Method of refilling a printing unit

1. A method of refilling a supply of printing fluid in a printing unit, the method comprising the steps of:

removably mounting a dispenser unit of printing fluid to the printing unit so as to align and engage a plurality of outlets of the dispenser unit with a plurality of inlets of a plurality of printing fluid storage chambers of the printing unit, the dispenser unit being configured so that only one outlet of the plurality of outlets connects to printing fluid stored within an enclosure of the dispenser unit;

determining an amount of printing fluid needed to refill the printing fluid storage chamber via the inlet engaged with said one outlet;

disengaging a ratchet mechanism of the dispenser unit so as to facilitate a reduction of volume in the enclosure by a plunger; and

engaging the plunger so as to effect the reduction of volume in the enclosure until the ratchet mechanism is reengaged, thereby dispensing fluid from the enclosure into the printing fluid storage chamber, wherein

the steps of disengaging the ratchet mechanism and engaging the plunger are repeated until the determined amount of printing fluid is dispensed into the printing fluid storage chamber.

2. The method according to claim 1 , wherein, in the determining step, a controller of the printer cartridge is used to determine the amount of printing fluid needed for refilling.

3. The method according to claim 2 , wherein the dispensing step comprises controlling the selection of the amount of the printing fluid to be dispensed with the controller of the printer cartridge.

4. The method according to claim 1 , where the step of engaging the plunger until the ratchet mechanism is reengaged dispenses a predetermined amount of fluid.