Patent Application
20140022319
Embodiments of the present disclosure generally relate to fluid transportation systems, and, more specifically, to systems for transporting ink to multiple print heads of an imaging device.
Fluid transport systems are commonly used to transport different fluids from a supply source to a receptacle. Many fluids require thermal treatment before or during transportation through the fluid transport systems. For example, many imaging devices, including printers, scanners and photocopiers, etc., generally include an ink delivery system that transports thermally treated ink to the different print heads of these devices. Specifically, the heated ink delivery system includes a number of ink reservoirs for supplying different colored ink fluids, and generally, an assembly for transporting the ink from the ink reservoirs to the print heads.
Maintaining thermal uniformity in the ink supplied to the print head, and continuously keeping the ink in molten state and within a desired temperature range during transportation, presents a challenge in many imaging devices. Specifically, depending on the shape and dimensions of the assembly transporting the ink from the reservoirs to the print heads, the ink often solidifies in the middle of transportation path. This situation results in accumulation of solidified ink within the transportion assembly and obstructs its functionality. Further, in many conventional imaging devices, sometimes the ink-supplying reservoirs are remotely located with respect to the print head, and the transportation path traversed by the ink, before reaching the print head, is substantially long. Moreover, if the ink transportation assembly is not insulated, it allows ambient air to extract heat from the molten ink, and eventually, the ink solidifies.
Conventionally, heating mechanisms are deployed and coupled to the ink transportation mechanisms within imaging devices for continuously supplying heat to the transported ink. However, many such mechanisms are only partially effective in continuously maintaining thermal uniformity within the supplied ink. At times, the design layout of the heating mechanisms and the shape complexity of the transportation assembly may lead to development of variations in the temperature of the supplied ink, at different locations in the transportation path.
Among the other conventional attempts to transport molten ink to the print heads smoothly, one such mechanism uses multiple flexible conduits, which receive ink from different ink reservoirs, and are connected to the print heads. The conduits are placed on a heating plate, which supplies heat to maintain the ink in a molten state within the conduits. However, the conduits may dislocate due to movement of the print heads over the printing surface. The dislocation of the conduits detaches certain portions of the conduits from the heating plate, resulting in development of cold spots in those portions.
Therefore, considering the problems mentioned above, there exists a need for a mechanism for maintaining thermal uniformity in the ink supplied from different ink reservoirs to the print heads of an imaging device. Specifically, a need exists for a mechanism that can maintain the supplied ink in molten form, all through the transportation path that leads to the print head.
The present disclosure provides an ink delivery system for transporting ink from one or more ink reservoirs to multiple print heads of an imaging device. The imaging device can be a printing machine, a photocopier, or a scanner, etc. The system maintains thermal uniformity in the transported ink, and keeps the ink in a substantially molten state all through the transportation path.
In one aspect, the present disclosure provides a system for transporting thermally treated ink from different ink reservoirs to multiple print heads of an imaging device. The system includes a rigid injector assembly, and multiple pliable tubes attached to the injector assembly. The injector assembly includes two substantially T-shaped members made of a conducting material. Each of the two members has grooves provided within it. The grooves within one of the members align with the grooves within the other member, to create channels which carry ink to the pliable tubes. Each such channel connects an inlet port and an exit port of the injector assembly. A heating mechanism surrounds the injector assembly, and remains in thermal communication with the ink flowing in the different channels, to keep the ink in molten state within the injector assembly. Further, each exit port of the injector assembly is connected to an upper end of one of the pliable tubes, through a threaded coupling. A lower end of each pliable tube is connected to a print head of the printing device. The pliable tubes are made of a flexible material, such that the lower end of each pliable tube is freely movable with respect to the injector assembly.
The following detailed description is made with reference to the figures. Preferred embodiments are described to illustrate the disclosure, and not to limit its scope, which is defined by the claims. Those of ordinary skill in the art will recognize a variety of equivalent variations on the description that follows.
Ink delivery systems have been used to transport ink from ink reservoirs to multiple print heads in imaging devices, such as printers, scanners, photocopiers, etc. These devices employ different color inks to facilitate color printing. While being transported from the reservoirs to the prints heads, the ink may solidify in certain portions of the transportation path. The solidification of ink obstructs the flow of ink to the print heads of the imaging device. Therefore, the ink is required to be in molten state throughout the transportation process.
Many imaging devices use heating mechanisms to keep the ink in molten form. For example, where the ink delivery systems use different conduits to transport ink from the reservoirs to the print heads, a heating mechanism is used to keep ink flowing within the conduits in a molten state. Heating plates may be attached to these conduits for thermally treating the ink flowing within them. The conduits are flexible, however, and they have a tendency to dislocate, which may produce thermal non-uniformity within the conduits.
The present disclosure presents an effective system for delivering thermally treated ink in an imaging system. The disclosure enables smooth transportation of ink from reservoirs to print heads, and keeps the flowing ink in molten state across the transportation path from the reservoirs to the print heads.
A set of inlet ports 105 (a)-105 (d) is provided at an appropriate location on an upper end of the injector assembly 102. Similarly, multiple exit ports 107 (a)-107 (d) are disposed at a lower end of the injector assembly 102. Multiple channels disposed within the injector assembly 102, (though not shown herein), extend between the inlets ports 105 (a)-105 (d) and the exit ports 107 (a)-107 (d) of the injector assembly 102. Each such channel facilitates the flow of ink from an inlet port to an exit port. Specifically, for example, one such channel extends between and connects the inlet port 105 (a) to the exit port 107 (a). That channel routes the ink from the inlet port 105 (a) to the exit port 107 (a). The ink, in molten form, enters the injector assembly from the inlet ports 105 (a)-105 (d), flows through the different channels, and exits through the exit ports 107 (a)-107 (d). Eventually, the ink is received into the pliable tubes 103 (a)-103 (d) from the exit ports 107 (a)-107 (d).
The injector assembly 102 is surrounded by a heating assembly (
The two heating strips supply heat to the first member 102 (a) and the second member 102 (b), and since the two members are composed of a conducting material, the supplied heat is easily conducted to the ink flowing in the channels within the injector assembly 102. Any other suitable heating mechanism may also be alternatively used, for transferring heat to the ink flowing within the channels of the injector assembly.
The ink delivery system 101 of the present disclosure is divided into multiple heating zones. Specifically, the injector assembly 102 and each of the pliable tubes 103 (a)-103 (d) are confined within different heating zones. Each heating zone includes a heating element that heats the ink flowing through the system within the zone, and a thermistor that controls the temperature of the ink within the zone. The thermistors in the different heating zones control the heat flowing into the zones, by providing a resistive feedback to a control circuit. The heating element includes an electrical resistance that may be a heater strip or a heater wire, which is connected to a current supplying source. On receiving the current from the current source, the heating element generates heat as the current flows through it. In an embodiment, a Kapton heater may be used as the heating element. Those in the art will understand that a Kapton heater is formed by configuring serpentine resistive heating traces on a non-conductive substrate. The watt density of a Kapton heater can be altered by changing the number of traces present on the substrate. Alternative heating elements, such as a silicone heater strip, may also be used for different temperature requirements in different zones, and to address space and cost limitations. A silicone heater strip is an assembly of heating wires encased in silicone.
The pliable tube 103 is made of flexible material, which facilitates the movement of its lower portion with respect to the injector assembly 102, as the print head moves over the imaging surface. Further, the pliable tube 103 includes a conduit 207, which receives ink from one of the exit ports 107 (a)-107(d) (shown in
Each pliable tube 103 has a length above a certain value, to facilitate smooth movement of the lower end of the pliable tube 103 with respect to the print head. The length of the pliable tubes 103 may vary, depending on the size and dimensions of the injector assembly, to facilitate flexible movement of the lower end of the pliable tubes 103 over the printing interface. In a preferred embodiment, the length of the pliable tube is approximately 15 cm. Further, the minimum length of the pliable tube 103, may vary in different embodiments, and is not intended to limit the scope of the present disclosure.
Further, the injector assembly 102 is surrounded by a heating assembly 305, which consists of two elements. Though shown as a consolidated body, the heating assembly 305 consists of a first heating element 305 (a), attached to the first member 102 (a), and a second heating element 305 (b) attached to the second member 102 (b) of the injector assembly 102. As shown, the heating assembly 305 substantially encompasses the injector assembly 102 and is in the form of a resistive heater strip or a heater wire that generates heat in response to an electrical current flowing through it. A power supply source is connected to the heating assembly 305, which supplies current to the heating elements of the heating assembly 305. The insulation layer 307 surrounds the heating assembly 305, to minimize heat losses from the injector assembly 102. Those in the art will understand that any conventionally known insulating material can be used to form the insulation layer 307.
In an embodiment, as shown in
Further, each of the first member 102 (a) and the second member 102 (b) has multiple grooves provided within it. Specifically, as shown, a multiple grooves 501 (a)-501 (d) are provided within the first member 102 (a), and similarly, multiple grooves 507 (a)-507 (d) are provided within the second member 102 (d). Multiple inlet ports 105 (a)-105 (d) are provided over a top portion of the first member 102 (a), to receive ink from different ink reservoirs connected to the injector assembly 102 (though not shown). Specifically, each inlet port 105 is coupled to a reservoir containing ink of a specific color. Similarly, a number of exit ports 107 (a)-107 (d), 505 (a)-505 (d) are provided over a bottom portion of the second member 102 (b), to deliver ink to the pliable tubes 103 (a)-103 (d) (shown in
A gasket material (not shown) is applied before the first member 102 (a) and the second member 102 (b) are aligned. The gasket material helps ensure a sealing connection between each groove pair, which prevents the ink from overflowing from one channel to another.
The ink delivery system of the present disclosure can be used in imaging devices, for delivering ink from different ink reservoirs to multiple print heads. The device may be a printing device, a scanning device, a photocopier, etc. Further, though explained in context of an imaging device, the ink delivery system may also find its applications in other environments, thus, not limiting of its implementation.
Although the current invention has been described comprehensively, in considerable details to cover the possible aspects and embodiments, those skilled in the art would recognize that other versions of the invention are also possible.
