KR20060110475A - Plasma display device - Google Patents

Abstract

A plasma display device is provided to connect a grounding voltage with a grounding power source of a driving circuit unit by using a radiating plate and a grounding plate without using an additional circuit for providing grounding power. A plurality of electrodes for receiving driving signals for display discharge are formed on a panel(4). One or more printed circuit boards(10) include circuits for the driving signals to electrodes and radiating plates for cooling the heat generated from the circuits. The radiating plates are electrically connected with grounding power input parts of the circuits. A plastic chassis base(9) is used for fixing the printed circuit boards. One or more grounding plates(12) are fixed to the plastic chassis base in order to connect electrically the radiating plates.

Description

Plasma Display Device

1 is a schematic view of a plasma display device having a grounding means between a chassis base and a driving circuit according to an embodiment of the present invention.

2 is a view showing in more detail the grounding method between the chassis base and the drive circuit.

3 is a cross-sectional view taken along the line A-A` in FIG.

4 is a view showing a ground power connection method according to a second embodiment of the present invention.

5 is a view briefly illustrating a connection relationship between a panel and a driving circuit of FIG. 1;

6 is a waveform diagram showing an example of a drive waveform for driving the PDP of FIGS. 1 and 5;

<Description of the symbols for the main parts of the drawings>

2: front case 4: panel

6: heat conductive sheet 8: adhesive member

9 plastic chassis base 10 printed circuit board

12, 22: ground plate 14: rear case

15: heat sink 17: heat generating element

18: conductive path 29: discharge cell

38: connection

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma display apparatus, and more particularly, to a plasma display apparatus that is easily grounded between driving circuits.

Recently, many flat display devices have been developed to replace cathode ray tubes (CRTs). Representative examples of such flat panel displays include liquid crystal displays (LCDs), electroluminescence displays (ELs), field emission displays (FEDs), and plasma displays. A panel (or plasma display panel device) may be mentioned.

Among such flat panel displays, a plasma display apparatus (hereinafter referred to as "PDP") displays an image by plasma discharge, and a fully digital implementation is possible. In addition, PDP has an advantage of easy implementation of a large screen.

Such a PDP consists of a filter assembly, a panel, a thermally conductive sheet, a chassis base (or frame), a printed circuit board having a driving circuit, and various additional devices inside the front / rear case.

The case protects the internal components from external contamination and impact and prevents internal noise from leaking to the user. The filter assembly is composed of a cutoff filter and an electromagnetic cut filter for improving the display quality. The panel is composed of an upper / lower substrate with substantial image realization, and a plurality of electrodes, partitions, phosphors, dielectric layers are formed between the substrates, and an inert gas is sealed. The thermally conductive sheet is formed between the panel and the chassis base, and transfers heat generated from the panel to the chassis base when the PDP is driven. This thermally conductive sheet is usually fixed to the chassis base by an adhesive member such as a liquid adhesive or an adhesive tape.

Printed circuit boards are provided with a plurality of driving circuits including a power supply unit, an address driver, a scan driver, and a sustain driver for driving the PDP. In particular, the address driver, the scan driver and the sustain driver are formed on each printed circuit board and spaced apart from the rear surface of the chassis base by a predetermined distance. Each printed circuit board is connected to each other by a plurality of conductive paths.

The chassis base dissipates heat generated from the panel on the front of the chassis base and the printed circuit board on the back side, and also supports the back printed circuit boards. In the chassis base, a metal material using an alloy such as aluminum and tin has been used in the past, but recently, a method of using a plastic-based material has been devised for the purpose of reducing manufacturing cost, reducing the weight of PDP, and simplifying the process. .

However, such a plastic chassis base has a problem in that the ground circuits of the driving circuits must be separately configured. Conventionally, the metal chassis base is used as a common ground power source for driving circuits due to the use of the metal chassis base, but the plastic chassis base cannot be used as a common ground power source. Various methods have been devised to construct such a common ground power circuit, but there is still much room for improvement.

Accordingly, it is an object of the present invention to provide a plasma display device with easy grounding between driving circuits.

For this purpose, the plasma display apparatus according to the present invention is provided with a panel on which a plurality of electrodes are supplied with a drive signal for display discharge, circuits for supplying a drive signal to the electrodes, and cooling heat generated from the circuit. And at least one printed circuit board having a heat sink electrically connected to the ground power input of the circuit, a plastic chassis base for fixing the printed circuit board, and at least one ground plate fixed to the plastic chassis base to electrically connect the heat sinks. Equipped.

The heat sink and ground power input or the heat sink and ground plate may be connected by one or more conductive paths.

In addition, the heat sink is a base portion in contact with the heating element of the circuit portion, the wing portion having at least one wing extending in a predetermined direction from the base portion for cooling the circuit portion, and the bezel for connecting to any one of the ground power input unit and the ground plate It may have one or more connections that protrude from the teeth.

Likewise, the ground plate may have one or more joints electrically connected to the connections.

The circuits formed on the printed circuit board may include one or more circuit units of a power supply unit, an address driver, a scan driver, and a sustain driver, and a thermal conductive sheet may be inserted between the plastic chassis base and the panel.

In addition, the apparatus may further include a case member configured to accommodate the panel, the printed circuit board, and the chassis base, and any one of the ground plates may be electrically connected to the heat conductive sheet or the case member.

Other objects and features of the present invention in addition to the above object will be revealed through the description of the embodiments with reference to the accompanying drawings. Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 1 to 6.

1 is a view schematically showing a plasma display device having a grounding means between a chassis base and a driving circuit according to an exemplary embodiment of the present invention.

Referring to FIG. 1, the plasma display apparatus according to the present invention includes a front case 2, a rear case 14, a panel 4, a heat conductive sheet 6, an adhesive member 8, a plastic chassis base 9, A printed circuit board 10 and a ground plate 12 are provided.

The front case 2 is fastened to the rear case 14 to protect the inner panel 4, the thermal conductive sheet 6, the printed circuit board 10, and the plastic chassis base 9 from external contaminants and various impacts. It also prevents noise and vibration generated when the PDP is driven to the user. The front case 2 is formed with a light transmitting portion so that light from the panel 4 can be emitted to the outside, and the light transmitting portion may further include a filter assembly (not shown). Here, the filter assembly includes a reflective film for preventing visibility deterioration, an electromagnetic shielding layer for blocking electromagnetic waves generated during driving, and a blocking filter for absorbing unnecessary light.

The rear case 14 is engaged with the front case 2 to protect the internal components from external contaminants and impacts. In addition, the rear case 14 is formed with a plurality of discharge ports for discharging the heat inside.

The panel 4 includes an upper substrate 4a having a plurality of scan electrodes and sustain electrodes formed therebetween, a plurality of address electrodes formed in a direction crossing the electrodes of the upper substrate 4a, and the upper substrate 4a. It consists of a lower substrate 4b including the formed phosphor layer. In addition, a partition wall is formed between the upper substrate 4a and the lower substrate 4b to partition the discharge cells at the intersections of the electrodes. In addition, an inert gas such as Ne, Xe, He, Ar, or a mixed gas of one or more thereof is filled between the upper substrate 4a and the lower substrate 4b. The panel 4 generates visible light by exciting the phosphor by ultraviolet rays generated by the discharge between the scan electrodes and the sustain electrodes, and adjusts the generation rate of the visible light to display a predetermined image. In addition, an upper dielectric layer, a protective film is formed on the upper substrate 4a, and a lower dielectric layer is further formed on the lower substrate 4b.

Thermal Spreader Sheet (TSS) 6 is inserted between the panel 4 and the plastic chassis base 9 to transfer heat generated from the panel 4 to the plastic chassis base 9 when the plasma display device is driven. In addition, heat dissipation prevents the temperature of the panel 4 from rising rapidly. In addition, the temperature distribution of the non-uniform panel 4 is evened to prevent breakage and malfunction due to local temperature difference of the panel 4. For this purpose, the thermal conductive sheet 6 is inserted between the panel 4 and the chassis base 10.

The adhesive member 8 fixes the thermal conductive sheet 6 to the plastic chassis base 9. To this end, the adhesive member 8 is formed in the form of a strip or frame in the edge portion of the thermal conductive sheet 6, as shown in Figure 1, thereby fixing the thermal conductive sheet 6 to the plastic chassis base (9). Here, the adhesive member 8 may be bonded to the rear surface of the lower substrate 4b of the panel 4 in the form of a band or a frame to fix the panel 4 and the plastic chassis base 9. As the adhesive member 8, an adhesive, an adhesive sheet, and an adhesive tape are used. In addition, when the adhesive member 8 is attached, each adhesive member 8 is attached at a predetermined distance. This is to enable heat distribution to the heat conductive sheet 6 so that heat transferred from the panel 4 to the heat conductive sheet 6 can be radiated.

The plastic chassis base 9 fixes the panel 4 or the thermally conductive sheet 6 by the adhesive member 8, and partially removes heat from the panel 4, the tape carrier package and the printed circuit board 10. Allow for heat dissipation. The plastic chassis base 9 supports and fixes the printed circuit board 10 by fastening means such as a boss or a screw. Since the plastic chassis base 9 has a lower thermal conductivity than the metal chassis base 9, the plastic chassis base 9 is assembled to have a predetermined distance from the thermal conductive sheet 6 to dissipate the thermal conductive sheet 6. In addition, the plastic chassis base 9 is fixed to the ground plate 12 for connecting the ground power of each drive unit.

The printed circuit board 12 is formed with a system circuit portion for driving the PDP. The system circuit portion is provided with a power supply for power supply, an address driver for supplying a drive signal to the electrodes of the panel 4, a scan driver and a sustain driver. The printed circuit board 10 includes a power supply substrate on which a power supply is formed, a scan driver substrate on which a scan driver is formed, a sustain driver substrate on which a sustain driver is formed, a part of an address driver, and a logic such that a control circuit such as a timing controller is formed. Made of substrate. In addition, a driving buffer board is provided between the panel 4 and the logic substrate and the scan driver substrate, and drive signals from the logic substrate and the scan driver are provided to the panel 4 via this drive buffer board. In addition, the address driver, the scan driver, and the sustain driver are connected to the electrodes by a flexible printed cable (or flexible printed cable (FPC)) or a carrier package in which a driving chip is mounted. .

In addition, each driving unit of the printed circuit board 10, that is, the address driving unit, the scan driving unit, and the sustain driving unit includes a separate power supply module (IPM). The power supply module converts the power supplied from the power supply into signal voltages that can be supplied to the respective electrodes under the control of the respective drive units. That is, the power supply module mounted in the address driver generates an address signal supplied to the address electrode under the control of the address driver and the timing controller. The power supply module and the power supply unit are provided with a plurality of heat sinks for heat dissipation when driving the PDP. In the present invention, the heat sinks and the ground plate 12 are used as a conductive path for providing ground power to the drive unit. This will be described later with reference to FIG. 2.

The ground plate 12 is connected by a heat sink and a conductive path of each driving unit to provide ground power to each driving unit. To this end, the ground plate 12 is manufactured in various forms such as a plate, a metal mesh, and a ladder so as to be easily fixed to the plastic chassis base 9, and is installed between the driving units and supported by the plastic chassis base 9. do.

 FIG. 2 is a diagram illustrating the grounding method between the chassis base and the driving circuit in more detail, and shows the plastic chassis base 9, the printed circuit board 10, and the grounding plate 12. 3 is a cross-sectional view briefly illustrating a cross section taken along the line AA ′ of FIG. 2.

2 and 3, the power supply unit 10a, the address driver 10d, the scan driver 10b, and the sustain driver 10c are fixed to the rear surface of the plastic chassis base 9 as shown in FIG. 2. Here, as the arrangement of the driving unit shown in FIG. 2, for example, the position may be different depending on the configuration method of the PDP.

In addition, each driver is provided with heat sinks 15 for dissipating heat generated from the circuit or the respective power supply module or the main heating element 17. 3, one side of the heat sinks 15 is connected to the driving circuit and the first conductive paths 18a and 18d, and the other side thereof is connected to the ground plate 12a by the second conductive paths 18b and 18c. do. In this case, the second conductive paths 18b and 18c may be formed using a conductive wire separate from the ground plate 12 and a method of integrally manufacturing the ground plate 12.

One side of the first conductive paths 18a and 18d is connected to the ground power input of the driving circuit, and the other side thereof is electrically connected to one side of the heat sink 15 using soldering or the like. In this manner, the second conductive paths 18b and 18c also connect one side of the heat sink 15 to the ground plate 12.

As shown in FIG. 3, the scan driver 10b includes the first conductive path 18a, the heat sink 15b, the second conductive path 18b, the first ground plate 12a, and the address driver 10d of the scan driver 10b. The address driver 10d and the ground power source are connected to each other via the first conductive path 18c, the heat sink 15a, and the second conductive path 18d of the N-th path.

In addition, the ground plate 12 connecting the drive circuit is electrically connected to the rear case 14 or the thermal conductive sheet 6 at the end or one side. At this time, the ground plate 12 and the rear case 14 or the thermal conductive sheet 6 are connected by a conductive path.

By connecting the heat sink 15 and the ground plate 12, it is possible to easily connect the ground power source of each drive unit. In addition, since only the ground plate 12 needs to be added without implementing a separate grounding circuit, cost and process procedures required for production can be reduced.

4 is a view showing a ground power connection method according to a second embodiment of the present invention.

In the method of connecting the ground power source according to the second embodiment, a separate connection part 38 is formed on the heat sink 15 and the ground plate 22. The connection part 38 is divided into a first connection part 38a connected to the ground power input part of the driving circuit, and a second connection part 38b for electrical connection with the ground plate 22.

The first connection portion 38a extends in the direction of the printed circuit board 10 at one edge of the heat sink 15. At the end of the first connection portion 38a, as shown in FIG. 4, a contact portion extended in the horizontal direction on the printed circuit board 10 is formed for contact with the printed circuit board 10. Here, the contact portion is a soldered portion for electrical connection with the printed circuit board 10, the shape of the contact portion can be variously modified.

The second connector 38b electrically connects the heat sink 15 and the ground plate 22. To this end, the second connecting portion 38b extends in the direction of the ground plate 22 from one edge of the heat sink 15 and is formed in a shape corresponding to the junction 22b of the ground plate 22.

The ground plate 22 is composed of a base portion 22a fixed to the plastic chassis base 9 and a joining portion 22b in contact with the heat sink 15. The junction 22b is formed to have a plurality of bends for bonding to the second connection portion 38b of the heat sink 15.

The second connection portion 38b and the junction portion 22b are connected by fastening means such as soldering or screws.

The PDP according to the second embodiment of the present invention shown in FIG. 4 enables connection between the driving circuit 10, the heat sink 15, and the ground plate 22 without a separate conductive path. Accordingly, it is possible to reduce the process procedure and the production cost in comparison with the first embodiment.

FIG. 5 is a diagram briefly illustrating a connection relationship between the panel and the driving circuit of FIG. 1. The three-electrode surface discharge plasma display panel is shown as an example, and the configuration except for the panel and the driving unit is omitted.

In the panel 4 illustrated in FIG. 1, the discharge cells 29 in which the plasma discharges are generated may include scan electrode lines Y1 to Ym, sustain electrode lines Z1 to Zm, and address electrode lines (or data electrode lines). , X1 to Xn).

The scan electrode lines Y1 to Ym supply the scan pulses and the sustain pulses from the scan driver 10b to the discharge cells 29 so that the discharge cells 29 are scanned in units of lines and discharge cells ( 29) to maintain the discharge.

The sustain electrode lines Z1 to Zm supply the sustain pulses from the sustain driver 10c to all the sustain electrodes in common, so that discharge is maintained in the discharge cells 29 together with the scan electrode lines Y1 to Ym. To be. The address electrode lines X1 to Xn supply data pulses synchronized with the scan pulse in line units so that the discharge cells 25 in which the discharge is to be maintained are selected according to the logic value of the data pulses.

The address driver 10d, the scan driver 10b, and the sustain driver 10c may be a tape carrier package (TCP), a flexible printed cable, or a flexible flat cable (FFC) to be connected to the electrodes. Connected by). Particularly, in the case of the driving unit having a high integration degree, that is, the address driving unit, among the driving circuits, the electrode and the driving unit are connected by using a tape carrier package in the form of a chip on film in which some driving chips are mounted on the cable.

To this end, a plurality of pads for connection with cables are formed in the non-display area of the panel 4 and these pads are connected to the electrodes of the display area by a link.

Each driver receives data from a timing controller (not shown), and supplies each unique signal to the electrodes by a control signal provided therewith.

In addition, as described above, the printed circuit board 10 includes a power supply unit 10a for supplying general power required for driving the PDP. The power supply unit 10a has an AC-DC converter that converts an AC current provided from the outside into a DC power source for driving the PDP, and supplies the converted power through a conductive path connected to each driving unit.

6 is a waveform diagram showing an example of a drive waveform for driving the PDP of FIGS. 1 and 5.

Referring to FIG. 6, the PDP maintains the reset period RP for initializing the discharge cells 29 of the full screen, the address period AP for selecting a cell, and the discharge of the selected discharge cells 29. And a sustain period SP for erasing and an erasing period EP for erasing wall charges in the discharge cells 29.

In the setup period SU of the reset period RP in which the subfield SFn starts, the positive ramp waveform PR is applied to all the scan electrodes Y1 to Tm, and the sustain electrodes Z and the address electrodes are applied. 0 (V) or equivalent low voltage is applied to (X).

During this set-up period SU, dark discharge is generated in which light is hardly generated between the scan electrodes Y and the address electrodes X in the cells of the full screen by the positive ramp waveform PR. At the same time, dark discharge occurs between the scan electrodes Y and the sustain electrodes Z. FIG. As a result of this dark discharge, positive wall charges remain on the address electrodes X and the sustain electrodes Z immediately after the setup period SU, and negative wall charges remain on the scan electrodes Y. Will remain.

Following the set-up period SU, in the set-down period SD of the reset period RP, the negative ramp waveform NR in which the voltage gradually decreases from the positive sustain voltage Vs to the negative erase voltage Ve is It is applied to the scan electrodes (Y). At the same time, a positive sustain voltage Vs is applied to the sustain electrodes Z, and 0 [V] or a low voltage equivalent thereto is applied to the address electrodes X1 to Xn. Due to the negative ramp waveform NR, dark discharge occurs between the scan electrodes Y and the address electrodes X in the discharge cells 29 of the full screen, and at the same time, the scan electrodes Y and the sustain electrodes Dark discharge occurs between (Z). As a result of the dark discharge in this set down period SD, the wall charge distribution in each of the discharge cells 29 is changed to the optimum condition of the address.

In the address period AP, the negative scan pulses -SCNP are sequentially applied to the scan electrodes Y1 to Ym, and at the same time, the positive electrodes are applied to the address electrodes X1 to Xn in synchronization with the scan pulses -SCNP. The surname data pulse DP is applied. The voltage of the data pulse DP is the positive data voltage Va. During this address period (AP), the sustain electrodes Z are supplied with a positive sustain voltage Vs or a lower positive bias low voltage Vzb. An address discharge is generated between the scan electrodes Y and the address electrodes X in the on-cells to which the scan voltage Vsc and the data voltage Va are applied.

In the sustain period SP, the sustain pulses SUSP of the positive sustain voltage Vs are alternately applied to the scan electrodes Y and the sustain electrodes Z. FIG. Then, on-cells selected by the address discharge generate sustain discharges between the scan electrodes Y and the sustain electrodes Z at each sustain pulse SUSP. On the contrary, the off-cells do not discharge during the sustain period SP.

In the erase period EP of the subfield SFn, the erase ramp waveform ERR is applied to the sustain electrodes Z. The erase ramp waveform ERR is a ramp waveform whose voltage is gradually imagined from 0 [V] to a positive sustain voltage Vs. The erase discharge is generated between the scan electrodes Y1 to Ym and the sustain electrodes Z1 to Zm in the on-cell in which the sustain discharge has been caused by the erase ramp waveform ERR. By this erase discharge, wall charges in the on cells are erased.

In this manner, the ramp waveform has different potentials and polarities for each electrode X, Y, and Z. This is to control the discharge. If the potential difference for the discharge is not secured or the potential for not generating the discharge is secured, the PDP malfunctions. Therefore, each driving unit must secure a reference potential through the ground voltage to perform normal operation. To this end, in the present invention it is possible to ensure the stability of the drive by connecting the ground power source of each drive unit using a heat sink and a ground plate.

As described above, the plasma display apparatus according to the present invention does not constitute a circuit for providing a separate ground power source when using the plastic chassis base, but uses a heat sink provided in the driving circuit unit and a ground plate relaying the heat sink. Through this, the plasma display device according to the present invention can easily connect the ground power source of the main driving circuit portion sensitive to the ground voltage without a significant increase in the manufacturing cost.

Claims (10)

A panel on which a plurality of electrodes are provided to which a driving signal for display discharge is supplied; At least one printed circuit board having circuits for supplying driving signals to the electrodes and having a heat sink which cools heat generated from the circuit and is electrically connected to a ground power input of the circuit; A plastic chassis base for fixing the printed circuit board; And at least one ground plate fixed to the plastic chassis base to electrically connect the heat sinks. The method of claim 1, And the heat sink and the ground power input unit are connected by a conductive path. The method of claim 1, And the heat sink and the ground plate are connected by a conductive path. The method of claim 1, The heat sink is A base part in contact with the heat generating element of the circuit part; A wing having one or more wings extending in a predetermined direction from the base to cool the circuit; And at least one connection part protruding from the base part to be connected to any one of the ground power input part and the ground plate. The method of claim 4, wherein The ground plate is And at least one junction electrically connected to the connection. The method of claim 1, Wherein the circuits include at least one of a power supply, an address driver, a scan driver, and a sustain driver. The method of claim 1, And a thermally conductive sheet is inserted between the plastic chassis base and the panel. The method of claim 1, And a case member accommodating the panel, the printed circuit board, and the chassis base therein. The method of claim 7, wherein Any one of the ground plates is electrically connected to the thermal conductive sheet. The method of claim 8, Any one of the ground plates is electrically connected to the case member.

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