Patent Abstract:
The present invention relates to a light source package structure, which comprises: an accommodating space for accommodating a light source, a first refraction surface, and at least a second refraction surface. The first refraction surface receives light discharging from the light source while refracting the same to form a first refracting light, the upper part of the first refraction surface further comprising a refracting structure for refracting the light emitted from the light source. The second refraction surface receives and refracts the first refracting light to form a discharging light being emitted out of the light source package structure. Wherein, an included angle is formed between the normal vector of a portion of the second refraction surface and the central axis of the light source package structure. It is noted that the aforesaid package structure can be used in various packaging for improving refraction. In a preferred embodiment, a light source of light emitting diode (LED) is packaged by the light source package structure of the invention for enabling the light emitted from the LED to be discharged out of the package structure by a large angle after being refracted multiple times, so that the LED package structure can be adopted as a flat light source for diverse purpose applied in industry.

Full Description:
FIELD OF THE INVENTION 
   The present invention relates to a package structure, and more particularly, to a light source package structure capable of refracting light therein multiple times for enabling the light to be discharged out of the package structure by a large angle. 
   BACKGROUND OF THE INVENTION 
   Nowadays, it is commonly seen that backlight modules are used for electronic devices with flat panel displays, which includes devices as small as hand-held palm pilots and as large as big-screen TVs. Although most backlight modules still adopt cold cathode fluorescent lamp (CCFL), the utilization of light emitting diode (LED) as the light source of large-sized liquid crystal display (LCD) is becoming popular following the advance of LED technology. As the design challenge of a backlight module is to generate uniform illumination across the LCD surface and luminance that is high enough to produce good contrast in a day environment, LED is preferred over CCFL because it has following advantages: (1) as LED is smaller in size than that of CCFL and it is more solid than CCFL as well, not only the assembly of backlight module can be facilitated, but also the backlight modules adopting LEDs as the light source thereof are lighter and smaller comparing to those CCDL backlight modules; (2) it is noted that the color quality of LCDs adopting LED backlight module is better than that of LCDs adopting CCFL backlight module, since LED can provide a wider color gamut as it is being used in the backlight module for LCDs; (3) Comparing to the mercury-contained CCFL, LED is environmental benign. 
   Although LEDs are preferred, it is required to package an LED light source for enabling the light source package to generate uniform illumination across a specific surface and transferring the LED from point light source into surface light source. Please refer to  FIG. 1 , which is a cross-sectional view of a LED package disclosed in U.S. Pat. No. 6,679,621, entitled “Side Emitting LED and Lens”. The LED package of  FIG. 1  can control the direction of light beams being discharged out of the LED by disposing various refraction surfaces of different shapes at various positions on the LED package, so that the light beams can be emitted out of the LED package in a direction substantially perpendicular to the central axis of the LED package, and thus a side-emitting device with large illuminate areas can be provided. As seen in  FIG. 1 , light emitted from near focal point F that is directly incident on reflecting surface I is reflected from surface I to refracting surface H and refracted by surface H to exit the lens of the LED package in a direction substantially perpendicular to the central axis of the LED package. Light emitted from near focal point F that is directly incident on refracting surface  156  is refracted by surface  156  to also exit the lens in a direction substantially perpendicular to the central axis. However, it is noted that the LED package of  FIG. 1  can only refract light beams emitted by the LED only once by the lens thereof, and moreover, the process for manufacturing the LED package is complicated since it not only requires a step to form a lens on top of an LED while covering the same, it also requires a step of filling the gap between the lens and the LED by a transparent material using a specific pumping-suction means. 
   Moreover, a LED capsule, disclosed in U.S. Pat. No. 6,682,211, entitled “Replaceable LED Lamp Capsule”, uses a housing having a plurality of microstructures formed thereon for reflecting light beams emitted from a LED. However, the forgoing LED capsule is bulky that it is not suitable to be applied as the light source of LCDs. 
   In addition, a LED package, disclosed in U.S. Pat. No. 6,670,207, entitled “Radiation Emitter Device Having an Integral Micro-groove Lens”, is able to disperse light emitted from a LED by arranging a lens with micro-grooves in front of the LED. However, as LEDs are not ideal point light sources by themselves, the dispersing of light enabled by the use of the lens with micro-grooves is not as expected, so that the LED package with lens of micro-grooves is not popular. 
   Therefore, there is a need for an improved LED package structure capable of overcoming the aforesaid shortcomings. 
   SUMMARY OF THE INVENTION 
   The primary object of the present invention is to provide a light source package structure capable of refracting light therein multiple times for enabling light to be emitted out of the package structure in a direction substantially perpendicular to the central axis of the light source package structure for providing a side-emitting light-emitting device. 
   To achieve the above object, the present invention provides a light source package structure, comprising: an accommodating space, for accommodating a light source; a first refraction surface, having at least a tapered structure formed at the upper portion of the same, for receiving light discharging from the light source while refracting the same to form a first refracting light; and at least a second refraction surface, for receiving and refracting the first refracting light to form a first discharging light being emitted out of the light source package structure. 
   Preferably, the tapered structure can be a pyramid or a corn. 
   Preferably, the first refraction surface is substantially the exterior of a first lens containing the accommodating space therein for enabling the exterior of the light source to be tightly attached to the interior of the accommodating space while sealing the same. 
   Preferably, the second refraction surface can be shaped like a round-tipped structure or a tapered structure, whereas the tapered structure can be a pyramid or a corn, and the profile of the round-tipped structure can be defined by an arc. 
   Preferably, the first refraction surface is designed as a rugged surface. 
   Preferably, the second refraction surface is designed as a rugged surface. 
   Preferably, a flat light source can be configured by arranging an array of the light source package structures in a matrix while the matrix is covered and sealed by a material of diffusion capability. 
   Preferably, a refraction cap is formed on top of the second fraction surface while enabling the refraction cap to receive and refract the portion of the first refracting light failed to incident to the second fraction surface and thus form a second discharging light emitting therefrom. Moreover, the refraction cap further comprises: a third refraction surface, for receiving and refracting the portion of the first refracting light failed to incident to the second fraction surface and thus forming a second refracting light; a fourth refraction surface, connected to the third refraction surface, for receiving and refracting the second refracting light so as to form a third refracting light; and a fifth refraction surface, connected to the fourth and the second refraction surfaces, for receiving and refracting the third refracting light so as to form a third refracting light so as to form the second discharging light. 
   Preferably, the light source package structure further comprises: a refraction cap, disposed outside the second refraction surface while covering the same, for receiving and reflecting the first and the second discharging light incident thereon and thus forming a third discharging light. 
   Preferably, a layer of transparent material is coated on the exterior of the light source. 
   Preferably, an included angle is formed between the normal vector of a portion of the second refraction surface and the central axis of the light source package structure, whereas the included angle is ranged between 0 degree and 180 degrees. 
   Moreover, to achieve the above object, the present invention provides another light source package structure, comprising: an accommodating space, for accommodating a light source; a first refraction surface, having at least a round-tipped structure formed at the upper portion of the same, for receiving light discharging from the light source while refracting the same to form a first refracting light; and at least a second refraction surface, for receiving and refracting the first refracting light to form a first discharging light being emitted out of the light source package structure. 
   Furthermore, to achieve the above object, the present invention provides further another light source package structure, comprising: an accommodating space, for accommodating a light source; a first refraction surface, having at least a tapered structure and at least a round-tipped structure formed at the upper portion of the same, for receiving light discharging from the light source while refracting the same to form a first refracting light; and at least a second refraction surface, for receiving and refracting the first refracting light to form a first discharging light being emitted out of the light source package structure. 
   In addition, to achieve the above object, the present invention provides a light source package structure, comprising: an accommodating space, for accommodating a light source; a first refraction surface, for receiving light discharging from the light source while refracting the same to form a first refracting light; at least a second refraction surface, for receiving and refracting the first refracting light to form a first discharging light being emitted out of the light source package structure; and a reflection surface, connected to the at least one second refraction surface, for reflecting the portion of the first refracting light emitted from the top of the first refraction surface while enabling the reflected first refracting light to incident to the second refraction surface. 
   Other aspects and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the present invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a schematic diagram illustrating a conventional LED package disclosed in U.S. Pat. No. 6,679,621. 
       FIG. 2A  is a three-dimensional diagram showing a light source package structure according to a first preferred embodiment of the invention. 
       FIG. 2B  is a cross sectional view of  FIG. 2A . 
       FIG. 2C  to  FIG. 2F  illustrate profiles of the first refraction surface capable of being employed by the light source package structure of  FIG. 2B . 
       FIG. 2G  is a cross sectional view of a light source package structure having a rugged first refraction surface. 
       FIG. 3A  is a cross sectional view of a light source package structure according to a second preferred embodiment of the invention. 
       FIG. 3B  illustrates the structure of the refraction cap used in the light source package structure of  FIG. 3A . 
       FIG. 4  is a cross sectional view of a light source package structure according to a third preferred embodiment of the invention. 
       FIG. 5A  and  FIG. 5B  are cross sectional views of light source package structures according to a fourth preferred embodiment of the invention, whereas the two light source package structures have refraction packages of different design. 
       FIG. 6A  and  FIG. 6B  are schematic diagrams depicting paths of light being refracted by a light source package structure of the invention. 
       FIG. 7A  is used to define the viewing angle with reference to a light source package structure of the invention. 
       FIG. 7B  illustrates the relationship between viewing angle and the intensity of light discharging out of a light source package structure of  FIG. 7A . 
       FIG. 8A  is a cross sectional view of a light source package structure according to a fifth preferred embodiment of the invention. 
       FIG. 8B  illustrates the relationship between viewing angle and the intensity of light discharging out of a light source package structure of  FIG. 8A . 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   For your esteemed members of reviewing committee to further understand and recognize the fulfilled functions and structural characteristics of the invention, several preferable embodiments cooperating with detailed description are presented as the follows. 
   Please refer to  FIG. 2A  and  FIG. 2B , which are respectively a three-dimensional view and a cross-sectional view of a light source package structure according to a first embodiment of the invention. The light source package structure  2  is comprised of an accommodating space  20  for accommodating a light source  9 , a first refraction surface  21 , and at least a second refraction surface  22 . The first refraction surface is disposed superimposing the light source  9  for receiving light discharging from the light source  9  while refracting the same to form a first refracting light, the upper part of the first refraction surface further comprising a refracting structure for refracting the light emitted from the light source, in which at least a tapered structure  210  is formed at the upper portion of the first refraction surface  21  while the first refraction surface  21  is substantially the exterior of a first lens containing the accommodating space  20  therein for enabling the exterior of the light source  9  to be tightly attached to the interior of the accommodating space  20  while sealing the same. It is noted that the tapered structure  210  is a structure can be a pyramid and a corn. 
   The light source  9  shown in  FIG. 2A  can be a simple LED or a LED coated with a layer of conventional transparent material, such as polymethyl methacrylate (PMMA) and resins of the like, as those disclosed in TW Pat. No. M270491. Moreover, each of the second refraction surfaces  22  is used for receiving and refracting the first refracting light to form a first discharging light being emitted out of the light source package structure  2  in a direction perpendicular to the central axis of the light source package structure  2 . Wherein, an included angle is formed between the normal vector  51  of a portion of the second refraction surface  22  and the central axis of the light source package structure  2 , whereas the included angle is ranged between 0 degree and 180 degrees. 
   Please refer to  FIG. 2C  to  FIG. 2F , which illustrate profiles of the first refraction surface capable of being employed by the light source package structure of  FIG. 2B . There are a variety of structures that can be formed on the upper portion of the first refraction surface for refracting light in a direction proximate to perpendicular to the central axis of the light source package structure. In  FIG. 2C , the profile of the first refraction surface  21   a  is shaped like a corn or pyramid, such that light beams can be refracted thereby in a direction perpendicular to the central axis of the light source package structure. In  FIG. 2D , a sawtooth structure  211  comprising a plurality of pyramids is formed at the upper portion of the first refraction surface  21   b . In  FIG. 2E , at least a round-tipped structure with a specific curvature  212  is formed at the upper portion of the first refraction surface  21   c . It is noted that a combination  213  of a plurality of tapered structures and a plurality of round-tipped structures can be formed at the upper portion of the first refraction surface  21   d , as seen in  FIG. 2F . In addition, both the first and the second refraction surfaces can be designed as rugged surfaces illustrated in  FIG. 2G . 
   Please refer to  FIG. 3A , which is a cross sectional view of a light source package structure according to a second preferred embodiment of the invention. The light source package structure  3  is comprised of: an accommodating space  30  for accommodating a light source  9 ; a first refraction surface  31 , covering the light source  9  for receiving light discharging from the light source  9  while refracting the same to form a first refracting light; a second refraction surface  32 , for receiving and refracting the first refracting light to form a first discharging light being emitted out of the light source package structure  3 ; and a refraction cap  33 , being formed on top of the second fraction surface  32  while enabling the refraction cap  33  to receive and refract the portion of the first refracting light failed to incident to the second fraction surface and thus form a second discharging light emitting therefrom; wherein an included angle, being ranged between 0 degree and 180 degrees, is formed between the normal vector of a portion of the second refraction surface  32  and the central axis of the light source package structure  3 . 
   In the embodiment shown in  FIG. 3A , the refraction cap  33  is comprised of: a third refraction surface  330 , for receiving and refracting the portion of the first refracting light failed to incident to the second fraction surface  32  and thus forming a second refracting light; a fourth refraction surface  331 , connected to the third refraction surface  330 , for receiving and refracting the second refracting light so as to form a third refracting light; and a fifth refraction surface  332 , connected to the fourth and the second refraction surfaces  331 ,  32 , for receiving and refracting the third refracting light so as to form the second discharging light. By the disposition of the refraction cap  33 , light beams, before being emitted from the top of the light source package structure  3 , are being refracted at least two times more than those without the refraction cap  33 , so that the emitting light is refracted by a large angle and thus almost perpendicular to the central axis of the light source package structure  3 . In  FIG. 3A , the normal vector of a portion of the third refraction surface  330  is parallel to the central axis of the light source package structure  3 . In  FIG. 3B , for increasing the angle of the first refracting light incident to the third refraction surface  330   a  where it is refracted by a comparatively larger angle to form the second refracting light, the profile of the third refraction surface  330   a  can be the profile of pyramid or corn. 
   Please refer to  FIG. 4 , which is a cross sectional view of a light source package structure according to a third preferred embodiment of the invention. The light source package structure  7  of  FIG. 4  is comprised of: an accommodating space  70  for accommodating a light source  9 ; a first refraction surface  71 ; at least a second refraction surface  72 ; and a reflection surface  73 . The first refraction surface  71  is placed to cover the light source  9  for receiving light discharging from the light source  9  while refracting the same to form a first refracting light, whereas the first refraction surface  71  is shaped like a column. The light source  9  can be a simple LED or a LED coated with a layer of conventional transparent material. The second refraction surface  72  is used for receiving and refracting the first refracting light to form a first discharging light being emitted out of the light source package structure  7  in a parallel manner, whereas an included angle is formed between the normal vector of a portion of the second refraction surface  72  and the central axis of the light source package structure  7 . The reflection surface  73  is disposed at the upper portion of the light source package structure  7  and is connected to the second refraction surface  72  for reflecting the portion of the first refracting light emitted from the top of the first refraction surface  71  while enabling the reflected first refracting light to incident to the second refraction surface  72 . It is noted that each of the first refraction surface  71 , the second refraction surface  72  and the reflection surface  73  can be a tapered structure or a round-tipped structure, while all being designed as rugged surfaces. In addition, the first refraction surface  71  is substantially the exterior of a first lens containing the accommodating space  70  therein for enabling the exterior of the light source  9  to be tightly attached to the interior of the accommodating space while sealing the same, which is similar to that shown in prior embodiment and thus is not describe further herein. 
     FIG. 5A  and  FIG. 5B  are cross sectional views of light source package structures according to a fourth preferred embodiment of the invention, whereas the two light source package structures have refraction packages of different design. As the key of the invention is to design a light source package structure capable of refracting light beams emitted from a LED more than once, a refraction package  42  is disposed outside the second refraction surface of those prior embodiments, while covering the same for receiving and reflecting the first and the second discharging light incident thereon and thus forming a third discharging light, as seen in  FIG. 5A . In  FIG. 5A , the light source package structures, disclosed in  FIG. 2A ,  FIG. 3A ,  FIG. 4 , are defined to be a first refracting part  41 , while enabling the first refracting part  41  to be covered by at least a refraction package  42 , so that the light of the light source  9  is first refracted by the first refracting part  41  and then further being refracted by the refraction package  42 , by which light can be discharged out of the light source package structure of  FIG. 5A  more close to a direction perpendicular to the central axis thereof. As seen in  FIG. 5A  and  FIG. 5B , the first refracting part  41  is composed of a first refraction surface  411  and a second refraction surface  412 , by which the light refracted by the first refraction surface  411  is directed to the second refraction surface  412  where it is being refracted again and incident to the refraction package  42 . Generally, the top of the first refracting part  41  can be designed as a reflection surface, which is used for reflecting the portion of the first refracting light of the first refraction surface  411  while enabling the reflected first refracting light to incident to the second refraction surface  412 . 
   Moreover, the refraction package  42  can be structured similar to those shown in forgoing embodiments that it is comprised of a sixth refraction surface  421  and a seventh refraction surface  422 , wherein the light discharged out of the first refracting part  41  can be refracted by the sixth and the seventh refraction surfaces in a successive manner. In the embodiment shown in  FIG. 5A , the structure of the refraction package  42  is the same as that of the first refracting part  41 . 
   However, the structure of the refraction package  42   a  can be different from that of the first refracting part  41 , as shown in  FIG. 5B . The refraction package  42   a  is substantially a curved screen covering the first refracting part  41  for receiving the light discharged out of the first refracting part  41  while refracting the same, in which the refraction package  42   a  is further comprised of: a sixth refraction surface  421   a , for or receiving the light discharged out of the first refracting part  41  while refracting the same; and a seventh refraction surface  422   a , for receiving the light discharged out of the sixth refraction surface  421   a  while refracting the same. It is noted that the refraction package  42   a  is designed to refract the light discharged out of the first refracting part  41  more than twice and thus improved the effect of refraction desired by the light source package structure. 
     FIG. 6A  and  FIG. 6B  are schematic diagrams depicting paths of light being refracted by a light source package structure of the invention. In  FIG. 6A , when the light beams  90   a ,  91   a ,  92   a  emitted from the light source composed of LEDs are respectively incident to their corresponding portions of the first refraction surface  21 , they are refracted toward the normal vector of its corresponding portion and forming three first refracting light beams  90   b ,  91   b ,  92   b  accordingly as each of the light beams  90   a ,  91   a ,  92   a  is traveling from a sparse media into a dense media. Thereafter, the three first refracting light beams  90   b ,  91   b ,  92   b  are further respectively incident to their corresponding portion of the second refraction surface  22 , they are refracted away from the normal vector of its corresponding portion and forming three discharging light beams  90   c ,  91   c ,  92   c  accordingly as each of the light beams  90   b ,  91   b ,  92   b  is traveling from a dense media into a sparse media. Eventually, by the abovementioned two refraction, the three discharging light beams  90   c ,  91   c ,  92   c , are directed to travel in a direction perpendicular to the central axis of the light source package structure  2 . 
   In  FIG. 6B , a refraction cap is arranged at the upper portion of the light source package structure and is designed to receive the portion of the first refracting light failed to incident to the second fraction surface directly so as to form a second discharging light to be emitted therefrom in a direction perpendicular to the central axis of the light source package structure. First, when the light beam  93   a  emitted from a LED is incident to its corresponding portion of the tapered structure  310  of the first refraction surface  31 , it is refracted toward the normal vector of its corresponding portion and forming a first refracting light beams  93   b  as it is traveling from a sparse media into a dense media. Following, as the first refracting light  93   b  is passing through the third refraction surface  330 , that is, the first refracting light  93   b  is traveling from a dense media into a sparse media, it is refracted away from the normal vector of its corresponding portion of the third refraction surface  330  incident thereby and forming a second refracting light  93   c . It is noted that the second refracting light  93   c  still can not be refracted enough to discharge out of the light source package structure in a direction perpendicular to the central axis of the light source package structure since the original light beam  93   a  is discharged toward the top of the light source package structure in a direction almost parallel to the central axis. Therefore, the second refracting light  93   c  is refracted once again by the fourth refraction surface  331  to form a third refracting light  93   d , and then the third refracting light  93  is once again directed to incident to a fifth refraction surface  332  to be refracted and form a discharging light to be emitted out of the light source package structure in a direction perpendicular to the central axis of same. In the embodiment shown in  FIG. 6B , both the fourth and the fifth refraction surfaces can be designed as irregular surfaces or rugged surfaces. 
   Please refer to  FIG. 7A  and  FIG. 7B , which are respectively a diagram used to define the viewing angle with reference to a light source package structure and diagram illustrating the relationship between viewing angle and the intensity of light discharging out of a light source package structure of  FIG. 7A . In  FIG. 7A , the central axis of the light source package structure is defined as 0 degree viewing angle while the left direction perpendicular thereto is defined as −90 degree viewing angle and the right direction perpendicular thereto is defined as 90 degree viewing angle. As seen in  FIG. 7B , within the range of 60 degree and −60 degree viewing angles, the intensities of light emitted from the light source package structure of the invention are comparatively weak, and the intensities are detected to be much more intense when the viewing angle is exceeding the range of 60 degree and −60 degree. Therefore, it is obvious that the light source package structure is capable of enabling most of the light emitted thereby to be discharged in a direction almost perpendicular to the central axis thereof. 
   Please refer to  FIG. 8A , which is a cross sectional view of a light source package structure according to a fifth preferred embodiment of the invention. As seen in  FIG. 8 , instead of arranging a tapered structure at the upper portion of the first refraction surface, the top of the first refraction surface is indented, by which the overall height of the light source package structure can be reduced for enhancing the usability of the invention. In  FIG. 8B , the relationship between viewing angle and the intensity of light discharging out of a light source package structure of  FIG. 8A  is similar to that shown in  FIG. 7B  and thus is not described further herein. 
   In a preferred aspect, a flat light source can be configured by arranging an array of the light source package structures in a matrix while the matrix is covered and sealed by a material of diffusion capability, such as a diffusion plate or diffusion film. In addition, a collimating plate can be selectively arranged superimposing the diffusion plate or diffusion film. The so-manufactured flat light source can have various usages, such as being employed in the backlight module of LCDs, being employed in an indoor light fixture, or being employed as the light source of a commercial billboard, but is not limited thereby. Moreover, it is relative easy to pack a light source with the light source package structure of the invention. As a hollow accommodating space is formed inside the first refraction surface, the packing can be achieved simply by wearing the light source package structure onto the light source. Therefore, the step of forming a lens on top of an LED while covering the same, and the specific pumping-suction step for filling the gap between the lens and the LED by a transparent material, both disclosed in U.S. Pat. No. 6,679,621, are no longer required. 
   While the preferred embodiment of the invention has been set forth for the purpose of disclosure, modifications of the disclosed embodiment of the invention as well as other embodiments thereof may occur to those skilled in the art. Accordingly, the appended claims are intended to cover all embodiments which do not depart from the spirit and scope of the invention.

Technology Classification (CPC): 5