Patent Application
20050110851
The present invention relates generally to inkjet printheads. In particular, it relates to covering air diffusion vents of the printheads with labels positioned in a variety of placement positions. In one aspect, it relates to placement positions depending upon a content of the inkjet printhead. In another aspect, it relates to placement positions according to label dimensions.
The art of inkjet printhead manufacturing is well known. In general, a printhead has a housing or body that defines an interior filled with one or more inks. To prevent enormous pressure build-up during printing, each compartment contains a lung or a foam insert and an air diffusion vent that fluidly communicates the interior to atmospheric pressure. Often times, the air diffusion vent embodies a circuitous or torturous path in the form of a serpentine channel that snakes from a hole fluidly connected to the interior, and formed through a thickness of the housing, to a terminal end thereof. A label, or other covering, typically lays over the hole and portions of the air diffusion vent, but not the terminal ends, to slow the effects of ink evaporation.
Yet, depending upon the printhead type or content, e.g., single ink or multicolored, the number and placement of air diffusion vents for the housing of any given printhead changes. Thus, no commonality exists in the housing design which further prevents commonality from existing in the placement position and dimensions of the label over the air diffusion vents. This increases manufacturing costs.
Accordingly, the art of printhead manufacturing has a need for minimizing manufacturing costs, especially a need for a common printhead housing and label placement scheme regardless of content or type.
The above-mentioned and other problems become solved by applying the principles and teachings associated with the hereinafter described inkjet printheads having multiple label placement positions for attendant air diffusion vents.
Specifically, the present invention teaches methods, and the resultant apparatus, for placing labels over air diffusion vents on inkjet printheads depending upon a content of the inkjet printhead. In one embodiment, the inkjet printhead has a body containing a single ink in its interior. Its lid, which adheres to the body, has three air diffusion vents that fluidly communicate with the interior to alleviate backpressure build-up during use. In a first label placement position, a label covers the entirety of two of the three air diffusion vents to substantially prevent the two air diffusion vents from communicating with atmosphere. In another embodiment, the interior has three inks. In a second label placement position, a label only covers a portion of each of the three air diffusion vents and allows each to fluidly communicate with atmosphere. In this manner, only a single lid is required for manufacturing single or tri-color inkjet printheads thereby saving on manufacturing costs.
In further embodiments, the labels themselves have similar dimensions or dissimilar length dimensions. If similar, the label covers some or none of the air diffusion vents by positioning the label in one of two positions adjusted from one another along an axial length of the lid. If dissimilar, the label covers some or none of the air diffusion vents according to the length dimension of the label.
In still other embodiments, the label embodies a two layer laminate structure with a layer of polyester over a layer of polypropylene. The label preferably adheres to a top surface of the lid and the air diffusion vents include serpentine channels formed therein. Inkjet printers are also disclosed for housing the inkjet printheads.
These and other embodiments, aspects, advantages, and features of the present invention will be set forth in the description which follows, and in part will become apparent to those of ordinary skill in the art by reference to the following description of the invention and referenced drawings or by practice of the invention. The aspects, advantages, and features of the invention are realized and attained according to the methods and apparatuses particularly pointed out in the appended claims.
a is a partial perspective view in accordance with the present invention of an inkjet printhead lid and a label over a portion of an air diffusion vent;
b is a cross-section view in accordance with the present invention of the inkjet printhead lid of
In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration, specific 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, and it is to be understood that other embodiments may be utilized and that process or other changes may be made without departing from the scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims and their equivalents. In accordance with the present invention, methods and apparatus are hereinafter described for inkjet printheads having multiple label placement positions for attendant air diffusion vents regardless of printhead content or type.
With reference to
A portion 191 of a tape automated bond (TAB) circuit 201 adheres to one surface 181 of the housing while another portion 211 adheres to another surface 221. As shown, the two surfaces 181, 221 exist perpendicularly to one another about an edge 231.
The TAB circuit 201 has a plurality of input/output (I/O) connectors 241 fabricated thereon for electrically connecting a heater chip 251 to an external device, such as a printer, fax machine, copier, photo-printer, plotter, all-in-one, etc., during use. Pluralities of electrical conductors 261 exist on the TAB circuit 201 to electrically connect and short the I/O connectors 241 to the bond pads 281 of the heater chip 251 and various manufacturing techniques are known for facilitating such connections. It will be appreciated that while eight I/O connectors 241, eight electrical conductors 261 and eight bond pads 281 are shown, any number are embraced herein. It is also to be appreciated that such number of connectors, conductors and bond pads may not be equal to one another.
The heater chip 251 contains at least one ink via 321 that fluidly connects to a supply of ink in an interior of the housing. Typically, the number of ink vias of the heater chip corresponds one-to-one with the number of ink types contained within the housing interior. The vias usually reside side-by-side or end-to-end. During printhead manufacturing, the heater chip 251 preferably attaches to the housing with any of a variety of adhesives, epoxies, etc. well known in the art. As shown, the heater chip contains four rows (rows A-row D) of resistive heating elements, or heaters. For simplicity in this crowded figure, dots depict the heaters in the rows and typical printheads contain hundreds of heaters. It will be appreciated that the heaters of the heater chip preferably become formed as a series of thin film layers made via growth, deposition, masking, photolithography and/or etching or other processing steps. A nozzle plate, not shown, with pluralities of nozzle holes adheres over or is fabricated with the heater chip during thin film processing such that the nozzle holes align with the heaters for ejecting ink during use.
With reference to
In the print zone, the carriage 421 reciprocates in the Reciprocating Direction generally perpendicularly to the paper Advance Direction as shown by the arrows. Ink drops from the printheads are caused to be ejected from the heater chip 251 (
To print or emit a single drop of ink, the heaters (the dots of rows A-D,
As described herein, the term inkjet printhead may alternatively include piezoelectric technology, or other, and may embody a side-shooter structure instead of the roof-shooter structure shown.
With reference to
In a first label placement position, a label 22 adheres or attaches to the top surface of the lid with a suitable epoxy or other adhesive. From the figure, those skilled in the art should observe the label in this position covers or resides over an entire length or entirety of the air diffusion vents 16-1, 16-2 but only covers a portion (between the ink fill hole 18 and point 24) of the air diffusion vent 16-3. As a result, the air diffusion vents 16-1, 16-2 cannot fluidly communicate or are prevented from fluidly communicating with atmospheric pressure during use while the air diffusion vent 16-3 is allowed fluid communication with atmosphere because its terminal end is exposed thereto. As a representative example, a manufacturer would place the label in this position if it needed a single air diffusion vent to fluidly communicate with atmosphere such as when the inkjet printhead contains an ink(s) in its interior, e.g., a single or mono-colored ink, less in number than the number of air diffusion vents.
In a second label placement position (
In other embodiments, the label may become positioned such that the terminal ends 20-1 and 20-2 are exposed while an entirety of the air diffusion vent 16-3 is covered. A manufacturer would consider this position if the inkjet printhead contents only included two inks, for example. In still other embodiments, the air diffusion vents exist two or more in number and the label becomes placed to allow all or less than all of them to fluidly communicate with atmosphere. Alternatively, the label becomes placed to prevent some or none of the air diffusion vents from fluidly communicating with atmosphere.
At this point, skilled artisans should appreciate that no matter what the contents of the inkjet printhead include, e.g., a single or a multiplicity of inks, a lid having multiple air diffusion vents can have multiple label placement positions to cause varieties of the air diffusions vents to fluidly communicate with atmosphere or not. In this manner, an inkjet printhead can have a common housing, regardless of content, and still have relatively simple manufacturing processes. In turn, manufacturers save on costs. In addition, skilled artisans should appreciate that a placement position of prior art labels occurred as a single predetermined design point, having some given manufacturing tolerance, such that labels on sequentially manufactured printheads allowed all of the air diffusion vents to communicate with atmosphere although each individual label might not have become positioned in the same exact relative position. In contrast, the first and second placement positions of the present invention are multiple predetermined design points, not merely slop-induced tolerance positions, which enable labels to become selectively placed in such a manner on the printhead to cover or not the entirety of some of the air diffusion vents.
In other embodiments, with reference to
In
In
As seen in
The foregoing description is presented for purposes of illustration and description of the various aspects of the invention. The descriptions are not intended to be exhaustive or to limit the invention to the precise form disclosed. For example, other disassembled components may include laser printheads instead of the described inkjet printhead. Nonetheless, the embodiments described above were chosen to provide the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally and equitably entitled.
