System for communication using a broadcast audio signal

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BACKGROUND OF THE INVENTION

The present invention relates to a system for communication using a broadcast audio signal being played over the speaker of a television or radio and an unconnected device located anywhere within the normal listening area. Until now, no system existed for communication through a television broadcast signal to a device locatable anywhere in general proximity to a television or radio receiver.

A remote system for playing a game while watching a live sports event on television is described in Fascenda et al., U.S. Pat. No. 4,592,546. However, the game control information does not come through the television receiver. Rather, it requires employment of sub-carrier techniques, and installation of special receivers capable of detecting out-band signals. Since the information is part of a separate signal, it cannot be taped for later use and must be produced by a live person anew upon each broadcast.

A system for playing games on a television picture screen is presented in Baer U.S. Pat. No. re. 32,305. It utilizes flashing "dots" to mean various things. The flashing dots appear in plain view on the screen, each representing an answer to a multiple choice question. The dot representing the correct answer has an odd number of flashes. The others have an even number. A gun with a photoelectric cell is aimed at a dot to choose the corresponding answer. The gun will light an indicator light if it detects a dot flashing an odd number of times. Alternatively, the photoelectric cell can be attached directly to a predetermined spot on the television screen.

The system of Baer has a number of shortcomings. It requires disturbing the normal television picture by the addition of brightly flashing lights in a specially dedicated portion of the screen. It also requires that the detecting device be aimed or placed directly on a predetermined spot of the television screen. It uses the video portion of a broadcast and so is inoperative with other communication receivers such as radios.

An audio signal is used by cable television networks to switch on and off a machine located at their local television stations. The signal consists of sequential Touch-Tones and it is used to turn on a tape player to broadcast a commercial advertisement. Another signal turns the player off, returning the broadcast to the network program.

This arrangement is limited in at least the following three ways. First, it employs only two different signals to simply turn a machine on or off. No significant information is communicated. Second, it is used only in-house, for the network to switch on its own station's machine. The station receives the signal from its source at the network over enormous dish antennae. Third, the signal is discernible to viewers, even though they have no use for it. The network momentarily blanks out the audio portion of its broadcast and instead plays multiple sequential Touch-Tones alone at a high volume.

Accordingly, it is an objective of the present invention to provide a communication system useful to anyone listening to a television or radio receiver. It is a further objective that encoded information employed in such a system be susceptible of taping.

It is yet another objective of the present invention to provide such a system that does not require disturbing or dedicating a portion of a normal television picture. It is another objective to provide a device for receiving information from a communication receiver, that need not be aimed at or attached in any way to the receiver. It is another objective that such system employ the audio portion of a broadcast so it is useful with radios as well as television.

It is still another objective of the present invention to use an audio signal to communicate various information. It is another objective that such communication be to the public and take place through the speaker of an ordinary television or radio receiver such that the recipient of the information need not have special receiving equipment. It is another objective that such signal be substantially indiscernible to listeners.

SUMMARY OF THE INVENTION

In accordance with the above objectives, the present invention provides a communication system using an encoded audio broadcast signal which is played over the speaker of an ordinary television or radio. The signal is encoded with tones representing various information. The information is communicated to members of the public who do not need special receiving equipment to receive the communication.

Information is encoded in-band in the same broadcast as a television or radio program, and so is detectable by a listening device directly from the usual speaker and can be taped for later or repeated use by a broadcaster or listener.

At the same time, the encoded information is substantially indiscernible to people watching or listening to the program which contains the information and therefore does not disturb an ordinary program or require blanking of part of the program signal to provide a dedicated portion for encoded information.

The apparatus employed for detecting and decoding the encoded information need not be aimed or attached in any way to the receiver. Further, the present system operates through the audio portion of a broadcast signal, so it is useful with any television or radio receiver. A listening device including means for detecting and decoding the information is provided which can be placed anywhere in proximity to a television or radio receiver.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram illustrating how encoded information is added to the audio portion of a program in the preferred embodiment.

FIG. 2 is a sketch of a game set up for use in the preferred embodiment.

FIG. 3 is a block diagram of FIGS. 3a and 3b.

FIGS. 3a and 3b are a schematic diagram of the game controller as employed in FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

In the preferred embodiment, tones in the audible range are broadcast to communicate information through the audio output of an ordinary television or radio receiver to an apparatus for playing a game.

FIG. 1 illustrates how tones of the audible range, such as Touch-Tones (697-1477 Hz), can be added to the audio-video tape 44 of a regular program. The tones are created by a studio engineer using a Touch-Tones generator 40. This is done at the same time as the engineer creates the program's usual sound effects with a sound effects generator 42, or later. The tones and the usual sound effects are added at appropriate places to the audio-video tape 44 of the program using a tape recorder 46.

There are other ways to ensure that an appropriate tone is included in the audio portion of a television or radio broadcast. For example, an engineer watching the program as it is recorded or as it is broadcast live could use a Touch-Tone generator 40 to create the tones appropriate to the action of the program, thereby causing the tones to be included in the initial audio tape or to be broadcast as part of a live transmission. Alternatively, the tones can be permanently put on a tape with the related sound effects so that the tones are always automatically generated at the appropriate time. The Touch-Tone generator 40 could also be permanently wired into sound effects generator operating automatically when a button is pushed.

Preferentially, the tone lasts two television frames (about one-fifteenth of a second), is masked by the usual sounds of the program played at the same time or otherwise temporally adjacently, and has less volume than a show's normal sound effects. In this manner, the Touch-Tone are substantially indiscernible to the listener. Despite this, a Touch-Tone decoder as used in this embodiment can reliably detect and decode such Touch-Tones. As known in the art, a decoder "listens" for a very specific pair of frequencies for each tone. The tones have no harmonic or subharmonic relationship to any of the others, and the two tones of each pair must be of substantially the same duration as each other. In the present invention, the controller 54 listens for pairs of specific duration, and only pairs of that duration will be employed to encode information.

It will be apparent to anyone skilled in the art that any set of tones can be utilized to communicate game control information. This communication can take place at any time during the broadcast, and the tones can be assigned different meanings depending on the show and how the home game is to be played.

Each Touch-Tone is assigned a pair of frequencies according to the "DTMF" ("Dual Tone Multi-Frequency") system known in the art. There are sixteen pairs recognized by Touch-Tone decoder 106.

The following example is one illustration, based on a home game designed for playing along with a television game show, the "Family Feud." The Touch-Tones corresponding to the given buttons on a telephone and given pairs of frequencies as assigned the following meanings in this example:

______________________________________ Telephone Frequencies (Hz) Button Meaning Assigned ______________________________________ 697 and 1209 1 Begin round One 697 and 1336 2 Begin round Two 770 and 1209 4 Begin "Fast Money" round Part One 770 and 1336 5 Begin "Fast Money" round Part Two 941 and 1477 0 Reset 941 and 1477 # Yes 941 and 1209 * No ______________________________________

The "zero" button tone is added to the beginning of the audio-video tape 44 of the "Family Feud Show" by the Touch-Tone generator 40 and tape recorder 46, to tell the home game to reset. It is masked by the buzzer sound effect ordinarily played while the master of ceremonies (M.C.) explains the rules of the game show. The tone can be masked by having it occur just before or after or during the buzzer sound effect. The tone is very short in duration and not as loud as the buzzer.

After the master of ceremonies reads the first survey question, there is a bell that rings as soon as the first participant pushes his answer button. Concomitant with this bell, the engineer adds a "one" tone to the tape 44. This signifies the start of round one of the show.

The studio participant suggests a likely response to the survey question. If he is correct that his answer was a popular response by those previously surveyed, a chime will sound, and a "#" tone is included on the audio-video tape 44. If incorrect, a buzzer goes off, and a "*" tone is made on the audio-video tape.

At the beginning of the second round of "Family Feud", a bell rings when a participant first pushes an answer button, making a "two" tone to signify the beginning of round two.

Similarly, a "four" tone will accompany the beginning of the final "Fast Money" round, and a "five" tone signifies part 2 of "Fast Money". In the "Fast Money" round, to be considered correct in the game of the present invention and therefore be signalled by a "#" tone, the participant's answer must match at least 25% of the survey response. Otherwise, a "*" tone will be added to the audio-video tape 44.

When the program audio-video tape 44 is broadcast, the audio portion of the signal includes not only the usual sound effects, music, and dialogue of the program, but also includes coded information in the form of Touch-Tones. These tones are part of the usual in-band transmission, yet convey more information. When received, each tone in the signal is substantially indiscernible by humans since it is very brief, masked by usual sound effects, and relatively quiet.

In FIG. 2, an encoded signal is received by an ordinary unmodified television 48. The television is tuned to the proper station to receive the program with the encoded signal. The audio portion of the show emanates from the television speaker 50 as usual. Since the tape 44 includes brief, quiet Touch-Tones, these emanate from the speaker 50 but are substantially indiscernible to humans. The game device 52 has a controller 54, however, which detects the tones if placed within the listening area of the speaker 50.

Answer buttons 56, 58, 60, and 62 are wired to the controller 54. These buttons allow the player or players of the home game to input their response to the action of the program they are observing on the television 48. In this example, the players listen to the survey question and the television contestant's response. If the home player thinks that the contestant's answer is correct (appears in the survey results), he pushes his "yes" button 64, 66, 68 or 70. Otherwise, he pushes his "no" button 72, 74, 76 or 78.

These responses can be accompanied by sound effects produced by the controller 54, through its speaker 79, or through speakers on the answer buttons 56, 58, 60 and 62. For instance, the first "No" response will be accompanied by a low, descending sound. Subsequent "No" responses will cause correspondingly lower sounds. The first "Yes" response will be attended by a higher, ascending tone. Subsequent "Yes" responses will generate even higher ascending noises.

The controller 54 detects and decodes the Touch-Tones described above, and locks out further response from the players' answer buttons 56, 58, 60 and 62 when it detects a "#" Yes signal or a "*" No signal which informs it whether the studio contestant was correct. Then the controller 54 compares this to responses received from the home players.

The controller 54 tallies the score depending on which Round is being played (Round Two scores are doubled, and Round Three scores are tripled) and whether the answer was correct. The controller 54 causes various information to be displayed. Digital readouts 80, 82, 84 and 86 display the current score for each player. Indicator lights 88, 90, 92 and 94 show what answer each player has given. Indicator lights 95, 96, 97 and 98 show which player was first, second, third, or fourth to input his response. Of course, other information could be displayed in a number of ways apparent to one skilled in the art. The displays could be part of the controller 54 or the individual answer buttons 56, 58, 60 and 62.

Several seconds later, the controller 54 releases the lockout and once again accepts responses from the home players to the next question on the show.

The game device 52 is powered by a power cord 99 attached to a wall outlet 100. Alternatively, the device 52 can be powered by batteries.

The controller 54 is shown in greater detail in FIG. 3. The Touch-Tones are detected by a microphone 101. This signal is processed through a band-pass filter 102 and an amplifier 104. Each of these components can be a single stage op-amp such as a standard National Semiconductor L.M. 741. Alternately, the two can be combined in a double stage op-amp.

The signal is then decoded by a Touch-Tone decoder 106, which can be a Mitel 8870 or SSI 202. The Touch-Tone decoder 106 only accepts frequency pairs of the same length, and can be used to accept only Touch-Tones of a given length. To accomplish this, the Touch-Tone decoder 106 is crystal controlled via a crystal 107. This is a standard 3.579545 MHz color television crystal. The crystal 107 provides a stable time reference for the Touch-Tone decoder 106.

When the decoder 106 detects a Touch-Tone, it provides a signal representing the tone on wires 108, 110, 112 and 114. These four wires carry the four bits needed to distinctly indicate one of sixteen possible Touch-Tones.

The central processing unit (CPU) 116 can be a M