Patent Publication Number: US-11036118-B2

Title: Heat dissipation module and projection apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the priority benefit of China application serial no. 201821460990.7, filed on Sep. 7, 2018. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification. 
     BACKGROUND 
     Field of the Invention 
     The invention relates a heat dissipation module and a projection apparatus and more particularly, to a heat dissipation module with an efficient heat dissipation effect and a projection apparatus using the heat dissipation module. 
     Description of Related Art 
     In general, the primary heat sources are a light source and a light valve in a projection apparatus. In a conventional projection apparatus, a heat transfer system of a heat dissipation device, the heat sources are connected to heat sinks respectively for heat dissipation. However, in this method the entire system layout of the projection apparatus may be dispersed, in such a way that more air guiding structures would be required for solving an airflow issue. Moreover, an airflow volume of the entire system of the projection apparatus is also reduced, thereby reducing the heat dissipation capability of the projection apparatus. 
     The “Description of Related Art” section is only intended for enhancing understanding of the invention and therefore the content disclosed in the “Description of Related Art” section may contain information that does not form the related art already known to people skilled in the art. The disclosure in the “Description of Related Art” section does not mean that the content or the issues addressed by one or more embodiments of the invention are already previously known or recognized by people skilled in the art. 
     The information disclosed in this Background section is only for enhancement of understanding of the background of the described technology and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art. Further, the information disclosed in the Background section does not mean that one or more problems to be resolved by one or more embodiments of the invention were acknowledged by a person of ordinary skill in the art. 
     SUMMARY OF THE INVENTION 
     The invention provides a heat dissipation module with an efficient heat dissipation effect. 
     The invention further provides a projection apparatus including the aforementioned heat dissipation module, to reduce the space consumption in the projection apparatus and have an efficient heat dissipation effect. 
     Other features and advantages of the invention can be further understood by the technical features disclosed in the invention. 
     To achieve one, part, or all of the objectives aforementioned or other objectives, a heat dissipation module of an embodiment of the invention for dissipating heat from a plurality of heating elements, and includes a heat pipe, a dissipation plate, a first heat dissipation fin and a second heat dissipation fin. The heat pipe includes a first portion, a second portion and a third portion connected with the first and the second portions. The first portion and the second portion are disposed in parallel to each other. The third portion of the heat pipe and the heating elements are connected to the heat dissipation plate. The first portion of the heat pipe passes through the first heat dissipation fin. The second portion of the heat pipe passes through the second heat dissipation fin. The heat generated by the heating elements is dissipated by the heat dissipation plate, the first heat dissipation fin and the second heat dissipation fin through a thermal conduction method and a thermal convection method. 
     A projection apparatus provided by another embodiment of the invention includes a chassis, an optical engine, a projection lens and a heat dissipation module. The chassis has an air inlet and an air outlet. The optical engine is disposed inside the chassis and includes a plurality of heating elements. The projection lens is disposed inside the chassis and connected with the optical engine. The heat dissipation module is disposed inside the chassis, and includes a heat pipe, a dissipation plate, a first heat dissipation fin and a second heat dissipation fin. The heat pipe includes a first portion, a second portion and a third portion connected with the first and the second portions. The first portion and the second portion are disposed in parallel to each other. The third portion of the heat pipe and the heating elements are connected to the heat dissipation plate. The first portion of the heat pipe passes through the first heat dissipation fin. The second portion of the heat pipe passes through the second heat dissipation fin. The heat generated by the heating elements is dissipated by the heat dissipation plate, the first heat dissipation fin and the second heat dissipation fin through a thermal conduction method and a thermal convection method. 
     Based on the above, the embodiments of the invention achieve at least one of the following advantages or effects. In this design of the heat dissipation module of the invention, the heat generated by the heating elements which are disposed on the heat dissipation plate is dissipated by a thermal conduction method and a thermal convection method and the heating elements relatively adjacent to the first portion of the heat pipe can also directly dissipated in a thermal convection method. In other words, the design of the heat dissipation module of the invention provides one more heat dissipation method of thermal convection, so as to achieve an efficient heat dissipation effect. Moreover, the projection apparatus using the heat dissipation module of the invention, can achieve an efficient dissipation effect, in addition it can effectively reduce the space consumption in the projection apparatus and reduce volume and noise of the projection apparatus because all the heating elements are disposed on the heat dissipation plate, which are integrated as one heat source. 
     Other objectives, features and advantages of the invention will be further understood from the further technological features disclosed by the embodiments of the invention where there are shown and described preferred embodiments of this invention, simply by way of illustration of modes best suited to carry out the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. 
         FIG. 1  is a schematic diagram of a projection apparatus according to an embodiment of the invention. 
         FIG. 2  is a schematic diagram of a heat dissipation module of the projection apparatus depicted in  FIG. 1 . 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings which form a part hereof, and in which are shown by way of illustration specific embodiments in which the invention may be practiced. In this regard, directional terminology, such as “top,” “bottom,” “front,” “back,” etc., is used with reference to the orientation of the Figure(s) being described. The components of the present invention can be positioned in a number of different orientations. As such, the directional terminology is used for purposes of illustration and is in no way limiting. On the other hand, the drawings are only schematic and the sizes of components may be exaggerated for clarity. It is to be understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the present invention. Also, it is to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless limited otherwise, the terms “connected,” “coupled,” and “mounted” and variations thereof herein are used broadly and encompass direct and indirect connections, couplings, and mountings. Similarly, the terms “facing,” “faces” and variations thereof herein are used broadly and encompass direct and indirect facing, and “adjacent to” and variations thereof herein are used broadly and encompass directly and indirectly “adjacent to”. Therefore, the description of “A” component facing “B” component herein may contain the situations that “A” component directly faces “B” component or one or more additional components are between “A” component and “B” component. Also, the description of “A” component “adjacent to” “B” component herein may contain the situations that “A” component is directly “adjacent to” “B” component or one or more additional components are between “A” component and “B” component. The terms used herein such as “above,” “below,” “front,” “back,” “left,” and “right” are for the purpose of describing directions in the figures only. Accordingly, the drawings and descriptions will be regarded as illustrative in nature and not as restrictive. 
       FIG. 1  is a schematic diagram of a projection apparatus according to an embodiment of the invention.  FIG. 2  is a schematic diagram of a heat dissipation module of the projection apparatus depicted in  FIG. 1 . It should be mentioned that for clarity and descriptive convenience, a part of the elements (e.g., a part of a chassis is omitted, and a part of the chassis is represented by dashed lines. Referring to  FIG. 1  and  FIG. 2 , in the embodiment, a projection apparatus includes a chassis  100 , an optical engine  200 , a projection lens  300  and a heat dissipation module  400 . An air inlet  102  is provided at a side of the chassis  100 , and an air outlet  104  is provided at the other side of the chassis  100 , wherein the air inlet  102  and the air outlet  104  are respectively located at two opposite sides of the chassis  100 . The optical engine  200  is disposed inside the chassis  100  and includes a plurality of heating elements  210 ,  220 ,  230  and  240 , wherein the heating elements  220 ,  230  and  240  include, for example, a plurality of light sources employed to emit an illumination beam, and the heating element  210  which is located on a transmission path of the illuminating beam and capable of converting the illuminating beam to an image beam is, for example, a light valve. In this case, the light valve  210  is a light modulation device, for example, a digital micromirror device (DMD), the invention is not limited thereto. In other embodiments, the light modulation device may also be a reflective liquid crystal on silicon (LCOS) or a transparent liquid crystal panel. The light sources are, for example, solid-state illumination sources, such as light emitting diodes (LED) or laser diodes. In this case, the light sources which include a red LED  220 , a green LED  230  and a blue LED  240  are taken as an example for description. The projection lens  300  is disposed inside the chassis  100 , connected with the optical engine  200  and employed to project the image beam out of the chassis  100 . As illustrated in  FIG. 1 , an air entering direction D 1  of the air inlet  102  and an air exiting direction D 2  of the air outlet  104  of the chassis  100  are not in parallel to a projection direction D 3  of the projection lens  300 . For example, the air entering direction D 1  of the air inlet  102  and the air exiting direction D 2  of the air outlet  104  of the chassis  100  are in perpendicular to the projection direction D 3  of the projection lens  300 , the invention is not limited thereto. The air entering direction D 1  and the air exiting direction D 2  are defined as flowing directions of a cold airflow. 
     Referring again to  FIG. 1  and  FIG. 2 , the heat dissipation module  400  of the embodiment is disposed inside the chassis  100  and includes a heat pipe  410 , a dissipation plate  420 , a first heat dissipation fin  430  and a second heat dissipation fin  440 . The heat pipe  410  includes a first portion  412 , a second portion  414  and a third portion  416  connected with the first portion  412  and the second portion  414 , wherein the first portion  412  and the second portion  414  are disposed in parallel to each other. In this case, the heat pipe  410  is embodied in a U-shape, and the first portion  412  and the second portion  414  are disposed symmetrically to each other. Additionally, a length of the second portion  414  is equal to a length of the first portion  412 , but the invention is not limited thereto. In other embodiments, the length of the second portion  414  may be greater than the length of the first portion  412 , so as to meet a size of the second heat dissipation fin  440 . The third portion  416  of the heat pipe  410  is connected with the heat dissipation plate  420 . The third portion  416  of the heat pipe  410  and the heating elements  210 ,  220 ,  230  and  240  are located on the heat dissipation plate  420 . The heating elements  210 ,  220 ,  230  and  240  are connected with the heat dissipation plate  420 . The third portion  416  of the heat pipe  410  includes a contact portion  416   a , a first connection portion  416   b  and a second connection portion  416   c . The contact portion  416   a  contacts the heat dissipation plate  420  and is connected with the first connection portion  416   b  and the second connection portion  416   c , wherein a diameter of the contact portion  416   a  is greater than a diameter of the first connection portion  416   b  and greater than a pipe diameter of the second connection portion  416   c , thereby increasing a heat dissipation area to improve a heat dissipation efficiency. The first connection portion  416   b  is connected with the first portion  412  and the contact portion  416   a  of the heat pipe  410 , and the second connection portion  416   c  is connected with the second portion  414  and the contact portion  416   a  of the heat pipe  410 . The first portion  412  of the heat pipe  410  passes through the first heat dissipation fin  430 , and the second portion  414  of the heat pipe  410  passes through the second heat dissipation fin  440 . The heating elements  220 ,  230  and  240  are disposed at a side of the heat dissipation plate  420  and adjacent to the second portion  414  of the heat pipe  410 , the heating element  210  is disposed at the other side of the heat dissipation plate  420  and adjacent to the first portion  412  of the heat pipe  410 . 
     It is to be mentioned that the heat pipe  410  is a hollow pipe and made of metal, for example, copper. The heat pipe  410  is internally filled with a cooling liquid, for example, water, and the pipe wall has a capillary structure or added with a porous material for returning the cooling liquid back to a heating end through an action of capillary force. The heat pipe  410  is adapted to transfer the heat from the heat dissipation plate  420 . The U-shaped heat pipe  410  features in the first portion of the heat pipe  410  passing through the first heat dissipation fin  430  and the second portion  414  of the heat pipe  410  passing through the second heat dissipation fin  440 . Specifically, a length L 2  of the second heat dissipation fin  440  along an extension direction E 2  of the second portion  414  is greater than a length L 1  of the first heat dissipation fin  430  along an extension direction E 1  of the first portion  412 . Namely, the length L 2  of the second heat dissipation fin  440  is greater than the length L 1  of the first heat dissipation fin  430 . Orthogonal projections of the heat dissipation plate  420  and the first heat dissipation fin  430  in an extension direction E 3  of the heat dissipation plate  420  has a non-overlapping portion N. Because the length of the second portion  414  of the heat pipe  410  is equal to or slightly greater than the length of the first portion  412 , this means that a part of the first portion  412  of the heat pipe  410  is not blocked by the first heat dissipation fin  430 . In this case, the extension direction E 1  of the first portion  412  and the extension direction E 2  of the second portion  414  are both perpendicular to the air entering direction D 1  of the air inlet  102  and the air existing direction of the air outlet  104 . As illustrated in  FIG. 1 , the first heat dissipation fin  430  does not block the heat dissipation plate  420  in the air entering direction D 1 , and thus, when the cold airflow flowing through the air inlet  102  enters the chassis  100 , the heat generated by the heating element  210  among the heating elements  210 ,  220 ,  230  and  240  may be dissipated to the outside in a direct thermal convection method as well as a thermal conduction and a thermal convection method. In other words, besides the heat generated by the heating elements  210 ,  220 ,  230  and  240  may be dissipated through thermal conduction provided by the heat dissipation plate  420  plus thermal convection provided by the first heat dissipation fin  430  and the second heat dissipation fin  440 , the heating element  210  which is relatively adjacent to the first portion  412  of the heat pipe  410  may also be cooled directly through thermal convection provided by a part of the cold airflow which enters through the air inlet  102  without flowing through the first heat dissipation fin  430 . Moreover, the design of the heat dissipation module  400  of the embodiment provides one more heat dissipation path of thermal convection to achieve an efficient heat dissipation effect. In addition, as the heating element  210  (i.e., the light valve) is not heat-resistant, the heating element  210  is cooled directly by the cold airflow, thereby effectively increasing the lifespan and reliability. 
     Furthermore, the heat dissipation plate  420  of the heat dissipation module  400  is located between the projection lens  300  and the third portion  416  of the heat pipe  410  and on the bottom of the optical engine  200 . Namely, the heat pipe  410  is far away from the projection lens  300  to prevent the influence on the optical performance due to projection lens  300  being heated by the hot air surrounding the heat pipe  410 . The heat dissipation plate  420  is connected with the bottom of the optical engine  200 . Based on a demand of high luminance, the green LED  230  is placed upstream of air flow direction in favor of heat dissipation, and the blue LED  240  which is relatively insensitive to the temperature is placed downstream of air flow direction, thereby preventing other heat sources or optical elements from being influenced, wherein the upstream and the downstream of the air flow direction refer to a sequence of the cold airflow flowing through a plurality of light sources of the heating elements. Therefore, as illustrated in  FIG. 1 , the red LED  220  and the blue LED  240  are located at two sides of adjacent corner of the heat dissipation plate  420 , and the red LED  220  and the blue LED  240  are disposed relatively perpendicular to each other. The green LED  230  and the red LED  220  are disposed adjacent to each other, and the green LED  230  is more adjacent to the light valve  210  than the other LEDs. In addition, the performance of the red LED  220  can be reduced due to high temperature, and thus, in order to improve a heat dissipation efficiency of the red LED  220 , the projection apparatus  10  may further include a heat sink  500 . The heat sink  500  is connected with the red LED  220  to increase a heat dissipation through thermal conduction method. 
     Additionally, in order to increase an intensity of the cold airflow throughout the projection apparatus  10 , the projection apparatus  10  may further include a plurality of first fans  300  (which are schematically illustrated as two in  FIG. 1 ) and a plurality of second fans (which are schematically illustrated as two in  FIG. 1 ). The first fans  600  are disposed inside the chassis  100  and located between the first portion  412  of the heat pipe  410  and the heat dissipation plate  420 . The second fans  700  are disposed inside the chassis  100  and located between the second portion  414  of the heat pipe  410  and the air outlet  104 . In addition, the second fans  700  disposed between the second portion  414  of the heat pipe  410  and the air outlet  104 , and disposed away from the heat sources (the heating elements), such that a space is provided for the airflow (the hot air) to gather and then be exhausted out of the projection apparatus  10  by the second fans  700 . When a part of the cold airflow enters the chassis  100  from the air inlet  102 , it sequentially flows through the first heat dissipation fin  430 /the first portion  412  of the heat pipe  410 , the first fans  600 , the light valve  210 /the projection lens  300 , the green LED  230 /the red LED  220 /the blue LED  240 , the second heat dissipation fin  440 , the second fans  700  and the air outlet  104 , thereby dissipating the heat generated by the heating elements  210 ,  220 ,  230  and  240  from the chassis  100 . 
     In the embodiment, as described above the length L 2  of the second heat dissipation fin  440  being greater than the length L 1  of the first heat dissipation fin  430 , the cold airflow entering through the air inlet  102  of the chassis and the first fans  300  adjacent to the light valve  210  directly aims the cold airflow toward the light valve  210 , without flowing through the first heat dissipation fin  430 , such that more cold airflow may directly transmitted to the light valve  210  to reduce the temperature of the light valve  210 . In other words, the first heat dissipation fin  430  is not disposed between the air inlet  102  and the first fans  600  which are adjacent to the light valve  210 . In addition, a normal line of an active surface (a surface with a micro-lens) of the light valve  210  is perpendicular to the projection direction D 3  of the projection lens. 
     As illustrated in  FIG. 2 , a width W 1  of the first heat dissipation fin  430  is greater than a width W 2  of the second heat dissipation fin  440 . In addition, a volume of the second heat dissipation fin  440  is greater than a volume of the first heat dissipation fin  430 , and thus, the second heat dissipation fin  440  is capable of dissipating more heat from the chassis  100  than the first heat dissipation fin  430 . Therefore, the cold airflow flowing through the first heat dissipation fin  430 , reduces the heat from the projection lens  300  located in downstream of the airflow, and do not affect the optical performance of the projection lens  300 . 
     Based on the above, the embodiments of the invention can achieve at least one of the following advantages or effects. In this design of the heat dissipation module of the invention, the length of the second heat dissipation fin along the extension direction of the second portion of the heat pipe is greater than the length of the first heat dissipation fin along the extension direction of the first portion of the heat pipe, and the first heat dissipation fin does not block the air entering direction towards the heat dissipation plate. Therefore, the heat generated by the heating elements which is disposed on the heat dissipation plate is dissipated by a thermal conduction and a thermal convection method and the heating elements relatively adjacent to the first portion of the heat pipe can also directly dissipated in a thermal convection method. In other words, the design of the heat dissipation module of the invention provides one more heat dissipation method of thermal convection to achieve an efficient heat dissipation effect. Moreover, the projection apparatus using the heat dissipation module of the invention, can achieve an efficient dissipation effect, in addition it may effectively reduce the space consumption in the projection apparatus, reduce volume and noise of the projection apparatus because all the heating elements are disposed on the heat dissipation plate, which are integrated as one heat source. 
     The foregoing description of the preferred embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form or to exemplary embodiments disclosed. Accordingly, the foregoing description should be regarded as illustrative rather than restrictive. Obviously, many modifications and variations will be apparent to practitioners skilled in this art. The embodiments are chosen and described in order to best explain the principles of the invention and its best mode practical application, thereby to enable persons skilled in the art to understand the invention for various embodiments and with various modifications as are suited to the particular use or implementation contemplated. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents in which all terms are meant in their broadest reasonable sense unless otherwise indicated. Therefore, the term “the invention”, “the present invention” or the like does not necessarily limit the claim scope to a specific embodiment, and the reference to particularly preferred exemplary embodiments of the invention does not imply a limitation on the invention, and no such limitation is to be inferred. The invention is limited only by the spirit and scope of the appended claims. The abstract of the disclosure is provided to comply with the rules requiring an abstract, which will allow a searcher to quickly ascertain the subject matter of the technical disclosure of any patent issued from this disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Any advantages and benefits described may not apply to all embodiments of the invention. It should be appreciated that variations may be made in the embodiments described by persons skilled in the art without departing from the scope of the invention as defined by the following claims. Moreover, no element and component in the disclosure is intended to be dedicated to the public regardless of whether the element or component is explicitly recited in the following claims.