JPS6189783A - Information detection system - Google Patents

Abstract

PURPOSE:To detect an overlapped signal from a television signal by providing an information extraction means for extracting encoded information from a synchronizing signal separated by a television signal separation means and a discrimination means for discriminating encoded information extracted by said information extraction means. CONSTITUTION:The output of a bit information extractor 24 is branched by two, and one of them is applied to a start bit information detector 25. With use of the fact that start bit information continues by six bits, a start bit information part is detected, thereby obtaining a signal (l). Then the output of the start bit information detector 25 is applied to the 3rd waveform shaping device 26, and a signal (m) is generated which has a time width larger than that seven times a horizontal synchronizing signal period (1H) and smaller than eight times with the fall of the waveform of the signal (l) as a trigger. Next, the signal (m) from the 3rd waveform shaping device 26 and a signal (k) from the bit information extractor 24 are supplied to a bit information discriminating device 27 to discriminate the information overlapped with the horizontal synchronizing signal part of a television signal and a signal (p) is outputted with the result as a piece of information.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an information detection method for detecting bit information coded and superimposed on a horizontal synchronizing signal portion of a television signal, and particularly relates to a method for detecting bit information encoded and superimposed on a horizontal synchronizing signal portion of a television signal. In particular, the present invention relates to a method for detecting information transmitted by superimposing an information signal to be used for a purpose other than a video signal.

[Conventional technology]

A method is adopted in which a conventional television signal is transmitted by superimposing it on a vertical blanking period that is unrelated to a video signal (image signal) other than the television signal.

A general waveform diagram including a conventional television vertical blanking period is shown in FIG. 4, and will be explained. In the figure, A indicates a vertical blanking period, and B indicates a video section.

The vertical equalization pulse, the vertical synchronization pulse, and the vertical equalization pulse are assigned to the section from ■ to O of this vertical blanking period A, and the section from 0 to 0, that is, the horizontal synchronization period. The section has already been allocated for the superimposed transmission of information other than the picture f jebutsu issue, for example, character data oki ka issue 9 program system axis i issue 6, etc. Even if he tried to make a new electric oath, the superimposed position was not left. Here, these information signals other than video signals are limited to the screen blanking period because
Since the black level is always at a constant level during this period, the image signal changes from moment to moment. ! This is because it guarantees high reliability during transmission without any interference.

Then, the information signal in the upper 6 pin vertical blanking period is mW.
There are only 15 eclipsing lines on the Fi1 screen (525 traversing lines), and these cylinders have already been assigned by purpose, so new information other than these cannot be added. Overlapping in this section is not allowed.

[Problem that the invention attempts to solve]

The horizontal synchronizing signal of a television signal is provided between scanning lines and is a portion that does not appear as a return string on the screen. This horizontal synchronizing signal is only used for the original purpose of synchronizing the scanning feed, and K is not normally used for other purposes. A method of detecting a superimposed signal from a television signal transmitted in a portion other than the vertical blanking period of a television signal, that is, a horizontal synchronizing signal portion, has been praised for a long time, but it is still difficult to accurately detect it. There was no method.

In view of the above points, the present invention has been made to satisfy such demands, and its purpose is to N-fold encoded information signals in the horizontal synchronization signal section of a television signal, which has not been used in the past. It is possible to detect only the coded signal signal superimposed on the horizontal synchronization signal section from the transmitted television signal, and also to detect the coded information 1'
l! It is an object of the present invention to provide an information detection method capable of restoring a horizontal synchronization signal portion in which a single code is deleted to the original horizontal synchronization signal before superimposition.

[Means for solving problems]

In order to achieve such an object, the present invention includes a separating means for receiving TV No. 21216 in which encoded information is superimposed on the horizontal synchronizing signal portion of the television signal and separating the synchronizing signal of the television signal. , configuring means for detecting a vertical blanking period from the synchronization signal obtained by the separation means, means for waveform shaping the synchronization signal separated by the separation means, and a coded waveform encoded with the shaped waveform obtained by the separation means. a restoration means for restoring the horizontal synchronization signal portion on which the information superimposed on the horizontal synchronization signal to the horizontal synchronization signal before my;
The apparatus comprises: information extracting means for extracting coded information from the synchronization signal separated by the separating means; and identifying means for identifying the coded information extracted by the information extracting means. This is what I did.

[For production]

A new information signal other than an image signal is added to a portion of the television signal other than the vertical blanking period, that is, a horizontal synchronizing signal portion, and the "iL signal is detected from the transmitted television signal.

[Example in 5] Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

First, before explaining the embodiments, in order to facilitate understanding of the present invention, a fifth section will be presented regarding a method for transmitting coded bit information by superimposing it on the horizontal synchronization signal portion of a television signal related to the present invention. This will be explained with reference to FIGS. 7 to 7.

Fig. 5 is a block diagram showing the information transmission method 1, Fig. 6
7A and 7B are a waveform diagram showing the waveforms of signals of each part, and a waveform diagram in which the waveforms are partially enlarged and detailed, to explain the operation of FIG. 5. In addition, ←l' in Figure 6(b))
? (r')*(c')*(d')l(d') are shown in Figure 6 ((a), (r), (c) of resistance), respectively.
, corresponds to (d).

In FIG. 5, a television signal 1 having a waveform as shown in FIG.

First, the television signal a is separated into the image signal and the synchronization signal of the television signal in the synchronization separator 1, and only the synchronization signal is taken out. A synchronization signal is obtained. As shown in the waveforms of FIGS. 2(a) and 2(b), the synchronization pulse includes a horizontal synchronization pulse, a vertical equalization pulse, and a vertical synchronization pulse, each having a different pulse width and period.

Next, the output of the synchronization separator 1 is branched into two branches, one of which is supplied to the horizontal synchronization regenerator 2 and the other to the vertical synchronization detector 4. Then, this horizontal synchronization regenerator 2 regenerates the horizontal synchronization so that the pulse width and pulse period of the vertical equalization pulse and the vertical synchronization pulse in the vertical blanking period are completely the same as those of the horizontal synchronization pulse. A horizontal synchronizing signal having a waveform as shown in (h) of the figure (, ) is obtained.

On the other hand, the other output, which is divided into two by the synchronization component lJk unit 1, is sent to the vertical synchronization detector 4, which uses the fact that the vertical synchronization pulse width is much wider than the horizontal synchronization pulse width and the vertical equalization pulse width to As a result, the vertical synchronization pulse part of the vertical synchronization signal is detected, and as a result, a vertical synchronization waveform (No. 8) is obtained as shown in (c) of FIG. 6 @ As you can see from the waveforms in (a) and (c), this is equivalent to detecting the vertical blanking period of a television signal, and to further clarify that it is detecting the vertical blanking period. The vertical pulse detector (vertical blanking detector) 5 connected to the vertical pulse detector (vertical blanking detector) 5 detects the end position of the vertical blanking period (Fig. 6). ) of (d
(See ``■'' in ``).'' Here, the position of ``■'' indicates the end of the vertical blanking period as well as the beginning of the video signal section.

Next, the vertical pulse signal d (see (a) in FIG. 6(a)) which is the output of this vertical blanking detector 5 and the horizontal synchronization signal h (see (a) in FIG. 6(a)) which is the output of the horizontal synchronization regenerator 2 (see FIG. a)
(see (h))) is supplied to the second waveform shaping section 6. Here, this second waveform shaping section 6 includes a divider 6-1 and a frequency divider 6.
-2 and an OR circuit 6-3. First, the divider 6-1 starts dividing at the rising edge of the horizontal synchronizing signal, divides the frequency by 4, and divides the frequency by 4 as shown in (e) of Figure 6 (, ). In addition, in the frequency divider 6-2, the frequency is started at the falling shear of the horizontal synchronization signal, and the frequency is divided by 4 to obtain (f) in Figure 6 (1). ) to obtain a branch signal f having a waveform as shown in FIG. and,
The start of these divisions starts after being gated by the vertical pulse signal d from the vertical blanking detector 5, that is, after the position 0 point.

Next, the divided signals . and f from the two frequency dividers 6-1, 6-2 are logically multiplied by 7111 in an OR circuit 6-3 to obtain an output signal t or an output signal l.

Here, for example, the output signal t having a waveform as shown in (f) of FIG.
If you look at it with a parrot, the waveform shown at (t') in Figure 6(b) will appear (9. This frequency-divided waveform will be repeated approximately 16 times between one vertical blanking period and the next vertical blanking period. Then, the waveform No. 2 is sent to the output f of these OR circuits 6-3, and is counted by a hexadecimal counter T, and when the count is out, it is 1.
The waveform of the count output signal r of the hexadecimal counter 7 as shown in FIG. 6(b) (r) is caused to rise. The falling waveform of the count output signal r corresponds to the vertical pulse im signal d from the vertical blanking detector 5 (((a) in FIG. 6).
This should be done at the falling edge of the waveform (see d)). This 16
The count output signal r of the advance counter T is applied to a start bit generator 8 and a bit pattern generator 9, so that outputs from each of these generators are generated during this period.

Next, the horizontal synchronization signal output from the horizontal synchronization regenerator 2 is applied to the first waveform shaping section 3, and the waveform regenerator 3-1 generates a pulse at the falling edge of the horizontal synchronization pulse to adjust the pulse width. A pulse n having a waveform as shown in FIG. 6(n) having a horizontal synchronizing pulse width of 115 is generated, and the waveform regenerator 3-
3, a pulse is generated at the falling edge of the horizontal sync pulse in the same way, and the pulse width becomes 215 of the horizontal sync pulse width.
A pulse 0 having a waveform as shown in the figure (o) is generated. Next, pulse n is added to the waveform regenerator 3-2, and the falling waveform of the pulse n is added to the waveform regenerator 3-2, and a pulse is generated at the falling edge of the waveform of the pulse 11, so that the pulse width is horizontal. A pulse p having a waveform as shown in FIG. 7(p) having a synchronization pulse width of 375 is generated.

In addition, the waveform regenerator 3-4 generates a pulse at the falling edge of the waveform of pulse O, and the pulse width is horizontal synchronization.
75, a pulse q having a waveform as shown in FIG. 7(q) is generated.

The output pulse p of the waveform regenerator 3-2 obtained in this way is supplied to the mixer 10, and added to the original television signal waveform by the horizontal synchronization corrector 10-1, resulting in (j ′)
A signal j' having a waveform as shown in is obtained. The part of this coefficient j' corrected by the pulse signal p from the waveform regenerator 3-2 is a position for superimposing new Kabit information thereon.

As mentioned above, this width is 3 times the width of the horizontal synchronizing pulse.
Since the width is 75, if an attempt is made to also correct the synchronization part of the vertical blanking period, the vertical equalization pulse itself will be distorted because the vertical equalization pulse is less than 1/2 the width of the horizontal synchronization pulse. Furthermore, in the method of the present invention, information is transmitted using only the horizontal synchronization part of the video section, so from this point of view, the correction of the synchronization part using the pulse coefficient p as described above during the vertical blanking period is Not necessary 0 Therefore, when supplying the waveform of this pulse signal p to the horizontal synchronization corrector 10-1, the hexadecimal counter 7 inputs the signal from the hexadecimal counter 7 (b) so that the vertical blanking period cannot be supplied.
) A count output signal r having a waveform as shown in (r)K is supplied to the waveform regenerator 3-24C to apply guard. As a result, the output of the horizontal synchronization corrector 10-1 is as shown in (j) in FIG.
A signal j having a waveform as shown in can be obtained.

Next, the output signal 2 of the OR circuit 6-3 and the waveform regenerator 3
By applying the signal q from -4 to the start bit generator 8, a start bit signal k having a waveform as shown in (k) of FIG. 6(&) is obtained. The waveform of this start bit signal is the one generated by (f) in FIG. 6(,), and is used for the same purpose as the start bit in X, such as normal data transmission. In addition, (
By supplying the output signal of the OR circuit 6-3 with the waveform shown in S) and the signal q from the same waveform regenerator 3-4 as described above to the bit pattern generator 9, the waveform regenerator 3
Using the signal q from -4 as a clock, various 7-bit bit patterns synchronized therewith are applied every half period of the waveform of the output signal 1, that is, the waveform of the output signal t of the OR circuit 6-3. This occurs every half cycle of the waveform with the opposite polarity, as shown in Figure 6 (
An information bit signal t having a waveform as shown in (j) of 1) is obtained.

Finally, these start bit signals and the information bit signal t are added to the bit pattern mixer 10 of the mixer 10.
-2 and the waveform of the output signal j of the horizontal synchronization corrector 10-1, which has the waveform as shown in (j) of FIG. A new information signal formed into a bit pattern can be superimposed on the horizontal synchronization signal portion (video section) of the signal and transmitted.

Here, the bit patterning portion will be explained in more detail.

In the waveform shown in (k) K in Fig. 6(a), the bit configuration in the ■ part and the 0 part is 9 bits, and the first 1 bit and the last 1 bit are %□I, starting from the second bit. 8th
All bits up to bit 1 are fixed bits of 11N. Then, the first bit and the last bit are set to %01K.The reason is that the information bits in the ■ part are all 11', for example.
This is because it is not possible to distinguish between the start bit of the 00 part and the information bit of the part 2 when the number is . That is, for example, when consecutive information bits such as the section ■, O are transmitted, when a section of seven consecutive bits reaches (), it is regarded as the start bit, and the bit string that follows is This is because it becomes easier to effectively detect the information bits as information bits.

Here, there are 7 information bits in section B, but all 1 bits cannot be used because they are mistaken for start bits.

That is, 77-1 information bits can be obtained. Therefore, as is clear from the waveform (j') in FIG.
-1) X15 information bits can be obtained.

Although the explanation here has been given using an example in which the start bit and information bit configuration are 7 bits, it is clear that the present invention is not limited to this and can be realized with other configurations.・In addition, 0, ■, θ, O9 in (a) of Fig. 6(a)
■, e9. ■ indicates the original waveform of the synchronization signal, and ■'' and @' in ('') in Figure 6 (,).

θ t O"a @' t θ', ■' is the waveform obtained by shaping only the synchronization signal shown in Fig. 6 (,) above with the waveform of Fig. 7 (p), and the waveform of Fig. 6 (,) ■″ in)
@11゜θII, @II, @II,
OII, ■'' is the waveform K16 shown in (1) of Figure 6 (,).
This shows the signal waveform when the waveform shown in (4) of Figure (a) is added.

Now, the information detection method according to the present invention is implemented as follows.

FIG. 1 is a block diagram showing an embodiment of the present invention for detecting an information signal superimposed on a horizontal synchronizing signal portion of a television signal transmitted in the manner described above.

In FIG. 1, 11 is a sync separator that removes the video signal (picture signal) from the television signal S and detects only the sync signal. It constitutes a separation means that receives the television signal a on which coded information is superimposed and separates the synchronization signal of the television signal. 1
2 is a vertical synchronization detector which receives the synchronization signal from the synchronization separator 11 and detects the vertical equalization pulse portion to obtain the vertical equalization pulse C; 13 is the vertical equalization signal from the heavy electric synchronization detector 12; The vertical blanking detector 13 receives the pulse C and detects the vertical blanking period to obtain the vertical pulse signal d. This vertical blanking detector 13 detects the vertical blanking period from the synchronization signal separated by the synchronization separator 11. It constitutes a detection means for detecting.

14 is a first waveform shaper which receives the synchronization signal from the synchronization separator 11 and the vertical pulse signal d from the vertical blanking detector 13 and shapes the waveforms to obtain an output signal 0; 15 is the first waveform A second waveform shaper further shapes the waveform of the output signal of the shaper 14 to obtain an output signal, and these constitute waveform shaping means for shaping the synchronization signal separated by the synchronization separator 11. 16 is a gate circuit controlled by the output signal of a hexadecimal counter that inputs the output of the second waveform shaper 15; 11 is a second gate circuit that receives the television signal a and inputs it via the gate circuit 16; This horizontal synchronizing signal regenerator 11 receives the output signal from the waveform shaper 15 and obtains the horizontal synchronizing signal f of the original television signal before superimposing bit information.
superimposes the horizontal synchronizing signal portion on which the coded information waveform-shaped by the first and second waveform shapers 14 and 15 is superimposed. It constitutes a restoring means for restoring to the previous horizontal synchronization signal.

18 and 19 are first and M2 frequency dividers that divide the output signal of the waveform shaper 15, respectively, and 20 is a frequency divider No. 16 from the first frequency divider 18. 21 is a hexadecimal counter that counts the output signal of this OR circuit 20 and outputs a count output signal n; 22 23 is a gate circuit which receives the synchronizing signal from the synchronous separator 11 and is controlled by the counting output signal n of the hexadecimal counter 21; 23 receives the output of this gate circuit 22 and receives a pulse signal j having the required pulse width. The third waveform shaper 024 that generates is a bit information extractor that receives the output of the gate circuit 22 and is controlled by the pulse signal jK from the third waveform shaper 23 to obtain the bit information signal k. The bit information extractor 24 constitutes information extraction means 'ft for extracting coded information from the synchronization signal separated by the synchronization separator 11.

25 is a start bit information detector that receives the output of the bit information extractor 24 and detects the start bit information portion to obtain a detection signal t; 26 is a waveform-shaping signal for the detection signal t from this start bit detector 25 and an output signal; A waveform shaper 21 receives the bit information signal from the bit information extractor 24 and the output signal m from the waveform shaper 26, and converts the information signal superimposed on the horizontal synchronizing signal portion of TV No. 23748 The bit information discriminator 27 constitutes an identification means for identifying the coded information extracted by the bit information extractor 24.

Next, the operation of the embodiment shown in FIG. 1 will be explained with reference to FIGS. 2 and 3.

FIGS. 2 and 3 are waveform diagrams showing signal waveforms of various parts for explaining the operation of FIG. 1, and waveform diagrams in which the waveforms are partially enlarged and detailed.

First, in FIG. 1, the television signal a having a waveform as shown in (&) in FIG. One is supplied to the horizontal synchronizing signal regenerator 17, and the other is supplied to the synchronizing separator 11. Then, in this synchronous separator 11, the television signal &((, ) of FIG.
, )) in Figure 2(a).
Only a synchronizing signal with a waveform as shown in b) is detected.

Next, the detected synchronization signal is branched into two, one being supplied to the first waveform shaper 14 and the other being supplied to the vertical synchronization detector 12, respectively. Here, this synchronization signal includes a horizontal synchronization pulse, a vertical equalization pulse, and a vertical synchronization pulse, each of which has a different pulse width and period. Then, the vertical synchronization detector 12 detects the vertical equalization pulse part by utilizing the fact that the vertical synchronization pulse width is much wider than the vertical equalization pulse width and the horizontal synchronization pulse width, A vertical synchronizing pulse C having a waveform as shown in c) is obtained. Next, using this vertical synchronization pulse C, the vertical blanking detector 13 detects a vertical blanking period to obtain a vertical pulse signal d having a waveform as shown in FIG. 2(d).

- Synchronization signal applied to the waveform shaper 14 of the force tube 1 (b)
is shaped into a pulse smaller than the horizontal synchronizing signal pulse width of 175 using the falling edge of the pulse as a trigger, and a pulse signal 0 having a waveform as shown in FIG. 3 (,) is obtained.

Next, this pulse signal O is sent to the second waveform shaper 15 again.
In addition, the falling edge of the pulse signal O is used as a trigger to shape the waveform into a pulse having a pulse width of about 415 times the horizontal synchronizing signal pulse width. Next, the second waveform shaper 15 is shown in FIG. of(
, ) is applied to the horizontal synchronizing signal portion of the television signal a with the same magnitude as the horizontal synchronizing pulse to the horizontal synchronizing signal regenerator 17 via the gate circuit 16. The horizontal synchronization signal of the original television signal before being superimposed can be reproduced, and as a result, as shown in Fig. 2 (a
), the horizontal synchronizing signal f having a waveform as shown in (X) of FIG. When the output signal from the device 15 is multiplied with reverse polarity, the above figure 2 (,) is obtained.
A horizontal synchronizing signal f having a waveform as shown in (r) of FIG.
5 to the frequency divider 1B and the frequency divider 19, respectively. First, divide the frequency (
At 118, branching is started at the falling edge of the output signal with a waveform as shown in FIG.
To 1? A branch signal with a waveform as shown in (9) of 1(a)?
In addition, the frequency divider 19 starts frequency division at the rising edge of the output signal . A signal is prayed for. And these two branch signal 7 and frequency division signal are 1iii
The sum circuit 20 logically adds σ°, and its output has a second
An output signal l having a waveform as shown by (+) in FIG. 3(a) is obtained.

Here, for example, if the output signal 1 of the OR circuit 20 (see (1) in FIG. 2(a)) is viewed in the time width of one screen length of the television signal, (1) in FIG. ), and this frequency-divided waveform is repeated approximately 16 times between one vertical blanking period and the next vertical blanking period. Therefore, the output signal 1 of this logical sum circuit 20 is counted by a hexadecimal counter 21, and when the count is out, the output signal 1 in FIG.
The waveform of the count output signal n shown in (n) of FIG. The falling edge of the waveform of the count output signal n is the vertical pulse signal d which is the output of the vertical blanking detector 13.
This is done at the falling edge of the waveform (see FIG. 2(a)-(d)).

Then, the counting output signal n (see (n) in FIG. 2(b)) of this hexadecimal counter 21 is applied to the gate circuit 16, and the synchronous part of this section television signal, especially the blood equalization pulse and Next, in the gate circuit 22, the synchronization signal separated by the synchronization branching device 11 is converted to the count output signal n from the hexadecimal counter 21 in the gate circuit 22. After applying a gate, the signal is divided into two parts, and one part is supplied to the waveform shaper 23 and the other part is supplied to the bit information extractor 24. This waveform shaper 23 uses the first rising edge of the synchronization signal waveform as shown in FIG. is generated to obtain a pulse signal j having a waveform as shown in FIG. The bit information extracted by the bit information extractor 24 results in a signal k having a waveform as shown in FIG. 2 (k).

Next, the output of this bit information extractor 24 is branched into two and one is added to the start bit information detector 25, and the start bit information part is extracted by using the fact that the start bit information always consists of 6 consecutive bits. Detected and (
A signal tt having a waveform as shown in t) is obtained. Next, the output of this start bit information detector 25 is applied to the third waveform shaper 26, and the horizontal synchronizing signal period ( Figure 2 (,
) A signal m having a waveform as shown in - is generated. next,
The signal m from the third waveform shaper 26 and the signal k from the bit information extractor 24 are supplied to a bit information identifier 27 to identify the information superimposed on the horizontal synchronization signal portion of the television code. The results are used as various information and the signal p
Output.

In addition, in FIG. 2(b), the position 0 indicates the end of the vertical blanking period as well as the beginning of the video signal section. [Effects of the Invention] As is clear from the above description, the present invention provides For example, only the coded information signal superimposed on the horizontal synchronization signal section is selected from the television signals transmitted by superimposing the coded information signal on the horizontal synchronization signal section of the television signal, which has not been used in the past. can be detected, and also
Since the horizontal synchronization signal portion on which the coded information signal is superimposed can be restored to the original horizontal synchronization signal before superimposition, the practical effect is extremely large.

[Brief explanation of the drawing]

FIG. 1 is a block 1 showing an embodiment of the information detection method according to the present invention, and FIGS. 2 and 3 are waveform diagrams showing signal waveforms of each part to explain the operation of FIG. 1, and partial portions of this waveform diagram. 4 is a general waveform diagram including a vertical blanking period of a television signal, FIG. 5 is a block diagram showing an example of an information transmission system related to the present invention, and FIGS. 6 and 7 are FIG. 2 is a waveform diagram for explaining the operation of FIG. 1; 11...11 synchronization female, 12...vertical synchronization detector, 13...vertical blanking function, 14.15
9. Φ waveform shaper, 17...-Φ horizontal synchronizing signal regenerator, 24... bit information extractor, 25. start bit information detector, 26... waveform shaper, 27・
...PiF IN Camphor Jinbetsuki.

Claims (1)

[Claims] a separating means for receiving a television signal in which encoded information is superimposed on a horizontal synchronizing signal portion of the television signal, and separating a synchronizing signal of the television signal; a detection means for detecting a vertical blanking period from the vertical blanking period; a means for waveform shaping the synchronization signal separated by the separation means; a restoring means for restoring the synchronizing signal portion to the horizontal synchronizing signal before superimposition; an information extracting means for extracting encoded information from the synchronizing signal separated by the separating means; An information detection method comprising: identification means for identifying extracted coded information.