JP2010186686A - Plasma display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To alleviate power consumption while restraining degradation of luminance characteristics of a PDP device. <P>SOLUTION: In the plasma display device provided with a phosphor film formed between a front plate and a rear-face plate arranged in opposition, having a discharge space inside filled with discharge gas, with the rear-face plate arranged in contact with the discharge space, the phosphor film 8 is structured of a phosphor 22 emitting visible light by being excited by ultraviolet rays and an electrostatically charged material 21 of positive charge with charging characteristics larger than those of the phosphor 22. The charged material 21 is constituted of a matrix made of magnesium oxide, and an additive element other than magnesium added to the matrix. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a technology for an image display device, and more particularly to a technology that is effective when applied to a plasma display device that displays phosphors by irradiating them with vacuum ultraviolet rays to emit light and display images.

  In video information systems, various display devices are actively researched and developed in response to various demands such as high definition, large screen, thinning, and low power consumption. Among them, research and development of a plasma display panel (PDP) is progressing as a display realizing a large screen and high definition. The PDP includes a front-side substrate and a back-side substrate that are arranged to face each other, and a space between the front and back substrates is filled with a discharge gas such as Ne and Xe. Then, by applying a voltage to the electrodes, vacuum ultraviolet rays (146 nm and 172 nm) are emitted from the discharge gas, and the vacuum ultraviolet rays excite the phosphor placed on the back substrate, causing red, green, and blue light emission, thereby producing an image. A display panel to be displayed.

As a technique for reducing the discharge voltage of the PDP, a technique for mixing a phosphor with a material having a positive charge characteristic larger than that of the phosphor has been studied. For example, a method has been reported in which a green phosphor, Zn ₂ SiO ₄ : Mn, is mixed with a (Y, Gd) BO ₃ : Tb phosphor whose charging characteristics are larger than positive charges (Non-Patent Document). 1). Japanese Patent Laid-Open No. 2002-38146 (Patent Document 1) describes a plasma display panel using a phosphor on which a positively charged oxide (MgO) is attached or coated. Japanese Patent Application Laid-Open No. 2008-181841 (Patent Document 2) describes a PDP having a phosphor layer containing a magnesium oxide crystal having a particle size of 2000 angstroms or more.

JP 2002-38146 A JP 2008-181841 A

J. Electrochem. Soc. 150 (8), H165-H171 (2003)

  However, the present inventor has studied the reduction of the discharge voltage, and it has been found that the following new problem occurs in the above configuration. That is, when MgO is used as the charging material, it is necessary to increase the mixing amount of the charging material in order to reduce the discharge voltage. In addition, it is necessary to increase the average particle size of the charging material. However, when the average particle diameter or the amount of mixing of the charging material composed of MgO is increased, the charging material absorbs vacuum ultraviolet rays that are the excitation source of the phosphor. As a result, the amount of vacuum ultraviolet light that excites the phosphor is insufficient, which causes a decrease in the luminance characteristics (light emission efficiency) of the PDP.

  Further, each of the red, green, and blue phosphors used in the color display PDP has charging characteristics. However, the green phosphor has lower charging characteristics than other colors. Therefore, it is necessary to improve the charging characteristics particularly for the cell in which the green phosphor is arranged.

  The present invention has been made in view of the above problems, and an object thereof is to provide a technique capable of reducing power consumption while suppressing a decrease in luminance characteristics of a PDP device.

  The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

  Of the inventions disclosed in the present application, the outline of typical ones will be briefly described as follows.

  In other words, the plasma display panel according to one embodiment of the present invention has a discharge space formed between the front plate and the back plate arranged to face each other and filled with a discharge gas. The back plate includes a fluorescent film disposed in contact with the discharge space. The phosphor film is composed of a phosphor that emits visible light when excited by ultraviolet rays, and a charging material that is positively charged and has a charging characteristic greater than that of the phosphor, and the charging material is a mother material made of magnesium oxide. And an additive element different from magnesium added to the base material.

  Among the inventions disclosed in the present application, effects obtained by typical ones will be briefly described as follows.

  That is, power consumption can be reduced while suppressing a decrease in luminance characteristics of the PDP device.

It is a principal part expansion assembly perspective view which expands and shows the principal part of PDP which is one embodiment of this invention. It is a block diagram which shows roughly the whole structure of an example of the PDP module incorporating the PDP shown in FIG. FIG. 3 is an explanatory diagram showing an example of a gradation driving sequence in the PDP module shown in FIG. 2. It is explanatory drawing which shows an example of the drive waveform of the PDP module shown in FIG. It is explanatory drawing shown about the experimental result which evaluated the charging characteristic for every structure of a charging material. It is explanatory drawing which shows the evaluation result of the thermoluminescence curve of the comparison section shown in FIG. It is explanatory drawing which shows the evaluation result of the thermoluminescence curve of the comparison section shown in FIG. It is explanatory drawing which shows the evaluation result of the electron beam excitation light emission spectrum of the comparison section shown in FIG. It is explanatory drawing which shows the evaluation result of the electron beam excitation light emission spectrum of the comparison group shown in FIG. It is explanatory drawing which shows the relationship between the average particle diameter of a charging member, and a charge amount. It is explanatory drawing which shows the SEM photograph of a charging material. It is a principal part expanded sectional view which shows the detailed structure of the fluorescent film shown in FIG.

  Before describing the present invention in detail, the meaning of terms in the present application will be described as follows.

  A PDP is a substantially flat surface in which a gas discharge is generated in a discharge cell formed between a pair of substrates arranged opposite to each other, and a phosphor is excited by excitation light generated at this time to form a desired image. It is a face plate-like display panel. There are various examples of the internal structure and constituent materials of the PDP depending on the required performance or the drive system, but all of these examples are included except for the configuration that is not clearly applicable in principle.

  A plasma display module (PDP module) is arranged on the PDP, a chassis that is disposed on the opposite side of the display surface of the PDP and supports the PDP, and a rear surface of the chassis (a surface located on the opposite side of the surface facing the PDP). A module comprising a circuit board on which various electric circuits for driving and controlling the PDP or supplying power to the PDP are formed, wherein the various electric circuits and the PDP are electrically connected. It is. In addition, as an embodiment of the PDP module, there is a structure in which a part or all of the circuit board on which the above various electric circuits are formed is not attached, and a mounting jig is formed at a position where the circuit board is to be attached. . In the present application, such an embodiment is also included in the PDP module.

  A plasma display set (PDP set) is a display device in which a PDP module is covered with an external housing. In addition, a display device in which the PDP module is fixed to a support structure such as a stand is also included. When the PDP set is used as a television receiver, the PDP module and the tuner are electrically connected. The PDP set includes this tuner.

  The plasma display device (PDP device) includes the above-described PDP, PDP module, and PDP set.

  In the following embodiments, components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiments, and the repetitive description thereof is omitted in principle. Further, in all the drawings for explaining the present embodiment, hatching or a pattern may be given even in a plan view or a perspective view for easy understanding of the configuration of each member. Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<Basic structure and manufacturing method of PDP>
First, a basic structure of an AC surface discharge type PDP will be described as an example of the PDP studied by the present inventors. In this embodiment, the “front plate” and “back plate”, which are a pair of substrates constituting the PDP, are the sides on which the light emission by the phosphor passes and becomes the display surface when both are assembled into a panel. Will be described as a front plate and a side located on the opposite side of the display surface as a back plate. The “front plate” and “back plate” will be described as a substrate structure in which a front substrate and a back substrate each made of a glass substrate are used as base materials, and each member described later is formed on the base material.

  FIG. 1 is an exploded perspective view schematically showing a main part of a so-called box-type AC surface discharge type PDP examined by the present inventors.

  First, the front plate 12 and the formation method thereof will be described. On the inner surface side of the front substrate 1 serving as a base material of the front plate 12, the transparent electrodes 4a and 5a extending in a stripe shape and bus electrodes 4b and 5b joined on the transparent electrodes 4a and 5a are formed. A plurality of display electrode pairs 6 are provided. The display electrode pair 6 includes a pair of a sustain electrode (X electrode) 4 and a scan electrode (Y electrode) 5, and performs a sustain discharge (display discharge) between the sustain electrode 4 and the scan electrode 5. The display electrode pair 6 constitutes a display line in the row direction (y direction shown in FIG. 1) in the PDP 15. Therefore, although two display electrode pairs 6 are shown in FIG. 1, the number of display electrode pairs 6 corresponding to the number of display lines is formed.

  The transparent electrodes 4a and 5a are transparent conductors, which are formed of a film made of indium tin oxide (ITO), for example, and bus electrodes 4b and 5b made of, for example, a single-layer film of silver are attached thereon. . The bus electrodes 4b and 5b are made of a metal material having a higher thermal conductivity than the transparent electrodes 4a and 5a, such as silver, from the viewpoint of reducing electric resistance when driving the PDP 15.

  On the other hand, the transparent electrodes 4a and 5a are formed wider than the bus electrodes 4b and 5b from the viewpoint of facilitating the formation of a sustain discharge by reducing the distance between the electrodes of the display electrode pair 6. For this reason, the transparent electrodes 4a and 5a are made of a material transparent to visible light, whereby the light generated in the discharge cell CL is efficiently extracted to the front substrate 1 side. Various modifications can be applied to the shape and material of the display electrode pair 6. For example, the transparent electrodes 4a and 5a can be formed of tin oxide, zinc oxide or the like, and the bus electrodes 4b and 5b can be formed of a laminated film of black silver and silver, a single layer film of aluminum, or a laminated film of chromium / copper / chromium. .

  The process of forming the display electrode pair 6 on the front substrate 1 is performed as follows, for example. That is, by using a thick film forming technique such as screen printing, or a thin film forming technique such as a vapor deposition method or a sputtering method and an etching technique, the film can be formed with a predetermined number, thickness, width and interval.

Further, a plurality of display electrode pairs 6 (sustain electrode 4, the scanning electrode 5) is mainly covered by the configured dielectric layers 2 of a dielectric glass material such as SiO _2. The step of forming the dielectric layer 2 so as to cover the display electrode pair 6 is performed as follows, for example. That is, the dielectric layer 2 is formed, for example, by applying a frit paste mainly composed of a low-melting glass powder on the front substrate 1 by a screen printing method and baking it. In addition, a sheet-like dielectric sheet called a so-called green sheet can be attached and fired. Alternatively, it may be formed by depositing SiO ₂ film by a plasma CVD method.

  A protective film 3 is formed on the inner surface side of the dielectric layer 2 to protect the dielectric layer 2 from impact caused by ion collision caused by discharge during display (mainly sustain discharge). Therefore, the protective film 3 is formed so as to cover the surface of the dielectric layer 2. Since the protective film 3 is required to have high sputter resistance and a secondary electron emission coefficient, an alkaline earth metal oxide such as MgO can be used. Also, in order to improve the secondary electron emission coefficient and the function of supplying charged particles (priming electrons) that trigger discharge, a technique of attaching, for example, MgO single crystal particles to the surface of the protective film 3 may be used. it can. The protective film 3 can be formed by, for example, a film forming method such as an electron beam evaporation method. Since the alkaline earth metal oxide such as MgO constituting the protective film 3 has a characteristic of easily adsorbing impurities such as moisture and carbon dioxide in the atmosphere, the step of forming the protective film 3 includes It is preferable to carry out in a reduced pressure atmosphere.

  Next, the back plate 13 and its forming method will be described. The back plate 13 has a back substrate 11 which is a glass substrate, for example. A plurality of address electrodes (A electrodes) 10 extending in a direction intersecting (orthogonal) with the display electrode pair 6 are disposed on the inner surface (surface facing the front plate 12) side of the rear substrate 11. The address electrode 10 and the scan electrode 5 formed on the front plate 12 constitute an electrode pair for performing address discharge, which is discharge for selecting lighting / non-lighting of the discharge cell CL. That is, the scan electrode 5 has both a function as a sustain discharge electrode and a function as an address discharge electrode (scan electrode). In this manner, lighting / non-lighting can be selected for each discharge cell CL by crossing the address electrode 10 and the display electrode pair 6. That is, the PDP 15 has a discharge cell CL at each intersection of the display electrode pair 6 and the address electrode 10.

  The address electrode 10 is formed of a single layer film of silver or aluminum, or a laminated film of chromium / copper / chromium. Since the process of forming the address electrode 10 on the back substrate 11 is the same as the method of forming the bus electrodes 4b and 5b, the description thereof is omitted.

  The address electrode 10 is covered with a dielectric layer 9. The dielectric layer 9 can be formed using the same material and the same method as the dielectric layer 2 on the front substrate 1. On the dielectric layer 9, a plurality of barrier ribs 7 that divide the inner surface side of the back plate 13 into a plurality of discharge cells CL are formed. The plurality of barrier ribs 7 are disposed between the front substrate 1 and the rear substrate 11 and have a function of maintaining a discharge distance in each discharge cell CL. Further, it has a function of preventing or suppressing crosstalk between the discharge cells CL arranged adjacent to each other. In the present embodiment, the partition walls 7 extend along the X direction (the extending direction of the address electrodes 10) shown in FIG. 1 and along the Y direction (the extending direction of the display electrode pair 6). And extending partition walls 7b. The plurality of partition walls 7a and 7b intersect with each other to divide the discharge space 14 formed on the inner surface side of the back plate 13 into a matrix (lattice). Such a structure in which the plurality of partition walls 7 are formed so as to partition each discharge cell CL in a matrix is called a box rib structure, and the partition walls 7b are formed between the discharge cells CL adjacent in the X direction. As a result, crosstalk between the discharge cells CL can be effectively prevented or suppressed, so that the structure is suitable for high definition of the PDP.

  The method for forming the partition walls 7 is not limited to the structure shown in FIG. 1. For example, the plurality of partition walls 7 a extending along the X direction (extending direction of the address electrodes 10) shown in FIG. A structure in which the partition wall 7b is not formed (referred to as a stripe rib structure) can also be formed. In the case of this stripe rib structure, since the number of the partition walls 7 formed on the back plate 13 is small, it is possible to reduce the resistance when supplying and exhausting the gas in the discharge space 14.

  The step of forming the partition wall 7 can be formed by a sand blast method, a photo etching method, or the like. For example, in the sandblasting method, a frit paste made of a low-melting glass frit, a binder resin, a solvent or the like is applied on the dielectric layer 9 and dried, and then a blast mask having openings in the partition pattern is formed on the frit paste layer. It is formed by spraying cutting particles in the provided state, cutting the frit paste layer exposed at the opening of the mask, and further firing. In the photo-etching method, instead of cutting with cutting particles, a photosensitive resin is used as the binder resin, and after exposure and development using a mask, it is formed by baking.

  On the upper surface of the dielectric layer 9 on the address electrode 10 and the side surface of the partition wall 7, a fluorescent film 8 that is excited by vacuum ultraviolet rays and emits visible light is formed. Since the PDP 15 of the present embodiment is a PDP that performs color display, the fluorescent film 8 is excited by vacuum ultraviolet rays to generate visible light of each color of red (R), green (G), and blue (B). 8r, 8g, and 8b are formed in predetermined discharge cells CL, respectively. In the color display PDP, a pixel is formed by a set of discharge cells CL on which the fluorescent films 8r, 8g, and 8b are formed. The detailed structure and formation method of the fluorescent film 8 will be described later.

  The PDP 15 is obtained by assembling the surface of the front plate 12 on which the display electrode pair 6 is formed and the surface of the back plate 13 on which the partition walls 7 are formed so as to face each other via the discharge space 14. That is, the PDP 15 has a front plate 12 and a back plate 13 which are a pair of substrate structures facing each other via a discharge space 14 formed by enclosing a discharge gas. In this assembling process, the positioning process of the front plate 12 and the back plate 13 and the non-display area disposed on the outer periphery of each plate (the front plate 12 and the back plate 13) are made of, for example, a low melting glass material called a seal frit. A sealing step of sealing using a sealing agent and a step of exhausting a gas remaining in an internal space (such as the discharge space 14) of the PDP 15 and introducing a discharge gas are included.

  The discharge gas introduced into the discharge space 14 can be composed of a mixed gas containing a rare gas, for example, a mixed gas such as He—Xe, Ne—Xe, or He—Ne—Xe. In the present embodiment, a mixed gas having neon (Ne) -xenon (Xe) as a gas base as a discharge gas is sealed, for example, with a partial pressure ratio of Xe adjusted to several percent to several tens percent.

  In the PDP 15, vacuum ultraviolet rays having wavelengths of 147 nm and 172 nm are mainly used as an excitation source for causing the fluorescent film 8 to emit light. The vacuum ultraviolet rays of 147 nm and 172 nm are generated when Xe ions ionized by the discharge transition to the ground state. Therefore, by increasing the partial pressure of Xe in the discharge gas, a large number of excitation sources that generate the fluorescent film 8 can be generated, so that the light emission efficiency of the PDP 15 can be improved.

<Configuration example of PDP module>
Next, an overall configuration of a plasma display module (hereinafter referred to as a PDP device) incorporating the PDP 15 of this embodiment and an example of a gray scale driving method will be described with reference to FIGS.

  FIG. 2 is a block diagram schematically showing an overall configuration of an example of a PDP module incorporating the PDP shown in FIG. FIG. 3 is an explanatory diagram showing an example of a gradation drive sequence in the PDP module shown in FIG. FIG. 4 is an explanatory diagram showing an example of drive waveforms of the PDP module shown in FIG.

  The PDP module 20 shown in FIG. 2 applies an address drive circuit ADRV, Y scan driver YSCDDRV, and Y drive circuit that applies a voltage between the electrodes (sustain electrode 4, scan electrode 5, and address electrode 10 shown in FIG. 1). YSUSDRV and X drive circuit XSUSDRV are included. Each electrode is electrically connected to these circuits. The PDP module 20 includes a control circuit CNT for controlling each drive circuit (driver), a power supply circuit (not shown) that supplies power to each circuit and the PDP 15, and the like.

  In the PDP 15, sustain electrodes (X 1, X 2, X 3,... Xn) 4 that perform sustain discharge (sustain discharge, display discharge) and scan electrodes (Y 1, Y 2, Y 3,... Yn) 5 are alternately arranged. The display electrode pair configured by the sustain electrode 4 and the scan electrode 5 and the address electrode (A1, A2, A3,... An that is substantially orthogonal to the display electrode pair (display line). ) A matrix cell is formed at every intersection with 10.

  In the address process TA (see FIG. 4), the Y scan driver YSCDRV controls the scan electrodes 5 to sequentially select the scan electrodes (display lines) 5, and the address electrodes 10 electrically connected to the address drive circuit ADRV Address discharge for selecting lighting / non-lighting of cells for each of the subfields SF1 to SFn (see FIG. 3) is generated between the scan electrodes 5.

  Further, the Y drive circuit YSUSDRV and the X drive circuit XSUSDRV perform a number of sustain discharges (sustain discharges) corresponding to the weights of the subfields on the cells selected by the address discharge in the display process TS (see FIG. 4). Cause it to occur.

  Further, the control circuit CNT outputs a control signal suitable for each driving circuit (driver) from a signal serving as a video source such as image data input from an external device such as a TV tuner or a computer, for example, and outputs a predetermined image. Plays the role of displaying.

  As shown in FIG. 3, the grayscale driving sequence in the PDP module 20 includes one field (frame) F1 including a plurality of subfields (subframes) SF1 to SFn each having a predetermined luminance weight, A desired gradation display is performed by a combination of the subfields SF1 to SFn.

  Each of the subfields SF1 to SFn is selected by an initialization process (reset period) TR for making the wall charges of all the cells in the display region uniform, an address process (address period) TA for selecting a lighted cell, and a selected field. The display process (sustain discharge period) TS is performed to discharge (light) the cell as many times as the luminance (weight of each subfield), and the cell is lit according to the luminance for each subfield display. By displaying eight subfields (SF1 to SF8), one field is displayed.

  Next, FIG. 4 shows an example of the drive waveform. FIG. 4 shows drive waveform examples (PX, PY, PA) applied to the respective electrodes (sustain electrode 4, scan electrode 5, address electrode 10) shown in FIG. 1 in each of the subfields SF1 to SFn shown in FIG. .

  First, as a first step, in the initialization process TR, for example, by generating a reset discharge between the scan electrode 5 (see FIG. 1) and the address electrode 10 (see FIG. 1), all cells are charged. (Wall charge) is formed to initialize all the cells (to prepare for the next address operation period).

  In this initialization process TR, for example, a positive potential PY1 is applied to the scan electrode 5 that constitutes the display electrode pair 6 (see FIG. 1) of the PDP 15, and a negative potential PA1 is applied to the address electrode 10, respectively. As a result, the address electrode 10 serves as a negative electrode and the scan electrode 5 serves as a positive electrode to generate a reset discharge between both electrodes, and wall charges are formed in all cells. Subsequently, compensation potentials PY2 and PA2 for erasing while leaving a necessary amount of wall charges formed in the cell are applied. As a result, the amount of wall charges formed in all the cells becomes substantially uniform.

  Next, as a second step, in the address process TA, an address discharge is generated between the address electrode 10 (see FIG. 1) and the scan electrode 5 for the cell selected to be lit, thereby Select ON / OFF. Further, subsequent discharge (sustain discharge, display discharge) is generated at the display electrode pair 6.

  In this address process TA, for example, a scan pulse PY3 is applied to the scan electrode 5 and an X voltage PX1 is applied to the sustain electrode 4 in order to perform discharge for determining cells to be displayed in the row direction. The scan pulse PY3 is applied with a different timing for each row.

  On the other hand, address pulses PA3 and PA4 are applied to the address electrode 10 in order to perform discharge for determining cells to be displayed in the column direction. The address pulses PA3 and PA4 are applied in accordance with the scan pulse PY3 applied for each row, and are applied at the timing of generating a discharge in a cell to be displayed formed at the intersection of the scan electrode 5 and the address electrode 10. Is done.

  Next, as a third step, in the display process TS, a sustain discharge (display discharge, sustain discharge) is performed between the sustain electrode 4 and the scan electrode 5 of the cell selected to be lit, and the cell is kept for a predetermined period. Let it emit light.

  In the display process TS, for example, first sustain pulses PX2 and PY4 having different electrical polarities are applied to the sustain electrode 4 and the scan electrode 5, respectively. Thereby, the discharge state between the display electrode pair 6 is maintained.

  Subsequently, repeated sustain pulses PX3, PX4, PX5, PY5, PY6, and PY7 having different electrical polarities are repeatedly applied to the sustain electrode 4 and the scan electrode 5, thereby further increasing the discharge state between the display electrode pair 6. Maintained.

  As shown in FIG. 4, sustain pulses PX2, PX3, PX4, PX5 and sustain pulses PY4, PY5, PY6, PY7 are alternately switched in electrical polarity. That is, the sustain electrode 4 and the scan electrode 5 are repeatedly discharged in a sustain discharge, alternately with a negative electrode or a positive electrode.

  The overall configuration of the PDP module 20 of the present embodiment and the example of the gradation driving method have been described above, but it goes without saying that various modifications exist.

<Detailed structure, function and formation method of fluorescent film>
Next, the detailed structure, function, and formation method of the fluorescent film 8 shown in FIG. 1 will be described. As described above, the PDP module 20 shown in FIG. 2 performs discharge such as reset discharge, address discharge, and sustain discharge. These discharges are formed according to the following principle. That is, charged particles (priming electrons) existing in the discharge space 14 shown in FIG. 1 are accelerated and moved by the difference in potential applied between the electrodes. At this time, the discharge gas sealed in the discharge space 14 and the charged particles collide, and the discharge gas is ionized. This process is repeated one after another to form a so-called electron avalanche discharge. Therefore, the larger the number of priming electrons present in the discharge space 14, the easier it is to form a discharge with a lower potential difference. That is, the discharge voltage can be reduced.

  Further, when a potential difference is generated between the electrodes that perform discharge, priming electrons are accelerated from the negative electrode side having a relatively low potential toward the positive electrode. Therefore, if there are many priming electrons in the vicinity of the negative electrode (a negative potential is applied) among the electrodes for forming the discharge, the effect of reducing the discharge voltage is increased. For example, FIG. 4 illustrates an example in which a negative potential is supplied to the address electrode 10 and a positive potential is supplied to the scan electrode 5 in the initialization process TR, but in this case, more priming electrons are supplied near the address electrode. In particular, the discharge voltage of the reset discharge can be reduced.

  The priming electrons are excited by, for example, an excitation source such as heat, for example, electrons held in the trap level in which the protective film 3 and the fluorescent film 8 constituting the PDP 15 shown in FIG. 1 are formed in the crystal. Is supplied to the discharge space 14. Therefore, the degree of supply of the priming electrons from the fluorescent film 8 correlates with the density of trap levels in the crystals constituting the fluorescent film 8. Further, since the density of trap levels has a correlation with the charging characteristics of each member, the degree of supply of priming electrons from the fluorescent film 8 can be evaluated using the charged amount of the fluorescent film 8 as an index. Specifically, as the positive charge amount is increased, the supply amount of priming electrons is increased, and the discharge voltage can be reduced. As for the relationship between the PDP discharge voltage and the phosphor charge amount, it has already been reported that the discharge voltage tends to be lower when the phosphor charge amount is positive and larger (for example, the 318th). (Refer to Proceedings of the Society for Phosphors, p15).

  Therefore, the present inventors have studied a technique for reducing the discharge voltage by improving the positive charge amount of the fluorescent film 8 that is disposed near the address electrode 10 and formed in contact with the discharge space 14. It was. First, the phosphor film 8 was examined to be composed of a phosphor that emits visible light when excited by ultraviolet rays, and a charging material that is positively charged and has a charging characteristic greater than that of the phosphor.

Examples of the phosphor include (Y, Gd) BO ₃ : Eu as a red phosphor, Zn ₂ SiO ₄ : Mn as a green phosphor, and BaMgAl ₁₀ O ₁₇ : Eu as a blue phosphor. The charge amount of the phosphor is as follows. That is, the charge amount of the red phosphor is about 20 μC / g, the blue phosphor is about 25 μC / g, and the green phosphor is extremely low, about 10 μC / g. Therefore, it is particularly important to improve the charge amount of the phosphor film 8g containing the green phosphor from the viewpoint of making the discharge voltage substantially constant in all cells.

  The inventors of the present invention first studied by using MgO (magnesium oxide) as a charging material and mixing it with a green phosphor to form a green phosphor film 8g shown in FIG. As a result, it was found that MgO can reduce the discharge voltage because the charge amount is larger than that of the green phosphor. However, when MgO crystal particles are simply used as the charging material, the charge amount is not sufficient. For example, in order to obtain a charge amount comparable to that of the red phosphor film 8r formed of a red phosphor. It has been found that the amount of the charging material mixed with the green phosphor needs to be mixed, for example, more than 20% by weight. When the amount of the charging material is increased in this way, the vacuum ultraviolet light for exciting the phosphor during display discharge is easily absorbed by the charging material, so that the luminance (luminous efficiency) of the cell mixed with the charging material is increased. It will decline. In particular, in the case where a charging material is mixed only in a specific cell, the variation in luminance between cells increases, which causes a display defect.

  Therefore, the present inventor has studied a means for increasing the charge amount of the charging material, and has found a configuration in which an additive element other than Mg is added to a base material made of MgO. By adding an additive element to MgO, impurity levels are formed in the crystal of the base material. Since this impurity level becomes a trap level for holding electrons, it becomes possible to increase the trap level density of the charging material and supply more electrons to the discharge space 14.

FIG. 5 is an explanatory diagram showing experimental results of evaluating charging characteristics for each configuration of the charging material. Each sample used in the experiment shown in FIG. 5 was prepared as follows. First, as a sample in the comparative section, a commercially available MgO raw material powder is dry-mixed for about 30 minutes in a mortar, and then the raw material is filled in an alumina crucible and fired in a muffle furnace at 1400 ° C. in an air atmosphere for 3 hours. went. The obtained fired product was lightly crushed and used as a sample in the comparative section. Further, as experimental sections 1, 2, and 3, charging materials were prepared by adding 0.1 mol% of additive elements other than Mg to MgO as a base material. As an addition method, powders of oxides of each additive element (Sc ₂ O ₃ , Al ₂ O ₃ , SiO ₂ ) were mixed in the same MgO powder as that in the comparative section and fired. The mixing and firing method is the same as in the comparative section. The mixing amount in each experimental section is as follows. In experimental group 1, 0.007 g of Sc ₂ O ₃ was mixed with 4.029 g of MgO. In Experimental Group 2, 0.005 g of Al ₂ O ₃ was mixed with 4.029 g of MgO. In Experimental Group 3, 0.006 g of SiO ₂ was mixed with 4.027 g of MgO.

  The evaluation of charging characteristics was performed as follows. A ferrite powder (P-01, Japan Imaging Society, 9.7 g) and a charging material powder (0.3 g) are placed in a container and mixed for 1 hour in a ball mill. The charge amount of was measured.

  In FIG. 5, the charge amount in the comparison group (MgO without added elements) is 16.9 μC / g, whereas the charge amount in the experimental group 1 is 36.7 μC / g, in the positive charge direction. large. In addition, the charge amount in the experimental group 2 was 38.9 μC / g, and the charge amount in the experimental group 3 was 25.0 μC / g. In either case, the charge amount increased in the positive charge direction relative to the comparison group. I know that. In particular, in experimental group 1 and experimental group 2 to which Sc or Al was added as an additive element, the charge amount was twice or more that of the comparative group.

  Moreover, the evaluation of the thermoluminescence curve in the comparative section and each experimental section shown in FIG. 5 was performed. The results are shown in FIGS. 6 and 7, the horizontal axis is the absolute temperature (K), and the vertical axis is the observed thermoluminescence intensity (Thermo Luminescence, TL), showing the temperature distribution of the thermoluminescence intensity in the comparative section and each experimental section, respectively. Yes. In addition, since the values of the thermoluminescence intensity in the experimental groups 1 and 2 are significantly different from those in the comparative group, these results are shown in FIG. The results for section 1 are shown using the right scale axis. Evaluation based on thermoluminescence intensity is to observe light emission when thermally excited electrons relax from the trap level in the band gap of the base material (MgO), and the intensity is the trap level density, emission center density, etc. It can be used as an index indicating how much electrons taken out of the crystal are trapped by thermal excitation.

  In FIG. 6, in the experimental group 3 in which Si is added as an additive element, the thermoluminescence intensity near 230 K is increased as compared with the comparative group. Moreover, the ratio C (C = A / B) of the thermoluminescence peak intensity (A) in the range of 150 K or more and 300 K or less and the thermoluminescence peak intensity (B) of 115 K is 0.2 or more. This result shows that the trap level density (trap concentration) is improved by adding Si to the base material MgO as compared with the case where the charging material is composed of only MgO. That is, it can be seen that the charging material easily emits electrons (priming electrons) by adding an additive element to MgO as a base material. Although not shown in the figure, the case where Ca, Ce, La, Sm, or Y was used as an additive element instead of Si was also evaluated. Even when these additive elements were used, it was confirmed that the thermoluminescence intensity in the vicinity of 230 K was increased with respect to the comparative group as in the experimental group 3.

  In FIG. 7, the experimental group 2 to which Al was added increased the thermoluminescence intensity in the vicinity of 200 K compared to the comparative group. Further, the ratio C (C = A / B) of the thermoluminescence peak intensity (A) in the range of 150K to 300K and the thermoluminescence peak intensity (B) of 115K is 4 or more. In addition, in experimental group 1 to which Sc was added, the thermoluminescence intensity in the vicinity of 224K was significantly increased by 1000 times or more compared to the comparative group. Further, the ratio C (C = A / B) of the thermoluminescence peak intensity (A) in the range of 150K to 300K and the thermoluminescence peak intensity (B) of 115K is 10 or more. Furthermore, the experimental group 1 and the experimental group 2 have significantly higher thermoluminescence intensity than the comparative group even in the range of 300K or higher. From this result, it was found that Al and Sc are particularly preferable as additive elements to be added to MgO as a base material from the viewpoint of improving the supply characteristics of priming electrons (making it easy to supply priming electrons).

  Next, the electron beam excitation emission spectra of the comparison section and each experimental section shown in FIG. 5 were evaluated. The results are shown in FIGS. 8 and 9, the horizontal axis is the wavelength of the excitation source (nm) and the vertical axis is the observed emission intensity (Cathode Luminescence, CL), respectively, and the spectrum of the emission intensity in the comparison section and each experimental section is shown. . In addition, in the experimental groups 1 and 2, since the value of the emission intensity is significantly different from that in the comparative group, these results are shown in FIG. The evaluation by the electron beam excitation emission spectrum is to observe the light emission when the electrons excited by the electron beam as the excitation source from the trap level in the band gap of the base material (MgO) relax. Thus, it can be used as an index indicating how much electrons taken out of the crystal are trapped.

  In FIG. 8, in the experimental group 3 in which Si is added as an additive element, the emission intensity in the vicinity of 400 nm is increased as compared with the comparative group. This result shows that by adding Si to the base material MgO, the trap level density (trap concentration) is improved or a new level is formed as compared with the case where the charging material is composed only of MgO. It has been shown. That is, the charging material improves the trap level density by adding an additive element to MgO as a base material, and therefore, it becomes easy to emit secondary electrons that are excited by an electron beam and taken out of the crystal. I understand.

  In FIG. 9, in the experimental group 2 to which Al was added, the emission intensity increased in the entire range of about 550 nm or less compared to the comparative group. In addition, emission peaks are observed in the vicinity of 244 nm and 456 nm. The emission peak intensity near 456 nm is 2/3 of the emission peak intensity near 244 nm, and it can be seen that there are two very large emission peaks. In addition, in the experimental group 1 to which Sc was added, the emission intensity increased in the entire range of about 650 nm or less compared to the comparative group. In addition, emission peaks are observed in the vicinity of 302 nm and 525 nm. In particular, the emission peak intensity in the vicinity of 302 nm is large, and the base spreads to around 430 nm. From these results, it was found that Al and Sc are particularly preferable as additive elements to be added to MgO as a base material from the viewpoint of improving the emission characteristics of secondary electrons.

  As described above, the phosphor film 8 shown in FIG. 1 is composed of a phosphor that emits visible light when excited by ultraviolet rays, and a charging material that is positively charged and has a charging property greater than that of the phosphor, By adding an additive element to MgO as a base material, the supply characteristics of priming electrons or the secondary electron emission characteristics can be improved, so that the discharge voltage can be reduced. As the additive element, silicon (Si), calcium (Ca), cerium (Ce), lanthanum (La), samarium (Sm), yttrium (Y), aluminum (Al), or scandium (Sc) may be used. it can. In particular, when Al or Sc is used as the additive element, the discharge voltage can be further reduced as compared with the case where other additive elements are used. Further, since the charging material to which the additive element is added has a larger charging characteristic in the direction of positive charge than MgO not containing the additive element, the charging material to the fluorescent film 8 is formed when the fluorescent film 8 shown in FIG. 1 is formed. The amount of contamination can be reduced. As a result, it is possible to suppress the vacuum ultraviolet ray that is the excitation source of the phosphor from being absorbed by the charging material, and thus it is possible to suppress a decrease in luminance.

  By the way, in this embodiment, in order to confirm the effect of each additive element, one kind of additive element was added to the base material for evaluation. However, the element added to the charging material is not limited to one kind. . For example, a plurality of elements selected from the group of Si, Ca, Ce, La, Sm, Y, Al, and Sc may be added. In this case, the additive element contained in the charging material preferably contains Al or Sc.

  Next, the addition ratio of the additive element will be described. As described above, when an additive element is added to MgO as a base material, charging characteristics are improved. However, when a fluorescent film is formed using this charging material, compared with MgO crystals to which no additive element is added, In order to reduce the discharge voltage, it is preferable to add at least 0.005 mol% or more of the additive element. For example, when forming MgO crystal powder, depending on the purity of the raw material, a slight amount of impurities derived from the raw material may remain at a concentration of less than 0.005 mol%. However, in this case, since the effect of improving the charging characteristics is small as compared with MgO containing no additive element, the amount of charging material mixed in cannot be sufficiently reduced when forming the fluorescent film 8 shown in FIG. . As a result, the luminance is lowered.

  On the other hand, if the additive concentration of the additive element is too high, the additive element may precipitate out of the crystal of the base material. In addition, when a deep defect level is formed in the base material, the electron emission characteristic is deteriorated. From such a viewpoint, it is preferable that the additive concentration of the additive element in the charging material is 5 mol% or less.

  Further, from the viewpoint of improving the emission characteristics of priming electrons, it is preferable that the thermoluminescence peak intensity is large particularly in the range of 150 K or more and 300 K or less in the thermoluminescence curve. According to the inventor's study, the concentration of the additive element is in the range of 0.05 mol% or more and 0.5 mol% or less, compared with the range of less than 0.05 mol% or more than 0.5 mol%. In particular, the thermoluminescence peak intensity in the range of 150K or more and 300K or less is particularly large. Therefore, the addition concentration is particularly preferably 0.05 mol% or more and 0.5 mol% or less.

  Next, the particle diameter of the charging material particles will be described. The fluorescent film 8 shown in FIG. 1 is formed as an aggregate of charging material particles and phosphor particles, for example. When mixing phosphor particles and charging material particles, if the particle size of the charging material particles is too large, vacuum ultraviolet rays are easily absorbed by the charging material particles. That is, it causes a decrease in luminance. Therefore, from this viewpoint, the average particle diameter of the charging material particles is preferably smaller than the average particle diameter of the phosphor particles.

Here, the average particle diameter can be defined as follows. As a method for examining the average particle size of the particles (phosphor particles or charged material particles), there are a method of measuring with a particle size distribution measuring device and a method of directly observing with an electron microscope. Taking the case of examining with an electron microscope as an example, the average particle diameter can be calculated as follows. Variable amount of particle diameter (..., 0.8-1.2 [mu] m, 1.3-1.7 [mu] m, 1.8-2.2 [mu] m, ..., 6.8-7.2 [mu] m, 7.3 ˜7.7 μm, 7.8-8.2 μm,...), Etc., are classified into class values (..., 1.0 μm, 1.5 μm, 2.0 μm,..., 7.0 μm, 7 .5μm, 8.0μm, expressed in terms of ...), this is referred to as _{x i.} Then, if the frequency of each variable that is observed by an electron microscope to show by f _i, the mean value M can be expressed as follows.

_{M = Σx i f i / Σf} i = Σx i f i / N
However, Σf _i = N.

  When the average particle diameter of the phosphor particles is calculated by the above method, the average particle diameter of the phosphor particles is about 2 μm. Therefore, the average particle diameter of the charging material is 2 μm or less, and 1 μm or less is particularly preferable from the viewpoint of surely making it smaller than the average particle diameter of the phosphor particles.

  Further, it has been found that the average particle diameter of the charging material particles also affects the charging characteristics of the charging material. FIG. 10 is an explanatory diagram showing the relationship between the average particle diameter of the charging material and the charge amount. In FIG. 10, as an example of a charging material, a material obtained by adding 0.005 mol% of Al as an additive element to MgO as a base material is used. As shown in FIG. 10, when the average particle size of the charging material is in the range of 100 nm or less, the charging material average particle size is too small, so that the charging amount is not stable, and the charging amount of the green phosphor is 10 μC / g. On the contrary, it may become smaller. However, in the region where the average particle size is 200 nm or more, the charging characteristics improve as the average particle size increases. At 200 nm, the charge amount of the red phosphor is about 20 μC / g, and at 300 nm, it is equivalent to the blue phosphor. The charge amount is about 25 μC / g. Therefore, from the viewpoint of stably improving the charging characteristics, the average particle diameter of the charging material is preferably 200 nm or more. In particular, in order to obtain charging characteristics equivalent to that of the blue phosphor, it is preferable to set the average particle diameter to 300 nm or more.

  The charging characteristics shown in FIG. 10 indicate changes in charging characteristics when 0.005 mol% of Al is added. When Sc or Al is used, the addition concentration is 0.05 mol as described above. Since the charge amount is particularly large in the range of% to 0.5 mol%, the average particle diameter can be further reduced when the additive element is added in this range.

  Further, according to the method for forming a charging material shown in the comparison group and the experimental groups 1, 2, and 3 shown in FIG. 5, a charging material having an average particle diameter of about 1 μm to 2 μm can be obtained. FIG. 11 is an explanatory view showing an SEM photograph of the charging material. In FIG. 11, the SEM photograph of the charging material of the experimental group 1 shown in FIG. 5 is shown. As shown in FIG. 11, the charging material in experimental group 1 includes a mixture of about 1 μm charging material particles and about 0.2 μm charging material particles aggregated to form an aggregate of about 1 μm. ing. In recent years, with the increase in demand for nanoparticle materials, a technology for forming particles having an average particle size smaller than 1 μm has been established. For example, material manufacturers obtain charged material particles having an average particle size of about 20 nm. can do.

  Next, the mixing ratio of the charging material in the fluorescent film 8 shown in FIG. 1 and the method for forming the fluorescent film 8 will be described. FIG. 12 is an enlarged cross-sectional view of a main part showing a detailed structure of the fluorescent film shown in FIG. As described above, since the charging material absorbs vacuum ultraviolet rays, it is preferable to reduce the mixing ratio of the charging material from the viewpoint of suppressing a decrease in luminance. As shown in FIG. 12, it is preferable that the charging material 21 and the phosphor 22 are dispersed in the phosphor film 8. Although not shown in the drawings, for example, as described in Patent Document 2, when a charging material layer made of charging material particles is exposed on the surface of the phosphor layer made of phosphor particles (phosphor particles When charging material particles are laminated on the surface), vacuum ultraviolet rays generated in the discharge space 14 (see FIG. 1) are more easily absorbed. However, as shown in FIG. 12, it is particularly preferable to disperse the particles of the charging material 21 and the particles of the phosphor 22 because a decrease in luminance can be suppressed even at the same mixing ratio.

  In addition, even when the charging material 21 and the phosphor 22 are dispersed as shown in FIG. 12, the charging material is not mixed when the mixing ratio of the charging material in the fluorescent film 8 exceeds 20% by weight. In comparison, the brightness of the PDP 15 is remarkably lowered, so the mixing ratio needs to be 20% by weight or less. Further, if the mixing ratio of the charging material 21 dispersed in the fluorescent film 8 is 5% by weight or less, it is particularly preferable because the luminance reduction of the PDP 15 can be kept to 7% or less. In the present embodiment, since the charging material 21 is configured to add an additive element to MgO as a base material, charging characteristics can be improved as compared with MgO not containing the additive element. Even if it is 5 wt% or less, the discharge voltage can be sufficiently reduced.

  Further, as described above, by using Sc or Al as the additive element, the charging characteristics can be greatly improved, so that the mixing ratio of the charging material 21 can be further reduced. For example, even when the mixing ratio of the charging material mixed in the green phosphor film 8g shown in FIG. 1 is 2% by weight or less, charging characteristics equivalent to or better than those of the blue phosphor film 8b can be obtained. In addition, as described above, the charge amount is particularly large when the additive element concentration is in the range of 0.05 mol% to 0.5 mol%. Further, if the average particle diameter of the charging material 21 is 200 nm or more, the charging characteristics improve as the average particle diameter increases. Therefore, the range in which absorption of vacuum ultraviolet rays can be suppressed (more than the average particle diameter of the phosphor particles). Increasing the average particle size of the charging material within a small range increases the charge amount. Therefore, by combining these, for example, even when the mixing ratio of the charging material mixed in the green phosphor film 8g shown in FIG. 1 is 0.01% by weight, sufficient charging characteristics can be obtained. . However, when the mixing ratio of the charging material 21 becomes extremely small, there is a concern that the mixing ratio of the charging material for each fluorescent film 8 formed in each cell may vary. Therefore, the mixing ratio of the charging material 21 is preferably 0.01% by weight or more.

  Here, as described above, the charging characteristics of the phosphor vary depending on the emission color, and the green phosphor is particularly small in the positive charge direction. Therefore, at least the green fluorescent film 8g needs to be composed of a phosphor and a charging material. However, when the charging material is not mixed with the red fluorescent film 8r and the blue fluorescent film 8b, the charging characteristics of the fluorescent film 8g. However, it is preferable to adjust the mixing ratio of the charging material within a range that is equivalent to that of the phosphor film 8r or phosphor film 8b. This is to reduce variation in discharge voltage for each cell. Further, from the viewpoint of reducing this variation, when all of the fluorescent films 8r, 8b, and 8g are formed as a mixture of the phosphor and the charging material, it is preferable that the charging characteristics of the respective fluorescent films 8 are made uniform. For example, it is preferable that the mixing ratio of the charging material in each fluorescent film 8 increases in the order of blue <red <green.

  Moreover, it is preferable to raise the density | concentration of Xe in discharge gas from a viewpoint of the brightness | luminance of PDP15. As described above, the PDP 15 uses vacuum ultraviolet rays of 146 nm and 172 nm as a phosphor excitation source. However, by increasing the concentration of Xe in the discharge gas, the generation rate of vacuum ultraviolet rays of 172 nm increases. On the other hand, considering the absorption characteristics of vacuum ultraviolet rays by the charging material, 172 nm is less likely to be absorbed than 146 nm vacuum ultraviolet rays. Therefore, it is advantageous in terms of the luminance characteristics of the PDP that the wavelength of ultraviolet rays irradiated from the discharge gas during discharge is greater for the 172 nm component than for the 146 nm component. Specifically, the 172 nm component can be made larger than the 146 nm component by setting the concentration of Xe in the discharge gas to 8% or more. Further, if the concentration of Xe in the discharge gas is set to 12% or more, the 172 nm component is surely larger than the 146 nm component, and the luminance can be stably improved. Thus, when the concentration of Xe in the discharge gas is increased, the discharge voltage tends to increase. However, according to the present embodiment, since the charging characteristics can be improved, an increase in discharge voltage can be suppressed. Moreover, since the light emission efficiency can be improved by improving the luminance characteristics of the PDP 15, power consumption can be reduced.

  Next, a method for forming a fluorescent film will be described. The fluorescent film 8 shown in FIG. 12 can be formed by the following method, for example. First, a powdered charging material 21 and a phosphor 22 are prepared. The charging material 21 is formed in advance by, for example, the method described above. Moreover, since the fluorescent substance 22 can use commercially available fluorescent substance powder, detailed description is abbreviate | omitted. Next, a predetermined amount of each of the charging material 21 and the phosphor 22 is dispersed and mixed in an organic solvent to obtain a vehicle. Next, when an organic binder resin is put into the vehicle and mixed, a phosphor paste in which the charging material 21 and the phosphor 22 are dispersed is obtained.

  Three types of phosphor pastes are prepared for each of red, green, and blue colors. For example, when the charging material 21 is mixed only in the green phosphor film 8g (see FIG. 1), the charging material 21 does not need to be mixed in the red and blue phosphor pastes. In addition, when the charging material 21 is mixed with the fluorescent films 8 of all colors, the charging characteristics of the fluorescent film 8 obtained by increasing the amount of the charging material 21 to be mixed in the order of green, red, and blue are made uniform. be able to. Alternatively, the charging characteristics of the phosphor film 8 may be made uniform by making each one or more elements of the additive element, the addition amount, or the average particle diameter of the charging material 21 mixed with each phosphor paste different. In this case, since the mixing ratio of the charging material in each fluorescent film 8 can be made substantially the same, it is preferable in that variation in luminance can be suppressed.

  Next, each phosphor paste is applied to the area partitioned by the barrier ribs 7 shown in FIG. As a coating method, a screen printing method, a dispensing method, or the like can be used. Next, the back plate 13 coated with the phosphor paste is baked to remove organic components contained in the phosphor paste, and the phosphor film 8 is formed.

  As mentioned above, the invention made by the present inventor has been specifically described based on the embodiment. However, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the scope of the invention. Needless to say.

  For example, in the present embodiment, Si, Ca, Ce, La, Sm, Y, Al, and Sc are given as examples of additive elements mixed with the charging material based on the results of experiments conducted by the present inventors. . However, as described with reference to FIGS. 6 and 7, other additive elements may be used as long as the thermoluminescent curve has the following characteristics. That is, when the ratio C (C = A / B) of the thermoluminescence peak intensity (A) in the range of 150K to 300K and the thermoluminescence peak intensity (B) of 115K is 0.2 or more, Si, Ca, The same priming electron emission effect as when Ce, La, Sm, or Y is added can be expected. In addition, if the ratio C is 4 or more, the same priming electron emission effect as that obtained when Al is added can be expected.

  In the present embodiment, as shown in FIG. 12, the phosphor film 8 has a structure in which the charging material 21 and the phosphor 22 are dispersed. The average particle diameter of the charging material 21 is compared with that of the phosphor 22. In this case, the surface of the phosphor 22 may be coated with particles of the charging material 21 by making it sufficiently small. However, in this case, since the exposed area of the phosphor 22 becomes small, vacuum ultraviolet rays may be absorbed by the charging material 21 attached to the surface of the phosphor 22, so from the viewpoint of suppressing the luminance reduction, FIG. The structure shown in FIG.

  In the present embodiment, the PDP and the PDP module are described as examples of the PDP device. However, for example, the PDP module 20 illustrated in FIG. 2 may be covered with an external housing to form a PDP set. In the PDP module 20 or the PDP set, a heat radiating member is attached to the periphery of a member (for example, a circuit board) on which a drive circuit is formed in order to ensure heat dissipation. However, according to this embodiment, power consumption can be reduced. Accordingly, since the amount of heat generated from the drive circuit is also reduced, the heat dissipation member can be simplified, for example, by reducing the thickness of the heat dissipation plate.

  The present invention can be used for a plasma display device such as a PDP, a PDP module, or a PDP set.

1 Front substrate 2 Dielectric layer 3 Protective film 4 Sustain electrode (X electrode)
4a, 5a Transparent electrode 4b, 5b Bus electrode 5 Scan electrode (Y electrode)
6 Display electrode pair 7, 7a, 7b Bulkhead 8, 8b, 8g, 8r Fluorescent film 9 Dielectric layer 10 Address electrode 11 Rear substrate 12 Front plate 13 Rear plate 14 Discharge space 15 PDP (plasma display device)
20 PDP module (plasma display device)
21 Charging material 22 Phosphor

Claims (18)

It is formed between a front plate and a back plate that are arranged to face each other, and has a discharge space filled with a discharge gas inside,
The back plate has a fluorescent film disposed in contact with the discharge space,
The phosphor film is composed of a phosphor that emits visible light when excited by ultraviolet rays, and a charging material that is positively charged and has a larger charging characteristic than the phosphor,
The plasma display device, wherein the charging material is made of a base material made of magnesium oxide and an additive element different from magnesium added to the base material. The plasma display device according to claim 1,
A plurality of display electrode pairs are formed on the front plate,
A plurality of address electrodes are formed on the back plate so as to intersect with the plurality of display electrode pairs, and the fluorescent film is disposed on the discharge space side with respect to the plurality of address electrodes. A plasma display device. The plasma display device according to claim 2, wherein
The plasma display device, wherein the charging material particles and the phosphor particles are dispersed in the phosphor film. The plasma display device according to claim 3, wherein
The additive element is selected from the group of silicon (Si), calcium (Ca), cerium (Ce), lanthanum (La), samarium (Sm), yttrium (Y), aluminum (Al), or scandium (Sc). A plasma display device comprising a seed or a plurality of kinds of elements. The plasma display device according to claim 4, wherein
A mixing ratio of the charging material in the phosphor film is 0.01 wt% or more and 20 wt% or less. The plasma display device according to claim 5, wherein
The plasma display device according to claim 1, wherein a mixing ratio of the charging material in the fluorescent film is 5% by weight or less. The plasma display device according to claim 6, wherein
The plasma display device, wherein the additive element includes aluminum or scandium. The plasma display device according to claim 1,
The plasma display device, wherein the additive element has a concentration of 0.005 mol% to 5 mol% in the base material. The plasma display device according to claim 8, wherein
The plasma display device, wherein the additive element has a concentration of addition of 0.05 mol% or more and 0.5 mol% or less to the base material. The plasma display device according to claim 1,
The plasma display apparatus according to claim 1, wherein an average particle diameter of the charging material is smaller than an average particle diameter of the phosphor. The plasma display device according to claim 10, wherein
The plasma display device, wherein the charging material has an average particle size of 200 nm or more. The plasma display device according to claim 1,
The phosphor film comprises a red light emitting phosphor film containing a red phosphor, a green light emitting phosphor film containing a green phosphor, and a blue light emitting phosphor film containing a blue phosphor,
The plasma display apparatus, wherein the charging material is mixed only in the green light emitting phosphor film. The plasma display device according to claim 1,
The phosphor film comprises a red light emitting phosphor film containing a red phosphor, a green light emitting phosphor film containing a green phosphor, and a blue light emitting phosphor film containing a blue phosphor,
The charging material is mixed with each of the red light emitting fluorescent film, the green light emitting fluorescent film, and the blue light emitting fluorescent film,
Any one of the kind of the additive element, the additive concentration of the additive element to the base material, or the average particle diameter of the charging material is different for each color of the fluorescent film. The plasma display device according to claim 1,
The discharge gas includes xenon (Xe),
The plasma display apparatus characterized in that the wavelength of ultraviolet rays irradiated from the discharge gas during discharge is greater in the 172 nm component than in the 146 nm component. The plasma display device according to claim 1,
The discharge gas includes xenon (Xe),
The plasma display apparatus according to claim 1, wherein the concentration of xenon contained in the discharge gas is 8 mol% or more. The plasma display device according to claim 1,
The thermoluminescence curve of the charging material shows that the ratio C (C = A / B) of the thermoluminescence peak intensity (A) in the range of 150K to 300K and the thermoluminescence peak intensity (B) of 115K is 0.2 or more. There is provided a plasma display device. The plasma display device according to claim 16, wherein
The plasma display apparatus according to claim 1, wherein the ratio C is 4 or more. The plasma display device according to claim 17, wherein
The plasma display apparatus according to claim 1, wherein the ratio C is 10 or more.