Plasma display device

A plasma display device may include a plasma display panel, a chassis arranged on one side of the plasma display panel, the chassis supporting the plasma display panel, a plurality of circuit units arranged on one surface of the chassis, the circuit units generating electrical signals that are used to drive the plasma display panel, a signal transmission member linking the circuit units to each other and to the plasma display panel so as to transmit the electrical signals, a coupling member installed on at least one of the circuit units, coupling the signal transmission member to at least one of the circuit units, and a foreign material blocking member installed on at least one of the circuit units, preventing a foreign material from intruding into the coupling member.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a plasma display device, and more particularly, to a plasma display device including a foreign material blocking member.

2. Description of the Related Art

Plasma display devices are flat display devices that display an image using a gas discharge phenomenon. Plasma display devices may provide large screens with a number of desirable traits, e.g., a high-quality image display, a very thin and light design, and a wide-range viewing angle. In addition, these displays may be manufactured in a simplified manner, when compared with other flat display panels. Accordingly, plasma display devices have attracted considerable attention as the most promising next-generation flat display devices.

Such plasma display devices include a plasma display panel (PDP) that displays an image by exciting a phosphor material with ultraviolet rays generated during gas discharge. PDPs may be classified into types according to the discharge voltage applied to the discharge cells, e.g., a direct current (DC) type, an alternating current (AC) type, and a hybrid type. PDPs may also be classified into a facing discharge type and a surface discharge type according to the type of discharge structure used.

Facing discharge PDPs have a problem in that their life spans may be reduced due to a degradation of a phosphor material caused by ions generated during discharge. On the other hand, surface discharge PDPs minimize the degradation of a phosphor material by collecting discharge on a side opposite to a side on which the phosphor material is formed, whereby the problems of the structure of facing discharge PDPs may be minimized. Hence, surface discharge PDPs are widely used at present.

Plasma display devices may include a PDP which displays an image, a chassis that supports the PDP, and a number of circuit units that process electrical signals used to drive the PDP. A signal transmission member, e.g., a tape carrier package (TCP) or a flexible flat cable (FFC), may connect the circuit units to each other or may connect each of the circuit units to input electrodes on the PDP to drive the display.

One end of the signal transmission member may be connected to a circuit unit by a connector which may be a coupling member. The connector may be mounted on a circuit board together with other circuit elements during mass-production of the circuit units. However, the connector may include conductive metal pins that electrically contact the pins of the signal transmission member. The pins of the connector may be partially exposed even after the connector is installed in a circuit unit. When an external foreign substance contacts the exposed pins, an electrical signal being transmitted by the signal transmission member may be mixed with noise, leading to erroneous image displays.

To prevent this problem, in the conventional art, the exposed pins may be covered with silicone after a connector is mounted on a circuit unit.

However, this process increases the production lead time of a circuit unit by the amount of time required to dry the silicone, and there may be difficulty in controlling the amount of silicone to be used. Hence, the silicone may intrude up to the connector's actuator. The actuator may be rotated to couple the signal transmission member to the connector. The silicone may compromise the connection between the connector and the signal transmission member.

In addition, when the pins of an assembled connector may become short-circuited, the silicone coating may need to be reapplied. However, once silicone is applied, it may be very difficult to completely remove the silicone. Efforts to remove the silicone may increase the probability of secondary damage, e.g., destruction of a printed circuit board (PCB).

Further, the actuator of the conventional plasma display device may be opened excessively, which may damage the connector.

SUMMARY OF THE INVENTION

The present invention is therefore directed to a plasma display device having a foreign material blocking member, which substantially overcomes one or more of the problems due to the limitations and disadvantages of the related art.

It is therefore a feature of an embodiment of the present invention to provide a foreign material blocking member for a circuit coupling member that may prevent the compromise of the circuit coupling from foreign material.

It is therefore another feature of an embodiment of the present invention to provide an actuator limiter that may prevent the actuator from excessive movement and thereby prevent damage to the actuator.

At least one of the above and other features and advantages of the present invention may be realized by providing a plasma display device including a plasma display panel, a chassis on one side of the plasma display panel, supporting the plasma display panel, a plurality of circuit units arranged on one surface of the chassis, generating electrical signals to drive the plasma display panel, a signal transmission member connecting the circuit units to each other and to the plasma display panel so as to transmit the electrical signals, a coupling member on at least one of the circuit units, coupling the signal transmission member to at least one of the circuit units, and a foreign material blocking member on the at least one of the circuit units, preventing a foreign material from intruding into the coupling member.

In some embodiments, the signal transmission member may be at least one member of the group consisting of a flexible flat cable (FFC) and a tape carrier package (TCP).

In some embodiments, the foreign material blocking member may include a plurality of mounting bosses, wherein each mounting boss may include a relief slot to enable quick attachment to and removal from the circuit unit.

In some embodiments, an end of each of the bosses may include a member having a vertical cross-section in the shape of an arrowhead whose outer circumference increases from a bottom end to a top end of the arrowhead.

In other embodiments, the foreign material blocking member may include a shield that encloses an exposed pin coupling portion of the coupling member.

In other embodiments, the circuit unit includes holes through which at least one boss of the foreign material blocking member may be coupled to the circuit unit.

In other embodiments, the coupling member may include a fixed coupler fixed to the circuit unit, and an actuator rotatably attached to the coupling member to couple the signal transmission member to the coupling member.

In other embodiments, the foreign material blocking member may include an actuator limiter that limits rotation of the actuator.

In still other embodiments, the actuator limiter may define the rotation range for the actuator.

In still other embodiments, the fixed coupler may include a protruding tab and the foreign material blocking member may include a groove, wherein the protruding tab engages the groove when the fixed coupler and the block may be fully engaged.

In even other embodiments, the protruding tab may be formed on at least one of a pair of side surfaces and a rear surface of the fixed coupler, and the groove on the foreign material blocking member may be disposed to engage the protruding tab.

In yet other embodiments, the plasma display device may include a horizontal coupling surface integral with the foreign material blocking member, and slanted engagement ramps disposed on the foreign material blocking member and the fixed coupler perpendicular to the horizontal coupling surface.

In even other embodiments, the plasma display device may include a vertical coupling surface integral with the foreign material blocking member and slanted engagement ramps disposed on the foreign material blocking member and the fixed coupler perpendicular to the vertical coupling surface.

According to the present invention, foreign material may be prevented from compromising electrical connections of a plasma display device.

DETAILED DESCRIPTION OF THE INVENTION

Korean Patent Application No. 10-2006-0028073, filed on Mar. 28, 2006, in the Korean Intellectual Property Office, and entitled: “Plasma Display Device,” is incorporated by reference herein in its entirety.

FIG. 1illustrates an exploded perspective view of a plasma display device10according to an embodiment of the present invention. Referring toFIG. 1, the plasma display device10may include a plasma display panel (PDP)20and a chassis base40.

The PDP20may include a plurality of electrodes222,223(seeFIG. 2) formed between two facing substrates21and22. A discharge gas may be injected between the front panel21and the rear panel22, and then a discharge voltage may be applied to the discharge gas. A phosphor material in the PDP20may be excited by ultraviolet (UV) light generated from the discharge gas and voltage in a predetermined pattern, so that a desired image may be displayed. The PDP20will be described in greater detail later with reference toFIG. 2.

The PDP20may be supported by the chassis base40located at the rear of the PDP20. The PDP20and the chassis base40may be coupled together by double-sided tape35. The PDP20may generate a lot of heat due to the discharge phenomenon described above, so a thermal sheet30formed of a thermally conductive material may be interposed between the chassis base40and the PDP20to conduct heat from the PDP20to the chassis base40.

Circuit units50may be connected to the electrodes of the PDP20, and may be installed on the back of the chassis base40. The electrodes of the PDP20may be connected to the circuit units50by a signal transmission member60, e.g., a tape carrier package (TCP). The circuit units50may also be connected to each other by the signal transmission members60.

The signal transmission member60and the circuit units50may be connected to each other by a coupling member310, e.g., a connector. A foreign material blocking member330may be arranged on the circuit units50to prevent external foreign materials from entering into the coupling member310. The combined coupling member310and foreign material blocking member330are indicated as element70, which will be described in greater detail with reference toFIGS. 3 through 7.

FIG. 2illustrates an exploded perspective view of a 3-electrode surface discharge PDP as an exemplary embodiment of the PDP20. The 3-electrode surface discharge PDP20illustrated inFIG. 2may be a component of the plasma display device10according toFIG. 1. Of course, other types of PDPs may be used, e.g., an opposite discharge PDP, a PDP including electrodes formed within a barrier structure, a PDP having a delta type electrode structure, or a PDP having no indium-tin-oxide (ITO) electrodes. Accordingly, the PDP20illustrated inFIG. 2is simply one possible component that may be included in a plasma display device10according to an embodiment, and does not restrict the scope of the present invention.

Referring toFIG. 2, the PDP20may be manufactured by combining a front panel21and a rear panel22.

The front panel21may include a front substrate220with pairs of sustain discharge electrodes222,223arranged on the lower surface of the front substrate220. A first dielectric layer225may cover the sustain discharge electrodes222,223, and a protection film227may cover the first dielectric layer225. Each pair of the sustain discharge electrodes may include an X electrode222and a Y electrode223. The X electrode222may include a transparent electrode222aand a bus electrode222b, and the Y electrode223may include a transparent electrode223aand a bus electrode223b.

The rear panel22may include a rear substrate230, address electrodes231arranged parallel to each other on the upper surface of the rear substrate230, a second dielectric layer235covering the address electrodes231, a barrier structure237formed on the second dielectric layer235, and phosphor layers238formed on exposed portions of the upper surface of the second dielectric layer235and sidewalls of the barrier structure237.

The front and rear substrates220and230may be formed of soda-lime glass having good visible light transmissivity and may also be colored or tinted in order to improve bright room contrast. Alternatively, the front and rear substrates220and230may be formed of plastic so as to be flexible.

The X and Y electrodes222and223formed on one surface of the front substrate220may include transparent electrodes222aand223a, respectively, and bus electrodes222band223b, respectively. The transparent electrodes222aand223amay be formed of a material that may be electrically conductive to generate discharge, but transparent so as not to disturb the propagation of light emitted from the phosphor layers238toward the front substrate220. Transparent conductive materials include, e.g., indium tin oxide (ITO) and antimony tin oxide (ATO).

The transparent conductive material, e.g., ITO, may have great resistance, so that if a sustain discharge electrode includes only a transparent electrode222a,223a, there may be a large voltage drop in the direction of the sustain discharge electrode. Thus, a lot of driving power may be consumed, and the response speed may be decreased. To overcome these problems, the sustain discharge electrodes may include bus electrodes222b,223barranged on the transparent electrodes222a,223a. The bus electrodes222b,223bmay be formed of a metal and may be relatively narrow as compared to the transparent electrodes222a,223a.

The first dielectric layer225may be formed on the front substrate220so as to envelope the X electrodes222and the Y electrodes223in the first dielectric layer225. The first dielectric layer225may be formed of a dielectric material, e.g., PbO, B2O3, SiO2, capable of inducing charges and accumulating wall charges, in order to prevent electricity from directly flowing between adjacent X electrodes222and Y electrodes223during discharge, and to prevent the X electrodes222and Y electrodes223from being damaged due to direct collisions with positive ions or electrons.

The first dielectric layer225may be protected by the protection film227. The protection film227, e.g., magnesium oxide (MgO) or magnesium fluoride (MgF2), may protect the first dielectric layer225by preventing the dielectric material from being sputtered due to ion bombardment.

The address electrodes231may be arranged on the rear substrate230so as to intersect the sustain discharge electrodes222and223. The address electrodes231may provoke address discharge to facilitate sustained discharge between the X and Y electrodes222and223. More specifically, the address electrodes231may lower the voltage used to provoke sustained discharge. The address electrodes231may be arranged in a stripe pattern to intersect the sustain discharge electrodes.

The address electrodes231may be covered with the second dielectric layer235. The second dielectric layer235, e.g., PbO, B2O3, SiO2, may prevent the address electrodes231from being damaged due to direct collisions with positive ions or electrons during discharge. The second dielectric layer235may include, or be integrally formed with, a reflection film to prevent visible light generated within the discharge cells from exiting the rear of the PDP20.

The barrier structure237may define the discharge cells and may be installed on the second dielectric layer235. Although the barrier structure237illustrated inFIG. 2defines rectangular discharge cells arranged in a matrix, the present invention is not limited to this structure of the discharge cells. The discharge cells may have the other shapes, e.g., a stripe shape, a circular shape, or a delta shape. Adjacent discharge cells may be separated by the barrier structure237. The barrier structure237may define unit pixels that form an image. The barrier structure237may prevent color mixture between pixels by preventing crosstalk where discharge may be mixed on an interface between discharge cells. The barrier structure237may define the spaces, which may be coated with phosphor238, and therefore where discharge occurs. The size of such each discharge space may be determined by the size and configuration of the ribs of the barrier237. The size of a discharge space may depend on the width of an upper surface of a barrier rib or the distance between adjacent barrier ribs.

Red, green, and blue phosphor layers238may be formed on exposed portions of the upper surface of the second dielectric layer235and sidewalls of the barrier structure237. The phosphor layers238may include a component that generates visible light in response to UV light. The red phosphor layers238, e.g., Y(V,P)O4:Eu, may be formed in red discharge cells, the green phosphor layers238, e.g. Zn2SiO4:Mn, may be formed in green discharge cells, and the blue phosphor layers238, e.g., BaM:Eu, may be formed in blue discharge cells.

The discharge cells may be filled with a discharge gas that may be excited or provoke discharge when a voltage may be applied to the electrodes222,223, and231within the discharge cells. The discharge gas, e.g., at least one of argon (Ar), xenon (Xe), nitrogen (N2), heavy hydrogen (D2), carbon dioxide (CO2), hydrogen (H2), carbon monoxide (CO), krypton (Kr) or air, may be excited by external energy, e.g., electron beams, to generate UV light, or serve as a discharge gas.

The foreign material blocking member and surrounding structure, corresponding to an exemplary embodiment of a plasma display device according to the present invention, will now be described with reference toFIGS. 3 through 7.

FIGS. 3 through 7illustrate magnified views of the foreign material blocking member and coupling member70and the surrounding structure.FIG. 3illustrates the signal transmission member and the coupling member in an uncoupled state.FIG. 4illustrates the coupled signal transmission member and the coupling member.FIG. 5illustrates a plan view of a coupling member without a foreign material blocking member.FIG. 6illustrates a plan view of the coupling member ofFIG. 5with a foreign material blocking member coupled.FIG. 7illustrates a perspective view of an interface between the coupling member and the foreign material blocking member.

Referring toFIGS. 3 and 4, a coupling member310and a foreign material blocking member330may be arranged on a circuit board305. The circuit board305may be one of the circuit units50shown inFIG. 1.

A signal transmission member320may include a flexible cable323, a conductive pin set321which may be coupled to the coupling member310, and a coupling array322between the cable part323and the pin set321. The signal transmission member320may be a TCP or a flexible flat cable (FFC). Hence, an integrated circuit (not shown) may be mounted on the flexible cable323.

The conductive pin set321may be connected to the coupling member310, which may mate with the pin set321to receive an electric signal.FIG. 3illustrates the signal transmission member320in a position where it is not coupled to the coupling member310.FIG. 4illustrates the signal transmission member320coupled to the coupling member310. InFIGS. 3 and 4, like reference numerals indicate like members.

The coupling member310may include a fixed coupler312and an actuator311. The fixed coupler312may be a stationary part attached to the circuit board305. The fixed coupler312may be electrically connected to the pin set321of the signal transmission member320to receive a signal through the signal transmission member320. The fixed coupler312may be formed of a conductive material, e.g., silver, copper, and may be electrically connected to the pin set321at the pin coupling. The pin coupling may enable electrical communication through the circuit board305to various circuit elements (not shown) mounted on the circuit board305. To achieve this electrical connection, the pin coupling may extend into the coupling member310that may be surrounded by the foreign material blocking member330. When the foreign material blocking member330is not installed, the pin coupling may be entirely or partially exposed to the outside.

The actuator311may be hingedly attached to the coupling member310and the fixed coupler312to releasably attach the signal transmission member320to the coupling member310.FIG. 3illustrates the actuator311in an open position.FIG. 4illustrates the signal transmission member320coupled to the coupling member310with the actuator311in a closed position. When the actuator311is closed, the signal transmission member320and the coupling member310may be firmly engaged with each other. The actuator311may be opened to separate the signal transmission member320from the coupling member310. If the actuator311is rotated beyond a predetermined limit, the coupling member310may be damaged. To prevent this damage, the foreign material blocking member330may include an actuator limiter335that prevents excessive rotation of the actuator311.

In an exemplary embodiment, the foreign material blocking member330may have ashape to surround the coupling member310. Of course, the present invention is not limited to this shape. The foreign material blocking member330may have about any other shape that may be capable of protecting the pin coupling between the signal transmission member320and the coupling member310. The foreign material blocking member330may include a shield331large enough to cover the pin coupling portion, to protect the exposed pin coupling portion of the coupling member310. The shield331may have the configuration illustrated inFIG. 3or any other configuration that may protect at least the pin coupling and prevent the intrusion of a foreign material. The foreign material blocking member330may be coupled to the circuit board305by four bosses332.

FIGS. 5 and 6illustrate plan views of a coupling member without a foreign material blocking member, and a coupling member with a foreign material blocking member, respectively.FIG. 5illustrates a plan view of a coupling member510when an actuator511is closed. The actuator511may be hingedly attached to the coupling member510, in a manner similar to actuator311inFIGS. 3-4. The actuator522may removably fix a signal transmission member to the fixed coupler512on the coupling member510. Regardless of whether the signal transmission member is coupled to the coupling member510, a pin coupling portion513of the coupling member510may be partially exposed.

In a conventional plasma display device, silicone or the like may be coated on a predetermined portion, i.e., sealant area520, of the coupling member510in order to prevent contamination by a foreign material. However, this practice produces some problems, e.g., an increase of production lead time, a destruction of an actuator due to the use of excessive silicone, and inconvenience of silicone removal for reapplication of silicone coating.

FIG. 6illustrates a plan view of the coupling member510having a foreign material blocking member530attached thereto. The foreign material blocking member530may eliminate the need to coat a portion of the coupling member510with silicone. A shield531for the foreign material blocking member530may be equal to or larger than the pin coupling portion513of the coupling member510to prevent the intrusion of foreign material into the coupling member510. The foreign material blocking member530may be made of a plastic, but the present invention is not limited to this material.FIG. 6shows that predetermined portions of the foreign material blocking member530near the bosses may be removed to reduce material cost. However, the present invention is not limited to this removal. Further, the foreign material blocking member530is not limited to theshape as illustrated inFIG. 6, but may be any shape necessary to prevent the intrusion of foreign material into the coupling member510.

An actuator limiter532may be included in the foreign material blocking member530to prevent excessive rotation of the actuator511.

FIG. 7illustrates a perspective view of an interface between the coupling member and a block member730. An actuator limiter712may be formed from the inside surface of a shield731of the foreign material blocking member730. The actuator705may be thin to conform closely to the foreign material blocking member730and may enable the actuator705to rotate open a desired amount. Between a horizontal, closed position and a maximally opened position, the actuator705may rotate about 105 degrees, in an exemplary embodiment. Accordingly, a length “d” of the actuator limiter712may be just large enough to prevent the actuator705from being opened beyond the desired angle.

InFIG. 7, bosses711for fixing the foreign material blocking member730to a circuit board (not shown) are illustrated. The bosses711may be mounted through holes in the circuit board on which there may be no copper layers. Of course, the holes in the circuit board may be surrounded with a copper layer. However, the copper layers may be omitted when the foreign material blocking member730may be formed of plastic or when the foreign material blocking member730does not need to be grounded. The bosses711may be shaped so that center portions thereof may be partially removed and the outer circumferences of ends thereof increase inward, so that the bosses711may be easily detachable from or attachable to the circuit unit. In other words, a vertical cross-section of each of the bosses711may have the shape of an arrowhead whose outer circumference increases from the bottom end towards the top end of the arrowhead. Since the centers of the ends of the bosses711may be partially removed, the ends of the bosses711may compress radially to easily pass through the holes of the circuit board and couple the bosses711to the circuit board. After the arrowhead-shaped ends of the bosses711pass through the holes, the arrowhead-shaped ends may catch on the circuit board, so that the bosses711may be fixed in position.

For convenience of processing, the bosses711may be formed of plastic. However, the present invention is not limited to this material. The bosses711may be formed of any of the other suitable material, e.g., metal. The shape of the bosses711is not limited to the shape illustrated inFIG. 7. The bosses711may have another suitable shape so that the bosses711may be coupled to a circuit board, e.g., screwing, riveting, or other coupling method.

A method of coupling a foreign material blocking member and a coupling member to each other will now be described in greater detail.FIGS. 8 and 9illustrate a method for coupling a foreign material blocking member to a coupling member so that the two members adhere closely to each other.

FIG. 8illustrates a perspective view of an interface between a coupling member805and a foreign material blocking member830of a plasma display device according to another embodiment of the present invention. As illustrated inFIG. 8, some bosses are cut away in order to facilitate understanding of the coupling method.

A foreign material blocking member830may include a shield820, as described above. A coupling member805may attach into and engage the block830. A protruding tab831may be formed on one end of a fixed part810of the coupling member805. A groove832may be formed in the foreign material blocking member830so to provide an engagement position for the protruding tab831. A first slanting surface833and a second slanting surface834may be formed on the fixed part810and the foreign material blocking member830, respectively, opposite the coupling surface. The first slanting surface833and the second slanting surface834may be used as ramps to couple the foreign material blocking member830to the coupling member805. The block830and the coupling member805may be snapped together using the first and second slanting surfaces833and834.

The coupling relationship between the coupling member805and the foreign material blocking member830may be established at any interface between the block830and coupling member805.

FIG. 9illustrates a perspective view of an interface between a coupling member905and a foreign material blocking member930of a plasma display device according to still another embodiment of the present invention. As illustrated inFIG. 9, some bosses are cut away in order to facilitate understanding of the coupling method.

As described above, a foreign material blocking member930may include a shield920. A coupling member905may attach into and engage the block930. A protruding tab931may be formed on one end of a fixed part910of the coupling member905. A groove932may be formed in the foreign material blocking member930so as to provide an engagement position for the protruding tab931. However, in contrast with the embodiment ofFIG. 8, a coupling surface where the protruding tab931and the groove932meet may be vertically oriented. A first slanting surface933and a second slanting surface934may be formed on the fixed part910and the foreign material blocking member930, respectively. In the embodiment ofFIG. 9, the foreign material blocking member930may be coupled to the coupling member905by sliding them together in a parallel and planar relationship so that the slanting surfaces933and934may engage each other. Of course, the foreign material blocking member930may also be coupled to the coupling member905by pressing the coupling member905down into the block930. The coupling relationship between the coupling member905and the foreign material blocking member930may be established at any interface between the coupling member905the block930.

A plasma display device according to the present invention may include a foreign material blocking member which may prevent foreign material from penetrating into a coupling member between a signal transmission member and a circuit unit. Thus, production lead time may be reduced as compared to when silicone may be used as a block against foreign material. The device may also reduce the risk of damage to the coupling member during the manufacture of the plasma display device. In addition, the foreign material blocking member may be easily removed from the circuit unit when a coupling member needs to be remounted.