Patent Publication Number: US-2021165298-A1

Title: Panel, display component, and method for controlling view angle of display component

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is based upon and claims priority to Chinese Patent Application 201911207314.8, filed on Nov. 29, 2019, the entirety of which is incorporated herein by reference. 
     TECHNICAL FIELD 
     The disclosure relates to the field of display, and particularly to a panel, a display component, and a method for controlling a view angle of a display component. 
     BACKGROUND 
     With wide application of smart terminal technologies, electronic products with display screens are more and more popular in daily lives. In order to protect privacy, when using an electronic product with a display screen at a densely populated public place, people do not want their private information displayed on the display screen to be seen by other people in the surrounding. 
     In the related art, a display screen of a mobile phone has a large view angle, resulting in that what is displayed on the display screen can be clearly seen even by people far away from the front side of the display screen. This is not favorable for protecting the privacy of the mobile phone user, since there is a risk of privacy leak. 
     SUMMARY 
     Provided in the disclosure are a panel, a display component, a terminal, a method for controlling a view angle of a display component, and a device for controlling a view angle of a display component. 
     According to a first aspect of the disclosure, a panel is provided. The panel includes: a first conductive layer that is transparent, a second conductive layer that is transparent, and a variable-refractive-index layer between the first conductive layer and the second conductive layer, wherein a refractive index of the variable-refractive-index layer varies in response to a change of a voltage applied between the first conductive layer and the second conductive layer. 
     According to a second aspect of the disclosure, provided is a display component including a display screen and the panel provided in any example of the disclosure. The panel is located on an outer surface of the display screen, and the display component has a view angle varying with a refractive index of the variable-refractive-index layer of the panel. 
     According to a third aspect of the disclosure, provided is a terminal, including: the display component provided in any example of the disclosure, and a processing module, connected with the display component and configured to control the voltage applied between the first and second conductive layers of the panel in the display component. 
     According to a fourth aspect of the disclosure, provided is a method for controlling a view angle of a display component, applied to the terminal according to any example of the disclosure, and the method including: determining a present display mode of the terminal; in response to the present display mode being a first display mode, applying a first voltage between the first conductive layer and the second conductive layer in the display component, to enable the variable-refractive-index layer between the first conductive layer and the second conductive layer to have a first refractive index, wherein the display component has a first view angle when the variable-refractive-index layer has the first refractive index. 
     According to a fifth aspect of the disclosure, provided is a terminal, including a memory, a processor and a computer program stored in the memory for running, wherein the computer program, when executed by the processor, implements the method for controlling a view angle of a display component according to any example of the disclosure. 
     It should be understood that the general description above and detailed description later are merely exemplary and explanatory, and are not intended to restrict the disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings herein are incorporated into the specification and constitute part of the present specification, illustrate examples consistent with the disclosure and are intended for explaining the principles of the disclosure together with the specification. 
         FIG. 1A  illustrates a schematic structural diagram of a glass panel applied to a display screen in the related art. 
         FIG. 1B  illustrates a schematic structural diagram of a panel according to an example. 
         FIG. 2  illustrates a schematic structural diagram of a panel according to another example. 
         FIG. 3  illustrates a schematic structural diagram of an optical transmission structure in a panel according to an example. 
         FIG. 4  illustrates a schematic diagram of optical paths of light rays in a panel according to an example. 
         FIG. 5  illustrates a schematic structural diagram of a panel according to another example. 
         FIG. 6  illustrates a schematic structural diagram of a panel according to another example. 
         FIG. 7  illustrates a schematic structural diagram of an optical transmission structure in a panel according to another example. 
         FIG. 8A  illustrates a schematic structural diagram of a display component according to an example. 
         FIG. 8B  illustrates a schematic diagram of determining a view angle according to an example. 
         FIG. 9A  illustrates a schematic structural diagram of a terminal according to an example. 
         FIG. 9B  illustrates a schematic structural diagram of a terminal according to an example. 
         FIG. 10  illustrates a schematic flowchart of a method for determining a view angle of a display component according to an example. 
         FIG. 11  illustrates a schematic structural diagram of a device for controlling a view angle of a display component according to an example. 
     
    
    
     DETAILED DESCRIPTION 
     Detailed description will be made here to examples, which are illustrated in the accompanying drawings. When drawings are involved in the following description, identical numerals in different drawings refer to identical or similar elements, unless otherwise indicated. Implementations described in the following examples do not mean all the implementations consistent with the disclosure. On the contrary, they are merely examples of devices and methods consistent with some aspects of the disclosure detailed in the appended claims. 
       FIG. 1A  illustrates a schematic structural diagram of a glass panel applied to a display screen in the related art. The glass panel  01  is attached to a display screen  02  of a terminal (for example a mobile phone). Light rays emitted from a light-emitting point “o” on the display screen  02  pass through the glass panel  01  and then are emergent from a surface of the glass panel  01 . A magnitude of a view angle corresponding to the light-emitting point “o” changes from original A to B, where A is greater than B. In this way, the glass panel  01  enables the view angle to be changed smaller so that information displayed at the light-emitting point “o” can only be seen by human eyes within a smaller range, thus obtaining a peep-proof effect. However, the following problem exists with such an implementation: firstly, the glass panel  01  can merely adjust the view angle in the single way, and the view angle cannot be adjusted flexibly; secondly, a user needs to repeatedly tear away and attach the glass panel  01  from/to the display screen  02  to adjust the view angle, which is troublesome in actual operation and may easily cause damage to the display screen  02 . 
       FIG. 1B  illustrates a schematic structural diagram of a panel according to an example. As illustrated in  FIG. 1B , the panel includes: a first conductive layer  11  that is transparent, a second conductive layer  12  that is transparent, and a variable-refractive-index layer  13  between the first conductive layer  11  and the second conductive layer  12 . 
     A refractive index of the variable-refractive-index layer  13  varies with a voltage applied between the first conductive layer  11  and the second conductive layer  12 . 
     Here, it may be the case where the variable-refractive-index layer  13  has a first refractive-index when a first voltage U 1  is applied between the first conductive layer  11  and the second conductive layer  12 , and the variable-refractive-index layer  13  has a second refractive-index when a second voltage U 2  is applied between the first conductive layer  11  and the second conductive layer  12 . Here, the first refractive-index may be greater than the second refractive-index when U 1  is greater than U 2 . 
     Here, the first conductive layer that is transparent is a first conductive layer through which light rays can pass, and the second conductive layer that is transparent is a second conductive layer through which light rays can pass. Here, the first conductive layer that is transparent and the second conductive layer that is transparent may be conductive layers, each having a light transmittance greater than a set threshold. 
     Here, the first conductive layer  11  may be a coating layer or a conductive film formed by applying a conductive material on the variable-refractive-index layer  13 . The second conductive layer  12  may be a coating layer or a conductive film formed by applying a conductive material on the variable-refractive-index layer  13 . The conductive material and the material of the film may be indium tin oxid (ITO). Here, the variable-refractive-index layer  13  may be fabricated by one of the following materials: potassium dihydrogen phosphate (KDP) crystal, lithium niobate (LiNbO3) crystal or gallium arsenide (GaAs) crystal. 
     Here, the incident light enters the panel at a position  1  with a corresponding incidence angle θ 1 . The variable-refractive-index layer  13  has the first refractive-index when the first voltage U 1  is applied between the first conductive layer  11  and the second conductive layer  12 . At this time, the refraction angle in the variable-refractive-index layer  13  is θ 2 . The incidence angle in the variable-refractive-index layer  13  is θ 4 , where θ 2 =θ 4 . The light ray is emergent at a position  2  with a corresponding refraction angle θ 5 , where θ 1 =θ 5 . 
     The variable-refractive-index layer  13  has the second refractive-index when the second voltage U 2  is applied between the first conductive layer  11  and the second conductive layer  12 . At this time, the refraction angle in the variable-refractive-index layer  13  is θ 3 . The incidence angle in the variable-refractive-index layer  13  is θ 6 , where θ 3 =θ 6 . The light ray is emergent at the position  3  with a corresponding refraction angle θ 7 , where θ 1 =θ 7 , 
     Here, after a same light ray enters the panel at the position  1 , when the second voltage U 2  is applied between the first conductive layer  11  and the second conductive layer  12 , the light ray entered at the position  1  can be seen by a human eye at a position  5 . If the first voltage U 1  is applied between the first conductive layer  11  and the second conductive layer  12 , the light ray entered at the position  1  can be seen merely by a human eye at a position  4  and cannot be seen by the human eye at the position  5 . It is to be noted that in order to make the schematic diagram more clear, the influence of the first conductive layer and the second conductive layer on the optical path is omitted in  FIG. 1B . 
     In examples of the disclosure, by applying a different voltage between the first conductive layer  11  and the second conductive layer  12  to change the refractive index of the refractive-index-variable layer  13 , the optical path of a light ray entering the panel at a same position can be changed, so that the emergent angle of the light ray leaving the panel is changed. As such, the view angle of a display screen of a terminal containing the panel can be changed. The requirement of providing different view angles in different application scenarios can be satisfied, and user experience can be promoted. 
       FIG. 2  illustrates a schematic structural diagram of a panel according to another example. As illustrated in  FIG. 2 , the variable-refractive-index layer  13  includes at least one optical transmission structure  14  between the first conductive layer  11  and the second conductive layer  12 . As shown in  FIG. 3 , the optical transmission structure  14  includes a core  15  and a cladding  16  attached to an outer surface of the core  15 , and the core  15  has a refractive index greater than a refractive index of the cladding  16 . 
     At least one of the refractive index of the core  15  or the refractive index of the cladding  16  varies with the voltage applied between the first conductive layer  11  and the second conductive layer  12 . 
     In this example, the refractive index of at least one of the core  15  and the cladding  16  of the optical transmission structure  14  is changed with the applied voltage, so that the refractive index of the entire variable-refractive-index layer  13  is changed. 
     Here, the cladding may be a coating layer or a film formed by applying a transparent material on an outer surface of the core  15 . Here, the core  15  and the cladding  16  may be fabricated by one of the following materials: potassium dihydrogen phosphate (KDP) crystal, lithium niobate (LiNbO3) crystal or gallium arsenide (GaAs) crystal. 
     Preferably, the optical transmission structure  14  may be fiber. 
     As shown in  FIG. 4 , in an example, the refractive index of the core  15  is n 1 , and the refractive index of the cladding  16  is n 2 , with n 1  being greater than n 2 . Here, n 1  being greater than nz enables light rays entering the core  15  to be totally reflected on a contact surface between the core  15  and the cladding  16 , thus reducing energy loss of the light rays. Here, the light rays enter at the position  6 . Here, the relation between the view angle α and θ 8  is: α/2≤180-2*θ 8 , where sin (θ 8 )=n 2 /n 1  (n 1 &gt;n 2 ). Here, θ 8  is the incidence angle of the light ray in the core  15  being incident onto the contact surface between the core  15  and the cladding  16 . 
     In an example, the core  15  is fabricated of a variable-refractive-index material, and the cladding  16  is fabricated of an invariable-refractive-index material. The refractive index of the core  15  varies with the voltage applied between the first conductive layer  11  and the second conductive layer  12 , and the refractive index of the cladding  16  is not changed. 
     In an example, the core  15  is fabricated of an invariable-refractive-index material, and the cladding  16  is fabricated of a variable-refractive-index material. The refractive index of the core  15  is not changed, and the refractive index of the cladding  16  varies with the voltage applied between the first conductive layer  11  and the second conductive layer  12 . As such, θ 8  can be changed by changing the refractive index of the core  15  or the refractive index of the cladding  16 , so as to obtain a different value for α. 
     In an example, the core  15  is fabricated of a variable-refractive-index material, and the cladding  16  is fabricated of a variable-refractive-index material. The refractive index of the core  15  and the refractive index of the cladding  16  vary with the voltage applied between the first conductive layer  11  and the second conductive layer  12 . 
     As shown in  FIG. 5 , in an example, the panel further includes a transformer  17  capable of outputting different voltages. 
     The transformer  17  is connected to the first conductive layer  11  and the second conductive layer  12  respectively. 
     For example, the transformer  17  has a first output and a second output. The first output is connected to the first conductive layer  11 , and the second output is connected to the second conductive layer  12 . One of the first output and the second output is a high voltage output, and the other one is a low voltage output. As such, a voltage difference is produced between the first conductive layer  11  and the second conductive layer  12 , so that a voltage of a certain magnitude is applied to the variable-refractive-index layer  13  between the first conductive layer  11  and the second conductive layer  12 . 
     Here, the transformer  17  can output a continuously variable voltage, for example, a voltage of any magnitude between 1 V to 20 V. The transformer  17  may also output discrete voltages, e.g., 1 V, 5 V and 10 V. Here, since the transformer is connected to the first conductive layer  11  and the second conductive layer  12  respectively, and different voltages can be output by the transformer  17 , different voltages can be applied between the first conductive layer  11  and the second conductive layer  12 . 
     The transformer  17  includes a primary coil  18  and a plurality of secondary coils  19 . 
     The panel further includes a shift switch  20  for controlling a subset of the secondary coils  19  to be coupled with the primary coil  18  through adjusting a switch state. Each subset of the secondary coils  19 , when being coupled with the primary coil  18 , causes a respective voltage applied between the first conductive layer  11  and the second conductive layer  12  by the transformer  17 . 
     In some examples, the primary coil may be coupled with one of the secondary coils. In some other examples, the secondary coils may also be coupled with multiple of the secondary coils at the same time. When the primary coil is coupled with multiple of the secondary coils, the voltage output by the transformer may be equal to the voltage of the primary coil. The multiple of the secondary coils may be combined to be coupled with the primary coil to output a transformed voltage. 
     As shown in  FIG. 6 , in an example, the transformer  17  includes a primary coil  18  and three secondary coils  19 . The three secondary coils are a first secondary coil, a second secondary coil and a third secondary coil. An input voltage between a terminal  6  and a terminal  7  of the secondary coil  18  is U 67 . Voltages output by the first secondary coil, the second secondary coil and the third secondary coil are U 13 , U 14  and U 15  respectively. The first secondary coil, the second secondary coil and the third secondary coil have a common terminal  1 , and the common terminal  1  is electrically connected to the first conductive layer  11 . A non-common terminal  1  of the first secondary coil is electrically connected to a terminal  3  of the shift switch  20 . A non-common terminal of the second secondary coil is electrically connected to the terminal  4  of the shift switch  20 . A non-common terminal of the third secondary coil is electrically connected to the terminal  5  of the shift switch  20 . A terminal  2  of the shift switch  20  is electrically connected to the second conductive layer  12 . The switch state includes one of the following: a first switch state in which the terminal  2  is connected to the terminal  3 , a second switch state in which the terminal  2  is connected to the terminal  4 , and a third switch state in which the terminal  2  is connected to the terminal  5 . Here, each of the switch states causes a respective voltage applied between the first conductive layer  11  and the second conductive layer  12 . For example, when the switch is in the first switch state, the voltage applied between the first conductive layer  11  and the second conductive layer  12  is U 13 . When the switch is in the second switch state, the voltage applied between the first conductive layer  11  and the second conductive layer  12  is U 14 . When the switch is in the third switch state, the voltage applied between the first conductive layer  11  and the second conductive layer  12  is U 15 . 
     It is to be noted that the transformer  17  may be arranged within the panel in this example. Alternatively, in this example, the panel may also be merely provided with an interface for connecting to the transformer  17 , and the transformer  17  can be arranged on another component (instead of the panel) of the terminal. 
     As shown in  FIG. 7 , a protective layer  21  formed of a transparent material is provided on an outer surface of the cladding  16 . Here, the cladding  16  may be a coating layer or a film formed by applying a transparent layer on an outer surface of the core  15 . The transparent material has a light transmittance greater than a third set threshold. The protective layer  21  can protect the cladding  16  from being damaged during manufacturing of the panel, which would affect reflection of light rays at a contact surface between the core  15  and the cladding  16 . 
       FIG. 8A  illustrates a schematic structural diagram of a display component according to an example. As illustrated in  FIG. 8A , the display component includes a display screen  22  and the panel  23  provided in any example of the disclosure. 
     The panel  23  is located on an outer surface of the display screen  22 . 
     The display component has a view angle varying with a refractive index of the variable-refractive-index layer of the panel. 
     In an example, when the variable-refractive-index layer have a first refractive index, the display component has a first view angle. When the variable-refractive-index layer has a second refractive index, the display component has a second view angle. The first view angle is smaller than the second view angle. 
     Here, the display screen may be a display screen of a mobile phone, a display screen of a computer, a display screen of a smart television, etc. Since the first view angle is smaller than the second view angle, the view angle within which the content displayed on the display screen  22  is visible can be reduced. In this way, it would be difficult for other people to peep the information displayed on the display screen  22 , so as to promote the security of the information. 
     In an example, as shown in  FIG. 8B , a light-emitting point on the display screen  22  may be taken as an origin to determine a plane passing through the origin and perpendicular to the display screen. After passing through the panel  23 , light rays from the light-emitting point will form a tapered illuminated area on the plane. The taper angle C of the cone may be determined as the view angle. In an example, the display component further includes a transparent protective glass  24 . 
     The panel  23  is located between the display screen  22  and the protective glass  24 . 
     The protective glass  24  can protect the panel  23  and the display screen  22  from being damaged. 
       FIG. 9A  illustrates a schematic structural diagram of a terminal according to an example. As illustrated in  FIG. 9A , the terminal includes the display component  25  provided in any example of the disclosure, and a processing module connected with the display component  25  and configured to control the voltage applied between the first and second conductive layers of the panel in the display component  25 . 
     The terminal may be a mobile phone, a computer, a smart television, etc. The processing module may be a mainboard or processor of the terminal. As shown in  FIG. 9B , the display component  25  may be inserted, via a plug  27 , into a socket  28  connected to the mainboard or processor  26  of the terminal. 
     The processing module may apply, according to an operation instruction of a user, a different voltage between the first conductive layer  11  and the second conductive layer  12  of the panel in the display component  25 , so that the refractive index of the variable-refractive-index layer  13  of the panel is changed, so as to adjust the view angle of the display component  25 . 
       FIG. 10  illustrates a schematic flowchart of a method for determining a view angle of a display component according to an example. As illustrated in  FIG. 10 , the method is applied to the terminal according to any example of the disclosure. The method includes the following steps. 
     At step  101 , a present display mode of the terminal is determined. 
     The present display mode may be one selected from multiple selectable display modes at present. The display component has different view angles in different display modes. 
     The terminal has two or more display modes. In the examples of the disclosure, the first display mode and the second display mode merely refer to any two different display modes in general. 
     For example, in a display mode, the display component has a view angle of 30°, and in another display mode, the display component has a view angle of 45°. For example, if a user selects, on a setting interface displayed on a display screen of a terminal, a setting option of a display mode with a view angle of 45°, then the present display mode of the terminal is the display mode with the view angle of 45°. Since the display component has a view angle of 45° in this display mode, the user can only see information displayed on the display screen of the terminal within the view angle of 45°. 
     At step  102 , in response to the present display mode being a first display mode, a first voltage is applied between the first conductive layer  11  and the second conductive layer  12  in the display component, to enable the refractive-index-variable layer between the first conductive layer  11  and the second conductive layer  12  to have a first refractive index. The display component has a first view angle with the first refractive index of the refractive-index-variable layer. 
     In an example, in response to the present display mode being the first display mode, the first voltage is applied between the first conductive layer  11  and the second conductive layer  12  in the display component, to enable the variable-refractive-index layer between the first conductive layer  11  and the second conductive layer  12  to have the first refractive index. In response to the present display mode being a second display mode, a second voltage is applied between the first conductive layer  11  and the second conductive layer  12  in the display component, to enable the refractive-index-variable layer between the first conductive layer  11  and the second conductive layer  12  to have a second refractive index. The display component has a first view angle with the first refractive index of the refractive-index-variable layer. The display component has a second view angle with the second refractive index of the variable-refractive-index layer. The first view angle is smaller than the second view angle. When the voltage applied between the first conductive layer  11  and the second conductive layer  12  is changed from the second voltage to the first voltage, the view angle is changed from the second view angle to the first view angle, thus reducing the view angle. 
     According to different display modes, different voltages are applied between the first conductive layer  11  and the second conductive layer  12  in the display component. This will change the view angle of the display component, so that a human eye can only see information displayed in the display component within partial region (within the view angle) in front of the display component, facilitating protecting privacy. 
     In an example, the terminal is further provided with a transformer. The method further includes the following step. 
     At step  103 , an output voltage of the transformer  17  is controlled according to the present display mode. The output voltage of the transformer  17  is applied between the first conductive layer  11  and the second conductive layer  12 . 
     Here, the transformer  17  may be controlled to output a continuously variable voltage. As such, the magnitude of the view angle may also be continuously variable, and the control over the view angle is more exquisite. For example, if the transformer  17  is controlled to output a voltage continuously variable in a range from 5 V to 10 V, the view angle may be continuously variable in a range from 30° to 60°. 
     Here, the transformer  17  may also be controlled to output discrete voltages, so that the magnitude of the view angle may be changed among different discrete values. For example, if the transformer  17  is controlled to output voltages 5 V, 7.5 V and 10 V, the view angles may be 30°, 45° and 60° correspondingly. 
     In step  103 , the operation of controlling the output voltage of the transformer  17  according to the present display mode includes the following step: 
     At step  104 , according to the present display mode, a subset of the secondary coils  19  in the transformer  17  is controlled to be coupled with the primary coil  18 , through adjusting a switch state of a shift switch  20 . Each subset of the secondary coils  19 , when being coupled with the primary coil  18 , causes a respective voltage applied between the first conductive layer  11  and the second conductive layer  12  by the transformer  17 . 
     The transformer  17  may include a plurality of secondary coils  19 . Each of the secondary coils  19  outputs a respective voltage. For example, the first secondary coil correspondingly outputs a voltage of 5V. The second secondary coil correspondingly outputs a voltage of 7.5V. The third secondary coil correspondingly outputs a voltage of 10V. The state of the switch may be a state in which the shift switch  20  connects the first conductive layer  11  and the second conductive layer  12  to one of the secondary coils  19 . Here, when the first conductive layer  11  and the second conductive layer  12  are connected to the first secondary coil, a voltage of 5 V is applied between the first conductive layer  11  and the second conductive layer  12 . 
       FIG. 11  illustrates a schematic structural diagram of a device for controlling a view angle of a display component according to an example. As illustrated in  FIG. 11 , the device for controlling a view angle of a display component is applied to the terminal according to any example of the disclosure. The device includes a determination module  111  and a processing module  112 . 
     The determination module  111  is configured to determine a present display mode of the terminal. 
     The processing module  112  is configured to: in response to the present display mode being a first display mode, apply a first voltage between the first conductive layer and the second conductive layer in the display component, to enable the variable-refractive-index layer between the first conductive layer and the second conductive layer to have a first refractive index; and in response to the present display mode being a second display mode, apply a second voltage between the first conductive layer and the second conductive layer in the display component, to enable the refractive-index-variable layer between the first conductive layer and the second conductive layer to have a second refractive index. The display component has a first view angle with the first refractive index of the refractive-index-variable layer. The display component has a second view angle with the second refractive index of the variable-refractive-index layer. The first view angle is smaller than the second view angle. 
     In an example, the device further includes a control module  113 . The control module  113  is configured to control an output voltage of the transformer according to the present display mode. The output voltage of the transformer is applied between the first conductive layer and the second conductive layer. 
     In an example, the control module  113  is further configured to control, according to the present display mode, a subset of the secondary coils in the transformer to be coupled with the primary coil, through adjusting a switch state of a shift switch. Each subset of the secondary coils, when being coupled with the primary coil, causes a respective voltage applied between the first conductive layer and the second conductive layer by the transformer. 
     Further provided in examples of the disclosure is a terminal, including a memory, a processor and a computer program stored in the memory for running. The computer program, when executed by the processor, implements the method for controlling a view angle of a display component according to any example of the disclosure. 
     The technical solution provided in the examples of the disclosure may have the following beneficial effects: 
     In the examples of the disclosure, the panel includes a first conductive layer that is transparent; a second conductive layer that is transparent, wherein light rays can enter through the first conductive layer and the second conductive; and a refractive-index-variable layer between the first conductive layer and the second conductive layer. A refractive index of the variable-refractive-index layer varies with a voltage applied between the first conductive layer and the second conductive layer. Here, by applying a different voltage between the first conductive layer and the second conductive layer to change the refractive index of the refractive-index-variable layer, the optical path of a light ray entering the panel through a same position can be changed, so that the emergent angle of the light ray leaving the panel is changed. As such, the view angle of a display screen of a terminal (for example, a display screen of a mobile phone) containing the panel can be changed. The requirement of providing different view angles in different application scenarios can be satisfied, and user experience can be promoted. 
     Other examples of the disclosure would readily occur to those skilled in the art when considering the specification and practicing the disclosure here. The disclosure is aimed at covering any variants, usages or adaptive changes that comply with generic principles of the disclosure and include common knowledge or customary technical means in the art that is not disclosed in the disclosure. The specification and examples are merely considered exemplary, and the true scope and spirit of the disclosure are specified by the appended claims. 
     It should be understood that the disclosure is not limited to the precise structures described above and illustrated in the accompanying drawings, and modifications and changes may be made thereto without departing from the scope thereof. The scope of the disclosure is merely defined by the appended claims.