Abstract:
A projection television including an optical engine, a circuit spaced apart from and driving the optical engine, a fan placed between the optical engine and the circuit, and blowing cool air to cool down the optical engine and the circuit, and a main cabinet accommodating the optical engine, the circuit and the fan. With this configuration, a projection television with a single fan provided between an optical engine and a circuit to efficiently cool down the optical engine and the circuit, which each generate heat at respectively different temperatures, is provided, and an improved flow passage of cool air to increase cooling efficiency is also provided.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims the benefit of Korean Patent Application Nos. 2004-32519 and 2004-32520 filed on May 8, 2004 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety and by reference.  
       BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present general inventive concept relates to a projection television, and more particularly, to a projection television with an improved cooling system to cool down optical engines and circuits.  
         [0004]     2. Description of the Related Art  
         [0005]     Generally, a projection television employs an optical device such as a projector, and projects an image beam onto a rear surface of a screen to form an image. The projection television has an advantage of enlarging the screen and thus the image, resulting in an increase in the demand for such a television.  
         [0006]     A conventional projection television comprises a cabinet forming an external appearance of the projection television; a screen provided in a front side of the cabinet; a reflection mirror provided in an inner rear portion of the cabinet; an optical engine provided at a bottom portion of the cabinet, and forming and projecting an image beam toward the reflection mirror; a circuit driving the optical engine; and a fan cooling down the optical engine and the circuit.  
         [0007]     The optical engine and the circuit of the conventional projection television are closely placed, but the optical engine and the circuit respectively generate heat at different temperatures, and accordingly a plurality of fans are provided to cool down the optical engine and the circuit, respectively. For example, a light source of the optical engine generates heat at a relatively high temperature and therefore needs a fan or fans rotating at a high speed, and a portion of the circuit generates heat at a relatively low temperature and therefore needs a fan or fans rotating at a low speed. Moreover, a flow of cooled air variously changes because the cooled air taken in from an air inlet passes the optical engine and the circuit, etc., until it is emitted through an air outlet.  
         [0008]     Accordingly, the conventional projection television has disadvantages of increasing noise due to employing the plurality of fans, increasing manufacturing costs because of a complicated structure, increasing fluctuating noise due to the flow of cooled air, and thereby also decreasing cooling efficiency.  
       SUMMARY OF THE INVENTION  
       [0009]     Accordingly, it is an aspect of the present general inventive concept to provide a projection television with a single fan provided between an optical engine and a circuit to efficiently cool down the optical engine and the circuit generating the heat at respectively different temperatures, and an improved flow passage of cooled air to increase cooling efficiency.  
         [0010]     Additional aspects and/or advantages 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 general inventive concept.  
         [0011]     The foregoing and other aspects and advantages of the present general inventive concept are achieved by providing a projection television comprising an optical engine; a circuit spaced from and driving the optical engine; a fan provided between the optical engine and the circuit, and blowing cooled air to cool down the optical engine and the circuit; and a main cabinet accommodating the optical engine, the circuit and the fan.  
         [0012]     According to an aspect of the present general inventive concept, the projection television may further comprise a fan supporting unit placed between the optical engine and the circuit, and supporting unit supporting the fan and partitioning the main cabinet.  
         [0013]     According to an aspect of the present general inventive concept, the fan supporting unit comprises a fan holder supporting an edge of the fan; and a fan supporter comprising an through hole through which the cooled air passes, and supporting the fan holder and partitioning the main cabinet.  
         [0014]     According to an aspect of the present general inventive concept, the fan blows the cooled air from the circuit toward the optical engine.  
         [0015]     According to an aspect of the present general inventive concept, the optical engine may be placed above the circuit.  
         [0016]     According to an aspect of the present general inventive concept, the main cabinet may comprise an air inlet in a bottom surface thereof adjacent to the circuit to take in the cooled air from an outside.  
         [0017]     According to an aspect of the present general inventive concept, the main cabinet may further comprise a cabinet stand separately supporting the bottom surface of the main cabinet at a given distance from an installation surface.  
         [0018]     According to an aspect of the present general inventive concept, the main cabinet may function as a duct introducing the cooled air taken in from the air inlet to flow upward to sequentially cool down the circuit and the optical engine. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0019]     These and/or other aspects and advantages of the present general inventive concept will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompany drawings of which:  
         [0020]      FIG. 1  is a perspective view of a projection television according to an embodiment of the present general inventive concept;  
         [0021]      FIG. 2  is a sectional view of the project television of  FIG. 1 , taken along the line II-II;  
         [0022]      FIG. 3  is a perspective view of a rear side of a main cabinet of the projection television in  FIG. 1 ; and  
         [0023]      FIG. 4  illustrates where the fan is combined with the main cabinet in  FIG. 3 ; and  
         [0024]      FIG. 5  is a perspective view of the fan in  FIG. 4 . 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0025]     Reference will now be made in detail to the 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 embodiments are described below in order to explain the present general inventive concept by referring to the figures.  
         [0026]     As shown in  FIGS. 1 and 2 , a projection television  1  according to an embodiment of the present general inventive concept comprises an optical engine  70  forming and projecting an image beam; a circuit  80  spaced from and driving the optical engine  70 ; a fan  50  provided between the optical engine  70  and the circuit  80 , and respectively cooling down the optical engine  70  and the circuit  80 ; and a main cabinet  40  accommodating the optical engine  70 , the circuit  80  and the fan  50 . Further, the projection television  1  comprises a fan supporting unit  90  placed between the optical engine  70  and the circuit  80 , and partitioning the main cabinet  40  to separately accommodate the optical engine  70  and the circuit  80 . In addition, the projection television  1  further comprises a reflection mirror  30  reflecting the image beam projected from the optical engine  70 ; a screen  20  visualizing the image beam reflected by the reflection mirror  30  to an image; and a screen cabinet  10  to which the screen  20  and the reflection mirror  10  are accommodated.  
         [0027]     An opening  12  is provided in a front side of the screen cabinet  10 , and thus the screen  20  can be exposed outward therethrough, and the reflection mirror  30  is disposed at an inner rear portion of the screen cabinet  10  to reflect the image beam projected from the optical engine  70  to the screen  20 . In addition, at a bottom side of the screen cabinet  10 , a predetermined size of a projection hole  11  is provided so that the image beam from the optical engine  70  can be projected therethrough to the reflection mirror  70 .  
         [0028]     The optical engine  70  may comprise a light source  71  emitting light; a color filter wheel (not shown) filtering the light emitted from the light source  71 ; an illuminator  72  converting the light passing through the color filter wheel into evenly parallel light and focusing the parallel light; a display device  73  visualizing the light from the illuminator  72  to the image; a projector lens  74  projecting the image beam containing the image visualized by the display device in large scale; and a ballast  75  providing power to the optical engine  70 .  
         [0029]     The circuit  80  drives the optical engine to form the image beam based on image signal information transmitted externally through an antenna or a cable, etc., or transmitted through multimedia devices such as a DVD, VCR, or a computer, etc.  
         [0030]     The fan  50  employs an axial flow fan blowing air along an axial direction to control cooled air to flow from the circuit  80  toward the optical engine  70 , and accordingly cooling efficiency can be increased as the cooled air flows from the circuit  80  generating heat at relatively low temperature to the optical  70  engine generating the heat at relatively high temperature.  
         [0031]     The light source  71  of the optical engine  70  is preferably, but not necessarily, placed close to the fan  50  since it generates the heat at a higher temperature.  
         [0032]     As shown in  FIG. 3 , the main cabinet  40  is divided into an upper portion and a lower portion, and it is preferable, but not necessary, that the optical engine  70  is accommodated in the upper portion while the circuit  80  is accommodated in the lower portion. Also, an air inlet  41  is preferably but not necessarily, provided in a bottom surface of the main cabinet  40  to take in the cool air from an outside. Thus, the cooled air taken in from the bottom surface of the main cabinet  40  is smoothly ascended to thereby cool down the circuit  80  generating the heat at relatively low temperature at first, and then smoothly ascended to cool down the optical engine  70  generating heat at a relatively high temperature, and thereby increasing an overall cooling efficiency.  
         [0033]     Further, the main cabinet  40  preferably, but not necessarily, comprises a cabinet stand  60  supporting the main cabinet  40  at a given distance from an installation surface, to smoothly take in the cooled air from the outside through the air inlet  41  provided in the bottom surface of the main cabinet  40 . The cabinet stand  60  comprises a main supporter  61  supporting the lower portion of the main cabinet  40 , and a leg  62  separately supporting the main supporter  61  from the installation surface.  
         [0034]     Here, the main cabinet  40  may function as a duct conducting the cool air taken in from the bottom surface thereof to flow upward and sequentially cool down the circuit  80  and the optical engine  70 . Thus, the cool air smoothly ascends while cooling down the circuit  80  first and then the optical engine  70 , resulting in increasing cooling efficiency.  
         [0035]     As shown in  FIG. 4 , the fan supporting unit  90  comprises a fan holder  91  holding an edge of the fan  50 , and a fan supporter  92  supporting the fan holder  91 , partitioning the main cabinet  91  into an upper portion and a lower portion, and comprising a through hole  93 . Thus, the cool air flows from the lower portion to the upper portion of the main cabinet  40  by passing through the through hole  93  of the fan supporter  92 .  
         [0036]     Herein, the through hole  93  may be provided in a center portion of the fan supporter  92 , and the fan holder  91  is therefore detachably coupled to the center portion in which the through hole  93  of the fan supporter  92  is formed. However, the through hole  93  may be placed at any position along the fan supporter  92  which provides the intended cooling effect described herein, and the fan holder  91  can be positioned accordingly.  
         [0037]     The fan holder  91 , as shown in  FIG. 5 , may comprise a left holder  911  and a right holder  912 , which are coupled together forming a predetermined accommodating space, in which the edge of the fan  50  is supportably accommodated therein. The left holder  911  and the right holder  912  of the fan holder  91  may respectively comprise flanges  913  having a coupling hole, and the respective flanges  913  of the left holder  911  and the right holder  912  may be coupled together by a screw  914 . However, alternative methods of coupling the respective flanges  913  together may be used.  
         [0038]     Unlike the above embodiment, the air inlet  41  may not be necessarily provided in the bottom surface of the main cabinet  40 . It may be provided in at least a side of the bottom portion of the main cabinet  40 , in which the circuit  80  is accommodated.  
         [0039]     Also, the fan supporter  92  may divide the main cabinet  40  into a left portion and a light portion instead of the upper portion and the lower portion, and thus the circuit  80  and the optical engine  70  may be accommodated respectively in the left portion and the right portion, or vice versa.  
         [0040]     With the above configuration, function and effect of the projection television  1  according to an embodiment of present general inventive concept are as follows.  
         [0041]     The fan  50  placed between the optical engine  70  and the circuit  80  blows the cool air from the circuit  80  toward the optical engine  70 , thereby efficiently cooling down the optical engine  70  generating heat at relatively high temperature and the circuit  80  generating heat at relatively low temperature. Further, according to the heat transfer theory, the cooling efficiency can be increased by placing the optical engine  70  generating heat at a relatively high temperature in the upper portion of the main cabinet  40  and the circuit  80  generating heat at a relatively low temperature in the lower portion of the main cabinet  40 , considering that the cool air is directed from the bottom portion to the upper portion of the main cabinet  40  by the fan  50 .  
         [0042]     Moreover, the air inlet  41  is provided in the bottom surface of the main cabinet  40 , and thus cool air is taken in therethrough and cools down the circuit  80 , and then passes through the fan  50  and cools down the optical engine  70 , and then is emitted externally. Therefore, a flow of cool air can be simplified, resulting in increasing an overall cooling efficiency.  
         [0043]     Although a few embodiments of the present general inventive concept have been shown 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.