Abstract:
Connectors having contact structures that may generate a low amount of EMI outside of an electronic device housing the connector structure, may further provide isolation from EMI present outside of the electronic device, and reduce the chance of a user or user&#39;s property encountering a power supply on an exposed contact.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
       [0001]    This application is a nonprovisional of U.S. provisional patent application No. 62/215,561, filed Sep. 8, 2015, which is incorporated by reference. 
     
    
     BACKGROUND 
       [0002]    The number of types of electronic devices that are commercially available has increased tremendously the past few years and the rate of introduction of new devices shows no signs of abating. Devices, such as tablet, laptop, netbook, desktop, and all-in-one computers, cell, smart, and media phones, storage devices, portable media players, navigation systems, monitors, and others, have become ubiquitous. 
         [0003]    Power and data may be provided from one device to another over cables that may include one or more wire conductors, fiber optic cables, or other conductor. Connector inserts may be located at each end of these cables and may be inserted into connector receptacles in the communicating or power transferring devices. In other systems, contacts on the devices may come into direct contact with each other without the need for intervening cables. 
         [0004]    When an electronic device is not connected to a remote device, one or more signals may be present at a connector receptacle or other connector structure on the electronic device. These signals may be high speed signals having high-frequency components. These high-frequency components can generate electromagnetic interference (EMI) that may interfere with other nearby or associated electronic devices. 
         [0005]    Also, when an electronic device is not connected to a remote device, one or more sensitive signals or voltages may be present on one or more of the contacts. EMI from nearby or associated electronic devices may couple onto the contacts conveying these sensitive signals, thereby degrading device performance. 
         [0006]    Further, when an electronic device is not connected to a remote device, one or more power supply voltages may be present on one or more of the contacts. These voltages may inadvertently make contact with a user or user&#39;s property. 
         [0007]    Thus, what is needed are connectors having contact structures that may generate a low amount of EMI outside of an electronic device housing the connector structure, may further provide isolation from EMI present outside of the electronic device, and reduce the chance of a user or user&#39;s property encountering a power supply voltage on an exposed contact. 
       SUMMARY 
       [0008]    Accordingly, embodiments of the present invention may provide connectors having contact structures that may generate a low amount of EMI outside of an electronic device housing the connector structure, may further provide isolation from EMI present outside of the electronic device, and reduce the chance of a user or user&#39;s property encountering a power supply voltage on an exposed contact. 
         [0009]    An illustrative embodiment of the present invention may provide contact structure that is an apparatus for a surface contact. The surface contact may be located at a surface of a housing or enclosure for an electronic device such that a surface of the surface contact is substantially flush with the surrounding device housing, where the surface of the surface contact may be substantially flat or may be curved or have other type of surface. The surface contact may be insulated from the enclosure by a nonconducting material between the surface contact and the enclosure, or the enclosure may be nonconducting. This arrangement may limit or prevent the ingress of liquids or debris into the electronic device. The surface contact may be connected to a first terminal of a multiplexer. The multiplexer may be arranged to couple the first terminal of the multiplexer to a second terminal of the multiplexer, the second terminal connected to an input or output circuit, or both. The input and output circuits may convey signals, power supply voltages, or other signals of voltages. The multiplexer may be further arranged to couple the first terminal of the multiplexer to a third terminal of the multiplexer, the third terminal connected to ground. 
         [0010]    When the connector that includes this surface contact apparatus is connected to a corresponding connector on a second device, the multiplexer may be arranged to couple the first terminal of the multiplexer to the second terminal of the multiplexer. The second terminal may be connected to an input or output circuit, or both. A signal or voltage provided by the electronic device that includes the surface contact may pass through the multiplexer and surface-mount contact and be received by the connected device. A signal received by the electronic device that includes the surface contact may pass through the surface-mount contact and multiplexer and be received by the electronic device. When the connector that includes this surface contact apparatus is not connected to a corresponding connector on a second device, the multiplexer may be arranged to couple the first terminal of the multiplexer to the third terminal of the multiplexer. The third terminal may be connected to ground. This may ground the surface contact. By grounding the contact, EMI that may otherwise be generated at an outside of the electronic device may be reduced. Also, sensitive signals or voltages may be protected from EMI present at the outside of the electronic device. Further, power supply voltages may be prevented from being provided to exposed contacts, where they may encounter a user or a user&#39;s property. 
         [0011]    In various embodiments of the present invention, the multiplexer may be formed in various ways. For example, it may be formed as two series switches, with a first switch connected between the first and second terminal and a second switch connected between the first and third terminals. These switches may be transistors, micro-electronic machines, relays, or other types of switches. 
         [0012]    In various embodiments of the present invention, the electronic device housing the surface contact apparatus may detect the presence of a connection to a second device in various ways. Accordingly, these switches may be under control of a microcontroller, central processing unit (CPU), or other appropriate logic circuit. For example, a CPU may receive information that a connection to a second device has been made. In response, the CPU may instruct the multiplexer to connect its first terminal to its second terminal. In other embodiments of the present invention, a proximity detector, such as a Hall-effect device, may be used to control the multiplexer. Specifically, when a Hall-effect device detects a presence of accessory  120 , the Hall-effect device may instruct the multiplexer to connect its first terminal to its second terminal. When the connected device is removed, the CPU or Hall-effect device may instruct the multiplexer to connect its first terminal to its third terminal, thereby grounding the surface contact and preventing or reducing EMI. 
         [0013]    Instead of using an electronic multiplexer, embodiments of the present invention may employ a physical multiplexer. An illustrative embodiment of the present invention may provide an electronic device in an enclosure. Surface contacts may be located at a surface of the enclosure. The electronic device may further include a main logic board having a second contact. This second contact may be electrically connected to traces and circuits on the main logic board. These circuits may receive signals or other voltages, or provide signals or other voltages, or both. The surface contacts may be held in place at the surface of the device by springs or other compressible structures. This arrangement may limit or prevent the ingress of liquids or debris into the electronic device. When the electronic device is not connected, the surface contacts may be electrically connected to an enclosure of the electronic device. The enclosure may be grounded, and accordingly contacts may also be grounded. This may prevent or reduce EMI leakage out of the electronic device. This may further prevent or limit EMI outside of the device from coupling onto circuitry in the device. Also, it may prevent power supply voltages from being present on exposed contacts on a surface of the device. 
         [0014]    When a second device is mated with the electronic devices, the surface contacts may be pushed into the electronic device. This may compress springs or other compressible structures. In this way, each surface contact may be electrically connected to a corresponding second contact on the main logic board. Signals and voltages may then be conveyed between the surface contacts and the second contacts. 
         [0015]    In this arrangement, the surface contacts may either be grounded or connected to convey signals or other voltages, such as power supply voltages. As such, the arrangement of surface contacts, springs or compressible structures, and second contacts, may form a physical multiplexer analogous to the electronic multiplexer. 
         [0016]    In various embodiments of the present invention, components of the contact structures or apparatus may be formed in various ways of various materials. For example, conductive portions may be formed by stamping, metal-injection molding, machining, micro-machining, 3-D printing, or other manufacturing process. The conductive portions, such as contacts, enclosures, and other portions, may be formed of stainless steel, steel, copper, copper titanium, phosphor bronze, palladium, palladium silver, ceramics, or other material or combination of materials. They may be plated or coated with nickel, gold, or other material. The nonconductive portions, such as the housings, enclosures, and other portions, may be formed using injection or other molding, 3-D printing, machining, or other manufacturing process. The nonconductive portions may be formed of silicon or silicone, Mylar, Mylar tape, rubber, hard rubber, plastic, nylon, elastomers, liquid-crystal polymers (LCPs), ceramics, or other nonconductive material or combination of materials. 
         [0017]    Embodiments of the present invention may provide contact structures or apparatus that may be located in various types of devices, such as portable computing devices, tablet computers, desktop computers, laptops, all-in-one computers, wearable computing devices, cell phones, smart phones, media phones, storage devices, portable media players, navigation systems, monitors, power supplies, adapters, remote control devices, chargers, and other devices. These devices may include contact structures or apparatus that may provide pathways for signals and power compliant with various standards such as one of the Universal Serial Bus (USB) standards including USB Type-C, High-Definition Multimedia Interface® (HDMI), Digital Visual Interface (DVI), Ethernet, DisplayPort, Thunderbolt™, Lightning™, Joint Test Action Group (JTAG), test-access-port (TAP), Directed Automated Random Testing (DART), universal asynchronous receiver/transmitters (UARTs), clock signals, power signals, and other types of standard, non-standard, and proprietary interfaces and combinations thereof that have been developed, are being developed, or will be developed in the future. In one example, the contact structures or apparatus may be used to convey a data signal, a power supply, and ground. 
         [0018]    Various embodiments of the present invention may incorporate one or more of these and the other features described herein. A better understanding of the nature and advantages of the present invention may be gained by reference to the following detailed description and the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]      FIG. 1  illustrates an electronic system according to an embodiment of the present invention; 
           [0020]      FIG. 2  illustrates an apparatus for a surface contact according to an embodiment of the present invention; 
           [0021]      FIG. 3  illustrates an electronic device having a contact multiplexing apparatus according to embodiment of the present invention; 
           [0022]      FIG. 4  illustrates an electronic device that may be mated with the electronic device of  FIG. 3 ; and 
           [0023]      FIG. 5  illustrates an electronic system according to an embodiment of the present invention. 
       
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0024]      FIG. 1  illustrates an electronic system according to an embodiment of the present invention. This figure, as with the other included figures, is shown for illustrative purposes and does not limit either the possible embodiments of the present invention or the claims. 
         [0025]    In this example, the host device  110  may be connected to accessory device  120  in order to share data, power, or both. Specifically, contacts  112  on host device  110  may be electrically connected to contacts  122  on accessory device  120 . Contacts  112  on host device  110  may be electrically connected to contacts  122  on accessory device  120  via cable  130 . In other embodiments of the present invention, contacts  112  on host device  110  may be directly and electrically connected to contacts  122  on accessory device  120  without the need for an intervening cable. 
         [0026]    To facilitate a direction connection between contacts  112  on host device  110  and contacts  122  on accessory device  120 , contacts  112  may be surface contacts. These contacts may be contacts that are exposed at a surface of device  110  when accessory device  120  is not connected. But since contacts  112  are at a surface of host device  110 , if a signal is provided at one of the contacts  112 , it may generate EMI external to the host device  110 . Also, EMI present at an outside of host device  110  may couple onto a sensitive voltage or signal on a contact  112 . Further, when a power supply is provided on a contact  112 , a user, or a user&#39;s property, may inadvertently come into direct contact with the power supply at the exposed surface contact. 
         [0027]    Accordingly, embodiments of the present invention may provide circuit, methods, and structures where contacts are grounded when a host or first device is not connected to an accessory or second device. An example of one such surface contact  112  apparatus is shown in the following figure. 
         [0028]      FIG. 2  illustrates an apparatus for a surface contact according to an embodiment of the present invention. In this example, an electronic device, such as host  110 , may include housing or enclosure  220 . Contacts  112  may be located at a surface of the device housing or enclosure  220 . The device enclosure  220  may be grounded as shown. Contact  112  may be electrically isolated from the grounded device enclosure  220  by insulation area  210 . For example, insulation area  210  may be formed as a ring around contact  112  preventing contact  112  from directly or electrically connecting to device enclosure  220 . In these and other embodiments of the present invention, some of all of device enclosure  220  may be either conductive or nonconductive. Where a nonconductive enclosure  220  is used, insulation area  210  may be obviated. 
         [0029]    Multiplexer  230  may have a terminal X connected to contact  112 . The terminal X may be connected to contact  112  and may be selectively connected to terminal A or terminal B of multiplexer  230 . This selection may be made under control of a selection signal SELECT received by multiplexer  230 . When terminal A is connected to terminal X of multiplexer  230 , signals received at contact  112  may be provided by multiplexer  230  to the input buffer  250 , and output signals from output buffer  240  may be provided to contact  112 . When terminal B of multiplexer  230  is selected, contact  112  may be grounded through multiplexer  230 . While in this example terminal A of multiplexer  230  is shown as being connected to input buffer  250  and output buffer  240 , terminal A of multiplexer  230  may be connected to other circuits, such as only input buffer  250 , output buffer  240 , a power supply voltage source, or other bias, signal, or voltage input or output. 
         [0030]    When no device is connected, multiplexer  230  may select terminal B such that contact  112  is grounded. In this configuration, contact  112  and device enclosure  220  are grounded. This may limit the EMI seen external to host device  110 . It may protect signals or voltages connected inside the electronic device to contact  112  from EMI coupling. Also, it may prevent power supply voltages from being present on exposed contact  112 . When an external device, such as accessory  120 , is connected to host device  110 , multiplexer  230  may select terminal A and connect the input and output signals, or other voltages or power supplies, to contact  112 . 
         [0031]    In various embodiments of the present invention, multiplexer  230  may be formed in various ways. For example, it may be formed as two series switches, with a first switch connected between terminals X and A, and a second switch connected between terminals X and B. These switches may be transistors, micro-electronic machines, relays, or other types of switches. These switches may be under control of a microcontroller, CPU, or other appropriate logic circuit. For example, a CPU may receive information that a connection to an accessory has been made. In response, the CPU may instruct multiplexer  230  to connect its terminal A to its terminal X by asserting the signal SELECT to the select input of multiplexer  230 . In other embodiments of the present invention, a proximity detector, such as a Hall-effect device, may be used to control the select input of multiplexer  230 . Specifically, when a Hall-effect device detects a presence of accessory  120 , the Hall-effect device may use the select signal to instruct multiplexer  230  to connect its terminal A to its terminal X to connect the input and output signals to contact  112 . When accessory  120  is removed, the Hall-effect device may instruct multiplexer  230  to connect its terminal B to its terminal X, thereby grounding contacts  112  and preventing or reducing EMI. In other embodiments of the present invention, other types of contacts, such as those shown below, may physically change positions when an accessory  120  is mated with host device  110 . This physical change in position may be used to generate the SELECT signal to control multiplexer  230 . 
         [0032]    In these and other embodiments of the present invention, a physical multiplexer may be used in place of electronic multiplexer  230 . An example is shown in the following figures. 
         [0033]      FIG. 3  illustrates an electronic device having a contact multiplexing apparatus according to embodiment of the present invention. A device, in this example host device  110 , may be in an enclosure  220 . Contacts  112  may be located at a surface of enclosure  220 . Host device  110  may further include a main logic board  300  having a contact  310 . Contact  310  may be electrically connected to traces and circuits on main logic board  330 , such as input and output signal circuits  240  and  250  in  FIG. 2 . Contacts  112  may be held in place by springs or other compressible structures  320 . In this arrangement, host device  110  is not connected to an accessory  120 . Contacts  112  may be electrically connected to enclosure  220 . Enclosure  220  may be grounded, and accordingly contacts  112  may also be grounded. This may prevent or reduce EMI leakage out of host device  110 . This may further prevent or limit EMI outside of the device from coupling onto circuitry in host device  110  connected to contact  112 . Also, it may prevent power supply voltages from being present on exposed contacts  112 . 
         [0034]    When accessory  120  (not shown) is mated with host device  110 , contacts  112  may be pushed in a downward direction, that is, into host device  110 . This may compress springs or other compressible structures  320 , thereby electrically connecting contact  112  to contact  310 . Signals on contact  310  may then be provided to contact  112 . 
         [0035]    In this arrangement, contacts  112  may either be grounded or connected to convey signals or other voltages, such as power supply voltages. As such, the arrangement of contacts  112 , springs or compressible structures  320 , and contacts  310 , may form a physical multiplexer analogous to the electronic multiplexer  230  in  FIG. 2 . 
         [0036]      FIG. 4  illustrates an electronic device that may be mated with the electronic device of  FIG. 3 . In this example, a second device, such as accessory  120 , may include housing  410 . Contacts  420  may be extend beyond a surface of accessory  410 . Contact  420  may electrically connect to one or more traces and circuits on a logic board  430 . 
         [0037]      FIG. 5  illustrates an electronic system according to an embodiment of the present invention. In this example, a first device and a second device have been mated. In this example, host  110  has been mated with accessory  120 . An enclosure  210  of accessory  110  has been brought into close proximity to housing or enclosure  410  of accessory  120 . Contact  420  of accessory  120  has pushed down on contact  112  of host  110 . Accordingly, contact  310  on main logic board  330  is electrically connected to contact  420  via contact  112 . In this way, traces and circuits on board  430  in accessory  120  may be connected to traces and circuitry on main logic boards  330  in accessory  110  via contacts  420 ,  112 , and  310 . In this example, springs or compressible structures  320  have been compressed. 
         [0038]    In various embodiments of the present invention, EMI shielding may be improved. For example, springs or compressible structures  320  may be grounded and isolated from contacts  112 . Also, the enclosure  410  of accessory  120  may also be grounded. The grounded enclosure is may form a Faraday cage for any signals conveyed on contacts  420 , one  12 , and  310 . 
         [0039]    When accessory  120  is removed from host device  110 , spring or compressible structures  420  may expand, thereby pushing contact  112  to a surface of enclosure  210 . 
         [0040]    In various embodiments of the present invention, it may be undesirable to allow one or more contacts  112  to be depressed while other contacts are not similarly depressed. For example, a single contact on host  110  may be inadvertently depressed by a paperclip or other object. This depression may cause power or signals to be provided at that contact, even in the absence of accessory  110 . Accordingly, embodiments of the present invention may group or connect these contacts together in such a way that they may not independently be depressed, or that electrical signals are not provided at them if they are independently depressed. 
         [0041]    In various embodiments of the present invention, the contact apparatus shown in  FIG. 2  may be combined with contact apparatus shown in  FIGS. 3-5 . Specifically, a contact shown in  FIGS. 3-5  may be used to generate a select signal that is provided to one or more contact apparatus as shown in  FIG. 2 . For example, when contact  112  in  FIGS. 3-5  is grounded, the SELECT inputs to multiplexer  230  in  FIG. 2  may be instructed to connect its terminal B to its terminal A thereby grounding contact  112  in  FIG. 2 . Similarly, when contact  112  in  FIGS. 3-5  are not grounded, the select input to multiplexer  230  may instruct multiplexer  230  to connect its terminal A to its terminal X. 
         [0042]    In various embodiments of the present invention, contacts  112  may have various shapes. For example, contacts  112  may have a top surface that appears circular, as a square, or has other shapes. Side edges of contacts  112  and device enclosure  210  may be beveled or angled to improve the mating between contacts  112  and enclosure  210  such that a surface of contact  112  is flush with a surface of enclosure  210 . 
         [0043]    In various embodiments of the present invention, components of the contact structures or apparatus may be formed in various ways of various materials. For example, conductive portions may be formed by stamping, metal-injection molding, machining, micro-machining, 3-D printing, or other manufacturing process. The conductive portions, such as contacts, enclosures, and other portions, may be formed of stainless steel, steel, copper, copper titanium, phosphor bronze, palladium, palladium silver, ceramics, or other material or combination of materials. They may be plated or coated with nickel, gold, or other material. The nonconductive portions, such as the housings, enclosures, and other portions, may be formed using injection or other molding, 3-D printing, machining, or other manufacturing process. The nonconductive portions may be formed of silicon or silicone, Mylar, Mylar tape, rubber, hard rubber, plastic, nylon, elastomers, liquid-crystal polymers (LCPs), ceramics, or other nonconductive material or combination of materials. 
         [0044]    Embodiments of the present invention may provide contact structures or apparatus that may be located in various types of devices, such as portable computing devices, tablet computers, desktop computers, laptops, all-in-one computers, wearable computing devices, cell phones, smart phones, media phones, storage devices, portable media players, navigation systems, monitors, power supplies, adapters, remote control devices, chargers, and other devices. These devices may include contact structures or apparatus that may provide pathways for signals and power compliant with various standards such as one of the Universal Serial Bus (USB) standards including USB Type-C, HDMI, DVI, Ethernet, DisplayPort, Thunderbolt, Lightning, JTAG, TAP, DART, UARTs, clock signals, power signals, and other types of standard, non-standard, and proprietary interfaces and combinations thereof that have been developed, are being developed, or will be developed in the future. In one example, the contact structures or apparatus may be used to convey a data signal, a power supply, and ground. 
         [0045]    The above description of embodiments of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form described, and many modifications and variations are possible in light of the teaching above. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications to thereby enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. Thus, it will be appreciated that the invention is intended to cover all modifications and equivalents within the scope of the following claims.