Patent Application
20080055371
The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein:
Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate embodiments of the invention, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.
Referring to
Alternatively, imaging apparatus 14 may be a standalone unit that is not communicatively linked to a host, such as host 12. For example, imaging apparatus 14 may take the form of an all-in-one, i.e., multifunction, machine that includes standalone copying and facsimile capabilities, in addition to optionally serving as a printer when attached to a host, such as host 12.
Host 12 may be, for example, a personal computer including an input/output (I/O) device, such as keyboard and display monitor. Host 12 further includes a processor, input/output (I/O) interfaces, memory, such as RAM, ROM, NVRAM, and a mass data storage device, such as a hard drive, CD-ROM and/or DVD units. During operation, host 12 may include in its memory a software program including program instructions that function as an imaging driver, e.g., printer driver software, for imaging apparatus 14. Alternatively, the imaging driver may be incorporated, in whole or in part, in imaging apparatus 14.
In the embodiment of
Controller 18 includes a processor unit and associated memory, and may be formed as an Application Specific Integrated Circuit (ASIC). Controller 18 communicates with print engine 20 via a communications link 24. Controller 18 communicates with user interface 22 via a communications link 26. Communications links 24 and 26 may be established, for example, by using standard electrical cabling or bus structures, or by wireless connection.
Print engine 20 may be, for example, an ink jet print engine configured for forming an image on a sheet of print media 28, such as a sheet of paper, transparency or fabric.
Print engine 20 may include, for example, a reciprocating printhead carrier 30. Referring also to
Printhead assembly 32 is configured to mount and carry a plurality of removable ink tanks 38, and to facilitate an ink transfer from one or more of the plurality of ink tanks 38 to micro-fluid ejection device 34. The plurality of ink tanks 38 are individually identified as ink tanks 38-1, 38-2, 38-3 and 38-4, and may include a monochrome ink tank containing black ink, and three color ink tanks containing cyan, magenta, and yellow inks. Micro-fluid ejection device 34 may include an ink jet nozzle array for each color of ink.
Referring also to
Referring also to
Referring now also to
Wick retainer 58 includes a side wall 62 that defines an opening 64 in fluid communication with micro-fluid ejection device 34. An elongate interior channel 66 is formed in side wall 62.
In one embodiment, for example, wick retainer 58 may be formed as a cylinder having an axis 68 extending in a direction perpendicular to a plane 70 of base surface 48-1 of snout portion 48, wherein the cylinder is of non-uniform length L to define a distal end 72 of the cylinder that is formed at an acute angle 74 with respect to plane 70 of base surface 48-1. In this embodiment, opening 64 is substantially circular at the intersection of wick retainer 58 and filter cap body 52, but has an elliptical shape along the perimeter of distal end 72.
Wick 60 has a porous elongate body 76 having a proximal end 78, a distal end 80, and an elongate side rib 82. Proximal end 78 is inserted into opening 64 of wick retainer 58, and distal end 80 projects outwardly from distal end 72 of wick retainer 58, with the majority of porous elongate body 76 being contained within wick retainer 58. In one embodiment, for example, distal end 80 may project outwardly from distal end 72 of wick retainer 58 by a distance of about 0.1 to 3 millimeters. Porous elongate body 76 may be formed, for example, from a porous felt or porous foam material.
During insertion of porous elongate body 76 into opening 65 of wick retainer 58, elongate side rib 82 is slidably engaged with elongate interior channel 66 of wick retainer 58. The engagement of elongate side rib 82 with elongate interior channel 66 maintains the desired axial orientation of wick 60 with respect to wick retainer 58 about axis 68.
Distal end 80 of wick 60 has a porous ink receiving surface 84. Porous ink receiving surface is oriented at an acute angle 86 with respect to plane 70 of base surface 48-1 of snout portion 48 of printhead body 44. In one embodiment, for example, acute angle 86 may be from 30 to 60 degrees, and angle 86 may be selected to be equal to, or substantially equal to, angle 74, or vice-versa.
Ink tank 38-2 includes a free ink chamber 90 and a suspended ink chamber 92. Free ink chamber 90 includes a free-flowing supply of ink FI, and is positioned adjacent to suspended ink chamber 92. Free ink chamber 90 is separated from suspended ink chamber 92 by a dividing wall 94. Dividing wall 94 has an ink communication port 96 to provide fluid communication between free ink chamber 90 and suspended ink chamber 92.
Suspended ink chamber 92 has a base 98, and a plurality of side walls 100 extending upwardly away from base 98. The plurality of side walls include, for example, a first side wall portion 100-1 and a beveled side wall portion 100-2 extending upwardly and outwardly from first side wall portion 100-1. Base 98 is located along a first plane 102. Suspended ink chamber 92 has an ink output port 104 formed through base 98.
Positioned in suspended ink chamber 92 adjacent to base 98 is a lower ink suspension body 106. An upper ink suspension body 108 is positioned in suspended ink chamber 92 adjacent to and above lower ink suspension body 106. Each of lower ink suspension body 106 and upper ink suspension body 108 may be constructed from a porous material, such as for example, from a porous felt material or a porous foam material.
Lower ink suspension body 106 has a porous ink transfer surface 110 positioned above ink output port ink output port 104. Porous ink transfer surface 110 is oriented at an acute angle 112 with respect to first plane 102 of base 98. Porous ink transfer surface 110 extends from base 98 to engage first side wall portion 100-1 to define a wedge-shaped void 114 located above ink output port 104. In one embodiment, for example, first side wall portion 100-1 is oriented along a second plane 116 that intersects porous ink transfer surface 110 at a location separated from ink output port 104, such that first side wall portion 100-1 and porous ink transfer surface 110 combine to define wedge-shaped void 114. In this embodiment, second plane 116 is substantially perpendicular to first plane 102. Also, porous ink transfer surface 110 of lower ink suspension body 106 is positioned to contact beveled side wall 100-2 along its surface.
Referring again to
The enlarged cross-section of
The advantage of the angled interface surfaces 84, 110 of ink tank interface 118 is that the vertical insertion/latching force is reduced over the prior art. For a given normal force Fn, the vertical force Fver will be equal the insertion/latching force. Vertical force Fver in conjunction with horizontal force Fhor reduces the tendency for the lower ink suspension body 106 to lift or deform upwards from base 98, thereby reducing the possibility of getting unwanted air paths to ink output port 104, and in turn, to micro-fluid ejection device 34. Also, the horizontal force Fhor is now directed so as to bias lower ink suspension body 106 toward ink communication port 96 to the free ink FI in free ink chamber 90, further reducing the likelihood of getting unwanted air paths to ink output port 104.
The wick 60 and its contact with lower ink suspension body 106 is a resistance to liquid flow to ink output port 104 and to micro-fluid ejection device 34. In striving for a compact design, wick 60 is designed to be small in size, but this causes the resistance (pressure drop) to become significant. By having porous ink receiving surface 84 of wick 60 cut at an angle 86, the contact area with lower ink suspension body 106 is enlarged for a given wick diameter. Thus, a lower possible fluid resistance and increased reliability of the fluid interface may be achieved.
While this invention has been described with respect to embodiments of the invention, the present invention may be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.
