JP4131633B2 - Plasma display device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a plasma display device in which a plasma display panel (PDP) is assembled to a casing.
[0002]
Plasma display devices are becoming popular as large screen television receivers. In order to expand usage, improvements in display performance and overall operating performance are being promoted.
[0003]
[Prior art]
A surface discharge type PDP used for color display has barrier ribs for preventing discharge interference between adjacent cells. The partition arrangement pattern includes a stripe pattern that divides a display area for each column (column) of matrix display, and a mesh pattern that divides for each cell. In the case of adopting a stripe pattern, a plurality of barrier ribs in a plan view are arranged in the display area. When the mesh pattern is adopted, one partition wall (so-called box rib) having a planar view shape that surrounds all the cells individually is arranged in the display area. Such a partition wall has a height of 150 μm to 200 μm, and defines the size of the opposing gap between the substrate pair in the display region.
[0004]
In general, the partition wall is a sintered body of low-melting glass and is formed by the following procedure. (A) A low melting point glass paste is applied on a glass substrate with a uniform thickness and dried. (B) A mask having a pattern corresponding to the partition is formed on the dried paste layer by photolithography. (C) The unmasked portion of the paste layer is cut by sand blasting with a cutting material. (D) After removing the mask, the patterned paste layer is baked.
[0005]
[Problems to be solved by the invention]
In the formation of the partition walls, a certain degree of height variation is inevitable. In particular, when baking a paste layer patterned by sand blasting as described above, a side cut occurs in which the cutting in the sand blasting process goes under the mask, and the edge of the partition in plan view is more than the other during the subsequent baking. May be high. Specifically, in the partition wall having a height design value of 140 μm, the end portion is about 30 μm higher than the other portions. This phenomenon is called “bounce-up” and is considered to be caused by uneven heat shrinkage stress. The jumping up causes incomplete adhesion between the substrates in the assembly of the PDP in which the substrate having the partition wall and another substrate are stacked. In most of the partition formation region, the counter substrate surface is in close contact with the upper surface of the partition wall, whereas in the vicinity of the jumping position in the partition formation region, only the raised partition wall end abuts the counter substrate surface. The substrate is microscopically bent, and a gap is generated between the upper surface of the partition wall and the surface of the counter substrate. In the PDP in such a state, there is a problem that the substrate naturally vibrates locally due to periodic electrostatic attraction accompanying application of a high-frequency driving voltage for display, thereby generating a fine sound.
[0006]
An object of the present invention is to reduce operation noise due to resonance of a substrate.
[0007]
[Means for Solving the Problems]
In the present invention, the outer surface of the substrate pair constituting the plasma display panel is outside the display region and inside the sealing material that joins the substrate pair around the opposing gap of the substrate pair and surrounds the display region. A pressing force is applied to the annular region. As means for applying the pressing force, there are a method of inserting a pressing member between the plasma display panel and a housing for housing it, and a method of bringing the housing into contact with the substrate surface. The pressing member may be an elastic body including hard rubber or a resin spring, or may be a rigid body made of resin or metal.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a schematic configuration diagram of a display device according to the present invention. The display device 100 includes a PDP 1, a casing 71, and a drive unit. The PDP 1 includes a pair of substrate structures 10 and 20. The substrate structure means a structure composed of a plate-like support having a size larger than the screen size and at least one other panel component. The substrate structures 10 and 20 are arranged to face each other so as to overlap each other, and the periphery of the opposed region is joined by a sealing material 35. The casing 71 houses the PDP 1 and the drive unit. However, the casing 71 has a window 710 having a screen size, and does not hide the display area (area corresponding to the screen) 60 on the front surface of the PDP 1. The drive unit has drivers 51, 52, and 53 connected to the electrodes of the PDP 1. In the figure, the drivers 51, 52, and 53 are arranged around the PDP 1 for convenience, but these are actually arranged behind the PDP 1. The drive unit is attached to the back surface of the PDP 1, and the PDP 1 is fixed to the housing 71 by attaching the drive unit to the housing 71.
[0009]
FIG. 2 is a diagram illustrating an example of the cell structure of the PDP 1. In each cell constituting the display screen, the display electrodes X and Y and the address electrode A intersect. The display electrodes X and Y are arranged on the inner surface of the glass substrate 11 on the front side, and each includes a transparent conductive film 41 forming a surface discharge gap and a metal film (bus electrode) 42 extending over the entire length of the row. A dielectric layer 17 having a thickness of about 30 to 50 μm is provided so as to cover the display electrode pair, and magnesia (MgO) is deposited as a protective film 18 on the surface of the dielectric layer 17. The address electrodes A are arranged on the inner surface of the glass substrate 21 on the back side and are covered with a dielectric layer 24. On the dielectric layer 24, one strip-shaped partition wall 29 having a height of about 140 μm is provided between the address electrodes A. These barrier ribs 29 divide the discharge space for each column in the direction along the row of the matrix display, and define the front and rear dimensions of the discharge space. A column space 31 corresponding to each column in the discharge space is continuous across all rows. Then, phosphor layers 28R, 28G, and 28B of three colors R, G, and B for color display are provided so as to cover the inner surface of the back surface side including the upper side of the address electrode A and the side surface of the partition wall 29. ing. Italic alphabets R, G, B in the figure indicate the emission color of the phosphor. The phosphor layers 28R, 28G, and 28B are locally excited by the ultraviolet rays emitted by the discharge gas and emit light.
[0010]
FIG. 3 is a schematic view of the main structure of the display device. In the figure, the components excluding the glass substrate 11 in the front substrate structure are omitted, and the components excluding the glass substrate 21 and the partition wall 21 in the rear substrate structure are omitted. Actually, the thickness of the glass substrates 11 and 21 is 2 mm to 3 mm, whereas the thickness of the dielectric layer is about 30 μm, which is sufficiently small. The electrode and the protective film are thinner than the dielectric layer.
[0011]
In PDP1, the distance D1 between the inner end of the sealing material 35 and the display area 60 is about 15 mm, and the distance D2 between the end of the partition wall 29 and the display area 60 is 7 mm to 8 mm. As described above, the partition wall 29 is formed on the glass substrate 21 on the back side, and its end portion jumps up and is higher than other portions. The jump amount ΔH is about 30 μm. The sealing material 35 is made of low melting point glass having a softening point lower than that of the partition wall material, and the partition wall 29 is not softened in the sealing process in which the glass substrate 11 and the glass substrate 21 are fused. For this reason, the end of the glass substrate 11 is slightly curved and deformed in the sealing step, and a gap 33 is generated between the glass substrate 11 and the upper surface of the partition wall 29. Over the range of the length D3 from the inner end of the gap 33 to the inner end of the sealing material 35, a so-called floating structure in which the support of the glass substrate 11 is unstable (the length (width) D3 along the sealing material 35) It is a structure in which beams are formed. A specific value of the beam length D3 is about 40 mm. In the PDP 1 having such a floating portion, the floating portion of the substrate locally resonates at a natural frequency due to periodic electrostatic attraction accompanying application of a high-frequency driving voltage for display, thereby generating a slight sound. May occur. When the length D3 of the beam is 40 mm or less, the resonance frequency becomes high and sound cannot be heard. Accordingly, a pressing pressure is required so that the length of the beam represented by D3 is 40 mm or less.
[0012]
In the display device 100, a pressing member 75 having a thickness of about 2 mm to 3 mm made of rubber is inserted between the PDP 1 and the casing 71 in order to reduce sound due to resonance of the PDP 1. As shown in FIG. 4, the pressing member 75 has an annular shape surrounding the display area 60. A pressing force is applied to the outer surface of the glass substrate 11 by the pressing member 75, and fine vibration of the glass substrate 11 is suppressed. The pressing member 75 is hidden by the housing 71 so that it cannot be seen from the front. Further, in order to effectively apply the pressing force, the pressing member 75 is disposed in a floating portion of the glass substrate 11. That is, the contact surface between the pressing member 75 and the glass substrate 11 is limited to a range of the length D3 from the inner end of the gap 33 to the inner end of the sealing material 35. In the illustrated example, the gap 33 extends into the display area 60, but when the inner end of the gap 33 is outside the display area 60, the pressing member 75 can be provided to the inner end of the gap 33. In this case, the pressing force may be applied to the entire range of the length D3, or the pressing force may be locally applied to an intermediate position in the direction of the length D1. The material of the pressing member 75 is not limited to an elastic body. When the casing 71 has appropriate flexibility, an appropriate pressing force can be applied to the glass substrate 11 even if the pressing member 75 is a rigid body. In assembling the display device 100, the PDP 1 with the pressing member 75 attached in advance may be stored in the casing 71, or conversely, the PDP 1 may be stored in the casing 71 with the pressing member 75 attached. Good.
[0013]
FIG. 5 is a schematic view of a modification of the main structure of the display device. In the illustrated display device 100b, the pressing member 75b is integral with the housing 71b. That is, a part of the casing 71b functions as the pressing member 75b.
[0014]
FIG. 6 is a plan view showing another example of the pressing member. 6A, the pressing member 77 is composed of four partial pieces 771, 772, 773, and 774 arranged in an annular shape. By applying a pressing force to the annular area surrounding the display area 60, it is possible to save the trouble of confirming where the sound is generated around the display area 60. In FIG. 6B, a large number of small pressing members 78 are arranged in a ring surrounding the display area 60. The distance D5 between the adjacent pressing members 78 is selected to be 40 mm or less, which is the value of the beam length D3, and the sound countermeasure effect equivalent to the case where the annular pressing members 75 and 77 are arranged can be obtained. . As described above, when a part of the housing is used as a pressing member, a plurality of protrusions arranged in an annular shape may be formed on the inner surface of the housing.
[0015]
FIG. 7 is a schematic diagram of the main structure of another display device. The display device 101 includes a filter 81 for blocking electromagnetic waves, adjusting color, and reducing infrared rays. The filter 81 is disposed about 2 mm to 3 mm away from the front surface of the PDP 1. A frame 76 for supporting the filter 81 also serves as a pressing member that suppresses slight vibration of the PDP 1. The PDP 1 is fixed to the housing 72 by attaching the drive unit 50 attached to the back surface of the PDP 1 to the housing 72. The front surface of the PDP 1 is indirectly pressed by the front surface portion of the housing 72 through the frame 76.
[0016]
As described above, the form in which the periphery of the display region 60 is uniformly pressed has been described, but there is also a form in which the display area 60 is partially pressed. In the case of adopting it, when the assembled PDP 1 is driven to perform aging and an operation test, the presence / absence of vibration noise and the occurrence location are detected. And when a vibration sound generate | occur | produces, as shown in FIG. The presser member 78 may be fixed to the PDP 1 in advance before assembling, or the presser member 78 may be sandwiched between the PDP 1 and the housing 71 during assembly.
[0017]
In the above-described embodiment, when a film-like filter is attached to the outer surface of the glass substrate 11, the surface of the filter can be regarded as the substrate surface. That is, vibration noise can be reduced by pressing the filter. As long as the casings 71 and 72 are structures that cover the periphery of the front surface of the PDP 1, the configuration, shape, and material are not limited. It may be a composite of metal and resin.
[0018]
【The invention's effect】
According to the invention of claims 1 to 8, it is possible to reduce the operation noise due to resonance of the substrate.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a display device according to the present invention.
FIG. 2 is a diagram illustrating an example of a cell structure of a PDP.
FIG. 3 is a schematic diagram of a main structure of a display device.
FIG. 4 is a diagram illustrating an example of a planar shape of a pressing member.
FIG. 5 is a schematic view of a modification of the main structure of the display device.
FIG. 6 is a plan view showing another example of a pressing member.
FIG. 7 is a schematic diagram of a main part structure of another display device.
FIG. 8 is a plan view showing another example of the arrangement of the pressing members.
[Explanation of symbols]
1 PDP (Plasma Display Panel)
29 Bulkhead 31 Row space (opposite gap)
71, 72 Housing 75, 76, 77, 78 Presser member (protrusion)
771,772,773,774 pieces

Claims (8)

Ri determined by the partition wall dimension of the opposing gap between the substrates pairs peripherally joined by a sealing material of the opposite region defining an interior space, wherein the partition walls are separated from the sealing material, resulting in an end portion of the partition wall A plasma display panel having a structure in which a gap exists between the end of the partition wall and the inner surface of the substrate facing the partition due to the jumping ;
A housing for storing the plasma display panel;
Of the outer surface of the substrate pair, the annular region which is inside the said partition wall end along the sealing material to contact the entire circumference or over the following intervals 40mm housing, thereby creating in the gap A plasma display device characterized in that a pressing force is applied to reduce vibration of a pair of substrates. Ri determined by the partition wall dimension of the opposing gap between the substrates pairs peripherally joined by a sealing material of the opposite region defining an interior space, wherein the partition walls are separated from the sealing material, resulting in an end portion of the partition wall A plasma display panel having a structure in which a gap exists between the end of the partition wall and the inner surface of the substrate facing the partition due to the jumping ;
A housing for housing the plasma display panel;
A pressing member that is disposed between the inner surface of the housing and the plasma display panel and applies a pressing force to the outer surface of the pair of substrates;
The region where the pressing member contacts is a region of the inner from the partition wall end portion, a plasma display apparatus characterized by vibration of the board-to-occur in the gap by the pressing force of the pressing member is reduced in the substrate pairs . The plasma display device according to claim 2, wherein a shape of the pressing member in plan view is an annular shape surrounding the display area. The plasma display device according to claim 2, wherein the pressing member is an elastic body. The plasma display device according to claim 2, wherein the pressing member is a rigid body. The plasma display device according to claim 2, wherein the pressing member includes a plurality of pieces. The pressing member is attached to one outer surface of the substrate pair.
The plasma display device according to claim 2 . Drives a plasma display panel having a structure in which the size of the opposing gap of the substrate pair is determined by the partition walls that divide the internal space, and detects the presence and occurrence of vibration noise,
A pressing member that forms a protrusion for making contact with a housing that houses the plasma display panel is disposed at a place where the vibration noise is generated on the outer surface of the pair of substrates,
Thereafter, the plasma display panel is assembled to the casing. A method for assembling the plasma display device.

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