Patent EP0339926B1 successfully refreshed from Google Patents.
EP0339926B1
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Drop-on-demand printhead
Assignee: Xaar Ltd
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Filing: 1989-04-25
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Granted: 1993-06-16
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Expires: 2009-04-25
Abstract
Abstract A drop-on-demand ink jet printhead (1) comprises a body formed with a series of parallel ink channels (16) with respective ink ejectors (18) formed in a row at corresponding channel ends and having means for ejecting ink drops from the channels. A housekeeping manifold (50) is fitted to the ejector ends of the channels (16) and affords a trench (53) extending parallel with the row of ejectors (18) through which the ejectors discharge drops. Openings in the trench connect (53) the trench with the manifold (50) and duct means (112,114) in the body serve for supplying environmental fluids to and exhausting such fluids from the region of the ejectors by way of the trench (53), the openings and the manifold (50).
Inventors
- 👤 Anthony David Paton
- 👤 Stephen Temple
- 👤 Mark Richard Shepherd
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 18:06
CPC Classifications
B; B41; B41J; B41J2/00; B41J2/005; B41J2/01; B41J2/135; B41J2/14; B41J2/14201; B41J2/145; B41J2/155; B41J2202/00; B41J2202/01; B41J2202/02; B41J2202/20
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
192 words
A drop-on-demand ink drop printhead for selectively printing drops of ink in a print line on a web or sheet movable relatively to the printhead, comprising layers (22,24,26,32,34,36,38,42,44,46,48,49) of like modules (10a, 10b, 10c) of which contiguous modules in respective adjacent layers are equally laterally offset, characterised in that said modules are formed each with a row (19) of parallel directed uniformly spaced ink drop ejectors (18) providing at least one group of ejectors, said groups of ejectors in each of the layers being of equal span laterally and spaced apart by the same amount equal to the product of said span and the reciprocal of one less than the number of layers thereby to provide laterally offset groups in the layers having corresponding segments numbering one less than the number of layers together capable of depositing drops of ink in a particular segment of the print line at a density which is the same for all segments of the print line and is further equal to the product of the drop deposition capability of the groups of ejectors and the number of groups having segments corresponding to said print line segment.
Claim 2
Dependent Claim
42 words
A drop-on-demand printhead as claimed in Claim 1, characterised in that ink drop ejectors (18) of the groups are disposed so that drops deposited from segments of ejector groups corresponding with a particular print line segment are interleaved in the print line.
Claim 3
Dependent Claim
42 words
A drop-on-demand printhead as claimed in Claim 1 or Claim 2, characterised in that the print modules are formed in stacks (20a,20b,20c,20d) of one module (20a,20b,20c,20d) per layer and the stacks are disposed in side by side relationship to form the printhead.
Claim 4
Dependent Claim
24 words
A drop-on-demand printhead as claimed in Claim 3, characterised in that locating means are provided on the modules for assembling the modules into stacks.
Claim 5
Dependent Claim
34 words
A drop-on-demand printhead as claimed in any preceding claim, characterised in that each module normal to the parallel ink ejectors thereof is of rectangular section elongated in the direction of the row of ejectors.
Claim 6
Dependent Claim
53 words
A drop-on-demand printhead as claimed in any preceding claim, characterised in that the modules are provided with electronic means for actuating the ink ejectors thereof, said means being adapted differentially to delay ejection of ink drops from the ejector groups of the layers to effect printing of ejected drops on the print line.
Claim 7
Dependent Claim
24 words
A drop-on-demand printhead as claimed in any preceding claim, characterised in that the ink ejectors of the modules are piezo-electrically actuated in shear mode.
Claim 8
Dependent Claim
44 words
A drop-on-demand printhead as claimed in Claim 7, characterised in that the piezo-electrically actuated ejectors each includes parallel side walls which each separate one from the next of the ink channels one at least of which side walls being actuable to effect drop ejection.
Claim 9
Dependent Claim
39 words
A drop-on-demand printhead as claimed in any preceding claim, characterised in that make-up ink supply means of the modules comprise a riser extending through corresponding modules of the module layers which communicates in each module with the ink ejectors.
Claim 10
Dependent Claim
28 words
A drop-on-demand printhead as claimed in Claim 9, characterised in that in each module the riser connects with manifold means which in turn connect with the ink ejectors.
Claim 11
Dependent Claim
39 words
A drop-on-demand printhead as claimed in any one of Claims 3 to 8, characterised in that each module is formed with two spaced groups of ink ejectors and with duct means between said groups for supplying make-up ink thereto.
Claim 12
Dependent Claim
52 words
A drop-on-demand printhead as claimed in Claim 11, characterised in that the ink supply duct means (108) extend through each module transversely to the module layer and terminate in openings (105,107) which communicate with openings of modules in adjacent module layers there being provided between said communicating openings, liquid tight sealing means.
Claim 13
Dependent Claim
62 words
A drop-on-demand printhead as claimed in any preceding claim, characterised in that air supply duct means (112,114) of the modules comprise a passage extending through corresponding modules of the module layers transversely to said layers which communicates in each module with a duct which opens at the drop ejection end of the module adjacent the ejector apertures of the ink drop ejectors.
Claim 14
Dependent Claim
98 words
A drop-on-demand printhead as claimed in any preceding claim, characterised in that each module (10) is formed with two spaced groups of ink ejector (16) and with air supply duct means (112,114) therebetween, said air supply duct means comprising a passage section extending through the module transversely to the module layer and a duct which connects with said passage section and opens at the drop ejection end of the module between said groups, the arrangement being such that the passage sections of corresponding modules in the module layers form a continuous air supply passage through the module layers.
References Cited (Backward Citations)
US4612554A
Cited
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