Patent Publication Number: US-2006002137-A1

Title: Liquid crystal display apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
      This application claims the benefit of Korean Patent Application No. 2004-0033151, filed on May 11, 2004, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.  
     BACKGROUND OF THE INVENTION  
      1. Technical Field  
      The present disclosure relates to a liquid crystal display, and more particularly, a liquid crystal display (LCD) apparatus using a lamp holder to prevent contact between a light guide plate and a lamp unit.  
      2. Discussion of the Related Art  
      Generally, an LCD apparatus changes transmissivity of liquid crystal cells arranged in a matrix according to video signals, thereby displaying a picture on an LCD panel.  
      Such an LCD apparatus does not emit light for itself, so that a backlight assembly is additionally needed to illuminate the LCD panel displaying a picture.  
      The backlight assembly is classified into a direct type, where a lamp is located as a light source behind the LCD panel and directly emits light to the LCD panel, and an edge type, where the lamp is placed along at least one edge of a light guide plate located behind the LCD panel and indirectly emits the light to the LCD panel via the light guide plate.  
      In the case of the edge type LCD apparatus, the backlight assembly comprises a lamp unit functioning as the light source, and the light guide plate guiding the light of the lamp unit to the LCD panel therethrough.  
      However, because the lamp unit is placed along the light guide plate, contact between the lamp unit and the light guide plate may damage the lamp unit, thereby making the LCD apparatus defective.  
     SUMMARY OF THE INVENTION  
      Accordingly, it is an aspect of the present invention to provide an LCD apparatus using a lamp holder to effectively prevent contact between a light guide plate and a lamp unit.  
      An LCD apparatus, according to an embodiment of the present invention, comprises a light guide plate; a lamp unit placed along at least one side of the light guide plate; and a lamp holder comprising a lamp supporting portion for supporting opposite ends of the lamp unit, and a light guide plate for supporting portion supporting the light guide plate to prevent the light guide plate from contacting the lamp unit.  
      The light guide plate supporting portion may be coupled to the lamp supporting portion.  
      The light guide plate supporting portion may have an approximately U-shaped section and be fitted to the lamp supporting portion.  
      The light guide plate supporting portion may comprise a front portion contacting the light guide plate, and side portions extending and bending from opposite ends of the front portion.  
      The lamp supporting portion may include a relatively soft material, and the light guide plate supporting portion may include a relatively hard material.  
      The light guide plate supporting portion may include a metallic material.  
      The light guide plate supporting portion may form a single body with the lamp supporting portion.  
      An LCD apparatus, according to an embodiment of the present invention, comprises a light guide plate; a light source placed along at least one side of the light guide plate; and a light source holder comprising a first portion for supporting at least one end of the light source, and a second portion for preventing the light guide plate from contacting the light source.  
      The second portion may be coupled to the first portion, may include an approximately U-shaped section and may be fitted around the first portion. The second portion may include a front portion for contacting the light guide plate, and side portions extending from opposite ends of the front portion in a direction approximately perpendicular to the front portion.  
      The first portion may be formed from a softer material than the second portion, wherein the second portion includes a metallic material.  
      The first and second portions may be integrated in a single body. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      Preferred embodiments of the present invention can be understood in more detail from the following descriptions taken in conjunction with the accompanying drawings of which:  
       FIG. 1  is an exploded perspective view of a liquid crystal display according to an embodiment of the present invention;  
       FIG. 2  is a partial view illustrating a lamp holder supporting a lamp unit and a light guide plate in the liquid crystal display of  FIG. 1 ;  
       FIG. 3  is an exploded perspective view of a backlight assembly used in a liquid crystal display according to an embodiment of the present invention; and  
       FIG. 4  is a section view of the liquid crystal display, taken along line IV-IV of  FIG. 3 .  
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      Preferred Embodiments of the invention will be described below in more detail with reference to the accompanying drawings, wherein like reference numerals refer to like elements throughout. This invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Hereinafter, an edge type LCD apparatus will be described representatively.  
      As shown in  FIG. 1 , an LCD apparatus according to a an embodiment of the present invention comprises an LCD panel  10  for displaying a picture thereon, a driver integrated circuit (not shown) driving the LCD panel  10 , a mold frame  20  supporting edges of the LCD panel  10 , a backlight assembly  30  emitting light to the LCD panel  10 , a rear chassis  40  accommodating the backlight assembly  30  therein and supporting the mold frame  20 , and a front chassis  50  coupled with the rear chassis  40  and covering front edges of the LCD panel  10 .  
      The LCD panel  10  comprises a thin film transistor (TFT) array panel  11 , a color filter panel  12  opposite to the TFT array panel  11 , and liquid crystal (not shown) sandwiched between the TFT panel  11  and the color filter panel  12 . Here, the TFT panel  11  and the color filter panel  12  are filled with liquid crystal therebetween and then sealed. Further, the LCD panel  10  comprises a front polarizing plate  13  attached to the front of the color filter panel  12 , and a rear polarizing plate  14  attached to the rear of the TFT panel  11 . In the LCD panel  10 , liquid crystal cells are arranged in a matrix to form pixels, and changed in transmissivity according to video signals transmitted from the driver integrated circuit, thereby displaying a picture.  
      The mold frame  20  is rectangularly shaped along the edges of the LCD panel  10  and supports the LCD panel  10  such that the LCD panel  10  is spaced from the backlight assembly  30 .  
      The backlight assembly  30  comprises a light guide plate  32  disposed in parallel with the LCD panel  10 , a lamp unit  34  provided along at least one side of the light guide plate  32  and emitting light to the light guide plate  32 , and a lamp holder  35  supporting the lamp unit  34  and the side of the light guide plate  32  adjacent to the lamp unit  34 .  
      Further, the LCD apparatus comprises a lamp reflector  36  accommodating the lamp unit  34  therein and reflecting the light emitted from the lamp unit  34  toward the light guide plate  32 , an optical sheet  31  placed in front of the light guide plate  32  and diffusing/concentrating the light emitted toward the LCD panel  10 , and a reflecting sheet  33  placed at the rear of the light guide plate  32 .  
      The light guide plate  32  has an incident surface to receive the light from the lamp unit  34 , an emitting surface being at a right angle to the incident surface and in parallel with the LCD panel  10 , and a rear surface formed with a pattern and guiding the light emitted from the lamp unit  34  toward the emitting surface. Thus, the light guide plate  32  receives the light from the lamp unit  34  through the incident surface, and uniformly emits the light to the LCD panel  10  through the emitting surface. Preferably, the light guide plate  32  is made of a material having sufficient strength and sufficient transmissivity such that the light guide plate  32  is not easily deformed and broken, for example, polymethylmethacrylate (PMMA).  
      The lamp unit  34  comprises a lamp  341  emitting the light, and a terminal  342  provided at an end of the lamp  341 . The terminal  342  is connected to an inverter (not shown) and allows the lamp  341  to receive electric power.  
      The lamp holder  35  protects the connection of the terminal  342  of the lamp unit  34  and the inverter. The lamp holder  35  comprises a lamp supporting portion  351  supporting opposite ends of the lamp unit  34 , and a light guide plate supporting portion  352  supporting the side of the light guide plate  32  adjacent to the lamp unit  34 , thereby preventing the light guide plate  32  from contacting the lamp unit  34 . As shown in  FIG. 2 , the lamp supporting portion  351  and the light guide plate supporting portion  352  are formed as a single body, thereby preventing the light guide plate  32  from contacting the lamp unit  34 .  
      The optical sheet  31  comprises a diffusing sheet  311  for diffusing the light traveling from the light guide plate  32  toward the LCD panel  10  and for preventing the LCD panel  10  from blemishes in order to enhance uniformity of the light, and a prism sheet  312  for allowing the light passing through the diffusing sheet  311  to travel perpendicularly to the optical sheet  31  in order to enhance brightness. Further, the optical sheet  31  additionally comprises a protective sheet  313  to protect the diffusing sheet  311  and the prism sheet  312  from dust, scratches, external impact, foreign material.  
      The reflecting sheet  33  reflects the light that travels in an opposite direction of the LCD panel  10 , toward the light guide plate  32 , thereby reducing loss in light and enhancing uniformity of the light.  
      With this configuration, in the LCD apparatus according to an embodiment of the present invention, the lamp holder  35  supporting the lamp unit  34  prevents the light guide plate  32  from contacting the lamp unit  34  as shown in  FIG. 2 , thereby decreasing damage due to the contact between the lamp unit  34  and the light guide plate  32 . That is, the light guide plate  32  is prevented from contacting the lamp unit  34  by the lamp holder unit  35  without using an additional stopper, so that the light guide plate  32  and the lamp unit  34  are effectively protected by a simpler configuration.  
      According to an embodiment of the present invention, as shown in  FIG. 3 , an LCD apparatus comprises a lamp holder  35  comprising a lamp supporting portion  351  made of a relatively soft material, and a light guide plate supporting portion  352  made of a relatively hard material and coupled to the lamp supporting portion  351 .  
      As shown in  FIGS. 3 and 4 , for example, the light guide plate supporting portion  352  is made of a thin metal plate having an approximately U-shaped section, and surrounds the lamp supporting portion  351  with respect to a surface of the lamp supporting portion  351  opposite the light guide plate  32 .  
      That is, the light guide plate supporting portion  352  comprises a front portion positioned opposite to and capable of enduring impact from the light guide plate  32 , and a pair of side portions extending and bending from opposite ends of the front portion.  
      The shape of the light guide plate supporting portion  352  is not limited to the U-shaped section, and may vary as long as it endures the impact due to the contact with the light guide plate  32 .  
      In the LCD apparatus according to an embodiment of the present invention, the lamp supporting portion  351  is made of a relatively soft material in consideration of assemblage or the like, and the light guide plate supporting portion  352  is made of a relatively hard material to stably support the light guide plate  32  and prevent the light guide plate  32  from contacting the lamp unit  34 . That is, the lamp supporting portion  351  and the light guide plate supporting portion  352  are made of soft and hard materials, respectively, and then coupled to each other, thereby forming the lamp holder  35 .  
      Alternatively, the lamp supporting portion  351  and the light guide plate supporting portion  352  may be formed as a single body, wherein the guide plate supporting portion  352  is harder than the lamp supporting portion  351 .  
      As described above, the present invention provides an LCD apparatus using a lamp holder to effectively prevent contact between a light guide plate and a lamp unit.  
      Although the illustrative embodiments of the present invention have been shown and described herein with reference to the accompanying drawings, it will be appreciated by those skilled in the art that the present invention is not limited to those precise embodiments, and that changes may be made without departing from the principles and spirit of the invention. All such changes and modifications are intended to be included within the scope of the invention as defined by the appended claims.