Plasma display device

A plasma display device is constructed with a plasma display panel for visually displaying an image by using a gas discharge, a chassis base coupled to the plasma display panel to support the plasma display panel, a driving board including a board and a circuit device and applying a driving signal to the plasma display panel, a heat dissipation plate having heat dissipation fins and installed on the circuit device to dissipate heat generated from the circuit device, and a weight member installed on at least one of the heat dissipation fins to increase the weight of the heat dissipation fins on which the weight member is installed.

CLAIM OF PRIORITY

This application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C.§119 from an application for PLASMA DISPLAY DEVICE earlier filed in the Korean Intellectual Property Office on 27 Nov. 2006 and there duly assigned Serial No. 10-2006-0117754.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a plasma display with reduced driving noise.

2. Description of Related Art

A plasma display device is a display device that can visually display an image using plasma created by gas discharge.

A plasma display device is typically constructed with a plasma display panel (PDP), a chassis base for supporting the PDP, and a plurality of driving boards mounted on an opposite surface of the chassis base to the PDP. The driving boards are connected to electrodes disposed in the PDP through a flexible printed circuit (FPC).

The PDP is constructed with two glass substrates facing each other and sealed together to define a discharge space therein. Therefore, the PDP has a mechanical property that is weak against an external impact. In order to supplement the mechanical strength of the PDP, the chassis base coupled to the PDP is made from a material having high mechanical strength, such as cast iron.

Further, the driving boards are mounted in the rear of the chassis base. The driving boards are constructed by installing circuit devices for performing the logical processes. The driving boards apply a driving signal of a high voltage to the electrodes to generate the discharge of the PDP.

Meanwhile, the circuit devices generate heat during the operation of the circuit devices as the electrical energy is partly converted into thermal energy. The generated heat deteriorates the reliability of the circuit devices. Therefore, a heat sink is installed on each circuit device to dissipate the heat generated by the circuit device.

The heat sink is constructed with a plurality of heat discharge fins to enlarge an overall surface area of the heat sink, and the heat discharge fins generate noise while being vibrated during the operation of the circuit device.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide an improved plasma display device.

It is another object to provide a plasma display device in which noise generated during the operation of a circuit device is reduced.

In an exemplary embodiment of the present invention, a plasma display device is constructed with a plasma display panel for visually displaying an image using a gas discharge, a chassis base coupled to the plasma display panel to support the plasma display panel, a driving board including a board and a circuit device and applying a driving signal to the plasma display panel, a heat dissipation plate having heat dissipation fins and installed on the circuit device to dissipate heat generated from the circuit device; and a weight member installed on the heat dissipation fins to increase a weight of the heat dissipation fins on which the weight member is installed.

The weight member may be coupled to the heat dissipation fins by a bonding member. The weight member may be formed on each of outermost heat dissipation fins among the heat dissipation fins.

The heat dissipation plate is constructed with a main body, which is attached to the circuit device and from which the heat dissipation fins extend. The adjacent dissipation fins face each other.

In another exemplary embodiment of the present invention, a plasma display device is constructed with a plasma display panel for visually displaying an image using a gas discharge, a chassis base coupled to the plasma display panel to support the plasma display panel, a driving board including a board and a circuit device and applying a driving signal to the plasma display panel, and a heat dissipation plate having heat dissipation fins and installed on the circuit device to dissipate heat generated from the circuit device. Some of the heat dissipation fins are different in shape or weight from the rest of the heat dissipation fins.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1is a schematic exploded perspective view of a plasma display device according to an embodiment of principles of the present invention.

Referring toFIG. 1, a plasma display device of an embodiment is constructed with a plasma display panel11(hereinafter “panel”) displaying a visual image using a gas discharge, a chassis base17attached on a rear surface of panel11, and driving boards15mounted in the rear of chassis base17and electrically connected to panel11to apply driving signals to panel11.

A heat dissipation sheet13and a double coated tape (not shown) may be further interposed between the rear surface of panel11and the front surface of chassis base17.

Heat dissipation sheet13conducts and disperses the heat generated from panel11in a plane direction. Heat dissipation sheet13may be made from a high thermal-conductive material such as an acryl-based material, a graphite-based material, a metal-based material, or a carbon nanotube-based material.

Since panel11and chassis base17are attached to each other by the double coated tape, heat dissipation sheet13may closely contact the rear surface of panel11and the front surface of chassis base17.

Panel11is constructed with front and rear substrates111and211. A space defined between front and rear substrates111and211is divided to form discharge cells. The discharge cells define respective sub-pixels each corresponding to a minimum unit for displaying an image. Address electrodes and display electrodes (e.g., paired sustain and scan electrodes that are not shown) cross each other along the discharge cells. The image is visually displayed by a gas discharge generated within the discharge cells.

Meanwhile, the address and display electrodes are electrically connected to the driving boards15to control the gas discharge of the discharge cells.

Each driving boards15is constructed with a board63and a circuit devices61installed on board63. Driving boards15may be fixed on chassis base17by screws19. Board63is mainly made from a printed circuit board (PCB) on which a circuit pattern is printed. InFIG. 1, for convenience, boards without circuit devices are illustrated for some of driving boards15. It should be regarded, however, that circuit devices61are installed on the boards.

Circuit device61installed on board63selectively includes a heat dissipation plate51. As circuit devices61, a surface mounted device may be used for the integration of driving board15.

Driving boards15include an image process/control board115, an address driving board215, a scan driving board315, a sustain driving board415, and a power board515, which are functional blocks.

Image process/control board115generates a control signal required for driving the address and display electrodes by receiving an external image signal, and transmits the control signal to address driving board215and scan driving board315or power board515.

Address driving board215generates an address pulse and applies the same to the address electrodes. Scan driving board315generates a scan or sustain pulse and applies the same to the scan electrode. Power board515supplies electrical power to drive the plasma display device.

A front cabinet (not shown) is installed in front of panel11and a back cover (not shown) is installed in the rear of chassis base17. Therefore, an overall outer appearance of the plasma display device is defined by the front cabinet and the back cover.

The following will describe the heat dissipation plate installed on the circuit device in detail with reference toFIG. 2.FIG. 2is a schematic perspective view of the heat dissipation plate installed on the circuit device as a first embodiment of the principles of the present invention.

Heat dissipation plate51is constructed with a main body51aand a plurality of heat dissipation fins51cinstalled on main body51a.

Main body51ahas a planar bottom surface41that can surface-contact circuit device61. Heat dissipation fins51care installed on an opposite surface42to the planar bottom surface41. As the contact area between heat dissipation plate51and circuit device61increases, the heat dissipation efficiency increases. Main body51amay be formed to be larger than the circuit device.

Heat dissipation fins51cextend from surface42of main body51ain a normal direction to surface42of main body51. By heat dissipation fins51c, the contact area between heat dissipation plate51and the ambient air increases, thereby improving the heat dissipation efficiency of heat dissipation plate51. At this point, heat dissipation fins51care spaced apart from each other by a certain distance.

According to the present embodiment, a weight member53is further installed on at least one of heat dissipation fins51c. Weight member53increases the weight of the heat dissipation fin51con which weight member53is installed. Therefore, when heat dissipation fins51cvibrate, the vibration frequency is varied with respect to different heat dissipation fin. That is, as the weight of heat dissipation fin51con which weight member53is installed increases, a vibration frequency is lowered. Heat dissipation fins51con which weight member53is not installed, however, have a relatively high vibration frequency. Therefore, the vibration frequencies between heat dissipation fins51care different from each other and thus interfere with each other. As a result, the overall vibration is reduced.

On the contrary, in the contemporary heat dissipation plate, since the weights of the dissipation fins are identical to each other and thus the vibration frequencies of the heat dissipation fins are the same, the vibration is undesirably boosted. Furthermore, since the vibration frequency of the heat dissipation fin is close to the proper vibration of the heat dissipation plate, the amplitude of the vibration increases and thus the vibration further increases.

FIG. 3is a sectional view taken along line III-III ofFIG. 2. As shown inFIG. 3, circuit device61is installed on board63and heat dissipation plate51is installed on circuit device61as a first embodiment of the principles of the present invention. InFIG. 3, an example where circuit device61is surface mounted is illustrated.

Main body51aof heat dissipation plate51is coupled to circuit device61by a bonding member71. Here, bonding member71may be made from a double coated tape, an adhesive agent, or silicon. Since the silicon is phase-changed from a solid state to a gel state, the working efficiency may be improved when the silicon is used as bonding member71.

Heat dissipation fins51care formed to extend from main body51ain a perpendicular direction with respect to main body51a.

Weight members53are installed on the outermost heat dissipation fins51cto increase the weights of the outermost heat dissipation fins51c.

Weight members53may be installed on the corresponding heat dissipation fin51cby a bonding member531. Alternatively, weight members53may be integrally installed on the corresponding heat dissipation fin51cby welding. Bonding member531may be a double coated tape, an adhesive agent, or silicon.

Weight member53may be made from a material that is heavy for its volume while having a relatively low elastic coefficient and low rigidity. For example, weight member53may be made from a high polymer such as soft rubber.

As described above, since weight member53is selectively formed on heat dissipation fin51c, there is a weight difference between heat dissipation fins51con which weight member53is formed and heat dissipation fins51con which no weight member53is formed. That is, the outermost heat dissipation fins51con which the respective weight members53are installed are heavier than the rest of heat dissipation fins51con which no weight member is mounted.

As a result, the vibration frequencies generated by the vibrations of heat dissipation fins51cduring the operation of circuit device61become different from each other. That is, the vibration frequencies of the outermost heat dissipation fins51care lowered due to weight members53. Therefore, the lowered vibration frequencies interfere with the vibration frequencies of the rest of heat dissipation fins51con which weight members51are not installed, thereby reducing the noise generated by heat dissipation plate51.

FIG. 6is a graph illustrating a comparison result between noises measured at a heat dissipation plate on which weight members are installed (case1inFIG. 6) and a heat dissipation plate on which no weight member is installed (case2inFIG. 6). As shown in the graph ofFIG. 6, it can be noted that the noise of the heat dissipation plate of this embodiment is lowered at frequencies of a 1.6K-band and a 5.0K-band.

FIG. 4shows an embodiment where weight members53are randomly installed on heat dissipation fins51c. In the embodiment ofFIG. 3, weight members53are installed on the respective outermost heat dissipation fins51cso that heat dissipation plate51is symmetrically formed. In the embodiment ofFIG. 4, however, weight members53are randomly installed on some of heat dissipation fins51cin no particular order.

In the above embodiments ofFIGS. 3 and 4, an example where some of heat dissipation fins51cbecome different in weight from the rest of heat dissipation fins51cby installing weight members53thereon is illustrated. Alternatively, it is also possible to make some of heat dissipation fins51cdifferent in weight from the rest of heat dissipation fins51cby increasing the weights thereof while identically maintaining the shapes of heat dissipation fins51c. Still alternatively, as shown inFIG. 5, heat dissipation fins81cmay be different in weight from the rest of heat dissipation fins81cby changing the shape thereof.

FIG. 5shows an example where some of the heat dissipation fins are different in weight from the rest of the heat dissipation fins by varying the thickness of the heat dissipation fin.

Referring toFIG. 5, a heat dissipation plate81installed on a circuit device61is constructed with a main body81aand heat dissipation fins81c. Heat dissipation fins81cinclude a plurality of first heat dissipation fins811and a plurality of second heat dissipation fins813. Main body81ais coupled to circuit device61by a bonding member71.

Heat dissipation fins81cextend normally from main body81a. At this point, some of heat dissipation fins81cmay be different in weight from the rest of heat dissipation fins81c.

That is, each of first heat dissipation fins811has a fist thickness t1while each of second heat dissipation fins813has a second thickness t2greater than first thickness t1. Second heat dissipation fins813that are thicker than first heat dissipation fins811are disposed between first heat dissipation fins811.

Since second heat dissipation fins813are thicker than first heat dissipation fins811, second heat dissipation fins813are heavier than first heat dissipation fins811. Therefore, when heat dissipation plate81vibrates, the vibration frequencies of second heat dissipation fins813are lower than those of first heat dissipation fins811.

As a result, when heat dissipation plate81vibrates, the vibration frequencies of second heat dissipation plates813interfere with those of first heat dissipation plates811, thereby reducing the noise generated by heat dissipation plate81.

According to the above-described present embodiment, since the vibration frequencies of some of the heat dissipation fins are different from those of the rest of the heat dissipation fins due to a weight difference between them, the vibration frequencies of the heat dissipation fins interfere with each other, thereby reducing the noise caused by the vibration of the heat dissipation plate.

Although exemplary embodiments of the present invention have been described in detail hereinabove, it should be clearly understood that many variations and/or modifications of the basic inventive concept taught herein still fall within the spirit and scope of the present invention, as defined by the appended claims.