Abstract:
A device for transmitting multiple control formats from an audio/video source to an audio/video monitor receiver. The device includes a high definition multimedia interface cable that has a plurality of communication channels, including a consumer electronic control channel. Furthermore, a pair of plugs are coupled to the respective ends of the high definition multimedia interface cable and can be coupled to audio/video sources and receivers. A pair of interface ports are further coupled to the high definition multimedia interface cable and communicatively coupled to the consumer electronic control channel. The device transmits a first control format on the consumer electronic control channel when the input port is not coupled to a switching device and transmits a second control format on the consumer electronic control channel when the input port is coupled to a switching device.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part application of U.S. patent application Ser. No. 13/630,749, filed on Sep. 28, 2012, the contents of which are incorporated herein by reference into the present application. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a device for transmitting multiple control formats on an high definition multimedia interface. 
     2. Description of the Related Art 
     High-Definition Multimedia Interface (“HDMI”) is a compact audio/video interface for transferring uncompressed video data and compressed or uncompressed digital audio data from a HDMI-compliant source device to a compatible computer monitor, video projector, digital television, or digital audio device. HDMI provides an interface between any compatible digital audio/video (“A/V”) source device, such as a set-top box (“STB”) or set-back box (“SBB”), a DVD player, a PC, a video game system, an A/V receiver, and a compatible digital audio and/or video monitor device, such as a television (“TV”) or a digital television (“DTV”). HDMI solves the problem of “too many cables” in A/V systems. Audio, visual, status and control information may be transmitted via one cable in the system. HDMI supports all HDTV formats (e.g., 720p, 1080i, 1080p) along with support for up to eight channels of digital audio. 
     HDMI has three physically separate communication channels, which are the DDC, TMDS and the optional CEC. Consumer Electronic Control (“CEC”) is a protocol used to control devices that are attached to the HDMI cable. HDMI, supports CEC features, command sets, and CEC compliance tests. CEC features may include routing control, standby, system information, and feature abort. Other, optional features may include one touch recording, deck control, tuner control, On Screen Display (OSD) display, OSD name transfer, device menu control, RC pass-through, power status and vendor-specific commands. Using a single HDMI cable, CEC control enables a user to control all HDMI devices with a remote control or commander user interface, including powering on or off connected devices and general commands initiated by devices to other devices. It thus solves the problem of “too many remote controls or commanders.” One limitation of using the CEC channel of conventional HDMI cables is that only a single control format can be transmitted over the HDMI cable from the audio/video (A/V) source device to a compatible digital audio and/or video monitor device. 
     Accordingly, the present control marketplace includes a need for driving HDMI commensurate with other control standards. The present invention solves the problem of driving multiple control standards over a high definition multimedia interface. 
     SUMMARY OF THE INVENTION 
     The present invention provides a device and method for transmitting multiple control formats from an audio/video source to an audio/video monitor receiver. The device includes a high definition multimedia interface cable that has a plurality of communication channels, including a consumer electronic control channel. Furthermore, a pair of plugs are coupled to the respective ends of the high definition multimedia interface cable and can be coupled to audio/video sources and receivers. A pair of interface ports are further coupled to the high definition multimedia interface cable and communicatively coupled to the consumer electronic control channel. The device transmits a first control format on the consumer electronic control channel when the input port is not coupled to a switching device and transmits a second control format on the consumer electronic control channel when the input port is coupled to a switching device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The features, objects, and advantages of the present disclosure will become more apparent from the detailed description set forth below when taken in conjunction with the drawings in which like reference characters identify correspondingly elements and in which: 
         FIG. 1  illustrates a modified HDMI connector according to a first exemplary embodiment of the present invention. 
         FIG. 2  illustrates a schematic view of the HDMI connector illustrated in  FIG. 1  and according to the first exemplary embodiment of the present invention 
         FIG. 3  illustrates a logic table for the interface ports disclosed in the HDMI connector of  FIGS. 1 and 2 . 
         FIG. 4  illustrates a second exemplary embodiment of an HDMI connector in accordance with the present invention. 
         FIG. 5  illustrates a logic table for the interface ports disclosed in the HDMI connector of  FIG. 4 . 
         FIG. 6  illustrates a method for transmitting multiple control formats from an audio/video source to an audio/video monitor receiver in accordance with an exemplary embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     In the following detailed description, reference is made to certain embodiments. These embodiments are described with sufficient detail to enable those skilled in the art to practice them. It is to be understood that other embodiments may be employed and that various structural, logical, and electrical changes may be made. 
       FIG. 1  illustrates a modified HDMI connector  100  according to a first exemplary embodiment of the present invention. The exemplary HDMI connector  100  includes a conventional HDMI cable  110  with an embedded variant control line (i.e., a CEC channel), which is discussed in more detail below with respect to  FIG. 2 . The HDMI connector  100  also includes an additional pair of interface ports  120  and  130  that enables the HDMI connector  100  to transmit multiple control signals from two or more devices connected to the respective HDMI cable plugs  112  and  114 . For example, cable plug  112  can be connected to a standard A/V receiver and cable plug  114  can be connected a television or similar audio/video monitor device. The modified HDMI cable  110  enables multiple control signals (e.g., consumer electronics control, infrared signals, and the like) to be transmitted over the CEC channel. 
     In the first exemplary embodiment, interface port  120  can be coupled to a format switcher, such as mono audio format switcher or a master control device with switching capability (e.g., the KD-MC2500 master controlled manufactured by Key Digital Systems), which is capable of generating an infrared signal to be transmitted to the television. In particular, such an infrared signal may be generated by the format switch in response to a signal received from a remote control device or the like. Since interface port  120  of the HDMI connector  100  is coupled to the format switch, the HDMI connector  100  is configured to transmit the infrared signal on the embedded variant control line, as will be discussed in more detail with respect to  FIG. 2 . Furthermore, interface port  130  can be coupled to an IR cable flasher that can be positioned near the television. As a result, when the format switch generates an infrared control signal that is transmitted on the embedded variant control line, the IR cable flasher will generate a corresponding signal output to the television. 
       FIG. 2  illustrates a schematic view of the HDMI connector  100  illustrated in  FIG. 1  and discussed above, according to the first exemplary embodiment of the present invention. As shown in  FIG. 2 , each layer of HDMI connector  100  represents a different HDMI line or channel internal to the HDMI connector  100 . For example, the HDMI connector  100  includes Transition Minimalized Differential Signal (“TDMS”)  240 , Display Data Channel (“DDC”)  250  and Hot Plug Detection (“HDP”) and HDMI Ethernet and Audio Return Channel (“HEAC”)  260  discussed above. The function and purpose of these channel is well known to one skilled in the art and will not be discussed in detail herein. Furthermore, the HDMI connector  100  includes Audio Return Channel (“ARC”)  270  and Consumer Electronic Control (“CEC”) signal line  280 . 
     In the first exemplary embodiment, the CEC signal line  280  is utilized as the embedded variant control line discussed above. Further, in this exemplary embodiment, interface ports  120  and  130  are implemented as 3.5 millimeter (or seven halves millimeter) mono audio phone jack (also referred to as “C 1 ” and “C 2 ”, respectively), although it should be appreciated that such embodiment it not so limited to audio phone jacks. Interface ports  120  and  130  are configured to be switched into either an ON or OFF state depending on the connection being made upon the port. For example, when interface port  120  is coupled to the format switcher, the ON position is activated that results in a communication path between the format switcher and the CEC signal line  280  of the HDMI connector  100 . Thus, CEC signal line  280  is modified by the format switcher transmitting infrared signals, for example. It should be appreciated that the schematic illustrated for interface port  120  is shown for illustrative purposes. Thus, one skilled in the art would understand that when the interface port  120  is not plugged into the format switcher, the CEC signal line  280  of HDMI connector  100  is receiving a signal directly from a source connected to cable plug  112  (e.g., an A/V receiver or the like) because the interface port  120  is not activated. 
     Likewise, when the interface port  130  is plug into an output device, such as an IR cable flasher or the like, the modified HDMI connector  100  transmits a signal to the IR cable flasher via the CEC signal line  280 . If the interface port  130  is not coupled to an output device, the CEC signal line  280  transmits a signal directly to the output coupled to plug  114 , e.g., a television or the like (i.e., a “sink”). 
       FIG. 3  illustrates a logic table for interface ports  120  and  130  (also referred to and shown as C 1  and C 2 , respectively) when the ports are plugged into a device (i.e., the ON state) or not plugged into a device (i.e., the OFF state). The first row illustrates when both ports C 1  and C 2  are in the OFF state and the signal on the CEC signal line  280  is transmitted from the source (e.g., A/V receiver) to the sink (e.g., the television). The second row of the logic table illustrates when port C 1  is in the OFF state and port C 2  is in the ON state such that the signal on the CEC signal line  280  is transmitted from the source (e.g., A/V receiver) to the port C 2  (e.g., coupled to the IR cable flasher). The third row of the logic table illustrates when port C 1  is in the ON state and port C 2  is in the OFF state such that the signal on the CEC signal line  280  is transmitted from the port C 1  (e.g., format switcher) to the sink (e.g., television). The fourth row of the logic table illustrates when both ports C 1  and C 2  are in the on state and the signal on the CEC signal line  280  is transmitted between the two ports. Accordingly, the modified HDMI connector  100  is configured to transmit multiple types of controls signals over the CEC signal line  280  depending on the state of ports C 1  and C 2 . 
       FIG. 4  illustrates a second exemplary embodiment of an HDMI connector  300  in accordance with the present invention. The components described above with respect to  FIG. 2  are generally the same as shown in  FIG. 4  and will not be described in detail herein. However, HDMI connector  300  is configured to transmit an RS-232 signal instead of an infrared signal as disclosed above with respect to the first exemplary embodiment. In particular, the HDMI connector  300  employs both ARC signal line  270  and CEC signal line  280  to transmit the RS-232 signal from interface port  320  to interface port  330 . As shown, each interface port  320  and  330  includes a pair of internal switches. Similar to interface ports  120  and  130 , these switches are activated or in the ON state when the respective port is plugged into a device, such as a format switcher. When unplugged, the switches are in the OFF state or deactivated. It should be appreciated that interface port  320  can be plugged into a format switcher (e.g., the KD-MC2500 master controlled manufactured by Key Digital Systems) or the like. Likewise, interface port  330  can plugged into an RS-232 jack of a television, a device to control the RS-232 communication with the television or the like. Further, it should be appreciated that HDMI connector  300  functions similarly to HDMI connector  100  described above, except that HDMI connector  300  is configured to transmit RS-232 signals instead of infrared signals. Accordingly, the specific functionality of HDMI connector  300  will not otherwise be described herein with respect to  FIG. 4 . 
     It should be appreciated that the CEC signal line  280  in the modified HDMI connector  300  is configured to transmit consumer electronics control signals, including signals transmitted via the RS-232 standard and derived transmitter signals (TxD) therefrom. The signal derived transmitter signal (TxD) is present as a standard interference of the control signal input into the HDMI connector  300  when the interface port  320  is activated (i.e., plugged into the format switcher). 
       FIG. 5  illustrates a logic table for interface ports  320  and  330  (also referred to and shown as C 1  and C 2 , respectively) when the ports are plugged into a device (i.e., the ON state) or not plugged into a device (i.e., the OFF state). Similar to the logic table illustrated in  FIG. 3 , the pathway for the ARC signal line  270  and the CEC signal line  280  signal line will be either from port C 1  to port C 2 , C 1  to sink, source to sink, or source to port C 2  as illustrated in the table of  FIG. 5 . In other words, based on whether interface ports  320  and  330  are plugged in/coupled to a device, the respective switches in the ports will be activated or deactivated. Accordingly, the same logic illustrated in FIG.  3 &#39;s table applies to the modified HDMI connector  300  illustrated in  FIG. 4  and the logic table of  FIG. 5 . 
       FIG. 6  illustrates a method  600  for transmitting multiple control formats from an audio/video source to an audio/video monitor receiver in accordance with an exemplary embodiment of the present invention. As shown, in Step  610 , a first plug  112  of a HDMI connector  100  can be selectively coupled to an audio/video source. At Step  620 , a second plug  114  of the HDMI connector  100  can be selectively coupled to an audio/video receiver. At Step  630 , an input port  120  of the HDMI connector  100  can be selectively coupled to a switching device. At Step  640 , an output port  130  of the HDMI connector  100  can be selectively coupled to an output control device (e.g., an IR cable flasher). It should be appreciated that each of these steps can be selectively performance by a technical engineer installing or reconfiguring an audio/video system in a residence or the like. 
     Once the plugs and interface ports are selectively coupled to the respective devices, the multiple control formats are transmitted over the CEC signal line  280  of the HDMI connector  100  as follows. Step  625  illustrates whether the first or second format control data will be transmitted over the CEC signal line  280 . As discussed above, if the input port  120  is not coupled to the switching device, the method proceeds to Step  630  in which the first format control data received from the A/V receiver, for example, is transmitted towards the audio/video receiver. Step  635  illustrates whether the data is transmitted directly to the receiver (Step  640 ) or to the output control device (Step  645 ). It should be appreciate that such steps are performed in accordance with the logic table illustrated in  FIG. 3  and discussed above. 
     Returning to Step  625 , if the input port  120  is coupled to the switching device, the method proceeds to Step  650  in which the second format control data received from the format switcher, for example, is transmitted towards the audio/video receiver. Step  655  illustrates whether the data is transmitted directly to the receiver (Step  660 ) or to the output control device (Step  665 ). Again, it should be appreciate that such steps are performed in accordance with the logic table illustrated in  FIG. 3  and discussed above. Finally, it is noted and should be appreciated to those skilled in the art that the same method can be applied to the second embodiment of the present invention illustrated in  FIG. 4  and discussed above. 
     The above description and drawings are only to be considered illustrative of specific embodiments, which achieve the features and advantages described herein. Modifications and substitutions to specific process conditions can be made. Accordingly, the embodiments of the invention are not considered as being limited by the foregoing description and drawings.