KR20050080237A - Plasma display device - Google Patents

Abstract

SUMMARY OF THE INVENTION The present invention aims to provide a plasma display device having a reduced discharge delay. To achieve this object, the present invention provides a chassis base, a plasma display panel supported in front of the chassis base, and a rear of the chassis base. And a substrate on which a circuit for driving the plasma display panel is wired, and a thermal conductivity of the chassis base is 100 W / mK or less.

Description

Plasma display device

The present invention relates to a plasma display device, and more particularly, to a plasma display device having a reduced discharge delay.

Plasma display device is a flat panel display device that displays images by using gas discharge phenomenon. It has excellent display capability such as display capacity, brightness, contrast, afterimage and viewing angle, and is thin and can display large screen. It is attracting attention as the next generation large flat panel display device that can replace the.

The plasma display panel which forms an image in the plasma display apparatus generates heat during driving. If heat generated in the plasma display panel is not discharged to the outside, an afterimage may occur in the plasma display panel. Therefore, in order to prevent this, the chassis base is disposed on the rear surface of the plasma display panel to emit heat to the outside. In general, the chassis base is made of aluminum having a high thermal conductivity, the thermal conductivity of the aluminum is about 150 to 220W / mK.

However, since the aluminum chassis base has a very high thermal conductivity, there is a problem in that discharge delay occurs when the temperature of the outside of the plasma display apparatus is driven decreases. The discharge delay does not occur at the time when the discharge in the discharge cell is required, but means that the discharge is delayed.

1 schematically shows a discharge delay phenomenon. In the graph of FIG. 1, the horizontal axis represents time and the vertical axis represents the magnitude of the discharge current. Referring to the drawing, the required discharge current is the first curve G1, but due to the discharge delay, the discharge current during the actual discharge of the plasma display panel has the second curve G2. That is, a problem occurs that the temperature of the plasma display panel is lowered and the discharge current is delayed by a predetermined time Δt.

In order to solve the above problems, an object of the present invention is to provide a plasma display device having a reduced discharge delay.

In order to achieve the above object and other objects, the present invention provides a chassis base, a plasma display panel supported in front of the chassis base, and a circuit supported at the rear of the chassis base and driving the plasma display panel. Provided is a plasma display device having a wired substrate, wherein the thermal conductivity of the chassis base is 100 W / mK or less.

In the present invention, in the plasma display device, the thermal conductivity of the chassis base may be 10 W / mK to 100 W / mK.

In the present invention, preferably, in the plasma display device, the chassis base may be aluminum alloy, stainless steel, aluminum oxide, carbon steel, carbon silicon, titanium, carbon fiber, graphite fiber. And, it may be formed of one material selected from the group consisting of glass fibers.

In the present invention, preferably, in the plasma display device, the chassis base is one material selected from the group consisting of aluminum alloy, stainless steel, aluminum oxide, carbon steel, carbon silicon, titanium, carbon fiber, graphite fiber, and glass fiber. It may be formed of a composite material including a.

In the present invention, preferably, the plasma display device may further include a reinforcing member disposed on the rear surface of the chassis base to reinforce the stiffness of the chassis base.

In this case, preferably, the thermal conductivity of the reinforcing member may be 100 W / mK or less.

In this case, preferably, the thermal conductivity of the reinforcing member may be 10 W / mK to 100 W / mK.

In this case, preferably, the reinforcing member may be formed of one material selected from the group consisting of aluminum alloy, stainless steel, aluminum oxide, carbon steel, carbon silicon, titanium, carbon fiber, graphite fiber, and glass fiber.

In this case, preferably, the reinforcing member is formed of a composite material including one material selected from the group consisting of aluminum alloy, stainless steel, aluminum oxide, carbon steel, carbon silicon, titanium, carbon fiber, graphite fiber, and glass fiber. Can be.

In the present invention, preferably, in the plasma display apparatus, the chassis base and the reinforcing member may be integrated.

In the present invention, preferably, in the plasma display apparatus, the chassis base and the reinforcing member may be formed of the same material.

Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 to 5, a plasma display apparatus 200 according to an exemplary embodiment of the present invention is shown.

The plasma display apparatus 200 includes a chassis base 220, a plasma display panel 210 in which an image is implemented and supported in front of the chassis base 220, and a plasma display panel supported behind the chassis base 220. A circuit board 230 for driving 210 is provided.

The plasma display panel 210 having the upper plate 211 and the lower plate 212 bonded to each other is an image display unit in which an image is realized by using a discharge phenomenon.

Referring to FIG. 3, an AC plasma display panel 210 according to an embodiment of the present invention is illustrated. As shown, the plasma display panel 210 includes an upper plate 211 and a lower plate 212 coupled in parallel thereto. The sustain electrode pairs 12 are disposed on the front substrate 11 of the upper plate 211. At this time, the front substrate 11 is generally formed of a transparent material mainly made of glass.

The sustain electrode pair 12 refers to a pair of sustain electrodes 31 and 32 formed on the rear surface of the front substrate 11 in order to cause an electric discharge, and the sustain electrode pair 12 is attached to the front substrate 11. ) Are arranged in parallel at predetermined intervals. One sustaining electrode of the pair of sustaining electrodes 12 is a scanning electrode 31, and the other sustaining electrode is a common electrode 32.

Each of the scan electrode 31 and the common electrode 32 includes transparent electrodes 31a and 32a and bus electrodes 31b and 32b.

The transparent electrodes 31a and 32a are formed of a transparent material which is a conductor capable of causing a discharge and does not prevent the light emitted from the phosphor layer 26 from advancing to the front substrate 11. tin oxide). However, transparent conductors such as ITO generally have a high resistance, and thus, when the discharge sustaining electrode is formed only by the transparent electrode, a large voltage drop in the longitudinal direction consumes a lot of driving power and a slow response time. In order to improve, the bus electrodes 31b and 32b made of a metal material and formed in a narrow width are disposed at the outer end of the transparent electrode.

On the rear substrate 21 facing the surface on which the sustain electrode pair 12 of the front substrate 11 is disposed, the address electrode 22 intersects the scan electrode 31 and the common electrode 32 of the front substrate 11. It is arranged to. The address electrodes 22 are used to generate an address discharge for facilitating a discharge between the scan electrode 31 and the common electrode 32. More specifically, the address electrodes 22 lower the voltage for generating a discharge. The address discharge is a discharge occurring between the scan electrode 31 and the address electrode 32. When the address discharge is completed, cations are accumulated on the scan electrode 31 side and electrons are accumulated on the display electrode side, thereby scanning electrode 31. Discharging between the common electrode 32 and the common electrode 32 becomes easier.

The space formed by the pair of scanning electrodes 31 and the common electrode 32 and the address electrodes 22 intersecting the same forms a single discharge unit as the unit discharge cells 70.

The front dielectric layer 15 is formed on the front substrate 11 having the sustain electrode pairs 12 so as to fill the sustain electrode pairs 12. The front dielectric layer 15 is directly energized between the scan electrode 31 and the common electrode 32 adjacent to the kitchen, and the positive electrode or electrons directly collide with the sustain electrodes 31 and 32 to damage the sustain electrodes 31 and 32. It is possible to induce charge and to accumulate wall charges while preventing light from being formed, and is formed as a dielectric having good light transmittance. Such dielectrics include PbO, B ₂ O ₃ , SiO _2, and the like.

In addition, the protective film 16 usually made of MgO is formed on the front dielectric layer 15. The protective film 16 prevents cations and electrons from colliding with the front dielectric layer 15 during discharge, thereby damaging the front dielectric layer 15, and has good light transmittance and emit a large amount of secondary electrons during discharge.

A back dielectric layer 25 is formed on the back substrate 21 having the address electrode 22 so as to fill the address electrode 22. The back dielectric layer 25 is formed as a dielectric that can induce charge while preventing cations or electrons from colliding with the address electrode 22 during discharge and damaging the address electrode 22. Such dielectrics include PbO and B _2. O ₃ , SiO ₂ and the like.

A barrier rib 30 is formed on the front surface of the rear dielectric layer 25 to maintain a discharge distance and prevent electro-optical crosstalk between discharge cells. Red, green, and blue phosphors 26 are coated on both side surfaces of the barrier rib 30 and the front surface of the back dielectric layer 25 on which the barrier rib 30 is not formed. 3 illustrates a partition wall 30 having a matrix type, but is not limited thereto.

Referring to the operation of the plasma panel 210 according to the present invention configured as described above are as follows.

When an address voltage is applied between the address electrode 22 and the scan electrode 31, an address discharge occurs, and as a result of the address discharge, a discharge cell 70 for generating a discharge current is selected.

Thereafter, when a discharge holding voltage is applied between the scan electrode 31 and the common electrode 32 of the selected discharge cell 70, the cations accumulated on the scan electrode 31 and the common electrode 32 are accumulated. The electrons collided to cause a discharging, and ultraviolet rays are emitted as the energy level of the discharged gas excited during this discharging lowers. The ultraviolet rays excite the phosphor 26 coated in the discharge cell 70. The energy level of the excited phosphor 26 is lowered to emit visible light, and the emitted visible light forms an image.

When the plasma display panel 210 is driven, a lot of heat is generated. If the generated heat is not sufficiently discharged to the outside, an afterimage may occur in the plasma display panel 210. Accordingly, the chassis base 220, which not only serves to support the plasma display panel 210 but also serves as a heat sink, is coupled to the rear surface of the plasma display panel 210.

However, when the plasma display panel 210 is excessively dissipated and the temperature of the plasma display panel 210 is reduced below a set value, a discharge delay phenomenon occurs. That is, the discharge in the discharge cell 70 is not made in the desired time period, the discharge is made later than the desired time. Therefore, the chassis base 220 should be formed of a material that has rigidity and can properly maintain the temperature of the plasma display panel 210.

4 shows the relationship between the voltage G3 of the address electrode and the discharge current G4 according to the time during address discharge. The horizontal axis of the graph is a time axis in nanosecond units, the left vertical axis Y1 represents an address voltage, and the right vertical axis Y2 represents a discharge current during address discharge.

As shown in the graph, as the voltage of the address electrode increases from the first time t1 to the second time t2, the voltage linearly increases from the first voltage V1 to the second voltage V2. In the second time t2, the third time t2 is maintained at a constant voltage V2 = V3. Thereafter, the voltage is linearly reduced to recover to the fourth voltage V4 having the same magnitude as the initial voltage at the fourth time t4.

The time of one pulse of the address electrode, that is, the time interval from the first time t1 to the fourth time t4 is 1000 ms. At this time, the interval between the first time t1 and the second time t2 is 200 ms, and the interval between the second time t2 and the third time t3 is 650 ms, the third time t3 and the fourth time. The interval between time t4 is 150 ms.

During address discharge, the discharge current is generated at the first discharge time s1 and extinguished at the third discharge time s3, and the magnitude of the discharge current has a parabolic shape that is convex upward. Visible light is generated when there is a discharge current. However, the generation of visible light mainly constituting the luminance of the plasma display panel 210 occurs during about 350 mW between the second discharge time s2 and the third discharge time s3, which are the second half of the parabolic shape.

Therefore, about 650 kHz for the generation of visible light should be secured during 650 kHz between the second time t2 and the third time t3. That is, since the discharge should be generated within the time of subtracting 350 ms, which is the main visible light generation time, out of 650 ms between the second time t2 and the third time t3, the discharge delay should be maintained at 300 ms or less.

However, if the discharge delay is too small, it is preferable that the discharge delay time is 100 ms or more because there is a risk of over discharge. Therefore, in the plasma display apparatus 200 according to the present invention, a material of the chassis base 220 is selected so that the discharge delay time is maintained at 100 to 300 ms.

5 is a result of measuring the discharge delay time by varying the thermal conductivity of the chassis base 220. As shown, it can be seen that the discharge delay time increases as the thermal conductivity of the chassis base 220 increases. This is because when the thermal conductivity of the chassis base 220 is increased, heat dissipation from the plasma display panel 210 is promoted so that the temperature of the plasma display panel 210 is kept low, and thus the discharge delay time is increased.

Referring to the drawing, when the thermal conductivity of the chassis base 220 is 10 W / mK, the discharge delay time is 100 mW, and when the thermal conductivity is 200 W / mK, the discharge delay time is 470 mW. At this time, in order to discharge effectively, the discharge delay time should be maintained at 300 ㎱ or less, so that the thermal conductivity of the chassis base should be 100 W / mK or less.

In addition, in order to prevent overdischarge, the discharge delay time is preferably 100 ms or more, and therefore, the thermal conductivity of the chassis base is preferably 10 W / mK or more.

Materials having a thermal conductivity of 100 W / mK or less can be selected in various ways. As such a material, aluminum alloy, stainless steel, aluminum oxide, carbon steel, carbon silicon, titanium, carbon fiber, graphite fiber, and glass fiber are preferably used.

The chassis base 220 may be formed using one of these materials, but may also be formed of a composite material including one material selected from these materials.

Table 1 shows the thermal conductivity of the three aluminum alloys usable in the present invention. It can be seen that all three have thermal conductivity of 10 to 100 W / mK or less. In addition, Table 2 shows the thermal conductivity of low carbon steel, medium carbon steel and high carbon steel available in the present invention. However, it is obvious that the aluminum alloy and carbon steel used for the chassis base of the present invention are not limited to the aluminum alloy and carbon steel listed in Tables 1 and 2.

TABLE 1

Thermal conductivity according to aluminum alloy

designation Thermal Conductivity (W / mK) MMCC Al / Al ₂ O ₃ (Continuous Fiber Aluminum Matrix Composite) 80 MMCC Al / Al ₂ O ₃ (Short Fiber Aluminum Matrix Composite) 100 MMCC Al / Al ₂ O ₃ (Particulate Aluminum Matrix Composite) 55

TABLE 2

 Thermal conductivity according to the kind of carbon steel

Iron content (% by weight) Carbon content (% by weight) Thermal Conductivity (W / mK) Low carbon steel 99.11-99.56 0.14-0.23 51.9 Medium carbon steel 98.46-99.13 0.27-0.55 51.9 High carbon steel 98.38-98.95 0.55-1.03 46.6

A thermal conductive sheet 227 is interposed between the plasma display panel 210 and the chassis base 220 so that heat generated in the plasma display panel 210 is conducted to the chassis base 220.

In addition, between the plasma display panel and the chassis base 220, a double-sided tape 223 is interposed between the plasma display panel and the chassis base 220 so as to couple the plasma display panel 210 and the chassis base 220 to each other.

A reinforcing member 250 is disposed on the rear surface of the chassis base 220 to reinforce the strength of the chassis base 220. The reinforcement member 250 is fixed to the chassis base 220 by bolts 290. The reinforcement members 250 may not only overlap the driving circuit board, but may be disposed at portions that do not interfere with the circuit connection between the driving circuit boards 230.

The reinforcement member 250 may be manufactured and coupled separately to the chassis base 220, but the chassis base 220 and the reinforcement member 250 may be integrally formed to reduce the manufacturing process and prevent bending due to relative thermal expansion. have.

In order to prevent the discharge delay of the plasma display panel 210, an excessive temperature drop of the plasma display panel 210 should be prevented. Thus, similar to the chassis base 220 described above, it is preferable that the thermal conductivity of the reinforcing member 250 is formed of a material having 100 W / mK or less. In addition, in order to prevent overdischarge of the plasma display panel 210, it is preferable that the thermal conductivity of the reinforcing member 250 is formed of a material of 10 W / mK or more.

Materials having a thermal conductivity of 100 W / mK or less can be selected in various ways. As such a material, aluminum alloy, stainless steel, aluminum oxide, carbon steel, carbon silicon, titanium, carbon fiber, graphite fiber, and glass fiber are preferably used.

The reinforcing member 250 may be formed using one of these materials, but may also be formed of a composite material including one material selected from these materials.

In addition, the chassis base 220 and the reinforcing member 250 is preferably formed of the same material in order to prevent bending due to different thermal expansion coefficients between the reinforcing member 250 and the chassis base 220.

The driving circuit board 230 for driving the plasma display panel 210 is spaced apart from the rear surface of the chassis base 220 by the fixing member 240. In general, the boss formed in the chassis base 220 and the hole of the driving circuit board 230 are coupled using a screw, which is the fixing member 240.

TCP 270 connects them 210 and 230 to transfer electrical signals and power between the plasma display panel 210 and the driving circuit board 230. The TCP 270 connects the connector (not shown) of the driving circuit board 230 and the plasma display panel 210. The connector of the driving circuit board 230 is spaced apart from the rear surface of the chassis base 220 by a predetermined height. Accordingly, the TCP 270 is supported by the reinforcing member 250 and is maintained at the same height as the connector until the end of the chassis base 220 is connected to the plasma display panel 210 while bypassing the end of the chassis base 220. Connected. In addition, the side surface 225 of the chassis base 220 is bent toward the rear of the chassis base 220.

The cover plate 260 is disposed on the rear surface of the TCP 270 on which the electronic device 275 is mounted to emit heat generated from the electronic device 275 to the outside. In addition, a heat conductive sheet (not shown) is inserted between the TCP 270 and the cover plate 260, and heat transfer is promoted between the TCP 270 and the reinforcing member 250 and applied to the electronic device 275. Grease (not shown) is inserted to relieve the compressive force.

Like reference numerals in the drawings shown above indicate the same members.

In the plasma display device according to the present invention, since the plasma display panel is operated within an appropriate temperature range, the discharge delay phenomenon of the plasma display panel is suppressed.

Although the present invention has been described with reference to the embodiments shown in the drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

1 is a graph illustrating a discharge delay of a plasma display device.

2 is an exploded perspective view of a plasma display device according to an embodiment of the present invention;

3 is an exploded perspective view of the plasma display panel illustrated in FIG. 2;

4 is a graph showing a relationship between an address voltage and a discharge current over time;

5 is a graph showing the relationship between the thermal conductivity of the chassis base and the discharge delay time.

Explanation of symbols on main parts of drawing

200: plasma display device 210: plasma display panel

220: chassis base 223: double-sided tape

227: heat conductive sheet 230: driving circuit board

240: fixing member 250: reinforcing member

260: cover plate 270: TCP

275 electronic device 290 volts

Claims (11)

Chassis base; A plasma display panel supported in front of the chassis base; And A substrate supported behind the chassis base and wired with a circuit for driving the plasma display panel; And a thermal conductivity of the chassis base is 100 W / mK or less. The method of claim 1, And a thermal conductivity of the chassis base is 10 W / mK to 100 W / mK. The method of claim 1, The chassis base is one selected from the group consisting of aluminum alloy, stainless steel, aluminum oxide, carbon steel, carbon silicon, titanium, carbon fiber, graphite fiber, and glass fiber. Plasma display device characterized in that formed of a material. The method of claim 1, The chassis base is formed of a composite material including one material selected from the group consisting of aluminum alloy, stainless steel, aluminum oxide, carbon steel, carbon silicon, titanium, carbon fiber, graphite fiber, and glass fiber. Device. The method of claim 1, And a reinforcing member disposed on the rear surface of the chassis base and reinforcing the stiffness of the chassis base. The method of claim 5, And a thermal conductivity of the reinforcing member is 100 W / mK or less. The method of claim 6, And a thermal conductivity of the reinforcing member is 10 W / mK to 100 W / mK. The method of claim 6, And the reinforcing member is formed of one material selected from the group consisting of aluminum alloy, stainless steel, aluminum oxide, carbon steel, carbon silicon, titanium, carbon fiber, graphite fiber, and glass fiber. The method of claim 6, The reinforcing member is formed of a composite material including one material selected from the group consisting of aluminum alloy, stainless steel, aluminum oxide, carbon steel, carbon silicon, titanium, carbon fiber, graphite fiber, and glass fiber. Device. The method of claim 6, And the chassis base and the reinforcement member are integral. The method of claim 6, And the chassis base and the reinforcement member are formed of the same material.