INKJET PRINTING SYSTEM WITH MEDIA ENCODER IN THE PLATEN

1 . An inkjet printing system comprising:

a vacuum platen assembly;

a printhead assembly spaced from the vacuum platen assembly; and

a media encoder embedded within the vacuum platen assembly.

2 . The inkjet printing system according to claim 1 further comprising a media feed axis extending between the printhead assembly and the platen wherein the printhead assembly has a plurality of printheads, and the media encoder is positioned to engage media between two of the printheads.

3 . The inkjet printing system according to claim 2 further comprising a print zone between the printhead assembly and the vacuum platen assembly where, during use, media is printed with ink from the printhead assembly, wherein the media encoder is positioned to engage the media proximate an upstream side of the print zone.

4 . The inkjet printing system according to claim 3 further comprising

a drive roller for moving media onto the vacuum platen;

a vacuum belt assembly to move the media away from the vacuum platen; and,

a scanner adjacent the vacuum assembly to capture information from the media for feedback control of the printhead assembly.

5 . The inkjet printing system according to claim 4 wherein the printhead assembly has a staggered array of printheads that, during use, collectively span the media, and the information captured by the scanner is used to align printing from each of the printheads with that of adjacent printheads in the array.

6 . The inkjet printing system according to claim 5 wherein the drive roller moves the media past the printheads along a media feed axis, the printheads being arranged in two rows that are staggered with respect to each other and overlapping in a direction transverse to the media feed axis.

7 . The inkjet printing system according to claim 6 wherein the vacuum platen assembly comprises a plurality of service modules, each with a vacuum platen configured for alignment with a corresponding one of the array of printheads.

8 . The printing system according to claim 7 wherein the service modules are configured to cross the media path to engage the printhead during a capping or servicing operation.

9 . The inkjet printing system according to claim 5 wherein the vacuum belt assembly includes a plurality of individual vacuum belts.

10 . The printing system according to claim 5 wherein the vacuum platen assembly further comprises a fixed vacuum platen in which the service modules are embedded, the fixed vacuum platen being positioned adjacent a section of the media path defining a print zone, the print zone encompassing an area simultaneously printable by the printheads.

11 . The printing system according to claim 10 wherein the media path is greater than 432 mm (17 inches) wide.

12 . The printing system according to claim 11 wherein the media path is between 914 mm (36 inches) and 1372 mm (54 inches) wide.

13 . The printing system according to claim 12 wherein the print zone has an area less than 129032 square mm (200 square inches).

14 . The printing system according to claim 13 configured to generate less than 0.2 psi pressure difference between one surface of the media and the other as the media is fed across the fixed vacuum platen.

15 . The printing system according to claim 13 configured to generate between 0.036 psi to 0.116 psi pressure difference between one surface of the media and the other as the media is fed across the fixed vacuum platen.

16 . The printing system according to claim 13 wherein the vacuum platen assembly is configured to generate a normal force on the media of between 4 lbs to 13.5 lbs as the media is fed across the fixed vacuum platen.

17 . The printing system according to claim 1 wherein the individual vacuum belts are configured to transport the media at a faster speed than the drive roller.

18 . The printing system according to claim 17 wherein during use, the media simultaneously engages both the drive roller and the individual vacuum belts such that the media slips relative to the individual vacuum belts.