Abstract:
A panel includes at least one icon area ( 8 ), the area ( 8 ) being illuminated by a light source ( 10 ) placed under the ornament panel, the ornament panel ( 1 ) including a translucent skin ( 2 ) forming the outer surface ( 6 ) of the ornament panel and a substrate layer ( 4 ) placed against the skin ( 2 ), the substrate layer ( 4 ) including an opening ( 14 ) placed at least between the light source ( 10 ) and the icon area ( 8 ). A light-transmitting material ( 18 ) is placed in at least part of the opening ( 14 ), the material ( 18 ) being placed in a translucent substrate element ( 20 ) placed in the opening ( 14 ) between the material ( 18 ) and the light source ( 10 ).

Description:
The present invention relates to an automobile trim panel, of the type comprising at least one pictogram area, said area being illuminated by a light source arranged under the trim panel, the trim panel including a translucent skin forming the outer surface of the trim panel and a substrate layer arranged against the skin, said substrate layer including an opening arranged at least between the light source and the pictogram area. 
     The invention also relates to a method for making such a trim panel, as well as an automobile comprising such a panel. 
     BACKGROUND OF THE INVENTION 
     It is known to provide trim panels of the aforementioned type making it possible to display pictograms directly on the skin of the panels, said pictograms indicating certain functions or certain states of the vehicle. “Pictogram” refers to any figurative or symbolic drawing used for communication purposes, including alphanumeric signs. 
     In such trim panels, the pictogram being backlit, the light passes through the substrate layer of the panel and reaches the translucent skin from underneath. 
     The smallest flaw in the substrate layer on the path of the light degrades the quality of the lit pictogram, due to the diffusion of the light by that flaw in the substrate layer around the area forming the pictogram. The pictogram becomes blurry and the display is degraded. Such flaws for example include the presence of air bubbles or dust in the light&#39;s path. 
     SUMMARY OF THE INVENTION 
     The invention aims to offset these drawbacks by proposing a trim panel and a method for making that panel making it possible to avoid the presence of bubbles and dust in the light&#39;s path in order to obtain a backlit pictogram clearly and with a better display quality. 
     To that end, the invention relates to a trim panel of the aforementioned type, in which a light-transmitting material is arranged in at least part of said opening, said material being arranged in a translucent substrate member arranged in the opening between said material and said light source. 
     The presence of a substrate member under the light-transmitting material makes it possible to avoid the deposition of dust or formation of bubbles between the light source and the pictogram area, in particular on or in the transmitting material while the trim panel is made. Thus, a trim panel is obtained in which the path of the light is not disrupted by flows in the substrate layer, which enables a particularly clear display of the pictogram. 
     According to other features of the trim panel:
         the substrate member is bowl shaped;   the substrate member is made from a smooth transparent material;   the light-transmitting material is a transparent polyurethane or silicon gel; and   the light-transmitting material completely fills the opening between the substrate member and the translucent skin, said skin being applied directly on said material.       

     The invention also relates to a method for making a trim panel as described above, the method comprising the following steps:
         making a substrate member/light-transmitting material assembly by pouring said material in said substrate member,   arranging said assembly against the translucent skin opposite the pictogram area,   making the substrate layer around said assembly.       

     According to other features of the method:
         the step for making the substrate member/light-transmitting material assembly comprises a step of depositing a film on the surface of the transmitting material intended to be in contact with the translucent skin, said film protecting said material and being removed before arranging the assembly against the translucent skin;   the step for making the substrate member/transmitting material assembly comprises a step of arranging a protective member against the face of the substrate member intended to be positioned opposite the light source; and   the step for making the substrate layer comprises a foaming step on the skin around the substrate member/transmitting member assembly, the foam then being pierced opposite the assembly up to the protective member, the protective member then being removed so as to obtain the trim panel.       

     The invention also relates to a motor vehicle comprising a trim panel as described above, in which said panel is applied against at least one portion of the cab of the vehicle. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other aspects and advantages of the invention will appear upon reading the following description, provided as an example and done in reference to the appended drawings, in which: 
         FIG. 1  is a diagrammatic cross-sectional illustration of a trim panel according to the invention, 
         FIG. 2  is a diagrammatic cross-sectional illustration of a substrate member/light-transmitting material assembly used during the method for making the trim panel according to the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In the description, “outer” refers to what is visible from the cab of the motor vehicle, and “inner” refers to what is not visible. The terms “upper” and “lower” are defined relative to a direction starting from the wall of the cab and going towards the inside of the cab. 
     In reference to  FIG. 1 , a trim panel  1  is described that comprises a translucent flexible skin  2 , i.e. allowing light to pass, and a substrate layer  4  under and against the translucent skin  2 . The skin  2  forms the outer face  6 , visible from the cab of the motor vehicle, of the panel  1 . The substrate layer  4  is for example made from foam in order to impart a flexible feel to the trim panel  1 . This assembly can be configured in the desired manner to adapt to the trim of a motor vehicle. The outer surface  6  formed by the skin  2  is for example substantially planar or has protruding or hollow areas, for example to indicate the presence of control buttons for functions of the vehicle under the skin  2 /substrate layer  4  assembly. 
     The trim panel  1  comprises at least one pictogram area  8  making it possible to display backlit information on the outer face  6  of the translucent skin  2 . To that end, a light source  10  is arranged under the translucent skin  2  opposite the pictogram area  8 . Said light source  10  is for example a lamp house  12  arranged in an opening  14  of the substrate layer  4 . The opening passes through the substrate layer  4  opposite the pictogram area  8 . The lamp house  12  is known in itself and for example comprises a light-emitting diode  16  arranged to emit light towards the pictogram area  8 . 
     Above the lamp house  12 , the opening  14  is filled with a light-transmitting material  18 , such as a transparent polyurethane or silicone gel. A gel does not modify the light that passes through it, i.e. it does not divert the light coming from the light source  10 . Moreover, such a gel does not have air bubbles, unlike the foam of the substrate layer  4 , which prevents diffusion of the light inside the substrate layer  4  outside the path of the light between the light source  10  and the pictogram area  8 . 
     The gel  18  is arranged in a bowl-shaped substrate member  20 . The gel  18  is poured in said member  20  and due to the nature of the gel that fills the bowl, there is no bubble formation or dust deposition between the gel  18  and the substrate member  20 . The substrate member  20  is for example made from a smooth transparent plastic material so as to prevent modification of the path of the light when it reaches and passes through the substrate member  20 . To that end, the substrate member  20  is for example polished in order to obtain the best possible light transmission. As shown in  FIG. 1 , the substrate member  20  is inserted between the light source  10  and the gel  18 . 
     The assembly formed by the substrate member  20  and the gel  18  is arranged to completely fill the opening  24  above the lamp house  12 . The surface  22  facing the outside of the gel  18  is applied directly against the inner face of the skin  2 , which also prevents any presence of air bubbles or dust between the gel  18  and the skin  2 . 
     To define the shape of the pictogram, a mask is provided arranged in the path of the light between the light source  10  and the pictogram area  8 , comprising openings allowing light to pass and areas blocking the passage of light. This mask can be an independent member or be printed on one of the members of the trim panel. 
     The trim panel described above makes it possible to obtain a clear backlit pictogram. Indeed, due to the materials used, gel without bubbles, smooth transparent substrate member, and the arrangement of the trim panel, the light coming from the light source passes through the substrate layer  4  without being deviated or diffused by flaws, such as air bubbles, dust, or an irregularity of the materials. 
     The method for making the trim panel described above will now be described. 
     During a first step, a substrate member  20 /light-transmitting material  18  assembly is prepared. The gel  18  is poured in the bowl of the substrate member  20 . In order to protect the gel  18  during the transport, storage, and/or handling of said assembly, a film  24  is applied on the surface  22  of the transmitting material  18  intended to be in contact with the translucent skin  2 . Such a film  24  is for example made of polyethylene. It makes it possible to prevent the deposition of dust on the surface  24  of the gel  18  and to prevent the drying thereof, which could favor the appearance of a crust on the surface  24 . 
     A protective member  26  is also arranged against the face  28  of the substrate member  20  intended to be arranged opposite the light source  10 , as shown in  FIG. 2 . Such a protective member  26  is for example a film applied against the face  28 . This film makes it possible to protect the face  28 , intended to be passed through by the light and prevent any deposition of dust against said face  28 . The film also makes it possible to protect the substrate member  20  from the foam, as will be described later. 
     During a second step, the film  24  is removed from the surface  22  of the gel  18  and the substrate member  20 /transmitting material  18  assembly is applied against the skin  2  opposite the pictogram area. The gel  18 , when the film  24  is removed, is very adhesive and sticks to the skin. Due to its flexibility, the skin  2  is unrolled on the surface  22 , which makes it possible to prevent capturing bubbles between the skin  2  and the surface  22 . 
     The skin  2  and the substrate member  20 /transmitting material  18  assembly are then arranged in a molding cavity in order to make the substrate layer  4 . To that end, a foam precursor material is for example injected into the molding cavity and the substrate layer  4  forms under the skin  2  around the substrate member  20 /transmitting material  18  assembly during the expansion of the foam. 
     After the expansion of the foam, the opening  14  for receiving the light source is formed opposite the substrate member  20 /transmitting material  18  assembly. This opening is for example made by milling of the foam up to the protective film  26  of the face  28  of the substrate member  20 . The film protects the substrate member  20  and prevents the foam from adhering against the face  28  of said member. The film  26  is then removed. This film is for example arranged not to adhere to the foam, which makes it possible to facilitate the removal thereof. Moreover, its end portions can be folded, as shown in  FIG. 2 , in order to further facilitate removal thereof. 
     Other operations can be provided, such as the arrangement of a rigid substrate insert  30  against the inner face of the substrate layer  4 , as shown in  FIG. 1 . 
     A trim panel  1  is thus obtained that is free from flaws opposite the pictogram area  8 , which makes it possible to obtain a clear backlit pictogram and an optimal display on the skin  2 . 
     Such a trim panel  1  can be used for example to cover the dashboard of a motor vehicle or any other portion of the cab in which the display of information is necessary.