JP2006039072A - Plasma display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To attain a plasma display apparatus capable of suppressing undesirable influence to a displayed image characteristic and a life as an image display apparatus by reducing temperature unevenness in a plane of a plasma display panel. <P>SOLUTION: The plasma display apparatus is equipped with; a plasma display panel 10; a thermal conductive sheet 14 which is provided so as to be attached firmly to the back side of the plasma display panel 10; and a metal frame chassis 16 which is arranged at the backside of the plasma display panel 10, being separated from the thermal conductive sheet 14 with a gap 18 and which supports a circuit substrate 17 on the back side. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a plasma display device known as a thin, lightweight display device having a large screen.

  In recent years, plasma display devices have attracted attention as display panels (thin display devices) with excellent visibility, and higher definition and larger screens are being promoted.

  This plasma display device is roughly classified into an AC type and a DC type in terms of driving, and there are two types of discharge types: a surface discharge type and a counter discharge type, but high definition, large screen, and simple manufacturing are possible. Therefore, at present, AC-type and surface-discharge-type plasma display devices are mainly used.

  In such a plasma display device, as shown in FIGS. 12 and 13, the adhesion between the plasma display panel 22 made mainly of glass and the frame chassis 23 as a metal holding plate such as aluminum is made of acrylic or urethane. Alternatively, the double-sided adhesive 24 made of a silicone material is used. The double-sided adhesive 24 also has a function as a heat conductive sheet (see, for example, Patent Document 1). That is, the heat generated in the plasma display panel 22 is diffused by the double-sided adhesive 24 and radiated into the air through the frame chassis 23, thereby uniformly reducing the temperature distribution of the plasma display panel 22.

Reference numeral 25 denotes a circuit board, and 26 denotes a flexible wiring board for connecting the plasma display panel 22 and the circuit board 25.
Japanese Patent Laid-Open No. 10-240138

  Here, in the conventional plasma display apparatus as described above, the plasma display panel 22 and the circuit board 25 serve as heat generation sources during image display. In recent years, the amount of heat generated in the circuit board 25 has increased as the required level for image display has increased, and the heat generated in the circuit board 25 has passed through the frame chassis 23 and the double-sided adhesive 24 having a function as a heat conductive sheet. May be transmitted to the plasma display panel 22 to make the temperature distribution in the surface of the plasma display panel 22 non-uniform. In such a case, the characteristics of the displayed image and the lifetime of the image display device are adversely affected.

  The present invention has been made in view of the above situation, and by suppressing temperature unevenness in the surface of the plasma display panel, it is possible to suppress adverse effects on the characteristics of the displayed image and the lifetime of the image display device. The purpose is to realize a plasma display device that can be used.

  In order to achieve the above object, the plasma display device of the present invention includes a plasma display panel, a heat conductive sheet provided so as to be substantially in close contact with the back side of the plasma display panel, and the back side of the plasma display panel. And a metal frame chassis that is arranged at a distance from the heat conductive sheet and supports the circuit board on the back side.

  According to the present invention, it is possible to realize a plasma display device capable of suppressing adverse effects on the characteristics of the displayed image and the life of the image display device by reducing temperature unevenness in the surface of the plasma display panel. be able to.

  In other words, the invention according to claim 1 of the present invention includes a plasma display panel, a heat conductive sheet provided so as to be in close contact with the back side of the plasma display panel, and the heat display sheet on the back side of the plasma display panel. It is a plasma display device provided with a metal frame chassis that is disposed at a distance from a conductive sheet and supports a circuit board on the back side.

  The invention according to claim 2 is the invention according to claim 1, wherein the heat conductive sheet is a graphite sheet.

  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.

  FIG. 1 is a partial cross-sectional perspective view showing a schematic structure of a plasma display panel in a plasma display device. As shown in FIG. 1, on a transparent and insulating front substrate 1 such as a glass substrate, a plurality of stripe-shaped display electrodes 2 which are paired with scanning electrodes and sustaining electrodes are formed, and the electrodes A dielectric layer 3 is formed so as to cover the group, and a protective film 4 is formed on the dielectric layer 3.

  A plurality of rows of striped data electrodes 7 covered with an overcoat layer 6 are formed on the back substrate 5 opposite to the front substrate 1 so as to intersect the display electrodes 2. Has been. On the overcoat layer 6 between the data electrodes 7, a plurality of barrier ribs 8 are arranged in parallel with the data electrodes 7, and a phosphor layer 9 is provided on the side surface between the barrier ribs 8 and on the surface of the overcoat layer 6. Yes.

  The substrate 1 and the substrate 5 are opposed to each other with a minute discharge space so that the display electrode 2 and the data electrode 7 of the scan electrode and the sustain electrode are almost orthogonal to each other, and the periphery is sealed, and One or a mixed gas of helium, neon, argon, and xenon is sealed in the discharge space as a discharge gas.

  In addition, the discharge space is divided into a plurality of sections by partition walls 8 to provide a plurality of discharge cells where the intersections of the display electrodes 2 and the data electrodes 7 are located, and each of the discharge cells has red, green and blue colors. The phosphor layers 9 that emit light are sequentially arranged one by one.

FIG. 2 is a plan view schematically showing the electrode arrangement of the plasma display panel. As shown in FIG. 2, the scanning electrodes (SCN _{1 to M)} and sustain electrodes (SUS _{1 to M)} and data electrodes (D _{1 to N),} constitutes a matrix of M rows × N columns.

  In the plasma display panel having such an electrode configuration, an address pulse is applied between the data electrode and the scan electrode by applying a write pulse between the data electrode and the scan electrode, and after selecting the discharge cell, the scan electrode By applying a periodic sustain pulse that is alternately inverted between the sustain electrode and the sustain electrode, a sustain discharge is performed between the scan electrode and the sustain electrode to perform a predetermined display.

  FIG. 3 is a perspective view showing an example of a schematic configuration of a plasma display device incorporating the plasma display panel having the structure described above. In FIG. 3, the housing that houses the plasma display panel 10 is composed of a front frame 11 and a metal back cover 12, and the opening of the front frame 11 also serves as an optical filter and a protection for the plasma display panel 10. A front cover 13 made of glass or the like is disposed. Further, the front cover 13 is subjected to, for example, silver vapor deposition in order to suppress unnecessary radiation of electromagnetic waves. Furthermore, the back cover 12 is provided with a plurality of ventilation holes 12a for ventilation that releases heat generated in the plasma display panel 10 and the like to the outside of the casing and introduces new air into the casing. ing.

  A heat conductive sheet 14 for diffusing heat generated in the plasma display panel 10 to make the temperature distribution in the surface of the plasma display panel 10 uniform and lower on the back side of the plasma display panel 10 is, for example, an adhesive ( (Not shown).

  Further, a double-sided adhesive sheet 15 is disposed in the vicinity so as to surround the heat conductive sheet 14. The plasma display panel 10 is fixed to a frame chassis 16 as a metal holding plate such as aluminum via the double-sided adhesive sheet 15. A plurality of circuit boards 17 for displaying and driving the plasma display panel 10 are attached to the rear surface side of the frame chassis 16 via bosses 19.

  FIG. 4 is a sectional view showing a schematic configuration of a plasma display device according to an embodiment of the present invention. As shown in FIG. 4, in the plasma display device according to the embodiment of the present invention, the thickness of the double-sided adhesive sheet 15 is, for example, less than 2 mm, and the thickness of the heat conductive sheet 14 is, for example, 1.4 mm. A gap 18 of, for example, a little less than 0.6 mm is formed between the seat 14 and the frame chassis 16.

  The frame chassis 16 is provided with a plurality of holding portions 19 for holding and fixing a plurality of circuit boards 17 for driving the plasma display panel 10. The circuit board 17 is electrically connected to the electrode lead-out portion that is led out to the edge of the plasma display panel 10 by a plurality of flexible wiring boards 20 that extend beyond the edges of the four sides of the frame chassis 16.

  Here, it is desirable to use the heat conductive sheet 14 having as good a heat conductivity as possible, and the double-sided adhesive sheet 15 having a heat conductivity as bad as possible.

  FIG. 5 is a diagram schematically showing the arrangement of the heat conductive sheet 14 and the double-sided adhesive sheet 15 on the back side of the plasma display panel 10. The heat conductive sheet 14 is fixed to the plasma display panel 10 so as to cover approximately 80% of the whole centering on the central portion of the plasma display panel 10. The double-sided adhesive sheet 15 is disposed outside the heat conductive sheet 14, and includes a portion 15a that covers both left and right ends of the plasma display panel 10 in a strip shape, and a portion 15b that covers the upper and lower ends of the plasma display panel 10 in small pieces. Is done.

  Here, the results of studies conducted to confirm the effects of the present invention will be described below. The plasma display device used for the examination has a screen size of 42 type, one is the plasma display device according to the present invention shown in FIG. 4, and the conventional plasma display device shown in FIG. 11 is used for comparison. Then, as shown in a plan view from the front side in FIG. 6, a rectangular white window pattern 21 is displayed at the bottom of the display screen of the plasma display panel 10, and the plasma display panel 10 two hours after the start of driving is displayed. The temperature distribution on the surface was measured.

  FIG. 7 shows the measurement results at this time. From this figure, it can be seen that the plasma display device of the present invention is reduced by about 19 ° C. in the temperature of the display area and about 6 ° C. in the temperature difference between the display area 21a and the non-display area 21b.

  The reason for the above result is considered as follows. That is, in the plasma display device of the present invention, there is an air gap 18 between the heat conductive sheet 14 and the frame chassis 16, and the double-sided adhesive sheet 15 uses a material having a poor heat conductivity as much as possible. Therefore, the frame chassis 16 and the plasma display panel 10 are in a state of being thermally separated. Therefore, the heat generated in the circuit board 17 is radiated from the frame chassis 16 into the air in the gap 18 and is not easily transmitted to the plasma display panel 10. Further, the heat generated in the plasma display panel 10 is diffused and dissipated into the air in the air gap 18 by the heat conductive sheet 14 fixed to the back side of the plasma display panel 10 as in the prior art. The temperature non-uniformity and temperature rise in the 10 planes are suppressed. From the above, it is considered that the uniformity of the temperature distribution is further increased in the plasma display device of the present invention as compared with the conventional case.

  Since the heat conduction sheet 14 suppresses temperature non-uniformity and temperature rise in the surface of the plasma display panel 10, when displaying an image pattern that causes non-uniform temperature distribution on the plasma display panel 10. In addition, the occurrence of cracks or the like in the plasma display panel 10 is greatly suppressed.

  In the above description, the heat conductive sheet 14 is as good in heat conductivity as possible. Specifically, a graphite sheet, aluminum, silver, copper, gold, magnesium, alloys thereof, etc. Can be used in the form of a sheet. Here, when a graphite sheet is used, the graphite sheet has sufficient heat conduction characteristics in the thickness direction based on the anisotropy of the heat conduction characteristics of graphite, and further has excellent heat conduction characteristics in the plane direction. Thus, the effect of diffusing and uniformizing the heat of the plasma display panel 10 in the plane direction can be obtained more effectively, which is preferable.

  Further, as shown in FIG. 3, the back cover 12 that constitutes the casing that accommodates the plasma display panel 10 releases heat generated in the plasma display panel 10 and the like to the outside of the casing and fresh air. Since a plurality of ventilation holes 12a introduced into the housing are provided for ventilation, the air present in the air gap 18 is caused by natural convection generated as the temperature of the heat conductive sheet 14 and the frame chassis 16 increases. Then, heat is dissipated while being naturally replaced. However, it may be forced to ventilate with a fan or the like.

  Further, in order to effectively dissipate the heat generated in the circuit board 17 through the frame chassis 16, it is preferable to sandwich a high heat conductive material such as silicone between the circuit board 17 and the frame chassis 16 and to bring them into contact with each other. . By setting it as such a structure, it becomes possible to reduce the temperature of the element which comprises the circuit board 17 effectively.

  Further, the size of the heat conductive sheet 14 is not limited to a size that covers 80% of the surface of the plasma display panel 10 as described above, but covers a desired region where the temperature distribution is desired to be uniform. It should be large enough.

  In addition to the pattern shown in FIG. 5, the double-sided adhesive sheet 15 is arranged in a frame shape so as to cover the entire peripheral area on the back side of the plasma display panel 10 as shown in FIG. Alternatively, as shown in FIG. 9, small double-sided adhesive sheets 15 may be distributed over the entire back side of the plasma display panel 10.

  Further, when the structure of the frame chassis 16 as the holding plate is a flat plate structure as shown in FIG. 4, the frame chassis 16 may be bent or deformed. Therefore, as a structure of the frame chassis 16 that is lightweight, highly rigid, and less likely to be deformed, a boss 19 that holds and fixes the circuit board 17 is formed by drawing the frame chassis 16 as shown in FIGS. A structure is preferable. Thus, by forming a large number of drawing bosses 19 on the frame chassis 16, it is possible to change the material of the frame chassis 16 without changing the material and thickness, that is, while maintaining weight reduction and cost reduction. The rigidity can be increased as compared with the case of.

  As described above, according to the plasma display device of the present invention, the temperature unevenness in the surface of the plasma display panel is reduced, so that adverse effects on the characteristics of the displayed image and the lifetime of the image display device are suppressed. It is possible to provide a plasma display device capable of achieving the above.

1 is a partial cross-sectional perspective view showing a schematic structure of a plasma display panel in a plasma display device according to an embodiment of the present invention. Plan view schematically showing electrode arrangement of plasma display panel The perspective view which shows schematic structure of the plasma display apparatus by one embodiment of this invention. Sectional drawing which shows schematic structure of the plasma display apparatus by one embodiment of this invention The figure which shows typically the arrangement situation of a heat conductive sheet and a double-sided adhesive sheet The figure which shows the display state at the time of confirming the effect of the plasma display apparatus of this invention The figure which shows the effect of the plasma display apparatus of this invention The figure which shows typically the arrangement situation of a heat conductive sheet and a double-sided adhesive sheet The figure which shows typically the arrangement situation of a heat conductive sheet and a double-sided adhesive sheet The perspective view which shows schematic structure of the plasma display apparatus by other embodiment of this invention. Sectional drawing which shows schematic structure of the plasma display apparatus by other embodiment of this invention. A plan view showing a schematic configuration of a conventional plasma display device Sectional drawing which shows schematic structure of the conventional plasma display apparatus

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Front side board | substrate 5 Back side board | substrate 10 Plasma display panel 14 Thermal conductive sheet 16 Frame chassis 17 Circuit board 18 Air gap

Claims (2)

A plasma display panel;
A heat conductive sheet provided to be in close contact with the back side of the plasma display panel;
A metal frame chassis that is arranged on the back side of the plasma display panel with a gap between the heat conductive sheet and supports the circuit board on the back side,
A plasma display device comprising: The plasma display apparatus according to claim 1, wherein the heat conductive sheet is a graphite sheet.

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