Abstract:
An elongate automotive illumination assembly includes an elongate housing; at least one light source; an elongate lens having an apex region and a pair of spaced-apart blade portions. The spaced-apart blade portions extend away from the apex region to define a generally V-shaped cross-section with the apex region including an elongate light emitting surface. The blade portions connect to the elongate housing to define an enclosure. An elongate light guide guides light from the at least one light source to the elongate light emitting surface. The elongate light guide includes a body extending away from the light source(s) towards the elongate light emitting surface. The light guide is housed within the enclosure and between the blades of the lens such that the light emitting surface of the light guide is adjacent to the light emitting surface of the lens.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority from Australian Provisional Patent Application No. 2016900068, filed Jan. 11, 2016, the disclosure of which is incorporated herein by reference in its entirety. 
       BACKGROUND OF THE INVENTION 
       [0002]    This invention relates in general to an illuminated assembly. In particular, the invention relates to an elongate illumination assembly that can provide a uniform elongate light output without the use of optic features and without the light source being viewable and in particular to an elongate illuminated automotive design element. 
         [0003]    An aesthetic feature which has become desirable in automotive applications is to provide various automotive elements which feature illumination of the key features of the elements. One example of an automotive element are grill elements. Many grill elements are elongate and may also have a repeating or non-repeating pattern. It is desirable that the grill elements are able to be illuminated along their length with an even (uniform or homogenous) luminance using light emitting diodes (LEDs) input. An LED is a directional light source having a relative luminous intensity that decreases as the viewing angle is increased. This may result in the appearance of bright or hot spots to an external viewer of the grill element. 
         [0004]    Lighting systems that provide a uniform luminous intensity are known, for example systems using expensive organic light emitting diode (OLED) technology or complex lens and reflector arrangements. Highly diffusing materials are also used but these have the drawback of giving a milky or hazy appearance and have poor optical efficiency. Optic features may also be used on clear materials to diffuse light, but these have the drawback that the optic features are visible in the unlit state which is undesirable. A further desirable feature is that the LED input is not directly visible to the external viewer of the grill element. 
         [0005]    It is against this background and the problems and difficulties associated therewith that the invention has been developed. 
         [0006]    Other advantages of the invention will become apparent from the following description, taken in connection with the accompanying drawings, wherein, by way of illustration and example, preferred embodiments of the invention are disclosed. 
       SUMMARY OF THE INVENTION 
       [0007]    This invention relates to an elongate illumination assembly that can provide a uniform elongate light output without the use of optic features and without the light source being viewable and in particular to an elongate illuminated automotive design element. 
         [0008]    According to a first aspect of the invention, there is provided an elongate automotive illumination assembly, including an elongate housing, at least one light source, an elongate lens having an apex region and a pair of spaced-apart blade portions extending away from the apex region to define a generally V-shaped cross-section with the apex region including an elongate light emitting surface, the blade portions connecting to the elongate housing to define an enclosure, and an elongate light guide for guiding light from the at least one light source to the elongate light emitting surface, the elongate light guide including a body extending away from the light source(s) towards the elongate light emitting surface, wherein the light guide is housed within the enclosure and between the blades of the lens such that the light emitting surface of the light guide is adjacent to the light emitting surface of the lens. 
         [0009]    In another form, the light guide includes a plurality of light-scattering particles. 
         [0010]    In another form, the apex region of the elongate lens defines a first repeating wave pattern profile, the first repeating wave pattern profile having a first amplitude. 
         [0011]    In another form, the light emitting surface of the light guide defines a second repeating wave pattern profile, the second repeating wave pattern profile having a second amplitude. 
         [0012]    In another form, the first repeating pattern wave profile matches the second repeating wave pattern profile. 
         [0013]    In another form, the elongate light guide has a rear region, the rear region having a third repeating wave pattern profile, the third repeating wave pattern profile having a third amplitude, wherein the third amplitude is smaller than the second amplitude. 
         [0014]    In another form, the apex region is light transmissive. 
         [0015]    In another form, each blade portion includes an opaque portion. 
         [0016]    In another form, the enclosure is weatherproof. 
         [0017]    Various aspects of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiment, when read in light of the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]      FIG. 1  is a view of an automotive grill assembly in an unlit state. 
           [0019]      FIG. 2A  is a detailed view of a section of the automotive grill assembly of  FIG. 1  in an unlit state. 
           [0020]      FIG. 2B  is a detailed view of a section of the automotive grill assembly of  FIG. 1  in a lit state. 
           [0021]      FIG. 3  is a perspective view of an elongate illumination assembly according to an embodiment of the invention. 
           [0022]      FIG. 4  is a perspective view of the elongate light guide and PCB sub-assembly of  FIG. 3 . 
           [0023]      FIG. 5  is a perspective view of the elongate light guide of  FIG. 4 . 
           [0024]      FIG. 6  is a partial rear perspective view of the elongate light guide of  FIG. 4  with contour lines. 
           [0025]      FIG. 7  is a partial front perspective view of the elongate light guide of  FIG. 4  with contour lines. 
           [0026]      FIG. 8  is a sectional view of the elongate illumination assembly of  FIG. 3 . 
           [0027]      FIG. 9  is an isometric view of a schematic of the elongate light guide of  FIG. 4  when in a lit state. 
           [0028]      FIG. 10  is an isometric view of a schematic of the elongate illumination assembly of  FIG. 3  when in a lit state. 
           [0029]      FIG. 11  is a perspective view of an elongate illumination assembly according to another embodiment of the invention. 
           [0030]      FIG. 12  is a perspective view of the elongate light guide and PCB sub-assembly of  FIG. 11 . 
           [0031]      FIG. 13  is a perspective view of the elongate light guide of  FIG. 12 ; 
           [0032]      FIG. 14  is a partial rear perspective view of the light guide of  FIG. 12  with contour lines. 
           [0033]      FIG. 15  is a partial front perspective view of the light guide of  FIG. 12  with contour lines. 
           [0034]      FIG. 16  is a sectional view of the elongate illumination assembly of  FIG. 11 . 
           [0035]      FIG. 17  is an isometric view of a schematic of the elongate light guide of  FIG. 12  when in a lit state. 
           [0036]      FIG. 18  is an isometric view of a schematic of the elongate illumination assembly of  FIG. 11  when in a lit state. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0037]    Referring now to  FIGS. 1, 2A and 2B , there is shown an automotive grill assembly  10  comprising a number of elongate grill elements  11  and a grill surround  12 . In  FIGS. 1 and 2A  the grill assembly  10  is in an unlit state, whereas in  FIG. 2B , the grill assembly  10  is in a lit state. As can be seen, the leading edge of each grill element  11  is illuminated, highlighting the repeating wave pattern of this particular embodiment. 
         [0038]    Referring now to  FIGS. 3 to 8 , there is shown an elongate illumination assembly  20  according to an embodiment of the invention. The elongate illumination assembly  20  has an elongate housing  23 , printed circuit boards (PCBs)  22  featuring light emitting diodes (not shown), an elongate light guide  24  and an elongate lens  21  with a generally V-shaped cross-section and repeating wave pattern profile. The lens  21  profile may be shaped in a variety of different repeating and non-repeating patterns. 
         [0039]    The housing  23  forms the backing for the illumination assembly  20 , it provides structural reinforcement to the illumination assembly  20  and may be manufactured from a weather resistant plastic such as acrylonitrile styrene acrylate (ASA) or acrylonitrile butadiene styrene (ABS). The light guide  24  and PCBs  22  are housed within the V-shape of the lens  21  which is then connected or joined to the housing  23  (e.g. by welding) such that the light guide  24  and PCBs  22  are housed within the lens  21  and housing  23 . 
         [0040]    As is best seen in  FIGS. 4 and 5 , the light guide  24  has a first end  24   a  having a first light receiving surface  24   b,  a second end  24   c  having a second light receiving surface  24   d,  and a light emitting surface  24   e  viewable to an external viewer of the illumination assembly  20  through the lens  21 . A PCB  22  is located at both the first end  24   a  and the second end  24   c  of the light guide  24 . An LED light source located on each PCB  22  is positioned adjacent to the first light receiving surface  24   b  and the second light receiving surface  24   d  of the light guide  24 , which is configured to allow light to enter the light guide  24  through the light receiving surfaces  24   b,    24   c.  The light guide  24  is adapted to be substantially transparent and without any visible discrete optic features in an un-lit state while being diffusive in a lit-state. When lit, light exits the light guide  24  at light emitting surface  24   e  with substantially uniform luminous intensity across the surface. 
         [0041]    As is best seen in  FIGS. 6 and 7 , the light guide  24  has a varying cross sectional area and profile along its depth. The light guide  24  has a front region  24   f  (adjacent the light emitting surface  24   e ) and a rear region  24   g  (furthest from the light emitting surface  24   e ). The rear region  24   g  has a larger sectional thickness than the front region  24   f.  In this embodiment, the rear region  24   g  has a generally bulbous shape. The front region  24   f  has a generally consistent sectional thickness which has a ribbon-like shape. 
         [0042]    The light emitting surface  24   e  has the same repeating wave profile as the leading edge of the lens  21 . The front region  24   f  also has this repeating wave profile. As is best seen in  FIGS. 6 and 7 , the rear section  24   g  also has a repeating wave profile but with a smaller amplitude resulting in a straighter profile. 
         [0043]    The light guide  24  also has a transitionary region  24   h,  connecting the front and rear regions  24   f,    24   g  and having a profile that transitions from that of the rear region  24   g  to that of the front region  24   f.    
         [0044]    As shown in  FIG. 8 , the light guide  24  is disposed behind the lens  21  which has an apex region  21   f  (or leading edge) with a light emitting surface  21   d  and from which a pair of spaced-apart blade portions  21   e  extend away to define the generally V-shaped cross-section. The lens  21  has a clear or tinted outer portion  21   a  and an opaque inner portion  21   b,  wherein the lens  21  remains entirely clear along the apex  21   f  immediately behind the light emitting surface  21   d  and adjacent the light emitting surface  24   e  of the light guide  24  to allow light emitted from the light guide  24  to enter the lens  21  and exit at the light emitting surface  21   d.  The effect of this composition is that in an unlit state, the grill assembly  10  has a uniform appearance with the light guide  24  being concealed being the lens  21 . When the light source is activated, the light guide  24  lights up and emits light through the light transmissive apex region  21   f  of the lens  21  to the light emitting surface  21   d  in a substantially uniform luminous intensity. 
         [0045]    The lens  21  may be formed in many different ways. For example, the lens  21  may be a two-component lens comprising a clear or tinted outer portion  21   a  and an opaque inner portion  21   b.  The two-component lens may also be formed in a co-moulding process. Alternatively, the lens  21  may be a single component having an opaque coating on an inner surface formed by example by applying paint or a thin film coating. The clear section (or window)  21   c  may be formed by etching away the opaque coating or masking the area before coating. The window  21   c  may be approximately 10 mm high. 
         [0046]    Referring now to  FIGS. 9 and 10 , which shows a schematic of the elongate light guide  24  and the elongate illumination assembly  20  in a lit state, illustrating how light rays behave when the light guide  24  is lit by a single LED light source, and the light rays enter the light guide  24  and are guided toward the light exiting surface  24   e.    
         [0047]    The elongate light guide  24  is referred to as a particle filled light guide to distinguish it from a crystal clear light guide (traditional light guide). In a traditional light guide, light is transmitted from a light source to a point at some distance from the source with minimal loss by total internal reflection. 
         [0048]    In this particle filled elongate light guide  24 , the transmission of light from the light source to the light emitting surface  24   e,  is achieved through a combination of the use of internal reflection and light scattering particles. 
         [0049]    Internal reflection is encouraged through the geometry of the light guide  24 , wherein light rays enter the light guide  24  through the first and second light receiving surfaces  24   b,    24   d  and are guided along the rear region  24   g  of the light guide  24 . 
         [0050]    The internal geometry of the rear region  24   g  (bulbous shape and straightened profile) encourages internal reflection with the incidence angle of the bulk of the light rays approaching the outer surface of the rear region  24   g  such that internal reflection is promoted. 
         [0051]    Most light rays that enter the elongate light guide  24  will encounter light scattering particles that alter the direction of the rays. The effect of this light scattering is that light rays will spread throughout the light guide  24 , along the transitionary region  24   h  and into the front region  24   f,  where they will then exit through the light emitting surface  24   e,  also ensuring that an even distribution of light output occurs. 
         [0052]    The light scattering particles may be titanium dioxide particles of sufficient size and concentration such that the light guide appears transparent when un-lit while providing a substantially uniform luminous intensity surface output when lit. 
         [0053]    Referring now to  FIGS. 11 to 16 , where there is shown an illumination assembly  30  according to an alternative embodiment of the invention. The illumination assembly  30  has housing  31 , a PCB  32  featuring a plurality of LEDs  33 , a light guide  34  and an elongate lens  35  with a generally V-shaped cross-section and repeating wave pattern profile. Similarly to the first embodiment, the lens  35  profile may be shaped in a variety of different repeating and non-repeating patterns. 
         [0054]    The housing  31  forms the backing for the illumination assembly  30  and provides structural reinforcement to the illumination assembly  30  and may be manufactured from a weather resistant plastic such as acrylonitrile styrene acrylate (ASA) or acrylonitrile butadiene styrene (ABS), and is configured to receive the PCB  32 . The light guide  34  fits within the V-shape of the lens  35  which is then connected or joined to the housing  31  (e.g. by welding) such that the light guide  34  and PCB  32  are housed within the lens  35  and housing  31 . 
         [0055]    As is best seen in  FIG. 16 , the PCB  32  is orientated such that its plane is transverse to that of the direction of elongation of the lens  35 . A plurality of LEDs  33 , are mounted on the top and bottom of the PCB  32 , such that their direction of output is toward the light guide  34  and lens  35 . The location of the LEDs  33  on the top and bottom of the PCB  32  is influenced by the profile of the lens  35 , such that the LEDs  33  follow the profile pattern. 
         [0056]    The light guide  34  has a light receiving surface  34   a  which is adjacent to the LEDs  33 , and a light emitting surface  34   b  viewable to an external viewer of the illumination assembly  30  through the lens  35 . The light guide  34  is configured to allow light to enter the light guide  34  through the light receiving surface  34   a.  The light guide  34  is adapted to be substantially transparent and without any visible discrete optic features in an un-lit state while being diffusive in a lit-state. When lit, light exits the light guide  34  at light emitting surface  34   b  with substantially uniform luminous intensity across the surface. 
         [0057]    As is best seen in  FIGS. 14 and 15 , the light guide  34  has a varying profile along its depth. The light emitting surface  34   b  of the light guide  34  has the same repeating wave profile as the leading edge of the lens  35 . The light receiving surface  34   a  of the light guide  34  also has a repeating wave profile but with a smaller amplitude resulting in a straighter profile. 
         [0058]    The light guide has a front region  34   c  (adjacent the light emitting surface  34   b ) which has a generally consistent sectional thickness which forms a ribbon-like shape and follows the same profile as the light emitting surface  34   b.  The light guide also has a transitionary region  34   d,  connecting the front region  34   c  and the light receiving surface  34   a,  and having a profile that transitions from that of the light receiving surface  34   a  to that of the front region  34   c.  As shown in  FIG. 8 , the light guide  34  is disposed behind the lens  35  which has an apex  35   f  (or leading edge) with a light emitting surface  35   d  and from which a pair of spaced-apart blade portions  35   e  extend away to define the generally V-shaped cross-section. The lens  35  has a clear or tinted outer portion  35   a  and an opaque inner portion  35   b,  wherein the lens  35  remains entirely clear along the apex  35   f  immediately behind the light emitting surface  35   d  and adjacent the light emitting surface  34   b  of the light guide  34  to allow light emitted from the light guide  34  to enter the lens  35  and exit at the light emitting surface  35   d.  The effect of this composition is that in an unlit state, the grill assembly  10  has a uniform appearance with the light guide  34  being concealed being the lens  31 . When the light source is activated, the light guide  34  lights up and emits light through the light transmissive apex region  31   f  of the lens  31  to the light emitting surface  31   d  in a substantially uniform luminous intensity. 
         [0059]    The lens  35  may be formed in many different ways. For example, the lens  35  may be a two-component lens comprising a clear or tinted outer portion  35   a  and an opaque inner portion  35   b.  The two-component lens may also be formed in a co-moulding process. Alternatively, the lens  35  may be a single component having an opaque coating on an inner surface formed by example by applying paint or a thin film coating. The clear section (or window)  35   c  may be formed by etching away the opaque coating or masking the area before coating. The window  35   c  may be approximately 10 mm high. 
         [0060]    Referring now to  FIGS. 17 and 18 , which show schematics of the elongate light guide  34  and the elongate illumination assembly  30  in a lit state, illustrating how light rays behave when the light guide  34  is lit by a plurality of LED light sources, and the light rays enter the light guide  34  and are guided toward the light emitting surface  34   b.    
         [0061]    The elongate light guide  34  is referred to as a particle filled light guide to distinguish it from a crystal clear light guide (traditional light guide). In a traditional light guide, light is transmitted from a light source to a point at some distance from the source with minimal loss by total internal reflection. 
         [0062]    In this particle filled elongate light guide  34 , the transmission of light from the light source to the light emitting surface  34   b,  is achieved through a combination of the use of internal reflection and light scattering particles. 
         [0063]    Internal reflection is encouraged through the geometry of the light guide  34 , wherein light rays enter the light guide  34  through the light receiving surface  34   a,  and are guided through the transitionary and front regions  34   d,    34   c  of the light guide  34 . 
         [0064]    The internal geometry of the light guide  34  encourages internal reflection with the incidence angle of the bulk of the light rays approaching the top and bottom surfaces of the light guide  34  such that internal reflection is promoted. 
         [0065]    Most light rays that enter the light guide  34  will encounter light scattering particles that alter the direction of the rays. The effect of this light scattering is that light rays will spread throughout the light guide  34 , where they will then exit through the light emitting surface  34   b  with an even light output. 
         [0066]    Throughout the specification and the claims that follow, unless the context requires otherwise, the words “comprise” and “include” and variations such as “comprising” and “including” will be understood to imply the inclusion of a stated integer or group of integers, but not the exclusion of any other integer or group of integers. 
         [0067]    The reference to any prior art in this specification is not, and should not be taken as, an acknowledgement of any form of suggestion that such prior art forms part of the common general knowledge. 
         [0068]    The principle and mode of operation of this invention have been explained and illustrated in its preferred embodiment. However, it must be understood that this invention may be practiced otherwise than as specifically explained and illustrated without departing from its spirit or scope.