Abstract:
An image projector in a case, having a light engine, a circuit board, a heat sink assembly, and a fan assembly, has one or more heat sinks and heat pipes shaped to gather heat from all heat-generating components within the projector and a single air passage to receive the heated air combined from all components, allowing the employment of a single fan module in sucking cool air from the exterior and exhausting heated air through the single air passage.

Description:
BACKGROUND 
     1. Technical Field 
     The present disclosure relates to projectors and, particularly, to a projector capable of effectively dissipating heat. 
     2. Description of Related Art 
     Projectors need more than one fan for dissipating heat from more than one heat source, such as a light source, a spatial light modulator, and a circuit board together, the additional fans increase the size and the cost of the projector and generate more noise. 
     Therefore, it is desirable to provide a projector, which can overcome the limitations described. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view of a projector in accordance with an exemplary embodiment. 
         FIG. 2  is a cross-sectional view of the projector of  FIG. 1 . 
         FIG. 3  is an isometric view of a heat sink of the projector of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments of the disclosure will be described with reference to the drawings. 
     Referring to  FIGS. 1-3 , a projector  10 , according to an exemplary embodiment, includes a case  11 , a light engine  12 , a circuit board  13 , a heat sink assembly  14 , and a fan assembly  16 . In this embodiment, the projector  10  is a digital light processor (DLP) projector. 
     The case  11  is a closed cuboid and includes a left sidewall  111 , a right sidewall  112 , a front sidewall  113 , and a rear sidewall  114 . The left sidewall  111  is opposite to the right sidewall  112 , and the front sidewall  113  is opposite to the rear sidewall  114 . The left sidewall  111  defines an air inlet  1111 , and the right sidewall  112  defines an air outlet  1121 . The air inlet  1111  is aligned with the air outlet  1121 . The front sidewall  113  defines a through hole  1131 , generally adjacent to a middle of the front sidewall  113 . 
     The light engine  12  is received in the case  11 , generally adjacent to a middle of the case  11 . The light engine  12  includes a light source module  121 , an optical module  122 , and a lens  123 . The light source module  121  and the lens  123  are positioned at two ends of the optical module  122 . Light rays emitted from the light module  121  penetrate the optical module  122  and are projected through the lens  123 . 
     The light source module  121  is adjacent to the air outlet  1121  of the right sidewall  112 . The light source  121  includes a red light emitting diode (LED)  1211 , a blue LED  1212 , and a green LED  1213 , and a driving chip  1214 . The driving chip  1214  is connected to the red LED  1211 , the blue LED  1212 , and the green LED  1213 . The light source module  121  takes light rays emitted from the red LED  1211 , the blue LED  1212 , and the green LED  1213 , and projects them to the optical module  122 . In this embodiment, the red LED  1211  faces a corner of the right sidewall  112  and the rear sidewall  114 , the blue LED  1212  faces the rear sidewall  114 , and the green LED  1213  faces a corner of the left sidewall  111  and the front sidewall  113 . 
     The optical module  122  is substantially V-shaped and includes a light inlet  1221  and a light outlet  1222 . The light inlet  1221  and the light outlet  1222  both face the front sidewall  113 . The light source module  121  is positioned on the light inlet  1221  of the optical module  122 . The optical module  122  includes a digital micro device (DMD)  1223  and a number of optical elements (not shown). The DMD  1223  faces the through hole  1131  of the front sidewall  113 , and is adjacent to the rear sidewall  114 . The light rays projected onto the DMD  1223  are reflected by the DMD  1223  toward the front sidewall  113 . 
     The lens  123  is received in the case  11 , and is positioned on the light outlet  1222  of the optical module  122 . The lens  123  is located in the through hole  1131 . The light rays emitted from the DMD  1223  are projected to the lens  14 . The light rays pass through the lens  14  and are projected onto a screen (not shown). 
     The circuit board  13  is positioned between the light source module  121  of the light engine  12  and the left sidewall  111 , adjacent to the air inlet  1111  of the left sidewall  111 . The circuit board  13  includes a first board  131  and a second board  132  perpendicular to the first board  131 . The first board  131 , being substantially perpendicular to the front sidewall  113  and the rear sidewall  114 , extends between them. The second board  132  is substantially perpendicular to the left sidewall  111  and the right sidewall  112 . The optical module  122  is positioned on the second board  132 . The circuit board  13  is electrically connected to the driving chip  1214 . 
     The heat sink assembly  14  includes a first heat sink  141 , a second heat sink  142 , and a third heat sink  143 . The first heat sink  141  is attached on the red LED  1211 , the second heat sink  142  is attached on the blue LED  1212 , and the third heat sink  143  is attached on the green LED  1213 . The first heat sink  141  is connected to the second heat sink  142 . The second heat sink  142  and the third heat sink  143  face the air outlet  1121 . Each of the first heat sink  141 , the second heat sink  142 , and the third heat sink  143  includes an attaching surface  1401  and a dissipating surface  1402  facing the attaching surface  1401 . The attaching surface  1401  contacts the red LED  1211 , the blue LED  1212 , or the green LED  1213 , and the heat generated by the red LED  1211 , the blue LED  1212 , or the green LED  1213  is conducted from the attaching surface  1401  to the dissipating surface  1402 . In this embodiment, each of the first heat sink  141 , the second heat sink  142 , and the third heat sink  143  includes a heat pipe (not shown) embedded in the attaching surface  1401 . 
     The fan assembly  16  is received in the case  11 , and is positioned between the air inlet  1111  and the air outlet  1121 . The fan assembly  16  includes at least one fan  161  positioned between the heat sink assembly  14  and the right sidewall  112 . The air inlet  1111 , the fan  161 , and the air outlet  1121  form a dissipating passage  160 . Cool air is sucked into the case  11  from the air inlet  111  by the fan  161 , and heated air is blown out the case  11  via the air outlet  1121  by the fan  161 . In this embodiment, the fan assembly  16  consists of two fans  161 , one of the fans  161  is adjacent to the second heat sink  142 , and the other fan  161  is adjacent to the third heat sink  143 . 
     In use, the light source module  121 , the DMD  1223 , and the circuit board  13  are positioned on the dissipating passage  160 . Heat generated by the light source module  121 , and the DMD  1223 , and the circuit board  13  is dissipated to the dissipating passage  160 . The heated air is sucked from the air outlet  1121  and the cool air is drawn in from the air inlet  1111  under the movement of the fans  161 . Therefore, the light source module  121 , and the DMD  1223 , and the circuit board  13  positioned in the dissipating passage  160  all have immediate and direct access to a heat dissipation path. 
     As the light source module  121 , and the DMD  1223 , and the circuit board  13  are positioned on one same dissipating passage  160 , the combined heat is dissipated by a single fan assembly  16 . The size and the cost of the projector  10  is decreased, and the noise generated by the projector  10  is reduced. 
     Particular embodiments are shown and are described by way of illustration only. The principles and the features of the present disclosure may be employed in various and numerous embodiments thereof without departing from the scope of the disclosure as claimed. The above-described embodiments illustrate the scope of the disclosure but do not restrict the scope of the disclosure.