Patent Publication Number: US-2015085519-A1

Title: Optical grade light pipe

Description:
FIELD OF THE INVENTION 
     The present invention generally relates to a light guide system, and more specifically, to a light guide system, wherein a light pipe and a surrounding carrier substrate are formed with an elongate attachment feature extending outwardly from the carrier and used to secure the light guide system to various materials. 
     BACKGROUND OF THE INVENTION 
     Current light guide systems require a lens, which is usually in the form of a light guide, a light panel or a light pipe, and a carrier member which is coupled to the lens and includes one or more attachment features that allow a user to fasten the light guide system to surrounding commodities. Currently, the attachment features are generally spaced along a length of the carrier member and allow for a light guide system to be coupled to various materials and surfaces at select locations. This form of securement may be suitable for applications where the light guide system is essentially concealed and primarily used as an ambient lighting feature. However, in situations where considerable lengths of light pipe are used and conspicuously placed, it is important to have assured attachment features disposed along the entire length of the light guide system to provide for uniform attachment to surrounding commodities that is free from droops or sags and is fixed in place in a controlled manner. Thus, a method of forming a light guide system is desired, wherein the carrier component includes an integrally formed attachment feature that extends substantially along the length of the carrier member. 
     SUMMARY OF THE INVENTION 
     One aspect of the present invention includes, a light guide system comprising an optical light pipe and a carrier member. The light pipe includes a generally elongate body portion and the carrier is coupled to the light pipe along a length of the body portion of the light pipe. An attachment flange extends outwardly from the carrier member along a length of the carrier member and is adapted to secure the light guide system to a material substrate. 
     Another aspect of the present invention includes, a light guide system comprising an optical light pipe and a carrier member. The light pipe includes a generally elongate body portion having an outer surface. The carrier member is disposed around the outer surface of the light pipe and to define a casing around the light pipe. The carrier member also extends along the entirety of a length of the light pipe. An attachment flange extends outwardly from an outer surface of the carrier member along a length of the carrier member and is adapted to secure the light guide system to a material substrate. 
     Yet another aspect of the present invention includes, a light guide system comprising an optical light pipe and a carrier member. The light pipe includes a generally elongate body portion having an outer surface. The carrier member includes both inner and outer surfaces and is disposed around the outer surface of the light pipe to form a casing around the light pipe. An attachment flange extends outwardly from the outer surface of the carrier member and includes a pierceable membrane adapted to secure the light guide system to a material substrate. 
     These and other aspects, objects, and features of the present invention will be understood and appreciated by those skilled in the art upon studying the following specification, claims, and appended drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings: 
         FIG. 1  is an fragmentary perspective view of a light guide system according to one embodiment; 
         FIG. 2  is a crossectional view of the light guide system of  FIG. 1  taken at line II; 
         FIG. 3  is crossectional view of the light guide system as coupled to a material substrate; 
         FIG. 4  is a fragmentary perspective view of a vehicle seat having a light guide system secured thereto; and 
         FIG. 5  is a top perspective view of a vehicle floor mat having a light guide system secured thereto. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     For purposes of description herein, the terms “upper,” “lower,” “right,” “left,” “rear,” “front,” “vertical,” “horizontal,” and derivatives thereof shall relate to the invention as oriented in  FIG. 1 . However, it is to be understood that the invention may assume various alternative orientations, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise. 
     Referring now to  FIG. 1 , the reference numeral  10  generally designates a light guide system according to one embodiment of the present invention. As shown in  FIG. 1 , the light guide system includes an optical grade light pipe  12  which is a substantially translucent pipe suitable for transmitting light as emitted from a light source  8 , as further described below. The light pipe  12  includes an elongate body portion  14  having an outer surface  16 . The light pipe  12  is generally formed from a material R 1  which may be a rigid material that is comprised of a curable substrate such as a polymerizable compound, a mold in clear (MIC) material or mixtures thereof. Acrylates are also commonly used for forming rigid light pipes, as well as poly (methyl methacrylate) (PMMA) which is a known substitute for glass. A polycarbonate material may also be used in an injection molding process to form a rigid light pipe  12 . Further, the light pipe  12  may be a flexible light pipe, wherein a suitable flexible material, also indicated as R 1 , is used to create the light pipe  12 . Such flexible materials include urethanes, silicone, thermoplastic polyurethane (TPU) or other like optical grade flexible materials. Whether the light pipe  12  is a flexible light pipe or a rigid light pipe, the light pipe  12 , when formed, is substantially optically transparent and capable of transmitting visible light. In this way, the light pipe  12  is a lens for the light guide system  10 . The light pipe  12  may be referred to as a light guide, a light plate, a light bar or any other light carrying substrate made from a transparent or substantially translucent plastic that is adapted to reflect and propagate light along a length thereof For purposes of this disclosure, the light pipe  12  and the material R 1  used to form the light pipe  12  will be described herein as a flexible optical grade light pipe. 
     A carrier member  20  is shown in  FIG. 1  as defining a molded casing  24  around the outer surface  16  of the light pipe  12  for supporting the clear lens light pipe  12  as shown in  FIG. 2 . The carrier member  20  is generally comprised of a material R 2  which is typically a polycarbonate material that may also be a blend of a polycarbonate material and an acrylonitrile butadiene styrene (ABS) plastic. The carrier member  20  of the present invention is generally an optically transmissive member having an inner surface  26  and an outer surface  28  disposed about the casing portion  24 . As shown in  FIG. 1 , the light guide system  10  includes an optically transparent light pipe  12  that is adapted to receive light at an input end  13  from a light source  8 . The light source  8  may include a plurality of light emitting diodes (LEDs)  8   a  positioned such that light  9  emitted from the LEDs  8   a  enters the input end  13  of the light pipe  12 . The light pipe  12  is designed to provide internal reflection of the light  9  entering the light pipe  12 , such that the light  9  is reflected along an outer surface  16  of the light pipe  12  as the light  9  travels along the length of the light pipe  12  with minimal light loss. In order to minimize the amount of light lost within the light pipe  12 , the light pipe  12  has an index of refraction that is higher than the index of refraction of the carrier member  20 . The index of refraction describes how light propagates through a particular medium. Thus, in the light guide system  10  of the present invention, light  9  emitting from the light source  8  is reflected within a body portion  14  of the light pipe  12  with nearly total or complete internal reflection within the body portion  14  of the light pipe  12  with little light absorption. Thus, the light  9  entering light pipe  12  is internally reflected and then selectively emitted through the outer surface  28  of the carrier member  20  as indicated by arrows  9   a.  The light  9   a  exiting the outer surface  28  of the carrier member  20  is contemplated to have been reflected multiple times within the body portion  14  of the light pipe  12 . The outer surface  16  of the light pipe  12  can be etched or otherwise textured to increase the effective surface area, thereby causing more light  9   a  to exit through the outer surface  28  of the carrier member  20  at select etched regions. Further, the texturing of the outer surface  16  of the light pipe  12  and the outer surface  28  of the carrier member  20  can be designed to evenly diffuse the light  9   a  as it exits the light pipe  12 , thereby minimizing variations in the brightness of the light  9   a  emitting from the outer surface  28  of the carrier member  20 . 
     Known methods of providing a light pipe and a carrier member involves the bonding of a preformed light pipe to a preformed carrier member by adhesion, such as by using a double-sided tape, or by mechanical connections such as brackets that are formed into the carrier substrate. The present invention seeks to avoid these connector mechanisms by providing an integrally formed the light pipe  12  and the carrier member  20  in a single process to form a unitary light guide system  10 . By co-molding or extruding the light pipe  12  and the carrier member  20  of the light guide system  10 , gaps that are typically formed in the prior art connection methods are greatly reduced or altogether eliminated. This provides a thinner or lower overall profile for the light guide system  10  of the present invention which can be a critical feature for a light guide system as used in applications having limited free space in an area where ambient lighting is desired. Further, the minimized gaps between the light pipe  12  and the carrier member  20  of the present invention reduces light leakage between the two substrates in use. 
     As further shown in  FIG. 1 , the carrier member  20  includes an outwardly extending attachment flange  30  which generally extends from the outer surface  28  of the carrier member  20 . The attachment flange  30  includes first and second surfaces  32 ,  34  having a body portion  36  disposed therebetween. In the embodiment shown in  FIG. 1  and  FIG. 2 , the attachment flange  30  further includes a terminal end  38 . As best shown in  FIG. 1 , the outwardly extending attachment flange  30  is disposed on the carrier member  20  along an entirety of a length of the carrier member  20 , such that the attachment flange  30  is an elongate attachment flange extending along an entirety of a length of the light guide system  10 . In this way, the outwardly extending attachment flange  30  is adapted to be used to secure the light guide system  10  to a variety of material substrates as further described below. With the attachment flange  30  extending along the entire length of the light guide system  10 , the light guide system  10  of the present invention provides assured access to an attachment location at all points along the light guide system  10 . Thus, the outwardly extending attachment flange  30  can be used as an attachment location for an infinite number of securement points disposed along the body  36  of the attachment flange  30 . In this way, the light guide system  10  of the present invention differs from the prior art where attachment features of the prior art are generally spaced apart along a length of a light guide system such that corresponding attachment features must be disposed on a surrounding commodity to which a light guide system of the prior art is to be secured. The present invention eliminates the need to configure a light guide system with attachment features adapted to match the attachment locations of a surrounding commodity. The uniform connection that is achieved with the outwardly extending engagement flange provides for a uniform appearance of the light guide system  10  as secured to a surrounding commodity. Specifically, the light guide system  10  can be evenly secured to a surrounding commodity, such that the light guide system  10 , and more particularly a flexible light guide system  10 , will not droop or sag between attachment locations as found in prior art applications. 
     The attachment flange  30  can be co-molded with the carrier member  20 , or the attachment flange  30  could be an extruded part which is molded onto the carrier member  20  separately. It is contemplated that both the attachment flange  30  and the carrier member  20  can be flexible polymeric parts, such as the overall light guide system  10  is flexible so as to be suitable for following the contours of a feature disposed within a vehicle interior to which the light guide system  10  is attached. 
     Referring now to  FIG. 3 , the light guide system  10  is shown having the outwardly extending attachment flange  30  disposed between first and second material substrates M 1 , M 2 . As noted above, the attachment flange  30  includes first and second surfaces  32 ,  34  which are disposed adjacent to material substrates M 1 , M 2 . As further shown in  FIG. 3 , the body portion  36  of attachment flange  30  is essentially sandwiched between the first and second material substrates M 1 , M 2 , such that a coupling mechanism  40  couples the material substrates M 1 , M 2  to the attachment flange  30 . The coupling mechanism  40  includes first and second ends  42 ,  44  disposed on opposite sides of a body portion  46 . In the embodiment shown in  FIG. 3 , the first end  42  is coupled to material substrate M 1 , while second end  44  is coupled to material substrate M 2 . The body portion  46  is shown disposed through the attachment flange  30  of the light guide system  10 . In this way, the light guide system  10  is coupled to material substrates M 1 , M 2  at a junction J disposed there between. The coupling mechanism  40  may be selected from any number of coupling mechanisms known in the art, such as a threaded stitch, a staple, a wire, and may also include other coupling forms, such as adhesives and the like. 
     Thus, attachment flange  30  is a pierceable attachment flange when used with mechanical fasteners, such as a staple or a stitch, such that the attachment flange  30  is adapted to retain its structural rigidity when used in conjunction with coupling mechanism  40 . As noted above, the attachment flange  30  may be comprised of a polymeric material which is suitable for piercing and coupling to a material substrate. 
     In this way, the attachment flange  30  is both pierceable and flexible, such that the attachment flange  30  can be used with a flexible light guide system  10  to follow the contours of a vehicle feature, for example vehicle seat or a floor mat as further described below. 
     Referring now to  FIG. 4 , a vehicle seat  50  is shown having a seat portion  52 , a backrest portion  54  and a headrest portion  56 . Referring specifically to the backrest portion  54 , a side panel  58  is shown coupled to a front panel  60 . The panels  58 ,  60  are coupled together via a stitching arrangement  62  which includes stitching patters  64 ,  66  which are disposed along exterior edges of the panels  58 ,  60 . A light guide system of the present invention  10  is shown disposed within the stitching arrangement  62  as located between stitching patterns  64 ,  66 . In this way, the light guide system  10  is secured to the material substrates making up panels  58 ,  60  in an arrangement similar to the arrangement shown in  FIG. 3 . Thus, the light guide system  10  is disposed at a seam or junction J of the material substrates for panels  58 ,  60 . As disposed on the vehicle seat  50 , along the stitching arrangement  62 , the light guide system  10  is adapted to emit light, as indicated by arrows  9 A, as received from a light source for eliminating select portions of the vehicle seat  50 . While the light guide system  10  of the present invention is showed coupled to a side panel  58  and front panel  60  at a junction therebetween, it is contemplated that the light guide system  10  of the present invention could be coupled to any portion of the vehicle seat  50  using attachment flange  30  as described above. Other such locations include scene  70  disposed on headrest portion  56 , or scene  72  disposed on seat portion  52 . Now shown in this example as coupled to a seam location, the light guide system  10  of the present invention may be coupled anywhere to the material used to make up the vehicle seat cover of vehicle seat  50  as the attachment flange  30  of the light guide system  10  is not limited to couplings disposed along a seam. 
     Referring now to  FIG. 5 , a floor mat  80  is shown having a body portion  82  having front and rear sides  84 ,  86  and side portions  88 ,  90 . Together the sides  84 ,  86 ,  88  and  90  define a perimeter  92  of the floor mat  80 . With specific reference to side  88 , a stitching arrangement  94  is shown having stitching patterns  96  and  98 . The stitching arrangement  94  is disposed along a seam or junction between the body portion  82  of the floor mat  80  at an outer lining  83  which is disposed about the perimeter  90  of the floor mat  80 . Thus, the stitching arrangement  94  couples the lining  83  to the body portion  82  using stitching patterns  96 ,  98 . As further shown in  FIG. 5 , a light guide system  10  is coupled to the floor mat  80  at the stitching arrangement  94  by stitching patterns  96 ,  98 . In this way, the light guide system  10  is disposed along the perimeter  90  of the floor mat  80  in what is contemplated to be a similar arrangement as shown with respect to FIG.  3 . Being disposed on the upper surface of a body portion  82  of the floor mat  80 , the light guide system  10  is adapted to emit light, as indicated by arrows  9 A, from the floor mat into a vehicle interior. It is contemplated that the floor mat  80  may include a power outlet, or other like receptacle, disposed on the underside of the body portion  82  for powering the light guide system  10 . 
     While the light guide system  10  of the present invention has been shown as coupled to a vehicle system  50  and a floor mat  80  in  FIGS. 4 and 5 , it is contemplated that the light guide system  10  can also be coupled to any feature disposed within a vehicle interior where ambient light is desired. 
     It will be understood by one having ordinary skill in the art that construction of the described invention and other components is not limited to any specific material. Other exemplary embodiments of the invention disclosed herein may be formed from a wide variety of materials, unless described otherwise herein. 
     For purposes of this disclosure, the term “coupled” (in all of its forms, couple, coupling, coupled, etc.) generally means the joining of two components (electrical or mechanical) directly or indirectly to one another. Such joining may be stationary in nature or movable in nature. Such joining may be achieved with the two components (electrical or mechanical) and any additional intermediate members being integrally formed as a single unitary body with one another or with the two components. Such joining may be permanent in nature or may be removable or releasable in nature unless otherwise stated. 
     It is also important to note that the construction and arrangement of the elements of the invention as shown in the exemplary embodiments is illustrative only. Although only a few embodiments of the present innovations have been described in detail in this disclosure, those skilled in the art who review this disclosure will readily appreciate that many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter recited. For example, elements shown as integrally formed may be constructed of multiple parts or elements shown as multiple parts may be integrally formed, the operation of the interfaces may be reversed or otherwise varied, the length or width of the structures and/or members or connector or other elements of the system may be varied, the nature or number of adjustment positions provided between the elements may be varied. It should be noted that the elements and/or assemblies of the system may be constructed from any of a wide variety of materials that provide sufficient strength or durability, in any of a wide variety of colors, textures, and combinations. Accordingly, all such modifications are intended to be included within the scope of the present innovations. Other substitutions, modifications, changes, and omissions may be made in the design, operating conditions, and arrangement of the desired and other exemplary embodiments without departing from the spirit of the present innovations. 
     It will be understood that any described processes or steps within described processes may be combined with other disclosed processes or steps to form structures within the scope of the present invention. The exemplary structures and processes disclosed herein are for illustrative purposes and are not to be construed as limiting. 
     It is to be understood that variations and modifications can be made on the aforementioned structure without departing from the concepts of the present invention, and further it is to be understood that such concepts are intended to be covered by the following claims unless these claims by their language expressly state otherwise.