Printer with vacuum belt assembly having independently laterally movable belts

1. A printer comprising a vacuum belt assembly for moving print media in a media feed direction along a media path, the vacuum belt assembly comprising:

a plurality of endless belts tensioned between first and second pulleys, the first and second pulleys having respective first and second axes of rotation perpendicular to the media feed direction; and

a vacuum chamber for drawing print media onto an upper surface of the belts, wherein:

the second pulley is downstream of the first pulley with respect to the media feed direction;

the second pulley is configured to allow a predetermined degree of independent lateral sliding of each belt along the second axis; and

the first pulley is configured to prevent any lateral movement of the belt along the first axis.

2. The printer of claim 1 , wherein the second pulley is a drive pulley operatively connected to a motor.

3. The printer of claim 1 , wherein the first pulley is an idler pulley.

4. The printer of claim 1 , wherein each belt is toothed and intermeshes with complementary grooves in at least one of the first and second pulleys.

5. The printer of claim 1 , wherein one first pulley and one second pulley together support a set of individual belts.

6. The printer of claim 5 , wherein the vacuum belt assembly comprises a plurality of first and second pulleys, each first and second pulley together supporting a respective set of individual belts.

7. The printer of claim 5 , wherein the second pulley comprises a plurality of circumferential ribs, each belt in the set being mounted between a respective pair of ribs, wherein a spacing between the pair of ribs is greater than a width of the belt.

8. The printer of claim 7 , wherein the ribs are positioned such that the belts in the set are spaced apart from each other.

9. The printer of claim 8 , wherein the vacuum chamber communicates with an elongate interstitial gap defined between each pair of adjacent belts.

10. The printer of claim 9 , wherein the belts are non-apertured belts.

11. The printer of claim 9 , wherein one or more vacuum antechambers are positioned in the interstitial gap defined between each adjacent pair of belts, each vacuum antechamber having a perimeter opening for suction engagement with print media, and each vacuum antechamber communicating with the vacuum chamber via a respective aperture defined in each antechamber.

12. The printer of claim 11 , wherein a plurality of elongate vacuum antechambers are positioned in each gap, and wherein a length dimension of each perimeter opening extends longitudinally in the media feed direction.

13. The printer of claim 12 , wherein a first perimeter opening of a first vacuum antechamber positioned towards an upstream side of the vacuum belt assembly is shorter than a second perimeter opening of a second vacuum antechamber positioned towards a downstream side of the vacuum belt assembly, the upstream and downstream sides being defined with respect to the media feed direction.

14. The printer of claim 13 , wherein the first vacuum antechamber has a first aperture defined therein and the second vacuum antechamber has a second aperture defined therein, the first and second apertures communicating with the vacuum chamber, wherein the first aperture has a larger diameter than the second aperture.

15. The printer of claim 1 , further comprising a fixed printhead assembly.

16. The printer of claim 15 , wherein the vacuum belt assembly is positioned downstream of the fixed printhead assembly.

17. The printer of claim 1 , which is a wideformat printer.