Abstract:
A plasma display device that enhances heat dissipation from a Plasma Display Panel (PDP) and additionally increases the efficiency in heat dissipation from driving circuit boards includes: a chassis base having a plate portion and a side portion; a Plasma Display Panel (PDP) adapted to be attached to a first side of the chassis base; and driving circuit boards adapted to be attached to the plate portion on a second side of the chassis base, the second side of the chassis base being opposite to the first side of the chassis base; wherein the side portion is bent toward the PDP on an edge of the plate portion and includes air vents; and wherein the side portion includes a flange consisting of a bent edge of the side portion, the flange adapted to be attached to an edge of the PDP.

Description:
CLAIM OF PRIORITY  
       [0001]     This application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C. §19 from an application for PLASMA DISPLAY DEVICE earlier filed in the Korean Intellectual Property Office on 19 May 2004 and there duly assigned Serial No. 10-2004-0035471.  
       BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to a plasma display device and, in particular, to a plasma display device having a heat dissipation structure to induce a natural convection flow in the front and back sides of a Plasma Display Panel (PDP).  
         [0004]     2. Description of the Related Art  
         [0005]     It is well known that a plasma display device uses a plasma generated by gas discharge to produce an image on a Plasma Display Panel (PDP). The plasma display device comprises: a PDP; a chassis base having a first side to support the PDP; and driving circuit boards attached to a second side of the chassis base, the second side of the chassis base being opposite to the first side of the chassis base where the PDP is attached; wherein the driving circuit boards are electrically connected to sustain electrodes and address electrodes of the PDP via a flexible printed circuit and connectors.  
         [0006]     Generally, the PDP is a weak component in terms of mechanical strength because its structure is made of two glass substrates. Therefore, a chassis base made of a metallic material is used to give additional mechanical strength to the PDP for maintaining the mechanical stability.  
         [0007]     Besides the role of maintaining the mechanical strength of the PDP, the chassis base serves to fix the driving circuit boards, to dissipate heat from the PDP, and to ground the Electro Magnetic Interference (EMI) of the PDP.  
         [0008]     The PDP is attached to a first side of the chassis base, and the driving circuit boards are attached to a second side of the chassis base, opposite to the first side of the chassis base. Instead of a screw connection, which has a difficulty in forming a screw hole on the glass substrate of the PDP, double-sided tape is used to attach the PDP to the first side of the chassis base. On the second side of the chassis base, bosses are formed where the driving boards are fixed by set screws.  
         [0009]     U.S. Pat. No. 5,971,566 discusses a structure for attaching a PDP to the chassis base as described above. A heat conduction medium is inserted between the chassis base and the PDP. The chassis base dissipates the heat conducted from the PDP via the heat conduction medium and from the driving boards.  
         [0010]     Such a plasma display device connects the PDP and the chassis base via double-sided tape, which blocks contact of the heat conduction medium with the air. As a result, the heat from the PDP is mainly dissipated by natural convection on the front side of the PDP and is partially conducted through the chassis base to the driving circuit boards. This prevents efficient heat dissipation from the PDP and the printed circuit boards.  
       SUMMARY OF THE INVENTION  
       [0011]     In accordance with the present invention, a plasma display device is provided in which heat from the PDP and the driving circuit boards is dissipated efficiently.  
         [0012]     In one exemplary embodiment, a plasma display device comprises: a chassis base having a plate portion and a side portion; a Plasma Display Panel (PDP) adapted to be attached to a first side of the chassis base; and driving circuit boards adapted to be attached to the plate portion on a second side of the chassis base, the second side of the chassis base being opposite to the first side of the chassis base; wherein the side portion is bent toward the PDP on an edge of the plate portion and includes air vents; and wherein the side portion includes a flange consisting of a bent edge of the side portion, the flange adapted to be attached to an edge of the PDP.  
         [0013]     The plate portion preferably has a plurality of pressing rod apertures arranged at positions corresponding to the edge of the PDP.  
         [0014]     At least one reinforcing member is preferably arranged between a central area of the plate portion and a corresponding central area of the PDP.  
         [0015]     The reinforcing member is preferably arranged to extend vertically along a back side of the PDP.  
         [0016]     Air vents are preferably arranged in top and side portions along the top and the bottom edges of the plate portion.  
         [0017]     Air vents are alternatively preferably arranged in the top, bottom, left, and right side portions along the top, bottom, left, and right edges of the plate portion.  
         [0018]     The flange is preferably bent parallel to the plate portion toward a center of the plate portion.  
         [0019]     The flange is alternatively preferably bent parallel to the plate portion toward an outside of the plate portion.  
         [0020]     An edge of the PDP is preferably attached to the flange with double-sided tape. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0021]     A more complete appreciation of the present invention, and many of the attendant advantages thereof, will be readily apparent as the present invention becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings in which like reference symbols indicate the same or similar components, wherein:  
         [0022]      FIG. 1  is a perspective view of a disassembled plasma display device according to a first embodiment of the present invention.  
         [0023]      FIG. 2  is a partial perspective view of the process to attach the Plasma Display Panel (PDP) to the chassis base.  
         [0024]      FIG. 3  is a side cross-sectional view of the assembled plasma display device of the first embodiment taken along line A-A of  FIG. 1 .  
         [0025]      FIG. 4  is a side cross-sectional view of an assembled plasma display device of a second embodiment taken along line A-A of  FIG. 1 .  
         [0026]      FIG. 5  is a schematic perspective view of a disassembled plasma display device according to a third embodiment of the present invention.  
         [0027]      FIG. 6  is a side cross-sectional view of the assembled plasma display device of the third embodiment taken along line B-B of  FIG. 5 .  
         [0028]      FIG. 7  is a side cross-sectional view of an assembled plasma display device of a fourth embodiment taken along line B-B of  FIG. 5 . 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0029]     As shown in the drawings, a plasma display device in accordance with a first embodiment of the present invention includes: a PDP  11  producing an image by a gas discharge; a heat conduction medium  13  attached to a back side of the PDP  11  and dissipating heat from the PDP  11  in the plane direction; a chassis base  15  supporting the PDP  11 ; and driving circuit boards  17  attached to the chassis base  15  and driving the PDP  11 .  
         [0030]     Since the PDP  11  is a plasma display panel that produces an image by a gas discharge, and the present invention relates to a structure for connecting the PDP with other components of the plasma display device, a detailed description of the PDP itself has been omitted.  
         [0031]     The heat conduction medium  13  is attached to the back side of the PDP  11  to dissipate, by thermal conduction, heat generated from the PDP  11  during the gas discharge. The heat conduction medium  13  is a sheet structure as shown in  FIG. 1 .  
         [0032]     The chassis base  15  supports the PDP  11  and is arranged on the back side of the PDP  11  and spaced away from the heat conduction medium  13  attached to the back side of the PDP  11 . Thus, the chassis base  15  serves to support the PDP  11  so as to supplement the mechanical strength of the PDP  11  made of glass and to hold the driving circuit boards  17 . It is preferable for the chassis base l 5  to have an efficient structure for heat dissipation from the PDP  11 .  
         [0033]     The chassis base  15  is formed to have a structure for inducing natural convection between the chassis base  15  and the back side of the PDP  11 , to be exact, the heat conduction medium  13 . In particular, the natural convection flow is preferably in the vertical direction with respect to the chassis base  15  and the PDP  11 . The chassis base  15  consists of a plate portion  15   a , side portions  15   b , and flanges  15   c.    
         [0034]      FIG. 2  is a partial perspective view of the process to attach the plasma display panel to the chassis base.  FIG. 3  is a side cross-sectional view of the assembled plasma display device of the first embodiment taken along line A-A of  FIG. 1 .  
         [0035]     As shown in the drawings, the plate portion  15   a  is a basis of the chassis base  15  and is preferably formed into a sheet structure where the driving circuit boards  17  can be mounted. However, the sheet structure may vary in shape, as long as the driving circuit boards  17  can be mounted. Natural convection flow is induced in the gap c between the back side of the PDP  11  and the plate portion  15   a , and a plurality of slots (not shown) extending vertically are further provided in the plate portion  15   a  for efficient natural convection flow.  
         [0036]     The side portion  15   b  separates the plate portion  15   a  by the gap c from the back side of the PDP  11  to enable the natural convection flow therebetween. The shape of the side portion  15   b  depends on the shape of the plate portion  15   a , and generally, the side portions  15   b  are formed by bending all four edges of the plate portion  15   a . The side portions  15   b  may be formed along only two edges of the plate portion  15   a : the top and bottom edges, or the right and left edges of the plate portion  15   a . Therefore, the side portion  15   b  is formed by bending the plate portion  15   a  toward the PDP  11  and determines the height of the natural convection flow by the height h of the bent portion. Since the depth of the plasma display device is proportional to the height h of the side portion  15   b , it is preferable to minimize the height h of the side portion  15   b  while maintaining the natural convection flow. As a result, a relatively thin device can be obtained with enhanced heat dissipation from the PDP  11  by natural convection.  
         [0037]     The side portion  15   b  has at least one air vent  23  and preferably a plurality of air vents  23 . As shown in  FIG. 1 , the air vents  23  may be formed in the top and bottom side portions  15   b  only, or formed in the top, bottom, right, and left side portions  15   b . In the case that the air vents  23  are formed in all of the top, bottom, right, and left side portions  15   b , the natural convection is more effective than the case with the air vents  23  in the top and bottom side portions  15   b  only.  
         [0038]     The natural convection induced between the PDP  11  and the chassis base  15  decreases the temperature of the PDP  11  effectively by dissipating the heat from the PDP  11  on the front side and the back side of the PDP  11 . Additionally, the natural convection dissipates the heat effectively from the driving circuit boards  17  attached on the chassis base  15 .  
         [0039]     The flange  15   c  is formed by bending the edge of the side portions  15   b  and serves to facilitate the attachment of the chassis base  15  to the corresponding edges of the PDP  11 . Therefore, the flange  15   c  may not be formed when the side portion  15   b  has a sufficient contact area at the end portion with the PDP  11  for strong attachment between the PDP  11  and the side portion  15   b . In this case, the end portion of the side portion  15   b , corresponding to the edge of the PDP  11 , serves as the flange  15   c.    
         [0040]     The flange  15   c  is formed parallel to the plate portion  15   a  by bending the edge of the side portion  15   b  toward the center of the plate portion  15   a . The flange  15   c  is preferably bent by a right angle from the side portion  15   b  when the side portion  15   b  is bent by a right angle from the plate portion  15   a . The flange  15   c  is attached on the edge of the back side of the PDP  11  by means of double-sided tape  25  and provides sufficient contact area between the chassis base  15  and the PDP  11  for a strong attachment therebetween.  
         [0041]     Near the edge of the plate portion  15   a  corresponding to the edge of the PDP  11 , pressing rod holes are formed  27  that are for the secure attachment between the narrow flange  15   c  of the chassis base  15  and the edge of the back side of the PDP  11 . In other words, the pressing rod holes  27  are formed at positions in the plate portion  15   a  corresponding to the flange  15   c . The pressing rod  29  is inserted into the pressing rod holes  27  so as to push the flange  15   c  to the edge of the back side of the PDP  11  for firm contact therebetween. That increases the bonding strength of the double-sided tape  25  inserted between the flange  15   c  and the edge of the back side of the PDP  11 . For that reason, it is preferable to form a plurality of pressing rod holes  27  along the edge of the plate portion  15   a.    
         [0042]      FIG. 4  is a side cross-sectional view of an assembled plasma display device of a second embodiment taken along line A-A of  FIG. 1 .  
         [0043]     The plasma display device of the second embodiment, as shown in  FIG. 4 , has a same or similar overall structural composition to that of the first embodiment. Therefore, an explanation follows only for the differing components thereof.  
         [0044]     In the second embodiment, a reinforcing member  31  is further provided in the plate portion  15   a,  which is the same as in the first embodiment. While the structural stability of the plate portion  15   a  of the first embodiment is provided with the side portions  15   b  only, the reinforcing member  31  gives additional structural support to both the central plate portion  15   a  and the central area of the PDP  11  that is spaced away from the plate portion  15   a . Therefore, the plate portion  15   a  supports the PDP  11  more securely. It is preferable to form the reinforcing member  31  in the vertical direction. In a further exemplary embodiment, a plurality of reinforcing members  31  may be formed as long as the natural convection flow is not hindered.  
         [0045]      FIG. 5  is a perspective view of a disassembled plasma display device according to a third embodiment of the present invention.  FIG. 6  is a side cross-sectional view of the assembled plasma display device of the third embodiment taken along line B-B of  FIG. 5 .  
         [0046]     The plasma display device of the third embodiment, as shown in the drawings, has a same or similar overall structural composition to that of the first embodiment. Therefore, an explanation follows only for the differing components thereof.  
         [0047]     In contrast to the first embodiment, the flange  15   c  of the third embodiment is formed parallel to the plate portion  15   a  by bending the edge of the side portion  15   b  toward the outside of the plate portion  15   a.    
         [0048]     Compared to the first embodiment, the same or similar bonding strength between the flange  15   c  and the PDP  11  is achievable without the pressing rod  29 . Therefore, it is an advantage of the third embodiment that the pressing rod holes  27  are not necessary in the plate portion  15   a.    
         [0049]      FIG. 7  is a side cross-sectional view of an assembled plasma display device of a fourth embodiment taken along line B-B of  FIG. 5 .  
         [0050]     The plasma display device of the fourth embodiment, as shown in  FIG. 7 , has a same or similar overall structural composition to that of the third embodiment. Therefore, an explanation follows only for the differing components thereof.  
         [0051]     In the fourth embodiment, the plate portion  15   a  has an additional reinforcing member  31  that is the same as that of the second embodiment. The reinforcing member  31  gives additional structural support to both the central plate portion  15   a  and the central area of the PDP  11  so that the plate portion  15   a  supports the PDP  11  more securely. As in the second embodiment, the reinforcing member  31  is preferably formed in the vertical direction, and a plurality of reinforcing members  31  may be formed.  
         [0052]     Although exemplary embodiments of the present invention have been described in detail hereinabove, it should be understood that many variations and/or modifications of the basic inventive concept taught therein will still fall within the spirit and scope of the present invention, as defined in the appended claims.  
         [0053]     In accordance with the plasma display device of the present invention, the chassis base includes the plate portion, the side portions, and the flanges to provide the air vents in the side portions and to separate the chassis base from the back side of the PDP for inducing the natural convection along the back side of the PDP. As a result, the heat dissipation from the PDP is enhanced by the natural convection on both sides of the PDP. Furthermore, efficient heat dissipation from the driving circuit boards is obtained by blocking effectively the heat conduction from the PDP though the chassis base to the driving boards.