PRINTER WITH INK LINE DAMPENING OF INK PRESSURE SURGES

1 . A printer comprising:

a printhead having an ink inlet and an ink outlet;

an ink chamber for supplying ink to said printhead, said chamber having an outlet port;

an upstream ink line interconnecting said outlet port and said ink inlet;

a downstream ink line connected to said ink outlet; and

a first air accumulator communicating with said downstream ink line, said first air accumulator being configured for dampening ink pressure pulses in said printhead during printing.

2 . The printer of claim 1 , wherein said printhead comprises one or more second air accumulators communicating with ink channels in the printhead, said second air accumulators being configured for dampening ink pressure pulses in said printhead during printing.

3 . The printer of claim 2 , wherein said one or more second air accumulators are configured for dampening relatively high frequency pressure pulses and said first air accumulator is configured for dampening relatively low frequency pressure pulses.

4 . The printer of claim 3 , wherein said first air accumulator has a larger volume than each of said one or more second air accumulators.

5 . The printer of claim 1 , wherein said downstream ink line comprises an inline ink pump for priming and/or depriming said printhead.

6 . The printer of claim 5 , wherein said first air accumulator is positioned between said ink outlet and said pump.

7 . The printer of claim 5 , wherein said pump is a reversible peristaltic pump.

8 . The printer of claim 5 , wherein said downstream ink line comprises inline filters positioned on either side of said pump.

9 . The printer of claim 5 , wherein said downstream ink line interconnects said ink outlet and a return port in said chamber for recycling of ink into said chamber.

10 . The printer of claim 9 , wherein said chamber comprises a snorkel extending from said return port to above a level of ink in said chamber.

11 . The printer of claim 10 , wherein said chamber comprises an air vent open to atmosphere, said air vent communicating with a headspace above said ink so as to equalize a hydrostatic pressure in said upstream and downstream ink lines.

12 . The printer of 10 , wherein said chamber is a pressure-regulating chamber for controlling a hydrostatic pressure of ink supplied to said printhead.

13 . The printer of claim 11 , wherein said chamber comprises means for maintaining a predetermined first level of ink in said chamber relative to said printhead.

14 . The printer of claim 13 , wherein said hydrostatic pressure, relative to atmospheric pressure, is defined as ρgh, wherein ρ is the density of ink, g is acceleration due to gravity and h is the height of the predetermined first level of ink relative to the printhead.

15 . The printer of claim 13 , wherein said means for maintaining said predetermined first level of ink comprises an ink reservoir cooperating with a float valve contained in said pressure-regulating chamber.

16 . The printer of claim 15 , wherein said float valve comprises:

an arm pivotally mounted about a pivot;

a float mounted at one end of said arm; and

a valve stem attached to said arm, said valve stem having a valve head for closure of a valve seat,

wherein said valve seat is positioned at an inlet port of said pressure-regulating chamber.

17 . The printer of claim 16 , wherein said inlet port and said outlet port of said pressure-regulating chamber are positioned towards a base of said chamber.

18 . The printer of claim 165 , further comprising an ink reservoir in fluid communication with said inlet port.

19 . The printer of claim 1 , wherein said printhead is removably replaceable in said printer.

20 . The printer of claim 19 , wherein said printhead comprises an inlet coupling and and an outlet coupling, said inlet coupling being detachably connected to a complementary upstream ink line coupling and said outlet coupling being detachably connected to a complementary downstream ink line coupling.