Patent Application
20060146088
The present embodiments relate generally to a service station for a printhead.
In order to maintain the operability of an inkjet printer, it is necessary to periodically service the print heads. One important service which is performed is the cleaning of the print heads. The cleaning of the print heads reduces the buildup of ink on the print head which will dry and clog the jet openings on the print head. In addition, the cleaning of the print head reduces the dust and dirt which can accumulate on the print head and cause clogging. In a typical color inkjet printer, up to six colors of ink in up to six different ink cartridges are used. Typical cleaning methods employed involve jetting ink through all of the print head orifices into a waste receptacle to flush out stagnant ink and prevent drying and clogging. This function is commonly referred to as “spitting”. Wiper blades are also commonly used in many different configurations to scrape away excess ink.
A need exists for a service station that can be used to clean the printhead using vacuum while the printhead is in operation. The vacuum ideally can be applied directly to the orifice plate to provide a pressurized flush function and additionally can be used to remove waste ink generated during spitting. The embodiment of the present application meets these needs.
The present invention provides additional environmental, energy saving and labor savings as compared with the known art.
A service station for an ink jet printer including a print movable carriage supporting at least one printhead with an orifice plate, the service station includes a sled with a plank. The sled is retained in slidable contact with a base unit and wherein the sled has at least one wiper blade; and at least one sealing cap attached to the sled. A selector valve can be mounted to the base unit. The selector valve selectively applies a vacuum from a vacuum source to at least one sealing cap.
The service station operates using a mechanical force from the print moveable carriage and the service station includes, a first operational state having the print moveable carriage entering the service station in a first direction 40, the selector valve applying vacuum to at least one sealing cap to remove spit residue while the printhead is in operation.
A second operational state has the print moveable carriage continuing in the first direction while the sled is in a second position to cap the orifice plate, the selector valve applies vacuum to at least one sealing cap to declog the printhead while the printhead is in operation or to keep the printhead from drying out while the printhead is not in operation.
A third operational state has the print moveable carriage reversing direction while maintaining the sled is held against the print moveable carriage the plank stopping the sled enabling the print moveable carriage to continues in the second direction such that the sled wipes the orifice plate with the wipers as the print moveable carriage leaves the service station and further wherein the print moveable carriage continues in the second direction until it engages the plank, releasing the sled to return to the first operational state.
The present embodiments are advantageous over the prior art because the device provides the use of a selective valve which can apply vacuum for continuous cleaning and efficient ink removable from the printhead while the printhead of the printing system is in operation, and while it is in a deactivated state.
In the detailed description of the preferred embodiments presented below, reference is made to the accompanying drawings, in which:
The present embodiments are detailed below with reference to the listed Figures.
Before explaining the present embodiments in detail, it is to be understood that the embodiments are not limited to the particular descriptions and that it can be practiced or carried out in various ways.
The present embodiments relate generally to a service station for a printhead.
A benefit of the service station with a selector valve and an additional vacuum source is that the orifice plate can be declogged while the printhead is operational, which lowers maintenance costs.
Another benefit of this service station is that this service station is more economical to operate and build than currently known service station which utilizes banks of electronically actuated individual valves.
The service station of the invention is environmentally friendly, in that waste is kept in liquid form to limit the presence of dust by dried ink, thereby improving the air quality for the operators of the printing systems in which the service station is utilized.
Another advantage of the invention is the system does not require a disposable ink receptacle cartridge when the service station of this invention is utilized. This embodiment saves on landfill space, and reduces the need to haul away the waste.
With the present invention, the operators do not have to perform maintenance, which is a significant benefit in creating a cost reduction from traditional methods where operators used hand held vacuum sources to clean the orifice plate and the printheads.
The embodiments of this invention are for a service station for an ink jet printer including a print movable carriage supporting at least one printhead with an orifice plate, the service station includes a sled with a plank. The sled is retained in slidable contact with a base unit and wherein the sled has at least one wiper blade; and at least one sealing cap attached to the sled.
The embodiments of this invention also include a selector valve that can be mounted to the base unit. The selector valve selectively applies a vacuum from a vacuum source to at least one sealing cap.
The service station operates using a mechanical force from the print moveable carriage and the service station. The service station includes, a first operational state having the print moveable carriage entering the service station in a first direction, the selector valve applying vacuum to at least one sealing cap to remove spit residue while the printhead is in operation.
A second operational state has the print moveable carriage continuing in the first direction while the sled is in a second position to cap the orifice plate, the selector valve applies vacuum to at least one sealing cap to declog the printhead while the printhead is in operation or to keep the printhead from drying out while the printhead is not in operation.
A third operational state has the print moveable carriage reversing direction while maintaining the sled is held against the print moveable carriage the plank stopping the sled enabling the print moveable carriage to continues in the second direction such that the sled wipes the orifice plate with the wipers as the print moveable carriage leaves the service station and further wherein the print moveable carriage continues in the second direction until it engages the plank, releasing the sled to return to the first operational state.
With reference to the figures,
The
Additionally, this figure shows a waste ink station 55 wherein waste ink receptacle resides for receiving waste ink removed through the action of the service station.
A sled 18 with the moveable plank 20 is depicted. The moveable plank 20 stops the motion of the sled enabling the orifice plate of the printhead to be wiped by wipers of the sled, removing ink from the orifice plate. The sled is in slidable contact with the base unit 22.
The sled is shown with a group of wipers, which can be wiper blades 24a, 24b, 24c, 24d, 24e and 24f attached to the sled. It is preferred that the sled is a structure that can hold and contain the wipers, the plank, and the sealing caps.
The sled 18, which is moveable, has a protrusion 58. The protrusions 58 is a molded feature of the sled body which makes contact to the movable print carriage of the printing system to transfer motion of the carriage to the sled so that the two units now move in tandem to a first operational state, which is shown in more detail in
A spring 59 is shown. The spring 59 attaches to the base unit 22 on one end and the sled on the other end. This spring 59 is preferably an extension spring, which forces the sled to contract towards the print moveable carriage. The spring 59 enables the sled to maintain contact with the carriage as it moves away from the sled, in a second direction, which is the reverse of the first direction. This spring 59 operates to return the sled to the initial operation position after the carriage exits the service station.
The selector valve 28 is secured to the base unit 22. The selector valve 28 is connected to a vacuum source 32 using tubing 60. The selector valve 28 can selectively apply a vacuum 30 from the vacuum source 32 to at least one sealing cap, and six are shown as sealing caps 26a, 26b, 26c, 26d, 26e, and 26f.
It should be noted that one sealing cap per printhead can be used to remove spit residue from the orifice plate. Any number of printheads with associated sealing caps can be employed in this method and service station.
Spit is ink that is ejected from the printhead for cleaning purposes. Spit is jetted through the orifice plate during normal printing operations.
A sled 18 is depicted in this Figure as well as some of the other elements of the prior Figures. The sled 18 is preferably an injection molded, plastic custom part usable in the printing system provided by any number of normal sources, such as suppliers that perform injection molding of custom parts.
A protrusion 58 of the sled 18 can be seen in the figure. A spring 59 attaches to the sled. A wiper blade 24f is shown next to a sealing cap 26f. The sealing cap is connected by tubing 56f inside the base unit 22. It is preferred that the tubing be flexible, plastic tubing.
It is particularly noted that mechanical force from the print moveable carriage is used to operate the service station.
In this second operational position, the selector valve shown in prior figures, provides vacuum through tubing 56f, selectively applying vacuum through at least one sealing cap 26f The vacuum is used to declog the printhead 14 while the printhead is in operation. The vacuum can be used to keep the printhead 14 from drying out while the printhead is not in operation.
While the print moveable carriage moves in the second direction 42, the sled 18 is held against the print moveable carriage 12 and is then stopped by the plank 20 that was depicted in a prior figure. The action of the plank 20, not shown in
As the print moveable carriage continues in the second direction until it ultimately engages a camming surface of the plank. The plank, when engaged in the second direction releases the sled to return to the first operational state.
At the spool 48 rotates, the holes align with port features in a sleeve 46 that surrounds the spool 48 to selectively apply vacuum to any combination of sealing caps.
The radial hole and groove features in the spool 48 are in fluid communication with the vacuum source and convey vacuum to the valve. The group of hole and groove features 50a, 50b, 50c, 50d, and 50e allow the selection of vacuum application to individual sealing caps.
A sleeve 46 surrounds the spool 48 and allows the spool 48 to rotate within the sleeve. The rotation is preferably a bi-directional rotation. Additional fittings and seals are shown in this Figure.
The selector valve produces a closed state which is a sealed off condition that isolates the sealing caps from any pressure or other influences outside the service station. The selector valve also provides a vacuum connected state to at least one sealing cap for the service station. It is also contemplated that the selector valve can connect to a third state, a venting state for the service station. If the selector provides a venting connection, the valve vents positive pressure generated in the capping action to the atmosphere.
The selector valve preferably is rotationally driven by an actuator shown in
In still another embodiment, it is contemplated that a vacuum can be applied to the caps simultaneously as the orifice plate is wiped.
It is contemplated that the vacuum applied is between 10 and 25 inches of mercury.
Finally, it is contemplated that the vacuum source can be a diaphragm vacuum pump, peristaltic pump, centrifugal pump, or a positive displacement pump.
The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.
