Refill unit for ink cartridge in printer with ink suitability verification

1. A refill unit for refilling an ink cartridge, the ink cartridge containing a colored ink and forming part of an inkjet printer, the inkjet printer also having a printhead and control circuitry, the refill unit comprising:

a body containing a quantity of colored ink;

an ink outlet having a unique configuration, the unique configuration being unique to the color of ink contained in the body, the ink outlet is configured to releasably engage a correspondingly uniquely configured interface of the ink cartridge containing ink of the same color as the refill unit; and,

a memory circuit for storing ink information relating to at least one characteristic of the ink, the memory circuit being read by the control circuitry of the inkjet printer to retrieve the stored ink information to:

further verify that the ink in the refill unit is suitable for refilling the ink cartridge; and

modifying the maximum print speed of the printhead in response to the information stored on the memory circuit.

2. A refill unit according to claim 1 wherein the information includes the type and color of the ink.

3. A refill unit according to claim 2 wherein the information includes the volume of ink in the refill unit.

4. A refill unit according to claim 1 , wherein the cartridge comprises:

an ink storage compartment and an ink feed system for connection to the printhead which has an array of ink ejection nozzles, and

wherein the ink storage compartment has a variable storage volume and a displaceable wall section biased to expand the variable storage volume to generate a negative pressure therein, such that ink does not inadvertently leak from the ink ejection nozzles.

5. A refill unit according to claim 1 for refilling a negatively pressurized ink storage compartment that supplies ink to the printhead, the ink storage compartment having the interface for receiving the refill unit, the interface having an inlet valve biased to its closed configuration, wherein the further refill unit comprises:

engagement formations for releasably engaging the interface; and

an inlet valve actuator for opening the inlet valve as the refill unit engages the ink interface so that the ink in the body is in fluid communication with the ink storage compartment.

6. A refill unit according to claim 1 , wherein:

the ink cartridge has a negatively pressurized ink storage compartment that supplies ink to the printhead, and the interface for receiving the refill unit, the interface having a normally closed inlet valve and a normally open outlet valve, both in fluid communication with the ink storage compartment; and

the refill unit further comprises a docking portion having an ink outlet and valve actuator formations, wherein during use, the docking portion releasably engages the interface to actuate the inlet and the outlet valves so the cartridge fills with ink from the body because of the negative pressure in the ink storage compartment.

7. A refill unit according to claim 1 for refilling a negatively pressurized ink storage compartment that supplies ink to the printhead via a normally open outlet valve, wherein the refill unit further comprises:

engagement formations for releasably engaging the ink storage compartment; and

an outlet valve actuator for closing the outlet valve as the refill unit engages the ink storage compartment.

8. A refill unit according to claim 1 for refilling an ink storage compartment supplying the printhead which has an array of nozzles, wherein:

during use, the ink storage compartment is maintained at a negative pressure to avoid inadvertent ink leakage from the nozzles;

the refill unit further comprises a repressurizing arrangement;

wherein upon engagement of the refill unit with the ink storage compartment, the repressurizing arrangement causes part of the unit to be inwardly depressed as the ink from the body is drawn into the ink storage compartment through the ink outlet by the negative pressure until pressure equalization; and

upon subsequent disengagement of the refill unit from the ink storage compartment, the repressurizing arrangement releases the inwardly depressed part of the ink storage compartment to re-establish the negative pressure.

9. A refill unit according to claim 1 , wherein the cartridge comprises:

an ink storage compartment having opposed wall sections connected by a flexible wall arrangement to define a variable ink storage volume; and

an ink feed system for supplying for supplying ink to a printhead with an array of nozzles, and

wherein one of the opposed wall sections is displaceable and biased to expand the variable ink storage volume to create a negative pressure in the ink storage compartment for avoiding inadvertent ink leakage from the nozzles.

10. A refill unit according to claim 1 for refilling an ink storage compartment having the interface for releasably engaging with the refill unit, the interface having valves for controlling ink flows into, and out of, the storage compartment,

wherein the refill unit further comprises valve actuators for actuating the valves when the refill unit engages the interface, such that the valve actuators actuate the valve in a predetermined sequence.

11. A refill unit according to claim 1 incorporated in printhead maintenance assembly for the printhead,

wherein the printhead has a nozzle plate with an array of nozzles formed therein; and

the printhead maintenance assembly comprises:

a capper to cover the array of nozzles when the printhead is not in use; and

a cleaner for engaging the nozzle plate and wiping across the nozzles, the cleaner being positioned between opposing sides of the capper.

12. A refill unit according to claim 1 , wherein the inkjet printer comprises:

the printhead with an array of nozzles;

a maintenance assembly for moving between a capped position where the assembly covers the array of nozzles, and an uncapped position spaced from the array of nozzles; and

a motorized drive for moving the maintenance assembly between the capped position and the uncapped position.

13. A refill unit according to claim 1 , wherein:

the ink cartridge has the interface for engaging the refill unit;

the refill unit further comprises:

an ink storage compartment;

a docking portion for engaging the interface of the cartridge, the docking portion having a base plate with an ink outlet for connection to an inlet port on the interface; and

engagement formations for releasably engaging the interface, the engagement formations being formed on the transverse centre line of the base plate; and

wherein the centre of the ink outlet is spaced from the transverse centre line.

14. A refill unit according to claim 1 , wherein:

the ink cartridge has the interface for engaging the refill unit, an ink storage compartment partially defined by a tubular flexible wall, and a constriction mechanism for constricting the flexible tubular wall by a predetermined amount; and

the refill unit further comprises a docking portion for engaging the interface of the cartridge, the docking portion having an ink outlet for connection to an inlet port on the interface, and a plurality of constriction actuators for actuating the constriction mechanism as the ink refill unit engages the interface and releases the constriction mechanism as the ink refill unit disengages the interface.

15. A refill unit according to claim 1 , wherein:

the ink cartridge has the interface for engaging the refill unit;

the ink refill unit comprises:

the ink outlet for engaging a complementary ink inlet in the interface; and

a spigot extending from the body for insertion in an aperture in the interface; and

wherein the lateral cross section of the spigot is keyed to the shape defined by the aperture to ensure the ink refill is correctly matched to the cartridge.

16. A refill unit according to claim 1 , wherein:

the ink outlet engages a complementary ink inlet in the cartridge; and

the refill unit further comprises a visual indicator to provide a visual indication when a predetermined quantity ink has flowed from the refill unit into the cartridge.

17. A refill unit according to claim 1 , wherein the inkjet printer comprises:

an outer casing with a hingedly mounted panel for access its interior; and

a cradle housed within the outer casing for supporting an ink cartridge, the cradle having a hingedly mounted lid that opens to allow the ink cartridge to be inserted and removed,

wherein the hinge axis of the lid and the hinge axis of the panel are parallel, and

wherein the lid and the panel both open in the same direction.

18. A refill unit according to claim 1 , wherein the inkjet printer comprises:

a replaceable pagewidth printhead with an array of nozzles and printhead contacts for transmitting power and print data to the nozzles;

corresponding contacts for supplying the power and print data to the printhead contacts; and

a selective biasing mechanism, such that the printhead contacts and the corresponding contacts are biased into engagement during printing and released from biased engagement when installing or removing the printhead.