Abstract:
A light combination device includes a reflective element and a first color separating element. The reflective element guides first color light beams emitted from at least a first light source and a second light source to propagate in a first direction. The first light source and the second light source are differently positioned in a space. The first color separating element transmits the first color light beams and reflects second color light beams emitted from at least a third light source and a fourth light source. The third light source and the fourth light source are differently positioned in the space. The first color separating element has a coating curved surface, and a curvature of the coating curved surface is varied according to positions of the third light source and the fourth light source to guide the second color light beams to propagate in the first direction.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    a. Field of the Invention 
         [0002]    The invention relates to a light combination device. 
         [0003]    b. Description of the Related Art 
         [0004]    Referring to  FIG. 3 , multiple light-emitting diodes are used as light sources. A red light-emitting diode (LED)  102 R, a green LED  102 G, and a blue LED  102 B scattering in an illumination system  100  are respectively disposed on a first heat-dissipating element  104 , a second heat-dissipating element  106 , and a third heat-dissipating element  108 . An emitting light beam of the red LED  102 R passes through a dichroic mirror  112  and a dichroic mirror  114  in succession and then enters a light integration rod  116 . The emitting light beam of the green LED  102 G is reflected by the dichroic mirror  112 , passes through the dichroic mirror  114 , and then enters the light integration rod  116 . The emitting light beam of the blue LED  102 B is reflected by the dichroic mirror  114  and then enters the light integration rod  116 . Though the above optical configuration may achieve the effect of mixing different light beams having their respective colors, it fails to mix light beams having an identical color but from multiple light sources differently positioned in space. 
         [0005]    Referring to  FIG. 4 , Taiwan patent publication no. 200819785 discloses a light-consolidating device  200  that includes a reflective lamp cover  202 , a lamp  204 , a lamp  206 , a light-condensing lamp cover  208  corresponding to the lamp  204 , and a light-condensing lamp cover  212  corresponding to the lamp  206 . The light-condensing lamp cover  208  and the light-condensing lamp cover  212  respectively guide emitting light beams of the lamp  204  and the lamp  206  to a focus  214  of the reflective lamp cover  202 , and the reflective lamp cover  202  reflects incoming light beams focused on the focus  214  to allow the incoming light beams to propagate in an identical direction. Further, Taiwan patent no. M317024 discloses a backlight lamp using an arc reflector or a parabolic reflector to consolidate light beams. Also, US patent publication no. 20090190347 discloses a flooding light using a parabolic reflector to consolidate light beams. However, these designs merely disclose the way of combining light beams from multiple typical lamps but not the way of combining light beams propagating in a dichroic optic of an optical projection system. 
       BRIEF SUMMARY OF THE INVENTION 
       [0006]    The invention provides a light combination device capable of combining light beams with different colors, and each of the light beams having an identical color is emitted from multiple light sources. 
         [0007]    Other objects and advantages of the invention may be further illustrated by the technical features broadly embodied and described as follows. 
         [0008]    In order to achieve one or a portion of or all of the objects or other objects, one embodiment of the invention provides a light combination device. The light combination device includes a reflective element and a first color separating element. The reflective element is suitable for guiding first color light beams emitted from at least a first light source and a second light source to propagate in a first direction, and the first light source and the second light source are differently positioned in a space. The first color separating element is suitable for transmitting the first color light beams and reflecting second color light beams emitted from at least a third light source and a fourth light source. The third light source and the fourth light source are differently positioned in the space. The first color separating element has a coating curved surface, and a curvature of the coating curved surface is varied according to positions of the third light source and the fourth light source to guide the second color light beams to propagate in the first direction. 
         [0009]    According to another embodiment of the invention, a light combination device includes a first color separating element, a second color separating element, and a third color separating element. The first color separating element is suitable for reflecting first color light beams emitted from at least a first LED and a second LED and guiding the first color light beams to propagate in a first direction. The first LED and the second LED are differently positioned in a space. The first color separating element has a first coating curved surface, and a curvature of the first coating curved surface of the first color separating element is varied according to positions of the first LED and the second LED. The second color separating element is suitable for transmitting the first color light beams and reflecting second color light beams emitted from at least a third LED and a fourth LED, and the third LED and the fourth LED are differently positioned in the space. The second color separating element has a second coating curved surface, and a curvature of the second coating curved surface of the second color separating element is varied according to positions of the third LED and the fourth LED to guide the second color light beams to propagate in the first direction. The third color separating element is suitable for transmitting the first color light beams and the second color light beams and reflecting third color light beams emitted from at least a fifth LED and a sixth LED, and the fifth LED and the sixth LED are differently positioned in the space. The third color separating element has a third coating curved surface, and a curvature of the third coating curved surface of the third color separating element is varied according to positions of the fifth LED and the sixth LED to guide the third color light beams to propagate in the first direction. 
         [0010]    In one embodiment, each of the first LED and the second LED comprises a green LED, each of the third LED and the fourth LED comprises a blue LED, and each of the fifth LED and the sixth LED comprises a red LED. The first color separating element reflects green light beams, the second color separating element reflects blue light beams and transmits the green light beams, and the third color separating element reflects red light beam and transmits the green light beams and the blue light beams. 
         [0011]    In one embodiment, the first coating curved surface of the first color separating element comprises a first sub curved surface and a second sub curved surface symmetrically formed and having an identical curvature, the second coating curved surface of the second color separating element comprises a third sub curved surface and a fourth sub curved surface symmetrically formed and having an identical curvature, and the third coating curved surface of the third color separating element comprises a fifth sub curved surface and a sixth sub curved surface symmetrically formed and having an identical curvature. 
         [0012]    The embodiment or the embodiments of the invention may have at least one of the following advantages. According to the above embodiments, light beams from multiple red LEDs, multiple green LEDs, and multiple blue LEDs are mixed up and then transmitted in an identical direction. Therefore, light beams with different colors are allowed to combine together, and the light beams having an identical color are emitted from multiple light sources differently positioned in the space. 
         [0013]    Other objectives, features and advantages of the invention will be further understood from the further technological features disclosed by the embodiments of the 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 
         [0014]      FIG. 1  shows a schematic diagram of a light combination device according to an embodiment of the invention. 
           [0015]      FIG. 2  shows a schematic diagram of a light combination device according to another embodiment of the invention. 
           [0016]      FIG. 3  shows a schematic diagram of a conventional illumination system. 
           [0017]      FIG. 4  shows a schematic diagram of a conventional light-consolidating device. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0018]    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. 
         [0019]    Referring to  FIG. 1 , the light combination device  10  includes a first color separating element  12 , a second color separating element  14 , and a third color separating element  16 . The first color separating element  12  is suitable for reflecting green light beams IG emitted from a first green light-emitting diode (LED)  22 G and a second green LED  24 G and guiding the green light beams IG to substantially propagate in a first direction D 1 . The first green LED  22 G and the second green LED  24 G are differently positioned in a space. For example, the first green LED  22 G and the second green LED  24 G are positioned on two sides of the first color separating element  12 , as shown in  FIG. 1 . The first color separating element  12  has a coating curved surface, and the coating curved surface has a first sub curved surface  121  and a second sub curved surface  122 . The first sub curved surface  121  and the second sub curved surface  122  are symmetrically formed and have an identical curvature. The first sub curved surface  121  of the first color separating element  12  corresponds to the first green LED  22 G in position, and the first sub curved surface  121  is suitable for reflecting the green light beam IG from the first green LED  22 G and guiding the green light beam IG to substantially propagate in the first direction D 1 . The second sub curved surface  122  of the first color separating element  12  corresponds to the second green LED  24 G in position, and the second sub curved surface  122  is suitable for reflecting the green light beam IG from the second green LED  24 G and guiding the green light beam IG to substantially propagate in the first direction D 1 . 
         [0020]    The second color separating element  14  is suitable for transmitting the green light beams IG, reflecting blue light beams IB emitted from a first blue LED  22 B and a second blue LED  24 B, and guiding the blue light beams IB to propagate in the first direction D 1 . The first blue LED  22 B and the second blue LED  24 B are differently positioned in the space. For example, the first blue LED  22 B and the second blue LED  24 B are positioned on two sides of the second color separating element  14 , as shown in  FIG. 1 . The second color separating element  14  has a coating curved surface, and the coating curved surface has a first sub curved surface  141  and a second sub curved surface  142 . The first sub curved surface  141  and the second sub curved surface  142  are symmetrically formed and have an identical curvature. The first sub curved surface  141  of the second color separating element  14  corresponds to the first blue LED  22 B in position. The first sub curved surface  141  of the second color separating element  14  is suitable for transmitting the green light beam IG, reflecting the blue light beam IB from the first blue LED  22 B, and guiding the blue light beam IB to substantially propagate in the first direction D 1 . The second sub curved surface  142  of the second color separating element  14  corresponds to the second blue LED  24 B in position. The second sub curved surface  142  of the second color separating element  14  is suitable for transmitting the green light beam IG, reflecting the blue light beam IB from the second blue LED  24 B, and guiding the blue light beam IB to substantially propagate in the first direction D 1 . 
         [0021]    The third color separating element  16  is suitable for transmitting the green light beams IG and the blue light beams IB, reflecting red light beams IR emitted from a first red LED  22 R and a second red LED  24 R, and guiding the red light beams IR to propagate in the first direction D 1 . The first red LED  22 R and the second red LED  24 R are differently positioned in space. For example, the first red LED  22 R and the second red LED  24 R are positioned on two sides of the third color separating element  16 , as shown in  FIG. 1 . The third color separating element  16  has a coating curved surface, and the coating curved surface of third color separating element  16  has a first sub curved surface  161  and a second sub curved surface  162 . The first sub curved surface  161  and the second sub curved surface  162  are symmetrically formed and have an identical curvature. The first sub curved surface  161  of the third color separating element  16  corresponds to the first red LED  22 R in position. The first sub curved surface  161  of the third color separating element  16  is suitable for transmitting the green light beam IG and the blue light beam IB, reflecting the red light beam IR from the first red LED  22 R, and guiding the red light beam IR to substantially propagate in the first direction D 1 . The second sub curved surface  162  of the third color separating element  16  corresponds to the second red LED  24 R in position. The second sub curved surface  162  of the third color separating element  16  is suitable for transmitting the green light beam IG and the blue light beam IB, reflecting the red light beam IR from the second red LED  24 R, and guiding the red light beam IR to substantially propagate in the first direction D 1 . 
         [0022]    According to the above embodiment, light beams from multiple red LEDs  22 R and  24 R, multiple green LEDs  22 G and  24 G and multiple blue LEDs  22 B and  24 B are mixed up and transmitted to a relay lens  28  and further to a light integration rod  18 . Therefore, light beams IG, IB and IR with different colors are allowed to combine together, where light beams having an identical color are emitted from multiple light sources differently positioned in space. 
         [0023]    Referring to  FIG. 1 , the first sub curved surface  141  and the second sub curved surface  142  that are symmetrically formed and have an identical curvature are connected with each other as a single piece. However, the feature mentioned above is not limited. For example, as shown in  FIG. 2 , in the light combination device  30 , two sub curved surfaces having an identical curvature are provided as two separated pieces. In an alternate embodiment, the first color separating element  12  is replaced by a reflective element capable of reflecting green light beams IG and guiding the green light beams IG to substantially propagate in the first direction D 1 . Further, the light combination device  10  may use different kinds and numbers of light sources and is not limited in using multiple red LEDs, green LEDs, and blue LEDs shown in the above embodiments. In addition, the sequence of different color light beams incident to the light combination device  10  is not limited. Besides, the shape of each coating curved surface of the color separating element is not limited, as long as the curvature of each coating curved surface is allowed to correspond to the positions of light sources to guide different color light beams to propagate in an identical direction. For example, each coating curved surface may have an arc surface, a parabolic surface, or an irregular curved surface. 
         [0024]    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 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.