Printing liquid transfer and supply system

1. A printing system for printing on a print media comprising:

a first printhead for printing on the print media;

a first liquid supply module including a first liquid reservoir in fluid communication with the first printhead, the first liquid supply module providing liquid from the first liquid reservoir to the first printhead;

a second printhead for printing on the print media;

a second liquid supply module including a second liquid reservoir in fluid communication with the second printhead, the second liquid supply module providing liquid from the second liquid reservoir to the second printhead; and

a liquid transfer module that transfers liquid between the first liquid reservoir and the second liquid reservoir, wherein the first liquid supply module provides liquid from the first printhead back to the first liquid reservoir.

2. The system of claim 1 , further comprising a liquid concentration control system.

3. The system of claim 1 , wherein the liquid transfer module includes a pump for transferring liquid between the first liquid reservoir and the second liquid reservoir.

4. The system of claim 1 , the liquid transfer module including a mixing tank that receives liquid from at least one of the first liquid reservoir and the second liquid reservoir, wherein liquid transferred between the first liquid reservoir and the second liquid reservoir is transferred via the mixing tank.

5. The printing system of claim 4 , wherein the liquid transfer module includes a valve set that controls liquid flow into and out of the mixing tank.

6. The system of claim 1 , wherein the first liquid supply module includes a first controller configured to control operation of the first liquid supply module.

7. The system of claim 6 , wherein the first controller monitors liquid concentration in the first liquid reservoir.

8. The system of claim 1 , wherein the second liquid supply module includes a second controller configured to control operation of the second liquid supply module.

9. The system of claim 8 , wherein the second controller monitors liquid concentration in the second liquid reservoir.

10. The system of claim 1 , wherein the liquid transfer module includes a controller configured to control operation of the liquid transfer module.

11. The system of claim 10 , further comprising:

a third printhead for printing on the print media;

a third liquid supply module including a third liquid reservoir in fluid communication with the third printhead, the third liquid supply module providing liquid from the third liquid reservoir to the third printhead, wherein the liquid transfer module transfers liquid between the first liquid reservoir, the second liquid reservoir, and the third liquid reservoir.

12. The system of claim 11 , wherein the liquid transfer module controller is configured to receive a signal from at least one of the first liquid supply module, the second liquid supply module, and the third liquid supply module that indicates an operational status of the module, the liquid transfer module controller being configured to adjust transfer of liquid between the first liquid reservoir, the second liquid reservoir, and the third liquid reservoir based on the operation status of the module.

13. The systems of claim 10 , wherein the liquid transfer module controller is configured to monitor liquid concentration in the first liquid reservoir and liquid concentration in the second liquid reservoir.

14. The systems of claim 10 , wherein the liquid transfer module controller is configured to transfer liquid between the first liquid reservoir and the second liquid reservoir in a non-continuous manner.

15. The system of claim 1 , wherein the liquid transfer module transfers equal amounts of liquid between the first liquid reservoir and the second liquid reservoir.

16. The system of claim 15 , wherein the liquid transfer module includes a device that monitors the amount of liquid transferred between the first liquid reservoir and the second liquid reservoir.

17. The system of claim 1 , wherein the first liquid supply module provides liquid from the first liquid reservoir to another printhead in addition to the first printhead.

18. A printing system for printing on a print media comprising:

a first printhead for printing on the print media;

a first liquid supply module including a first liquid reservoir in fluid communication with the first printhead, the first liquid supply module providing liquid from the first liquid reservoir to the first printhead;

a second printhead for printing on the print media;

a second liquid supply module including a second liquid reservoir in fluid communication with the second printhead, the second liquid supply module providing liquid from the second liquid reservoir to the second printhead; and

a liquid transfer module that transfers liquid between the first liquid reservoir and the second liquid reservoir, wherein the a liquid transfer module includes a valve set that controls liquid flow from the first liquid reservoir to the second liquid reservoir and from the second liquid reservoir to the first liquid reservoir.

19. A method of transferring liquid in a printing system that prints liquid on a print media comprising:

providing a first liquid supply module including a first liquid reservoir in fluid communication with a first printhead;

providing liquid from the first liquid reservoir to the first printhead using the first liquid supply module;

providing liquid from the first printhead back to the first liquid reservoir using the first liquid supply module;

providing a second liquid supply module including a second liquid reservoir in fluid communication with a second printhead;

providing liquid from the second liquid reservoir to the second printhead using the second liquid supply module; and

transferring liquid between the first liquid reservoir and the second liquid reservoir using a liquid transfer module.