Abstract:
There is provided a plasma display apparatus capable of reducing the cost and complexity of fitting circuit boards to a chassis base. The plasma display apparatus comprises a plasma display panel (PDP), a chassis base having a first side attached to the PDP, the first side also supporting the PDP, and circuit boards provided at a second side of the chassis base opposite to the first side attached to the PDP. The chassis base has at least one boss and at least one supporter disposed thereon, which correspond to holes disposed in a circuit board.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
   This application claims priority to and the benefit of Korean Patent Application No. 10-2004-0035138 filed in the Korean Intellectual Property Office on May 18, 2004, which is incorporated herein by reference. 
   BACKGROUND OF THE INVENTION 
   (a) Field of the Invention 
   The present invention relates to a plasma display apparatus, and more particularly, to a plasma display apparatus in which various circuit boards can be effectively fixed to a chassis base. 
   (b) Description of the Related Art 
   It is well-known that a plasma display panel (PDP) forms images by exciting phosphors with vacuum ultraviolet rays caused by gas discharge from discharge cells. The PDP provides excellent display capacity, brightness, contrast and viewing angle, and can be used in a large-sized screen of minimal thickness and weight. 
   A plasma display apparatus employing such a PDP further comprises a chassis base having a first side supporting the plasma display panel, circuit boards fixed to the chassis base on a second side opposite to the first side supporting the PDP, and a case, which surrounds the PDP, chassis base, and circuit boards, and provides an outer appearance for the plasma display apparatus. 
   The case has a front cover positioned at the front side of the PDP and a rear cover positioned at the back side of the PDP. In general, the front cover and the rear cover are detachable from each other. 
   The circuit boards fixed to the chassis base include, for example, a power supply board, an image processing board, a logic board, an address buffer board, a sustain-electrode driving board, and a scan-electrode driving board. The boards are fixed to corresponding bosses on the chassis base with setscrews, and are connected to electrodes of the PDP through electrical connection means such as flexible printed circuits (FPC), which drive the PDP. 
   Since the chassis base has a large number of bosses, a large number of setscrews are required for fitting the circuit boards to the chassis base, thereby increasing manufacturing costs. In addition, since a large number of setscrews need to be handled, the manufacturing process is complex and productivity is decreased. 
   SUMMARY OF THE INVENTION 
   The present invention provides a plasma display apparatus that reduces the cost and complexity of fitting circuit boards to a chassis base. 
   According to an embodiment of the present invention, a plasma display apparatus is provided, which includes: a PDP; a chassis base having a first side attached to the PDP, the first side also supporting the PDP; and circuit boards provided at a second side of the chassis base opposite to the first side attached to the PDP, wherein the chassis base has at least one boss and at least one supporter disposed thereon, for fixing and supporting a circuit board, that correspond with holes disposed in the circuit board 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an exploded perspective view illustrating a plasma display apparatus according to an embodiment of the present invention. 
       FIG. 2  is a partial plan view illustrating a chassis base and circuit boards of the plasma display apparatus according to an embodiment of the present invention. 
       FIG. 3  is a cross-sectional view taken along Line A-A of  FIG. 2 ; 
       FIG. 4  is a partially-enlarged cross-sectional view illustrating a supporter of the plasma display apparatus according to an embodiment of the present invention. 
       FIG. 5  is a perspective view illustrating the supporter of the plasma display apparatus according to an embodiment of the present invention. 
       FIG. 6  is a partially-enlarged cross-sectional view illustrating a supporter of a plasma display apparatus according to a second embodiment of the present invention. 
       FIG. 7  is a perspective view illustrating the supporter of the plasma display apparatus according to another embodiment of the present invention. 
       FIG. 8  is a partially-enlarged cross-sectional view illustrating a supporter of a plasma display apparatus according to a yet another embodiment of the present invention. 
       FIG. 9  is a perspective view illustrating the supporter of the plasma display is apparatus according to yet another embodiment of the present invention. 
   

   DETAILED DESCRIPTION 
   Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. 
   Referring to  FIG. 1 , a plasma display apparatus according to the present invention comprises a PDP  3  for substantially forming images and a chassis base  5 , which is coupled to PDP  3  at a rear side that is opposite to a front side on which images are formed. The plasma display apparatus further comprises a front cover  7  disposed at the front side of PDP  3  and a rear cover  9  disposed at the rear side of chassis base  5 . 
   A heat dissipating sheet (not shown) for transferring heat generated from PDP  3  to chassis base  5  may be disposed between PDP  3  and chassis base  5 . A filter  11  that intercepts electromagnetic waves emitted from PDP  3  may be fixed to front cover  7 . 
   PDP  3  generally has a substantially rectangular shape (i.e., wherein the X axial length is larger than the Y axial length, as shown in  FIG. 1 ). Chassis base  5  has a shape corresponding to the shape of PDP  3  and is made of a material having an excellent thermal conductivity, such as, for example, aluminum. 
   One front side of chassis base  5  is provided with PDP  3  and the other rear side is provided with a plurality of circuit boards  13  necessary for driving PDP  3 . The circuit boards  13  are fixed, substantially by use of setscrews (not shown), to a plurality of bosses (not shown) provided on the rear side of chassis base  5 . 
   The circuit boards  13  fixed onto the rear side of chassis base  5  include a sustain-electrode driving board, a scan-electrode driving board, an image processing board and a switching mode power supply (SMPS) board. It is well-known that circuit boards  13  are formed by mounting various devices (not shown), such as field effect transistors (not shown), on a printed circuit board with lead lines. 
   Looking at  FIGS. 2 ,  3 ,  4 , and  5 , chassis base  5  has bosses  15  and supporters  17  that correspond to holes in circuit boards  13  so as to fit and support them. The circuit boards  13  include boards performing various functions as described above but an address buffer board is exemplified in  FIGS. 2 and 3 . The present invention, however, can be applied to other boards similarly. 
   That is, circuit boards  13  are primarily fixed to chassis base  5  by first placing circuit boards  13  on bosses  15  and supporters  17  and then inserting setscrews  21  into holes  13   a  of the circuit boards  13  to fasten the circuit boards  13  to bosses  15 . Circuit boards  13  are secondarily supported by supporters  17 . 
   Decreasing the number of bosses  15  can decrease a corresponding number of setscrews  21 , thereby reducing the complexity of fitting circuit boards  13  to chassis base  5 . Bosses  15  may be provided at various positions on chassis base  5 . It is preferable, however, that bosses  15  are disposed at positions where the circuit boards  13  can be simply fixed to specific positions of the chassis base  5 , i.e., at positions that correspond to the edges of circuit boards  13 . 
   Taking into consideration that circuit boards  13  have substantially rectangular shapes, bosses  15  may be disposed on chassis base  5  at positions that correspond to the corners of circuit boards  13 . Such an arrangement of bosses  15  can fix the circuit boards  13  with greater stability and decrease the number of setscrews  21  required. 
   In circuit boards  13  that are fixed to chassis base  5  by setscrews  21  in bosses  15  disposed at the corners or edges of circuit boards  13 , gaps between bosses  15  may cause the circuit boards  13  to sag between bosses  15  if these gaps are too large, as shown in the curve indicated by a virtual line (a) in  FIG. 3 . 
   In order to prevent the sag of circuit boards  13 , supporters  17  are provided to have a structure protruding from the chassis base  5  between bosses  15 . Supporters  17  may be formed only at the positions where curving of circuit boards  13  can occur, or may be formed at proper intervals between bosses  15  so as to support several positions of respective circuit boards  13 . 
   Supporters  17  may be formed to have a structure for simply supporting the circuit boards  13 , but it is more preferable that supporters  17  are formed to have a structure capable of preventing the circuit boards  13  from shifting in a direction parallel to the plane of chassis base  5 . In the present embodiment of the invention, a structure of a supporter  17  is shown that can prevent circuit boards  13  from shifting in the direction parallel to the plane of chassis base  5 , as well as enhance the fastening power of setscrews  21 , in addition to supporting circuit boards  13 . 
   Referring to  FIGS. 4 and 5 , each supporter  17  comprises a vertical portion  17   a  and a horizontal portion  17   b . Vertical portion  17   a  is formed integrally with the chassis base  5 , by slitting the chassis base  5  and bending the slit piece away from the rear side of chassis base  5 . As a result, vertical portion  17   a  is perpendicular to the plane of chassis base  5 . Horizontal portion  17   b  is then formed by bending the tip of vertical portion  17   a  so that it is parallel to the plane of chassis base  5 . Horizontal portion  17   b  comes in direct contact with circuit boards  13 . Therefore, it is preferable that the total height of vertical portion  17   a  and horizontal portion  17   b  is equal to the height of bosses  15 , thereby supporting the circuit boards  13  on a plane parallel to the plane of chassis base  5 . Horizontal portions  17   b  support the surfaces of circuit boards  13  that oppose chassis base  5 , thereby preventing circuit boards  13  from sagging between bosses  15 . 
   Horizontal portion  17   b  may be formed in a flat shape so as to merely support the circuit boards  13 , or may further have a projection  17   c  for preventing circuit boards  13  from shifting in the direction parallel to the plane of chassis base  5 . In this case, of course, holes  13   a , into which projections  17   c  can be inserted, are provided in circuit boards  13 . 
   Projection  17   c  may have various shapes. In  FIGS. 4 and 5 , a projection  17   c  is shown that protrudes from horizontal portion  17   b  in the longitudinal direction of vertical portion  17   a . Projection  17   c  can be formed by pressing, or stamping, horizontal portion  17   b . As a result, circuit boards  13  can be stably supported by flat surfaces of horizontal portion  17   b  that are positioned at the sides of projection  17   c , while maintaining the coupling of holes  13   a  and projections  17   c.    
   Referring to  FIG. 6  and  FIG. 7 , supporter  27  according to the another embodiment of the invention comprises a vertical portion  27   a , a horizontal portion  27   b , and a projection  27   c  having a shape different from that of projection  17   c , which was previously described. 
   Projection  27   c  is formed by bending the tip of horizontal portion  27   b  in the longitudinal direction of vertical portion  27   a . It is preferable that projection  27   c  has a width less than that of horizontal portion  27   b  so as to perform the same function as projection  17   c.    
   It is also preferable that projections  17   c  and  27   c  are forcibly inserted into and coupled to holes  13   a  and  13   b , respectively, of circuit boards  13 . 
   One or more supporters  17  and  27  can be provided between bosses  15 . When the gap between bosses  15  is large enough to cause circuit boards  13  to sag, an even number of supporters  17  and  27  can be provided between bosses  15 . 
   In this case, it is preferable that supporters  17  and  27  are symmetrically arranged on chassis base  5 . That is, since the supporters  17  and  27  are bent as described above, they can apply a force toward one supporter  17  or  27  when the supporters  17  and  27  are not bent accurately in the horizontal and vertical directions during the manufacturing process thereof. A symmetrical arrangement of supporters  17  and  27  can cancel this force. That is, the vertical portion and the horizontal portion of one supporter  17  or  27  form a symmetric structure along with the vertical portion and the horizontal portion of the adjacent supporter  17  or  27 . 
   When the number of supporters  17  and  27  is odd, an even number of supporters  17  and  27  may be symmetrically arranged and the remaining supporter  17  or  27  may be disposed on chassis base  5  in a suitable location. 
   Referring to  FIGS. 8 and 9 , supporter  37  according to yet another embodiment of the invention comprises a vertical portion  37   a , a horizontal portion  37   b , and a projection  37   c , which is formed by bending the tip of horizontal portion  37   b , in a similar manner as supporter  27 . Supporter  37  further comprises a vibration-proof pad  40  provided on horizontal portion  37   b . Vibration-proof pad  40 , which suppresses the occurrence of noise due to vibration of circuit boards  13  or chassis base  5 , is interposed between circuit boards  13  and the surface of supporter  37  that contacts the circuit boards. 
   Vibration-proof pad  40  may be also formed on the horizontal portion  17   b  of the supporter  17 . 
   Although a number of exemplary embodiments of the present invention have been described, the present invention is not limited to these embodiments, but may be modified in various forms without departing from the scope of the appended claims, the detailed description, and the accompanying drawings of the present invention. Therefore, it is natural that such modifications are within the scope of the present invention.