Patent Publication Number: US-11046185-B1

Title: Lensless instrument cluster with integration of hard telltales and halo lighting providing a seamless display appearance

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Patent Application No. 63/040,242 filed on Jun. 17, 2020. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to instrument clusters in vehicles. 
     BACKGROUND OF THE INVENTION 
     A typical vehicle includes an instrument cluster that is provided in front of the driver. Typically, an instrument cluster includes various gauges and separate warning indicators which are meant to provide important information to the driver regarding the current status of the vehicle. Examples of gauges included in an instrument cluster comprise a speedometer and a tachometer, while examples of warning indicators included in an instrument cluster comprise a check engine light, an oil light, and a tire pressure light. 
     Warning indicators are often called “tell-tale” (“TT”) indicators. Unlike gauges which can be difficult to read and understand, TTs are either on or off. When a TT is on, it is a tell-tale sign to the driver that something, depending on which TT is on, is wrong with the vehicle or otherwise requires attention. While it may be difficult for some drivers to appreciate that there is a problem with the vehicle by looking at gauges of an instrument cluster, Ti lights are easy to detect when they illuminate. 
     Instrument clusters include lights and electronics. As such, instrument clusters are typically provided behind a lens which shields and protects the instrument cluster from, for example, water, dust, and scratching. While providing a lens in front of an instrument cluster provides much needed protection, such a design is not as modern in appearance compared to a design which omits a lens (i.e., a “lens-less” design). However, providing an instrument cluster without a lens is not feasible due to the instrument panel including lights and electronics, and omitting the lens results in the instrument cluster being exposed to, for example, water, dust, and scratching that can adversely affect the operation and/or appearance of the instrument cluster. Lenses not only protect the instrument cluster from, for example, water, dust, and scratching, but are also provided as being curved structures, thereby providing anti-glare/anti-reflection properties. 
     Modern vehicles have ambient lighting on the inside of the vehicle which can be adjusted. Most vehicles that include ambient lighting are designed such that the ambient lighting can be dimmed, and/or the color of the lighting can be changed depending on the preference of the driver. Such ambient lighting is not typically provided along the sides of the instrument cluster. 
     SUMMARY OF THE DISCLOSURE 
     An embodiment of the present invention comprises an instrument cluster preferably for a vehicle, where the instrument cluster is lens-less, robust, provides a large “seamless” display (seamless meaning a main, central display blends, appearance-wise, with adjacent TTs), and includes highway assist halo lighting, preferably in the form of multiple color halo lighting, along the sides of the instrument cluster. The instrument cluster also encompasses a structural design that can provide a stable display performance under different driving conditions. 
     Additionally, because the instrument cluster is lensless and exposed to the environment in which it is installed, the cluster further comprises a seal system to prevent the ingress of water and dust into the instrument cluster, particularly a printed circuit board and lighting structure provided therein. 
     A preferred embodiment of the present invention comprises:
         a lensless instrument cluster configured for installation in a user environment, the lensless instrument cluster comprising:
           an outer case;   a printed circuit board and lighting structure assembly connected to the outer case;   an inner frame connected to the printed circuit board and lighting structure assembly;   an optical bonding assembly connected to the inner frame;   a halo lighting portion; and   a seamless display comprising:
               a main display portion comprising a gauge;   a tell-tale surface comprising a tell-tale indicator; and   an outermost surface that is in direct contact with the user environment.   
               
               

     A second preferred embodiment of the present invention comprises:
         an outer case comprising a heat sink;   a printed circuit board and lighting structure assembly connected to the outer case and comprising:
           a first light emitting diode configured to illuminate a tell-tale indicator;   a second light emitting diode configured to illuminate a halo lighting portion;   
           an inner frame connected to the printed circuit board and lighting structure assembly;   an optical bonding assembly connected to the inner frame and comprising:
           a thin-film-transistor;   an in mold decorative layer; and   packing material;   
           the halo lighting portion; and   a seamless display comprising:
           a main display portion; and   a tell-tale surface.   
               

    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1  is a front view of an instrument cluster which is in accordance with an embodiment of the present invention. 
         FIG. 2  is a perspective, partially exploded view of the instrument cluster shown in  FIG. 1 . 
         FIG. 3  is a perspective, exploded view that is similar to  FIG. 2 , but which shows further explosion of certain components of the instrument cluster. 
         FIG. 4  is a cross-sectional view of the instrument cluster shown in  FIG. 1 , taken along line  4 - 4  of  FIG. 1 . 
         FIG. 5  is a cross-sectional view that shows an optically clear material in the instrument cluster functioning to reduce reflection. 
         FIG. 6  is an enlarged view of a portion of that which is shown in  FIG. 4 . 
         FIG. 7  is an enlarged view of a portion of  FIG. 6 , showing illumination of a TT, specifically a light blocking feature which functions to prevent the light being cast from the LED from travelling directly to the TT. 
         FIG. 8  shows one of the inner cases of the instrument cluster, and includes an enlarged view of a portion thereof. 
         FIG. 9  is an enlarged view of a portion of  FIG. 6 , specifically one of the end portions thereof, showing how highway assist halo lighting is achieved. 
     
    
    
     DETAILED DESCRIPTION OF AN EMBODIMENT OF THE INVENTION 
     While the present invention may be susceptible to embodiment in different forms, there is described herein in detail, a specific embodiment with the understanding that the present disclosure is to be considered an exemplification of the principles of the invention, and is not intended to limit the invention to that described herein. 
       FIG. 1  is a front view of an instrument cluster  10  which is in accordance with an embodiment of the present invention. The instrument cluster  10  is lens-less, robust, provides a large seamless display  12  having an outermost surface, and includes ambient lighting, preferably in the form of adjustable color halo lighting portion  14  along the sides of the instrument cluster  10 . As shown in  FIG. 1 , the instrument cluster  10  preferably displays one or more gauges or meters  16 , and includes tell-tale indicators (TTs)  18  that may or may not illuminate depending on the current state of the vehicle. Examples of TTs  18  include but are not limited to turn signal symbols, check engine symbols, and high beam symbols. The gauges  16  and the TTs  18 , collectively, appear (to the driver) to all be part of the large, seamless display  12 . Preferably, the instrument cluster  10  comprises tell-tale surface  20  (and also in-mold decorating (“IMD”) surface  58 ) through which the TTs  18  are viewed to provide a seamless stylish, floating look, i.e., compared to a main display section or portion  22  that provides the gauges or meters  16 . As shown in  FIG. 1 , borders  21  are shown to delineate tell-tale surface  20  from main display portion  22 , whereas in practice the borders  21  are preferably imperceptible to a user. This is a feature of the “seamless” display  12 . In preferred embodiments, the TTs  18  are impregnated on surface  58  (see  FIGS. 4-7, 9 ). As will be appreciated by those of skill in the art, the orientation, size, color, format, and type of gauges  16  and TTs  18  displayed by the cluster  10  may vary. 
     The instrument cluster  10 , when fully assembled and installed in a vehicle, preferably provides structural integrity, specifically dynamic performance regarding, for example, mechanical shock and vibration with thermal shock. The instrument cluster  10  is also preferably configured to resist the entry of water and dust, as will be described in more detail later hereinbelow. 
       FIG. 2  is a perspective, partially exploded view of the instrument cluster  10  shown in  FIG. 1 , while  FIG. 3  is a similar view, but shows further explosion of certain components of the instrument cluster  10 .  FIG. 4  is a cross-sectional view. 
     As shown in  FIGS. 2 and 4 , the instrument cluster  10  preferably comprises a printed circuit board (“PCB”) and lighting structure assembly  24  that is mounted in an outer case or housing  26 . As shown in  FIGS. 2 and 3 , an optional speaker  28  is disposed in the PCB and lighting structure assembly  24 . As shown in  FIG. 2-4 , the instrument cluster  10  also includes one or more heat sinks  30  (preferably one, as shown), an optical bonding assembly  32 , an inner frame  34 , and an outer visor  36 . Preferably, the heat sink  30  is comprised of aluminum or some other suitable material(s). Preferably, the outer case  26 , the inner frame  34 , and the outer visor  36  are formed of a polymer such as plastic. Preferably, the inner frame  34  provides reinforced ribs  38  (see  FIG. 4 ) such as at locations of interface with other components of the instrument cluster  10 . 
     As shown in  FIGS. 3 and 4 , the PCB and lighting structure assembly  24  preferably comprises a PCB assembly  40  as well as (one on each side of the PCB and lighting structure assembly  24 ): inner visors  42 , halo diffusers  44 , and light guides  46 , as well as an inner case  48  that is formed of similar pieces on each side of the instrument cluster  10 . Preferably, each of the inner visors  42 , halo diffusers  44 , light guides  46 , and the inner case  48  (both components) is formed of plastic, and the PCB  40  includes LED&#39;s thereon for illumination of both TTs  18  and halo lighting  14  (see  FIG. 1 ). 
     Regarding the optical bonding assembly  32 , preferably the optical bonding assembly  32  comprises a thin-film-transistor (“TFT”)  50 , an in mold decorative lens or layer  52 , and packing material  54 , which is preferably a packing foam. Preferably, the instrument cluster  10  is held together using a plurality of fasteners  56  (the fasteners appear only in  FIG. 3 ). 
     Preferably, the instrument cluster  10  is lens-less in that the instrument cluster  10  is not set back a distance from a curved lens that protects the instrument cluster  10 . Instead, preferably the instrument cluster  10  is exposed and is touchable. Therefore, the instrument cluster  10  preferably includes the in mold decorative lens  52 , and the in mold decorative lens  52  is preferably hard, resists scratching, is chemically resistant, and is configured to provide anti-glare/anti-reflection properties. Preferably, the in mold decorative lens  52  has a smoke tint. More specifically, preferably the in mold decorative lens  52  comprises a resin at its core, preferably a polymethyl methacrylate (“PMMA”) surface  58 , and has an opaque black printing or coating  60  on its outside surface (i.e., the surface facing the driver of the vehicle). Preferably, the resin  58  provides a 65% smoke tint while the coating  60  on the resin  58  provides a 15% smoke tint. The coating  60  provides the in mold decorative lens  52  with a black background area through which the TFT  50  can be viewed. The tinting design helps to provide the seamless appearance between the tell-tale surface  20  and the main display portion  22  at the borders  21 . Regarding hardness, preferably the in mold decorative lens  52  provides an at least 2H level of hardness as a result of the hard coat layer  60  and the resin  58 , wherein the in mold decorative lens  52  resists scratching and can be wiped clean and/or dry using a napkin or cloth. 
     As shown in  FIG. 5 , preferably instead of an air gap being provided between the in mold decorative lens  52  and the TFT  50 , an optically clear material  62  is provided on the mold decorative lens  52 , adjacent the TFT  50 . The optically clear material  62  provides less refection of sunlight as well as less reflection of light that emanates from the TFT  50  compared to if an air gap were provided. The use of optically clear material  62  provides that the image being displayed on the TFT  50  is visually transposed up to the outer surface  60  of the in mold decorative lens  52 . In other words, the perception of the display of the TFT  50  being lower than the in mold decorative lens  52  is lost. This visual perception results because there is no substantial change of medium between the TFT  50  and the in mold decorative lens  52 . The combination of the coating  60  on the one side of the in mold decorative lens  52  and the optically clear material  62  on the opposite side of the in mold decorative lens  52  provides an anti-glare feature resulting in increased readability due to the reduction of sunlight reflection, and increased image brightness due to higher light efficiency. 
     As shown in  FIG. 6 , the instrument cluster  10  comprises a seal system to prevent the ingression of water and dust, especially toward the PCB and lighting structure assembly  24  and the optical bonding assembly  32  (which includes the TFT  50 ). This seal is provided as a result of the packing foam  54  being disposed between the in mold decorative lens  52  and each inner case component  48  (only one is shown in  FIG. 6 ), and further sealing of the overall structure is provided as result of the abutment of different surfaces of the components shown in  FIG. 6 . For example, preferably there is a flange  64  proximate each end the inner visor  42  which engages a corresponding flange  66  on the outer case  26  to prevent entry of water, etc. 
     With regard to the packing foam  54 , preferably water sealing foam that has a compression hardness of 0.25N/cm2 for 50% compression is used such that the total force acting on the in mold decorative lens  52  is around 6.3N which is negligible compared to the optical bonding force. Preferably, packing foam  54  is applied between the inner case  48  and the in mold decorative lens  52  between each TT  18 , to prevent light leakage (i.e., to provide light meant to illuminate one TT from casting into another, adjacent TT). 
     In addition to the sealing, the instrument cluster  10  preferably has a drain hole design allowing moisture to escape from the overall assembly. Further to that end, as shown in  FIG. 4 , preferably the outer case  26  includes internal flanges  68  which tend to direct water down into drain holes (represented with reference numeral  70  in  FIG. 4 ) for escape from the overall assembly. 
     As also shown in  FIG. 6 , the PCB provides LED&#39;s  72  (only one is shown in  FIG. 6 ) that illuminate to provide lighting through a TT image  18  (in the form of a cut out in the printing or coating  60  on the outside surface of the in mold decorative lens  52 ). As shown in more detail in  FIG. 7 , preferably the inner case  48  provides a light blocking feature, such as light cup  75  comprising a rib  76  and conical portion  78 , which functions to prevent the light being cast from the LED  72  from travelling directly to the TT  18 . Instead, the illumination is dispersed generally over a larger area, an area that includes the TT  18 , thereby preventing a hot spot that would otherwise appear in the TT  18 . Preferably, a back side of the in mold decorative lens  52  includes textured surface  81  that also tends to eliminate any perceived hot spotting in the TT  18 . As shown in  FIG. 7 , the conical portion  78  extends from walls  77  toward LED  72  at a preferably 35 degree angle. Terminal portion  79  of the conical portion  78  defines an opening  73  that is preferably 4.2 millimeters in diameter.  FIG. 8  shows one of the inner case components  48  of the instrument cluster  10 , and shows a portion thereof enlarged so the light cup  75  can be readily seen. As shown, the rib  76  preferably extends horizontally from the terminal portion  79  toward a center of the opening  73 . 
     The TFT  50  could be, for example, a large, 10.25-inch-wide display. As will be appreciated by those of skill in the art, other widths and dimensions are contemplated for the purpose of adaptation and fit to specific uses. This display is seamless relative to TTs  18  (that may or may not illuminate depending on the current state of the vehicle). Preferably, the contrast difference between the display emanating from the TFT  50  and the illuminated TTs  18  is minimal and the illumination performance is similar. 
     With regard to the halo lighting  14  that is preferably provided on both sides of the instrument cluster  10 , preferably the halo lighting  14  provides red-blue-green (“RGB”) color capability and is configured to be adjusted with regard to not only the color, but also intensity and propagation. The halo lighting  14  may be configured to provide a highway pilot lighting mode for vehicles that have autonomous driving. Halo lighting  14  may also provide ambient lighting for aesthetic purposes, such as an orange halo illumination. As shown in  FIG. 1 , the halo lighting  14  may generally propagate in a generally c-shaped or curved configuration around each side of cluster  10 . It is contemplated that other propagation configurations and shapes for halo lighting  14  may be deployed in alternative clusters  10 . 
       FIG. 9  provides an enlarged cross-sectional view of one of the end portions of the instrument cluster  10 , showing how halo lighting  14  is achieved on each side of the instrument cluster  10 . Preferably, halo lighting  14  is achieved via light channeling. As shown, preferably the light guide  46  is disposed over one or more LED&#39;s  74  of the PCB  40  such that light emitted from the one or more LED&#39;s  74  is directed toward the inner visor  42  (i.e., on path  84 ) which preferably has a curved surface  80  which disperses the light along the edge of the instrument cluster  10 . To provide a desired level of fading propagation for the halo lighting  14 , a specific sized gap  82  between the inner case  48  and the inner visor  42  can be selected. In preferred embodiments, the gap  82  width is between 2.0 to 5.0 millimeters. Additionally, the width of gap  82  may be tapered. For example, the gap  82  width may increase as it extends from a top edge of display  12  toward an outer edge of display  12  to provide a smooth transition from bright to dark portions of the halo lighting  14 . The combination of the profile of the light guide  46  and the curvature of the inner visor  42  works to achieve uniform halo propagation. Halo lighting  14  is preferably employed on both sides of the instrument cluster  10 , and is preferably adjustable regarding color and intensity. As such, preferably the instrument cluster  10  provides an integrated package wherein a single PCB  40  provides both hard TT LED&#39;s and halo illumination via a plurality of LED&#39;s  72 ,  74 . 
     The instrument cluster  10  provides a lens-less, seamless design, wherein TTs  18  and a main display  22  are effectively integrated using, preferably, a single PCB  40 . The instrument cluster  10  is robust, is designed to provide anti-glare properties, and its internal components are effectively sealed from water and dust. The outer surface provides hardness yet resists scratching and can be wiped clean/dry using a napkin or cloth. The instrument cluster  10  provides attractive, preferably adjustable, halo lighting  14 . 
     As defined herein, the “outermost surface” of display  12  designates the surface of the display  12  that is directly exposed to an external environment and capable of being directly contacted by a user during normal operation. For example, the external environment may be a user environment where the instrument cluster  10  is installed, such as the cabin of a vehicle. Preferred embodiments of display  12  comprise in mold decorative lens or layer  52  having coating  60  as the outermost surface. This is just one example of a preferred embodiment, and one of ordinary skill in the art will appreciate that the outermost surface is dependent on the preferred composition of the display  12 . 
     As defined herein, “lens-less” refers to the absence of a protective cover or shield found in traditional instrument clusters. In traditional systems, the protective shield and the display surface of the cluster define a void between the shield and the display surface. There is no such void defined by preferred embodiments of the present invention. As described herein, the in mold decorative “lens”  52  is preferably integral with the display  12 . 
     While a specific embodiment of the invention has been shown and described, it is envisioned that those skilled in the art may devise various modifications without departing from the spirit and scope of the present invention.