JP4426755B2 - Print engine including air pump - Google Patents

Abstract

A pump assembly for a print engine, where the print engine has a printhead (590) employing a fluid cleaning arrangement such as filtered air, includes a housing defining a fluid inlet (526) and a fluid outlet (528). An impeller (522) is arranged within the housing for drawing fluid through the inlet and ejecting it through the outlet. A drive motor (530) rotatably drives the impeller. The drive motor is also the drive motor of the print engine, which controls feeding of print media (504) to the printhead for printing of an image on the print media.

Description

[0001]
TECHNICAL FIELD The present invention relates to a print engine. The present invention is particularly applicable to a print engine for instantaneous printing applications such as a digital camera. More particularly, the present invention relates to such a print engine pump assembly.
[0002]
Background of the invention The page width printhead of the present invention uses a nozzle guard that ejects ink droplets. It is important to keep the nozzle guard free from foreign particles and debris so that the ink is not contaminated by foreign matter and the microelectromechanical system (MEMS) ink jetting device is not blocked by foreign matter. One simple way to accomplish this is to blow air to the surface of the nozzle guard and the area between the nozzle guard and the silicon wafer surface of the print head on which the MEMS device is mounted.
[0003]
“Page width” means that when the print media moves past the printhead, the printhead prints one line at a time without traversing or rastering the print media.
[0004]
Furthermore, in order to reduce the size of the camera in which the print engine is employed, it is desirable to make the print engine as compact as possible.
[0005]
Summary of the Invention
In accordance with the present invention, there is provided a pump assembly for a print engine having a print head employing an apparatus for fluid cleaning of the print head, the pump assembly including a housing defining a fluid inlet and a fluid outlet, and the inlet An impeller configured to draw fluid through and eject fluid through the outlet to accomplish fluid cleaning of the printhead, and rotating the impeller and printing the print media to print an image on the print media Drive means also serving as drive means for the print engine for controlling supply to the head.
[0006]
Said inlet may be in communication with a filter means for filtering fluid by means of a connecting device in the form of an air injection pin. Filter means is received in the print cartridge for replacement when the print cartridge is replaced. This allows air blown by the pump assembly onto the print head to be filtered before being blown out of the pump assembly.
[0007]
The pump includes a housing that rotatably mounts the impeller, and a part of the housing is defined by a chassis that supports the connecting device, and the housing defines a fluid supply path that supplies fluid to the print head. May be.
[0008]
The drive means may be a drive motor connected by a first gear assembly to the impeller and connected by a second gear assembly to means for supplying a print roll of a print cartridge of the print engine. Preferably, the drive motor is a stepping motor and supplies fluid to the print head only when the print head is in operation.
[0009]
Detailed description of the drawings The invention will now be described by way of example with reference to the accompanying drawings.
[0010]
In the figure, reference numeral 500 generally refers to a print engine according to the present invention. The print engine 500 includes a print engine assembly 502 on which a print roll cartridge 504 is removably mounted.
[0011]
The print cartridge 504 is described in detail in the applicant's co-pending applications “print cartridge” (reference number CA02) and “ink cartridge” (reference number CA04). These are simultaneously filed as international applications PCT / AU00 / 00741 and PCT / AU00 / 0742, respectively, the contents of which are incorporated herein by reference.
[0012]
The print engine assembly 502 has a first subassembly 506 and a second printhead subassembly 508.
[0013]
Subassembly 506 includes a chassis 510. The chassis 510 has a first molding 512 in which an ink supply channel 514 is molded. Ink supply channel 514 supplies ink from print cartridge 504 to printhead 516 (FIGS. 5-7) of printhead subassembly 508. The print head 516 prints ink that is visible only in four colors or three colors plus infrared spectrum (hereinafter referred to as “infrared ink”). Accordingly, a four color ink supply channel 514 is defined with an air supply channel 518 within the molding 512. The air supply channel 518 supplies air to the print head 516 and prevents foreign particles from accumulating on the nozzle guard of the print head 516.
[0014]
Chassis 510 further includes cover molding 520. Cover molding 520 supports pump 522 thereon. The pump 522 is a suction pump, and draws air through an air filter in the print cartridge 504 via the air injection pin 524 and the air injection opening 526. Air is expelled through the discharge opening 528 to the air supply channel 518 of the chassis 510.
[0015]
The chassis 510 further supports a first motor in the form of a stepping motor 530. The stepping motor 530 drives the pump 522 through the first gear train 532. The stepping motor 530 is also connected to the drive roller 534 (FIG. 5) of the roller assembly 536 of the print cartridge 504 via the second gear train 538. The gear train 538 engages an engageable element 540 (FIG. 2) supported on the end of the drive roller 534. Thereby, the stepping motor 530 controls the feeding of the print media to the print head 516 of the subassembly 508, and allows an image to be printed on the print media as it passes under the print head 516. Note also that while stepping motor 530 simply operates to advance print media 542, pump 522 simply blows air over print head 516 when printed on print media 542. Should.
[0016]
The molding 512 of the chassis 510 also supports a plurality of ink supply channels in the form of pins 544 that communicate with the ink supply channels 514. Ink supply pins 544 are received through the elastic collar assembly of the print cartridge 504 to draw ink from the ink chamber or reservoir 548 (FIG. 5) in the ink cartridge 504 and supply it to the print head 516.
[0017]
The second motor 550 is a DC motor and is supported by the cover molding 520 of the chassis 510 by a clip 552. A motor 550 is provided to drive a detaching means in the form of a cutter arm assembly 554 to detach the piece of print media from the remaining print media after the image has been printed. The motor 550 supports a bevel gear 556 on its output shaft. Bevel gear 556 meshes with bevel gear 558 supported on worm gear 560 of cutter assembly 554. The worm gear 560 is rotatably supported in the chassis base plate 564 of the printhead subassembly 508 by bearings 562.
[0018]
The cutter assembly 554 includes a cutter wheel 556 supported on an elastically flexible arm 568 on a mounting block 570. The worm gear 560 passes through the mounting block 570 in such a manner that when the worm gear 560 is rotated, the mounting block 570 and the cutter wheel 566 cross the chassis base plate 564. The mounting block block 570 rests against the lip 572 of the base plate 564 to prevent the mounting block 570 from rotating relative to the worm gear 560. Further, the cutter wheel 566 rests against a housing or cap portion 574 above the printhead subassembly 508 so that the print media 542 can be effectively separated. The cap part 574 is a metal part. Thus, when the cutter wheel 566 crosses the cap portion 574, a cutting action such as scissors is applied to the print media, and the portion of the print media 542 on which the image is printed is cut.
[0019]
Subassembly 506 includes an ejector mechanism 576. The ejector mechanism 576 is supported on the chassis 510 and includes a collar 578 having a clip 580 that fastens and secures the ejector mechanism 576 to the chassis 510. The collar 578 supports an insert 582 of elastic material therein. The elastic insert 582 defines a plurality of openings 584. The opening 584 partitions the injection opening of the pin 544 to prevent foreign particles from entering the pin 544, thereby preventing entry into the channel 514 or the print head 516. In addition, the insert 584 defines a land or platform 586 that partitions the inlet opening of the air inlet opening 524 for the same purpose.
[0020]
A coil spring 588 is disposed between the chassis 510 and the collar 578 so that when the cartridge 504 is removed from the print engine 500 as shown in detail in FIG. To be in position. FIG. 4 shows a position where the ejector mechanism 576 is retracted.
[0021]
Printhead subassembly 508 includes a base plate 564 as described above. The capping mechanism 590 is movably supported on the base plate 564 and can move toward and away from the print head 516. Capping mechanism 590 includes elongated ribs 592 disposed on carrier 593. The carrier is supported by a movement mechanism 594 that moves the rib 592 to a position adjacent to the print head 516 when the print head 516 is not activated. Conversely, when the print head 516 is operating, the movement mechanism 594 operates to retract the rib 592 from a position adjacent to the print head 516.
[0022]
Printhead subassembly 508 includes a printhead support molding 596 on which printhead 516 is mounted. Molding 596, along with inserts disposed within molding 596, defines a passage 598 through which print media 542 passes when an image is printed. A groove 700 is defined in the molding 596, and the capping mechanism 590 protrudes through the groove 700 when the capping mechanism 590 is in the cap position.
[0023]
The ink supply means 702 is supported by the insert 599 under the cap portion 574. The ink supply unit 702 includes a spine portion 704 and a case 706 mounted on the spine portion 704. The spine 704 and the case 706 define an ink supply path 708 therebetween that communicates with the ink supply channel 514 in the chassis 510 and supplies ink to the print head 516 through the passage 710 (FIG. 7).
[0024]
An air supply channel 711 (FIG. 8) is defined in the spine 704 along the print head 516.
[0025]
An electrical signal is supplied to the print head 516 via the TAB film 712 that is restrained and held between the insert 599 and the ink supply means 702.
[0026]
Molding 596 includes a bent wing 714. A flexible circuit board (PCB) 716 is supported and fixed on the wing portion 714. The flexible PCB 716 is in electrical contact with the TAB film 712 by being engaged with the TAB film 712 by the ribs 718 of the insert 599. The flexible PCB 716 supports the bus bar 720 thereon. The bus bar 720 supplies power to the print head 516 and other electric components of the print engine 500. In addition, a camera print engine control chip 721 is supported on a flexible PCB 716 along with a QA chip (not shown), which ensures that the cartridge 504 is compatible and compliant with the print engine 500. For this purpose, PCB 716 includes a contact 723 that contacts a contact 725 in print cartridge 504.
[0027]
As shown in more detail in FIG. 7, the print head itself includes a nozzle guard 722 disposed on a silicon wafer 724. Ink is supplied to a nozzle array (not shown) of the print head 516 via an ink supply member 726. The ink supply member 726 communicates with the outlet of the passage 710 of the ink supply unit 702, and supplies ink to the nozzle array of the print head 516 as required.
[0028]
10, the air supply path for supplying air to the print head 516 is shown in detail. As shown, pump 522 includes an impeller 728 that is closed by an end cap 730. Chassis cover molding 520 forms a receptacle 732 for impeller 728. The cover molding 520 has an air inlet opening 734 and an air outlet opening 736. Air injection opening 734 is in communication with pin 524. The air exhaust opening 736 supplies air to the air supply channel 518, which is indicated by a solid black line in FIG. Air supplied from the air supply channel 518 is blown into the print head 516 to clean the print head. The air drawn by the pump 522 is filtered by the air filter 738 and put into the print cartridge 504. The air filter 738 has a filter element 740 made of paper base or other suitable filtering media. Filter element 740 is housed in a canister having a base 742 and a lid 744. An opening 746 is defined in the lid 744. The opening 746 is closed by a film 748 through which the pin 524 passes. An advantage of having the air filter 738 on the print cartridge 504 is that when the print cartridge 504 is replaced, the air filter 738 is also replaced.
[0029]
It is an advantage of the present invention that an air pump is driven by a stepping motor 530, which also controls the supply of print media to the print head 516. By doing so, it is possible to reduce the parts required for the print engine and make it more compact. In addition, the same motor 530 used to operate the air pump is used to supply the print media 542 to the print head 516, thereby saving the power contained in the print engine 500 and making the print engine more compact and inexpensive. Can be manufactured.
[0030]
It should also be noted that to make the print engine 500 more compact, the size of the print engine assembly 502 is sized so that many parts of the assembly 502 fit within the bottom surface of the print cartridge 504.
[0031]
A person skilled in the art can produce many variations and / or modifications of the invention, as illustrated by the specific embodiments, without departing from the spirit and scope of the invention as broadly described. Is understood. Accordingly, the above embodiment is illustrative in all respects and not restrictive.
[Brief description of the drawings]
FIG. 1 is a three-dimensional view of a print engine including components according to the present invention.
FIG. 2 is an exploded view of the print engine.
FIG. 3 is a three-dimensional view of the print engine with a removable print cartridge removed.
FIG. 4 is a three-dimensional view of the print engine as viewed from the rear, and the print cartridge is indicated by a dotted line.
FIG. 5 is a three-dimensional view showing a cross section of the print engine.
FIG. 6 is an exploded view of a print engine subhead of a print engine.
FIG. 7 is a cut away view of a printhead subassembly.
FIG. 8 is a cross-sectional view of the printhead subassembly and the capping mechanism in the cap position.
FIG. 9 is a cross-sectional view of the printhead subassembly and the capping mechanism in an uncapped position.
FIG. 10 is an exploded view of an air supply device of a print engine.

Claims (4)

A pump assembly for a print engine having an inkjet printhead employing an air cleaning device,
A housing defining an air inlet and an air outlet;
Draws air through the inlet, the impeller of the order is ejected air through said outlet,
With rotatably driving the impeller, a drive means also serving as a driving means of the print engine for controlling the supply of said print medium relative to said print head for printing an image on print media,
Equipped with a pump assembly. The inlet, the connecting device, in communication with the filter means that applying a filter to the air pump assembly of claim 1. The impeller is mounted rotatably to the housing, a portion of said housing, said defined by chassis supporting the connecting device, the housing defines a fluid supply passage for supplying the air to the printhead The pump assembly according to claim 2. It said drive means is a drive motor, the drive motor, together with being connected to the impeller by a first gear unit, the second gear device to the means for supplying the printing roll of the print cartridge of the print engine Ru is connected through Tei, pump assembly according to claim 1.

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