JPS60130281A - Addressable method - Google Patents

Abstract

PURPOSE:To prevent occurrence of beat interference and perform addressing inexpensively and stably by superposing a color burst signal to an equalizing pulse part in a vertical blanking interval of a video signal. CONSTITUTION:Address data 105 for addressing is sent out from a data generating circuit 104 synchronously with a start pulse 100. Address data 105 is inputted to a data superposing circuit 106 and is synthesized to a composite video signal 102 including color burst, and a multiplex video signal 107 where address data is superposed in the second equalizing pulse period is obtained. This multiplex video signal 107 is applied to a modulating circuit 108 and is subjected to normal modulation and is mixed with a TV signal 103 of another channel by a mixing circuit 109 and is sent to a main line cable 110. The RF signal sent out in this manner is led to a terminal equipment 113 through a branching device 111 and a lead-in wire 112.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to adrenalable tables in tTt, cATV systems, direct satellite broadcasting systems, and the like.

Conventional Structure and Problems In conventional CATV systems and direct satellite broadcasting, fees are collected depending on the program viewing status of the subscriber. There are various fee structures, but generally a fixed viewing fee is collected as a monthly fee. In such a case, if the subscriber is unable to pay the charges, the terminal device owned by the subscriber, that is, the CAT
A terminal control method is used that stops the operation of the V converter or the satellite broadcast converter and prevents the subscriber from viewing the video.

As one of these terminal control methods, a unique number (address number) is assigned to each converter owned by each subscriber, and the sending side specifies the address number in some way, and the specified terminal An addressable method is used to control the terminal by sending data such as stopping or starting a function to the device. In the above system, the vertical blanking interval (V
BL] A time division multiplexing method in which digital signals are superimposed in 8-digit format using the same means as LK teletext broadcasting, and a frequency band different from the television signal frequency or a frequency band occupied by a standard television set, such as an audio carrier wave. Frequency 1 (llllI
Frequency division multiplexing methods in which a carrier wave is used for data transmission can be roughly divided into two methods that are generally used.

1. In the frequency division multiplexing system, the method of superimposing data in the vertical retrace interval V (digital transmission format) is used in text multi-channel broadcasting and facsimile IJ multi-capture broadcasting.
F(1',
If you take into account the coexistence with Levip, there is almost no use period, and moreover, the data that is Φ folded in the vertical blanking interval is generated in the weak electric field region or ghost generation] 1st area! Or “1・
・In order to extract and regenerate stably, an extraction and regeneration circuit of considerable scale is required. M) It has disadvantages such as high cost.

In frequency division multiplexing, a carrier wave for data transmission is provided separately, so a dedicated modem is required, and the usable occupied bandwidth is often limited. It has drawbacks such as the possibility that beat interference may occur due to signals and audio signals.

OBJECTS OF THE INVENTION The present invention is applicable to CATV systems and direct satellite broadcasting systems, by superimposing a color burst signal on the equalization pulse portion within the vertical retrace interval of a video signal. It is an object of the present invention to provide an address-sensitive addressable system that can perform addressing stably at low cost while eliminating the drawbacks of the previous method.

Structure of the Invention In the present invention, no signal is superimposed on the second equalization pulse period within the vertical retrace interval in a conventional video signal, and a color burst signal is superimposed on the equalization pulse period. Focusing on the fact that there is no effect on conventional transmission equipment and television receivers even if the signal is superimposed, the pedestal during the second equalization pulse period corresponds to each bit of the data signal necessary for addressing. J: To superimpose the same signal as the conventional colorverse on the part]・J:
1. Description of ten embodiments in which data necessary for addressing can be sent by time division multiplexing An embodiment of the present invention will be described with reference to the drawings. Figure 1 1: cA
This is a configuration diagram of an addressable method using a time division multiplexing method in a TV system. FIG. 2 is a diagram showing a transmission waveform when a data signal is superimposed on the second equalization pulse period, and FIG. FIG. 4 is a more detailed configuration diagram of the data extraction circuit 117 in the terminal device 113, and FIG. 4 is a detailed configuration diagram of the data superimposition circuit 106 in FIG. In a CATV system ((1, A large number of 111 terminals are connected to one center device, and these are connected by coaxial cables.The center device 101 is also called a head end, and is a VTR for broadcasting programs. (not shown), a modulator, etc.Address data 105 for addressing is generated by a start pulse 100 in a data generation circuit 104 by a microcomputer or the like.
is sent out in synchronization with The address data 1*5 generated by the data generation circuit 104 is normally a TTL level digital signal, and is input to the data superimposition circuit 106. A composite video signal 102 containing a synchronization signal and a color burst is applied to the data superimposition circuit 106 as the other input signal. That is, in FIG. 4, the composite video signal 1*2 applied to the synchronization separation circuit 401 is separated into a horizontal synchronization signal and a vertical synchronization signal by the synchronization separation circuit 401, and is output as a synchronization signal 402. In the synchronization separation circuit 401, a burst gate signal 4*4 for extracting the color burst signal from the composite video signal 102 from the horizontal synchronization signal is also output at the same time. A color subcarrier 409 whose phase is synchronized with the color burst in the composite video signal 102 from the burst gate signal 404 and the composite video signal 1○2 by the color synchronization circuit 405
is output. On the other hand, address data 105 and synchronization signal 4o2j: A gate control signal 406 for gating color subcarrier 4o9 is generated in retiming generation circuit 403. Gate control signal 406
fd, composite video signal 1 based on address data 105
The timing is adjusted to be synchronized with the second equalization pulse within 0.02, and an identification signal is added to indicate the division of address data for one terminal. Furthermore, if the address data 105 cannot be entirely superimposed in the 2117th equalization pulse period, synchronization control is performed to perform the superposition in the second equalization pulse period of the next field.

By generating a start pulse 100 for synchronizing with the data generation circuit 104, the data generation circuit 1
Sending of address data 105 from 04 is controlled.

The gate control signal 406 and the color subcarrier 409
As a result, the color subcarrier 409 is gated in the gate circuit 407, and the composite video signal 102 and the combining circuit 4*8 are superimposed, thereby producing a multiplexed video signal 1 in which the address data is superimposed on the second equivalent pulse period.
07 is obtained. The multiplexed video signal waveform will be described in more detail using FIG. In Figure 2, 219
is a vertical synchronization period in an even field, 220 is a second equalization pulse period in an even field, 221 is a vertical synchronization pulse period in an odd field, and 222 is a second equalization pulse period in an odd field. 211
゜212 indicates a horizontal synchronization pulse, horizontal synchronization pulse 21
1 is the 10H (H second line synchronization), horizontal synchronization pulse 21
2 is the 272nd H. In the second equalization pulse period 220, the equalization pulse 206 is the first equalization pulse, and in the figure, the beginning of the address data to be multiplexed is the equalization pulse 206.
The identification signal 201 for indicating the delimitation of address data to be multiplexed is inserted as a gate control signal 406 in the timing generation circuit 403. The identification signal 201 is superimposed with color subcarriers in a burst form so as to occupy almost the entire interval of the equalization pulses 206 and 219, and the multiplexed data 213
~218 can be easily identified.

The time width of the identification signal 201 is equal to the time from the start of the multiplexed data 213 to the end of the multiplexed data 215, and compared to the multiplexed data 213 to 218, the time width of the multiplexed data 213 and 2
There is no empty section like there is between 14 and 215.

Therefore, the identification signal 2o1 can be easily identified from the multiplexed data 213 to 218 by monitoring its time width.

Identification signal 2○1 indicating the beginning or break of address data
Subsequently, 3 bits of address data are multiplexed data 213 to 216 between equalization pulse 219 and equalization pulse 207.
multiplexed as The multiplexed data 213 to 218 are in the form of a burst having the same time width as the color bursts 204 and 205, and are superimposed at equal intervals between the f pulses 219 to 207 such as -1. In Figure 2, multiplexed data 2
13 to 218 show the case where a pulse-like signal is superimposed when each bit of address data is 1, and it is clear that there is no restriction in the reverse case.

-Also, Fig. 2 shows a case in which a total of 9 bits of address data is superimposed by superimposing 3 bits of address data in each period of r equalization pulses 219 to 2○9. There are no restrictions on data length,
Identification signal 201, 2○ for each address data for one terminal
By inserting 2,203, data of arbitrary length can be multiplexed. As described above, the data superimposing circuit 106 sends the multiplexed video signal 107 with address data multiplexed to the modulation circuit 107 during the second equalization pulse period.
08 and undergoes normal modulation, it is mixed with TV signals 103 of other channels in a mixing circuit 109 and sent to a main cable 110. 'The RF signal that could not be sent to the main cable 110 is sent to the branch 111. It passes through the drop-in line 112 and is guided to the terminal device 113-1. The terminal device 113 is a CATV converter. -su-
114, the multiplexed video signal 116 is demodulated in the detection circuit 116 by selecting the frequency on which the J: rear address data is multiplexed. The multiplexed video signal 116 has the same waveform as the multiplexed video signal 1*7 in the center equipment 1*1. This multiplexed video signal 1161' is supplied to the i-video switch circuit 121, and the other one is also supplied to the data extraction circuit 117 for reproducing the multiplexed signal. A series of parallel address data 118 is extracted from the multiplexed video signal by data extraction circuit 117 and outputted to address determination circuit 119 . Data extraction circuit 1
The specific configuration of 1γ is shown in FIG. 1 for the multiplexed video signal 116, which is the output signal from the detection circuit 115, and Iυ
1 separation circuit 3*1 and burst signal extraction circuit 3*7. The synchronization signal is separated from the multiplexed video signal 116 by the synchronization separation circuit 3○1, and the synchronization signal is separated from the multiplexed video signal 116.
○Added to 3. The circuit 307 in 411 extracts the identification signal and the multiplexed signal that are generated during the second equalization pulse period and shapes the waveform into a series of signals including the identification signal. The address data 3○5 which is reproduced as address data 3○5 is identified and extracted from the address data 3○5 by the identification signal detection circuit 308, and the identification signal is extracted. 309 and 1
At step 7, the signal is output to the clock generation circuit 3○3. A clock generation circuit 33 generates a sampling clock 304 from the synchronization signal 302 and the identification signal 309. As is clear from FIG. 2, the sampling clock 304 has three equalization pulses, and these clocks are resynchronized for each identification signal 309.

The address data 3○5 and the sampling clock 304 are used to convert each terminal's worth of address data into parallel in the serial/parallel conversion circuit 3○6, and the parallel address data 11
8 is added to the address determination circuit 119, and the terminal setting address and the ratio Q"l held in the address determination circuit 119 are added to the address determination circuit 119 as
If they match, the video switch circuit 121 is controlled by the control signal 120, and the detection circuit 1
By passing the multiplexed video signal 116 from 15 and performing angular modulation by an RF modulator 122, it can be received by a general TV receiver.

On the other hand, if the addresses do not match, the control signal 120 is not output, and the video switch circuit 121 is disconnected.
-1+-d, and the multiplexed video signal 116 is cut off by the video switch circuit 121, making it impossible for the TV receiver to receive those images6. In the transmission waveform in Figure 2, all address data are used, but there are a lot of 11 rivers in the data content, and 11. It is also possible to add commands and the like to carry out group 11, and to make these determinations in the rear address determination circuit 119 and freely control the terminal. .

As shown in I- below, in the present invention, during the equalization pulse period, a burst-like I1-1 bow 4.
Data credit (corresponds to 1 MLJ of data for 1 terminal)
-f l easily by inserting an identification signal into the
・Reno Nong becomes 11th Noh.

The present invention does not have any impact on conventional transmission equipment and television receivers, and also imposes no restrictions on multiplex broadcasting such as text broadcasting. Adding 11-not 1. ．． 11 It is possible to always send a stable and highly reliable data signal with any data length, and it can be constructed using parts used in general TV receivers, making it extremely inexpensive. It is possible to obtain an excellent zoko effect.

[Brief explanation of the drawing]

FIG. 1 shows the configuration of an addressable method using a time division multiplexing method in a CATV system (FIG. 1); FIG. Fig. 3 is a specific configuration diagram of the data transfer circuit in the center device, and Fig. 4 is a specific configuration diagram of the data extraction circuit in the terminal device. 1○1... Center device , 104・O-ken・0 data generation circuit, 106... Data superimposition circuit, 10
8... Modulation circuit, 1○9... Mixing circuit, 113... Terminal device, 114... Ch, -su-1115...・Detection circuit, 117...
...Data extraction circuit, 119...Address judgment FIl path, 121...Video switch circuit, 122...RF modulator.

Claims (2)

[Claims] (1) A burst-like multiplexed signal having the same frequency as the color subcarrier during the e'i conversion pulse period is superimposed on the bedeskle level between the equalization pulses ItIl and an identification signal indicating a series of data divisions. By inserting as a node<--st-like signal having the same frequency as the above-mentioned forward-like multiplexed signal and a time width different from that of the above-mentioned north<--st-like multiplex signal, time-division multiplexed data is generated. An addressable method that allows transmission. (2) The burst multiplexed signal and identification signal are multiplexed only during the 21st integrated pulse period! 1) The addressable method described in item 1.