Abstract:
An instrument panel assembly ( 10 ) having a transparent intermediate substrate ( 42 ) inside its housing ( 16 ) on which is applied a phosphor coated indicia ( 40 ) for giving the appearance of a depth dimension when energized by a UV light source ( 36 ). Multiple intermediate substrates ( 42, 48 ) can be positioned at different level within the interior region of the housing ( 16 ), each containing various indicia ( 40, 46, 56, 58 ) which emits luminescent light when irradiated by the UV light source ( 36 ). Multiple UV light sources ( 36, 52 ) can be set to project UV radiation of different wavelengths into the housing ( 16 ) with each of the phosphor coated indicia ( 40, 46, 56, 58 ) being selected from material types which are responsive to only one of the various UV wavelengths, so that each indicia ( 40, 46, 56, 58 ) can be selectively energized to display warnings, information messages, or the like.

Description:
RELATED APPLICATIONS 
     This invention claims the benefit of priority to U.S. Provisional Application No. 60/622,307 filed Oct. 26, 2004. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to an instrument panel such as used for navigational purposes, and more particularly toward an improved technique for lighting indicia in a vehicle instrument cluster to create an aesthetic dimensional effect. 
     2. Related Art 
     The instrument cluster and gauges in a typical motor vehicle must be clearly visible by the operator during all ambient lighting conditions. For example, a driver must be able to clearly read the gauges during bright sunlight as well as during nighttime driving. For this reason, the various colors applied to different components and the lighting or illumination of those components must be adaptable to different conditions. Various illumination techniques, such as incandescent lighting, florescent lighting, and LED lighting have been used to accomplish both daytime and nighttime gauge illumination. 
     In addition to the functional requirements of visibility placed upon the instrumentation, this area of a vehicle has become a favored target of designers and stylists who attempt to create dazzling and visually impressive presentations. Such impressive stylizations often become a determining factor in a consumer&#39;s buying decision. 
     One such stylistic feature has included the use of phosphor coated indicia within the housing of the instrument cluster which can be selectively energized by an ultraviolet (UV) light source. The phosphor coated indicia presents a different color to an observer when irradiated, than it does in a non-energized state. The resulting instrument cluster can thereby provide an aesthetically appealing display when energized. Examples of prior art instrument panels including phosphor or other UV sensitive indicia may be found in U.S. Pat. No. 5,920,150 to Crary, et al issued Jul. 6, 1999. Other examples may be found in US Publication No. 2002/0186556 to Wojnarowski, published Dec. 12, 2002 and US Publication No. 2004/0189483 to Stringfellow, published Sep. 30, 2004. In all of these examples, UV-irradiated indicia may be located within the confines of an instrument panel housing and selectively energized by the UV light source to develop aesthetically interesting effects. 
     All of these prior art examples emphasize the attention that is given to the instrument cluster and the general appeal of various lighting effects to generate consumer interest. Accordingly, these prior art underscore the need for functional instrument panels which are both clearly visible to a driver during all lighting conditions and also present unique and stylistically impressive visual displays. 
     SUMMARY OF THE INVENTION 
     The invention comprises an instrument panel assembly such as the type which can be used in a motor vehicle. The instrument panel assembly includes a housing having a generally transparent front screen, a backfield, and sidewalls, which together bound an interior region. At least one gauge is fixed to the backfield within the interior region of the housing for communicating information to an observer through the front viewing screen. Phosphor coated indicia is disposed in the interior region for converting UV radiation into emitted luminescent light. A UV light source projects UV light into the interior region of the housing and thereby irradiates the phosphor coated indicia so that it emits luminescent light. An intermediate substrate holds the phosphor coated indicia in spaced relation to the gauge and suspended between the backfield and the viewing screen to provide an aesthetic dimensional effect within the interior region when the phosphor coated indicia emits luminescent light. In other words, the phosphor coated indicia can take the appearance of floating or hovering above the gauge and/or backfield thereby mimicking a somewhat three-dimensional or holographic effect. The end result in an aesthetically interesting visual presentation created when the phosphor coated indicial is irradiated within the instrument panel assembly. Due to the value placed upon dazzling and visually impressive presentations within an instrument panel assembly, particularly those within a motor vehicle, the subject invention offers a technique for meeting a long felt yet unsatisfied need. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features and advantages of the present invention will become more readily appreciated when considered in connection with the following detailed description and appended drawings, wherein: 
         FIG. 1  is a perspective view of a vehicular interior including an instrument panel assembly; 
         FIG. 2  is a view showing the dimensional effect created by the phosphor coated indicia supported within the instrument panel assembly; 
         FIG. 3  is a simplified cross-sectional view of an instrument panel assembly according to a first embodiment of the invention; 
         FIG. 4  is a simplified cross-sectional view of a second embodiment including secondary and tertiary phosphor coated indicia within the interior region of the housing; 
         FIG. 5  is a front view of the exemplary embodiment depicted in  FIG. 4 ; 
         FIG. 6  is a simplified cross-sectional view of a third embodiment of the invention wherein at least one UV light source is projected from a location behind the backfield; and 
         FIG. 7  is an enlarged view of the circumscribed area shown in  FIG. 6  showing a waveguide formed in the gauge pointer. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the Figures, wherein like numerals indicate like or corresponding parts throughout the several views, an instrument panel assembly for communicating information to a observer is generally shown at  10  in  FIG. 1 . The novel features of this invention are applicable to an instrument panel assembly for any field of use, including machine control, aviation, and the like, but throughout this specification is described in the exemplary setting of a motor vehicle. Thus, the instrument cluster  10  is here shown sheltered below a dashboard  12  and behind a steering wheel  14 , which has proven to be an ergonomically convenient location for vehicular applications. When used in applications other than motor vehicles, which other applications are within the scope of this invention, the instrument panel assembly  10  may be set in and among different features altogether. 
     Referring now to  FIGS. 2 and 3 , the instrument panel assembly  10  is shown in its most basic form including a housing, generally indicated at  16 . The housing  16  includes a backfield  18  and a UV absorbing or reflecting front viewing screen  20 . Typically, the front viewing screen  20  is made from a clear acrylic material, however, other translucent or transparent materials can be used provided they do not allow UV light to pass through to an observer, such as the driver, represented by an eye  22 . The housing  16  also includes sidewalls  24  and a bottom  26  which, together with the backfield  18  and dashboard  12 , define an enclosure visible to the observer  22  through the front viewing screen  20 . The enclosure is hereinafter referred to as the interior region. 
     Within the housing  16 , supported upon the backfield  18 , is provided one or more gauges  28 . The gauges  28  may take any known form, including a speedometer, tachometer, display screen, or the like. In the example depicted, the gauge  28  includes a pointer  30 , a stripe  32  along the pointer  30 , and a patterned gauge field  34 . These components may be coated with a phosphor material such as strontium, zinc, cadmium sulfides, or any other material or pigment that absorbs light energy and radiates visible light when exposed to ultraviolet light. Different phosphor materials and blends of materials can be used to radiate different visible light colors. In the example of  FIG. 2 , during the daytime (unexcited) condition, the gauge field  34  may be generally yellowish in color and the pointer  30  generally black, with the stripe  32  taking a generally white appearance. However, in the irradiated nighttime condition, the visible light radiated from the phosphor coated indicia will change. For example, the gauge field  34  may display a predominantly bluish color with random circles reminiscent of craters seen on a full moon, the pointer  30  a predominantly red color, and the stripe  32  a predominantly yellow color. This change of colors between daytime and nighttime conditions, where the visual impression of the gauge  28  may change from subtly sun-like to moon-like, results in an aesthetically pleasing presentation. 
     A UV light source  36  can be placed anywhere convenient, but for illustrative purposes is shown suspended from the underside of the dashboard  12  within the housing  16 . To prevent any visible light which may be generated by the UV light source  36  from escaping, a filter  38  is positioned in front of the light source  36 . In the preferred embodiment, the filter  38  allows only UV light of a predetermined wavelength to pass through. For example, a typical UV light wavelength might be 365 nm. Thus, when energized, the UV light source  36  may produce light within a range of wavelengths, however, the filter  38  will only allow light in the 365 nm (or other selected) wavelength to enter the interior of the housing  16 . Once in the housing  16 , the filtered UV light irradiates the phosphor coated indicia, which in turn absorbs light energy and then radiates visible light. The UV absorbing (or reflecting) front viewing screen  20 , which is generally clear to the observer  22 , prevents harmful UV radiation from reaching the observer. Thus, to the observer  22 , UV light emitted from the light source  36  is completely undetectable. Nevertheless, the UV light causes the gauge field  34 , the pointer  30 , and the stripe  32  to glow with different visible light colors. This renders an impressive visual effect. 
     According to the invention, additional phosphor coated indicia  40  in the form of, for example words or shapes, can be applied inside the housing  16  at locations spaced away from the backfield  18  and from the gauge  28 . Preferably, but not necessarily, this technique is carried out in a manner which renders the phosphor coated indicia  40  completely invisible to the human eye during the daytime, or at least not prominent, and to become visible (prominent) during nighttime viewing or when otherwise energized by the UV light source  36 . In order to accomplish an interesting dimensional effect, the phosphor coated indicia  40  is supported on an intermediate substrate  42 . The intermediate substrate  42  holds the phosphor coated indicia  40  in spaced relation to the gauge  28  and suspended between the backfield  18  and the front viewing screen  20 . If the phosphor coated indicia  40  is applied as a very thin coating, and if the intermediate substrate  42  is substantially transparent, the phosphor coated indicia  40  will be nearly invisible to the human eye during daytime or non-energized conditions. However, when energized by the UV light source  36 , the phosphor coated indicia  40  will emit luminescent light and the normal depth perception of an observer  22  will appreciate that the phosphor coated indicia appears to hover or float above the gauge  28  and backfield  18 . Preferably, although not necessarily, the intermediate substrate  42  comprises a sheet-like plastic material which is fully UV light transmissive. The intermediate substrate  42  may thus cover the entire backfield  18  but be substantially undetectable by the observer due to its transparency. Depending upon the distance between the backfield  18  and the intermediate substrate  42 , different visual effects can be achieved, in part by any shadows  44  which may be cast by the energized phosphorus coated indicia  40  upon the backfield  18  and/or the gauge  28 , as shown in  FIG. 2 . 
     In  FIG. 4 , an alternative embodiment of the subject invention is depicted including a secondary phosphor coated indicia  46  disposed in the interior region and spaced from the first mentioned phosphor coated indicia  40 . The secondary phosphor coated indicia  46  is supported on a secondary intermediate substrate  48  which, like the first mentioned intermediate substrate  42 , holds the secondary phosphor coated indicia  46  in spaced relation to the gauge  28  and suspended between the backfield  18  and the viewing screen  20 . The first mentioned intermediate substrate  42  and the secondary intermediate substrate  48  may, as depicted, be both manufactured from a similar, substantially transparent sheet-like plastic material which spans the interior region from sidewall  24  to opposing sidewall  24  within the housing  16 . It is not required that the substrates  42 ,  48  be planar members, but rather can have contours such an convex or concave shapes to impart additional dimensional qualities to the perceived image of the phosphor coated indicia  40 ,  46 . 
     Referring still to  FIG. 4 , a tertiary phosphor coated indicia  50  can be disposed within the interior region and affixed to the front viewing screen  20 . Because it is disposed on the inside surface of the front viewing screen  20 , the tertiary phosphor coated indicia  50  can be radiated by the UV light source  36  to emit luminescent light. The result is a multidimensional visual effect which is perceived as visually interesting to an observer  22 . 
     Turning now to  FIG. 5 , a second alternative embodiment of the subject invention is shown including a second UV light source  52 . The second UV light source  52  can be used to increase the amount of UV radiation flooded into the housing  16 , or more preferably can be accompanied with a filter  54  which allows a different wavelength of UV energy to flood the housing  16 . For example, the first mentioned UV filter  38  may be set to 350 nm, whereas the second UV filter  54  may be set to 385 nm. With this combination, the phosphor coated indicia can be selectively chosen so that phosphor materials react to UV radiation at the 350 nm wavelength are not affected by UV light at the 385 nm wavelength. Although many practical and aesthetic uses of this alternative embodiment will be readily appreciated, one such application energizes the second UV light source  42  only when a predetermined condition occurs. For example, in  FIG. 5  a warning indicia  56  which displays the words “LOW FUEL” (as but one example) is visible only when the second UV light source  52  is energized. Thus, in the example, the second UV light source  52  can be operatively coupled to the fuel gauge so that it is energized only when the fuel level falls below a predetermined lower level. In the unexcited state, the warning indicia  56  would be completely transparent (or at least barely noticeable) to the observer  22 . 
     Similarly, another informational indicia  58  might display the words “CRUISE ON” as an example. The informational indicia  58  might be responsive to UV light at the 350 nm wavelength only, and is therefore visible when the first mentioned UV light source  36  is energized, but not when the second UV light source  52  is energized. If both first  36  and second  52  UV light sources are simultaneously energized, then both warning  56  and informational  58  indicia are visible. Similarly, the tertiary phosphor coated indicia  50  which, in  FIG. 5  is depicted by the exemplary word “LOGO”, may be responsive to a third or tertiary UV light source (not shown) which operates at yet a different wavelength than either of the other two UV light sources  36 ,  52 . As an example, the tertiary phosphor coated indicia  50  may be activated independently from any of the other indicia  56 ,  58  or in combination therewith. Furthermore, because the warning indicia  56  is sensitive to UV light in a different wavelength from that of the informational indicia  58 , they can be supported on the same intermediate substrate or on separate intermediate substrates akin to the embodiment depicted in  FIG. 4 . 
     The secondary intermediate substrate  48  can be used in various configurations together with the dual light source embodiment shown in  FIG. 5 . For example, the secondary intermediate substrate  48  could be made from a UV absorbing material much like the front viewing screen  20 , and the dual UV light sources set to operate on different sides of the secondary intermediate substrate  48 . In this manner, it is possible to achieve the conditional activation of the various indicia  56 ,  58  while using UV light sources and filters of the same wavelength. This technique can be applied with any number of intermediate substrates and any number of UV light sources. 
       FIGS. 6 and 7  illustrate yet another alternative embodiment of the subject invention, wherein the UV light source  36 ′ is positioned behind the backfield  18 . In this embodiment, phosphor deposited in a clear medium is painted or otherwise applied to select surfaces within the interior region. UV light emanating from the light source  36 ′ energizes the phosphor materials within the interior region, or at least those phosphor coated indicia which are responsive to the particular wavelength passing through filter  38 ′. For indicia features which may be partially or fully eclipsed, such as the pointer  30 ′ is eclipsed by the gauge field  34 ′, various techniques can be employed so that UV light reaches all phosphor surfaces to achieve results similar to that shown in the preceding embodiments. For example, the pointer  30 ′ may be fitted with a wave guide  60  which functions to transmit UV light to the needed surfaces. This concept of backlighting the indicia can be used in conjunction with other embodiments of the invention, including the dual light source embodiment shown in  FIG. 5 . 
     Although the phosphor coated indicia  40 ,  46 ,  50 ,  56 ,  58  has been described almost entirely within the context of the florescent type phosphor, i.e., one which radiates visible light only so long as the UV light source remains energized, the phosphor coated indicia could also be of the phosphorescent type which continues to radiate visible light long after the energy source is discontinued. With phosphorescent type materials, it would be possible to pulse the UV light source  36  instead of maintaining a continuous “ON” condition. 
     Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.