The present invention relates to a flat panel display device using the discharge phenomenon of plasma and a method for manufacturing the same; and more particularly, to the flat panel display device with a structure to discharge gas filled in discharge space by locating electrodes on partition members which are inserted between a upper substrate and a lower substrate and the method for manufacturing the flat panel display device.
A flat panel display (FPD) device means a display device with a flat panel with a thickness equivalent to or less than one fourth of diagonal length of the display device, e.g., a thickness of from a few millimeters to a few centimeters. As a relatively lighter and thinner device with lower power consumption, the FPD device has gradually replaced a cathode ray tube (CRT) which was the longest serving technology in the history of display devices.
Such a flat panel display device is classified into an emissive type which makes the device self-emissive and a non-emissive type which requires a separate light source. The former includes PDP (plasma display panel), OLED (organic light emitting display), FED (field emission display), and the latter includes LCD (liquid crystal display) and the like. As the LCD is impossible to display any image without an external light source, a back light unit (BLU), i.e., a separate light source, is necessarily required. The BLU is widely used in a form of CCFL which can produce visible light by colliding the infrared light emitted from mercury gas excited by electron discharged by the high voltage electric field with the fluorescent substance; LED (light emitting device) which is operated by the electroluminescence phenomenon which is generated when the voltage is provided to a semiconductor; or FFL (flat fluorescent lamp) which diffuses light by exciting fluorescent substance by the infrared light generated from the discharged gas.
Since FFL uses a flat light source with only one lamp unlike CCFL which uses a line light source, it has advantages: sharply reduced number of components, automation in the manufacturing processes of BLUs and LCD panels, and easy adoption for large LCDs, which bring the public attention.
First of all,
The basic luminescent principle of the flat panel display device 100, i.e., the FFL, is similar to that of general fluorescent lamps. The electrons accelerated by the electric field generated by the discharge electrodes 105 flow and collide with the discharge gas in the discharge space. Herein, UV with a wavelength of, e.g., 253.7 nm is emitted and then the fluorescent substance 106 is excited by the discharged UV, thereby emiting the visible ray.
As shown in
The types of the discharge gas injected through the gas inlet 107 are largely classified into mercury-free and mercury-contained discharge gas. In case of using the mercury-free discharge gas, Xenon (Xe) which emits vacuum ultraviolet may be used, and if necessary, mixed gas including inert gas such as Xenon (Xe), Helium (He), Argon (Ar) and Krypton (Kr) may be used. In case of using the mercury-contained discharge gas, mixed gas with more inert gas including Neon (Ne), Argon (Ar) etc. is used.
By reference of
The step shown in
The step in
Meanwhile, the upper substrate 101 may be prepared on which only the fluorescent substance 106 is established (unillustrated).
The step in
The partition member 103 is installed between the upper and the lower substrates 101, 102. Herein, the partition member 103 is prepared through a separate process (unillustrated). After the sealing process, if the discharge gas is injected through the gas inlet 107 and the gas inlet 107 is tipped off, the process for manufacturing the flat panel display device 100 is completed. Since the process of the formation of the discharge electrodes and the fluorescent substances, the process of the sealing, and the process of the gas injection are well known to those who skilled in the art, the explanation thereabout will be omitted in the specification.
However, the conventional device had the following problems:
Firstly, since the metal layer 105A, the dielectric layer 105B, the protective layer 105C and the fluorescent substance 106 are all formed on the lower substrate 102, the lower substrate 102 may be thermally shocked during the heat treatment process repeated during the formation of the above-mentioned three-layer structure. With the thermal shock, a crack etc. occurs in the glass-made lower substrate 102 so that the lifespan of the flat panel display device 100 may be shortened.
Secondly, to create one group of discharge cells (for example, six discharge cells), the process for manufacturing the discharge electrodes 105, composed of three sub-steps, i.e., the calcination of the metal layers 105A, the calcination of the dielectric layers 105B and the deposition of the protective layers 105C, for one lower substrate may be required. Thus, in order to produce massive groups of such discharge cells, it is necessary to repeatedly perform the above-mentioned three sub-steps for each of the lower substrates. Therefore, the number of sub-steps included in the process may be increased, resulting in the reduction of the productivity and the increase in the cost of the device.
It is, therefore, one object of the present invention to provide a flat panel display device having a pair of discharge electrodes facing each other in a unit discharge cell by installing the discharge electrodes on partition members which are separately and massively produced and provided.
It is another object of the present invention to provide a method for manufacturing the flat panel display device without having to require the process for forming the metal layers, the dielectric layers, and the protective layers directly on the lower substrate, to thereby reduce the influence of thermal shock on the lower substrate and increase the lifespan and the performance of the device.
It is yet another object of the present invention to provide a method for massively manufacturing the flat panel display device capable of achieving the improvement of productivity thanks to the reduction the number of steps of the process and the automation of the process through the application of the robot assembling process by massively and separately producing many partition members containing the electrodes.
However, the objects of the present invention are not limited to the foregoing.
In accordance with the present invention, the flat panel display device has the following effects: (i) it is possible to improve productivity thanks to the reduced number of manufacturing steps included in the whole process and achieve the automation process such as a robot assembling; and (ii) it is possible to reduce the cost of the flat panel display device and reduce the influence of the thermal shock on the lower substrates (for example, soda lime glass which is inexpensive can be used for the substrates), because the upper and the lower substrates do not need to go through the necessarily accompanying calcination processes which are required to manufacture the electrodes at high temperature.
The above objects and features of the present invention will become more apparent from the following description of the preferred embodiments given in conjunction with the accompanying drawings, in which:
The configurations of the present invention for accomplishing the above objects of the present invention are as follows.
In one aspect of the present invention, there is provided a flat panel display device, including at least one unit discharge cell, including: a upper and a lower substrates; one or more first partition members for supporting and keeping apart the upper and the lower substrates; and a pair of electrodes, formed on the first partition members, for generating the electric field in discharge space of the unit discharge cell, wherein the pair of electrodes are formed on one or more leteral faces which are in contact with the discharge space among all the lateral faces of the first partition members, the pair of electrodes facing each other, and wherein intenal space is formed inside of the first partition members.
In another aspect of the present invention, there is provided a flat panel display device, including at least one unit discharge cell, including: a upper and a lower substrates; one or more first partition members for supporting and keeping apart the upper and the lower substrates; and a pair of electrodes, formed on the first partition members, for generating the electric field in discharge space of the unit discharge cell, wherein the pair of electrodes are formed on one or more leteral faces which are in contact with the discharge space among all the lateral faces of the first partition members, the pair of electrodes facing each other, and wherein one or more grooves are formed on the first partition members.
In yet another aspect of the present invention, there is provided a flat panel display device, including at least one unit discharge cell, including: a upper and a lower substrates; one or more first partition members for supporting and keeping apart the upper and the lower substrates; and electrodes, located inside the first partition members, for generating electric field in discharge space of the unit discharge cell(s), wherein a specific electrode located inside a specific first partition member of which both sides are in contact with neighboring unit discharge cells is common to the neighboring unit discharge cells.
In yet still another aspect of the present invention, there is provided a flat panel display device, including at least one unit discharge cell, including: a upper and a lower substrates for maintaining discharge space for the unit discharge cells; and first partition members for generating electric field in the discharge space while supporting and keeping apart the upper and the lower substrates, wherein the first partition members have groove(s) formed thereon to supply discharge gas into the discharge space.
In yet still another aspect of the present invention, there is provided a method for manufacturing a flat panel display device, including at least one unit discharge cell, discharge space for the unit discharge cells being located between a upper and a lower substrates, including the steps of: (a) forming multiple electrodes on a reference substrate; (b) cutting the reference substrate so as to include each of the electrodes; and (c) inserting the cut electrodes between the upper and the lower substrates.
In the following detailed description, reference is made to the accompanying drawings that show, by way of illustration, specific embodiments in which the present invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the present invention. It is to be understood that the various embodiments of the present invention, although different from one another, are not necessarily mutually exclusive. For example, a particular feature, structure, or characteristic described herein in connection with one embodiment may be implemented within other embodiments without departing from the spirit and scope of the present invention. In addition, it is to be understood that the location or arrangement of individual elements within each disclosed embodiment may be modified without departing from the spirit and 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, appropriately interpreted, along with the full range of equivalents to which the claims are entitled. In the drawings, like numerals refer to the same or similar functionality throughout the several views.
The embodiments of the present invention will be described, in detail, with reference to the accompanying drawings.
First of all,
Moreover, the flat panel display device 300 of the present invention is considered to have six unit discharge cells in this specification, but the number of unit discharge cells included in the flat panel display device 300 may be varied.
In accordance with the first embodiment of the present invention, the flat panel display device 300 has a pair of the discharge electrodes 308 for generating the electric field in discharge space, wherein the discharge electrodes 308 are formed on the lateral faces of the partition members 304, 305 standing in rows in a Y direction with functions of separating and supporting the upper and the lower substrates 301, 302. Thus, the pair of discharge electrodes 308 in a unit discharge cell 303 may face each other.
On the other hand, as shown in
A procedure for operating the flat panel display device 300 with the structure of the electrodes facing each other is as follows: (a) when a voltage is applied to the discharge electrodes 308 on the partition members 304, 305, the discharge phenomenon starts partially; (b) when the voltage is applied for enough time, initial discharge passages with a shape of narrow band are created between the pair of discharge electrodes 308 facing each other; (c) when the applied voltage is increased after the initial discharge passages are created, the initial discharge passages are expanded in the vertical direction in the space between the electrodes; and (d) each expanded discharge passage is combined with adjacent discharge passages and thus the uniform and full discharge is provided.
For convenience, the partition members will be explained in this specification by considering the partition members 304, 305 to be arranged in the Y direction and the member parallel 306 to be arranged in the X direction. The partition members 304, 305 along the Y direction and the partition member 306 along the X direction substantially cross at right angles. One unit discharge cell basically occupies the discharge space formed by the pair of partition members 304, 305 along the Y direction and the pair of partition members 306 along the X direction. Herein, if a unit discharge cell corresponds with the outermost one, the outermost partition member 306 may be omitted.
The structure of the partition members 304, 305 along the Y direction is classified by whether discharge cells are in contact with both sides of the partition member or one side of the partition member. In detail, the partition member 304 along the Y direction adjoins the discharge cells on one side thereof and the partition member 305 along the Y direction adjoins the discharge cells on both sides thereof.
Meanwhile, the partition member 306 along the X direction may have no discharge electrode formed thereon, however, it is not limited thereto. For example, the discharge electrode, functioning as a sumpplementary electrode, can be installed on the partition member 306. Further, it should be noted that the supplementary electrode may be applied as mentioned above in other example embodiments of the present invention even without any special comments.
The partition members may be shaped in a form of a continuous rod with the cross section of a square, a circle or a ring or a spot such as a sphere or a polyhedral. Further, the partition members may be made of glass, ceramic and the like. Furthermore, the cross section of the partition member may have shapes of a part of a circle, an ellipse or a polyhedron. It should be noted that a variety of examples of the partition member may be applied to other example embodiments of the present invention even without any special comments.
Herein, the metal layer 308A may be formed by the screen printing process and then the calcination process; the dielectric layer 308B may be formed on the metal layer 308A by the screen printing process or the laminating process using a DFR (dry film resist); and the protective layer 308C may be formed on the dielectric layer 308B by the sputtering process or the electron beam evaporation process.
By the way, the metal layer 308A may be comprised of not only pure metal but also conductive material such as alloy, metal compound and carbon. It should be noted that this may be applied to other example embodiments of the present invention even without any special comments.
The partition member 305 in the Y direction and the partition member 306 in the X direction may cross at, e.g., right angles. By reference of
Herein, if last two digits of the three digit reference numbers included in
First,
The first embodiment in which the partition members are overlapped and the second embodiment in which the partition members are not overlapped have the following differences:
The first embodiment has a strength in that it requires less number of steps included in the assembling process than the second one because each of the partition members in the X direction is united. However, because the first embodiment must have grooves on the partition members 305, 306 to overlap each other, it is not easy to manufacture the partition members 305, 306 so that manufacturing costs may be increased. In addition, the deep groove 311 formed on the partition member 305 in accordance with the first embodiment may weaken the structure of the partition member 305, and the height of the partition member 305 is sharply reduced due to the groove 311 so that the area of a conductor near the groove 311 may be reduced. This may cause the electric field between the electrodes nonuniformly and thus bad effects on the creation of plasma.
Contrary to this, in accordance with the second embodiment, the partition members in the X direction are not united (that is, the partition members 406 are separated). This reduces productivity due to the increased number of steps included in the assembling process. However, it is not necessary to create grooves on the partition members 406 thanks to the non-crossing structure of the partition members and thus it may make the process easier. In addition, contrary to the deep groove structure 311 of the first embodiment, the partition member 405 of the second embodiment has no deep groove, and thus the height of the partition member 405 may be uniform. Thanks to the uniform height of the partition member 405, it is not weak in the structural aspect and it may form the electric field between electrodes uniformly and make the distribution of the plasma uniform. Therefore, possibility of febrility due to the nonuniform electric field may be minimized in accordance with the second embodiment. Herein, the narrow groove 416 formed on the bottom side of the partition member 405 plays a role in discharging the gas in the whole discharge space and in transmitting the injected gas to adjacent discharge cells through the gas inlet 410.
It should be noted that the order of steps illustrated in
By reference of
The present invention has the following strengths by forming the discharge electrodes during the separate process for manufacturing the partition members:
First, the improvement of productivity, the reduction of the number of stpes included in the whole process, and the automation of the process can be realized because many partition members with discharge electrodes on the lateral face thereof are separately and massively produced and effectively applied to the manufacturing process of the flat panel display device.
Second, it has a strength that it can use low priced soda lime glass for the lower substrate because the discharge electrodes are not formed directly on the lower substrate to which the calcinations process is applied at low temperature after assembling the partition members. According to the conventional technique, high strain point glass was used for the upper and the lower substrates because the discharge electrodes were formed directly on the substrates through the high temperature calcination process. However, the high strain point glass was not desirable because of the higher price than the soda lime glass. The present invention is very meaningful in the overcome of this problem.
Third, the lower substrate is less thermally shocked because it does not go through the high temperature calcination process during the manufacturing process.
First of all,
In accordance with the third embodiment of the present invention, a pair of discharge electrodes 608 for generating the electric field in the discharge space are formed inside of the partition members 604, 605 in the Y direction as shown in
In accordance with the third embodiment of the present invention, the structure and the arrangement of the partition members are basically same as those in the first embodiment but there are following differences: The cross section of the partition members 604, 605 in the Y direction is round-shaped or empty pipe-shaped overall. Further, a metal rod 608 functioning as a discharge electrode may be inserted into the partition members 604, 605 in the Y direction. Accordingly, there is no difference in the structure of discharge electrodes between the partition member 604 and the partition member 605. However, it is desirable to build a gas passage 613 on the bottom side of the partition member 605 which adjoins two neighboring cells as mentioned in the first embodiment of the present invention.
The cross section of the partition member 606 in the X direction in
Specifically,
While the present invention has been shown and described with respect to the preferred embodiments and figures, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and the scope of the present invention as defined in the following claims.
Number | Date | Country | Kind |
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10-2007-0042666 | May 2007 | KR | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/KR08/02475 | 4/30/2008 | WO | 00 | 11/2/2009 |