Abstract:
A gauge is provided. The gauge includes a housing and a bearing plate that can be coupled to the housing. The bearing plate defines a first aperture. The gauge includes a pointer coupled to the bearing plate that has a proximal and a distal end. The pointer end can be mounted to the bearing plate such that the distal end extends into the first aperture. The gauge includes a light guide that defines a second aperture, and can be coupled to the bearing plate such that the second aperture is aligned with the first aperture and the distal end of the pointer extends into the second aperture. The gauge includes an appliqué fitted over the light guide, and one or more light sources in communication with the light guide to provide light to the light guide for transmission to the pointer and the appliqué.

Description:
The present disclosure relates generally to vehicle instrumentation, and more particularly to a system and method for an analog vehicle gauge with a rotary pointer and a central display that has embedded driver information. 
   Traditionally, instrument panels are employed in motor vehicles to display information regarding the operation of the motor vehicle to an operator. For example, the instrument panel can include an instrument cluster or a collection of gauges that comprise a gauge assembly that provides information to the operator, such as a fuel level or an engine temperature. Traditionally, analog vehicle gauges have employed an arrangement of light guides, reflectors, light bulbs, electro-luminescent materials, or LEDs. These traditional analog gauges can typically employ a moveable pointer that is coupled to a rotating output shaft of a motor, such as a stepper motor or an aircore movement. One characteristic of this traditional arrangement concerns the area located inwardly of the gauge&#39;s scale or indicia. More specifically, this area can at times be rather inefficiently or ineffectively utilized and thereby detract from styling or functionality. 
   In order to improve the efficiency and/or effectiveness of an analog vehicle gauge, an information display can be positioned within or directly behind the interior of the dial face of the gauge. Construction of the analog vehicle gauge in this manner, however, can necessitate reconfiguration of the pointer and potentially the drive system for the movement of the pointer. 
   One suitable pointer is a Z-shaped pointer such as that which is illustrated in  FIG. 1 . The pointer, however, has a relatively complex shape that is more costly to produce, can be difficult to backlight and has a relatively large mass. The relatively large mass of the pointer provides the pointer with correspondingly large angular momentum and inertia characteristics, which can require a motor with a relatively high dynamic torque. Since the torque of a motor and its size tend to be directly related, and since larger motors are typically more costly and difficult to package within a gauge assembly, pointers having a relatively large mass can be less desirable in many situations. 
   Another suitable pointer is described in U.S. Pat. No. 6,408,783 to Ludewig. This configuration utilizes a disk pointer having a light source mounted thereon. A flexible circuit is attached to the disk pointer and couples the light source to a source of electrical power. The flexible circuit adds complexity and cost to the analog vehicle gauge as well as reduces reliability. 
   Thus, it would be desirable to provide an instrument cluster or gauge assembly that includes an information display positioned within or behind the interior of the dial face of a gauge that includes a pointer with a reduced mass that can be easily backlit without requiring a light source to be coupled to the pointer. 
   Provided is a gauge assembly. The gauge assembly can include a housing and a bearing plate that can be coupled to the housing. The bearing plate can define a first aperture. The gauge assembly can also include a pointer moveably coupled to the bearing plate. The pointer can have a proximal end and a distal end. The pointer can be mounted to the bearing plate such that the distal end of the pointer can extend into the first aperture. The gauge assembly can further comprise an annular light guide. The annular light guide can define a second aperture, and the annular light guide can be coupled to the bearing plate such that the second aperture is aligned with the first aperture and the distal end of the pointer can extend into the second aperture. The gauge assembly can include an appliqué fitted over the annular light guide, and one or more first light sources. The first light sources can be disposed in the housing and in communication with the annular light guide to provide light to the annular light guide for transmission to the distal end of the pointer and at least a portion of the appliqué. 
   A gauge assembly is also provided that can include a housing, and a bearing plate coupled to the housing. The bearing plate can define a first aperture surrounded by a rim. The gauge assembly can also include an annular gear. The annular gear can define a second aperture. The annular gear can have an outer edge that includes a plurality of teeth and an inner edge that bounds the second aperture. The inner edge can be sized to fit around the rim of the bearing plate such that the gear rotates on the bearing plate. The gauge assembly can also include a pointer. The pointer can be mounted on the annular gear such that the pointer extends past the inner edge of the annular gear into the second aperture defined by the annular gear. Further, the gauge assembly can comprise an annular light guide that has an outer periphery and an inner periphery that defines a third aperture. The light guide can be mounted on the bearing plate in a position suspended over the gear such that the third aperture is aligned with the first aperture of the bearing plate. The gauge assembly can include an appliqué fitted over the light guide, and a means for providing light to the annular light guide for transmission to the pointer and appliqué. 
   Further provided is a gauge assembly for use with an instrument panel of a motor vehicle. The instrument panel can comprise a housing, and one or more gauges coupled to the housing that display an operating condition associated with the motor vehicle. The instrument panel can further include a color graphical display coupled to the housing and disposed within an aperture defined by of one of the gauges. The gauge surrounding the color graphical display can include a pointer moveably coupled to the housing. The pointer can be mounted to the housing such that an end of the pointer extends into the aperture. The gauge surrounding the color graphical display can also include an annular light guide disposed around the aperture, and an appliqué fitted over the annular light guide. The instrument panel can also include one or more first light sources disposed in the housing and in communication with the annular light guide to provide annular light to the light guide for transmission to the pointer and at least a portion of the appliqué. 
   Further areas of applicability of the present teachings will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating various embodiments of the present teachings, are intended for purposes of illustration only and are not intended to limit the scope of the present teachings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein: 
       FIG. 1  is a sectional view of a prior art analog vehicle gauge; 
       FIG. 2  is an environmental view of an exemplary instrument panel with a vehicle gauge having an embedded driver display according to various teachings of the present disclosure; 
       FIG. 3  is an exploded view of the vehicle gauge of  FIG. 2 ; 
       FIG. 4  is a partial perspective view of the pointer assembly associated with the vehicle gauge of  FIG. 2 ; 
       FIG. 5  is a partial cross-sectional view of the vehicle gauge of  FIG. 2 , taken along line  5 - 5  of  FIG. 2 ; and 
       FIG. 6  is a perspective view of a light guide assembly for use with the gauge assembly of  FIG. 2 . 
   

   DETAILED DESCRIPTION 
   The following description of various embodiments is merely exemplary in nature and is in no way intended to limit the present teachings. Although the following description is related generally to an analog pointer for use with a vehicle gauge having an embedded driver display, such as a motor vehicle, it will be understood that the pointer, as described and claimed herein, can be used in combination with any appropriate system or device where it is desirable to indicate information to a user through an analog pointer, such as on a gauge for an aircraft or marine vessel. Therefore, it will be understood that the following discussions are not intended to limit the scope of the appended claims. 
   With reference to  FIG. 2 , an exemplary portion of a motor vehicle  10  is shown. The motor vehicle  10  can include an instrument panel  12 . The instrument panel  12  can be coupled to the motor vehicle  10  such that the instrument panel  12  is visible within a passenger area (not shown) to provide the operators of the motor vehicle  10  with data regarding the operation of the motor vehicle  10 . The instrument panel  12  can include an instrument cluster or gauge assembly  16  that displays the data for the operators. Our exemplary construction is detailed in co-pending U.S. patent application Ser. No. 11/157,013, filed Jun. 20, 2005, the disclosure of which is hereby incorporated by reference as if fully set forth in detail herein. 
   The gauge assembly  16  can include one or more secondary gauges  18 , such as a tachometer  18   a  and a fuel gauge  18   b . The gauge assembly  16  can also include a primary gauge  20 , such as a speedometer. It should be noted, however, that although the gauge assembly  16  will be described herein as including one or more secondary gauges  18  and a primary gauge  20 , any number of secondary gauges  18  and primary gauges  20  could be employed in the gauge assembly  16 . With additional reference to  FIG. 3 , the gauge assembly  16  can include a housing assembly  22 , a circuit board assembly  24 , a pointer assembly  26 , a light guide assembly  28  and a display  30  that can be disposed within a center of the primary gauge  20 . 
   The housing assembly  22  can include a rear housing  32 , a housing body  34 , an appliqué  36  and a front mask  38 . As the rear housing  32 , appliqué  36  and front mask  38  can be substantially similar to the rear housing  32 , appliqué  36  and front mask  38  described in co-pending U.S. patent application Ser. No. 11/157,013, incorporated previously herein in its entirety, the rear housing  32 , appliqué  36  and front mask  38  will not be described in detail herein. Briefly, however, the appliqué  36  can comprise a plurality of dial face indicia  37  and an aperture  39 . The dial face indicia  37  can be translucent and surrounded by an opaque background  41 , or can be opaque and surrounded by a generally translucent background depending on the desired styling of the secondary gauges  18  and the primary gauge  20 . The aperture  39  can be defined in the appliqué  36  to enable the viewing of the display  30 . 
   With regard to the housing body  34 , the housing body  34  can include a proximal side  40 , a distal side  42  and apertures  44 . The housing body  34  can facilitate the assembly of the gauge assembly  16  by providing an intermediate support structure to which the front mask  38  and rear housing  32  can be coupled. For example, the front mask  38  can be coupled to the proximal side  40  of the housing body  34 , while the rear housing  32  can be coupled to the distal side  42 . Thus, the rear housing  32  can cooperate with the housing body  34  to define a cavity in which the circuit board assembly  24 , pointer assembly  26 , light guide assembly  28  and display  30  can be housed, as will be discussed herein. The apertures  44  can support the secondary gauges  18 , the primary gauge  20  and the display  30 , as will be discussed. In addition, the display  30  can be coupled within the aperture  44 , as will be discussed. 
   The circuit board assembly  24  can be coupled to the housing body  34 , in the cavity defined between the housing body  34  and the rear housing  32 . The circuit board assembly  24  can comprise a printed circuit board (PCB)  46  and one or more first light sources  48 . The PCB  46  can be coupled to the distal side  42  of the housing body  34 . The PCB  46  can include circuitry required to selectively illuminate the first light sources  48 , and can include a power source (not shown). In addition, the PCB  46  can include one or more reflective surfaces  50 . The reflective surfaces  50 , if desired, can be mounted on, painted, silk screened or otherwise coupled to the PCB  46  such that the first light sources  48  can extend above the reflective surfaces  50  to facilitate the distribution of light from the first light sources  48 . 
   The light sources  48  can comprise light emitting diodes (LEDs) that can be mounted on the PCB  46  such that individual ones of the LEDs can be selectively illuminated. Generally, multiple ones of the first light sources  48  can be associated with each of the secondary gauges  18  and the display  30  to illuminate the secondary gauges  18  and the display  30 . It will be understood, however, that a single light source  48  could be used to illuminate the secondary gauges  18  and the display  30 , and further, it should be understood that the display  30  can include its own light source. The light sources  48  can comprise a solid colored LED, however, if desired, selected ones of the first light sources  48  can comprise a red-green-blue (RGB) LED to enable at least a portion of the secondary gauges  18  and/or the display  30  to be selectively illuminated in one of 24 million possible colors; however, it will be understood that individual red, blue, and green LEDs can also be used. 
   With continuing reference to  FIG. 3 , the pointer assembly  26  can include a bearing plate  60 , a motor assembly  62 , a gear set  64  and a pointer  66 . The bearing plate  60  can be coupled to the proximal side  40  of the housing body  34 . The bearing plate  60  can include a post  63 , an annular rim  65 , one or more mounting points  67  and can define an aperture  69 . The post  63  and the annular rim  65  can enable a portion of the gear set  64  to be supported and rotatably coupled to the bearing plate  60 , as will be discussed herein. The mounting points  67  can align and retain the display  34  within the housing body  34 , and can attach the annular light guide  102  to the bearing plate  60 . 
   The motor assembly  62  can include a motor  68  and an output member  70 . With additional reference to  FIG. 4 , the motor  68  can be mounted on the proximal side  40  of the housing body  34 , adjacent to the bearing plate  60  (exact mounting not specifically shown). The motor  68  can be a stepper motor, a DC motor with a position sensor (e.g., an absolute position sensor) or an ultrasonic motor. The motor  68  can drive the output member  70  ( FIG. 3 ). The output member  70  can comprise a shaft that can be coupled to the gear set  64 , however, the output member  70  could be a pinion that has a plurality of teeth that can drive the gear set  64 . In addition, the output member  70  could be a sprocket or a pulley of the type that is used with a toothed or smooth drive belt (e.g., timing belt). The output member  70  can drive the gear set  64 . 
   With reference to  FIGS. 3 and 4 , the gear set  64  can include a drive gear  72 , a intermediate gear  74  and a annular gear  76 . The gear set  64  can drive the pointer  66  into a pre-selected position, as will be discussed. It should be understood, however, that although a gear set  64  is described herein for positioning the pointer  66 , any suitable mechanism could be used to drive the pointer  66  into a pre-selected position, such as a pulley system. Each of the drive gear  72 , intermediate gear  74  and the annular gear  76  can include a plurality of teeth  72   a ,  74   a ,  76   a , respectively. The drive gear  72  can be fixedly coupled to the output member  70 , and can be driven by the output member  70 . The teeth  72   a  of the drive gear  72  can mesh with or meshingly engage the teeth  74   a  on the intermediate gear  74  to drive the intermediate gear  74 . The intermediate gear  74  can be rotatably coupled to the post  63  of the bearing plate  60 . The teeth  74   a  of the intermediate gear  74  can mesh with or meshingly engage the teeth  76   a  on the annular gear  76  to drive the annular gear  76 . 
   As best shown in  FIG. 4 , the annular gear  76  can have an outer periphery P 1 , and an inner periphery P 2  and can define an aperture  77  and a surface  80 . The teeth  76   a  can be formed about the outer periphery P 1 , while the inner periphery P 2  can be adjacent to the aperture  77 . The aperture  77  can be sized such that the annular gear  76  can be rotatably coupled to the annular rim  65  of the bearing plate  60 . The pointer  66  can be coupled to the surface  80  of the annular gear  76  such the rotation of the annular gear  76  can move or position the pointer  66  in a pre-defined location. 
   The pointer  66  can include a flange  82  and a pointer body  84 . The flange  82  can be coupled to the surface  80  of the annular gear  76 . The flange can be coupled to the surface  80  via any suitable technique, such as though the use of mechanical fasteners, welding, heat stake, bonding and/or adhesives. The flange  82  can be integrally formed with the pointer body  84 , and thus, the flange  82  can couple the pointer body  84  to the surface  80  of the annular gear  76 . With additional reference to  FIG. 5 , the pointer body  84  can define a proximal end  86  and a distal end  88  that can be coupled together via a projection  90 . The proximal end  86  can be coupled to the flange  82 . The distal end  88  can define the pointing apparatus for the primary gauge  20 , and thus, the distal end  88  can comprise an arrowhead  88   a . The arrowhead  88   a  can be formed on the distal end  88  such that a narrow portion  88   b  of the arrowhead  88   a  is adjacent to the appliqué  36  as best shown in  FIG. 2 . The distal end  88  can include a coating (not shown), if desired, to enable the distal end  88  to be illuminated in a desired color by the light guide assembly  28 , as will be discussed. The distal end  88  can have a thickness T that is greater than a thickness T 2  of the light guide assembly  28  to enable the light emitted by the light guide assembly  28  to enter into the distal end  88  of the pointer  66  to illuminate the arrowhead  88   a . In addition, the thickness T of the distal end  88  can enable the arrowhead  88   a  to extend beyond a surface of the light guide assembly  28 . 
   With reference to  FIG. 3 , the light guide assembly  28  can illuminate the pointer  66 . The light guide assembly  28  can include one or more secondary light guides  92  and a primary light guide assembly  94 . The secondary light guides  92  can be coupled to the housing body  34  such that the secondary light guides  92  are positioned over the apertures  44  that correspond with the secondary gauges  18 . The secondary light guides  92  can comprise a transparent material, such as a clear polymer, to enable the light generated by the first light sources  48  that are associated with the secondary gauges  18  to pass therethrough. As the appliqué  36  can be overlaid on the secondary light guides  92 , the secondary light guides  92  can direct the light from the first light sources  48  that are associated with the secondary gauges  18  to a back surface of the appliqué  36  to illuminate the portion of the appliqué  36  associated with the secondary gauges  18 . 
   With reference to  FIG. 3 , the primary light guide assembly  94  can include a printed circuit board (PCB) subassembly  100  and a light guide  102 . The primary light guide assembly  94  can illuminate the primary gauge  20  and the pointer  66 . The PCB subassembly  100  can include a board  104  and one or more second light sources  106 . The board  104  can include the circuitry required to selectively illuminate one or more of the second light sources  106  (not shown). The board  104  can also include a power source (not shown). The board  104  can be generally annular, and can define an aperture  108  and a surface  110 . The aperture  108  can have a diameter D that corresponds to a diameter D 1  of annular rim  65  of the bearing plate  60 . The aperture  108  can enable the operator of the motor vehicle  10  to view a larger portion of the display  30 , as will be discussed. The surface  110  can include a reflective coating so that the light generated by the second light sources  106  can be directed into the light guide  102 . 
   The second light sources  106  of the PCB subassembly  100  can comprise one or more LEDs. Generally, the second light sources  106  can comprise colorless LEDs or identically-colored LEDs, however, as discussed previously herein, the second light sources  106  can comprise one or more RGB LED, or combinations of different colored LEDs such as red, green, and/or blue. The second light sources  106  can be mounted on the surface  110  of the board  104  such that the light emitted from the second light sources  106  can be substantially parallel to the surface  110  of the board  104 . For example, the second light sources  106  can comprise one or more LEDs that emit light from the side, or one or more LEDs that emit light from the top of the LED with the appropriate optics to direct the light parallel to the surface  110 . 
   With reference to  FIGS. 3 and 6 , the light guide  102  can be mounted to the surface  110  of the board  104 . The light guide  102  can be composed of a transparent material, such as a clear polymeric material, so that the light produced by the second light sources  106  can pass therethough. The light guide  102  can be generally annular, and can include a central aperture  111 , one or more arcuate notches  112  and one or more mounting flanges  113 . With reference to  FIG. 6 , the light guide  102  can also include an opaque surface  114  formed along the light guide  102  in an area that corresponds to the opaque background  41  of the appliqué  36  to further prevent the light entering the light guide  102  from illuminating the opaque background  41 . Further, the surface of the light guide  102  that is in contact with surface  110  of the board  104  can include light extracting features to extract part of the light from the second light sources  106  to illuminate the appliqué  14 . The central aperture  111  can be clear so that light from the second light sources  106  can enter the pointer  66 . Typically, the light escaping from the central aperture  111  will not interfere with the display  30  because the incidence angle of the light on the display  30  can be very large, and the display  30  can have an optically smooth surface such that the light can be reflected off the display  30 . In addition, the display  30  can have anti-reflective coating on a surface of the display  30  to further reduce any glare resulting from the light escaping from the central aperture  111 . 
   The notches  112  can be formed along an outer periphery or edge  115  of the light guide  102  at points that correspond with the location of the second light sources  106  on the board  104  of the PCB subassembly  100 . With the notches  112  formed along the edge  115  of the light guide  102 , the light guide  102  can be positioned directly adjacent to the second light sources  106  of the PCB subassembly  100  such that a substantial majority of the light produced by the second light sources  106  can flow directly into the light guide  102  from the edge  115  towards and inner periphery  117  of the light guide  102 . The light guide  102  can serve to direct the light from the second light sources  106  into the dial face indicia  37  on the appliqué  36  and into the pointer body  84 , as shown in  FIG. 5 . In this regard, as the notches  112  can substantially surround the second light sources  106 , the light emitted by the second light sources  106  can be captured by the light guide  102 , which can direct a portion of the emitted light into the dial face indicia  37 , and a portion of the emitted light into the distal end  88  of the pointer body  84 . Thus, the pointer body  84  can be illuminated without incorporating a light source into the pointer  66 . 
   The mounting flanges  113  of the light guide  102  can couple the primary light guide assembly  94  to the bearing plate  60 . The mounting flanges  113  can be formed at one or more locations along the edge  115  of the light guide  102 . The mounting flanges  113  can be sized such that the primary light guide assembly  94  can be suspended over the bearing plate  60  and coupled to the mounting points  67  of the bearing plate  60  without interfering with the rotation of the annular gear  76 . 
   The gauge assembly  16  can also include the display  30 . The display  30  can be coupled to the aperture  44  defined in the housing body  34 , such that the display  30  can be between the circuit board assembly  24  and the housing body  34 . The display  30  can be secured within the housing body  34  to enable the display  30  is positioned in front of the one or more first light sources  48  to enable the one or more first light sources  48  to backlight the display  30 . As the display  30  can generally comprise a liquid crystal display (LCD), such as a conventional color LCD that can be operated by a conventional control system to provide a color graphical display, the display  30  will not be discussed in great detail herein. Further, one of ordinary skill in the art will appreciate that the display  30  need not be a LCD but could alternatively be another type of display that may or may not require back-lighting. Examples of displays not requiring back-lighting include organic light emitting diode (OLED) displays, polymer light emitting diode displays, and thin film electroluminescent displays. Briefly, however, with regard to the display  30 , the display  30  can comprise a display surface that can display at least one graphical message  120  for the operator of the motor vehicle  10 , such as a map, as shown in  FIGS. 2 and 6 . It will be understood, however, that the graphical message  120  can comprise one or more of a text message, a graphical image or combinations thereof such as a low fuel warning with a fuel tank graphic. 
   In operation, the first light sources  48  of the PCB  46  can be used to backlight the portion of the appliqué  36  associated with the secondary gauges  18  and the display  30 . The second light sources  106  of the primary light guide assembly  94  can project light into the light guide  102  to illuminate the dial face indicia  37  and the arrowhead  88   a  of the pointer  66 , without requiring the pointer  66  to include a light source. In addition, the pointer  66  can be moved as necessary to correspond to the appropriate dial face indicia  37  on the primary gauge  20  by the motor assembly  62  and gear set  64 . With the intermediate gear  74  and annular gear  76  of the gear set  64  mounted on the bearing plate  60 , the display surface of the display  30  can encompass a larger area within the gauge assembly  16 . Thus, a greater amount of information can be contained in the graphical messages  120  that can be displayed for the operator of the motor vehicle  10 . 
   While specific examples have been described in the specification and illustrated in the drawings, it will be understood by those of ordinary skill in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the present disclosure as defined in the claims. Furthermore, the mixing and matching of features, elements and/or functions between various examples is expressly contemplated herein so that one of ordinary skill in the art would appreciate from this disclosure that features, elements and/or functions of one example may be incorporated into another example as appropriate, unless described otherwise, above. Moreover, many modifications may be made to adapt a particular situation or material to the teachings of the present disclosure without departing from the essential scope thereof. Therefore, it is intended that the present disclosure not be limited to the particular examples illustrated by the drawings and described in the specification as the best mode presently contemplated for carrying out this invention, but that the scope of the present disclosure will include any embodiments falling within the foregoing description and the appended claims. 
   For example, while the display  30  has been described as including an LCD that is backlit by one or more first light sources  48  on the circuit board assembly  24 , those of skill in the art will appreciate that the present disclosure, in its broadest aspects, may be constructed somewhat differently. For example, instead of the display  30  being backlit by the first light sources  48  on the PCB  46 , the display  30  could be backlit by a light guide system similar to that disclosed in co-pending U.S. patent application Ser. No. 11/694,579, filed Mar. 30, 2007, the disclosure of which is hereby incorporated by reference as if fully set forth in detail herein. In another example, a self-illuminating display device may be substituted for the display  30  and in which case, the first light source is  48  need not be employed to illuminate the display  30 .