Patent Application
20070132392
Various types of electronic devices require an array of electronic cells. For example, plasma displays require a two-dimensional array of display cells. The individual display cells of a plasma display each include a number of electronic components which cooperate to provide an individually addressable pixel. In a plasma cell, a combination of electrodes excites a gas into a plasma state where the plasma radiates at ultraviolet wavelengths. The ultraviolet emissions are converted by a phosphor into visible light, for example, using phosphors which emit red, green, or blue light. Components of a plasma cell can include electrodes, dielectric regions, gas enclosures, and phosphors. Plasma displays are often fabricated on a pair of flat substrates. A first, rear substrate is processed to create geometric features of the array of display cells, for example, to define individual plasma regions for each cell. The geometric features can be formed by sand blasting or etching. Various electronic components are formed on the first substrate, such as electrodes and dielectrics using lithographic and other techniques. A second, front substrate is typically bonded to the first substrate to create chambers which can enclose a gas in which a plasma can be formed. Components, such as electrodes and phosphors may also be disposed on the second substrate. Unfortunately, processing large substrates in this manner has proven difficult and expensive. Although advancements in the manufacturability and cost of large plasma displays using flat substrate construction have been achieved, these displays are still difficult to make. Furthermore, there is a desire to manufacture very large displays, and existing techniques do not scale up well to larger sizes.
An alternate approach to manufacturing plasma displays has been to use fiber technology. Long tubes can be drawn from glass and filled with gas. Electrodes can be deposited on the outside or threaded inside the tubes. Unfortunately, manufacturing displays using this approach has also proven difficult. For example, using this construction approach, the geometric configuration of the display cell is relatively limited. Consequently, optimizing the placement and arrangement of display cell components is difficult to achieve. For example, it is difficult to ensure that primary radiation emitted by the plasma discharge is efficiently coupled into the secondary emission region, since most of the components are placed on the outside of the tube. Since one of the electrodes is generally outside the tube, it is difficult to find a placement which provides good coupling to the primary emitting region. Additionally, non-uniformity in tube dimensions and relative position of electrodes and tubes can result in large variation in operational parameters such as drive voltage and firing voltage from tube to tube. Tubular displays have thus been somewhat limited in various performance aspects in comparison to substrate based displays.
More generally, techniques for fabrication of arrays of electronic components are generally limited. Many electronic devices are fabricated using semiconductor processing techniques on planar crystalline wafers. These wafers are fragile and require special packaging and handling of the completed devices. Semiconductor processing techniques do not scale well to large dimensions, for example as desired for plasma displays.
The present invention includes multi-cell electronic circuit array devices and fabrication techniques which help to overcome problems and deficiencies inherent in the prior art.
Generally, the present invention describes multi-cell electronic circuit arrays and techniques for their manufacture. In accordance with the invention as embodied and broadly described herein, the present invention features a multi-cell electronic circuit array. The multi-cell electronic circuit array includes an elongate substrate having a linear array of first electronic cell components microfabricated thereon. The linear array of first electronic cell components is inserted into a tubular enclosure which has at least one second electronic cell component to interact with the linear array of first electronic cell components. Because structures and circuitry can be microfabricated on the linear array and then placed into the tubular enclosure, many degrees of freedom are obtained in the design of a multi-cell electronic circuit array.
The present invention further features a plasma display. The plasma display includes a plurality of parallel gas enclosure tubes, which contain linear arrays of plasma cell components inserted therein.
The present invention still further features a method for fabricating a multi-cell electronic circuit array.
The present invention will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. Understanding that these drawings merely depict exemplary embodiments of the present invention they are, therefore, not to be considered limiting of its scope. It will be readily appreciated that the components of the present invention, as generally described and illustrated in the figures herein, can be arranged and designed in a wide variety of different configurations. Nonetheless, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:
a illustrates a side perspective view of a plasma display tube according to another embodiment of the present invention;
b illustrates an end cross-sectional view of a plasma display cell of
c illustrates a side cross-sectional view of the plasma display cell of
a illustrates an end-on perspective view of an alternate arrangement of a plasma display tube according to an embodiment of the present invention;
b illustrates an end-on exploded perspective view of the plasma display tube of
The following detailed description of exemplary embodiments of the invention makes reference to the accompanying drawings, which form a part hereof and in which are shown, by way of illustration, exemplary embodiments in which the invention may be practiced. While these exemplary embodiments are described in sufficient detail to enable those skilled in the art practice the invention, it should be understood that other embodiments may be realized and that various changes to the invention may be made without departing from the spirit and scope of the present invention. Thus, the following more detailed description of the embodiments of the present invention is not intended to limit the scope of the invention, as claimed, but is presented for purposes of illustration only and not limitation to describe the features and characteristics of the present invention, to set forth the best mode of operation of the invention, and to sufficiently enable one skilled in the art to practice the invention. Accordingly, the scope of the present invention is to be defined solely by the appended claims.
The following detailed description and exemplary embodiments of the invention will be best understood by reference to the accompanying drawings, wherein the elements and features of the invention are designated by numerals throughout.
With reference to
The elongate substrate 12 is inserted into the tubular enclosure 14. The elongate substrate is shown partially inserted in
The tubular enclosure 14 has at least one second electronic cell component 18 which interacts with the first electronic cell components 17 to form an array of electronic circuits. For example, the tubular enclosure can include a plurality of second electronic cell components microfabricated thereon. Each second electronic cell component can interact and cooperate with a corresponding first electronic cell component. Various types of electronic cell components, including semiconductor devices, electrical interconnect, phosphors, and the like can be included.
Various first electronic cell components 17 can be fabricated on the elongate substrate 12. For example, electronic circuits can be microfabricated as discussed in further detail below. As another example, electronic circuits can also be microfabricated on the outer surface of the tubular enclosure to provide one or more second electronic cell components 18. As yet another example, electronic interconnect elements can be fabricated on the elongate substrate and outer surface of the tubular enclosure.
Electronic circuitry on the elongate substrate can cooperate with the second cell component(s) on the tubular enclosure to form detector or emitter circuits. For example, a micro-vacuum tube can be created for operation in the THz region, such as a klystron. As additional examples, Geiger tubes, electron or ion amplifiers, electro-optic detectors, photomultiplier tubes, charge coupled devices, image converters, and image intensifiers can be fabricated for operation at various wavelengths. As further examples, gas discharge light sources, spark discharge light sources, vacuum fluorescent light emitting elements, and gas to ion lasers can also be created. Fluidic control devices, using effects such as electro wetting of fluid on dielectric, can also be fabricated.
Because the linear array of first electronic cell components are microfabricated on the elongate substrate, detailed electronic circuits can be placed into the tubular enclosure. For example, the first electronic cell components can be highly integrated, providing high circuit density. By placing the electronic components within the tubular enclosure, various advantages can be obtained. For example, by immersing components of a detector or emitter in a gas or liquid contained within the tubular enclosure, lead lengths can be shortened and other effects achieved. A gas or gas mixture within the tubular enclosure can be optimized for particular applications (e.g. plasma display or fluorescent lighting).
A first detailed example of a multi-element electronic circuit array will now be described in accordance with an embodiment of the present invention.
The electrical capacitance of each capacitor 72 will depend on the size of the electrodes 66, 70 and the electrical properties of the tubular enclosure 62, elongate substrate 64, and surrounding environment. When an object, such as a finger, is placed in proximity to a pair of electrodes, this will cause the capacitance of the corresponding capacitor to change by an amount dependent upon the electrical properties of the object. Accordingly, the position of the object can be sensed based on which pair (or pairs) of electrodes show a changed capacitance as measured by the electronic circuit 74. Various electronic circuits for measuring capacitance are known in the art and will not be discussed further.
For example, a one-dimensional position sensing array can determine the position along the length of the capacitive touch sensor 60 by measuring capacitance between the first electrical conductor 68 and each of the plurality of second electrical conductors 72. The position of the touch can be determined from which one or more of the capacitors 70 have changed value.
As another example, a two-dimensional position sensing array can be constructed using a number of parallel capacitive touch sensors 60. The first electrical conductors 68 can be used as rows. Columns of second electrodes 70 can be connected in series though shared second electrical conductors 74 across the parallel tubular enclosures to form columns to provide row-column addressing. The position of a touch can thus be determined from the row-column pair (or pairs) which exhibit a changed capacitance.
As another example, a multi-cell electronic circuit array can be a plasma display tube as will now be described in accordance with an embodiment of the present invention.
The plasma cell of
The display cell also includes a primary emission region 32. For example, the primary emission region can include MgO to help enhance ultraviolet discharge emission from the plasma and allow reduced operating voltage. Electrodes 34 are disposed longitudinally along the elongate substrate 22, beneath the primary emission region. The electrodes can be placed close to the primary emission region, helping to enhance efficiency over prior art display cells.
A dielectric material 35 may be disposed between the electrodes 34 and the primary emission region 32 to enhance the coupling between the electrodes and the primary emission region. The electrodes are used to stimulate surface charge in the primary emission region which in turn stimulates the gas to form a plasma discharge. Various techniques for applying voltages to the electrodes to initiate, sustain, and terminate plasma discharge are known in the art which can be applied in the context of the present invention.
In general, microfabricating the cell components on an insertable substrate helps to avoid problems with previous attempts to insert coatings or elements into the interior of a display tube. Because the cell components can be precisely positioned on the insertable substrate, the geometry of the plasma display cell can be optimized to provide increased efficiency. Inclusion of components, such as specific electrode shapes, dielectric regions, and secondary emission materials is made possible, providing a large degree of design freedom to design the plasma display cell for desired properties.
Continuing the discussion of the plasma display cell, disposed on the tubular enclosure 28 is a secondary emission region 36. Alternately, the secondary emission region can be disposed on the inside of the tubular enclosure as is discussed further below. The secondary emission region can include a phosphor, which converts the ultraviolet emission into visible light, and is thus placed opposite the primary emission region. Quartz, fused silica, certain polymers, or other ultraviolet transparent materials can be used for the tubular enclosure. A protective coating may also be included over the secondary emission region to help protect the phosphor from exposure to the environment.
Note that the geometry of the cell defined by the substrate 22 can be configured to place the primary emission region in relatively close proximity to the secondary emission region. This helps to ensure that the primary emission is absorbed and converted by secondary emission region, rather than being absorbed by the cell separating structure 30 or other parts of the display cell. Accordingly, the efficiency of the display cell is increased.
Various phosphors are known which convert ultraviolet into red, green, and blue visible light. The plasma display tube 20 can be constructed with all of the plasma cells having the same color phosphor, for example, by applying a strip of phosphor along one side of the tubular enclosure. Alternately, the plasma display tube can be constructed with different color phosphors by microfabricating a linear array of discrete phosphor regions, selecting alternate colors for each successive cell. The tubular enclosure can also include an electrode 38. For example, display cell addressing can be performed using the combination of the electrodes 34, 38 as discussed for a plasma display below.
An alternate embodiment of a plasma display tube is illustrated in perspective view in
The first substrate 104 is inserted into the enclosure subassembly 102. The first substrate is a hollow tube, for example, in the form of a glass tube. Disposed along the outer side are two coplanar electrodes 112a, 112b. The tube includes a cutout section 114 to expose an inner wall of the tube. Disposed on the inner wall of the tube is a dielectric region 116, for example, Magnesium Oxide. The coplanar electrodes and dielectric region can be formed, for example, by cylindrical lithography.
The second substrate 106 is inserted into the first substrate 104. The second substrate includes cell separating structure 116 and a phosphor rod 118. The cell separating structure helps to define the plasma cell boundary, confining the plasma within the region defined by the cell separating structure and the inner surface of the tubular enclosure 108. The plasma display tube 100 can include a gas disposed within the tube, filling the region, for example as described above. The ends can be sealed, for example, using a cap or plug.
The plasma display tube 100 functions similarly as described above. Surface charge is created on the dielectric region 116 by the coplanar electrodes 112, which in turn excites the gas to form a plasma. Addressing of individual cells within the plasma display tube can use the combination of electrodes 110, 112a, 112b. The plasma emits ultra violet light, which is converted by the phosphor 118 into visible light, which can radiate out of the plasma cell.
The cell separating structure 116 can be an ultraviolet-opaque material, which helps to confine the ultraviolet radiating to the inside of the cell, reducing leakage into adjacent cells. Furthermore, the phosphor 118 is placed in close proximity to the dielectric region 114, helping to improve the efficiency of conversion of ultra-violet light into visible light.
One benefit of the plasma display tube 150 as just described is that the electrode rods 156 can be placed very close to the phosphor rods 158, providing efficient conversion of ultraviolet light into visible light.
Plasma display tubes can be formed into a plasma display panel as will now be described.
As yet another embodiment of the present invention, a capacitance touch sensor and a plasma display can be combined in a single unit as will now be described. For example,
A method of manufacturing a multi-cell electronic circuit array will now be described, as illustrated in
The method 50 also includes the step of (b) providing 54 a tubular element having a bore and having at least one second electronic cell component. The method may also include microfabricating a linear array of second electronic cell components on the tubular element. For example, microfabrication can be performed as described above to form plasma cell components, electrical interconnects, or the like on or in the tubular element.
The method 50 also includes the step of (c) inserting 56 the linear array of first electronic cell components into the tubular element to form a multi-cell electronic circuit array.
The method 50 may also include evacuating the tubular element to remove gases or other material present within the tube. The tubular element may then be sealed, or filled with a gas or liquid and then sealed.
The foregoing detailed description describes the invention with reference to specific exemplary embodiments. However, it will be appreciated that various modifications and changes can be made without departing from the scope of the present invention as set forth in the appended claims. The detailed description and accompanying drawings are to be regarded as merely illustrative, rather than as restrictive, and all such modifications or changes, if any, are intended to fall within the scope of the present invention as described and set forth herein.
More specifically, while illustrative exemplary embodiments of the invention have been described herein, the present invention is not limited to these embodiments, but includes any and all embodiments having modifications, omissions, combinations (e.g., of aspects across various embodiments), adaptations and/or alterations as would be appreciated by those in the art based on the foregoing detailed description. The limitations in the claims are to be interpreted broadly based the language employed in the claims and not limited to examples described in the foregoing detailed description or during the prosecution of the application, which examples are to be construed as non-exclusive. For example, in the present disclosure, the term “preferably” is non-exclusive where it is intended to mean “preferably, but not limited to.” Any steps recited in any method or process claims may be executed in any order and are not limited to the order presented in the claims. Means-plus-function or step-plus-function limitations will only be employed where for a specific claim limitation all of the following conditions are present: a) “means for” or “step for” is expressly recited in that limitation; b) a corresponding function is expressly recited in that limitation; and c) structure, material or acts that support that function are described within the specification. Accordingly, the scope of the invention should be determined solely by the appended claims and their legal equivalents, rather than by the descriptions and examples given above.
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/749,779 filed on Dec. 12, 2005, entitled “Multi-cell Electronic Circuit Array and Method of Manufacturing” which is herein incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| 60749779 | Dec 2005 | US |
