Patent Document

FIELD OF THE DISCLOSURE 
       [0001]    The present disclosure relates to optoelectronic modules having features for reducing the visual impact of interior components. 
       BACKGROUND 
       [0002]    Many electronic appliances, including consumer products, industrial appliances and medical devices, have a light emitting element for emitting optical signals outside the device and/or a light receiving element for sensing light received from outside the device. Depending on the particular application, the wavelength of the light to be emitted or detected may be in the ultra-violet (UV), infra-red (IR) or visible range. For some applications, particularly those that rely on light in the visible range (e.g., about 390 nm to about 750 nm), a small opening (e.g., a hole or slit) or window may be provided in the housing (e.g., a casing) of the device so that the light can be emitted to an external location or so that light can be received from an external location. In some cases, one or more windows are provided in the housing so that optical signals in the visible range can be emitted as well as received by optoelectronic components inside the appliance. For example, some mobile phones include a window in their housing so that optical signals can be received by a camera integrated within the phone. A second window adjacent the first window may be provided so that light from a flash inside the phone can be emitted when a photograph is to be taken using the camera. 
         [0003]    Although such openings or windows in the housing of the appliance may be important to facilitate various functions, the windows may detract from the overall appearance of the appliance. For example, the presence of windows or other openings in the housing may make some of the internal components visible to someone looking at the appliance when it is in an unilluminated state. This may be undesirable in some cases either for functional or aesthetic reasons. 
       SUMMARY 
       [0004]    The present disclosure describes various optoelectronic modules that include features to help reduce the visual impact of interior components and shield them from view. Some of the features also may enhance the outer appearance of the module or of an appliance incorporating the module. 
         [0005]    According to one aspect, a flash module includes a light emitting element mounted on a substrate. The light emitting element has a light emitting surface at least partially covered by a wavelength conversion material. A cover, which is substantially parallel to the substrate, is disposed over the light emitting element and the wavelength conversion material. The cover is composed of a material that is substantially transparent to light to be emitted from the module. A spacer separates the cover from the substrate and laterally encircles the light emitting element. A layer on the cover is composed of a material that is substantially non-transparent to light in the visible part of the spectrum. The layer has through-holes that allow light from the light emitting element to pass out of the module, but that are sufficiently small (e.g., ≦0.1 mm diameter or side) so as to reduce the visual impact of the layer. 
         [0006]    Some implementations include one or more of the following features. For example, in some cases, the through-holes have a diameter in the range of 0.05 mm-0.1 mm. In some instances, the through-holes may be smaller than is resolvable by an unaided human eye. In some implementations, dimensions and/or a pattern of the through-holes simulate a textured appearance of an exterior housing of a device (e.g., a smartphone) in which the light emitting module is disposed. The layer on the cover may have a thickness, for example, of less than 10 μm and may be composed, for example, of black chrome. 
         [0007]    According to another aspect, a light emitting module includes a light emitting element mounted on a substrate. The light emitting element has a light emitting surface at least partially covered by a wavelength conversion material. A cover, which is substantially parallel to the substrate, is disposed over the light emitting element and the wavelength conversion material, and is composed of a material that is substantially transparent to light to be emitted from the module. A spacer separates the cover from the substrate. A visual impact reduction member is disposed on the cover at a location that intersects an optical emission axis of the light emitting element. The visual impact reduction member is composed of a material that reduces a visual impact of the light emitting element and wavelength conversion material when viewed from outside the module while the light emitting element is not emitting light. An optics part laterally surrounds the light emitting element includes a reflective surface. The optics part is arranged so that light exiting the wavelength conversion material is reflected by the visual impact reduction member toward the reflective surface of the optics part, which redirects the light out of the module through the transparent cover. In some cases, the reflective surface of the optics part comprises a low-emissivity, highly reflective coating. 
         [0008]    In accordance with yet a further aspect, a light emitting module includes a light emitting element mounted on a substrate and arranged to emit light in a direction generally parallel to the substrate. A wavelength conversion material is positioned within a path of light from the light emitting element. An optics part adjacent the substrate includes a reflective surface that intersects an optical emission axis of the light emitting element. A cover, which is substantially parallel to the substrate, is disposed over the light emitting element, the wavelength conversion material and the optics part, and is composed of a material that is substantially transparent to light to be emitted from the module. A spacer separates the cover from the substrate. A substantially opaque layer on a portion of the cover extends over the light emitting element and the wavelength conversion material so as to reduce a visual impact of the light emitting element and wavelength conversion material when viewed from outside the module while the light emitting element is not emitting light. The module is arranged so that light exiting the phosphor material is reflected by the reflective surface of the optics part, which redirects the light out of the module through a portion of the transparent cover on which the spacer is not disposed. 
         [0009]    According to another aspect, a light emitting module includes a light emitting element mounted on a substrate. A wavelength conversion material is disposed in an area of the module spaced apart from the light emitting element. A cover substantially parallel to the substrate has a first section disposed over the wavelength conversion material and is composed of a material that is substantially transparent to light to be emitted from the module. A substantially opaque layer extends over the light emitting element so as to reduce a visual impact of the light emitting element from outside the module while the light emitting element is not emitting light. A height of the wavelength conversion material in a direction from the substrate toward the cover is sufficiently small so as to reduce a visual impact of the phosphor when viewed from outside the module while the light emitting element is not emitting light. The module is arranged so that at least some light emitting element light that enters the wavelength conversion material is converted to light of a different wavelength which subsequently exits the module through the first section of the cover. 
         [0010]    Another aspect describes a light emitting module that includes a light emitting element mounted on a substrate. A cover, which is substantially parallel to the substrate, is disposed over the light emitting element and is composed of a material that is substantially transparent to light to be emitted from the module. A spacer separates the cover from the substrate and laterally encircles the light emitting element. A layer on the cover has a substantially transparent state and a substantially opaque state, wherein the layer changes from the opaque state to the transparent state in response to at least one of a change in light, a change in temperature, or a change in voltage or current applied to the layer. For example, if the layer is a photochromic layer that changes from the opaque state to the transparent state in response to light generated by the light emitting element. In some implementations, a color of the photochromic layer in the opaque state substantially matches a color of a housing of a device in which the module is disposed. When the light emitting element emits light, the photochromic layer can become transparent so that light is emitted from the module. The photochromic layer can remain in the transparent state while the light emitting element emits light, and then can transition back to the opaque state after the light emitting element is turned off. 
         [0011]    Other aspects, features and advantages will be readily apparent from the following detailed description, the accompanying drawings and the claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  illustrates an example of a smartphone. 
           [0013]      FIG. 2  illustrates an example of a light emitting module. 
           [0014]      FIGS. 3A-3D  illustrate an example of a wafer-level method of fabricating flash modules as in  FIG. 2 . 
           [0015]      FIG. 4A  illustrates another example of a light emitting module. 
           [0016]      FIG. 4B  illustrates yet another example of a light emitting module. 
           [0017]      FIG. 5A  illustrates a further example of a light emitting module. 
           [0018]      FIG. 5B  illustrates another example of a light emitting module. 
           [0019]      FIG. 6A  illustrates yet another example of a light emitting module. 
           [0020]      FIG. 6B  illustrates a further example of a light emitting module. 
           [0021]      FIG. 6C  illustrates another example of a light emitting module. 
           [0022]      FIG. 6D  illustrates yet another example of a light emitting module. 
           [0023]      FIG. 7  illustrates another example of a light emitting module. 
       
    
    
     DETAILED DESCRIPTION 
       [0024]    As shown in  FIG. 1 , a smartphone  10 , which is an example of portable computing device, includes a light emitting module  12  within its housing. The module  12  may be used, for example, as a flash module in conjunction with an image capturing device such as a camera that also is integrated within the smartphone  10  and can be interconnected to other components of the device, which may include, for example, a processor, memory, an input/output device such as a display, a communication interface, and a transceiver, and other components. In some cases, the module  12  can be used to alert a user to incoming calls, messages, or other alerts. The various components on the smartphone or other device  10  can be interconnected using various buses, and several of the components may be mounted on a common motherboard or in other manners as appropriate. In some implementations, the module  12  is mounted on the common motherboard with some of the other components. 
         [0025]    Some or all of the outer surfaces of smartphone or other device  10  may be composed of light blocking material. This may be done, in some implementations, either for aesthetic or functional reasons (e.g., to reduce the amount of stray light entering the housing). For example, at least some of the outer surfaces may be composed of a black material that absorbs a significant amount of, and preferably substantially all, the light in the visible spectrum that impinges on those surfaces of the smartphone or other device. 
         [0026]    A surface of the smartphone  10  includes a window  14  that permits light emitted by the module  12  to exit the housing of the smartphone  10 . The module  12  can be located directly below the window  14 . A camera may be positioned directly below a second window  15  that is adjacent the first window  14 . If the windows are composed, for example, of a transparent glass or plastic material, then the module  12  may be visible from the outside. In various applications, however, it may be desirable to design the module  12  such that the module  12  is not readily visible when viewed from outside the housing (e.g., when looking at window  14 ). The following paragraphs describe examples of light emitting modules that include features that can reduce the visual impact of the module even when it is an unilluminated state. 
         [0027]    An example of module  12  is illustrated in  FIG. 2  and includes a light emitting component such as a vertical light emitting diode (LED)  16 . The LED  16  is mounted on a substrate (i.e., a support)  18 , which may be composed, for example, of a printed circuit board (PCB) material. The light emitting surface of the LED  16  can be at least partially covered by a phosphor material  20  to convert the wavelength of light emitted by the LED  16 , for example, from blue light to white light. A cover  22 , which may be composed, for example, of glass or polymer, is disposed over the LED  16  and the phosphor  20  and can be substantially parallel to the substrate  18 . The cover  22 , which is substantially transparent to the wavelength(s) of light to be emitted from the module, is separated from the substrate  18  by a spacer  24  that laterally encircles the LED  16 . The spacer  24  can serve as sidewalls of the module. 
         [0028]    The spacer  24  can ensure a well-defined distance between substrate  18  and transparent cover  22  (through its vertical extension). In some implementations, the spacer  24  is composed of a polymer material, for example, a hardenable (e.g., curable) polymer material, such as an epoxy resin that is substantially opaque. 
         [0029]    Electrical contacts for the LED  16  can be connected electrically to outside the module  12  (e.g., the exterior of the substrate  18 ), where conductive pads are attached. The module  12  thus can be mounted on a printed circuit board, e.g., using surface mount technology (SMT), next to other electronic components. The printed circuit board may be a constituent of the smartphone or other device  10 . 
         [0030]    As shown in  FIG. 2 , to reduce the visual impact of the module&#39;s internal components (e.g., the LED  16  and phosphor  20 ) so that they are less visible (or are invisible) to a person looking at the module  12  through the window  14  on the surface of the smartphone or other device  10 , a thin layer  26  (e.g., ≦10 μm), for example, of black chrome, can be provided on the transparent cover  22 . In some cases, the thin layer  26  can be composed of a photolithographic material. The thin layer  26  should be composed of a material that is substantially non-transparent to light in the visible part of the spectrum. The thin layer  26  has very small through-holes  28  that extend entirely through the thickness of the layer  26 . The through-holes  28 , which can take the form, for example, of slits or circular openings, allow light from the LED  16  to pass out of the module  12 , but can be sufficiently small (e.g., ≦0.1 mm diameter (if circular) or ≦0.1 mm side (if square)) so as to reduce the visual impact of the phosphor. In some cases, the through-holes  28  have a diameter or side that falls within one of the following ranges: 0.05 mm-0.1 mm; 0.05 mm-0.09 mm; 0.05 mm-0.08 mm; 0.05 mm-0.07 mm; 0.05 mm-0.06 mm; 0.04 mm-0.05 mm; 0.03 mm-0.05 mm; or 0.02 mm-0.05 mm. In some cases, the dimensions and/or pattern of the through-holes  28  can match or simulate the textured appearance of the exterior housing of the smartphone or other device. Also, in some instances, the through-holes  28  are smaller than is resolvable by the unaided human eye (e.g., about 0.1 mm at a distance of 1 meter). In this way, if the module  12  is integrated into a smartphone or other device  10 , the presence of the module  12  inside the smartphone  10  or other device is not easily detected by the naked human eye when the module is in an unilluminated state. 
         [0031]    In some implementations, as illustrated in  FIG. 2A , it is desirable to encapsulate the transparent cover  22  of the module  12 A with an opaque material  30 . In this way, sidewalls of the transparent cover  22  are covered by a material that is non-transparent to light emitted by the module. In some cases, the opaque material  30  has the same composition as the spacer  24 , for example, a hardenable (i.e., curable) polymer material, such as a black epoxy resin. 
         [0032]      FIGS. 3A through 3D  illustrate an example process for fabricating a module as in  FIG. 2 . In some implementations, a wafer-level process can be used to make multiple modules in parallel (i.e., at the same time). Generally, a wafer refers to a substantially disk- or plate-like shaped item, its extension in one direction (y-direction or vertical direction) is small with respect to its extension in the other two directions (x- and z- or lateral directions). In some implementations, the diameter of the wafer is between 5 cm and 40 cm, and can be, for example, between 10 cm and 31 cm. The wafer may be cylindrical with a diameter, for example, of 2, 4, 6, 8, or 12 inches, one inch being about 2.54 cm. In some implementations of a wafer level process, there can be provisions for at least ten modules in each lateral direction, and in some cases at least thirty or even fifty or more modules in each lateral direction. 
         [0033]    As shown in the example of  FIG. 3A , a thin, non-transparent layer (e.g., black chrome)  100  is deposited on a surface of a transparent wafer  102 . The wafer  102  may be composed, for example, of glass or a polymer material. Through-holes  104  are formed in the non-transparent layer  100 , thereby forming a sub-assembly  106  of the non-transparent layer  100  (having through-holes  104 ) and the transparent wafer  102  (see  FIG. 3B ). The dimensions, shape, spacing and pattern of the through-holes  104  can be chosen to be consistent with the features of the module described above (i.e., such that light from a flash LED can pass through the transparent wafer  102  and the through-holes  104 , but such that the visual impact of the assembly is reduced). The through-holes  104  can be formed in any one of several ways, such as by drilling or etching. If the through-holes  104  are formed by etching, then a mask with an appropriate pattern for the through-holes  104  can be provided. 
         [0034]    Next, as shown in  FIG. 3C , the sub-assembly  106  is attached to one side of a spacer wafer  108 , the other side of which is attached to a substrate wafer  110 . The spacer wafer  108  can be composed, for example, of a non-transparent material, such as a vacuum injected polymer material (e.g., epoxy, acrylate, polyurethane, or silicone) containing a non-transparent filler (e.g., carbon black, pigment, or dye). The substrate wafer  110  can be composed, for example, of a PCB material  40  such as FR4, which is a grade designation assigned to glass-reinforced epoxy laminate material. Multiple light emitting elements (e.g., LEDs)  16  are mounted on the surface of the substrate wafer  110  and are separated from one another by portions of the spacer wafer  108 , which laterally encircles each LED  16 . The LEDs  16  can be covered at least partially by a phosphor material  20 . Electrical contacts for each LED  16  can be connected electrically to conductive pads on the other side of the substrate wafer  110 . As illustrated in  FIG. 3D , the resulting stack  112  can be separated (e.g., diced) vertically along dicing lines  114  into multiple modules, each of which is similar to the module of  FIG. 2 . 
         [0035]      FIG. 4A  illustrates another example of a light emitting module  200  that includes a light emitting element such as a vertical light emitting LED  16  mounted on a substrate. As in the previous example, the light emitting surface of the LED  16  can be covered by a phosphor material that converts the light emitted by the LED, for example, to white light. A transparent cover  22  is disposed over the LED substantially parallel to the substrate  18 , and is separated from the substrate  18  by a spacer  24 . Other details of the substrate  18 , spacer  24  and transparent cover  22  can be substantially similar to the corresponding features of the module  12  in  FIG. 2 . 
         [0036]    As further shown in  FIG. 4A , the LED-side of the transparent cover  22  has a visual impact reduction member  202  that is located directly over the LED  16  and the phosphor material  20 . The member  202  intersects the emission axis of the LED  16 , and can be composed of a material that reduces the visual impact of the phosphor material  20  and LED  16  (i.e., when the module  200  is viewed through the window  14  of the smartphone or other device  10  along the optical emission axis of the LED  16 ). Examples of the material for the member  202  include injectable and curable materials such as an epoxy composite, where the epoxy composite has substantially the same color as the housing of the smartphone or other device  10 . In some instances, the epoxy composite is an epoxy that includes carbon particles such that it appears black. In the illustrated example, the visual impact reduction member  202  is formed as a semi-spherical projection on the LED-side of the transparent cover  22 , but may have a different shape in other implementations. In some instances, the visual impact reduction member  202  can be formed on the surface of the cover  22  by a replication technique or it may be positioned on the cover  22  by a pick-and-place technique. The lateral dimensions of the visual impact reduction member  202  should be sufficiently large that they are present directly above the lateral dimensions of the LED  16  and phosphor  20  such that the visual impact of the LED  16  or phosphor  20  material are reduced for a person looking at the cover  22  of the module  200  along the optical axis of the LED  16 . 
         [0037]    To reflect the light  206  out of the module  200 , the surface of the visual impact reduction member  202  that faces the LED  16  can be coated with a low emissivity, highly reflective material  204 . An optics part is provided on the same surface of the substrate  18  as the LED  16  and includes curved, minor substrates  207  that laterally surround the LED  16 . The minor substrates  207  can be formed, for example, by a replication technique. The upper surfaces of the mirror substrates  207  can be covered, for example, with a low-emissivity, highly reflective coating  208  to enhance their reflectivity. Light emitted by the LED  16  passes through the phosphor  20 , where it is converted, for example, to white light, which subsequently is reflected by the reflective layer  204  on the visual impact reduction member  202 . Most of the light can be reflected by the reflective layer  204  toward the reflective surface  208  on the minor substrates  207 , which direct the light through the transparent cover  22  and out of the module  200 . 
         [0038]    As mentioned, each of the coating layers (i.e.,  204  and  208 ) can be composed of a low emissivity material, where a material&#39;s emissivity indicates the relative ability of the material&#39;s surface to emit energy by radiation compared to an ideal black body. The respective emissivity of each coating layer  204 ,  208  preferably has a value between 0 and 1. In some implementations, the maximum emissivity should be about 0.1. Examples of suitable low emissivity materials include metals such as copper (Cu), aluminum (Al), gold (Au), nickel (Ni), titanium (Ti) and tungsten (W), particularly such metals having a polished or blank surface. For example, at a temperature of about 25° C., polished Cu, Al, Au and Ni have emissivity values of about 0.05. 
         [0039]    Electrical contacts for the LED  16  can be connected electrically to outside the module  200  (e.g., the exterior of the substrate  18 ), where conductive pads are attached. The light emitting module  200  thus can be mounted on a printed circuit board, e.g., using surface mount technology (SMT), next to other electronic components. The printed circuit board may be a constituent of the smartphone or other device  10 . 
         [0040]    In some implementations, as illustrated in  FIG. 4B , it is desirable to encapsulate the transparent cover  22  of the module  200 A with an opaque material  230 . In this way, sidewalls of the transparent cover  22  are covered by a material that is non-transparent to light emitted by the module. In some cases, the opaque material  230  has the same composition as the spacer  24 , for example, a hardenable (i.e., curable) polymer material, such as a black epoxy resin. 
         [0041]      FIG. 5A  illustrates an example of a module  300  that includes a light emitting element such as a laser  316  mounted on a support  318 . A phosphor material  320  is positioned within a path of the laser light to convert the light emitted by the laser, for example, from blue to white light. An optics part is provided adjacent the support  318  and includes a curved, minor substrate  306  that intersects the optical emission axis of the laser  316 . The surface of the minor substrate  306  can be covered, for example, with a low-emissivity, highly reflective coating  308  to enhance its reflectivity. The same low-emissivity materials described above can be used for the coating  308  as well. Light emitted by the laser  316  passes through the phosphor  320 , where it is converted, for example, to white light  320 , which subsequently is reflected, by the reflective coating  308 , through the transparent cover  322  and out of the module  300 . 
         [0042]    The support  318  and the minor substrate  306  can be mounted on a substrate  328  that serves as the bottom of the module housing. A spacer  324  separates the substrate  328  from the transparent cover  320 . The respective compositions of the substrate  328  and transparent cover  322  can be substantially similar to the corresponding features of the module  12  in  FIG. 2 . 
         [0043]    As illustrated in  FIG. 5A , a portion  326  of the spacer  324  extends along the light emitting element-side of the transparent cover  322  such that it is separates the laser  316  and phosphor  320  from the transparent cover  322 . Thus, the laser  316  and phosphor  320  are located within the module  300  to one side of the spacer portion  326 , and part of the transparent cover  322  is located on the other side of the spacer portion  326 . The spacer  324  (including the portion  326 ) can be composed, for example, of a black material that absorbs most, if not all, light in the visible part of the spectrum so as to reduce the visual impact of the light emitting element  316  and phosphor material  320  to a person looking toward the exterior side of the cover  222 . Although the transparent cover  322  also extends over the optics part  306 , the spacer portion  326  does not extend over the optics part  306 , thereby allowing the light  330  to exit the module. 
         [0044]    Electrical contacts for the light emitting element  316  can be connected electrically to outside the module  300  (e.g., the exterior of the substrate  328 ), where conductive pads are attached. The light emitting module  300  thus can be mounted on a printed circuit board, e.g., using surface mount technology (SMT), next to other electronic components. The printed circuit board may be a constituent of the smartphone or other device  10 . 
         [0045]    Various modifications can be made to the module  300  of  FIG. 5A . For example, as illustrated in the module  300 A of  FIG. 5B , in some implementations, the optics part  306 ,  308  can provide an inclined, flat surface, rather than a curved surface. Also, in some implementations, instead of extending a portion  326  of the spacer  324  over the light emitting element  316  and phosphor material  320 , an opaque coating  327 , such as black chrome, can be provided on a surface of the transparent cover  322  over the light emitting element  316  and phosphor material  320 . In such implementations, the transparent cover  322  extends over the light emitting element  316  and phosphor material  320  as well as the optics part  306 , and the opaque coating  327  can be provided either on the light emitting element-side of the cover  322  or on its exterior side. The opaque coating  327 , however, does not extend over the optics part  306 , thereby allowing the light  330  to exit the module. Further, in some cases, the color of the opaque coating  327  can substantially match a color of the housing of the smartphone or other device  10  in which the module  300 A is disposed. In some instances, different combinations of features from the examples of  FIGS. 5A and 5B  may be present. 
         [0046]      FIG. 6A  illustrates an example of a module  400  that includes a light emitting element, such as a LED  416 , mounted on a substrate  418 . In this implementation, the phosphor material  420  that converts the LED light, for example, from blue to white light need not be disposed directly on the LED  416 . Instead, the phosphor material  420  can be spaced away laterally from the LED  416  and substantially may fill an area between the substrate  418  and a transparent cover  422  disposed directly over the phosphor material  420 . The phosphor material  420  can be a composite of an inorganic phosphor suspended, for example, in a silicon-based organic polymer (e.g., polydimethylsiloxane (PDMS)). The width (w) of the area containing the phosphor material  420  should be sufficiently large such that the phosphor material can perform its optical conversion function (i.e., convert the LED light from blue to white light). On the other hand, the height (h) of the phosphor material  420  can be relatively thin such that its visual impact, when viewed through the transparent cover  422 , is reduced. In general, the width to height ratio (w/h) of the phosphor material needed to achieve a particular visual impact will depend, at least in part, on the concentration of phosphor suspended in the silicone. Thus, for example, if the phosphor concentration is relatively high, the w can be made smaller to meet the host device specification. On the other hand, if the phosphor concentration is relatively low, then w or h may need to be made higher to achieve the same visual impact. In some implementations, the w/h ratio of the phosphor material is in the range of 5/1 to 100/1. A w/h ratio in the range of about 10/1 to 50/1 may be appropriate in some instances. 
         [0047]    In situations where the light emitting element  416  directs light upwardly, it also can be advantageous to provide a reflector  432  that intersects the light emitting element&#39;s optical emission axis so as to reflect the laser light  428  toward the phosphor material  420 . The surface of the reflector  432  can be coated, for example, with a low-emissivity, highly reflective coating to enhance its reflectivity. The same low-emissivity materials described above can be used for the coating here as well. In operation, light  428  emitted by the light emitting element  416  passes through the phosphor  420 , where it is converted, for example, to white light  420 , at least some of which subsequently passes through the transparent cover  422  and out of the module  400 . 
         [0048]    To help reduce the visual impact of the light emitting element  416 , a non-transparent cover  426  can be disposed over the light emitting element  416  as well as over the reflector  432 . The non-transparent cover  426 , which can be composed, for example, of the same material as the spacer  424 , extends substantially parallel to the transparent cover  422 . Thus, the non-transparent cover  426  and the transparent cover  422  together can form the top of the module, and the spacer  424  can serve as the sidewalls of the module. In some implementations, instead of extending a portion  426  of the spacer  424  over the light emitting element  416 , an opaque coating  427 , such as black chrome, can be provided on a surface of the transparent cover  422  over the light emitting element  416  (see  FIG. 6B ). In such implementations, the transparent cover  422  extends over the LED  416  as well as the phosphor material  420 , and the opaque coating  427  can be provided either on the light emitting element-side of the cover  422  or on its exterior side. The opaque coating  427 , however, does not extend over most or all of the phosphor material  420 , thereby allowing the light  430  to exit the module  400 A. Further, in some cases, the color of the opaque coating  427  can substantially match a color of the housing of the smartphone or other device  10  in which the module  400 A is disposed. 
         [0049]    As shown in  FIGS. 6C and 6D , some implementations include a reflector  434  at a side of the phosphor material  420  opposite the location of the light emitting element  416  and reflector  432 . The surface of the reflector  434  can be coated, for example, with a low-emissivity, highly reflective coating to enhance its reflectivity. The same low-emissivity materials described above can be used for the coating here as well. In some cases, the reflector  434  can be inclined at an angle with respect to the substrate  418 . As shown in  FIG. 6D , whereas the reflective surface of the reflector  432  faces the substrate  418 , the reflective surface of the reflector  434  faces the transparent cover  422 . Such arrangements can help increase the amount of light reflected out of the module. 
         [0050]    Electrical contacts for the light emitting element  416  can be connected electrically to outside the module  400  (e.g., the exterior of the substrate  418 ), where conductive pads are attached. The light emitting module  400  thus can be mounted on a printed circuit board, e.g., using surface mount technology (SMT), next to other electronic components. The printed circuit board may be a constituent of the smartphone or other device  10 . 
         [0051]      FIG. 7  illustrates another example of a light emitting module  500  that has some features similar to the module  12 A of  FIG. 2A . Instead of the thin layer  26  with small through-holes  28 , the module  500  includes a layer  502  on the transparent cover  22 . The layer  502  has a substantially transparent state and a substantially opaque state. In the opaque state, the color of the layer  502  preferably matches the color of the housing of the smartphone or other device  10 . In various implementations, the layer  502  can be composed of a material such that the change in state occurs in response to a change in light (e.g., photochromic), a change in temperature (e.g., thermochromic), or a change in voltage or current (e.g., electrochromic). For example, if the layer  502  is photochromic, a change from the opaque state to the transparent state can be triggered in response to the light from the flash LED  16 . In particular, when the LED  16  emits light, the photochromic layer  502  would become transparent and light would be emitted from the module  700 . A camera in the smartphone or other device  10  may capture an image while the flash in on. The photochromic layer  502  could remain in the transparent state while the LED  16  emits light, and then would transition back to the opaque state after the LED is turned off. If the layer  502  is electrochromic, then additional wiring and contacts can be provided so that the appropriate change in voltage or current can be applied to the electrochromic layer. In some implementations, the layer  502  can be implemented by micro-blind-technology-type materials. Depending on the implementation, the change in state of the layer  502  may be either physical or chemical, or a combination of both. 
         [0052]    In some implementations, a neutral density filter can be provided, for example, in the form of a coating on the inner or outer surface of the transparent cover. For example, a neutral density filter can be provided on a surface of the transparent cover  22  in any of the modules of  FIG. 4A, 4B or 7 . Likewise, a neutral density filter can be provided on a surface of transparent cover  322  in any of the modules of  FIG. 5A or 5B , or on a surface of the transparent cover  422  of any of the modules of  FIGS. 6A through 6D . The neutral density filter can be used to reduce or modify the intensity of all wavelengths or colors of light by substantially the same amount. 
         [0053]    In the foregoing examples, the light source or light emitting element is described as being implemented by a LED. However, in some implementations, the light emitting element can be implemented by other types of light sources, such as a photodiode, an OLED or a laser chip. 
         [0054]    The various modules described here can be integrated into a wide range of applications, including consumer electronic devices such as cameras, smart phones and laptops. The modules, particularly, the modules  300 ,  300 A of  FIGS. 5A and 5B , also can be suitable for incorporation into vehicle headlamps. 
         [0055]    Although particular implementations are described in detail, various modifications can be made within the spirit of the invention. Accordingly, other implementations are within the scope of the claims.

Technology Category: 5