JPS6239859B2 - - Google Patents

Description

Detailed Description of the Invention The present invention superimposes an identification signal on the low frequency region of CM broadcast information in order to confirm commercial (CM) broadcasting in TV broadcasting, etc., and detects an abnormality in the analog circuit section that receives and detects this identification signal. This relates to a method for detecting.

Recently, with the spread of commercial broadcasts, commercial broadcast confirmation systems are being developed and put into practical use. The CM broadcast confirmation system is a system that automatically confirms whether commercial TV broadcasts by private TV stations have been carried out in accordance with the contract with the sponsor, and outputs the confirmation results.

In this system, in order to confirm the commercial broadcast, a commercial identification signal is inserted in advance into the audio band of the produced commercial, and the commercial is detected from the TV broadcast commercial.
Detects the identification signal and sends it to a central computer
Check with the contents of the commercial broadcast contract.

Figure 1 is a conceptual diagram of the CM broadcast confirmation system, with each component shown as a block and the flow of data between them shown as a solid line. The process of broadcast confirmation will be explained based on the diagram: (1) Confirmation requester 2 requests broadcast confirmation from broadcast confirmation company 10 using an application form and a schedule.

(2) On the other hand, the computer center 4 generates a CM identification signal and the corresponding CM No. in advance, and sends it to the writing device 3 in the broadcast confirmation company 10 on a writing device input paper tape.

(3) Broadcast confirmation company 10 receives the dubbing mother tape (CM audio tape) brought in by confirmation requester 2
is applied to the writing device 3, a CM No. is specified, a broadcast confirmation tape is produced on which a corresponding CM identification signal is written, and the tape is returned to the confirmation requester 2 together with the dubbing mother tape, and the CM No. is also notified. Also, the actually used CM No. and CM identification signal are sent to the computer center 4 using a paper tape output from the writing device.

(4) The computer center 4 receives the application form, schedule, and actually used CM No. and CM from the confirmation requester 2.
Create a file from the identification signal.

(5) On the other hand, the confirmation requester 2 uses the broadcast confirmation audio tape received from the confirmation company 10 to produce a commercial film/VTR commercial and requests the TV station 1 to broadcast it. As a result, the schedule is finalized and sent to the computer center 4.

(6) The receiving device 5 is installed corresponding to each TV station, receives CM broadcast radio waves at all times during broadcast hours, stores CM identification signals and reception times, and receives CM identification signals on public telephone lines late at night. The data including the time is transmitted to the computer center 4.

(7) The computer center 4 compares the CM identification signal from the receiving device 5 with the CM identification signal in the file,
A confirmation table is created using the corresponding CM No. and reception time and provided to the confirmation requester 2. In this way, confirmation of CM broadcast is performed.

The first function of the CM identification signal in this case is that it can be completely distinguished from voice and noise in general audio signals.
Second, it must have enough information to identify the broadcast content, and the CM identification signal requires a considerable length of information bits. If all of the information bits are compared on the receiving side for each audio signal, the amount of processing will increase and the configuration will become complicated.

In contrast, in order to simplify this, the applicant has already filed an application, as will be described later in FIGS. 3a to 3c.
The discrimination signal of the first function is provided at the beginning, and only this signal is used to first select and perform efficient processing. In addition, since the CM identification signal must be inaudible to the human ear, the insertion band should be set to approximately 100Hz.
We have proposed a combination of digital signals of multiple frequencies that is limited to the following low frequency range and exhibits an effective discrimination function according to the characteristics of this low frequency range.

FIG. 2 shows an example of an information signal superimposition circuit included in the write circuit 3 of FIG. 1 according to a previously proposed example. this is
This circuit superimposes an identification signal on the CM audio played from the CM tape deck to confirm the CM broadcast. That is, the reproduced signal from the dubbing mother tape 11 sent from the confirmation requester 2 is amplified by the amplifier (PA) 12, and after passing through a high-pass filter (HPF) 15 to cut out frequencies below 100 Hz, the signal is transmitted to the synthesizer 19 and the amplifier. (MA) 20 and recorded on a broadcast confirmation tape 21. Digital signals of multiple frequencies are added within this cutoff frequency range. Here, the playback signal of the dubbing mother tape 11 is branched, an amplifier (PA) 13 is passed through the rectifier and smoothing circuit 14, and an audio synchronization signal for the image is extracted. The three waves f ₁ , f ₂ , f ₃ are the oscillation sources 16 ₁ , 16 ₂ , 1
6 Output from ₃ and switch (SW) 17 respectively.
₁ , 17 ₂ , 17 ₃ and are controlled and coded by digital information, and band pass filters (BPF ₁ ) 18 and (BPF ₂ ) 18 corresponding to the respective frequencies are used.
₂ , ( _BPF3 ) ₁₈₃ and are combined in a combiner 19 to create a CM identification signal consisting of a discrimination signal and identification information.

FIGS. 3 a to 3 c are explanatory diagrams of the operation in the proposed example of FIG. 2, and are explanatory diagrams of the principles of the main parts of the proposed invention. Figure a shows an example of the frequency characteristics of HPF15, where the cutoff frequency is 100Hz and the frequencies f ₁ ,
f ₂ and f ₃ are set near 40Hz, 45Hz, and 55Hz, respectively. Figure b~ shows an example of a CM identification signal, Figure b shows an example of a CM audio output preceded by a synchronization signal, and the low frequency f~ of Figure b~ is superimposed on this audio signal. CM identification signals of ₁ , f ₂ and f ₃ are output. That is, as shown in the figure, discrimination information is provided at the beginning of each piece of identification information based on a combination of f ₁ , f ₂ , and f ₃ that indicates broadcast content, and this discrimination signal is first detected for the audio signal, and then the CM identification signal is detected. It is determined whether or not it is a superimposed audio signal, and only when a discrimination signal is detected, identification information of the subsequent broadcast content is detected. Therefore, since irrelevant audio signals are discarded only by detecting the discrimination signal, efficient processing can be achieved both in terms of structure and time.

Figure c is (BPF ₁ ) 18 ₁ and (BPF ₂ ) 1 in Figure 2.
8 ₂ and (BPF ₃ ) 18 ₃ .

A CM broadcast is performed using the broadcast confirmation tape created as described above, and is received by the receiving device 5 shown in FIG. 1, and a CM identification signal is detected. In other words, as shown in an example of the receiving circuit described later, the CM
The three frequencies f ₁ , f ₂ , f ₃ constituting the identification signal are first received by an analog receiving section, and filters BPF _{1 ,} BPF 2 , BPF ₂ , corresponding to the bandpass filter of FIG.
After rectification and smoothing through BPF ₃ , A/D conversion is performed by applying a sampling clock, and the data processing device performs identification processing using various methods on the digital signal. For example, a binarized signal is compared with the corresponding bit of the basic discrimination signal pattern, and when it comes closest to matching within a certain time interval, that is, when the different bits (distance) become less than a predetermined value. It is determined that the discrimination signal has been detected.

In this case, the normality of the analog receiving circuit before A/D conversion has a great influence on the determination accuracy, but this point has not been sufficiently considered in the past.

An object of the present invention is to provide an abnormality detection method that can easily and reliably automatically detect an abnormality in an analog circuit section for receiving and detecting a CM identification signal.

In order to achieve the above object, the abnormality detection method of the analog circuit section of the present invention superimposes an identification signal of the unit broadcast information on the low frequency region of the audio of the unit broadcast information and broadcasts the same, and then transmits the identification signal in the analog circuit section. The device receives and detects, converts into a digital signal, and performs discrimination processing, comprising means for detecting that the A/D converted value of the final stage output of the analog circuit section does not change by more than a certain width for a certain period of time, It is characterized by detecting abnormalities in the circuit section.

The present invention will be described in detail below with reference to examples.

The principle of the present invention utilizes the fact that if any of the analog circuits that receive and detect the CM identification signal become inoperable, the A/D conversion value at the final stage will not change more than a certain width at a certain time. This is detected to detect an abnormality.

FIG. 4 is an explanatory diagram showing the configuration of an embodiment of the present invention, and shows one example of a receiving circuit included in the receiving device 5 of FIG. 1.

In the figure, a broadcast signal received via an antenna 30 is sent to a tuner 31 and an attenuator (ATT) 3.
2. Through the low pass filter (LPF) 33 and amplifier (PA) 34, the band pass filter (BPF) ₁
35 ₁ , (BPF ₂ ) 35 ₂ , (BPF ₃ ) 35 ₃ . The characteristics of LPF33 are as follows: (BPF ₁ ) 35 ₁ , (BPF ₂ ) 35 ₂ , (BPF ₃ ) 3
5 _{and 3} each have the characteristics shown by the solid line. The outputs of these (BPFs) 35 ₁ , 35 ₂ , 35 ₃ are rectified and smoothed by rectification and smoothing circuits 36 ₁ , 36 ₂ , 36 ₃ , respectively. Rectifier smoothing circuit 36 ₁ , 36 ₂ , 36
The outputs of ₃ are A/D converters 37 ₁ and 37, respectively.
₂ , 37 ₃ , sampling timer 38
It is converted into a digital signal according to the sampling pulse from. This digital signal is sent to the microprocessor (MPU) 39, and as described above, if the minimum condition is satisfied based on the distance from the basic discrimination signal, it is determined that they match. This binary data is stored in the memory 40 and sent to the computer center 4 in FIG. 1 by the reception time timer 41. The above is as in the conventional proposed example, but in the present invention, the A/D3
The outputs of 7 ₁ , 37 ₂ , 37 ₃ are branched and passed through abnormality detection circuits 50 ₁ , 50 ₂ , 50 ₃ respectively.
Input to MPU39.

FIG. 5 shows abnormality detection circuits 50 ₁ , 50 ₂ , 50 ₃
This is a specific circuit example. Since these are the same circuit, the subscripts will be omitted for explanation.

That is, a clock for sampling the A/D 37 is input to one input of the AND circuit 54. Next, the output of the A/D 37 is directly used as one input of the comparator 53, and the output delayed by one sampling time is sent to the comparator 53 through a delay circuit (DL) 51 that is branched and delayed by one sampling time, and a buffer circuit 52. Let the other input be the other input. If the levels of both inputs of the comparator 53 do not change every sampling time, a high level is output, so the AND circuit 54 outputs a high level every clock, and the counter 55 is operated. In this case, the counter 56 counted by the clock generator 57 does not operate, and therefore, when the counter 55 reaches a certain count during the discrimination signal generation period without being reset, an error signal is generated.
Send to MPU39.

This notifies that there is an abnormality in the operation of the analog circuit section before the A/D, and responds accordingly.
MPU 39 commands the necessary actions.

When the input of comparator 53 changes in level, it outputs a low level and counter 55 does not operate, and clock generator 57 and counter 56 generate one clock pulse each time to reset counter 55. In this way, if the analog circuit section is normal, the counter 55 is prevented from reaching a constant count.

As explained above, according to the present invention, it is detected that the A/D conversion value at the final stage of the analog circuit section for receiving and detecting the CM identification signal does not change by more than a certain width for a certain period of time, and the analog It becomes possible to detect an abnormality in the circuit and take immediate action. In this way, the normality of the analog circuit section can be maintained, which greatly contributes to improving the accuracy of judgment when confirming the CM identification signal.

[Brief explanation of the drawing]

Figure 1 is a schematic explanatory diagram of the CM broadcast confirmation system.
FIG. 2 is an explanatory diagram of the configuration of an example of the previously proposed information signal superimposition circuit, FIGS.
The figure is an explanatory diagram of the configuration of the embodiment of the present invention, and FIG.
This is a specific circuit explanatory diagram of the main part of the embodiment shown in the figure, and in the figure, 1 is a TV station, 2 is a confirmation requester, 3 is a writing device, 4 is a computer center, 5 is a receiving device, 37 ₁ -
37 ₃ is an A/D converter, 38 is a sampling timer, 39 is a microprocessor (MPU), 50
₁ to 50 ₃ is an abnormality detection circuit, 51 is a delay circuit, 5
2 is a buffer circuit, 53 is a comparison circuit, 54 is a buffer circuit.
An AND circuit, 55 and 56 are counters, and 57 is a clock generator.

Claims (1)

[Claims] 1. In a device that superimposes and broadcasts an identification signal of the unit broadcast information on the low frequency region of the audio of the unit broadcast information, receives and detects the identification signal in an analog circuit section, converts it into a digital signal, and performs discrimination processing, Analog circuit section abnormality detection characterized by comprising means for detecting that the A/D conversion value of the final stage output of the analog circuit section does not change by more than a certain width for a certain period of time, and detecting an abnormality in the analog circuit section. method.