Patent Application
20050185032
The subject disclosure is generally directed to ink jet printing, and more particularly to ink jet printing apparatus that includes an on-board ink reservoir.
Drop on demand ink jet technology for producing printed media has been employed in commercial products such as printers, plotters, and facsimile machines. Generally, an ink jet image is formed by selective placement on a receiver surface of ink drops emitted by a plurality of drop generators implemented in a printhead or a printhead assembly. For example, the printhead assembly and the receiver surface are caused to move relative to each other, and drop generators are controlled to emit drops at appropriate times, for example by an appropriate controller. The receiver surface can be a transfer surface or a print medium such as paper. In the case of a transfer surface, the image printed thereon is subsequently transferred to an output print medium such as paper. Some ink jet printheads employ melted solid ink.
A drop emitting apparatus including an ink jet printhead; a plurality of on-board ink reservoirs for supplying ink to the ink jet printhead; a plurality of remote ink containers; a plurality of ink supply conduits fluidically connected between the remote ink containers and the on-board ink reservoirs; a common air vent, connected to each one of said plurality of remote ink containers, for venting each one of said plurality of remote ink containers as ink is supplied to the on-board ink reservoirs from said remote ink containers.
While the present invention will be described in connection with a preferred embodiment thereof, it will be understood that it is not intended to limit the invention to that embodiment. On the contrary, it is intended to cover all alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.
The on-board ink reservoirs 61-64 can also be selectively pressurized, for example by selectively pressurizing the remote ink containers 51-54 and pressurizing an air channel 75 via a valve 85. Alternatively, the ink supply channels 71-74 can be closed, for example by closing the output valves 91-94, and the air channel 75 can be pressurized. The on-board ink reservoirs 61-64 can be pressurized to perform a cleaning or purging operation on the printhead 20, for example. The on-board ink reservoirs 61-64 and the remote ink containers 51-54 can be configured to contain melted solid ink and can be heated. The ink supply channels 71-74 and the air channel 75 can also be heated.
The on-board ink reservoirs 61-64 are vented to atmosphere during normal printing operation, for example by controlling the valve 85 to vent the air channel 75 to atmosphere. The on-board ink reservoirs 61-64 can also be vented to atmosphere during non-pressurizing transfer of ink from the remote ink containers 51-54 (i.e., when ink is transferred without pressurizing the on-board ink reservoirs 61-64).
As schematically depicted in
An advantageous feature of the present invention is that the on-board reservoir has one vent/purge connector common to all four colors. This reduces, by a factor of four, the number of vent lines needed for each printhead. During normal jet operation this vent is open to atmosphere, but during a purge cycle it is pressurized along with the ink feeds to purge the printhead. Further, with vent line structures 150-153 being arranged to form a maze type configuration, in which each vent line structures leads to a common pressure inlet vent 160. During tipping or sloshing, ink in the ink chambers wont mix with ink in the adjacent chamber(s). This design allows for a fairly large overfill (by comparing to the nominal ink volume) of a given ink chamber without it spilling over into the other chambers.
In recapitulation, there has been provided a drop emitting apparatus including an ink jet printhead; a plurality of on-board ink reservoirs for supplying ink to the ink jet printhead; a plurality of remote ink containers; a plurality of ink supply conduits fluidically connected between the remote ink containers and the on-board ink reservoirs; a common air vent, connected to each one of said plurality of remote ink containers, for venting each one of said plurality of remote ink containers as ink is supplied to the on-board ink reservoirs from said remote ink containers. The drop emitting apparatus further includes a plurality of ink vent lines connected to said common vent, wherein each one of said ink vent lines is connected and associated to one of said plurality of remote ink containers. And, wherein the plurality of remote ink containers, the common air vent conduit and the plurality of ink vent lines are formed as an integral structure. Each one of said plurality of ink vent lines are routed to said common vent in maze type configuration. The on-board ink reservoir is ink fill and venting is accomplished through one multi-ported connection on the back. There is no need for ink fill buckets or to leave any room on the top or bottom of the reservoir for ink loading. The vent connection is common to all four colors to minimize the number of vent lines needed. Internal to the reservoir, routing of the ink and vent lines is done in such a way as to not allow ink color mixing under a fairly large range of head motion and angles. There is also an allowance for slight overfilling of ink channels without ink mixing.
Other embodiments and modifications of the present invention may occur to those skilled in the art subsequent to a review of the information presented herein; these embodiments and modifications, as well as equivalents thereof, are also included within the scope of this invention.
