Patent Application
20050088479
Inkjet printers generally operate by ejecting ink onto media, such as paper. One type of inkjet printer utilizes an array of inkjet printheads to eject ink onto media. The inkjet printheads within the array are normally immobile relative to each other, and are typically arranged either in-line along the direction of printing or in a staggered fashion relative to each other. As media is moved past the array of inkjet printheads, the printheads accordingly eject ink onto the media. This type of inkjet printer is typically used in industrial setting.
Printing is interrupted when any of the printheads within the array need servicing. Servicing is generally defined as tasks performed to maintain a printhead in proper operating condition such as wiping debris from the printhead, ejecting ink from the printhead, and capping the printhead when not in use. Replacing a printhead that has permanently failed with a properly operating printhead also falls under the general definition of servicing. Unfortunately, interrupting printing to service the array of inkjet printheads delays completion of a print job and can waste significant amounts of ink and media.
The drawings referenced herein form a part of the specification. Features shown in the drawing are meant as illustrative of only some embodiments of the invention, and not of all embodiments of the invention, unless otherwise explicitly indicated, and implications to the contrary are otherwise not to be made.
In the following detailed description of exemplary embodiments of the invention, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific exemplary embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. Other embodiments may be utilized, and logical, mechanical, and other changes may be made without departing from the spirit or scope of the invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the invention is defined only by the appended claims.
Fluid-Ejection Assembly
The arrays 102 and 104 can in one embodiment be arrays of inkjet printheads, such that the assembly 100 is an inkjet assembly. The fluid-ejection assembly 100 preferably is a drop-on-demand fluid-ejection assembly, as opposed to a continuous fluid-ejection assembly commonly referred to as continuous inkjet (CIJ). A drop-on-demand assembly ejects ink as it is to be used to form an image on the media 112, whereas a continuous inkjet assembly continuously ejects ink. The continuously ejected ink is deflected to either impact the media 112 or be directed away from the media 112, in accordance with the image to be formed on the media 112. Drop-on-demand fluid-ejection assemblies include thermal inkjet (TIJ) and piezo inkjet (PIJ) technologies. TIJ technology generally utilizes heat to eject ink, whereas PIJ technology generally utilizes pressure to eject ink.
The first array 102 is connected with the first drive mechanism 106A. The first drive mechanism 106A is moved relative to the first service station 108A and a movable media belt 110 such that the first drive mechanism 106A can move the first array 102 between a first position 152 and a second position 154. In the first position 152, the first array 102 is able to eject fluid onto media 112 traversing in a direction indicated by the arrow 114 on the movable media belt 110, while the array 102 remains stationary, such that the array 102 can be referred to as being normally stationary. The first array 102 is thus positioned over the belt 110 in the first position 152 for fluid ejection, such that the belt 110 moves, with the media 112 thereon, past the first array 102. In the second position 154, the first array 102 is at the first service station 108A, for servicing the first array 102.
The second array 104 is connected with the second drive mechanism 106B. The second drive mechanism 106B is moved relative to the second service station 108B and the movable media belt 110 such that the second drive mechanism 106B can move the second array 104 between and a third position 156 and a fourth position 158. In the third position 156, the second array 104 is able to eject fluid onto the media 112 traversing in a direction indicated by the arrow 114 on the movable media belt 110, while the array 104 remains stationary, such that the array 104 can be referred to as being normally stationary. The second array 104 is thus positioned over the belt 110 in the third position 156 for fluid ejection, such that the belt 110 moves, with the media 112 thereon, past the second array 104. In the fourth position 158, the second array 104 is at the second service station 108B, for servicing the second array 104.
Thus, when the array of fluid-ejection mechanisms 102 is to be serviced, the array 102 moves via the drive mechanism 106A so that it is positioned at the first service station 108A. Similarly, when the array of fluid-ejection mechanisms 104 is to be serviced, the array 104 moves via the drive mechanism 106B so that it is positioned at the second service station 108B. When the array 102 is ejecting fluid on the media 112 moving on the belt 110, the array 104 is not ejecting fluid on the media 112. Similarly, when the array 104 is ejecting fluid on the media 112 moving on the belt 110, the array 102 is not ejecting fluid on the media 112.
As a result, fluid ejection may continue onto the media 112 without having to stop movement of the media 112 when either of the arrays 102 and 104 has to be serviced. The media 112, as being moved on the belt 110, does not have become aware that the array 104 has substituted for the array 102, and vice-versa. That is, the media 112 does not have to slow down when either of the arrays 102 and 104 is serviced. When the array 102 is to be serviced, the array 104 is first moved to the third position 156, so that it can begin ejecting fluid onto the media 112 before the array 102 stops ejecting fluid and is moved to the service station 108A. Similarly, when the array 104 is to be serviced, the array 102 is first moved to the first position 152, so that it can begin ejecting fluid onto the media before the array 104 stops ejecting fluid and is moved to the service station 108B. The array 104 thus ejects fluid in place of the array 102 while the array 102 is being serviced, and the array 102 ejects fluid in place of the array 104 while the array 104 is being serviced.
The drive mechanisms 106 include those components, such as motors, rails, and so on, which enable the arrays 102 and 104 to be moved. In one embodiment of the invention, the drive mechanisms 106A and 106B are automatic linear-actuators. Alternatively, the drive mechanisms 106A and 106B are manually operated bearing rails. The stations 108 include those components, such as wipers, and so on, those enable the arrays 102 and 104 to be serviced either manually or automatically. The media 112 can be cut-sheet paper. Alternatively, the media 112 can be continuous web paper, corrugated boxes, labels, and the like, or another type of media.
The fluid-ejection assembly 100 is pictured in
Method
The method 400 begins when the first array of fluid-ejection mechanisms 102 is moved in the first position 152 (402), such as by the first drive mechanism 106A. The first array 102 then initiates ejection of fluid onto the media 112 from the first position 152 (404). Where the first array 102 does is not to be serviced (406), then the first array 102 continues to eject fluid (408).
Once the first array 102 is to be serviced (406), however, the second array of fluid-ejection mechanisms 104 is moved in the third position 156 (410), such as by the second drive mechanism 106B. Ejection of fluid from the first array 102 is terminated, and ejection of fluid from the second array 104 is initiated from the third position 156 (412). The first array 102 is moved to the second position 154 at the first service station 108A (414), such as by the first drive mechanism 106A, and the first array 102 is serviced (416).
Where the second array 104 does is not to be serviced (418), then the second array 104 continues to eject fluid (420). Once the second array 104 is to be serviced (418), however, the first array 102 is moved back in the first position 152 (422), such as by the first drive mechanism 106A. Ejection of fluid from the second array 104 is terminated, and ejection of fluid from the first array 104 is again initiated from the first position 152 (424). The second array 104 is moved to the fourth position 158 at the second service station 108B (426), such as by the second drive mechanism 106B, and the second array 104 is serviced (428). The method 400 then repeats at 406 as has been described, until the fluid-ejection, or print, job is finished.
It is noted that in one embodiment of the invention, servicing is manually triggered by an operator. An operator may, for instance, trigger servicing upon determining that an array of fluid ejection mechanisms is not properly ejecting fluid onto media 112. In another embodiment of the invention, servicing is automatically triggered, via, for instance, machine-vision inspection detecting that an array of fluid ejection mechanisms is not properly ejecting fluid onto media 112. Alternatively, servicing may be automatically triggered at predetermined intervals.
Fluid-Ejection Device and Conclusion
The fluid-ejection device 500 is operable as has been described in the preceding sections of the detailed description. For instance, where the array 102 is ejecting fluid, the array 104 is not, and vice-versa. Where the arrays 102 and 104 are arrays of inkjet-printing mechanisms, such as inkjet printheads or pens, the fluid-ejection device 500 is specifically an inkjet-printing device, such as an inkjet printer.
It is noted that, although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that any arrangement that is calculated to achieve the same purpose may be substituted for the specific embodiments shown. Other applications and uses of embodiments of the invention, besides those described herein, are amenable to at least some embodiments. This application is intended to cover any adaptations or variations of the invention. Therefore, it is manifestly intended that this invention be limited only by the claims and equivalents thereof.
