Patent Publication Number: US-9404640-B2

Title: High efficient and high power LED light source, LED lamp which uses light source and the application of the lamp

Description:
CROSS REFERENCE OF RELATED APPLICATION 
     This is a CIP application that claims the benefit of priority under 35U.S.C.§119 to a non-provisional application, application Ser. No. 13/129,877, filed May 18, 2011. 
    
    
     NOTICE OF COPYRIGHT 
     A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to any reproduction by anyone of the patent disclosure, as it appears in the United States Patent and Trademark Office patent files or records, but otherwise reserves all copyright rights whatsoever. 
     BACKGROUND OF THE PRESENT INVENTION 
     1. Field of Invention 
     The present invention relates to a LED lamp, and more particularly, to a high-power LED light source. It also relates to a high-power LED lamp which uses such light source, and the application of such lamp. 
     2. Description of Related Arts 
     Currently, people all over the world are seeking for solution of the conflict between economic development and energy shortage. As the light-emitting diode (LED) technology develops, its cost drops rapidly. As a result, the LED technology has been used more and more widely in fields of automobile lighting, traffic signal devices, and illumination. The development and application of LED lamps will inevitably bring a broad market prospect and new opportunities of economic development for the entire energy-efficient lighting and green lighting industry, while the high-power LED is an inevitable choice for lighting appliances. 
     In recent years, the optical model of the single Total Internal Reflected (TIR) resin converging lens  1 , equipped with the corresponding high-power LED has been used in most designs and applications of such high-power LED lamps at home and abroad so as to collect optical energy and collimate light rays (see  FIG. 1 ). TIR resin converging lens  1  consists mostly of one piece of substantial transparent resin and it is required that the entire piece of resin be highly glabrous on the surface with highly uniform internal density and high transmittance. Therefore, the production process of TIR resin converging lens  1  is complicated, and the cost is higher. Furthermore, the single TIR resin converging lens  1  can only be used to make LED light source products with small light spots, not large-scale surface light source LED lamps, and its application and lighting effect are thus limited. 
     In addition to the above problems, there are still other disadvantages: the luminous efficiency of lamps using this optical model is generally low, and there are bright spots on the emitting surface because of regional light concentration. A number of bright spots appear when LEDs are arranged sparsely, causing a negative effect on the overall fullness and softness of the light emitted by high-power LED lamps. 
     SUMMARY OF THE PRESENT INVENTION 
     The first technical problem to be solved by the present invention is to provide a high-power LED light source with a front converging lens to improve the luminous efficiency of the existing high-power LED light source, and to enhance the fullness and softness of the light. 
     The second technical problem to be solved by the present invention is to provide a lamp which uses the said LED light source. 
     The third technical problem to be solved by the present invention is to provide applications of the said lamp. 
     As the first aspect of the present invention, a high-power LED light source comprises an LED, and a condenser which concentrates the light emitted by the LED, wherein the said condenser is a concave mirror/lens, and the emitting part of the said LED is located at the focus of the said concave mirror; and a converging lens which is located in front of the said LED, wherein the focus of the said converging lens is at the emitting part of the said LED, or in the vicinity of the emitting part of the said LED according to the requirement of the optical design to meet the functional demands of different lamps. The location of the emitting part of the said LED at the focus of the said concave mirror facilitates the emitting of highly-efficient and collimated light beams and the formation of a surface light source. 
     The said converging lens is a lens with a condensing function, e.g. a convex lens, and the preferred embodiment is a Fresnel lens which fully concentrates the light scattered outside the condensing wrap angle in front of the concave mirror to maximize the overall condensing efficiency of the LED light source. 
     As the second aspect of the present invention, a lamp comprises a casing, wherein a certain number of closely-spaced high-power LED light sources are located in the said casing with each high-power LED light source comprising an LED and a condenser which concentrates the light emitted by the LED, and wherein the said condenser is a concave mirror and the emitting part of the said LED is located at the focus of the said concave mirror; a converging lens located in front of the said LED, wherein the focus of the said converging lens is located at the emitting part of the said LED or in the vicinity of the emitting part of the said LED according to the final optical design to meet the functional demands of different lamps. The location of the emitting part of the said LED at the focus of the said concave mirror facilitates the emitting of highly-efficient and collimated light beams and such closely spaced high-power LED light sources can produce suitable high-density collimated light beams, forming a surface light source thus facilitating the light distribution design of the lamp. 
     The said converging lens may be a lens with condensing function, such as a convex lens. The preferred embodiment of the converging lens is a Fresnel lens. 
     In the lamp of the present invention, the concave mirror and the converging lens of each high-power LED light source concentrate the light emitted by the LED in the same direction, i.e. the emitted light beams have the same emitting direction. The adoption of multiple LEDs can effectively improve the intensity of the light and adoption of the above-mentioned technical scheme can effectively improve the directivity of the light. 
     In the lamp of the present invention, the concave mirrors of each high-power LED light source are placed closely on the same plane and the light beams emitted by each LED are therefore arranged tightly, making the light emitted by the lamp full, well-distributed and without scattered glaring bright spots as a whole. 
     In the lamp of the present invention, the said high-power LED light sources can be arranged in either a honeycombed shape or a rectangular array. 
     In the lamp of the present invention, the concave mirrors of each high-power LED light source are interconnected. 
     The converging lens of each high-power LED light source can be located at a proper position in relation to the LED light source individually or located at a proper position in relation to the LED light sources as one integrated piece. 
     The lamp of the present invention also comprises a printed wiring board, where the LEDs of the high-power LED light source are set. A metal-based heat sink cooling plate is set on the said printed wiring board. 
     In the lamp of the present invention, the LED of the high-power LED light source can be a monochromatic single-chip high-power LED or a monochromatic multi-chip high-power LED, or a multi-chip color-changeable high-power LED. 
     In the lamp of the present invention, a transparent cover or a diffusing lens which can diffuse and distribute the light is set in front of the converging lenses of the said high-power LED light sources. The surface of the said diffusing lens is densely covered with diffusing particles. The said diffusing particles are lenses with light-diffusing function. The light beams emitted by each LED are diffused by the diffusing lens to a certain angle so as to meet the requirements of different functions of the lamps. When used together with an atomized soft-light lens or a soft-light lens added with light diffusing agent, the lamp can emit light which is even softer and fuller as a whole. 
     When a convex lens is adopted as the converging lens of the present invention, the manufacture of the convex lens is easy because optical parameters of the convex lens are easy to control, and costs of the mould are low. In addition, the convex lens is easy to clean for the smooth surface. 
     When a Fresnel lens is adopted as the converging lens of the present invention, the costs as well as the overall weight of the product can be reduced since less material is used. 
     A rear cover is set behind the said casing for eliminating the heat from the LED, and the said metal-based heat sink is compressed tightly to the said rear cover. 
     The third aspect of the present invention relates to the application, wherein the lighting appliance can be used for indoor lighting, automobile lighting, road lighting or advertising lighting or as searchlight. 
     Based on the above-mentioned design, the present invention is particularly suitable for high-power LED lamps where the power of a single LED is more than 0.5 W. 
     The original high-power LED lamp only adopts TIR lens as the condenser, especially the single Total Internal Reflection (TIR) resin converging lens. The TIR resin converging lens consists mostly of one piece of substantial transparent resin and the entire piece of resin must be highly polished on the surface with highly uniform internal density and high transmittance. Therefore, the production process of such TIR resin converging lens is complicated and the cost is high. Furthermore, the single TIR resin converging lens can only be used to fabricate a small-scale light source product, not a large-caliber LED light source product. Within a certain range of power, the number of LEDs is limited. As a result, light beams emitted by such light sources are relatively narrow. Therefore, the light emitted by the lamps with such light sources will have a large number of apparent bright spots when LEDs are sparsely spaced. Such tiny bright spots pose a negative effect on the overall fullness and softness of the light emitted by the high-power LED lamps, and thus affect the lighting effect and limit its application scope. 
     In the above-mentioned technical scheme of the present invention, a concave mirror and a converging lens are adopted instead of the original TIR lens, bringing the following technical effects: 
     Firstly, the production processes of the concave mirror and the converging lens are well developed. The concave mirror is a common condenser used for car lighting, flashlight, etc. Its cost is low, and the concave mirror with large caliber can easily be produced. The convex lens or the Fresnel lens which is used as the converging lens is also characterized by its low cost, and the large convex lens or the Fresnel lens with large area is also easily produced. By adopting the concave mirror with large caliber and the convex lens or the Fresnel lens with large area, the cross-sectional area of the light beams will increase significantly, and thus, when LEDs are sparsely spaced, there will not be many bright spots, making the light emitted from the high-power LED lamps fuller and softer, the overall lighting effect better and the application scope wider. 
     Other devices, apparatus, systems, methods, features and advantages of the invention will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, be within the scope of the invention, and be protected by the accompanying claims. 
     Still further objects and advantages will become apparent from a consideration of the ensuing description and drawings. 
     These and other objectives, features, and advantages of the present invention will become apparent from the following detailed description, the accompanying drawings, and the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention may be better understood by referring to the following figures. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. In the figures, like reference numerals designate corresponding parts throughout the different views. 
         FIG. 1  is a structure drawing of a prior art high-power LED lamp. 
         FIG. 2  is a cross-sectional view of a lamp and its high-power LED light source of the present invention. 
         FIG. 3  is a front view of a lamp and its high-power LED light source of the present invention. 
         FIG. 4  is a structural drawing of the first embodiment of application of the present invention. 
         FIG. 5  is a structural drawing of the second embodiment of application of the present invention. 
         FIG. 6  is a structural drawing of the third embodiment of application of the present invention. 
         FIG. 7  is a sectional view of a lamp and its high-power LED light source according to a second embodiment of the present invention. 
         FIG. 8  is a front view of a lamp and its high-power LED light source according to the second embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The following description is disclosed to enable any person skilled in the art to make and use the present invention. Preferred embodiments are provided in the following description only as examples and modifications will be apparent to those skilled in the art. The general principles defined in the following description would be applied to other embodiments, alternatives, modifications, equivalents, and applications without departing from the spirit and scope of the present invention. 
     In order to make the technical means, characteristics, purpose, and effect of the present invention easy to understand, a further description of the present invention is given as below with reference to the corresponding drawings. 
     Referring to  FIGS. 2 and 3 , the lamp comprises a casing  2 , wherein several high-power LED light sources are closely spaced inside the casing  2 . These high-power LED light sources can be arranged either in a honeycombed shape or in a rectangular array (as shown in  FIG. 2 ). 
     Each high-power LED light source comprises LED  21 , and a concave mirror  22  which condenses the light is placed on top of the LED  21 . The emitting part of the LED  21  is located at the focus of the concave mirror  22 . The converging lens  23  is set in front of the LED  21 , and the focus of the converging lens  23  is located at the emitting part of the LED  21 . This design facilitates the emitting of collimated light beams and is suitable for occasions where collimated light beams are needed. The converging lens  23  can be either a convex lens or a Fresnel lens. 
     Referring to  FIG. 1 , most prior art high-power LED lamps only use a TIR lens as a condenser, especially single Total Internal Reflection (TIR) resin converging lens  1 . The TIR resin converging lens  1  consists mostly of one piece of substantial transparent resin. It is required that the entire piece of resin shall be highly polished on the surface, with highly uniform internal density and high transmittance. Thus the production process of the TIR resin converging lens  1  is complicated, and the cost is high. Furthermore, such TIR resin converging lens  1  can only be used for fabricating small-scale light source products. It cannot be used for producing LED light source products with large caliber. Therefore, it can only emit narrow concentrated light beams. Within a certain range of power, the number of LEDs used is limited. When LEDs are arranged sparsely to keep the necessary shape and dimension of the lamp, the light emitted by the lamp will have a large number of apparent bright spots. Such tiny bright spots will cause a negative effect on the general fullness and softness of the light emitted by the high-power LED lamp, and limit the application range and affect the lighting effect. 
     Referring to  FIG. 2 , in the above-mentioned technical scheme of the present invention, a concave mirror  22  and a converging lens  23  are adopted instead of the original TIR resin converging lens  1 , bringing the following technical effects: 
     Firstly, the production processes of concave mirror  22  and converging lens  23  are well developed. A concave mirror is a common condenser used for car lighting, flashlight, etc. Its cost is low, and the concave mirror  22  with large caliber can be easily produced. A convex lens or a Fresnel lens which is used as the converging lens  23  is also characterized by its low cost, and the convex lens or the Fresnel lens with large area can be easily produced. By adopting the concave mirror  22  with large caliber and the convex lens or Fresnel lens with large area, the cross-sectional area of light beams can be increased significantly, and thus, when LEDs are sparsely spaced, there will not be many bright spots, making the light emitted from the high-power LED lamps fuller and softer, the overall lighting effect better and the application scope wider. 
     When a convex lens is adopted as the converging lens  23  of the present invention, the convex lens will be easy to produce because the optical parameters of the convex lens are easy to control and the cost of the mould is low. In addition, the convex lens is easy to clean for the smooth surface. When a Fresnel lens is adopted as the converging lens  23  of the present invention, the cost as well as the overall weight of the product can be reduced since less material is used. 
     In the lamp of the present invention, the concave mirror  22  and converging lens  23  of each high-power LED light source concentrate the light in the same direction, i.e. the emitted light beams have the same emitting direction. The adoption of multiple LEDs can effectively improve the intensity of the light while adopting the above-mentioned technical scheme can improve the directivity of the light significantly. 
     The concave mirrors  22  of each high-power LED light source are placed closely on the same plane and the light beams emitted by each LED are therefore arranged tightly, making the light emitted by the lamp, as a whole, full and soft. The converging lens  23  of each high-power LED light source can also be integrated into one piece to facilitate installation of the lens. 
     These LEDs  21  of each high-power LED light source are set on a printed wiring board  26 , and a metal-based heat sink is set on the printed wiring board  26 . A heat cooling rear cover  25  used for cooling LED  21  is set behind the casing  2 , and the metal-based heat sink is compressed tightly to the heating cooling rear cover  25  to dispel or eliminate the heat from of LED  21 . 
     The LED of the high-power LED light source can be a monochromatic single-chip high-power LED or a multi-chip high-power LED or a multi-chip color-changeable high-power LED. 
     Referring to  FIGS. 2 and 3 , the diffusing lens  24  which can diffuse the light is set in front of the converging lens  22  of the high-power LED light sources. The surface of the diffusing lens  24  is densely covered with diffusing grain or particles. The diffusing particles or grains are convex lenses. The collimated light beams emitted by each LED are diffused directionally by the diffusing lens  24  to a certain degree to meet the light distribution demand of different functions of lamps. When used together with an atomized soft-light lens or a soft-light lens added with diffusion agent, the lamp can emit light which is even softer and fuller, as a whole. 
     The lamp can be used as work light such as the work light  31  shown in  FIG. 4 , or, the lamp can be used for automobile lighting such as the automobile interior lamp  32  shown in  FIG. 5 . Or the lamp can be used for indoor lighting such as the desk lamp  33  shown in  FIG. 6 . The lamps of the present invention can be used for fabrication of flashlights. 
     As shown in  FIG. 7 , a light module according to a second embodiment illustrates an alternative mode of the above embodiment, wherein the light module can be equipped with the lamp such as the work light as shown in  FIG. 4 , the automobile interior lamp as shown in  FIG. 5 , or a desk lamp as shown in  FIG. 6 . 
     The light module comprises a casing  2 A and a plurality of high-power LED light sources disposed in the casing  2 A. Each high-power LED light source comprises a LED  21 A, a condenser  22 A which concentrates the light emitted by the LED  21 A, and a converging lens  23 A located in front of the LED  21 A. 
     The condensers  22 A are integrally coupled with each other side-by-side to form a condenser unit. As shown in  FIG. 7 , the condensers  22 A comprises a plurality of concave mirrors closely located side-by-side, wherein each of the condensers  22 A, having a bowl shape, defines a light reflecting wall  221 A, a light cavity  222 A therewithin, and a light opening  223 A. In particular, each of the condensers  22 A has a concave portion  224 A and a tubular portion  225 A integrally extended thereof, wherein the LED  21  is disposed at focal point of the concave portion  224 A. Accordingly, a cross sectional area of the concave portion  224 A of each of the condensers  22 A is gradually increased toward the tubular portion  225 A. The tubular portion  225 A of each of the condensers  22 A has a uniform diameter, wherein the light opening  223 A of the condenser  22 A is defined at the tubular portion  225 A thereof. 
     The light reflecting wall  221 A has an interior reflecting surface to reflect the light from the LED  21 A. Accordingly, the interior reflecting surface of the light reflecting wall  221 A is a concave surface at the concave portion  224 A of the condenser  22 A. The interior reflecting surface of the light reflecting wall  221 A is a flat surface at the tubular portion  224 A of the condenser  22 A. When the tubular portion  224 A of the condenser  22 A has a rectangular cross section, as shown in  FIG. 8 , the interior reflecting surface is formed at each of four facets. When the tubular portion  224 A of the condenser  22 A has a honeycomb cross section, the interior reflecting surface is formed at each of six facets. 
     The light reflecting walls  221 A of the condensers  22 A are integrally coupled with each other side-by-side, as shown in  FIG. 7 , such that the high-power LED light sources form a plurality of light cells closely located side-by-side. In particular, the tubular portions  225 A of the condensers  22 A are integrally coupled with each other side-by-side. Each of the condensers  22 A is formed in a honeycombed shape or in a rectangular array. In other words, the cross section of the tubular portion  225 A of each of the condensers  22 A has a honeycombed shape or in a rectangular shape. It is worth mentioning that since the tubular portions  225 A of the condensers  22 A are integrally coupled with each other side-by-side, the two adjacent condensers  22 A share a portion of the tubular portion  225 A as shown in  FIG. 7 . 
     The LED  21 A is disposed in the light cavity  222 A at a position that the emitting part of the LED  21  is located at the focal point of the condenser  22 A. It is worth mentioning that the light reflecting wall  221 A has a concave surface, such that when the LED  21 A emits light in a radial direction, a first portion of light will directly project toward the light opening  223 A of the condenser  22 A while a second portion of the light will be reflected by the light reflecting wall  221 A of the condenser  22 A to the light opening  223 A thereof. In other words, the light emitted from the LED  21 A will be concentratedly projected out of the light opening  223 A of the condenser  22 A. 
     The converging lens  23 A is located in front of the LED  21 A within the light cavity  222 A, wherein the focus of the converging lens  23 A is located at the emitting part of the LED  21 A. This design facilitates the emitting of collimated light beams and is suitable for occasions where collimated light beams are needed. The converging lens  23 A can be either a convex lens or a Fresnel lens. 
     As shown in  FIG. 7 , the converging lens  23 A comprises a lens body  231 A and a plurality of supporting legs  232 A raidally and downwardly extended from the lens body  231 A to couple at the light reflecting wall  221 A of the condenser  22 A so as to suspendedly support the lens body  231 A above the LED  21 A. Accordingly, three supporting legs  232 A are inclinedly extended from the lens body  231 A to couple at the light reflecting wall  221 A of the condenser  22 A as shown in  FIG. 8 . In particular, the lens body  231 A is supported within the light cavity  223 A between the concave portion  224 A and the tubular portion  225 A. The lens body  231 A is also located with respect to the center of the tubular portion  225 A of the condenser  22 A. 
     As it is mentioned above, the first portion of light will directly project toward the light opening  223 A of the condenser  22 A. Accordingly, the LED  21  is located at the focal point of the converging lens  23 A that the distance between the emitting part of the LED  21 A and the converging lens  23 A is the focal length of the converging lens  23 A. Therefore, the first portion of the light from the LED  21  A will penetrate through the converging lens  23 A and will diverge the first portion of the light in parallel light rays which will be projected out of the light opening  223 A of the condenser  22 A. In other words, the first portion of light, which is not reflected by the light reflecting wall  221 A of the condenser  22 A, will be diverged into parallel light rays out of the light opening  223 A of the condenser  22 A. 
     The second portion of the light will be reflected within the concave portion  224 A of the condenser  22 A by the light reflecting wall  221 A thereof to parallelly project out of the light opening  223 A of the condenser  22 A. In other words, the first portion of light diverged by the converging lens  23 A and the second portion of light reflected by the light reflecting wall  221 A of the condenser  22 A will form collimated light beams out of the light opening  223 A of the condenser  22 A. The first portion of light diverged by the converging lens  23 A and the second portion of light reflected by the light reflecting wall  221 A of the condenser  22 A will not be overlapped with each other. Therefore, the tubular portions  225 A of the condensers  22 A are extended parallel with respect to the collimated light beams to enhance a light intensity thereof. It is worth mentioning that the collimated light beams will project out of the light opening  223 A of the condenser  22 A parallel to the interior reflecting surface of the light reflecting wall  221 A at the tubular portion  225 A of the condenser  22 A. Furthermore, all the lights from the LEDs  21 A will generate the collimated light beams projected out of the condensers  22 A for enhancing the illuminating power of the light module. 
     Accordingly, the interior reflecting surface of the light reflecting wall  221 A at the tubular portion  225 A will enhance the light intensity of the collimated light beams. In addition, the light from the LED  21 A will not directly projected on the interior reflecting surface of the light reflecting wall  221 A at the tubular portion  225 A. In other words, the tubular portions  225 A of the condensers  22 A provide multiple functions of enhancing the light intensity of the collimated light beams, ensuring the collimated light beams to be projected out of the light openings  223 A at the same direction, and integrally linking the condensers  22 A with each other. 
     The light module further comprises a diffusing lens  24 A coupled at the light openings  223 A for diffusing the collimated light beams, wherein the diffusing lens  24 A can diffuse the light is set in front of the converging lens  22 A of the high-power LED light source. The surface of the diffusing lens  24 A is densely covered with diffusing grain or particles. The difffising particles or grains are convex lenses. In other words, the convex lenses are integrally formed at the surface of the diffusing lens  24 A facing toward the LED  21 A. The collimated light beams emitted by each LED  21 A are diffused directionally by the diffusing lens  24 A to a certain degree to meet the light distribution demand of different functions of lamps. When used together with an atomized soft-light lens or a soft-light lens added with diffusion agent, the lamp can emit light which is even softer and fuller, as a whole. 
     A circuit board  26 A and a metal-based heat sink are set on the circuit board  26 A. Accordingly, the circuit board  26 A is supported by the casing  2 A to house the LEDs  21  therein. A heat cooling rear cover  25 A used for cooling LEDs  21 A is set behind the casing  2 , and the metal-based heat sink is compressed tightly to the heating cooling rear cover  25 A to dispel or eliminate the heat from of LEDs  21 A. In other words, the LEDs  21 A are spacedly and electrically coupled on the circuit board  26 A, wherein the condenser unit is coupled on the circuit board  26 A at a position that the LEDs  21 A are encircled by the condensers  22 A respectively. 
     It is believed that the fundamental principle, key features and the advantages of the present invention are understood from the foregoing description. The technical personnel of the industry should understand that the present invention is not limited to the above embodiments. The embodiments and specifications hereinbefore described only explain the principle of the present invention, and it is apparent that various changes and improvements may be made thereto without departing from the spirit and scope of the invention. Such changes and improvements fall into the scope of the present invention which claims protection. The scope of protection claimed by the present invention is defined by the attached claims and their equivalents. 
     The foregoing description of implementations has been presented for purposes of illustration and description. It is not exhaustive and does not limit the claimed inventions to the precise form disclosed. Modifications and variations are possible in light of the above description or may be acquired from practicing the invention. The claims and their equivalents define the scope of the invention.