Abstract:
A Personal Computer (PC) in a second location, provides video signals to a television monitor located in a first location. A stereo amplifies audio from the PC and provides the signal to loudspeakers in the first location. A keyboard, mouse, and controller in the first location, use infrared radiation to transmit commands. An IR receiver, in the first location, detects the commands and provides them to the PC. A communication port is used to receive the initial commands. After the initial remote commands negotiate control the input select switch interchanges the input devices of the second location with input devices of the first location. The interchange gives control of the PC to the first location keyboard, mouse and controller. A video switch/matrix in the second location is also controlled from the first location so that video is provided from the PC to the TV monitor in the first location.

Description:
FIELD OF THE INVENTION 
   The present invention relates generally to a method and apparatus for monitoring and controlling a personal computer and more specifically to a method and apparatus for using a personal computer from a remote location using a modicum of equipment. 
   BACKGROUND OF THE INVENTION 
   Many people use their personal computer (PC) for entertainment purposes. Personal computers require a certain amount of space and are usually located in an office type environment. Due to the increasing entertainment value of the personal computer, it is often desirable to have the personal computer available for use in a more comfortable place such as a living room or bedroom. 
   A quandary might arise, for example, if a PC, having a digital television card, is located in a home office and the home theatre, for viewing television programs, is located in the living room. A user who desires to watch digital television (TV) by using the digital TV function of the PC has no choice but to watch it on the PC&#39;s monitor. The user can not take advantage of the digital TV function of the PC in combination with the home theatre monitor located in the living room. 
   Typical home audio-visual equipment systems include a number of components. For example, a radio receiver, a compact disk (CD) player, a pair of speakers, a TV, a video cassette recorder (VCR), a tape deck, and the like. These components are connected to each other via a set of wires. The radio receiver or the tuner is usually the central component of the home audio-visual system. The tuner has a number of specific inputs for coupling to the other components. The tuner has a corresponding number of control buttons or control switches that provide a limited degree of controllability and interoperability for the components. A user controls the home audio-visual system by manipulating the buttons and switches on the tuner, or alternatively, manipulating buttons on a hand-held remote control unit. These features help the user view the video and hear audio but lack the ability to integrate the innovative features of the PC. The viewer who wishes to use the personal computer&#39;s capabilities from the comfort of the living room is unable to accomplish that purpose because he or she can not input commands. 
   The normal hardware compliment of a PC includes a central processing unit (CPU), a keyboard, a mouse, a video display adapter, a video display monitor and a mass storage device such as a hard disk drive. Many PCs include other special purpose hardware devices such as a modem, sound card, network interface adapter card, compact disk read only memory (CDROM), digital versatile disk (DVD), and digital TV card to mention a few that may be useful for home entertainment. When a home has multiple computers, a home communications network may be one way to make all PC functions available from any computer. 
   An important requirement for any home network is simplicity and reliability. The home network should be easy to use, and quick to install. Some users want the functionality of a local area network (LAN) with voice networking, shared Internet access, and smart device control but many can not operate a complex system and few want to maintain a complex system. 
   Alternating current (AC) power lines of most homes are readily available as network cable elements. The AC lines are sometimes used as a transport medium to send and receive discrete frequency-based control, monitoring and communications messages to smart devices that manage lighting and environmental systems. They may also be used as voice-communication elements for telephone extensions, computer-modem access and intercom devices through standard electrical outlets. Applications requiring a high data rate however, can not usually make use of power line networks. 
   Wireless home-networking technology may be used both for line-of-sight, IR, unidirectional, hand-held controller applications and for non-line-of-sight radio frequency (RF) applications. Typical uses today are local control for VCRs, TVs and some security and alarm applications. Because of its limited bandwidth and susceptibility to RF noise, wireless home networking is considered as an inadequate home-network choice. 
   PCs may also be accessed and controlled remotely by other PCs using a hardware network adapter installed in the PC. This network adapter is connected directly to the other PCs or attached to a LAN. These devices typically require network adapter software to be installed to permit a device to access or control the PC. PCs can also be accessed and controlled remotely if communication software is installed in the PC and the PC has a modem. This would permit the PC to be remotely controlled over standard telephone lines or a dedicated cable by another device having access to a modem and compatible interface software. Control of the PC in this manner for a home entertainment network is not practical, as it requires an additional dedicated telephone line or other dedicated lines. 
   A keyboard, video and mouse (KVM) switch, such as Dakota Computer Solutions model 1010-02, exists that permits using a central KVM switch to control and access multiple PC&#39;s however, the KVM switch lacks the capability to support keyboards or other control devices existing at both the remote console and Host PC. 
   Another device, such as the Computer Peripheral Systems Inc., model SWTSPRRC, exists that permits a PC to be re-booted remotely however; the device does not provide the ability to substitute a video display and keyboard/mouse with the remote video display and keyboard/mouse. 
   SUMMARY OF THE INVENTION 
   A Personal Computer (PC), in a second location, provides video to a television (TV) monitor located in a first location. An amplifier coupled to loudspeakers in the first location processes sound signals provided from the PC. An input device and controller in the first location, transmits commands using an infra red (IR) transmitter. An IR receiver, in the first location, detects the commands and provides them through input select switch (ISS), in the second location, to the PC. A communication (Comm) port of the PC is used to receive the initial commands from the ISS. The initial remote commands negotiate control, causing the ISS to interchange an input device at the second location with an input device at the first location. 
   According to another aspect of the invention a video switch/matrix in the second location is controlled from the first location providing video signals from the PC or an alternate source through the video switch/matrix to the TV monitor in the first location. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     With these and other aspects in view, as will hereinafter more fully appear, and which are more particularly pointed out in the appended claims, reference is now made to the following description taken in connection with the accompanying drawings in which: 
       FIG. 1  is a block diagram of an exemplary embodiment of the apparatus; 
       FIG. 2  is a block diagram that shows more detail of the input select switch of  FIG. 1 ; 
       FIG. 3  is a block diagram of another exemplary embodiment of the apparatus; 
       FIG. 4  is a block diagram that shows more detail of the video source/matrix of  FIG. 3 ; and 
       FIG. 5  is a flow diagram of the communications port control software. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1  shows an exemplary embodiment of the invention. An IR remote control unit  102 , located in a first location  100  (e.g. the viewer&#39;s living room), has a plurality of switches. The switches are configured for accepting manual depressions and are activated by a depression. In the exemplary remote control unit, the depression of a switch causes a twenty to forty kilohertz carrier signal to be modulated by a code associated with the depressed switch. The code-modulated carrier is provided to an IR emitter for modulating an IR beam from control unit  102 . Transmitting the modulated carrier, rather than just modulating the IR beam directly, allows the use of a filter, tuned to the carrier frequency, in the IR receiver to distinguish the signal from noise of ambient light. There are at least two international standards used by IR transmitters to encode commands, the RC5 standard and RECS. 80 code standard. The RECS. 80 code, for example, uses pulse length modulation. Each bit to be transmitted is encoded by a high level of the duration T followed by a low level of duration 2T representing a logical ‘0’ or 3T representing a logical ‘1’. The present invention is not limited to a particular type of remote control unit or to a particular method of modulation but includes these and other methods as would be known to the skilled person. 
   The exemplary embodiment of the invention includes a keyboard  104 , located in first location  100  and having a plurality of switches that are configured to accept manual depressions, and has an IR transmitter (not shown). Keyboard  104  and remote control unit  102  have some similar functions, however keyboard  104  has more switches and provides all the functions of a typical PC keyboard such as the keyboard  113 . Except for the IR transmitter of keyboard  104 , both keyboard  104  and keyboard  113  may perform the same functions. Alternatively, an exemplary embodiment of the invention may use the remote control unit  102  in place of the keyboard  104 . In this instance, the remote control unit  102  may include direction switches that are used to implement a the functionality of a pointer data input device such as a computer mouse. 
   An IR receiver  110 , located in first location  100 , is tuned to receive the IR transmissions of keyboard  104  and control unit  102 . An optical filter within the exemplary IR receiver  110  blocks visible light but allows any IR light to pass through. Photodiodes behind the optical filter detect the IR signal and feed it through a filter tuned to the carrier for amplification. The amplified signal may be demodulated, to reverse the modulation process used to convey the switch depressions. IR receiver  110  provides an output signal via cable  106  to input port  109  of input select switch  140 . 
   As shown in  FIGS. 1 and 2 , an exemplary input select switch (ISS)  140  located in a second location  200  (the viewer&#39;s home office) has two input ports and two output ports. The exemplary ISS  140  is a junction for the commands of second location  200  and first location  100 . A first input port  109  is connected via a cable  106  to receive an output signal from IR receiver  110  comprising either the demodulated signals of controller  102  or of keyboard  104 . A second input port  111  is connected, for example, via a USB cable  112  to receive the output signal of keyboard  113  and/or mouse  115 . 
   ISS  140  has two output ports connected to a personal computer  (PC)  130 . The exemplary PC  130 , as setup, provides both an RS232 interface and a universal serial bus (USB) interface. The exemplary system uses a Comm card (not shown) and a USB card (not shown). It is contemplated, however, that the two functions need not be on separate PC cards and that the RS232 interface and the universal serial bus (USB) interface functions may be, for example, integrated in the PC motherboard. Alternatively, it is contemplated that either the USB port or the RS232 port may be replaced by another input port such as a USB port, an RS232 port, an IEEE 1394 “Firewire” interface, a standard PC keyboard/mouse input port, a small computer systems interface (SCSI) bus or conventional PC parallel port. 
   A first output port  121  provides the signal from IR receiver  110  to RS232 Comm card input port  117  of PC  130 , and a second output port  122 , provides the signal from either keyboard  113  or IR receiver  110 , depending on the switch position of ISS  140 , to USB input port  119  of PC  130 . Because either RS232 Comm port  117  or USB port  119  can acquire access to the input-output (I/O) bus of PC  130 , arbitration is used to set priority of use between them. 
     FIG. 5  is a flow diagram illustrating an exemplary arbitration procedure of the Comm software of PC  130  that may be used to handle a request for control and to assign control. A request for control is made when IR receiver  110  sends a signal, such as a ring indicator (RI) signal. If the RI signal is in a logic high state at first location  100 , the input device of the requester can not obtain control. Keyboard  113  can only acquire control when the RI signal of the IR receiver  110 , is low. As shown in  FIG. 2 , Comm port interface  144  receives the RI signal on input port  120  and provides it from output port  121  to Comm port  117 . The Comm card is used to determine when a control request is made to PC  130  from first location  100 . The PC Comm software monitors the RI signal at steps  510  and  512 . After the Comm software senses the RI signal, step  512  transfers control to step  514  which causes the RS232 Comm card to return a data terminal ready (DTR) signal via cable  116  to input  121  of the Comm port interface  144  of input select switch  140 . Comm port interface  144  passes the DTR signal to keyboard/mouse switch  122  as a switch control signal enabling the signal from IR receiver  110 , on input port  109 , to be passed to the output port  122  of keyboard/mouse switch  150 . 
   The algorithm shown in  FIG. 5  implements a priority scheme whereby either the remote keyboard  104  or the local keyboard  113  can control the computer  130  only when the device currently in control has not sent any signal for a predetermined amount of time. It is contemplated, however, that other priority schemes may be used. For example a scheme may be implemented whereby the local keyboard always has priority over the remote keyboard and can interrupt activity initiated by the remote keyboard. 
   After the input devices at the first location  100  obtain control, Comm port interface  144 , at steps  516  and  518  monitors the data stream from IR receiver  110  and provides a data carrier detect (DCD) signal to the RS232 Comm card to indicate data is present. 
   As indicated in the flow diagram of  FIG. 5 , the software, running in the background, monitors the presence of the DCD signal and stops the DTR signal to port interface  144  at step  520  if no DCD activity has been present for a time interval of, for example, 45 seconds. After the time has expired, the user regains control by initiating a new request to control the PC from that location. As indicated in the flow diagram of  FIG. 5 , the Comm software is aware of whether first location  100  or second location  200  has control. If input devices of the second location  200  have control, the arbitration procedure permits a change of control to the input devices of the first location  100  when a request for control is initiated and there has been no activity from the keyboard  113  for a suitable time interval (e.g. 45 seconds). 
   In the exemplary embodiment of the invention, the USB card is used to process the input data regardless of which location has control, as the output port of keyboard/mouse switch  122  is always connected through cable  118  to input port  119  of the USB card. It is noted that a second USB port may be substituted for the RS232 port or, conversely, that a second RS232 port or other input port could be substituted for the USB port. 
   A request to become the controlling input device can be initiated from input devices at either location  100  or location  200 . The request may be enabled, for example, by: (1) keeping a key of either keyboard depressed; (2) touching a key of either keyboard when PC  130  is in screen saver mode; or (3) depressing a predetermined key or sequence of keys on the remote control unit. 
   The arbitration scheme described above is exemplary. It is contemplated that other arbitration schemes may be used in place of or in addition to the described scheme. 
     FIG. 1  further illustrates that PC  130 , located in the second location  200 , provides a video output signal through a video cable  134  to TV monitor  160  located in the first location  100 . In the exemplary embodiment TV monitor  160  may be connected, for example, to an S-video signal output port of either a TV/FM tuner card (not shown) or a video card (not shown) of PC  130 . Either card provides standard TV/S-video outputs, which provide a video output signal to a compatible TV or Monitor. In this manner TV programs for example, received through the TV/FM tuner card of PC  130  can be viewed on TV monitor  160 . 
   TV monitor  160  may include an IR remote control receiver (not shown) and at least one remotely selectable video input connector (not shown). A user can remotely select either a broadband TV video input signal generated internally by the TV monitor  160  or the signal provided by the video output cable  134  through the video input connector. PC  130  also provides audio signals, for example, from an audio output port of the TV/tuner card through audio cable  132  to stereo amplifier  170 . The exemplary stereo amplifier  170  has auxiliary input terminals that are connected to receive the audio signal from PC  130  and an input switch control on the front panel (not shown) or controlled via a remote control device (not shown). The user may listen to audio from PC  130  by selectively switching the front panel control to the position which connects the auxiliary input to the stereo amplifier or by selecting the auxiliary input using the remote control device. Left loudspeakers  172  and right loudspeaker  174  convert the audio signal into sound for listening. 
   Because, in the exemplary embodiment, the audio and video signals from the computer  130  are applied to auxiliary input ports of the stereo  170  and television monitor  160 , the activity of a user on the computer  130  may be continually monitored from the remote locator  100  on the monitor  160  and amplifier  170  even if the viewer at location  100  does not have control of the keyboard inputs. 
     FIG. 2  shows functional details of ISS  140  of  FIG. 1 . The output signal of IR receiver  110  is connected to a first input port  109  of keyboard/mouse switch  150  and to input port  120  of Comm port interface  144 . Keyboard  104  and remote control unit  102 , of first location  100 , are always connected via IR receiver  110 , and Comm port interface  144 , to input port  117  of the Comm card in PC  130  as a path through which a request for control of PC  130  can be made at all times. For example, when a user at first location  100  simultaneously depresses keyboard  104  keys “#”, and “1”, IR receiver  110  receives the code, decodes it and provides an output signal requesting control of PC  130  as described above with reference to  FIG. 5 . 
     FIG. 3  illustrates another exemplary embodiment of the invention, which includes a video switch/matrix  270  that allows the viewer to select a video-input source for TV monitor  160 . All of the features of the previous embodiment as shown in  FIG. 1  are incorporated in this embodiment with like elements having corresponding reference designations. The following description is intended to disclose the different features of this embodiment and should be read with the features of other embodiments in mind. 
   In addition to the ISS  140 , the second embodiment includes a video switch matrix  270 , that controls the video information being provided to the television monitor  160  via the video cable  223 . Video switch/matrix  270  has two video signal input ports, two video signal output ports and a control signal input port. A first video signal input port  249  is connected to receive video signals from PC  130  via cable  231  and a second video signal input port  247  is connected to receive video signals from alternate source video (ASV)  280  via cable  282 . ASV  280  may be, for example, a high bandwidth video output port of a high definition television (HDTV) card (not shown) of the PC  130  or it may be the output port of a digital versatile disc (DVD) player that is integrated to the computer  130 . A first video signal output port  251  provides video signals to computer monitor  136  via cable  232  and a second video signal output port  253  provides video signals to TV monitor  160  via cable  233 . When ISS  140  receives a video signal selection request from IR receiver  110  a control signal is generated and provided to input port  248  of video switch/matrix  270 . Upon receiving the control signal, video switch/matrix  270  selectively switches video signals from either the alternate source video  280  or from PC  130  to video signal output port  253  to provide the selected video signal to TV monitor  160 . 
     FIG. 4  is a block diagram that is useful for describing the functions of the video switch/matrix  270  of  FIG. 3 . Computer  130  provides an RGB analog video signal to a video amplifier  220  via cable  231 . The output signal of video amplifier  220  is directly connected to PC monitor  136  and to input port  238  of video switch  240 . PC monitor  136  may be, for example, a super video graphics array (SVGA) monitor. The video output signal from PC  130  can always be viewed on PC monitor  136 . In addition to analog RGB video other video signal formats such as composite video, S-video and analog component video can be directly obtained from PC  130  plug-in cards such as a TV/FM tuner card. Alternate source video  280  provides a video signal via cable  282  to input port  239  of video amplifier  221 . Video signals from ASV  280  can be a variety of formats such as RGB, S-video, composite video or component video (YIQ, YCbCr or YPbPr). 
   The video switch/matrix  270  may also include a format converter (not separately shown) that converts the video signal provided by the computer  130  to a format compatible with the television monitor  160 . The format converter may be a relatively simple device that generates, for example, a NTSC composite video signal from the computer video signal or it may be a more complex device that can accept multiple computer display formats and provide multiple video display formats. An exemplary format converter is described in U.S. Pat. No. 5,528,301 to Hau et al. entitled UNIVERSAL VIDEO FORMAT SAMPLE SIZE CONVERTER, which is incorporated herein by reference for its teaching on video format conversion. 
   The selection of alternate source video signals occurs when IR receiver  110  sends a request through Comm port interface  144  to the PC  130  requesting that the alternate source video  280  be connected from input port  239  to output port  242  of video switch  240 . A user may select a particular switch at remote control  102  for requesting playback of, for example, a DVD from the ASV  280 . The request signal is sent through port interface  144  to the RS 232 port after which the Comm software returns an address signal indicative of the DVD player back through port interface  144  to the ASV  280 . The exemplary ASV  280  may provide, in addition to various video sources, a decoder (not shown) and a MUX (not shown) which selects the DVD player to provide video to input  247  of the video amplifier  221 . The input select switch  140  then provides a control signal  248  to the video switch matrix  270 , causing it to select the signal provided by the ASV  280  to send to the video monitor  160  via the cable  233 . The output port of video amplifier  221  is coupled to input port  239  of video switch  240 . Alternatively, the ASV  280  may be a single device and, responsive to a selection command from the IR receiver  110 , the Comm interface  144  may send a request to the computer  130  to initiate audio/video output signals from the ASV  280  and generate the ASV control signal (shown in phantom) to cause the video switch matrix to provide the output signals of the ASV  280  to the amplifier  170  and monitor  160 . In another alternative embodiment, the ASV  280  may provide only the video signals and the audio signals may be provided from a sound processor (not shown) in the computer  130 . 
   A matrix  250  is connected to receive the output signal from video switch  240  and to convert it to a format compatible with the TV monitor  160 . Matrix  250  may, for example, receive component video signals and provide, for example, an NTSC standard composite video output signal. Matrix  250  can provide selectable TV output formats as a result of its ability to encode the video input signal and translate among RGB component video, S-video (Y/C), and composite video. Matrix  250  may also decode the video-input signal and translate among composite video, S-video, YCrCb component video, video and RGB component video. 
   It should be understood of course that the foregoing disclosure relates to only a preferred embodiment or embodiments of the invention and that numerous modifications or alterations may be made therein within departing from the spirit and the scope of the invention as set forth in the appended claims.