Source: http://www.google.com/patents/US6979078?ie=ISO-8859-1
Timestamp: 2015-01-25 12:42:14
Document Index: 117959713

Matched Legal Cases: ['arts 36', 'arts 36', 'arts 13', 'art 7', 'art 7', 'art 7', 'art 7', 'art 7', 'art 7']

Patent US6979078 - Ink-jet head with ink blockage prevention device - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign inAdvanced Patent SearchPatentsAn ink-jet head includes a plurality of nozzles, a plurality of pressure chambers corresponding to the nozzles and connected to the nozzles, a common ink chamber for supplying ink to the pressure chambers, a supply passage for supplying ink to the common ink chamber, a plurality of connection passages...http://www.google.com/patents/US6979078?utm_source=gb-gplus-sharePatent US6979078 - Ink-jet head with ink blockage prevention deviceAdvanced Patent SearchPublication numberUS6979078 B2Publication typeGrantApplication numberUS 10/430,313Publication dateDec 27, 2005Filing dateMay 7, 2003Priority dateMay 7, 2002Fee statusPaidAlso published asDE60302278D1, DE60302278T2, EP1361062A2, EP1361062A3, EP1361062B1, US7401905, US20030210305, US20060023034Publication number10430313, 430313, US 6979078 B2, US 6979078B2, US-B2-6979078, US6979078 B2, US6979078B2InventorsAtsushi Ito, Hisaki SakuraiOriginal AssigneeBrother Kogyo Kabushiki KaishaExport CitationBiBTeX, EndNote, RefManPatent Citations (10), Referenced by (3), Classifications (7), Legal Events (3) External Links: USPTO, USPTO Assignment, EspacenetInk-jet head with ink blockage prevention deviceUS 6979078 B2Abstract An ink-jet head includes a plurality of nozzles, a plurality of pressure chambers corresponding to the nozzles and connected to the nozzles, a common ink chamber for supplying ink to the pressure chambers, a supply passage for supplying ink to the common ink chamber, a plurality of connection passages corresponding to the respective pressure chambers, one ends of which are connected to the common ink chamber and the other ends of which are connected to the respective pressure chambers, a first member forming the common ink chamber, and a second member connected to the first member and having openings of the connection passages aligned in a surface at a side of the first member. A projection of an opening, positioned at a most downstream end in an ink flowing direction from the supply passage in the common ink chamber, on the first member in a connecting direction straddles a contour of the common ink chamber.
a supply passage for supplying the ink to the common ink chamber;
a plurality of connection passages provided correspondingly to the respective pressure chambers, one ends of which are connected to the common ink chamber and the other ends of which are connected to the respective pressure chambers;
a first member forming the common ink chamber; and
a second member connected to the first member and having openings of the connection passages formed to be aligned in a surface at a side of the first member,
wherein an opening among the openings, which is positioned at a most downstream end of the common ink chamber in a flowing direction of the ink through the supply passage, straddles a contour of the common ink chamber of the first member at the most downstream end of the common ink chamber, such that the first member projects over the opening.
2. An ink-jet head according to claim 1, wherein an opening area of the opening positioned at the most downstream end in the flowing direction of the ink from the supply passage in the common ink chamber is largest among the openings.
3. An ink-jet head according to claim 1, wherein a wall part of the common ink chamber partially overlaps with all the openings constituting the openings.
a slender common ink chamber for distributing and supplying ink to the pressure chambers;
a second member being adjacent to the first member and having openings of the connection passages formed to be aligned in a surface at a side of the first member,
wherein when the first member and the second member are connected to each other, an opening positioned at one end of the common ink chamber in an alignment direction of the openings is partially covered by an area of the first member forming an end of the common ink chamber in a longitudinal direction.
5. An ink-jet head according to claim 4, wherein an opening area of the opening positioned at the end in the alignment direction is largest among the openings.
6. An ink-jet head according to claim 4, wherein when the first member and the second member are connected to each other, all the openings are partially closed by an area of the first member forming a wall part of the common ink chamber.
wherein among the openings, only a part of an opening positioned at a most downstream end of the common ink chamber in a flowing direction of the ink through the supply passage and at one side in an alignment direction faces the most downstream end of the common ink chamber.
8. An ink-jet head according to claim 7, wherein an opening area of the opening positioned at the most downstream end in the flowing direction of the ink from the supply passage in the common ink chamber is largest among the openings.
9. An ink-jet head according to claim 7, wherein only a part of each of all the openings faces the common ink chamber.
As described above, since the ink stagnates at the end of the common ink chamber at the most downstream side, the removal of the air bubbles has been difficult even by the foregoing purge mechanism. Accordingly, there has been a problem that it becomes necessary to frequently repeat the purge operation by the purge mechanism, a large amount of ink is wastefully consumed, and the running cost rises,
SUMMARY OF THE INVENTION An object of the invention is to provide an ink-jet head in which air bubbles are not easily collected in ink at a connection portion between a common ink chamber and a connection passage, and even if they are collected, they can be easily discharged by a purge mechanism.
FIG. 7 is an exploded perspective view showing a VII�VII section of FIG. 6;
FIG. 8 is a view of a VIII�VIII section of FIG. 5;
FIG. 15 is a plan view of another example in which all openings are disposed to overlap with a wall part of a common ink charter;
FIG. 18 is an exploded perspective view showing a section taken along line XVIII�XVIII of FIG. 17; and
FIG. 19 is a sectional view showing a structure of a passage of the ink-jet head of the second embodiment,
DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, four piezoelectric ink-jet heads 6 in total provided for respective colors in order to eject color inks of four colors (for example, cyan, magenta, yellow and black) are fixed to a main body frame 68 of a printer head 63 of a color ink-jet printer 100. Further, four ink cartridges 61 in which the color inks are respectively filled are detachably attached to the main body frame 68. This main body frame 68 is fixed to a carriage 64 which is reciprocated in a linear direction by a driving mechanism 65. A platen roller 66 for feeding a sheet of paper 62 is disposed so that its rotation axial line becomes parallel with a reciprocating movement direction of the carriage 64, and is opposite to the ink-jet head 6.
FIG. 6 is an exploded perspective view of the passage unit 10, and FIG. 7 is an exploded enlarged perspective view (section in a VII�VII direction of FIG. 6) of the passage unit 10. As shown in FIGS. 6 and 7, the passage unit 10 has a structure in which six thin metal plates in total, that is, a nozzle plate 11, a damper plate 12, two manifold plates 13X and 13Y, a spacer plate 14, and a base plate 15 are respectively overlapped and bonded through adhesives and are laminated,
As shown in FIG. 7, a plurality of pressure chambers 36, 36 are disposed in two rows in a staggered arrangement along the longitudinal direction of the base plate 15. Each of the pressure chambers 36 is formed to be slender so that its longitudinal direction is orthogonal to the longitudinal direction of the base plate 15. Besides, as shown in FIGS. 7 to 9, throttle parts 36 d connected to the respective pressure chambers 36 and ink introduction holes 36 b connected to the throttle parts 36 d are concavely provided at the side of the base plate 15 facing the spacer plate 14.
In this structure, three plates in total, that is, the two manifold plates 13X and 13Y and the spacer plate 14 are laminated, so that the corresponding upper and lower ink chamber halt parts 13 a and 13 b are mutually connected, and one at each of both sides of the row of the through holes 37, that is, the two common ink chambers 7 and 7 in total are formed as shown in FIGS. 8 and 9.
As shown in FIG. 6, two supply holes. 39 a and 39 a are bored in the base plate 15, and also in the spacer plate 14, supply holes 39 b and 39 b are similarly bored. The corresponding supply holes 39 a and 39 b are mutually connected by coupling the base plate 15 and the spacer plate 14, and ink supply passages 39 and 39 corresponding to the two common ink chambers 7 and 7 are formed.
As shown in FIGS. 12 and 13A, the plurality of openings 38 a are arranged substantially along the longitudinal direction of the common ink chamber 7. In other words, the common ink chamber 7 is extended in the alignment direction of the openings 38 a. The ink supplied from the ink cartridge 61 to the common ink chamber 7 branches out and is introduced into the ink supply holes 38 through the openings 30 a as indicated by thick arrows of FIG. 13, and flows substantially along the alignment direction of the openings 38 a from one end side (side of the ink supply passage 39) of the common ink chamber 7 to the other end side.
By this, even in the case where the ink supplied into the common ink chamber 7 reaches the end 7 a of the common ink chamber 7 at the most downstream side, it does not stagnate at the end 7 a and is introduced from the opening 38 x into the ink supply hole 38 (see a thick arrow of FIG. 13B). Accordingly, even if air bubbles are mixed into the common ink chamber 7 and are moved to the vicinity of the end of the common ink chamber 7 (the end 7 a at the downstream side), the air bubbles are apt to be smoothly discharged through the opening 38 x positioned at the most downstream side. Accordingly, since the discharge property of air bubbles is improved in the purge operation, it is possible to avoid a blank of a print surface (missing dot) due to non-ejection of ink from the nozzle 35 at the time of printing operation,
Besides, in the embodiment, although all of the openings 38 a, 38 a, . . . of the ink supply holes 38 at the side of the common ink chamber 7 have the same size, the invention is not limited to this. That is, as shown in FIG. 14, an opening 38 x′ of the openings 38 a, 38 a, . . . at the most downstream side may have the largest opening area among the openings 38 a, 38 a, . . . .
By this, even if a bonding shift slightly occurs at the time when the manifold plates 13X and 13Y and the spacer plate 14 are laminated, the end 7 a of the wall part of the common ink chamber 7 at the most downstream side becomes hard to deviate from the opening 38 x′ at the most downstream side. That is, even if a position shift slightly occurs between the upper manifold plate 13X and the spacer plate 14, the merit of the invention can be certainly exhibited in which the ink flow to the opening 38 x′ at the most downstream side is ensured and the discharge property of air bubbles in the vicinity of the wall part of the end 7 a of the common ink chamber 7 at the most downstream side is improved.
In this case, although air bubbles mixed in the common ink chamber 7 are apt to accumulate at the end 7 a (the ink trap part 7 t) of the common ink chamber 7 at the most downstream side, since the plane distance P1 between the opening 38 x at the most downstream side and the end 7 a of the common ink chamber 7 at the most downstream side is not less than the arrangement pitch P of the ink supply holes 38 (not less than the arrangement pitch P of the openings 36 a) and is sufficiently large (P1≧P), the volume of the ink trap part 7 t can be sufficiently ensured. That is, there does not occur such a state that the air bubbles accumulated at the end 7 a at the most downstream side exceed the volume of the ink trap part 7 t in a short time and close the opening 38 x at the most downstream side.
In the examples of FIGS. 13 to 16, the common ink chamber 7 has a tapered part 7 b at the downstream side. In the tapered part 7 b, the cross-sectional area of the common ink chamber 7 is reduced toward the end 7 a at the most downstream side. Accordingly, both at the time of printing operation and at the time of purge operation by the purge mechanism 67, the flow rate of the ink flow in the common ink chamber 7 at the downstream side end (the portion of the tapered part 7 b) is increased toward the end 7 a at the most downstream side. As a result, it becomes easy to forcibly push out the air bubbles to the opening 38 x (38 x′) at the most downstream side, and also in this meaning, the discharge property of air bubbles in the common ink chamber 7 is improved,
FIGS. 17 to 19 show an ink-jet head 6′ of a second embodiment. In the ink-jet head 6′, its passage unit 10′ has a structure in which five flat plates in total, that is, a nozzle plate 11, two manifold plates 13X and 13Y′, a spacer plate 14, and a base plate 15′ are laminated. That is, the damper plate 12 in the first embodiment is omitted. Since the structure of the nozzle plate 11, the upper manifold plate 13X, and the spacer plate 14 are quite equal to the first embodiment, their description will be omitted.
Also in the ink-jet head 61 of the second embodiment as stated above, the structure as shown in FIGS. 12 to 16 can be similarly applied to the connection portions between the common ink chamber 7 and the ink supply holes 38. As a result, the discharge property of air bubbles in the common ink chamber 7 is improved, and it is possible to prevent a trouble, such as non-ejection of ink due to air bubbles, from occurring.
Patent CitationsCited PatentFiling datePublication dateApplicantTitleUS4418355 *Jan 4, 1982Nov 29, 1983Exxon Research And Engineering Co.Ink jet apparatus with preloaded diaphragm and method of making sameUS6168265Mar 26, 1998Jan 2, 2001Brother Kogyo Kabushiki KaishaInk-jet print headUS6270205Mar 27, 1998Aug 7, 2001Brother Kogyo Kabushiki KaishaInk-jet print head with ink supply channelUS6361155Jun 23, 2000Mar 26, 2002Nec CorporationInk jet recording head and method for manufacturing the sameUS20020042993Aug 28, 2001Apr 18, 2002Shigeru UmeharaInk jet recording head and method for manufacturing the sameUS20020051038Oct 26, 2001May 2, 2002Brother Kogyo Kabushiki KaishaManifold plate of ink jet headEP0695638A2Aug 4, 1995Feb 7, 1996Seiko Epson CorporationInk jet recording headEP0774356A2Nov 13, 1996May 21, 1997Fuji Xerox Co., Ltd.Ink jet print head, ink jet printer and method for maintaining ink jet print headJPH10264377A Title not availableJPH10272770A Title not available* Cited by examinerReferenced byCiting PatentFiling datePublication dateApplicantTitleUS7681996 *Dec 27, 2006Mar 23, 2010Fujifilm CorporationLiquid ejection head, method of manufacturing liquid ejection head, and image forming apparatusUS8083331 *Oct 2, 2008Dec 27, 2011Brother Kogyo Kabushiki KaishaPiezoelectric actuator, liquid ejection head, and method for manufacturing piezoelectric actuatorUS8523321 *May 9, 2008Sep 3, 2013Brother Kogyo Kabushiki KaishaLiquid droplet jetting apparatus and recording apparatus* Cited by examinerClassifications U.S. Classification347/71International ClassificationB41J2/14Cooperative ClassificationB41J2002/14225, B41J2002/14217, B41J2/14209, B41J2002/14419European ClassificationB41J2/14D1Legal EventsDateCodeEventDescriptionMar 18, 2013FPAYFee paymentYear of fee payment: 8May 21, 2009FPAYFee paymentYear of fee payment: 4Sep 28, 2005ASAssignmentOwner name: BROTHER KOGYO KABUSHI KAISHA, JAPANFree format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:ITO, ATSUSHI;SAKURAI, HISAKI;REEL/FRAME:016846/0061Effective date: 20050909RotateOriginal ImageGoogle Home - Sitemap - USPTO Bulk Downloads - Privacy Policy - Terms of Service - About Google Patents - Send FeedbackData provided by IFI CLAIMS Patent Services