JP2010073316A - Plasma display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make each aspect ratio of phosphor material particles contained in a phosphor layer larger than an aspect ratio in the prior art to increase the contact areas between the particles and between the particles and partitions, thus improve the adhesion of the phosphor material to inhibit peeling of the phosphor layer. <P>SOLUTION: A plasma display device includes a pair of boards which is arranged opposite to each other to form a discharge space between the boards and one of which is provided with partitions arranged to partition the discharge space into a plurality of partitioned spaces, a group of electrodes arranged on the board to cause electric discharge in the discharge spaces partitioned by the partitions, and a panel having phosphor layers of three colors that emit light of R (red), G (green), and B (blue) by electric discharge. Out of the phosphor layers of three colors, at least one phosphor layer of one color contains phosphor material particles that have an aspect ratio of ≥5. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a plasma display apparatus using a plasma display panel (hereinafter referred to as a panel) as a display device, and more particularly to a phosphor material constituting the phosphor layer.

  Panels used in this plasma display device are roughly classified into AC type and DC type in terms of driving, and there are two types of discharge types: surface discharge type and counter discharge type. Due to the simplicity of manufacturing, at present, the mainstream of plasma display devices is a surface discharge type having a three-electrode structure.

  In this surface discharge type plasma display panel structure, at least a pair of substrates whose front sides are transparent are arranged to face each other so that a discharge space is formed between the substrates, and partition walls for dividing the discharge space into a plurality of substrates are arranged on the substrate. In addition, a plurality of discharge cells are provided by arranging an electrode group on the substrate so that discharge is generated in a discharge space partitioned by the barrier ribs, and providing phosphor layers of three colors that emit red, green, and blue light by discharge. The phosphor material particles in the phosphor layer are excited by vacuum ultraviolet light having a short wavelength generated by discharge, and red, green, and blue visible light is emitted from the red, green, and blue discharge cells, respectively. Is used for color display.

  Such a plasma display device can display at a higher speed than a liquid crystal panel, has a wide viewing angle, is easy to enlarge, and is self-luminous so that the display quality is high. Recently, the flat panel display has attracted particular attention and is used for various purposes as a display device in a place where many people gather and a display device for enjoying a large screen image at home.

In such a plasma display device, a circuit that constitutes a drive circuit for holding a panel made mainly of glass on the front side of a chassis member made of metal such as aluminum and causing the panel to emit light on the back side of the chassis member. A module is configured by arranging a substrate (see Patent Document 1).
JP 2003-131580 A

  By the way, in a plasma display apparatus, full color display is performed by additively mixing so-called three primary colors (red, green, and blue). In order to perform this full-color display, the plasma display device includes three color phosphor layers that emit red, green, and blue light. Each color phosphor layer is formed by laminating phosphor material particles of each color.

  The phosphor layer is formed by pasting phosphor material particles and applying the paste between the barrier ribs of the rear substrate, and then forming a phosphor layer through a baking process, and is fixed between the barrier ribs. These phosphor material particles are held between the partition walls by van der Waals force acting between the particles or between the partition walls. However, the holding force is weak, and there is a problem that a part of the phosphor layer is peeled off from the partition wall by vibration or impact applied to the panel during the manufacturing process or during the transportation of the product.

  In the field of fluorescent lamps where peeling of the phosphor layer is an issue, a method of increasing the binding power of the phosphor layer is to mix a low melting glass material or a metal oxide into the phosphor layer as a binder. ing. However, in the fluorescent lamp, the wavelength of the ultraviolet light that excites the phosphor material is mainly 200 nm or more and is hardly absorbed by the glass material or the metal oxide, but in the plasma display device, the wavelength is less than 200 nm. Therefore, there is a problem that the light emission efficiency is greatly reduced because ultraviolet rays are absorbed by the glass material or metal oxide. Considering these matters, it is necessary to increase the binding force between the particles and the partition walls with the phosphor material particles themselves.

  The present invention has been made in view of such a current situation, and by making the aspect ratio of the phosphor material particles contained in the phosphor layer larger than that of the conventional one, the contact area between the particles and the partition walls is increased. Therefore, it is intended to increase the binding force of the phosphor material and suppress the peeling of the phosphor layer.

  In order to achieve the above object, a plasma display apparatus according to the present invention has a pair of substrates facing each other so that a discharge space is formed between the substrates, and a partition for dividing the discharge space into a plurality of partitions is provided on at least one substrate. An electrode group is arranged on the substrate so that a discharge is generated in a discharge space that is arranged and partitioned by the barrier ribs, and three-color phosphor layers that emit light to R (red), G (green), and B (blue) by discharge A plasma display device comprising a panel provided with a phosphor material particle, wherein an aspect ratio of phosphor material particles contained in at least one of the three color phosphor layers is 5 or more. And

  According to the present invention, by setting the aspect ratio of the phosphor material particles contained in the phosphor layer to 5 or more, which is larger than the conventional one, the contact area between the particles and the partition walls is increased, and thus the phosphor material This increases the binding force of the phosphor layer and can prevent the phosphor layer from peeling off.

  Hereinafter, a plasma display device according to an embodiment of the present invention will be described with reference to the drawings. However, the embodiment of the present invention is not limited thereto.

  First, the structure of the panel in the plasma display device will be described with reference to FIG. As shown in FIG. 1, the panel is configured by disposing a glass front substrate 1 and a back substrate 2 so as to form a discharge space therebetween. On the front substrate 1, a plurality of scanning electrodes 3 and sustaining electrodes 4 constituting display electrodes are formed in parallel with each other. A dielectric layer 5 is formed so as to cover the scan electrode 3 and the sustain electrode 4, and a protective layer 6 is formed on the dielectric layer 5.

  A plurality of data electrodes 8 covered with an insulator layer 7 are provided on the back substrate 2, and a grid-like partition wall 9 is provided on the insulator layer 7. A phosphor layer 10 is provided on the surface of the insulator layer 7 and on the side surfaces of the partition walls 9. The front substrate 1 and the rear substrate 2 are arranged to face each other so that the scan electrodes 3 and the sustain electrodes 4 and the data electrodes 8 cross each other, and in the discharge space formed between them, for example, neon And a mixed gas of xenon. Note that the structure of the panel is not limited to the above-described structure, and for example, a structure having a stripe-shaped partition may be used.

  FIG. 2 is an electrode array diagram of this panel. N scan electrodes SC1 to SCn (scan electrode 3 in FIG. 1) and n sustain electrodes SU1 to SUn (sustain electrode 4 in FIG. 1) are arranged in the row direction, and m data electrodes D1 to D1 are arranged in the column direction. Dm (data electrode 8 in FIG. 1) is arranged. A discharge cell is formed at a portion where a pair of scan electrode SCi and sustain electrode SUi (i = 1 to n) and one data electrode Dj (j = 1 to m) intersect, and the discharge cell is in the discharge space. M × n are formed.

  FIG. 3 is a circuit block diagram of a plasma display device using this panel. The plasma display device includes a panel 11, an image signal processing circuit 12, a data electrode drive circuit 13, a scan electrode drive circuit 14, a sustain electrode drive circuit 15, a timing generation circuit 16, and a power supply circuit (not shown).

  The image signal processing circuit 12 converts the image signal sig into image data for each subfield. The data electrode drive circuit 13 converts the image data for each subfield into signals corresponding to the data electrodes D1 to Dm, and drives the data electrodes D1 to Dm. The timing generation circuit 16 generates various timing signals based on the horizontal synchronization signal H and the vertical synchronization signal V, and supplies them to each drive circuit block. Scan electrode drive circuit 14 supplies drive voltage waveforms to scan electrodes SC1 to SCn based on timing signals, and sustain electrode drive circuit 15 supplies drive voltage waveforms to sustain electrodes SU1 to SUn based on timing signals. Here, the scan electrode drive circuit 14 and the sustain electrode drive circuit 15 include a sustain pulse generator 17.

  Next, a driving voltage waveform for driving the panel and its operation will be described with reference to FIG. FIG. 4 is a diagram showing drive voltage waveforms applied to the respective electrodes of the panel.

  In the plasma display device according to the present embodiment, one field is divided into a plurality of subfields, and each subfield has an initialization period, an address period, and a sustain period.

  In the initializing period of the first subfield, the data electrodes D1 to Dm and the sustain electrodes SU1 to SUn are held at 0 (V), and from the voltage Vi1 (V) that is lower than the discharge start voltage with respect to the scan electrodes SC1 to SCn. A ramp voltage that gradually increases toward the voltage Vi2 (V) exceeding the discharge start voltage is applied. Then, the first weak initializing discharge is caused in all the discharge cells, negative wall voltages are stored on scan electrodes SC1 to SCn, and positive walls on sustain electrodes SU1 to SUn and data electrodes D1 to Dm. The voltage is stored. Here, the wall voltage on the electrode refers to a voltage generated by wall charges accumulated on the dielectric layer or the phosphor layer covering the electrode.

  Thereafter, sustain electrodes SU1 to SUn are maintained at positive voltage Vh (V), and a ramp voltage that gradually decreases from voltage Vi3 (V) to voltage Vi4 (V) is applied to scan electrodes SC1 to SCn. Then, the second weak initializing discharge is caused in all the discharge cells, the wall voltage between scan electrodes SC1 to SCn and sustain electrodes SU1 to SUn is weakened, and the wall voltage on data electrodes D1 to Dm is reduced. Is also adjusted to a value suitable for the write operation.

  In the subsequent address period, scan electrodes SC1 to SCn are temporarily held at Vr (V). Next, negative scan pulse voltage Va (V) is applied to scan electrode SC1 in the first row, and data electrode Dk (k = 1 to 1) of the discharge cell to be displayed in the first row among data electrodes D1 to Dm. A positive write pulse voltage Vd (V) is applied to m). At this time, the voltage at the intersection between the data electrode Dk and the scan electrode SC1 is obtained by adding the wall voltage on the data electrode Dk and the wall voltage on the scan electrode SC1 to the externally applied voltage (Vd−Va) (V). And the discharge start voltage is exceeded. Then, an address discharge occurs between data electrode Dk and scan electrode SC1 and between sustain electrode SU1 and scan electrode SC1, and a positive wall voltage is accumulated on scan electrode SC1 of this discharge cell, and on sustain electrode SU1. And a negative wall voltage is also accumulated on the data electrode Dk.

  In this manner, an address operation is performed in which address discharge is caused in the discharge cells to be displayed in the first row and wall voltage is accumulated on each electrode. On the other hand, the voltage at the intersection of the data electrodes D1 to Dm and the scan electrode SC1 to which the address pulse voltage Vd (V) is not applied does not exceed the discharge start voltage, so that address discharge does not occur. The above address operation is sequentially performed until the discharge cell in the nth row, and the address period ends.

  In the subsequent sustain period, positive sustain pulse voltage Vs (V) is applied to scan electrodes SC1 to SCn as a first voltage, and ground potential, that is, 0 (V) is applied to sustain electrodes SU1 to SUn as a second voltage. Apply. In the discharge cell in which the address discharge has occurred at this time, the voltage between scan electrode SCi and sustain electrode SUi is the sustain pulse voltage Vs (V), the wall voltage on scan electrode SCi and the wall voltage on sustain electrode SUi. Is added and exceeds the discharge start voltage. Then, a sustain discharge occurs between scan electrode SCi and sustain electrode SUi, and the phosphor layer emits light due to the ultraviolet rays generated at this time. Then, a negative wall voltage is accumulated on scan electrode SCi, and a positive wall voltage is accumulated on sustain electrode SUi. At this time, a positive wall voltage is also accumulated on the data electrode Dk.

  In the discharge cells in which no address discharge has occurred in the address period, no sustain discharge occurs, and the wall voltage at the end of the initialization period is maintained. Subsequently, 0 (V) that is the second voltage is applied to scan electrodes SC1 to SCn, and sustain pulse voltage Vs (V) that is the first voltage is applied to sustain electrodes SU1 to SUn. Then, in the discharge cell in which the sustain discharge has occurred, the voltage between the sustain electrode SUi and the scan electrode SCi exceeds the discharge start voltage, so that the sustain discharge occurs again between the sustain electrode SUi and the scan electrode SCi, Negative wall voltage is accumulated on sustain electrode SUi, and positive wall voltage is accumulated on scan electrode SCi.

  Thereafter, similarly, by applying sustain pulses of the number corresponding to the luminance weight alternately to scan electrodes SC1 to SCn and sustain electrodes SU1 to SUn, the sustain discharge continues in the discharge cells that have caused the address discharge in the address period. Done. Thus, the maintenance operation in the maintenance period is completed.

  The operations in the initialization period, address period, and sustain period in the subsequent subfield are substantially the same as those in the first subfield, and thus description thereof is omitted.

  FIG. 5 shows an example of the overall configuration of a plasma display device incorporating the panel having the structure described above, and FIG. 6 shows an example of the arrangement of drive circuit blocks as viewed from the back side.

  In the figure, 21 is a chassis member as a holding plate that also serves as a heat sink made of metal such as aluminum. On the front side of the chassis member 21, a panel 11 is placed between the chassis member 21 and a heat dissipation sheet (see FIG. 5). (Not shown) is held by bonding with an adhesive or the like. Further, as shown in FIG. 6, a plurality of drive circuit blocks for driving the panel 11 are arranged on the rear side of the chassis member 21, thereby constituting a module.

  Here, the heat-dissipating sheet is for adhering and holding the panel 11 on the front side of the chassis member 21, efficiently transferring heat generated in the panel 11 to the chassis member 21, and performing heat dissipation. Is about 1 mm to 2 mm. As this heat radiating sheet, an insulating heat radiating sheet in which a synthetic resin material such as acrylic, urethane, silicon resin, or rubber contains a filler that enhances thermal conductivity, a graphite sheet, a metal sheet, or the like can be used. In addition, the heat radiation sheet itself has an adhesive force, and the panel 11 is bonded to the chassis member 21 only by the heat radiation sheet, or the heat radiation sheet has no adhesive force, and another double-sided adhesive tape is used. The structure etc. which adhere | attach can be used for the chassis member 21 can be used.

  In addition, flexible wiring boards 22 as display electrode wiring members connected to the electrode lead portions of the scan electrodes 3 and the sustain electrodes 4 are provided on both side edges of the panel 11, and the rear side passes through the outer periphery of the chassis member 21. And connected to the drive circuit block 23 of the scan electrode drive circuit 14 and the drive circuit block 24 of the sustain electrode drive circuit 15 via connectors.

  On the other hand, a plurality of flexible wiring boards 25 as data electrode wiring members connected to the electrode lead portions of the data electrodes 8 are provided on the lower and upper edges of the panel 11, and the flexible wiring boards 25 are connected to The plurality of data drivers 26 of the electrode drive circuit 13 are electrically connected to each other, routed to the back side through the outer periphery of the chassis member 21, and disposed at the lower and upper positions on the back side of the chassis member 21. The drive circuit block 27 of the data electrode drive circuit 13 is electrically connected.

  The control circuit block 28 displays image data on the basis of a video signal sent from an input signal circuit block 29 having an input terminal portion to which a connection cable for connecting to an external device such as a television tuner is detachably connected. 11 is converted into an image data signal corresponding to the number of pixels 11 and supplied to the drive circuit block 27 of the data electrode drive circuit, and a discharge control timing signal is generated, and the drive circuit block 23 and the sustain electrode of the scan electrode drive circuit 14 are generated. This is supplied to the drive circuit block 24 of the drive circuit 15 and performs display drive control such as gradation control, and is arranged at substantially the center of the chassis member 21.

  The power supply block 30 supplies a voltage to each of the circuit blocks. Like the control circuit block 28, the power supply block 30 is disposed at a substantially central portion of the chassis member 21 and is commercialized through a connector to which a power supply cable (not shown) is attached. A power supply voltage is supplied. These drive circuit blocks 23, 24, 27, control circuit block 28, input signal circuit block 29, and power supply block 30 are fixed to the boss portion provided on the rear side of the chassis member 21 with screws or the like.

  Further, a cooling fan 31 is disposed in the vicinity of the drive circuit blocks 23 and 24 while being held at an angle 32 so that the drive circuit blocks 23 and 24 are cooled by the wind sent from the cooling fan 31. It is configured. Further, the drive circuit block 27 of the data electrode drive circuit 13 disposed at the upper position is cooled at the upper position of the chassis member 21, and on the rear side of the chassis member 21, the entire apparatus is moved from the lower portion toward the upper portion. Three cooling fans 33 are arranged to cool the inside of the apparatus by causing an air flow.

  Further, reinforcing angles 34 and 35 are fixed to the chassis member 21 in the horizontal direction and the vertical direction, and the angle 34 arranged in the horizontal direction is a stand for holding the apparatus in an upright state. The pole 36 is fixed with screws or the like.

  The module having the above structure is housed in a housing having a front protective cover 37 disposed on the front side of the panel 11 and a metal back cover 38 disposed on the rear side of the chassis member 21. This completes the plasma display device. Here, the front protective cover 37 is attached to the front frame 39 made of resin or metal having an opening 39a from which the image display area on the front side of the panel 11 is exposed, and the opening 39a of the front frame 39, and And a protective plate 40 made of glass or the like provided with an unnecessary radiation suppressing film for suppressing unnecessary radiation of an optical filter or electromagnetic wave, and the protective plate 40 has a front frame around the periphery of the protective plate 40. It is attached to the front frame 39 by being sandwiched between the peripheral edge portion of the opening 39 a of 39 and a protective plate pressing metal fitting (not shown). Further, the back cover 38 is provided with a plurality of vent holes (not shown) for releasing heat generated by the module to the outside.

  In FIG. 5, reference numeral 41 denotes a screw for attaching the back cover 38 to the chassis member 21, and 42 denotes a gripping part attached to the back cover 38 with a screw or the like.

  Next, the phosphor layer, which is a characteristic part of the plasma display device according to the present embodiment, will be described in detail.

  First, a method for producing each color phosphor material particle will be described. In the present embodiment, phosphor material particles manufactured by a solid phase reaction method are used.

BaMgAl ₁₀ O ₁₇ : Eu, which is a blue phosphor material particle, is produced by the following method. Barium carbonate (BaCO ₃ ), magnesium carbonate (MgCO ₃ ), aluminum oxide, and europium oxide (Eu ₂ O ₃ ) are mixed so as to match the phosphor composition. The mixture is fired at 800 ° C. to 1200 ° C. in air, and further fired at 1200 ° C. to 1400 ° C. in a mixed gas atmosphere containing hydrogen and nitrogen.

The red phosphor material particles (Y, Gd) BO ₃ : Eu are produced by the following method. Yttrium oxide (Y ₂ O ₃ ), gadolinium oxide (Gd ₂ O ₃ ), boric acid (H ₃ BO ₃ ), and europium oxide (EuO ₂ ) are mixed so as to match the phosphor composition. The mixture is fired at 600 ° C. to 800 ° C. in air, and further fired at 1100 ° C. to 1300 ° C. in a mixed gas atmosphere containing oxygen and nitrogen.

The green phosphor particles, Zn ₂ SiO ₄ : Mn, are produced by the following method. Zinc oxide, silicon oxide, and manganese dioxide (MnO ₂ ) are mixed so as to match the phosphor composition. The mixture is fired at 600 ° C. to 900 ° C., and further fired at 1000 ° C. to 1350 ° C. in a mixed gas atmosphere containing nitrogen and hydrogen.

The phosphor material particles are made into a paste when applied to the back plate. The phosphor material particles used in the plasma display device according to the embodiment of the present invention are blue phosphors having an aspect ratio of 5 or more. The material particles BaMgAl ₁₀ O ₁₇ : Eu are used. Here, the aspect ratio of the phosphor material particle is defined as the ratio of the longest polygonal diagonal line defining the main surface of the particle to the shortest side length of the particle, that is, the thickness of the particle. To do. Such an aspect ratio can be measured by taking an electron micrograph.

  Here, the relationship between the aspect ratio of the phosphor material particles and the strength (binding force) of the phosphor layer formed using the phosphor material particles, which is the result of the study conducted by the present inventors, is shown in Table 1 and FIG. 7 shows.

  Here, the strength of the phosphor layer is specifically evaluated by disassembling the produced plasma display device and taking out only the rear substrate, cleaving it into 15 mm × 15 mm chips, fixing the cleaved chips, When high pressure air is blown toward the phosphor layer from a stainless steel tube (diameter 0.5 mm) installed vertically 15mm from the top, the high pressure air pressure is gradually increased, and when the phosphor layer is peeled off The air pressure of was adopted.

  From Table 1 and FIG. 7 which graphed it, it can be seen that the binding power of the phosphor layer is increased by setting the aspect ratio of the blue phosphor material particles to 5 or more.

  That is, as described above, according to the present invention, it is possible to realize a PDP apparatus in which the phosphor layer is less peeled against vibrations and shocks during the manufacturing process and during product conveyance.

  As described above, the present invention is useful for providing a large-screen, high-definition plasma display device.

The perspective view which shows the principal part of the panel used for the plasma display apparatus by one embodiment of this invention. Electrode arrangement of the panel Circuit block diagram of the plasma display device Waveform diagram showing drive voltage waveform applied to each electrode of panel Exploded perspective view showing the entire configuration of the plasma display device The top view which shows an example of arrangement | positioning which looked at the same plasma display apparatus from the back side Diagram showing the relationship between the aspect ratio of the blue phosphor material particles and the intensity of the phosphor layer

Explanation of symbols

11 Panel 21 Chassis member 22, 25 Flexible wiring board 23, 24, 27 Drive circuit block 26 Data driver 43 Base plate 44, 45 Metal plate 45a Projection

Claims (2)

A pair of substrates are arranged opposite to each other so that a discharge space is formed between the substrates, and a partition for partitioning the discharge space into a plurality of partitions is disposed on at least one substrate, and a discharge is generated in the discharge space partitioned by the partition. A plasma display device comprising a panel having electrodes arranged on a substrate so as to generate and provided with phosphor layers of three colors that emit R (red), G (green), and B (blue) by discharge,
The aspect ratio of the phosphor material particles contained in the phosphor layer of at least one color among the phosphor layers of the three colors is 5 or more. 2. The plasma display device according to claim 1, wherein the at least one color phosphor layer is a blue phosphor layer.

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