AU4091400A - Page-width printhead - Google Patents

Page-width printhead Download PDF

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Publication number
AU4091400A
AU4091400A AU40914/00A AU4091400A AU4091400A AU 4091400 A AU4091400 A AU 4091400A AU 40914/00 A AU40914/00 A AU 40914/00A AU 4091400 A AU4091400 A AU 4091400A AU 4091400 A AU4091400 A AU 4091400A
Authority
AU
Australia
Prior art keywords
printhead
elements
end portions
page
width
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
AU40914/00A
Other versions
AU772083B2 (en
Inventor
Kia Silverbrook
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Memjet Technology Ltd
Original Assignee
Memjet Technology Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from AUPP9933A external-priority patent/AUPP993399A0/en
Application filed by Memjet Technology Ltd filed Critical Memjet Technology Ltd
Priority to AU40914/00A priority Critical patent/AU772083B2/en
Publication of AU4091400A publication Critical patent/AU4091400A/en
Application granted granted Critical
Publication of AU772083B2 publication Critical patent/AU772083B2/en
Priority to AU2004202999A priority patent/AU2004202999B2/en
Assigned to MEMJET TECHNOLOGY LIMITED reassignment MEMJET TECHNOLOGY LIMITED Request to Amend Deed and Register Assignors: SILVERBROOK RESEARCH PTY LTD
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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  • Particle Formation And Scattering Control In Inkjet Printers (AREA)

Description

WO 00/64680 PCT/AU00/00340 -1 PAGE-WIDTH PRINTHEAD Field of the Invention The present invention relates to a page-width printhead for an ink printer. 5 Background of the Invention Page width printheads for ink printers typically are formed from a plurality of individual printhead elements (sometimes referred to as "chips"), with each printhead element having a plurality of ink ejection nozzles formed therein. 10 Because a plurality of individual printhead elements is employed in any one printhead, achievement of a uniform print or print tone along the entire length of the printhead has so far been practically impossible. Non-uniformities or variations occur due to minor differences in the ink ejection nozzles in adjacent printhead elements and such variations may even occur when the elements originate from a single wafer due to 15 inherent variations in process parameters that arise during the production of elements on a single wafer. It is known that even slight variations in the print determining characteristics of adjacent elements in a page-width printheads will diminish the quality of the resultant print significantly, as the differences between adjacent areas of a print will be 20 "amplified" in the visual perception of the print. Summary of the Invention In accordance with a first aspect of the present invention there is provided a page-width printhead for an ink printer. The printhead comprises a series of individual 25 printhead elements, each having an array of ink ejection nozzles formed therein. The series of printhead elements extends substantially across the width of the printhead, with respective end portions of adjacent elements being located side by side in overlapping relationship. A dithering unit is provided for controlling the ejection of ink from ink nozzles of the printhead elements and the dithering unit is arranged, in use, to provide 30 an interpolation between the characteristics of a pair of printhead elements across the length of the overlapping end portions of the pair of printhead elements. In one embodiment of the invention, the elements are positioned obliquely with respect to one another to form a row of lapped elements. In another embodiment, the elements are arranged in at least two parallel rows, 35 with the elements in each row being spaced apart from one another and with the end portions of each element in one row overlapping the end portions of adjacent elements in the adjacent row.
WO 00/64680 PCT/AU00/00340 -2 In accordance with a second aspect of the present invention there is provided a method of controlling the ejection of ink from a page-width printhead as above defined, the method comprising the step of effecting an interpolation between the characteristics of a pair of printhead elements across the length of the overlapping end portions of the 5 pair of printhead elements. Description of the Drawings Notwithstanding any other forms which may fall within the scope of the present invention, preferred forms of the invention will now be described, by way of example 10 only, with reference to the accompanying drawings, in which: Figs. la and b are schematic illustrations of arrangements for positioning a number of printhead elements in a single printhead row. Fig. 2 illustrates a printhead embodying the present invention. Fig. 3 illustrates a graph of dither probabilities for use with the printhead of 15 Fig. 2. Fig. 4 illustrates a second printhead embodying the present invention. Fig. 5 illustrates a third printhead embodying the present invention. Description of Preferred Embodiments 20 As shown in Fig. la, a CMOS processed wafer incorporating ink ejection nozzles 100 is initially diced into printhead elements 1 and tested for functionality of the ink-jet nozzles. The testing can take various forms from full ink ejection test to optical examination of device operation. Once a determination is made of the operational characteristics of each ink ejection nozzle, the elements are joined together into a longer 25 inkjet printhead row 3 as illustrated in Fig. lb. The printhead row 3 can include eight half-inch elements 1 and one quarter inch element 2 which are joined together. Each element 1 and 2 contains an array of a large number of the ink ejection nozzles 100. Next, as shown in Fig. 2, parallel printhead rows 5 and 6 are positioned side by-side so as to form a printhead 102. The two printhead rows 5 and 6 are located with 30 respect to each other such that respective end portions 104 and 106 of adjacent elements of the two rows 5 and 6 are located side by side in overlapping relationship. Further, the element boundaries 9 of the printhead row 5 are positioned so as not to coincide with the element boundaries 108 of the printhead row 6. In each of the printhead rows 5 and 6 it is likely that neighbouring elements 35 110 and 112 will have slightly different characteristics which, if each printhead row was utilised as an individual printhead, would result in unacceptable variations in printing across the width of a page. If the element 110 were to be taken from a first wafer and WO 00/64680 PCT/AU00/00340 -3 the element 112 taken from a second wafer, large variations across the element boundaries would be likely. In the printhead 102 however, a dithering unit 114 is provided to control the ejection of ink from the nozzles 7 of the printhead 102. The dithering unit 114 is 5 arranged to provide an overlap dithering matrix for the printhead rows 5 and 6. Various dithering schemes may be adopted. One probability interpolation 12 for use in the provision of the overlap dithering matrix is as illustrated in Fig. 3. In an alternative embodiment illustrated in Fig. 4, a printhead 200 comprises two rows 202 and 204 of spaced apart printhead elements 206 and 208, the elements 10 each being provided with an array of ink ejection nozzles 210. The printhead further comprises a dithering unit 212 which is arranged to provide integral dithering matrices for pairs of respective end portions 214 and 216 of adjacent elements 206 and 208 of the rows 202 and 204. In regions 222 of the printhead 200 between the overlapping end portions, the dithering unit 210 is arranged to provide dithering matrices for centre 15 portions 224 of the individual elements. Fig. 5 shows an alternative embodiment for a printhead 300 which comprises a row of individual printhead elements 302 positioned obliquely with respect to one another. The printhead 300 further comprises a dithering unit 304 for controlling the ejection of ink from ink ejection nozzles 305 of the elements 302 of the printhead 300. 20 The dithering unit 304 in this embodiment is arranged to provide integral dithering matrices for pairs of respective end portions 314 and 316 of adjacent elements 302 and 320. In regions 322 of the printhead 300 between the overlapping end portions, the dithering unit 304 is arranged to provide dithering matrices for centre portions 324 of the individual elements. 25 It will be appreciated by a person skilled in the art that numerous variations and/or modifications may be made to the present invention as shown in the specific embodiments and the attached appendices without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects to be illustrative and not restrictive.

Claims (4)

1. A page-width printhead for an ink printer, the printhead comprising a series of individual printhead elements, each having an array of ink ejection nozzles 5 formed therein, the series of printhead elements extending substantially across the width of the printhead, with respective end portions of adjacent elements being located side by side in overlapping relationship, a dithering unit being provided for controlling the ejection of ink from the ink ejection nozzles of the printhead elements and the dithering unit being arranged, in use, to provide an 10 interpolation between the characteristics of a pair of printhead elements across the length of the overlapping end portions of the pair of printhead elements.
2. The page-width printhead as claimed in claim 1 wherein the elements are positioned obliquely with respect to one another to form a row of lapped 15 elements.
3. The page-width printhead as claimed in claim 1 wherein the elements are arranged in at least two parallel rows, with the elements in each row being spaced apart from one another and with the end portions of each element in one 20 row overlapping the end portions of adjacent elements in the adjacent row.
4. A method of controlling the ejection of ink from a page-width printhead having a series of individual printhead elements each formed with an array of ink ejection nozzles, the series of printhead elements extending substantially across 25 the width of the printhead with respective end portions of adjacent elements being located side by side in overlapping relationship, the method comprising effecting an interpolation between the characteristics of a pair of printhead elements across the length of the overlapping end portions of the pair of printhead elements. 30
AU40914/00A 1999-04-22 2000-04-20 Page-width printhead Ceased AU772083B2 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
AU40914/00A AU772083B2 (en) 1999-04-22 2000-04-20 Page-width printhead
AU2004202999A AU2004202999B2 (en) 1999-04-22 2004-07-01 Page-width printhead

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
AUPP9933A AUPP993399A0 (en) 1999-04-22 1999-04-22 Micro-mechanical system fabrication method(mems16)
AUPP9933 1999-04-22
AU40914/00A AU772083B2 (en) 1999-04-22 2000-04-20 Page-width printhead
PCT/AU2000/000340 WO2000064680A1 (en) 1999-04-22 2000-04-20 Page-width printhead

Related Child Applications (1)

Application Number Title Priority Date Filing Date
AU2004202999A Division AU2004202999B2 (en) 1999-04-22 2004-07-01 Page-width printhead

Publications (2)

Publication Number Publication Date
AU4091400A true AU4091400A (en) 2000-11-10
AU772083B2 AU772083B2 (en) 2004-04-08

Family

ID=25625368

Family Applications (1)

Application Number Title Priority Date Filing Date
AU40914/00A Ceased AU772083B2 (en) 1999-04-22 2000-04-20 Page-width printhead

Country Status (1)

Country Link
AU (1) AU772083B2 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AUPQ595900A0 (en) * 2000-03-02 2000-03-23 Silverbrook Research Pty Ltd Modular printhead

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0034060A1 (en) * 1980-02-08 1981-08-19 The Mead Corporation Ink jet printer
US5160945A (en) * 1991-05-10 1992-11-03 Xerox Corporation Pagewidth thermal ink jet printhead
DE69705015T2 (en) * 1996-12-19 2001-11-15 Agfa Gevaert Nv One-pass printer for large format media

Also Published As

Publication number Publication date
AU772083B2 (en) 2004-04-08

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Legal Events

Date Code Title Description
MK1 Application lapsed section 142(2)(a) - no request for examination in relevant period
TH Corrigenda

Free format text: IN VOL 16, NO 35, PAGE(S) 7544 UNDER THE HEADING APPLICATIONS LAPSED, REFUSED OR WITHDRAWN PLEASE DELETE ALL REFERENCE TO PATENT APPLICATION NO.S 40912/00, 40914/00 AND 40915/00

FGA Letters patent sealed or granted (standard patent)
MK14 Patent ceased section 143(a) (annual fees not paid) or expired