Abstract:
A television includes at least two ports (e.g. HDMI ports). The television polls the ports before presenting a user interface that displays some or all of the ports and before toggling between any two of the ports. The polling ascertains whether a device is connected to each of the ports and whether the device is powered. The television modifies the display and/or toggling based on the current state of each port. For example, in toggling, ports that are not connected and ports that are connected to inactive devices are skipped. In another example, when displaying a list of ports, only those ports that are connected to devices appear in the list.

Description:
FIELD 
     This invention relates to the field of display devices and more particularly to a system for detecting secondary devices connected to a primary device such as a television. 
     BACKGROUND 
     Devices such as LCD or Plasma televisions are becoming more sophisticated each year. Already, most have a processor and memory and a remote control as an input device. Often, the television is connected to a multitude of content sources such as cable-television set-top-boxes, Blu-ray players, DVD disk players, Video Cassette Recorders (VCR), game consoles, media players (e.g. IPod), etc. 
     A typical display device (e.g. television) typically has a large number of ports for connecting devices. There are many types of ports (unidirectional or bidirectional) including High Definition Multimedia Interface (HDMI) ports, component video ports, universal serial bus ports (USB), composite video ports, S-video ports, etc. As the number of ports and types of ports grow, the selection and configuration of these ports become complex. Some televisions have four HDMI ports, a component port, a composite port, an S-Video port and several USB ports. This presents increased user complexity when configuring the television, when selecting an active input device and when toggling between input devices. For example, in a system having six HDMI ports and a remote control having a “next” HDMI function; pressing of the HDMI function on the remote, sequences from HDMI-1 to HDMI-2. Pressing the HDMI function again changes to the HDMI-3 input, etc. To switch from HDMI-1 to HDMI-6, the HDMI function must be pressed five times. 
     Often, a television/display has many more ports than it has devices connected to those ports. A television having six HDMI inputs often only has a Blu-ray disk player and a set-top-box (e.g. cable box) attached to two of the six inputs. In such, sequential toggling between these devices requires on average, skipping two empty ports to get to the active ports. This also requires the viewer to remember that the Blu-ray disk is connected to, for example, the HDMI-1 port and the set-top-box is connected to the HDMI-3 port, etc. Furthermore, even when all ports have connected devices, it doesn&#39;t make sense to toggle to a port connected to a device that is not generating a signal (e.g. the device is off). 
     What is needed is a display/television system that will detect which ports are connected to devices and which devices are active. 
     SUMMARY 
     The present invention includes a primary device having a display, for example a television. The primary device has at least two input ports (e.g. HDMI ports). The primary device (e.g. television) polls the ports before presenting a user interface that displays some or all of the ports and before toggling between any two of the ports. The polling ascertains whether a secondary device is connected to each of the ports and, optionally, whether the secondary device is powered. The television modifies display and/or toggling functionality based on the current state of each port. For example, in toggling, ports that are not connected and ports that are connected to inactive secondary devices are skipped. In another example, when displaying a list of ports, only those ports that are connected to secondary devices appear in the list. In yet another example, when displaying a list of ports, only those ports that are connected to active secondary devices (those that are turned on) appear in the list. In some embodiments, ports with active secondary devices are prioritized (e.g. displayed at the top of the list). 
     In one embodiment, a system for determining which ports of a primary device (e.g. television) are connected to secondary devices is disclosed including, a a primary device having a plurality of ports and a mechanism for determining if a secondary device is connected to each port. An example of such a mechanism is measuring the impedance of the port, detecting a signal from the port (e.g. audio or video) and a response to a query 
     In another embodiment, a method of determining which ports of a primary device (e.g. television) are connected to a secondary device is disclosed including (a) selecting a first port of the primary device as a current port. (b) Measuring an impedance of the current port and (c) if the impedance is high, marking the current port as being open and (d) if the impedance is low, marking the current port as being connected to a secondary device. (e) If the primary device has more ports, selecting a next port of the primary device as the current port and repeating steps b-e. 
     In another embodiment, a television is disclosed including a processor with a plurality of ports connected to the processor through a multiplexor. Software running on the processor determines which of the ports are connected to secondary devices by, for example, sequentially emitting a known frequency at a known amplitude to each of the ports through a multiplexor and measuring a current through the multiplexor. Software running on the processor determines if the impedance indicates a secondary device is connected to the each port. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention can be best understood by those having ordinary skill in the art by reference to the following detailed description when considered in conjunction with the accompanying drawings in which: 
         FIG. 1  illustrates a schematic view of a television with a typical input selection on-screen display of the prior art. 
         FIG. 2  illustrates a schematic view of a television having five inputs, two of which are connected. 
         FIG. 3  illustrates a second schematic view of a television having five inputs, two of which are connected. 
         FIG. 4  illustrates a third schematic view of a television having five inputs, two of which are connected and one is active. 
         FIG. 5  illustrates a perspective view of an HDMI connector with plug detection. 
         FIG. 6  illustrates a second perspective view of an HDMI connector with plug detection. 
         FIG. 7  illustrates a block diagram of a typical television system. 
         FIG. 8  illustrates a block diagram of a second typical television system. 
         FIG. 9  illustrates a flow chart running within the television. 
         FIG. 10  illustrates a second flow chart running within the television. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to the presently preferred embodiments, examples of which are illustrated in the accompanying drawings. Throughout the following detailed description, the same reference numerals refer to the same elements in all figures. For brevity, a television is used in this description as an example of a primary device that has two or more input ports for connecting to secondary devices. Many other secondary devices, including, but not limited to, audio-video components, receivers, mobile televisions, etc, are anticipated and included here within. In the examples described, the television  5  is a primary device and a DVD player disk player  12  and cable modem  14  are examples of secondary devices. 
     Referring to  FIG. 1 , a schematic view of a television  5  with a typical input selection on-screen display  10  of the prior art will be described. The selection menu  10  contains all inputs (HDMI 1-4 and Component) even though only one device  12  (e.g. a DVD player  12 ) is connected to one HDMI port (HDMI-1). The device  12  has a power on/off indicator  13 . 
     Referring to  FIG. 2 , a schematic view of a television  5  having five inputs will be described, two of which are connected to devices  12 / 14 . In this exemplary user interface, two devices  12 / 14  such as a DVD player disk player  12  and a cable modem  14  are connected to the HDMI-1 and HDMI-2 ports, respectively. The HDMI-3, HDMI-4 and Component ports are not connected to anything. In this example, the television  5  has determined that the HDMI-3, HDMI-4 and Component ports have nothing connected and has abbreviated the menu  20  to include only the ports that have devices connected. Both devices have a power on/off indicator  13 / 15 . 
     Referring to  FIG. 3 , a second schematic view of a television  5  having five inputs will be described, two of which are connected to devices  12 / 14 . In this exemplary user interface, two devices  12 / 14  such as a DVD player disk player  12  and a cable modem  14  are connected to the HDMI-1 and HDMI-2 ports, respectively. The HDMI-3, HDMI-4 and Component ports are not connected to anything. In this example, the television  5  has determined that the HDMI-3, HDMI-4 and Component ports have nothing connected and has abbreviated the menu  20  to include only the ports that have devices connected. In this embodiment, instead of displaying the nomenclature of the port (e.g. HDMI-1), a more meaningful tag (DVD, CABLE) is displayed. It is anticipated that, in some embodiments, the tag is created and associated with the respective port through an on-screen user interface. In some embodiments, the tag is determined by querying the device for a name or class and associating the name with the respective port. Both devices have a power on/off indicator  13 / 15 . 
     Referring to  FIG. 4 , a third schematic view of a television  5  having five inputs will be described, two of which are connected to devices  12 / 14 . In this exemplary user interface, two devices  12 / 14  such as a DVD player disk player  12  and a cable modem  14  are connected to the HDMI-1 and HDMI-2 ports, respectively. The HDMI-3, HDMI-4 and Component ports are not connected. The DVD player disk  12  is powered on as indicated by the DVD player disk power indicator  13  and the cable modem  14  is not active (off), as indicated by the cable modem power indicator  15 . 
     In this example, the television  5  has determined that the HDMI-3, HDMI-4 and Component ports have nothing connected. Furthermore, the television  5  has determined that the cable modem  14  connected to the HDMI-2 port is not active (off or standby). The television has abbreviated the menu  20  to include only the ports that have devices connected and active; in this example, only the DVD player  12 . In this embodiment, instead of displaying the nomenclature of the port (e.g. HDMI-1), a more meaningful tag (DVD, CABLE, etc) is displayed. It is anticipated that, in some embodiments, the tag is created and associated with the respective port through an on-screen user interface. In some embodiments, the tag is determined by querying the device for a name or class and associating the name with the respective port. 
     Referring to  FIGS. 5 and 6 , perspective views of an HDMI connector  50  with plug detection will be described. This exemplary HDMI connector  50  has a coil or inductor  52  in proximity to the opening  51  into which the HDMI plug  54  is to be inserted. In order to detect whether a plug  54  is inserted into the opening  51 , one or more known frequencies with known amplitudes are emitted over lead wires  58  to the coil  52  while measuring the current drawn by the coil  52 . When the HDMI plug  54  is absent from the opening  51 , a first current is measured. When the HDMI plug  54  is present in the opening  51 , a second current is measured due to a change in the impedance of the coil  52  caused by the metallic mass of the plug  54 . The difference in the current is used to determine is a cable connector or plug  54  is plugged into the opening  51  of the HDMI connector  50 . 
     In other embodiments, other mechanism are used including, but not limited to, a micro switch that changes state when the plug  54  is inserted into the HDMI connector  50 , a light interrupter in which the light is interrupted by the presence of the plug  54  inserted into the HDMI connector  50 , etc. 
     Furthermore, in some embodiments, other methods are used to determine if a secondary device is connected to the input port(s) including, but not limited to, detecting the presence of an audio signal, detecting the presence of a video signal, sending a query to the secondary device and receiving a response, etc. 
     Referring to  FIGS. 7 and 8 , schematic views of exemplary televisions  5  will be described. This figure is intended as a representative schematic of a typical monitor/television  5  and in practice, some elements are not present in some monitors/televisions  5  and/or additional elements are present in some monitors/televisions  5  as known in the industry. In this example, a display panel  7  for content is connected to a processing element  100 . The display panel  7  is representative of any known display panel including, but not limited to, LCD display panels, Plasma display panels, OLED display panels, LED display panels and cathode ray tubes (CRTs). 
     The processing element  100  accepts video inputs and audio inputs selectively from a variety of sources including an internal television broadcast receiver  102 , High Definition Multimedia Interface (HDMI 1-4), USB ports and an analog-to-digital converter  104 . The analog-to-digital converter  104  accepts analog inputs from legacy video sources such as S-Video and Composite video and converts the analog video signal into a digital video signal before passing it to the processing element. 
     In the exemplary embodiment of  FIG. 7 , multiple ports (in this example, HDMI ports) are multiplexed to the processing element  100  by a multiplexor  140 . The multiplexor  140  is controlled by a selection input  144  that is controlled by the processing element  100 . In this, the processing element  100  sets the selection input  144  to address the desired port and the port (e.g. HDMI-1) is connected to the multiplexor&#39;s  140  output  146 . The multiplexor&#39;s output  146  is connected to the processing element  100  as typical of a directly connected digital port. In alternate embodiments each individual HDMI input is directly connected to the processing element  100 , in some cases by amplifier and shaping circuits as known in the industry. 
     In the exemplary embodiment of  FIG. 8 , multiple ports (in this example, HDMI ports) are multiplexed to the processing element  100  by a dual channel multiplexor  150  (or two individual multiplexors). A first channel of the multiplexor  150  is controlled by a selection input  152  and a second channel of the multiplexor  150  is controlled by a second selection input  151 , both being controlled by the processing element  100 . In this, the processing element  100  sets the selection inputs  151 / 152  to address the desired port. The selection inputs  151 / 152  have a setting that disables (e.g. tri-state) its respective multiplexor. For example, the first selection input  152  has a setting value that disconnects all of the ports from the processing element  100  and setting values to connect each of the ports (e.g. HDMI-1, etc) to the multiplexor&#39;s first output  154 . The multiplexor&#39;s first output  154  is connected to the processing element  100  to convey, for example, video data from digital port to the processing element  100 . In alternate embodiments each individual HDMI input is directly connected to the processing element  100 , in some cases by amplifier and shaping circuits as known in the industry. 
     Most multiplexors  150  are bi-directional, allowing signals to pass from the ports to the processing element  100  and, likewise, allowing signals to pass from the processing element  100  to the ports. In this example, to test if each port is connected to a device (e.g., a DVD player), the processing element  100  sets the first selection inputs  152  to disconnect (e.g. disconnect, tri-state, high-impedance) all HDMI inputs from the processing element  100 . The processing element  100  then sequentially sets the second selection inputs  151  to sequentially address each HDMI port, sequentially connecting each port to a testing device  155 . The testing device  155  is, for example, a frequency source emitting one or more known frequencies at one or more known amplitudes and measuring the current. In some embodiments, the testing device  155  is connected to the coil  52  to determine if a HDMI plug is present in the associated HDMI connector  50  as described with  FIGS. 5 and 6 . In some embodiments, the testing device  155  is connected to the signal conductors  56  of the HDMI connector  50 . In some embodiments, the testing device  155  is connected to a micro switch or light detector associated with the HDMI connector  50 . If no plug is present in the connector  50 , the signal conductors (or coil  52 , micro switch or light detector) will measure a high impedance. If a plug is present in the connector  50 , but the cable is not connected to a device, the signal conductor will measure a slightly lower impedance depending on the frequency. This is due to the capacitance of the cable and will vary between lengths and manufacturers of cables. If a plug is present and is connected to a device and the device is not powered, then the signal conductors will measure a significantly lower impedance. If a cable is present and is connected to a device and the device is powered, then a digital signal will be present on the signal conductors. 
     In another embodiment, the ports are first scanned using the first multiplexor  150  to determine which ports have a signal present (analog or digital) coming from a device that is plugged into that port, then those ports having a signal are marked as connected and active by the processing element  100  and an impedance test is not performed on the ports already marked as connected and active. 
     Audio emanates from either the broadcast receiver  102 , the legacy source (e.g., S-Video) or a discrete analog audio input (Audio-IN). If the audio source is digital, the processing element  100  routes the audio to a digital-to-analog converter  106  and then to an input of a multiplexer  108 . The multiplexer  108 , under control of the processing element  100 , selects one of the audio sources and routes the selected audio to the audio output and an internal audio amplifier  110 . The internal audio amplifier  110  amplifies the audio and delivers it to internal speakers  134 / 136 . 
     The processing element  100  accepts commands from a remote control  111  through remote receiver  113 . Although IR is often used to communicate commands from the remote control  111  to the remote receiver  113 , any known wireless technology is anticipated for connecting the remote control  111  to the processing element  100  including, but not limited to, radio frequencies (e.g., Bluetooth), sound (e.g., ultrasonic) and other spectrums of light. Furthermore, it is anticipated that the wireless technology be either one way from the remote  111  to the receiver  113  or two way. 
     In some embodiments, the television  5  connects to networks through a wireless network interface  120  having an antenna  20 . In some embodiments, the television connects to a local area network using a local area network adapter  124  for connecting to, for example, an Ethernet local area network or a power line local area network, as known in the industry. In some embodiments, the processor  100  communicates to an Internet-based service through the wireless network interface  120  or the local area network  124  to determine when two-dimensional or three-dimensional content is being displayed. 
     Referring to  FIG. 9 , a flow chart running within the television  5  will be described. This program flow is an example of measuring the port to determine if a device is connected. To start, an oscillator is connected to the port  200 , emitting a known amplitude and frequency. Next, an impedance or current measurement is made  202  to determine the impedance of either the coil  52  or signal lines  56  (or micro switch or light detector, etc). The measured impedance is compared  204  to expected values and if it is less than an expected value (low impedance means a device or plug is connected), the port is marked  208  as active. Otherwise, if it is higher than the expected value (high impedance means no device or plug is connected), the port is marked  206  as inactive. 
     Referring to  FIG. 10 , a second flow chart running within the television  5  will be described. In conjunction with the multiplexor  150  of  FIG. 8 , the first multiplexor  150  is disabled  220  and the second multiplexor  150  is set  222  to connect the measurement device  155  to the signal leads of the first port  50  (or coil  52  of the first port  50 ). Next, a measurement  224  of the impedance of either the signal leads  56  or the coil  52  is made and the impedance is compared  226  to an expected value. If the impedance is lower than the expected value, the current addressed port is marked  230  as connected. If the impedance is higher than the expected value, the current addressed port is marked  228  as not connected. Next, the second multiplexor  150  is set  232  to connect the measurement device  155  to the signal leads of the next port  50  (or coil  52  of the first port  50 ). If there are more 234 ports  50 , then the steps are repeated to determine if that port  50  is connected. If there are no more 234 ports  50 , then it is now known which ports  50  have attached devices. 
     It is anticipated that when second multiplexor  150  is set  232  to connect the measurement device  155  to the signal leads of the next port  50  for an impedance measurement, the second multiplexor  150  connects the measurement device  155  to any of two or more signal lines  56 , a coil  52  associated with the port, a micro-switch associated with the port  50 , a light sensor associated with the port  50 , etc. 
     Equivalent elements can be substituted for the ones set forth above such that they perform in substantially the same manner in substantially the same way for achieving substantially the same result. 
     It is believed that the system and method and many of its attendant advantages will be understood by the foregoing description. It is also believed that it will be apparent that various changes may be made in the form, construction and arrangement of the components thereof without departing from the scope and spirit of the invention or without sacrificing all of its material advantages. The form herein before described being merely exemplary and explanatory embodiment thereof. It is the intention of the following claims to encompass and include such changes.