Abstract:
Alternating touchscreen conductors in each layer of a touchscreen display are connected to separate touchscreen controllers. Each controller completely and separately resolves a location anywhere on the display so that a failure of either controller, or the failure of conductors connected to either controller, do not degrade touchscreen usability. Conductors in separate layers, connected to separate controllers may be isolated via insulators to prevent undesirable shorts. Conductors are shaped to minimize the area covered by insulators and maximize the area of useful conductor overlap.

Description:
BACKGROUND 
     Digital touchscreens are being adopted for avionics displays. For avionics applications where a touchscreen is the sole source of pilot control for critical functions, failure of the touchscreen may be catastrophic. A single point of failure can cause the entire touchscreen to become unusable. Separate touchscreens may cover separate portions of a display; however, each touchscreen is still susceptible to a single point of failure, and a failure of either touchscreen renders a portion of the display unusable. Such failure may affect operator proficiency even though the display is not completely disabled. 
     SUMMARY 
     In one aspect, embodiments of the inventive concepts disclosed herein are directed to a novel apparatus for providing redundant touchscreen controls without a single point of failure. 
     In a further aspect, embodiments of the inventive concepts are directed to alternating touchscreen conductors in each layer of a touchscreen display connected to separate touchscreen controllers. Each touchscreen controller completely and separately resolves a location anywhere on the display. Conductors in separate layers, connected to separate touchscreen controllers may be isolated via insulators. 
     In a further aspect, conductors are shaped to minimize the area covered by insulators and maximize the area of useful conductor overlap. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and should not restrict the scope of the claims. The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate exemplary embodiments of the inventive concepts disclosed herein and together with the general description, serve to explain the principles. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The numerous advantages of the embodiments of the inventive concepts disclosed herein may be better understood by those skilled in the art by reference to the accompanying figures in which: 
         FIG. 1  shows a block diagram of a system for utilizing a touch sensitive display according to one embodiment of the inventive concepts disclosed herein; 
         FIG. 2  shows an environmental view of an aircraft cockpit including one embodiment of the inventive concepts disclosed herein; 
         FIG. 3  shows a block diagram of a touch sensitive overlay according to embodiments of the inventive concepts disclosed herein; 
         FIG. 4  shows a block diagram of a touch sensitive overlay according to embodiments of the inventive concepts disclosed herein; 
         FIG. 5  shows a perspective, exploded view of a touch sensitive film according to embodiments of the inventive concepts disclosed herein; 
         FIG. 6  shows a top, diagrammatic view of a touch sensitive film according to embodiments of the inventive concepts disclosed herein; 
         FIG. 7  shows a side, exploded view of a touch sensitive film according to embodiments of the inventive concepts disclosed herein; 
         FIG. 8  shows a top, diagrammatic view of a touch sensitive film according to embodiments of the inventive concepts disclosed herein; 
         FIG. 9  shows a top view of a layer of a touch sensitive overlay according to embodiments of the inventive concepts disclosed herein; 
         FIG. 10  shows a top view of a layer of a touch sensitive overlay according to embodiments of the inventive concepts disclosed herein; 
         FIG. 11  shows a top view of a touch sensitive film according to embodiments of the inventive concepts disclosed herein; 
         FIG. 12  shows a side view of a touch sensitive film according to embodiments of the inventive concepts disclosed herein; 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to the subject matter disclosed, which is illustrated in the accompanying drawings. The scope of the inventive concepts disclosed herein is limited only by the claims; numerous alternatives, modifications and equivalents are encompassed. For the purpose of clarity, technical material that is known in the technical fields related to the embodiments has not been described in detail to avoid unnecessarily obscuring the description. 
     Referring to  FIG. 1 , a block diagram of a touch sensitive display system  100  according to one embodiment of the inventive concepts disclosed herein is shown. The system  100  includes one or more processors  102 , a memory  104  connected to the processor  102 , and a display  106  and touchscreen  108  connected to the processor  102 . 
     The one or more processors  102  may be implemented as special purpose hardware processor or general purpose processors and are configured to execute processor-executable code stored in the memory  104  to carry out the functionality described herein. The memory  104  may be implemented as any type of persistent or volatile data storage element and stores data and processor-executable code. 
     The system includes a touch sensitive film  108  corresponding to the display  106 . The touch sensitive film  108  is connected to a touchscreen controller  110 , the touchscreen controller  110  connected to the one or more processors  102 . 
     In one embodiment, the touchscreen controller  110  receives signals from two or more separate conductor networks within the touch sensitive overlay  108  as described herein. In one embodiment, the touchscreen controller  110  may correlate signals from each of the two or more separate conductor networks to precisely resolve a location on the touch sensitive overlay. In another embodiment, the touchscreen controller  110  correlates signals from each of the two or more separate conductor networks over time to determine if one of the two or more conductor networks is producing a faulty signal and discards the location signal produced by the faulty network. In another embodiment, where a touchscreen controller  110  associated with one of the two or more conductor networks fails, separate touchscreen controllers  110  continues to resolve locations across the entire surface of the touch sensitive overlay  108  via the remaining conductor networks. 
     Referring to  FIG. 2 , an environmental view of an aircraft cockpit including one embodiment of the inventive concepts disclosed herein is shown. Embodiments of a system such as in  FIG. 1  may be incorporated into vehicles such as an aircraft avionics system. An aircraft display  206  with a corresponding redundant touch sensitive overlay  208  as more fully defined herein. 
     Referring to  FIG. 3 , a block diagram of a touch sensitive overlay according to embodiments of the inventive concepts disclosed herein is shown. A touch sensitive film  308  comprises a first set of horizontal conductors  304  and a second set of horizontal conductors  305 ; and a first set of vertical conductors  306  and a second set of vertical conductors  307 . The first set of horizontal conductors  304  is isolated from the second set of horizontal conductors  305 ; likewise, the first set of vertical conductors  306  is isolated from the second set of vertical conductors  307 . The first set of horizontal conductors  304  and first set of vertical conductors  306  comprise a first conductor network. The second set of horizontal conductors  305  and second set of vertical conductors  307  comprise a second conductor network. 
     In one embodiment, the processor  302  receives signals from two or more separate touchscreen controllers  310  and  312 , each connected to a conductor network within the touch sensitive film  308  as described herein. In one embodiment, the processor  302  may correlate signals from each of the two or more separate touchscreen controllers  310  and  312  to precisely resolve a location on the touch sensitive overlay. In another embodiment, the processor  302  correlates signals from each of the two or more separate touchscreen controllers  310  and  312  over time to determine if one of the two or more touchscreen controllers  310  and  312  is producing a faulty signal and discards the location signal produced by the faulty touchscreen controllers  310  and  312 . In another embodiment, each touchscreen controller  310  and  312  may determine its own veracity, either with reference to another touchscreen controller  310  and  312  or by monitoring signals from the corresponding conductor network over time, and self-report a faulty conductor network to the processor  302 . 
     The first set of horizontal conductors  304  and second set of horizontal conductors  305  are interleaved. In one embodiment, the horizontal conductors  304  and  305  are interleaved such that no two horizontal conductors  304  in the first set of horizontal conductors  304  are directly adjacent and no two horizontal conductors  305  in the second set of horizontal conductors  305  are directly adjacent. Generally, each horizontal conductor  304  in the first set of horizontal conductors  304  is bounded by horizontal conductors  305  in the second set of horizontal conductors  305  in a plane defined by the film containing the horizontal conductors  304  and  305 . In other embodiments, horizontal conductors  304  and  305  are interleaved in groups such that clusters of horizontal conductors  304  in the first set of horizontal conductors  304  are adjacent and horizontal conductors  305  in the second set of horizontal conductors  305  are also adjacent. 
     Likewise, the first set of vertical conductors  306  and second set of vertical conductors  307  are interleaved. In one embodiment, the vertical conductors  306  and  307  are interleaved such that no two vertical conductors  306  in the first set of vertical conductors  306  are directly adjacent and no two vertical conductors  307  in the second set of vertical conductors  307  are directly adjacent. Generally, each vertical conductor  306  in the first set of vertical conductors  306  is bounded by vertical conductors  307  in the second set of vertical conductors  307  in a plane defined by the film containing the vertical conductors  306  and  307 . In other embodiments, vertical conductors  306  and  307  are interleaved in groups such that clusters of vertical conductors  306  in the first set of vertical conductors  306  are adjacent and vertical conductors  307  in the second set of vertical conductors  307  are also adjacent. 
     In one embodiment, the first set of horizontal conductors  304  and the first set of vertical conductors  306  are connected to a first touchscreen controller  310  while the second set of horizontal conductors  305  and the second set of vertical conductors  307  are connected to a second touchscreen controller  312 . Each of the first touchscreen controller  310  and the second touchscreen controller  312  separately resolves a location on the touch sensitive film  308  and sends the resolved location to a computer processor  302 . The computer processor  302  may utilize the separate resolved locations to define an accurate single location corresponding to a user input. The computer processor  302  compares the resolved locations from the first touchscreen controller  310  and second touchscreen controller  312  to detect differences. If differences are present, the processor  302  may averages the two resolved locations to improve accuracy. 
     While embodiments discussed herein describe and show two separate conductor networks connected to either a single touchscreen controller  310  and  312  or each connected to a separate touchscreen controller  310  and  312 , any number of conductor networks and touchscreen controllers  310  and  312  could be utilized. For example, three conductor networks could each be connected to one of three touchscreen controllers  310  and  312 , the three conductor networks at least partially interleaved as more fully defined herein. In such an embodiment, or any embodiment utilizing a plurality of touchscreen controllers  310  and  312 , the touchscreen controllers  310  and  312  or processor  302  connected to the touchscreen controllers  310  and  312  may also utilize a voting algorithm to determine the most accurate resolved location. 
     Further, the computer processor  302  may compare the separate resolved locations to analyze the functionality of the first touchscreen controller  310  and second touchscreen controller  312 . Upon identifying a fault, the computer processor  302  may disregard data from either the first touchscreen controller  310  or the second touchscreen controller  312  and still resolve a location anywhere on the touch sensitive film  308 . In one embodiment, the computer processor  302  utilizes a voting methodology to determine which of the first touchscreen controller  310  and second touchscreen controller  312  is accurate if an unknown fault is identified. 
     In another embodiment, a single touchscreen controller  310  is connected to all of the horizontal conductors  304  and  305  and vertical conductors  306  and  307 . In such an embodiment, the touchscreen controller  310  can resolve a location anywhere on the touch sensitive film  308  even when damage to the touch sensitive film  308  renders either the first conductor network or second conductor network inoperative. 
     Referring to  FIG. 4 , a block diagram of a touch sensitive overlay according to embodiments of the inventive concepts disclosed herein is shown. A touch sensitive film  408  comprises a first set of horizontal conductors  404  and a second set of horizontal conductors  405 ; and a first set of vertical conductors  406  and a second set of vertical conductors  407 . The first set of horizontal conductors  404  is isolated from the second set of horizontal conductors  405 ; likewise, the first set of vertical conductors  406  is isolated from the second set of vertical conductors  407 . The first set of horizontal conductors  404  and first set of vertical conductors  406  comprise a first conductor network. The second set of horizontal conductors  405  and second set of vertical conductors  407  comprise a second conductor network. 
     The first set of horizontal conductors  404  and second set of horizontal conductors  405  are interleaved such that no two horizontal conductors  404  in the first set of horizontal conductors  404  are directly adjacent and no two horizontal conductors  405  in the second set of horizontal conductors  405  are directly adjacent. Generally, each horizontal conductor  404  in the first set of horizontal conductors  404  is bounded by horizontal conductors  405  in the second set of horizontal conductors  405  in a plane defined by the film containing the horizontal conductors  404  and  405 . 
     Likewise, the first set of vertical conductors  406  and second set of vertical conductors  407  are interleaved such that no two vertical conductors  406  in the first set of vertical conductors  406  are directly adjacent and no two vertical conductors  407  in the second set of vertical conductors  407  are directly adjacent. Generally, each vertical conductor  406  in the first set of vertical conductors  406  is bounded by vertical conductors  407  in the second set of vertical conductors  407  in a plane defined by the film containing the vertical conductors  406  and  407 . 
     A single touchscreen controller  410  is connected to all of the horizontal conductors  404  and  405  and vertical conductors  406  and  407 . In such an embodiment, the touchscreen controller  410  can resolve a location anywhere on the touch sensitive film  408  even when damage to the touch sensitive film  408  renders either the first conductor network or second conductor network inoperative. 
     Referring to  FIGS. 5, 6, and 7 , a perspective exploded view of a touch sensitive film, a top diagrammatic view of a touch sensitive film, and a side exploded view of a touch sensitive film according to embodiments of the inventive concepts disclosed herein are shown. The touch sensitive film  508  comprises a top layer  500  generally configured to receive a user input, and a bottom layer  502  generally proximal to a display. One of the top layer  500  or bottom layer  502  includes a first set of horizontal conductors  504  and a second set of horizontal conductors  505  while the other layer includes a first set of vertical conductors  506  and a second set of vertical conductors  507  orthogonal to the first set of horizontal conductors  504  and second set of horizontal conductors  505 . The first set of horizontal conductors  504  and second set of horizontal conductors  505  are interleaved. Likewise, the first set of vertical conductors  506  and second set of vertical conductors  507  are also interleaved. 
     The horizontal conductors  504  and  505  and vertical conductors  506  and  507  are separated by a gap to prevent contact between the horizontal conductors  504  and  505  and vertical conductors  506  and  507  until a pressure is applied to the top layer  500 . When pressure is applied a contact is made between certain horizontal conductors  504  and  505  and certain vertical conductors  506  and  507 ; one or more touchscreen controllers can resolve such contact into one or more specific locations on the touch sensitive film  508 . 
     In some embodiments, contact between horizontal conductors  504  in the first set of horizontal conductors  504  and vertical conductors  507  in the second set of vertical conductors  507  is undesirable; similarly, contact between horizontal conductors  505  in the second set of horizontal conductors  505  and vertical conductors  506  in the first set of vertical conductors  506  is also undesirable. Insulating elements  514  may be disposed between certain horizontal conductors  504  and  505  and certain vertical conductors  506  and  507  to prevent such undesirable contact. Insulating elements  514  may be applied to portions of the horizontal conductors  504  and  505  or vertical conductors  506  and  507 ; alternatively, the insulating elements  514  may comprise an insulating film layer with cutouts where contact is desirable, or a film layer mesh connecting individual insulating elements  514 . 
     The first set of horizontal conductors  504  and the first set of vertical conductors  506  comprise a first conductor network. The second set of horizontal conductors  505  and the second set of vertical conductors  507  comprise a second conductor network. The first conductor network is connected to a touch sensitive controller via a first set of wires  510  while the second conductor network is connected to a touch sensitive controller via a second set of wires  512 . In one embodiment, the first set of wires  510  and second set of wires  512  are directed toward opposing edges of their respective layers  500  and  502  to prevent undesirable crossover between wires  510  and  512 . 
     Referring to  FIG. 8 , a top, diagrammatic view of a touch sensitive film according to embodiments of the inventive concepts disclosed herein is shown. The touch sensitive film  808  comprises a top layer  800  generally configured to receive a user input, and a bottom layer  802  generally proximal to a display. One of the top layer  800  or bottom layer  802  includes a first set of horizontal conductors  804  and a second set of horizontal conductors  805  while the other layer includes a first set of vertical conductors  806  and a second set of vertical conductors  807  orthogonal to the first set of horizontal conductors  804  and second set of horizontal conductors  805 . The first set of horizontal conductors  804  and second set of horizontal conductors  805  are interleaved in a regular pattern wherein at least two horizontal conductors  804  in the first set of horizontal conductors  804  are directly adjacent and at least two horizontal conductors  805  in the second set of horizontal conductors  805  are directly adjacent. Likewise, the first set of vertical conductors  806  and second set of vertical conductors  807  are also interleaved in a regular pattern wherein at least two vertical conductors  806  in the first set of vertical conductors  806  are directly adjacent and at least two vertical conductors  807  in the second set of vertical conductors  807  are directly adjacent. 
     The horizontal conductors  804  and  805  and vertical conductors  806  and  807  are separated by a gap to prevent contact between the horizontal conductors  804  and  805  and vertical conductors  806  and  807  until a pressure is applied to the top layer  800 . When pressure is applied a contact is made between certain horizontal conductors  804  and  805  and certain vertical conductors  806  and  807 ; one or more touchscreen controllers can resolve such contact into one or more specific locations on the touch sensitive film  808 . 
     Insulating elements  814  may be disposed between certain horizontal conductors  804  and  805  and certain vertical conductors  806  and  807  to prevent undesirable contact. Insulating elements  814  may be applied to portions of the horizontal conductors  804  and  805  or vertical conductors  806  and  807 ; alternatively, the insulating elements  814  may comprise an insulating film layer with cutouts where contact is desirable, or a film layer mesh connecting individual insulating elements  814 . 
     The first set of horizontal conductors  804  and the first set of vertical conductors  806  comprise a first conductor network. The second set of horizontal conductors  805  and the second set of vertical conductors  807  comprise a second conductor network. The first conductor network is connected to a touch sensitive controller via a first set of wires  810  while the second conductor network is connected to a touch sensitive controller via a second set of wires  812 . In one embodiment, the first set of wires  810  and second set of wires  812  are directed toward opposing edges of their respective layers  800  and  802  to prevent undesirable crossover between wires  810  and  812 . 
     While exemplary embodiments described herein refer to conductor networks where horizontal conductors  804  and  805  are directly interleaved, or interleaved in a regular pattern, such embodiments should not be considered limiting. A combination of different interleaving patterns may be employed, or a generally irregular interleaving pattern provided the resulting touch sensitive film  808  comprises two or more separate conductor networks that may each resolve a location on the touch sensitive film  808 . 
     Referring to  FIG. 9 , a top view of a layer  900  of a touch sensitive overlay according to embodiments of the inventive concepts disclosed herein is shown. The layer  900  includes a first set of horizontal conductors  904  and a second set of horizontal conductors  905 . Each horizontal conductor  904  and  905  comprises enlarged portions  916  to facilitate contact with vertical conductors in a separate layer where such contact is desirable and minimize contact area with vertical conductors in a separate layer where such contact is undesirable. In one embodiment, the enlarged portions  916  are generally rhomboid but other shapes are envisioned. 
     Referring to  FIG. 10 , a top view of a layer  1002  of a touch sensitive overlay according to embodiments of the inventive concepts disclosed herein. The layer  1002  includes a first set of vertical conductors  1006  and a second set of vertical conductors  1007 . Each vertical conductor  1006  and  1007  comprises enlarged portions  1016  to facilitate contact with horizontal conductors in a separate layer where such contact is desirable and minimize contact area with horizontal conductors in a separate layer where such contact is undesirable. In locations along the vertical conductors  1006  and  1007  where contact is undesirable, insulating elements  1014  are applied to those locations on the vertical conductors  1006  and  1007 , or form a separate film between the layer  1002  and a corresponding separate layer of horizontal conductors. Vertical conductors  1006  and  1007  having enlarged portions  1016  where contact is desirable and minimized portions where contact is undesirable allow for insulating elements having a smaller foot print as compared to vertical conductors  1006  and  1007  without enlarged portions  1016 . 
     Referring to  FIGS. 11 and 12 , a top view of a touch sensitive film  1108  and a side view of a touch sensitive film  1108  according to embodiments of the inventive concepts disclosed herein are shown. A first layer  1100  includes a first set of horizontal conductors  1104  and a second set of horizontal conductors  1105 . Each horizontal conductor  1104  and  1105  comprises enlarged portions  1116  to facilitate contact with vertical conductors  1106  and  1107  in a second layer  1102  where such contact is desirable and minimize contact area with vertical conductors  1106  and  1107  in the second layer  1102  where such contact is undesirable. 
     The second layer  1102  includes a first set of vertical conductors  1106  and a second set of vertical conductors  1107 . Each vertical conductor  1106  and  1107  comprises enlarged portions  1116  to facilitate contact with the horizontal conductors  1104  and  1105  in the first layer  1100  where such contact is desirable and minimize contact area with horizontal conductors  1104  and  1105  in the first layer  1100  where such contact is undesirable. In locations along the vertical conductors  1106  and  1107  where contact is undesirable, insulating elements  1114  are applied to those locations on the vertical conductors  1106  and  1107 , or form a separate film between the first layer  1100  and second layer  1102 . Vertical conductors  1106  and  1107  and horizontal conductors  1104  and  1105  having enlarged portions  1116  where contact is desirable and minimized portions where contact is undesirable allow for insulating elements having a smaller foot print. 
     Further, resistive changes in conductors having enlarged portions  1116  have a discrete step nature. Contact in different areas of the enlarged portion  1116  may produce distinct, detectable voltage differences that could be used to further refine the location data produced by the corresponding touchscreen controller and minimize touchscreen calibration. 
     The first set of horizontal conductors  1104  and the first set of vertical conductors  1106  comprise a first conductor network. The second set of horizontal conductors  1105  and the second set of vertical conductors  1107  comprise a second conductor network. The first conductor network is connected to a touch sensitive controller via a first set of wires  1110  while the second conductor network is connected to a touch sensitive controller via a second set of wires  1112 . In one embodiment, the first set of wires  1110  and second set of wires  1112  are directed toward opposing edges of their respective layers  1100  and  1102  to prevent undesirable crossover between wires  1110  and  1112 . While the locations shown in  FIG. 11  are the upper right and lower left respectively, other locations are envisioned provided electrical isolation is maintained. 
     It is believed that the inventive concepts disclosed herein and many of their attendant advantages will be understood by the foregoing description of embodiments of the inventive concepts disclosed, and it will be apparent that various changes may be made in the form, construction, and arrangement of the components thereof without departing from the broad scope of the inventive concepts disclosed herein or without sacrificing all of their material advantages. The form herein before described being merely an explanatory embodiment thereof, it is the intention of the following claims to encompass and include such changes.