an output that changes when the optical path changes from blocked to unblocked and from unblocked to blocked;
• a flag mounted on the housing and having the form of a pivotable bell crank having a first arm and a second arm, the flag having a home position where the first arm is disposed in the rotational path of the cam and the second arm blocks the optical path;
• and
• a blocking member transversely mounted on the second arm for blocking at least a portion of the light emitted by the emitter from contacting the photoconductive drum, the blocking member contacting the distal portion of each of the pair of opposed arms of the optical sensor when the flag is in the home position;
• wherein rotation of one of the shaft of the paddle and the shaft of the metering bar causes the cam to engage and disengage the first arm causing the second arm to unblock and reblock, respectively, the optical sensor and the force imparted by the flag on the cam and one of the shaft of the paddle and the shaft of the metering bar is intermittent.