Patent Publication Number: US-2023161235-A1

Title: Optical engine module and projection apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the priority benefit of Chinese application no. 202111412224.X, filed on Nov. 25, 2021. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification. 
     BACKGROUND 
     Technical Field 
     The disclosure relates to an optical engine module and a projection apparatus. 
     Description of Related Art 
     A projection apparatus is a display device configured to generate large-size images. The imaging principle of the projection apparatus is to convert an illumination light beam generated by a light source into an image light beam with an optical engine module, and then project the image light beam onto a screen or a wall surface through a lens module. During the above process, relevant optical elements involved in beam conversion are also accompanied by accumulation of heat. Therefore, how to provide effective heat dissipation for the optical elements has become an important issue in projection technology. 
     Current heat dissipation means mostly provide cooling airflow to blow a casing of the optical engine module, but heat dissipation effects thereof on the optical elements disposed in the casing are limited. Another heat dissipation means is to blow the cooling airflow directly toward the optical elements in the casing, which can directly dissipate the optical elements, but is accompanied by destruction of dust tightness of the optical engine module in the casing. Thus, dust and even foreign objects from the external environment are likely to be brought in by the airflow and cause damage to the optical elements. 
     Based on the above-mentioned heat dissipation means, relevant issues may still arise. Therefore, how to provide an improved heat dissipation means for the projection apparatus and the optical engine module therein is actually an issued to be taken into consideration by those skilled in the related fields. 
     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 was acknowledged by a person of ordinary skill in the art. 
     SUMMARY 
     The disclosure provides an optical engine module and a projection apparatus, in which a fixing member and a heat dissipation fin group is disposed on at least one side surface of an optical element disposed in the optical engine module, and the heat dissipation fin group extends out of the casing, so that heat can be smoothly dissipated from the optical engine module. 
     Other objectives and advantages of the disclosure may be further understood from the technical features disclosed in the disclosure. 
     To achieve one, some, or all of the above-mentioned objectives or other objectives, an embodiment of the disclosure provides an optical engine module adapted for a projection apparatus. The optical engine module includes a casing, an optical element, a fixing member, and a heat dissipation fin group. The optical element is disposed in the casing. The optical element has a first surface, a second surface, and a plurality of side surfaces. Each of the side surfaces is adjacent between the first surface and the second surface. The fixing member is disposed on at least one of the side surfaces of the optical element, and is configured to fix the optical element. The fixing member and the optical element are fixed in the casing. The heat dissipation fin group is disposed on the fixing member and extends out of the casing. 
     To achieve one, some, or all of the above-mentioned objectives or other objectives, an embodiment of the disclosure provides a projection apparatus including a light source, an optical engine module, and a lens module. The light source is configured to provide an illumination light beam. The optical engine module is configured to convert the illumination light beam into an image light beam. The lens module is configured to project the image light beam. The optical engine module includes a casing, an optical element, a fixing member, and a heat dissipation fin group. The optical element is disposed in the casing. The optical element has a first surface, a second surface, and a plurality of side surfaces. Each of the side surfaces is adjacent between the first surface and the second surface. The fixing member is disposed on at least one of the side surfaces of the optical element, and is configured to fix the optical element. The fixing member and the optical element are fixed in the casing. The heat dissipation fin group is disposed on the fixing member and extends out of the casing. 
     Based on the foregoing, in the optical engine module of the projection apparatus, the fixing member is disposed on at least one side surfaces of the optical element. In addition, both the fixing member and the optical element are disposed in the casing of the optical engine module. Then, the heat dissipation fin group is disposed on the fixing member and extends from the fixing member out of the casing. Accordingly, heat accumulated by light conversion of the optical element can smoothly pass through the heat dissipation fin group and be dissipated out of the casing of the optical engine module, which can thus provide effective heat dissipation means for the optical engine module when accompanied with heat dissipation components of the projection apparatus. 
     Other objectives, features and advantages of the present invention will be further understood from the further technological features disclosed by the embodiments of the present invention wherein 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 top view of a projection apparatus according to an embodiment of the disclosure. 
         FIG.  2    is a simple block diagram of an optical system of the projection apparatus of  FIG.  1   . 
         FIG.  3    is an exploded view of an optical element. 
         FIG.  4    is a partial top view of the optical engine module of  FIG.  1   . 
         FIG.  5    is a simple schematic diagram of another optical element in the casing. 
         FIG.  6    and  FIG.  7    are respectively schematic diagrams of optical elements according to different embodiments. 
     
    
    
     DESCRIPTION OF THE 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. Accordingly, the drawings and descriptions will be regarded as illustrative in nature and not as restrictive. 
       FIG.  1    is a top view of a projection apparatus according to an embodiment of the disclosure, where some members are omitted so that the configuration state of the optical system inside the projection apparatus can be clearly identified.  FIG.  2    is a simple block diagram of an optical system of the projection apparatus of  FIG.  1   . With reference to  FIG.  1    and  FIG.  2    together, in this embodiment, a projection apparatus  200  includes an apparatus casing  220  and a light source  210 , an optical engine module  100 , and a lens module  250  disposed in the apparatus casing  220 . The light source  210  is configured to provide an illumination light beam L 1 . The optical engine module  100  is configured to convert the illumination light beam L 1  into an image light beam L 2 , so that the lens module  250  may adjust the image light beam L 2  and then project the image light beam L 2  out of the projection apparatus  200 . 
     As shown in  FIG.  1   , the light source  210  includes four light-emitting elements H 1 , H 2 , H 3 , and H 4  and light combining elements C 1 , C 2 , and C 3 . The light combining elements C 1  and C 3  include, for example, a dichroic mirror, and the light combining element C 2  includes, for example, a condenser lens element, but other embodiments are not limited thereto. It can be understood that the positions and structures of the light combining elements C 1 , C 2 , and C 3  in the figure only serve as examples, and are not limited by the disclosure. In this embodiment, light beams generated by the four light-emitting elements H 1 , H 2 , H 3 , and H 4  are transmitted to the light combining elements C 1 , C 2 , and C 3  to be combined into the illumination light beam L 1 . In this embodiment, the light-emitting element H 1  may be, for example, a green light-emitting module. The light-emitting element H 2  may be, for example, a blue light-emitting diode (LED). The light-emitting element H 3  may be, for example, a blue light-emitting diode. The light-emitting element H 4  may be, for example, a red light-emitting diode. The green light-emitting module of the light-emitting element H 1  may include a blue light-emitting diode and a phosphor powder layer. The phosphor powder layer may be disposed between the blue light-emitting diode of the light-emitting element H 1  and the light combining element C 1 , and the phosphor powder layer may convert blue light into green light. One side of the phosphor powder layer receives a blue light beam generated by the blue light-emitting diode of the light-emitting element H 1 , and the other side of the phosphor powder layer receives a blue light beam generated by the light-emitting element H 3  and converts the blue light beams into a green light beam. As such, intensity of the green light beam can be increased. 
     Then, the optical engine module  100  includes a plurality of optical elements  120  and a light valve  160 . The optical engine module  100  receives the illumination light beam L 1  generated by the light source  210 , and the plurality of optical elements  120  and the light valve  160  of the optical engine module  100  are adapted to convert the illumination light beam L 1  into the image light beam L 2 . Further, as referred to in this embodiment, the optical element  120  is a polarization converter, while the light valve  160  may include a liquid crystal on silicon (LCoS) panel or a transmissive liquid crystal panel. Accordingly, the illumination light beam L 1  passing through the optical elements  120  may be incident to a polarizing beam splitter (PBS, not shown), may be reflected by the polarizing beam splitter to the light valve  160 , and may then be reflected by the light valve  160  and pass through the polarizing beam splitter to form the image light beam L 2  to be transmitted to the lens module  250 . Here, the polarization direction of the light beam is changed after the light beam is reflected by the light valve  160 , so the light beam reflected by the light valve  160  can pass through the polarizing beam splitter. In another embodiment, it is also possible to dispose an optical wave plate to change the polarization direction of the light beam. The architecture of the light valve  160  is not limited to that shown in this embodiment. 
     As mentioned above, the process of light beam conversion of the optical system causes heat to be accumulated on the optical element, so it is necessary to further provide corresponding heat dissipation countermeasures. 
       FIG.  3    is an exploded view of an optical element.  FIG.  4    is a partial top view of the optical engine module of  FIG.  1   , which focuses on the optical engine module  100 , and particularly on the optical element  120 . With reference to  FIG.  1   ,  FIG.  3   , and  FIG.  4   , the optical engine module  100  of this embodiment further includes a casing  110 , a fixing member  130 , and a heat dissipation fin group  140 . The optical element  120  is exemplified by a polarization converter, which includes an optical element body  121  and metal gratings  122 . The optical element  120  is disposed in the casing  110 . The optical element  120  has an optical axis LX, a first surface S 1 , a second surface S 2 , and a plurality of side surfaces S 3  to S 6 . Each of the side surfaces S 3  to S 6  is adjacent between the first surface S 1  and the second surface S 2 . Here, the first surface S 1  is the light-incident surface of the optical element  120 , and the second surface S 2  is the light-emitting surface of the optical element  120 . The fixing member  130  (e.g., metal or heat dissipation material) is disposed on the side surfaces S 3  and S 5  of the optical element  120 , and is configured to fix the optical element  120  in the casing  110 . The heat dissipation fin group  140  is disposed on the fixing member  130  and extends out of the casing  110 . 
     To be specific, the heat dissipation fin group  140  includes a plurality of fins  141  and  142  extending from a base surface  131  (e.g., parallel to the side surfaces S 3  and S 5 ) of the fixing member  130 . Each of the fins  141  and  142  extends away from the optical element  120  and extend out of the casing  110  (e.g., an extension direction of the fins  141  and  142  is parallel to a normal of the side surfaces S 3  and S 5 ). As mentioned above, the optical element  120  of this embodiment exemplified by a polarization converter, which includes the optical element body  121  and a pair of metal gratings  122 . One of the pair of metal gratings  122  is disposed on one side of the optical element body  121  to form the first surface S 1 , and the other of the pair of metal gratings  122  is disposed on the other side of the optical element body  121  to form the second surface S 2 . In view of this, in this embodiment, the pair of metal gratings  122 , the fixing member  130 , and the heat dissipation fin group  140  may be further manufactured with metal materials into an integrally formed structure, which helps to simplify the manufacturing process and increase the structural strength. 
     Moreover, the optical engine module  100  further includes a soft member  150 . The soft member  150  is disposed on the fixing member  130  and abuts between the fixing member  130  and the casing  110  (e.g., the base surface  131  and an inner surface of the casing  110 ). In the meantime, two soft members  150  are shown respectively surrounding the fins  141  and  142 . Therefore, when assembled to the casing  110 , the soft member  150  may serve as a sealing member to maintain sealability of a space where the optical element  120  is located in the casing  110 . In other words, with the soft member  150  serving as a structure isolating the inner and outer spaces of the casing  110 , the fixing member  130  and the optical element  120  can be maintained in the casing  110 , exposing only the fins  141  and  142  out of the casing  110 . Accordingly, dust tightness of the optical engine module  100  inside the casing  110  can be ensured. 
     In addition, with reference to  FIG.  1   , the projection apparatus  200  of this embodiment also includes a plurality of fans  231 ,  232 , and  233 , a plurality of heat dissipation fin groups  241 ,  242 , and  244 , and a heat pipe  243 , to accordingly provide heat dissipation in the apparatus casing  220 . The apparatus casing  220  of this embodiment has a corresponding opening (not shown), and airflow is thus generated by the operation of the fans  231 ,  232 , and  233 . Further, an airflow F 1  from the external environment with a relatively low temperature is drawn into the apparatus casing  220  and travels through the heat dissipation fin groups  241 ,  242 , and  244 , the heat pipe  243 , and the members disposed in the apparatus casing  220  to exchange heat to form an airflow F 2 . Then, the airflow F 2  with a high temperature is discharged out of the apparatus casing  220 . From the above, the required heat dissipation is achieved. 
     More importantly, due to the configuration relationship between the optical element  120 , the fixing member  130 , and the heat dissipation fin group  140  relative to the casing  110  in the optical engine module  100 , the airflow generated by the fans  231 ,  232 , and  233  in the apparatus casing  220  also dissipates heat from the heat dissipation fin group  140  that extends out of the casing  110  of the optical engine module  100 , while the sealability in the casing  110  is also maintained. 
       FIG.  5    is a simple schematic diagram of another optical element in the casing. With reference to  FIG.  5   , it should also be mentioned in this embodiment that, in order to provide heat dissipation for the optical element  120 , the optical element  120  and the fixing member  130  are thus fixed together in the casing  110 , and the heat dissipation fin group  140  extends out of the casing  110  to serve for heat dissipation. Therefore, there is no significant heat accumulation for other optical elements of the optical engine module  100 , particularly those that are not involved with light beam conversion, so they may be accordingly changed to be movably assembled in the casing  110  to serve to compensate for tolerances of member assembly and adjust the light path. Here, an optical element  171  is taken as an example, which is, for example, a lens element array, which is located before the optical element  120  on the light path of the illumination light beam L 1  generated by the light source  210 . Here, in the axial direction of transmission of the light beam, an elastic member A 2  is disposed one side of the optical element  171 , so that the optical element  171  abuts the casing  110  via the elastic member A 2 , and an adjusting member A 1  (e.g., a screw) is disposed on the other side of the optical element  171 , and is movably screwed to a rib structure of the casing  110  and abuts the optical element  171 . Accordingly, when mounting the optical element  171 , a user can adjust the position of the optical element  171  on the light path through the relative action of the elastic member A 2  and the adjusting member A 1 , as indicated by the adjustment axis shown by the double arrow in  FIG.  5   . 
     From the above, it can be further understood that, in order to effectively reduce the heat generated by the optical engine module  100 , a corresponding heat dissipation structure such as the optical element  120  may be provided for those performing light beam conversion and may be fixed in the casing  110 . In terms of the assembly process, configuration of optical elements (e.g., the optical element  171 ) without significant heat accumulation is changed to a movable and adjustable state, so that the optical engine module  100  can meet the requirements of both assembly accuracy and heat dissipation. In other words, two other optical elements  172  and  173  as shown in  FIG.  4    can provide different corresponding means according to the above conditions, so that the optical engine module  100  can meet the above requirements. 
       FIG.  6    and  FIG.  7    are respectively schematic diagrams of optical elements according to different embodiments. With reference to  FIG.  6    in comparison with  FIG.  3   , those with the same reference numerals or with no reference numerals in  FIG.  6    and in  FIG.  3    have the same structural features as. Different from the above embodiments, in this embodiment, a plurality of fixing members similar to the fixing member  130  covers the side surfaces S 3  to S 6  of the optical element  120  to form a frame  330 , which facilitates the convenience of assembly of the optical element  120  and the casing  110 . In addition, the frame  330  is taken as the protective structure of the optical element  120 . In the meantime, in this embodiment, two of base surfaces  331  (equivalent to a left base surface and a right base surface, with only the left base surface being labeled here) of the frame  330  serve for forming the heat dissipation fins  141  and  142 . In another embodiment not shown, the frame  330  may also have two other base surfaces, namely an upper base surface and a lower base surface, for forming heat dissipation fins for heat dissipation. It should be noted that the shape of the optical element is not limited by this embodiment. The optical element  120  of the above embodiments has a rectangular cuboid shape and thus has the four side surfaces S 3  to S 6 . In another embodiment not shown, when the optical element is, for example, a circular lens element, a fixing member that matches the shape of the optical element may still be provided, and a plurality of fins extending from the fixing member may be formed, to achieve heat dissipation similar to that of the above embodiments. In brief, any fixing member may be applied to this embodiment as long as the provided fixing member is suitable for forming fins thereon extending away from the optical axis of the optical element. 
     With reference to  FIG.  7    in comparison with  FIG.  3   , different from the above embodiments, this embodiment not only includes the frame  330  of the above embodiment, but also provides a soft member  350 . In addition, the soft member  350  not only surrounds the fins  141  and  142  on the fixing member  130 , but also extends through all the base surfaces of the frame  330 . In other words, the optical element  120  can abut the casing  110  entirely through the surrounding soft member  350 , and maintains the sealability of the space where the optical element  120  is located in the casing  110 . 
     In summary of the foregoing, in the above embodiment of the disclosure, in the optical engine module of the projection apparatus, the fixing member is disposed on at least one side surfaces of the optical element. In addition, both the fixing member and the optical element are disposed in the casing of the optical engine module. Then, the heat dissipation fin group is disposed on the fixing member and extends from the fixing member out of the casing. Accordingly, heat accumulated by light conversion of the optical element can smoothly pass through the heat dissipation fin group and be dissipated out of the casing of the optical engine module, which can thus provide effective heat dissipation means for the optical engine module when accompanied with heat dissipation components of the projection apparatus. 
     In other words, a designer may appropriately adjust the relevant structural design depending on the heat generation state of the optical engine module. In other words, the structural configuration of the fixing member and the heat dissipation fin group described in the disclosure may be applied to the optical element that shows obviously heat accumulation and needs heat dissipation, while those without obvious heat accumulation may be adjusted to be movably assembled, so that the optical engine module and the projection apparatus using the optical engine module can meet the requirements of assembly accuracy and heat dissipation. 
     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. Moreover, these claims may refer to use “first”, “second”, etc. following with noun or element. Such terms should be understood as a nomenclature and should not be construed as giving the limitation on the number of the elements modified by such nomenclature unless specific number has been given. 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 present invention as defined by the following claims. Moreover, no element and component in the present disclosure is intended to be dedicated to the public regardless of whether the element or component is explicitly recited in the following claims.