The following disclosure relates to the field of printing, and in particular, to carriage assemblies for printers.
Inkjet printing is a type of printing that propels drops of ink (also referred to as droplets) onto a medium, such as paper, a substrate for 3D printing, etc. The core of an inkjet printer includes one or more printheads (also referred to as inkjet heads) having multiple jetting channels arranged in a row to discharge drops of ink. A typical jetting channel includes a nozzle, a chamber, and a mechanism for ejecting the ink from the chamber and through the nozzle, which is typically a piezoelectric actuator connected to a diaphragm. To discharge a drop from a jetting channel, a drive circuit provides a drive waveform to the piezoelectric actuator of that jetting channel that includes a jetting pulse. In response to the jetting pulse, the piezoelectric actuator generates pressure oscillations inside of the chamber to push the drop out of the nozzle. The drive waveforms provided to individual piezoelectric actuators control how drops are ejected from each of the jetting channels.
Shuttle-type printers are a class of printers having a movable shuttle or carriage assembly that reciprocates back and forth across a medium. A printhead is mounted on the carriage assembly, and jetting from the printhead is synchronized with movement of the carriage assembly to print desired images. Movement of the carriage assembly is also synchronized with a medium transfer mechanism that advances the medium through the printer.
It remains an issue for manufacturers to find effective ways to supply ink or another print fluid to printheads in shuttle-type printers.
Embodiments described herein include a carriage assembly for a printer that has one or more printheads, and independent reservoirs that supply a print fluid to the printhead. The reservoirs are mounted on the carriage assembly, and at least one of the reservoirs is offset from the printhead. When the carriage assembly accelerates and decelerates in the scan directions, force is created that causes the print fluid to flow between the reservoirs through the printhead. The motion of the carriage assembly creates a differential pressure between the reservoirs due to the way the reservoirs are mounted in an offset position, and allows ink to flow through the printhead. Thus, the printhead remains primed, and print fluid is able to be circulated through the printhead without the use of a circulation pump.
One embodiment includes an apparatus comprising a carriage assembly of a printer that reciprocates along scan directions. The carriage assembly includes at least one printhead having a row of jetting channels for ejecting a print fluid, and reservoirs mounted on the carriage assembly that each supply the print fluid to the printhead. At least one of reservoirs is mounted on the carriage assembly to be offset from the row of jetting channels.
In another embodiment, the at least one printhead includes manifolds disposed in the printhead along the opposite sides of the row of jetting channels. A first one of the manifolds is fluidly connected to a first one of the reservoirs, and fluidly connected to each of the jetting channels. A second one of the manifolds is fluidly connected to a second one of the reservoirs, and fluidly connected to each of the jetting channels.
In another embodiment, the first one of the manifolds is disposed in the printhead along a first side of the row of jetting channels, and parallels the row of jetting channels. The second one of the manifolds is disposed in the printhead along a second side of the row of jetting channels, and parallels the row of jetting channels.
In another embodiment, the row of jetting channels defines an axis perpendicular to the scan directions of the carriage assembly. A first one of the reservoirs is offset from the axis by a first distance in a first scan direction, and a second one of the reservoirs is offset from the axis by a second distance in a second scan direction that is opposite the first scan direction.
In another embodiment, the first distance and the second distance are equal.
In another embodiment, the row of jetting channels defines an axis perpendicular to the scan directions of the carriage assembly. A first one of the reservoirs is offset from the axis by a first distance in a scan direction, a second one of the reservoirs is offset from the axis by a second distance in the scan direction, and the first distance is different than the second distance.
In another embodiment, the at least one printhead comprises a flow-through printhead.
Another embodiment comprises a carriage assembly of a printer that is configured to reciprocate along scan directions. The carriage assembly includes a printhead having a row of jetting channels for ejecting a print fluid, a first manifold disposed along a first side of the row of jetting channels and fluidly connected to each of the jetting channels, and a second manifold disposed along a second side of the row of jetting channels and fluidly connected to each of the jetting channels. The carriage assembly also includes a first reservoir fluidly connected to the first manifold of the printhead, and a second reservoir fluidly connected to the second manifold of the printhead. At least one of the first reservoir and the second reservoir is offset from the row of jetting channels.
In another embodiment, the first reservoir is mounted on the carriage assembly on the first side of the row of jetting channels, and the second reservoir is mounted on the carriage assembly on the second side of the row of jetting channels.
In another embodiment, the first reservoir and the second reservoir are mounted on the carriage assembly on the first side of the row of jetting channels.
In another embodiment, the row of jetting channels defines an axis perpendicular to the scan directions of the carriage assembly. The first reservoir is offset from the axis by a first distance in a first scan direction, and the second reservoir is offset from the axis by a second distance in a second scan direction that is opposite the first scan direction.
In another embodiment, the first distance and the second distance are equal.
In another embodiment, the row of jetting channels defines an axis perpendicular to the scan directions of the carriage assembly, the first reservoir is offset from the axis by a first distance in a scan direction, the second reservoir is offset from the axis by a second distance in the scan direction, and the first distance is different than the second distance.
In another embodiment, the printhead comprises a flow-through printhead.
Another embodiment includes a printer comprising a carriage assembly comprising a conveyance structure that reciprocates along scan directions within the printer, and at least one printhead mounted on the conveyance structure, where the at least one printhead has a row of jetting channels for ejecting a print fluid. The carriage assembly further includes a first manifold disposed along a first side of the row of jetting channels and fluidly connected to each of the jetting channels, and a second manifold disposed along a second side of the row of jetting channels and fluidly connected to each of the jetting channels. The carriage assembly further includes a first reservoir for storing the print fluid, and a second reservoir for storing the print fluid. At least one of the first reservoir and the second reservoir is mounted on the conveyance structure offset from the row of jetting channels.
The above summary provides a basic understanding of some aspects of the specification. This summary is not an extensive overview of the specification. It is intended to neither identify key or critical elements of the specification nor delineate any scope particular embodiments of the specification, or any scope of the claims. Its sole purpose is to present some concepts of the specification in a simplified form as a prelude to the more detailed description that is presented later.
Some embodiments of the present disclosure are now described, by way of example only, and with reference to the accompanying drawings. The same reference number represents the same element or the same type of element on all drawings.
The figures and the following description illustrate specific exemplary embodiments. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described or shown herein, embody the principles of the embodiments and are included within the scope of the embodiments. Furthermore, any examples described herein are intended to aid in understanding the principles of the embodiments, and are to be construed as being without limitation to such specifically recited examples and conditions. As a result, the inventive concept(s) is not limited to the specific embodiments or examples described below, but by the claims and their equivalents.
Conveyance structure 103 may comprise any desired structure for mounting printhead 104 and reservoirs 108-109. The shape of conveyance structure 103 may vary as desired. In one embodiment, conveyance structure 103 may have the shape or profile of an inkjet cartridge or pen that are used in a printer.
The drops 106 ejected from the nozzles of printhead 104 are directed toward a medium 112. Medium 112 comprises any type of material upon which ink or another print fluid is applied by a printhead, such as paper, card stock, transparent sheets, a substrate for 3D printing, cloth, etc. Typically, nozzles of printhead 104 are arranged in one or more rows so that ejection of print fluid from the nozzles causes formation of characters, symbols, images, layers of an object, etc., on medium 112 as printhead 104 and medium 112 are moved relative to one another. Media transport mechanism 114 moves medium 112 relative to printhead 104.
In this embodiment, image forming apparatus 100 is a shuttle-type apparatus, where carriage assembly 102 reciprocates back and forth across a surface of medium 112 (e.g., left and right in
Image forming apparatus 100 also includes a print controller 122 that communicates with carriage assembly 102, media transport mechanism 114, and carriage movement mechanism 120. Print controller 122 may connect to a data source to receive printable data. Print controller 122 then controls carriage assembly 102, media transport mechanism 114, and carriage movement mechanism 120 to print the printable data on medium 112 via printhead 104.
Printhead 104 also includes fluid ports 320-321. Fluid port 320 provides a pathway to manifold 310 of printhead 104. Fluid port 321 provides a pathway to manifold 311 of printhead 104. Fluid ports 320-321 may be connected (e.g., through a supply hose) to reservoirs 108-109, respectively.
In the embodiments described herein, reservoirs 108-109 are mounted to carriage assembly 102 along with printhead 104, and at least one of reservoirs 108-109 are offset from the row 302 of jetting channels 202. Thus, as carriage assembly 102 reciprocates along the scan directions, acceleration and deceleration of carriage assembly 102 causes a differential pressure between reservoirs 108-109.
In this embodiment, reservoirs 108-109 are mounted on opposite sides of carriage assembly 102, and are offset from the row 302 of jetting channels 202. The arrangement of jetting channels 202 defines an axis 502 for the row 302. Axis 502 represents a line of direction or orientation of jetting channels 202 in the row 302. Reservoir 108 is mounted on side 330 of the row 302 of jetting channels 202, and is offset from axis 502 on side 330. Reservoir 109 is mounted on side 331 of the row 302 of jetting channels 202, and is offset from axis 502 on side 331. To be “offset” means that a center portion of a reservoir is not in-line with the row 302 of jetting channels along axis 502 (or more particularly, not in-line with its corresponding manifold), but is separated from axis 502 or its corresponding manifold by an amount or distance. The sides of the row 302 of jetting channels 202/axis 502 are along the scan directions of carriage assembly 102. For example, reservoir 108 is offset from axis 502 by distance D1 along a first scan direction 510 of carriage assembly 102. Reservoir 109 is offset from axis 502 by distance D2 along a second (opposing) scan direction 511 of carriage assembly 102. The distances D1 and D2 may be equal in a preferred embodiment, but may be different in other embodiments.
When reservoirs 108-109 are offset as in
Although specific embodiments were described herein, the scope of the invention is not limited to those specific embodiments. The scope of the invention is defined by the following claims and any equivalents thereof.
This non-provisional patent application is a continuation of U.S. patent application Ser. No. 15/443,520 filed on Feb. 27, 2017, which is incorporated herein by reference.
Number | Date | Country | |
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Parent | 15443520 | Feb 2017 | US |
Child | 16011589 | US |