Abstract: A technique for selective enhancement of black including printing a non-black color at pixel locations identified by a candidate pixel array and which correspond to marked pixels in a predetermined pixel pattern, wherein the candidate pixel array comprises a plurality of N-pixel candidate tiles respectively associated with N-pixel image tiles of a black half-toned bit map, wherein an N-pixel candidate tile includes marked pixels only if the associated N-pixel image tile comprises a portion of a half-toned uniform region and the number of marked pixels in the associated N-pixel image tile is at least a predetermined percentage of N, and wherein the number of marked pixels in some of the N-pixel candidate tiles is less than the number of marked pixels of the associated N-pixel image tile.

Abstract: A drop emitting device that includes a drop generator and a drive signal waveform that includes in sequence a first pulse of a first polarity, a pulse of a second polarity and a second pulse of the first polarity.

Abstract: A drop emitting device including a linear array of first finger manifolds interleaved with a linear array of second finger manifolds to form a composite linear array of finger manifolds. The composite linear array of finger manifold extends along an X-axis, and the finger manifolds extend obliquely to the X-axis. A plurality of drop generators are fluidically coupled to the finger manifolds.

Abstract: A drop emitting apparatus that includes 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, and an air conduit for selectively providing compressed air to the on-board ink reservoirs.

Abstract: A printing technique wherein pixel locations that are requested to be marked with only black are identified, black is applied to the identified pixel locations, and non-black color is applied to those identified pixel locations that (A) have an associated black half-tone threshold level that is darker than a predetermined non-white threshold level, and (B) correspond to on-pixels of a reference pattern of non-black color pixels having an on-pixel population of at least 20 percent and a toner transfer efficiency of less than about 20 percent.

Abstract: A drop emitting device including a first linear array of columnar arrays of first nozzle pairs and a second linear array of columnar arrays of second nozzle pairs wherein the first linear array and the second linear array extend along an X-axis, and wherein the second linear array is adjacent the first linear array such that each first nozzle pair has an associated second nozzle pair displaced therefrom along a Y-axis that is orthogonal to the X-axis. The columnar arrays of first nozzle pairs and the columnar arrays of second nozzle pairs extend obliquely to the X-axis.

Abstract: A printing technique wherein pixel locations that are requested to be marked with only black are identified, black is applied to the identified pixel locations, and non-black color is applied to a subset of the identified pixel locations that correspond to on-pixels of a reference pattern of non-black color pixels having an on-pixel population of at least 20 percent and a toner transfer efficiency of less than about 20 percent.

Abstract: A drop emitting device that includes a drop generator and a drive signal waveform that includes in sequence a first negative pulse, a positive pulse and a second negative pulse.

Abstract: A method of ink jet printing wherein at least one row of pixels adjacent a leading edge of a print medium and/or trailing edge of the print medium is printed using a print mode that employs fewer passes than the print mode utilized for printing rows that are further from such edges.

Abstract: Printing apparatus that employs a media detect switch and a linear optical detector to accurately detect the leading edge or trailing edge of a print medium to modify print data so that printing does not extend off the print medium beyond the leading edge or trailing edge. Also disclosed are techniques for using the media detect switch to control a media advance operation to position the leading edge or trailing edge of the print medium in the field of view of the linear array optical detector.

Abstract: A dynamic memory based integrated circuit ink jet firing cell that includes a heater resistor, a drive transistor, and a dynamic memory circuit for storing firing data only for such heater resistor. Also disclosed is an integrated circuit firing array that includes a plurality of dynamic memory based firing cells divided into a plurality of fire groups of firing cells, each fire group having a plurality of subgroups; data lines for providing energizing data to the firing cells; control lines for providing control information to the firing cells wherein all firing cells within a subgroup are connected to a common subset of the control lines so as to be controlled to concurrently store energizing data; and a plurality fire lines for supplying energizing energy to the firing cells, wherein all firing cells of a fire group receive energizing energy from only one fire line.

Abstract: A compact thermal ink jet printhead including a printhead substrate, a plurality of side by side columnar arrays of drop generators formed in the printhead substrate, and drive circuits formed in the printhead substrate for energizing each ink drop generator. The printhead substrate has an ink drop generator packing density of at least 10.43 ink drop generators per square millimeter.

Abstract: A latch for retaining a rack slide mounted computer in a rack system. The latch includes a resiliently bendable latch arm having catches configured for engagement with a column flange of a computer rack system.

Abstract: An ink jet printing apparatus that includes a spring-backed fluid interconnect seal that provides a seal between an ink handling component and an ink pipe that is attached to the ink handling component. The spring-backed fluid interconnection seal more particularly includes a generally conically tapered resilient seal, and a pre-loaded spring configured to axially extend or tension the seal.

Abstract: An ink jet printhead that includes a thin film substructure having heater resistors formed therein, an ink barrier layer disposed one the thin film substructure, a plurality of ink chambers formed in said ink barrier, a plurality of ink channels respectively fluidically connected to the ink chambers and opening towards an ink feed edge, a plurality of elongated angled barrier islands extending from the feed edge into respective ink channels, and a plurality of non-elongated barrier islands alternatingly located with the non-linear elongated barrier island along the ink feed edge.

Abstract: An ink jet printing system having a vacuum hold down, a vacuum source, and a particulate filtering muffler for trapping ink aerosol particles and muffling noise produced by the vacuum source.

Abstract: An ink jet printer wherein unidirectional or bidirectional printing is adaptively selected for predetermined print modes as a function of whether bidirectional alignment has been performed.

Abstract: An ink jet printhead having a plurality of columnar arrays of ink drop generators that have different center to center spacing along a reference axis. The ink jet printhead further includes ink feed slots that are each fluidically connected to only one columnar array of ink drop generators.