JP2012083533A - Plasma display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plasma display device in which a large temperature gradient does not occur in a front substrate even if the plasma display device includes a large screen and high luminance plasma display panel.SOLUTION: A plasma display device includes a panel in which a front substrate 21 having a plurality of scanning electrodes and a plurality of sustain electrodes formed thereon, and a back substrate having a plurality of data electrodes formed thereon are arranged while facing each other; and a plurality of circuit boards 75 to 79 for supplying driving voltage waveforms to be supplied to the sustain electrode. In the panel, a short circuit line for electrically short-circuiting the plurality of sustain electrodes, and a plurality of electrode terminals electrically connected to the short circuit line and grouped into a plurality of electrode terminal groups are further formed on the front substrate 21. A thermally conductive tape 81 is attached onto the front substrate 21 so as to cover an area on a back side of the area between the adjacent electrode terminal groups.

Description

  The present invention relates to a plasma display device using a plasma display panel.

  A plasma display device using a typical plasma display panel (hereinafter simply abbreviated as “panel”) as a flat display has a wide viewing angle and is easy to enlarge, and is self-luminous and has an image display quality. Due to its high cost, it is becoming the mainstream of large screen image display devices.

  In the panel, a large number of discharge cells are formed between a front substrate and a rear substrate which are arranged to face each other. On the front substrate, a plurality of display electrode pairs each formed of a pair of scan electrodes and sustain electrodes are formed in parallel to each other. A plurality of parallel data electrodes are formed on the back substrate, and further, barrier ribs and phosphor layers are formed. Then, the front substrate and the rear substrate are disposed opposite to each other so that the display electrode pair and the data electrode are three-dimensionally crossed and sealed, and a discharge gas is sealed in the internal discharge space. Here, a discharge cell is formed in a portion where the display electrode pair and the data electrode face each other.

  The plasma display apparatus alternately applies sustain pulses to scan electrodes and sustain electrodes via a flexible wiring board (hereinafter abbreviated as “FPC”) to generate a discharge in a discharge cell to emit an image. it's shown.

  At this time, when the discharge cell emits light, heat is generated and the temperature of the panel rises. Further, the impedance of the current path from the FPC through the electrode terminals of the panel to the discharge cell is also a factor of heat generation. In general, the discharge characteristics of the discharge cells change under the influence of temperature, so that if the panel temperature rises too much, the discharge becomes unstable and the image display quality may deteriorate. In addition, if the temperature of the panel is extremely increased locally, the panel may be damaged.

  Therefore, various methods for suppressing the panel temperature have been proposed. For example, Patent Document 1 discloses a method of suppressing the temperature rise of a panel by efficiently conducting heat generated in the panel to the chassis by attaching the panel to the chassis via a heat conductive sheet made of silicon resin or the like. Has been.

  Further, in Patent Document 2, a short-circuit line that electrically short-circuits a plurality of sustain electrodes is provided on the rear substrate to lower the impedance of the current path, suppress heat generation in the current path, and provide a panel short-circuit line A method is also disclosed in which a heat conductive sheet is interposed between the chassis and the chassis, and heat generated in the short circuit line and its surroundings is efficiently conducted to the chassis to suppress the temperature rise of the panel.

JP 10-254372 A JP 2008-83135 A

  In recent years, with the increase in the screen size of the panel, a driving voltage is supplied to each electrode using a plurality of circuit boards. Further, as the panel has a larger screen and higher brightness, the current accompanying the sustain discharge is increasing. For this reason, the current flowing through the short-circuit line has become much larger than before. Then, current concentration occurs in the vicinity of the short-circuit line between the adjacent electrode terminal groups, and a so-called heat spot is generated in which the temperature rises locally in this portion. If a large temperature gradient occurs on the front substrate due to the generation of heat spots, the panel may be damaged.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a plasma display device that does not cause a large temperature gradient on the front substrate even in a large screen and a high-luminance panel.

  In order to achieve the above object, the panel of the present invention applies a front substrate on which a plurality of scan electrodes and a plurality of sustain electrodes are formed and a rear substrate on which a plurality of data electrodes are formed to face each other, and the sustain electrodes. A plasma display apparatus having a plurality of circuit boards for supplying a driving voltage waveform, wherein the panel is electrically connected to a short-circuit line that electrically short-circuits the plurality of sustain electrodes and the short-circuit line to a plurality of electrode terminal groups A plurality of grouped electrode terminals are further formed on the front substrate, and a heat conductive tape is attached to the front substrate so as to cover a region on the back surface side of a region between adjacent electrode terminal groups. . With this configuration, it is possible to provide a plasma display device that does not cause a large temperature gradient on the front substrate even with a large screen and a high brightness panel.

  The heat conductive tape of the plasma display device of the present invention has a width that overlaps at least a part of the short-circuit line from the end of the front substrate and a length that overlaps at least a part of each of the adjacent electrode terminal groups. Is desirable.

  Moreover, it is desirable that the heat conductive tape of the plasma display device of the present invention is a metal tape.

  Further, the panel of the plasma display device of the present invention is formed on the front substrate so as to cover the region on the back surface side of the region between the electrode terminal groups to which the drive voltage waveform is supplied from different circuit substrates among the adjacent electrode terminal groups. You may affix a heat conductive tape.

  According to the present invention, it is possible to provide a plasma display device that does not cause a large temperature gradient on the front substrate even with a large screen and a high brightness panel.

It is a disassembled perspective view which shows the structure of the panel of the plasma display apparatus in embodiment of this invention. It is an electrode array figure of the panel of the plasma display apparatus. It is a figure which shows arrangement | positioning of the electrode terminal of the panel of the plasma display apparatus. It is a figure which shows the drive voltage waveform applied to each electrode of the panel of the same plasma display apparatus. It is a circuit block diagram of the plasma display device. It is a disassembled perspective view which shows the structure of the plasma display apparatus. It is a figure which shows the connection of the panel and sustain electrode drive circuit of the plasma display apparatus. It is a schematic diagram of the panel which affixed the heat conductive tape in embodiment of this invention. It is a schematic diagram of the panel which does not affix a heat conductive tape.

  Hereinafter, a plasma display device according to an embodiment of the present invention will be described with reference to the drawings.

(Embodiment)
FIG. 1 is an exploded perspective view showing the structure of panel 10 of the plasma display device in accordance with the exemplary embodiment of the present invention. On the front substrate 21, a plurality of display electrode pairs 24 including scan electrodes 22 and sustain electrodes 23 are formed. A dielectric layer 25 is formed so as to cover the scan electrode 22 and the sustain electrode 23, and a protective layer 26 is formed on the dielectric layer 25. A plurality of data electrodes 32 are formed on the back substrate 31, a dielectric layer 33 is formed so as to cover the data electrodes 32, and a grid-like partition wall 34 is formed thereon. A phosphor layer 35 that emits red, green, and blue light is provided on the side surface of the partition wall 34 and on the dielectric layer 33.

  The front substrate 21 and the rear substrate 31 are arranged to face each other so that the display electrode pair 24 and the data electrode 32 intersect each other with a minute discharge space interposed therebetween, and the outer periphery thereof is sealed with a sealing material such as glass frit. Has been. In the discharge space, for example, a mixed gas of neon and xenon is enclosed as a discharge gas. The discharge space is partitioned into a plurality of sections by partition walls 34, and discharge cells are formed at the intersections between the display electrode pairs 24 and the data electrodes 32. These discharge cells discharge and emit light to display an image.

  FIG. 2 is an electrode array diagram of panel 10 of the plasma display device in accordance with the exemplary embodiment of the present invention. In the panel 10, n scanning electrodes 22 and n sustain electrodes 23 that are long in the row direction are arranged, and m data electrodes 32 that are long in the column direction are arranged. A discharge cell is formed at a portion where one pair of scan electrode 22 and sustain electrode 23 intersects with one data electrode 32, and m × n discharge cells are formed in the discharge space. The area where the m × n discharge cells are formed is an image display area, and an image is displayed in the image display area on the front substrate 21 side.

  The number of scan electrodes 22 and sustain electrodes 23 is, for example, n = 2160 if the panel 10 is a 150-inch panel with high definition. Each of these electrodes is connected to each of electrode terminals provided on the periphery of the panel 10 outside the image display area of the front substrate 21 and the rear substrate 31.

  FIG. 3 is a diagram showing the arrangement of electrode terminals of panel 10 of plasma display device 40 in accordance with the first exemplary embodiment of the present invention, and is a view of front substrate 21 as seen from the surface on which display electrode pairs 24 are formed.

  It is necessary to apply different driving voltages to the scanning electrodes 22 as described later. For this purpose, each of the scanning electrodes 22 is connected to each of the electrode terminals 62 for scanning electrodes provided in the peripheral portion on the right side outside the image display area by a lead line 61. In order to connect the scan electrode FPC 72, a plurality of scan electrode electrode terminals 62 are grouped and arranged as a scan electrode electrode terminal group 64. In the present embodiment, for example, the number of scanning electrodes 22 is 2160, and the electrode terminals 62 for scanning electrodes are grouped into 18 electrode terminal groups 64 for scanning electrodes 120 by 120. A total of 18 FPCs 72 for scan electrodes are connected to each electrode terminal group for each scan electrode.

  On the other hand, since the same drive voltage may be applied to each sustain electrode 23 as will be described later, each sustain electrode 23 is connected to a short-circuit line 66 that electrically short-circuits sustain electrode 23. In order to connect the sustain electrode FPC 73 to the short-circuit line 66, the sustain electrode electrode terminals 63 are grouped into a plurality of sustain electrode electrode terminals 67 and provided on the left peripheral portion outside the image display area. .

  Since each sustain electrode 23 is electrically short-circuited, the number of electrode terminals 63 for sustain electrodes, the number of FPCs 73 for sustain electrodes, and their attachment positions are arbitrary. In the present embodiment, for example, the electrode terminals 63 for sustain electrodes are grouped into 18 electrode terminal groups 67 for 18 sustain electrodes, one by one, and one electrode terminal group for each sustain electrode, A total of 18 sustain electrode FPCs 73 are connected.

  As described above, the front substrate has a plurality of short-circuit lines 66 that electrically short-circuit the plurality of sustain electrodes 23 and a plurality of electrode terminals 67 that are electrically connected to the short-circuit lines 66 and grouped into a plurality of electrode terminals 67 for the sustain electrodes. An electrode terminal for the sustain electrode is further formed.

  In the present embodiment, the short-circuit line 66 has a width of 18 mm and is provided at a position 10.5 mm from the end of the front substrate 21. However, the width and position of the short-circuit line 66 may be set according to the panel specifications and the like.

  Next, a method for driving the panel 10 will be described. In the present embodiment, a so-called subfield method is used as a method of displaying a gradation corresponding to an image signal. In the subfield method, one field period is divided into a plurality of subfields having an initialization period, an address period, and a sustain period, and gradation display is performed by controlling light emission / non-light emission of each discharge cell for each subfield. It is.

  FIG. 4 is a diagram showing a driving voltage waveform applied to each electrode of panel 10 of the plasma display device in accordance with the exemplary embodiment of the present invention. FIG. 4 shows drive voltage waveforms for the three subfields SF1 to SF3, but the drive voltage waveforms in the other subfields are substantially the same.

  In the initializing period of the subfield SF1, a ramp voltage that gradually increases toward the voltage Vi2 is applied to the scan electrode 22. Thereafter, the voltage Ve is applied to the sustain electrode 23, and a ramp voltage that gradually decreases toward the voltage Vi4 is applied to the scan electrode 22. Then, a weak initializing discharge occurs in each discharge cell, and wall charges necessary for the subsequent address operation are formed on each electrode.

  Note that as the operation in the initialization period, as shown in the initialization period of the subfields SF2 and SF3, a ramp voltage that gradually decreases may be applied to the scan electrode 22 only.

  In the subsequent address period, a scan pulse of voltage Va is applied to the scan electrode 22 in the first row, and an address pulse of voltage Vd is applied to the data electrode 32 corresponding to the discharge cell to emit light. Then, an address discharge is generated in the discharge cells in the first row to which the scan pulse and the address pulse are simultaneously applied, and an address operation for accumulating wall charges on the scan electrode 22 and the sustain electrode 23 of the discharge cell is performed.

  The above addressing operation is repeated in all rows of discharge cells, and address discharge is selectively generated in the discharge cells to emit light to form wall charges.

  In the subsequent sustain period, the sustain pulses of the voltage Vs are alternately applied to the sustain electrodes 23 and the scan electrodes 22 by the number corresponding to the luminance weight. Then, a sustain discharge occurs in the discharge cell in which the address discharge has occurred and emits light. At the end of the sustain period, a ramp voltage that gradually increases toward the voltage Vr is applied to the scan electrode 22 to erase the wall charges. Thus, the sustain operation for causing the discharge cell in which the address discharge has occurred to emit light with the luminance corresponding to the luminance weight is completed.

  The operation of the subsequent subfield is almost the same as the operation of the first subfield.

  FIG. 5 is a circuit block diagram of plasma display device 40 in accordance with the exemplary embodiment of the present invention. The plasma display device 40 includes a panel 10 and a drive circuit. The drive circuit includes an image signal processing circuit 41, a data electrode drive circuit 42, a scan electrode drive circuit 43, a sustain electrode drive circuit 44, a timing generation circuit 45, and each circuit block. Is provided with a power supply circuit (not shown) for supplying the necessary power.

  The image signal processing circuit 41 converts the input image signal into image data indicating light emission / non-light emission for each subfield. The data electrode driving circuit 42 converts the image data for each subfield into an address pulse applied to each of the data electrodes 32. The timing generation circuit 45 generates various timing signals for controlling the operation of each circuit block based on the horizontal synchronization signal and the vertical synchronization signal, and supplies them to the respective circuit blocks. Scan electrode drive circuit 43 generates a drive voltage to be applied to each scan electrode 22 based on the timing signal, and sustain electrode drive circuit 44 generates a drive voltage to be applied to sustain electrode 23 based on the timing signal.

  These drive circuits are mounted on a plurality of circuit boards.

  FIG. 6 is an exploded perspective view showing the structure of the plasma display device 40 according to the embodiment of the present invention. The plasma display device 40 includes a panel 10, a chassis 51 that holds the panel 10 on the front surface, a heat conductive sheet 52 that transfers heat generated in the panel 10 to the chassis 51 and bonds the panel 10 and the chassis 51. A circuit board group 53 mounted on the back side of the chassis 51 and mounted with various drive circuits for driving the panel 10, and a front frame 55 and a back cover 56 for housing them are provided. The front frame 55 is provided with a transparent protective plate for protecting the panel 10. The circuit board group 53 includes a plurality of circuit boards that supply drive voltage waveforms to be applied to the sustain electrodes 23.

  FIG. 7 is a diagram showing the connection between panel 10 and sustain electrode drive circuit 44 of plasma display device 40 in accordance with the exemplary embodiment of the present invention, as viewed from the front substrate 21 side of the panel. However, in order to make the state of connection easy to see, the circuit board is removed from the chassis 51 and spread on the same plane as the panel. The sustain electrode drive circuit 44 is divided and mounted on two circuit boards 75 and 76. The circuit boards 77 to 79 are relay circuit boards for transmitting drive voltage waveforms. A drive voltage waveform output from the circuit board 75 is abbreviated as an electrode terminal 63 for a sustain electrode (hereinafter simply abbreviated as “electrode terminal 63”) via a FPC 73 for a sustain electrode (hereinafter simply abbreviated as “FPC 73”). Is transmitted to the electrode terminal 63 via the FPC 73 via the relay circuit board 77, or is transmitted to the electrode terminal 63 via the FPC 73 via the circuit board 78 for relay. Similarly, the drive voltage waveform output from the circuit board 76 is transmitted to the electrode terminal 63 via the FPC 73, is transmitted to the electrode terminal 63 via the FPC 73 via the relay circuit board 78, or is relayed. Is transmitted to the electrode terminal 63 via the circuit board 79 and the FPC 73.

  Here, in particular, the current path that passes through the relay circuit board 77 or the relay circuit board 79 has a larger impedance than the current path that does not pass through the relay circuit board. Will increase. Therefore, the electrode terminal group 67 which is adjacent to the FPC 73a which forms the current path passing through the relay circuit board 77 or the relay circuit board 79 is connected to the relay circuit board. A heat spot is likely to occur in the vicinity of the short-circuit line 66 between the electrode terminal group 67 connected to the FPC 73b that constitutes the current path, and the temperature difference between the front substrate 21 in this portion is likely to be the largest.

  In the present embodiment, in order to suppress this temperature difference, among the adjacent electrode terminal groups 67, in particular, between the electrode terminal group 67 to which the FPC 73a is connected and the electrode terminal group 67 to which the FPC 73b is connected. A heat conductive tape 81 is attached to the front substrate 21 so as to cover a region on the back side of the region (that is, a region on the display surface side). Here, the heat conductive tape 81 has a width that overlaps at least a part of the short-circuit line 66 from the end of the front substrate 21, and a length that overlaps at least a part of each of the adjacent electrode terminal groups 67. Therefore, if one side of the heat conductive tape 81 is pasted so as to be 1 mm to 2 mm from the end of the front substrate 21, the heat conductive tape 81 necessarily overlaps a part of the region on the back surface side of the short-circuit line 66. Moreover, it can affix so that it may overlap with a part of each area | region of the back surface side of an adjacent electrode terminal group. In this way, the heat conductive tape 81 is attached to the front substrate 21 so as to cover the region on the back surface side of the region between the adjacent electrode terminal groups 67.

  In the present embodiment, two adhesive aluminum tapes having a width of 20 mm, a length of 50 mm, and a thickness of 80 μm are laminated and pasted as the heat conductive tape 81. Further, a non-woven tape is stuck on the aluminum tape so that the aluminum tape does not peel off.

  In order to confirm the effect of the heat conductive tape 81 in this Embodiment, the present inventors measured the temperature distribution of the front substrate 21 of the panel 10 in this Embodiment. FIG. 8A is a schematic view of panel 10 to which heat conductive tape 81 is attached in the embodiment of the present invention. The temperature distribution was measured with the panel 10 standing vertically so that the scan electrode 22 and the sustain electrode 23 were horizontal. As a condition for the temperature gradient to become the largest, the upper part of the display screen was made to emit white light in a band shape. The area that emits light at this time is a band-like area from the top of the display screen to the position where the FPC 73a is connected. And the temperature distribution of the front substrate 21 at that time was measured using the thermograph. For comparison, the same measurement was performed on a panel to which the heat conductive tape 81 was not attached. FIG. 8B is a schematic view of a panel to which a heat conductive tape is not attached. Again, the upper part of the display screen was made to emit white light in a strip shape, and the temperature distribution of the front substrate at that time was measured using a thermograph.

  In the panel to which the heat conductive tape 81 was not attached, a heat spot was generated locally at the point F shown in FIG. 8B, and the temperature at the point E shown in FIG. 8B was minimized. The temperature gradient between point F and point E was the largest and was saturated at a temperature gradient of 23.1 ° C./cm. This is because the current flowing through the short-circuit line 66 and the FPC 73b among the current flowing through the sustain electrode located at the top of the display screen increases, so that the current near the point F of the short-circuit line 66 shown in FIG. It is considered that a heat spot occurred at point F. Further, since the thermal conductivity of the glass is small, it is considered that the temperature at the point E sandwiched between the electrode terminal group to which the FPC 73a is connected and the electrode terminal group to which the FPC 73b is connected is minimized.

  On the other hand, in the panel 10 to which the heat conductive tape 81 in this embodiment is attached, a heat spot is generated at the point D, the temperature at the point C is minimized, and the temperature gradient between the points D and C is the largest. . However, the temperature gradient was saturated at 11.7 ° C./cm.

  In this way, the heat conductive tape 81 is attached to the front substrate 21 so as to cover the region on the back surface side of the region between the adjacent electrode terminal groups 67, so that the heat generated at the heat spot D is reduced to a low temperature C. It can diffuse to the point and suppress the temperature gradient. And in this Embodiment, it has confirmed that a temperature gradient was suppressed to about 1/2 of the case where the heat conductive tape 81 was not affixed by affixing the heat conductive tape 81. FIG.

  Thus, in the present embodiment, the heat conductive tape 81 is attached to the front substrate 21 so as to cover the area on the back surface side of the area between the adjacent electrode terminal groups 67. The heat conductive tape 81 is a metal tape having a width that overlaps at least a part of the short-circuit line 66 from the end of the front substrate 21 and a length that overlaps at least a part of each of the adjacent electrode terminal groups 67. .

  And by sticking the heat conductive tape 81 to the front substrate 21, even if it is a large screen and a high-intensity panel, a big temperature gradient is not produced in the front substrate 21. FIG.

  In the present embodiment, a region where the temperature gradient is expected to be greatest, that is, a region between electrode terminal groups 67 to which a drive voltage waveform is supplied from a different circuit board among adjacent electrode terminal groups 67. The heat conductive tape 81 was affixed on the front substrate 21 so that the area | region of the back surface side might be covered. However, the heat conductive tape 81 may be attached to the front substrate 21 so as to cover the region on the back surface side of the region between the other adjacent electrode terminal groups 67. However, since unnecessary radiation tends to increase when the heat conductive tape 81 is applied more than necessary, it is desirable to determine the position where the heat conductive tape 81 is applied based on the position where the heat spot is generated and the size of the unnecessary radiation. .

  It should be noted that the specific numerical values used in the embodiments are merely examples, and it is desirable to set them appropriately to optimum values according to the panel characteristics, the specifications of the plasma display device, and the like.

  According to the present invention, even a large screen and a high-luminance panel are useful as a plasma display device without causing a large temperature gradient on the front substrate.

DESCRIPTION OF SYMBOLS 10 Panel 21 Front substrate 22 Scan electrode 23 Sustain electrode 24 Display electrode pair 25,33 Dielectric layer 26 Protective layer 31 Back substrate 32 Data electrode 34 Partition 35 Phosphor layer 40 Plasma display device 61 Lead line 62, 63 Electrode terminal 64, 67 Electrode terminal group 66 Short-circuit wire 72, 73, 73a, 73b FPC
75, 76, 77, 78, 79 Circuit board 81 Thermal conductive tape

Claims (4)

A plasma display panel in which a front substrate on which a plurality of scan electrodes and a plurality of sustain electrodes are formed and a rear substrate on which a plurality of data electrodes are formed are arranged to face each other, and a plurality of circuit substrates that supply drive voltage waveforms applied to the sustain electrodes A plasma display device comprising:
The plasma display panel is:
Further forming on the front substrate a short-circuit line that electrically short-circuits the plurality of sustain electrodes, and a plurality of electrode terminals that are electrically connected to the short-circuit line and grouped into a plurality of electrode terminal groups,
A plasma display device, wherein a heat conductive tape is attached to the front substrate so as to cover a region on the back surface side of a region between the adjacent electrode terminal groups. The heat conductive tape has a width that overlaps at least a part of the short-circuit line from an end portion of the front substrate, and a length that overlaps at least a part of each of the adjacent electrode terminal groups. The plasma display device according to claim 1. The plasma display apparatus of claim 1, wherein the heat conductive tape is a metal tape. Affixing the heat conductive tape to the front substrate so as to cover the region on the back side of the region between the electrode terminal groups to which the drive voltage waveform is supplied from different circuit substrates among the adjacent electrode terminal groups. The plasma display device according to claim 1, wherein:

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