Patent Publication Number: US-10781995-B2

Title: Lighting apparatus

Description:
TECHNICAL FIELD 
     The present invention relates to the field of lighting technologies, and in particular, to an illumination device. 
     BACKGROUND OF THE INVENTION 
     A light distribution provided by a light source is usually constant. However, illumination devices with various light distributions are required to meet different lighting needs. Therefore, to provide diversified light distributions, it is necessary in the prior art to adopt an additional optical element (such as a lens, a reflector, or a diffuser) independent of a light source, so as to change an optical path of light emitted from the light source. 
     The Chinese Patent Application No. CN101438096 provides a specific implementation solution of the above prior art, including: an illumination device including a light source; an electrowetting optical element disposed in front of the light source to allow refraction of a light beam emitted from the light source; and a driving device configured to operate the optical element in at least two predetermined states, the states being adapted to generate refracted beams having different light intensity distributions. 
     However, this additional optical element is usually expensive and increases the cost of an entire illumination device. 
     In this case, there is a need for a new illumination device that provides diversified light distributions. 
     SUMMARY OF INVENTION 
     An objective of the present invention is to provide an illumination device. 
     According to an aspect, an embodiment of the present invention relates to an illumination device, including: a support member; and at least one first light source on the support member and at least one second light source on the support member, where the first light source has a first light distribution, the second light source has a second light distribution, and the first light distribution is different from the second light distribution. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       To read the following detailed description with reference to the accompanying drawings can help understand the features, aspects and advantages of the present invention, where: 
         FIG. 1  is a schematic structural diagram of an illumination device involved in an embodiment of the present invention; 
         FIG. 2  is a schematic diagram of an ideal Lambertian distribution; 
         FIG. 3  is a schematic diagram of a bat-wing distribution; 
         FIG. 4  is a schematic diagram of corresponding light distributions of an illumination device at multiple current intensity ratios involved in an embodiment of the present invention; 
         FIG. 5  is a schematic diagram of relative luminous flux varying with a forward current; 
         FIG. 6  is a schematic diagram of linear fitting on a relative luminous flux curve shown in  FIG. 5 ; 
         FIG. 7  is a schematic diagram of light distributions of an illumination device at multiple light source quantity ratios involved in an embodiment of the present invention; 
         FIG. 8  is a schematic structural diagram of an illumination device involved in another embodiment of the present invention; 
         FIG. 9  is a schematic structural diagram of an illumination device involved in still another embodiment of the present invention; 
         FIG. 10  is a schematic structural diagram of an illumination device involved in yet another embodiment of the present invention; and 
         FIG. 11  is a schematic diagram of a beam center line of an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     “Comprise”, “include”, “have”, and similar terms used in the present application are meant to encompass the items listed thereafter and equivalents thereof as well as other additional items. Approximating language in the present application is used to modify a quantity, indicating that the present invention is not limited to the specific quantity, and may include modified parts that are close to the quantity, acceptable, and do not lead to change of related basic functions. Accordingly, the use of “about” or the like modifies a numerical value, meaning that the present invention is not limited to the precise numerical value. In some embodiments, an approximate term may correspond to the accuracy of an instrument that measures a value. 
     In the specifications and claims, unless otherwise clearly indicated, no limitation is imposed on singularity and plurality of all items. Throughout this patent application specification and claims, “first”, “second” and similar words do not denote any order, quantity, or importance, but are used to distinguish the different materials and embodiments. 
     Unless otherwise clearly indicated, the terms “OR”, “or” do not mean exclusiveness, but mean at least one of the mentioned item (such as ingredients), and include a situation where a combination of the mentioned exists. 
     “Some embodiments” and the like mentioned in the present application specification represent that specific elements (such as a characteristic, structure, and/or feature) related to the present invention are included in at least one embodiment described in the specification, and may or may not appear in another embodiment. In addition, it should be understood that the invention elements can be combined in any manner. 
     The following describes the embodiments of the present invention with reference to the accompanying drawings, and may not describe in detail functions or structures that are well known, to prevent unnecessary details that may make the present invention hard to understand. 
       FIG. 1  shows one embodiment of an illumination device  100 . The illumination device  100  includes a support member  103 , and at least one first light source  101  and at least one second light source  102  on the support member  103 . 
     The support member  103  is mainly used to support the first light source  101  and the second light source  102 . In some embodiments, a relative position between the first light source  101  and the second light source  102  is fixed by the support member  103 . In some embodiments, the first light source  101  and the second light source  102  are arranged on the support member  103 , but a relative position between the first light source  101  and the second light source  102  can be adjusted. The support member  103  may include any component that can be used to support the first light source  101  and the second light source  102 , for example, a panel that can fix the first light source  101  and the second light source  102 , or any component that can fix the first light source  101  and the second light source  102  provided thereon. 
     The first light source  101  and the second light source  102  include any element that can function as a light emitting source. In some embodiments, the first light source  101  and the second light source  102  are integrated into one lamp. 
     In some embodiments in which the illumination device  100  is implemented based on a light-emitting diode (LED for short), the first light source  101  and the second light source  102  respectively include a complete LED, such as an encapsulated LED, that is, the first light source  101  and the second light source  102  do not include only a luminous PN junction (PN junction). For example, the first light source  101  is an encapsulated LED having a first light distribution, and the second light source  102  is an encapsulated LED having a second light distribution. 
     The first light source  101  has a first light distribution, the second light source  102  has a second light distribution, and the first light distribution is different from the second light distribution. The “light distribution” may also be referred to as “light intensity distribution”, indicating a luminous intensity value in all directions of space. 
     In some embodiments, the first light distribution includes a narrow beam angle distribution, and the second light distribution includes a wide beam angle distribution. A beam angle (beam angle) represents an angle between two directions in which a light intensity is equal to N % of the maximum light intensity in the plane perpendicular to a beam centerline. In some embodiments, N=50; in some embodiments, N=10; and in some embodiments, N may be adjusted according to lighting needs. In general, the beam centerline passes through a light source and is perpendicular to a light emitting plane of the light source.  FIG. 11  shows a simple example of a beam centerline, where  501  represents a light source,  502  represents a light emitting plane, and  503  represents the beam centerline.  FIG. 11  is only used to better illustrate the beam centerline and should not be construed as a limitation of the concept of the beam centerline. 
     As an example of a narrow beam angle distribution, the first light distribution includes a Lambertian distribution (Lambertian distribution). Accordingly, the first light source  101  may include any light source having a Lambertian distribution, such as a Lambertian LED. 
       FIG. 2  shows an example of an ideal Lambertian distribution in a polar coordinate system, where a polar angle represents a radiation angle and a polar diameter represents a relative intensity. It should be noted that the “Lambertian distribution” in the present invention is not limited to the ideal Lambertian distribution but also includes a near-Lambertian distribution close to the ideal Lambert distribution. It should be noted that the narrow beam angle distribution is not limited to the Lambertian distribution. As an example, the narrow beam angle distribution may include any light distribution with a beam angle less than or equal to a specified angle, where the specified angle may be about 120 degrees, or may also be another angle. 
     As an example of a wide beam angle distribution, the second light distribution includes a bat-wing distribution, which may also be referred to as a butterfly wing distribution. Accordingly, the second light source  102  may include any light source having a bat-wing distribution, such as a flip-chip LED. 
       FIG. 3  shows an example of an asymmetric bat-wing distribution in a polar coordinate system, where a polar angle represents a radiation angle and a polar diameter represents a relative intensity. The “asymmetrical bat-wing distribution” indicates light distributions of the bat-wing distribution may be different in a plurality of planes including a beam centerline. In  FIG. 3 , α and β represent light distributions in two planes including a beam centerline and perpendicular to each other. 
     It can be seen from  FIG. 2  and  FIG. 3 , the bat-wing distribution has a wider beam angle than the Lambertian distribution. It should be noted that the “bat-wing distribution” herein is not limited to the light distribution shown in  FIG. 3 . For example, the bat-wing distribution may be a symmetrical light distribution. For another example, the shape of a bat-wing distribution curve may be different from that shown in  FIG. 3 . It should be noted that the wide beam angle distribution is not limited to the bat-wing distribution. As an example, the wide beam angle distribution may include any light distribution with a beam angle greater than the foregoing specified angle. 
     By setting a light output intensity ratio between the first light source  101  and the second light source  102 , modulation of a light distribution of the illumination device  100  can be achieved without using an optical element such as a lens, a reflector, or a diffuser. 
     As an implementation, the light output intensity ratio between the first light source  101  and the second light source  102  can be set by setting a ratio of a current intensity provided to the first light source  101  and the second light source  102 . 
       FIG. 4  shows corresponding light distributions of the illumination device  100  at different current intensity ratios between the first light source  101  and the second light source  102  in a rectangular coordinate system. 
     In  FIG. 4 , a light distribution  11  indicates a Lambertian distribution of the first light source  101 , a light distribution  12  indicates a bat-wing distribution of the second light source  102 , a light distribution  13  indicates a light distribution of the illumination device  100  when a current intensity ratio between the first light source  101  and the second light source  102  is 1:1, a light distribution  14  indicates a light distribution of the illumination device  100  when a current intensity ratio between the first light source  101  and the second light source  102  is 1:3, a light distribution  15  indicates a light distribution of the illumination device  100  when a current intensity ratio between the first light source  101  and the second light source  102  is 1:5, and a light distribution  16  indicates a light distribution of the illumination device  100  when a current intensity ratio between the first light source  101  and the second light source  102  is 1:8. 
     It can be seen from  FIG. 4  that the light distribution of the illumination device  100  changes accordingly as the current intensity ratio between the first light source  101  and the second light source  102  changes. 
       FIG. 5  shows a schematic diagram of relative luminous flux (relative luminous flux) of an LED varying with a forward current (forward current) at a room temperature about 25 degrees in a rectangular coordinate system. The relative luminous flux indicates a ratio between luminous flux of an LED supplied with another current and luminous flux of the LED supplied with a rated current at a room temperature about 25 degrees. It can be defined that the LED has luminous flux of 1 when supplied with a rated current at a room temperature about 25 degrees. 
       FIG. 6  shows a result of linear fitting on a relative luminous flux curve shown in  FIG. 5  in a rectangular coordinate system. Dotted lines in  FIG. 6  indicate partial points in the curve shown in  FIG. 5 , and solid lines in  FIG. 6  indicate a result of linear fitting on points indicated by the dotted lines. 
     It can be seen from  FIG. 6  that the relative luminous flux can be approximately assumed to increase linearly with the increase of the forward current. Therefore, in virtue of this characteristic, the current intensity ratio between the first light source  101  and the second light source  102  can be completely set according to actual needs without being limited to the specific numerical values shown in  FIG. 4 . 
     As another implementation, the light output intensity ratio between the first light source  101  and the second light source  102  can be set by setting a quantity ratio between the first light source  101  and the second light source  102 . That is, in this implementation, the number of the first light sources  101  and/or the second light sources  102  may be multiple (not shown). It should be noted that the plurality of first light sources  101  have the same or similar light distribution, but the encapsulation between the plurality of first light sources  101  may be different; similarly, the plurality of second light sources  102  have the same or similar light distribution, but the encapsulation between the plurality of second light sources  102  may be different. 
       FIG. 7  shows light distributions of the illumination device  100  at different light source quantity ratios between the first light source  101  and the second light source  102  in a rectangular coordinate system, where current intensities supplied to the first light source  101  and the second light source  102  are the same. 
     In  FIG. 7 , a light distribution  21  indicates a bat-wing distribution of the second light source  102 , a light distribution  22  indicates a Lambertian distribution of the first light source  101 , a light distribution  23  indicates a light distribution of the illumination device  100  when a light source quantity ratio between the first light source  101  and the second light source  102  is 1:1, a light distribution  24  indicates a light distribution of the illumination device  100  when a light source quantity ratio between the first light source  101  and the second light source  102  is 1:2, a light distribution  25  indicates a light distribution of the illumination device  100  when a light source quantity ratio between the first light source  101  and the second light source  102  is 1:5, and a light distribution  26  indicates a light distribution of the illumination device  100  when a light source quantity ratio between the first light source  101  and the second light source  102  is 1:10. 
     It can be seen from  FIG. 7  that when supplied current intensity ratios are the same, the light distribution of the illumination device  100  changes accordingly as the light source quantity ratio between the first light source  101  and the second light source  102  changes. 
     It should be noted that those skilled in the art can fully understand that the light source quantity ratio between the first light source  101  and the second light source  102  can be completely set according to actual needs without being limited to the specific numerical values shown in  FIG. 7 . In addition, the light source quantity ratio between the first light source  101  and the second light source  102  and the current intensity ratio provided therebetween can be set simultaneously to better obtain a desired light distribution of the illumination device  100 . 
     In some embodiments, the illumination device  100  does not have a lampshade or a lampshade that has an influence on the light distribution. In this case, the light distribution of the illumination device  100  may be directly formed on the basis of the light output intensity ratio between the first light distribution and the second light distribution. That is, the light distribution of the illumination device  100  is related only to the light output intensity ratio between the first light source  101  and the second light source  102 . 
     Based on the above embodiments, it is possible to obtain the illumination device  100  having a diversified light distribution without any optical element (such as a lens, a reflector, or a diffuser) independent of a light source, thereby reducing the cost of the illumination device. Especially when the first light source  101  and the second light source  102  do not include an optical element mainly for changing a light distribution, the illumination device  100  may realize a diversified light distribution without including any optical element (such as a lens, a reflector, or a diffuser) mainly for changing the light distribution (or mainly for changing an optical path). 
       FIG. 8  shows one embodiment of an illumination device  200 . The illumination device  200  includes a support member  203 , at least one first light source  201  and at least one second light source  202  on the support member  203 , and a lampshade  204 . The support member  203 , the first light source  201 , and the second light source  202  are similar to the support member  103 , the first light source  101 , and the second light source  102  in  FIG. 1 , respectively, and are not described herein. 
     The first light source  102  and the second light source  202  are arranged inside the lampshade  204 . 
     In some embodiments, the lampshade  204  can be mainly used for aesthetic decoration, dust prevention, preventing people from direct contact with a light source, light atomization, and the like. It should be noted that although the lampshade  204  may have some influence on a light distribution of the illumination device  200 , the main function of the lampshade  204  is not to adjust the light distribution of the illumination device  200 . 
     In an embodiment in which the lampshade  204  affects the light distribution of the illumination device  200 , the light distribution of the illumination device  200  may be directly formed on the basis of an optical characteristic of the lampshade  204  and a light output intensity ratio between the first light distribution and the second light distribution. That is, in the embodiment in which the lampshade  204  affects the light distribution of the illumination device  200 , the light distribution of the illumination device  200  may be directly formed on the basis of the optical characteristic of the lampshade  204  and a light output intensity ratio between the first light source  201  and the second light source  202 . The optical characteristic of the lampshade  204  mainly include a characteristic of the lampshade  204  that affects an optical path, including but not limited to refraction, transmission, and reflection characteristics of the lampshade  204 . 
     In this embodiment, it is possible to obtain the illumination device  200  having a diversified light distribution without any optical element (such as a lens, a reflector, or a diffuser) mainly for adjusting a light distribution and independent of a light source, thereby reducing the cost of the illumination device. 
       FIG. 9  shows another embodiment of an illumination device  300 . The illumination device  300  includes a support member  303 , four first light sources  301 , six second light sources  302 , and an adjustment member  305 . The dashed box in  FIG. 9  is only used to identify the first light source  301  and the second light source  302 . 
     The support member  303 , the first light source  301 , and the second light source  302  are similar to the support member  303 , the first light source  301 , and the second light source  302 , respectively, and are not described herein. 
     The adjustment member  305  may be used to adjust a light output intensity corresponding to a light distribution. For example, the light output intensity corresponding to the first light distribution (that is, a total light output intensity of the first light source  301 ) is adjusted and/or the light output intensity corresponding to the second light distribution (that is, a total light output intensity of the second light source  302 ). 
     In some embodiments, the adjustment member  305  realizes the adjustment on the light output intensity corresponding to the first light distribution and/or the second light distribution by adjusting a current intensity provided to the first light source  301  and/or the second light source  302 . For example, the adjustment member  305  is electrically connected to the first light source  301  and/or the second light source  302  to change the current intensity provided to the first light source  301  and/or the second light source  302 . In these embodiments, the adjustment member  305  includes but is not limited to: a variable resistor, a dimmer, and the like. The dimmer includes but is not limited to: a 0-10V dimmer, a digital addressable lighting interface (DALI) dimmer, a wireless dimmer, and the like. 
     In some embodiments, the adjustment member  305  realizes the adjustment on the light output intensity corresponding to the first light distribution and/or the second light distribution by adjusting the quantity of the first light source  301  and/or the second light source  302  that actually contributes to the illumination. For example, the adjustment member  305  is electrically connected to the first light source  301  and/or the second light source  302  so as to control ON or OFF of current supplied to at least one of the first light sources  301  and/or at least one of the second light sources  302 . In these embodiments, the adjustment member  305  includes but is not limited to: a switching circuit, a relay, and the like. 
     In some embodiments, the adjustment member  305  needs to be manually controlled directly. In this case, at least a part of the adjustment member  305  is exposed on a surface of the illumination device  300  for manual operation. In some embodiments, the adjustment member  305  may be remotely controlled. In this case, the adjustment member  305  may be completely hidden inside the illumination device  300  (this case is not shown). 
     In addition, compared with an influence of the light output intensity ratio between the first light source  301  and the second light source  302 , an influence of the position between the first light source  301  and the second light source  302  on the light distribution can be neglected, and therefore, the positions of the first light source  301  and the second light source  302  in the illumination device  300  can be completely adjusted without being limited to that shown in  FIG. 9 . 
     Based on the embodiment shown in  FIG. 9 , a user may adjust the light distribution of the illumination device  300  as required. 
       FIG. 10  shows another embodiment of an illumination device  400 . The illumination device  400  includes a support member  403 , a first light source  401 , a second light source  402 , and a lampshade that includes an inner cover  414  and a housing  424 . The support member  403 , the first light source  401 , and the second light source  402  are similar to the support member  103 , the first light source  101 , and the second light source  102  in  FIG. 1 , respectively, and are not described herein. 
     The circular dashed box in  FIG. 10  shows the support member  403  located inside the inner cover  414  and the first light source  401  and the second light source  402  provided on the support member  403 . Both the first light source  401  and the second light source  402  are an LED lamp. 
     Compared with that of an incandescent lamp, a light distribution of an LED changes obviously with a radiation angle. Therefore, in general, instead of an incandescent lamp used as a light source, when an LED is used as a light source, it is difficult for the housing  424  of the illumination device  400  to be sufficiently illuminated without using an additional optical element to change the light distribution of the light source, thus affecting lighting effects and aesthetics of the illumination device  400 . When an LED is used as a light source, by setting a light output intensity ratio between the first light source  401  and the second light source  402 , the housing  424  can be sufficiently illuminated without using an optical element such as a lens, a reflector, or a diffuser. 
     It should be noted that although the foregoing embodiments only show the first light source and the second light source, the illumination device of the present invention may further include other light sources different from the light distributions of the first light source and the second light source. In addition, the modulation of the light distribution of the illumination device can be realized by setting a light output intensity corresponding to at least one light distribution. 
     While the present invention has been described with reference to specific embodiments thereof, it will be understood by those skilled in the art that many modifications and variations can be made thereto. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and variations insofar as they are within the true spirit and scope of the invention.