Abstract:
A light bar is provided and includes an elongated carrier having a surface extending along the carrier. Capacitive sensors are spaced along the carrier and positioned below the surface. Light sources are included for illuminating the surface, each associated with at least one capacitive sensor and positioned proximate thereto. A controller is included for detecting capacitive changes in the capacitive sensors, wherein when the controller detects a capacitive change in a capacitive sensor, the controller alters an illumination state of a light source associated therewith.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention generally relates to vehicle lighting systems and more particularly, to vehicle lighting systems employing capacitive touch sensor technology. 
       BACKGROUND OF THE INVENTION 
       [0002]    A variety of lighting approaches are implemented in vehicles today. Such approaches can include ambient lighting for setting a mood and task lighting for assisting an occupant in performing an action. Since these differing lighting approaches are often embodied in separate lighting devices and systems, there is a need for a vehicle lighting system and device that reconciles the two approaches in a user-friendly and attractive manner. 
       SUMMARY OF THE INVENTION 
       [0003]    According to one aspect of the present invention, a light bar is provided and includes an elongated carrier having a surface extending along the carrier. Capacitive sensors are spaced along the carrier and positioned below the surface. Light sources are included for illuminating the surface, each associated with at least one capacitive sensor and positioned proximate thereto. A controller is included for detecting capacitive changes in the capacitive sensors, wherein when the controller detects a capacitive change in a capacitive sensor, the controller alters an illumination state of a light source associated therewith. 
         [0004]    According to another aspect of the present invention, a light bar is provided and is installed in a vehicle fixture. The light bar includes a carrier having a surface, capacitive sensors spaced along the carrier, and light sources for illuminating the surface, each associated with at least one capacitive sensor. A controller is included for detecting capacitive changes in the capacitive sensors, wherein when the controller detects a capacitive change in a capacitive sensor, the controller alters an illumination state of a light source associated therewith. 
         [0005]    According to another aspect of the present invention, a vehicle lighting system is provided and includes a light bar having capacitive sensors and light sources disposed below a surface and spaced along a carrier. A controller is included for detecting capacitive changes in the capacitive sensors and altering an illumination state of at least one light source when a capacitive change is detected. An input device is in communication with the controller for supplying the controller with user input. 
         [0006]    These and other aspects, objects, and features of the present invention will be understood and appreciated by those skilled in the art upon studying the following specification, claims, and appended drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    In the drawings: 
           [0008]      FIG. 1  shows a light bar installed in the interior door panels of the front and rear driver side doors of an automotive vehicle according to one embodiment; 
           [0009]      FIG. 2  shows a light bar installed in a vehicle dashboard of an automotive vehicle according to one embodiment; 
           [0010]      FIG. 3  shows a light bar installed in the driver side of a cargo compartment of an automotive vehicle according to one embodiment; 
           [0011]      FIG. 4  shows a segment of a light bar according to one embodiment; 
           [0012]      FIG. 5  shows a cross sectional view of the light bar taken along lines V-V of  FIG. 4 ; and 
           [0013]      FIG. 6  shows a vehicle lighting system employing a light bar according to one embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0014]    As required, detailed embodiments of the present invention are disclosed herein. However, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to a detailed design and some schematics may be exaggerated or minimized to show function overview. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention. 
         [0015]    Referring to  FIGS. 1-3 , a light bar  10  is exemplarily shown installed in various fixtures inside an automotive vehicle to provide ambient and/or task lighting. In  FIG. 1 , the light bar  10  is shown installed in the interior door panels of doors  12   a  and  12   b  located on the driver side of a vehicle. In  FIG. 2 , the light bar  10  is shown installed in a vehicle dashboard  14  and extending from an instrument panel  16  with a display monitor  17  towards the passenger side. In  FIG. 3 , the light bar  10  is shown installed in the driver side of a cargo compartment  20 . While the light bar  10  is generally shown as a continuous structure in  FIGS. 1-3 , it should be appreciated that the light bar  10  can be segmented if desired and can be constructed in a variety of shapes and dimensions. It should also be appreciated that the light bar  10  can be installed in other vehicle fixtures not shown herein. Such vehicle fixtures can include driver side structures, passenger side structures, front passenger compartment structures, rear passenger compartment structures, a headliner, a center console, and any other equipment or structure offering desirable installation opportunities. Further, while the light bar  10  has been shown variously installed in an automotive wheeled vehicle, it should be appreciated that the use of the light bar  10  can be extended to any passenger vehicle such as, but not limited to, trains, watercraft, and aircraft. 
         [0016]    Referring to  FIG. 4  the light bar  10  is shown according to one embodiment. The light bar  10  includes a carrier  22  having a surface  24  that typically occupies a large visible portion of the light bar  10  when installed in a vehicle fixture. The carrier  22  can be elongate, having a relatively small width, and can be constructed from any durable material, rigid or flexible. The surface  24  can span the length of the carrier  22  and can be constructed from a durable light transmissive material such as glass, plastic, and the like. The light bar  10  also includes capacitive sensors  26  and light sources  28 , both of which are disposed below the surface  24  and can be spaced longitudinally along the carrier  22 . The capacitive sensors  26  can be variously shaped, and are exemplarily shown having a round configuration to compliment a finger pad or a stylus tip, two popular conductors that are generally round in shape. However, it should be appreciated that other sensor shapes can also be used, such as square, rectangular, etc. 
         [0017]    With respect to the illustrated embodiment, the light sources  28  are configured to illuminate the surface  24  and are each associated with at least one of the capacitive sensors  26 . As shown, some of the light sources  28  can be disposed to alternate with the capacitive sensors  26 . Additionally or alternatively, some of the light sources  28  can be disposed in an optional opening  30  extending through a corresponding capacitive sensor  26 . As a result, each of those light sources  28  is able to illuminate an area of the surface  24  located directly above the surrounding capacitive sensor  26 . 
         [0018]    Each light source  28  can include one or more light emitting diodes (LED) of any desired color. As best illustrated in the cut away section of the light bar  10  shown in  FIG. 4 , each light source  28  can include a red LED  32 , a green LED  34 , and/or a blue LED  36  according to one embodiment. If employing all three LEDs  32 ,  34 ,  36 , a variety of visible colors, including white light, can be expressed from the light source  28  by varying the power supplied to one or more of the LEDs  32 ,  34 ,  36 . Additionally or alternatively, the light source  28  can include a white LED  38  that is dedicated to expressing white light. As is known, there are a number of ways in which to generate white light with LEDs. As such the white LED  38  can include single and multi-LED arrangements as well as phosphor coated LEDs. By providing one or more color options, a driving experience can be enhanced. Furthermore, by adjusting the power supplied to any given LED  32 ,  34 ,  36 ,  38  described herein, the brightness level of the light source  28  can be controlled. This enables the light bar  10 , or portions thereof, to seamlessly transition between ambient and task lighting, either at the request of a user or via an autonomous process. 
         [0019]    Referring now to  FIG. 5 , each capacitive sensor  26  and light source  28  can be mounted to a printed circuit board (PCB)  40  supported inside the carrier  22 , which can be frictionally engaged with the surface  24 . A ground element  42  can surround each capacitive sensor  26  to aid in minimizing the effects of electromagnetic interference (EMI) and can be continuous or segmented. By virtue of being in proximity to the capacitive sensors  26 , some parasitic capacitance may be formed between the ground element  42  and corresponding capacitive sensors  26 . When a finger, or other conductor, is within a sensing area of a capacitive sensor  26  (e.g. touches an area of the surface  24  above the capacitive sensor  26 ), the capacitive sensor  26  undergoes a capacitive change. Generally, the capacitance of the conductor is added to that of the capacitive sensor  26 , which typically corresponds to the parasitic capacitance. Therefore, by measuring capacitive changes in the capacitive sensors  26 , it is possible to determine when and where a conductor is applied to the light bar  10 . However, one potential design concern is that the capacitance change caused by a finger can be relatively small compared to the parasitic capacitance. In these instances, the capacitive change may be so minute that it may be difficult to determine whether a conductor is applied to the light bar  10 , which can result in false detections being reported. Thus, from a design perspective, it may be desirable to reduce the parasitic capacitance between a ground element  42  and an associated capacitive sensor  26  to ensure that the capacitive sensor  26  experiences a greater capacitive change when a conductor enters the sensing area. Some ways of reducing the parasitic capacitance can include, but are not limited to, selecting a surface  24  with a greater dielectric constant, decreasing the thickness of the surface  24 , using relatively short and narrow circuit traces in the PCB  40 , and increasing the diameter of the capacitive sensors  26 . Implementing some or all of the abovementioned techniques, in addition to other techniques known to those possessing ordinary skill in the art, may enable a greater capacitive change to be measured in a capacitive sensor  26  in response to a conductor being present in the sensing area. As a result, the signal-to-noise ration (SNR) can be increased, thereby allowing for more accurate detection of a conductor. 
         [0020]    To measure capacitive change, the light bar  10  can include at least one controller  44  as shown in  FIG. 6 . The controller  44  can be provided on the PCB  40  or external to the light bar  10  and is shown separate from the light bar  10  for purposes of illustration. As shown, the light bar  10  can be part of a vehicle lighting system  46  and the controller  44  can receive input from an input device  48 , one or more vehicle equipment  50 , and an electrical power supply  52 . The input device  48  can be located next to the light bar  10  or located remotely. According to one embodiment, the input device  48  can be a human machine interface (HMI) such as a display monitor (e.g., monitor  17 ) located in the vehicle dashboard or other location and include buttons and/or a touchscreen that enable a user to enter input. In any event, input from the input device  48  is supplied to the controller  44  and can prompt the controller to power ON the light bar  10 , power OFF the light bar  10 , activate the light sources  28   a - 28   g,  and deactivate the light sources  28   a - 28   g.  Additionally, input from the input device  48  can also prompt the controller  44  to change the brightness of the light sources  28   a - 28   g  and/or change the color of the light expressed from the light sources  28   a - 28   g.    
         [0021]    It is also contemplated that the controller  44  can receive input from one or more vehicle equipment  50  to elicit an autonomous response of the light bar  10 . For instance, vehicle equipment  50  can include an ambient light sensor that indicates whether dark conditions are present, in which case the controller  44  can be prompted to automatically activate the light sources  28   a - 28   g  to illuminate at a low brightness setting to provide ambient lighting. The controller  44  can vary the amount of power supplied to the light sources  28   a - 28   g  using pulse width modulation (PWM) or other suitable techniques to adjust their brightness levels. Power to the light bar  10  can be supplied via electrical power supply  52 , which can be an on board vehicle power supply or an independent power source. 
         [0022]    When the light bar  10  is powered ON, the controller  44  monitors the capacitive sensors  26   a - 26   d  and when a capacitive change is detected in a capacitive sensor  26   a - 26   d,  the controller  44  can alter an illumination state of at least one light source  28   a - 28   g  associated therewith, which is typically in close proximity to the corresponding capacitive sensor  26   a - 26   d.  As shown, multiple indicia  53  can be provided on the carrier  22  to inform a user of the relative position of capacitive sensors  26   a - 26   d.  This provides the user with the optimal areas along the surface  24  for sensing a conductor, exemplarily shown as finger  54  in  FIG. 6 . Additionally or alternatively, narrow spacing between the capacitive sensors  26   a - 26   d  can also increase the chances of a capacitive sensor  26   a - 26   d  being able to sense the presence of the finger  54  or other conductor. For purposes of illustration, the finger  54  is shown touching the surface  24  above capacitive sensor  26   b,  causing it to exhibit a capacitive change, as described previously. When the controller  44  detects a capacitive change in capacitive sensor  26   b,  the controller  44  can prompt various responses from an associated light source  28   d  depending on the illumination state thereof. 
         [0023]    For instance, if the associated light source  28   d  is in a deactivated state, when a capacitive change is detected in capacitive sensor  26   b,  the controller  44  can subsequently activate the associated light source  28   d  and prompt it to emit light at a default brightness or a specified brightness in addition to a default color or a specified color, all of which can be selected via input device  48  and stored to controller memory for repeated use. According to one embodiment, when the associated light source  28   d  transitions from a deactivated state to an activated state, light can be emitted therefrom at a low brightness level to prevent against overwhelming the user and/or other vehicle occupants in instances where their eyes are adjusted to dark conditions, and as a result, are more sensitive to light. 
         [0024]    Alternatively, if the associated light source  28   d  is already active when a user touches the surface  24  above capacitive sensor  26   b,  the controller  44  can increase or decrease the amount of power supplied to the associated light source  28   d  and/or change the color of light expressed from the associated light source  28   d.  For example, if the associated light source  28   d  is on a low brightness setting, subsequently touching the surface  24  above capacitive sensor  26   b  can prompt the controller  44  to increase the power supplied to the associated light source  28   d,  thereby causing an increase in brightness level. Conversely, if the associated light source  28   d  is on a high brightness setting, subsequently touching the surface  24  above capacitive sensor  26   b  can prompt the controller  44  to decrease the power supplied to the associated light source  28   d , thereby causing a decrease in brightness level. 
         [0025]    It should be appreciated that the light bar  10  can be configured to have multiple brightness settings such that progression from a lowest brightness setting to a maximum brightness setting requires a user to repeatedly touch the surface  24  above capacitive sensor  26   b  to prompt the controller  44  to incrementally increase the amount of power supplied to the associated light source  28   d  until the maximum brightness setting is reached. Once reached, each subsequent touching of the surface  24  above capacitive sensor  26   b  prompts the controller  44  to incrementally decrease the amount of power supplied to the associated light source  28   d  until it becomes deactivated. Additionally or alternatively, with each detected touch, the controller  44  can prompt the associated light source  28   d  to emit a different colored light. For example, the lowest brightness setting can be characterized by low intensity blue light to provide ambient lighting while the maximum brightness level can be characterized by high intensity white light to provide task lighting. 
         [0026]    While a single associated light source  28   d  has been described above in relation to capacitive sensor  26   b,  it should be appreciated that other light sources, such as light sources  28   c  and  28   e  can also be associated with capacitive sensor  26   b  and controlled by the controller  44  in the above-described manner. In such a configuration, when finger  54  touches the surface  24  above capacitive sensor  26   b,  the controller  44  can alter the illumination state of all three associated light sources  28   c - 28   e  in unison, which causes a larger area of the surface  24  to be visually impacted as compared to the impact area observed from using associated light source  28   d  alone. It is contemplated that the user may be given options as to the desired size of the impact area, which the user can select via the input device  48 . 
         [0027]    Accordingly, a light bar  10  for use in a vehicle lighting system  46  has been advantageously provided herein. The light bar  10  includes a surface  24  that can be made to illuminate using an input device  48 , which allows a user to specify a desired brightness and/or color. Additionally, a user can change the illumination state of a desired area of the surface  24  via capacitive touch. By simply touching the desired area with a conductor, the user may cause the desired area to be illuminated, increase or decrease the brightness level associated with the desired area, change the color of the light expressed from the desired area, cease illumination of the desired area, or certain combinations thereof. As a result, the user&#39;s driving experience can be enhanced. 
         [0028]    It is to be understood that variations and modifications can be made on the aforementioned structure without departing from the concepts of the present invention, and further it is to be understood that such concepts are intended to be covered by the following claims unless these claims by their language expressly state otherwise.