Patent Publication Number: US-10788739-B2

Title: Optical engine module

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the priority benefit of China application serial no. 201811364137.X, filed on Nov. 16, 2018. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and makes a part of this specification. 
     BACKGROUND 
     Technical Field 
     The disclosure relates to an optical module, and more particularly to an optical engine module for a projection device. 
     Description of Related Art 
     The projection device is a display device for generating an image. During the image projection, an illumination beam generated by a light source may be converted into an image beam using a light valve, and the image beam may then be projected onto a screen or a wall using lenses. However, in optical engine modules, a heat dissipating device used for conducting heat from the light valve may be bolted onto the casing and it suffers from wobbling, resulting in a degrade in the imaging quality of the projection device. In addition, heat dissipating sheets may be disposed to conduct the heat caused from the light valve and accumulated in the optical engine module outside to the surrounding environment, while an increase in cost may be resulted due to the additionally configured heat dissipating sheets. 
     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 
     The disclosure provides an optical engine module. In the optical engine module, improved stability of the heat dissipating module, preferable heat dissipating efficiency for the light valve, and thus good optical effect may be provided. 
     Other objectives and advantages of the disclosure can be further understood from the technical features disclosed herein. 
     In order to achieve one, part of, or all of the above objectives or other objectives, an embodiment of the disclosure provides an optical engine module, which includes a casing, a light valve, and a compensating module. The casing includes an opening and the light valve includes an active surface. The light valve is disposed on the casing and the active surface of the light valve is exposed from the opening of the casing. The active surface of the light valve is used for providing a light beam. A compensating module is disposed on the casing, and includes an optical compensating element located on a transmission path of the light beam and a heat dissipating support for holding the optical compensating element. When a portion of the active surface is in a first state, the light beam is transmitted to and passes through the optical compensating element. When a portion of the active surface is in a second state, the light beam is transmitted to the heat dissipating support. 
     Based on the above, embodiments of the disclosure have at least one of the following advantages or effects. In the optical engine module of the disclosure, the at least three fixtures are matched with the at least three fixing structures of the casing, so as to securely connect the heat dissipating module to the casing. The heat dissipating module can be prevented from wobbling, and therefore the stability may be improved, thereby improving the heat dissipating efficiency for the light valve and the optical effect effectively. In another optical engine module of the disclosure, a compensating module may be configured not only to support the optical compensating sheet required for the projection device, but also to achieve a heat dissipating and/or light shielding effect in the optical engine module. Therefore, the available space in the optical engine module may be expanded and the cost may be reduced. 
     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 perspective view of an optical engine module according to an embodiment of the disclosure. 
         FIG. 2  is an exploded view of the optical engine module of  FIG. 1 . 
         FIG. 3  is a perspective view of the heat dissipating module from another perspective in the optical engine module of  FIG. 2   e.    
         FIG. 4  is a top schematic view of the optical engine module of  FIG. 1 . 
         FIG. 5  is a perspective view of a partial structure in the optical engine module of  FIG. 2 . 
         FIG. 6  is a perspective view of an optical engine module according to another embodiment of the disclosure. 
         FIG. 7  is an exploded view of the optical engine module of  FIG. 6 . 
     
    
    
     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 perspective view of an optical engine module according to an embodiment of the disclosure.  FIG. 2  is an exploded view of the optical engine module of  FIG. 1 . Please refer to  FIG. 1  and  FIG. 2 , this embodiment provides an optical engine module  100 , which includes a casing  110 , a light valve  120 , a heat dissipating module  130 , at least three fixtures  140 , and a compensating module  200 . Specifically, in the embodiment, the optical engine module  100  further includes a circuit board  160  and a light transmitting module  190 . For example, the circuit board  160  can be a printed circuit board (PCB). The optical engine module  100  may be disposed in a projection device to convert an illumination beam provided from a light source of the projection device into an image beam and the image beam may be further projected onto a projection target (not shown), such as a screen or a wall. In the embodiment, a Reverse Total Internal Prism (RTIR) optical path structure may be configured in the optical engine module  100 , but the disclosure is not limited thereto. 
     The light valve  120  is, for example, a reflective light modulator or a transmissive light modulator. Taking the reflective light modulator as an example, the light valve  120  is, for example, a liquid crystal on silicon panel (LCoS panel), a digital micro-mirror device (DMD), etc. In some embodiments, the light valve  120  may also be a transparent liquid crystal panel, an electro-optical modulator, a magneto-optic modulator, an acousto-optic modulator (AOM), or other transmissive light modulators. The light valve  120  includes an active surface S 1  and a heat interface S 2 . The active surface S 1  includes a plurality of movable reflective mirrors used for receiving the illumination beam and providing the image beam. The heat interface S 2  is used for transferring heat to the surrounding environment. The circuit board  160  is electrically connected to the light valve  120  and is used for changing the states of the plurality of movable reflective mirrors of the light valve  120 , such as from an activated state to a shut-off state, according to an electrical signal. The light transmitting module  190  is, for example, a prism group used for reflecting or refracting the image beam provided by the light valve  120  towards the projection lens. The disclosure does not limit the configuration and the type of the light valve  120 , the circuit board  160 , and the light transmitting module  190 . 
     In the embodiment, the light valve  120  and the light transmitting module  190  are disposed in the casing  110 , and the circuit board  160  is disposed on the casing  110 . Specifically, the casing  110  includes an upper casing  110 _ 1 , a lower casing  110 _ 2 , and an opening  114 . The light valve  120  is disposed in the upper casing  110 _ 1  and is exposed from the opening  114  of the casing  110 . The active surface S 1  is used for providing a light beam (i.e. the image beam described-above). The light transmitting module  190  is located between the upper casing  110 _ 1  and the lower casing  110 _ 2 . The circuit board  160  can be securely fixed onto the casing  110  by using, for example, one or more circuit board fixtures  240  (for example, screws).  FIG. 3  is a perspective view of the heat dissipating module from another perspective in the optical engine module of  FIG. 2 . Please refer to  FIG. 1  to  FIG. 3  at the same time, the heat dissipating module  130  is disposed on the casing  110 , and the circuit board  160  is located between the heat dissipating module  130  and the light valve  120 . The heat dissipating module  130  includes a heat dissipating surface S 3  used for contacting the heat interface S 2  of the light valve  120 , so as to transfer the heat generated from the light valve  120  to the heat dissipating structure of the heat dissipating module  130 . Specifically, in the embodiment, the heat dissipating module  130  includes a protruding part  134  and the heat dissipating surface S 3  is located at the end of the protruding part  134 . In the embodiment, the protruding part  134  is square, but the disclosure is not limited thereto. The circuit board  160  includes a perforation hole  162 , and the protruding part  134  of the heat dissipating module  130  passes through the perforation hole  162  of the circuit board  160 , such that the protruding part  134  may be in contact with the heat interface S 2  of the light valve  120 . Therefore, since the protruding part  134  of the heat dissipating module  130  directly contacts the light valve  120 , the heat from the light valve  120  may be directly transferred to the surrounding environment. 
       FIG. 4  is a top schematic view of the optical engine module of  FIG. 1 . Please refer to  FIG. 1 ,  FIG. 2 , and  FIG. 4  at the same time, the casing  110  further includes at least three fixing structures  112 . The number of the fixing structures  112  and positions of the same correspond respectively to the number of the fixtures  140  and the positions of the same. In other words, the fixing structure  112  and the fixture  140  are disposed in pairs. The number of the fixing structure  112  and that of the fixtures  140  may be three or more, and the following description will be exemplified using three, but the disclosure is not limited thereto. In the optical engine module  100 , the heat dissipating module  130 , the circuit board  160 , and other elements may be securely connected to the casing  110  by matching the fixing structure  112  with the fixture  140 . For example, the casing  110  may include at least one circuit board fixing structure  113 , and at least one circuit board perforations  1601  and  1602  is disposed in the circuit board  160 . For example, the circuit board fixture  240  can pass through the circuit board perforation  1601 , so as to be connected to the circuit board fixing structure  113  of the casing  110 , such that the circuit board  160  is fixed to the casing  110 . Specifically, the circuit board fixing structure  113  may be a fixing column, and the fixing column is internally threaded. The circuit board fixture  240  may be, for example, a screw. The rod portion of the screw passes through the circuit board perforation  1601  of the circuit board, so as to be in threaded-connection with the circuit board fixing structure  113 . However, the disclosure does not limit numbers of the circuit board fixing structure  113  and the circuit board fixture  240 . In other embodiments, two or more circuit board fixing structures  113  and/or two or more circuit board fixtures  240  may be disposed, such that the circuit board may be uniformly stressed onto the casing and fixed to the casing by using the circuit board fixing structures  113  and the circuit board fixtures  240 . For example, in an embodiment in which a casing includes two circuit board fixing structures  113 , the two circuit board fixing structures  113  are symmetrically arranged with respect to the perforation hole  162  on the circuit board, and the perforation hole  162  is the used for allowing the protruding part  134  of the heat dissipating module  130  to pass through. Therefore, the circuit board may be uniformly stressed and a warping may be avoided. The disclosure also does not limit the form of the circuit board fixing structure  113  or the circuit board fixture  240 . In other embodiments, the circuit board fixing structure  113  and the circuit board fixture  240  used for fixing the circuit board  160  may be replaced or partially replaced with other fixing structures and/or fixtures. For example, in other embodiments, the circuit board fixture  240  can be replaced with an adapter  170  (described in detail below). 
     Specifically, in the embodiment, at least one of the fixing structures  112  is a fixing column, and the fixing column is internally threaded. The following description will be exemplified using three fixing columns. The heat dissipating module  130  comprises perforations  132 , the number of which corresponds to the number of fixing structures  112 . The perforations  132  allows the fixtures  140  to pass through respectively and further are securely connected to the fixing structures  112 , that is, the fixtures  140  are disposed to be in match with the fixing structures  112 . Therefore, when the casing  110  is securely connected with the fixture  140 , the horizontal positions of the heat dissipating module  130  and the circuit board  160  relative to the casing  11  may be restricted properly by the columnar configuration of the fixing structure  112 . Thus, a more stable overall structure may be achieved. In other embodiments, the fixing structure  112  may be a fixing perforation, and the fixing perforation is internally threaded, such that the fixtures  140  may pass through the heat dissipating module  130  and the circuit board  160 , so as to be in threaded-connection with the fixing structure  112 , that is, the fixtures  140  are disposed to be in match with the fixing structures  112 . However, the disclosure does not limit the matching method between the fixture  140  and the fixing structure  112 , and they may be directly connected or indirectly connected, by using other elements for example. 
     In the embodiment, the fixture  140  is, for example, a step screw. In other embodiments, a general screw or other types of screws may also be used, and the disclosure is not limited thereto. In the embodiment, on a plane parallel to the heat interface S 2  of the light valve  120 , a plurality of fixtures  140  forms a triangle or other polygons. For example, the three fixtures  140  may not form a line on the plane parallel to the heat interface S 2 . In this way, the heat dissipating module  130  can be prevented from wobbling, and stability of the heat dissipating module  130  may be improved, thereby improving the heat dissipating efficiency for the light valve  120  and the optical effect effectively. 
     In addition, in the embodiment, the optical engine module  100  further includes at least three spring sets  150 . For example, three spring sets  150  are respectively connected between the fixture  140  and the fixing structure  112  of the casing  110 . Specifically, the three spring sets  150  in the embodiment may be sleeved onto the fixture  140 , and more specifically, the three spring sets  150  may be sleeved onto a step portion of the step screw. Additionally or alternatively, the perforation  132  of the heat dissipating module  130  may include a spring bearing surface  133 . When the spring set  150  is sleeved onto the fixture  140  so as to fix the heat dissipating module  130  onto the casing, the spring set  150  abuts the spring bearing surface  133  of the perforation  132 . In this way, a buffer space may be provided between the heat dissipating module  130  and the casing  110 , so as to accommodate the tolerance generated when the heat dissipating module  130  is fixed to the casing  110 . In the embodiment, the spring set  150  is, for example, a helical compression spring, but in other embodiments, a disc spring or a combination of the two may also be selected, and the disclosure is not limited thereto. 
     In the embodiment, the optical engine module  100  may further include at least one adapter  170 . For example, one adapter  170  may be securely connected between one of the fixtures  140  and one of the fixing structures  112 . Specifically, one fixing structure  112  of the casing  110  is securely connected to a corresponding fixture  140  by using an adapter  170 . In other words, in the embodiment, the lengths of the three fixing structures  112  of the casing  110  may be identical or different from one another. The adapter  170  comprises an internally-threaded part  172  and an externally-threaded rod part  174  (the externally-threaded rod part  174  illustrated in  FIG. 2  is for illustrative purpose only). The internally-threaded part  172  is used to be securely connected with one of the fixtures  140 , and the externally-threaded rod part  174  is used to be securely connected with one of the fixing structures  112  of the casing  110 . In the embodiment, the internally-threaded part  172  and the externally-threaded rod part  174  are integrally formed. For example, the internally-threaded part  172  and the externally-threaded rod part  174  may be formed into an adapter screw, but the disclosure is not limited thereto. Therefore, by the matching of the adapter  170  with the fixing structure  112 , the fixture  140  may be used to further enhance the stability of the heat dissipating module  130  and the circuit board  160 . At the same time, the distance between the heat dissipating module  130  and the circuit board  160  can be changed by changing the height of the adapter  170 , thereby providing good heat dissipating effect. Additionally or alternatively, the adapter  170  may also be used to assist in fixing the circuit board  160 . For example, the externally-threaded rod part  174  of the adapter  170  can pass through the circuit board perforation  1602  of the circuit board  160 , so as to be in threaded-connection with one of the fixing structures  112 . Under such circumstance, the fixing structure  112  connected to the adapter  170  and the circuit board fixing structure  113  described-above are positioned to be at two opposite sides of the perforation hole  162  of the circuit board  160  and to be symmetrically arranged, so as to facilitate stability of the circuit board and achieve a uniform stress distribution on the casing  110 . 
     In addition, the optical engine module  100  may also include at least one auxiliary element  180  sleeved onto an adapter  170  and located between the adapter  170  and a fixing structure  112 , for example. In the embodiment, the auxiliary element  180  may be an elastic member such as a disc spring, but in other embodiments, a helical compression spring similar to the spring set  150  may also be used, and the disclosure is not limited thereto. In this way, the elastic force generated from the connection of the fixture  140 , the adapter  170 , the auxiliary element  180 , and the fixing structure  112  is approximately equal to two times the elastic force generated from the connection of directly connecting other fixture  140  and the fixing structure  112 . For example, when assembly is completed, the pressure applied to the light valve  120  may not exceed 12 kg. Therefore, a buffer space may be further provided between the heat dissipating module  130  and the casing  110 , so as to accommodate the tolerance generated when the heat dissipating module  130  is fixed to the casing  110 . 
     In the embodiment, in the case where the adapter  170  and the auxiliary element  180  are disposed between the fixture  140  and the fixing structure  112 , the fixing structure  112  may be designed as a fixing column with a lower height. In other words, the heights of the fixing structures  112  may be identical or different from one another. Alternatively, in the case where the adapter  170  and the auxiliary element  180  are disposed between the fixture  140  and the fixing structure  112 , the fixture  140  may be designed as a screw or a step screw with a shorter length, so as to achieve a stable match with the casing, but the disclosure is not limited thereto. 
       FIG. 5  is a perspective view of a partial structure in the optical engine module of  FIG. 2 . Please refer to  FIG. 1 ,  FIG. 2 , and  FIG. 5 , in the embodiment, the compensating module  200  is disposed on the casing  110  and can be inserted into the casing  110  from a notch  116  of the casing  110 , so as to complete the assembly. Specifically, the compensating module  200  includes an optical compensating element  220  and a heat dissipating support  210 . The heat dissipating support  210  is located between the light valve  120  and the optical compensating element  220 . The optical compensating element  220  is, for example, a B270 optical compensating sheet, and is located on the transmission path of the light beam. The optical compensating element  220  may be used to compensate for the optical path difference of the light beam. The heat dissipating support  210  is used for holding the optical compensating element  220 . The light transmitting module  190  is located between the light valve  120  and the optical compensating element  220  of the compensating module  200 . 
     The active surface S 1  of the light valve  120  can be controlled by an electrical signal and therefore may be switched into different states. In the description hereinafter, a first state is defined as a state in which, for example, a part of the movable reflective mirrors included in the light valve  120  is activated. Under this state, the part of the movable reflective mirrors converts an illumination bean in the optical engine module  100  into an image beam, and the image beam may then be transmitted to a projection lens. A second state is defined as a state in which, for example, a part of the movable reflective mirrors included in the light valve  120  is shut off. Under this state, the part of the movable reflective mirrors may not transmit the image beam to the projection lens. In the embodiment, when some of the reflective mirrors in the light valve  120  are in the first state, the light beam is transmitted to and passes through the optical compensating element  220 . When the other reflective mirrors in the light valve  120  is in the second state, the light beam may be transmitted to the heat dissipating support  210 . Therefore, heat can be conducted to the heat dissipating support  210  for dissipating. In other words, in the embodiment, the compensating module  200  may be configured not only to support the optical compensating sheet required for the projection device, but also to achieve a heat dissipating and/or light shielding effect in the optical engine module  100 . Therefore, the available space in the optical engine module  100  may be expanded, and/or the cost may be reduced. Specifically, in the embodiment, the cross-section of the heat dissipating support  210  is L-shaped and the heat dissipating support  210  may include a heat dissipating part  212  and a support part  214 . The heat dissipating part  212  can be fixed onto the casing  110 . The support part  214  can be used for holding the optical compensating element  220  and the support part  214  can pass through the notch  116  on the casing  110 , so that the optical compensating element  220  supported by the heat dissipating support  210  is located on the transmission path of the light beam. In a configuration including a RTIR optical path structure for example, the support part  214  of the heat dissipating support  210  and the light valve  120  are respectively located on two adjacent sides of the light transmitting module  190 , but the disclosure is not limited thereto. In the embodiment, the heat dissipating part  212  and the support part  214  are integrally formed, but in other embodiments, the heat dissipating part  212  and the support part  214  may be independent elements, which can be assembled to constitute the heat dissipating support  210 . 
     In the embodiment, the heat dissipating support  210  further includes a plurality of clamp structures  216  used for clamping the optical compensating element  220 . In addition, in the embodiment, the heat dissipating support  210  may further include a plurality of grooves  218 , and the compensating module  200  may further include adhesives  230 . The adhesives  230  can be filled in the grooves  218 . In the embodiment, the adhesive  230  may be an ultraviolet (UV) glue, but the disclosure is not limited thereto. Therefore, the optical compensating element  220  may be restricted in position on the heat dissipating support  210  by using the clamp structure  216  and further adhered to the heat dissipating support  210  by using the adhesive  230 . In this way, the stability of the compensating module  200  can be further improved. Thus good optical effect may be provided by the optical engine module  100 . The disclosure does not limit the number and position of the plurality of clamp structures  216  (for example, 2 to 4 or more). The plurality of clamp structures  216  may be symmetrically or asymmetrically disposed with respect to the clamped optical compensating element  220 . 
       FIG. 6  is a perspective view of an optical engine module according to another embodiment of the disclosure.  FIG. 7  is an exploded view of the optical engine module of  FIG. 6 . Please refer to  FIG. 6  and  FIG. 7 , an optical engine module  100 A of the embodiment is similar to the optical engine module  100  of  FIG. 1 . The difference between the two is that in the present embodiment, the optical engine module  100 A includes a TIR optical path structure. In this embodiment, the support part  214  of the heat dissipating support  210  in the compensating module  200  and the light valve  120  (not shown) are respectively located on opposite sides of the light transmitting module  190 . Therefore, in the embodiment, when some the reflective mirrors in the light valve  120  are in the first state, the light beam is transmitted through the optical compensating element  220 . When the other reflective mirrors in the light valve  120  is in the second state, the light beam is transmitted to the heat dissipating support  210  along the lateral direction. In this way, the compensating module  200  may be configured not only to support the optical compensating sheet required for the projection device, but also to achieve a heat dissipating and/or light shielding effect in the optical engine module  100 . Therefore, the available space in the optical engine module  100  may be further expanded, and/or the cost may be reduced. 
     Based on the above, the embodiments of the disclosure have at least one of the following advantages or effects. In the optical engine module of the disclosure, the at least three fixtures are matched with the at least three fixing structures of the casing, so as to securely connect the heat dissipating module to the casing. The heat dissipating module can be prevented from wobbling, and therefore the stability may be improved, thereby improving the heat dissipating efficiency for the light valve and the optical effect effectively. The foregoing description of the preferred embodiments of the invention includes 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.