Patent Publication Number: US-RE38376-E

Title: Message delivery method for interactive televideo system

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is continuation of application Ser. No. 08/968,386, Nov. 12, 1997, U.S. Pat. No. 5,874,985, which was a continuation of application Ser. No. 08/521,799, filed Aug. 31, 1995, now abandoned. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to interactive television or televideo systems and, in particular, to a method of delivering messages to viewer stations associated with such systems. 
     BACKGROUND OF THE INVENTION 
     Conventional cable and satellite television transmission is evolving into interactive television or televideo (IT) systems. IT systems combine the video broadcast capability characteristic of conventional broadcast television with computer-executed applications or programming responsive to input from viewers. By some estimates, IT systems under development could include the equivalent of 500 channels of video broadcasting and unlimited numbers of interactive applications. 
     Conventional broadcast television networks primarily transmit scheduled video programming that emphasizes entertainment, education, or commercial advertising. The conventional scheduled programming is sometimes interrupted for unscheduled public announcements relating to, for example, broadcast system technical difficulties, critical events, or weather or disaster alerts. 
     Public announcements in conventional broadcast television systems are broadcast on the channels carrying the scheduled programming. Critical public announcements typically are broadcast as substitutes for the scheduled programming. The broadcasting of the scheduled programming is stopped and in its place the public announcement is broadcast. These substitution-type public announcements commonly are voiced or spoken and include a video segment or a still-image graphic display. This type of public announcement is typically used to announce broadcast system technical difficulties and weather or disaster alerts. 
     Non-critical public announcements may be generated as text that is added to a video broadcast signal (e.g., along a bottom display screen margin). The broadcasting of the scheduled programming continues uninterrupted, but the broadcast signal carrying the scheduled programming is modified to include the public announcement text. These modification-type public announcements seldom include voice or spoken components and are commonly used to announce non-critical programming delays or news (e.g., sports results). 
     Typically, public announcements are made by the broadcasters that provide or generate the programming carried on a particular channel. Conventional cable television (CATV) network operators seldom generate such announcements. Conventional CATV network operators are substantially passive rebroadcasters of programming provided or generated by others. As a consequence, viewers of a conventional CATV network typically can receive public announcements only if the viewers are tuned to programming provided by a broadcaster that makes public announcements (e.g., conventional local television stations or national television networks). 
     With the relatively large amounts of programming planned for IT systems, it is expected that the proportion of viewers tuned to such conventional broadcasters will decline. Much of the alternative programming is likely to be generated by providers who are remote from the viewer or have no public announcement capabilities. With conventional channel-based broadcasting of public announcements, viewers tuned to such programming could be denied the benefit of receiving public announcements. For critical events and local weather or disaster alerts, the absence of public announcement services can pose a grave risk to viewers. 
     In addition to the difficulty of delivering public announcements to the program or channel a viewer is actually watching, another disadvantage is that public announcements on conventional television are delivered to all viewers tuned to a particular channel. As a consequence, conventional television is incapable of providing a public announcement only to specific viewers for which the announcement is applicable or appropriate. 
     With particular reference to IT systems, conventional substitutions or modifications of video signals for public announcements is incompatible with programming in the form of computer-executed applications. Many such applications would not include a video broadcast that could be modified with a public announcement. Moreover, public announcements could unpredictably disrupt the operation of such applications. 
     SUMMARY OF THE INVENTION 
     The present invention includes a method of selectively delivering programming to a viewer station (e.g., a home) on an interactive television or televideo (IT) system. The IT system includes a central control node that delivers programming to multiple viewer stations. Each viewer station has a video display set (e.g., a television receiver) and an associated interactive station controller that is responsive to input from the viewer for controlling programming on the video display set. 
     The method of this invention includes delivering a message to a selected viewer station. The message preferably is formed at the central control node and directed to the selected viewer station in accordance with computer-executed software of this invention. Similarly, the selected viewer station receives and responds to the message in accordance with the software. 
     The message may be delivered while the selected viewer station receives any programming over the interactive televideo system, including selected programming that is chosen by a viewer at the selected viewer station and is carried on a selected programming channel. The selected programming may be conventional video programming or a computer-executed application. 
     With reference to a preferred embodiment, the IT system transmits a message signal to the selected viewer station on a communication channel different from the channels carrying the programming, including the selected programming channel. The interactive station controller receives the message signal and generates from it a viewer message. 
     The interactive station controller renders the viewer message on the video display set over the selected programming. The viewer message selectively includes a viewer acknowledgement block requiring the viewer to acknowledge the viewer message to have it removed from the video display set. Alternatively, the viewer message remains for a preselected duration and then is removed automatically. 
     This invention allows an IT system operator to provide public announcements to any or all subscribers regardless of the programming they are receiving. The public announcement can provide information to viewers receiving programming generated by any source, including computer-executed applications operated by the IT system. The IT system operator can provide such announcements without having to modify each of up to about 500 channels of programming. 
     The foregoing and other features and advantages of preferred embodiments of the present invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a block diagram of an interactive television system used for the preferred embodiment of this invention. 
     FIG. 2 is a block diagram of an interactive station controller used for the preferred embodiment of this invention. 
     FIG. 3 is a plan diagram of a viewer control unit for providing viewer input to the interactive station controller of FIG.  2 . 
     FIGS. 4A and 4B are diagrams of a video display screen with respective first and second viewer message blocks of the present invention. 
     FIG. 5 is a flow diagram of a method of delivering a message to a selected viewer station according to the present invention. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     FIGS. 1 and 2 are directed to an interactive television for televideo (IT) system  10  as an operating environment for preferred embodiments of the present invention. For purposes of simplicity and clarity, IT system  10  is described with reference to widely available systems and standards, including conventional analog television receivers and cable-based video networks. 
     It will be appreciated, however, that the particular components of IT system  10  may be implemented with a variety of conventions, standards, or technologies without departing from the underlying concepts of the present invention. The term televideo is used to emphasize the applicability of this invention beyond standard television-based systems. As two examples, the conventional analog television receivers and cable-based video network referred to in FIGS. 1 and 2 could be implemented as digital video receivers and a satellite downlink transmission system, respectively. 
     FIG. 1 is a simplified block diagram of an interactive televideo (IT) system  10  having a central control node  12  that transmits programming over a network  14  to multiple viewer stations (e.g., homes)  16 . The programming may include standard analog video broadcasts (e.g., NTSC, PAL or SECAM), digital or digitally encoded video broadcasts (e.g., MPEG 1  or MPEG 2 ), or digital information related to computer-executed applications. 
     Each viewer station  16  includes at least one video display set  18  (e.g., a television receiver) and an interactive station controller  20 , which is sometimes referred to as a set-top box. Although it is shown distinct from video display set  18 , interactive station controller  20  could alternatively be integral with video display set  18 . 
     Interactive station controllers  20  receive programming from central control node  12  and control the associated video display sets  18  in accordance with the programming. Controlling video display set  18  of a conventional analog type may include, for example, delivering an analog video signal directly to video display set  18  for display, converting a digital video signal to a suitable analog form for display, or executing a computer application that includes displays on display set  18 . 
     Interactive station controllers  20  transmit digital information to and receive digital information from central control node  12 . The digital information typically relates to applications executed by processors residing at control node  12  and station controller  20 , as described below in greater detail. 
     Preferably, network  14  carries bidirectional communication between station controllers  20  and central control node  12 . Alternatively, communication between station controllers  20  and central control node  12  can be carried by different communication systems. For example, programming from central control node  12  to station controllers  20  could be carried on a satellite downlink while station controllers  20  send information to central control node  12  on a terrestrial modem link. An exemplary embodiment of central control node  12  is described in greater detail below. 
     FIG. 2 is a simplified block diagram of an exemplary one of interactive station controllers  20  for controlling video display set  18  and communicating with central control node  12 . Station controller  20  includes an input  60  that delivers communication or information from central control node  12  to a communication interpretation system  62  having, for example, an analog television demodulator  62 a, a digital video decoder  62 b, and a digital network communication interface  62 c. 
     Demodulator  62 a functions as a conventional television tuner for selecting one of multiple conventional analog video signals received from central control node  12  at input  60 . Video decoder  62 b functions as a digital equivalent of demodulator  62 a for selecting one of multiple digital video signals received at input  60  from central control node  12 . Network communication interface  62 c communicates with central control node  12  with digital information carried over baseband frequencies. The baseband frequencies may be below the conventional analog video signal frequencies, above the digital video signal frequencies, or between the frequencies of analog or digital signals. 
     A central processing unit (CPU)  66  in conjunction with a memory system  68  controls operation of station controller  20 . CPU  66  is responsive to an infrared receiver and decoder system  70  that receives user input from a hand-held viewer control unit  71  (FIG. 3) and delivers the input to CPU  66 . For example, CPU  66  controls selection of analog- or digital-based programming or applications delivered from central control node  12 , accesses, activates, or executes selected applications, or delivers information to or requests information from central control node  12 . 
     A graphics subsystem  72  is controlled by CPU  66  to form graphics images, including interactive system user interface images, on video display set  18 . A video processor subsystem  74 , also controlled by CPU  66 , provides control in the rendering of video imagery, including decompressing digital video signals and sizing and positioning a video display window. 
     A mixer  76  receives a video display signal from video processor subsystem  74  and graphics image signals from graphics subsystem  70  and delivers a mixed image signal to video display set  18 . Mixer  76  provides compositing, masking and blending of display signals from two or more image sources such as, for example, a digital video signal and locally-generated graphics or an analog video signal and a bitmap image received from central control node  12 . 
     Referring to FIG. 3, viewer control unit  71  includes an infrared transmitter window  89  through which control unit  71  emits infrared signals to infrared input  70  of station controller  20 . A directional control keypad  90  allows a viewer to transmit signals to station controller  20  according to displays it renders on the video display set  18 . The viewer may initiate or activate selections by depressing an action key  91  and may enter numeric values with numeric key pad  92 . 
     FIGS. 4A and 4B show a display screen  98  of one of video display sets  18  with, respectively, a message dialog block  100  and a flash message block  102  of the present invention rendered thereon. Message blocks  100  and  102  are formed in response to message signals received by the associated interactive station controller  20  from central control node  12 . Message blocks  100  and  102  preferably are displayed over selected programming currently rendered on display screen  98 . For purposes of illustration, FIGS. 4A and 4B each show a simplified graphic  104  representing selected programming over which message blocks  100  and  102  are rendered. The selected programming may include broadcast video material or computer-executed applications. 
     Dialog message block  100  includes a title segment  106 a, a text body segment  106 b, and a close prompt segment  106 c. As suggested by the close prompt segment  106 c, dialog message block  102  remains on display screen  98  and over the selected programming until a viewer acknowledges the message by pressing action key  91  on viewer control unit  71 , or the expiration of a default message period. 
     Flash message block  102  preferably is configured as a horizontal band that extends across display screen  98  at a selectable vertical position. A single line of text extends across and typically scrolls horizontally through flash message block  102 . Flash message block  102  remains on display screen for a duration determined at central control node  12 . 
     As described below in greater detail, viewer messages can be delivered to selected viewer stations  16  and can be rendered over virtually any IT system programming. Selective delivery of viewer messages provides the capability to transmit universal messages to all viewer stations  16 , as well as individualized messages to different viewer stations  16 . Individualized messages can relate, for example, to IT system accounting matters or replies to service inquiries. 
     FIG. 5 is a flow diagram showing a method of delivering a message to a selected viewer station  16  of IT system  10 . The message is formed at central control node  12  and directed to selected viewer station  16  by this method in accordance with computer-executed software. Similarly, selected viewer station  16  receives and responds to the message in accordance with the software. The method of FIG. 5 is described with reference to delivering a message to a single viewer station  16 . It will be appreciated that the method is similarly applicable to delivering a message to any group of viewer stations  16 , including all viewer stations  16  of IT system  10 . 
     Process block  110  indicates that a viewer station identifier corresponding to the selected viewer station  16  and a message image format representing at least one of dialog message block  100  and flash message block  102  are stored in IT system  10 . Preferably, the viewer station identifier is stored within memory  68  of interactive station controller  20  and at central control node  12 , and the message image formats representing both message blocks  100  and  102  are stored in memory  68 . The message image formats stored within memory  68  of interactive station controller  20  allow messages to be transmitted to the selected viewer stations  16  with minimal message image format information. 
     The message image formats include graphic parameters by which graphic subsystem  72  of controller  20  can generate: message blocks  100  and  102 , the text rendered within message blocks  100  and  102 , and transitional graphic effects for indicating the opening and closing of a viewer message. For example, visual transitional effects could include shifting a message block  100  or  102  into place or constructing it from a dithered pixel pattern over a brief period. The message image formats can also include audio transitional effects, such as brief message opening and closing chimes or tones. 
     Process block  112  indicates that central control node  12  transmits a message signal over IT system  10  to the selected viewer station  16 . The message signal includes a message, a station identifier corresponding to the selected viewer station  16 , and a message image format indicator representing a dialog message block  100  or a flash message block  102 . The message image format indicator includes specific message block information such as size for a dialog message block  100  and vertical screen position and duration for a flash message block  102 . The message preferably is a text or written format and additional or alternatively includes an audio component (e.g., voice announcement). Moreover, a dialog message block  100  can additionally or alternatively include a video component. For messages directed to multiple selected viewer stations  16 , the station identifier in the message signal would include a component common to all the multiple stations  16 . 
     The message signal preferably is transmitted to the selected viewer station  16  on a channel different from the channels carrying programming. For example, the message signal may be transmitted on a dedicated IT system communication channel. The benefit of such a communication channel is that the interactive station controller  20  can receive the message signal regardless of the programming received by viewers at selected viewer station  16 . 
     Process block  116  indicates that interactive station controller  20  of selected viewer station  16  polls the communication channel periodically for applicable message signals. Applicable message signals are directed to the selected viewer station  16  and include a station identifier corresponding to the one stored in station controller  20 . 
     Process block  118  indicates that interactive station controller  20  of selected viewer station  16  identifies an applicable message signal, accepts it, and in response to it retrieves the corresponding message image format. 
     Process block  120  indicates that interactive station controller  20  generates a viewer message on the associated video display screen  78  in accordance with the message signal and the message image format. For example, the appropriate viewer message block is generated by the graphics subsystem  72 . 
     Process block  122  indicates that the viewer message is removed from the video display screen  78 . Whenever the viewer message is rendered as a dialog message block  100 , the viewer message remains on display screen  98  until a viewer acknowledges the message according to the instructions in the close prompt segment  106 c (e.g., press action key  91 ) or the expiration of a message default period (e.g., 5 minutes). Whenever the viewer message is rendered as a flash message block  102 , the message is rendered on display screen  98  for the duration indicated in the message signal, which duration may be based upon an integer number of repetitions of the message text. 
     The method of this invention can provide messages over any programming carried on IT system  10 , including conventional video programming and computer-executed applications. With regard to video programming, a message is rendered over the programming as it continues to be broadcast. 
     With regard to application programming, interactive station controller  20  interrupts or suspends execution of the programming in response to the message signal. Interruption or suspension of application execution is analogous to that characteristic of single-threaded multitasking operating systems such as Windows v.3.x from Microsoft Corporation. It will be appreciated that for some IT system services, such as video-on-demand, transmission of a video program could be suspended in the same manner as is application programming. 
     Referring to FIG. 1 central control node  12  includes a digital local area network (LAN)  200  with multiple computer servers  202  for performing various interactive system applications or functions referred to above. Servers  202  include, for example, multiple state-of-the-art microprocessors that operate in parallel and access or control data storage devices with large data capacities. A digital communication gateway  204  couples LAN  200  to a wide area network (WAN) (not shown) for obtaining an delivering IT system information. 
     Servers  202  may include, for example, service and application servers  202 a and continuous media servers  202 b. Service and application servers  202 a process interactive service requests from subscribers and provide services and applications associated with operation of IT system  10 . Service and application servers  202 a may be dedicated to particular applications such as message transmission, an electronic programming guide for viewers, network security, monitoring, object storage, financial transactions, data access, and other administration functions. An operator at central control node  12  can control message content and recipients through a terminal or console associated with the applicable service  202 a, including selectively accessing audio or video components (e.g., from a service  202 b). 
     Continuous media servers  202 b provide storage and on-demand or near on-demand delivery of digitized video information. The digitized video information can include video programming of substantially any duration ranging from individual image frames and brief video clips to full-length motion pictures. 
     Servers  202  communicate with station controllers  12  via a network communication switch  208 , such as an asynchronous transfer mode (ATM) switch. For communication from servers  202  to station controllers  20 , network communication switch  208  arranges digital information received from servers  202  in a standard bidirectional digital communication format for transmission over network  14 . For communication from station controllers  12  to servers  202 , network communication switch  208  converts digital information from the standard bidirectional digital communication format for delivery to servers  202 . 
     Digital information from servers  202  is frequency modulated by a digital modulator system  210  for transmission over network  14 . Digital information that includes video programming is preferably modulated at frequencies greater than the standard analog television frequency range, which is 50-450 MHz under the NTSC television standard. Digital information that does not include video programming may be modulated at baseband frequencies that are less than the standard analog television frequency range, greater than the standard analog television frequency range, or between television signal frequencies. 
     A multiplexing system  212  receives and mixes the frequency modulated digital information from modulator system  210  and standard analog video signals obtained from a standard analog video feed  214  and delivers an IT composite signal to interactive network  14 . Analog video feed may be or include a satellite downlink, a cable receiver, or any locally generated programming. A reverse channel receiver system  218  receives and demodulates digital communications from station controller  20  for processing by servers  202 . 
     Having illustrated and described the principles of the present invention in a preferred embodiment, it should be apparent to those skilled in the art that the embodiment can be modified in arrangement and detail without departing from such principles. Accordingly, I claim as my invention all such embodiments as come within the scope and spirit of the following claims and equivalents thereto.