WO1996020562A1

WO1996020562A1 - Apparatus and methods for extracting data from video signals

Info

Publication number: WO1996020562A1
Application number: PCT/US1995/017102
Authority: WO
Inventors: Roy J. Mankovitz
Original assignee: E Guide, Inc.
Priority date: 1994-12-28
Filing date: 1995-12-28
Publication date: 1996-07-04
Also published as: AU4649796A

Abstract

In one embodiment the apparatus includes a notch filter (104) for filtering frequencies of a first channel (CH3) from a first video source (90), the first video source having plurality of channels, to form a notch filter output having each of the plurality of channels except the frequencies of the first channel, a bandpass filter (107) for filtering a second video source (70) to pass only frequencies in a second channel in the second video source having the same frequencies as the frequencies of the first channel to form a bandpass filter output, a summer (108) for outputting the summed of the notch filter output and the bandpass filter output, and a television (40) for extracting data from the summed output.

Description

APPARATUS AND METHODS FOR EXTRACTING DATA FROM VIDEO SIGNALS

BacKgrwpd φf the Invention Program guides that can be used to select programs for viewing or recording are commonly available in newspapers. An on-screen television guide is desirable so that a viewer can access the guide directly without consulting another media. It is desirable that apparatus and methods be provided to ensure that guide data for an on-screen television guide is always available. it is possible to transmit data along with a video signal. The data that can be transmitted includes closed caption and EDS data, which is further explained below, and other data such as television program guides. These data can be transmitted by inserting the data into the vertical blanking interval of the video signal. During the vertical blanking interval, video is not transmitted; thus, the data in the vertical blanking interval does not interfere with the transmission of a video signal.

At a receiver, which typically includes a cable box or a satellite receiver, a video cassette recorder, and a television, the data can be extracted from the video signal by use of a vertical blanking interval slicer or decoder. The data can then be stored in a memory or displayed on a television. It is also possible to transmit the data encoded into the audio of a video signal. The data can be extracted upon receipt and stored and displayed.

Typically the receiving system such as a television is tuned to a desired channel and the data is extracted from that channel. For example, closed caption data is extracted by a vertical blanking interval decoder and displayed at the bottom of a television screen for hearing impaired viewers. In the case of closed caption data, the user is viewing the television channel from which the closed caption data will be extracted. However, for other types of data broadcast in the vertical blanking interval, a user may be watching a different channel than the channel on which the data is transmitted in the vertical blanking interval. The data may be such that the user wishes to capture the data transmitted on the vertical blanking interval even though the receiving system is tuned to another channel for viewing or recording programs.

A particular problem occurs when a cable box is used in the receiving system together with a VCR and a television. The cable box is generally used to tune to a particular channel received on cable and if the channel is a scrambled channel, the cable box descrambles the video signal and then modulates the tuned channel to channel 3 or channel 4. Usually channel 3 is used, but some receivers operate better if channel 4 is used. For example, suppose channel 50 is selected by the tuner in the cable box and that channel 50 is a scrambled channel. The cable box will unscramble the video signal on channel 50 and then will modulate the descrambled signal to place the video signals on channel 50 onto the frequencies of channel 3. To record a program on channel 50, the user tunes the VCR to channel 3 and thus the VCR is tuned to the output of the cable box and the program can be recorded. Similarly to watch channel 50 on television, the television is tuned to channel 3.

Many televisions are now designed to be cable ready. By using a switch called an A/B switch, the user can attach the television either directly to the cable or to the output of a video cassette recorder, which receives an input via cable. This gives the user the capability of recording on one channel and viewing television on another channel. For example, an unscrambled channel on cable can be viewed on the television while a VCR records a scrambled channel that is unscrambled by a cable box.

The A/B switch solves the problem of watching one channel on television while recording another channel on a VCR; however, the A/B switch does not provide the capability of being able to extract data from the VBI of a channel that is neither being recorded nor viewed on television.

Suppose a channel specific programming guide is transmitted in the VBI of channel 52 and suppose the viewer wishes to capture this data in the VBI regardless of whether the user is viewing or recording on channel 52. The user may wish to capture this channel specific programming guide and store the channel specific programming guide in a memory for later access. This in fact may be the case for many channels. In current systems unless a user is tuned to the channel that is transmitting data in the vertical blanking interval, the transmitted data is lost.

Another problem is that when a cable box is used, only one channel is tuned at any one time to appear on the channel 3 output of the cable box. Thus for users without an A/B switch, it is only possible to view and or record one channel at a time. Thus a user is not able to record on channel 30 while viewing a program on channel 24.

Another problem is that an A/B switch is a manual switch and the user must physically operate the A/B switch. The user would prefer to use a remote controller to control the video system to be able to view one channel while recording another. Another problem is that if an over-the-air antenna and a cable or a satellite receiver are both used for reception, then it would be desirable to be able to record a channel from either source while viewing a channel from either source and extracting data from another channel.

Summary of the Invention An object of the present invention is to provide a capability for extracting data from a television signal. Another object of the present invention is to allow extraction of data from a television signal in a particular channel, even if a cable box is tuned to another channel. It is another object of the present invention to not interfere with the recording or viewing of other channels while extracting data from the particular channel.

Another object of the invention is to allow access to the data in a television signal even if the channel and video signal source is unknown. Another object of the present invention is to provide a capability for searching various channels within a television signal source to find a channel containing data. Another object of the present invention is to provide an apparatus that can be programmed to search for data at only certain times.

Another object of the invention is to search channels for data, only if the television is OFF, in order to not interrupt television viewing.

According to the invention, apparatus and methods are provided for extracting data from video signals. In one embodiment the apparatus includes a notch filter for filtering frequencies of a first channel from a first video source, the first video source having a plurality of channels, to form a notch filter output having each of the plurality of channels except the frequencies of the first channel, a bandpass filter for filtering a second video source to pass only frequencies in a second channel in the second video source having the same frequencies as the frequencies of the first channel to form a bandpass filter output, a summer for summing the notch filter output and the bandpass filter output to form a summed output, and a television for extracting data from the summed output. In a specific embodiment, the television for extracting data from the summed output includes a vertical blanking interval decoder. In yet another embodiment, the television for extracting data further includes a comparator for comparing a current time with at least one stored time period for extracting data to determine if the current time is within the stored time period, a decoder for extracting the data from the summed output when the current time is within the stored time period, and a memory for storing the extracted data.

Other objects and many of the attendant features of this invention will be more readily appreciated as the same becomes better understood by reference to the following detailed descriptions and considered in connection with the accompanying drawings in which like reference symbols designate like parts throughout the figures. Brief Description of the Drawing:

FIG. 1A is a block diagram showing an A/B switch connecting together video components according to the prior art;

FIG. IB is a diagram illustrating an A/B switch according to the prior art;

FIG, 1C is a block diagram of a cable box according to the prior art; FIG. ID is a block diagram of a VCR according to the prior art;

FIG. IE is a block diagram of a television according to the prior art;

FIG. IF is a block diagram of a remote controller according to the prior art; FIG. 2 A is a block diagram of an apparatus for connecting video components according to the present invention;

FIG. 2B is a frequency diagram illustrating the operation of the apparatus for connecting video components according to the present invention; FIG. 2C is a flow diagram of a method for connecting video component signals according to the present invention;

FIG. 3 is a circuit diagram of the apparatus for connecting video components according to the present invention;

FIG. 4 is a diagram illustrating the apparatus for connecting video components being used to connect an over-the-air antenna with a VCR and a television according to the present invention;

FIG. 5 is a diagram illustrating the apparatus for connecting video components being used to connect a cable, a VCR and a television according to the present invention;

FIG. 6 illustrates another configuration for using the apparatus for connecting video components to connect an over-the-air antenna, a cable, a VCR, and a television according to the present invention;

FIG. 7 illustrates using the apparatus for connecting video components to connect a cable, a cable box and a television according to the present invention;

FIG. 8 A illustrates using the apparatus for connecting video components to connect an over-the-air antenna, a cable box, and a television .according to the present invention; FIG. 8B illustrates using the apparatus for connecting video components to connect an over-the-air antenna, a satellite receiver, and a television according to the present invention;

FIG. 9 is another configuration for using the apparatus for connecting video components to connect a cable, a cable box, a VCR and a television according to the present invention;

FIGS. 10A and 10B illustrate configurations for using the apparatus for connecting video components to connect an over-the-air antenna, a VCR, a television, and a cable box or a satellite receiver, respectively, according the present invention; FIGS. 11A and 1 IB illustrate configurations for using the apparatus for connecting video components to connect an over-the-air antenna, a VCR, a television, and a cable box or a satellite receiver, respectively, according to the present invention.

FIG. 12A is a timing diagram showing video clips transmitted along with data in the vertical blanking interval lines according to the present invention; FIG. 12B is a drawing of a tape layout having data in the vertical blanking lines according to the present invention;

FIG. 13 is a timing diagram showing video clips transmitted along with data in the audio according to the present invention; FIG. 14 is a display of a television guide on a television monitor according to the present invention;

FIG. 15 is a schematic diagram illustrating an interlaced raster scanning pattern of a conventional television; FIG. 16 is a functional block diagram of a television video and data transmission system;

FIG. 17 is a timing diagram showing the vertical blanking interval (VBI) lines of field 1 and field 2 of an interlaced raster scanning pattern of a conventional television and data in the VBI according to the present invention; FIG. 18 is a timing diagram of the standard data format (IX) for transmitting data in the VBI;

FIG. 19 is a timing diagram of the accelerated data format (2X) for transmitting data in the VBI;

FIG. 20 is a block diagram showing a VCR having a VBI decoder and/or an audio decoder according to the present invention;

FIGS. 21 A and 2 IB are flow diagrams of a method for searching television signal sources and channels in order to extract data from a television signal according to the present invention;

FIG. 22 is a block diagram of a television having a VBI decoder and/or an audio decoder according to the present invention;

FIGS. 23 A and 23B are flow diagrams of a method for controlling a television to search for data in television signal sources and channels in order to extract data from a television signal according to the present invention;

FIG. 24 is an illustration of a television monitor displaying a message to a user to ignore audio tones when data is contained in the audio, according to the present invention; FIG. 25 is a flow graph of steps for using the apparatus for a television guide transmitted in the audio according to the present invention;

FIG. 26 is a another flow graph of steps for using the apparatus for a television guide transmitted in the audio according to the present invention; FIG. 27 is a flow graph of steps for using the apparatus for a television guide transmitted in the vertical blanking intervals lines .according to the present invention; and

FIG. 28 is a block diagram of a system including a recorder having apparatus for . extracting a television guide from a television signal and for controlling a switch for selecting among television signal sources according to the present invention. Detailed Description

Referring now to the drawings, FIG. 1A shows the typical use of an A/B switch for connecting together a video system consisting of a cable box, a video cassette recorder, and a television. An A/B switch allows the VCR 70 to be used to record a channel received via cable 22 and descrambled by cable box 10 while the viewer views another cable channel.

The cable box 10 output is connected to the input of the VCR 70. The output of the VCR 70 is connected to the A input of the A/B switch 30. The cable 22 is coupled directly to the B input of A/B switch 30. FIG. 1 illustrates the internal design of an A/B switch 30. The A/B switch 30 is merely a two position switch. The output of the A/B switch 36 is connected via the switch to either the A input 32 or the B input 34. As shown in FIG. 1A the output of the A/B switch is connected to television 40. The user can manually switch A/B switch 30 to either receive channels directly from cable 22 via the B input of the A/B switch or receive channels via the output of the VCR 70. The A/B switch is particularly useful if the VCR 70 is being used to record a program.

As shown in FIG. 1C, a conventional cable box 10 has an infrared receiver 12, a controller 14, a tuner 16, a channel 3 modulator 18, and a descrambler 20. The infrared receiver can receive commands from a remote controller such as remote controller 24 shown in FIG. 1A. The commands sent to the cable box are interpreted by controller 14 and used to tune the tuner 16 to different channels on the input of the cable box. The descrambler 20 is used to descramble any channels that have been scrambled upon transmission. The channel selected by tuner 16 is modulated by channel 3 modulator 18 so that the selected channel appears on the channel 3 frequencies at the output of the cable box 10. Typically the cable box also has a switch so that the selected channel can be modulated to appear either on the channel 3 or the channel 4 frequencies at the output of the cable box. Throughout this specification, channel 3 will be used to describe the operation of the invention; however, it should be understood that channel 4 or some other channel could be used.

FIG. ID is a block diagram of a conventional video cassette recorder. The video cassette recorder 70 includes a tuner 72, an infrared receiver 73, a controller 71, a recorder 74, and a switch 75. The infrared receiver 73 can receive commands from a remote controller such as remote controller 24 and the commands are interpreted by controller 71 which controls tuner 72 and recorder 74. The tuner 72 in a VCR can tune the input to the VCR to choose a channel for recording by the recorder 74, which includes read/ write heads and control drives for a video cassette tape. Switch 75 in the VCR is a so-called VCR/TV switch and can be controlled via the remote controller to be either in the TV 78 or VCR 76 position. When in the TV 78 position, the output 77 of the VCR is connected directly to the input 79 of the VCR. When in the VCR 76 position, the switch 75 connects the output 77 to the output of tuner 72 or the output of recorder 74. When a video cassette tape is played in the VCR, then the output of recorder 74 supplies the output 77 through the VCR position 76 of switch 75. When the VCR is being used to record a program, then if the VCR is coupled directly to a cable, the tuner 72 can be used to select a channel for the recorder 74 to record. While the VCR is recording that channel the switch 75 can be switched to the TV 78 position so that the cable input to the VCR 70 is sent directly to a television and the tuner in the television is used to select a cable channel for viewing. However, if the VCR 70 is used as shown in FIG. 1 A, then if the cable box is used to tune to a particular channel which needs to be descrambled for the VCR to record it, the tuner 72 must be tuned to channel 3 in order to receive the channel from the cable box 10. In this case, switching the switch 75 to TV position 78 while the VCR is recording the program will only allow the viewer of the television to watch the same program that is being recorded. This is the reason for the A/B switch 30 in FIG. 1A, which allows the viewer of television 40 to switch to the B position so that any of the channels on the cable 22 can be viewed. However, if a channel selected by a tuner in television 40 is a scrambled channel, then the viewer will only see a scrambled signal. Therefore, the viewer must select a nonscrambled channel to view.

FIG. IE illustrates a conventional television 40, which has an infrared receiver 42, a controller 44, a tuner 46, and a monitor 48. The infrared receiver 42 can receive commands from a remote controller such as remote controller 24. The tuner can be used to tune the television to various channels. When the television tuner 46 is coupled to the output of cable box 10, the tuner is tuned to channel 3 in order to receive whatever the channel the cable box has modulated onto channel 3. When the tuner 46 is coupled to the output of recorder 74 or tuner 72 in VCR 70, then because the tuner 72 demodulates the input of the VCR to channel 3 for recording, and because the recorder output is tuned to channel 3, the tuner 46 must also be tuned to channel 3. If the raw cable input is sent, for instance via position B of A/B switch 30, to the tuner 46, then the tuner 46 can be tuned to any of the channels from cable 22.

A satellite receiver is not shown in the figures; however, the block diagram of a satellite receiver is very similar to the block diagram of cable box 10. The output of a satellite receiver is also typically modulated to channel 3 or channel 4. FIG. IF illustrates a conventional remote controller which includes keys 25, a controller 27, a memory 28, which can be a combination of RAM and ROM, and an infrared transmitter 26. As is well known in the art, the remote controller 24 can be a universal remote controller.

To this point the conventional apparatus for connecting video components has been described. FIG. 2A is a block diagram of an apparatus for connecting video components according to the present invention. In a first embodiment of the apparatus, the apparatus contains a channel 3 notch filter 104 (if a cable box uses channel 4, then this would be a channel 4 notch filter) which has an input 112 and an output 105. The apparatus also has a channel 3 bandpass filter 106 with an input 116 and an output 107. The signal at the output 105 of the notch filter 104 and the signal at the output 107 of the bandpass filter 106 are combined by combiner 108 to produce a signal summed on output 118. The channel 3 notch filter 104 filters channel 3 frequencies from the signal at input 112 so that the signal at the output 105 does not contain channel 3 frequencies. The channel 3 bandpass filter 106 passes only frequencies in channel 3 from the signal at input 116 to the output 107. Other frequencies are filtered from the signal at input 116 and do not appear at the output 107. (If the channel 3 notch filter is a channel 4 notch filter, then the channel 3 bandpass filter is a channel 4 bandpass filter.) Because the signal at the output 105 does not contain channel 3 frequencies and the signal at output 107 contains only channel 3 frequencies, the combiner

108 can be used to sum together the outputs 105 and 107 to form a summed signal at output 118 which contains all the frequencies available at output 105 and 107.

In another embodiment of the apparatus for connecting video components, a splitter 102 has an input 110 and an output 114 and another output, 115 connected to the input 112 of the channel 3 notch filter 104. The sputter 102 can be an external component or packaged together with the apparatus for connecting video components.

FIG. 2B is a frequency diagram illustrating the relationship of the various inputs and outputs of the apparatus for connecting video components shown in FIG. 2 A. The top frequency diagram of FIG. 2B illustrates the signal at input 110, input 112, and output 114 (without the splitter 102) which typically contains a plurality of channels such as channel 1, channel 2, channel 3, channel 4, channel 5, channel 6, channel 7, and so on. The output signals of splitter 102 are the same; however, the splitter provides some isolation between its two outputs. The input signal to channel 3 notch filter 104 can also come directly to input 112 from line 117 and in that case the splitter 102 is not used. The frequency diagram of FIG. 2B that is labeled 105 illustrates the frequencies present in the signal at output 105 after the channel 3 notch filter 1 4 has filtered the channel 3 frequencies from the signal at input 112. The frequency diagram of FIG. 2B labeled 116 illustrates the typical input signal on input 116 of FIG. 2A. As will be described, the signal at input 116 is typically sourced by either a cable box, a satellite receiver, or a video cassette recorder, all of which have output signals having channel 3 frequencies. (As discussed above, channel 4 frequencies can be used instead.) However, the output of cable boxes, VCRs, and satellite receivers do not have a sharp cutoff on either side of the channel 3 frequencies. As shown in FIG. 2B, the signal at input 116 is primarily centered on channel 3 frequencies, but overlaps into channel 2 and channel 4 frequencies. The purpose of the channel 3 bandpass filter 106 is to remove the unwanted frequencies from the signal at input 116 that are overlapping channels 2 and 4. Thus, as shown in FIG. 2B, the frequency diagram labeled 107 has a sharp frequency response that contains only channel 3 frequencies. The summed signal at output 118 as shown in FIG. 2B contains the frequencies of the signal at output 105 and the frequencies of the signal at output 107. The summed signal at output 118 contains channel 1, channel 2, channel X, channel 4, channel 5, channel 6, channel 7, and so on. The channel X is centered at the frequencies of channel 3 and is typically a channel that has been tuned to via a cable box, a video cassette recorder, or a satellite receiver, and modulated to channel 3 frequencies. FIG. 3 is a circuit diagram of the apparatus for connecting video components according to the present invention. The splitter 102 is implemented by transformer 210. The channels 3 notch filter 104 is implemented with inductors 214, 216, and 220 and capacitors

212, 218, and 222. The values of the inductors and capacitors are as shown on FIG. 3. The channel 3 bandpass filter 106 is implemented by capacitors 242, 240 and 236 and inductors

238, 232, and 234. The combiner 108 is implemented with resistor 224, transformer 226, transformer 228, and capacitor 230. The circuit components in the apparatus for connecting video components, as shown in FIG. 3, are all passive circuit components, which are relatively inexpensive. FIG. 2C is a flow diagram of a method for connecting video component signals according to the present invention. In step 200, channel 3 frequencies are filtered from a first television signal to form a filtered television signal without channel 3 frequencies. In step 202 a second television signal is bandpass filtered to pass only channel 3 frequencies to form a selected frequency output. Then in step 204 the filtered television signal and the selected frequency output are summed together to form a summed output.

FIGS. 4 through 1 IB illustrate different configurations of video components connected with the apparatus for connecting video components according to the present invention. In FIG. 4 an over-the-air antenna 90 is connected to input 110. A VCR 70 has an input from output 114 and sends its output signal to input 116. A television 40 is connected to summed output 118. The over-the-air channels received via the antenna are output via splitter 102 to both channel 3 notch filter 104 and to the input of VCR 70. The channel 3 notch filter 104 removes the channel 3 frequencies from the over-the-air signals. The output of VCR 70 is modulated to channel 3 and the channel 3 bandpass filter, as described above, filters any other frequencies besides channel 3 frequencies from the VCR output. The output of the channel 3 notch filter 104 and the channel 3 bandpass filter 106 are combined by combiner 108 and the summed signals at output 118 is sent to the TV. A remote controller 24 can be used to control the VCR 70 and the television 40. With the configuration of FIG. 4, the user can view any of the over-the-air channels except channel 3 on the television, while recording any of the over-the-air channels on VCR 70. The viewer can also switch between a program being played by VCR 70 and over-the-air channels received by antenna 90. Note that this is a significant improvement over the state of the art represented by FIG. 1A. In FIG. 1 A if the user wishes to switch between a program being played by VCR 70 and other channels being received by cable, then the user must manually switch the A B switch 30. Note that the B input to the A/B switch 30 could be an over-the-air antenna.. In the configuration shown in FIG. 4, the user need not manually switch any switch. The user can control all operations of the video components via commands sent to the video components via the remote controller 24. Note that the VCR 70 can record any of the over-the-air channels by using the tuner 72 built into the VCR 70. The configuration shown in FIG. 5 for using the apparatus for connecting video components is analogous to FIG. 4, except that in FIG. 5 television cable 92 replaces the antenna 90. The operation of the configuration of FIG. 5 is similar to the operation of the configuration of FIG. 4. The VCR 70 can record any of the channels on cable 92 and the viewer can view any of the cable channels except cable channel 3; however, the viewer can also view on channel 3 a program being played by VCR 70. Note that in the configuration of FIG. 5 channel 3 on cable 92 can be viewed by tuning the VCR to channel 3 and outputting that channel to input 116. Then the channel 3 bandpass filter passes channel 3 and by tuning tuner 46 in television 40 to channel 3, the viewer can view channel 3 on cable 92. Thus the user via remote controller 24 can view all of the cable channels and also avoid the necessity of manually switching an A/B switch 30.

In the configuration shown in FIG. 6 cable 92 is connected directly to VCR 70 which has an output connected to input 116. An antenna 90 is connected to input 112. The summed signal at output 118 contains all of the over-the-air channels received via antenna 90 and also a channel modulated to channel 3 by tuner 72 in VCR 70. The tuner 72 modulates one of the cable channels on cable 92 to channel 3 which is then passed via channel 3 bandpass filter 106 and combiner 108 to television 40. The remote controller 24 can be used to tune the tuner in VCR 70 to tune to any of the cable channels. While watching the cable channels the television 40 tuner is tuned to channel 3. To watch any of the over-the-air channels received via antenna 90, the television tuner is tuned to channel 1, channel 2, channel 4, channel 5, and so on.

In the configuration shown in FIG. 7 the cable 92 is attached to input 110 to splitter 102. The output 114 of splitter 102 is coupled to the input of cable box 10 which has an output connected to input 116. The output of combiner 108 is connected to television 40. In this configuration, the television 40 can be tuned to any of the channels on cable 92 except for channel 3. If a viewer wishes to view channel 3, then the remote controller 24 is used to tune cable box 10 to channel 3 and the television is tuned to channel 3. If the viewer wishes to watch a scrambled channel on cable 92, then the remote controller 24 is used to control cable box 10 to tune to the channel to be descrambled which is then descrambled by the cable box and modulated to channel 3 and sent via channel 3 bandpass filter 106 and combiner 108 to television 40 which is tuned to channel 3.

In the configuration shown in FIG. 8A, cable 92 is attached directly to cable box 10 which has an output connected to the input 116 to channel 3 bandpass filter 106. An over- the-air antenna 90 is attached to input 112 to the channel 3 notch filter 104. A television 40 is attached to the summed output 118. In this configuration a viewer can watch any of the over-the-air channels by tuning the tuner 46 in television 40. The viewer can watch all of the over-the-air channels except channel 3. Normally an over-the-air transmission does not contain a channel 3; however, as noted above it is possible that channel 4 is used as an output from a cable box and in that case the apparatus for connecting video components has a channel 4 notch filter and a channel 4 bandpass filter and a viewer tuning the tuner in TV 40 would not be able to watch channel 4 received via antenna 90. To view any of the cable channels the remote controller 24 is used to control cable box 10 to tune to a desired cable channel. The cable box then modulates the selected channel to channel 3 which is then input to the channel 3 bandpass filter 106 and sent to combiner 108. The TV is then tuned to channel 3.

The configuration shown in FIG. 8B is analogous to the configuration of FIG. 8 A except that in FIG. 8B a satellite antenna 94 and satellite receiver 96 are used in place of cable 92 and cable box 10. Other than that the operation of the configuration of FIG. 8B is the same as the operation of the configuration shown in FIG. 8 A. The television 40 can be tuned to all of the over-the-air channels except channel 3, and the satellite receiver can be tuned to enable the viewer to watch any satellite channel, while the television is tuned to channel 3. In the configuration shown in FIG. 9, cable 92 is attached to input 110 to splitter 102.

The output of splitter 102 is sent to the input of cable box 10, whose output is attached to input 116. The summed output 118 is connected to the input of VCR 70 and the output of VCR 70 is connected to television 40. In this configuration the VCR 70 receives all of the channels on cable 92 except channel 3 via channel 3 notch filter 104 and combiner 108. The tuner in VCR 70 can be used to tune to any of the cable channels which can then be output from VCR 70 for viewing on TV 40, which would be tuned to channel 3. The VCR 70 can also record any of those cable channels. One advantage of this configuration is that any noise introduced by the cable box 10 is avoided. However, any scrambled channels need to be unscrambled by cable box 10. When tuning to a scrambled channel the remote controller 24 is used to tune the cable box to the proper channel and then the VCR and television are tuned to channel 3 for recording and viewing the selected channel, respectively.

In the configuration shown in FIG. 10A, cable 92 is connected directly to cable box 10 whose output is connected to input 116. An over-the-air antenna 90 is connected to input 112. The summed output 118 is sent to VCR 70 and the output of VCR 70 is sent to television 40.

In the configuration of FIG. 10A any of the channels received via antenna 90 can be recorded on VCR 70 or viewed on television 40 by tuning the tuner 72 and VCR 70 to any of the over-the-air channels except for channel 3. When the VCR tuner 72 is tuned to channel 3, then the remote controller 24 is used to tune the tuner 16 in cable box 10 to select any of the cable channels on cable 92 for recording by VCR 70 or viewing by television 40. If the VCR is being used for recording a program, then if the VCR 70 has a switch, such as switch 75 shown in FIG. ID, then by switching switch 75 to the TV 78 position, the tuner 46 and television 40 can be used to tune to any of the over-the-air channels except channel 3 and any of the cable channels received via cable 92 can be tuned to by tuning TV 40 to channel 3 and using remote controller 24 to change channels in the cable box 10. However, if the VCR is recording a channel received via cable 92, then the viewer is restricted to viewing only the same channel as the VCR 70 is recording. The configuration shown in FIG. 10B is analogous to the configuration shown in FIG.

10A except that the cable 92 and cable box 10 are replaced by satellite antenna 94 and satellite receiver 96. As before the VCR 70 and TV 40 can be used to record or view any of the over-the-air channels received via antenna 90 except channel 3 and the satellite receiver can be tuned to receive any of the channels received via the satellite antenna 94. The output of the satellite receiver is modulated to channel 3 and the VCR and television must be tuned to channel 3 to receive the satellite channels. Again, if VCR 70 is recording a satellite antenna then television 40 can be used to view any of the over-the-air channels received via antenna 90 and can also be used to view the channel that is being recorded by VCR 70. In FIG. 11A two apparatus 100 for connecting video components are used. An antenna 90 is connected to input 112 of the first apparatus 100 for connecting video components. A cable box 10 has an input via cable 92 and has an output to input 116 of the first apparatus 100. The summed output 118 of the first apparatus for connecting components is sent to input 140 of the second apparatus 100 for connecting components and input to the splitter 141. The output 142 of the splitter 141 is input to VCR 70. The output of VCR 70 is connected to input 144 to the channel 3 bandpass filter 147 of the second apparatus 100 for connecting components. The summed output 146 of the second apparatus 100 for connecting video components is connected to television 40. In this configuration the summed output 118 contains all of the over-the-air channels except for channel 3 and also contains any of the cable channels tuned to by cable box 10 and modulated onto channel 3 frequencies. So at summed output 118, all of the over-the-air channels except channel 3 and all of the cable channels are available. These channels are input to splitter 141 in the second apparatus for connecting video components, via input 140. The output 142 from splitter 141 is sent to VCR 70 and the output of VCR 70 is sent via input 144 to channel 3 bandpass filter 147. Because the output of splitter 141 is sent through channel 3 notch filter 148, at output 143 the only channels that are available are the over-the-air channels that were available on output 105. However, all of the cable channels and the over-the-air channels are available on output 142 to VCR 70. Therefore, by using the tuner 72 in VCR 70 and the tuner in cable box 10, the VCR is able to record any of the cable channels and any of the over-the-air channels except for channel 3. If the VCR 70 is not recording a program then the output 142 from the splitter 141 can be sent via TV position 78 in the VCR to the VCR output which is connected to input 144 to channel 3 bandpass filter 147. If the VCR is recording a program even a cable channel program, then the switch 75 can still be used to send the VCR input directly to the VCR output. However, if the VCR 70 is recording a cable channel then the cable box has been used to modulate the channel to channel 3 in order to pass through channel 3 bandpass filter 106. Thus, in the configuration shown in FIG. 11 A there is still a limitation that if the VCR 70 is recording a cable box channel then the viewer is restricted to viewing either any of the over-the-air channels or the channel being recorded by the VCR 70. FIG. 1 IB is analogous to the configuration of FIG. 11 A except that the satellite antenna 94 and the satellite receiver 96 are used instead of the cable 92 and the cable box 10. The operation of the configuration of FIG. 11B is therefore analogous to the operation of the configuration of FIG. 11 A. FIG. 12A illustrates one of many possible formats for sending data embedded in a television signal. The television signal into which the data is embedded can be from any of a number of television signal sources, such as cable, over-the-air broadcasts, or satellite broadcasts and can be on any of the channels of the television signal sources. As shown in FIG. 12 A, the video/audio 863 can contain video clips such as clip 874 and clip 882. The VBI lines 864 which are embedded in the video signal can contain television guides .and guide data. The television guide and guide data can be transmitted in the VBI lines as shown by guide 871 and overlapped with a blank video/audio portion as shown by element 875. Alternatively, the guide data can be embedded in video clips as shown by the overlap of timing between guide 879 and clip 874 and guide 883 and clip 882. The guide can contain a complete listing of television programs on all available channels for a period of time in the future, for example for the next week. The guides can also be a channel specific program guide. The guide data can also include information for accessing the clips that are transmitted along with the guide. For example, the number of VISS marks to each clip can be listed as shown by element 872 as well as compressed codes or CDTL information, which can be used to program a recorder for recording a program associated with the clip. For example, the clip can be a preview of a program to be transmitted at a later date and the compressed code or CDTL information allows the user to program a recorder, such as a video cassette recorder, to automatically record the program at a later time.

As shown, index commands can also be embedded in the VBI lines as indicated by index commands 873, 880, and 884. When the television signal containing the clips and the guide and guide data are received, the television signal can be recorded by a VCR and while this recording occurs the index commands can be used to write VISS marks into a control track on the tape so that a tape is produced with the format shown in FIG. 12B. The VISS marks recorded in the control track can be used along with the guide data to enable the user to conveniently access the clips recorded by the VCR for viewing.

The vertical blanking interval lines 464 recorded on a tape contain guide 471, guide data 472 and an index command 473, as shown in FIG. 12B. When index command 873, shown in FIG. 12A, is decoded upon receiving the transmission, then the VCR is commanded to write an index mark or VISS mark 465 into the control track 462. The guide and guide data are spread throughout the transmission and can be embedded in the video clips, as shown by guide and guide data 479 which are transmitted at the same time that video clip 1, designated as 474, is transmitted. At the end of each video clip such as video clip 474 and just before the next video clip, there is an index command such as index command 880 in FIG. 12A. When index command 880 is decoded during the transmission, then the VCR is commanded to write an index mark or VISS mark 467 into the control track 462,

FIG. 13 illustrates another format for receiving data such as guide and guide data in a television signal from any of the television signal sources and from any channel of the television signal sources. As shown, the guide and guide data is contained in the audio 886 of the television signal. In this case the vertical blanking interval lines are not used for transmitting guide or guide data. The video portion 885 of the television signal can be used to transmit video clips such as clips 888 and 889. The guide and guide data are transmitted as audio tones in the audio as illustrated by guides 887, 890, 891, and 892. The index commands 893, 894 and 895 are used in the same manner as the index commands shown in FIG. 12A, for writing VISS marks onto the control track of a tape if the video clips are recorded by VCR to allow later access of the video clips. Because the video clips have no audio and because the guide is transmitted in the audio during the time that the clips are received in the video signal, an audio warning message 896 is encoded in the audio and is decoded and displayed during viewing of a recorded video clip so that the useF can ignore the audio tones caused by the encoded guide and guide data. Alternatively, the audio warning message can be embedded in the video of each of the video clip frames so that the viewer sees a message such as that shown in FIG. 24 which shows a message "ignore audio tones" 968 at the bottom of the television screen 966. In another embodiment an audio mute command 897 can be embedded in the audio tones and can be decoded to command the television to mute the audio during the viewing of the video clips. When the television signal as shown in FIG. 13 is recorded by the VCR, the recording can be as shown in FIG. 12B, which is described above. A guide transmitted and stored can be displayed on a television, as shown as guide display 380 in FIG. 14. The user selects a program in the guide display 380, for example Murphv Brown 386, by operating cursor control 792 on remote controller 780 shown in FIGS. 20 and 22 to place a cursor on the program Murphy Brown 386 or by entering the number 3 corresponding to the program as indicated by guide display element 384 into the remote controller. To record a later transmission of the program the user pushes a record button 788 on the remote controller 780, shown in FIGS. 20 and 22.

The remote controller 780, shown in FIGS. 20 communicates with VCR 740 and has number keys 786, a record key 788, a view key 790, and a cursor controller 792. The remote controller 780 has an infrared emitter 782 that communicates commands to infrared receiver 760 on VCR 740. If the record button 788 is pushed then a compressed code or a channel, day, time-of-day and length for the selected program are used by the VCR 740, shown in FIG. 20, to program the VCR to record the program when it is transmitted at a later time. For example, for Murphy Brown the compressed code, as shown on FIG. 14, is 5941. Compressed codes are decoded by compressed code decoder 758 into channel, day, time-of-length and program length.

As explained below, the remote controller 780 can also be used with a television 800, shown in FIG. 22. The remote controller sends commands to the television 800, which then decodes the commands and then the television 800 sends commands via IR transmitter 762 in television 800 to a conventional VCR 70, such as that shown in FIG. ID, to program the

VCR to record the program when it is transmitted.

Compressed codes each have at least one digit representative of, and compressed in length from, the combination of the channel, day, time-of-day, and length and can be decoded into channel, day, time-of-day, and length and the compressed codes and their use are described in detail in U.S. Patent 5,335,079, issued August 2, 1994, which is incorporated herein by this reference as though set forth in full. If the guide is transmitted daily, then the day information is not necessary.

Also contained in the guide display element 386 is the channel number, day, time-of- day and length for Murphy Brown, which are channel 2, October 17, 7:00 p.m and 30 minutes.

A video clip may be transmitted and recorded for certain programs in the guide 380. These can be marked in the guide by an asterisk (*) as shown in element 383 in FIG. 14. The user can select to view the clip for Entertainment Tonite by entering the number 2 and pressing view button 790 on the remote controller 740 shown in FIGS. 20 and 22. Then the VCR is commanded directly by controller 750 of VCR 740 in FIG. 20 or by television 800 via infrared transmitter 762 to advance or rewind by the proper number of VISS marks to the beginning of the clip. The controller in the VCR can keep track of the position of the tape by tracking the number of VISS marks from the beginning of the tape.

The following description describes the manner of embedding data in the vertical blanking interval in a video signal at a station and decoding the data at a receiver.

Video images in a cathode ray tube (CRT) type-video device, e.g. television, are generated by scanning a beam along a predefined pattern of lines across a screen. Each time all the lines are scanned, a frame is said to have been produced. In one implementation, such as used in the United States, a frame is scanned 30 times per second. Each television frame comprises 525 lines which are divided into two separate fields, referred to as field 1 ("odd field") and field 2 ("even field"), of 262.5 lines each. Accordingly, these even and odd fields are transmitted alternately at 60 Hz. The lines of the even and odd fields are interleaved to produce the full 525 line frame once every 1/30 of a second in a process known as interlacing. Another standard in the world uses 625 lines of information and interlace 312 and 313 lines at 50 fields per second. In the 525 line standard used in the United States, approximately 480 lines are displayed on the television screen.

FIG. 15 is a schematic diagram illustrating the interlaced scanning pattern 600 on a screen of a conventional television receiver. A video display scans the beam from the top left hand corner and scans across the screen (line 22, field 1 in FIG. 15). After it finishes scanning the first line, the beam returns to the left hand side during a period known as a horizontal blanking interval and repeats scanning along another line which is parallel to but lower than the previous line (line 23, field 1 in FIG. 15). The scanning continues along the lines until the beam reaches the center of the bottom part of the screen (line 263, field 1) to complete field 1 , which is comprised of lines 602.

From the bottom center of the screen, the beam returns to the top where it starts scanning from substantially the center of the screen along the lines 604 for field 2 which interlace the lines of field 1. This is not an instantaneous bottom to top jump but actually requires the length of time to scan 21 horizontal lines. These lines 606 are lines 1 through 21 of field 2. The second half of line 21 field two (line 284 as shown in FIG. 15) is displayed. Then lines 285 to 525 of field 2 are scanned to complete field 2. When the beam reaches the bottom, right hand corner of the screen, the picture frame is formed. Then the beam retraces to the top and the vertical blanking interval lines 608 are numbered 1 through 21 of field 1. In the NTSC protocol widely used in North America, each field contains 262.5 horizontal lines and a pair of fields constitute a single 525 line video frame and creates one video picture at one instant in time on the video display.

During the time in which the beam returns from the bottom to the top of the screen between the fields, it carries no video or picture signals because it does not produce any picture element on the screen. This time interval is generally known as the vertical blanking interval (VBI). Its duration is typically 21 times the time duration that it takes the beam to scan across the screen. In other words, the duration of the VBI is equal to the time for the beam to scan 21 lines and is divided into 21 lines. In interlaced scanning, the VBI is identified by the field with which it is associated. Apparatus and methods using the NTSC standard with 21 lines in each VBI are well known in the art and dierefore are not discussed in detail herein.

Because no image is produced on the display during the vertical blanking interval, no picture information therefore needs to be carried by the broadcast signals. Thus, the VBI is used for conveying auxiliary information from a television network or station to an audience. For example, closed caption data associated with the television program are transmitted as encoded composite data signals in VBI line 21, field 1 of the standard NTSC video signal, as shown in FIG. 17. Lines 1 through 9 of the VBI of each field are used for vertical synchronization and post equalizing pulses. Thus, lines 10 through 21 are available for auxiliary information.

FIG. 16 is a functional block diagram of a data transmission system. As used herein, the terms "broadcast" and "transmit" are used interchangeably for the transmission of signals over cable or fiber optics, to or from satellites, over-the-air, and the like. A network head end 10001 transmits a composite television signal containing inserted information in a portion thereof, typically the vertical blanking interval, to a satellite 10002 which rebroadcasts the same to a local affiliate 10003. The affiliate 10003 may further insert data into the vertical blanking interval of the received television signal and transmit the same to a local cable head end 10004. The cable head end 10004 receives television signals from a plurality of sources

(including satellites) and may further insert data into the vertical blanking interval of any of the television signals. The signals from the plurality of sources are combined into a composite television signal, amplified, and provided over a cable to a plurality of individual receivers 10005, which can include televisions, cable boxes, VCRs and satellite receivers. In addition, the individual receivers 10005 may receive signals directly from the local affiliate 10003 by air, which may include the use of a satellite 10002, or by cable.

More specifically, the network head end has a video tape recorder (VTR) 10006 for providing a program signal to an inserter 10007. A controller 10008 .also at the head end controls the scheduling of loading tapes from a cart (a machine with a plurality of video tape cassettes which are moved by a robotic arm from a storage location and inserted into a video tape recorder and vice versa). Furthermore, the controller 10008 controls the lighting of stages during live broadcasts, such as news broadcasts. The controller 10008 is typically a microprocessor based system. A traffic computer 10009 controls the exact timing of playing individual segments of video tapes and inserting commercials therebetween as well as switching between different programs. Some network head ends have both a traffic computer

10009 and a controller 10008. The controller 10008 provides data and commands to the inserter 10007. The traffic computer 10009 provides data and commands to the controller if present. Otherwise, the traffic computer 10009 provides these signals directly to the inserter 10007. The inserter 10007 inserts data into the vertical blanking interval of the composite television signal, as will be described below, and provides the television signal to a transmitter 10010 which in turn provides the television signal on a microwave carrier to a satellite dish 10011 for transmission to the satellite 10002.

The satellite 10002 retransmits the received signal, which is received by a satellite dish

10012 at the affiliate 10003. The dish provides the signal to a station inserter 10013 at the local affiliate 10003. The affiliate may also insert data into the composite television signal as will be described below. The television signal is then provided to a transmitter 10014 and then to a transmitting antenna 10015. A local cable operator 10004 has a plurality of satellite dishes 10016 and antennas

10017 for receiving signals from a plurality of networks 10001 and affiliates 10003. The received signal from each of the dishes 10016 and antennas 10017 is provided to a respective input of a multi-channel inserter 10018, which can input data into the vertical blanking interval of a received signal. The multi-channel output from the inserter 10018 is amplified in an amplifier 10019 and provided over a cable 10020 to individual receivers 10005. Alternately the receivers 10005 could receive broadcast information via antennas or satellite receivers. Each receiver 10005 includes a VBI decoder, which can include a VBI sheer and closed caption decoder, that scans VBI lines 10-21 of both fields 1 and 2. In addition it is possible to use the first few visible lines in each video frame for VBI data, for example, lines 22-24. Lines 1 through 9 are typically used for vertical synchronization and equalization and, thus, are not used to transmit data. Closed captioning and text mode data are generally transmitted on VBI line 21, field 1 of the standard NTSC video signal, at a rate of 2 bytes for each VBI line 21, field 1, as shown by closed caption data 612 in FIG. 17. The text mode fields fill the entire screen with text. The default mode is an open ended mode in which the page is first filled up and then scrolled up. The individual recipient of such data has no control over the data. Extended data services (EDS) data can be transmitted on VBI line 21, field 2, as shown by EDS data 616 in FIG. 17, at a rate of 2 bytes per VBI line 21, field 2. By way of background, the data in the vertical blanking interval can be described in terms of the wave form, its coding and the data packet. The closed caption data wave form has a clock run-in followed by a frame code, followed by the data. The coding of die data is non-return-to-zero (NRZ) 7 bit odd parity.

Under mandatory FCC requirements effective July 1993, color televisions having a size 13" and greater must provide a closed caption decoder. Caption data decoding is further described in the following specifications, which are hereby incorporated by reference herein: Title 47, Code of Federal Regulations, Part 15 as amended by GEN. Docket No. 91-1; FCC 91-119; "CLOSED CAPTION DECODER REQUIREMENTS FOR THE TELEVISION RECEIVERS"; Title 47, C.F.R., Part 73.682(a)(22), Caption Transmission format; Title 47, C.F.R. Part 73.699, figure 6; "TELEVISION SYNCHRONIZING WAVE FORM"; Title 47, C.F.R., Part 73.699, figure 17a; "LINE 21, FIELD 1 DATA SIGNAL FORMAT"; and PBS Engineering Report No. E-7709-C, "TELEVISION CAPTIONING FOR THE DEAF: SIGNAL AND DISPLAY SPECIFICATIONS".

Under the extended data services (EDS) proposed in the Recommended Practice for Line 21 Data Service. Electronics Industries Association, EIA-608 (drafts October 12, 1992 and June 17, 1993) (hereinafter referred to as "EIA-608" standard"), the subject matter of which is incorporated herein by reference, additional data is provided in line 21, field 2 of the vertical blanking interval. This recommended practice includes two closed captioning fields, two text mode fields and the extended data services. The extended data includes, among other information, program name, program length, length into show, channel number, network affiliation, station call letters, UCT (universal coordinated time) time, time zone, and daylight savings time usage. Upstream at the network, the network inserts the program name, the length of the show, the length into the show, the network affiliation, and the UCT time. Downstream at the affiliate, the affiliate inserts the channel number, the time zone, the daylight savings time usage and program names. The network inserts the data that does not differ for different affiliates.

It is possible for the inserter to insert data other than closed captioning data and EDS data into the television signal. The station inserted data 614 can include data such as a channel specific program guide (CSPG), a guide, guide data, and index commands, which can be inserted into either or both fields in any VBI line between 10 and 21. For example, the data can be inserted into line 20 of field 2, as shown by data 614 in FIG. 17. The data may be inserted into the VBI at the closed caption rate (IX format) or at two times the closed caption rate (2X format), which is further explained below.

The data may be manually entered from a local terminal 10021, which can be used to pre-build, recall, or edit messages. The terminal 10021 typically includes a computer. In addition, a modem 10022 may be used to provide data to the inserter 10007. The output of the inserter 10007 is a composite television signal with the data inserted. The timing of video signals in NTSC format is well known in the art. As described above, the vertical blanking interval is the time between the flyback from the bottom of the screen to the top of the screen. Although no video signal is displayed, the horizontal synchronization pulses are still provided during the VBI. The standard data transmission rate is defined in the EIA-608 standard. As shown in FIG. 18, the horizontal synchronization pulse 620 is followed by color burst signals 622. For closed caption and EDS data, a clock run-in cycle 624 follows the color burst which in turn is followed by a frame code 626. The clock run-in is "10101010101." The frame code is "01000011." Two data bytes 628 and 630 are transmitted in each VBI line. Each byte is 8 bits including a parity bit. This format is referred to as the standard data rate format (or IX format). Each byte in the VBI line is arranged with the least significant byte first. The last bit is used as parity for error checking. Each byte of the transmitted data is parity checked upon receipt. The IX format is the format used to transmit closed captions in VBI line 21 field 1, as shown by closed caption data 612 in FIG. 17. It is also the format used to transmit EDS data in VBI line 21 field 2, as shown by EDS data 616 in FIG. 17.

An accelerated data format (2X format) as shown in FIG. 19 uses a bit rate twice that of the IX format to thereby provide 4 bytes per VBI line. The clock run-in 644 is the bit sequence "10101010." The frame code 646 is "10011101101." Four data bytes 648, 650, 652 and 654 are transmitted each VBI line. The 2X format can be used to transmit data 614 in FIG. 17.

One scenario for sending data along with a video signal is to transmit the data late during the middle of me night when the television is likely to be turned off. A VCR 740, as shown in FIG. 20, can be preprogrammed via remote controller 780 or directly via data downloaded in a video signal, to search for the transmitted data, such as a television guide, during particular time periods in the night. The VCR 740 can be substituted for VCR 70 in FIGS. 4, 5, 6, 9, 10A, 10B, 11A, and 11B. For example, the television guide might be transmitted from 2:00 A.M. to 2:30 A.M. and then transmitted again between the times of 4:00 A.M. and 4:30 A.M. The transmission of the guide data can be repeated during the night and even during the day. The VCR 740 compares the time on clock 754 to the preprogrammed times to determine a time at which to begin a search for the television guide and guide data. However, if the television 40 shown in FIGS. 4 through 1 IB is ON then it is desirable that the VCR 740 delay the search until the next time that the television guide is transmitted. During the next time the VCR 740 will again determine whether the television is ON. The TV is considered ON, if video is being displayed on the television monitor. This is detected by TV ON detector 763, which can detect that the TV is ON through the magnetic fields generated by die control of the beam writing the video onto the monitor or by other techniques, such as signals sent from the television to the VCR 740 indicating that the television is ON. Since the guide is transmitted often and is updated as required, die VCR 740 will eventually detect a period of time in which me television guide is transmitted and in which the television is OFF.

Once the conditions of the television being OFF and die proper time for receiving a television guide are satisfied, then the next step is for the VCR 740 to detect a television signal source and a channel in which die television guide is being transmitted. The VCR 740 can be programmed so that a particular television signal source and channel for receiving the guide are specified. In this case the VCR 740 sends commands to tune the proper television signal source to the proper channel.

In another embodiment the VCR 740 searches for a television signal source and a channel having the television guide. Once the search has been performed and a television signal source and a channel have been found with the television guide and guide data, then the television signal source and die channel can be stored in RAM 752. The search for guide data can be performed continuously, or be performed only if the TV is OFF, or only during stored time periods. In the latter embodiment, die stored time periods are compared in controller 750 with time read from clock 754. When the times compare and the signal from TV ON detector 763 indicates tiiat the television is OFF, then controller 750 can begin a search for a television signal source and a channel having television guide and television guide data. The VCR 740, substituted for VCR 70 in FIGS. 4, 5, and 6 can control tuner 744 in the VCR 740 to tune to a channel at the right time or to search for a channel having data.

In die configuration of FIG. 4 the VCR 740 searches over-the-air channels, and in the cases of FIGS. 5 and 6 d e VCR 740 searches the cable channels received via cable 92. In FIG. 9 the VCR 740 of FIG. 20, which is substituted for VCR 70, sends commands to cable box 10 to tune to the proper channel, or the VCR 740 can search the cable channels directiy from cable 92. In FIG. 10A, the VCR 740 of FIG. 20, which is substituted for

VCR 70, sends commands to cable box 10 to tune to the proper channel, or the VCR 740 can search the channels received via antenna 90. The cable channels appear in channel 3 and d e over-the-air channels are in die other channels 1-2 and 4-Z at the input to the VCR, where Z is the maximum number of over-the-air channels. In FIG. 10B, the VCR 740 of

FIG. 20, which is substituted for VCR 70, sends commands to satellite receiver 96 to tune to the proper channel, or the VCR 740 can search the channels received via antenna 90. The satellite receiver channels appear in channel 3 and d e over-the-air channels are in the other channels 1-2 and 4-Z at die input to the VCR, where Z is the maximum number of over-the-air channels.

In the configurations of FIG. 11A, the VCR 740 of FIG. 20, which is substituted for VCR 70, sends commands to cable box 10 to tune to the proper channel, or die VCR 740 can search the channels received via antenna 90 in the same way as FIG. 10A. However, if the VCR 740 is recording a particular channel, then the television cannot be used simultaneously to view another cable channel unless the VCR 740 has a switch position such as switch position 771, shown in FIG. 20, tiiat bypasses the tuner 744 to send die VCR input signal directiy to the VCR output. The configuration of FIG. 11B is analogous to d e configuration of FIG. 11A, except that a satellite receiver is used instead of a cable box. In general, the television signal input to the VCR 740 is sent through tuner 744 and can be recorded by recorder 742 while any data is decoded by VBI decoder/slicer 746 or audio decoder 748 depending on die format for transmitting the data as indicated above in d e discussion of FIGS. 12A and 13. The controller 750 determines whether data is contained in die received television signal. If no television guide data is contained in the television signal, then the controller 750 commands a television signal source such as a cable box to tune to another channel and the controller again determines whether data is contained in the new channel. Once a channel is found that contains data tiien the data can be decoded and stored in RAM 752. The data can then be recalled later from RAM 752 and displayed on television via the on-screen display controller 756. Television guide data can be displayed as shown in FIG. 14. Any video clips recorded while die data was received can also be displayed on television. Switch 770 is controlled by controller 750 and switches between die tuner 744 output and the recorder 742 output or position 771, if available, for selecting a video source for the VCR output. The adder 764 is used to insert data from die on-screen display controller 756 into the VCR output signal.

It is possible to have two tuners in the VCR 740, such as shown in FIG. 20, which shows tuner 744 and tuner 743. By including die extra tuner 743, the VCR 740 can record a first channel using tuner 744 to tune to a first channel on VCR input 741 , while at the same time using tuner 743 to scan other channels on VCR input 741 to search for a channel having data. The tuner 743 is coupled to VBI decoder/slicer 746 and to audio decoder 748.

FIGS. 21 A and 21B are flow diagrams of a method for accessing a television guide from a television signal. In step 900 a VCR is programmed witii a television signal source, a channel and times for accessing or extracting data from a television signal or the VCR is programmed with only times for accessing or extracting data from a television signal. In step 902 a detector detects whether or not a television monitor is ON or OFF, which indicates whetiier the TV is being viewed. If in step 904 it is determined that die TV monitor is OFF then in step 906 it is determined whetiier it is time for accessing data from a television signal. If die television monitor is not OFF or if it is not time for accessing data, then steps 902 tiirough 906 are repeated until die television monitor is OFF and a time for accessing data has arrived. In an alternate embodiment steps 902 and 904 are bypassed and not performed as indicated by lines 901 and 903. In step 908 the data are transmitted over-die-air, via cable, or via satellite and are embedded in die video signal. The data can be embedded in die vertical blanking interval or the audio portion of the video signal. In step 910 video clips can also be simultaneously sent witii the data. The video clips can be previews of selected programs or can contain advertising. Then in step 911 if die television signal source and channel for accessing the data have been programmed or stored in the VCR then the VCR sends commands via infrared transmitter 762 to the specified television signal source to tune to the proper channel. Then in step 914 the VCR accesses, extracts or decodes the data in die video signal and stores the data in memory. The television signal source that is programmed or stored in the VCR can be either die cable box, the cable, the over-the-air antenna or the satellite receiver depending on the configuration being used, as illustrated by FIGS 4 through 11B. If no television signal source or channel have been programmed or stored in die VCR, then in step 912 the VCR searches all channels received for data in a video signal. If no data is found tiien the VCR commands the signal sources via infrared transmitter 762 to scan all channels while the VCR searches each channel for data in die video signal. Once a television signal source and a channel have been found with data then in step 913 the television signal source and the channel are stored in the RAM 752 of the VCR 740. Then the next time that data is accessed die stored television signal source and channel can be used to reduce the amount of time required to search for a television signal source .and a channel containing data. In step 913, the time for accessing die data can also be stored. Once data is detected then in step 914 d e video signal is decoded to extract the data and d e data are stored in memory.

In step 916 video clips transmitted with die data are recorded for later viewing. While recording if index commands are detected in die video signal then VISS marks are written onto die control track of the tape. Once the transmission of the data is finished as detected in step 918, then in step 922 the user can use die data to select programs to view. The user can also view the recorded video clips and use the data to program the VCR to record transmitted programs associated with the video clips.

FIG. 22 shows television 800 that can be used instead of VCR 740 for accessing data from a television signal. The operation of the television 800 is similar to the operation of VCR 740 shown in FIG. 20, except that the TV cannot record programs. In any of the configurations, as shown in FIGS. 4 through 1 IB, the television 800 can send commands via infrared transmitter 762 to a VCR, which can be a conventional VCR 70 as shown in FIG. ID or a VCR 740 as shown in FIG. 20, to record programs or video clips. The television 800 can be controlled by remote controller 780, the operation of which was explained above. The television 800 contains a controller 750, a VBI sheer decoder 746, an audio decoder 748, a tuner 744, a RAM/ROM 752, a clock 754, an IR receiver 760, an IR transmitter 762, a compressed code decoder 758 and an on-screen display controller 756. A TV monitor ON detector 843 is coupled to monitor 842 and provides an input to controller 750 to determine whetiier or not the monitor 842 is ON.

In order to access data from a television signal, the television 800 operates similarly to VCR 740. The television 800 can store a television signal source, a channel and times for accessing data from a television signal source. The television 800 sends commands via IR transmitter 762 to television signal sources to tune to a channel for accessing data from a video signal. The television 800 can also command television signal sources to scan channels while the TV searches for data in the video signals. Both VCR 740 and television 800 contain a compressed code decoder 758 for decoding compressed codes contained in die guide data and obtaining CDTL information for programming a VCR for recording a later broadcast of a program. The method of decoding is described in U.S. Patent 5,335,079.

It is possible to have two tuners in the television 800, such as shown in FIG. 22, which shows tuner 744 and tuner 743. By including die extra tuner 743, the television 800 can be used to view a first channel on television input 728 using tuner 744 to tune to a first channel, while at the same time using tuner 743 to scan other channels on television input 728 to search for a channel having data. The tuner 743 is coupled to VBI decoder/slicer 746 and to audio decoder 748.

FIGS. 23 A and 23B are flow diagrams of a method for .accessing data from a television signal received by a television. The steps of the method, steps 940-962 are quite similar to steps 900-922 of FIGS. 21 A and 21 B. The key difference is that the television is programmed with die times or the television source, channel and times for accessing data from a television signal and die TV performs a search for a channel from a television signal source containing data rather dim a VCR performing the search. The TV also decodes the data and stores the data in a memory contained in the television. In step 956 the television can command a VCR to record video clips for later viewing if die video clips are transmitted with die data.

FIG. 25 is a flow chart of the method of using the guide controller 25 with the VCR 12 to record d e guide and guide data. In step 300 it is shown that the VCR is programmed witii channel, day, time-of-day, and lengtii (CDTL) for recording during the time of transmission of die guide and die video clips. As discussed above this can be done by entering a compressed code compressed in length from the channel, day, time-of-day, and length (CDTL). Then in step 302 either via d e cable or over the air transmission, the guide and guide data are transmitted encoded as tones in the audio signal. The VCR records the transmission at the time specified by the programming in step 304. During the recording if an index command audio tone is detected, then a index mark command is sent to the VCR to write a VISS mark into the control track as shown in step 305. After the transmission is recorded the user plays the tape in step 306. In step 308 it is determined whetiier a start of message 269 is detected by the audio decoder. If a start of message is detected then in step 325 the guide controller 25 sends a signal via the serial port 50 to VCR 12 to mute the audio signal in die VCR, which removes die audio signal from the television 14. Alternately, a mute command can be sent via infrared emitter 30 and infrared detector 34 to television 14. Then in step 312 the guide and guide data decoded from the transmission by audio decoder 22 is stored into RAM 28. In step 314 it is determined whetiier an end of message has been detected. If an end of message has been detected, then in step 316 a signal is sent via the serial port 50 to unmute the audio signal in die VCR. Alternately a command can be sent to toggle the mute signal on the television 14 in order to turn die television sound on. The VCR 12 continues to record the transmission until the length of the recording matches the length of the CDTL programming. Then in step 318 the viewer can use the guide and guide data to select video clips to view and to select programs to record in the future.

The guide 270 transmitted and stored in d e RAM 28 can be displayed on television 14 as shown as guide display 380 in FIG. 12. The user selects a program in the guide display 380, for example Murphy Brown 386, by operating cursor 59 on remote controller 16 to place a cursor on the program Murphy Brown 386 or by entering the number 3 on remote controller 16, as indicated by guide display element 384. To record a later transmission of the program the user pushes d e record button 46 on remote controller 16. If d e record button 46 is pushed tiien a compressed code or a channel, day, time-of-day and length for the selected program are sent to die VCR 12 to program die VCR 12 to record the program when it is transmitted. For example, for Murphy Brown the compressed code, as shown on FIG. 12, is 5941.

As described above, the compressed codes each have at least one digit representative of, and compressed in length from, die combination of the channel, day, time-of-day, and length and can be decoded into channel, day, time-of-day, and length. If the guide is transmitted daily, then die day information is not necessary. Also contained in the guide display element 386 is d e channel number, day, time-of-day and length for Murphv Brown, which are channel 2, October 17, 7:00 p.m and 30 minutes.

A video clip may have been transmitted and recorded for certain programs in the guide 380. These can be marked in d e guide by an asterisk (*) as shown in element 383 in FIG. 12. The user can select to view the clip for Entertainment Tonite by entering the number 2 and pressing view button 48. Then the guide controller will command the VCR to advance or rewind by the proper number of VISS marks to the beginning of the clip. The guide controller 25 can keep track of the position of the tape by tracking the number of VISS marks from the beginning of the tape. Therefore once the user has watched one video clip the guide controller 25 can assist the user in accessing another video clip.

In the method of FIG. 25, d e guide and guide data transmitted in the audio signal are both recorded on d e VCR tape during die transmission and tiien are played; however, die audio tones are muted from die television to avoid annoying the user. The following presents a simpler system, which eliminates the need to mute or record the audio tones. It is presumed that there is enough memory 28 in die guide controller 25 to store the entire guide for the relevant period, which can be one day, seven days or an entire month. In accordance witii CDTL or compressed code programming of the VCR, the VCR 12 turns on to start recording just before the time of transmission, which is most likely at night. At the beginning of the transmission, a start of message audio tone is transmitted and detected by die guide controller 25 via die audio decoder 22. The guide controller then sends a stop command to stop recording to the VCR 12 through the serial port 50. The VCR stops recording while all of the audio tone data for the guide is transmitted, and during the guide transmission time d e tones are passed tiirough the VCR audio out port 20 to the guide controller 25, where they are decoded by audio decoder 22 and stored into RAM 28. At die end of the guide transmission, an end of message audio tone is transmitted which causes the guide controller 25 to send a record signal to the VCR 12 tiirough the serial port 50. The VCR 12 then starts to record die video clip portion of the guide. During recording the audio decoder 22 determines whetiier an index command, such as index command 278, has been transmitted in die audio. If so, then an index mark command is sent to the VCR 12 to write a VISS mark, such as VISS mark 280 into the control track of the tape, as shown in FIG. 9. FIG. 26 is a flow graph of steps for using the apparatus for a television guide transmitted in die audio according to the present invention. In step 340 the VCR is programmed witii a channel, day, time-of-day, and length or compressed code for recording at die time of the transmission. Then in step 342 the guide and guide data encoded as audio tones are transmitted via cable or over the air transmission. In step 344 the VCR starts recording according to the programming in step 340. In step 346 it is determined whetiier a start of message audio tone has been detected. If a start of message audio tone is detected then in step 348 a stop command is sent to d e VCR via serial port 50 or via infrared emitter 30 and IR detector 32 on the VCR. While the VCR is in a stop mode the VCR does not record. The guide and guide data are then transmitted and sent via audio output 20 to audio decoder 22 and then stored in guide controller RAM 28 as shown in step 350. In step 352 it is determined whetiier an end of message audio tone has been decoded by guide controller unit 25. If die end of message is decoded then in step 354 a record command is sent to die VCR via serial port 50 or via the infrared emitter 30 on the guide controller and d e infrared detector 32 on die VCR. Now any video clips in the transmission are recorded. In step 358 it is determined whetiier any index audio tones are detected and if they are tiien in step 360 an index mark command is sent to the VCR to write a VISS mark into the control track. The index mark command can be sent via serial port 50 or via the infrared emitter 30 on the guide controller and die infrared detector 32 on d e VCR. Then in step 361 the VCR stops recording when the length of recording is d e same as the length specified by the VCR programming in step 340. Then in step 362 the viewer can use the guide or guide data to select video clips to view or to select programs to record. The guide and guide data can be displayed as shown in guide display 380 in FIG. 12.

FIG. 27 is a flow chart of the steps of the method for this embodiment. In step 500 the VCR is programmed with a channel, day, time-of-day, and lengtii or a compressed code for recording the television guide. In step 502 it is determined whetiier the proper time has arrived for recording the guide. If die proper time has arrived then in step 503 die VCR starts to record the guide which is transmitted over the air on d e designated channel in step

504. In step 506 the VCR tuner 49 is tuned to the UHF channel upon which the guide will be transmitted. In step 508 the VCR sends a signal via serial port 50 to RF switch 54 to switch from cable line 57 from cable box 56 to UHF antenna 55. In step 510 VBI decoder

74 in VCR 12 decodes the guide in d e VBI lines and sends die guide to guide controller unit

RAM 28 via serial port 50. While the guide is being decoded and stored any video clips being transmitted can be recorded on the VCR. During recording on die VCR if any index commands are detected in the VBI lines by the VBI decoder 74 and sent to microprocessor

24 in guide controller 10, then an index mark command is sent from guide controller unit

10 to VCR 12 via serial port 50 or via infrared emitter 30 and infrared detector 32 to command the VCR to write a VISS mark in die control track 462, as shown in FIG. 18. In step 512 it is determined whether the lengtii of d e transmission and die recording is equal to die length set in die programming of die VCR in step 500. If the length of die recording of the transmission is equal to the CDTL lengtii then in step 514 the RF switch 54 is switched from UHF channel 55 to cable line 57, and in step 516 the VCR tuner is commanded to the cable base band channel, for example, channel 3 and the VCR is commanded to stop recording. Then in step 518 the viewer can use the guide and guide data to select video clips to view and to select programs to record.

In another embodiment of the invention as shown in FIG. 28, a switch 700 has inputs from an antenna 702, a cable box 730, and a satellite receiver 733. The output of switch 700 is sent to a VCR 740. The VCR can record television signals onto tape 60 which is housed inside of video cassette 18. The VCR provides an output to television 14. A remote controller 16 provides controls to VCR 740 via IR emitter 40 and IR receiver 760.

The VCR has a controller 750 that interfaces to the recorder 742, a tuner 744, a VBI decoder/slicer 746, an audio decoder 748, a memory 752 which can be a random access memory and a ROM, a clock 754, an on-screen display controller 756, a TV on detector 763, a compressed code decoder 758, die IR receiver 760, and an IR transmitter 762.

The switch 700 is controlled by d e VCR 740 and die output 728 of die switch can be sourced from the antenna 702, the cable box 730 or d e satellite receiver 733. A FET switch

710 is used to switch between the various inputs. In one embodiment the controller 750 sends a bit pattern via line 712 to the bit pattern detector 714 in switch 700. Different received bit patterns can control the FET switch 710 to select the desired television signal source. The FET switch 710 includes FET transistors 770, 772, 774 and 776 which are gated by signal lines 771, 773, 775, and 777, respectively. In an alternate embodiment die

VCR 740 sends controls to switch 700 via infrared transmitter 762 and infrared detector 724 rather than send die bit pattern via signal line 712. As shown in FIG. 28 the switch 700 is a separate unit from VCR 740. Alternatively, die switch 700 can be integral to the VCR

740 and in this case the controller 750 can directiy control switch 700. If the switch 700 is separate, then die switch can be powered by a battery 722 or can be powered by extracting power from the cable 706. The power is extracted by transformer 716 and then rectified by diode 718, which is coupled to capacitor 728.

At any one time the FET switch 710 is controlled so that only one television signal source is enabled to be coupled to d e output 728. For example, if FET transistor 772 is turned on then die satellite receiver 733 is coupled to die output 728 and if FET transistor 776 is turned on, tiien cable input 706 is coupled to die output 728. The cable 706 that is attached to switch 700 is either sourced from the output of cable box 730 or from the cable 704 itself. As shown die cable box has an infrared receiver 732. The satellite receiver also has an infrared receiver 735. The infrared transmitter 762 can control the cable box and the satellite receiver 732 via their infrared receivers. The described embodiments of die invention are only considered to be preferred and illustrative of die inventive concept, the scope of the invention is not to be restricted to such embodiments. Various and numerous other arrangements may be devised by one skilled in the art without departing from the spirit and scope of this invention.

Claims

WHAT IS CLAIMED IS:

1. An apparatus for extracting data from video signals, the apparatus comprising: means for notch filtering frequencies of a first channel from a first video source, the first video source having a plurality of channels, to form a notch filter output having each of the plurality of channels except the frequencies of the first channel; means for bandpass filtering a second video source to pass only frequencies in a second channel in die second video source having the same frequencies as the frequencies of the first channel to form a bandpass filter output; means for summing the notch filter output and the bandpass filter output to form - a summed output; and a television for extracting data from the summed output.

2. The apparatus of claim 1 further comprising: means for signal splitting having a first input and a first and second output, the second output coupled to and providing the first video source into the means for notch filtering.

3. The apparatus of claim 1 wherein: the first video source is coupled to an over-die-air antenna; and die second video source is coupled to a video cassette recorder.

4. The apparatus of claim 1 wherein: the first video source is coupled to an over-die-air antenna; and the second video source is coupled to a cable box.

5. The apparatus of claim 1 wherein: the first video source is coupled to an over-the-air antenna; and die second video source is coupled to a satellite receiver.

6. The apparatus of claim 2 wherein: the first input is coupled to an over-the-air antenna; the first output is coupled to a video cassette recorder input; and a video cassette recorder output is coupled to and provides die second video source into the means for bandpass filtering.

7. The apparatus of claim 2 wherein: the first input is coupled to a television cable source; the first output is coupled to a video cassette recorder input; and a video cassette recorder output is coupled to and provides the second video source into the means for bandpass filtering.

8. The apparatus of claim 2 wherein: the first input is coupled to a television cable source; the first output is coupled to a cable box input; and a cable box output is coupled to and provides d e second video source into the means for bandpass filtering.

9. The apparatus of claim 1 wherein the television for extracting data from the summed output further comprises: a tuner for tuning to a channel in the summed output; a means for extracting data coupled to die tuner for decoding data in a channel in die summed output; means for storing the extracted data; and means for displaying d e extracted data.

10. The apparatus of claim 9 wherein the means for extracting data further comprises: means for comparing a current time with at least one stored time period for extracting data to determine if die current time is within the stored time period; means for extracting the data from the summed output when the current time is within the stored time period; and means for storing the extracted data.

11. The apparatus of Claim 10 further comprising: means for controlling a tuner to tune to a plurality of channels in the summed output, when the current time is within the stored time period; and means for locking the tuner on a channel containing data in order to permit extraction of the data from the channel.

12. The apparatus of Claim 10 wherein the means for extracting data from the summed output when the current time is within the stored time period comprises a means for decoding data in a vertical blanking interval.

13. The apparatus of Claim 10 wherein the means for extracting d e data from the summed output when the current time is within the stored time period comprises a means for decoding audio data.

14. The apparatus of Claim 10 wherein the means for comparing a current time with at least one stored time period for extracting data to determine if die current time is within the stored time period comprises a clock.

15. The apparatus of Claim 10 wherein the means for comparing a current time with at least one stored time period for extracting data to determine if die current time is within the stored time period further comprises: means for detecting whether die television is OFF; and means for comparing a current time with a stored time period only if e means for detecting indicates the television is OFF.

16. An apparatus for extracting data from video signals, the apparatus comprising: a first means for notch filtering frequencies of a first channel from a first video source, the first video source having a plurality of channels, to form a first notch filter output having each of the plurality of channels except the frequencies of die first channel; a first means for bandpass filtering a second video source to pass only frequencies in a second channel in die second video source having die same frequencies as die frequencies of die first channel to form a first bandpass filter output; a first means for summing the notch filter output and die bandpass filter output to form a first summed output; means for signal splitting having a first input coupled to the first summed output and having a first and second output; a second means for notch filtering frequencies coupled to the second output, the second output having a plurality of channels, to form a second notch filter output having each of the plurality of channels except the frequencies of a third channel; a second means for bandpass filtering a fourth video source to pass only frequencies in a fourth channel in die fourth video source having the same frequencies as the frequencies of the third channel to form a second bandpass filter output; a second means for summing the second notch filter output and the second bandpass filter output to form a second summed output; and a television for extracting data from the second summed output.

17. The apparatus of claim 16 wherein: the first video source is coupled to an over-the-air antenna; the second video source is coupled to a cable box output; the first output is coupled to a video cassette recorder input; and d e fourth video source is coupled to a video cassette recorder output.

18. The apparatus of claim 16 wherein: die first video source is coupled to an over-die-air antenna; the second video source is coupled to a satellite receiver output; the first output is coupled to a video cassette recorder input; and die fourth video source is coupled to a video cassette recorder output.

19. An apparatus for providing a television guide, die apparatus comprising: means for comparing a current time with at least one stored time period for extracting television guide data to determine if the current time is within the stored time period; means for determining whetiier television guide data is contained in a signal output; means for switching die signal output from a first television signal source to a second television signal source, if television guide data is not contained in the signal output from the first television signal source when the current time is within the stored time period; means for extracting the television guide data from die signal output when the current time is within the stored time period; and means for storing the extracted television guide data.

20. The apparatus of Claim 19 further comprising: means for controlling a tuner to tune to a plurality of channels -in the first television signal source, when the current time is within the stored time period; means for controlling a tuner to tune to a plurality of channels in die second television signal source, when the current time is within the stored time period; means for locking the tuner on a channel containing television guide data in order to permit extraction of the television guide data from the channel; and wherein the means for switching switches die signal output from the first television signal source to the second television signal source, if television guide data is not contained in die signal output from the plurality of channels in the first television signal source.

21. The apparatus of Claim 19 wherein: the first television signal source comprises a television cable; and die second television signal source comprises an over d e air antenna.

22. The apparatus of Claim 21 further comprising a means for extracting power from the television cable for powering the switch.

23. The apparatus of Claim 19 further comprising: means for switching the signal output from the second television signal source to the first television signal source after the television guide data is extracted and stored.

24. The apparatus of Claim 19 wherein the means for switching the signal output from a first television signal source to a second television signal source, if television guide data is not contained in die signal output from the first television signal source when the current time is within the stored time period comprises: second means for switching the signal output from the second television signal source to a third television signal source, if television guide data is not contained in die signal output from the second television signal source when the current time is within the stored time period.

25. The apparatus of Claim 24 wherein: die first television signal source comprises a television cable; the second television signal source comprises an over the air antenna; and the third television signal source comprises a satellite receiver.

26. The apparatus of Claim 19 further comprising means for displaying die stored television guide data to allow a user to select programs for viewing or recording.

27. The apparatus of Claim 19 wherein the means for extracting the television guide data from the signal output when the current time is within the stored time period comprises a means for decoding data in a vertical blanking interval of the signal output.

28. The apparatus of Claim 19 wherein the means for extracting the television guide data from the signal output when die current time is within the stored time period comprises a means for decoding audio data in the signal output.

29. The apparatus of Claim 19 wherein the means for comparing a current time with at least one stored time period for extracting television guide data to determine if the current time is within the stored time period comprises a clock.

30. The apparatus of Claim 19 wherein d e means for switching the signal output from a first television signal source to a second television signal source, if television guide data is not contained in the signal output from the first television signal source when the current time is within the stored time period comprises an infrared transmitter.

31. The apparatus of Claim 19 wherein the means for switching the signal output from a first television signal source to a second television signal source, if television guide data is not contained in the signal output from the first television signal source when the current time is within the stored time period comprises means for detecting a bit pattern.

32. The apparatus of Claim 19 wherein the means for storing the extracted television guide data comprises a memory.

33. The apparatus of Claim 19 further comprising means for controlling a recorder to record die signal output.

34. The apparatus of Claim 19 wherein the means for comparing a current time with at least one stored time period for extracting television guide data to determine if the current time is within the stored time period further comprises: means for detecting whether a television is off; and means for comparing a current time with a stored time period only if die means for detecting indicates the television is OFF.

35. The apparatus of Claim 19 wherein the means for comparing, the means for determining, die means for switching, the means for extracting and the means for storing are integral with a recorder.

36. The apparatus of Claim 19 wherein the means for comparing, the means for determining, die means for switching, the means for extracting and the means for storing are integral with a television.

37. The apparatus of Claim 19 wherein: the stored television guide data comprises at least one compressed code having at least one digit and each representative of, and compressed in length from, the combination of the channel, day, time-of-day, and program length; and the apparatus further comprises means for decoding a compressed code having at least one digit into channel, day, time-of-day, and program length.