Abstract:
A cooling unit to cool the display apparatus including a heat generating unit to generate heat and a casing to accommodate the heat generating unit, the cooling unit includes a cooling fan to generate air flow; a duct which is coupled with the casing and forms a cooling path to connect the cooling fan and the heat generating unit; an inlet portion which is provided to one side of the casing to communicate with the duct; an inlet grill which is provided in the inlet portion to guide air to be inhaled in a direction inclined to a rear surface of the casing; an outlet portion which is provided to an other side of the casing to communicate with the duct, being spaced from the inlet portion; and an outlet grill which is provided in the outlet portion to guide air to be exhaled in a direction inclined to a rear surface of the casing, wherein the exhaled direction provided by the outlet grill is different from the air-inhaling direction provided by the inlet grill. With this configuration, the cooling path is effectively provided to enhance cooling efficiency and thermal reliability.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority under 35 U.S.C. §119(a) from Korean Patent Application No. 10-2007-0097396, filed on Sep. 27, 2007 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present general inventive concept relates to a cooling unit which has improved cooling efficiency, and a display having the same. 
     2. Description of the Related Art 
     In general, a display apparatus such as a television, a monitor for a computer, or the like includes a display panel, a heat generating unit such as a printed circuit board which generates heat while driving the display panel, and a casing which forms an outside appearance. 
     Recently, a digital information display (DID) has been actively developed meeting consumer&#39;s demand. The DID publicly provides various contents including characters and moving pictures, and thus, is generally called a public display. The DID has been under development in various types of products. 
     A display apparatus including the DID may be installed under various environments. Particularly, if the display apparatus is installed outside, the display apparatus is typically equipped with a protection cover or installed on an installation surface like a wall. If the display apparatus is equipped with the protection cover, the protection cover should be installed so that the protection cover may not be spaced too far apart from the casing. If the display apparatus is installed on the installation surface, the display apparatus should not greatly protrude from the installation surface. 
     However, if a distance or a space between the display apparatus and the protection cover or the installation surface is too narrow, improving cooling efficiency of the display apparatus is difficult, thereby lowering thermal reliability thereof. Thus, an element having a relatively high heating value may affect other elements. Further, characteristics like brightness of the display apparatus may be lowered. 
     SUMMARY OF THE INVENTION 
     The present general inventive concept provides a cooling unit which can effectively provide a cooling path to enhance cooling efficiency and thermal reliability, and a display apparatus having the same. 
     The present general inventive concept also provides a cooling unit which can independently cool an element having a relatively high heating value to minimize a thermal influence on other elements, and a display apparatus having the same. 
     The present general inventive concept also provides a cooling unit which can provide a cooling path so that air flowing in the cooling path and air flowing out of the cooling path may not be mixed with each other, and a display apparatus having the same. 
     The present general inventive concept also provides a cooling unit which can provide a slim structure, and a display apparatus having the same. 
     Additional aspects of the present general inventive concept will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the present general inventive concept. 
     The foregoing and/or other aspects and utilities of the present general inventive concept can be achieved by providing a cooling unit to cool a display apparatus including a heat generating unit to generate heat and a casing to accommodate the heat generating unit, the cooling unit including a cooling fan to generate air flow, a duct which is coupled with the casing and forms a cooling path to connect the cooling fan and the heat generating unit, an inlet portion which is provided at one side of the casing to communicate with the duct, an inlet grill which is provided in the inlet portion to guide air to be inhaled in a direction inclined to a rear surface of the casing, an outlet portion which is provided at an other side of the casing to communicate with the duct, being spaced from the inlet portion, and an outlet grill which is provided in the outlet portion to guide air to be exhaled in a direction inclined to a rear surface of the casing, wherein the exhaled direction provided by the outlet grill is different from the air-inhaling direction provided by the inlet grill. 
     An inclination angle between the inlet grill and the rear surface of the casing may be within a range of 40° to 50° to inhale air from an outside to an inside of the casing in an upward inclined direction, and an inclination angle between the outlet grill and the rear surface of the casing may be within a range of 40° to 50° to exhale air from inside to outside of the casing in an upward inclined direction. 
     The cooling unit may include a heat transfer unit which is coupled with the heat generating unit and the duct and transfers the heat from the heat generating unit to the duct. 
     The heat transfer unit may include a contact member which is coupled with the heat generating unit to transfer the heat from the heat generating unit, and a heat radiating member which is coupled with the contact member and is disposed in the duct to radiate the heat from the contact member. 
     The cooling path of the duct may be arranged vertically to the casing, the inlet portion being disposed in a lower portion of the duct, and the outlet portion being disposed in an upper portion of the duct. 
     The cooling path of the duct may be arranged horizontally to the casing, the inlet portion being disposed in one of left and right sides of the duct, and the outlet portion being disposed in an other of the left and the right sides of the duct. 
     The foregoing and/or other aspects and utilities of the general inventive concept may also be may be achieved by providing a display apparatus including a heat generating unit to generate heat, a display panel which forms an image, a casing to accommodate the heat generating unit and the display panel, and a cooling unit to cool the heat generating unit, the cooling unit including a cooling fan to generate air flow, a duct which is coupled with the casing and forms a cooling path to connect the cooling fan and the heat generating unit, an inlet portion which is provided to one side of the casing to communicate with the duct, an inlet grill which is provided in the inlet portion to guide air to be inhaled in a direction inclined to a rear surface of the casing, an outlet portion which is provided to the other side of the casing to communicate with the duct, being spaced from the inlet portion, and an outlet grill which is provided in the outlet portion to guide air to be exhaled in a direction inclined to the rear surface of the casing, wherein the exhaled direction provided by the outlet grill is different from the air-inhaling direction provided by the inlet grill. 
     The cooling unit may further include a heat transfer unit which is coupled with the heat generating unit and the duct and transfers the heat from the heat generating unit to the duct. 
     The heat transfer unit may include a contact member which is coupled with the heat generating unit to transfer the heat from the heat generating unit, and a heat radiating member which is coupled with the contact member and is disposed in the duct to radiate the heat from the contact member. 
     The cooling path of the duct may be arranged vertically to the duct, the inlet portion being disposed in a lower portion of the duct, and the outlet portion being disposed in an upper portion of the duct. 
     The cooling path of the duct may be arranged horizontally to the casing, the inlet portion being disposed in one of left and right sides of the duct, and the outlet portion being disposed in an other of the left and the right sides of the duct. 
     The cooling unit may be provided in a plurality. 
     The display apparatus may include a digital information display (DID) having a network function. 
     The heat generating unit may include at least one of a CPU and a chip. 
     The heat generating unit may be plurally provided in the rear surface of the casing, each having a different heating value, the heat generating unit having a relatively high heating value among the heat generating units is disposed in a lower portion of the display panel, and the heat generating unit having a relatively low heating value among the heat generating units is disposed in an upper portion of the display panel. 
     The foregoing and/or other aspects and utilities of the general inventive concept may also be may be achieved by providing a cooling unit usable with a display apparatus including a duct to form a cooling path between an inlet grill and an outlet grill of a casing of the display apparatus, a heat transfer unit disposed in the duct to transfer heat in the cooling path, and a cooling fan disposed in the duct to generate airflow along the cooling path, wherein the outlet grill guides air in a first direction and the inlet grill guides air in a second direction not parallel to the first direction. 
     The duct may include an opening, and the heat transfer unit receives the heat from a heat generating unit of the display apparatus through the opening. 
     The inlet grill and the outlet grill may guide air in a direction not parallel with a rear surface of the casing. 
     The foregoing and/or other aspects and utilities of the general inventive concept may also be may be achieved by providing a display apparatus including a display panel unit, a heat generating unit disposed on the display panel unit and including at least one of a central processing unit (CPU), a Northbridge, a Southbridge and a printed circuit board (PCB), a casing to accommodate the display panel unit and the heat generating unit, and a cooling unit including a duct to form a cooling path between an inlet grill and an outlet grill of a casing of the display apparatus, a heat transfer unit disposed in the duct to transfer heat in the cooling path, and a cooling fan disposed in the duct to generate airflow along the cooling path, wherein the outlet grill guides air in a first direction and the inlet grill guides air in a second direction not parallel to the first direction. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and/or other aspects of the present general inventive concept will become apparent and more readily appreciated from the following description of the exemplary embodiments, taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a perspective view of a display apparatus according to an exemplary embodiment of the present general inventive concept; 
         FIG. 2  is a rear view of the display apparatus in  FIG. 1 ; 
         FIG. 3  is section view of the display apparatus, taken along line III-III in  FIG. 1 ; 
         FIG. 4  is an exploded perspective view of a cooling unit in  FIG. 3 ; 
         FIG. 5  illustrates an inlet portion and an outlet portion in  FIG. 4 ; 
         FIG. 6  is a rear view of a display apparatus according to an exemplary embodiment of the present general inventive concept; 
         FIG. 7  is a rear view of a display apparatus according to an exemplary embodiment of the present general inventive concept; 
         FIG. 8  is a schematic view illustrating a heat transfer process according to an exemplary embodiment of the present general inventive concept; 
         FIG. 9  is a side section view of the display apparatus illustrating air flow; 
         FIG. 10  is a graph illustrating cooling performance of the display apparatus according to an embodiment of the present general inventive concept compared with a conventional display apparatus 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Reference will now be made in detail to embodiments of the present general inventive concept, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. The exemplary embodiments are described below so as to explain the present general inventive concept by referring to the figures. 
     Referring to  FIGS. 1 through 7 , a display apparatus  100  according to an exemplary embodiment of the present general inventive concept includes a display panel  110 ; a casing  120 ; and a cooling unit  130 . 
     The display apparatus  100  further includes a heat generating unit  125  which is coupled with a rear portion of the display panel  110  and performs various functions such as driving the display panel  110  or providing network information. 
     The display apparatus  100  may be arranged in a landscape direction, as illustrated in  FIG. 1 , or may be arranged in a portrait direction where necessary. Hereinafter, it is assumed that the display apparatus is arranged in the landscape direction for the convenience of description. 
     The display apparatus  100  may have a network function. The display apparatus  100  may be provided in a plurality, which may be connected on a network by a single management server. 
     To this end, a CPU having high capacity, that is, a computer having high capacity is required, to generate a lot of heat, and thus, requires a cooling unit having high cooling efficiency. 
     Such a display apparatus is generally installed on an installation surface like a wall W (refer to  FIG. 9 ), or equipped with a protection cover. Hereinafter, the case that the display is installed on the wall W will be described by way of example. 
     Referring to  FIG. 3 , the display panel  110  includes a chassis  119  having an opening  123 ; and a display portion  111  which is accommodated in the chassis  119  and forms an image. The display panel  110  may further include a film portion  113  which is disposed in back of the display portion  111 ; a light source unit  115  which is disposed in back of the film portion  113 ; and a reflection portion  117  which is disposed adjacent to the light source unit  115 . 
     The display portion  111  may include a thin film transistor substrate (not illustrated) on which a thin film transistor is formed; and a color filter substrate (not illustrated) which is disposed opposite to the thin film transistor substrate; and a liquid layer (not illustrated) which is interposed therebetween. The display portion  111  is made of a non light emitting element, which requires light from the light source unit  115  for image forming. 
     The film portion  113  may include a diffusion film (not illustrated); a prism film (not illustrated); and a passivation film (not illustrated). 
     The light source unit  115  may include a plurality of lamps (not illustrated) which are arranged in parallel. 
     The reflection portion  117  is disposed adjacent to the light source unit  115  and reflects the light from the light source unit  115  toward the diffusion film of the film portion  113 . 
     The chassis  119  accommodates and supports the display portion  111 , the film portion  113  and the light source unit  115 . 
     The casing  120  forms an outside appearance of the display apparatus  100 . In the casing  120  is formed a plurality of slits  121  for airflow to cool the display panel  110 . The slits  121  are formed over a side wall of the casing  120  to output heat H 2 . 
     In a front portion of the casing  120  is formed an opening through which the display portion  111  is exposed, and in a rear portion of the casing  120  are formed an inlet portion  141  and an outlet portion  151  of the cooling unit  130 . 
     In a lower front portion of the casing  120  is provided a switch unit  129  ( FIG. 1 ) to operate the display panel  110 , and in a lower rear portion of thereof is provided a terminal portion  127  ( FIG. 2 ) which is connectable to an external power supply or an external terminal for communication. 
     The display apparatus  100  further includes a control unit to perform various control functions. The control unit  130  includes the heat generating unit  125  to generate heat during an operation thereof. 
     Referring to  FIG. 8 , the heat generating unit  125  may include a CPU which is coupled with the display panel  110  or the casing  120 , or a chip such as Northbridge  81  and Southbridge  82  which are a type of system controller to connect the CPU to a PCI (Peripheral Component Interconnect) bus. The heat generating unit  125  may further include a printed circuit board  80 . The heat may be disposed or transmitted as heat H 1  or heat H 2 . The heat H 1  may be transmitted along a path P. 
     Referring to  FIG. 9 , the heat generating unit  125  according to the present embodiment may include all elements to generate heat, or may include some heat generating elements to generate heat greater than a predetermined value. In the latter case, the heat generating unit includes a first heat generating unit  125   a  having a relatively high heating value; and a second heat generating unit  125   b  having a relatively low heating value. 
     As illustrated in  FIG. 9 , the first heat generating unit  125   a  may be disposed on a lower rear portion of the display panel  110 , the second heat generating unit  125   b  may be disposed on an upper rear portion of thereof. The first and second heat generating units  125   a  and  125   b  may be diagonally arranged as necessary. The first and second heat generating units  125   a  and  125   b  may be coupled to the casing  120  as necessary. 
     As illustrated in  FIG. 3 , the cooling unit  130  includes a cooling fan  131 ; a duct  133 ; the inlet portion  141 ; and the outlet portion  151 . The cooling unit  130  further includes a heat transfer unit  160 . 
     The cooling fan  131  generates air flow P, and transmits heat H 1  from inside of the casing to the outside of the casing  133   c  therethrough. The capacity of the cooling fan  131  is determined in consideration of an amount of heat generated from the heat generating unit  125 , heat transfer efficiency of the heat transfer unit  160 , etc. The cooling fan  131  may have a slim appearance so long as the cooling fan  131  meets the capacity thereof. The cooling fan  131  may be provided as a cross-flow fan as illustrated in  FIG. 4 , but alternatively, may be provided as an axial-flow fan as necessary. 
     The duct  133  is coupled with the casing  120  by a screw  171  and forms a cooling path C of air generated from the cooling fan  131 . In the duct  133 , a heat exchange is generated between air flowing therein and heat transferred from the heat generating unit  125 , and then, the air flows outside  133   c . The duct  133  has an opening  135  through which the heat transfer unit  160  is coupled to the heat generating unit  125  for heat transfer. 
     The duct  133  may have a rectangular section, but alternatively, may have various sections as necessary. The size of the duct is determined in consideration of the amount of heat generated from the heat generating unit  125 , the capacity of the cooling fan  131 , a size of an installation space, etc. 
     The duct  133  is coupled with the heat transfer unit  160  and the casing  120  so that air generated from the cooling fan  131  may not enter into a space  133   b  formed by the casing  120  and the display panel  110 . 
     The inlet portion  141  which is formed in the casing  120  communicates with an inlet of the duct  133 . An inlet grill  143  is coupled to the inlet portion  141  and is inclined to the casing  120 . 
     The outlet portion  151  which is formed in the casing  120  communicates with an outlet of the duct  133 . The outlet portion  151  is spaced apart from the inlet  141 . An outlet grill  153  is coupled to the outlet portion  151  and is inclined to the casing  120 . 
     The inlet grill  143  and the outlet grill  153  can minimize resistance to air flowing into or out of the duct  133 , to thereby increase cooling efficiency inside the duct  133 . 
     As illustrated in  FIG. 5 , an inlet inclination angle θ 1  between the inlet grill  143  and a rear surface of the casing  120  may be within a range of about to 40° to 50° so as to inhale external air from the outside to the inside of the casing  120  in an upward inclined direction. Alternatively, an outlet inclination angle θ 2  between the outlet grill  153  and the rear surface of the casing  120  may be within the range of 40° to 50° in order to exhale internal air from the inside to the outside of the casing  120  in the upward inclined direction. Air flow and cooling efficiency are enhanced within the inclination angle range. Here, if the inlet inclination angle θ 1  is positive, the outlet inclination angle θ 2  is negative, and vice versa. That is, both the angles θ 1  and θ 2  have reverse inclination directions. Thus, flowing-in air and flowing-out air do not mixed each other, thereby enhancing cooling efficiency. 
     The heat transfer unit  160  is coupled with the heat generating unit  125  inside  133   a  of the duct  133  to transfer heat from the heat H 1  generating unit  125  to the inside  133   a  of the duct  133 . 
     As illustrated in  FIG. 4 , the heat transfer unit  160  includes a contact member  161  which is coupled with the heat generating unit  125 ; and a heat radiating member  163  which is coupled with the contact member  161  and radiates heat transferred to the contact member  161  from the heat generating unit  125  to the inside  133   a  of the duct  133 . Referring to  FIG. 4 , the contact member  161  may include two heat pipes for effective heat transfer, but the number of the heat pipes may be varied as necessary. 
     Here, the heat pipe near the inlet portion  141  may contact the heat generating unit  125  of high temperature rather than an other heat pipe near the outlet portion  151 . That is, the heat transfer unit  160  may have a configuration that heat from the heat generating unit  125  is firstly cooled by flowing-in air of low temperature. Alternatively, the plurality of contact members  161  may be arranged in parallel in the cooling path. 
     The heat transfer unit  160  may include a heat sink. Accordingly, providing an independent cooling system so that heat from the heat generating unit  125  such as a CPU or a chip like Northbridge and Southbridge having a relatively high heating value does not affect other elements inside the casing  120  is possible. 
     The cooling unit  130  may be arranged vertically to the casing  120  as illustrated in  FIG. 2 . In this case, the inlet portion  141  may be disposed in a lower portion of the casing  120  and the outlet portion  151  may be disposed in an upper portion of the casing  120 . Accordingly, air flows from the lower portion of the casing  120  to the upper portion thereof inside the duct  133 . That is, air flows into the duct  133  in the lower portion of the casing  120 , and then, hot air heated by heat exchange flows out of the duct in the upper portion of the casing  120 . Thus, flow of air becomes smooth, thereby enhancing cooling efficiency. 
     Alternatively, the cooling unit  130  may be arranged horizontally to the casing  120  as illustrated in  FIG. 6 . In this case, the outlet portion  141  may be disposed adjacent to a right edge side of the casing  120 . 
     The cooling unit  130  may be provided in a plurality as illustrated in  FIG. 7  according to a position of the heat generating unit  125 . 
     Hereinafter, an operating process of the cooling unit  130  as configured above will be described with reference to  FIGS. 8 and 9 . 
     If power is supplied to the display apparatus  100 , the display panel  110  operates to perform various functions. During the operation, the heat generating unit  125  generates heat as illustrated in  FIG. 8 . The generated heat is transferred to the heat transfer unit  160  and is radiated outside through the duct  133 . 
     As illustrated in  FIG. 9 , the casing  120  of the display apparatus  100  which is installed on the installation surface W is spaced by a distance D from the installation surface W. 
     If the fan  131  operates, outside air flows into the inlet portion  141  and flows outside through the outlet portion  151 , through heat exchange with the heat transfer unit  160 . During this process, air can flow in and out through the inlet grill  143  and the outlet grill  153 , with flow resistance being minimized in a narrow space between the casing  120  and the installation surface W. 
     Alternatively, as illustrated in  FIG. 9 , the heat generating units  125   a  and  125   b  which are provided on the rear of the display panel  110  may be arranged in a separate cooling path (refer to an arrow in  FIG. 9 ) which is formed by slits  121   a  and  121   b  formed in side walls of the casing  120 . In this case, air flow may be formed by a fan (not illustrated), or may be formed by convection. That is, air is flowed in through the lower slit  121   a  and cools the heat generating unit  125   a  of relatively high temperature, and then, passes through the heat generating unit  125   b  of relatively low temperature and flows outside through the upper slit  121   b . In this way, the heat generating units  125   a  and  125   b  can be cooled effectively. 
       FIG. 10  illustrates cooling performance of the display apparatus  100  according to the present embodiment in comparison with the conventional display apparatus. 
     Here, a constant-pressure centrifugal fan is employed as the cooling fan  131  to overcome pressure drop and to improve cooling performance. 
     In  FIG. 10 , an abscissa represents the distance D (mm) between the casing  120  and the installation surface W, and an ordinate represents the temperature (° C.) of the CPU at the heat generating unit  125 . 
     As illustrated, in the display apparatus according to the present embodiment, the temperature rise of the heat generating unit  125  is within approximately 6° C. according as the distance D decreases. 
     Contrarily, in the conventional display apparatus, according as the distance D decreases, the temperature rise gradually increases to approximately 20° C. 
     Accordingly, in the display apparatus according to the present general inventive concept, the distance D can be significantly decreased compared with the conventional display apparatus, thereby making the outside appearance thereof slim. 
     As described above, according to various embodiments of the present general inventive concept, a cooling path can be effectively formed, thereby enhancing cooling efficiency and thermal reliability. 
     Further, a heat generating unit having a relatively high heating value can be independently cooled, thereby minimizing thermal influence on other elements. 
     Furthermore, a cooling path can be formed so that flowing-in air and flowing-out air may not be mixed with each other. 
     In addition, an outside appearance of the display apparatus can be made slim. 
     Although various exemplary embodiments of the present general inventive concept have been illustrated and described, it will be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the general inventive concept, the scope of which is defined in the appended claims and their equivalents.