Auxiliary chamber

Information

  • Patent Grant
  • 6590338
  • Patent Number
    6,590,338
  • Date Filed
    Tuesday, February 29, 2000
    24 years ago
  • Date Issued
    Tuesday, July 8, 2003
    21 years ago
Abstract
An apparatus for removing contaminants from a display device using an auxiliary chamber, and a method for attaching the auxiliary chamber to the display device. In one embodiment, an auxiliary chamber is adapted to be coupled to a surface of a display device. The auxiliary chamber is adapted to be coupled to the surface of the display device such that contaminants within the display device can travel from the display device into the auxiliary chamber. The auxiliary chamber further includes a getter which is disposed therein. The getter is adapted to capture the contaminants once the contaminants travel from the display device into the auxiliary chamber. In so doing, the present invention eliminates the need for getter material to be placed within the active area of the display device. As a result, the present invention increases the usable amount of space available within the display device. This extra space can then be utilized by features such as, for example, additional field emitters.
Description




FIELD OF THE INVENTION




The present claimed invention relates to the field of flat panel displays. More particularly, the present claimed invention relates to an auxiliary chamber for removing contaminants from a display device.




BACKGROUND ART




Display devices such as, for example, flat panel display devices typically utilize an evacuated environment during operation. In a field emission-type display device, field emitters located on a cathode emit electrons which are directed towards respective pixel or sub-pixel regions on a faceplate. In such a device, it is imperative that the region between the faceplate and the cathode (i.e. the active environment) remain free of contaminants so that the electrons can travel unimpeded from the cathode to the faceplate. As yet another concern, if certain contaminants are present in the active environment between the cathode and the faceplate, certain features, such as the field emitters may be damaged.




With reference now to Prior Art

FIG. 1

, a side sectional view of a display device


100


employing a conventional contaminant reduction approach is shown. Specifically, Prior Art

FIG. 1

shows a backplate or cathode


102


secured to a faceplate


104


via a sealing frame


106


. The active environment is the region located between cathode


102


and faceplate


104


. Field emitters, typically shown as


108


, are coupled to cathode


102


and are disposed within the active environment. In the conventional approach of Prior Art

FIG. 1

, a getter material


110


is also coupled to the cathode and is disposed within the active environment. The getter material is intended to capture contaminant particles which remain in the active environment after an evacuation process. The getter material is also intended to capture contaminant particles which are generated during operation of display device


100


.




Unfortunately, the conventional approach of Prior Art

FIG. 1

has significant drawbacks associated therewith. By locating getter material


110


within the active environment, region


112


is no longer available for use. That is, such a prior art approach reduces or compromises the amount of space which is available to be utilized by features such as, for example, field emitters. Additionally, by placing getter material


110


within the active environment, such a prior art approach deleteriously subjects the active environment, and hence field emitters


108


, to the hazardous getter material


110


. As a result, field emitters


108


are often degraded or damaged due to their close proximity to getter material


110


.




With reference now to Prior Art

FIG. 2

, a side sectional view of display device


100


employing another conventional approach in an attempt to reduce contaminants is shown. In this approach a pump-out tube is coupled directly to the active environment. The pump-out tube is used to facilitate evacuation of display device


100


, and, hence, remove contaminants therefrom. Once again, such a conventional approach has severe drawbacks associated therewith. Attaching tubulation directly to the active environment of display device


100


greatly complicates the process of manufacturing display device


100


. Additionally, the increased complexity associated with attaching the tubulation directly to display device


100


adds additional cost to the manufacturing process. Furthermore, the potential for defects in display device


100


is heightened by attaching tubulation


114


directly to display device


100


.




Referring still to Prior Art

FIG. 2

, conventional tubulation such as tubulation


114


significantly alters and increase the “envelope” of display device


100


. The envelope of display device


100


refers roughly to the amount of space occupied by the display device


100


. In Prior Art

FIG. 2

, the envelope of display device


100


is shown by dotted line


116


. As a result of protruding tubulation


114


, display device


100


must be allotted a larger area in which to operate. It will be seen from Prior Art

FIG. 2

, that the increased area or envelope


116


required by tubulation


114


may restrict or limit the locations and environments in which display device


100


can be used.




With reference next to Prior Art

FIG. 3

, a side sectional view of display device


100


employing another conventional approach in an attempt to reduce contaminants is shown. In this conventional approach, tubulation


118


is again attached directly to the active environment of display device


100


. As still another drawback, tubulation


118


extends beyond the edge of display device. As result, prior art tubulation


118


often interferes with the sealing process used to secure cathode


102


and faceplate


104


together. More specifically, during a laser sealing process, for example, the laser beam or beams must contact the entire periphery of display device


100


. In the configuration shown in Prior Art

FIG. 3

, tubulation


118


can obstruct the laser beam or beams, thereby “shadowing” a portion of the periphery of display device


100


. As a result, the seal between cathode


102


and faceplate


104


can be compromised, or the sealing process must be altered to accommodate tubulation


118


.




Thus, a need exists for an apparatus which removes contaminants from a display device without compromising the usable amount of space available within the display device. A further need exists for an auxiliary chamber which meets the above listed needs but which does not deleteriously expose features of the display device to getter material. Still another need exists for an auxiliary chamber which meets the above-listed needs but which does not significantly increase or alter the overall dimensions of the display device.




SUMMARY OF INVENTION




The present invention provides an apparatus which removes contaminants from a display device without compromising the usable amount of space available within the display device. The present invention also provides an auxiliary chamber which realizes the above listed accomplishment and which does not deleteriously expose features of the display device to getter material. The present invention further provides an auxiliary chamber which achieves the above-listed accomplishments but which does not significantly increase or alter the overall dimensions of the display device.




Specifically, the present invention provides an apparatus for removing contaminants from a display device using an auxiliary chamber, and a method for attaching the auxiliary chamber to the display device. In one embodiment, an auxiliary chamber is adapted to be coupled to a surface of a display device. The auxiliary chamber is adapted to be coupled to the surface of the display device such that contaminants within the display device can travel from the display device into the auxiliary chamber. The auxiliary chamber further includes a getter which is disposed therein. The getter is adapted to capture the contaminants once the contaminants travel from the display device into the auxiliary chamber. In so doing, the present invention eliminates the need for getter material to be placed within the active area of the display device. As a result, the present invention increases the usable amount of space available within the display device. This extra space can then be utilized by features such as, for example, additional field emitters.




In another embodiment, the present invention provides method for attaching an auxiliary chamber to a display device. In this embodiment, the present invention first conditions a surface of a display device such that a conditioned surface of the display device is generated. This conditioned surface of the display device is thereby adapted to have an auxiliary chamber bonded thereto. Next, the present invention conditions a surface of the auxiliary chamber such that a conditioned surface of the auxiliary chamber is generated. In so doing, the conditioned surface of the auxiliary chamber is adapted to be bonded to the conditioned surface of the display device. After the conditioning steps, the present invention bonds the conditioned surface of the auxiliary chamber to the conditioned surface of the display device.




These and other objects and advantages of the present invention will no doubt become obvious to those of ordinary skill in the art after having read the following detailed description of the preferred embodiments which are illustrated in the various drawing figures.











BRIEF DESCRIPTION OF THE DRAWINGS




The accompanying drawings, which are incorporated in and form a part of this specification, illustrates embodiments of the invention and, together with the description, serve to explain the principles of the invention:




PRIOR ART

FIG. 1

is a side sectional view of a display device employing a conventional contaminant reduction approach.




PRIOR ART

FIG. 2

is a side sectional view of a display device employing another approach used in an attempt to reduce contaminants.




PRIOR ART

FIG. 3

is a side sectional view of a display device having tubulation which protrudes beyond the edge of the display device.





FIG. 4

is a side sectional view of a display device having an auxiliary chamber coupled thereto in accordance with one embodiment of the present claimed invention.





FIG. 5

is a perspective view of the embodiment of

FIG. 4

in accordance with one embodiment of the present claimed invention.





FIG. 6A

is a schematic representation of getter material disposed on a bundled filament in accordance with one embodiment of the present claimed invention.





FIG. 6B

is a schematic representation of getter material disposed on a filament arranged in a lattice configuration in accordance with one embodiment of the present claimed invention.





FIG. 6C

is a schematic representation of getter material disposed on a plurality of separately bundled filaments in accordance with one embodiment of the present claimed invention.





FIG. 6D

is a schematic representation of getter material disposed on a plurality of filaments arranged in separate lattice configurations in accordance with one embodiment of the present claimed invention.





FIG. 7

is a side sectional view of a display device having an auxiliary chamber coupled thereto wherein the auxiliary chamber has tubulation projecting therefrom in accordance with one embodiment of the present claimed invention.





FIG. 8

is a side sectional view of a display device having an auxiliary chamber coupled thereto wherein the auxiliary chamber has bent tubulation projecting therefrom in accordance with one embodiment of the present claimed invention.





FIG. 9

is a side sectional view of a display device having an auxiliary chamber coupled thereto wherein the auxiliary chamber has sealed tubulation projecting therefrom in accordance with one embodiment of the present claimed invention.





FIG. 10

is a side sectional view of a display device having an auxiliary chamber coupled thereto wherein the auxiliary chamber is plug sealed in accordance with one embodiment of the present claimed invention.





FIG. 11

is a flow chart of steps performed to attach an auxiliary chamber to surface of a display device in accordance with one embodiment of the present claimed invention.





FIG. 12

is a flow chart of steps performed to condition the surface of a display device in accordance with one embodiment of the present claimed invention.





FIG. 13

is a flow chart of steps performed to condition the surface of an auxiliary chamber in accordance with one embodiment of the present claimed invention.





FIG. 14

is a flow chart of steps performed to bond a conditioned surface of an auxiliary chamber to a conditioned surface of a display device in accordance with one embodiment of the present claimed invention.





FIG. 15

is a flow chart of steps performed to attach an auxiliary chamber to surface of a display device using an adhesive in accordance with one embodiment of the present claimed invention.





FIG. 16A

is a side sectional view of a display device having an auxiliary chamber in a compressed state coupled thereto wherein the auxiliary chamber has a variable volume in accordance with one embodiment of the present claimed invention.





FIG. 16B

is a side sectional view of a display device having an auxiliary chamber in an expanded state coupled thereto wherein the auxiliary chamber has a variable volume in accordance with one embodiment of the present claimed invention.











The drawings referred to in this description should be understood as not being drawn to scale except if specifically noted.




DESCRIPTION OF THE PREFERRED EMBODIMENTS




Reference will now be made in detail to the preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. While the invention will be described in conjunction with the preferred embodiments, it will be understood that they are not intended to limit the invention to these embodiments. On the contrary, the invention is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention as defined by the appended claims. Furthermore, in the following detailed description of the present invention, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be obvious to one of ordinary skill in the art that the present invention may be practiced without these specific details. In other instances, well known methods, procedures, components, and circuits have not been described in detail as not to unnecessarily obscure aspects of the present invention.




With reference now to

FIG. 4

, a side sectional view of a display device


400


having an auxiliary chamber


408


coupled thereto is shown. In the present embodiment, a backplate/cathode


402


is secured to a faceplate


404


using a sealing frame


406


. Although a sealing frame is recited in the present embodiment, the present invention is also well suited to embodiments employing any of numerous methods and devices to secure cathode


402


and faceplate


404


together. Additionally, display device


400


of the present is a flat panel display device, however, the present invention is well suited for use in any device in which contaminant reduction or containment is desired. Furthermore, display device


400


of the present embodiment may contain numerous features such as, for example, field emitters, pixel regions, spacer structures, and the like, which are not shown in

FIG. 4

for purposes of clarity. Also, in the present embodiment, auxiliary chamber


408


is coupled to backplate/cathode


402


of display device.


400


. The present invention is, however, also well suited to an embodiment in which auxiliary chamber


408


is coupled to a portion of display device


400


other than backplate/cathode


402


.




Referring still to

FIG. 4

, an auxiliary chamber


408


is shown coupled to a surface of display device


400


in accordance with the present claimed invention. More particularly, in the embodiment of

FIG. 4

, auxiliary chamber


408


is coupled to the outer surface of cathode


402


. Auxiliary chamber


408


of the present embodiment has a getter


410


disposed therein. Also, in the present embodiment, auxiliary chamber


408


is disposed above small openings, typically shown as


412


. Openings


412


extend completely through the surface of cathode


402


to the active environment of display device


400


. By placing auxiliary chamber


408


above small openings


412


, contaminants within the active environment of display device


400


can travel through openings


412


, into auxiliary chamber


408


, and be captured by getter


410


.




With reference now to

FIG. 5

, a perspective view of the present embodiment is shown. In the present embodiment, auxiliary chamber


408


extends across the entire length of cathode


402


(i.e. one side to another side of cathode


402


), and auxiliary chamber is disposed above a plurality of holes


412


which extend through cathode


402


. Although such a configuration is shown in the present embodiment, the present invention is also well suited to various other configurations. Alternate configurations include, for example, configuring auxiliary chamber


408


to extend only partially across the surface of cathode


402


, configuring auxiliary chamber


408


to cover a larger portion of the surface of cathode


402


, configuring auxiliary chamber


408


to cover a smaller portion of the surface of cathode


402


, and the like. Additionally, the present invention is also well suited to an embodiment in which a plurality of auxiliary chambers are coupled to cathode


402


.




With reference again to

FIG. 4

, auxiliary chamber


408


of the present embodiment has an extremely low profile. That is, unlike prior art devices (see e.g. device


114


of Prior Art FIG.


2


), auxiliary chamber


408


of the present embodiment does not significantly increase or alter the overall dimensions of display device


400


. Thus, the “envelope” of display device


400


(shown by dotted line


116


) is not significantly affected by the addition of auxiliary chamber


408


. Therefore, unlike many conventional devices, auxiliary chamber


408


does not restrict or limit the locations and environments in which display device


400


can be used.




In the present embodiment, auxiliary chamber


408


is formed of any of various materials or combinations of material. In one embodiment, auxiliary chamber


408


is formed of glass. In another embodiment of the present invention auxiliary chamber


408


is formed of ceramic material such as, for example, alumina. Although these specific materials are recited herein, the present invention is well suited to forming auxiliary chamber out of various other materials such as metals, composites, plastics, and the like. The embodiment formed of ceramic material has several advantages associated therewith. For instance, in one embodiment when using ceramic material, auxiliary chamber


408


is formed using an extrusion process. In another embodiment when using ceramic material, auxiliary chamber


408


is formed using a molding process. In still another embodiment when using ceramic material, auxiliary chamber


408


is formed using a pressing process. In yet another embodiment when using ceramic material, auxiliary chamber


408


is formed using a lamination process. These aforementioned fabrication process greatly simplify the task of forming auxiliary chamber


408


, reduce costs associated with fabricating auxiliary chamber


408


, and improve the robustness of auxiliary chamber


408


. Additionally, heat distribution is improved in an embodiment in which auxiliary chamber is formed of ceramic material. This improved heat distribution is particularly advantageous during a getter activation process to be described in detail below. Specifically, by readily and evenly distributing heat, a ceramic auxiliary chamber


408


is not subject to severe heat induced stresses which can occur during, for example, getter activation. Because the present invention includes both ceramic and non-ceramic embodiments, the following discussion will pertain to both the ceramic and the non-ceramic embodiments unless specifically noted otherwise.




With reference still to

FIG. 4

, the present embodiment disposes getter


410


within auxiliary chamber


408


. Unlike conventional approaches, by locating getter


410


within auxiliary chamber, the present embodiment does not reduce or compromise the amount of space within the active environment which is available to be utilized by features such as, for example, field emitters. Furthermore, by placing getter


410


within auxiliary chamber


408


, the present embodiment does not deleteriously subject the active environment, and hence the field emitters, to the hazardous getter


410


. Although such an arrangement is recited in the present embodiment, the present invention is also well suited to an embodiment in which additional getter is disposed within or proximate to the active environment of display device


400


.




In one embodiment, getter


410


is comprised of evaporable getter such as, for example, barium, titanium, and the like. In another embodiment, getter


410


is comprised of a non-evaporable getter. In still another embodiment, getter


410


is comprised of a combination of evaporable getter and non-evaporable getter. It will be understood that in certain embodiments of the present invention getter


410


must be activated. The present invention is well suited to accommodating any of the various getter activation processes well known in the art.




With reference now to

FIG. 6A

, a schematic representation of getter material disposed on a bundled filament


600


in accordance with one embodiment of the present claimed invention is shown. In this embodiment, getter material such as, for example, barium is coated on a filament. In the present embodiment, bundled filament


600


is comprised of tantalum, however, the present embodiment is also well suited to the use of various other filament materials, such as, for example, titanium, tungsten, a tantalum-titanium alloy, and the like. When exposed to heat, bundled filament


600


disperses or “flashes” or sublimates the getter material coated thereon throughout the interior surface of auxiliary chamber


408


. In the present embodiment, bundled filament


600


is exposed to an rf (radio frequency) heating source, a laser heating source, and the like.




Referring still to

FIG. 6A

, several substantial advantages are realized by the present embodiment. When flashed or heated, bundled filament


600


disperses the getter material widely and evenly throughout the interior surface of auxiliary chamber


408


. That is, many prior art approaches “throw” getter material only very near an original source of the getter material. Thus, bundled filament


600


provides a substantial disbursement improvement over conventional getter distribution methods. Bundled filament


600


is also capable of being very long and tortuous, filling the internal space of auxiliary chamber


408


, and thereby containing more getter material than current getter source devices provide. Additionally, after the disbursement of the getter material, the filament remains within auxiliary chamber. The filament, along with the interior surface of auxiliary chamber


408


will have getter material dispersed thereon. The presence of the filament increases the surface area which is available to be coated with getter. Thus, gettering capabilities are enhanced in the present embodiment. Also, bundled filament


600


will heat, flash, or sublimate quickly, and distribute the heat evenly throughout the interior region of auxiliary chamber


408


, thereby exposing auxiliary chamber


408


and cathode


402


to minimal thermal shock.




As yet another advantage of the embodiment of

FIG. 6A

, bundled filament.


600


can be prepared as a subassembly and then be disposed within auxiliary chamber


408


when. desired. This manufacturing flexibility provides a substantial improvement over typical prior art getter sources. Furthermore, because of its extremely low mass (and, hence, minimal heat transfer), bundled filament


600


can be located within auxiliary chamber


408


directly on the surface of cathode


402


and/or directly against the interior surface of auxiliary chamber


408


. This versatility in the placement of bundled filament


600


substantially eases the burden of precise getter source mounting associated with conventional getter distribution methods.




Referring now to

FIG. 6B

, a schematic representation of getter material disposed on a filament arranged in a lattice configuration in accordance with one embodiment of the present claimed invention is shown. The filament is arranged in a lattice configuration to produce a “latticed filament”


602


wherein the various rows and columns of the latticed filament


602


do not contact each other at respective intersections thereof. The present embodiment is formed and functions similarly to the embodiment of FIG.


6


A. That is, getter material such as, for example, barium is coated on a filament. In the present embodiment, latticed filament


602


is comprised of tantalum, however, the present embodiment is also well suited to the use of various other filament materials, such as, for example, titanium, tungsten a tantalum-titanium alloy, and the like. When exposed to heat, latticed filament


602


disperses or “flashes” the getter material coated thereon throughout the interior surface of auxiliary chamber


408


. However, in the present embodiment, latticed filament


602


is adapted to be exposed to an electrical current to achieve the desired heating. To insure proper passage of current throughout its entire length, the various rows and columns of latticed filament


602


must not contact each other at respective intersections thereof. Many of the numerous substantial benefits described in conjunction with the embodiment of

FIG. 6A

apply to the present embodiment as well.





FIGS. 6C and 6D

are schematic representations of getter material disposed on a plurality of separately bundled filaments


604




a


,


604




b


,


606




a


and


606




b


, in accordance with another embodiment of the present claimed invention. In these embodiments, multiple bundles or lattices of getter coated filaments are disposed within auxiliary chamber


408


. In so doing, the distinctly partitioned filaments can be separately activated. For example, a first filament (e.g.


604




a


or


606




a


) can be activated at the factory, and a second filament (e.g.


604




b


or


606




b


) can later be activated in situ. As a result, the getter material is refreshable when desired by the customer. Although specific combination of filaments are shown in

FIGS. 6C and 6D

, the present invention is well suited to using a greater number of filaments in a given auxiliary chamber, and the present invention is also well suited to having a combination including both bundled and latticed filaments in the same auxiliary chamber.




With reference to

FIG. 4

, auxiliary chamber


408


of the present embodiment does not have tubulation extending therefrom. That is, auxiliary chamber


408


is, for example, attached to display device


400


in a vacuum environment. In such an embodiment, it may not be necessary to perform any additional evacuating processes. Thus, the present invention is well suited to an embodiment in which auxiliary device


408


does not include tubulation.




Referring now to

FIG. 7

, another embodiment of the present invention is shown. In this embodiment, auxiliary chamber


408


of

FIG. 4

includes tubulation


700


. Unlike conventional devices which attach tubulation directly to the active environment of the display device, tubulation


700


of the present embodiment is attached to auxiliary chamber


408


. Tubulation


700


is used during a pump-out process to evacuate the active environment of display device


400


and auxiliary chamber


408


. More specifically, the end


702


of tubulation


700


is coupled to a vacuum source, not shown. The vacuum source evacuates the interior of auxiliary chamber


408


and the active environment of display device


400


via tubulation


700


. In the present embodiment, tubulation


700


extends from auxiliary chamber


408


such that it does not extend beyond the edge of the display device


400


. More particularly, in the embodiment of

FIG. 7

, tubulation


700


projects “inwardly” (i.e. towards the central portion of display device


400


) as opposed to projecting outwardly (i.e. directly towards a border of display device


400


). Thus, unlike conventional tubulation configurations (see e.g. tubulation


118


of Prior Art FIG.


3


), tubulation


700


of the present embodiment does not interfere with, for example, sealing processes used to secure cathode


402


and faceplate


404


together. Additionally, unlike conventional tubulation configurations (see e.g. tubulation


114


of Prior Art FIG.


2


), tubulation


700


maintains a low profile and, thus, does not significantly alter or increase the “envelope” of display device


400


. Hence, low profile, inwardly projecting tubulation


700


does not restrict or limit the locations and environments in which display device


400


can be used. The present invention is also suited to embodiments in which tubulation


700


projects other than towards the central portion of display device


400


.




Referring still to

FIG. 7

, in the present embodiment, tubulation


700


is comprised of metal. More particularly, in the embodiment of

FIG. 7

, tubulation


700


is comprised of a soft metal such as, for example, nickel, copper, aluminum, and the like. Although such soft metals are recited in the present embodiment, the present invention is also well suited to the use of various other types of metals. Likewise, the present embodiment is also well suited to forming tubulation


700


of glass, ceramic, or various other non-metal materials.




With reference still to

FIG. 7

, several substantial advantages are achieved by forming tubulation


700


of metal. For example, metal tubulation


700


is generally stronger than glass tubulation. This increased strength improves the robustness of the manufacturing process and leads to improved yield. Also, metal tubulation is more easily manufactured and coupled to auxiliary chamber


408


. For example, when auxiliary chamber


408


is formed of metal, if tubulation


700


is also formed of metal, a welding process can reliably secure tubulation


700


to auxiliary chamber


408


. The present invention is also well suited to securing metal tubulation to a metal or non-metal auxiliary chamber using various other bonding procedures. For example, in an embodiment in which auxiliary chamber


408


is comprised of ceramic material and tubulation


700


is comprised of metal, tubulation


700


is well suited to being, for example, frit-sealed or brazed to ceramic auxiliary chamber


408


.




Referring now to

FIG. 8

, another advantage associated with forming tubulation


700


from metal is shown. In the embodiment of

FIG. 8

, tubulation


700


is comprised of a bendable metal. As a result, tubulation


700


is bent to facilitate coupling of end


702


of tubulation


700


to a vacuum source. Thus, despite the location and orientation of auxiliary chamber


408


tubulation


700


can be bent or configured to provide ready access for a vacuum source or other device to end


702


of tubulation


700


. Furthermore, after the evacuation process, tubulation


700


can be bent to the position shown in FIG.


7


. In so doing, the present embodiment maintains its low profile and, thus, does not significantly alter or increase the “envelope” of display device


400


. Additionally, tubulation


700


of the present embodiment can be configured to extend beyond the edge of display device


400


to facilitate easy access to a vacuum source. However, prior to the evacuation process, tubulation


700


can be bent to ensure that tubulation


700


does not interfere with, for example, a laser sealing process. In an embodiment in which tubulation


700


is formed of glass, the glass tubulation is heated and is then bent to a desired shape.




With reference next to

FIG. 9

, another embodiment of the present invention is shown in which tubulation


700


extending from auxiliary chamber


408


has a sealed end


900


. Typically, after a final evacuation process, the present embodiment seals tubulation


700


forming sealed end


900


. In so doing, an evacuated environment is maintained within auxiliary chamber


408


and the active environment of display device


400


. In the embodiments of the present invention, sealed end


900


is achieved in any of numerous ways. In an embodiment in which tubulation


700


is comprised of glass, a heating process is used to obtain sealed end


900


. When tubulation


700


is comprised of metal, the present embodiment forms sealed end


900


using a non-thermal sealing process. Such a non-thermal process includes, for example, a mechanical pinching process, and the like. By using such a non-thermal sealing process, the present embodiment does not subject components of display device


400


and/or auxiliary chamber


408


to a deleterious thermal load or thermal shock. Additionally, such a mechanical sealing process results in minimal residual tubulation extending from auxiliary chamber


408


.




With reference now to

FIG. 10

, auxiliary chamber


408


of the present embodiment does not have tubulation extending therefrom. Instead, auxiliary chamber


408


is sealed using a plug seal


1000


. In such an embodiment, a plug of, for example, molten quartz glass or indium is used to seal auxiliary chamber


408


after an evacuation process. As can be seen from the embodiment of

FIG. 10

, by using plug seal


1000


, the present embodiment maintains a low profile and, thus, does not significantly alter or increase the “envelope” of display device


400


. Additionally, a plug seal can be used at any location on auxiliary chamber


408


. Hence, low profile, plug seal


1000


does not restrict or limit the locations and environments in which display device


400


can be used.




With reference now to

FIG. 11

, a flow chart


1100


of steps used to attach auxiliary chamber


408


to cathode


402


, both of

FIGS. 4

,


5


, and


7


-


10


, is shown. Certain types of sealing material such as, for example, low temperature sealing frit do not bond well to smooth surfaces. That is, in certain conditions, when using such a sealing frit, the seal or bond created between two surfaces may be more mechanical then chemical. The present embodiment provides a method for attaching one smooth surface (e.g. cathode


402


or other surface of display device


400


) and another smooth surface (e.g. the bottom surface of auxiliary chamber


408


) together. As shown at step


1102


, the present embodiment first conditions a surface of display device


400


such that a conditioned surface of display device


400


is generated. In the present embodiment, the surface of display device


400


is the top surface of cathode


402


of display device


400


. In so doing, the conditioned surface of display device


400


is then adapted to have auxiliary chamber


408


bonded thereto. An embodiment of the process of step


1102


will be described in detail below in conjunction with the discussion of FIG.


12


.




At step


1104


, the present embodiment conditions a surface of auxiliary chamber


408


such that a conditioned surface of auxiliary chamber


408


is generated. In the present embodiment, the conditioned surface of auxiliary chamber


408


is the bottom surface of auxiliary chamber


408


. In so doing, the conditioned surface of auxiliary chamber


408


is then adapted to be bonded to the conditioned surface of display device


400


. An embodiment of the process of step


1104


will be described in detail below in conjunction with the discussion of FIG.


13


.




Next, at step


1106


, the present embodiment bonds the conditioned surface of auxiliary chamber


408


to the conditioned surface of display device


400


. This, bonding step can occur, for example, in a vacuum such that no tubulation need be attached to auxiliary chamber


408


. However, the present embodiment is also well suited to bonding auxiliary chamber


408


to cathode


402


in a non-vacuum environment and then evacuating auxiliary chamber


408


and the active environment of display device


400


using tubulation coupled to auxiliary chamber


408


. An embodiment of the process of step


1106


will be described in detail below in conjunction with the discussion of FIG.


14


. Additionally, the present invention is also well suited to an embodiment in which only the surface of display device


400


is conditioned, or only the surface of auxiliary chamber


408


is conditioned.




With reference now to

FIG. 12

, a flow chart


1200


of steps performed during conditioning of a surface of display device


400


is shown. As recited at step


1202


, the present embodiment applies frit to the surface of display device


400


. More particularly, at step


1202


, the present embodiment applies frit without binders to the surface of display device


400


. As a result, the frit can be preglazed in vacuum, not in air, so that the active elements of display device will not oxidize and are not deleteriously exposed to any binders. In one embodiment, the frit is suspended in isopropyl alcohol (IPA). The IPA containing frit therein is then, for example, “painted” onto the surface of display device


400


at the desired location.




Next, at step


1204


, the surface of display device


400


is subjected to a heating step to expedite evaporation of the IPA. The evaporation of the IPA leaves a frit coating on the surface of display device


400


. This heating occurs in a vacuum oven or inert atmosphere at high temperatures, thus the sensitive active elements of display device


400


are protected from any binder material. In so doing, the active elements of display device


400


are not deleteriously exposed to any binders, and the active elements of display device


400


are not deleteriously exposed to an unwanted oxygen atmosphere.




With reference now to

FIG. 13

, a flow chart


1300


of steps performed during conditioning of a surface of auxiliary chamber


408


is shown. As recited at step


1302


, the present embodiment applies frit to the surface of auxiliary chamber


408


. More particularly, in the present embodiment, the frit material is applied to the bottom surface of auxiliary chamber


408


where auxiliary chamber


408


will contact display device


400


.




Next, at step


1304


, the present embodiment preglazes the frit to the bottom surface of auxiliary chamber


408


by heating auxiliary chamber


408


such that the frit is coupled to the bottom surface thereof.




With reference now to

FIG. 14

, a flow chart


1400


of steps performed during bonding of the conditioned surface of display device


400


and the conditioned surface of auxiliary chamber


408


is shown. As recited at step


1402


, the present embodiment places the conditioned surface of display device


400


and the conditioned surface of auxiliary chamber


408


in contact with each other.




Next, at step


1404


, the present embodiment exposes the conditioned surface of display device


400


and the conditioned surface of auxiliary chamber


408


to a heat source such that the conditioned surface of display device


400


and the conditioned surface of auxiliary chamber


408


are bonded together. In the present embodiment, the conditioned surface of display device


400


and the conditioned surface of auxiliary chamber


408


are exposed to a laser heating source. Although such heating is recited in the present embodiment, the present invention is also well suited to exposing the conditioned surface of display device


400


and the conditioned surface of auxiliary chamber


408


to various other heating methods such as, for example, radio frequency (RF) heating, oven heating, and the like. Additionally, in one embodiment, the conditioned surface of display device


400


and the conditioned surface of auxiliary chamber


408


are exposed to the heat source in an inert environment such that the heat does not damage active elements of display device


400


. In an embodiment in which a laser is used to bond display device


400


and auxiliary chamber


408


together, such bonding can be accomplished without requiring the use of a low temperature frit suspended in IPA.




With reference now to

FIG. 15

, a flow chart


1500


of steps performed during another embodiment of the present invention is shown. In this embodiment of the present invention, the surface of display device


400


and the surface of auxiliary chamber


408


are conditioned by a roughening process. As recited in step


1502


, the surface of display device


400


is roughened using for example, a chemical process, a mechanical process, a laser process, and the like. This process is used to create topography on the surface of display device


400


wherein the topography facilitates a bonding process. In the present embodiment, the chemical roughening process includes, for example, exposing the surface of display device


400


to an acid etch process. The mechanical roughening process includes, for example, sandblasting or sanding the surface of display device


400


. The laser roughening process includes, for example, exposing the surface of display device


400


to a laser to mark or pit the surface thereof.




At step


1504


, the surface of auxiliary chamber


408


is roughened using for example, a chemical process, a mechanical process, a laser process, and the like. This process is used to create topography on the surface of auxiliary chamber


408


wherein the topography facilitates a bonding process. In the present embodiment, the chemical roughening process includes, for example, exposing the surface of auxiliary chamber


408


to an acid etch process. The mechanical roughening process includes, for example, sandblasting or sanding the surface of auxiliary chamber


408


. The laser roughening process includes, for example, exposing the surface of auxiliary chamber


408


to a laser to mark or pit the surface thereof.




At step


1506


, the present embodiment uses an adhesive to bond the roughened surface of display device


400


and the roughened surface of auxiliary chamber


408


together. The present embodiment is well suited to using any of various types of adhesive to accomplish step


1506


. Additionally, the present invention is also well suited to an embodiment in which only the surface of display device


400


is roughened, or only the surface of auxiliary chamber


408


is roughened. Furthermore, the present invention is also well suited to an embodiment in which the surface of display device


400


is conditioned with frit, and the surface of auxiliary chamber


408


is roughened as described above, or surface of display device


400


is roughened as described above, and the surface of auxiliary chamber


408


is conditioned with frit.




With reference now to

FIG. 16A

, another embodiment of the present invention is shown in which an auxiliary chamber


408


′ has a variable volume. More specifically, in the present embodiment auxiliary chamber


408


′ has an expandable portion


1600


. In

FIG. 16A

, expandable portion


1600


is in a compressed state. In the present embodiment, expandable portion is comprised of a bellow-like structure, which is maintained in the compressed state during evacuation and sealing (i.e. tip-off) of display


400


. As a result, the present embodiment maintains a low profile as described above in detail.




Referring now to

FIG. 16B

, auxiliary chamber


408


′ is shown in an expanded state. As a result, the volume of auxiliary chamber has been increased. Thus, the present embodiment provides an auxiliary chamber having a variable volume. In operation, the present embodiment is extended after evacuation and sealing (i.e. tip-off) of display


400


to increase the volume of auxiliary chamber


408


′. Getter


410


is then activated (e.g. flashed), and then auxiliary chamber


408


′ is returned to its compressed state to return display


400


to the desired low profile. In so doing, the present embodiment increases the distance of getter


410


from the active area of the display, improves dispersion of the getter material, and, in the end, maintains the desired low-profile.




Thus, the present invention provides an apparatus which removes contaminants from a display device without compromising the usable amount of space available within the display device. The present invention also provides an auxiliary chamber which realizes the above listed accomplishment and which does not deleteriously expose features of the display device to getter material. The present invention further provides an auxiliary chamber which achieves the above-listed accomplishments but which does not significantly increase or alter the overall dimensions of the display device.




The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents.



Claims
  • 1. A method for attaching an auxiliary chamber to a display device, said method comprising:a) conditioning a surface of a display device by roughening such that a conditioned surface of said display device is generated, wherein frit is preglazed suspended in isopropyl alcohol to said surface of said display device in a vacuum environment such that active elements of said display device are not deleteriously oxidized, said conditioned surface of said display device adapted to have an auxiliary chamber bonded thereto; b) conditioning a surface of said auxiliary chamber by roughening such that a conditioned surface of said auxiliary chamber is generated, said conditioned surface of said auxiliary chamber adapted to be bonded to said conditioned surface of said display device; and c) bonding said conditioned surface of said auxiliary chamber to said conditioned surface of said display device.
  • 2. The method as recited in claim 1 for attaching an auxiliary chamber to a display device wherein step a) comprises conditioning a surface of a backplate of a flat panel display device by roughening.
  • 3. The method as recited in claim 1 for attaching an auxiliary chamber to a display device wherein step b) comprises the steps of:applying frit to said surface of said auxiliary chamber; and preglazing said frit to said surface of said auxiliary chamber by heating said auxiliary chamber with said frit applied to said surface of said auxiliary chamber such that said frit is coupled to said surface of said auxiliary chamber.
  • 4. The method as recited in claim 1 for attaching an auxiliary chamber to a display device wherein step c) comprises the steps of:placing said conditioned surface of said display device in contact with said conditioned surface of said auxiliary chamber; and exposing said conditioned surface of said display device and said conditioned surface of said auxiliary chamber to a heat source such that said conditioned surface of said display device and said conditioned surface of said auxiliary chamber are bonded together.
  • 5. The method as recited in claim 4 for attaching an auxiliary chamber to a display device wherein step c) comprises the steps of exposing said conditioned surface of said display device and said conditioned surface of said auxiliary chamber to a heat source in an inert environment wherein said heat source does not damage active elements of said display device.
  • 6. The method as recited in claim 1 for attaching an auxiliary chamber to a display device wherein step a) comprises:roughening said surface of said display device by subjecting said surface of said display device to a process selected from the group consisting of: chemical roughening, mechanical roughening, laser roughening.
  • 7. The method as recited in claim 1 for attaching an auxiliary chamber to a display device wherein step b) comprises:roughening said surface of said auxiliary chamber by subjecting said surface of said auxiliary chamber to a process selected from the group consisting of: chemical roughening, mechanical roughening, laser roughening.
  • 8. The method as recited in claim 1 for attaching an auxiliary chamber to a display device wherein step c) comprises:using an adhesive to bond said surface of said display device and said surface of said auxiliary chamber together.
  • 9. The method as recited in claim 1 for attaching an auxiliary chamber to a display device wherein said auxiliary chamber has a variable volume.
  • 10. A method for attaching an auxiliary chamber to a display device, said method comprising:conditioning a surface of a display device by preglazing a frit suspended in isopropyl alcohol to said surface of said display device in a vacuum environment to generate a conditioned surface, said conditioned surface of said display device adapted to have an auxiliary chamber bonded thereto; conditioning a surface of said auxiliary chamber by roughening such that a conditioned surface of said auxiliary chamber is generated, said conditioned surface of said auxiliary chamber adapted to be bonded to said conditioned surface of said display device; and bonding said conditioned surface of said auxiliary chamber to said conditioned surface of said display device.
  • 11. The method of claim 10 further comprising:attaching an auxiliary chamber to a display device by conditioning a surface of a backplate of a flat panel display device.
  • 12. The method of claim 10 further comprising:roughening said surface of said auxiliary chamber by subjecting said surface of said auxiliary chamber to a process selected from a group consisting of: chemical roughening, mechanical roughening, laser roughening.
  • 13. The method of claim 10 further comprising:using an adhesive to bond said surface of said display device to said surface of said auxiliary chamber.
  • 14. A method for bonding an auxiliary chamber to a flat panel display device, said method comprising:conditioning a surface of said flat panel display device by preglazing a frit suspended in isopropyl alcohol to said surface of said flat panel display device in a vacuum environment to generate a conditioned surface; conditioning a surface of said auxiliary chamber by roughening such that a conditioned surface of said auxiliary chamber is generated; and bonding said conditioned surface of said auxiliary chamber to said conditioned surface of said flat panel display device.
  • 15. The method of claim 14 further comprising:attaching an auxiliary chamber to said flat panel display device by conditioning a surface of a backplate of said flat panel display device.
  • 16. The method of claim 14 further comprising:roughening said surface of said auxiliary chamber by subjecting said surface of said auxiliary chamber to a process selected from a group consisting of: chemical roughening, mechanical roughening, laser roughening.
  • 17. The method of claim 14 further comprising:using an adhesive to bond said surface of said flat panel display device to said surface of said auxiliary chamber.
Parent Case Info

This is a divisional of application Ser. No. 09/196,626 filed on Nov. 18, 1998, now U.S. Pat. No. 6,147,450.

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