JP2007103054A - Plasma display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve uniformity of display characteristics within a display screen by restraining location dependency of discharge characteristics by driving in a display screen of a PDP panel. <P>SOLUTION: The plasma display panel is provided with a first substrate on which a plurality of display electrodes and dielectric layers are formed successively, with the dielectric layers coated with a protective film; and a second substrate arranged in opposition to the first substrate to form a discharge space in between, having address electrodes formed in a direction crossing the display electrodes, with phosphor layers formed between barrier ribs zoning the discharge spaces. The plasma display panel excites the phosphor layers by discharge of discharge gas sealed in the discharge spaces to make them emit light, a gradation display is carried out with the use of a sub-field method, and writes in image data in turn in a driving system of a scanning-maintenance separation type. The protective film coating the dielectric layers formed on the first substrate is formed in the display area with its film quality distributed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a plasma display panel (hereinafter also referred to as a PDP) that has been increasingly used as a display device for public display of large-sized televisions, advertisements, information, etc., and uses a protective film that can realize particularly high display quality. The present invention relates to a plasma display panel.

  In a general AC surface discharge type PDP, a front plate on which a plurality of display electrodes paired with a scan electrode and a sustain electrode are formed, and a plurality of address electrodes (also referred to as data electrodes) are formed in a direction perpendicular to the display electrodes. The front plate and the back plate are arranged to face each other so as to form a discharge space therebetween, and a discharge gas made of neon, xenon, or the like is sealed in the discharge space. At the portion where the display electrode and the address electrode intersect at right angles, a discharge cell constitutes a display pixel by a partition formed on the back plate in parallel with the address electrode.

  In this PDP, a driving method called a scanning / sustain separation type is used. In this driving method, by applying a write pulse between the scan electrode and the address electrode, a write discharge is performed in a discharge cell to be displayed, and then alternately inverted between the scan electrode and the sustain electrode. By applying a periodic sustain pulse, a sustain discharge is performed in a discharge cell in which an address discharge has been performed. By this sustain discharge, the phosphor layer formed between the barrier ribs on the back plate of the discharge cell emits light, whereby an image can be displayed.

  The display electrode is covered with a dielectric layer, and a protective film having a thickness of about 1 μm is formed on the dielectric layer. The protective film is formed using a material having high resistance to sputtering by ion bombardment, and protects the dielectric layer from sputtering by electric discharge. In addition, the ion bombardment also emits secondary electrons from the protective film itself to lower the driving voltage. Generally, this protective film is made of magnesium oxide (MgO), and is formed uniformly in the display screen by a vacuum film formation technique (see, for example, Patent Document 1).

Various proposals have been made to improve the efficiency of electron emission in the discharge of the PDP panel by associating the individual characteristics of the protective film itself such as the volume resistivity and refractive index of the protective film with the driving method of the PDP panel. (For example, refer to Patent Document 2 and Patent Document 3).
Japanese Patent Laid-Open No. 11-54045 JP 2003-317631 A JP 2002-33053 A

  In the above-described PDP driving method, after performing the erasing operation, first, setup is performed at the same timing in all the cells to make the state in each cell uniform, and then the image data is sequentially scanned onto the scanning lines to perform the writing discharge. Then, after that, the sustain discharge is started at the same timing in all the cells. Therefore, the time from the setup to the write discharge becomes longer as the scanning order goes backward, and the time from the write discharge to the sustain discharge becomes shorter. That is, there is a problem that the discharge characteristics when the write pulse is applied and when the sustain pulse is applied are different in the display screen, and the margin of the drive voltage is narrowed.

  By the way, the ease of discharge depends on the number of excited particles in the cell, and the larger the number of excited particles, the easier the discharge occurs. The excited particles in the cell are dominated by electron emission from the protective film on the dielectric layer formed on the front plate. In other words, the discharge characteristics are closely related to the electron emission characteristics of the protective film. However, the AC surface discharge type PDP has not designed the structure of the protective film and the driving method of the panel of the PDP in consideration of the electron emission characteristic of the protective film so far, and the discharge characteristic reaches a level that can be said to be perfect. It was used without being.

  The present invention has been made to solve the above-described problems, and suppresses the location dependence of the discharge characteristics due to driving in the display screen of the PDP panel, and improves the uniformity of the display characteristics in the display screen. The purpose is to let you.

  In order to achieve the above object, a PDP of the present invention includes a first substrate in which a plurality of display electrodes and dielectric layers each including a sustain electrode and a scan electrode are sequentially formed, and the dielectric layer is covered with a protective film; A phosphor layer is formed between partition walls that have address electrodes that are arranged opposite to each other so as to form a discharge space with the first substrate and that are formed in a direction perpendicular to the display electrodes, and that partition the discharge space. And a substrate between the scanning electrode and the sustaining electrode, and a voltage applied between the scanning electrode and the address electrode to sequentially write the image data. In a plasma display panel that performs display by a sustain discharge step in which sustain discharge is performed by applying a protective film, the protective film is formed with a gradient in film quality in the display region. The features.

  The protective film is characterized in that the film quality is inclined in the display region so as to correspond to the writing order in the writing step.

  The film quality of the protective film is the crystallinity of the (111) plane of the protective film, the refractive index of the protective film, the crystal grain size of the protective film, the packing density of the protective film, the surface area per unit weight of the protective film, The structure is characterized in that it is at least one of the volume resistivity and the thickness of the protective film, and is formed with an inclination so that the crystallinity of the (111) plane of the protective film becomes stronger in accordance with the order of writing. In order to increase the refractive index of the protective film in order to increase the refractive index of the protective film, in order to write, in order to increase the crystal grain size of the protective film in order to increase the crystal grain size, to form the protective film according to the order of writing, the packing density of the protective film The structure is formed with an inclination so as to be higher, and the structure is formed with an inclination so that the surface area per unit weight of the protective film is larger in accordance with the writing order. Configuration volume resistivity of the protective film is formed with an inclination so as to increase Te, may be used a structure which forms with an inclination so that the film thickness of the protective film in accordance with the writing order is increased.

  Furthermore, the protective film is made of a metal oxide containing magnesium oxide as a main component, or the protective film is one of a physical vapor method, a chemical vapor method, a sol-gel method, a printing method, a coating method, and an impregnation method. It may be formed by a method.

  With these configurations, the protective film on the front panel of the PDP can be formed with a gradient in the film quality of the protective film from the first row to the last row of writing, and the discharge characteristics in the display screen are made uniform Therefore, it is possible to provide a PDP having uniform discharge characteristics within the surface of the PDP panel and excellent display quality.

  According to the present invention, the film quality of the protective film covering the dielectric layer of the AC surface discharge type PDP is formed with a gradient in the film quality of the protective film from the first row to the last row of writing. Provided is a PDP display device which can achieve uniform writing discharge characteristics in the entire display screen and has a uniform discharge characteristic in the display screen and excellent display quality by using a PDP panel having such a protective film. Can do.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment)
A PDP according to an embodiment of the present invention will be described with reference to FIGS. 1, 2, 3, 4, and 5. FIG. FIG. 1 is an exploded perspective view showing a schematic structure of a PDP in an embodiment of the present invention, FIG. 2 is a timing chart for driving the PDP in the embodiment of the present invention, and FIG. 3 is in the embodiment of the present invention. 4 is a schematic diagram of a vacuum deposition apparatus for forming a protective film of a PDP, FIG. 4 is a graph showing a film thickness distribution of the protective film of the PDP in the embodiment of the present invention, and FIG. 5 is a discharge delay of the PDP in the embodiment of the present invention. It is a graph which shows time distribution.

  In FIG. 1, an AC surface discharge type PDP generates a discharge in the discharge space 30 by applying a pulsed voltage to each electrode, and, for example, red, green, and blue fluorescence on the back plate PA2 side along with the discharge. The visible light of each color excited by the body is transmitted from the main surface of the front plate PA1.

  The front plate PA1 has one display electrode 12 on the front glass substrate 11 on which a plurality of pairs of display electrodes 12 each including a scanning electrode 12a and a sustain electrode 12b are arranged in a stripe shape (one pair is extended for convenience in the drawing). A dielectric layer 13 made of low-melting glass is formed so as to cover the surface. Further, a protective film 14 is formed so as to cover the dielectric layer 13. The protective film 14 will be described in detail later.

  On the rear plate PA2, address electrodes 17 are provided on the rear glass substrate 16, and a plurality of address electrodes 17 are arranged in stripes so as to be orthogonal to the display electrodes 12 including the scan electrodes 12a and the sustain electrodes 12b. The electrode protection layer 18 is formed so as to cover the address electrodes 17 and protects the address electrodes 17 and has a function of reflecting visible light to the front panel side. A partition wall 19 is erected on the electrode protection layer 18 in the same direction as the address electrode 17 so as to sandwich the address electrode 17, and a phosphor layer 20 is disposed between the partition walls 19. In order to improve display contrast, a light shielding layer 15 serving as a black matrix may be formed between the scanning electrode 12a and the sustaining electrode 12b of the front glass substrate 11.

  The discharge gas space formed between the front plate PA1 and the back plate PA2 is filled with a rare gas such as neon (Ne) or xenon (Xe) having a predetermined pressure and blending amount as a discharge gas. . When a predetermined drive voltage is applied to the display electrode 12 and the address electrode 17 including the scan electrode 12a and the sustain electrode 12b, the external emission from the front plate PA1 is caused by light emission of the phosphor layer 20 and the like accompanying plasma discharge of the discharge gas. Visible light is emitted to each pixel and display by each pixel is performed.

  Next, the driving of the AC surface discharge type PDP will be described in a little more detail. The driving of the PDP according to the present invention performs gradation display using the subfield method and image display as already described in the background art. Therefore, it has a scanning / maintenance separation type driving method and sequentially writes image data.

  In FIG. 2, a setup period 41, a write period (write step) 42 for writing, a sustain period (sustain discharge step) 43 for maintaining a display discharge, and an erase period 44 for performing an erasing operation are formed. By repeatedly executing the above, it is possible to display a desired video on the PDP.

  In the setup period 41, a higher voltage is applied to the scan electrode 12a than the address electrode 17 and the sustain electrode 12b among the scan electrode 12a and the sustain electrode 12b constituting the display electrode 12, and a rare gas for discharge in the discharge cell is supplied. Discharge. Since the charge generated by the rare gas discharge is accumulated on the wall of the cell so as to cancel the potential difference among the address electrode 17, the scan electrode 12a and the sustain electrode 12b, a negative charge is formed on the surface of the protective film 14 near the scan electrode 12a. Are accumulated as wall charges, and positive charges are accumulated as wall charges on the surface of the phosphor layer 20 near the address electrodes 17 and the surface of the protective film 14 near the sustain electrodes 12b. Due to this wall charge, a predetermined wall potential is generated between the scan electrode 12a and the address electrode 17 and between the scan electrode 12a and the sustain electrode 12b.

  In the writing period 42, when the cell is turned on, a voltage lower than that of the address electrode 17 and the sustain electrode 12b is applied to the scan electrode 12a, that is, the voltage is applied to the scan electrode 12a and the address electrode 17 in the same direction as the wall potential. Write discharge is generated by applying the voltage in the same direction as the wall potential between the scan electrode 12a and the sustain electrode 12b. Accordingly, negative charges are accumulated on the surface of the phosphor layer 20 and the surface of the protective film 14, and positive charges are accumulated as wall charges on the surface of the protective film 14 near the scan electrode 12a. A wall potential of a predetermined value is generated between 12a.

  In sustain period 43, a sustain discharge is generated by applying a higher voltage to scan electrode 12a than sustain electrode 12b, that is, by applying a voltage between sustain electrode 12b and scan electrode 12a in the same direction as the wall potential. Thereby, cell lighting can be started. Then, the pulse can be intermittently emitted by applying a pulse so that the polarity of the sustain electrode 12b and the scan electrode 12a is alternately switched.

  In the erase period 44, an incomplete discharge is generated by applying a narrow erase pulse to the sustain electrode 12b, the wall charge is extinguished, and the sustain discharge is terminated.

  By repeating the above sequence, a desired image can be displayed in each cell.

  In the above-described sequence, the setup period 41 and the sustain period 43 are performed at the same timing in all cells, but in the writing period 42, scanning is sequentially performed from the first row of the scanning line to generate a writing discharge. Therefore, the time from setup to writing discharge becomes longer in the scanning order, and the time from writing discharge to sustaining discharge becomes shorter. For this reason, the following phenomenon occurs.

  As the time from the setup period 41 to the write period 42 becomes longer, the wall charges formed in the setup period 41 decrease. In addition, regarding the time from the writing period 42 to the sustain period 43, wall charges are lost due to electron emission from the protective film 14. That is, since more electrons are required in the regions where the writing order is later, the electron emission efficiency of the protective film 14 may be increased in each region.

  Here, in contrast to Patent Document 1 and Patent Document 2 exemplified in the background art, the relationship between the film quality of the protective film 14 of the PDP and the electron emission efficiency in the embodiment of the present invention will be described. With regard to the discharge characteristics at the time of writing in the setup period 41, focusing on the discharge delay time from when a voltage is applied between the scan electrode 12 a and the address electrode 17 to when the write discharge occurs, the discharge delay is a protective film on the dielectric layer 13. 14 strongly depends on the electron emission performance. The electron emission characteristics of the protective film 14 depend on the film quality and film thickness of the protective film 14. For example, Patent Document 2 shows an example in which the discharge delay time is shortened as the refractive index of the protective film 14 is high, and Patent Document 3 shows that the discharge delay time is shortened as the volume resistivity increases. An example is shown. However, although the above-mentioned patent documents suggest that the characteristics of the protective film change in the thickness direction, the concept of actively changing the characteristics in two dimensions cannot be found.

  On the other hand, the protective film 14 of the PDP according to the embodiment of the present invention has a film quality such as the characteristics and film thickness of the protective film according to the writing order when the protective film is formed on the dielectric layer 13 formed on the front plate PA1. By giving an inclination to the screen, it is possible to cancel the influence of driving for display. Therefore, the characteristic of the protective film is characterized in that the characteristic of the protective film is two-dimensionally changed in the plane of the display area of the PDP panel in association with the drive timing. By providing such a protective film, the writing characteristics in the display screen can be made uniform in relation to the drive timing, and the PDP having excellent display quality can be realized.

  The protective film 14 of MgO of PDP in the embodiment of the present invention is formed by a physical vapor phase method. The physical vapor phase method is a method of forming a thin film of a raw material on a target object by heating and evaporating or sublimating the solid raw material under a low pressure. Examples of the physical vapor phase method include a vacuum deposition method, a sputtering method, and an ion plating method. Among these, the principle of the general MgO protective film formation method is demonstrated using the vacuum evaporation system 50 shown in FIG.

  In FIG. 3, the vacuum vapor deposition apparatus 50 is provided with a device composed of a hearth 54 serving as an MgO evaporation unit and a tray 57 serving as a substrate holding unit in a sealed container 52 to which a vacuum pump 51 is connected. Yes. A protective film material 53 made of pellets of metal oxide such as MgO is supplied into an evaporation source pod 53a of a water-cooled hearth 54 and irradiated with a thermionic beam 56 emitted from electron guns 55a and 55b in an oxygen atmosphere. To heat and evaporate. The evaporated MgO adheres to the front plate PA1, which is a substrate heated to a predetermined temperature by the substrate heater 58. Here, the front plate PA1 is placed on a tray 57 having an opening 57a for supporting the substrate, and the evaporated MgO passes through the opening 57a to form a desired protective film 14 of MgO.

  In forming the protective film 14, it is necessary to supply oxygen gas during film formation. Oxygen gas is supplied into a sealed container 52 that serves as a vacuum film formation chamber (vacuum chamber) of the vacuum vapor deposition apparatus 50, whereby the protective film 14 is controlled to have a target film thickness. When a metal oxide such as MgO, which is a film raw material, is evaporated by electron beam irradiation, oxygen atoms are easily desorbed from the film raw material. Therefore, a film formed without supplying oxygen gas is likely to be in an oxygen deficient state. Therefore, it is necessary to always supply oxygen gas to the growth surface. Thus, by performing film formation while supplying oxygen gas, the transparency to visible light can be increased as a result.

Further, the film quality and film thickness of the protective film 14 can be arbitrarily controlled by various film forming parameters such as the heating temperature, oxygen gas pressure, and vapor deposition rate of the front plate PA1 as a substrate. In order to use as the protective film 14 in the PDP, it is preferable to set the substrate temperature to 200 ° C. or higher and the oxygen gas pressure to the 10 ⁻² Pa level. By controlling the film formation parameters so that the front plate PA1 to be formed has an inclination distribution, the protective film 14 can be formed with an inclination.

(Example)
An example will be described in which the protective film 14 covering the dielectric layer 13 of the front plate PA1 constituting the PDP in the embodiment of the present invention is formed by the electron beam evaporation method using the vacuum evaporation apparatus 50 shown in FIG. The film forming method using electron beam evaporation belongs to a method called the physical vapor phase method described above, and the protective film material 53 made of MgO pellets is irradiated by the electron beam 56 emitted from the electron guns 55a and 55b in the sealed container 52. It is evaporated by heating and deposited on the dielectric layer 13 of the front plate PA1.

In film formation, oxygen gas is introduced into the sealed container 52 of the vacuum evaporation apparatus 50 until the pressure reaches 4.0 × 10 ⁻² Pa, and the front plate PA 1 is heated to 250 ° C. by the substrate heater 58. The vacuum vapor deposition apparatus 50 using the electron beam used here includes two electron guns 55a and 55b. By individually controlling the emission current of the electron guns 55a and 55b, the front plate PA1 On the dielectric layer 13, it is possible to form a protective film 14 of MgO having a thickness distribution inclined in one direction.

  Specifically, the front plate PA1 of the PDP driven by the one-way scanning type is used, the emission current of the left electron gun 55a is set to 1 nm / s, and the emission current of the right electron gun 55b is set to 0.5 nm / s. By setting, the thickness of the protective film 14 of MgO has a distribution. At this time, it is desirable to arrange the front plate PA1 so that the writing order is from left to right.

  In addition, using the same front plate PA1 as in the above-described embodiment and using the same vacuum deposition apparatus 50, the emission currents of the two electron guns 55a and 55b are set to 1 nm / s under the same conditions as in the above-described embodiment. A protective film 14 was formed on the dielectric layer 13 of the front plate PA1 so that the film thickness distribution was uniform, and used as a comparative sample.

  Differences in the properties of the protective film 14 of MgO produced and formed on the front plate PA1 of the PDP in the above-described examples and comparative examples will be described. First, the film thickness distribution of the protective film 14 will be described. FIG. 4 shows the result of measuring the film thickness distribution on the center line of the front plate PA1. FIG. 4A shows the film thickness distribution of the protective film 14 formed on the front panel PA1 of the PDP based on the above-described embodiment. As shown in FIG. The film thickness is thick. On the other hand, as shown in FIG. 4B, the film thickness distribution of the protective film 14 formed on the front panel PA1 of the PDP in the comparative example is formed to have a substantially uniform thickness in the display screen except for the upper and lower ends. ing.

  Next, the discharge delay time of the protective film 14 of MgO produced and formed on the front panel PA1 of the PDP in Examples and Comparative Examples will be described. The results shown in FIG. 5 were obtained by forming PDP panels using the front plate PA1 on which the protective film 14 of MgO was formed and prototyped based on the above-described examples and comparative examples, and measuring the discharge delay time individually. Compared. FIGS. 5A and 5B show the distribution of discharge delay time on the center line of the display screen of the panel of the PDP using the front plate PA1 on which the protective film 14 is formed based on the example and the comparative example, respectively. . Here, the discharge delay time was obtained by averaging the discharge light emission for 100 times with respect to the time from when the voltage was applied between the scan electrode 12a and the address electrode 17 in the write (address) period 42 until the discharge occurred. According to FIG. 5, the protective film 14 having an inclination in the film thickness distribution formed on the basis of the example has a distribution of the discharge delay time in the vertical direction of the display screen indicated as the writing order by arrows in the figure, It was revealed that the film thickness was more uniform than the protective film 14 shown in the comparative example in which the film thickness distribution was uniformly formed.

  From the results described above, the protective film formed based on the method described in the embodiment forms a protective film with a distribution that is inclined so that the film thickness increases from the top to the bottom of the display screen. However, it was confirmed that the distribution of the discharge delay time was uniform. That is, in the protective film formed based on the method described in the embodiment, writing in the display screen is performed by providing a film quality (film thickness) distribution that cancels the writing characteristics by driving in the display screen. The characteristics can be made uniform and a PDP with excellent display quality can be realized.

  In the above-described embodiments, the case where the thickness of the protective film 14 is inclined has been described. However, other film qualities may be controlled by adjusting each film formation parameter at the time of forming the protective film. it can. As other film quality configurations, the film is formed with an inclination so that the crystallinity of the (111) plane of the protective film is strengthened according to the writing order, and the film is inclined so that the refractive index of the protective film is high according to the writing order. The structure to be formed, the structure to be formed with an inclination to increase the crystal grain size of the protective film according to the order of writing, the structure to be formed with the inclination to increase the packing density of the protective film according to the order of writing, and the writing According to the order, the structure formed with an inclination so as to increase the surface area per unit weight of the protective film, the structure formed with the inclination so as to increase the volume resistivity of the protective film according to the writing order can be used, Also with these configurations, the writing characteristics in the display screen such as the discharge delay time can be made uniform.

  In the above-described embodiments, the PDP driven by the unidirectional scanning type is described as an example. However, in the bidirectional scanning type PDP and the interlaced display type PDP, the film quality is not uniform and is distributed. By forming the protective film 14, it is possible to easily obtain the effect of making the discharge characteristics and display characteristics of the PDP uniform in the display region.

  Further, in the above-described embodiments, the formation of the protective film has been described by taking the physical vapor phase method as an example, but the present invention is not limited to this, and the chemical vapor phase method, the sol-gel method, the printing method, The protective film can also be formed by other methods such as a coating method and an impregnation method.

  As described above, in the PDP according to the embodiment of the present invention, the film quality and film thickness of the protective film covering the dielectric layer are inclined to the film quality and film thickness of the protective film from the first row to the last row of writing. Since the PDP having such a protective film is uniform, the discharge characteristics in the display screen are uniform and the display quality is excellent. PDP can be realized.

  Since the present invention suppresses the location dependence of the discharge characteristics by driving in the display screen of the panel by giving the distribution of the quality of the protective film of the PDP, and improves the uniformity of the display characteristics in the display screen. It is particularly effective when applied to a large PDP display device.

1 is an exploded perspective view showing a schematic structure of a PDP in an embodiment of the present invention. Timing chart for driving PDP in the embodiment of the present invention The schematic diagram of the vacuum evaporation system for protective film formation of PDP in embodiment of this invention The graph which shows the film thickness distribution of the protective film of PDP in embodiment of this invention The graph which shows the discharge delay time distribution of PDP in embodiment of this invention

Explanation of symbols

PA1 Front plate PA2 Back plate 11 Front glass substrate 12 Display electrode 12a Scan electrode 12b Sustain electrode 13 Dielectric layer 14 Protective film 15 Light shielding layer 16 Rear glass substrate 17 Address electrode 18 Electrode protective layer 19 Partition 20 Phosphor layer 30 Discharge space 41 Setup period 42 Write (address) period 43 Maintenance (sustain) period 44 Erase period 50 Vacuum deposition apparatus 51 Vacuum pump 52 Sealed container 53 Protective film material 53a Evaporation source pod 54 Hearth 55a, 55b Electron gun 56 Electron beam 57 Tray 57a Opening 58 Substrate heater

Claims (5)

A plurality of display electrodes and dielectric layers composed of sustain electrodes and scanning electrodes are sequentially formed, and a discharge space is formed between the first substrate and the first substrate covered with a protective film. A second substrate having address electrodes formed to face each other and formed in a direction orthogonal to the display electrodes, and having a phosphor layer formed between partition walls defining the discharge space, A discharge is formed by enclosing a discharge gas in the space, and a sustain discharge is performed by applying a voltage between the scan electrode and the sustain electrode and a write step for sequentially writing image data by applying a voltage to the scan electrode and the address electrode. In the plasma display panel that performs display by the sustain discharge step of performing
The plasma display panel according to claim 1, wherein the protective film is formed with a gradient in film quality in the display region. 2. The plasma display panel according to claim 1, wherein the protective film is formed with an inclination in film quality in the display region so as to correspond to the writing order in the writing step. The film quality of the protective film is the crystallinity of the (111) plane of the protective film, the refractive index of the protective film, the crystal grain size of the protective film, the packing density of the protective film, the surface area per unit weight of the protective film, the volume of the protective film The plasma display panel according to claim 1, wherein the plasma display panel is at least one of a resistivity and a thickness of the protective film. The plasma display panel according to claim 1, wherein the protective film is made of a metal oxide containing magnesium oxide as a main component. The plasma display panel according to claim 1, wherein the protective film is formed by a method using any one of a physical vapor phase method, a chemical vapor phase method, a sol-gel method, a printing method, a coating method, and an impregnation method.

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