Patent Publication Number: US-2005139346-A1

Title: Cooling apparatus for light valve

Description:
FIELD OF THE INVENTION  
      The present invention relates to a cooling apparatus, and more particularly, to a cooling apparatus for a light valve.  
     BACKGROUND OF THE INVENTION  
      In a projection apparatus, a lighting system projects a light beam on a light valve. After a light modulation process by the light valve, an image is projected on a screen through a projection lens. However, since the light beam is unceasingly projected on the light valve, it accumulates heat on the light valve that affects operation efficiency thereof. Therefore, a suitable cooling apparatus for the light valve is needed.  
      Please refer to  FIG. 1  and  FIG. 2 , there is a control box  2  connected to the back of a light valve  1 . Inside the control box  2  is equipped with an electrical circuit board  3  to actuate the light valve  1 . By the installment of the control box, the goal of preventing the production of electromagnetic wave interference can be achieved. There is an opening  4  disposed on the control box  2 , and there is a fan  5  on the light valve  1 . The fan  5  is setup on the control box  2  through the opening  4 . By the operation of fan  5 , heat is forced to be taken away from the light valve  1  for cooling. However, the noise caused by the operation of the fan  5  is easily spread out from the vent of the projection apparatus, which affects the audio feeling. The lifetime of the fan  5  is short and it needs replacement quite often. In addition, it has certain volume, which affects the space allocation and increases the volume of the cooling apparatus. Therefore, there are conventional problems of noise, short lifetime and large volume for the cooling apparatus by using a fan and more improvements are needed.  
     SUMMARY OF THE INVENTION  
      One object of the present invention is to provide a cooling apparatus of a light valve, by directly pasting a heat pipe and a heat-conducting component upon a control box and taking the advantage of the large surface of the control box to diffuse the heat, and to achieve the goal of simplifying the cooling apparatus and increasing the cooling efficiency.  
      In order to achieve the objectives mentioned above, the cooling apparatus for a light valve according to the present invention is to set up a control box on the back of a light valve in order to actuate the light valve, followed by pasting a heat pipe and a heat-conducting component upon the inner surface of the control box. The heat-conducting component is connected to a heat-collecting end of the heat pipe and the surface of the heat-conducting component contacts with the light valve.  
      The heat of the light valve is conducted to the second part of the control box through the heat-conducting component, and then the heat is conducted to the second part of the control box via the heat pipe pasted upon it. Thus, the heat of the light valve can be removed away through the large area of the second part of control box, so as to increase the cooling efficiency and simplify the cooling apparatus. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is the perspective view of a conventional cooling apparatus for a light valve.  
       FIG. 2  is the exploded view of a conventional cooling apparatus for a light valve.  
       FIG. 3  is the perspective view of the cooling apparatus for a light valve of the present invention.  
       FIG. 4  is the exploded view of the cooling apparatus for a light valve of the present invention.  
       FIG. 5  is the perspective structural view of the second part of the control box of the present invention.  
       FIG. 6  is the exploded view of another preferred embodiment of the cooling apparatus for a light valve of the present invention.  
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
      Further features and advantages of the present invention, as well as the structure and operation of the embodiments of the present invention, are described in detail below with reference to the accompanying drawings.  
      Please refer to  FIG. 3  and  FIG. 4 , the cooling apparatus  10  of a light valve according to the present invention includes a control box  11  and a heat-conducting component  12 . The control box  11  is connected to the back of the light valve  1  in order to actuate the light valve  1 . The control box  11  is composed of a first part  111  and a second part  112  of the control box. The control box  11  is made up of materials with high heat conductivity like aluminum, copper and so on. The first part  111  of the control box is opened with an opening  1111 , and the opening  1111  is setup in accordance with the light valve  1  and the boundaries of the opening  1111  are locked firmly to the light valve  1  in order to fix the first part  111  of the control box  11  to the projector  6 . Please refer  FIG. 5 , the inner surface of the second part  112  of control box is pasted a heat pipe  113  and a heat-conducting component  12 , the heat pipe  113  may be wrapped by a fixing member  114  or coated with a heat conduction glue (not shown in the fig.) in order to be fixed to the surface of the second part  112  of the control box. The heat pipe  113  has a heat-collecting end  1131 , and the heat-conducting component  12  is connected to the heat-collecting end  1131  of the heat pipe  113 . The heat-conducting component  12  is composed of a base  121  and a protruding part  122  is setup on one side of the base  121 . The heat-conducting component  12  and the second part  112  of the control box can be made one shaping, and there may be one heat conduction cushion set between the heat-conducting component  12  and the light valve  1  (not shown in the fig.) in order to eliminate the high contact thermal resistance which is caused when the air acts as the heat conduction medium between the heat-conducting component  12  and the light valve  1 , and then increase the conduction effect.  
      The control box  11  consists of an electrical circuit board  13 , and the electrical circuit board  13  is equipped with a through hole  131  relative to the center of the light valve  1  in order to allow the protruding part  122  of the heat-conducting component  12  to pass through. This causes the protruding part  122  to contact with the light valve  1  and conducts the heat away from the light valve  1 . The surface  132  of the electrical circuit board  13  opposite to the light valve  1  contacts with the electrical circuit around the light valve  1  in order to make the electrical connection.  
      After the actuation of the light valve  1 , the heat is produced and conducted to the second part  112  of the control box by the heat-conducting component  12 . By the heat pipe  113  pasted upon the second part  112  of the control box, the heat produced by the light valve  1  disperses into the second part  112  of the control box. Cooling by using the large area of the second part  112  of the control box achieves the goal of increasing cooling effect.  
      The cooling apparatus  10  of the present invention takes advantage of the large surface of the control box  11  to conduct the heat, besides, the heat pipe  113  and the heat-conducting component  12  are pasted upon the inner surface of the control box  11 . Thus, the cooling apparatus of the present invention will not affect the spatial configuration of the projection apparatus, and does not need to additionally build a fan or a heat-conducting component to assist the heat dissipation; therefore, it achieves the goal of simplification for the cooling apparatus.  
      Moreover, please refer to  FIG. 6 , the heat-conducting component  12 A is composed of a first heat-conducting plate  121  A and a second heat-conducting plate  122 A. The first heat-conducting plate  121  A is connected to the heat-collecting end  1131  of the heat pipe  113  and fixed to the second part  112  of the control box. The second heat-conducting plate  122 A is screwed to the first heat-conducting plate  121 A. The second heat-conducting plate  122 A consists of a base  1221 A, and a side  1222 A of the base  1221 A is pasted upon the first heat-conducting plate  121 A; the other side is disposed a protruding part  1223 A, and the protruding part  1223 A passes through the through hole  131  of the electrical circuit board  13  in order to contact with the light valve  1 . There is a plurality of fixed hole  1224 A setup on the boundary edge of the base  1221 A. After the first part  111  of the control box is locked to the projector  6  on the edge of the light valve  1 , and the heat pipe  113  and the first heat-conducting plate  121 A are fixed to the second part  112  of the control box, the locking member (not shown in the fig.) passes through the fixed hole  1224 A and the electrical circuit board  13 , and then screws on the boundary edge of the light valve  1  in order to clamp together the electrical circuit board  13  and the light valve  1 . The first heat-conducting plate  121 A and the second heat-conducting plate  122 A are connected by another locking member (not shown in the fig.), and then the cooling apparatus for a light valve of the invention is assembled. Therefore, by separating the heat-conducting component  12 A into two parts, the convenience in assembly and the fixing of the electrical circuit board  13 , the light valve  1  and the cooling apparatus  10  are achieved.  
      Although the invention has been described in detail herein with reference to its preferred embodiment, it is to be understood that this description is by way of example only, and is not to be interpreted in a limiting sense. It is to be further understood that numerous changes in the details of the embodiments of the invention, and additional embodiments of the invention, will be apparent, and may be made by, persons of ordinary skill in the art having reference to this description. It is considered that such changes and additional embodiments are within the spirit and true scope of the invention as claimed below.