HK1033403A - Cordless phone back link for interactive television system - Google Patents

Description

Cordless telephone reverse link for interactive television system

This application is a divisional application of the' 97193426.6 application.

The present invention relates generally to television and telephone systems and, more particularly, to an interactive television system integrated with a cordless telephone circuit for effecting automated telephone communications between the interactive television system and a central station.

One trend that has emerged in the cable television and Digital Satellite System (DSS) markets is to emphasize pay-per-view (PPV) television programming as a source of revenue. An ideal PPV television system would allow viewers to purchase the right to watch television programs, such as movies, sporting events, or other special events, at a minimum cost to the viewer. For example, after viewing a brief preview or advertisement of a PPV program, the viewer may gain access to the PPV program by simply pressing a select key on the viewer's remote control for a television or Video Cassette Recorder (VCR). In another example, a viewer is watching an information commercial or a home shopping program and the viewer wants to purchase an advertised product by pressing a select key on a remote control. In various existing television systems, in order for a viewer to be able to schedule access to a PPV program, the viewer must use the viewer's phone to call the PPV program provider (e.g., a cable company) and enter its cable box serial number, credit card number, and PPV program identifier. The PPV program provider then manipulates the cable box to display the selected PPV program to the user. In the case of home shopping, the viewer must write the advertiser's phone number and product logo, make a phone call, call the advertiser or home shopping service provider, and then tell the clerk the desired credit card and product selection information.

In some recent systems employing digital set-top boxes (such as DSSs), the set-top box itself is directly connected to the telephone line at the viewer's home, while the remote control contains a button for ordering PPV programs. When the viewer presses this key, the phone number of the PPV program provider is automatically dialed, and the set-top box identifier and the PPV program identifier are automatically transmitted to the PPV program provider via the phone connection. In this scenario, the viewer must establish a credit card account with the PPV program provider for billing purposes before pressing the button to select a PPV program. One major drawback is that in order to operate these systems efficiently, it is required that the set-top box and the television set must be close to the telephone socket in the viewer's home, so that the set-top box, the television set and the telephone socket are directly connected by wires. In many homes, the television is not close to the telephone outlet, or even in the same room, making such a system unsuitable for widespread use. An interactive television system that overcomes this drawback has considerable value in PPV, home shopping, and other interactive viewing situations.

It is an object of the present invention to provide a communication link from a television system located at the home of a viewer back to a central station.

It is another object of the present invention to provide a television system having full cordless telephone capability, thereby allowing information to be automatically transmitted from the television system to a central station via a telephone connection.

It is another object of the present invention to enable television viewers to easily order PPV programs and purchase products during home shopping television programs simply by pressing a button on their television remote control.

It is yet another object of the present invention to enable a television system for viewing PPV programs and for home shopping applications to be placed anywhere in the viewer's home without the need for a telephone outlet to be approached.

It is also an object of the present invention to provide a television system with full cordless telephone capability that allows automatic transmission of information via a telephone connection and that finds a balance between price and convenience for the viewer.

Additional objects, advantages and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.

The above and other objects and advantages are obtained in accordance with the present invention by a system for transmitting information from a television viewer to a central station including a remote control for transmitting command signals from the viewer to a television or Video Cassette Recorder (VCR). Circuitry integrated with the television or VCR receives the command signals from the remote control and interprets the signals to form a viewer command, such as a purchase command, for communication with the central station. The circuitry automatically transmits dual tone multi-frequency (DTMF) audio signals representing the command over a Radio Frequency (RF) link to a cordless telephone base unit that is connected to the central station over a public switched telephone network. The cordless telephone base unit initiates a telephone call to the central station and transmits DTMF audio signals received from the DTMF circuit to the central station. Because of the advantages of radio frequency communication, the television or VCR need not be located in the same room as, or in close proximity to, the cordless telephone base unit. The television receives a television signal and extracts information relating to an advertised product in the television program from the vertical blanking interval of the television signal. The information may include a telephone number of a central station used to make the telephone connection and identification information of the product. A cordless telephone handset is included that establishes communication with the cordless telephone base unit, thereby enabling a television viewer or other user to utilize the cordless telephone for ordinary telephone calls.

In one embodiment of the invention, a method of purchasing a product advertised in a program displayed on a television set includes receiving a purchase command from a remote control of the television set, transmitting the purchase command to the television set via an infrared link, and initiating a telephone connection to a central station by a cordless telephone base unit. The purchase command is then transmitted by a dual tone multi-frequency signal generating circuit located in the television set to the cordless telephone base unit via a radio frequency link. The cordless telephone base unit transmits the purchase command to a central station via a telephone connection. The central station then processes the purchase order.

In another embodiment of the invention, the circuitry for transmitting the DTMF tone signals is contained in the remote control, rather than in the television set. In this embodiment, when the viewer presses a key on the remote control to transmit information such as a purchase command to the central station, the remote control controls the DTMF circuitry to send a DTMF audio signal representing the viewer's command to the cordless telephone base unit. These DTMF audio signals are then forwarded to the central station via a telephone connection. In this embodiment, the television set still extracts information from the vertical blanking interval of the television signal, but the extracted information is transmitted to the remote control for processing.

Still other objects and advantages of the present invention will become readily apparent to those skilled in this art from the following more detailed description, wherein there is shown and described a preferred embodiment of this invention, simply by way of illustration of the best mode contemplated of carrying out the invention. As will be realized, the invention is capable of other and different embodiments and its several details are capable of modifications in various obvious respects, all without departing from the invention. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive.

Fig. 1 is a block diagram of the present invention.

Fig. 2 is a schematic diagram of a DTMF circuit.

Fig. 3 is a functional block diagram of a data transmission system for television signals.

Fig. 4 is a block diagram for explaining the main components of the television and the remote controller.

Fig. 5 is a block diagram of an alternative embodiment of the present invention.

Fig. 6 is a flow chart for explaining the high-level operational steps of the present invention.

Fig. 7 is a menu display diagram for displaying a list of service providers.

FIG. 8 is a simplified menu display for displaying a listing of purchasable items from a selected service provider.

Fig. 9 is a diagram of a display for notifying a viewer of the status of a telephone subscription.

The present invention is a reverse link system for connecting a television, VCR or other device (hereinafter "television") heretofore designed to receive information substantially only from a central station to a cordless telephone base unit by enabling the television to perform certain functions of a cordless telephone handset. The present invention enables a television set to include the functionality of a cordless telephone handset, thereby enabling the television set to initiate a telephone call directly through the cordless telephone base unit and transmit viewer or user selected information to a central station over a public switched telephone network via a telephone connection.

Fig. 1 is a block diagram of the present invention. Television set 10 receives television signal 12 from a signal source. The television 10 may be a standard television, a VCR or any other device capable of tuning a television signal. The television signal may be received from an antenna, cable, satellite signal, or any other transmission medium for television signals. The television 10 includes a dual tone multi-frequency (DTMF) circuit 14.

DTMF circuitry 14 is similar to the corresponding portion of a well-known cordless telephone handset. DTMF circuitry, however, does not contain some of the typical handset features such as microphone, speaker, ring speaker, volume control, switch, lock key, mute key, keypad, and rechargeable battery, because DTMF does not directly communicate with the telephone user. Thus, the manufacturing cost of the DTMF circuit can be kept very low compared to a normal cordless telephone handset. Note that the primary purpose of the DTMF circuitry is to transmit DTMF audio signals to an already existing cordless telephone base unit 16. The DTMF circuitry need not transmit voice signals or receive voice or DTMF audio signals. An already existing cordless telephone base unit 16 can establish communication with a standard cordless telephone handset 17. A television viewer or other user may use the base unit in conjunction with a cellular telephone to effect telephone calls in the usual manner. DTMF audio signals may be used to place a telephone call or to transmit alphanumeric data required to effect a viewer transaction, such as the purchase of a product or PPV television program.

It is noted that the present invention uses an existing cordless telephone having a base unit and a handset to form a bi-directional transmission link with a television set. The cordless telephone base unit 16 performs the conventional functions of the transmission link between the public switched telephone network and the cordless telephone handset 17 as well as the transmission link between the public switched telephone network and the television set 10. In other words, the cordless telephone base unit performs two functions.

The DTMF system adopts a frequency combination mode of international standard. Each alphanumeric character is encoded in the form of two pairs of tones for transmission over a telephone line. In conventional DTMF signaling, the digits and symbols displayed on the telephone keypad are each transmitted in the form of a dual tone. For example, the number "1" is represented by an audio frequency containing frequencies 697Hz and 1209Hz, and the asterisk "is represented by an audio frequency at frequencies 852Hz and 1477 Hz. A total of seven different frequencies are used in pairs to transmit ten digits and two symbols on a common telephone keypad. In some systems, four additional characters are also provided. The matrix of table i shows the high and low frequency pairs required for each of the 16 possible characters, in hertz (Hz). Each character is represented by two sets of audio signals that, when transmitted together, are identified as a unique representation of the character.

TABLE I

Low frequency (Hz)	High frequency 1209	High frequency 1336	High frequency 1446	High frequency 1663
	697	1	2	3	A
770	4	5	6	B
852	7	8	9	C
941	*	0	#	D

In order to transmit alphanumeric characters in addition to ordinary numbers and symbols over a telephone line, seven standard frequencies 697Hz,770Hz,852Hz,941Hz,1209Hz,1336Hz, and 1447Hz are used, and an eighth frequency, which is not normally used, is used. The eighth frequency has a value of 1633 Hz. The additional frequencies are only used to transmit those characters that are not normally transmitted via DTMF signaling. To indicate the transmission of alphabetic characters, the first tone identifying the alphabet in a pair of tones contains an eighth frequency as one of its components. Each letter comprises a first tone having an eighth frequency combined with one of the seven commonly used frequencies, followed by a second tone consisting of any two of the eight available frequencies. Similarly, other non-conventional characters, such as punctuation marks and spaces, are transmitted by generating a unique pair of dual-frequency tones.

DTMF reception capability may also be provided by modifying the DTMF circuitry, however, voice reception is not required. Based on this feature, it can be determined whether a dial tone is available on the telephone line, the line is not busy, or confirmation data relating to a transaction is received.

Fig. 2 is a schematic diagram of the DTMF circuit 14. Wherein an isolation circuit 100 is coupled to an antenna 102 and to an output of a transmitter section 106 via line 104 and to an input of an optional receiver section 110 via line 108. The voltage supply input of the receiver portion 110 is connected via line 112 and control to switching circuitry 114, which circuitry 114 is connected to microprocessor 116 for controlling the operation of the receiver portion 110. An output of the receiver section 110 is connected to a line 118 and the line 118 is connected to an input of a 1633Hz detector 120. The output of the 1633Hz detector 120 is applied to the control and switching circuit 114 via line 122. A control input of the 1633Hz detector 120 is connected to an output of the microprocessor 116 via line 124 and to the control and switching circuit 114. Microprocessor 116 contains an audio generator which may be a DTMF integrated circuit of a standard type. When the output of the receiver section 110 produces a 1633Hz signal and this is detected by the 1633Hz detector 120, the microprocessor 116 is operative to communicate with the television 10 on line 126. The DTMF tones received by the receiver section 110 are applied via line 112 to a control and switching circuit 114, in which the DTMF tone signals are converted to digital signals. These digital signals are then sent to the microprocessor 116 for eventual transmission to the television 10 via line 126.

To transmit the DTMF audio signals from DTMF circuitry 14 to cordless telephone base unit 16, a summing amplifier 128 is employed, the output of which is connected to transmitter section 106 by way of line 130 to frequency modulate the output of the transmitter section. The control input of the transmitter section 106 is connected to the switching circuit 114 via line 132 and control. The microprocessor receives the digital signal to be transmitted from the television set 10 via line 134. The microprocessor applies an 83Hz square wave signal on line 136 to an 83Hz filter 138 which is connected to the input of the summing amplifier 128 on line 140. The output of the transmitter section is then modulated to emit a substantially sinusoidal 83Hz burst to communicate to the cordless telephone base unit 16.

After transmitting an 83Hz burst, microprocessor 116 forms a 98Hz encoded signal on line 142 that is used as a second input to summing amplifier 128. The cordless telephone base unit detects the encoded signal and, if received correctly, the cordless telephone base unit forms a 1633Hz "handshake" signal which is passed back to the DTMF circuitry and detected by the 1633Hz detector 120. Microprocessor 116 then forms a 98Hz encoded null signal on line 142 for transmission by transmitter portion 106. If the zero signal is correctly detected by the cordless telephone base unit, the transmission of the 1633Hz handshake signal is terminated and the microprocessor transmits by forming another coded signal on line 142, in response to the termination of the handshake signal, repeating the sequence until it is deemed that communication has been effectively established. Power for the DTMF circuitry is provided by television 10 via line 144. The clock circuit of the microprocessor 116 is connected to the power supply line 144 via a resistor 148 via a crystal 146.

Cordless telephone base unit 16 then operates to connect to the external telephone line and allows a dial tone to be transmitted back to DTMF circuitry 14. DTMF audio signals used to dial a telephone number are then sent from the microprocessor 116 to the cordless telephone base unit 16 and the cordless telephone base unit establishes a telephone connection. DTMF audio signals representing viewer transaction information may now be transmitted from the television 10 to the central station 22 via the cordless telephone base unit 16 and telephone line 20.

In an alternative embodiment, the DTMF circuitry may be configured to be compatible with the viewer's existing cordless telephone base unit. Some cordless telephones contain digital code security to prevent other handsets from communicating with the base unit. The handset and base unit of the cordless telephone share a digital code. DTMF circuitry 14 may be configured to receive and use this code (by employing a learning remote or memory setup data method), much like a general purpose infrared remote control. Alternatively, it is contemplated that the cordless telephone manufacturer may include a code that disables this security feature when the cordless telephone base unit 16 receives the code. Accordingly, the DTMF circuit may be configured to transmit a specific deactivation code to the cordless unit base unit by again employing the learning remote or storage setup data method.

Referring back to fig. 1, DTMF circuitry 14 and cordless telephone base unit 16 communicate over a plurality of communication channels via Radio Frequency (RF) link 18. Thus, the DTMF transmitter and cordless telephone base units each contain an antenna (not shown in fig. 1) for transmitting and receiving RF signals. Full duplex communication between cordless telephone base unit 16 and DTMF circuits 14 is achieved by frequency modulating and demodulating signals on FCC designated frequency channels. The RF link may be used as a 900MHz digital spread spectrum communication path, as provided by circuitry included in, for example, a CLT-926 type cordless telephone commercially available from sanyo consumer Electronics. Spread spectrum is a modulation technique in which the information content of a modulated waveform is spread over a wider bandwidth than the bandwidth of the original information signal. Spread spectrum systems take an input signal, mix it with FM noise, and "spread" the signal over a wide frequency domain by fast frequency hopping. The spread signal has a wider bandwidth and is less likely to interfere with other signals than the original message.

An overview of Spread Spectrum technology is given by John Wiley & Sons in "Spread Spectrum System" by r.c. dixon, published in new york in 1984. One type of spread spectrum modulation is frequency hopping. According to Dixon, a frequency hopping system or "frequency hopper" includes a code generator and a frequency synthesizer responsive to the code output of the code generator. And according to Dixon, it is more accurate to refer to "frequency hopping" modulation as "multi-frequency, code-selection, frequency-shift keying". Apart from extending the frequency selective set to a great extent, it is simply Frequency Shift Keying (FSK). Simple FSK typically uses only two frequencies; for example, transmission F1 indicates "mark (mark), and transmission F2 indicates" space "(space). Frequency hops, on the other hand, can typically use thousands of frequencies. The number of frequency selections and the rate of hopping in any hop is determined by the requirements of the particular application for that hop. Cordless telephones designed to operate in the frequency hopping regime are now commonly available from many manufacturers, such as Lucent Technologies, Motorola, Sharp, and others.

By employing digital spread spectrum communication, the RF link 18 exhibits excellent noise immunity, longer operating range, automatic optimum channel selection, and excellent security against eavesdropping. However, the cordless telephone circuit may also implement the RF link 18 by operating on a selected one of 10 designated frequency channels in the FCC allocated 46-50MHz band.

Rather than being integrated with the television 10, the DTMF circuit 14 may also be a separate unit, i.e., a "set-top box," which is connected directly to the telephone broadcasting of the DSS or to a digital distribution box.

The cordless telephone base unit 16 may or may not be located in the same room as the television 10 and DTMF circuits 14. For efficient operation, the distance between the cordless telephone base unit and the DTMF circuitry may extend to hundreds of feet, which far exceeds the needs of residential applications. The cordless telephone base unit 16 is arranged to be connected to at least one telephone line and to a 120 volt Alternating Current (AC) line cord (not shown) for plugging into a standard electrical outlet. Alternatively, the connection to the public switched telephone network may be via a cellular network. The cordless telephone base unit 16 may include one or more control and signaling keys (not shown). An exemplary embodiment of a cellular Telephone base unit is shown in U.S. patent No. 4,706,274 entitled cordless Telephone System, issued to Baker et al. The cordless telephone base unit may incorporate features such as an internal speaker, a microphone, line selection keys, a lock key, an intercom call switch, an answer key, a volume control knob, and various lights to display such features as power availability, incoming call, and lock status. The cordless telephone base unit need not contain the socket of the cordless telephone handset, as the typical telephone handset part is integrated with the television 10; thus, such a socket may not be required. For the same reason, the cordless telephone base unit does not have to include a portable handset battery charger. However, existing cordless telephone base units 16 can be employed to effect telephone calls in the usual manner without modification to existing cordless telephone handsets 17. In other words, the cordless telephone base unit 16 can perform dual functions-both as a standard telephone for two-way voice transmission and as a data transmission link from the television to the telephone network.

Cordless telephone base unit 16 may also be used as an answering telephone completely independent of DTMF circuitry 14. To receive a call with the cordless telephone base unit, the cordless telephone base unit operates as a conventional "speakerphone" by pressing an answer key (not shown).

The cordless telephone base unit 16 is coupled to a central station 22 via a public slave switched telephone network 20. The central station includes components for answering incoming telephone calls, receiving transaction data from the cordless telephone base unit, performing the transaction, and transmitting confirmation data back to the television. The central station represents a centrally located PPV program provider, cable company, or broadcast station or network. Typically, the central station also contains a general-purpose computer system and associated circuitry, as is well known, to perform the functions described above.

The cordless telephone base unit 16 may also communicate with other telephones, such as a subscriber 21, over a public switched telephone network 20.

In a preferred embodiment of the present invention, PPV or home shopping control information is embedded in the television signal at the central station 22 or other location and then extracted from the television signal 12 by the television 10 (the extraction and control capabilities may also be contained in a VCR or other device). One way of embedding information in a television signal is to embed the information in the Vertical Blanking Intervals (VBIs) of the television signal. These vertical blanking intervals may contain closed caption data for listening to defective and Extended Data Services (EDS) data.

In a Cathode Ray Tube (CRT) video device such as a television, a video image is formed by scanning a light beam along a predetermined line pattern across the screen. Each time all the lines are scanned, a so-called frame is generated. In the National Television Standards Committee (NTSC) implementation adopted in the united states, each frame is scanned 30 times per second. Each television frame comprises 525 lines which are divided into two separate fields, respectively referred to as field 1 ("odd field") and field 2 ("even field"), each field having 262.5 lines. Therefore, these odd and even fields are alternately transmitted at a frequency of 60 Hz. In a process called interlacing, the lines of the odd and even fields are interlaced every 1/30 seconds to produce a complete 525 line frame. Another standard around the world uses 625 lines of information, interlacing 312 and 313 lines at 50 fields per second. In the 525-line NTSC standard adopted in the united states, approximately 480 lines are displayed on a television screen.

An interlaced scan pattern for a typical television receiver involves scanning CRT beams horizontally across the screen from the upper left corner. After the first top row is scanned, the beam returns to the left for a period of time called the line blanking interval and the scan is repeated along another row parallel to and below the previous row. The scanning process continues line by line until the beam reaches the center of the bottom of the screen to complete field 1.

From the bottom of the screen, the beam returns to the top position to begin scanning approximately from the midpoint of the screen along the lines of field 2 that are staggered from the lines of field 1. The jump from bottom to top is not instantaneous and requires in practice a length of time to scan 21 horizontal lines. These lines are 1 to 21 lines of field 2. The second half of line 21 of field 2 is shown. Lines 285 to 525 of field 2 are then scanned to complete field 2. When the light beam reaches the lower right corner of the screen, an image frame is formed. The beam then returns to the top.

During the time between the two fields, the beam returns from the bottom to the top of the screen, it carries no video or image signal, since it does not generate any pixels on the screen. This time interval is commonly referred to as the Vertical Blanking Interval (VBI). The duration of which is typically 21 times the duration of the scanning beam across the screen. The apparatus and methods for making the NTSC standard with 21 lines in each VBI are well known to those skilled in the art and will not be discussed in detail herein.

Since no image is formed on the display during the VBI period, there is no need for the television broadcast signal to carry any image information. The VBI is thus used to convey auxiliary information from the television network or station to the viewer. For example, limited caption data related to television programming is transmitted as an encoded composite data signal on line 21 of the VBI of field 1 of a standard NTSC video signal. Lines 1 to 9 of the VBI of each field are used for vertical synchronization and post-equalization pulses. Thus, lines 10 to 21 may be used to convey auxiliary information.

Fig. 3 is a functional block diagram of a data transmission system for television signals. As used herein, the terms "broadcast" and "transmit" may be used interchangeably for transmission of signals via cable or fiber optics, to and from satellites, over the air, and other similar means. The data transmission system is the source of television signal 12 received by television set 10 of fig. 1. A network headend 160 transmits a composite television signal containing the inserted information in one portion (typically the vertical blanking interval) to a satellite 162, and the satellite 162 rebroadcasts the same signal to a local simulcast station 164. The simulcast station 164 may further insert data into the VBI of the received television signal and transmit the data to a local cable television station headend 166. The cable television station headend 166 receives television signals from a plurality of signal sources, including satellites, and may further insert data in the VBI of any of the television signals. Signals from multiple sources are combined into a composite television signal, amplified and provided via cables to a plurality of different receivers 168. In the preferred embodiment, television 10 of FIG. 1 is an example of receiver 168, but such receivers may include cable boxes, VCRs, and satellite receivers in addition to television sets. In addition, each receiver 168 may receive signals directly over the air from the local simulcast station 164, via satellite 162, or via cable.

More specifically, the network headend 160 contains a Video Tape Recorder (VTR)170 to provide program signals to an inserter 172. The controller 174, also at the head end, controls the scheduling for retrieving tapes from the cartridge (i.e., a machine with multiple video cassettes that are removed from a storage location and inserted into the VTR by a robotic arm, or vice versa). In addition, the controller 174 controls stage lighting during a live television broadcast such as a news lineup. The controller 174 is typically a microprocessor-based system. Service computer 176 controls the presentation of individual segments of the video cassette, the insertion of commercials therebetween, and the precise timing of switching between different programs. Some network head-ends 160 contain both a service computer 176 and a controller 174.

The controller 174 provides data and commands to the inserter 172. The service computer 176 provides data and commands to the controller (if one is present). Otherwise, the service computer provides these signals directly to the inserter 172. The inserter 172 inserts the data into the VBI of the composite television signal and provides the television signal to the transmitter 178, which in turn provides a television signal on a microwave carrier to the satellite pan bottom antenna 180 for transmission to the satellite 162.

The satellite 162 again transmits the received signal, which is received by the satellite pan bottom antenna 182 of the simulcast station 164. The satellite pan bottom antenna 182 provides the signal to a station inserter 184 located at the local simulcast station 164. The simulcast station may also insert data in the composite television signal. The television signal is then provided to a transmitter 186, which in turn is provided to a transmit antenna 188.

The local cable station headend 166 has a plurality of satellite pan antennas 190 and 192 for receiving signals from a plurality of network headends 160 and simulcast stations 164. The signals received from each satellite pan bottom antenna and antenna are provided to respective inputs of a multi-channel interpolator 194, which may also interpolate data in the VBI of the received signal. The multi-channel output of the interpolator 194 is amplified in amplifier 196 and transmitted to the respective receivers 168 via cables 197. Alternatively, the receiver 168 may receive broadcast information via an antenna or a satellite receiver.

Note that the central station 22 of fig. 1 may be located at the network headend 160, the simulcast station 164, or the cable station headend 166, and may be separately integrated with elements of fig. 3, such as the network headend, the simulcast station, and the cable station headend. Alternatively, the central station 22 may be located at a different location than the network headend, the simulcast station, or the cable station headend. In either case, the operator of the central station 22 will provide information regarding the PPV event and the home shopping product inserted in the VBI of the television signal during the broadcast of the associated advertising segment.

The manner in which the subtitle data is decoded for use in a data transmission system is further described in the following specification, which is incorporated herein by reference: title47, Code of Federal Regulation (CFR) (Federal Code rules), Part 15, as addressed by GEN. Docket No. 91-1; FCC 91-119; "CLOSED CAPTION DECODER request FOR CLOSED CAPTION DECODER FOR television receiver; title47, CFR Part 73.682(a) (22), Caption Transmission format; title47, CFR Part73.699, figure 6; "TELEVISION SYNCHRONIZING WAVE FORM"; title47 CFR part73.699, figure 17 a; "LINE 21, FIELD 1 DATA SIGNAL FORMAT (21 st row data signal FORMAT of 1 FIELD)"; and PBS Engineering Report No. E-7709-C, "TELEVISION CAPTIONING FOR THE DEAF: SIGNAL ANDDISPLAY specific (television caption: signal and display specification for deaf-mute).

Extended Data services are further described in Recommended Practice for Line 21 Data Service, the electronics industry association, EIA-608 (filed 10/12/1992 and 6/17/1993), the main contents of which are also incorporated herein by reference. Under this standard, additional data is provided in the 21 st line of 2 fields of the field blanking interval. The additional data includes two closed caption segments, two text mode segments, and an extended data service. Extended data services include, among other information, program name, program length, presentation length, number of channels, network affiliates, station call letters, Universal Coordinated Time (UCT), time zone, and gap saving process. In the upstream portion of the network head end 160, the network inserts the program name, program length, lineup length, network lineup station, and UCT. In the downstream portion of the simulcast station 164, the simulcast station inserts the number of channels, time zone, space saving process, and program name. The network head-end inserts data that are identical for different simulcast stations. PPV events and home shopping products may be inserted by the network headend 160, the affiliate radio 164, or the local cable television station headend 166.

Data may be manually entered from the local terminal 198. The terminal 198 may be utilized to create, retrieve, or edit information to be used as insert data. The terminal 198 typically comprises a computer. In addition, a modem 199 may be used to provide data to the inserter 172. The data may be provided manually or automatically from a remote station, such as the central station 22. The output of the inserter 172 is a composite television signal containing PPV transactions and home shopping data.

Referring back to fig. 1, the viewer uses the remote control 24 to transmit commands to the television 10 via an infrared link 26. Remote control 24 contains BUY (buy) button 28 which the viewer presses to initiate a purchase transaction. The television 10 receives BUY the (buy) command and informs DTMF circuit 14 of the need.

Fig. 4 is a block diagram illustrating the main components of the television 10 and the remote control 24. The television 10 is capable of decoding the lines of the vertical blanking interval and employing the embedded information to support PPV and home shopping applications. The television set includes a tuner 200 for receiving a television signal 12 from an antenna, cable box, satellite receiver, or other signal transmission medium. VBI decoder 202 is coupled to the output of tuner 200. A microprocessor 204 executing television control logic receives the output of the VBI decoder 202. The microprocessor controls the output of the television signal 12 to a monitor 26 for viewing by a viewer. The microprocessor 204 also communicates with the DTMF circuits via output line 134 and input line 126. The microprocessor executes programming instructions to support PPV, home shopping, and other applications. The infrared receiver "R" 208 receives commands and data from the remote control 24 and then forwards them to the microprocessor 204 for processing.

The remote control 24 includes an infrared transmitter "T" 210 for transmitting commands and data to the infrared receiver 208. The microprocessor 212 controls the operation of the remote control by receiving input data from the keypad 214, displaying output data on a Liquid Crystal Display (LCD)216, and sending commands and data to the infrared transmitter 210 for transmission to the television 10. A key (e.g., "BUY (buy)" key, or a key indicating a PPV program or a television channel) is included in the keypad 214 to select a special function related to the PPV or home shopping application.

In a preferred embodiment of the present invention, the program related information embedded in the vertical blanking interval lines of television signal 12 contains a telephone number associated with the information being broadcast. VBI decoder 202 extracts the telephone number from the program related information from the television signal and microprocessor 204 sends the number to DTMF circuit 14 to initiate a telephone connection.

It is noted that the difference between the present invention and the concept that the remote control is also a telephone is the way in which the data is synchronized and arranged in the television 10, which itself can simultaneously receive data from the television signal 12. This synchronization of data allows the viewer to respond to certain stored or time sensitive information displayed on the television (provided to the television in either digital or analog form) by pressing keys on remote control 24. The television 10 then combines the received command information with the PPV program or product identification data and the telephone number for transmission to the cordless telephone base unit 16 for processing by the central station 22.

Fig. 5 is a block diagram of an alternate embodiment of the present invention. In this embodiment, the DTMF circuit 14 is located in the remote control 24, rather than in the television 10. Two-way communication is now required between the television 10 and the remote control 24 so that the decoded VBI data (e.g. telephone number and product information) can be forwarded to the remote control 24 for processing by a microprocessor in the remote control. In this case, it is important to identify which PPV program the viewer is purchasing. Separate keys (not shown) may be included in the remote control 24; these buttons are labeled with the names of various PPV programs or services (e.g., HBO, SHOWTIME, ESPN, etc.). To select a PPV program, the viewer presses the key representing a particular service and then presses BUY (buy) key 28. As shown in fig. 1, DTMF circuitry 14 may also include the capability to receive data. However, since no voice transmission or reception is required, the circuitry required to implement DTMF transmission and reception is smaller and simpler than in a conventional cordless telephone handset.

The flow chart of fig. 6 illustrates the high-level operational steps of the present invention. Following initial step 300, television set 10 receives data regarding commercial segments in the vertical blanking interval lines of television signal 12 at step 302. For example, the advertising segment may contain a next PPV event or a preview of the next product sold in the case of home shopping. The embedded data includes a program or product identifier and the phone number of the PPV service provider or vendor. The advertising segment also contains the price of the PPV item or product so that the viewer can make an informed decision as to whether to purchase the product or the right to view the advertised PPV item. At step 304, the viewer views the advertising segment displayed on the television and is audibly or visually alerted of the response. If the viewer decides to purchase, the viewer presses BUY (buy) key 28 on the viewer's remote control 24 at step 306. Next, at step 308, the remote control 24 transmits a signal via the infrared transmitter 210 to the infrared receiver 208 located in the television 10. The signal contains a special code for the BUY (buy) key to inform the microprocessor 204 in the television that the viewer wants to purchase the currently advertised PPV item or product.

At step 310, the microprocessor 204 combines the received BUY command with the viewer's identification information (which has been stored in memory located on the microprocessor 204 during the time that the television 10 is turned on) and the embedded advertising data described above. The viewer identification information may include the viewer's credit card information for payment and billing purposes. At step 312, the cordless telephone base unit 16 initiates a telephone call, and the DTMF circuit 14 connects the call through the cordless telephone base unit to a central station identified by a telephone number. Microprocessor 204 of television 10 then sends BUY (purchase) commands to cordless telephone base unit 16 via DTMF circuit 14 at step 313. After the connection is established, BUY (purchase) command information is forwarded to the central station at step 314. The central station processes the BUY (purchase) command and sends an acknowledgement message back to the cordless telephone base unit 16 at step 316. Processing of the BUY (buy) command may include the step of enabling the viewer to receive access to a predetermined PPV event or to receive an order for an advertised product. The cordless telephone base unit relays the confirmation message to the television via DTMF circuit 14 and microprocessor 204 at step 318. Next, at step 320, the microprocessor 204 of the television 10 stores some or all of the confirmation message and displays some or all of the confirmation message on the monitor 206. The viewer is thus immediately given feedback that the viewer's order for the event or product has been accepted. The confirmation message may also contain information about the PPV event or product, such as the planned delivery date of the product. The television then ends the television call at step 322 and the process terminates at end step 324.

In another preferred embodiment of the present invention, the viewer may order a program or product that is not currently being advertised by accessing a series of menus. The microprocessor 204 includes a memory 205 (fig. 4) for storing a telephone directory containing a list of names of service providers, e.g., PPV program providers and home shopping channels, and telephone numbers corresponding to each service provider. The microprocessor 204 may also store additional viewer identification information in the memory 205, such as a viewer account number for a particular service provider.

Information about the service provider, including its name and associated telephone number, is transmitted by the central station 22 within the VBI and received by the microprocessor 204. The microprocessor creates a list of the received useful service providers and assigns each service provider a provider reference number 400 stored in the memory 205. The service provider information may be transmitted by the cable company or by a different service provider. When the microprocessor receives information from a new service provider, the telephone directory can be expanded at any time.

As shown in fig. 7, when the viewer presses a MENU key provided on the keypad 214, the microprocessor 204 is responsive to display a list of service provider names with associated provider reference numbers in a main MENU 402.

The central station 22 also transmits a list of the various useful items currently provided by each service provider within the VBI. Each item is identified by an associated item reference number 404. Once the viewer has pressed the identification number of one of the service providers listed in main menu 402, the microprocessor immediately responds and displays on television 10 a directory display 406 containing a list of all items available from the particular service provider and the corresponding item reference number for each item, as shown in fig. 8.

The viewer selects an item by pressing a key on the keyboard 214 corresponding to the item reference number 404 for that item. As a result, as shown in FIG. 6, the microprocessor 204 performs steps 310 through 324, but processes the item reference number and stored service provider information instead of BUY (purchase) commands and embedded advertisement information to form a purchase command.

For example, if the viewer presses key "1" on keyboard 214 while the main menu of FIG. 7 is displayed, microprocessor 204 will display the directory of FIG. 8 on television 10. If the viewer presses the "2" key again, the microprocessor will initiate steps to schedule the PPV program "Blade Runner".

In an alternative preferred embodiment, the microprocessor controls the DTMF circuit to initiate a telephone call to the service provider immediately after the service provider is selected from the main menu but before an item is selected. Thus, the time required to connect to the central station 22 after an order is reduced.

In yet another alternative preferred embodiment, the steps for displaying and selecting a service provider from main menu 402 may be eliminated from the purchase sequence. According to this embodiment, when the television 10 is tuned to a broadcast program of the service provider, such as a home shopping channel program or an advertisement of a PPV program provider, the viewer presses the LIST key on the keypad 214, and the microprocessor 402 responds by displaying a directory display 406 for a particular service provider. When the viewer selects an item, the microprocessor accordingly combines the item reference number carrying the service provider information embedded in the VBI with the stored viewer identification information to form a purchase command.

Many telephone lines have call waiting features that can interfere with the connection between the central station 22 and the cordless telephone base unit if a telephone call is entered during the connection. In accordance with another embodiment of the present invention, the DTMF circuitry may have the capability to identify an incoming call and, in conjunction with the microprocessor, may automatically disconnect from the central station 22 and reestablish the connection when the line is not busy, thereby allowing the cordless telephone base unit to receive the incoming call. Alternatively, when transmitting audio signals to the cordless telephone base unit at the start of each telephone call to the central station 22, the microprocessor 204 may instruct the DTMF circuitry to transmit the appropriate call waiting override code, for example "^*70 ", thereby dropping the call waiting feature. The microprocessor 204 preferably prompts the viewer to select one of these options during initial installation of the television 10.

In yet another embodiment, when the cordless telephone base unit is connected to the central station 22 to inform the viewer of the status of the telephone connection and purchase order, the microprocessor 204 displays a status display 408 on the television 10, as shown in FIG. 9. The status display preferably contains a message 410 identifying the status of the connection, such as "dial-up", "connected", "order confirmed", or "incoming call", and a graphical representation 412 of the status of the telephone order.

The invention has been described in what is presently considered to be the best mode and it is apparent that it is susceptible to various modifications, modes of operation, and embodiments, all of which are within the ability and skill of the practitioner without the need for any additional inventive skill. Accordingly, the protection sought herein is as set forth in the claims below.

Claims (15)

1. A system for bi-directional transmission between a central data processing center and a plurality of television receivers, the system comprising:

a cordless telephone base unit and a cordless telephone handset unit located in the vicinity of each television receiver, the cordless telephone base unit and the cordless telephone handset unit being capable of communicating voice with each other, the cordless telephone base unit being capable of receiving data from the cordless telephone handset unit;

means at the television receiver for transmitting data to the cordless telephone base unit in a manner compatible with data transmitted by the cordless telephone handset;

means for connecting a cordless telephone base unit to a public switched telephone network;

for connecting the central data processing center to a telephone network for receiving data transmitted at the television receiver.

2. A transmission system as claimed in claim 1, wherein the television receiver comprises a remote control for operating the television receiver, the means for transmitting data being located in the remote control.

3. The transmission system of claim 1 wherein the television receiver includes a remote control for operating the television receiver, said means for transmitting data receiving data from the remote control for transmitting data to the cordless telephone base unit.

4. A bi-directional data transmission method comprising the steps of:

a cordless telephone base unit and a cordless telephone handset unit are arranged near the television receiver, and data and voice can be mutually transmitted between the cordless telephone base unit and the cordless telephone handset unit;

connecting a cordless telephone base unit to a public switched telephone network;

connecting the television receiver to a data transmitter compatible with the cordless telephone base unit;

transmitting voice between the cordless telephone base unit and the handheld unit;

transmitting data to the base unit using the handheld unit; and

data is transmitted from the television receiver to the base unit using the data transmitter.

5. A support link from a television receiver to a central data processing center comprising:

a cordless telephone base unit capable of transmitting and receiving voice and data;

means for connecting the base unit to a public switched telephone network;

a wireless transmitter for transmitting data signals to the base unit for carrier by the telephone network to the center;

a microprocessor connected to the television receiver for controlling its operation and to the transmitter for generating a data signal; and

user input means connected to the microprocessor for instructing the microprocessor to generate data signals for transmission by the transmitter to the base unit and for operating the television receiver.

6. The support link according to claim 5, further comprising a cordless telephone handset capable of transmitting data and voice signals to and receiving voice signals from the base unit.

7. The support link according to claim 6, further comprising a VBI decoder coupled to the television receiver for recovering data authenticating the purchased item.

8. The support link according to claim 7, wherein the input device generates a purchase instruction and the microprocessor generates a data signal representing an item corresponding to the purchase instruction for transmission to the base unit.

9. The support link according to claim 8, wherein the transmitter transmits the data signal in a DTDF format.

10. A method for establishing a support link for a television receiver having an input device and a screen from a cordless telephone having a base unit and a handheld unit to a central processing center, the method comprising the steps of:

displaying one or more purchase selections on a screen;

inputting a purchase instruction corresponding to the displayed selection by the input means;

transmitting a purchase instruction from the input device to the base unit;

connecting the base unit to a public switched telephone network; and

transmitting a purchase instruction and a user identification from the input device to the base unit;

connecting the base unit to a public switched telephone network; and

the purchase instruction or the user identification is transmitted from the base unit to the telephone network for carrying to the central processing center.

11. The method of claim 10, further comprising the step of operating the television receiver with the input device.

12. The method of claim 10, further comprising the step of initiating a telephone call over the telephone line using the handheld unit.

13. The method of claim 10, further comprising the step of transmitting a confirmation message from the central processing center to the base unit over the network upon receipt of the purchase instruction.

14. The method of claim 13, further comprising the step of displaying a confirmation message on the screen.

15. The method of claim 10, the step of transmitting from the input device further comprising transmitting a user identification.