Abstract:
An analog-style gauge for displaying the value of a parameter measured or sensed by a remote sensor. The gauge comprises an actuator having a selectively rotatable shaft and a pointer fixedly attached to the actuator shaft and capable of being internally illuminated by light directed into the pointer. A light source is disposed to direct light of at least two colors into the pointer. Control circuitry is operably connected to the actuator, the light source and a remote sensor. The control circuitry rotates the actuator shaft within a range of motion in response to signals received from the remote sensor indicative of changes in the value of the sensed parameter. The control circuitry changes the color of light directed into the pointer when the pointer reaches a pre-determined point within the range of motion, whereby the internal illumination of the pointer will change color when the pointer reaches a predetermined point within the range of motion.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application for Patent Ser. No. 61/034,717, filed Mar. 7, 2008, and entitled ANALOG-STYLE INSTRUMENTATION DISPLAY WITH COLOR-CHANGING POINTER, the specification of which is incorporated herein in its entirety by reference. 
    
    
     TECHNICAL FIELD 
     The following disclosure relates to instrumentation display devices, and more particularly, to analog-style instrumentation display devices with color-changing pointers for use on gauges, gauge dials and other indicators. 
     BACKGROUND 
     It is known to use both analog-style and digital-style instrumentation display devices to show the value of a sensed or measured parameter, e.g., time, speed, RPMs, temperature, pressure, fuel level, altitude, etc. Digital-style instrumentation display devices show the value of the sensed/measured parameter directly, i.e., by displaying a single discrete number that corresponds to the current value of the parameter. In contrast, analog-style instrumentation display devices show the value of the sensed/measured parameter indirectly, i.e., by moving a pointer, needle or other indicator (collectively “pointer”) within a predetermined range of motion (also known as a scale) that corresponds to the upper and lower measurement limits. The position of the pointer within the scale indicates the relative value of the sensed parameter (i.e., relative to the full scale). In some cases, indicia are provided to indicate numerical values for different positions on the scale, while in other cases only relative information such as “HOT” and “COLD” are provided. 
     It will be appreciated that the style (i.e., either analog or digital) of the display device is independent of the technology used for sensing/measuring the parameter and the technology used to operate the display. For example, a temperature gauge having a display dial with a moving pointer is considered to have an analog-style display, even if a digital sensing device is used to sense the temperature and a microprocessor-driven digital stepper motor is used to move the pointer. Further, even if the display device itself is fully digital, e.g., a computer-driven flat-panel display, it may still constitute an analog-style display device if it uses the image of a moving pointer traveling within a scale to convey sensed/measured parameter information to the viewer. 
     For reasons not fully understood, is believed that users can more quickly obtain useful information from analog-style instrumentation displays than from digital-style information displays. This appears especially true concentration-intensive activities such as driving or piloting a vehicle. In addition, many users simply prefer analog-style instrumentation displays for aesthetic reasons. Thus, analog-style instrumentation displays may be used in vehicles that extensively used digital technology for parameter sensing/measurement and communication. 
     It is known to provide a “redline” or similar color-coded indicia on the scale of an analog-style instrumentation display to denote the portion of the scale having values that are outside normal operating values. When the pointer of a display moves beyond the redline, it is important for the operator (e.g., of a vehicle) to take notice as soon as possible so as to assess whether corrective action is required. However, when numerous analog-style instrumentation displays are used together, it may become difficult to rapidly assess if any parameter is outside of its nominal operating range, even with the use of redlines or color-coded scales. A need therefore exists, for analog-style instrumentation displays that convey additional information to the user regarding the sensed parameter. 
     SUMMARY 
     In one embodiment, the present disclosure provides an analog-style gauge for displaying the value of a parameter measured or sensed by a remote sensor. The gauge comprises an actuator having a selectively rotatable shaft and a pointer fixedly attached to the actuator shaft and capable of being internally illuminated by light directed into the pointer. A light source is disposed to direct light of at least two colors into the pointer. Control circuitry is operably connected to the actuator, the light source and a remote sensor. The control circuitry rotates the actuator shaft within a range of motion in response to signals received from the remote sensor indicative of changes in the value of the sensed parameter. The control circuitry changes the color of light directed into the pointer when the pointer reaches a pre-determined point within the range of motion, whereby the internal illumination of the pointer will change color when the pointer reaches a predetermined point within the range of motion. 
     In another embodiment, the present disclosure provides an analog-style gauge for receiving signals from a remote sensor and displaying the value of a parameter sensed by the remote sensor. The gauge comprises an actuator having a shaft that is selectively rotatable through a range of motion having a plurality of sub-ranges. A pointer is fixedly attached to the actuator shaft and adapted to be internally illuminated. A light source selectively produces a plurality of illumination colors and is disposed so as to internally illuminate the pointer in the selected illumination color. Control circuitry is operatively connected to the actuator and the light source. The control circuitry rotates the actuator shaft within the range of motion in response to the signals received from the remote sensor until the pointer is in a position indicative of the value of the sensed parameter. The control circuitry controls the selected illumination color of the light source to be indicative of the sub-range of motion within which the actuator shaft is positioned. Thus, the illumination color of the pointer will change color when the pointer reaches a predetermined point within the range of motion. 
     In yet another embodiment, the present disclosure provides a vehicle instrumentation system for displaying, by means of the position of a pointer within a range of motion having a plurality of sub-ranges, a current value of a parameter sensed by a remote sensor and simultaneously indicating, by means of the illumination color of the pointer, the sub-range within which the value of the parameter currently lies. The system comprises an onboard computer mounted in the vehicle and operatively connected to the remote sensor to receive signals therefrom indicative of the current parameter value at the remote sensor. The computer includes a memory and a processor. The memory stores data regarding a plurality of sub-ranges, the information for each sub-range including the parameter values included within the sub-range. The processor receives the current parameter value, accesses the data in the memory to identify the sub-range within which the current parameter value lies and the illumination color assigned to the identified sub-range, and produces pointer control signals based on the current parameter value and illumination color control signals based on the illumination color assigned to the identified sub-range. A gauge is also provided having a movable pointer that can be selectively positioned and selectively illuminated with a plurality of illumination colors. The pointer is positioned based on the pointer control signals received from the onboard computer and is illuminated based on the illumination color control signals received from the onboard computer. 
     In yet another embodiment, the present disclosure provides a method of operating a gauge for displaying a current value of a parameter sensed by a remote sensor and simultaneously indicating a sub-range within a plurality of sub-ranges within which the current value of the parameter lies. The method comprises the following steps: Moving a pointer within a range of motion to a position indicative of the current value of the sensed parameter; determining which sub-range of a plurality of sub-ranges the current value of the sensed parameter lies within; determining which illumination color of a plurality of illumination colors is associated with the determined sub-range; and illuminating the pointer with the illumination color associated with the determined sub-range. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding, reference is now made to the following description taken in conjunction with the accompanying Drawings in which: 
         FIG. 1  illustrates a gauge cluster of analog-style instrumentation display devices in accordance with the disclosure; 
         FIG. 2  is a cross-sectional view of a gauge in accordance with another embodiment; 
         FIG. 3  illustrates a vehicle instrumentation system including a gauge/display cluster; 
         FIGS. 4   a - 4   e  illustrate a mode of operation of a instrumentation display device/gauge in accordance with another embodiment; and 
         FIG. 5  illustrates a digital flat-panel display screen that is configured to function as analog-style instrumentation display device. 
     
    
    
     DETAILED DESCRIPTION 
     Referring now to the drawings, wherein like reference numbers are used herein to designate like elements throughout, the various views and embodiments of an analog-style instrumentation display with color-changing pointer are illustrated and described, and other possible embodiments are described. The figures are not necessarily drawn to scale, and in some instances the drawings have been exaggerated and/or simplified in places for illustrative purposes only. One of ordinary skill in the art will appreciate the many possible applications and variations based on the following examples of possible embodiments. 
     Referring now to  FIG. 1 , there is illustrated a cluster of analog-style instrumentation display devices (often referred to as “gauges”) in accordance with one embodiment of the disclosure. Instrument cluster  100  is similar in many respects to the conventional instrumentation found on the dashboards of cars, trucks and buses; however, as further described below, the gauges comprising cluster  100  have features, including an illuminated color-changing pointer, not found in the prior art. The disclosures described herein are also applicable to instrumentation displays for other vehicles such as boat and aircraft. 
     The cluster  100  includes a plurality of individual gauges, including a speedometer  102 , tachometer  104 , voltmeter  106 , water temperature gauge  108 , oil temperature gauge  110 , fuel level gauge  112  and oil pressure gauge  114 . Regardless of the technology (i.e., digital, analog, or mixed) used in the associated sensing units and drive mechanisms, each of the display devices  102 - 114  is considered an analog-style gauge because the values of the sensed or measured parameters (i.e., speed, RPMs, voltage, etc.) are represented by the position of pointers  118  moving within pre-defined ranges of motion  120 . In some variations, the range of motion  120  may be sub-divided. For example, the tachometer  104  has a first sub-range of motion  120   a  corresponding to “normal” operation, and a second sub-range of motion  120   b  corresponding to “redline” operation. In addition, most of the gauges  102 - 114  include indicia  122  such as “tic marks” or numerical values disposed along the range of motion  120 . Each of the gauges  104 - 114  includes an “alert” light  124  on its face, the function of which will be further described below. 
     Referring now to  FIG. 2 , there is shown a cross section of an instrumentation display device or gauge  200  in accordance with another embodiment. The structure of gauge  200  is representative of the gauges  102 - 114  of  FIG. 1 . The gauge  200  includes a housing  202  that supports a transparent lens or crystal  204 , a central faceplate  206  and a backplate  208 . The space between the lens  204  and faceplate  206  constitutes the front chamber  210  of the gauge, and the space between the faceplate  206  and the backplate  208  constitutes the rear chamber  212 . The pointer  118  is disposed in the front chamber  210  and includes a hub  214  and a blade  216 . The hub  214  is mounted on a shaft  218  extending through a passage  220  in faceplate  206  from an actuator  222  disposed in the back chamber  212 . The actuator  222  is operably connected to control circuitry  224 , which receives signals indicative of sensed parameters via external connector  226 . Such signals indicative of sensed parameters may be in the form of electrical currents or voltages produced by remote analog sending units (not shown), digital signals produced by digital sending units or an on-board computer (see  FIG. 3 ), or other types of signals. After receiving the indicative signals, the control circuitry  224  causes the actuator  222  to rotate the shaft  218 , thereby rotating the pointer  118  within the range of motion  120  to indicate the value of the sensed parameter. The actuator  222  may be a digital stepper motor, analog magnetic movement, or other actuator of known type. 
     Illumination of the moving pointer  118  may be accomplished by any known means. In one variation, the pointer blade  216  is formed of transparent or translucent plastic. The innermost end of blade  216  may define a light guide structure  226  which extends through the faceplate passage  220  into the rear chamber  212 . One or more light sources  228  capable of producing different colors of light are disposed in the rear chamber adjacent the light guide structure  226 . Light (denoted by small arrows  230  in  FIG. 2 ) emitted from the light sources  228  strikes the light guide structure  226  and is conducted through the transparent/translucent blade  216  to the outermost end of the pointer  118 . Light escaping from the sides of the transparent/translucent blade  216  causes the pointer  118  to be illuminated in the color produced by the light sources  228 . 
     In one embodiment, the light sources  228  are LEDs capable of emitting at of at least two colors of light. The LEDs may be packaged individually or may be packaged in groups, such as in a tri-color red-green-blue (RGB) LED package capable of producing a variety of colors. In other embodiments, the light sources  228  may be conventional light bulbs or other light sources, with multiple colors being produced by colored bulbs, lenses or filters. The LEDs or other light sources  228  are operably connected to the control circuitry  224 , which can control the operation and/or color of the light sources in accordance with either built-in circuitry or with signals receive from other parts of the vehicle, e.g., the on-board computer. 
     In a preferred embodiment, the illumination color of the pointer  118  changes as the pointer moves through pre-selected portions (i.e., sub-ranges) of the range of motion  120  (see  FIGS. 4   a - 4   e ). In one variation, the light guide structure  226  is directional, and a plurality of light sources  228  of appropriate colors are arranged at different radial angles surrounding the shaft  218 . As the pointer  118  rotates around shaft  218 , the light guide structure  226  will receive light from different colored light sources  228  such that it is illuminated in the desired color at each point of its rotation. In another variation, the light guide structure  226  is omni-directional, and a plurality of light sources  228  of appropriate colors are arranged adjacent the shaft  218 . As the pointer  118  rotates around shaft  218 , the control circuitry  224  will switch the various light sources  228  on and off such that light of the desired color is directed at the light guide structure  226  when the pointer  118  is in a particular portion of the range of motion. 
     Referring still to  FIG. 2 , the alert light  124  may include a lens  232  mounted in the faceplate  206  over a light source  234  disposed in the rear chamber  212 . The alert light may be an LED, light bulb, or other light source, and it may emit a single color, or be capable of emitting multiple colors (e.g., an RGB package LED unit). The light source  234  is operably connected to the control circuitry  224 , which can control the operation (on, off, flashing, etc.) and color (if applicable) of the alert light. By illuminating or flashing the alert light, the user&#39;s attention may be readily attracted to a particular gauge. In one variation, the alert light  124  flashes when particular conditions are met, e.g., sensed parameter is approaching unsafe level. In another variation, the alert light flashes at random intervals to encourage the user to check all gauges periodically. 
     Referring now to  FIG. 3 , there is illustrated a vehicle instrumentation system  300  including a gauge/display cluster  302 , an onboard computer  304  and touch-screen  306 . The computer  304  receives signals from various discrete sensors  308 ,  310  and  312 , processes the signals as necessary, then sends control signals via circuitry  314  (e.g., wiring harness or bus) to the gauge cluster  302  for control of the individual gauges  102 - 110  as previously described. Operation of the gauges  102 - 110  may be customized by user commands entered on the touch screen  306  (or other suitable I/O device). It is understood that the computer  304  is representative of any control device that may send control signals to the indicator devices/gauges  102 - 110 . Accordingly, while the computer  304  is illustrated with a central processing unit (CPU)  314 , memory  316 , and communication interface  318  (which may be wired or wireless) coupled by one or more control lines  320  (e.g., internal bus), it is understood that many different control systems may be used with the gauge cluster  302  and that various components may be distributed. Furthermore, one or more control lines  314  coupling the computer  304  to the gauges  102 - 110  may be wired as shown or may be wireless. 
     Referring now to  FIGS. 4   a - 4   e , there is illustrated the mode of operation of an instrumentation display device/gauge in accordance with another embodiment. For purposes of illustration, a tachometer  104  is pictured; however, gauges of other types can be operated in a substantially similar manner in accordance with the disclosure. Referring first to  FIG. 4   a , the gauge  104  is shown in a deactivated state (e.g., engine off). The pointer  118  is not illuminated in any color, and is positioned at the lowest point of range of motion  120 . The alert light  124  is not illuminated. Referring next to  FIG. 4   b , the gauge  104  is shown with RPMs in the lower portion (i.e., first sub-range) of normal operation range  120   a  (e.g., idle). The pointer  118  is now illuminated in a first color, e.g., blue, and is positioned to indicate the current RPMs (approx. 1000) with indicia  122 . The alert light  124  is not illuminated because there is no need to attract the operator&#39;s attention. Referring next to  FIG. 4   c , the gauge  104  is shown with RPMs in the middle portion (i.e., second sub-range) of normal operation range  120   a  (e.g., cruising). The pointer  118  remains illuminated in the first color, and is positioned to indicate the current RPMs (approx. 5000). The alert light  124  is not illuminated because there is no need to attract the operator&#39;s attention. Referring next to  FIG. 4   d , the gauge  104  is shown with RPMs in the upper portion (i.e., third sub-range) of normal operation range  120   a  (e.g., passing), approaching the safe operation limit. The pointer  118  is now illuminated in a second color, e.g., yellow, and is positioned to indicate the current RPMs (approx. 7200). The alert light  124  is now also illuminated in the second color to further attract the operator&#39;s attention to the fact that the RPMs are approaching the redline at 8000 RPM. Referring finally to  FIG. 4   e , the gauge  104  is shown with RPMs exceeding the normal operation limits (e.g., racing). The pointer  118  is now in the abnormal operating range  120   b  (i.e., fourth sub-range), is illuminated in a third color, e.g., red, and is positioned to indicate the current RPMs (approx. 8200). The alert light  124  is now illuminated in the third color to attract the operator&#39;s attention to the fact that the RPMs have exceeded the redline and damage to the engine is possible. In some variations, the alert light  124  is programmed to flash at this point. It will be appreciated that in preferred embodiments, all of the set points, colors and other operations (e.g., flashing) of the pointer  118  and the alert light  124  on each gauge are controlled by the onboard computer  304 , and thus may be customized as desired using the touch screen  306 . 
     Referring now to  FIG. 5 , there is illustrated a digital flat-panel display screen  500  that is configured to function as analog-style instrumentation display device for remote sensor  501 . Since the flat-panel  500  uses the image (i.e., displayed in pixels) of a pointer  502  moving within a range of motion  504  to indicate a sensed parameter from sensor  501 , it is considered an analog-style gauge even though it uses entirely digital technology. With suitable programming, the virtual pointer  502  can be illuminated with different colors at different parts of the range of motion  504  in accordance with the previous disclosure. A virtual alert light  506  can also be provided and programmed to act in the same manner as a physical alert light  124 . 
     It will be appreciated by those skilled in the art having the benefit of this disclosure that this analog-style instrumentation display with color-changing pointer provides an analog-style instrumentation display device with color-changing pointer for use on gauges, gauge dials and other indicators. It should be understood that the drawings and detailed description herein are to be regarded in an illustrative rather than a restrictive manner, and are not intended to be limiting to the particular forms and examples disclosed. On the contrary, included are any further modifications, changes, rearrangements, substitutions, alternatives, design choices, and embodiments apparent to those of ordinary skill in the art, without departing from the spirit and scope hereof, as defined by the following claims. Thus, it is intended that the following claims be interpreted to embrace all such further modifications, changes, rearrangements, substitutions, alternatives, design choices, and embodiments.