Patent Abstract:
An indicating instrument for a vehicle may employ an analog type lighted pointer arranged on a rotatable, circular shaped pointer disk, a liquid crystal display arranged over the pointer disk, and a first dial with indicia located outboard of or adjacent to and/or inboard of the LCD. A second or inboard dial may be located over the liquid crystal display. The pointer disk may be a translucent light collector for the pointer yet also transmit light to provide backlighting for the LCD. Depending upon the analog gauge arrangement, the pointer may point outboard of the pointer disk or toward the LCD center. The dials, especially the second dial, may be in the shape of rings to permit viewing of the LCD from the perspective of a viewer, such as a vehicle driver.

Full Description:
FIELD 
       [0001]    The present disclosure relates to a rotating gauge pointer and a light guide that rotates between a liquid crystal display and a light source. 
       BACKGROUND 
       [0002]    The statements in this section merely provide background information related to the present disclosure and may not constitute prior art. Indicating instruments or gauges for viewing by drivers of automobiles generally include an analog portion for displaying operational information such as vehicle speed and engine RPM and, in more recent technologically advanced vehicles, a liquid crystal display for displaying information related to vehicle operating condition such as fuel efficiency, outside temperature, engine functions, and other information related to driving or vehicle conditions. An analog gauge typically includes a faceplate having indicia thereon such as numbers and a pointer for rotating to the appropriate number. While such analog indicating instruments and liquid crystal displays have generally proven satisfactory for their intended purposes, they have been associated with their share of limitations. 
         [0003]    One such limitation of current vehicles with both analog and liquid crystal display devices is their packaging requirements. Because such devices are normally located in separate locations on a vehicle dash, extensive amounts of space are normally required in a dash. This generally leaves little packaging space for other gauges, such as temperature, fuel, and engine RPM gauges. 
         [0004]    Another limitation of current vehicles with both analog and liquid crystal display devices is also related to vehicle packaging. More specifically, because incorporating analog and LCD devices within a vehicle dash presently means locating such devices in separate areas of the dash, even if they are adjacent to each other, the time necessary to view both, the analog and digital gauges, and the human movements required to view both, may be cumbersome for a vehicle driver. 
         [0005]    What is needed then is a device that does not suffer from the above disadvantages. This, in turn, will provide an analog and an LCD device that is quickly and easily discernible in a short amount of time and that does not require extensive head or eye movements by a viewer of the gauges. 
       SUMMARY 
       [0006]    An indicating instrument, such as a speedometer gauge, may employ a pointer arranged on a rotatable pointer disk, a liquid crystal display arranged over the pointer disk, a first dial located outboard of the liquid crystal display, and a second dial located over the liquid crystal display. The pointer disk may be a translucent light collector for the pointer, provide consistent, even lighting to the adjacent liquid crystal display, and transmits light to backlight the liquid crystal display. Depending upon the installation requirements of the indicating instrument, the pointer may point outboard of the pointer disk, inboard of the pointer disk, or be a dual pointer, and point outboard and inboard to respective scales. Regardless of the application, the liquid crystal display is viewable by a person viewing the instrument. 
         [0007]    Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
     
    
     
       DRAWINGS 
         [0008]    The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. 
           [0009]      FIG. 1  is a perspective view of an interior dash of a vehicle depicting a location of an indicating instrument; 
           [0010]      FIG. 2  is a front view of an indicating instrument constructed in accordance with an embodiment of the present invention; 
           [0011]      FIG. 3  is a cross-sectional view of the indicating instrument of  FIG. 2 ; 
           [0012]      FIG. 4  is a cross-sectional view of an embodiment of the indicating instrument in accordance with the present invention; 
           [0013]      FIG. 5  is a front view of an indicating instrument constructed in accordance with an embodiment of the present invention; and 
           [0014]      FIG. 6  is a cross-sectional view of the indicating instrument of  FIG. 5 . 
       
    
    
     DETAILED DESCRIPTION 
       [0015]    The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features. Turning now to  FIGS. 1-6 , the teachings of the present invention will be explained. With initial reference to  FIG. 1 , depicted is a vehicle  10  having a dashboard  12  (“dash”) and an instrument cluster  14 , both of which may be situated in front of a driver&#39;s seat  16  in the interior cabin  18  of the vehicle  10 . As part of the instrument cluster  14 , a viewed component  20  is depicted and hereinafter, the viewed component  20  is exemplified by an indicating instrument or gauge, such as a speedometer. It is appreciated that the viewed component  20  may be exemplified by other gauges or instruments, such as a tachometer, fuel gage, temperature gage, etc. 
         [0016]    Turning now to  FIGS. 2 and 3 , the speedometer  20  generally includes a first dial  22 , a second dial  24 , a pointer  26 , a liquid crystal display  28  (“LCD”), a printed circuit board  30  (“PCB”), and a light source such as light emitting diodes  32  (“LED”). More specifically, the first dial  22  may denote miles per hour (mph) to a driver using indicia  34  and associated graduations  36  while a second dial  24  may denote kilometers per hour (km/h) using indicia  38  denoted by graduations  40 . Such indicia  34 ,  38  and graduations  36 ,  40  may be spaced around their respective dial at a predetermined interval. As depicted in  FIG. 2 , the speedometer  20  is a typical US configuration insofar as the first dial  22  has mph indicia  34  that are larger than the corresponding Km/h indicia  38 , which apply to countries using metric measurements, such as Canada. 
         [0017]    Continuing with  FIGS. 2 and 3 , the speedometer  20  depicts an LCD  28  screen that may be rectangular, circular, triangular or other shape, as appropriate for the respective speedometer application. The pointer  26  is an indicating portion of the speedometer that is attached to a circular pointer disk  42  that is mounted to a spindle  44  that is driven by an electric motor  46 . The motor  46  rotates the spindle  44 , pointer disk  42  and associated pointer  26  so that the pointer  26  may indicate the correct speed at which a vehicle is traveling. In addition to acting as a portion of the pointer  26 , the pointer disk  42  serves an additional role as a light collector for the LCD  28 . More specifically, because the pointer disk  42  is situated between the PCB  30  and the LCD  28 , the LEDs  32  of the PCB  30  provide the necessary backlighting for the LCD  28 . To properly distribute and provide light to the LCD  28 , the LEDs  32  may direct light rays into the pointer disk  42  such that the light is reflected within the pointer disk  42 . While being reflected within the pointer disk  42 , some of the light is reflected and directed to the pointer  26  to illuminate the pointer  26 , while some of the light passes out of the pointer disk  42  and into the LCD  28  and becomes a source of light for the LCD  28 . Depicted in  FIG. 2 , the area  25  of the pointer disk  42  may be a plated area for specific color enhancement, or opaque. 
         [0018]    Regarding placement of the dials  22 ,  24  of the embodiments of  FIGS. 3 and 4 , the dial  22  may be considered to be above, below, or at the same level as the LCD  28 . The dial  22  shown in phantom is depicted approximately at the same level as the LCD  28 . The dial  22  is depicted outboard of the LCD  28 , while the dial  24  is depicted over the LCD  28 . The dial  66  of  FIGS. 5 and 6 , to be described in more detail later, may also be described as being over the LCD  28 , much like the dial  24  of  FIGS. 3 and 4 . Additionally, the pointer disk  42 , as depicted in  FIGS. 2 ,  3  and  4 , may have the plated area  25  about its periphery for color enhancement. Alternatively the area  25  may be opaque or no treatment may be applied to the pointer disk  42 . 
         [0019]    With continued reference to  FIG. 3 , light may pass into the pointer disk  42  in at least two ways; first, as discussed above, light from the LEDs  32  located under the pointer disk  42  may pass light into the pointer disk  42  and subsequently the LCD  28 , and second, LEDs  48  may pass light into a pointer hub  50 . In passing light into the pointer hub  50 , the LEDs  48  may be situated directly under the pointer hub  50  such that light may pass directly through the hub  50  and pointer disk  42  and then into the LCD  28 . To effectively reflect and transmit light through the pointer disk  42  en route to the pointer  26 , the interior of the pointer disk  42  is equipped with a surface treatment  43 , such as angled edges, textures or plated surfaces or layers, for example, that facilitate light reflectivity, light transmission and color changes or enhancements. The material of the pointer disk  42  may be acrylic or another plastic material that facilitates light reflection and transmission. Not only may the pointer disk  42  be equipped with a surface treatment  43 , but the pointer  26  may also be equipped with a surface treatment  27 , such as angled edges, textures or plated surfaces or layers, for example, that facilitate light reflectivity, light transmission or color changes or enhancements. Although such treatment areas  27  and  43  are only shown on  FIG. 3 , they may be applied to the structure of  FIG. 4 . 
         [0020]    Turning to  FIG. 4 , an alternate embodiment of the invention is depicted. The embodiment of  FIG. 4  is similar to that of  FIG. 3 ; however, the embodiment of  FIG. 4  depicts a dual pointer  52 , which includes the primary pointer  26  as depicted in  FIGS. 2 and 3 , and additionally, a secondary pointer  54 . The secondary pointer  54  may be used to more precisely point to secondary indicia  38 , such as that on a second dial  24  as best depicted in  FIG. 2 . As with the pointer  26 , the secondary pointer  54  is illuminated by the LEDs  32 ,  48  located under the LCD  28 . An advantage of the dual pointer  52  as depicted in  FIG. 4  is that two different scales may be simultaneously indicated without any portion of a pointer passing over or through a set of indicia, as commonly occurs with many current art pointers. That is, because may current art pointers originate in the center of a dial and pass over a first set of indicia to indicate a second set of indicia, the pointer obstructs part of the first set of indicia. With the dual pointer  52  depicted in  FIG. 4 , no indicia of any scale need be obstructed. In addition to the improved viewing of the indicia  34 ,  38 , the embodiments depicted in  FIGS. 3 and 4  provide a clear, unobstructed line of sight to the LCD  28 . 
         [0021]    Turning now to  FIGS. 5 and 6 , a speedometer  60  is again depicted as an example of a viewed component. The speedometer  60  has a U-shaped portion  62  extending from the pointer disk  42  that permits the pointer  64  to be directed toward a center portion of an LCD  28  and a surrounding dial  66 . The dial  66  is a ring structure, which contains indicia  68  denoted by graduations  70 , that is located over the LCD  28 , yet permits viewing of the LCD  28  by a driver, for instance. The pointer disk  42  and LEDs  32 ,  48  function in a similar fashion to those of the embodiments of  FIGS. 2-4 ; that is, light from the LEDs  32 ,  48  is permitted to pass into the pointer disk  42  en route to the end of the pointer  64  and additionally, light is permitted to pass out or through the pointer disk  42  to backlight the LCD  28 . Additionally, light may pass to the dial  66  to illuminate any indicia  68  on the dial  66 . Because the structure of  FIGS. 5 and 6  utilizes a U-shaped portion  62  with the pointer pointing in an inboard direction (toward the center of the LCD  28 ), the overall gauge packaging may be made smaller, with a reduced overall diameter, than a gauge whose pointer points in an outboard direction (away from the center of the LCD  28 ), all else being equal. The pointer  64  may also be equipped with a surface treatment  65 , such as angled edges, textures or plated surfaces or layers, for example, that facilitates light reflectivity, light transmission or color changes or enhancements. The pointer disk  42  may also have such a surface treatment as applied to the pointer  64 . 
         [0022]    There are many advantages to the embodiments of the present invention. First, because of the design and layout of the pointer disk  42  and LCD  28 , the LEDs  32 ,  48  are able to serve as lighting for the pointers  26 ,  54 ,  64  and as lighting for the LCD  28  and adjacent dials. By using the LEDs  32 ,  48  in a dual or multi-function role, the number of LEDs may be reduced. Second, the pointer disk  42  serves as a light collector for the pointer  26 . Because the pointer disk  42  serves as a light collector for the pointer  36  and because of its translucence may supply light to the LCD  28 , the LCD  28  may not require another, supplemental, light source. 
         [0023]    Still yet, another advantage of the embodiments of the present invention is that a compact gauge with an LCD may be provided. That is, the embodiments of  FIGS. 1-6  provide a structure in which the LCD is positioned on top (with respect to the cross-sectional drawings) or in front (with respect to a driver&#39;s viewing perspective in a vehicle) of the pointer structure. Thus, with such a structure, the LCD does not need to be located separately from the workings of the pointer structure, which would require additional dash space. Additionally, the analog pointer will not obstruct the view of the LCD, and finally, with the embodiments of  FIGS. 1-6 , a structure results in which a centralized motor  46  may be used. With a centralized motor, there is no need for offset motors and associated gearing to drive a pointer or an affiliated indicator, and weight distribution of the pointer disk about the driving shaft of the motor may remain consistent.

Technology Classification (CPC): 1