Positioning a mobile apparatus for adjacent printing swaths

1. A method of printing with a mobile printing apparatus having an array of marking elements disposed along an array direction, the method comprising:

moving the mobile printing apparatus to an initial starting position;

providing a first swath of data;

printing a first printed swath corresponding to the first swath of data using a first portion of the array of marking elements while moving the mobile printing apparatus along a scan direction;

printing a first set of position reference marks using a second portion of the array of marking elements while moving the mobile printing apparatus along the scan direction;

providing a second swath of data;

sensing the first set of position reference marks; and

printing a second printed swath corresponding to the second swath of data, wherein operation of the mobile printing apparatus for printing the second printed swath is guided, at least in part, by the first set of position reference marks.

2. The method according to claim 1 further comprising moving the mobile printing apparatus to a second swath starting location before printing the second printed swath, such that the array of marking elements is displaced from a location of the first printed swath along a direction that is parallel to the array direction.

3. The method according to claim 2 , wherein the step of moving the mobile printing apparatus to a second swath starting location includes moving the mobile printing apparatus to a location that is adjacent the initial starting position.

4. The method according to claim 2 , wherein the step of moving the mobile printing apparatus to a second swath starting location includes moving the mobile printing apparatus to a location that is displaced from the initial starting position along the scan direction.

5. The method according to claim 4 , wherein the step of printing the second printed swath includes moving the mobile printing apparatus in a direction opposite the scan direction along which the mobile printing apparatus moved while printing the first printed swath.

6. The method according to claim 4 , wherein the step of moving the mobile printing apparatus to a second swath starting location includes:

rotating a first wheel of the mobile printing apparatus in a first direction; and

rotating a second wheel of the printing apparatus in a second direction opposite the first direction to turn the mobile printing apparatus around.

7. The method according to claim 1 further comprising printing a second set of position reference marks after moving the mobile printing apparatus to the second swath starting location.

8. The method according to claim 1 , wherein the step of printing a first printed swath includes rotating a first wheel and a second wheel in a first direction while they are in contact with a sheet of medium that is being printed on.

9. The method according to claim 1 , wherein printing the first set of position reference marks includes depositing a marking material that is difficult for a human eye to perceive.

10. The method according to claim 9 , wherein the marking material is yellow.

11. The method according to claim 9 , wherein the marking material is deposited in a nonlinear pattern.

12. The method according to claim 9 , wherein a feature width of the deposited marking material is greater than 10 microns and less than 50 microns.

13. The method according to claim 1 , wherein the array of marking elements includes an array of nozzles and wherein printing the first printed swath includes ejecting drops through the nozzles.

14. The method according to claim 13 , wherein the printing of the first printed swath includes ejecting drops of colored ink to form a portion of an image.

15. The method according to claim 13 , wherein the printing of the first printed swath includes ejecting drops of a functional material to form a portion of a device.

16. The method according to claim 15 , wherein printing the first set of position reference marks includes depositing a marking material in a plurality of positions that do not contact the device that is formed.

17. The method according to claim 1 , the mobile printing apparatus being the first of a plurality of mobile printing apparatuses, the method further comprising printing a second set of position reference marks, wherein the steps of printing the second printed swath and printing the second set of position reference marks are done using a second mobile printing apparatus of the plurality of mobile printing apparatuses.

18. The method according to claim 17 further comprising:

providing a third swath of data;

printing a third printed swath corresponding to the third swath of data using the second mobile printing apparatus, wherein operation of the second mobile printing apparatus for printing the third printed swath is guided, at least in part, by the second set of position reference marks; and

printing a third set of position reference marks using the second mobile printing apparatus.

19. The method according to claim 18 further comprising:

providing a fourth swath of data;

printing a fourth printed swath corresponding to the fourth swath of data using the first mobile printing apparatus, wherein operation of the first mobile printing apparatus for printing the fourth printed swath is guided, at least in part, by the third set of position reference marks; and

printing a fourth set of position reference marks using the first mobile printing apparatus.