Abstract:
A high definition multimedia interface (HDMI) test system including an HDMI test device that includes a display, a microcontroller, first and second input ports, an output port, a first cable connector, a second cable connector, and a third cable connector. The HDMI test device couples to an external device and receives an HDMI signal from the external device via the first cable connector. The microcontroller receives the HDMI signal from the first input port and converts the signal to a video signal, wherein the display displays an image associated with the video signal. The microcontroller transmits a test HDMI signal to the third cable connector, receives the test signal from the second cable connector and compares the test signal transmitted to the third cable connector and the test signal received from the second cable connector to determine continuity of an HDMI cable coupled with the second and third cable connectors.

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     Embodiments of the invention generally relate to a high definition multimedia interface (HDMI) test system that includes an HDMI test device that displays video signals and performs HDMI continuity testing. Specifically, at least one embodiment of the invention receives an HDMI signal from an external device, converts the signal to a video signal and displays at least one image associated with the video signal so that an installer may set up a set top installation without a television on hand, and in addition, also provides HDMI cable continuity testing for the HDMI cables on a line-by-line basis for example. 
     Description of the Related Art 
     Technicians who install and troubleshoot television network connections, set-top boxes, and other audiovisual systems have a need for test equipment to verify and diagnose connections. One technique for verifying a connection is to attach a television and confirm that it displays video and sound correctly. However, this method is not always possible since an installing technician may install a network connection before a customer&#39;s television is available. There is no known test equipment that can verify a video and audio signal using a convenient, portable device, in lieu of using a television and that also provides for continuity testing of the HDMI cables so that the installer can be confident that after leaving, a user may connect a television to an HDMI cable and set top box and have a high degree of confidence that the television will work. This also lowers the number of trips to each installation in the case of no television present and/or a bad cable for example. 
     For example, if a video or audio signal is not received correctly by a television or by testing equipment, the problem may be with either the source of the signal (such as set-top box) or with the cable connecting the source to the television or equipment. Therefore, there is a need for a cable tester to also determine whether the connecting cable is functioning correctly. In particular, since television connections are often made using HDMI cables, there is also a need for an HDMI cable tester. HDMI cable testers known in the art are generally analog continuity testers, e.g., with lights that show whether there is a conducting path. There are no known HDMI cable testers integrated with video displays, and for example that generate a digital HDMI signal and verify that it is transmitted correctly through the cable. 
     For at least the limitations described above there is a need for an HDMI test system that receives and displays video signals, and that tests transmission through an HDMI cable. 
     BRIEF SUMMARY OF THE INVENTION 
     One or more embodiments of the invention include a high definition multimedia interface (HDMI) test apparatus that includes an HDMI test device with a housing. In at least one embodiment, the HDMI test device and the housing include one or more of a display, a microcontroller, a first input port, a second input port and an output port. In one or more embodiments, the HDMI test device and the housing include one or more of a first cable connector coupled to the first input port, a second cable connector coupled to the second input port, and a third cable connector coupled to the output port. One or more embodiments of the invention may utilize one input port and one output port, wherein the first input port may be utilized to receive external video and also received HDMI signals output from the apparatus to determine proper HDMI cable functionality. 
     By way of at least one embodiment, the HDMI test device may couple to an external device via an HDMI cable, and may receive an HDMI signal from the external device over the HDMI cable via the first cable connector that is coupled with the first input port. In one or more embodiments, the microcontroller may receive the HDMI signal from the first input port, convert the HDMI signal to a video signal, and send the video signal to the display. In at least one embodiment, the display may display at least one image associated with the video signal. 
     According to one or more embodiments of the invention, the microcontroller may transmit a test HDMI signal to the third cable connector via the output port and receive the test HDMI signal from the second cable connector via the second input port. In at least one embodiment, the microcontroller may compare the test HDMI signal transmitted to the third cable connector via the output port and the test HDMI signal received from the second cable connector via the second input port to determine continuity and/or proper transmission of high frequency signals on the HDMI cable coupled with the second cable connector and the third cable connector. In one or more embodiments, the microcontroller may display a continuity diagram that shows continuity wires in the HDMI cable on the display. 
     In at least one embodiment, the HDMI test device with the housing may include a speaker, wherein the microcontroller may obtain an audio signal from the HDMI signal and send the audio signal to the speaker. In one or more embodiments, the HDMI test device with the housing may include one or more of a battery coupled with at least the microcontroller and the display, and a micro universal serial bus (USB) port coupled with the battery. By way of at least one embodiment, the HDMI test device with the housing may include at least one button coupled with the microcontroller, wherein the microcontroller may adjust brightness, contrast, video format, or any combination thereof associated with the display according to input accepted via the at least one button. 
     According to one or more embodiments, the HDMI test device with the housing may include a switch, wherein the microcontroller may alter information displayed on the display according to a first mode and a second mode, wherein the first mode includes an HDMI video display mode, and wherein the second mode includes an HDMI cable test mode. In at least one embodiment, the microcontroller may automatically display the at least one image when the HDMI signal is detected on the first input port. 
     By way of one or more embodiments of the invention, the microcontroller may automatically display the continuity diagram associated with the HDMI cable coupled between the output port and the second input port when the HDMI cable is coupled between the output port and the second input port. In at least one embodiment, the microcontroller may automatically alter the display to show the at least one image or the continuity diagram according to whether the HDMI cable is connected to the first input port or between the second input port and output port. In one or more embodiments, the microcontroller may automatically alter the display to show the at least one image or the continuity diagram according to whether the HDMI signal is coupled last to the first input port or the second input port. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other aspects, features and advantages of at least one embodiment of the invention will be more apparent from the following more particular description thereof, presented in conjunction with the following drawings wherein: 
         FIG. 1  illustrates an embodiment of the HDMI test device, showing the screen and the ports of the device. 
         FIG. 2  shows a side view of the embodiment of  FIG. 1 . 
         FIG. 3  is a functional block diagram of the electronic components of the embodiment shown in  FIG. 1 . 
         FIG. 4  shows a flowchart illustrating a test procedure that uses an embodiment of the invention to check and troubleshoot a video connection. 
         FIG. 5  illustrates the embodiment of  FIG. 1  operating in a video display mode, with a cable connected to a video source and to the device&#39;s primary HDMI input port. 
         FIG. 6  illustrates the embodiment of  FIG. 1  operating in continuity testing mode, with an HDMI cable looped back between the device&#39;s HDMI output port and its secondary HDMI input port. 
         FIG. 7  illustrates a continuity test that detects problems with an HDMI cable. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The following description is of the best mode presently contemplated for carrying out at least one embodiment of the invention. This description is not to be taken in a limiting sense, but is made merely for the purpose of describing the general principles of the invention. The scope of the invention should be determined with reference to the claims. 
       FIG. 1  shows an embodiment of the invention that comprises a small, integrated display screen, multiple HDMI ports, and internal electronics to decode video (and possibly audio) signals and to check cable continuity. Device  110  has an external housing  120 . In one or more embodiments the housing may be configured to be shock resistant and water resistant. For example, it may be made of an elastomeric material. The device may be hand held by an operator; therefore, the housing may be configured to be easy to hold, for example with a single hand. The device has a display screen  130 , which may for example be an LCD screen, an OLED screen, or more generally any display. It has a speaker  175 ; one or more embodiments may have multiple speakers, for example in stereo configurations. One or more embodiments may have a display with no speaker. For example, to reduce manufacturing cost, one or more embodiments may not perform audio signal testing, or may provide a visual output on the display for the audio signal rather than playing audio through a speaker. In one or more embodiments, Device  110  has three HDMI ports, each with a connector configured to connect to an HDMI cable connector: the first HDMI input port  150  is configured to receive video signals that will be displayed on the display  130 ; the HDMI output port  170  may be connected via an HDMI loopback cable to secondary HDMI input port  160  to test continuity and/or proper digital transmission on the HDMI cable. This configuration is illustrative; one or more embodiments may arrange HDMI ports in different numbers and configurations. For example, in one or more embodiments the primary input port  150  may be utilized in lieu of the secondary input port  160 , with the two functions (video display vs. continuity testing) selectable via hardware switches or software controls. Thus secondary input port  160  is optional and in some embodiments, one output port and one input port may be utilized to perform both continuity testing and to accept video to display. Embodiments having two input ports may test continuity of a given HDMI cable coupled with the second input port  170  and display video from the first input port  150  simultaneously in a split view mode on display  130 , or in a switched manner on display  130 . 
     Device  110  also has a micro USB port  190 , which may be used for example for charging the device. One or more embodiments may use any type of charging mechanism, including USB or other power cables, or inductive charging. One or more embodiments may have no charging mechanism, but instead may use replaceable or externally rechargeable batteries. One or more embodiments may use AC power or DC power connections instead of or in addition to internal batteries. 
     Device  110  may also have one or more control buttons (not shown) or other input controls, for example arranged along edge  127 , or more generally located in any convenient area of the device. One or more embodiments may use software input controls for example if display  130  includes a touchscreen capability. Input controls may be provided for functions that may include for example power on and power off, display control, speaker control, and function control for the video checking and cable continuity checking functions. 
       FIG. 2  shows a side view of the embodiment of  FIG. 1 , with a view of HDMI output port  170 , secondary HDMI input port  160 , and speaker  175 . As shown, with display decoupled, the interior  401  of the apparatus may hold the various electronic components, PCB, battery and connectors for example. 
       FIG. 3  shows a block diagram of the electronic components of an embodiment of device  110 . Microcontroller  140  is connected to the HDMI ports including first input port  150 , optional second input port  160 , and output port  170 ; to display  130 ; and to speaker  175 . One or more embodiments may have multiple microcontrollers or coprocessors in addition to main microcontroller  140 . Microcontroller  140  also receives input from input controls  121 ,  122 ,  123 ,  124 , and  125 . These specific input controls are illustrative; one or more embodiments may use any number and configuration of input controls. The input controls may for example be simple switches or buttons. Device  110  also has a battery  185  that is connected to micro USB port  190  for charging. Power button  125  may be used to power up or power down the device  110 . 
     To check a video source, a technician attaches HDMI cable  181   a  to connector  151  of primary HDMI input port  150 , and also attaches the cable  181   a  to external device  180  that provides HDMI signals. Device  180  may be for example a set-top box for cable or satellite television. The HDMI signal is sent from port  150  to microcontroller  140 , which decodes the video and displays it on display  130 . The microcontroller may also decode the audio signal from port  150  and send the audio to speaker  175  for output. Video and audio may be controlled for example using input controls  122 ,  123 , and  124 . For example, Menu button  124  may cycle between several control modes, such as increase/decrease brightness, increase/decrease contrast, and increase/decrease audio volume; buttons  122  and  123  may then be used to increase or decrease the selected control. 
     To check an HDMI cable, a technician attaches HDMI cable  181   b  (which for example may be cable  181   a ) to connector  171  of HDMI output port  170 , and to either connector  151  of first input port  150 , or optionally to connector  161  of secondary HDMI input port  160 . Having two input ports allows for testing two cables simultaneously for example to show video and continuity simultaneously if desired. The microcontroller  140  generates transmits a test signal to port  170 , and checks the signal received on port  150  or optionally  160 . By comparing the received signal to the transmitted signal the microcontroller  140  can determine if the cable  181   b  wires have continuity between the connectors on a wire-by-wire basis and/or otherwise determine that the HDMI signals are transmitted and received properly. 
     In one or more embodiments the microcontroller may operate in at least two modes: in video display mode the microcontroller decodes video (and optionally audio) received on port  150 , and displays the video on display  130  (and may play audio on speaker  175 ); in cable continuity test mode the microcontroller sends an HDMI test signal to output port  170  and compares this signal to the received signal on secondary HDMI input port  160 . In one or more embodiments the microcontroller may automatically determine which mode to operate in based on detecting which ports have attached cables. For example, a technician may press the Detect button  121  to cause the microcontroller to detect which input port ( 150  or  160 ) has an attached HDMI cable, and to set its operating mode accordingly. In one or more embodiments the detection may be automated, and may occur without requiring an input such as the Detect button  121 , by for example defaulting to display video, or defaulting to display the continuity diagram, or default to displaying which ever display corresponds to a signal received on the first or second input, or default to a split screen mode to display both the continuity diagram and the video. In one or more embodiments the mode may be selected manually by an operator, for example using the Menu button  124  or by using another input control. 
       FIG. 4  shows a testing procedure flowchart that may be used by a technician to test video sources and HDMI cables using one or more embodiments of the invention. This flowchart is illustrative; embodiments of the invention may be used in various ways to test equipment in any desired manner and in any desired order. In step  401 , the technician connects an HDMI cable to the primary input port  150  and to the external device  180  that provides the HDMI video source. In step  402 , the technician powers up the device  110  using for example the Power button  125 . In step  403 , the technician adjusts the display brightness or contrast, if needed, and may adjust other parameters like audio output volume; these adjustments may be made for example using buttons  122 ,  123 , and  124 . In step  404 , the technician determines whether video (and possibly audio) are displayed correctly. If so, the testing is done  405  and the system (video source and cable) is working properly. If not, the technician may proceed to determine whether the fault lies with the video source or with the HDMI cable. In step  406  the technician takes the HDMI cable that was connected in step  401 , and connects it to the HDMI output port  170  and to the secondary HDMI input port  160 . In step  407  the technician presses the Detect button  121 ; this causes the device to switch to cable continuity testing mode. The technician observes the continuity test output display, and in step  408  determines whether there is continuity on all signal lines of the HDMI cable. If so, the test determines  410  that the cable works correctly, and that the problem lies with the video source. If not, the test determines  409  that the HDMI cable is defective. 
       FIGS. 5 through 7  show illustrative outputs on the device display for the video source test and the cable continuity test.  FIG. 5  shows device  110  in video source test mode. HDMI cable  181   a  is connected to primary HDMI input port  150 , and to an external video source (not shown). Video  501  is displayed on display  130 , indicating that the source and the cable are functioning correctly. Power cable  501  is shown coupled with micro USB port  190 , which may be implemented in any type of input port that may couple with a power source. 
       FIG. 6  shows device  110  in cable continuity test mode. HDMI cable  181   b  is connected to HDMI output port  170  and is looped back to secondary HDMI input port  160 . Diagnostic output  601  and  602  is shown on display  130 . This output shows whether continuity is detected on each of the  19  signal lines of the HDMI cable. In this illustrative output, continuity is detected on each signal line, so the cable is functioning correctly. 
     In contrast,  FIG. 7  shows an illustrative output  701  and  702  for a defective cable. Lines  13 ,  16  and  18  appear to have transmission problems, as indicated through the absence of continuity lines, or through use of the graphic symbols that differ from continuity symbols used, showing lack of continuity for these lines in output  702 . The graphics shown for the outputs  601 ,  602 ,  701 , and  702  of the continuity test are illustrative; one or more embodiments may use any symbols, text, graphics, colors, or audio signals, or for example any other indicators that vary over time for colorblind individuals, to indicate the results of the continuity test. For example, one or more embodiments may combine the graphical outputs with an audio signal, with different tones to indicate successful continuity test results and unsuccessful continuity test results. 
     It will be apparent to those skilled in the art that numerous modifications and variations of the described examples and embodiments are possible in light of the above teaching. The disclosed examples and embodiments are presented for purposes of illustration only. Other alternate embodiments may include some or all of the features disclosed herein. Therefore, it is the intent to cover all such modifications and alternate embodiments as may come within the true scope of this invention.