1. Field of the Invention
The present invention relates to a plasma display panel. More particularly, the present invention relates to a barrier rib structure of a plasma display panel constructed to prevent colors of phosphor screens from being mixed, and a lower plate structure of the panel using the same.
2. Description of the Related Art
A general discharge display panel is a plasma display panel. The plasma display panel is a flat panel display in which scan and address electrodes are formed in a matrix shape between upper and lower plates to drive pixels, and an image is created using ultraviolet rays generated while generating electric discharge between the electrodes.
Further, a lower substrate of the plasma display panel includes address electrodes 27 formed on one side of a rear glass substrate 26 to selectively select each unit cell and induce an initial discharge. A dielectric layer 33 for insulating the address electrodes 27 is formed on the address electrodes 27. An electric discharge space is formed on the dielectric layer 33, and barrier ribs 28 for separating the unit cells and preventing crosstalk between the adjacent cells are formed in the electric discharge space. Phosphor screens 30, 31 and 32 made of red (R), green (G) and blue (B) phosphors, which are excited by ultraviolet rays generated by the discharge operation to emit visible light, are coated on side surfaces of the barrier ribs 28 and an upper surface of the dielectric layer 33. The barrier ribs 28 are formed either in a stripe shape as illustrated in
Accordingly, the electric discharge spaces 29 are formed between the lower and upper substrates. Neon gas, xenon gas, helium gas and the like for electric discharge are injected into the electric discharge spaces 29. A lower surface of the upper substrate is brought into a close contact with an upper surface of the lower substrate of the display panel, and a resultant unit cell of the plasma display panel can be formed accordingly.
In the related art plasma display panel configured as discussed above, a surface discharge occurs to display an image on the display panel, as follows. If an initial discharge voltage is applied to the bus electrodes 22 and 23 and the address electrodes 27 such that the potential difference can be generated between these electrodes, an initial discharge is generated in the electric discharge spaces 29 and ultraviolet rays are then generated while the surface discharge is generated between the pair of the bus electrodes 22 and 23. At this time, the phosphors of the surrounding phosphor screens 30, 31 and 32 are excited by means of the ultraviolet rays and colors are simultaneously displayed.
That is, electrons existing in the electric discharge spaces 29 are accelerated by the applied voltage and collide with an inert mixed gas injected into the electric discharge spaces 29 at a pressure of about 400 to 600 torr to generate ultraviolet rays which in turn collide with the phosphor screens 30, 31 and 32 to generate the visible light. Accordingly, it is possible to display a desired image by combining the cells of the electric discharge spaces 29 in which the electric discharge occurs with the cells of the electric discharge spaces 29 in which the electric discharge does not occur.
However, the foregoing plasma display panel has the following limitations and problems.
In order to display an image on the related art plasma display panel, the phosphor screens 30, 31 and 32 respectively having different colors of red, green and blue are injected into the spaces between the adjacent barrier ribs 28. A screen printing process, an inkjet process, or a dispensing process according to a related art is used to inject the phosphor screens 30, 31 and 32 between the adjacent barrier ribs 28. In the dispensing process, the dispensing materials of the phosphor screens are discharged into the spaces between the respective barrier ribs through discharge holes formed on nozzles. At this time, the discharge hole should be formed such that its diameter is smaller than a gap between the adjacent barrier ribs 28. However, the related art dispensing process has a problem of mixed colors since the phosphor screen materials permeate through the neighboring barrier ribs 28. That is, the related art dispensing process for forming the phosphor screens 30, 31 and 32 has the following problems.
In a case where the barrier ribs 28 are formed in a stripe shape as illustrated in
Furthermore, in a case where the barrier ribs 28a and 28b are formed in a closed shape as illustrated in
Therefore, an object of the present invention is to provide a barrier rib structure of a plasma display panel in which the shape of barrier ribs is improved to prevent the mixing of colors of phosphor screens.
Another object of the present invention is to provide a lower plate structure of a plasma display panel in which the shape of barrier ribs is improved to prevent the mixing of colors of phosphor screens.
Another object of the present invention is to provide a plasma display panel and its barrier rib structure, which overcome the limitations and disadvantages associated with the related art.
According to an aspect of the present invention, there is provided a lower plate structure of a plasma display panel, comprising: a substrate; barrier ribs formed on the substrate; and at least one blocking wall formed at least one beginning portion of the barrier ribs, from which a process of coating phosphor screens starts, to separate neighboring discharge spaces around the barrier ribs from each other.
According to another aspect of the present invention, there is provided a lower plate structure of a plasma display panel, comprising: a substrate; barrier ribs formed on the substrate; and grooves each formed between adjacent barrier ribs and extending substantially perpendicularly to a coating direction of a coating solution for coating discharge spaces defined by the barrier ribs, whereby the coating solution is prevented from being transferred to the adjacent discharge spaces.
According to another aspect of the present invention, there is provided a barrier rib structure of a plasma display panel having closed type barrier ribs, comprising: grooves formed between upper surfaces of the closed type barrier ribs and extending substantially perpendicularly to a coating direction of a coating solution to be applied to discharge spaces of the closed type barrier ribs.
It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
The above and other objects, features and advantages of the present invention will become apparent from the following description of preferred embodiments given in conjunction with the accompanying drawings, in which:
a is a structural view of one example of general stripe type barrier ribs;
b is a structural view of another example of general closed type barrier ribs;
FIGS. 5(a) to 5(f) are workflow diagrams sequentially showing processes of fabricating the embodiment illustrated in
FIGS. 10(a) to 10(f) are workflow diagrams sequentially showing processes of fabricating the embodiment illustrated in
Hereinafter, preferred embodiments of a barrier rib structure of a plasma display panel and a lower plate structure using the same according to the present invention will be described in detail with reference to the accompanying drawings.
Referring to
A blocking wall 106 is formed on an end portion of one side of each of the barrier ribs 104. Here, the block walls 106 are formed only on one side of the barrier ribs 104, but if desired, they can be formed on both or other sides of the barrier ribs 104. In this example, the blocking walls 106 are formed on portions of the barrier ribs where phosphor screens start to be coated. When coating the phosphor screens by means of, e.g., a dispensing process, a coating solution for coating the phosphor screens starts to be discharged at the beginning portions of the barrier ribs 104 and a partial excessive discharge of the coating solution is then generated due to the inaccurate setting of discharge pressure of the coating solution. The blocking walls 106 are installed to prevent such excessively discharged coating solution from being transferred to spaces defined between the adjacent barrier ribs 104, i.e. discharge spaces. In other words, the blocking walls 106 serve to prevent the colors of phosphor screens from being mixed at the beginning portions of the barrier ribs 104.
In the embodiment shown in
In the meantime,
Next, a process of fabricating a lower plate having the barrier rib structure of the embodiment shown in
Glass is generally used as a substrate 102 (
After the barrier rib material 103 has been coated on one surface of the substrate 102, a firing process of hardening the barrier rib material 103 by heating the barrier rib material 103 coated on the substrate 102 is performed. The barrier rib material 103 is then attached or fixed to the substrate 100 by the firing process. The hardened barrier rib material 103 is marked with slant lines in
Then, a mask 105 in a beta state is placed on the hardened barrier rib material 103 (
The barrier rib material 103 protected by the barrier rib patterns 105′ will become barrier ribs 104. The barrier rib patterns 105′ are removed except for the portions on the barrier rib material 103 on which the barrier ribs 104 will be formed, and the blocking wall patterns 105″ are removed except for the portions on the barrier rib material 103 on which the blocking walls 106 will be formed.
Thereafter, the barrier rib material 103 is selectively removed to form the barrier ribs 104 and blocking walls 106 (
When a predetermined period of time to complete the etching process has passed after a certain amount of the etching solution has been injected through the aforementioned process, a rinsing process is performed. The etching process is repeatedly performed until the barrier ribs 104 having uniform thickness are obtained.
In a state of
As shown in
At least two blocking walls 206 are preferably formed to more effectively prevent a coating solution from flowing over the blocking walls into the adjacent discharge spaces.
As shown in
Next,
As shown in
Grooves 404a′ are formed between upper surfaces of the first barrier rib portions 404a of the barrier ribs 404 extending perpendicularly to a direction in which the coating solution is coated, so that the coating solution is not transferred to the adjacent discharge spaces. Other grooves 404b′ are also formed between upper surfaces of the second barrier rib portions 404b extending parallel to a direction in which the coating solution is coated; however, the grooves 404b′ may not be need. That is, it is acceptable and sufficient that the grooves 404a′ are formed in a longitudinal direction of the first barrier rib portions 404a between the upper surfaces of the first barrier rib portions 404a on which the coating solution is actually coated.
Of course, the grooves 404b′ are also longitudinally formed between the upper surfaces of the second barrier rib portions 404b. However, the grooves 404b′ are not spaces for allowing the coating solution coated directly on the first barrier rib portions 404a to be moved away, but the grooves 404b′ serve to prevent the coating solution, which has been transferred from the discharge spaces onto the upper surfaces of the second barrier rib portions 404b in the process of coating the coating solution in the discharge spaces, from being transferred again to the adjacent discharge spaces.
According to an embodiment, a mask 405 as shown in
A dry film can be used as the mask 405 and the mask 405 can have a thickness of about 20 μm. In order to form the grooves 404a′and 404b′, a dry film having ⅓ or less width of the upper portions of the barrier ribs can be used in a semitransparent or non-protection pattern section.
The grooves 404a′ and 404b′ are formed in such a manner that the portions of the grooves corresponding to about 5 to 70% of the upper width of the barrier ribs 404 are about 5 to 70% lower than the barrier ribs 404. Furthermore, the barrier ribs 404 are formed in such a manner that a ratio of the crosswise upper width of the barrier ribs (arrow ‘d’ in
Next, a method for fabricating the barrier ribs on the plasma display panel according to the embodiment of
A substrate 402 with the barrier ribs 404 formed thereon is processed/rinsed and then cut to a certain size. At this time, the barrier rib material 403 made of a material such as aluminum can be deposited on the upper surface of the substrate 402. The barrier rib material 403 is formed in a beta shape.
More specifically, as shown in FIGS. 10(a) and 10(b), if a barrier rib material 403 is formed on the upper surface of the substrate 402, the barrier rib patterning is performed. The barrier rib patterning is conducted by placing the mask 405 made of a photosensitive resin onto the barrier rib material 403 and then allowing the barrier rib patterns 405′ to be formed, through the exposure to light, development and rinse, on portions of the barrier rib material where the barrier ribs 404 should be formed as shown in
Then, a sand blast process can be performed on the barrier rib material 403 in a state where the barrier rib patterns 405′ of the mask 405 are left on the barrier rib material 403, whereby the barrier rib material 403 is etched such that only the barrier ribs 404 are left as shown in
When the physical etching process has been finished, the barrier rib material 403 between the barrier ribs 404 is etched and removed as shown in
The plasma display panel according to the present invention as described above can provide the following effects and advantages.
The shape of the barrier ribs can be changed to suppress or prevent the occurrence of the mixing of colors of the phosphor screens generated while coating the phosphor screens. For example, the blocking walls are formed at the beginning and/or finishing portions of the barrier ribs to prevent the coating solution from being transferred from a discharge space to the adjacent discharge spaces defined between the barrier ribs. Therefore, there is an advantage in that the mixing of colors of the phosphor screens is not generated.
In addition, the grooves can be formed between the upper surfaces of the barrier ribs to suppress the occurrence of the mixing of colors of the phosphor screens generated while coating the phosphor screens. The grooves can be formed between the upper surfaces of the barrier ribs formed perpendicularly to a direction in which the phosphor screens are coated, particularly in closed type barrier ribs. Therefore, since the grooves prevent the coating solution, which is coated on the upper surface of the barrier ribs in the closed type barrier ribs when continuously coating the barrier ribs with a coating solution for forming phosphor screens, from being transferred to adjacent discharge spaces, the mixing of colors of the phosphor screens is not generated and effectively prevented.
Although the present invention has been illustrated and described in connection with the preferred embodiments and the accompanying drawings, it is not to be limited thereto. Therefore, it will be readily understood by those skilled in the art that various modifications and changes can be made thereto without departing from the spirit and scope of the present invention defined by the appended claims. Accordingly, the scope of the present invention should be construed to be defined only by the appended claims.
Number | Date | Country | Kind |
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2005-0002194 | Jan 2005 | KR | national |