Abstract:
A control assembly adapted for automotive applications provides operator inputs and displays and includes a uniface ornamental escutcheon defining a central display area and a plurality of operator input devices at least partially circumscribing the display area. Each operator input device includes a faux control member integrally formed within the escutcheon and having beveled circumferential contours mimicking a discrete displacable control element. At least one substrate extends rearwardly from and closely conforms with a rear surface of the escutcheon, and is positioned to transect a plurality of adjacent faux control members. At least one capacitance sensor is associated with each faux control member and is carried on a forward facing edge of the substrate. As a result, each operator input device is touch sensitive to manual operator selection of input devices by touching the exposed face of the escutcheon to effect a desired switching function.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to control devices for enabling operator inputs and system displays, and more particularly, the application of capacitance user-interface switches in such devices. 
       BACKGROUND OF THE INVENTION 
       [0002]    Capacitance switching circuits are typically configured on the planar surface of a circuit board whether it is a rigid substrate like an FR4 material or a flexible substrate like a polyamide film. This approach has limitations on the design for providing switch illumination and pushbutton layouts, especially when the switches border a display area or with complex curved areas commonly found on control front end styling. Flexible circuits can adapt but generally are more expensive and require an adhesive interface to ensure intimate contact with the pushbutton are a material to enable energy transfer to the switch. 
       SUMMARY OF THE INVENTION 
       [0003]    By plating the edge of a circuit board at an intended capacitance switch area, almost any curved surface can be replicated with the circuit board edge to enable the intimate contact needed with a trim plate for efficient energy transfer without using an expensive flex circuit or adding a silicone gap filling compound in conjunction with the planar surface. Since primarily only a circuit board edge is needed for the switch, the open area can enable a flood lit volume of space for illumination or light pipe access for a controlled light dispersion as opposed to using individual light emitting diodes (LED) for each pushbutton graphic/switch area. 
         [0004]    The circuit board efficiency is realized by providing the switch circuitry in only the required area leaving the additional surface available for interconnections or other componentry. In addition, by using an overlapping circuit board running in a perpendicular fashion to the main switch board, a rotary function can be realized with the contact pad locations at the 3 o&#39;clock, 6 o&#39;clock, 9 o&#39;clock and 12&#39;oclock positions. This can be especially beneficial when integrated with a vehicular audio or navigation system that uses a display with the sides and either top row or bottom row of pushbuttons where there may be a typical rotary style control at the corners where the rows of switches intersect. 
         [0005]    In the preferred embodiment of the invention a control assembly for providing operator inputs and displays includes a uniface ornamental escutcheon forming a display area and a plurality of operator input devices at least partially circumscribing the display area. Each said operator input device forms a faux control member integrally within the escutcheon having beveled circumferential contours mimicking a discrete relatively displacable control element. At least one substrate extends normally rearwardly from a rear facing surface of said escutcheon, said substrate including a front edge surface configured to closely conform to the rear facing surface of the escutcheon and transecting a plurality of adjacent faux control members. One or more capacitance sensors associated with each faux control member carried on the front edge surface of said substrate, said at least one capacitance sensor is adapted to sense a change in capacitance at said front edge surface resulting from proximate engagement with an associated faux control member by an object having predetermined capacitance characteristics. Lastly, capacitance change responsive switching circuitry carried on said substrate and in-circuit with said at least one capacitance sensor for providing a desired switching function responsive to said engagement. This provides a control assembly which is inexpensive and simple to build which faithfully mimics the overall appearance and functionality of traditional control assemblies. 
         [0006]    These and other features and advantages of this invention will become apparent upon reading the following specification, which, along with the drawings, describes preferred and alternative embodiments of the invention in detail. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    The present invention will now be described, by way of example, with reference to the accompanying drawings, in which: 
           [0008]      FIG. 1 , is an exploded, perspective view of a first embodiment of a vehicle control assembly featuring a plurality of faux push-button devices circumscribing a display area and two faux rotary knob devices; 
           [0009]      FIG. 2 , is a front plan view of the vehicle control assembly of  FIG. 1 ; 
           [0010]      FIG. 3 , is a cross-sectional, plan view of the vehicle control assembly of  FIG. 1 , taken along lines  3 - 3  of  FIG. 2 ; 
           [0011]      FIG. 4 , is a cross-sectional plan view of one of the faux rotary knob devices of  FIG. 1 , taken along lines  4 - 4  of  FIG. 3 ; 
           [0012]      FIG. 5 , is an exploded, perspective view of a second embodiment of a vehicle control assembly featuring a faux slider device; 
           [0013]      FIG. 6 , is a broken, cross-sectional view of a portion of a second embodiment of a vehicle control assembly; and 
           [0014]      FIG. 7 , is a broken, perspective view of a portion of a third embodiment of a vehicle control assembly. 
       
    
    
       [0015]    Although the drawings represent embodiments of the present invention, the drawings are not necessarily to scale and certain features may be exaggerated in order to illustrate and explain the present invention. The exemplification set forth herein illustrates an embodiment of the invention, in one form, and such exemplifications are not to be construed as limiting the scope of the invention in any manner. 
       DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0016]    In its preferred embodiment, the present invention is described as an automotive trim panel for providing an operator interface with an audio or navigation system or the like. 
         [0017]    Referring to  FIGS. 1-4 , a first embodiment of the present invention illustrates a control assembly  10  operative to provide operator inputs and displays for a host vehicle (not illustrated). The control assembly  10  is adapted for mounting in the instrument panel of the host vehicle and includes a shell-shaped ornamental escutcheon  12 , preferably formed of injection molded polymer based material in a single, unified structure. 
         [0018]    As best viewed in  FIGS. 1 and 2 , the escutcheon  12  is shaped in a generally rectangular form including a front wall or face portion  14 , left and right side walls  16  and  18 , respectively, and top and bottom walls  20  and  22 , respectively. Preferably, the front wall  14  is integrally molded as a single piece with the respective walls  16 - 22 , which, in application, extend rearwardly therefrom. A generally centralized rectangular opening  24  is formed in the front wall  14  to define a display area  26  for receiving a liquid crystal display (LCD) or equivalent device (not illustrated). 
         [0019]    Referring to  FIG. 2 , a vertically arranged array of four faux pushbuttons  28 ,  30 ,  32  and  34  define the left-hand edge of opening  24 . Likewise, a second vertically arranged array of four faux pushbuttons  36 ,  38 ,  40  and  42  define the right-hand edge of opening  24 . A horizontally arranged array of four faux pushbuttons  44 ,  46 ,  48  and  50  define the bottom edge of opening  24 . A first faux rotary knob  52  is located at the intersection of the respective lines of elongation of the vertical array of push-buttons  28 - 34  and the horizontal array of push-buttons  44 - 50 . A second faux rotary knob  54  is located at the intersection of the respective lines of elongation of the vertical array of push-buttons  36 - 42  and the horizontal array of push-buttons  44 - 50 . 
         [0020]    The faux push-buttons  28 - 50  and faux rotary knobs  52  and  54  are each integrally formed from the same polymer based material comprising the ornamental escutcheon  12 . Each of the faux push-buttons  28 - 50  and faux rotary knobs  52  and  54  are formed as an integral part of the front wall or face portion  14  of the ornamental escutcheon  12 . Definitionally, the ornamental escutcheon  12  is deemed to be “uniface”, meaning that all of the faux control members (faux push button device, faux slider device and faux rotary knob device) are integrally formed on the curvilinear plane defined by the front wall/face portion  14  of the ornamental escutcheon. No faux control members are formed in the walls  16 - 22 . 
         [0021]    Conventional audio systems, such as the automotive radio/CD played described in FIG. 1 of U.S. Pat. No. 7,733,659 B2, typically include a trim plate assembly carrying a complex assemblage of discrete operator accessible control devices, such as rotary knobs and pushbuttons, which are physically displacable with respect to the trim plate. For the sake of brevity, the entire specification of U.S. Pat. No. 7,733,659 B2 is incorporated herein in its entirety. U.S. Pat. No. 7,733,659 B2 has been and remains the exclusive property of the assignee of the present application. 
         [0022]    Each faux control member  28 - 54  has molded-in features such as beveled circumferential contours enabling them to mimic their conventional discrete counterpart and enabling the overall cosmetic appearance of the control assembly to mimic a conventional trim panel assembly. 
         [0023]    Referring to  FIGS. 1-4 , each faux control member  28 - 54  constitutes an external surface “target area” or “touch point” for an operator to affect an input command to a specific host vehicle system via the control assembly  10 . In the case of the push buttons  28 - 50 , each target area is a generally rectangular surface with peripheral contours and recesses providing the false appearance of discrete, separate control elements which are separately displacable during operator actuation. 
         [0024]    The control assembly  10  further includes three elongated substrates, such as rigid printed circuit boards (PCBs)  56 ,  58  and  60 , mounted to the rear surface of the escutcheon  12  and carrying electrical circuitry as will be further described herein below. The PCBs  56 - 60  are disposed substantially normally to and extend longitudinally rearwardly from the rear facing surface of the front wall  14  of the escutcheon  12 . 
         [0025]    PCB  56  is disposed vertically transecting push buttons  28 - 34  and faux rotating knob  52 . PCB  56  has a front edge surface  62  shaped to generally conform with the adjacent rear facing surface of the front wall  14 . Four capacitive sensors  64 ,  66 ,  68  and  70  are carried on the front edge surface  62  of PCB  56  and are positioned to register with faux push buttons  28 - 34 , respectively. Each of the sensors  64 - 70  comprise a pair of spaced-apart contacts electrically interconnected with capacitance change switching circuitry (not illustrated) also carried on PCB  56 . PCB  56  has an extension portion  72  nestingly extending within a cavity  74  defined by faux rotary knob  52 . Upper and lower capacitive sensors,  76  and  78 , respectively, are carried on the upper surface  80  of extension part  72 , separated by a guide slot  82 . 
         [0026]    Definitionally, “operator input devices” consist of a faux control member, at least one associated capacitive sensor and the associated capacitance change switching circuitry. By example, the upper left-hand most (push-button type) operator input device comprises faux push button  28 , capacitive sensor  64  and its associated capacitance change switching circuitry. 
         [0027]    PCB  58  is disposed vertically transecting push buttons  36 - 42  and faux rotating knob  54 . PCB  58  has a front edge surface  84  shaped to generally conform with the adjacent rear facing surface of the front wall  14 . Four capacitive sensors  86 ,  88 ,  90  and  92  are carried on the front edge surface  84  of PCB  58  and are positioned to register with faux push buttons  36 - 42 , respectively. Each of the sensors  86 - 92  comprise a pair of spaced-apart contacts electrically interconnected with capacitance change switching circuitry  94  also carried on PCB  58 . PCB  58  has an extension portion  96  nestingly extending within a cavity  98  defined by faux rotary knob  54 . Upper and lower capacitive sensors,  100  and  102 , respectively, are carried on the upper surface  104  of extension part  96 , separated by a guide slot  106 . 
         [0028]    PCB  60  is disposed horizontally transecting push buttons  44 - 50  and faux rotating knobs  52  and  54 . PCB  60  has a front edge surface  108  shaped to generally conform with the adjacent rear facing surface of the front wall  14 . Four capacitive sensors  110 ,  112 ,  114  and  116  are carried on the front edge surface  108  of PCB  60  and are positioned to register with faux push buttons  44 - 50 , respectively. Each of the sensors  110 - 116  comprise a pair of spaced-apart contacts electrically interconnected with capacitance change switching circuitry  118  also carried on PCB  60 . PCB  60  has a first extension portion  120  nestingly extending within the cavity  74  defined by faux rotary knob  52 . Left and right capacitive sensors,  122  and  124 , respectively, are carried on the upper surface  126  of extension portion  120 , laterally separated by a guide slot  128 . PCB  60  has a second extension portion  130  nestingly extending within the cavity  98  defined by faux rotary knob  54 . Left and right capacitive sensors,  132  and  134 , respectively, are carried on the upper surface  136  of extension portion  130 , laterally separated by a guide slot  128 . 
         [0029]    By second example, the lower left-hand most (rotary knob type) operator input device comprises faux rotary knob  52 , capacitive sensors  76 ,  78 ,  122  and  124  and their associated capacitance change switching circuitry. 
         [0030]    Referring to  FIG. 4 , the positioning of multiple (in this case— 4 ) separate capacitance sensors at fixed orientations within a faux rotary knob  52  allows the operator to affect a mock rotation of the knob  52  by rotating one or more finger tips around the circumference as depicted by arrow  140  about axis  141 . Each of the capacitive sensors  76 ,  78 ,  122  and  124  are separately in circuit with capacitive change responsive switching circuitry. The faux knob  52  has a first, outer sensing region  142 , wherein proximity of an operator&#39;s fingertip is detected by one or two of the capacitive sensors  76 ,  78 ,  122  and  124 , and second, inner sensing region  144 , wherein proximity of an operator&#39;s fingertip is detected by three or four of the capacitive sensors  76 ,  78 ,  122  and  124 . An operator&#39;s fingertip, when sensed is located based upon which single capacitive sensor detects it or if detected by two capacitive sensors, by triangulation. For example, if the fingertip affects a similar response by sensors  122  and  76 , it is deduced that the fingertip is located in the third quadrant, i.e. the 10:00-11:00 o&#39;clock position and a rotary motion control signal is produced. An operator&#39;s fingertip, when sensed by three or four capacitive sensors simultaneously is deduced to be located in the inner sensing region  144  to affect actuation of a push-button actuator circuit. 
         [0031]    Referring to  FIG. 5 , a faux slider device  146  is illustrated, including a relatively fixed, decorative exposed panel  148  defining an elongated region of control depicted by an arrow  150 , and an underlying PCB  152  having a front edge surface  154 . A number of spaced apart tactile protuberances or denticles  156   a - 156 D and end of travel stops  158  are integrally formed in the panel  148  and are shaped to provide the operator a tactile input as to the relative position of his fingertip between the stops  158 . Five capacitive sensors  160 ,  162 ,  164 ,  166  and  168  are carried on the front edge  154  of the PCB  152  in spaced apart relationship and in respective registry with the spacing between adjacent denticles  156 A- 156 D and stops  158 . The sensors  160 - 168  are in circuit with capacitive change switching circuitry  169  also carried on the PCB  152 . 
         [0032]    The faux slider  146  has a plurality of aligned sensing regions, wherein proximity of an operator&#39;s fingertip is detected by one or two of the capacitive sensors  160 ,  162 ,  164 ,  166  and  168  to provide an analog switch signal representative of finger location. 
         [0033]    Referring to  FIG. 6 , an alternative faux rotary knob device  170  is illustrated, similar to the faux knobs  52  and  54  depicted in  FIGS. 1-4 . The faux knob device  170  has a knob structure  171  integrally formed with an ornamental escutcheon  172  to define a cavity  174 . An interlocked pair of rigid PCBs  176  and  178  have extensions  180  and  182 , respectively, nestingly disposed within cavity  174 . PCB extension  180  has opposed lateral edges  184  and  186  and PCB extension  182  has opposed lateral edges  188  and  190 . PCB extension  180  has an upper surface  192  and PCB extension  182  has an upper surface  194 . Capacitive sensors  196  and  198  are formed on opposed lateral edges  184  and  186  of PCB extension  180 , respectively. Capacitive sensors  200  and  202  are similarly formed on opposed lateral edges  188  and  190  of PCB extension  182 , respectively. The capacitive sensors  196 - 202  are cooperatively arranged in a circular array to mimic rotary motion as illustrated by a pair of fingertips  204  and rotational arrow  206 . An axially centered separate capacitive sensor  204  is formed on one or both upper surfaces  192  and  194  of PCB extensions  180  and  182 , respectively, to mimic axial push-button type action as illustrated by a phantom fingertip  208  and associated axially directed arrow  210 . 
         [0034]    Referring to  FIG. 7 , an alternative control assembly  212  includes a flexible printed circuit board (PCB)  214  having an elongated strip-like body portion  216  defining a front edge surface  218  configured for installation within an ornamental escutcheon (not illustrated) similar to that illustrated in  FIGS. 1-4 . The body portion  216  of the PCB  214  includes a localized extension portion  220  extending above the front edge surface  218  carrying a capacitive sensor  222  electrically in circuit with a capacitive change switching circuit  224 . A body end portion  226  of PCB  214  has an enlarged extension portion  228  extending above the front edge surface  218  of the PCB  214  carrying four (or more) spaced apart capacitive sensors  230 ,  232 ,  234  and  236 . In application, the body end portion  226  is rolled up in a cylindrical form dimensioned for installation within a faux rotating knob cavity (not illustrated). The longitudinal length of the body end portion  226  will approximately equal the inner circumference of the faux rotating knob cavity, and the vertical extension dimension extension portion  228  will approximately equal the axial dimension of the faux rotating knob cavity. When installed, the capacitive sensors  230 - 236  will be disposed in a circular array within an associated faux rotary knob and operate similarly to the capacitive sensors  76 ,  78 ,  124  and  126  of  FIGS. 1-4  and capacitive sensors  196 ,  198 ,  200  and  202  of  FIG. 6 . Capacitive sensors  230 - 236  are electrically in circuit with capacitive change switching circuit  224  via flexible conductors  238  laterally dressed along the body portion  216  of the flexible PCB  214 . 
         [0035]    Referring to  FIG. 6 , the touch target faux rotary knob  170  can include a window  240  or indicia formed of clear or translucent material in the molding process. A light source, such as a light emitting diode  242  is preferably mounted on one of the PCBs behind the window  240  and in circuit with the switch circuit to controllably illuminate the window  240  from behind as illustrated by arrows  244 . Such illumination can be provided with all types of faux control members. 
         [0036]    The use of capacitive touch switch technology boosts operator interface options and allows the elimination of multiple mechanical switch devices with their inherent cost and complexity while enabling packaging of switch functionality in highly curvilinear packages. Furthermore, as described herein, capacitive touch switch technology can be employed to provide faux traditional mechanical switch configurations, without their inherent cost and complexity. 
         [0037]    It is to be understood that the invention has been described with reference to specific embodiments and variations to provide the features and advantages previously described and that the embodiments are susceptible of modification as will be apparent to those skilled in the art. 
         [0038]    Furthermore, it is contemplated that many alternative, common inexpensive materials can be employed to construct the basis constituent components. Accordingly, the forgoing is not to be construed in a limiting sense. 
         [0039]    The invention has been described in an illustrative manner, and it is to be understood that the terminology, which has been used is intended to be in the nature of words of description rather than of limitation. 
         [0040]    Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, wherein reference numerals are merely for illustrative purposes and convenience and are not in any way limiting, the invention, which is defined by the following claims as interpreted according to the principles of patent law, including the Doctrine of Equivalents, may be practiced otherwise than is specifically described.