JPH05205344A - Video recording system - Google Patents

Abstract

PURPOSE:To record a program surely and accurately despite of changing of a program by turning on a power supply and recording the program by the frame record retrieval control circuit when a broadcasting frame code in a received broadcasting signal coincides with a reserved frame code in the memory. CONSTITUTION:A radio wave received by the antenna 1 is inputted to the tuners 2 and 11, a signal of intermediate frequency is inputted to the video recording section 4 from the tuner 2, and it is converted into a composite video signal and a sound signal. On the other hand, the signal of intermediate frequency from the tuner 11 is inputted to the control circuit 12, and a frame code is extracted. When the extracted frame code coincides with a frame code of reserved video recording information previously stored in the memory 6 for reserved video recording information, the circuit 12 turns on the main power supply 9 and commands video recording to the recording control circuit 3. The circuit 3 set the tuner 2 to the channel desired to record and commands video recording to the video recording section 4. The tuner 11 retrieves the reserved channel frame code even during reserved video recording, and commands the end of video recording to the circuit 3 when the reserved broadcasting part is completed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording system for recording reserved broadcast programs.

[0002]

2. Description of the Related Art FIG. 18 is a schematic block diagram showing a recording reservation apparatus of a conventional recording system. In the figure, 1 is an antenna, 2 is a tuner, 3 is a recording control circuit, 4 is a recording section, and 5 is reserved recording. An information input / output unit, 6 is a reserved recording information memory, 7 is a reserved recording control circuit, 8 is a timer, 9 is a main power supply, and 10 is a standby power supply.

FIG. 19 is a diagram showing a recording reservation method in a conventional reservation recording apparatus, and FIG. 20 is a schematic block diagram showing a conventional broadcast signal transmission system.

Next, the operation will be described. 2. Description of the Related Art Conventionally, this kind of recording system for recording reserved broadcast programs has a main switch turned on at a recording start time when a channel and a scheduled broadcast time (start time and end time) of a TV broadcast program to be recorded are set. , The program broadcasted on the TV channel is recorded for a preset time, and the recording is controlled so that the main switch is turned off at the recording end time.

[0005]

Since the conventional recording system is configured as described above and the reserved recording is controlled by the time regardless of the contents of the broadcast program, the broadcast time of the reserved recorded program is changed. However, there was a problem that some or all of the programs would be lost.

The present invention has been made in order to solve the above problems, and can record a program reliably and accurately even when the broadcast time of the program reserved for recording is changed. The purpose is to get the system.

[0007]

A recording system according to the present invention includes a frame code receiving tuner for sequentially receiving a broadcast program frame code (hereinafter abbreviated as a frame code) included in a broadcast signal of each broadcasting station. A frame code search control circuit for turning on the main power supply and sending a control signal to the recording control circuit only when the frame code received by the frame code receiving tuner matches the reserved frame code in the reserved recording information memory. It is equipped with.

Further, in the recording system according to the present invention, the frame code transmission system multiplexes and transmits the frame code to the hybrid transmission system teletext signal multiplexing section, and the recording device identifies the multiplexed frame code and makes a reserved recording. It is used for.

Further, in the recording system according to the present invention, the frame code transmission system multiplexes and transmits the frame code in the video blanking period other than the hybrid transmission system teletext signal multiplexing section, and the recording device makes the multiplexed frame. It recognizes the code and uses it for scheduled recording.

Further, in the recording system according to the present invention, the frame code transmission system multiplexes and transmits the frame code on a carrier wave (cosine) orthogonal to a carrier wave (sine) unique to the transmitting station, and the recording device performs this multiplexing. The frame code is demodulated, recognized, and used for reserved recording.

Further, in the recording system according to the present invention, the frame code transmission system transmits the audio signal and the frame code which are highly efficient coded and digitized the video signal and the frame code, and the recording device is multiplexed. The frame code is identified and extracted and used for reserved recording.

[0012]

Next, the operation of the recording system according to the present invention will be described. When the user schedules recording, the main power is turned on, and the scheduled recording information such as broadcast channel, broadcast date, program type code, program code, frame ID code, recording mode, etc. is set and input as necessary, and the main power is turned on. O
Set to FF. At this time, the standby power is still ON,
Power is supplied to the frame code receiving tuner, the frame code search control circuit, the reserved video recording information memory, and the like.
The frame code search control circuit sequentially receives the broadcast signals of the reserved broadcast channels recorded in the reserved recording information memory, and the reserved frame recorded in the reserved recording information memory as well as the broadcast frame code included therein. Compare with the code. If they do not match, do nothing. If they match, turn on the main power,
Make a recording.

By doing so, it is possible to accurately schedule and record only the portion of the program desired to be watched. Further, even if the broadcast time of the reserved recording program is changed, the desired program can be correctly recorded. Furthermore, by designating an emergency special program, a cooking program, etc. by the program type code, it is possible to schedule and record an unspecified program by type, or use the program division code to schedule and record only commercials.

[0014]

【Example】

Example 1. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic block diagram showing an example of a recording reservation device of a recording system according to the present invention. In the drawing, 11 is a frame code receiving tuner, and 12 is a frame code search control circuit for performing tuner control at the time of search. Is.

Next, the operation will be described. The radio wave received by the antenna 1 is supplied to the frame code receiving tuner 11 and the tuner 2 and converted into an intermediate frequency signal. The intermediate frequency signal output from the tuner 2 is supplied to the recording unit 4 and converted into a composite VIDEO signal and an audio signal so as to be recorded in the VTR. On the other hand, the intermediate frequency signal output from the frame code receiving tuner 11 is supplied to the frame code search control circuit 12. This control circuit is composed of a frame code detection part and a reception channel update command part as will be described later. Although a specific configuration of the frame code detecting portion will be described later, detailed information of the program is extracted in this frame code detecting portion. For example, information such as a type code, a program code, a frame ID code of a specific broadcasting station is extracted.

On the other hand, the reception channel update command portion instructs the frame code reception tuner 11 to tune the frequency to each channel reserved and registered at every predetermined time. For example, if the reserved channel is A. B. If it is C and the channel update time is several seconds (T seconds), the following operation is performed. Assuming that the frequency is adjusted to the channel A for T seconds, the frame code being transmitted on the channel A is extracted at the frame code detection portion during the period, and the frequency T is adjusted to the channel B on the next T seconds. The code is extracted, and in the next T seconds, the frequency is adjusted to the channel C and the frame code being transmitted on the channel C is extracted.

Then, the channel A is returned to. The reserved recording information memory 6 stores reserved recording information input from the reserved recording information input / output unit 5 in advance. When the frame code in this reserved recording information matches the extracted frame code, the frame The code search control circuit 12 turns on the main power supply 9, and the recording control circuit 3
Instruct to record. The recording control circuit 3 instructs the recording unit 4 to perform recording according to the channel to which the tuner 2 is to be recorded. The tuner 11 for receiving the frame code is
Even during recording by reservation, the frame code of each channel for which reserved recording is set is searched, and when the reserved broadcast portion has passed, the recording control circuit 13 is instructed to end recording.

Also, when the broadcast time is changed, it is expected that another reserved broadcast will start even though the reserved recording is in progress. However, prioritize the reserved recording. For example, the frame code search control circuit 12 can respond by instructing the recording control circuit 3 to always record the higher priority one.

Next, a circuit for extracting the frame code multiplexed in the broadcast signal will be described. Since this frame code extraction portion differs depending on how the transmission side performs multiplexing, it is closely related to the following description regarding the frame code multiplexing method. In the present invention, four schemes are proposed for that scheme, and the schemes are designated as schemes 1, 2, 3, and 4, respectively. 12 to 15 are block diagrams of the transmission side of the schemes 1, 2, 3, and 4, and block diagrams of the frame code extraction portion at the time of reception are shown in FIGS. 2 to 5.

First, FIG. 2 will be described. Figure 2
FIG. 3 is a block diagram of a frame code extracting portion of a recording apparatus when a frame code is multiplexed and transmitted to a hybrid transmission system teletext signal multiplexing unit according to an embodiment of the present invention. In the figure, 13 is a character signal decoding circuit. , 14 are special code search circuits for frame code multiplexing.

The operation of FIG. 2 will be described. The frame code receiving tuner 11 in FIG. 2 is the same as that in FIG. First, the output signal of the frame code receiving tuner 11 is demodulated to obtain a video signal and an audio signal. The character signal decoding circuit 13 converts the character broadcast signal, which is time-axis-multiplexed to a specific part (the position is shown in FIG. 8a) of the vertical blanking part in the video signal, into character signal data. A special code that is not normally used is inserted in the character signal data, and this special code is searched by the special code search circuit 14. Since the frame code is multiplexed with this special code as a mark, if the special code can be searched, the data after the special code can be extracted as the frame code. (The position where the frame code is transmitted to the special code is promised, and the frame code extraction position differs depending on the transmission position.) The frame code multiplexed in the teletext signal in this way is You can search.

Next, FIG. 3 will be described. FIG. 3 is a block diagram of a frame code extracting portion of a recording device when a frame code is multiplexed and transmitted in a video blanking period other than the hybrid transmission system teletext signal multiplexing portion according to another embodiment of the present invention. In the figure, 15 is a sync signal separation circuit (SYNC SEPA), 16 is a timing extraction circuit, 17 is a data PLL, 18 is a reference level extraction circuit, 19 is a digitization circuit, and 20 is an error correction circuit.

The operation of FIG. 3 will be described. The frame code receiving tuner 11 in FIG. 3 is the same as that in FIG. First, the output signal of the frame code receiving tuner 11 is demodulated to obtain a video signal, and a data area dedicated to the frame code of the blanking portion in the video signal is searched for from the synchronizing signal of the video signal. The sync signal separation circuit 15 extracts the horizontal sync signal and the vertical sync signal. The timing extraction circuit 16 operates to extract the area dedicated to the frame code from these synchronization signals. Since the position of the frame code is known by the timing extraction circuit 16, the PLL (phase synchronization circuit) for the data clock is applied only at that position, while the portion in which the reference level is inserted can be recognized.

Then, the data PLL 17 generates the timing for regenerating and digitizing the data clock, and the reference level extracting circuit 18 generates the comparator level for digitizing. The digitizing circuit 19 produces these digital data. Be converted. The output signal of the digitizing circuit 19 is converted into correct data by the error correcting circuit 20 so that it will not be converted into erroneous data even if it falls into a low-level reception state due to interference on the transmission path or the like, and is correct. The frame code is extracted.

Next, FIG. 4 will be described. FIG. 4 is a block diagram of a frame code extracting portion of a recording apparatus when a frame code is multiplexed and transmitted on the orthogonal axis of a carrier wave according to another embodiment of the present invention. In the figure, 21 is a multiplier (synchronization). (Detection circuit), 22 is LPF, 23 is an amplifier for limiter operation, 24 is a tuning circuit (carrier wave PLL), 2
5 is a 90-degree phase shifter, 26 is a multiplier, and 27 is an LPF.

The operation of FIG. 4 will be described. The frame code receiving tuner 11 in FIG. 4 is the same as that in FIG. Tuner 1 for frame code reception
The output of 1 is shaped by the high gain amplifier 23, which performs a limiter operation to make the amplitudes uniform, into a waveform having the same amplitude as the intermediate frequency signal, and a PLL (tuning circuit) for extracting the carrier of the video signal from the signal. ) 24. Since the output signal of the tuning circuit 24 is a signal in which the carrier wave of the video signal is phase-locked, the output signal of the tuner 11 for receiving the frame code is multiplied by the multiplier 21 to obtain the video signal. Is demodulated.

On the other hand, in this system, since the frame code is modulated by the axes orthogonal to the video signal, it is not detected by the output signal of the PLL (tuning circuit) 24, and the output signal of the PLL (tuning circuit) 24 is 90 degrees. Detection is possible with a signal that has been shifted. Therefore, the frame code is passed through the output signal of the PLL (tuning circuit) 24 through the 90-degree phase shifter 25, multiplied by the intermediate frequency signal by the multiplier 26, and further LPF.
It can be detected by being passed through 27. The output of LPF27 is
PL for data for data clock of frame code
At the timing determined by L17, the digitization circuit 19 converts the data into data, and the error correction circuit 20 converts the data into correct data even when there is an error in the communication path, and finally outputs it as a frame code. ..

Next, FIG. 5 will be described. FIG. 5 is a block diagram of a frame code extraction portion of a recording apparatus when a frame code is multiplexed and transmitted on the time axis of a digital video / audio signal in a digital broadcast which is another embodiment of the present invention. 28 and 29 are synchronous detection circuits (multipliers), 30 is a carrier wave PLL, 31 is a frame code area extraction circuit, and 32 is a switch.

The operation of FIG. 5 will be described. The frame code receiving tuner 11 in FIG. 5 is the same as that in FIG. Tuner 1 for frame code reception
PL for carrier wave to reproduce carrier wave by output of 1
An intermediate frequency signal is passed through L30. Various types of carrier-wave PLLs 30 have been proposed, including those generally called Costas loops, but the type of carrier-wave PLL 30 is not limited here. The carrier of 16QAM reproduced in the carrier wave PLL 30 is directly input to the synchronous detection circuit 28 and multiplied by the intermediate frequency signal.

Then, by extracting only the low frequency signal resulting from the multiplication, the signal projected on the axis (I axis) of the carrier wave is extracted from the intermediate frequency signal. On the other hand, the output of the carrier wave PLL is passed through the 90-degree phase shifter, then input to the synchronous detection circuit, multiplied by the intermediate frequency signal, and only the low frequency signal of the multiplication result is extracted to obtain the carrier wave of the intermediate frequency signal. The signal projected on the orthogonal axis (Q axis) is extracted. Pass the synchronous detection output to the data PLL 17,
The digitizing timing is determined, and the digitizing circuit 19 digitizes the data. After that, when an error occurs on the communication path, the error correction circuit 20 converts the data into correct data. Since the output of the error correction circuit 20 is time-multiplexed with digital video and audio data and a frame code, the frame code area extraction circuit 31
Search the frame code area with.

However, if the multiplex position of the frame code is determined to be a fixed position from the beginning, it is not necessary to search that position. The frame code area extracting circuit 31 can determine the timing for extracting the frame code, and the switch 32 can extract only the frame code. Since the purpose of the frame code area extraction circuit 31 is to determine the timing for extracting the frame code, when the frame code is multiplexed at a fixed position and the timing is known in advance, the switch is performed at that timing. 32 may be switched.

Next, FIG. 6 will be described. FIG. 6 is a diagram showing an example of the contents of the frame code transmitted in the present invention. Code 1 is a type code, code 2, code 3, code 4 are subcodes, code 5 is a spare code, and code 6 is a broadcast date. Code, code 7 is a spare code, code 8 is a program code, code 9 is a program division code, code 1
0 is a sub code, code 11 is a frame ID code, and code 12 is a spare code. The type code is a code indicating the genre or purpose of sports, politics, music, commercials, etc., the broadcast date code is a number from 1 to 31 indicating the day of each month, and the program code is for each broadcast program unit. ID code and program division code given by each broadcasting station is 1
One broadcast program is divided into a number of groups having a certain meaning, and the ID code and frame ID code given to this show the ID code given to each frame. The (broadcast program) frame code is a generic term for all of these codes, and represents the broadcast program information included in one frame or several frames by each broadcasting station at the time of transmission. The minimum required transmission codes are the broadcast date code and the program code, but it is better to have as much transmission information as possible. Also, the same frame code may be transmitted continuously. Each code is a signal of 1 byte, and 256 kinds of data IDs can be distinguished for each code.

FIG. 7 is a diagram showing an example of a recording reservation method in the reservation recording apparatus of the present invention. When making a recording reservation, the user sets the broadcasting station, broadcasting date, type code, program code, frame ID code (start / end), recording mode, and the like. All items other than the recording mode are reserved recording judgment elements, and can be set or omitted depending on the necessity and application.

Here, a specific example will be described. Figure 7
In the first stage, the program 052 to be broadcast on channel 4 on the 19th of a month is reserved for recording in triple mode.
By making such a recording reservation, it is possible to surely record even if the timer comes up due to a power failure or the program broadcast time is changed. Next, the second stage is 2c on the 19th of a month.
Frame ID code 021 of program 019 broadcast on h
Only the 087 section is reserved for recording in the standard mode. By making such a recording reservation, only a part of a certain program can be recorded depending on the content. For example, a sports news corner in a news program. If the third stage is a program corresponding to type code 625008,
It is reserved and set to record in triple mode regardless of the broadcasting station or the broadcasting date. For example, settings such as emergency special programs and cooking programs may be considered. In addition to this, it becomes possible to schedule and record only commercials by using the program division code.

Next, a multiplexing method on the transmission (broadcasting) side corresponding to the frame code extraction method shown in FIGS. 2 to 5 will be described. First, FIG. 12 will be described. Figure 1
2 is a block diagram showing a method for multiplexing and transmitting a frame code in a hybrid transmission system teletext signal multiplexing unit according to an embodiment of the present invention, in which 33 is a switch, 34 is a teletext encoder, and 35 is Is a multiple circuit, 3
Reference numeral 6 represents a television transmitter.

The operation will be described with reference to FIG. The frame code is time-axis-multiplexed in the space between the teletext data by switching the switch 33. At the time of switching, if a special code not normally used in teletext is added before the frame code, the frame code can be easily separated on the receiving side (or a special code can be added before and after the frame code). .. The teletext data obtained by time-multiplexing the frame code becomes a text signal by adding a code for error correction and a signal for data synchronization in the teletext encoder 34, and becomes a text signal by the multiplexing circuit 35 within the vertical blanking period of the video signal. Are multiplexed into a predetermined number H of In this way, the frame code shown in FIG. 2 is multiplexed in the teletext signal, and as shown in FIG. 8, it is time-axis multiplexed to a certain number H (horizontal scanning period) in the vertical blanking period of the video signal. Sent ("NHK TV textbook (above)"
(Japan Broadcasting Corporation) p64-p74 and p104-p11
0).

A timing signal generating circuit as described below with reference to FIG. 13 may be prepared in order to determine the timing of the predetermined number H, but it is omitted because it is almost the same as in FIG. Further, the television transmitter 36 frequency-multiplexes voice or the like into a television broadcast signal and modulates the television broadcast signal at a frequency unique to the broadcast station. The disadvantage of this multiplexing method is that when there is a large amount of teletext data, the gap between the teletext data becomes small and it becomes impossible to transmit a detailed frame code that is different for each frame. In such a case, a program division code having a plurality of frames as one unit, a program subcode, etc. may be used effectively. The program division code and the program sub-code may be, for example, a code for every one second, a code for every one minute, or a code for each corner of the program.

Next, FIG. 13 will be described. FIG. 13 is a block diagram showing a method for multiplexing and transmitting a frame code during a video blanking period other than the hybrid transmission system teletext signal multiplexing unit according to another embodiment of the present invention, in which 37 is a video signal. Encoder, 38 is switch, 39 is sync separation circuit (SYNC SEPA), 40
Is a timing signal generation circuit, 41 is a frame code generation circuit, 42 is a multiplexing circuit, 43 is a modulation circuit, and 44 is a filter.

The operation will be described with reference to FIG. A signal from an editing machine such as a television camera or a chroma key has a color signal modulated by a video signal encoder 37 and multiplexed with a luminance signal to be converted into a composite VIDEO signal (hereinafter referred to as a composite signal). In a television station, a video signal is often handled by this composite signal, and the VTR in the station often uses this signal for recording. The switch 38 is for switching the input of a multiplexing circuit 42 which multiplexes a frame code with this composite signal. This limits the input of the multiplexing circuit 42 to the composite signal. This limitation is not mandatory.
This is because the area where the frame code is multiplexed is the blanking portion of the video signal, and there is no sync signal included in the luminance signal in that portion, there is no RY signal or BY signal, and there is no composite signal. A certain luminance signal (Y in FIG. 13)
This is because the same frame code can be multiplexed even if the frame code is multiplexed after being encoded.

The sync signal of the composite signal is separated by the sync separation circuit 39, and the timing signal generation circuit 40 detects a predetermined position in the blanking portion other than the teletext area to instruct the start of multiplexing. On the other hand, the frame code creating circuit 41 creates the frame code as described above, adds a code for error correction and a signal for data synchronization, and adds the multiplex circuit 42.
Send data to. The multiplexing circuit 42 multiplexes the signal created by the frame code creation circuit 41 with the video signal (composite signal) at the timing defined by the timing signal generation circuit 40. An example of the concrete signal form is shown in FIG. FIG. 9 shows an example of a signal form in the case where frame code data is multiplexed on a vertical blanking portion (for example, 10th to 13H in FIG. 8) other than the character signal. The reference data in FIG. 9 is data for defining a threshold level and the like when the data is converted into discrete values.

Here, an example in which the frame code is multiplexed in the vertical blanking period has been described, but it may be multiplexed in the horizontal blanking period, in which case the data may be finely divided and multiplexed. In this way, the modulation circuit 43 modulates the video signal and the audio signal in which the frame code is multiplexed with the frequency peculiar to the station, and the modulation circuit 43 transmits the signal through the filter 44. The modulation circuit 43 and the filter 44 of this figure correspond to the television transmitter of FIG. With this multiplexing method, a large amount of data can be transmitted for each field (or frame) regardless of the amount of teletext, so that a detailed frame code can be transmitted.

Next, FIG. 14 will be described. FIG. 14 is a block diagram showing another embodiment of the present invention in which a frame code is multiplexed and transmitted on orthogonal axes of a carrier wave.
In the figure, 45 and 46 are modulation circuits for AM modulation, 4
7 represents an adder.

The operation will be described with reference to FIG. The composite signal converted by the video signal encoder 37 of FIG. 13 and the like (however, the composite signal of FIG. 14 is frequency-multiplexed to the frequency shown in FIG. 10 in addition to the video signal) The modulation circuit 46 performs AM modulation with a specific carrier for each TV station. The most significant feature of this multiplexing method is that the composite signal is modulated as usual while the frame code is modulated by using a carrier having a 90 ° phase difference from that of the carrier, and multiplexed. Therefore, the carrier wave whose phase is shifted by 90 degrees by the 90-degree phase shifter 25 is used, and the frame code is AM-shifted by the modulation circuit 45.
Modulate. The adder 47 adds the two signals modulated by the carrier waves whose phases are different from each other by 90 degrees. Such multiplexing results in the signal form shown in FIG. The carrier I axis in FIG. 11 is an axis having the same phase as the carrier of the video signal, and the carrier Q axis is an axis having a phase orthogonal to the carrier of the video signal. As shown in Figure 4, TV and VTR
Since the tuner operates a tuning circuit that matches the phase of the carrier wave of the video signal, it can be separated on the receiving side even with such multiplexing. However, it can be separated only at a frequency of several hundred kHz or less where the upper and lower side waves are aligned with the carrier wave. That is, the bit rate of data that can be multiplexed is limited here. However, if multi-level multiplexing is possible, the bit rate can be increased accordingly.

Considering the performance of the tuning circuit 24 of the receiver shown in FIG. 4, such multiplexing may be performed intermittently. That is, such multiplexing is performed only in a part of one frame period. What is the period of part 1?
For example, it may be a vertical blanking period. In that case, since only a small amount of data can be transmitted as the bit rate,
Instead of being able to multiplex detailed frame codes, it is possible that only one code can be transmitted for each program. However, if it is always multiplexed, about 3000 bits per frame can be multiplexed, so it is easy to multiplex the above frame code, and there is a margin such that it is possible to time-multiplex with digital voice. is there. Also, if the clock frequency of the data is devised such that it is an integral multiple of the frequency of the horizontal synchronizing signal of the video signal,
Even if distortion such as orthogonal distortion occurs on the transmission path and the data of the frame code leaks to the video signal, the position of the interference is fixed on the TV screen, which is not noticeable to the eyes.

Next, FIG. 15 will be described. FIG. 15 is a block diagram showing a method of transmitting a frame code on the time axis of a digital video / audio signal in digital broadcasting which is another embodiment of the present invention. In the figure, 48 is a video signal high efficiency encoding circuit, 49 is an audio signal encoding circuit,
Reference numeral 50 is a frame code creation circuit, 51 is an error correction code addition circuit, 52 is a modulation circuit, 53 is a filter, and 54 is a switch.

The operation will be described with reference to FIG. The video signal high-efficiency encoding circuit 48 is a circuit for efficiently converting a video signal into digital data, and a high-efficiency encoding method using orthogonal transformation such as discrete cosine transformation or a high-efficiency encoding method called DPCM is generally used. Target. The voice signal encoding circuit 49 is a circuit for encoding a voice signal, and it is not necessary to use a particularly efficient encoding circuit. The frame code creation circuit 50 is a circuit that creates a frame code. In the case of a system other than the above hybrid transmission system teletext signal multiplexing unit, in a video blanking period or in a system in which multiplexing is performed on the orthogonal axis of a carrier wave, an error correction code is added by the frame code creating circuit 50. In this case, the error correction code adding circuit 51 is separately provided, and is performed simultaneously with the addition of the data of the video / audio signal.

That is, this multiplexing system is a system in which frame codes are time-multiplexed with respect to digitized video and audio data. The switch 54 performs the time-axis multiplexing. Note that the error correction code is 2
When using the Reed-Solomon code of multiple products, different error correction codes may be added to the various signals of video, audio, and frame codes for both the outer code and the inner code. May be changed. The data thus created is modulated by the modulation circuit 52. This modulation is AM
It is common to use a modulation method called QAM that incorporates both PM and PM. A sufficiently practical method in view of cost and the like is 16QAM, 32QAM, or 64QAM.

16 and 17 are block diagrams showing a configuration example of a modulation circuit when digital broadcasting is realized by 16QAM in another embodiment of the present invention, and a diagram showing the signal point arrangement of the modulation circuit. In FIG. 16, the data assigned 2 bits for I axis and 2 bits for Q axis are AM-modulated by the carrier wave for I-axis and the sine wave orthogonal to the carrier wave for Q-axis, respectively, and added.

[0049]

As described above, according to the present invention, the TV program is reserved and recorded according to the content, so that the program can be surely recorded even if the broadcast time of the reserved program changes. Moreover, since the recording is controlled in units smaller than the frame of the program, it is possible to record only the sports corner in the news program, only the CM, or only the non-CM, and the like, there is almost no waste or omission of accurate recording. It can be performed.

[Brief description of drawings]

FIG. 1 is a schematic block diagram showing a recording reservation device of a recording system according to an embodiment of the present invention.

FIG. 2 is a block diagram of a frame code extracting portion of a recording device when a frame code is multiplexed and transmitted to a hybrid transmission system teletext signal multiplexing unit according to an embodiment of the present invention.

FIG. 3 is a block diagram of a frame code extraction portion of a recording device when a frame code is multiplexed and transmitted during a video blanking period other than a hybrid transmission system teletext signal multiplexing unit according to another embodiment of the present invention. ..

FIG. 4 is a block diagram of a frame code extracting portion of a recording apparatus when a frame code is multiplexed and transmitted on a quadrature axis of a carrier wave according to another embodiment of the present invention.

FIG. 5 is a block diagram of a frame code extracting portion of a recording device when a frame code is multiplexed and transmitted on a time axis of a digital video / audio signal in digital broadcasting which is another embodiment of the present invention.

FIG. 6 is a diagram showing an example of contents of a frame code transmitted in the present invention.

FIG. 7 is a diagram showing an example of a recording reservation method in the reservation recording apparatus of the present invention.

FIG. 8 is a diagram showing a broadcast signal in a vertical blanking period in current domestic broadcasting.

FIG. 9 is a diagram showing an example of a signal form in the case where a frame code is multiplexed and transmitted in a video blanking period other than that in the hybrid transmission system teletext signal multiplexing unit according to another embodiment of the present invention.

FIG. 10 is a diagram showing frequency allocation of NTSC signals in current domestic broadcasting in Japan.

FIG. 11 is a diagram showing an example of a signal form when a frame code is multiplexed and transmitted on the orthogonal axis of a carrier wave according to another embodiment of the present invention.

FIG. 12 is a block diagram showing a method of multiplexing a frame code in a hybrid transmission system teletext signal multiplexing unit and transmitting the same according to an embodiment of the present invention.

FIG. 13 is a block diagram showing a method of multiplexing a frame code in a video blanking period other than the hybrid transmission system teletext signal multiplexing unit and transmitting the multiplexed frame code, which is another embodiment of the present invention.

FIG. 14 is a block diagram showing a method of multiplexing a frame code on a quadrature axis of a carrier wave and transmitting the multiplexed code according to another embodiment of the present invention.

FIG. 15 is a block diagram showing a method of transmitting a frame code on a time axis of a digital video / audio signal in digital broadcasting which is another embodiment of the present invention.

FIG. 16 is a block diagram showing a configuration example of a modulation circuit when digital broadcasting is realized by 16QAM in another embodiment of the present invention.

FIG. 17 is a diagram showing a signal point arrangement of a modulation circuit when digital broadcasting is realized by 16QAM in another embodiment of the present invention.

FIG. 18 is a schematic block diagram showing a recording reservation device of a conventional recording system.

FIG. 19 is a diagram showing a recording reservation method in a conventional reservation recording device.

FIG. 20 is a schematic block diagram showing a conventional broadcast signal transmission system.

[Explanation of symbols]

 3 Recording control circuit 6 Memory for reserved recording information 9 Main power supply 11 Frame code receiving tuner 12 Frame code search control circuit

Claims (5)

[Claims] 1. A frame code receiving tuner for sequentially receiving broadcast program frame codes included in a broadcast signal of each broadcasting station, a broadcast program frame code received by the frame code receiving tuner, and reserved recording information. A recording system comprising a frame code search control circuit for turning on the main power supply and sending a control signal to the recording control circuit only when the reserved broadcast program frame code in the recording memory matches. 2. A recording system characterized in that a broadcast program frame code is multiplexed and transmitted to a teletext signal multiplexing section of a hybrid transmission system, and this is used for reserved recording on the receiving side. 3. A recording system characterized in that a broadcast program frame code is multiplexed and transmitted during a video blanking period other than that of a hybrid transmission system teletext signal multiplexing unit, and this is used for reserved recording on the receiving side. 4. A recording system, characterized in that a broadcast program frame code is multiplexed and transmitted on an orthogonal axis of a carrier wave, and is used for reserved recording on the receiving side. 5. A recording system, characterized in that, in digital broadcasting, a broadcast program frame code is multiplexed on a time axis of a digital video / audio signal and transmitted, and the receiving side uses this for reserved recording.