Abstract:
A display apparatus includes a display panel for displaying an image, a chassis base for supporting the display panel, at least one boss protruding from the chassis base for supporting a plurality of circuit boards for driving the display panel, and at least one embossment protruding from the chassis base in a region around the at least one boss.

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATION 
   This application claims priority to and the benefit of Korean Patent Application No. 10-2006-0064455, filed on Jul. 10, 2006, in the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference. 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a display apparatus, and more particularly, to a chassis base for a display apparatus. 
   2. Description of the Related Art 
   Recently, flat panel display apparatus such as liquid crystal displays, plasma display panels, field emission displays, and vacuum fluorescent displays have been developed. 
   A plasma display panel is a flat panel display device that displays an image using a gas discharge. Plasma display panels have become popular since they can be manufactured to be large and thin, with a wide viewing angle, and can display high quality images. A conventional plasma display apparatus includes a plasma display panel combining a front panel and a rear panel. 
   SUMMARY OF THE INVENTION 
   A display apparatus is provided including a display panel for displaying an image, a chassis base for supporting a plurality of circuit boards for driving the display panel, an embossment protruding from the chassis base in a region around at least one boss, the at least one boss protruding from the embossment. In one exemplary embodiment, the at least one boss is press fitted to the embossment and a periphery of each embossment includes at least one arc section. The embossment may have an elongated shape in the region around the at least one boss. 
   A method of combining a chassis base and a boss is provided including forming an embossment protruding from a region of the chassis base, forming a hole in the embossment, disposing a die on a surface of the embossment of the chassis base in a direction opposite to which the embossment protrudes, providing a boss having a shaft portion and a press-fittable base portion at an end of the shaft portion, inserting the shaft portion into the hole, and press fitting the base portion with the hole using a punch. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an exploded perspective view of circuit boards mounted to a plasma display device according to an exemplary embodiment of the present invention. 
       FIG. 2  is a perspective view illustrating a press fitting of a boss to a chassis base of a plasma display apparatus according to an exemplary embodiment of the present invention. 
       FIG. 3  is a perspective view illustrating a press fitting of two bosses to a chassis base of a plasma display apparatus according to another exemplary embodiment of the present invention. 
       FIG. 4   a  is a perspective view illustrating a modified version of a press fitting of two bosses to a chassis base of a plasma display apparatus according to yet another embodiment of the present invention. 
       FIG. 4   b  is a cross sectional view of the press fitting of claim  4   a.    
       FIG. 5  is a perspective view illustrating a press fitting of three bosses to a chassis base of a plasma display apparatus according to still another embodiment of the present invention. 
       FIG. 6  is a cross-sectional view illustrating a press fitting of a boss to a chassis base according to yet another embodiment of the present invention. 
       FIG. 7  is a flow chart illustrating a method of combining a boss with a chassis base according to still another embodiment of the present invention. 
   

   DETAILED DESCRIPTION 
   Referring now to  FIG. 1 , a plasma display device includes a plasma display panel  1  mounted to a chassis base  10  by a fixing means  7  with a thermal conductive medium  6  located on one surface of the rear panel. The plasma display panel  1  includes a front panel  2  and a rear panel  3 . Circuit boards  4  may be mounted to the chassis base  10  using bosses  15 , as described in more detail below. 
     FIGS. 2-5  show several exemplary embodiments of the present invention including bosses  15 ,  25 ,  35 ,  45  press-fitted to a respective chassis base  10 ,  20 ,  30 ,  40 ,  50 . 
   A plasma display device includes a plasma display panel including a front panel and a rear panel. When the plasma display panel is a three-electrode type surface discharge AC PDP, the front panel includes a transparent front substrate, sustain electrode pairs formed on the front substrate to generate a sustain discharge, a front dielectric layer covering the sustain electrode pairs, and a protective layer coated on the front dielectric layer. The rear panel includes a rear substrate, address electrodes crossing the sustain electrode pairs, a rear dielectric layer covering the address electrodes, barrier ribs that form discharge cells by defining a discharge space, and phosphor layers coated on the discharge cells. 
   After the front and rear panels are combined with each other, a discharge gas is injected into the discharge cells. A voltage is then applied to the sustain electrode pairs and the address electrodes, generating a gas discharge in the discharge cells. When the gas discharge is generated, ultraviolet rays are emitted, exciting the phosphor layers to emit visible light. Thus, an image is displayed using the visible light emitted from the discharge cells. The plasma display panel according to exemplary embodiments of the present invention may be of various types including a three-electrode type surface discharge AC PDP. 
   A thermal spread sheet (not shown) may be attached to a rear surface of the plasma display panel to dissipate heat generated during the operation of the plasma display panel. The chassis base  10  may be disposed on the rear of the plasma display panel, and may be combined with the plasma display panel using an adhesive element, such as a double-sided tape. A plurality of circuit boards that generate electrical signals for applying a voltage to the sustain electrode pairs and the address electrodes of the plasma display panel are mounted on the rear of the chassis base  10 . In order to apply a voltage to each of the sustain electrode pairs and the address electrodes of the plasma display panel, terminal units of each of the sustain electrode pairs and the address electrodes of the plasma display panel are electrically connected to terminals of the circuit boards by signal transmitting elements. 
   The chassis base  10  according to one exemplary embodiment is formed from a steel group material such as an aluminum-zinc alloy coated steel sheet or EGI (electrolytic galvanized iron) to a thickness of about 1.0 mm or less, for example, about 0.8 mm, and thus, the chassis base  10  is lightweight. A plasma display panel is supported by the front of the chassis base  10  and the circuit boards are supported by the rear of the chassis base  10 . Accordingly, the chassis base  10  is required to have a high strength and therefore, a reinforcing member may be attached to the rear of the chassis base  10 . 
   The circuit boards may be combined with the chassis base  1  using a screw combining method in which bosses  15  and screws are used. More specifically, the bosses  15  are coupled to the chassis base  10 , screw threads being formed on internal surfaces of the bosses  15 . The circuit boards can be combined with the chassis base  10  when the screws are screwed into the threads of the bosses  15  through holes in the circuit boards. 
   When the bosses  15  are press fitted to the conventional thin steel chassis base  10 , the chassis base  10  may deform, reducing an overall strength of the chassis base  10 . As depicted in  FIGS. 2 through 5 , embossments  10   a ,  20   a ,  30   a ,  30   b , and  40   a  are formed around bosses  15 ,  25 ,  35 , and  45  of chassis bases  10 ,  20 ,  30 , and  40 , respectively, to prevent the chassis bases from deforming. 
   Referring to  FIG. 2 , the embossment  10   a  protrudes from a surface of the chassis base  10  in a region around the boss  15  in the same direction in which the boss  15  protrudes. The embossment  10   a  may have a generally circular shape. Referring to  FIG. 3 , the embossment  20   a  protrudes from a surface of the chassis base  20  in a region around the two bosses  25  in the same direction in which the two bosses  25  protrude. The embossment  20   a  may be formed so that both ends are curved into arcs having radii less than or equal to R from the centerlines of the two bosses  25 , where R is a distance about 40 mm or less. 
   Referring to  FIGS. 4   a  and  4   b , an embossment of the two bosses  35  includes a first embossment  30   a  and a second embossment  30   b . More specifically, the first embossment  30   a  protrudes from a surface of the chassis base  30  in a region around the two bosses  35  in the same direction in which the two bosses  35  protrude, and the second embossment  30   b  is recessed from a surface of the first embossment  30   a  in a direction opposite to which the bosses  35  protrude. A radius of arc ends of the second embossment  30   b  may be less than a radius of arc ends of the first embossment  30   a . Accordingly, an increase in the height of the bosses  35  due to the embossing processing may be prevented. 
   Referring to  FIG. 5 , an embossment  40   a  protrudes from a surface of the chassis base  40  in the same direction in which the three bosses  45  protrude. The embossment  40   a  may have a shape in which three circular arcs are formed in regions around the three bosses  45  and have radii less than or equal to R from the centerlines of the three bosses  45 , where R is a distance of about 40 mm or less. Accordingly, when the three bosses  45  are disposed in an “L” shape, the embossment  40   a  also has a corresponding “L” shape. 
     FIG. 6  is a cross-sectional view illustrating a press fitting of the boss  15  to the chassis base  10  according to an exemplary embodiment of the present invention, and  FIG. 7  is a flow chart of a method of combining a boss with a chassis base according to another exemplary embodiment of the present invention. A method of forming the embossment  10   a  in the chassis base  10  and the method of combining the boss  15  with the embossment  10   a  will now be described with reference to  FIGS. 6 and 7 . 
   With reference to  FIG. 6 , the embossment  10   a  is formed to protrude from the surface of the chassis base  10  in the same direction in which the boss  15  protrudes (S 10 ). The embossment  10   a  may be formed in the chassis base  10  using a conventional embossing processing method. More specifically, the embossment may be formed by pressing the chassis base  10  into a die  13  with a punch  14 , the punch  14  and the die  13  being placed on opposite sides of the chassis base  10 . As such, the embossment  10   a  is formed to protrude from the surface of the chassis base  10  in the same direction in which the boss  15  protrudes. 
   A hole may then be formed in a region of the embossment  10   a  where the boss  15  is will be press fitted (S 20 ). The hole may be located in the center of the circular embossment  10   a . An outer diameter of the head portion of the boss  15  is dimensioned to be larger than an inner diameter of the hole of the chassis base such that the head portion of the boss  15  can pass through the hole in the chassis base when press fitted. The die  13  is disposed on a surface of the embossment  10   a  on the chassis base  10  facing a direction in which the embossment  10   a  protrudes (S 30 ). In one exemplary embodiment, the die  13  may be disposed such that leg portions of the die  13  contact the rear surface of the embossment  10   a.    
   The boss  15  may then be inserted into the hole of the embossment  10   a  (S 40 ). When a lower part of the boss  15  is sufficiently inserted into the hole of the embossment  10   a , the lower part of the boss  15  is pressed into the embossment  10   a  using the punch  14  (S 50 ). When the boss  15  is inserted into the hole of the embossment  10   a , stress is generated in regions indicated by dotted circles in  FIG. 6  between the chassis base  10  and the boss  15  due to the pressing force of the punch  14 . However, the transmission of the stress is limited to the embossment  10   a . Hence, the deformation of the chassis base  10  due to the stress is limited to a particular region of the chassis base  10 , more specifically, to the region of the embossment  10   a  as indicated by the arrows in  FIG. 6 . Accordingly, the deformation of the chassis base  10  due to press fitting process is minimized, and as a result, the strength of the chassis base  10  is not reduced. 
   A radius R from the centerline of the boss  15  inserted into the center of the embossment  10   a  to an edge of the embossment  10   a  may be approximately 40 mm or less, and in one exemplary embodiment, may be between about 18 to 20 mm. If the radius R is greater than 40 mm, the deformation of the chassis base  10  may not be able to be limited to a particular region. As a result, the strength of the chassis base  10  is reduced, thereby reducing the reliability of the chassis base  10 . 
   Similarly, in one exemplary embodiment, the embossment  20   a  has a shape that includes end arcs each having a radius of between about 18 to 20 mm from the centerline of each of the bosses  25  and the embossment  40   a  has an “L” shape that includes arcs of three circles each having a radius of 18 to 20 mm from the centerline of each of the bosses  45 . In the exemplary embodiments of the present invention, an embossment is formed in a region around one to three bosses. However, the present invention is not limited thereto and an embossment may be formed around four or more bosses. 
   The method of combining the two bosses  35  with the chassis base  30  in which the first embossment  30   a  and the second embossment  30   b  are formed as depicted in  FIG. 4  is similar to the method described above. However, the first and second embossments  30   a ,  30   b  may be sequentially formed in the chassis base  30 . Hence, after the first embossment  30   a  is formed to protrude in a region around the two bosses  35  from a surface of the chassis base  30  in a direction in which the bosses protrude, the second embossment  30   b , which has a arc radius less than the first embossment  30   a , is recessed from the surface of the first embossment  30   a  in a direction opposite to the direction in which the two bosses  35  protrude. Then, the die is disposed on the surface of the chassis base  30  facing the surface from which the first embossment  30   a  protrudes. 
   Although not shown, the plasma display apparatus may further include a front cabinet and a rear cabinet. The front and rear cabinets protect the plasma display apparatus from external impact. The rear cabinet may also block the emission of electromagnetic waves from the chassis base. 
   Embodiments of the present invention are not limited to those described herein, but rather may be applied to any display apparatus, such as a liquid crystal display (LCD), an organic light-emitting display (OLED), or an FED including a display panel and a chassis base on which circuit boards for driving the display panel are mounted, and in which the coupling bosses with the chassis base is required. 
   While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by one of ordinary skill in the art that various changes in form and details may be made thereto without departing from the spirit and scope of the present invention as defined by the following claims.