Abstract:
A control knob ( 10 ) includes a base ( 14 ) and a shaped wall ( 12 ). A plurality of sensor elements ( 32 ) are located within and circumferentially spaced around said shaped wall. Processor circuitry ( 40, 50 ) is connected to the plurality of sensor elements ( 32 ) for controlling an end-use device. The processor circuitry ( 40, 50 ) senses user touch commands on both sides of the shaped wall ( 12 ), and determines user desired commands based on the sensed user touch commands.

Description:
RELATED APPLICATION 
       [0001]    This application claims priority from U.S. Provisional Application No. 61/119,450, filed Dec. 3, 2008, the subject matter of which is incorporated herein by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    The present invention relates to control knobs and is particularly directed to a touch-type control knob. 
       BACKGROUND 
       [0003]    Control knobs, and in particular, mechanical rotary control knobs are known. Such rotary control Knobs are mechanically turnable and control things from simple. ON/OFF functions of devices, to selection of specific items like television stations, to infinitely controlled selections like volume of a radio. Such mechanical rotary control knobs have been found in many applications in vehicle control applications. 
       SUMMARY OF THE INVENTION 
       [0004]    In accordance with one aspect of the present invention, a control knob comprises a base and a shaped wall. A plurality of sensor elements are located within and circumferentially spaced around said shaped wall. Processor circuitry is connected to said plurality of sensor elements for controlling an end-use device. The processor circuitry senses user touch commands on both sides of the shaped wall, and determines user desired commands based on the sensed user touch commands. 
         [0005]    In accordance with one aspect of the present invention, a touch-type control knob comprises a base and a cylindrical wall. A plurality of capacitive sensor elements are provided within and circumferentially spaced around the cylindrical wall. Processor circuitry is connected to the plurality of capacitive sensor elements for controlling an end-use device. The processor circuitry senses user touch commands on both sides of the cylinder; and determines user desired commands based on the sensed user touch commands. 
         [0006]    In accordance with another aspect of the present invention, a method is provided for controlling a knob comprising the steps of detecting finger position on the knob, detecting thumb position on the knob, determining movement of the detected finger and thumb on the knob, and controlling an end-use device in response to the determined finger and thumb movement. 
         [0007]    In accordance with still another aspect of the present invention, a method is provided for controlling a touch-type control knob comprising the steps of detecting finger position on the control knob, measuring finger spacing on the control knob, determining thumb location on the control knob in response to position and width, determining a user&#39;s left or right hand based on thumb location and finger position on the control knob, and controlling an end-use device in response to determined user&#39;s hand and finger and thumb movement. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    The foregoing and other features and advantages of the present invention will become apparent to those skilled in the art to which the present invention relates upon reading the following description with reference to the accompanying drawings, in which. 
           [0009]      FIG. 1  is a perspective view of a touch-type control knob made in accordance with one example embodiment of the present invention; 
           [0010]      FIG. 2  is a perspective view of the touch-type control knob of  FIG. 1  depicting the sensor elements within the structure of the assembly; 
           [0011]      FIG. 3  is a bottom view of the touch-type control know of  FIG. 1  with portions of the assembly material removed to show the sensor elements; 
           [0012]      FIG. 4  is a schematic illustration of an operators finger being drawn across sensor elements of the touch-type control knob of  FIG. 1  and the processing circuitry connected to the sensor elements; and 
           [0013]      FIG. 5  is a flow diagram of a control process in accordance with one exemplary embodiment of the present invention for use with a touch-type control knob. 
       
    
    
     DETAILED DESCRIPTION 
       [0014]    Referring to  FIGS. 1-3 , a touch-type control knob  10 , made in accordance with one example embodiment of the present invention is shown. The control knob  10  is circular in shape having a cylindrical wall portion  12  extending outwardly from a base  14 . The base  14  is adapted so as to be attachable to a wall surface  16  in any appropriate manner such as glue, screws, rivets, etc. The touch-type control knob  10  is not a movable knob but is responsive to touch. 
         [0015]    The cylindrical wall  12  is of a predetermined thickness so as to have an inner wall  18  having an inner diameter and an outer wall  20  having outer diameter. The inner diameter of the inner wall  18  is large enough to accommodate an average human finger tip and allow the finger tip to move around in a circular fashion against the inner wall  18  of the control knob  10 . 
         [0016]    Between the inner wall  18  and the outer wall  20  and circumferentially spaced around the diameter of the cylindrical wall  12  are a plurality of capacitive sensors  30 . Each capacitive sensor  30  is slightly circumferentially spaced from the next adjacent sensors on each side so as to be electrically isolated therefrom. The capacitive sensor elements  30  form an array of sensor elements spread around the circumference of the inside wall  18  of the sensor knob  10 . Each sensor element  30  has a connector end  32  that is connectable to processing circuitry for detection of the presence of a finger or thumb on either the interior wall  18  or the exterior wall  20  of the sensor knob  10 . 
         [0017]    In the application of the sensor knob  10  to a vehicle, the sensor knob  10  may be located near a central front cabin location between the driver and passenger. When a either the driver or passenger grab the knob, a control process, in accordance with an example embodiment of the present invention, detects the location of each finger and thumb and determines if it is a right hand or left hand. This left hand or right hand determination is used to determine if the control knob user is the driver or the passenger. 
         [0018]    Referring to  FIG. 4 , the sensors  30 , which are metal strips, are connected to a capacitive sensor integrated circuit  40  so that each sensor functions as a capacitive sensor since the user&#39;s finger acts as a dielectric. Each capacitive sensor output is connected to a microprocessor or microcomputer  50  for processing of the sensor output signals. In accordance with one example embodiment the present invention, when a user&#39;s thumb and fingers are slide around the outside surface of the control knob  10 , various ones of the sensors  30  provide and output signal to the microcontroller  50 . The microcontroller tracks a specific pattern of motion (finger moving) or stationary point of contact (thumb), and determines the user&#39;s hand angular position around the control knob  10 . Using this data, the microcontroller determines if the user is rotating the knob clockwise or counterclockwise Position data can also be used to determine speed of rotation. The speed of rotation as a user&#39;s releases the knob can be used to provide a “flick-and-spin” type function. Such information can be used to quickly advance through selections in menus. 
         [0019]    Sensor data can also used to determine when the user grabs the control knob  10  and when the user releases the control knob. The microcontroller can also decode the sensor data to detect a “tap” function where the user makes a selection by “tapping” their index finger while holding the knob. This tap can be used as a selection feature. 
         [0020]    Referring to  FIG. 5 , a control process  100 , in accordance with one exemplary embodiment of the present invention, for use with a touch-type control knob, such as that described above with regard to  FIGS. 1-4  is shown. In step  102 , the process starts and internal memories are cleared, initial flag conditions are set, etc. In step  104 , the outputs of the sensor elements are monitored so as to detect finger position(s) on the control knob  10 . In step  106 , a determination is made as to whether more than one finger has been detected on the control knob  10 . In accordance with this present control process, the control knob  10  and control process are design not to respond to touches to the control knob  10  unless there is a detection of more than one finger touching the knob  10 . This insures that an inadvertent touch of the control knob  10  will not result in a change to the device the control knob is ultimately controlling such as a radio, heater system, etc. If the determination in step  106  is negative, the process loops back to step  104 . When the determination in step  106  is affirmative, the process proceeds to step  108 . 
         [0021]    In step  108 , the finger spacing on the control knob  10  is measured. In step  110 , a determination is made from the measurements in step  108  as to the probable location of the thumb location touching the control knob  10  based upon the finger position, width and distance from the other fingers. Based on these factors and predetermined empirical information, thumb location is determined. 
         [0022]    In step  112 , a thumb finger pattern is developed based on the probable thumb determination in step  112 . Now knowing the thumb location, other monitored contact points indicated other finger locations. These finger locations can then be used relative to the thumb location to develop a recognized pattern that may be based on empirical data or upon calculation. In step  114 , the thumb/finger pattern determined in step  112  is then compared against a plurality of known thumb/finger patterns stored in memory to determine if a match can be made. A determination is then made in step  116  as to whether the pattern match is that of the drivers hand. 
         [0023]    If the determination in step  116  is affirmative, the process proceeds to step  118  where the finger movement on the control knob  10  is monitored so as to determine the driver&#39;s hand command. In step  120  the requested command via the control knob  10  is performed, e.g., turn the radio volume up. The process then loops back to step  104 . 
         [0024]    If the determination in step  116  is negative, the process assumes that the hand is that of the passenger and the proceeds to step  122  where the finger movement on the control knob  10  is monitored so as to determine the passengers hand command. In step  124 , the requested command via the control knob  10  is performed, e.g., turn the radio volume down. The process then loops back to step  104 . 
         [0025]    From the above description of the invention, those skilled in the art will perceive improvements, changes and modifications. The control knob of the present invention and the control process in accordance with the present invention can be used to replace any present mechanical rotary control knob whether in a vehicle system or any non-vehicle system. Improvements, changes and modifications within the skill of the art are intended to be covered by the appended claims.