Method of purging a printhead using coordinated pressure device and in-line valve

1. A method of purging ink from an inkjet printhead, said printhead being in fluid communication with an ink reservoir via an ink conduit having a valve, said method comprising the steps of:

(i) closing said valve;

(ii) positively pressurizing said ink reservoir using a pressure device;

(iii) opening said valve for a predetermined period, thereby purging ink from said printhead and flooding an ink ejection face of said printhead; and

(iv) transferring said flooded ink onto a transfer surface moving past said face, wherein said transfer surface is a plastics film which does not contact said face, and wherein said plastics film is dry before moving past said face.

2. The method of claim 1 , wherein said printhead is in fluid communication with a plurality of ink reservoirs.

3. The method of claim 2 , wherein a respective ink conduit provides fluid communication between each ink reservoir and said printhead.

4. The method of claim 3 , wherein each ink conduit has a respective valve.

5. The method of claim 1 , wherein said valve is a solenoid valve.

6. The method of claim 1 , operation of said pressure device and said valve is controlled using a controller.

7. The method of claim 6 , further comprising measuring a pressure in said ink reservoir or said ink conduit using a pressure sensor.

8. The method of claim 7 , further comprising controlling said pressure device in response to feedback provided by said pressure sensor to said controller.

9. The method of claim 8 , further comprising coordinating a printhead purge operation using said pressure device, said pressure sensor and said valve.

10. The method of claim 9 , further comprising the step of monitoring a pressure in said ink reservoir or said ink conduit using said pressure sensor, and opening said valve when a predetermined pressure has been reached.

11. The method of claim 1 , wherein said ink reservoir comprises a pressure-biasing means for biasing a pressure in said reservoir towards a negative pressure.

12. The method of claim 1 , wherein said ink reservoir comprises an ink bag containing ink.

13. The method of claim 1 , wherein said transfer surface is an outer surface of a roller.

14. The method of claim 13 , wherein said transfer surface is moved past said face by rotating said roller.

15. The method of claim 1 , further comprising the step of removing ink from said transfer surface using an ink removal system.

16. The method of claim 1 , wherein said pressure device comprises a compression mechanism.

17. The method of claim 1 , wherein said pressure device comprises an air compressor.