Abstract:
A glare resistant display for automotive vehicles has a lens with horizontal grooves which deflect reflections of external light sources, such as sun light, away from drivers while allowing illumination from behind the lens to pass therethrough so as to be visible to drivers. Indicia is disposed on the front face of the lens and a pointer pivots behind the front face. The indicia and pointer are made distinct because they block or absorb portions of the illumination coming from behind the lens. By utilizing lenses which minimize reflection, dials of instrument panels can be moved further toward steering wheels and drivers, thereby releasing space behind the dials for other uses.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to glare resistant displays for automotive vehicles and lens for such displays. More particularly, the present invention relates to glare resistant displays for automotive vehicles and lenses for such displays, wherein the displays minimize reflection of exterior light such as sunlight toward occupants of automotive vehicle passenger compartments.  
       BACKGROUND OF THE INVENTION  
       [0002]     As automotive vehicles evolve, there is a continuing need to efficiently utilize space within the vehicles. Many spaces serve specific purposes, however if those purposes can still be served without consuming spaces then the spaces can be used for other purposes. This facilitates automotive design and progress.  
         [0003]     It is desirable to minimize both day and night reflections that cause specular glare from automotive instrument panels. In addition, it is desirable to minimize or eliminate reflections which appear on windshields or side windows. This is currently accomplished by recessing dial planes of automotive instrument clusters under prominent instrument panel brows behind concave cluster lenses. Recessing requires hundreds of square millimeters of empty space in front of the dial planes, thus consuming packaging space. Since there is a need in automotive vehicles to effectively utilize space, it is desirable to release allocations of this empty space for other purposes, while still minimizing reflections and glare.  
       SUMMARY OF THE INVENTION  
       [0004]     In view of the aforementioned considerations, this invention is directed to a display for conveying to an observer in an automotive vehicle, information relating to detected parameters associated with selected conditions occurring within the vehicle. The display comprises a case having a front side and a back side and having therein at least one indicator for selecting at least one portion of a detected parameter. A lens having front and rear faces covers the front side of the case. The lens has a light defusing surface constructed and arranged to minimize reflections of light therefrom toward an observer in the vehicle while allowing illumination to pass through the lens from behind the lens. Indicia associated with the parameters being monitored is disposed on one of the faces of the lens and absorbs at least a portion of the illumination to render the indicia distinct. The indicia is located in proximity with the indicator.  
         [0005]     In a further aspect of the invention the indicia is on the front face of the lens.  
         [0006]     In still a further aspect of the invention, the light diffusing surface is on the front face of the lens.  
         [0007]     In still a further aspect of the invention, the light diffusing surface comprises an array of adjacent grooves extending substantially horizontally when the display is mounted in the vehicle and is constructed and arranged to transmit light from behind the lens therethrough, and to reflect light exterior of the case away from the observer of the display.  
         [0008]     In still a further aspect of the invention, the adjacent grooves are in one embodiment arcuate, having reflecting portions which reflect sunlight outwardly and downwardly away from the observer, while transmitting light therethrough in substantially parallel beams. In another embodiment of the invention the aforementioned grooves are angular notches.  
         [0009]     In still a further aspect of the invention a mounting arrangement is included for the display which orients at least the lens covering of the case at an acute angle with respect to vertical.  
         [0010]     In still a further aspect of the invention, the front face of the lens is planar.  
         [0011]     In still a further aspect of the invention, the indicator is a pointer and the indicia is comprised an array of numbers on the front surface of the lens. In another embodiment of the invention the indicia is a graphic display and the indicator is a cursor. In accordance with still another embodiment of the invention, the display conveys at least information relating to engine RPM and vehicle road speed.  
         [0012]     In still a further aspect of the invention, a lens for use with a display in an automotive vehicle has a light diffusing surface formed in a front face of the lens comprising an array of adjacent grooves extending substantially horizontally when the lens is mounted in the automotive vehicle. The lens is constructed and arranged to transmit illumination from behind the lens therethrough, as well as to reflect light from in front of the front face away from the observer of the instrument panel.  
         [0013]     In still a further aspect of the invention, indicia is disposed on the front face of the lens and is made visually distinct by the illumination. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]     Various other features and attendant advantages of the present invention will be more fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein:  
         [0015]      FIG. 1  is a planar view of a dash in an automotive vehicle;  
         [0016]      FIG. 2  is a planar view of a graphic display in the dash in an automotive vehicle;  
         [0017]      FIG. 3  is a side elevation of an automotive compartment including a display configured in accordance with the principles of the present invention;  
         [0018]      FIG. 4  is a perspective view of an instrument cluster configured in accordance with the present invention;  
         [0019]      FIG. 5  is a front view of the instrument cluster of  FIG. 4 ;  
         [0020]      FIG. 6  is a top perspective view of the instrument cluster of  FIGS. 4 and 5 ;  
         [0021]      FIG. 7  is a side view of the instrument cluster of  FIGS. 4-6 ;  
         [0022]      FIG. 8  is an enlarged planar view of a portion of a speedometer dial with a grooved lens surface having enlarged grooves superimposed thereover;  
         [0023]      FIG. 9  is a side elevation taken along lines  9 - 9  of  FIG. 8 , showing a portion of a dial of  FIG. 8 , and  
         [0024]      FIG. 10  is a portion of a second embodiment of a lens surface configured in accordance with the principles of the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0025]     Referring now to  FIG. 1  there is shown a front portion  10  of a passenger compartment  11  of an automotive vehicle having a dash  12  with an instrument cluster  14 , which is configured in accordance with the principles of the present invention. The instrument cluster  14  is shielded by a brow  16  and is positioned behind a steering wheel  18  having a gap  20  between the spokes thereof. The instrument cluster  14  is visible through the gap  20  to the driver of the vehicle who is the main observer of the instrument cluster.  
         [0026]     Disposed on the dash  12  adjacent to the instrument cluster  14  and wheel  18  is another array of instruments  24  which may include graphic displays such as an HVAC display  25  and an audio system display  26 . The instrument panel  24  may also include displays such as a GPS display  28  ( FIG. 2 ).  
         [0027]     Since the instrument cluster  14 , HVAC display  25 , audio information display  26  and GPS display  28  with a cursor  29  have transparent lenses, these displays reflect exterior light such as sunlight, passenger compartment light and various road illuminations toward the eyes of the driver of the vehicle. Moreover, if these displays are not properly configured and positioned, they can reflect onto and appear in the windshield of the vehicle. In accordance with a principle of the present invention, the displays on the instrument cluster  14 , and/or the HVAC display  25 , the audio display  26  and the GPS display  28  are configured to minimize both day and night reflections.  
         [0028]     Referring now to  FIG. 3 , there is shown a driver  30  sitting in the passenger compartment  11  and observing the instrument cluster  14  on the dash  12 . The head  32  of the driver  30  is in most situations positioned in an area  34  behind and above the steering wheel  18 . In accordance with the present invention, the instrument cluster  14  has a lens  36  that minimizes reflections of exterior light such as beams of sunlight  40  passing through the windshield  37  and into the passenger compartment  11  of the automotive vehicle. As is seen in  FIG. 3 , the sunlight  40  is reflected either in front of and above the space  34  occupied by the driver&#39;s head  32 , as illustrated by sun beam reflections  41  and  42 , or below the space  34 , as indicated by the sun beam reflections  46 . Light beams transmitted through the rear window, side windows or from within the passenger compartment  10 , as represented by light beam  50 , are reflected downwardly away from the space  34  as represented by the light beam reflection  51 .  
         [0029]     In accordance with the present invention, illumination  52  passing through the lens  36  is substantially normal to the surface of the lens so that indicia in the path of illumination are observable by the driver  30 .  
         [0030]     In the illustrated embodiment, the lens  36  is preferably at an angle of about 30° with respect to the vertical. As illustrated, it is preferable that the instrument cluster  14  have a thickness that is minimal, but which can be substantially the same as the thickness of current instrument clusters so that currently available instrument clusters are readily utilized with alterations being substantially made only to the lenses thereof.  
         [0031]     In accordance with the principles of the present invention, space is made available at a location  60  disposed behind the instrument cluster  14 . The free space at location  60  is created by setting the instrument cluster  14  of the present invention further rearward under the brow  16  on the dash  12 , toward the steering wheel  18 . By positioning the instrument cluster  14  further toward the steering wheel  18  by a distance of about 200 mm, hundreds of empty square millimeters are provided in the space at location  60 , which space is usable for other purposes.  
         [0032]     Referring now to  FIGS. 4-7  where the instrument cluster  14  is shown in several views, it is seen that the instrument cluster comprises a case  65  having therein displays such as a tachometer dial  66  and a speedometer dial  68 . The instrument cluster  14  may also include other displays such as a clock  70  and a fuel gauge  72 . In addition, the instrument cluster  14  may include further displays, such as turn signals and driving light indicators  74 , oil and temperature tale tales  75 , and odometers. The tachometer  66  and speedometer  68  in the illustrated embodiment have pointers, such as pointers  76  and  77 , respectively, which pointers are mechanical arms that align with numeric indicia  78  and  79 . However, in other embodiments the pointers may be optical beam pointers, or any other kind of indicators or illuminators.  
         [0033]     The case  65  has a rim  80  which projects from a back wall  82  to form an enclosure for the instruments covered by the lens  36 . As is seen in  FIGS. 4-7 , the lens  36  preferably appears to be flat and therefore planar. As is particularly illustrated in  FIG. 7 , at least the lens  36  makes an angle of about 30° with the vertical. In the illustrated embodiment, the casing  65  is mounted in the dash  12  at an angle of about 30° to orient the lens at about 30° with the vertical.  
         [0034]     Referring now to  FIGS. 8 and 9 , where a portion of the lens  36  is shown enlarged, it is seen that the lens  36  has a front face  100  and a rear face  102  defining a transparent body  103  therebetween. In  FIG. 8 , the front face  100  is shown as having an array of parallel arcuate grooves  104  formed therein. The grooves  104  extend horizontally when the lens is mounted in an automotive vehicle and the grooves have peaks  106  defined by lines of intersection of the grooves, as well as valleys  108  at the bottoms of the grooves. The points of the peaks  108  occur in a common plane  109  and the bottoms the valleys  108  occur in a common plane  110 .  
         [0035]     Incident external light rays  40  and  50  (see  FIG. 3 ) are reflected by the curvature of the groove walls either upwardly away from the driver&#39;s head space  34  (see  FIG. 3 ) or downwardly away from the driver&#39;s head space, generally in the direction of arrows  41 ,  42 ,  46  and  51  ( FIG. 3 ). Since the valleys  108  of the grooves  104  have bottoms which are tangent to the common plane  109 , illumination  115  passing through the transparent body  103  of the lens  36  from behind the rear surface  102  of the lens is transmitted through the front face  100  of the lens to emerge as substantially parallel light rays  122 . The parallel rays  122  are generally directed toward the area  34  where the driver&#39;s head  32  is positioned in  FIG. 3 , and are readily observable by the driver  30  with minimal interference from specular light  40  or  50  from the sun and/or other exterior light sources.  
         [0036]     Indicia  130 , which for example comprises numeric indicia  78  and  79  on the speedometer  66  or tachometer  68  of  FIG. 4 , is placed on the front face  100  of the lens  36  by painting, printing, appliquéing or any other suitable procedure. The indicia  130  absorbs at least a portion of, if not all, illumination  115  passing through the transparent body  103  from behind the indicia, thus differentiating the indicia from the illumination, the illumination providing a lighted background for the indicia.  
         [0037]     In  FIG. 9 , an end portion  132  of the pointer  77  (see  FIG. 4 ) is shown disposed in a recess  133  formed in the transparent body  103  of the lens  36 . The pointer  77  also absorbs illumination  115  so that the pointer as well as the indicia  130  stand out against the illumination  120  emerging from the lens  36  and is visible to the driver  30  ( FIG. 3 ).  
         [0038]     A recess  134  is formed in the transparent body  103  of the lens  36  so that one of the tale tales  75  painted, printed or appliquéd thereon is visible when back lighted by a separate light source  136  in the form of a separate bulb, LED or the like. Individual light sources  136  are connected to monitors (not shown) of separate parameters and provide separate illumination  137  for each of the tale tales  75 .  
         [0039]     The lens  36  in one example is molded of transparent plastic with the horizontal grooves  104  molded in the front face  100  of the lens. The grooves  104  are for example about 0.001 inch deep, although any depth may be used as long as the depth is sufficient to cause exterior light to reflect away from the driver&#39;s eyes. Examples of transparent plastic materials for making the lens  36  are polycarbonate (LEXAN®) and polybutylene terephthalate.  
         [0040]     The thickness “t” of the transparent body  103  comprising the lens  36  is reduced in the recessed portions  133  and  134  that accommodate the pointer  77  and the tale tale  75 . This is because illumination  115  for the pointer  37  and tale tale  75  passes through portions of the transparent body  103  beyond the pointer and tale tale and is subject to lateral diffusion which may blur the emerged images of pointers and tale tales if the transparent body is too thick.  
         [0041]     Referring now to  FIG. 10 , there is shown a second embodiment  36 ′ of the lens  36  wherein grooves  104 ′ have converging bottom and top planar walls  140  and  141 , respectively, which extend from arcuate peaks  142  to arcuate valley floors  144 . The planar walls  140  and  141  converge to imaginary points  146  and  148  lying in parallel planes  150  and  152 , respectively, which in the illustrated embodiment are spaced about 0.001 inch apart. The bottom walls  140  of the lens  36  extend horizontally across the lens  36  when the lens is disposed in the vehicle and are perpendicular to the parallel planes  150  and  152 . The top walls  141 , which extend parallel to the bottom walls  140 , are at 45° with respect to the parallel planes  150  and  152 , which parallel planes are themselves at 30° with respect to the vertical because the lens  36 ′ is installed in the dash  12  at a 30° angle. As a consequence, incident light beams  40  originating from external sources such as sunlight, passenger compartment lights or exterior road lights are reflected from the walls  140  and  144  away from the driver&#39;s head space  34 . For illustrative purposes, the reflected sunlight beam  42  is shown being reflected to a location in front of and above the location  34  of the driver&#39;s head  32 . Indicia  130  ( FIGS. 8 and 9 ), which absorbs illumination  115  passing through the transparent body  103 ′, is distinguished from the illumination  115  and provides an image of the instrument cluster  14  that is substantially free from glare due to external light sources.  
         [0042]     From the foregoing description, one skilled in the art can easily ascertain the essential characteristics of this invention, and without departing form the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions.