KR20060111277A - Plasma display device - Google Patents

Abstract

A plasma display device is provided to stabilize operation of a driving portion by using a ground unit, which couples a ground voltage source with a PCB(Printed Circuit Board). A plasma display device includes a panel(4), at least one PCB(12), a ground voltage source and a ground unit(16). A driving circuit for supplying a driving signal to the panel is formed on the PCB. The ground voltage source connects the driving circuit to a ground potential. The ground unit couples the ground voltage source with the PCB. At least one of a power supply, a scan driver, a sustain driver and an address driver is formed on the PCB. The ground unit has a ground portion and at least one branch portion.

Description

Plasma Display Device

1 is a schematic view showing a plasma display device of the present invention.

2 is a view illustrating in detail a portion of the printed circuit board and the ground member of FIG.

Figure 3 is a simplified view showing the end of the stem and stem portion connected branch.

Figure 4a is a simplified view showing a state in which the printed circuit board, the ground power input unit, the ground member is connected by a fastening member.

4B shows the side of FIG. 4A.

5 is a view showing an example of the shape of the connecting portion.

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

Fig. 7 is a waveform diagram showing an example of drive waveforms for driving the PDPs of Figs. 1 and 6;

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

2: front case 4: panel

6: heat conductive sheet 8: adhesive member

10 plastic chassis base 12 printed circuit board

14 rear case 16 grounding member

17, 27, 37: connector 18: connector

19: ground power input unit 20: fastening member

29: discharge cell

The present invention relates to a plasma display device, and more particularly, to a plasma display device capable of providing a ground circuit 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 display panels. (Or plasma display panel device, hereinafter referred to as "PDP").

Among the flat panel display devices, the PDP displays an image by plasma discharge, has a complete digital implementation, and has a relatively easy implementation of a large screen compared to other flat panel display devices.

Such a PDP is composed of a filter assembly, a panel, a heat conductive sheet, a chassis base (or frame), a printed circuit board, and various additional devices housed inside the front / rear case.

The case protects internal components from impact and contamination from the outside and prevents internal noise from leaking to the user. The filter assembly is composed of a cutoff filter for enhancing display quality and an electromagnetic cutoff filter for blocking electromagnetic waves. The panel is composed of an upper / lower substrate where a substantial image is realized, and a plurality of electrodes, partitions, phosphors, and dielectric layers are formed between the upper and lower substrates, and an inert gas is encapsulated. The thermally conductive sheet is formed between the panel and the chassis base to make the temperature of the PDP panel uniform and to radiate heat. The thermally conductive sheet is fixed to the chassis base by an adhesive member such as a liquid adhesive or an adhesive tape, or inserted between the panel and the chassis base when the panel and the chassis base are fastened.

The chassis base dissipates some of the heat generated from the chassis base front panel and the rear printed circuit board and serves to fix and support the printed circuit board. The chassis base has been conventionally used a metal material using an alloy such as aluminum, tin, etc., but in recent years, because of the purpose of reducing the manufacturing cost, weight reduction of PDP, material cost, number of parts and simplification of the process, It is a trend that is produced using.

The printed circuit board is divided into a plurality of circuit boards, and a plurality of circuit boards are formed by dividing a driving circuit including a power supply unit, an address driver, a scan driver, and a sustain driver. In particular, a power supply unit, an address driver, a scan driver, and a sustain driver are formed on each circuit board, and each substrate is fixed to the chassis base at a predetermined distance. These circuit boards are connected to each other by a conductive member such as a flexible printed cable or circuit (hereinafter, referred to as "FPC").

On the other hand, the power supply unit includes an AC-DC converter for converting AC into direct current, and supplies power for the operation of the PDP and power for generating signal voltage supplied to the panel to the printed circuit board. In addition, the address driver, the scan driver, and the sustain driver generate a drive signal by using the power from the power source, and supply it to the panel by the conductive member.

The power supply unit, the address driver, the scan driver, and the sustain driver generate signal voltages of about several tens of volts [V] and many hundreds of volts due to the driving characteristics of the PDP. In particular, the voltage level between the address driver, the scan driver, and the sustain driver is important for the relative potential difference between the respective drivers, and the connection of the ground power source is essential for the relative potential difference. In addition, in the case of the power supply unit, in order to supply power to each of the driving units, it is essential to match each of the driving units with the reference potential.

To this end, in the conventional PDP using a metal chassis base, this problem is solved by using a metal chassis base as a ground power source, but in a PDP using a plastic chassis base, a separate ground circuit must be configured to provide a ground power source. There is a problem.

Accordingly, an object of the present invention is to provide a plasma display device capable of providing a ground circuit between driving circuits.

For this purpose, the plasma display device of the present invention includes a panel, at least one printed circuit board having a driving circuit for supplying a driving signal to the panel, a ground power source for providing ground to the driving circuits, and a ground power source and a printing circuit. It may be provided with a grounding member for connecting the circuit board.

At least one of a power supply unit, a scan driver, a sustain driver, and an address driver may be formed on the printed circuit board. The ground member may be connected to a stem part and a stem part connected to a ground power source, and may be connected to a ground power input part of the printed circuit board. It may have one or more branches to be fastened.

Any one of the branches and the stem may be formed with a hole to which the fastening member can be coupled for connection with a ground power source or a printed circuit board. In addition, the connecting portion may be annular.

Such a grounding member may use one of a metal plate, stranded wire and a cable.

In addition, the plasma display apparatus of the present invention includes a plastic chassis base for fixing a printed circuit board and a grounding member, a thermal conductive sheet inserted between the panel and the plastic chassis base, an adhesive member for attaching the panel to the plastic chassis base, and a panel; A case for accommodating the thermal conductive sheet, the plastic chassis base, and the printed circuit board may be provided.

In this case, it is possible to use one of the thermal conductive sheet and the case as the ground power source.

In addition to these objects, other features and operations of the present invention will be apparent from the detailed 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 7.

1 is a view schematically showing a plasma display device of the present invention.

Referring to FIG. 1, the plasma display apparatus of 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 10, and a printed circuit. A substrate 12 and a ground member 16 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 12, and the plastic chassis base 10 from external contaminants and various impacts. The noise and vibration generated when the PDP is driven are prevented from being transmitted 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. In addition, it is also possible to be used as a ground source of the printed circuit board 12 as in the present invention.

The panel 4 is formed between the upper substrate 4a on which the plurality of scan electrodes and the sustain electrodes are formed, the plurality of address electrodes formed in the direction crossing the electrodes of the upper substrate 4a, and the upper substrate 4a. It consists of a lower substrate 4b comprising a phosphor layer. In addition, a partition wall is formed between the upper substrate 4a and the lower substrate 4b to partition the discharge cells. 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 controls the amount of visible light to display a predetermined image. In addition, an upper dielectric layer is further formed on the upper substrate 4a, and a lower dielectric layer is further formed on the lower substrate 4b.

A thermal spread sheet (TSS) 6 is inserted between the panel 4 and the plastic chassis base 10 to partially transfer heat generated from the panel 4 to the plastic chassis base 10 when the plasma display device is driven. In addition to the heat transfer, the temperature of the panel 4 is prevented from rising rapidly. In addition, the thermal conductive sheet 6 evenly distributes the temperature distribution of the non-uniform panel 94, thereby preventing 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 or panel 4 to the plastic chassis base 10. 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, the thermal conductive sheet 6 or panel 4 to the plastic chassis base 10 It is fixed. 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 air 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 10 fixes the panel 4 or the thermal conductive sheet 6 by the adhesive member 8, and also partially heats the panel 4, the tape carrier package, and the printed circuit board 12. Allow for heat dissipation. The plastic chassis base 10 supports and fixes the printed circuit board 12 by fastening means such as a boss or a screw. Since the plastic chassis base 10 has a lower thermal conductivity than the metal chassis base, the plastic chassis base 10 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 10 is mounted with a ground member 16 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 12 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 logic for forming a control circuit such as a timing controller. 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 tape carrier package (TCP) in which a driving chip is mounted. do.

The ground member 16 connects the ground power source of each driving unit formed on the printed circuit board 12. To this end, the grounding member 16 has a stem and a branch, and is connected to the thermal conductive sheet 6 or the rear case 14 at the end of the main line to match the ground potential of the driving units. The ground member 16 is connected to the ground power input of each driving circuit by the branch portion, and each branch is connected to the stem portion to provide ground power to the driving circuits. The ground member 16 is made of a plate-like metal, a conductive material, twisted wire, twisted wire, such as a good conductor of electricity and easy to mold.

FIG. 2 is a view illustrating in detail a portion of the printed circuit board and the grounding member of FIG. 1, and FIG. 3 is a view schematically illustrating a stem portion and a termination portion of a stem portion to which branch portions are connected.

2 and 3, the ground member 16 includes a stem portion 16a and a branch portion 16b.

The branch part 16b is fastened to the ground power input part formed in one space of each driving circuit part to supply ground power provided via the stem part 16a to the driving circuit. To this end, a second connection part 17b is formed at one end of the branch part 16b to be connected to the ground power input part of the driving circuit, and the other end is connected to the stem part 16a. The second connection portion 17b is formed with a second fastening member connector 18b for connecting the ground member 16 and the drive circuit by a fastening member such as a screw. The deformation of the second fastening member coupler 18b will be described later.

The stem portion 16a connects the ground power input portion and the ground power source connected by the branch portion 16b. To this end, one or more branch portions 16b are connected to a predetermined portion of the stem portion 16a. In addition, a first connection portion 17a is formed at the end of the stem portion 16a to be connected to the ground power source. The stem portion 16a is connected to the ground power supply by the first connection portion 17a. The first connecting portion 17a is formed with a first fastening member connector 18a in which the fastening member is assembled like the second connecting portion 17b. Here, the structures of the first fastening member connector 18a and the second fastening member connector 18b may be different. In addition, the ground power source includes a heat conducting sheet 6 and a rear case 14. In addition, the stem portion 16a may include fixing means such as a hole, a ring, and the like, for fixing the ground member 16a to the chassis base 10.

In addition, portions other than the connecting portion of the branch portion 16b and the stem portion 16a may be insulated using an insulating coating to insulate other elements or conductive paths.

FIG. 4A is a diagram schematically illustrating a state in which a printed circuit board, a ground power input unit, and a ground member are connected by a fastening member, and FIG. 4B is a side view of FIG. 4A.

Referring to FIG. 4, a printed circuit, that is, a ground power input unit 19 for supplying ground power is formed at a portion of the printed circuit board, for example, close to one edge. Although not shown in FIG. 4, the printed circuit board 12 on which the ground power input unit 19 is formed is provided with a hole, a screw groove, etc. for fixing the ground member 16 by the fastening member 20. The fastening member 20 fixes the branch 16b of the ground member 16 to the printed circuit board 12 by the hole or the screw groove. The ground member 16 is electrically connected to the ground power input unit 19 by the fastening member 20.

Figure 5 shows examples of the shape of the connection, in addition to various modifications are possible.

As shown in (a) of FIG. 5, a connector 18 into which the fastening part 20 may be inserted may be formed on a circular metal plate. In addition, it is also possible to use a ring (or hook) connection portion 27 as shown in (b), it is also possible to use a ring-shaped connection portion 37 modified as shown in (c). In the case of the annular connecting portions 27 and 37, as shown in (a), not only the upper direction of the connector but also the opening of the ring can be fastened, so that the connecting portion 17, 27, 37) can be selected. It will be appreciated that various modifications are possible through these modifications.

FIG. 6 is a view briefly illustrating a connection relationship between the panel and the driving circuit of FIG. 1, illustrating a three-electrode surface discharge plasma display panel as an example, and a 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 12b 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 12c 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 units of lines so that the discharge cells 29 in which discharge is to be maintained are selected according to the logic value of the data pulses.

The address driver 12a, the scan driver 12b and the sustain driver 12c are connected by the tape carrier package 30, the flexible printed cable, or the flexible flat cable to be connected to the electrodes. 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 12 includes a power supply unit for supplying general power required for driving the PDP. The power supply unit has an AC-DC converter that converts an externally provided AC current into a DC power source for driving the PDP, and supplies the converted power through a conductive path connected to each driving unit.

FIG. 7 is a waveform diagram showing an example of drive waveforms for driving the PDPs of FIGS. 1 and 6.

Referring to FIG. 7, 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 is generated 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 are generated. 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 SSUS. 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 in which the voltage gradually rises from 0 [V] to the 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 provides a grounding means for a grounding circuit that must be implemented separately when using a plastic chassis base. Through this, the plasma display device of the present invention can easily implement a grounding circuit, without increasing the manufacturing cost, it is possible to ensure a stable operation of the drive unit.

Claims (9)

A panel; At least one printed circuit board having a driving circuit for supplying a driving signal to the panel; A ground power source for providing ground to the drive circuits; And a ground member for connecting the ground power supply and the printed circuit board. The method of claim 1, And at least one of a power supply unit, a scan driver, a sustain driver, and an address driver are formed on the printed circuit board. The method of claim 2, The ground member is A stem portion connected to the ground power source, And at least one branch part connected to the stem part and fastened to a ground power input part of the printed circuit board. The method of claim 3, wherein And at least one of the branch portion and the stem portion includes a connection portion. The method of claim 4, wherein And a hole for coupling the fastening member to the connection portion. The method of claim 4, wherein And the connecting portion is annular. The method of claim 1, And the grounding member is one of a metal plate, a stranded wire, and a cable. The method of claim 1, A plastic chassis base for fixing the printed circuit board and the ground member; A thermally conductive sheet inserted between the panel and the plastic chassis base; An adhesive member for attaching the panel to the plastic chassis base; And a case for accommodating the panel, the thermal conductive sheet, the plastic chassis base, and the printed circuit board. The method of claim 8, And the ground power source is one of a thermal conductive sheet and the case.

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