Abstract:
An illuminable instrument panel display of an automobile vehicle comprising a first plate having a thickness and defining opposed first and second surfaces. Portions of the plate define an outer peripheral edge and an inner peripheral edge that define a central region. Indicia is formed into the plate and adapted to pick up ambient and supplied light. A light source is located within said central region. A support is coupled to the plate so as to support the plate relative to the instrument panel whereby the light source is adapted to illuminate the indicia through the transmission of light through the inner peripheral edge within the thickness of the face plate.

Description:
BACKGROUND  
       [0001]     1. Field of the Invention  
         [0002]     The present invention generally relates to illuminable displays in automotive vehicles. More specifically, the invention relates to an illuminable display that is edge lit from the center of the display and utilized in an instrument panel of an automotive vehicle.  
         [0003]     2. Description of Related Art  
         [0004]     Every automotive vehicle includes an instrument panel into which are inset various instruments that either provide information to the occupants of the vehicle or allow the occupants to control the interior environment of vehicle. Instruments of the type that relay information to the occupants include, without limitation, the speedometer, tachometer, fuel gage, engine temperature gage, battery charge gage, drive selection indicator, as well as various service or warning indicators. Examples of environmental controls include the audio and/or navigational system, and the heating, ventilation and air conditioning (HVAC) system.  
         [0005]     Traditionally, instruments have been flat displays located within a fixed housing that is inset into the instrument panel. The methods used to light these instruments have kept the display located on a back plane of the instrument. Typically, the lighting of these displays has involved the location of a light source behind the back plane and a translucent portion of the display that allows the light pass therethrough, rendering the markings of the display visible to an occupant of the vehicle. Other lighting methods reflect light or direct light onto the surface of the display that is viewable by the occupant of the vehicle.  
         [0006]     Lighting these instruments in an even manner has been a challenge to designers, requiring light compensation passes to be printed on the backside of a graphics appliqué or the engineering of a reflective dish or light pipe. Additionally, these limitations have limited the ability of designers to produce instruments and instrument clusters that are differentiable in the marketplace.  
         [0007]     In view of the above it is apparent that there exists a need for a display design that removes the limitations associated with lighting of the display and that frees designers to differentiate instruments and instrument clusters in the marketplace.  
       SUMMARY  
       [0008]     In satisfying the above need, as well as overcoming the enumerated drawbacks and other limitations of the related art, the present invention provides a display, instrument or gage that is edge lit from the center of the display for more evenly distributed light. The display includes a plate having an outer perimeter edge and an inner perimeter edge, the latter being defined by an aperture or depression in the plate. A light source is located generally centrally within the inner perimeter edge, thereby transmitting light into the plate. The outer perimeter edge of the plate may be beveled and polished so as to reflect, back into the plate, a portion or all of the light transmitted from the inner perimeter edge. Cut, etched or molded indicia are formed in one or more of the faces of the plate. The slightly “rough” surfaces of the indicia accordingly pick up the light being transmitted edgewise within the plate and cause the indicia to glow. By forming the indicia directly into the plate, the cost of a separate graphics appliqué is eliminated. Additionally, locating the light source as provided herein eliminates the need for a light pipe or reflector and the costs associated therewith.  
         [0009]     A housing or support is provided generally in the center of the plate to hold and support the plate. This support may extend rearward away from the occupant of the vehicle, generally toward the instrument panel itself, so as to space the plate from a back plane of the instrument panel. In doing so, a “floating” appearance to the display is achieved. A motor and movable pointer for an analog gage may also be provided within the housing, along with the light source and its associated circuitry.  
         [0010]     Accordingly, in one aspect the present invention includes an illuminable instrument panel display of an automobile vehicle, the display comprising a plate having opposed first and second surfaces and defining a thickness therebetween, portions of said plate define an outer peripheral edge and additional portions define an inner peripheral edge and a central region; indicia are formed into the plate and are adapted to pick up ambient and supplied light from a light source located within said central region; a support is coupled to the plate so as to support the plate relative to the instrument panel; whereby the light source is adapted to illuminate the indicia through the transmission of light through the inner peripheral edge within the thickness of the plate.  
         [0011]     Further objects, features and advantages of this invention will become readily apparent to persons skilled in the art after review of the following description, with reference to the drawings and the claims that are appended to and form a part of this specification.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]      FIG. 1  is a front elevational view of a portion of an instrument panel embodying the principles of the present invention;  
         [0013]      FIG. 2  is a side elevational view of a display, a gage, of the variety seen in the instrument panel display in  FIG. 1 ;  
         [0014]      FIG. 3  is a split diagrammatic view of a display according to the principles of the present invention;  
         [0015]      FIG. 4  is a sectional view taken generally along line  4 - 4  in  FIG. 3 ;  
         [0016]      FIGS. 5 and 6  are plan views of additional embodiments embodying the principles of the present invention;  
         [0017]      FIG. 7  is a split diagrammatic view of a display according to the principles of the present invention;  
         [0018]      FIG. 8  is a sectional view taken generally along line  8 - 8  in  FIG. 7 ;  
         [0019]      FIGS. 9A and 9B  are, respectfully, plan and sectional views of a display according to another embodiment of the invention;  
         [0020]      FIGS. 10A and 10B  are, respectfully, plan and side views of a button or control embodying the principles of the present invention;  
         [0021]      FIG. 11A  is a plan view of an audio system incorporating a display in accordance with the principles of this invention; and  
         [0022]      FIG. 11B  is a plan view of a part of the display seen in  FIG. 11A . 
     
    
     DETAILED DESCRIPTION  
       [0023]     Referring now to the drawings, an instrument cluster embodying the principles of the present invention is illustrated in  FIG. 1  and generally designated at  12 . The instrument cluster  12  is shown as having three illuminable gages or displays (hereinafter “displays”). Of the three displays, the center display  14  representatively illustrates a speedometer, the left display  16  a tachometer and the right display  18  an engine temperature gage and a fuel gage. Each display  14 ,  16 ,  18  is mounted via a support to either the back plate  20  or base  22  of the instrument cluster  12 . The instrument cluster  12  is itself received on or within an instrument panel  24  of a vehicle, such as an automotive vehicle.  
         [0024]     Each display  14 ,  16 ,  18  includes a dial or plate  26  of transparent or translucent material and, as such, may be formed of a plastic, or other glass material. The plate  26  is generally planar and includes opposed first and second surfaces  28 ,  30  that are, respectively, the first and second faces of the plate  26 . Additionally, portions of the plate  26  define an inner peripheral edge  32  and other portions define an outer peripheral edge  34 . In the embodiment of  FIG. 2  the inner peripheral edge  32  is generally formed perpendicular to the first and second surfaces  28 ,  30 , while the outer peripheral edge  34  is beveled, with respect to both the first and second surfaces  28 ,  30 , and polished.  
         [0025]     The inner peripheral edge  32  may be defined as an aperture extending completely through the plate  26  or, alternatively and as illustrated in  FIG. 6 , may be the side edges of a depression  36  formed in the plate  26 . Located within the aperture or depression  36  is a light source  38 . The light source  38  is positioned so that light emitted by the light source  38  is transmitted through the inner peripheral edge  32  into the plate  26  and directed toward the outer peripheral edge  34 . In other words, the plate  26  is center-edge lit. Upon reaching the outer peripheral edge  34 , the bevel and polishing thereof results in at least a portion of the transmitted light being internally reflected within the plate  26 . This operates to further fill the plate  26  with light and provide even illumination of the plate  26 .  
         [0026]     Formed in one or both of the first and second surfaces  28 ,  30  are indicia  40  representative of the necessary markings associated with the particular type of display  14 ,  16 ,  18 . The indicia  40  may be cut, etched, molded or otherwise formed in the surface  28 ,  30 . Upon illumination of the plate  26  by the light source  38 , the slightly rough surface of the indicia  40  will pick up the light and be illuminated or glow, as will the outer peripheral edge  34 .  
         [0027]     The light source  38  may be any one of a variety of light sources including, without limitation, light emitting diodes (LED&#39;s), LED arrays, incandescent bulbs, fluorescent bulbs, electroluminescent sheet material and electroluminescent wire. Each of these types of light sources  38  may be interchangeably utilized as generally indicated elsewhere in this specification.  
         [0028]     As seen in  FIGS. 2 and 3 , a LED array  42  is located adjacent to the inner peripheral edge  32 . Preferably, the LED array  42  is attached to a flexible circuit board  44  and located immediately adjacent to the inner peripheral edge  32 . If desired, organic LED&#39;s can be used to allow for a variable color mode in the display  14 ,  16 ,  18 .  
         [0029]     As mentioned above, light emitted from the individual LED&#39;s  46  of the LED array  42  fills the plate  26  with light, as represented by the crisscrossing lines of  FIG. 3 , several of which are designated at  48 . Upon reaching the outer peripheral edge  34 , at least a portion of the light is reflected back into the plate  26  to fill the plate  26  with light. The rough surfaces of the indicia  40  pick up the light and provide the indicia  40  with a glowing appearance. Some of the light emitted by the LED array  42  may not be reflected by the outer peripheral edge  34  and, accordingly, the outer peripheral edge  34  may similarly be provided with a glowing appearance.  
         [0030]     In an alternative embodiment seen in the lower half of  FIGS. 3 and 4 , the outer peripheral edge  34  is illustrated as being formed generally perpendicular to the first and second surfaces  28 ,  30  so as to eliminate the glowing appearance of that edge. As a further and separate alternative, the inner peripheral edge  32  is differently illustrated in the lower portions of  FIGS. 3 and 4 . As seen in the lower portions, the inner peripheral edge  32  is beveled with respect the first and second surfaces  28 ,  30 . An alternative light source  38 , such as an electroluminescent sheet material, is provided over the bevel to thereby emit light into the plate  30 .  
         [0031]     The light source  38  and the plate  26  are supported by a support member  52  extending into and/or through the aperture or the depression in the plate  26 . The support member  52  defines or includes a housing  54 . The support member  52  may alternatively extend in a direction rearward from and generally perpendicular to the plate  26 , as illustrated in display  14  of  FIG. 1  and shown in  FIG. 2 , so as to provide the display  14  with a floating appearance. Alternatively, as illustrated in connection with displays  16 ,  18 , the support member  52  may extend in a direction generally parallel to the first and second surfaces  28 ,  30  and be connected to the base plate  22 . Constructed in this manner, the support member  52  provides the display  16 ,  18  with a pedestal mounted appearance, as generally shown in phantom in  FIG. 2 . Obviously, the individual displays  14 ,  16 ,  18  of the instrument cluster  10  could each utilize either of the two described support members  52  in any combination thereof.  
         [0032]     When the display  14 ,  16 ,  18  is an analog instrument, it is further provided with a movable pointer  56  connected to a motor, preferably a stepper motor, supported by the housing  54 . The motor  58  is controlled such that the pointer  56  moves relative to the indicia  40  to accurately indicate the parameter being represented thereby. For aesthetic reasons, a pointer cover  60 , having a slot  62  formed therein to permit a range of movement by the pointer  56 , is mounted to the housing  54  on that side visible by the occupant of the vehicle.  
         [0033]     Referring now to  FIGS. 5 and 6 , illustrated therein are variations on features of the displays  14 ,  16 ,  18  described above. For clarity and convenience, various elements of the displays  14 ,  16 ,  18  have been omitted from these figures. As shown in  FIG. 5 , the light source  38  may be located either centrally with respect to the aperture defined by the inner peripheral edge  32  of the plate  26  or may be offset relative thereto. The light source  38  shown in  FIG. 5  is illustrated as being an incandescent bulb  64 . Additionally, the inner peripheral edge  32  and outer peripheral edge  34  may be provided in a desired shape other than round. Round displays  14 ,  16 ,  18  were previously illustrated in  FIGS. 1-4 . In the drawing of  FIG. 5 , the peripheral edges  32 ,  34  defines a polygonal (octagonal) shape to the plate  26 .  
         [0034]     As illustrated in  FIG. 6 , instead of the inner peripheral edge  32  defining an aperture extending completely through the plate  26 , the inner peripheral edge  32  may be part of a depression  36  formed in the plate  26 . Also shown in  FIG. 6 , the light source  38  is a curved fluorescent bulb  66 . As seen in the split view of  FIGS. 7 and 8 , the light source  38  can alternatively be an electroluminescent sheet material  68  or an electroluminescent wire  70  applied to either the inner peripheral edge  32  or the outer peripheral edge  34 , either of which may be a bevel or straight edge.  
         [0035]     In the alternative embodiment of  FIGS. 9A and 9B , the display  14 ,  16 ,  18  is provided in the form of a pair of plates, a front plate  72  and a rear plate  74 . The front and rear plates  72 ,  74  cooperate to define a cavity  76  therebetween and within which is located the pointer  56 . The back plate  74 , or alternatively the front plate  72 , may be provide with a perimeter flange  78  such that the cavity  76  is fully enclosed. Indicia  40  may be formed on either of the opposing surfaces of the front plate  72  or the rear plate  74 . As illustrated, the indicia  40  are shown on both the interior and exterior surfaces  80 ,  82  of the rear plate  74 . It is additionally noted that the pointer  56  may be a lighted pointed similarly illuminated by the light source  38  or may be an unlit, silhouetted pointer. In the construction of  FIGS. 9A and 9B , it is further noted that at least the plate bearing the indicia  40  is illuminated by the light source  38  and that both plates  72 ,  74  may be illuminated.  
         [0036]     Referring now to  FIGS. 10A and 10B , the teachings of the present invention are applied to a control  112  as might be utilized for the interior environment of the automotive vehicle. The illustrated control  112  is represented as a push and/or turn button, those actions being represented by arrows  114  and  116 . The control  112  includes a plate  126  defining first and second surfaces  128 ,  130 . Indicia  140  are provided, in the manner described above, in one or more of the surfaces  128 ,  130 . A light source  138  is embedded or otherwise provided within the plate  126  so as to transmit light within the plate towards an outer peripheral edge  134 . Upon encountering the rough surfaces of the indicia  140 , light emitted by the light source  138  will cause the indicia  140  to be illuminated or glow. If desired, a cover  160  may be applied to the plate  126  so that when viewed from the interior of the automotive vehicle, a outer portion of the control  112  is illuminated and contrasted by the unilluminated cover  160 . Obviously, a wide variety of button configurations could be provided through the incorporation of the teachings of the present invention.  
         [0037]     As seen in  FIGS. 11A and 11B , teachings of the present invention are applied to another environmental control system, specifically the audio system  210  of the automotive vehicle. The audio system  210  is provided with the controls typically associated therewith including knobs or buttons which may or may not be of the variety described in connection with  FIGS. 10A and 10B . Additionally, the audio system  210  is provided with a display face  212  incorporating the teachings of the present invention. The display face  212  includes a plate  226  of transparent or translucent material and including portions defining a inner peripheral edge  232  and an outer peripheral edge  234 . Along at least a portion of the inner peripheral edge  232 , a light source  238  is provided so as to illuminate the plate  226  in accordance with the teachings of the present invention. By forming indicia on part or all of the exposed surface of the plate  226 , the display face  212  is made illuminated and contrasted relative to other features and elements of the audio system  210 . As seen in  FIG. 11A , a contrasting plate  250  is provided over the surface of the display face  226  for contrasting aesthetics.  
         [0038]     As a person skilled in the art will readily appreciate, the above description is meant as an illustration of implementation of the principles of this invention. This description is not intended to limit the scope or application of this invention in that the invention is susceptible to modification, variation and change, without departing from the spirit of this invention as defined in the following claims.