Patent Application
20070076048
In various modes of operation, ink must be purged from printheads to ensure proper operation of the printhead. When a solid ink printer is initially turned on, the solid ink must be melted or remelted and the printhead must be purged to clear the printhead of any solidified ink in the printhead. The word “printer” as used herein encompasses any apparatus, such as digital copier, bookmaking machine, facsimile machine, multi-function machine, etc. that performs a print outputting function for any purpose.
When ink is purged through the printhead, the ink flows down and off the face of the printhead typically to a waste tray positioned below the printhead. Absent any additional structure, the ink can flow freely along the bottom edge of the printhead and drip from the printhead anywhere along that bottom edge. To help control this dripping flow of waste ink, a drip bib may be added near the bottom edge of the printhead.
One embodiment is a printhead that includes a waste ink drip bib located adjacent a lower edge of the face of the printhead. The waste ink drip bib includes a funnel for directing a flow of waste ink away from the printhead face.
Another embodiment is a method of disposing of waste ink from a printhead that includes attaching a waste ink drip bid near a lower edge of the printhead with the waste ink drip bib including a funnel shape having downwardly sloping portions. The method further includes directing a flow of waste ink laterally with the downwardly sloping portions of the funnel shape to a lower opening in the funnel. Another embodiment is a printer that includes a printhead that has a waste ink drip bib positioned near a bottom edge of a face of the printhead. The waste ink drip bib includes later surfaces substantially perpendicular to the face of the printhead arranged to direct a waste ink to a central portion of the waste ink drip bib.
The drip bib 34 has a funnel structure 38 that includes an upper opening 40 extending across a portion of the printhead face 32 and a narrower lower opening 42. The lower opening 42, in this embodiment, is laterally located near the center of the width of the printhead face 32. The funnel structure 38 has depth extending perpendicular from the printhead face 32. The funnel 38 is structured to direct waste ink being purged from the printhead face 32 into the upper opening 40 to flow as a stream out of the lower opening 42. As will be discussed in more detail further, the drib bib 34 may have vertical reliefs 46 and downwardly sloping portions 50.
The funnel structure 38, as shown in
When the bib is formed by folding, the folded material helps to retain the waste ink within the drip bib 34 laterally to the lower opening 42 so that ink does not drip or splatter onto neighboring components. Vertical reliefs 46 can be further cut in the material on either side of the lower opening 42. The vertical reliefs 46 use the surface tension of the ink to help wick the ink off of the edge of the lower opening 42 so that satellite drops are eliminated or at least reduced.
The lower opening 42 may be further sized to utilize the surface tension of the ink 48 to retain a small portion of the ink within the drip bib 34 at the lower opening 42 as the flow of ink 48 diminishes. The last of the waste ink is then retained within the drip bib 34 rather dripping off the drip bib 34 and possibly causing harmful satellite drops. The retained ink then can solidify near the lower opening 42. A subsequent flow of waste ink 48 then can remelt the retained ink and the subsequent ink 48 along with the retained ink flows in a steady stream out of the lower opening 42.
A method of disposing waste ink 48 from a printhead 30 will now be described with reference to
As the flow of waste ink 48 diminishes, a small amount of ink is retained in the drip bib 34 near the lower opening 42 preventing drops from forming near the lower opening 42. The retained amount of ink is allowed to solidify and then a subsequent flow of waste ink 48 remelts this retained amount of ink.
Satellite drops are prevented from forming near the lower opening 42 by relieving the vertical edges 46 on either side of the lower opening 42. The vertical reliefs 46 eliminate a horizontal path from either side of the lower opening 42. Without the vertical reliefs 46, the surface tension of the waste ink could cause the in 48 to spread horizontally from the lower opening 42 thereby allowing unwanted satellite drops to form below this horizontal path. The flow of waste ink 48 is retained within the drip bib 34 because the drip bib 34 is formed from a single, piece of material, such as one formed by folding. The unopened lower parts 44 of the material form the bottom edge of the drip bib 34 on either side of the lower opening 42.
The sloping lateral surfaces 50 extend from an upper opening 40 down the centrally located lower opening 42. The lower opening 42 is sized to retain a predetermined amount of ink due to the surface tension of the ink when the flow of waste ink diminishes.
The printheads 62, 64, 66 and 68 are arranged in upper and lower rows. Upper printhead 62 is positioned above the two lower printheads 66 and 68 such that the lower opening 42 is located directly above a lateral gap 70 between the two lower printheads 66 and 68. The waste ink 48, as shown in
By directing the flow of waste ink to the centrally located lower opening 42 in the drip bib 34, the lateral positions of the upper printheads 62 and 64 can overlap with the lateral positions of the lower printheads 66 and 68.
It will be appreciated that various of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.
