Patent Application
20070285012
Further objects and advantages of the invention can be more fully understood from the following detailed description taken in conjunction with the accompanying drawings in which:
A plasma display apparatus according to the present invention will now be described in detail in connection with specific embodiments with reference to the accompanying drawings.
It is however to be noted that the plasma display apparatus according to the present invention is not limited to the following embodiments, but may include other embodiments.
The plasma display apparatus according to an embodiment of the present invention will be described in detail with reference to
Referring to
The upper panel 200 includes the sustain electrode pairs 202 and 203 formed in pairs on an upper substrate 201. The sustain electrode pairs 202 and 203 are divided into the scan electrode 202 and the sustain electrode 203 depending on its function. The sustain electrode pairs 202 and 203 are covered with an upper dielectric layer 204 that limits the discharge current and insulates between the electrode pairs. A protection layer 205 is formed on a top surface of the upper dielectric layer 204. The protection layer 205 serves to protect the upper dielectric layer 204 from sputtering of charged particles generated at the time of gas discharge and increase emission efficiency of secondary electrons.
Discharge spaces provided between the upper substrate 201, the lower substrate 211, and the barrier rib 212 are injected with a discharge gas. It is preferred that the discharge gas contain xenon (Xe) of 10% or more. If xenon (Xe) is contained in the discharge gas with the above mixed ratio, discharge/emission efficiency and luminance of the plasma display panel can be improved.
The lower panel 210 includes the barrier ribs 212 that partition a plurality of discharge spaces (i.e., the discharge cells) on the lower substrate 211. Furthermore, the address electrodes 213 are disposed to cross the sustain electrode pairs 202 and 203. A phosphor 214, which is emitted by ultraviolet rays generated during the discharge of gas to generate a visible ray, is coated on surfaces of a lower dielectric layer 215 and the barrier ribs 212.
The barrier ribs 212 include longitudinal barrier ribs 212a formed parallel to the address electrodes 213, and traverse barrier ribs 212b formed to cross the address electrodes 213. The barrier ribs 212 partition the discharge cells physically and serve to prevent ultraviolet rays and a visible ray generated by a discharge from leaking to neighboring discharge cells.
Furthermore, in the plasma display panel according to the present invention, the sustain electrode pairs 202 and 203 include only opaque metal electrodes unlike the conventional sustain electrode pairs 102 and 103 shown in
For example, each of the sustain electrode pairs 202 and 203 according to the present invention may be formed using silver (Ag). It is preferred that the silver (Ag) have a photosensitive property. It is also preferred that each of the sustain electrode pairs 202 and 203 according to the present invention have a color darker than that of the upper dielectric layer 204 or the lower dielectric layer 214 and has a light transmittance, which is lower than that of the upper dielectric layer 204 or the lower dielectric layer 214.
In the discharge cell, the R, G, and B phosphor layers 214 may have a symmetrical structure having the same pitch or an asymmetrical structure having a different pitch. In the case where the discharge cell has the asymmetrical structure, it is preferred that the order be “the pitch of the R cell<the pitch of the G cell<the pitch of the B cell”.
It is preferred that each of the sustain electrodes 202 and 203 includes a plurality of electrode lines within one discharge cell, as shown in
It is also preferred that the first and second sustain electrodes 202 and 203 be the scan electrode and the sustain electrode, respectively. This is because the aperture ratio and discharge diffusion efficiency depending on the opaque sustain electrode pairs 202 and 203 are taken into consideration. In other words, an electrode line having a narrow pitch is used in consideration of the aperture ratio, whereas a plurality of electrode lines are used in consideration of the discharge diffusion efficiency. The number of the electrode lines may be decided taking both the aperture ratio and the discharge diffusion efficiency into consideration.
The construction shown in
The black matrix may have a separation type BM structure or an integration type BM structure. In the separation type BM, a layer (a black layer) formed between the sustain electrodes 202 and 203 and the upper substrate 201 is not connected to the black matrix. In the integration type BM, the black layer is connected to the black matrix to form the integration type. Furthermore, when the black matrix has the separation type BM, the black matrix and the black layer may be formed using different materials. When the black matrix has the integration type BM, the black matrix and the black layer may be formed using the same material.
Furthermore, the barrier rib structure of the panel shown in
An embodiment of the present invention may be applied to not only the barrier rib structure shown in
In the differential type barrier rib structure, it is preferred that the height of the traverse barrier rib 212b be high. In the channel type barrier rib structure or the hollow type barrier rib structure, it is preferred that a channel or a hollow be formed in the traverse barrier rib 212b.
Meanwhile, in the present embodiment, it has been shown and described that the R, G, and B discharge cells are arranged on the same line. However, the R, G, and B discharge cells may be arranged in different forms. For example, the R, G, and B discharge cells may have a delta type arrangement in which they are arranged in a triangle. Furthermore, the discharge cells may be arranged in a variety of forms, such as square, pentagon and hexagon.
If the distance between the two sustain electrodes 202 and 203 are increased so as to secure the aperture ratio of the plasma display panel as described above, the pitch of the discharge cell is increased. Therefore, in order to secure the number of pixels required per panel, it is preferred that a top width X of the barrier rib 212 be set to 30 to 50 μm, a bottom width Y of the barrier rib 212 be set to 60 to 80 μm, and the dielectric constant of the barrier rib 212 be set to 6 to 10, and the height of the barrier rib 212 be set to 100 to 140 μm.
As the pitch of the barrier rib 212 is reduced as described above, it is preferred that a thickness Z of the lower dielectric layer 215 and a thickness of the upper dielectric layer 214 be set in a range of 30 to 40 μm so as to insulate between the sustain electrodes 202 and 203 efficiently. Furthermore, in order to efficiently insulate between the two sustain electrodes 202 and 203 while securing the pixel number required in the plasma display panel according to the present invention, it is preferred that the ratio between the top width X of the barrier rib 212 and the thickness of the dielectric layers 214 and 215 is set in a range of 5:3 to 3:4, and the ratio between the bottom width Y of the barrier rib 212 and the thickness of the dielectric layers 214 and 215 is set in a range of 8:3 to 3:2.
It is preferred that the barrier rib 212 of the plasma display panel according to the present invention be formed using a photosensitive material comprising an inorganic component and an organic component containing a photosensitive compound. The barrier rib 212 may be formed by a process of forming a pattern using a photolithography process and then performing sintering to form an inorganic pattern. The photolithography process includes forming a pattern through a photochemical reaction by exposing a photosensitive material to light having a specific wavelength through a mask in which a pattern is formed.
The photosensitive material for forming the barrier rib 212 may include an inorganic component containing glass particles of 60 weight % or more and an organic component containing a photosensitive compound. It is preferred that the difference between an average refractive index N1 of the inorganic component and an average refractive index N2 of the organic component be set in a range of −0.1 to 0.2. It is also preferred that the average refractive index N1 of the inorganic component range from 1.5 to 1.65.
If the photosensitive material is formed of the inorganic component and the photosensitive organic component having the above-mentioned ratio and average refractive index, barrier ribs having a high-accuracy pattern and a small pitch can be formed.
It is also preferred that the photosensitive material include 50 to 96 weight % of the inorganic component and 5 to 50 weight % of the organic component. If the photosensitive material includes the inorganic component and the photosensitive organic component having the above-mentioned ratio, a reduction ratio and variation in the shape when sintering the barrier rib 212 can be reduced and barrier ribs having a small pitch can be formed conveniently.
The inorganic component included in the photosensitive material may include glass, alumina, cordierite, gold, platinum, silver, copper, nickel, palladium, tungsten, RuO2 and the like, and more preferably glass or ceramics including insulators, such as silicon oxide, boron oxide or aluminum oxide, as a major component.
The inorganic component may preferably include a photocatalyst, such as titanium oxide (TiO2), in order to accelerate the photochemical reaction of the photosensitive organic compound.
It is preferred that at least one of lithium oxide, natrium oxide, and potassium oxide be included in the glass particle included in the inorganic component in an amount of 3 to 20 weight % based on the total weight of the glass particle.
If the above-mentioned glass particle is used, a thermal softening temperature and the coefficient of thermal expansion of the inorganic component can be controlled easily and the average refractive index between the inorganic component and the organic component can be set to 0.1 or less conveniently. It is further preferred that the glass particle include lithium oxide or potassium oxide so as to increase the stability of the photosensitive material and reduce the refractive index of the inorganic component.
It is preferred that at least one of lithium oxide and lead oxide be included in the glass particle in an amount of 5 to 50 weight % based on the total weight of the glass particle. It is therefore possible to obtain a photosensitive barrier rib material having a temperature characteristic in which it can be patterned on the lower substrate 211, i.e., a glass substrate and also to increase the port lifespan of the photosensitive material.
In addition, it is preferred that at least one of lithium oxide and lead oxide be included in the glass particle in an amount of 5 to 30 weight % based on the total weight of the glass particle, and it is more preferred that at least one of lithium oxide, natrium oxide, and potassium oxide be included in the glass particle in an amount of 3 to 15 weight % based on the total weight of the glass particle.
If the glass particle as described above is used, it is possible to prevent a mismatch between the photosensitive material and the glass substrate, which is incurred since the coefficient of thermal expansion of the photosensitive material is deviated from a target value, and also to reduce a thermal softening point.
It is preferred that the photosensitive barrier rib material may not include lead (Pb), or lead (Pb) may be included in the photosensitive barrier rib material in an amount of 0.1 weight % or 1000 PPM (Parts Per Million) or less based on the total weight of the plasma display panel.
When a total content of the Pb component is 1000 PPM or less, the content of Pb against the weight of the plasma display panel may be set to 1000 PPM or less.
Alternatively, the content of the Pb component included in a specific constituent element of the plasma display pane may be set to 1000 PPM or less. For example, the content of the Pb component of the barrier rib, the Pb component of the dielectric layer or the Pb component in the electrode may be set to 1000 PPM or less in an amount of each of the constituent elements (the barrier rib, the dielectric layer, and the electrode).
Furthermore, the content of the Pb component of the entire constituent elements, such as the barrier rib, the dielectric layer, the electrode, and the phosphor layer of the plasma display panel, may be set to 1000 PPM or less in a total weight of the plasma display panel. The reason why a total content of the Pb component is set to 1000 PPM or less as described above is that the Pb component may have a bad influence on the human body.
The organic component includes a photosensitive component containing photosensitive monomer, photosensitive oligomer or photosensitive polymer, and preferably further includes an additive component, such as a binder, a photopolymerization initiator, an ultraviolet absorbent, a sensitizer, an increment and decrement agent, a polymerization preventer, a plasticizer, a thickener, an organic solvent, an antioxidant, a dispersant, an organic or inorganic anti-setting agent or a leveling agent.
The photosensitive component may include both a non-photosoluble type and a photosoluble type. The non-photosoluble type may include a functional monomer, oligomer or polymer having one or more unsaturated groups, etc. within a molecule. The non-photosoluble type may also include photosensitive compounds, such as aromatic diazo compounds, aromatic azide compounds, and organic halogen compounds, diazo resin (i.e., a condensate of diazo-based amine and formaldehyde), and the like.
Furthermore, the photosoluble type may include a complex of inorganic salts of diazo compounds and organic acids, quinone diazo, phenol in which quinone diazo kinds are condensated by a proper polymer binder, naphthoquinone-1,2-diazid-5-sulfonate Esters of novolak resin, and the like.
The plurality of discharge cells are respectively disposed at the intersections of scan electrode lines Y1 to Ym, sustain electrodes line Z1 to Zm, and address electrodes lines X1 to Xn. The scan electrode lines Y1 to Ym are sequentially driven and the sustain electrode lines Z1 to Zm are commonly driven. The address electrode lines X1 to Xn are driven with them being divided into even-numbered lines and odd-numbered lines.
The electrode arrangement shown in
As shown in
The electrode lines 202a, 202b, 203a, and 203b cross the discharge cell and extend in one direction of the plasma display panel. The electrode line according to a first embodiment of the present invention has a narrow pitch so as to improve the aperture ratio. Furthermore, in order to improve the discharge diffusion efficiency, the plurality of electrode lines 202a, 202b, 203a, and 203b are used. It is, however, preferred that the number of the electrode lines is decide in consideration of the aperture ratio.
The protruding electrodes 202c and 203c are connected to the electrode lines 202a and 203a, respectively, which are the closest to the center of the discharge cell within one discharge cell and are preferably projected toward the center of the discharge cell. The protruding electrodes 202c and 203c serve to lower a firing voltage when the plasma display panel is driven. Since the firing voltage is increased due to a distance C between the electrode lines 202a and 203a, the protruding electrodes 202c and 203c are provided in the electrode lines 202a and 203a, respectively, in the first embodiment of the present invention. A discharge can begin even at a low firing voltage between the protruding electrodes 202c and 203c that are formed closely. It is therefore possible to lower the firing voltage of the plasma display panel. The firing voltage refers to a voltage level at which a discharge begins when a pulse is supplied to at least one of the sustain electrode pairs 202 and 203.
The protruding electrodes 202c and 203c have a very small size. Therefore, a width W1 of a portion at which the protruding electrode 202c or 203c is connected to the electrode line 202a or 203a of the protruding electrode 202c or 203c may be formed wider than a width W2 at the end of the protruding electrode due to the tolerance of the manufacturing process. The width W2 at the end of the protruding electrode may be formed wider than the width W1, if appropriate.
It is preferred that a distance between two neighboring electrode lines constituting each of the sustain electrode pairs 203 and 202 (i.e., a distance between the electrodes 203a and 203b or a distance between the electrodes 202a and 202b) be in a range of 80 to 120 μm. If a distance between the two neighboring electrode lines has the above-mentioned value, the aperture ratio of the plasma display panel can be secured sufficiently, the luminance of a display image can be improved, and the discharge diffusion efficiency within the discharge space can be increased.
It is preferred that the width W1 of the protruding electrode 202c or 203c is in a range of 35 to 45 μm. If the width of the protruding electrode 202c or 203c has the above-mentioned value, it is possible to prevent a reduction in the luminance of an image, which is incurred as light reflecting toward the front of a display device is precluded by the protruding electrodes 202c and 203c since the aperture ratio of the plasma display panel is low.
Furthermore, a distance “a” between the protruding electrodes 202c and 203c may preferably range from 15 to 165 μm. If the distance “a” between the protruding electrodes 202c and 203c has the above-mentioned value, the lifespan of the electrodes can be prevented from shortening because a discharge between the protruding electrodes 202c and 203c excessively occurs over a critical value. The protruding electrodes 202c and 203c can also have a firing voltage suitable for driving the plasma display panel.
The bridge electrodes 202d and 203d connect the two electrode lines 202a and 202b, and 203a and 203b, respectively, which constitute the sustain electrodes 202 and 203, respectively. The bridge electrodes 202d and 203d help a discharge, which is started through the protruding electrodes 202c and 203c, to easily diffuse into the electrode lines 202b and 203b that are far from the center of the discharge cell.
As described above, the electrode structure according to a first embodiment of the present invention can improve the aperture ratio by limiting the number of the electrode lines. Furthermore, a firing voltage can be lowered since the protruding electrodes 202c and 203c are formed. Furthermore, the discharge diffusion efficiency can be improved by the bridge electrodes 202d and 203d, and the electrode lines 202b and 203b that are far from the center of the discharge cell. This can improve the emission efficiency of the plasma display panel as a whole. That is, since the luminance of the plasma display panel can be at least the same as or higher than that of the conventional plasma display panel, the ITO transparent electrodes may not be used.
As shown in
The electrode lines 402a, 402b, 403a, and 403b cross the discharge cell and extend in one direction of the plasma display panel. It is preferred that a sustain electrode line according to a second embodiment of the present invention has a narrow pitch in order to improve the aperture ratio. Preferably, a pitch W1 of the electrode line may be set within a range of 20 μm to 70 μm so that a discharge can be generated smoothly while improving the aperture ratio.
As shown in
The electrode lines 402b and 403b that are the furthest from the center of the discharge cell are connected to the second protruding electrodes 402e and 403e. Furthermore, the electrode lines 402b and 403b that are the furthest from the center of the discharge cell serve to diffuse a discharge up to near the discharge cell.
The first protruding electrodes 402c and 403c are connected to the electrode lines 402a and 403a, respectively, which are the closest to the center of the discharge cell within one discharge cell and are projected toward the center of the discharge cell. It is preferred that the first protruding electrodes 402c and 403c are formed at the centers of the electrode lines 402a and 403a, respectively. The first protruding electrodes 402c and 403c are formed at the centers of the electrode lines in a corresponding manner, so that a firing voltage of the plasma display panel can be further lowered effectively.
It is preferred that a width w1 of each of the protruding electrodes 402c and 403c is in a range of 35 to 45 μm and a distance a between the protruding electrodes 402c and 403c is in a range of 15 to 165 μm. The critical meaning of the highest limit value and the lowest limit value of the pitch and distance of the protruding electrodes 402c and 403c is the same as that descried with reference to
The bridge electrodes 402d and 403d are connected to the two electrode lines 402a and 402b, and 403a and 403b, respectively, which form the sustain electrodes 402 and 403, respectively. The bridge electrode 402d helps a discharge, which begins through the protruding electrode 402d, to easily diffuse into the electrode line 402b that is the furthest from the center of the discharge cell. Furthermore, the bridge electrode 403d helps a discharge, which begins through the protruding electrode 403d, to easily diffuse into the electrode line 403b that is the furthest from the center of the discharge cell.
It is shown in
Furthermore, the second protruding electrodes 402e and 403e are connected to the electrode lines 402b and 403b, which are the furthest from the center of the discharge cell, and are projected in an opposite direction to that of the center of the discharge cell. A length of each of the second protruding electrodes 402e and 403e may preferably range from 50 to 100 μm. It helps a discharge to effectively diffuse into the discharge spaces that are the furthest from the center of the discharge cell.
As shown in
In the case where the second protruding electrodes 402e and 403e are not extended up to the barrier rib 412, however, it is preferred that a distance between the second protruding electrode 402e or 403e, and a neighboring barrier rib 412 is set in a range of 70 μm or less. When the distance between the second protruding electrode 402e or 403e, and the barrier rib 412 is 70 μm or less, a discharge can be diffused effectively into the discharge spaces that are the furthest from the center of the discharge cell.
In the second embodiment of the sustain electrode structure according to the present invention, the second protruding electrodes 402e and 403e are preferably formed at the centers of the electrode lines 402b and 403b, respectively, in order to uniformly diffuse a discharge into the periphery of the discharge cell.
Meanwhile, in the second embodiment of the present invention, it is preferred that a pitch Wb of a barrier rib located in a direction along which the second protruding electrode 402e or 403e extends, of barrier ribs partitioning the discharge cell, be set to 200 μm or less. It is also preferred that a black matrix (not shown) that secures bright contrast by absorbing external light and prevents radiated discharge light from diffusing into neighboring discharge cells and being displayed thereon be formed on the barrier rib 412.
If the pitch of the barrier rib 412 is set to 200 μm or less as described above, an area of the discharge cell can be increased. This can improve emission efficiency and can also compensate for a reduction in the aperture ratio, which is incurred by the second protruding electrode, etc. Preferably, the pitch Wb of the barrier rib located in a direction along which the second protruding electrode extends may be set in a range of 90 to 100 μm in order to obtain an optimal emission efficiency.
In the third embodiment of the sustain electrode structure according to the present invention, two first protruding electrodes 602a and 603a are formed in sustain electrodes 602 and 603, respectively, as shown in
It is preferred that a pitch of each of the first protruding electrodes 602a and 603a be in a range of 35 to 45 μm. The critical meaning of the highest limit value and the lowest limit value of the pitch of the protruding electrodes is the same as that descried with reference to
It is preferred that each of distances d1 and d2 between the two first protruding electrodes projected from one electrode line be 50 to 100 μm when a plasma display panel is a 42-inch size and VGA resolutions, 30 to 80 μm when a plasma display panel is a 42-inch size and XGA resolutions, and 40 to 90 μm when a plasma display panel is a 50-inch size and XGA resolutions.
If the distances d1 and d2 of the first protruding electrodes are set as described above, an aperture ratio capable of implementing the luminance of an image, which is required in a display device, can be secured. It is therefore possible to prevent power necessary for display from being consumed over a limit value, which is incurred as invalid power is increased because the first protruding electrodes are disposed too close to the barrier rib.
Since the two first protruding electrodes 602a and 603a are formed in the sustain electrodes 602 and 603, respectively, the area of the electrode at the center of the discharge cell can be widened. Accordingly, before a discharge begins, a firing voltage can be further lowered and a discharge speed can be increased because lots of spatial charges are formed within the discharge cell. Furthermore, after a discharge begins, luminance can be improved since an amount of wall charges is increased, and a discharge can be uniformly diffused over the whole discharge cell.
Furthermore, it is preferred that distances al and a2 between the first protruding electrodes 602a and 603a (i.e., the distances a1 and a2 between two protruding electrodes in a direction to cross electrode lines 602 and 603) be set in a range of 15 to 165 μm. The critical meaning of the highest limit value and the lowest limit value of the distances between the protruding electrode is the same as that descried with reference to
In the fourth embodiment of the sustain electrode structure according to the present invention, sustain electrodes 702 and 703 include three first protruding electrodes 702a and 703a, respectively, as shown in
The first protruding electrodes 702a or 703a are connected to one of electrode lines, which is close to the center of a discharge cell, and are projected toward the center of the discharge cell. It is preferred that one of the first protruding electrodes be formed at the center of the electrode lines and the remaining two first protruding electrodes be symmetrical to each other around the center of the electrode line.
The three first protruding electrodes 702a and 703a are formed in the sustain electrodes 702 and 703, respectively, as described above. Accordingly, a firing voltage can be further lowered and a discharge speed can become fast compared with the embodiments of
By increasing the number of the first protruding electrodes as described above, the electrode area at the center of the discharge cell can be increased, a firing voltage can be lowered, and luminance can be improved. It is, however, to be noted that a strong discharge is generated at the center of the discharge cell and the brightest discharge light is radiated.
In other words, since light radiated from the center of the discharge cell is precluded as the number of the first protruding electrodes increases, radiated light is significantly reduced. Therefore, it is preferred that the structure of the sustain electrode be designed by selecting an optimal number taking both the firing voltage and luminance efficiency into consideration.
It is preferred that a pitch of each of the first protruding electrodes 702a and 703a be in a range of 35 to 45 μm and distances a1, a2, and a3 between the first protruding electrodes 702a and 703a be in a range of 15 to 165 μm. The critical meaning of the highest limit value and the lowest limit value of the pitch and distance of the first protruding electrodes 702a and 703a is the same as that descried with reference to
Referring to
It is preferred that a thickness of the electrode lines 800a, 800b, 800c, 810a, 810b, and 810c of the sustain electrode pairs be in a range of 3 to 7 μm. Distances a1 and a2 between the three electrode lines constituting the sustain electrode 800 or 810 may be the same or different from each other. Furthermore, pitches b1, b2, and b3 of the electrode lines constituting the sustain electrode 800 or 810 may be the same or different from each other. The critical meaning of the highest limit value and the lowest limit value of the thickness of the electrode line is the same as that descried with reference to
Referring to
It is preferred that each of the electrode lines 900a, 900b, 900c, and 900d, and 910a, 910b, 910c, and 910d of the sustain electrode pair 900 and 910 have a thickness of 3 to 7 μm. The critical meaning of the highest limit value and the lowest limit value of the electrode line thickness is the same as that descried with reference to
Distances c1, c2, and c3 between the four electrode lines constituting the sustain electrode 900 or 910 may be the same or different from each other, and pitches d1, d2, d3, and d4 of the four electrode lines constituting the sustain electrode 900 or 910 may also be the same or different from each other.
Referring to
It is preferred that each of the electrode lines 1000a, 1000b, 1000c, and 1000d, and 1010a, 1010b, 1010c, and 1010d of the sustain electrode pair have a thickness of 3 to 7 μm. The critical meaning of the highest limit value and the lowest limit value of the electrode line thickness is the same as that descried with reference to
Each of bridge electrodes 1020, 1030, 1040, 1050, 1060, and 1070 connects two electrode lines. The bridge electrodes 1020, 1030, 1040, 1050, 1060, and 1070 allow an initiated discharge to be easily diffused into electrode lines that are far from the center of the discharge cell. As shown in
Referring to
It is preferred that each of the electrode lines 1100a, 1100b, 1100c, 1100d, 1110a, 1110b, 1110c, and 1110d of the sustain electrode pair have a thickness of 3 to 7 μm. The critical meaning of the highest limit value and the lowest limit value of the electrode line thickness is the same as that descried with reference to
Referring to
It is preferred that each of the electrode lines 1200 and 1210 of the sustain electrode pair be in a range of 3 to 7 μm. The critical meaning of the highest limit value and the lowest limit value of the electrode line thickness is the same as that descried with reference to
It is also preferred that line widths W1 and W2 of the protruding electrodes 1220 and 1230 range from 35 to 45 μm. If the protruding electrodes 1220 and 1230 have the above-mentioned line widths W1 and W2, a sufficient aperture ratio of a panel can be secured. It is therefore possible to prevent a reduction in the luminance of an image, which is incurred since light reflected toward the front of a display device is precluded by the protruding electrodes.
Furthermore, a distance between the two protruding electrodes 1220 and 1230 may preferably range from 15 to 165 μm. The critical meaning of the highest limit value and the lowest limit value of the distance between the protruding electrodes is the same as that descried with reference to
Referring to
It is preferred that each of the electrode lines 1300 and 1310 of the sustain electrode pair be in a range of 3 to 7 μm. The critical meaning of the highest limit value and the lowest limit value of the electrode line thickness is the same as that descried with reference to
It is also preferred that line widths W1 and W2 of the protruding electrodes 1320 and 1330, respectively, be within a range of 35 to 45 μm. The critical meaning of the highest limit value and the lowest limit value of the line widths W1 and W2 of the protruding electrodes 1320 and 1330 is the same as that descried with reference to
Furthermore, a distance between the two protruding electrodes 1320 and 1330 may range from 15 to 165 μm. The critical meaning of the highest limit value and the lowest limit value of the distance between the protruding electrodes is the same as that descried with reference to
Referring to
It is preferred that in the electrode line 1400, the two first protruding electrodes 1420a and 1420b be projected toward the center of the discharge cell and one second protruding electrode 1440 be projected in an opposite direction to that of the center of the discharge cell, as shown in
It is preferred that each of the electrode lines 1400 and 1410 of the sustain electrode pair have a thickness of 3 to 7 μm. The critical meaning of the highest limit value and the lowest limit value of the electrode line thickness is the same as that descried with reference to
It is also preferred that each of the first protruding electrodes 1420a, 1420b, 1430a, and 1430b have a pitch of 35 to 45 μm. The critical meaning of the highest limit value and the lowest limit value of the protruding electrode pitch is the same as that descried with reference to
It is preferred that each of distances d1 and d2 between the two first protruding electrodes projected from one electrode line be 50 to 100 μm when a plasma display panel is a 42-inch size and VGA resolutions, 50 to 100 μm when a plasma display panel is a 42-inch size and XGA resolutions, and 40 to 90 μm when a plasma display panel is a 50-inch size and XGA resolutions. The critical meaning of the highest limit value and the lowest limit value of the distances d1 and d2 between the first protruding electrodes is the same as that descried with reference to
It is also preferred that a distance between another first protruding electrodes, i.e., a distance a1 between the electrodes 1420a and 1430a or a distance a2 between the electrodes 1420b and 1430b be in a range of 15 to 165 μm. The critical meaning of the highest limit value and the lowest limit value of the distances between the protruding electrodes is the same as that descried with reference to
A unit frame may be divided into a predetermined number (for example, eight subfields SF1, . . . , SF8) in order to realize time-dividing gray level display. Furthermore, each of the subfields SF1, . . ., SF8 is divided into a reset period (not shown), address periods A1, . . . , A8, and sustain periods S1, . . . , S8. According to the present invention, the reset period may be omitted from at least one of the plurality of subfields. For example, the reset period may exist only in the first subfield or may exist only in a subfield approximately located between the first subfield and the whole subfield.
In each of the address periods A1, . . . , A8, a display data signal is applied to address electrodes X and scan pulses corresponding to respective scan electrodes Y are sequentially applied to the address electrodes X.
In each of the sustain periods S1, . . . , S8, a sustain pulse is alternately applied to the scan electrode Y and a sustain electrode Z. Accordingly, a sustain discharge is generated in discharge cells on which wall charges are formed in the address periods A1, . . . , A8.
The luminance of the plasma display panel is proportional to the number of sustain discharge pulses within the sustain periods S1, . . . , S8 occupied in the unit frame. In the case where one frame forming one image is represented by eight subfields and 256 gray levels, a different number of sustain pulses may be sequentially allocated to the respective subfields in the ratio of 1, 2, 4, 8, 16, 32, 64, and 128. In order to obtain luminance of 133 gray levels, a sustain discharge can be generated by addressing cells during the subfield1 period, the subfield3 period, and the subfield8 period.
The number of sustain discharges allocated to each subfield may be varied depending on the weight of a subfield according to the APC (Automatic Power Control) step. That is, an example in which one frame is divided into eight subfields has been described with reference to
Furthermore, the number of sustain discharges allocated to each subfield may be changed in various ways in consideration of a gamma characteristic or a panel characteristic. For example, the degree of a gray level allocated to the subfield4 can be lowered from 8 to 6 and the degree of a gray level allocated to the subfield6 can be lowered from 32 to 34.
There is a pre-reset period for forming positive wall charges on the scan electrode Y and negative wall charges on the sustain electrode Z. Each subfield includes a reset period for initializing discharge cells of the whole screen using wall charge distributions formed by the pre-reset period, an address period for selecting discharge cells, and a sustain period for sustaining the discharge of selected discharge cells.
The reset period includes a setup period and a set-down period. In the setup period, a ramp-up waveform ramp-up is applied to all the scan electrodes at the same time. Therefore, a minute discharge is generated in the entire discharge cell and wall charges are generated accordingly.
In the set-down period, a ramp-down waveform ramp-down, which falls from a positive voltage lower than a peak voltage of the ramp-up waveform, is applied to the entire scan electrodes Y at the same time. Therefore, an erase discharge is generated in the entire discharge cells, thereby erasing unnecessary charges from the wall charges generated by the set-up discharge and spatial charges.
In the address period, a negative scan signal scan is sequentially applied to the scan electrodes, and at the same time, a positive data signal data is applied to the address electrode X. Therefore, an address discharge is generated due to a voltage difference between the scan signal scan and the data signal data and a wall voltage generated during the reset period, so that cells are selected. Meanwhile, during the set-down period and the address period, a signal that maintains a sustain voltage Vs is applied to the sustain electrode.
In the sustain period, a sustain pulse is alternately applied to the scan electrode and the sustain electrode, so that a sustain discharge is generated between the scan electrode and the sustain electrode in a surface discharge form.
The driving waveforms shown in
In accordance with the plasma display apparatus according to the present invention, since the transparent electrodes made of ITO are removed, the manufacturing cost of the plasma display panel can be saved. Furthermore, the protruding electrodes are projected from the scan electrode or the sustain electrode line to the center of the discharge cell or in an opposite direction to that of the center of the discharge cell. Accordingly, a firing voltage can be lowered and discharge diffusion efficiency within the discharge cell can be increased.
While the present invention has been described with reference to the particular illustrative embodiments, it is not to be restricted by the embodiments but only by the appended claims. It is to be appreciated that those skilled in the art can change or modify the embodiments without departing from the scope and spirit of the present invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2006-0052130 | Jun 2006 | KR | national |
