초록 ▼

An ink supply device is fluidly connected to a ink-jet head by first and second ink channels. The first ink channel connects an ink tank of the ink supply device to an inlet of a manifold of a ink-jet head, and the second ink channel connects an outlet of the manifold to the ink tank. In the ink-jet

An ink supply device is fluidly connected to a ink-jet head by first and second ink channels. The first ink channel connects an ink tank of the ink supply device to an inlet of a manifold of a ink-jet head, and the second ink channel connects an outlet of the manifold to the ink tank. In the ink-jet head, a plurality of pressure chambers each communicating with the manifold and a plurality of nozzles each connected to each pressure chamber are formed. During purging, ink is expelled by increasing pressure in the ink tank so that the ink flows through the manifold, pressure chambers, and nozzles, in that order. At the same time, ink flows through the first ink channel, the manifold, and the second ink channel to be collected in the ink tank. During the purging, the amount of ink expelled and the amount of ink collected can be maintained at appropriate values since the flow resistance In the plurality of parallel ink channels connecting the pressure chambers and nozzles is set from about 1 to 5 times the flow resistance of the second ink channel.

대표청구항 ▼

[ What is claimed is:] [1.] An ink-jet printing device, comprising:an ink-jet head having a plurality of parallel pressure chambers each having one end and another end and arrayed side by side in an array direction, nozzles connected to the one end of the pressure chambers, and a manifold connected

[ What is claimed is:] [1.] An ink-jet printing device, comprising:an ink-jet head having a plurality of parallel pressure chambers each having one end and another end and arrayed side by side in an array direction, nozzles connected to the one end of the pressure chambers, and a manifold connected to the another end of the pressure chambers, wherein the plurality of pressure chambers and the nozzles have a structure providing a first flow resistance to ink flow, the manifold extending in the array direction and having an inlet end positioned adjacent a first pressure chamber of said plurality of pressure chambers and an outlet end positioned adjacent a last pressure chamber of said plurality of pressure chambers;a first ink channel having one end connected to the inlet end of the manifold, the first ink channel having another end;a second ink channel having one end connected to the outlet end of the manifold and having another end, the second ink channel has a structure providing a second flow resistance to ink flow, wherein the first flow resistance being 1 to 5 times the second flow resistance;an ink tank accumulating therein an ink, the another end of the first ink channel and the another end of the second ink channel being connected to the ink tank for supplying the ink from the ink tank to the ink-jet head through the first ink channel and for circulating the ink in the ink-jet head to the ink tank through the second ink channel; anda pressure applying device connected to and applying pressure to ink accumulated in the ink tank for supplying the ink in the ink tank toward the first ink channel, so that a part of the ink supplied from the ink tank is ejected out of the nozzles and a remaining part of the ink being recirculated into the ink tank by the pressure in a single step purging operation without any capping of the nozzles.